Commit Graph

3154 Commits

Author SHA1 Message Date
Kent Overstreet a1f0358b2b bcache: Incremental gc
Big garbage collection rewrite; now, garbage collection uses the same
mechanisms as used elsewhere for inserting/updating btree node pointers,
instead of rewriting interior btree nodes in place.

This makes the code significantly cleaner and less fragile, and means we
can now make garbage collection incremental - it doesn't have to hold a
write lock on the root of the btree for the entire duration of garbage
collection.

This means that there's less of a latency hit for doing garbage
collection, which means we can gc more frequently (and do a better job
of reclaiming from the cache), and we can coalesce across more btree
nodes (improving our space efficiency).

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:37 -08:00
Kent Overstreet 8835c1234d bcache: Add make_btree_freeing_key()
Refactoring, prep work for incremental garbage collection.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:37 -08:00
Kent Overstreet f269af5a07 bcache: Add btree_node_write_sync()
More refactoring - mostly making the interfaces more explicit about what
we actually want to do.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:36 -08:00
Kent Overstreet 0eacac2203 bcache: PRECEDING_KEY()
btree_insert_key() was open coding this, this is just refactoring.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:36 -08:00
Kent Overstreet d5cc66e957 bcache: bch_(btree|extent)_ptr_invalid()
Trying to treat btree pointers and leaf node pointers the same way was a
mistake - going to start being more explicit about the type of
key/pointer we're dealing with. This is the first part of that
refactoring; this patch shouldn't change any actual behaviour.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:35 -08:00
Kent Overstreet 3a3b6a4e07 bcache: Don't bother with bucket refcount for btree node allocations
The bucket refcount (dropped with bkey_put()) is only needed to prevent
the newly allocated bucket from being garbage collected until we've
added a pointer to it somewhere. But for btree node allocations, the
fact that we have btree nodes locked is enough to guard against races
with garbage collection.

Eventually the per bucket refcount is going to be replaced with
something specific to bch_alloc_sectors().

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:34 -08:00
Kent Overstreet 280481d06c bcache: Debug code improvements
Couple changes:
 * Consolidate bch_check_keys() and bch_check_key_order(), and move the
   checks that only check_key_order() could do to bch_btree_iter_next().

 * Get rid of CONFIG_BCACHE_EDEBUG - now, all that code is compiled in
   when CONFIG_BCACHE_DEBUG is enabled, and there's now a sysfs file to
   flip on the EDEBUG checks at runtime.

 * Dropped an old not terribly useful check in rw_unlock(), and
   refactored/improved a some of the other debug code.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:34 -08:00
Kent Overstreet e58ff15503 bcache: Fix bch_ptr_bad()
Previously, bch_ptr_bad() could return false when there was a pointer to
a nonexistant device... it only filtered out keys with PTR_CHECK_DEV
pointers.

This behaviour was intended for multiple cache device support; for that,
just because the device for one of the pointers has gone away doesn't
mean we want to filter out the rest of the pointers.

But we don't yet explicitly filter/check individual pointers, so without
that this behaviour was wrong - a corrupt bkey with a bad device pointer
could cause us to deref a bad pointer. Doh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:33 -08:00
Kent Overstreet 81ab4190ac bcache: Pull on disk data structures out into a separate header
Now, the on disk data structures are in a header that can be exported to
userspace - and having them all centralized is nice too.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:33 -08:00
Kent Overstreet 2599b53b7b bcache: Move sector allocator to alloc.c
Just reorganizing things a bit.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:32 -08:00
Kent Overstreet 220bb38c21 bcache: Break up struct search
With all the recent refactoring around struct btree op struct search has
gotten rather large.

But we can now easily break it up in a different way - we break out
struct btree_insert_op which is for inserting data into the cache, and
that's now what the copying gc code uses - struct search is now specific
to request.c

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:32 -08:00
Kent Overstreet cc7b881921 bcache: Convert bch_btree_insert() to bch_btree_map_leaf_nodes()
Last of the btree_map() conversions. Main visible effect is
bch_btree_insert() is no longer taking a struct btree_op as an argument
anymore - there's no fancy state machine stuff going on, it's just a
normal function.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:31 -08:00
Kent Overstreet 6054c6d4da bcache: Don't use op->insert_collision
When we convert bch_btree_insert() to bch_btree_map_leaf_nodes(), we
won't be passing struct btree_op to bch_btree_insert() anymore - so we
need a different way of returning whether there was a collision (really,
a replace collision).

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:30 -08:00
Kent Overstreet 1b207d80d5 bcache: Kill op->replace
This is prep work for converting bch_btree_insert to
bch_btree_map_leaf_nodes() - we have to convert all its arguments to
actual arguments. Bunch of churn, but should be straightforward.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:29 -08:00
Kent Overstreet faadf0c965 bcache: Drop some closure stuff
With a the recent bcache refactoring, some of the closure code isn't
needed anymore.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:10 -08:00
Kent Overstreet b54d6934da bcache: Kill op->cl
This isn't used for waiting asynchronously anymore - so this is a fairly
trivial refactoring.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:09 -08:00
Kent Overstreet c18536a72d bcache: Prune struct btree_op
Eventual goal is for struct btree_op to contain only what is necessary
for traversing the btree.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:08 -08:00
Kent Overstreet cc23196631 bcache: Clean up cache_lookup_fn
There was some looping in submit_partial_cache_hit() and
submit_partial_cache_hit() that isn't needed anymore - originally, we
wouldn't necessarily process the full hit or miss all at once because
when splitting the bio, we took into account the restrictions of the
device we were sending it to.

But, device bio size restrictions are now handled elsewhere, with a
wrapper around generic_make_request() - so that looping has been
unnecessary for awhile now and we can now do quite a bit of cleanup.

And if we trim the key we're reading from to match the subset we're
actually reading, we don't have to explicitly calculate bi_sector
anymore. Neat.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:08 -08:00
Kent Overstreet 2c1953e201 bcache: Convert bch_btree_read_async() to bch_btree_map_keys()
This is a fairly straightforward conversion, mostly reshuffling -
op->lookup_done goes away, replaced by MAP_DONE/MAP_CONTINUE. And the
code for handling cache hits and misses wasn't really btree code, so it
gets moved to request.c.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:07 -08:00
Kent Overstreet df8e89701f bcache: Move some stuff to btree.c
With the new btree_map() functions, we don't need to export the stuff
needed for traversing the btree anymore.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:07 -08:00
Kent Overstreet 48dad8baf9 bcache: Add btree_map() functions
Lots of stuff has been open coding its own btree traversal - which is
generally pretty simple code, but there are a few subtleties.

This adds new new functions, bch_btree_map_nodes() and
bch_btree_map_keys(), which do the traversal for you. Everything that's
open coding btree traversal now (with the exception of garbage
collection) is slowly going to be converted to these two functions;
being able to write other code at a higher level of abstraction  is a
big improvement w.r.t. overall code quality.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:06 -08:00
Kent Overstreet 5e6926daac bcache: Convert writeback to a kthread
This simplifies the writeback flow control quite a bit - previously, it
was conceptually two coroutines, refill_dirty() and read_dirty(). This
makes the code quite a bit more straightforward.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:05 -08:00
Kent Overstreet 72a44517f3 bcache: Convert gc to a kthread
We needed a dedicated rescuer workqueue for gc anyways... and gc was
conceptually a dedicated thread, just one that wasn't running all the
time. Switch it to a dedicated thread to make the code a bit more
straightforward.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:04 -08:00
Kent Overstreet 35fcd848d7 bcache: Convert bucket_wait to wait_queue_head_t
At one point we did do fancy asynchronous waiting stuff with
bucket_wait, but that's all gone (and bucket_wait is used a lot less
than it used to be). So use the standard primitives.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:04 -08:00
Kent Overstreet e8e1d4682c bcache: Convert try_wait to wait_queue_head_t
We never waited on c->try_wait asynchronously, so just use the standard
primitives.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:03 -08:00
Kent Overstreet 0b93207abb bcache: Move keylist out of btree_op
Slowly working on pruning struct btree_op - the aim is for it to only
contain things that are actually necessary for traversing the btree.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:02 -08:00
Kent Overstreet a34a8bfd4e bcache: Refactor journalling flow control
Making things less asynchronous that don't need to be - bch_journal()
only has to block when the journal or journal entry is full, which is
emphatically not a fast path. So make it a normal function that just
returns when it finishes, to make the code and control flow easier to
follow.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:02 -08:00
Kent Overstreet cdd972b164 bcache: Refactor read request code a bit
More refactoring, and renaming.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:01 -08:00
Kent Overstreet 84f0db03ea bcache: Refactor request_write()
Try to improve some of the naming a bit to be more consistent, and also
improve the flow of control in request_write() a bit.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:00 -08:00
Kent Overstreet c2f95ae2eb bcache: Clean up keylist code
More random refactoring.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:56:00 -08:00
Kent Overstreet 4f3d40147b bcache: Add explicit keylist arg to btree_insert()
Some refactoring - better to explicitly pass stuff around instead of
having it all in the "big bag of state", struct btree_op. Going to prune
struct btree_op quite a bit over time.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:59 -08:00
Kent Overstreet e7c590eb63 bcache: Convert btree_insert_check_key() to btree_insert_node()
This was the main point of all this refactoring - now,
btree_insert_check_key() won't fail just because the leaf node happened
to be full.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:59 -08:00
Kent Overstreet 403b6cdeb1 bcache: Insert multiple keys at a time
We'll often end up with a list of adjacent keys to insert -
because bch_data_insert() may have to fragment the data it writes.

Originally, to simplify things and avoid having to deal with corner
cases bch_btree_insert() would pass keys from this list one at a time to
btree_insert_recurse() - mainly because the list of keys might span leaf
nodes, so it was easier this way.

With the btree_insert_node() refactoring, it's now a lot easier to just
pass down the whole list and have btree_insert_recurse() iterate over
leaf nodes until it's done.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:58 -08:00
Kent Overstreet 26c949f806 bcache: Add btree_insert_node()
The flow of control in the old btree insertion code was rather -
backwards; we'd recurse down the btree (in btree_insert_recurse()), and
then if we needed to split the keys to be inserted into the parent node
would be effectively returned up to btree_insert_recurse(), which would
notice there was more work to do and finish the insertion.

The main problem with this was that the full logic for btree insertion
could only be used by calling btree_insert_recurse; if you'd gotten to a
btree leaf some other way and had a key to insert, if it turned out that
node needed to be split you were SOL.

This inverts the flow of control so btree_insert_node() does _full_
btree insertion, including splitting - and takes a (leaf) btree node to
insert into as a parameter.

This means we can now _correctly_ handle cache misses - for cache
misses, we need to insert a fake "check" key into the btree when we
discover we have a cache miss - while we still have the btree locked.
Previously, if the btree node was full inserting a cache miss would just
fail.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:57 -08:00
Kent Overstreet d6fd3b11ce bcache: Explicitly track btree node's parent
This is prep work for the reworked btree insertion code.

The way we set b->parent is ugly and hacky... the problem is, when
btree_split() or garbage collection splits or rewrites a btree node, the
parent changes for all its (potentially already cached) children.

I may change this later and add some code to look through the btree node
cache and find all our cached child nodes and change the parent pointer
then...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:57 -08:00
Kent Overstreet 8304ad4dc8 bcache: Remove unnecessary check in should_split()
Checking i->seq was redundant, because since ages ago we always
initialize the new bset when advancing b->written

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:56 -08:00
Kent Overstreet 2d679fc756 bcache: Stripe size isn't necessarily a power of two
Originally I got this right... except that the divides didn't use
do_div(), which broke 32 bit kernels. When I went to fix that, I forgot
that the raid stripe size usually isn't a power of two... doh

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:55 -08:00
Kent Overstreet 77c320eb46 bcache: Add on error panic/unregister setting
Works kind of like the ext4 setting, to panic or remount read only on
errors.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:55 -08:00
Kent Overstreet 49b1212dfa bcache: Use blkdev_issue_discard()
The old asynchronous discard code was really a relic from when all the
allocation code was asynchronous - now that allocation runs out of a
dedicated thread there's no point in keeping around all that complicated
machinery.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:54 -08:00
Kent Overstreet dd9ec84da5 bcache: Fix a lockdep splat
bch_keybuf_del() takes a spinlock that can't be taken in interrupt context -
whoops. Fortunately, this code isn't enabled by default (you have to toggle a
sysfs thing).

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-11-10 21:55:54 -08:00
Kent Overstreet 7857d5d470 bcache: Fix a journalling performance bug 2013-11-10 21:55:53 -08:00
Kent Overstreet 1fa8455deb bcache: Fix dirty_data accounting
Dirty data accounting wasn't quite right - firstly, we were adding the key we're
inserting after it could have merged with another dirty key already in the
btree, and secondly we could sometimes pass the wrong offset to
bcache_dev_sectors_dirty_add() for dirty data we were overwriting - which is
important when tracking dirty data by stripe.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-11-10 21:55:27 -08:00
Joe Thornber c9d28d5d09 dm cache: promotion optimisation for writes
If a write block triggers promotion and covers a whole block we can
avoid a copy.

Introduce dm_{hook,unhook}_bio to simplify saving and restoring bio
fields (bi_private is now used by overwrite).  Switch writethrough
support over to using these helpers too.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:26 -05:00
Joe Thornber c86c30706c dm cache: be much more aggressive about promoting writes to discarded blocks
Previously these promotions only got priority if there were unused cache
blocks.  Now we give them priority if there are any clean blocks in the
cache.

The fio_soak_test in the device-mapper-test-suite now gives uniform
performance across subvolumes (~16 seconds).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:25 -05:00
Joe Thornber 01911c19be dm cache policy mq: implement writeback_work() and mq_{set,clear}_dirty()
There are now two multiqueues for in cache blocks.  A clean one and a
dirty one.

writeback_work comes from the dirty one.  Demotions come from the clean
one.

There are two benefits:
- Performance improvement, since demoting a clean block is a noop.
- The cache cleans itself when io load is light.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:25 -05:00
Heinz Mauelshagen ffcbcb6720 dm cache: optimize commit_if_needed
Check commit_requested flag _before_ calling
dm_cache_changed_this_transaction() superfluously.

Also, be sure to set last_commit_jiffies _after_ dm_cache_commit()
completes.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:24 -05:00
Joe Thornber 40c57f475f dm space map disk: optimise sm_disk_dec_block
Don't waste time spotting blocks that have been allocated and then freed
in the same transaction.

The extra lookup is expensive, and I don't think it really gives us much.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:24 -05:00
Mikulas Patocka 5442851edb dm: fix Kconfig menu indentation
The option DM_LOG_USERSPACE is sub-option of DM_MIRROR, so place it
right after DM_MIRROR.  Doing so fixes various other Device mapper
targets/features to be properly nested under "Device mapper support".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:22 -05:00
Mikulas Patocka 2c140a246d dm: allow remove to be deferred
This patch allows the removal of an open device to be deferred until
it is closed.  (Previously such a removal attempt would fail.)

The deferred remove functionality is enabled by setting the flag
DM_DEFERRED_REMOVE in the ioctl structure on DM_DEV_REMOVE or
DM_REMOVE_ALL ioctl.

On return from DM_DEV_REMOVE, the flag DM_DEFERRED_REMOVE indicates if
the device was removed immediately or flagged to be removed on close -
if the flag is clear, the device was removed.

On return from DM_DEV_STATUS and other ioctls, the flag
DM_DEFERRED_REMOVE is set if the device is scheduled to be removed on
closure.

A device that is scheduled to be deleted can be revived using the
message "@cancel_deferred_remove". This message clears the
DMF_DEFERRED_REMOVE flag so that the device won't be deleted on close.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:22 -05:00
Mike Snitzer 7833b08e18 dm table: print error on preresume failure
If preresume fails it is worth logging an error given that a device is
left suspended due to the failure.

This change was motivated by local preresume error logging that was
added to the cache target ("preresume failed").  Elevating this
target-agnostic context for the where the target-specific error occurred
relative to the DM core's callouts makes sense.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
2013-11-09 18:20:21 -05:00
Milan Broz ed04d98169 dm crypt: add TCW IV mode for old CBC TCRYPT containers
dm-crypt can already activate TCRYPT (TrueCrypt compatible) containers
in LRW or XTS block encryption mode.

TCRYPT containers prior to version 4.1 use CBC mode with some additional
tweaks, this patch adds support for these containers.

This new mode is implemented using special IV generator named TCW
(TrueCrypt IV with whitening).  TCW IV only supports containers that are
encrypted with one cipher (Tested with AES, Twofish, Serpent, CAST5 and
TripleDES).

While this mode is legacy and is known to be vulnerable to some
watermarking attacks (e.g. revealing of hidden disk existence) it can
still be useful to activate old containers without using 3rd party
software or for independent forensic analysis of such containers.

(Both the userspace and kernel code is an independent implementation
based on the format documentation and it completely avoids use of
original source code.)

The TCW IV generator uses two additional keys: Kw (whitening seed, size
is always 16 bytes - TCW_WHITENING_SIZE) and Kiv (IV seed, size is
always the IV size of the selected cipher).  These keys are concatenated
at the end of the main encryption key provided in mapping table.

While whitening is completely independent from IV, it is implemented
inside IV generator for simplification.

The whitening value is always 16 bytes long and is calculated per sector
from provided Kw as initial seed, xored with sector number and mixed
with CRC32 algorithm.  Resulting value is xored with ciphertext sector
content.

IV is calculated from the provided Kiv as initial IV seed and xored with
sector number.

Detailed calculation can be found in the Truecrypt documentation for
version < 4.1 and will also be described on dm-crypt site, see:
http://code.google.com/p/cryptsetup/wiki/DMCrypt

The experimental support for activation of these containers is already
present in git devel brach of cryptsetup.

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:20 -05:00
Milan Broz da31a0787a dm crypt: properly handle extra key string in initialization
Some encryption modes use extra keys (e.g. loopAES has IV seed) which
are not used in block cipher initialization but are part of key string
in table constructor.

This patch adds an additional field which describes the length of the
extra key(s) and substracts it before real key encryption setting.

The key_size always includes the size, in bytes, of the key provided
in mapping table.

The key_parts describes how many parts (usually keys) are contained in
the whole key buffer.  And key_extra_size contains size in bytes of
additional keys part (this number of bytes must be subtracted because it
is processed by the IV generator).

| K1 | K2 | .... | K64 |      Kiv       |
|----------- key_size ----------------- |
|                      |-key_extra_size-|
|     [64 keys]        |  [1 key]       | => key_parts = 65

Example where key string contains main key K, whitening key
Kw and IV seed Kiv:

|     K       |   Kiv   |       Kw      |
|--------------- key_size --------------|
|             |-----key_extra_size------|
|  [1 key]    | [1 key] |     [1 key]   | => key_parts = 3

Because key_extra_size is calculated during IV mode setting, key
initialization is moved after this step.

For now, this change has no effect to supported modes (thanks to ilog2
rounding) but it is required by the following patch.

Also, fix a sparse warning in crypt_iv_lmk_one().

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:20 -05:00
Heinz Mauelshagen 2c2263c93f dm cache: log error message if dm_kcopyd_copy() fails
A migration failure should be logged (albeit limited).

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:19 -05:00
Heinz Mauelshagen 80f659f3f5 dm cache: use cell_defer() boolean argument consistently
Fix a few cell_defer() calls that weren't passing a bool.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:19 -05:00
Mikulas Patocka 4cb3e1db21 dm cache: return -EINVAL if the user specifies unknown cache policy
Return -EINVAL when the specified cache policy is unknown rather than
returning -ENOMEM.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:18 -05:00
Joe Thornber dd8b0c2096 dm cache metadata: return bool from __superblock_all_zeroes
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:17 -05:00
Joe Thornber 0184b44e32 dm cache policy mq: a few small fixes
Rename takeout_queue to concat_queue.

Fix a harmless bug in mq policies pop() function.  Currently pop()
always succeeds, with up coming changes this wont be the case.

Fix typo in comment above pre_cache_to_cache prototype.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:17 -05:00
Joe Thornber 3351937e4a dm cache policy: remove return from void policy_remove_mapping
No need to return from a void function.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:16 -05:00
Joe Thornber 238f8363b6 dm cache: improve efficiency of quiescing flag management
Make the quiescing flag an atomic_t and stop protecting it with a spin
lock.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:19:59 -05:00
Joe Thornber 66cb1910df dm cache: fix a race condition between queuing new migrations and quiescing for a shutdown
The code that was trying to do this was inadequate.  The postsuspend
method (in ioctl context), needs to wait for the worker thread to
acknowledge the request to quiesce.  Otherwise the migration count may
drop to zero temporarily before the worker thread realises we're
quiescing.  In this case the target will be taken down, but the worker
thread may have issued a new migration, which will cause an oops when
it completes.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-09 17:55:50 -05:00
Joe Thornber f8e5f01a32 dm cache: io destined for the cache device can now serve as tick bios
Previously only origin bios could trigger ticks, which meant if all
the io was destined for the cache no ticks were generated.  If no ticks
are generated then multiple hits, and movements in general, are
attributed to the same tick.

Only a stop gap fix, we need a better solution.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 17:55:49 -05:00
Joe Thornber 99ba2ae4cd dm cache policy mq: protect residency method with existing mutex
It is safe to use a mutex in mq_residency() at this point since it is
only called from ioctl context.  But future-proof mq_residency() by
using might_sleep() to catch new contexts that cannot sleep.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 17:54:34 -05:00
Kent Overstreet 6678d83f18 block: Consolidate duplicated bio_trim() implementations
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 09:02:31 -07:00
Linus Torvalds 0324e74534 Driver Core / sysfs patches for 3.13-rc1
Here's the big driver core / sysfs update for 3.13-rc1.
 
 There's lots of dev_groups updates for different subsystems, as they all
 get slowly migrated over to the safe versions of the attribute groups
 (removing userspace races with the creation of the sysfs files.)  Also
 in here are some kobject updates, devres expansions, and the first round
 of Tejun's sysfs reworking to enable it to be used by other subsystems
 as a backend for an in-kernel filesystem.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...
2013-11-07 11:42:15 +09:00
Joe Thornber 9c1d4de560 dm array: fix bug in growing array
Entries would be lost if the old tail block was partially filled.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-05 11:20:50 -05:00
Hannes Reinecke b63349a7a5 dm mpath: requeue I/O during pg_init
When pg_init is running no I/O can be submitted to the underlying
devices, as the path priority etc might change.  When using queue_io for
this, requests will be piling up within multipath as the block I/O
scheduler just sees a _very fast_ device.  All of this queued I/O has to
be resubmitted from within multipathing once pg_init is done.

This approach has the problem that it's virtually impossible to
abort I/O when pg_init is running, and we're adding heavy load
to the devices after pg_init since all of the queued I/O needs to be
resubmitted _before_ any requests can be pulled off of the request queue
and normal operation continues.

This patch will requeue the I/O that triggers the pg_init call, and
return 'busy' when pg_init is in progress.  With these changes the block
I/O scheduler will stop submitting I/O during pg_init, resulting in a
quicker path switch and less I/O pressure (and memory consumption) after
pg_init.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[patch header edited for clarity and typos by Mike Snitzer]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-05 11:20:34 -05:00
Shiva Krishna Merla 954a73d5d3 dm mpath: fix race condition between multipath_dtr and pg_init_done
Whenever multipath_dtr() is happening we must prevent queueing any
further path activation work.  Implement this by adding a new
'pg_init_disabled' flag to the multipath structure that denotes future
path activation work should be skipped if it is set.  By disabling
pg_init and then re-enabling in flush_multipath_work() we also avoid the
potential for pg_init to be initiated while suspending an mpath device.

Without this patch a race condition exists that may result in a kernel
panic:

1) If after pg_init_done() decrements pg_init_in_progress to 0, a call
   to wait_for_pg_init_completion() assumes there are no more pending path
   management commands.
2) If pg_init_required is set by pg_init_done(), due to retryable
   mode_select errors, then process_queued_ios() will again queue the
   path activation work.
3) If free_multipath() completes before activate_path() work is called a
   NULL pointer dereference like the following can be seen when
   accessing members of the recently destructed multipath:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
RIP: 0010:[<ffffffffa003db1b>]  [<ffffffffa003db1b>] activate_path+0x1b/0x30 [dm_multipath]
[<ffffffff81090ac0>] worker_thread+0x170/0x2a0
[<ffffffff81096c80>] ? autoremove_wake_function+0x0/0x40

[switch to disabling pg_init in flush_multipath_work & header edits by Mike Snitzer]
Signed-off-by: Shiva Krishna Merla <shivakrishna.merla@netapp.com>
Reviewed-by: Krishnasamy Somasundaram <somasundaram.krishnasamy@netapp.com>
Tested-by: Speagle Andy <Andy.Speagle@netapp.com>
Acked-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2013-10-31 21:39:47 -04:00
Mikulas Patocka f36afb3957 dm: allocate buffer for messages with small number of arguments using GFP_NOIO
dm-mpath and dm-thin must process messages even if some device is
suspended, so we allocate argv buffer with GFP_NOIO. These messages have
a small fixed number of arguments.

On the other hand, dm-switch needs to process bulk data using messages
so excessive use of GFP_NOIO could cause trouble.

The patch also lowers the default number of arguments from 64 to 8, so
that there is smaller load on GFP_NOIO allocations.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-10-31 13:55:45 -04:00
Shaohua Li d47648fcf0 raid5: avoid finding "discard" stripe
SCSI discard will damage discard stripe bio setting, eg, some fields are
changed. If the stripe is reused very soon, we have wrong bios setting. We
remove discard stripe from hash list, so next time the strip will be fully
initialized.

Suitable for backport to 3.7+.

Cc: <stable@vger.kernel.org> (3.7+)
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 13:00:24 +11:00
Shaohua Li 37c61ff31e raid5: set bio bi_vcnt 0 for discard request
SCSI layer will add new payload for discard request. If two bios are merged
to one, the second bio has bi_vcnt 1 which is set in raid5. This will confuse
SCSI and cause oops.

Suitable for backport to 3.7+

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
2013-10-24 12:57:36 +11:00
Bian Yu 905b0297a9 md: avoid deadlock when md_set_badblocks.
When operate harddisk and hit errors, md_set_badblocks is called after
scsi_restart_operations which already disabled the irq. but md_set_badblocks
will call write_sequnlock_irq and enable irq. so softirq can preempt the
current thread and that may cause a deadlock. I think this situation should
use write_sequnlock_irqsave/irqrestore instead.

I met the situation and the call trace is below:
[  638.919974] BUG: spinlock recursion on CPU#0, scsi_eh_13/1010
[  638.921923]  lock: 0xffff8800d4d51fc8, .magic: dead4ead, .owner: scsi_eh_13/1010, .owner_cpu: 0
[  638.923890] CPU: 0 PID: 1010 Comm: scsi_eh_13 Not tainted 3.12.0-rc5+ #37
[  638.925844] Hardware name: To be filled by O.E.M. To be filled by O.E.M./MAHOBAY, BIOS 4.6.5 03/05/2013
[  638.927816]  ffff880037ad4640 ffff880118c03d50 ffffffff8172ff85 0000000000000007
[  638.929829]  ffff8800d4d51fc8 ffff880118c03d70 ffffffff81730030 ffff8800d4d51fc8
[  638.931848]  ffffffff81a72eb0 ffff880118c03d90 ffffffff81730056 ffff8800d4d51fc8
[  638.933884] Call Trace:
[  638.935867]  <IRQ>  [<ffffffff8172ff85>] dump_stack+0x55/0x76
[  638.937878]  [<ffffffff81730030>] spin_dump+0x8a/0x8f
[  638.939861]  [<ffffffff81730056>] spin_bug+0x21/0x26
[  638.941836]  [<ffffffff81336de4>] do_raw_spin_lock+0xa4/0xc0
[  638.943801]  [<ffffffff8173f036>] _raw_spin_lock+0x66/0x80
[  638.945747]  [<ffffffff814a73ed>] ? scsi_device_unbusy+0x9d/0xd0
[  638.947672]  [<ffffffff8173fb1b>] ? _raw_spin_unlock+0x2b/0x50
[  638.949595]  [<ffffffff814a73ed>] scsi_device_unbusy+0x9d/0xd0
[  638.951504]  [<ffffffff8149ec47>] scsi_finish_command+0x37/0xe0
[  638.953388]  [<ffffffff814a75e8>] scsi_softirq_done+0xa8/0x140
[  638.955248]  [<ffffffff8130e32b>] blk_done_softirq+0x7b/0x90
[  638.957116]  [<ffffffff8104fddd>] __do_softirq+0xfd/0x330
[  638.958987]  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.960861]  [<ffffffff8174a5cc>] call_softirq+0x1c/0x30
[  638.962724]  [<ffffffff81004c7d>] do_softirq+0x8d/0xc0
[  638.964565]  [<ffffffff8105024e>] irq_exit+0x10e/0x150
[  638.966390]  [<ffffffff8174ad4a>] smp_apic_timer_interrupt+0x4a/0x60
[  638.968223]  [<ffffffff817499af>] apic_timer_interrupt+0x6f/0x80
[  638.970079]  <EOI>  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.971899]  [<ffffffff8173fa6a>] ? _raw_spin_unlock_irq+0x3a/0x50
[  638.973691]  [<ffffffff8173fa60>] ? _raw_spin_unlock_irq+0x30/0x50
[  638.975475]  [<ffffffff81562393>] md_set_badblocks+0x1f3/0x4a0
[  638.977243]  [<ffffffff81566e07>] rdev_set_badblocks+0x27/0x80
[  638.978988]  [<ffffffffa00d97bb>] raid5_end_read_request+0x36b/0x4e0 [raid456]
[  638.980723]  [<ffffffff811b5a1d>] bio_endio+0x1d/0x40
[  638.982463]  [<ffffffff81304ff3>] req_bio_endio.isra.65+0x83/0xa0
[  638.984214]  [<ffffffff81306b9f>] blk_update_request+0x7f/0x350
[  638.985967]  [<ffffffff81306ea1>] blk_update_bidi_request+0x31/0x90
[  638.987710]  [<ffffffff813085e0>] __blk_end_bidi_request+0x20/0x50
[  638.989439]  [<ffffffff8130862f>] __blk_end_request_all+0x1f/0x30
[  638.991149]  [<ffffffff81308746>] blk_peek_request+0x106/0x250
[  638.992861]  [<ffffffff814a62a9>] ? scsi_kill_request.isra.32+0xe9/0x130
[  638.994561]  [<ffffffff814a633a>] scsi_request_fn+0x4a/0x3d0
[  638.996251]  [<ffffffff813040a7>] __blk_run_queue+0x37/0x50
[  638.997900]  [<ffffffff813045af>] blk_run_queue+0x2f/0x50
[  638.999553]  [<ffffffff814a5750>] scsi_run_queue+0xe0/0x1c0
[  639.001185]  [<ffffffff814a7721>] scsi_run_host_queues+0x21/0x40
[  639.002798]  [<ffffffff814a2e87>] scsi_restart_operations+0x177/0x200
[  639.004391]  [<ffffffff814a4fe9>] scsi_error_handler+0xc9/0xe0
[  639.005996]  [<ffffffff814a4f20>] ? scsi_unjam_host+0xd0/0xd0
[  639.007600]  [<ffffffff81072f6b>] kthread+0xdb/0xe0
[  639.009205]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
[  639.010821]  [<ffffffff81748cac>] ret_from_fork+0x7c/0xb0
[  639.012437]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170

This bug was introduce in commit  2e8ac30312
(the first time rdev_set_badblock was call from interrupt context),
so this patch is appropriate for 3.5 and subsequent kernels.

Cc: <stable@vger.kernel.org> (3.5+)
Signed-off-by: Bian Yu <bianyu@kedacom.com>
Reviewed-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 12:57:11 +11:00
Lukasz Dorau 61e4947c99 md: Fix skipping recovery for read-only arrays.
Since:
        commit 7ceb17e87b
        md: Allow devices to be re-added to a read-only array.

spares are activated on a read-only array. In case of raid1 and raid10
personalities it causes that not-in-sync devices are marked in-sync
without checking if recovery has been finished.

If a read-only array is degraded and one of its devices is not in-sync
(because the array has been only partially recovered) recovery will be skipped.

This patch adds checking if recovery has been finished before marking a device
in-sync for raid1 and raid10 personalities. In case of raid5 personality
such condition is already present (at raid5.c:6029).

Bug was introduced in 3.10 and causes data corruption.

Cc: stable@vger.kernel.org
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 12:55:17 +11:00
Kent Overstreet d4eddd42f5 bcache: Fixed incorrect order of arguments to bio_alloc_bioset()
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-23 07:55:36 +01:00
Greg Kroah-Hartman a7204d72db Merge 3.12-rc6 into driver-core-next
We want these fixes here too.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 13:05:38 -07:00
Mikulas Patocka e9c6a18264 dm snapshot: fix data corruption
This patch fixes a particular type of data corruption that has been
encountered when loading a snapshot's metadata from disk.

When we allocate a new chunk in persistent_prepare, we increment
ps->next_free and we make sure that it doesn't point to a metadata area
by further incrementing it if necessary.

When we load metadata from disk on device activation, ps->next_free is
positioned after the last used data chunk. However, if this last used
data chunk is followed by a metadata area, ps->next_free is positioned
erroneously to the metadata area. A newly-allocated chunk is placed at
the same location as the metadata area, resulting in data or metadata
corruption.

This patch changes the code so that ps->next_free skips the metadata
area when metadata are loaded in function read_exceptions.

The patch also moves a piece of code from persistent_prepare_exception
to a separate function skip_metadata to avoid code duplication.

CVE-2013-4299

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-10-16 03:17:47 +01:00
Michael Opdenacker aa5e5dc2a8 treewide: fix "distingush" typo
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:38:33 +02:00
Kent Overstreet 2fe80d3bbf bcache: Fix a null ptr deref regression
Commit c0f04d88e4 ("bcache: Fix flushes in writeback mode") was fixing
a reported data corruption bug, but it seems some last minute
refactoring or rebasing introduced a null pointer deref.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Reported-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-10 18:17:39 -07:00
Greg Kroah-Hartman 88502b9c0a Merge 3.12-rc3 into driver-core-next
We want the driver core and sysfs fixes in here to make merges and
development easier.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-29 18:29:23 -07:00
Tejun Heo 388975ccca sysfs: clean up sysfs_get_dirent()
The pre-existing sysfs interfaces which take explicit namespace
argument are weird in that they place the optional @ns in front of
@name which is contrary to the established convention.  For example,
we end up forcing vast majority of sysfs_get_dirent() users to do
sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
especially as @ns and @name may be interchanged without causing
compilation warning.

This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
around sysfs_get_dirent_ns().  This makes confusions a lot less
likely.

There are other interfaces which take @ns before @name.  They'll be
updated by following patches.

This patch doesn't introduce any functional changes.

v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
    error on module builds.  Reported by build test robot.  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 15:33:18 -07:00
Linus Torvalds e93dd910b9 A set of device-mapper fixes for 3.12.
A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error
 handling fixes for dm-multipath.  A fix for the thin provisioning target
 to not expose non-zero discard limits if discards are disabled.
 
 Lastly, add two DM module parameters which allow users to tune the
 emergency memory reserves that DM mainatins per device -- this helps fix
 a long-standing issue for dm-multipath.  The conservative default
 reserve for request-based dm-multipath devices (256) has proven
 problematic for users with many multipathed SCSI devices but relatively
 little memory.  To responsibly select a smaller value users should use
 the new nr_bios tracepoint info (via commit 75afb352 "block: Add nr_bios
 to block_rq_remap tracepoint") to determine the peak number of bios
 their workloads create.
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Merge tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error
  handling fixes for dm-multipath.  A fix for the thin provisioning
  target to not expose non-zero discard limits if discards are disabled.

  Lastly, add two DM module parameters which allow users to tune the
  emergency memory reserves that DM mainatins per device -- this helps
  fix a long-standing issue for dm-multipath.  The conservative default
  reserve for request-based dm-multipath devices (256) has proven
  problematic for users with many multipathed SCSI devices but
  relatively little memory.  To responsibly select a smaller value users
  should use the new nr_bios tracepoint info (via commit 75afb352
  "block: Add nr_bios to block_rq_remap tracepoint") to determine the
  peak number of bios their workloads create"

* tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: add reserved_bio_based_ios module parameter
  dm: add reserved_rq_based_ios module parameter
  dm: lower bio-based mempool reservation
  dm thin: do not expose non-zero discard limits if discards disabled
  dm mpath: disable WRITE SAME if it fails
  dm-snapshot: fix performance degradation due to small hash size
  dm snapshot: workaround for a false positive lockdep warning
  dm stats: fix possible counter corruption on 32-bit systems
  dm mpath: do not fail path on -ENOSPC
2013-09-25 15:12:46 -07:00
Kent Overstreet c0f04d88e4 bcache: Fix flushes in writeback mode
In writeback mode, when we get a cache flush we need to make sure we
issue a flush to the backing device.

The code for sending down an extra flush was wrong - by cloning the bio
we were probably getting flags that didn't make sense for a bare flush,
and also the old code was firing for FUA bios, for which we don't need
to send a flush to the backing device.

This was causing data corruption somehow - the mechanism was never
determined, but this patch fixes it for the users that were seeing it.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet 84786438ed bcache: Fix for handling overlapping extents when reading in a btree node
btree_sort_fixup() was overly clever, because it was trying to avoid
pulling a key off the btree iterator in more than one place.

This led to a really obscure bug where we'd break early from the loop in
btree_sort_fixup() if the current key overlapped with keys in more than
one older set, and the next key it overlapped with was zero size.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet a698e08c82 bcache: Fix a shrinker deadlock
GFP_NOIO means we could be getting called recursively - mca_alloc() ->
mca_data_alloc() - definitely can't use mutex_lock(bucket_lock) then.
Whoops.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet 79e3dab90d bcache: Fix a dumb CPU spinning bug in writeback
schedule_timeout() != schedule_timeout_uninterruptible()

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet 1394d6761b bcache: Fix a flush/fua performance bug
bch_journal_meta() was missing the flush to make the journal write
actually go down (instead of waiting up to journal_delay_ms)...

Whoops

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet c2a4f3183a bcache: Fix a writeback performance regression
Background writeback works by scanning the btree for dirty data and
adding those keys into a fixed size buffer, then for each dirty key in
the keybuf writing it to the backing device.

When read_dirty() finishes and it's time to scan for more dirty data, we
need to wait for the outstanding writeback IO to finish - they still
take up slots in the keybuf (so that foreground writes can check for
them to avoid races) - without that wait, we'll continually rescan when
we'll be able to add at most a key or two to the keybuf, and that takes
locks that starves foreground IO.  Doh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Geert Uytterhoeven 61cbd250f8 bcache: Correct printf()-style format length modifier
Fix

  drivers/md/bcache/btree.c: In function ‘bch_btree_node_read’:
  drivers/md/bcache/btree.c:259: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 3 has type ‘size_t’

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet c426c4fd46 bcache: Fix for when no journal entries are found
The journal replay code didn't handle this case, causing it to go into
an infinite loop...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Gabriel de Perthuis aee6f1cfff bcache: Strip endline when writing the label through sysfs
sysfs attributes with unusual characters have crappy failure modes
in Squeeze (udev 164); later versions of udev are unaffected.

This should make these characters more unusual.

Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet 6d9d21e35f bcache: Fix a dumb journal discard bug
That switch statement was obviously wrong, leading to some sort of weird
spinning on rare occasion with discards enabled...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Mike Snitzer e8603136cb dm: add reserved_bio_based_ios module parameter
Allow user to change the number of IOs that are reserved by
bio-based DM's mempools by writing to this file:
/sys/module/dm_mod/parameters/reserved_bio_based_ios

The default value is RESERVED_BIO_BASED_IOS (16).  The maximum allowed
value is RESERVED_MAX_IOS (1024).

Export dm_get_reserved_bio_based_ios() for use by DM targets and core
code.  Switch to sizing dm-io's mempool and bioset using DM core's
configurable 'reserved_bio_based_ios'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
2013-09-23 10:42:24 -04:00
Mike Snitzer f47908269f dm: add reserved_rq_based_ios module parameter
Allow user to change the number of IOs that are reserved by
request-based DM's mempools by writing to this file:
/sys/module/dm_mod/parameters/reserved_rq_based_ios

The default value is RESERVED_REQUEST_BASED_IOS (256).  The maximum
allowed value is RESERVED_MAX_IOS (1024).

Export dm_get_reserved_rq_based_ios() for use by DM targets and core
code.  Switch to sizing dm-mpath's mempool using DM core's configurable
'reserved_rq_based_ios'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-23 10:42:24 -04:00
Mike Snitzer 6cfa58573f dm: lower bio-based mempool reservation
Bio-based device mapper processing doesn't need larger mempools (like
request-based DM does), so lower the number of reserved entries for
bio-based operation.  16 was already used for bio-based DM's bioset
but mistakenly wasn't used for it's _io_cache.

Formalize difference between bio-based and request-based defaults by
introducing RESERVED_BIO_BASED_IOS and RESERVED_REQUEST_BASED_IOS.

(based on older code from Mikulas Patocka)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-23 10:42:23 -04:00
Mike Snitzer b60ab990cc dm thin: do not expose non-zero discard limits if discards disabled
Fix issue where the block layer would stack the discard limits of the
pool's data device even if the "ignore_discard" pool feature was
specified.

The pool and thin device(s) still had discards disabled because the
QUEUE_FLAG_DISCARD request_queue flag wasn't set.  But to avoid user
confusion when "ignore_discard" is used: both the pool device and the
thin device(s) have zeroes for all discard limits.

Also, always set discard_zeroes_data_unsupported in targets because they
should never advertise the 'discard_zeroes_data' capability (even if the
pool's data device supports it).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-09-23 10:42:06 -04:00
Mike Snitzer f84cb8a46a dm mpath: disable WRITE SAME if it fails
Workaround the SCSI layer's problematic WRITE SAME heuristics by
disabling WRITE SAME in the DM multipath device's queue_limits if an
underlying device disabled it.

The WRITE SAME heuristics, with both the original commit 5db44863b6
("[SCSI] sd: Implement support for WRITE SAME") and the updated commit
66c28f971 ("[SCSI] sd: Update WRITE SAME heuristics"), default to enabling
WRITE SAME(10) even without successfully determining it is supported.
After the first failed WRITE SAME the SCSI layer will disable WRITE SAME
for the device (by setting sdkp->device->no_write_same which results in
'max_write_same_sectors' in device's queue_limits to be set to 0).

When a device is stacked ontop of such a SCSI device any changes to that
SCSI device's queue_limits do not automatically propagate up the stack.
As such, a DM multipath device will not have its WRITE SAME support
disabled.  This causes the block layer to continue to issue WRITE SAME
requests to the mpath device which causes paths to fail and (if mpath IO
isn't configured to queue when no paths are available) it will result in
actual IO errors to the upper layers.

This fix doesn't help configurations that have additional devices
stacked ontop of the mpath device (e.g. LVM created linear DM devices
ontop).  A proper fix that restacks all the queue_limits from the bottom
of the device stack up will need to be explored if SCSI will continue to
use this model of optimistically allowing op codes and then disabling
them after they fail for the first time.

Before this patch:

EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null)
device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121)
device-mapper: multipath: XXX snitm debugging: failing WRITE SAME IO with error=-121
end_request: critical target error, dev dm-6, sector 528
dm-6: WRITE SAME failed. Manually zeroing.
device-mapper: multipath: Failing path 8:112.
end_request: I/O error, dev dm-6, sector 4616
dm-6: WRITE SAME failed. Manually zeroing.
end_request: I/O error, dev dm-6, sector 4616
end_request: I/O error, dev dm-6, sector 5640
end_request: I/O error, dev dm-6, sector 6664
end_request: I/O error, dev dm-6, sector 7688
end_request: I/O error, dev dm-6, sector 524288
Buffer I/O error on device dm-6, logical block 65536
lost page write due to I/O error on dm-6
JBD2: Error -5 detected when updating journal superblock for dm-6-8.
end_request: I/O error, dev dm-6, sector 524296
Aborting journal on device dm-6-8.
end_request: I/O error, dev dm-6, sector 524288
Buffer I/O error on device dm-6, logical block 65536
lost page write due to I/O error on dm-6
JBD2: Error -5 detected when updating journal superblock for dm-6-8.

# cat /sys/block/sdh/queue/write_same_max_bytes
0
# cat /sys/block/dm-6/queue/write_same_max_bytes
33553920

After this patch:

EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null)
device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121)
device-mapper: multipath: XXX snitm debugging: WRITE SAME I/O failed with error=-121
end_request: critical target error, dev dm-6, sector 528
dm-6: WRITE SAME failed. Manually zeroing.

# cat /sys/block/sdh/queue/write_same_max_bytes
0
# cat /sys/block/dm-6/queue/write_same_max_bytes
0

It should be noted that WRITE SAME support wasn't enabled in DM
multipath until v3.10.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # 3.10+
2013-09-20 10:36:34 -04:00
Mikulas Patocka 60e356f381 dm-snapshot: fix performance degradation due to small hash size
LVM2, since version 2.02.96, creates origin with zero size, then loads
the snapshot driver and then loads the origin.  Consequently, the
snapshot driver sees the origin size zero and sets the hash size to the
lower bound 64.  Such small hash table causes performance degradation.

This patch changes it so that the hash size is determined by the size of
snapshot volume, not minimum of origin and snapshot size.  It doesn't
make sense to set the snapshot size significantly larger than the origin
size, so we do not need to take origin size into account when
calculating the hash size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2013-09-20 10:36:34 -04:00
Mikulas Patocka 5ea330a75b dm snapshot: workaround for a false positive lockdep warning
The kernel reports a lockdep warning if a snapshot is invalidated because
it runs out of space.

The lockdep warning was triggered by commit 0976dfc1d0
("workqueue: Catch more locking problems with flush_work()") in v3.5.

The warning is false positive.  The real cause for the warning is that
the lockdep engine treats different instances of md->lock as a single
lock.

This patch is a workaround - we use flush_workqueue instead of flush_work.
This code path is not performance sensitive (it is called only on
initialization or invalidation), thus it doesn't matter that we flush the
whole workqueue.

The real fix for the problem would be to teach the lockdep engine to treat
different instances of md->lock as separate locks.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.5+
2013-09-20 10:36:34 -04:00
Mikulas Patocka bbf3f8cbdc dm stats: fix possible counter corruption on 32-bit systems
There was a deliberate race condition in dm_stat_for_entry() to avoid the
overhead of disabling and enabling interrupts.  The race could result in
some events not being counted on 64-bit architectures.

However, on 32-bit architectures, operations on long long variables are
not atomic, so the race condition could cause the counter to jump by 2^32.
Such jumps could be disruptive, so we need to do proper locking on 32-bit
architectures.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Alasdair G. Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-09-18 14:41:06 -04:00
Jun'ichi Nomura cc9d3c382b dm mpath: do not fail path on -ENOSPC
Since ENOSPC is a target-side error, dm-mpath should just pass the error
information to upper layer instead of retrying itself with path failover.
Otherwise it will end up failing all paths down while path checkers find
all paths ok.

ENOSPC can now be returned from SCSI device after commit a9d6ceb8
("[SCSI] return ENOSPC on thin provisioning failure").

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-09-18 14:41:06 -04:00
Linus Torvalds 26935fb06e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 4 from Al Viro:
 "list_lru pile, mostly"

This came out of Andrew's pile, Al ended up doing the merge work so that
Andrew didn't have to.

Additionally, a few fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits)
  super: fix for destroy lrus
  list_lru: dynamically adjust node arrays
  shrinker: Kill old ->shrink API.
  shrinker: convert remaining shrinkers to count/scan API
  staging/lustre/libcfs: cleanup linux-mem.h
  staging/lustre/ptlrpc: convert to new shrinker API
  staging/lustre/obdclass: convert lu_object shrinker to count/scan API
  staging/lustre/ldlm: convert to shrinkers to count/scan API
  hugepage: convert huge zero page shrinker to new shrinker API
  i915: bail out earlier when shrinker cannot acquire mutex
  drivers: convert shrinkers to new count/scan API
  fs: convert fs shrinkers to new scan/count API
  xfs: fix dquot isolation hang
  xfs-convert-dquot-cache-lru-to-list_lru-fix
  xfs: convert dquot cache lru to list_lru
  xfs: rework buffer dispose list tracking
  xfs-convert-buftarg-lru-to-generic-code-fix
  xfs: convert buftarg LRU to generic code
  fs: convert inode and dentry shrinking to be node aware
  vmscan: per-node deferred work
  ...
2013-09-12 15:01:38 -07:00
Dave Chinner 7dc19d5aff drivers: convert shrinkers to new count/scan API
Convert the driver shrinkers to the new API.  Most changes are compile
tested only because I either don't have the hardware or it's staging
stuff.

FWIW, the md and android code is pretty good, but the rest of it makes me
want to claw my eyes out.  The amount of broken code I just encountered is
mind boggling.  I've added comments explaining what is broken, but I fear
that some of the code would be best dealt with by being dragged behind the
bike shed, burying in mud up to it's neck and then run over repeatedly
with a blunt lawn mower.

Special mention goes to the zcache/zcache2 drivers.  They can't co-exist
in the build at the same time, they are under different menu options in
menuconfig, they only show up when you've got the right set of mm
subsystem options configured and so even compile testing is an exercise in
pulling teeth.  And that doesn't even take into account the horrible,
broken code...

[glommer@openvz.org: fixes for i915, android lowmem, zcache, bcache]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:32 -04:00
Linus Torvalds 7426d62871 Add the ability to collect I/O statistics on user-defined regions of a
device-mapper device.  This dm-stats code required the reintroduction of
 a div64_u64_rem() helper, but as a separate method that doesn't slow
 down div64_u64() -- especially on 32-bit systems.
 
 Allow the error target to replace request-based DM devices
 (e.g. multipath) in addition to bio-based DM devices.
 
 Various other small code fixes and improvements to thin-provisioning, DM
 cache and the DM ioctl interface.
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Merge tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper updates from Mike Snitzer:
 "Add the ability to collect I/O statistics on user-defined regions of a
  device-mapper device.  This dm-stats code required the reintroduction
  of a div64_u64_rem() helper, but as a separate method that doesn't
  slow down div64_u64() -- especially on 32-bit systems.

  Allow the error target to replace request-based DM devices (e.g.
  multipath) in addition to bio-based DM devices.

  Various other small code fixes and improvements to thin-provisioning,
  DM cache and the DM ioctl interface"

* tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm stripe: silence a couple sparse warnings
  dm: add statistics support
  dm thin: always return -ENOSPC if no_free_space is set
  dm ioctl: cleanup error handling in table_load
  dm ioctl: increase granularity of type_lock when loading table
  dm ioctl: prevent rename to empty name or uuid
  dm thin: set pool read-only if breaking_sharing fails block allocation
  dm thin: prefix pool error messages with pool device name
  dm: allow error target to replace bio-based and request-based targets
  math64: New separate div64_u64_rem helper
  dm space map: optimise sm_ll_dec and sm_ll_inc
  dm btree: prefetch child nodes when walking tree for a dm_btree_del
  dm btree: use pop_frame in dm_btree_del to cleanup code
  dm cache: eliminate holes in cache structure
  dm cache: fix stacking of geometry limits
  dm thin: fix stacking of geometry limits
  dm thin: add data block size limits to Documentation
  dm cache: add data block size limits to code and Documentation
  dm cache: document metadata device is exclussive to a cache
  dm: stop using WQ_NON_REENTRANT
2013-09-10 13:06:15 -07:00
Linus Torvalds 4d7696f1b0 md update for v3.12
Headline item is multithreading for RAID5 so that more
 IO/sec can be supported on fast (SSD) devices.
 Also TILE-Gx SIMD suppor for RAID6 calculations and an
 assortment of bug fixes.
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Merge tag 'md/3.12' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Headline item is multithreading for RAID5 so that more IO/sec can be
  supported on fast (SSD) devices.  Also TILE-Gx SIMD suppor for RAID6
  calculations and an assortment of bug fixes"

* tag 'md/3.12' of git://neil.brown.name/md:
  raid5: only wakeup necessary threads
  md/raid5: flush out all pending requests before proceeding with reshape.
  md/raid5: use seqcount to protect access to shape in make_request.
  raid5: sysfs entry to control worker thread number
  raid5: offload stripe handle to workqueue
  raid5: fix stripe release order
  raid5: make release_stripe lockless
  md: avoid deadlock when dirty buffers during md_stop.
  md: Don't test all of mddev->flags at once.
  md: Fix apparent cut-and-paste error in super_90_validate
  raid6/test: replace echo -e with printf
  RAID: add tilegx SIMD implementation of raid6
  md: fix safe_mode buglet.
  md: don't call md_allow_write in get_bitmap_file.
2013-09-10 13:03:41 -07:00
Mike Snitzer 7fff5e8f72 dm stripe: silence a couple sparse warnings
Eliminate the following sparse warnings:
drivers/md/dm-stripe.c:443:12: warning: symbol 'dm_stripe_init' was not declared. Should it be static?
drivers/md/dm-stripe.c:456:6: warning: symbol 'dm_stripe_exit' was not declared. Should it be static?

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-06 11:36:01 -04:00
Mikulas Patocka fd2ed4d252 dm: add statistics support
Support the collection of I/O statistics on user-defined regions of
a DM device.  If no regions are defined no statistics are collected so
there isn't any performance impact.  Only bio-based DM devices are
currently supported.

Each user-defined region specifies a starting sector, length and step.
Individual statistics will be collected for each step-sized area within
the range specified.

The I/O statistics counters for each step-sized area of a region are
in the same format as /sys/block/*/stat or /proc/diskstats but extra
counters (12 and 13) are provided: total time spent reading and
writing in milliseconds.  All these counters may be accessed by sending
the @stats_print message to the appropriate DM device via dmsetup.

The creation of DM statistics will allocate memory via kmalloc or
fallback to using vmalloc space.  At most, 1/4 of the overall system
memory may be allocated by DM statistics.  The admin can see how much
memory is used by reading
/sys/module/dm_mod/parameters/stats_current_allocated_bytes

See Documentation/device-mapper/statistics.txt for more details.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer 94563badaf dm thin: always return -ENOSPC if no_free_space is set
If pool has 'no_free_space' set it means a previous allocation already
determined the pool has no free space (and failed that allocation with
-ENOSPC).  By always returning -ENOSPC if 'no_free_space' is set, we do
not allow the pool to oscillate between allocating blocks and then not.

But a side-effect of this determinism is that if a user wants to be able
to allocate new blocks they'll need to reload the pool's table (to clear
the 'no_free_space' flag).  This reload will happen automatically if the
pool's data volume is resized.  But if the user takes action to free a
lot of space by deleting snapshot volumes, etc the pool will no longer
allow data allocations to continue without an intervening table reload.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer f11c1c5693 dm ioctl: cleanup error handling in table_load
Make use of common cleanup code.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer 00c4fc3b1f dm ioctl: increase granularity of type_lock when loading table
Hold the mapped device's type_lock before calling populate_table() since
it is where the table's type is determined based on the specified
targets.  There is no need to allow concurrent table loads to race to
establish the table's targets or type.

This eliminates the need to grab the lock in dm_table_set_type().

Also verify that the type_lock is held in both dm_set_md_type() and
dm_get_md_type().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Alasdair Kergon c2b0482462 dm ioctl: prevent rename to empty name or uuid
A device-mapper device must always have a name consisting of a non-empty
string.  If the device also has a uuid, this similarly must not be an
empty string.

The DM_DEV_CREATE ioctl enforces these rules when the device is created,
but this patch is needed to enforce them when DM_DEV_RENAME is used to
change the name or uuid.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer d6fc204201 dm thin: set pool read-only if breaking_sharing fails block allocation
break_sharing() now handles an arbitrary alloc_data_block() error
the same way as provision_block(): marks pool read-only and errors the
cell.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer 4fa5971a69 dm thin: prefix pool error messages with pool device name
Useful to know which pool is experiencing the error.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:05 -04:00
Mike Snitzer 169e2cc279 dm: allow error target to replace bio-based and request-based targets
It may be useful to switch a request-based table to the "error" target.
Enhance the DM core to allow a hybrid target_type which is capable of
handling either bios (via .map) or requests (via .map_rq).

Add a request-based map function (.map_rq) to the "error" target_type;
making it DM's first hybrid target.  Train dm_table_set_type() to prefer
the mapped device's established type (request-based or bio-based).  If
the mapped device doesn't have an established type default to making the
table with the hybrid target(s) bio-based.

Tested 'dmsetup wipe_table' to work on both bio-based and request-based
devices.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:05 -04:00
Linus Torvalds f66c83d059 SCSI misc on 20130903
This patch set is a set of driver updates (ufs, zfcp, lpfc, mpt2/3sas,
 qla4xxx, qla2xxx [adding support for ISP8044 + other things]) we also have a
 new driver: esas2r which has a number of static checker problems, but which I
 expect to resolve over the -rc course of 3.12 under the new driver exception.
 We also have the error return updates that were discussed at LSF.
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull first round of SCSI updates from James Bottomley:
 "This patch set is a set of driver updates (ufs, zfcp, lpfc, mpt2/3sas,
  qla4xxx, qla2xxx [adding support for ISP8044 + other things]).

  We also have a new driver: esas2r which has a number of static checker
  problems, but which I expect to resolve over the -rc course of 3.12
  under the new driver exception.

  We also have the error return that were discussed at LSF"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (118 commits)
  [SCSI] sg: push file descriptor list locking down to per-device locking
  [SCSI] sg: checking sdp->detached isn't protected when open
  [SCSI] sg: no need sg_open_exclusive_lock
  [SCSI] sg: use rwsem to solve race during exclusive open
  [SCSI] scsi_debug: fix logical block provisioning support when unmap_alignment != 0
  [SCSI] scsi_debug: fix endianness bug in sdebug_build_parts()
  [SCSI] qla2xxx: Update the driver version to 8.06.00.08-k.
  [SCSI] qla2xxx: print MAC via %pMR.
  [SCSI] qla2xxx: Correction to message ids.
  [SCSI] qla2xxx: Correctly print out/in mailbox registers.
  [SCSI] qla2xxx: Add a new interface to update versions.
  [SCSI] qla2xxx: Move queue depth ramp down message to i/o debug level.
  [SCSI] qla2xxx: Select link initialization option bits from current operating mode.
  [SCSI] qla2xxx: Add loopback IDC-TIME-EXTEND aen handling support.
  [SCSI] qla2xxx: Set default critical temperature value in cases when ISPFX00 firmware doesn't provide it
  [SCSI] qla2xxx: QLAFX00 make over temperature AEN handling informational, add log for normal temperature AEN
  [SCSI] qla2xxx: Correct Interrupt Register offset for ISPFX00
  [SCSI] qla2xxx: Remove handling of Shutdown Requested AEN from qlafx00_process_aen().
  [SCSI] qla2xxx: Send all AENs for ISPFx00 to above layers.
  [SCSI] qla2xxx: Add changes in initialization for ISPFX00 cards with BIOS
  ...
2013-09-03 15:48:06 -07:00
Shaohua Li bfc90cb093 raid5: only wakeup necessary threads
If there are not enough stripes to handle, we'd better not always
queue all available work_structs. If one worker can only handle small
or even none stripes, it will impact request merge and create lock
contention.

With this patch, the number of work_struct running will depend on
pending stripes number. Note: some statistics info used in the patch
are accessed without locking protection. This should doesn't matter,
we just try best to avoid queue unnecessary work_struct.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-09-02 10:31:29 +10:00
NeilBrown 4d77e3ba88 md/raid5: flush out all pending requests before proceeding with reshape.
Some requests - particularly 'discard' and 'read' are handled
differently depending on whether a reshape is active or not.

It is harmless to assume reshape is active if it isn't but wrong
to act as though reshape is not active when it is.

So when we start reshape - after making clear to all requests that
reshape has started - use mddev_suspend/mddev_resume to flush out all
requests.  This will ensure that no requests will be assuming the
absence of reshape once it really starts.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:58:44 +10:00
NeilBrown c46501b2de md/raid5: use seqcount to protect access to shape in make_request.
make_request() access various shape parameters (raid_disks, chunk_size
etc) which might be changed by raid5_start_reshape().

If the later is called at and awkward time during the form, the wrong
stripe_head might be used.

So introduce a 'seqcount' and after finding a stripe_head make sure
there is no reason to expect that we got the wrong one.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:58:36 +10:00
Shaohua Li b721420e87 raid5: sysfs entry to control worker thread number
Add a sysfs entry to control running workqueue thread number. If
group_thread_cnt is set to 0, we will disable workqueue offload handling of
stripes.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:56:52 +10:00
Shaohua Li 851c30c9ba raid5: offload stripe handle to workqueue
This is another attempt to create multiple threads to handle raid5 stripes.
This time I use workqueue.

raid5 handles request (especially write) in stripe unit. A stripe is page size
aligned/long and acrosses all disks. Writing to any disk sector, raid5 runs a
state machine for the corresponding stripe, which includes reading some disks
of the stripe, calculating parity, and writing some disks of the stripe. The
state machine is running in raid5d thread currently. Since there is only one
thread, it doesn't scale well for high speed storage. An obvious solution is
multi-threading.

To get better performance, we have some requirements:
a. locality. stripe corresponding to request submitted from one cpu is better
handled in thread in local cpu or local node. local cpu is preferred but some
times could be a bottleneck, for example, parity calculation is too heavy.
local node running has wide adaptability.
b. configurablity. Different setup of raid5 array might need diffent
configuration. Especially the thread number. More threads don't always mean
better performance because of lock contentions.

My original implementation is creating some kernel threads. There are
interfaces to control which cpu's stripe each thread should handle. And
userspace can set affinity of the threads. This provides biggest flexibility
and configurability. But it's hard to use and apparently a new thread pool
implementation is disfavor.

Recent workqueue improvement is quite promising. unbound workqueue will be
bound to numa node. If WQ_SYSFS is set in workqueue, there are sysfs option to
do affinity setting. For example, we can only include one HT sibling in
affinity. Since work is non-reentrant by default, and we can control running
thread number by limiting dispatched work_struct number.

In this patch, I created several stripe worker group. A group is a numa node.
stripes from cpus of one node will be added to a group list. Workqueue thread
of one node will only handle stripes of worker group of the node. In this way,
stripe handling has numa node locality. And as I said, we can control thread
number by limiting dispatched work_struct number.

The work_struct callback function handles several stripes in one run. A typical
work queue usage is to run one unit in each work_struct. In raid5 case, the
unit is a stripe. But we can't do that:
a. Though handling a stripe doesn't need lock because of reference accounting
and stripe isn't in any list, queuing a work_struct for each stripe will make
workqueue lock contended very heavily.
b. blk_start_plug()/blk_finish_plug() should surround stripe handle, as we
might dispatch request. If each work_struct only handles one stripe, such block
plug is meaningless.

This implementation can't do very fine grained configuration. But the numa
binding is most popular usage model, should be enough for most workloads.

Note: since we have only one stripe queue, switching to multi-thread might
decrease request size dispatching down to low level layer. The impact depends
on thread number, raid configuration and workload. So multi-thread raid5 might
not be proper for all setups.

Changes V1 -> V2:
1. remove WQ_NON_REENTRANT
2. disabling multi-threading by default
3. Add more descriptions in changelog

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:46:38 +10:00
Shaohua Li d265d9dc1d raid5: fix stripe release order
patch "make release_stripe lockless" changes the order stripes are released.
Originally I thought block layer can take care of request merge, but it appears
there are still some requests not merged. It's easy to fix the order.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:36:26 +10:00
Shaohua Li 773ca82fa1 raid5: make release_stripe lockless
release_stripe still has big lock contention. We just add the stripe to a llist
without taking device_lock. We let the raid5d thread to do the real stripe
release, which must hold device_lock anyway. In this way, release_stripe
doesn't hold any locks.

The side effect is the released stripes order is changed. But sounds not a big
deal, stripes are never handled in order. And I thought block layer can already
do nice request merge, which means order isn't that important.

I kept the unplug release batch, which is unnecessary with this patch from lock
contention avoid point of view, and actually if we delete it, the stripe_head
release_list and lru can share storage. But the unplug release batch is also
helpful for request merge. We probably can delay wakeup raid5d till unplug, but
I'm still afraid of the case which raid5d is running.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 11:55:53 +10:00
NeilBrown 260fa034ef md: avoid deadlock when dirty buffers during md_stop.
When the last process closes /dev/mdX sync_blockdev will be called so
that all buffers get flushed.
So if it is then opened for the STOP_ARRAY ioctl to be sent there will
be nothing to flush.

However if we open /dev/mdX in order to send the STOP_ARRAY ioctl just
moments before some other process which was writing closes their file
descriptor, then there won't be a 'last close' and the buffers might
not get flushed.

So do_md_stop() calls sync_blockdev().  However at this point it is
holding ->reconfig_mutex.  So if the array is currently 'clean' then
the writes from sync_blockdev() will not complete until the array
can be marked dirty and that won't happen until some other thread
can get ->reconfig_mutex.  So we deadlock.

We need to move the sync_blockdev() call to before we take
->reconfig_mutex.
However then some other thread could open /dev/mdX and write to it
after we call sync_blockdev() and before we actually stop the array.
This can leave dirty data in the page cache which is awkward.

So introduce new flag MD_STILL_CLOSED.  Set it before calling
sync_blockdev(), clear it if anyone does open the file, and abort the
STOP_ARRAY attempt if it gets set before we lock against further
opens.

It is still possible to get problems if you open /dev/mdX, write to
it, then issue the STOP_ARRAY ioctl.  Just don't do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:45:00 +10:00
NeilBrown 7a0a5355cb md: Don't test all of mddev->flags at once.
mddev->flags is mostly used to record if an update of the
metadata is needed.  Sometimes the whole field is tested
instead of just the important bits.  This makes it difficult
to introduce more state bits.

So replace all bare tests of mddev->flags with tests for the bits
that actually need testing.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:28:23 +10:00
Dave Jones c9ad020fec md: Fix apparent cut-and-paste error in super_90_validate
Setting a variable to itself probably wasn't the intention here.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:06:17 +10:00
NeilBrown 275c51c4e3 md: fix safe_mode buglet.
Whe we set the safe_mode_timeout to a smaller value we trigger a timeout
immediately - otherwise the small value might not be honoured.
However if the previous timeout was 0 meaning "no timeout", we didn't.
This would mean that no timeout happens until the next write completes,
which could be a long time.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:43 +10:00
NeilBrown 60559da4d8 md: don't call md_allow_write in get_bitmap_file.
There is no really need as GFP_NOIO is very likely sufficient,
and failure is not catastrophic.

Calling md_allow_write here will convert a read-auto array to
read/write which could be confusing when you are just performing
a read operation.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:32 +10:00
Hannes Reinecke 7e782af576 [SCSI] Return ENODATA on medium error
When a medium error is detected the SCSI stack should return
ENODATA to the upper layers.

[jejb: fix whitespace error]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23 12:54:53 -04:00
Joe Thornber f722063ee0 dm space map: optimise sm_ll_dec and sm_ll_inc
Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function.  This avoids traversing the data
structures twice and hence improves performance.

Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber 04f17c802f dm btree: prefetch child nodes when walking tree for a dm_btree_del
dm-btree now takes advantage of dm-bufio's ability to prefetch data via
dm_bm_prefetch().  Prior to this change many btree node visits were
causing a synchronous read.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber cd5acf0b44 dm btree: use pop_frame in dm_btree_del to cleanup code
Remove a visited leaf straight away from the stack, rather than
marking all it's children as visited and letting it get removed on the
next iteration.  May also offer a micro optimisation in dm_btree_del.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer c9ec5d7c7b dm cache: eliminate holes in cache structure
Reorder members in the cache structure to eliminate 6 out of 7 holes
(reclaiming 24 bytes).  Also, the 'worker' and 'waker' members no longer
straddle cachelines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer f610937214 dm cache: fix stacking of geometry limits
Do not blindly override the queue limits (specifically io_min and
io_opt).  Allow traditional stacking of these limits if io_opt is a
factor of the cache's data block size.

Without this patch mkfs.xfs does not recognize the cache device's
provided limits as a useful geometry (e.g. raid) so these hints are
ignored.  This was due to setting io_min to a useless value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer 0cc67cd9c5 dm thin: fix stacking of geometry limits
Do not blindly override the queue limits (specifically io_min and
io_opt).  Allow traditional stacking of these limits if io_opt is a
factor of the thin-pool's data block size.

Without this patch mkfs.xfs does not recognize the thin device's
provided limits as a useful geometry (e.g. raid) so these hints are
ignored.  This was due to setting io_min to a useless value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer 0547304463 dm cache: add data block size limits to code and Documentation
Place upper bound on the cache's data block size (1GB).

Inform users that the data block size can't be any arbitrary number,
i.e. its value must be between 32KB and 1GB.  Also, it should be a
multiple of 32KB.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:13 -04:00
Tejun Heo 670368a8dd dm: stop using WQ_NON_REENTRANT
dbf2576e37 ("workqueue: make all workqueues non-reentrant") made
WQ_NON_REENTRANT no-op and the flag is going away.  Remove its usages.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:13 -04:00
Geert Uytterhoeven b936bf8b78 dm cache: avoid conflicting remove_mapping() in mq policy
On sparc32, which includes <linux/swap.h> from <asm/pgtable_32.h>:

drivers/md/dm-cache-policy-mq.c:962:13: error: conflicting types for 'remove_mapping'
include/linux/swap.h:285:12: note: previous declaration of 'remove_mapping' was here

As mq_remove_mapping() already exists, and the local remove_mapping() is
used only once, inline it manually to avoid the conflict.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-16 15:56:51 -04:00
Linus Torvalds c271f5bc9a 2 more bugfixes for md in 3.11
Both marked for -stable, both since 3.3.  I guess I should spend more
 time testing...
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Merge tag 'md/3.11-fixes' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
 "Two more bugfixes for md in 3.11

  Both marked for -stable, both since 3.3.  I guess I should spend more
  time testing..."

* tag 'md/3.11-fixes' of git://neil.brown.name/md:
  md/raid5: fix interaction of 'replace' and 'recovery'.
  md/raid10: remove use-after-free bug.
2013-07-26 11:20:10 -07:00
NeilBrown f94c0b6658 md/raid5: fix interaction of 'replace' and 'recovery'.
If a device in a RAID4/5/6 is being replaced while another is being
recovered, then the writes to the replacement device currently don't
happen, resulting in corruption when the replacement completes and the
new drive takes over.

This is because the replacement writes are only triggered when
's.replacing' is set and not when the similar 's.sync' is set (which
is the case during resync and recovery - it means all devices need to
be read).

So schedule those writes when s.replacing is set as well.

In this case we cannot use "STRIPE_INSYNC" to record that the
replacement has happened as that is needed for recording that any
parity calculation is complete.  So introduce STRIPE_REPLACED to
record if the replacement has happened.

For safety we should also check that STRIPE_COMPUTE_RUN is not set.
This has a similar effect to the "s.locked == 0" test.  The latter
ensure that now IO has been flagged but not started.  The former
checks if any parity calculation has been flagged by not started.
We must wait for both of these to complete before triggering the
'replace'.

Add a similar test to the subsequent check for "are we finished yet".
This possibly isn't needed (is subsumed in the STRIPE_INSYNC test),
but it makes it more obvious that the REPLACE will happen before we
think we are finished.

Finally if a NeedReplace device is not UPTODATE then that is an
error.  We really must trigger a warning.

This bug was introduced in commit 9a3e1101b8
(md/raid5:  detect and handle replacements during recovery.)
which introduced replacement for raid5.
That was in 3.3-rc3, so any stable kernel since then would benefit
from this fix.

Cc: stable@vger.kernel.org (3.3+)
Reported-by: qindehua <13691222965@163.com>
Tested-by: qindehua <qindehua@163.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-25 16:46:57 +10:00
NeilBrown 0eb25bb027 md/raid10: remove use-after-free bug.
We always need to be careful when calling generic_make_request, as it
can start a chain of events which might free something that we are
using.

Here is one place I wasn't careful enough.  If the wbio2 is not in
use, then it might get freed at the first generic_make_request call.
So perform all necessary tests first.

This bug was introduced in 3.3-rc3 (24afd80d99) and can cause an
oops, so fix is suitable for any -stable since then.

Cc: stable@vger.kernel.org (3.3+)
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-25 16:46:53 +10:00
Linus Torvalds d4c90b1b9f Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block
Pull block IO driver bits from Jens Axboe:
 "As I mentioned in the core block pull request, due to real life
  circumstances the driver pull request would be late.  Now it looks
  like -rc2 late...  On the plus side, apart form the rsxx update, these
  are all things that I could argue could go in later in the cycle as
  they are fixes and not features.  So even though things are late, it's
  not ALL bad.

  The pull request contains:

   - Updates to bcache, all bug fixes, from Kent.

   - A pile of drbd bug fixes (no big features this time!).

   - xen blk front/back fixes.

   - rsxx driver updates, some of them deferred form 3.10.  So should be
     well cooked by now"

* 'for-3.11/drivers' of git://git.kernel.dk/linux-block: (63 commits)
  bcache: Allocation kthread fixes
  bcache: Fix GC_SECTORS_USED() calculation
  bcache: Journal replay fix
  bcache: Shutdown fix
  bcache: Fix a sysfs splat on shutdown
  bcache: Advertise that flushes are supported
  bcache: check for allocation failures
  bcache: Fix a dumb race
  bcache: Use standard utility code
  bcache: Update email address
  bcache: Delete fuzz tester
  bcache: Document shrinker reserve better
  bcache: FUA fixes
  drbd: Allow online change of al-stripes and al-stripe-size
  drbd: Constants should be UPPERCASE
  drbd: Ignore the exit code of a fence-peer handler if it returns too late
  drbd: Fix rcu_read_lock balance on error path
  drbd: fix error return code in drbd_init()
  drbd: Do not sleep inside rcu
  bcache: Refresh usage docs
  ...
2013-07-22 19:02:52 -07:00
NeilBrown 30bc9b5387 md/raid1: fix bio handling problems in process_checks()
Recent change to use bio_copy_data() in raid1 when repairing
an array is faulty.

The underlying may have changed the bio in various ways using
bio_advance and these need to be undone not just for the 'sbio' which
is being copied to, but also the 'pbio' (primary) which is being
copied from.

So perform the reset on all bios that were read from and do it early.

This also ensure that the sbio->bi_io_vec[j].bv_len passed to
memcmp is correct.

This fixes a crash during a 'check' of a RAID1 array.  The crash was
introduced in 3.10 so this is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:04 +10:00
NeilBrown 5024c29831 md: Remove recent change which allows devices to skip recovery.
commit 7ceb17e87b
    md: Allow devices to be re-added to a read-only array.

allowed a bit more than just that.  It also allows devices to be added
to a read-write array and to end up skipping recovery.

This patch removes the offending piece of code pending a rewrite for a
subsequent release.

More specifically:
 If the array has a bitmap, then the device will still need a bitmap
 based resync ('saved_raid_disk' is set under different conditions
 is a bitmap is present).
 If the array doesn't have a bitmap, then this is correct as long as
 nothing has been written to the array since the metadata was checked
 by ->validate_super.  However there is no locking to ensure that there
 was no write.

Bug was introduced in 3.10 and causes data corruption so
patch is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:03 +10:00
NeilBrown 7bb23c4934 md/raid10: fix two problems with RAID10 resync.
1/ When an different between blocks is found, data is copied from
   one bio to the other.  However bv_len is used as the length to
   copy and this could be zero.  So use r10_bio->sectors to calculate
   length instead.
   Using bv_len was probably always a bit dubious, but the introduction
   of bio_advance made it much more likely to be a problem.

2/ When preparing some blocks for sync, we don't set BIO_UPTODATE
   except on bios that we schedule for a read.  This ensures that
   missing/failed devices don't confuse the loop at the top of
   sync_request write.
   Commit 8be185f2c9 "raid10: Use bio_reset()"
   removed a loop which set BIO_UPTDATE on all appropriate bios.
   So we need to re-add that flag.

These bugs were introduced in 3.10, so this patch is suitable for
3.10-stable, and can remove a potential for data corruption.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:01 +10:00
Kent Overstreet 79826c35eb bcache: Allocation kthread fixes
The alloc kthread should've been using try_to_freeze() - and also there
was the potential for the alloc kthread to get woken up after it had
shut down, which would have been bad.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-12 00:22:49 -07:00
Kent Overstreet 29ebf465b9 bcache: Fix GC_SECTORS_USED() calculation
Part of the job of garbage collection is to add up however many sectors
of live data it finds in each bucket, but that doesn't work very well if
it doesn't reset GC_SECTORS_USED() when it starts. Whoops.

This wouldn't have broken anything horribly, but allocation tries to
preferentially reclaim buckets that are mostly empty and that's not
gonna work with an incorrect GC_SECTORS_USED() value.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:48 -07:00
Kent Overstreet faa5673617 bcache: Journal replay fix
The journal replay code starts by finding something that looks like a
valid journal entry, then it does a binary search over the unchecked
region of the journal for the journal entries with the highest sequence
numbers.

Trouble is, the logic was wrong - journal_read_bucket() returns true if
it found journal entries we need, but if the range of journal entries
we're looking for loops around the end of the journal - in that case
journal_read_bucket() could return true when it hadn't found the highest
sequence number we'd seen yet, and in that case the binary search did
the wrong thing. Whoops.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:48 -07:00
Kent Overstreet 5caa52afc5 bcache: Shutdown fix
Stopping a cache set is supposed to make it stop attached backing
devices, but somewhere along the way that code got lost. Fixing this
mainly has the effect of fixing our reboot notifier.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:47 -07:00
Kent Overstreet c9502ea442 bcache: Fix a sysfs splat on shutdown
If we stopped a bcache device when we were already detaching (or
something like that), bcache_device_unlink() would try to remove a
symlink from sysfs that was already gone because the bcache dev kobject
had already been removed from sysfs.

So keep track of whether we've removed stuff from sysfs.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:47 -07:00
Kent Overstreet 54d12f2b4f bcache: Advertise that flushes are supported
Whoops - bcache's flush/FUA was mostly correct, but flushes get filtered
out unless we say we support them...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:46 -07:00
Dan Carpenter d2a65ce2ac bcache: check for allocation failures
There is a missing NULL check after the kzalloc().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2013-07-12 00:22:46 -07:00
Kent Overstreet 6aa8f1a6ca bcache: Fix a dumb race
In the far-too-complicated closure code - closures can have destructors,
for probably dubious reasons; they get run after the closure is no
longer waiting on anything but before dropping the parent ref, intended
just for freeing whatever memory the closure is embedded in.

Trouble is, when remaining goes to 0 and we've got nothing more to run -
we also have to unlock the closure, setting remaining to -1. If there's
a destructor, that unlock isn't doing anything - nobody could be trying
to lock it if we're about to free it - but if the unlock _is needed...
that check for a destructor was racy. Argh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:33 -07:00
Linus Torvalds 9903883f1d Add a device-mapper target called dm-switch to provide a multipath
framework for storage arrays that dynamically reconfigure their
 preferred paths for different device regions.
 
 Fix a bug in the verity target that prevented its use with some
 specific sizes of devices.
 
 Improve some locking mechanisms in the device-mapper core and bufio.
 
 Add Mike Snitzer as a device-mapper maintainer.
 
 A few more clean-ups and fixes.
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Merge tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper changes from Alasdair G Kergon:
 "Add a device-mapper target called dm-switch to provide a multipath
  framework for storage arrays that dynamically reconfigure their
  preferred paths for different device regions.

  Fix a bug in the verity target that prevented its use with some
  specific sizes of devices.

  Improve some locking mechanisms in the device-mapper core and bufio.

  Add Mike Snitzer as a device-mapper maintainer.

  A few more clean-ups and fixes"

* tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: add switch target
  dm: update maintainers
  dm: optimize reorder structure
  dm: optimize use SRCU and RCU
  dm bufio: submit writes outside lock
  dm cache: fix arm link errors with inline
  dm verity: use __ffs and __fls
  dm flakey: correct ctr alloc failure mesg
  dm verity: remove pointless comparison
  dm: use __GFP_HIGHMEM in __vmalloc
  dm verity: fix inability to use a few specific devices sizes
  dm ioctl: set noio flag to avoid __vmalloc deadlock
  dm mpath: fix ioctl deadlock when no paths
2013-07-11 13:05:40 -07:00
Jim Ramsay 9d0eb0ab43 dm: add switch target
dm-switch is a new target that maps IO to underlying block devices
efficiently when there is a large number of fixed-sized address regions
but there is no simple pattern to allow for a compact mapping
representation such as dm-stripe.

Though we have developed this target for a specific storage device, Dell
EqualLogic, we have made an effort to keep it as general purpose as
possible in the hope that others may benefit.

Originally developed by Jim Ramsay. Simplified by Mikulas Patocka.

Signed-off-by: Jim Ramsay <jim_ramsay@dell.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:19 +01:00
Mikulas Patocka 2a7faeb176 dm: optimize reorder structure
This reorder actually improves performance by 20% (from 39.1s to 32.8s)
on x86-64 quad core Opteron.

I have no explanation for this, possibly it makes some other entries are
better cache-aligned.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka 83d5e5b0af dm: optimize use SRCU and RCU
This patch removes "io_lock" and "map_lock" in struct mapped_device and
"holders" in struct dm_table and replaces these mechanisms with
sleepable-rcu.

Previously, the code would call "dm_get_live_table" and "dm_table_put" to
get and release table. Now, the code is changed to call "dm_get_live_table"
and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and
dm_put_live_table unlocks it.

dm_get_live_table_fast/dm_put_live_table_fast can be used instead of
dm_get_live_table/dm_put_live_table. These *_fast functions use
non-sleepable RCU, so the caller must not block between them.

If the code changes active or inactive dm table, it must call
dm_sync_table before destroying the old table.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka 2480945cd4 dm bufio: submit writes outside lock
This patch changes dm-bufio so that it submits write I/Os outside of the
lock. If the number of submitted buffers is greater than the number of
requests on the target queue, submit_bio blocks. We want to block outside
of the lock to improve latency of other threads that may need the lock.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka 43aeaa2957 dm cache: fix arm link errors with inline
Use __always_inline to avoid a link failure with gcc 4.6 on ARM.
gcc 4.7 is OK.

It creates a function block_div.part.8, it references __udivdi3 and
__umoddi3 and it is never called. The references to __udivdi3 and
__umoddi3 cause a link failure.

Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka 553d8fe029 dm verity: use __ffs and __fls
This patch changes ffs() to __ffs() and fls() to __fls() which don't add
one to the result.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Alasdair G Kergon 75e3a0f55b dm flakey: correct ctr alloc failure mesg
Remove the reference to the "linear" target from the error message
issued when allocation fails in the flakey target.

Cc: Robin Dong <sanbai@taobao.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka 5d8be84397 dm verity: remove pointless comparison
Remove num < 0 test in verity_ctr because num is unsigned.
(Found by Coverity.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka 220cd058d9 dm: use __GFP_HIGHMEM in __vmalloc
Use __GFP_HIGHMEM in __vmalloc.

Pages allocated with __vmalloc can be allocated in high memory that is not
directly mapped to kernel space, so use __GFP_HIGHMEM just like vmalloc
does. This patch reduces memory pressure slightly because pages can be
allocated in the high zone.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:16 +01:00
Mikulas Patocka b1bf2de072 dm verity: fix inability to use a few specific devices sizes
Fix a boundary condition that caused failure for certain device sizes.

The problem is reported at
  http://code.google.com/p/cryptsetup/issues/detail?id=160

For certain device sizes the number of hashes at a specific level was
calculated incorrectly.

It happens for example for a device with data and metadata block size 4096
that has 16385 blocks and algorithm sha256.

The user can test if he is affected by this bug by running the
"veritysetup verify" command and also by activating the dm-verity kernel
driver and reading the whole block device. If it passes without an error,
then the user is not affected.

The condition for the bug is:

Split the total number of data blocks (data_block_bits) into bit strings,
each string has hash_per_block_bits bits. hash_per_block_bits is
rounddown(log2(metadata_block_size/hash_digest_size)). Equivalently, you
can say that you convert data_blocks_bits to 2^hash_per_block_bits base.

If there some zero bit string below the most significant bit string and at
least one bit below this zero bit string is set, then the bug happens.

The same bug exists in the userspace veritysetup tool, so you must use
fixed veritysetup too if you want to use devices that are affected by
this boundary condition.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # 3.4+
Cc: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:16 +01:00
Mikulas Patocka 1c0e883e86 dm ioctl: set noio flag to avoid __vmalloc deadlock
Set noio flag while calling __vmalloc() because it doesn't fully respect
gfp flags to avoid a possible deadlock (see commit
502624bdad).

This should be backported to stable kernels 3.8 and newer. The kernel 3.8
doesn't have memalloc_noio_save(), so we should set and restore process
flag PF_MEMALLOC instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:15 +01:00
Hannes Reinecke 6c182cd88d dm mpath: fix ioctl deadlock when no paths
When multipath needs to retry an ioctl the reference to the
current live table needs to be dropped. Otherwise a deadlock
occurs when all paths are down:
- dm_blk_ioctl takes a reference to the current table
  and spins in multipath_ioctl().
- A new table is being loaded, but upon resume the process
  hangs in dm_table_destroy() waiting for references to
  drop to zero.

With this patch the reference to the old table is dropped
prior to retry, thereby avoiding the deadlock.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:15 +01:00
Linus Torvalds 80cc38b163 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "The usual stuff from trivial tree"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  treewide: relase -> release
  Documentation/cgroups/memory.txt: fix stat file documentation
  sysctl/net.txt: delete reference to obsolete 2.4.x kernel
  spinlock_api_smp.h: fix preprocessor comments
  treewide: Fix typo in printk
  doc: device tree: clarify stuff in usage-model.txt.
  open firmware: "/aliasas" -> "/aliases"
  md: bcache: Fixed a typo with the word 'arithmetic'
  irq/generic-chip: fix a few kernel-doc entries
  frv: Convert use of typedef ctl_table to struct ctl_table
  sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
  doc: clk: Fix incorrect wording
  Documentation/arm/IXP4xx fix a typo
  Documentation/networking/ieee802154 fix a typo
  Documentation/DocBook/media/v4l fix a typo
  Documentation/video4linux/si476x.txt fix a typo
  Documentation/virtual/kvm/api.txt fix a typo
  Documentation/early-userspace/README fix a typo
  Documentation/video4linux/soc-camera.txt fix a typo
  lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
  ...
2013-07-04 11:40:58 -07:00
NeilBrown 1376512065 md/raid10: fix bug which causes all RAID10 reshapes to move no data.
The recent comment:
commit 7e83ccbecd
    md/raid10: Allow skipping recovery when clean arrays are assembled

Causes raid10 to skip a recovery in certain cases where it is safe to
do so.  Unfortunately it also causes a reshape to be skipped which is
never safe.  The result is that an attempt to reshape a RAID10 will
appear to complete instantly, but no data will have been moves so the
array will now contain garbage.
(If nothing is written, you can recovery by simple performing the
reverse reshape which will also complete instantly).

Bug was introduced in 3.10, so this is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Cc: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-04 16:42:57 +10:00
NeilBrown fdcfbbb653 md/raid5: allow 5-device RAID6 to be reshaped to 4-device.
There is a bug in 'check_reshape' for raid5.c  To checks
that the new minimum number of devices is large enough (which is
good), but it does so also after the reshape has started (bad).

This is bad because
 - the calculation is now wrong as mddev->raid_disks has changed
   already, and
 - it is pointless because it is now too late to stop.

So only perform that test when reshape has not been committed to.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-04 16:42:52 +10:00
NeilBrown 78eaa0d4cb md/raid10: fix two bugs affecting RAID10 reshape.
1/ If a RAID10 is being reshaped to a fewer number of devices
 and is stopped while this is ongoing, then when the array is
 reassembled the 'mirrors' array will be allocated too small.
 This will lead to an access error or memory corruption.

2/ A sanity test for a reshaping RAID10 array is restarted
 is slightly incorrect.

Due to the first bug, this is suitable for any -stable
kernel since 3.5 where this code was introduced.

Cc: stable@vger.kernel.org (v3.5+)
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-03 09:43:28 +10:00
Kent Overstreet 8e51e414a3 bcache: Use standard utility code
Some of bcache's utility code has made it into the rest of the kernel,
so drop the bcache versions.

Bcache used to have a workaround for allocating from a bio set under
generic_make_request() (if you allocated more than once, the bios you
already allocated would get stuck on current->bio_list when you
submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT
when allocating bios under generic_make_request() so that allocation
could fail and it could retry from workqueue. But bio_alloc_bioset() has
a workaround now, so we can drop this hack and the associated error
handling.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-07-01 14:43:53 -07:00
Kent Overstreet f3059a5461 bcache: Delete fuzz tester
This code has rotted and it hasn't been used in ages anyways.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-01 14:43:48 -07:00
Kent Overstreet 36c9ea9837 bcache: Document shrinker reserve better
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-01 14:42:48 -07:00
Kent Overstreet e49c7c374e bcache: FUA fixes
Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node
writes have... weird ordering requirements.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-07-01 14:42:47 -07:00
Gabriel de Perthuis ab9e14002e bcache: Send label uevents
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:58:06 -07:00
Gabriel de Perthuis a25c32bede bcache: Send a uevent with a cached device's UUID
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
2013-06-26 21:58:05 -07:00
Kent Overstreet 72c270612b bcache: Write out full stripes
Now that we're tracking dirty data per stripe, we can add two
optimizations for raid5/6:

 * If a stripe is already dirty, force writes to that stripe to
   writeback mode - to help build up full stripes of dirty data

 * When flushing dirty data, preferentially write out full stripes first
   if there are any.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:58:04 -07:00
Kent Overstreet 279afbad4e bcache: Track dirty data by stripe
To make background writeback aware of raid5/6 stripes, we first need to
track the amount of dirty data within each stripe - we do this by
breaking up the existing sectors_dirty into per stripe atomic_ts

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:57:23 -07:00
Kent Overstreet 444fc0b6b1 bcache: Initialize sectors_dirty when attaching
Previously, dirty_data wouldn't get initialized until the first garbage
collection... which was a bit of a problem for background writeback (as
the PD controller keys off of it) and also confusing for users.

This is also prep work for making background writeback aware of raid5/6
stripes.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:16 -07:00
Kent Overstreet 6ded34d1a5 bcache: Improve lazy sorting
The old lazy sorting code was kind of hacky - rewrite in a way that
mathematically makes more sense; the idea is that the size of the sets
of keys in a btree node should increase by a more or less fixed ratio
from smallest to biggest.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:16 -07:00
Kent Overstreet 85b1492ee1 bcache: Rip out pkey()/pbtree()
Old gcc doesnt like the struct hack, and it is kind of ugly. So finish
off the work to convert pr_debug() statements to tracepoints, and delete
pkey()/pbtree().

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:15 -07:00
Kent Overstreet c37511b863 bcache: Fix/revamp tracepoints
The tracepoints were reworked to be more sensible, and fixed a null
pointer deref in one of the tracepoints.

Converted some of the pr_debug()s to tracepoints - this is partly a
performance optimization; it used to be that with DEBUG or
CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it
was changed to an empty inline function.

Some of the pr_debug() statements had rather expensive function calls as
part of the arguments, so this code was getting run unnecessarily even
on non debug kernels - in some fast paths, too.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:15 -07:00
Kent Overstreet 5794351146 bcache: Refactor btree io
The most significant change is that btree reads are now done
synchronously, instead of asynchronously and doing the post read stuff
from a workqueue.

This was originally done because we can't block on IO under
generic_make_request(). But - we already have a mechanism to punt cache
lookups to workqueue if needed, so if we just use that we don't have to
deal with the complexity of doing things asynchronously.

The main benefit is this makes the locking situation saner; we can hold
our write lock on the btree node until we're finished reading it, and we
don't need that btree_node_read_done() flag anymore.

Also, for writes, btree_write() was broken out into btree_node_write()
and btree_leaf_dirty() - the old code with the boolean argument was dumb
and confusing.

The prio_blocked mechanism was improved a bit too, now the only counter
is in struct btree_write, we don't mess with transfering a count from
struct btree anymore.

This required changing garbage collection to block prios at the start
and unblock when it finishes, which is cleaner than what it was doing
anyways (the old code had mostly the same effect, but was doing it in a
convoluted way)

And the btree iter btree_node_read_done() uses was converted to a real
mempool.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:14 -07:00
Kent Overstreet 119ba0f828 bcache: Convert allocator thread to kthread
Using a workqueue when we just want a single thread is a bit silly.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:13 -07:00
Gabriel de Perthuis a9dd53adbb bcache: Warn when a device is already registered.
Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:08:52 -07:00
Kent Overstreet bbc77aa7fb bcache: fix a spurious gcc complaint, use scnprintf
An old version of gcc was complaining about using a const int as the
size of a stack allocated array. Which should be fine - but using
ARRAY_SIZE() is better, anyways.

Also, refactor the code to use scnprintf().

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:06:33 -07:00
Kumar Amit Mehta 5c694129c8 md: bcache: io.c: fix a potential NULL pointer dereference
bio_alloc_bioset returns NULL on failure. This fix adds a missing check
for potential NULL pointer dereferencing.

Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:06:19 -07:00
Jonathan Brassow c4a3955145 MD: Remember the last sync operation that was performed
MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:24 +10:00
NeilBrown eea136d69f md: fix buglet in RAID5 -> RAID0 conversion.
RAID5 uses a 'per-array' value for the 'size' of each device.
RAID0 uses a 'per-device' value - it can be different for each device.

When converting a RAID5 to a RAID0 we must ensure that the per-device
size of each device matches the per-array size for the RAID5, else
the array will change size.

If the metadata cannot record a changed per-device size (as is the
case with v0.90 metadata) the array could get bigger on restart.  This
does not cause data corruption, so it not a big issue and is mainly
yet another a reason to not use 0.90.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:19 +10:00
Phil Viana 48a73025cb md: bcache: Fixed a typo with the word 'arithmetic'
The word 'arithmetic' was typed as 'arithmatic'

Signed-off-by: Phil Viana <phillip.l.viana@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-06-18 13:41:16 +02:00
NeilBrown 725d6e579f md/raid10: check In_sync flag in 'enough()'.
It isn't really enough to check that the rdev is present, we need to
also be sure that the device is still In_sync.

Doing this requires using rcu_dereference to access the rdev, and
holding the rcu_read_lock() to ensure the rdev doesn't disappear while
we look at it.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:27 +10:00
NeilBrown 635f6416a2 md/raid10: locking changes for 'enough()'.
As 'enough' accesses conf->prev and conf->geo, which can change
spontanously, it should guard against changes.
This can be done with device_lock as start_reshape holds device_lock
while updating 'geo' and end_reshape holds it while updating 'prev'.

So 'error' needs to hold 'device_lock'.

On the other hand, raid10_end_read_request knows which of the two it
really wants to access, and as it is an active request on that one,
the value cannot change underneath it.

So change _enough to take flag rather than a pointer, pass the
appropriate flag from raid10_end_read_request(), and remove the locking.

All other calls to 'enough' are made with reconfig_mutex held, so
neither 'prev' nor 'geo' can change.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:27 +10:00
Jingoo Han b29bebd66d md: replace strict_strto*() with kstrto*()
The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:26 +10:00
Hannes Reinecke 90f5f7ad4f md: Wait for md_check_recovery before attempting device removal.
When a device has failed, it needs to be removed from the personality
module before it can be removed from the array as a whole.
The first step is performed by md_check_recovery() which is called
from the raid management thread.

So when a HOT_REMOVE ioctl arrives, wait briefly for md_check_recovery
to have run.  This increases the chance that the ioctl will succeed.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Neil Brown <nfbrown@suse.de>
2013-06-14 08:10:26 +10:00
NeilBrown 3f6bbd3ffd dm-raid: silence compiler warning on rebuilds_per_group.
This doesn't really need to be initialised, but it doesn't hurt,
silences the compiler, and as it is a counter it makes sense for it to
start at zero.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:26 +10:00
Jonathan Brassow a4dc163a55 DM RAID: Fix raid_resume not reviving failed devices in all cases
DM RAID:  Fix raid_resume not reviving failed devices in all cases

When a device fails in a RAID array, it is marked as Faulty.  Later,
md_check_recovery is called which (through the call chain) calls
'hot_remove_disk' in order to have the personalities remove the device
from use in the array.

Sometimes, it is possible for the array to be suspended before the
personalities get their chance to perform 'hot_remove_disk'.  This is
normally not an issue.  If the array is deactivated, then the failed
device will be noticed when the array is reinstantiated.  If the
array is resumed and the disk is still missing, md_check_recovery will
be called upon resume and 'hot_remove_disk' will be called at that
time.  However, (for dm-raid) if the device has been restored,
a resume on the array would cause it to attempt to revive the device
by calling 'hot_add_disk'.  If 'hot_remove_disk' had not been called,
a situation is then created where the device is thought to concurrently
be the replacement and the device to be replaced.  Thus, the device
is first sync'ed with the rest of the array (because it is the replacement
device) and then marked Faulty and removed from the array (because
it is also the device being replaced).

The solution is to check and see if the device had properly been removed
before the array was suspended.  This is done by seeing whether the
device's 'raid_disk' field is -1 - a condition that implies that
'md_check_recovery -> remove_and_add_spares (where raid_disk is set to -1)
-> hot_remove_disk' has been called.  If 'raid_disk' is not -1, then
'hot_remove_disk' must be called to complete the removal of the previously
faulty device before it can be revived via 'hot_add_disk'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:25 +10:00
Jonathan Brassow f381e71b04 DM RAID: Break-up untidy function
DM RAID:  Break-up untidy function

Clean-up excessive indentation by moving some code in raid_resume()
into its own function.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:25 +10:00
Jonathan Brassow 9092c02d94 DM RAID: Add ability to restore transiently failed devices on resume
DM RAID: Add ability to restore transiently failed devices on resume

This patch adds code to the resume function to check over the devices
in the RAID array.  If any are found to be marked as failed and their
superblocks can be read, an attempt is made to reintegrate them into
the array.  This allows the user to refresh the array with a simple
suspend and resume of the array - rather than having to load a
completely new table, allocate and initialize all the structures and
throw away the old instantiation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:24 +10:00
Linus Torvalds 82ea4be61f A few bugfixes for md
Some tagged for -stable.
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Merge tag 'md-3.10-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "A few bugfixes for md

  Some tagged for -stable"

* tag 'md-3.10-fixes' of git://neil.brown.name/md:
  md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
  md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
  md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
  md: md_stop_writes() should always freeze recovery.
2013-06-13 10:13:29 -07:00
H. Peter Anvin 5026d7a9b2 md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
There are cases where the kernel will believe that the WRITE SAME
command is supported by a block device which does not, in fact,
support WRITE SAME.  This currently happens for SATA drivers behind a
SAS controller, but there are probably a hundred other ways that can
happen, including drive firmware bugs.

After receiving an error for WRITE SAME the block layer will retry the
request as a plain write of zeroes, but mdraid will consider the
failure as fatal and consider the drive failed.  This has the effect
that all the mirrors containing a specific set of data are each
offlined in very rapid succession resulting in data loss.

However, just bouncing the request back up to the block layer isn't
ideal either, because the whole initial request-retry sequence should
be inside the write bitmap fence, which probably means that md needs
to do its own conversion of WRITE SAME to write zero.

Until the failure scenario has been sorted out, disable WRITE SAME for
raid1, raid5, and raid10.

[neilb: added raid5]

This patch is appropriate for any -stable since 3.7 when write_same
support was added.

Cc: stable@vger.kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 14:49:54 +10:00
NeilBrown e2d5992522 md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
Various places in raid1 and raid10 are calling raise_barrier when they
really should call freeze_array.
The former is only intended to be called from "make_request".
The later has extra checks for 'nr_queued' and makes a call to
flush_pending_writes(), so it is safe to call it from within the
management thread.

Using raise_barrier will sometimes deadlock.  Using freeze_array
should not.

As 'freeze_array' currently expects one request to be pending (in
handle_read_error - the only previous caller), we need to pass
it the number of pending requests (extra) to ignore.

The deadlock was made particularly noticeable by commits
050b66152f (raid10) and 6b740b8d79 (raid1) which
appeared in 3.4, so the fix is appropriate for any -stable
kernel since then.

This patch probably won't apply directly to some early kernels and
will need to be applied by hand.

Cc: stable@vger.kernel.org
Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:40:48 +10:00
Alex Lyakas 3056e3aec8 md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
Without that fix, the following scenario could happen:

- RAID1 with drives A and B; drive B was freshly-added and is rebuilding
- Drive A fails
- WRITE request arrives to the array. It is failed by drive A, so
r1_bio is marked as R1BIO_WriteError, but the rebuilding drive B
succeeds in writing it, so the same r1_bio is marked as
R1BIO_Uptodate.
- r1_bio arrives to handle_write_finished, badblocks are disabled,
md_error()->error() does nothing because we don't fail the last drive
of raid1
- raid_end_bio_io()  calls call_bio_endio()
- As a result, in call_bio_endio():
        if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
this code doesn't clear the BIO_UPTODATE flag, and the whole master
WRITE succeeds, back to the upper layer.

So we returned success to the upper layer, even though we had written
the data onto the rebuilding drive only. But when we want to read the
data back, we would not read from the rebuilding drive, so this data
is lost.

[neilb - applied identical change to raid10 as well]

This bug can result in lost data, so it is suitable for any
-stable kernel.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:20:03 +10:00
NeilBrown 6b6204ee92 md: md_stop_writes() should always freeze recovery.
__md_stop_writes() will currently sometimes freeze recovery.
So any caller must be ready for that to happen, and indeed they are.

However if __md_stop_writes() doesn't freeze_recovery, then
a recovery could start before mddev_suspend() is called, which
could be awkward.  This can particularly cause problems or dm-raid.

So change __md_stop_writes() to always freeze recovery.  This is safe
and more predicatable.

Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Tested-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:18:15 +10:00
Linus Torvalds b2cc9c19e4 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "Outside of bcache (which really isn't super big), these are all
  few-liners.  There are a few important fixes in here:

   - Fix blk pm sleeping when holding the queue lock

   - A small collection of bcache fixes that have been done and tested
     since bcache was included in this merge window.

   - A fix for a raid5 regression introduced with the bio changes.

   - Two important fixes for mtip32xx, fixing an oops and potential data
     corruption (or hang) due to wrong bio iteration on stacked devices."

* 'for-linus' of git://git.kernel.dk/linux-block:
  scatterlist: sg_set_buf() argument must be in linear mapping
  raid5: Initialize bi_vcnt
  pktcdvd: silence static checker warning
  block: remove refs to XD disks from documentation
  blkpm: avoid sleep when holding queue lock
  mtip32xx: Correctly handle bio->bi_idx != 0 conditions
  mtip32xx: Fix NULL pointer dereference during module unload
  bcache: Fix error handling in init code
  bcache: clarify free/available/unused space
  bcache: drop "select CLOSURES"
  bcache: Fix incompatible pointer type warning
2013-06-12 16:42:39 -07:00
Kent Overstreet 4997b72ee6 raid5: Initialize bi_vcnt
The patch that converted raid5 to use bio_reset() forgot to initialize
bi_vcnt.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Tested-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-05-30 08:44:39 +02:00
Alasdair G Kergon 610bba8b93 dm thin: fix metadata dev resize detection
Fix detection of the need to resize the dm thin metadata device.

The code incorrectly tried to extend the metadata device when it
didn't need to due to a merging error with patch 24347e9 ("dm thin:
detect metadata device resizing").

  device-mapper: transaction manager: couldn't open metadata space map
  device-mapper: thin metadata: tm_open_with_sm failed
  device-mapper: thin: aborting transaction failed
  device-mapper: thin: switching pool to failure mode

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-19 18:57:50 +01:00
Jens Axboe c0a363f5cf Merge branch 'bcache-for-upstream' of git://evilpiepirate.org/~kent/linux-bcache into for-linus
Kent writes:

Jens - couple more bcache patches. Bug fixes and a doc update.
2013-05-15 10:36:25 +02:00
Kent Overstreet f59fce847f bcache: Fix error handling in init code
This code appears to have rotted... fix various bugs and do some
refactoring.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-05-15 00:48:14 -07:00
Paul Bolle bbb1c3b5ae bcache: drop "select CLOSURES"
The Kconfig entry for BCACHE selects CLOSURES. But there's no Kconfig
symbol CLOSURES. That symbol was used in development versions of bcache,
but was removed when the closures code was no longer provided as a
kernel library. It can safely be dropped.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
2013-05-15 00:42:51 -07:00
Emil Goode 867e116206 bcache: Fix incompatible pointer type warning
The function pointer release in struct block_device_operations
should point to functions declared as void.

Sparse warnings:

drivers/md/bcache/super.c:656:27: warning:
	incorrect type in initializer (different base types)
	drivers/md/bcache/super.c:656:27:
	expected void ( *release )( ... )
	drivers/md/bcache/super.c:656:27:
	got int ( static [toplevel] *<noident> )( ... )

drivers/md/bcache/super.c:656:2: warning:
	initialization from incompatible pointer type [enabled by default]

drivers/md/bcache/super.c:656:2: warning:
	(near initialization for ‘bcache_ops.release’) [enabled by default]

Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-05-15 00:42:50 -07:00
Joe Thornber 2f14f4b51e dm cache: set config value
Share configuration option processing code between the dm cache
ctr and message functions.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Alasdair G Kergon 2c73c471fb dm cache: move config fns
Move process_config_option() in dm-cache-target.c to make the
next patch more readable.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Joe Thornber ac8c3f3df6 dm thin: generate event when metadata threshold passed
Generate a dm event when the amount of remaining thin pool metadata
space falls below a certain level.

The threshold is taken to be a quarter of the size of the metadata
device with a minimum threshold of 4MB.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Joe Thornber 2fc48021f4 dm persistent metadata: add space map threshold callback
Add a threshold callback to dm persistent data space maps.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber 7c3d3f2a87 dm persistent data: add threshold callback to space map
Add a threshold callback function to the persistent data space map
interface for a subsequent patch to use.

dm-thin and dm-cache are interested in knowing when they're getting
low on metadata or data blocks.  This patch introduces a new method
for registering a callback against a threshold.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber 24347e9595 dm thin: detect metadata device resizing
Allow the dm thin pool metadata device to be extended.

Whenever a pool is resumed, detect whether the size of the metadata
device has increased, and if so, extend the metadata to use the new
space.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber 1921c56d95 dm persistent data: support space map resizing
Support extending a dm persistent data metadata space map.

The extend itself is implemented by switching back to the boostrap
allocator and pointing to the new space.  The extra bitmap indexes are
then allocated from the new space, and finally we switch back to the
proper space map ops and tweak the reference counts.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber 5d0db96d13 dm thin: open dev read only when possible
If a thin pool is created in read-only-metadata mode then only open the
metadata device read-only.

Previously it was always opened with FMODE_READ | FMODE_WRITE.

(Note that dm_get_device() still allows read-only dm devices to be used
read-write at the moment: If I create a read-only linear device for the
metadata, via dmsetup load --readonly, then I can still create a rw pool
out of it.)

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber b17446df2e dm thin: refactor data dev resize
Refactor device size functions in preparation for similar metadata
device resizing functions.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Joe Thornber 8c5008fac4 dm cache: replace memcpy with struct assignment
Use struct assignment rather than memcpy in dm cache.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Joe Thornber aeed1420a3 dm cache: fix typos in comments
Fix up some typos in dm-cache comments.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Alasdair G Kergon e12c1fd9d6 dm cache policy: fix description of lookup fn
Correct the documented requirement on the return code from dm cache policy
lookup functions stated in the policy module header file.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:17 +01:00
Joe Thornber 88a488f624 dm persistent data: fix error message typos
Fix some typos in dm-space-map-metadata.c error messages.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:17 +01:00
Joe Thornber f8350daf7a dm cache: tune migration throttling
Tune the dm cache migration throttling.

i) Issue a tick every second, just in case there's no i/o going through.

ii) Drop the migration threshold right down to something suitable for
background work.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mike Snitzer 042bcef889 dm mpath: enable WRITE SAME support
Enable WRITE SAME support in dm multipath.  As far as multipath is
concerned it is just another write request.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Bharata B Rao <bharata.rao@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mike Snitzer dc019b21fb dm table: fix write same support
If device_not_write_same_capable() returns true then the iterate_devices
loop in dm_table_supports_write_same() should return false.

Reported-by: Bharata B Rao <bharata.rao@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mikulas Patocka 502624bdad dm bufio: avoid a possible __vmalloc deadlock
This patch uses memalloc_noio_save to avoid a possible deadlock in
dm-bufio.  (it could happen only with large block size, at most
PAGE_SIZE << MAX_ORDER (typically 8MiB).

__vmalloc doesn't fully respect gfp flags. The specified gfp flags are
used for allocation of requested pages, structures vmap_area, vmap_block
and vm_struct and the radix tree nodes.

However, the kernel pagetables are allocated always with GFP_KERNEL.
Thus the allocation of pagetables can recurse back to the I/O layer and
cause a deadlock.

This patch uses the function memalloc_noio_save to set per-process
PF_MEMALLOC_NOIO flag and the function memalloc_noio_restore to restore
it. When this flag is set, all allocations in the process are done with
implied GFP_NOIO flag, thus the deadlock can't happen.

This should be backported to stable kernels, but they don't have the
PF_MEMALLOC_NOIO flag and memalloc_noio_save/memalloc_noio_restore
functions. So, PF_MEMALLOC should be set and restored instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:15 +01:00
Wei Yongjun 09e8b81389 dm snapshot: fix error return code in snapshot_ctr
Return -ENOMEM instead of success if unable to allocate pending
exception mempool in snapshot_ctr.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:15 +01:00
Wei Yongjun fa4d683af3 dm cache: fix error return code in cache_create
Return -ENOMEM if memory allocation fails in cache_create
instead of 0 (to avoid NULL pointer dereference).

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:14 +01:00
Mike Snitzer d793e68427 dm stripe: fix regression in stripe_width calculation
Fix a regression in the calculation of the stripe_width in the
dm stripe target which led to incorrect processing of device limits.

The stripe_width is the stripe device length divided by the number of
stripes.  The group of commits in the range f14fa69 ("dm stripe: fix
size test") to eb850de ("dm stripe: support for non power of 2
chunksize") interfered with each other (a merging error) and led to the
stripe_width being set incorrectly to the stripe device length divided by
chunk_size * stripe_count.

For example, a stripe device's table with: 0 33553920 striped 3 512 ...
should result in a stripe_width of 11184640 (33553920 / 3), but due to
the bug it was getting set to 21845 (33553920 / (512 * 3)).

The impact of this bug is that device topologies that previously worked
fine with the stripe target are no longer considered valid.  In
particular, there is a higher risk of seeing this issue if one of the
stripe devices has a 4K logical block size.  Resulting in an error
message like this:
"device-mapper: table: 253:4: len=21845 not aligned to h/w logical block size 4096 of dm-1"

The fix is to swap the order of the divisions and to use a temporary
variable for the second one, so that width retains the intended
value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:14 +01:00
Linus Torvalds ebb3727779 Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "It might look big in volume, but when categorized, not a lot of
  drivers are touched.  The pull request contains:

   - mtip32xx fixes from Micron.

   - A slew of drbd updates, this time in a nicer series.

   - bcache, a flash/ssd caching framework from Kent.

   - Fixes for cciss"

* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
  bcache: Use bd_link_disk_holder()
  bcache: Allocator cleanup/fixes
  cciss: bug fix to prevent cciss from loading in kdump crash kernel
  cciss: add cciss_allow_hpsa module parameter
  drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
  mtip32xx: Workaround for unaligned writes
  bcache: Make sure blocksize isn't smaller than device blocksize
  bcache: Fix merge_bvec_fn usage for when it modifies the bvm
  bcache: Correctly check against BIO_MAX_PAGES
  bcache: Hack around stuff that clones up to bi_max_vecs
  bcache: Set ra_pages based on backing device's ra_pages
  bcache: Take data offset from the bdev superblock.
  mtip32xx: mtip32xx: Disable TRIM support
  mtip32xx: fix a smatch warning
  bcache: Disable broken btree fuzz tester
  bcache: Fix a format string overflow
  bcache: Fix a minor memory leak on device teardown
  bcache: Documentation updates
  bcache: Use WARN_ONCE() instead of __WARN()
  bcache: Add missing #include <linux/prefetch.h>
  ...
2013-05-08 11:51:05 -07:00
Linus Torvalds 4de13d7aa8 Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block
Pull block core updates from Jens Axboe:

 - Major bit is Kents prep work for immutable bio vecs.

 - Stable candidate fix for a scheduling-while-atomic in the queue
   bypass operation.

 - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging
   discard bios.

 - Tejuns changes to convert the writeback thread pool to the generic
   workqueue mechanism.

 - Runtime PM framework, SCSI patches exists on top of these in James'
   tree.

 - A few random fixes.

* 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits)
  relay: move remove_buf_file inside relay_close_buf
  partitions/efi.c: replace useless kzalloc's by kmalloc's
  fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read()
  block: fix max discard sectors limit
  blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
  Documentation: cfq-iosched: update documentation help for cfq tunables
  writeback: expose the bdi_wq workqueue
  writeback: replace custom worker pool implementation with unbound workqueue
  writeback: remove unused bdi_pending_list
  aoe: Fix unitialized var usage
  bio-integrity: Add explicit field for owner of bip_buf
  block: Add an explicit bio flag for bios that own their bvec
  block: Add bio_alloc_pages()
  block: Convert some code to bio_for_each_segment_all()
  block: Add bio_for_each_segment_all()
  bounce: Refactor __blk_queue_bounce to not use bi_io_vec
  raid1: use bio_copy_data()
  pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
  pktcdvd: use bio_copy_data()
  block: Add bio_copy_data()
  ...
2013-05-08 10:13:35 -07:00
Al Viro db2a144bed block_device_operations->release() should return void
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-07 02:16:21 -04:00
Kent Overstreet ee66850642 bcache: Use bd_link_disk_holder()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-30 19:14:43 -07:00
Kent Overstreet 86b26b824c bcache: Allocator cleanup/fixes
The main fix is that bch_allocator_thread() wasn't waiting on
garbage collection to finish (if invalidate_buckets had set
ca->invalidate_needs_gc); we need that to make sure the allocator
doesn't spin and potentially block gc from finishing.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-30 19:14:40 -07:00
Shaohua Li 32f9f570d0 MD: ignore discard request for hard disks of hybid raid1/raid10 array
In SSD/hard disk hybid storage, discard request should be ignored for hard
disk. We used to be doing this way, but the unplug path forgets it.

This is suitable for stable tree since v3.6.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Markus <M4rkusXXL@web.de>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:36 +10:00
NeilBrown 486adf72cc md: bad block list should default to disabled.
Maintenance of a bad-block-list currently defaults to 'enabled'
and is then disabled when it cannot be supported.
This is backwards and causes problem for dm-raid which didn't know
to disable it.

So fix the defaults, and only enabled for v1.x metadata which
explicitly has bad blocks enabled.

The problem with dm-raid has been present since badblock support was
added in v3.1, so this patch is suitable for any -stable from 3.1
onwards.

Cc: stable@vger.kernel.org (3.1+)
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:32 +10:00
Hirokazu Takahashi 0fea7ed82b md: raid1/raid10 md devices leak memory when stopping
Hi.

Raid1 and raid10 devices leak memory every time they stop.
This is a patch for linux-3.9.0-rc7 to fix this problem.

Thanks,
Hirokazu Takahashi.

Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:26 +10:00
Kent Overstreet 8abb2a5dba bcache: Make sure blocksize isn't smaller than device blocksize
Sanity check to make sure we don't end up doing IO the device doesn't
support.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-24 13:07:39 -07:00
Jonathan Brassow be83651f00 DM RAID: Add message/status support for changing sync action
DM RAID:  Add message/status support for changing sync action

This patch adds a message interface to dm-raid to allow the user to more
finely control the sync actions being performed by the MD driver.  This
gives the user the ability to initiate "check" and "repair" (i.e. scrubbing).
Two additional fields have been appended to the status output to provide more
information about the type of sync action occurring and the results of those
actions, specifically: <sync_action> and <mismatch_cnt>.  These new fields
will always be populated.  This is essentially the device-mapper way of doing
what MD controls through the 'sync_action' sysfs file and shows through the
'mismatch_cnt' sysfs file.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:43 +10:00
Jonathan Brassow a91d5ac048 MD: Export 'md_reap_sync_thread' function
MD: Export 'md_reap_sync_thread' function

Make 'md_reap_sync_thread' available to other files, specifically dm-raid.c.
- rename reap_sync_thread to md_reap_sync_thread
- move the fn after md_check_recovery to match md.h declaration placement
- export md_reap_sync_thread

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:43 +10:00
NeilBrown b6d428c669 md: don't update metadata when stopping a read-only array.
read-only arrays should stay that way as much as possible.
Updating the metadata - which could be triggered by a re-add
while assembling the array metadata - should be avoided.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown 7ceb17e87b md: Allow devices to be re-added to a read-only array.
When assembling an array incrementally we might want to make
it device available when "enough" devices are present, but maybe
not "all" devices are present.
If the remaining devices appear before the array is actually used,
they should be added transparently.

We do this by using the "read-auto" mode where the array acts like
it is read-only until a write request arrives.

Current an add-device request switches a read-auto array to active.
This means that only one device can be added after the array is first
made read-auto.  This isn't a problem for RAID5, but is not ideal for
RAID6 or RAID10.
Also we don't really want to switch the array to read-auto at all
when re-adding a device as this doesn't really imply any change.

So:
 - remove the "md_update_sb()" call from add_new_disk().  This isn't
   really needed as just adding a disk doesn't require a metadata
   update.  Instead, just set MD_CHANGE_DEVS.  This will effect a
   metadata update soon enough, once the array is not read-only.

 - Allow the ADD_NEW_DISK ioctl to succeed without activating a
   read-auto array, providing the MD_DISK_SYNC flag is set.
   In this case, the device will be rejected if it cannot be added
   with the correct device number, or has an incorrect event count.

 - Teach remove_and_add_spares() to be careful about adding spares
   when the array is read-only (or read-mostly) - only add devices
   that are thought to be in-sync, and only do it if the array is
   in-sync itself.

 - In md_check_recovery, use remove_and_add_spares in the read-only
   case, rather than open coding just the 'remove' part of it.

Reported-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
Martin Wilck 7e83ccbecd md/raid10: Allow skipping recovery when clean arrays are assembled
When an array is assembled incrementally with mdadm -I -R
and the array switches to "active" mode, md starts a recovery.

If the array was clean, the "fullsync" flag will be 0. Skip
the full recovery in this case, as RAID1 does (the code was
actually copied from the sync_request() method of RAID1).

Signed-off-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown c0b32972fb md/raid5: avoid an extra write when writing to a known-bad-block.
If we write to a known-bad-block it will be flags as having
a ReadError by analyse_stripe, but the write will proceed anyway
(as it should).  Then the read-error handling will kick in an
write again, then re-read.

We don't need that 'write-again', so set R5_ReWrite so it looks like
it has already been done.  Then we will just get the re-read, which we
want.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
majianpeng 6f608040ce md/raid5: Change or of some order to improve efficiency.
As the function call is the most expensive of these tests it should be
done later in the chain so that it can be avoided in some cases.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
Akinobu Mita 3f810b6c4a md: use set_bit_le and clear_bit_le
The value returned by test_and_set_bit_le() drivers/md/bitmap.c is not used.
So just use set_bit_le(). The same goes for test_and_clear_bit_le().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown 3ea8929da3 md: HOT_DISK_REMOVE shouldn't make a read-auto device active.
If a fail device or a spare is removed from an array, there is
not need to make the array 'active'.  If/when the array does become
active for some other reason the metadata will be update to reflect
the removal.
If that never happens and the array is stopped while still read-auto,
then there is no loss in forgetting the that the device had 'failed'.

A read-only array will leave failed devices attached to
the array personality, so we need to explicitly call
remove_and_add_spares() to free it (clearing Blocked just
like we do in store_slot()).

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown 746d3207ae md: use common code for all calls to ->hot_remove_disk()
slot_store and remove_and_add_spares both call ->hot_remove_disk(),
but with slightly different tests and consequences, which is
at least untidy and might be buggy.

So modify remove_and_add_spaces() so that it can be asked
to remove a specific device, and call it from slot_store().

We also clear the Blocked flag to ensure that doesn't prevent
removal.  The purpose of Blocked is to prevent automatic removal
by the kernel before an error is acknowledged.
If the array is read/write then user-space would have not reason
to remove a device unless it was known to be 'spare' or 'faulty' in
which it would have already cleared the Blocked flag.
If the array is read-only, the flag might still be blocked, but
there is no harm in clearing the flag for read-only arrays.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown d87f064f58 md: never update metadata when array is read-only.
Normally we don't even try to update the metadata if
the array is read-only.  However future patches
will increase the number of things that can happen on a read-only
array, so it is safest to explicitly disable this.

Every time that mddev->ro is set to 0, either
 - md_update_sb will be called again (at least if MD_CHANGE_DEVS
   is set) or
 - the mddev->thread is scheduled, which will also run
   md_update_sb if needed.

So this is safe: if the array ever become read-write the
metadata will be updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:40 +10:00
Kent Overstreet a09ded8edf bcache: Fix merge_bvec_fn usage for when it modifies the bvm
Stacked md devices reuse the bvm for the subordinate device, causing
problems...

Reported-by: Michael Balser <michael.balser@profitbricks.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-22 14:44:24 -07:00
Kent Overstreet 1545f13730 bcache: Correctly check against BIO_MAX_PAGES
bch_bio_max_sectors() was checking against BIO_MAX_PAGES as if the limit
was for the total bytes in the bio, not the number of segments.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:57:42 -07:00
Kent Overstreet bca97adaf5 bcache: Hack around stuff that clones up to bi_max_vecs
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:57:41 -07:00