In order to avoid wasting cache space a partial block at the end of the
origin device is not cached. Unfortunately, the check for such a
partial block at the end of the origin device was flawed.
Fix accesses beyond the end of the origin device that occured due to
attempted promotion of an undetected partial block by:
- initializing the per bio data struct to allow cache_end_io to work properly
- recognizing access to the partial block at the end of the origin device
- avoiding out of bounds access to the discard bitset
Otherwise, users can experience errors like the following:
attempt to access beyond end of device
dm-5: rw=0, want=20971520, limit=20971456
...
device-mapper: cache: promotion failed; couldn't copy block
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
During demotion or promotion to a cache's >2TB fast device we must not
truncate the cache block's associated sector to 32bits. The 32bit
temporary result of from_cblock() caused a 32bit multiplication when
calculating the sector of the fast device in issue_copy_real().
Use an intermediate 64bit type to store the 32bit from_cblock() to allow
for proper 64bit multiplication.
Here is an example of how this bug manifests on an ext4 filesystem:
EXT4-fs error (device dm-0): ext4_mb_generate_buddy:756: group 17136, 32768 clusters in bitmap, 30688 in gd; block bitmap corrupt.
JBD2: Spotted dirty metadata buffer (dev = dm-0, blocknr = 0). There's a risk of filesystem corruption in case of system crash.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This has been a relatively long-standing issue that wasn't nailed down
until Teng-Feng Yang's meticulous bug report to dm-devel on 3/7/2014,
see: http://www.redhat.com/archives/dm-devel/2014-March/msg00021.html
From that report:
"When decreasing the reference count of a metadata block with its
reference count equals 3, we will call dm_btree_remove() to remove
this enrty from the B+tree which keeps the reference count info in
metadata device.
The B+tree will try to rebalance the entry of the child nodes in each
node it traversed, and the rebalance process contains the following
steps.
(1) Finding the corresponding children in current node (shadow_current(s))
(2) Shadow the children block (issue BOP_INC)
(3) redistribute keys among children, and free children if necessary (issue BOP_DEC)
Since the update of a metadata block's reference count could be
recursive, we will stash these reference count update operations in
smm->uncommitted and then process them in a FILO fashion.
The problem is that step(3) could free the children which is created
in step(2), so the BOP_DEC issued in step(3) will be carried out
before the BOP_INC issued in step(2) since these BOPs will be
processed in FILO fashion. Once the BOP_DEC from step(3) tries to
decrease the reference count of newly shadow block, it will report
failure for its reference equals 0 before decreasing. It looks like we
can solve this issue by processing these BOPs in a FIFO fashion
instead of FILO."
Commit 5b564d80 ("dm space map: disallow decrementing a reference count
below zero") changed the code to report an error for this temporary
refcount decrement below zero. So what was previously a harmless
invalid refcount became a hard failure due to the new error path:
device-mapper: space map common: unable to decrement a reference count below 0
device-mapper: thin: 253:6: dm_thin_insert_block() failed: error = -22
device-mapper: thin: 253:6: switching pool to read-only mode
This bug is in dm persistent-data code that is common to the DM thin and
cache targets. So any users of those targets should apply this fix.
Fix this by applying recursive space map operations in FIFO order rather
than FILO.
Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=68801
Reported-by: Apollon Oikonomopoulos <apoikos@debian.org>
Reported-by: edwillam1007@gmail.com
Reported-by: Teng-Feng Yang <shinrairis@gmail.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
i) by the time DM core calls the postsuspend hook the dm_noflush flag
has been cleared. So the old thin_postsuspend did nothing. We need to
use the presuspend hook instead.
ii) There was a race between bios leaving DM core and arriving in the
deferred queue.
thin_presuspend now sets a 'requeue' flag causing all bios destined for
that thin to be requeued back to DM core. Then it requeues all held IO,
and all IO on the deferred queue (destined for that thin). Finally
postsuspend clears the 'requeue' flag.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The spin lock in requeue_io() was held for too long, allowing deadlock.
Don't worry, due to other issues addressed in the following "dm thin:
fix noflush suspend IO queueing" commit, this code was never called.
Fix this by taking the spin lock for a much shorter period of time.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Ideally a thin pool would never run out of data space; the low water
mark would trigger userland to extend the pool before we completely run
out of space. However, many small random IOs to unprovisioned space can
consume data space at an alarming rate. Adjust your low water mark if
you're frequently seeing "out-of-data-space" mode.
Before this fix, if data space ran out the pool would be put in
PM_READ_ONLY mode which also aborted the pool's current metadata
transaction (data loss for any changes in the transaction). This had a
side-effect of needlessly compromising data consistency. And retry of
queued unserviceable bios, once the data pool was resized, could
initiate changes to potentially inconsistent pool metadata.
Now when the pool's data space is exhausted transition to a new pool
mode (PM_OUT_OF_DATA_SPACE) that allows metadata to be changed but data
may not be allocated. This allows users to remove thin volumes or
discard data to recover data space.
The pool is no longer put in PM_READ_ONLY mode in response to the pool
running out of data space. And PM_READ_ONLY mode no longer aborts the
pool's current metadata transaction. Also, set_pool_mode() will now
notify userspace when the pool mode is changed.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If a thin metadata operation fails the current transaction will abort,
whereby causing potential for IO layers up the stack (e.g. filesystems)
to have data loss. As such, set THIN_METADATA_NEEDS_CHECK_FLAG in the
thin metadata's superblock which:
1) requires the user verify the thin metadata is consistent (e.g. use
thin_check, etc)
2) suggests the user verify the thin data is consistent (e.g. use fsck)
The only way to clear the superblock's THIN_METADATA_NEEDS_CHECK_FLAG is
to run thin_repair.
On metadata operation failure: abort current metadata transaction, set
pool in read-only mode, and now set the needs_check flag.
As part of this change, constraints are introduced or relaxed:
* don't allow a pool to transition to write mode if needs_check is set
* don't allow data or metadata space to be resized if needs_check is set
* if a thin pool's metadata space is exhausted: the kernel will now
force the user to take the pool offline for repair before the kernel
will allow the metadata space to be extended.
Also, update Documentation to include information about when the thin
provisioning target commits metadata, how it handles metadata failures
and running out of space.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Commit b5330655 ("dm thin: handle metadata failures more consistently")
increased potential for the pool's mode to be changed in response to
metadata operation failures.
When the pool mode is changed it isn't synchronized with the mode in
pool_features stored in the target's context (ti->private) that is used
as the basis for (re)establishing the pool mode during resume via
bind_control_target.
It is important that we synchronize the pool mode when it is changed
otherwise the pool may experience and unexpected mode transition on the
next resume (especially if there was no new table load).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Commit 55494bf294 ("dm snapshot: use dm-bufio") broke snapshots.
Before that 3.14-rc1 commit, loading a snapshot's list of exceptions
involved reading exception areas one by one into ps->area and inserting
those exceptions into the hash table. Commit 55494bf294 changed
it so that dm-bufio with prefetch is used to load exceptions in batchs.
Exceptions are loaded correctly, but ps->area is left uninitialized.
When a new exception is allocated, it is stored in this uninitialized
ps->area which will be written to the disk. This causes metadata
corruption.
Fix this corruption by copying the last area that was read via dm-bufio
into ps->area.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Since DM_DEBUG_BLOCK_STACK_TRACING is a DM_PERSISTENT_DATA config option
move it from drivers/md/Kconfig to drivers/md/persistent-data/Kconfig.
Doing so fixes indentation for other DM config options.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When remapping a block to the cache's fast device that is larger than
2TB we must not truncate the destination sector to 32bits. The 32bit
temporary result of from_cblock() was being overflowed in
remap_to_cache() due to the logical left shift.
Use an intermediate 64bit type to store the 32bit from_cblock() result
to fix the overflow.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
It was always intended that a user could provide a thin metadata device
that is larger than the max supported by the on-disk format. The extra
space would just go unused.
Unfortunately that never worked. If the user attempted to use a larger
metadata device on creation they would get an error like the following:
device-mapper: space map common: space map too large
device-mapper: transaction manager: couldn't create metadata space map
device-mapper: thin metadata: tm_create_with_sm failed
device-mapper: table: 252:17: thin-pool: Error creating metadata object
device-mapper: ioctl: error adding target to table
Fix this by allowing the initial metadata space map creation to cap its
size at the max number of blocks supported (DM_SM_METADATA_MAX_BLOCKS).
get_metadata_dev_size() must also impose DM_SM_METADATA_MAX_BLOCKS (via
THIN_METADATA_MAX_SECTORS), otherwise extending metadata would cap at
THIN_METADATA_MAX_SECTORS_WARNING (which is larger than supported).
Also, the calculation for THIN_METADATA_MAX_SECTORS didn't account for
the sizeof the disk_bitmap_header. So the supported maximum metadata
size is a bit smaller (reduced from 33423360 to 33292800 sectors).
Lastly, remove the "excess space will not be used" warning message from
get_metadata_dev_size(); it resulted in printing the warning multiple
times. Factor out warn_if_metadata_device_too_big(), call it from
pool_ctr() and maybe_resize_metadata_dev().
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
An invalid ioctl will never be valid, irrespective of whether multipath
has active paths or not. So for invalid ioctls we do not have to wait
for multipath to activate any paths, but can rather return an error
code immediately. This fix resolves numerous instances of:
udevd[]: worker [] unexpectedly returned with status 0x0100
that have been seen during testing.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
dm_pool_close_thin_device() must be called if dm_set_target_max_io_len()
fails in thin_ctr(). Otherwise __pool_destroy() will fail because the
pool will still have an open thin device:
device-mapper: thin metadata: attempt to close pmd when 1 device(s) are still open
device-mapper: thin: __pool_destroy: dm_pool_metadata_close() failed.
Also, must establish error code if failing thin_ctr() because the pool
is in fail_io mode.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
When restoring bi_end_io, increase bi_remaining before retrying the bio
to avoid BUG_ON(atomic_read(&bio->bi_remaining) <= 0) in bio_endio().
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 003b5c5719 ("block: Convert drivers
to immutable biovecs") broke dm-mirror due to dm-io breakage.
dm-io had three possible iterators (DM_IO_PAGE_LIST, DM_IO_BVEC,
DM_IO_VMA) that iterate over pages where the I/O should be performed.
The switch to immutable biovecs changed the DM_IO_BVEC iterator to
DM_IO_BIO. Before this change the iterator stored the pointer to a bio
vector in the dpages structure. The iterator incremented the pointer in
the dpages structure as it advanced over the pages. After the immutable
biovecs change, the DM_IO_BIO iterator stores a pointer to the bio in
the dpages structure and uses bio_advance to change the bio as it
advances.
The problem is that the function dispatch_io stores the content of the
dpages structure into the variable old_pages and restores it before
issuing I/O to each of the devices. Before the change, the statement
"*dp = old_pages;" restored the iterator to its starting position.
After the change, struct dpages holds a pointer to the bio, thus the
statement "*dp = old_pages;" doesn't restore the iterator.
Consequently, in the context of dm-mirror: only the first mirror leg is
written correctly, the kernel locks up when trying to write the other
mirror legs because the number of sectors to write in the where->count
variable doesn't match the number of sectors returned by the iterator.
This patch fixes the bug by partially reverting the original patch - it
changes the code so that struct dpages holds a pointer to the bio vector,
so that the statement "*dp = old_pages;" restores the iterator correctly.
The field "context_u" holds the offset from the beginning of the current
bio vector entry, just like the "bio->bi_iter.bi_bvec_done" field.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 905e51b ("dm thin: commit outstanding data every second")
introduced a periodic commit. This commit occurs regardless of whether
any thin devices have made changes.
Fix the periodic commit to check if any of a pool's thin devices have
changed using dm_pool_changed_this_transaction().
Reported-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
When completing an overwrite bio, in overwrite_endio(), the associated
migration should not be added to the 'completed_migrations' until the
bio's fields are restored with dm_unhook_bio().
Otherwise, do_worker() can race to process 'completed_migrations' before
dm_unhook_bio() -- so the bio's bi_end_io is incorrect. This is
unlikely to cause any problems given the current code but should be
fixed on the basis of correctness.
Also, the cache's spinlock only needs to be held when manipulating the
'completed_migrations' list -- other changes don't need protection.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Commit c9d28d5d ("dm cache: promotion optimisation for writes")
incorrectly placed the 'hook_info' member in the writethrough-only
portion of the per_bio_data structure.
Given that the overwrite optimization may be used for writeback the
'hook_info' member must be placed above the 'cache' member of the
per_bio_data structure. Any members above 'cache' are available from
both writeback and writethrough modes' per_bio_data structure.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
both tagged for -stable
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Merge tag 'md/3.14-fixes' of git://neil.brown.name/md
Pull md fixes from Neil Brown:
"Two bugfixes for md
both tagged for -stable"
* tag 'md/3.14-fixes' of git://neil.brown.name/md:
md/raid5: Fix CPU hotplug callback registration
md/raid1: restore ability for check and repair to fix read errors.
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Interestingly, the raid5 code can actually prevent double initialization and
hence can use the following simplified form of callback registration:
register_cpu_notifier(&foobar_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
put_online_cpus();
A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.
So reorganize the code in raid5 this way to fix the deadlock with callback
registration.
Cc: linux-raid@vger.kernel.org
Cc: stable@vger.kernel.org (v2.6.32+)
Fixes: 36d1c6476b
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
free_scratch_buffer() helper to condense code further and wrote the changelog.]
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
commit 30bc9b5387
md/raid1: fix bio handling problems in process_checks()
Move the bio_reset() to a point before where BIO_UPTODATE is checked,
so that check now always report that the bio is uptodate, even if it is not.
This causes process_check() to sometimes treat read-errors as
successful matches so the good data isn't written out.
This patch preserves the flag until it is needed.
Bug was introduced in 3.11, but backported to 3.10-stable (as it fixed
an even worse bug). So suitable for any -stable since 3.10.
Reported-and-tested-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: stable@vger.kernel.org (3.10+)
Fixed: 30bc9b5387
Signed-off-by: NeilBrown <neilb@suse.de>
Pull block IO driver changes from Jens Axboe:
- bcache update from Kent Overstreet.
- two bcache fixes from Nicholas Swenson.
- cciss pci init error fix from Andrew.
- underflow fix in the parallel IDE pg_write code from Dan Carpenter.
I'm sure the 1 (or 0) users of that are now happy.
- two PCI related fixes for sx8 from Jingoo Han.
- floppy init fix for first block read from Jiri Kosina.
- pktcdvd error return miss fix from Julia Lawall.
- removal of IRQF_SHARED from the SEGA Dreamcast CD-ROM code from
Michael Opdenacker.
- comment typo fix for the loop driver from Olaf Hering.
- potential oops fix for null_blk from Raghavendra K T.
- two fixes from Sam Bradshaw (Micron) for the mtip32xx driver, fixing
an OOM problem and a problem with handling security locked conditions
* 'for-3.14/drivers' of git://git.kernel.dk/linux-block: (47 commits)
mg_disk: Spelling s/finised/finished/
null_blk: Null pointer deference problem in alloc_page_buffers
mtip32xx: Correctly handle security locked condition
mtip32xx: Make SGL container per-command to eliminate high order dma allocation
drivers/block/loop.c: fix comment typo in loop_config_discard
drivers/block/cciss.c:cciss_init_one(): use proper errnos
drivers/block/paride/pg.c: underflow bug in pg_write()
drivers/block/sx8.c: remove unnecessary pci_set_drvdata()
drivers/block/sx8.c: use module_pci_driver()
floppy: bail out in open() if drive is not responding to block0 read
bcache: Fix auxiliary search trees for key size > cacheline size
bcache: Don't return -EINTR when insert finished
bcache: Improve bucket_prio() calculation
bcache: Add bch_bkey_equal_header()
bcache: update bch_bkey_try_merge
bcache: Move insert_fixup() to btree_keys_ops
bcache: Convert sorting to btree_keys
bcache: Convert debug code to btree_keys
bcache: Convert btree_iter to struct btree_keys
bcache: Refactor bset_tree sysfs stats
...
Pull core block IO changes from Jens Axboe:
"The major piece in here is the immutable bio_ve series from Kent, the
rest is fairly minor. It was supposed to go in last round, but
various issues pushed it to this release instead. The pull request
contains:
- Various smaller blk-mq fixes from different folks. Nothing major
here, just minor fixes and cleanups.
- Fix for a memory leak in the error path in the block ioctl code
from Christian Engelmayer.
- Header export fix from CaiZhiyong.
- Finally the immutable biovec changes from Kent Overstreet. This
enables some nice future work on making arbitrarily sized bios
possible, and splitting more efficient. Related fixes to immutable
bio_vecs:
- dm-cache immutable fixup from Mike Snitzer.
- btrfs immutable fixup from Muthu Kumar.
- bio-integrity fix from Nic Bellinger, which is also going to stable"
* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
xtensa: fixup simdisk driver to work with immutable bio_vecs
block/blk-mq-cpu.c: use hotcpu_notifier()
blk-mq: for_each_* macro correctness
block: Fix memory leak in rw_copy_check_uvector() handling
bio-integrity: Fix bio_integrity_verify segment start bug
block: remove unrelated header files and export symbol
blk-mq: uses page->list incorrectly
blk-mq: use __smp_call_function_single directly
btrfs: fix missing increment of bi_remaining
Revert "block: Warn and free bio if bi_end_io is not set"
block: Warn and free bio if bi_end_io is not set
blk-mq: fix initializing request's start time
block: blk-mq: don't export blk_mq_free_queue()
block: blk-mq: make blk_sync_queue support mq
block: blk-mq: support draining mq queue
dm cache: increment bi_remaining when bi_end_io is restored
block: fixup for generic bio chaining
block: Really silence spurious compiler warnings
block: Silence spurious compiler warnings
block: Kill bio_pair_split()
...
The BUG_ON at the end of __bch_btree_mark_key can be triggered due to
an integer overflow error:
BITMASK(GC_SECTORS_USED, struct bucket, gc_mark, 2, 13);
...
SET_GC_SECTORS_USED(g, min_t(unsigned,
GC_SECTORS_USED(g) + KEY_SIZE(k),
(1 << 14) - 1));
BUG_ON(!GC_SECTORS_USED(g));
In bcache.h, the SECTORS_USED bitfield is defined to be 13 bits wide.
While the SET_ code tries to ensure that the field doesn't overflow by
clamping it to (1<<14)-1 == 16383, this is incorrect because 16383
requires 14 bits. Therefore, if GC_SECTORS_USED() + KEY_SIZE() =
8192, the SET_ statement tries to store 8192 into a 13-bit field. In
a 13-bit field, 8192 becomes zero, thus triggering the BUG_ON.
Therefore, create a field width constant and a max value constant, and
use those to create the bitfield and check the inputs to
SET_GC_SECTORS_USED. Arguably the BITMASK() template ought to have
BUG_ON checks for too-large values, but that's a separate patch.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
All bug fixes, two tagged for -stable.
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Merge tag 'md/3.14' of git://neil.brown.name/md
Pull md updates from Neil Brown:
"All bug fixes, two tagged for -stable"
* tag 'md/3.14' of git://neil.brown.name/md:
md/raid5: close recently introduced race in stripe_head management.
md/raid5: fix long-standing problem with bitmap handling on write failure.
md: check command validity early in md_ioctl().
md: ensure metadata is writen after raid level change.
md/raid10: avoid fullsync when not necessary.
md: allow a partially recovered device to be hot-added to an array.
md: Change handling of save_raid_disk and metadata update during recovery.
A lot of attention was paid to improving the thin-provisioning target's
handling of metadata operation failures and running out of space. A new
'error_if_no_space' feature was added to allow users to error IOs rather
than queue them when either the data or metadata space is exhausted.
Additional fixes/features include:
- a few fixes to properly support thin metadata device resizing
- a solution for reliably waiting for a DM device's embedded kobject to
be released before destroying the device
- old dm-snapshot is updated to use the dm-bufio interface to take
advantage of readahead capabilities that improve snapshot activation
- new dm-cache target tunables to control how quickly data is promoted
to the cache (fast) device
- improved write efficiency of cluster mirror target by combining
userspace flush and mark requests
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Merge tag 'dm-3.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device-mapper changes from Mike Snitzer:
"A lot of attention was paid to improving the thin-provisioning
target's handling of metadata operation failures and running out of
space. A new 'error_if_no_space' feature was added to allow users to
error IOs rather than queue them when either the data or metadata
space is exhausted.
Additional fixes/features include:
- a few fixes to properly support thin metadata device resizing
- a solution for reliably waiting for a DM device's embedded kobject
to be released before destroying the device
- old dm-snapshot is updated to use the dm-bufio interface to take
advantage of readahead capabilities that improve snapshot
activation
- new dm-cache target tunables to control how quickly data is
promoted to the cache (fast) device
- improved write efficiency of cluster mirror target by combining
userspace flush and mark requests"
* tag 'dm-3.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (35 commits)
dm log userspace: allow mark requests to piggyback on flush requests
dm space map metadata: fix bug in resizing of thin metadata
dm cache: add policy name to status output
dm thin: fix pool feature parsing
dm sysfs: fix a module unload race
dm snapshot: use dm-bufio prefetch
dm snapshot: use dm-bufio
dm snapshot: prepare for switch to using dm-bufio
dm snapshot: use GFP_KERNEL when initializing exceptions
dm cache: add block sizes and total cache blocks to status output
dm btree: add dm_btree_find_lowest_key
dm space map metadata: fix extending the space map
dm space map common: make sure new space is used during extend
dm: wait until embedded kobject is released before destroying a device
dm: remove pointless kobject comparison in dm_get_from_kobject
dm snapshot: call destroy_work_on_stack() to pair with INIT_WORK_ONSTACK()
dm cache policy mq: introduce three promotion threshold tunables
dm cache policy mq: use list_del_init instead of list_del + INIT_LIST_HEAD
dm thin: fix set_pool_mode exposed pool operation races
dm thin: eliminate the no_free_space flag
...
In the cluster evironment, cluster write has poor performance because
userspace_flush() has to contact a userspace program (cmirrord) for
clear/mark/flush requests. But both mark and flush requests require
cmirrord to communicate the message to all the cluster nodes for each
flush call. This behaviour is really slow.
To address this we now merge mark and flush requests together to reduce
the kernel-userspace-kernel time. We allow a new directive,
"integrated_flush" that can be used to instruct the kernel log code to
combine flush and mark requests when directed by userspace. If not
directed by userspace (due to an older version of the userspace code
perhaps), the kernel will function as it did previously - preserving
backwards compatibility. Additionally, flush requests are performed
lazily when only clear requests exist.
Signed-off-by: Dongmao Zhang <dmzhang@suse.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Pull cgroup updates from Tejun Heo:
"The bulk of changes are cleanups and preparations for the upcoming
kernfs conversion.
- cgroup_event mechanism which is and will be used only by memcg is
moved to memcg.
- pidlist handling is updated so that it can be served by seq_file.
Also, the list is not sorted if sane_behavior. cgroup
documentation explicitly states that the file is not sorted but it
has been for quite some time.
- All cgroup file handling now happens on top of seq_file. This is
to prepare for kernfs conversion. In addition, all operations are
restructured so that they map 1-1 to kernfs operations.
- Other cleanups and low-pri fixes"
* 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits)
cgroup: trivial style updates
cgroup: remove stray references to css_id
doc: cgroups: Fix typo in doc/cgroups
cgroup: fix fail path in cgroup_load_subsys()
cgroup: fix missing unlock on error in cgroup_load_subsys()
cgroup: remove for_each_root_subsys()
cgroup: implement for_each_css()
cgroup: factor out cgroup_subsys_state creation into create_css()
cgroup: combine css handling loops in cgroup_create()
cgroup: reorder operations in cgroup_create()
cgroup: make for_each_subsys() useable under cgroup_root_mutex
cgroup: css iterations and css_from_dir() are safe under cgroup_mutex
cgroup: unify pidlist and other file handling
cgroup: replace cftype->read_seq_string() with cftype->seq_show()
cgroup: attach cgroup_open_file to all cgroup files
cgroup: generalize cgroup_pidlist_open_file
cgroup: unify read path so that seq_file is always used
cgroup: unify cgroup_write_X64() and cgroup_write_string()
cgroup: remove cftype->read(), ->read_map() and ->write()
hugetlb_cgroup: convert away from cftype->read()
...
As release_stripe and __release_stripe decrement ->count and then
manipulate ->lru both under ->device_lock, it is important that
get_active_stripe() increments ->count and clears ->lru also under
->device_lock.
However we currently list_del_init ->lru under the lock, but increment
the ->count outside the lock. This can lead to races and list
corruption.
So move the atomic_inc(&sh->count) up inside the ->device_lock
protected region.
Note that we still increment ->count without device lock in the case
where get_free_stripe() was called, and in fact don't take
->device_lock at all in that path.
This is safe because if the stripe_head can be found by
get_free_stripe, then the hash lock assures us the no-one else could
possibly be calling release_stripe() at the same time.
Fixes: 566c09c534
Cc: stable@vger.kernel.org (3.13)
Reported-and-tested-by: Ian Kumlien <ian.kumlien@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This bug was introduced in commit 7e664b3dec ("dm space map metadata:
fix extending the space map").
When extending a dm-thin metadata volume we:
- Switch the space map into a simple bootstrap mode, which allocates
all space linearly from the newly added space.
- Add new bitmap entries for the new space
- Increment the reference counts for those newly allocated bitmap
entries
- Commit changes to disk
- Switch back out of bootstrap mode.
But, the disk commit may allocate space itself, if so this fact will be
lost when switching out of bootstrap mode.
The bug exhibited itself as an error when the bitmap_root, with an
erroneous ref count of 0, was subsequently decremented as part of a
later disk commit. This would cause the disk commit to fail, and thinp
to enter read_only mode. The metadata was not damaged (thin_check
passed).
The fix is to put the increments + commit into a loop, running until
the commit has not allocated extra space. In practise this loop only
runs twice.
With this fix the following device mapper testsuite test passes:
dmtest run --suite thin-provisioning -n thin_remove_works_after_resize
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # depends on commit 7e664b3dec
Here's the big driver core and sysfs patch set for 3.14-rc1.
There's a lot of work here moving sysfs logic out into a "kernfs" to
allow other subsystems to also have a virtual filesystem with the same
attributes of sysfs (handle device disconnect, dynamic creation /
removal as needed / unneeded, etc. This is primarily being done for
the cgroups filesystem, but the goal is to also move debugfs to it when
it is ready, solving all of the known issues in that filesystem as well.
The code isn't completed yet, but all should be stable now (there is a
big section that was reverted due to problems found when testing.)
There's also some other smaller fixes, and a driver core addition that
allows for a "collection" of objects, that the DRM people will be using
soon (it's in this tree to make merges after -rc1 easier.)
All of this has been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.14-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 and sysfs patch set for 3.14-rc1.
There's a lot of work here moving sysfs logic out into a "kernfs" to
allow other subsystems to also have a virtual filesystem with the same
attributes of sysfs (handle device disconnect, dynamic creation /
removal as needed / unneeded, etc)
This is primarily being done for the cgroups filesystem, but the goal
is to also move debugfs to it when it is ready, solving all of the
known issues in that filesystem as well. The code isn't completed
yet, but all should be stable now (there is a big section that was
reverted due to problems found when testing)
There's also some other smaller fixes, and a driver core addition that
allows for a "collection" of objects, that the DRM people will be
using soon (it's in this tree to make merges after -rc1 easier)
All of this has been in linux-next with no reported issues"
* tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits)
kernfs: associate a new kernfs_node with its parent on creation
kernfs: add struct dentry declaration in kernfs.h
kernfs: fix get_active failure handling in kernfs_seq_*()
Revert "kernfs: fix get_active failure handling in kernfs_seq_*()"
Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq"
Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()"
Revert "kernfs: remove KERNFS_REMOVED"
Revert "kernfs: restructure removal path to fix possible premature return"
Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"
Revert "kernfs: remove kernfs_addrm_cxt"
Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed"
Revert "kernfs: implement kernfs_{de|re}activate[_self]()"
Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
Revert "pci: use device_remove_file_self() instead of device_schedule_callback()"
Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()"
Revert "s390: use device_remove_file_self() instead of device_schedule_callback()"
Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()"
kernfs: remove unnecessary NULL check in __kernfs_remove()
drivers/base: provide an infrastructure for componentised subsystems
...
The cache's policy may have been established using the "default" alias,
which is currently the "mq" policy but the default policy may change in
the future. It is useful to know exactly which policy is being used.
Add a 'real' member to the dm_cache_policy_type structure and have the
"default" dm_cache_policy_type point to the real "mq"
dm_cache_policy_type. Update dm_cache_policy_get_name() to check if
real is set, if so report the name of the real policy (not the alias).
Requested-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 787a996cb2 ("dm thin: add error_if_no_space feature")
mistakenly forgot to increase the number of feature args supported.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Before a write starts we set a bit in the write-intent bitmap.
When the write completes we clear that bit if the write was successful
to all devices. However if the write wasn't fully successful we
should not clear the bit. If the faulty drive is subsequently
re-added, the fact that the bit is still set ensure that we will
re-write the data that is missing.
This logic is mediated by the STRIPE_DEGRADED flag - we only clear the
bitmap bit when this flag is not set.
Currently we correctly set the flag if a write starts when some
devices are failed or missing. But we do *not* set the flag if some
device failed during the write attempt.
This is wrong and can result in clearing the bit inappropriately.
So: set the flag when a write fails.
This bug has been present since bitmaps were introduces, so the fix is
suitable for any -stable kernel.
Reported-by: Ethan Wilson <ethan.wilson@shiftmail.org>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Verify that the cmd parameter passed to md_ioctl() is valid before
doing anything.
This fixes mddev->hold_active being set to 0 when an invalid ioctl
command is passed to md_ioctl() before the array has been configured.
Clearing mddev->hold_active in that case can lead to a livelock
situation when an invalid ioctl number is given to md_ioctl() by a
process when the mddev is currently being opened by another process:
Process 1 Process 2
--------- ---------
md_alloc()
mddev_find()
-> returns a new mddev with
hold_active == UNTIL_IOCTL
add_disk()
-> sends KOBJ_ADD uevent
(sees KOBJ_ADD uevent for device)
md_open()
md_ioctl(INVALID_IOCTL)
-> returns ENODEV and clears
mddev->hold_active
md_release()
md_put()
-> deletes the mddev as
hold_active is 0
md_open()
mddev_find()
-> returns a newly
allocated mddev with
mddev->gendisk == NULL
-> returns with ERESTARTSYS
(kernel restarts the open syscall)
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NeilBrown <neilb@suse.de>
All of these fix real bugs the people have hit, and are tagged
for -stable.
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Merge tag 'md/3.13-fixes' of git://neil.brown.name/md
Pull late md fixes from Neil Brown:
"Half a dozen md bug fixes.
All of these fix real bugs the people have hit, and are tagged for
-stable. Sorry they are late .... Christmas holidays and all that.
Hopefully they can still squeak into 3.13"
* tag 'md/3.13-fixes' of git://neil.brown.name/md:
md: fix problem when adding device to read-only array with bitmap.
md/raid10: fix bug when raid10 recovery fails to recover a block.
md/raid5: fix a recently broken BUG_ON().
md/raid1: fix request counting bug in new 'barrier' code.
md/raid10: fix two bugs in handling of known-bad-blocks.
md/raid5: Fix possible confusion when multiple write errors occur.
This reverts commit be35f48610 ("dm: wait until embedded kobject is
released before destroying a device") and provides an improved fix.
The kobject release code that calls the completion must be placed in a
non-module file, otherwise there is a module unload race (if the process
calling dm_kobject_release is preempted and the DM module unloaded after
the completion is triggered, but before dm_kobject_release returns).
To fix this race, this patch moves the completion code to dm-builtin.c
which is always compiled directly into the kernel if BLK_DEV_DM is
selected.
The patch introduces a new dm_kobject_holder structure, its purpose is
to keep the completion and kobject in one place, so that it can be
accessed from non-module code without the need to export the layout of
struct mapped_device to that code.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This patch modifies dm-snapshot so that it prefetches the buffers when
loading the exceptions.
The number of buffers read ahead is specified in the DM_PREFETCH_CHUNKS
macro. The current value for DM_PREFETCH_CHUNKS (12) was found to
provide the best performance on a single 15k SCSI spindle. In the
future we may modify this default or make it configurable.
Also, introduce the function dm_bufio_set_minimum_buffers to setup
bufio's number of internal buffers before freeing happens. dm-bufio may
hold more buffers if enough memory is available. There is no guarantee
that the specified number of buffers will be available - if you need a
guarantee, use the argument reserved_buffers for
dm_bufio_client_create.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use dm-bufio for initial loading of the exceptions.
Introduce a new function dm_bufio_forget that frees the given buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Change the functions get_exception, read_exception and insert_exceptions
so that ps->area is passed as an argument.
This patch doesn't change any functionality, but it refactors the code
to allow for a cleaner switch over to using dm-bufio.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The list of initial exceptions is loaded in the target constructor. We
are allowed to allocate memory with GFP_KERNEL at this point. So,
change alloc_completed_exception to use GFP_KERNEL when being called
from the constructor.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
level_store() currently does not make sure the metadata is
updates to reflect the new raid level. It simply sets MD_CHANGE_DEVS.
Any level with a ->thread will quickly notice this and update the
metadata. However RAID0 and Linear do not have a thread so no
metadata update happens until the array is stopped. At that point the
metadata is written.
This is later that we would like. While the delay doesn't risk any
data it can cause confusion. So if there is no md thread, immediately
update the metadata after a level change.
Reported-by: Richard Michael <rmichael@edgeofthenet.org>
Signed-off-by: NeilBrown <neilb@suse.de>
This is the raid10 equivalent of
commit 4f0a5e012c
MD RAID1: Further conditionalize 'fullsync'
If a device in a newly assembled array is not fully recovered we
currently do a fully resync by don't need to.
Signed-off-by: NeilBrown <neilb@suse.de>
When adding a new device into an array it is normally important to
clear any stale data from ->recovery_offset else the new device may
not be recovered properly.
However when re-adding a device which is known to be nearly in-sync,
this is not needed and can be detrimental. The (bitmap-based)
resync will still happen, and further recovery is only needed from
where-ever it was already up to.
So if save_raid_disk is set, signifying a re-add, don't clear
->recovery_offset.
Signed-off-by: NeilBrown <neilb@suse.de>
Since commit d70ed2e4fa
MD: Allow restarting an interrupted incremental recovery.
we don't write out the metadata to devices while they are recovering.
This had a good reason, but has unfortunate consequences. This patch
changes things to make them work better.
At issue is what happens if the array is shut down while a recovery is
happening, particularly a bitmap-guided recovery.
Ideally the recovery should pick up where it left off.
However the metadata cannot represent the state "A recovery is in
process which is guided by the bitmap".
Before the above mentioned commit, we wrote metadata to the device
which said "this is being recovered and it is up to <here>". So after
a restart, a full recovery (not bitmap-guided) would happen from
where-ever it was up to.
After the commit the metadata wasn't updated so it still said "This
device is fully in sync with <this> event count". That leads to a
bitmap-based recovery following the whole bitmap, which should be a
lot less work than a full recovery from some starting point. So this
was an improvement.
However updates some metadata but not all leads to other problems.
In particular, the metadata written to the fully-up-to-date device
record that the array has all devices present (even though some are
recovering). So on restart, mdadm wants to find all devices and
expects them to have current event counts.
Obviously it doesn't (some have old event counts) so (when assembling
with --incremental) it waits indefinitely for the rest of the expected
devices.
It really is wrong to not update all the metadata together. Do that
is bound to cause confusion.
Instead, we should make it possible to record the truth in the
metadata. i.e. we need to be able to record that a device is being
recovered based on the bitmap.
We already have a Feature flag to say that recovery is happening. We
now add another one to say that it is a bitmap-based recovery.
With this we can remove the code that disables the write-out of
metadata on some devices.
So this patch:
- moves the setting of 'saved_raid_disk' from add_new_disk to
the validate_super methods. This makes sure it is always set
properly, both when adding a new device to an array, and when
assembling an array from a collection of devices.
- Adds a metadata flag MD_FEATURE_RECOVERY_BITMAP which is only
used if MD_FEATURE_RECOVERY_OFFSET is set, and record that a
bitmap-based recovery is allowed.
This is only present in v1.x metadata. v0.90 doesn't support
devices which are in the middle of recovery at all.
- Only skips writing metadata to Faulty devices.
- Also allows rdev state to be set to "-insync" via sysfs.
This can be used for external-metadata arrays. When the
'role' is set the device is assumed to be in-sync. If, after
setting the role, we set the state to "-insync", the role is
moved to saved_raid_disk which effectively says the device is
partly in-sync with that slot and needs a bitmap recovery.
Cc: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Heinz Mauelshagen