Commit Graph

127 Commits

Author SHA1 Message Date
Bob Peterson 942b0cddfb GFS2: Withdraw for IO errors writing to the journal or statfs
Before this patch, if GFS2 encountered IO errors while writing to
the journal, it would not report the problem, so they would go
unnoticed, sometimes for many hours. Sometimes this would only be
noticed later, when recovery tried to do journal replay and failed
due to invalid metadata at the blocks that resulted in IO errors.

This patch makes GFS2's log daemon check for IO errors. If it
encounters one, it withdraws from the file system and reports
why in dmesg. A similar action is taken when IO errors occur when
writing to the system statfs file.

These errors are also reported back to any callers of fsync, since
that requires the journal to be flushed. Therefore, any IO errors
that would previously go unnoticed are now noticed and the file
system is withdrawn as early as possible, thus preventing further
file system damage.

Also note that this reintroduces superblock variable sd_log_error,
which Christoph removed with commit f729b66fca.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-08-25 10:59:09 -05:00
Abhi Das b066a4eebd gfs2: forcibly flush ail to relieve memory pressure
On systems with low memory, it is possible for gfs2 to infinitely
loop in balance_dirty_pages() under heavy IO (creating sparse files).

balance_dirty_pages() attempts to write out the dirty pages via
gfs2_writepages() but none are found because these dirty pages are
being used by the journaling code in the ail. Normally, the journal
has an upper threshold which when hit triggers an automatic flush
of the ail. But this threshold can be higher than the number of
allowable dirty pages and result in the ail never being flushed.

This patch forces an ail flush when gfs2_writepages() fails to write
anything. This is a good indication that the ail might be holding
some dirty pages.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-08-10 10:51:03 -05:00
Linus Torvalds c96e6dabfb We've got eight GFS2 patches for this merge window:
1. Andreas Gruenbacher has four patches related to cleaning up the GFS2
    inode evict process. This is about half of his patches designed to
    fix a long-standing GFS2 hang related to the inode shrinker.
    (Shrinker calls gfs2 evict, evict calls DLM, DLM requires memory
    and blocks on the shrinker.) These 4 patches have been well tested.
    His second set of patches are still being tested, so I plan to hold
    them until the next merge window, after we have more weeks of testing.
    The first patch eliminates the flush_delayed_work, which can block.
 2. Andreas's second patch protects setting of gl_object for rgrps with
    a spin_lock to prevent proven races.
 3. His third patch introduces a centralized mechanism for queueing glock
    work with better reference counting, to prevent more races.
 4. His fourth patch retains a reference to inode glocks when an error
    occurs while creating an inode. This keeps the subsequent evict from
    needing to reacquire the glock, which might call into DLM and block
    in low memory conditions.
 5. Arvind Yadav has a patch to add const to attribute_group structures.
 6. I have a patch to detect directory entry inconsistencies and withdraw
    the file system if any are found. Better that than silent corruption.
 7. I have a patch to remove a vestigial variable from glock structures,
    saving some slab space.
 8. I have another patch to remove a vestigial variable from the GFS2
    in-core superblock structure.
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Merge tag 'gfs2-4.13.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull GFS2 updates from Bob Peterson:
 "We've got eight GFS2 patches for this merge window:

   - Andreas Gruenbacher has four patches related to cleaning up the
     GFS2 inode evict process. This is about half of his patches
     designed to fix a long-standing GFS2 hang related to the inode
     shrinker: Shrinker calls gfs2 evict, evict calls DLM, DLM requires
     memory and blocks on the shrinker.

     These four patches have been well tested. His second set of patches
     are still being tested, so I plan to hold them until the next merge
     window, after we have more weeks of testing. The first patch
     eliminates the flush_delayed_work, which can block.

   - Andreas's second patch protects setting of gl_object for rgrps with
     a spin_lock to prevent proven races.

   - His third patch introduces a centralized mechanism for queueing
     glock work with better reference counting, to prevent more races.

    -His fourth patch retains a reference to inode glocks when an error
     occurs while creating an inode. This keeps the subsequent evict
     from needing to reacquire the glock, which might call into DLM and
     block in low memory conditions.

   - Arvind Yadav has a patch to add const to attribute_group
     structures.

   - I have a patch to detect directory entry inconsistencies and
     withdraw the file system if any are found. Better that than silent
     corruption.

   - I have a patch to remove a vestigial variable from glock
     structures, saving some slab space.

   - I have another patch to remove a vestigial variable from the GFS2
     in-core superblock structure"

* tag 'gfs2-4.13.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  GFS2: constify attribute_group structures.
  gfs2: gfs2_create_inode: Keep glock across iput
  gfs2: Clean up glock work enqueuing
  gfs2: Protect gl->gl_object by spin lock
  gfs2: Get rid of flush_delayed_work in gfs2_evict_inode
  GFS2: Eliminate vestigial sd_log_flush_wrapped
  GFS2: Remove gl_list from glock structure
  GFS2: Withdraw when directory entry inconsistencies are detected
2017-07-05 16:57:08 -07:00
Bob Peterson 722f6f62a5 GFS2: Eliminate vestigial sd_log_flush_wrapped
Superblock variable sd_log_flush_wrapped is set, but never referenced,
so this patch eliminates it.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-06-20 09:52:57 -05:00
Jan Kara 0f0b9b63e1 gfs2: Make flush bios explicitely sync
Commit b685d3d65a "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

Fixes: b685d3d65a
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: cluster-devel@redhat.com
CC: stable@vger.kernel.org
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-05-24 13:35:20 +02:00
Linus Torvalds 9763dd6f81 We've got eight GFS2 patches for this merge window:
1. Andy Price submitted a patch to make gfs2_write_full_page a
    static function.
 2. Dan Carpenter submitted a patch to fix a ERR_PTR thinko.
 
 I've also got a few patches, three of which fix bugs related to
 deleting very large files, which cause GFS2 to run out of
 journal space:
 
 3. The first one prevents GFS2 delete operation from requesting too
    much journal space.
 4. The second one fixes a problem whereby GFS2 can hang because it
    wasn't taking journal space demand into its calculations.
 5. The third one wakes up IO waiters when a flush is done to restart
    processes stuck waiting for journal space to become available.
 
 The other three patches are a performance improvement related to
 spin_lock contention between multiple writers:
 
 6. The "tr_touched" variable was switched to a flag to be more atomic
    and eliminate the possibility of some races.
 7. Function meta_lo_add was moved inline with its only caller to make
    the code more readable and efficient.
 8. Contention on the gfs2_log_lock spinlock was greatly reduced by
    avoiding the lock altogether in cases where we don't really need
    it: buffers that already appear in the appropriate metadata list
    for the journal. Many thanks to Steve Whitehouse for the ideas and
    principles behind these patches.
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Merge tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull GFS2 updates from Robert Peterson:
 "We've got eight GFS2 patches for this merge window:

   - Andy Price submitted a patch to make gfs2_write_full_page a static
     function.

   - Dan Carpenter submitted a patch to fix a ERR_PTR thinko.

  Three patches fix bugs related to deleting very large files, which
  cause GFS2 to run out of journal space:

   - The first one prevents GFS2 delete operation from requesting too
     much journal space.

   - The second one fixes a problem whereby GFS2 can hang because it
     wasn't taking journal space demand into its calculations.

   - The third one wakes up IO waiters when a flush is done to restart
     processes stuck waiting for journal space to become available.

  The final three patches are a performance improvement related to
  spin_lock contention between multiple writers:

   - The "tr_touched" variable was switched to a flag to be more atomic
     and eliminate the possibility of some races.

   - Function meta_lo_add was moved inline with its only caller to make
     the code more readable and efficient.

   - Contention on the gfs2_log_lock spinlock was greatly reduced by
     avoiding the lock altogether in cases where we don't really need
     it: buffers that already appear in the appropriate metadata list
     for the journal. Many thanks to Steve Whitehouse for the ideas and
     principles behind these patches"

* tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Make gfs2_write_full_page static
  GFS2: Reduce contention on gfs2_log_lock
  GFS2: Inline function meta_lo_add
  GFS2: Switch tr_touched to flag in transaction
  GFS2: Wake up io waiters whenever a flush is done
  GFS2: Made logd daemon take into account log demand
  GFS2: Limit number of transaction blocks requested for truncates
  GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next
2017-02-21 07:46:34 -08:00
Bob Peterson 9862ca056e GFS2: Switch tr_touched to flag in transaction
This patch eliminates the int variable tr_touched in favor of a
new flag in the transaction. This is a step toward reducing contention
on the gfs2_log_lock spin_lock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-01-27 08:20:13 -05:00
Bob Peterson b63f5e8482 GFS2: Wake up io waiters whenever a flush is done
Before this patch, if a process called function gfs2_log_reserve to
reserve some journal blocks, but the journal not enough blocks were
free, it would call io_schedule. However, in the log flush daemon,
it woke up the waiters only if an gfs2_ail_flush was no longer
required. This resulted in situations where processes would wait
forever because the number of blocks required was so high that it
pushed the journal into a perpetual state of flush being required.

This patch changes the logd daemon so that it wakes up io waiters
every time the log is actually flushed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-01-06 22:14:28 -05:00
Bob Peterson f07b352021 GFS2: Made logd daemon take into account log demand
Before this patch, the logd daemon only tried to flush things when
the log blocks pinned exceeded a certain threshold. But when we're
deleting very large files, it may require a huge number of journal
blocks, and that, in turn, may exceed the threshold. This patch
factors that into account.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-01-05 16:01:45 -05:00
Christoph Hellwig 70fd76140a block,fs: use REQ_* flags directly
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Mike Christie e1b1afa6f8 gfs2: use bio op accessors
Separate the op from the rq_flag_bits and have gfs2
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Benjamin Marzinski 400ac52e80 gfs2: clear journal live bit in gfs2_log_flush
When gfs2 was unmounting filesystems or changing them to read-only it
was clearing the SDF_JOURNAL_LIVE bit before the final log flush.  This
caused a race.  If an inode glock got demoted in the gap between
clearing the bit and the shutdown flush, it would be unable to reserve
log space to clear out the active items list in inode_go_sync, causing an
error in inode_go_inval because the glock was still dirty.

To solve this, the SDF_JOURNAL_LIVE bit is now cleared inside the
shutdown log flush.  This means that, because of the locking on the log
blocks, either inode_go_sync will be able to reserve space to clean the
glock before the shutdown flush, or the shutdown flush will clean the
glock itself, before inode_go_sync fails to reserve the space. Either
way, the glock will be clean before inode_go_inval.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-12-14 12:19:41 -06:00
Benjamin Marzinski 2e60d7683c GFS2: update freeze code to use freeze/thaw_super on all nodes
The current gfs2 freezing code is considerably more complicated than it
should be because it doesn't use the vfs freezing code on any node except
the one that begins the freeze.  This is because it needs to acquire a
cluster glock before calling the vfs code to prevent a deadlock, and
without the new freeze_super and thaw_super hooks, that was impossible. To
deal with the issue, gfs2 had to do some hacky locking tricks to make sure
that a frozen node couldn't be holding on a lock it needed to do the
unfreeze ioctl.

This patch makes use of the new hooks to simply the gfs2 locking code. Now,
all the nodes in the cluster freeze and thaw in exactly the same way. Every
node in the cluster caches the freeze glock in the shared state.  The new
freeze_super hook allows the freezing node to grab this freeze glock in
the exclusive state without first calling the vfs freeze_super function.
All the nodes in the cluster see this lock change, and call the vfs
freeze_super function. The vfs locking code guarantees that the nodes can't
get stuck holding the glocks necessary to unfreeze the system.  To
unfreeze, the freezing node uses the new thaw_super hook to drop the freeze
glock. Again, all the nodes notice this, reacquire the glock in shared mode
and call the vfs thaw_super function.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-11-17 10:36:39 +00:00
Benjamin Marzinski 24972557b1 GFS2: remove transaction glock
GFS2 has a transaction glock, which must be grabbed for every
transaction, whose purpose is to deal with freezing the filesystem.
Aside from this involving a large amount of locking, it is very easy to
make the current fsfreeze code hang on unfreezing.

This patch rewrites how gfs2 handles freezing the filesystem. The
transaction glock is removed. In it's place is a freeze glock, which is
cached (but not held) in a shared state by every node in the cluster
when the filesystem is mounted. This lock only needs to be grabbed on
freezing, and actions which need to be safe from freezing, like
recovery.

When a node wants to freeze the filesystem, it grabs this glock
exclusively.  When the freeze glock state changes on the nodes (either
from shared to unlocked, or shared to exclusive), the filesystem does a
special log flush.  gfs2_log_flush() does all the work for flushing out
the and shutting down the incore log, and then it tries to grab the
freeze glock in a shared state again.  Since the filesystem is stuck in
gfs2_log_flush, no new transaction can start, and nothing can be written
to disk. Unfreezing the filesytem simply involes dropping the freeze
glock, allowing gfs2_log_flush() to grab and then release the shared
lock, so it is cached for next time.

However, in order for the unfreezing ioctl to occur, gfs2 needs to get a
shared lock on the filesystem root directory inode to check permissions.
If that glock has already been grabbed exclusively, fsfreeze will be
unable to get the shared lock and unfreeze the filesystem.

In order to allow the unfreeze, this patch makes gfs2 grab a shared lock
on the filesystem root directory during the freeze, and hold it until it
unfreezes the filesystem.  The functions which need to grab a shared
lock in order to allow the unfreeze ioctl to be issued now use the lock
grabbed by the freeze code instead.

The freeze and unfreeze code take care to make sure that this shared
lock will not be dropped while another process is using it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-05-14 10:04:34 +01:00
Bob Peterson 428fd95d85 GFS2: Re-add a call to log_flush_wait when flushing the journal
Upstream commit 34cc178 changed a line of code from calling function
log_flush_commit to calling log_write_header. This had the effect of
eliminating a call to function log_flush_wait. That causes the journal
to skip over log headers, which results in multiple wrap points,
which itself leads to infinite loops in journal replay, both in the
kernel code and fsck.gfs2 code. This patch re-adds that call.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-03-12 14:46:29 +00:00
Steven Whitehouse b1ab1e44b4 GFS2: Remove extra "if" in gfs2_log_flush()
By reordering some of the assignments in gfs2_log_flush() it
is possible to remove one of the "if" statements as it can be
merged with one higher up the function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-25 11:52:20 +00:00
Steven Whitehouse 022ef4feed GFS2: Move log buffer accounting to transaction
Now we have a master transaction into which other transactions
are merged, the accounting can be done using this master
transaction. We no longer require the superblock fields which
were being used for this function.

In addition, this allows for a clean up in calc_reserved()
making it rather easier understand. Also, by reducing the
number of variables used to track the buffers being added
and removed from the journal, a number of error checks are
now no longer required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-24 19:49:12 +00:00
Steven Whitehouse d69a3c6561 GFS2: Move log buffer lists into transaction
Over time, we hope to be able to improve the concurrency available
in the log code. This is one small step towards that, by moving
the buffer lists from the super block, and into the transaction
structure, so that each transaction builds its own buffer lists.

At transaction commit time, the buffer lists are merged into
the currently accumulating transaction. That transaction then
is passed into the before and after commit functions at journal
flush time. Thus there should be no change in overall behaviour
yet.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-24 16:54:54 +00:00
Steven Whitehouse 885bceca7f GFS2: Plug on AIL flush
When we do a flush of the AIL list, we are writing out what is
likely to be a lot of small I/Os, which are possibly in an order
which is not ideal performance-wise. Since this is done by calling
filemap_fdatatwrite for each individual inode's address space there
is no overall plugging going on.

In addition to that, we do not always wait for AIL i/o when we flush
it, so that it is possible for things to get left behind on the queue.
By adding explicit plugging here, we reduce the chances of this
being an issues. A quick test using the AIL flush tracepoint shows a
small, but measurable improvement.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-02-03 09:57:29 +00:00
Bob Peterson 9290a9a7c0 GFS2: Fix use-after-free race when calling gfs2_remove_from_ail
Function gfs2_remove_from_ail drops the reference on the bh via
brelse. This patch fixes a race condition whereby bh is deferenced
after the brelse when setting bd->bd_blkno = bh->b_blocknr;
Under certain rare circumstances, bh might be gone or reused,
and bd->bd_blkno is set to whatever that memory happens to be,
which is often 0. Later, in gfs2_trans_add_unrevoke, that bd fails
the test "bd->bd_blkno >= blkno" which causes it to never be freed.
The end result is that the bd is never freed from the bufdata cache,
which results in this error:
slab error in kmem_cache_destroy(): cache `gfs2_bufdata': Can't free all objects

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-12-13 21:42:23 +00:00
Benjamin Marzinski 5d054964f5 GFS2: aggressively issue revokes in gfs2_log_flush
This patch looks at all the outstanding blocks in all the transactions
on the log, and moves the completed ones to the ail2 list.  Then it
issues revokes for these blocks.  This will hopefully speed things up
in situations where there is a lot of contention for glocks, especially
if they are acquired serially.

revoke_lo_before_commit will issue at most one log block's full of these
preemptive revokes. The amount of reserved log space that
gfs2_log_reserve() ignores has been incremented to allow for this extra
block.

This patch also consolidates the common revoke instructions into one
function, gfs2_add_revoke().

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-06-19 09:41:59 +01:00
Benjamin Marzinski 16ca9412d8 GFS2: replace gfs2_ail structure with gfs2_trans
In order to allow transactions and log flushes to happen at the same
time, gfs2 needs to move the transaction accounting and active items
list code into the gfs2_trans structure.  As a first step toward this,
this patch removes the gfs2_ail structure, and handles the active items
list in the gfs_trans structure.  This keeps gfs2 from allocating an ail
structure on log flushes, and gives us a struture that can later be used
to store the transaction accounting outside of the gfs2 superblock
structure.

With this patch, at the end of a transaction, gfs2 will add the
gfs2_trans structure to the superblock if there is not one already.
This structure now has the active items fields that were previously in
gfs2_ail.  This is not necessary in the case where the transaction was
simply used to add revokes, since these are never written outside of the
journal, and thus, don't need an active items list.

Also, in order to make sure that the transaction structure is not
removed while it's still in use by gfs2_trans_end, unlocking the
sd_log_flush_lock has to happen slightly later in ending the
transaction.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-04-08 08:46:22 +01:00
Steven Whitehouse 4513899092 GFS2: Use ->writepages for ordered writes
Instead of using a list of buffers to write ahead of the journal
flush, this now uses a list of inodes and calls ->writepages
via filemap_fdatawrite() in order to achieve the same thing. For
most use cases this results in a shorter ordered write list,
as well as much larger i/os being issued.

The ordered write list is sorted by inode number before writing
in order to retain the disk block ordering between inodes as
per the previous code.

The previous ordered write code used to conflict in its assumptions
about how to write out the disk blocks with mpage_writepages()
so that with this updated version we can also use mpage_writepages()
for GFS2's ordered write, writepages implementation. So we will
also send larger i/os from writeback too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-01-29 10:29:17 +00:00
Bob Peterson c0752aa7e4 GFS2: eliminate log elements and simplify
This patch eliminates the gfs2_log_element data structure and
rolls its two components into the gfs2_bufdata. This makes the code
easier to understand and makes it easier to migrate to a rbtree
to keep the list sorted.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-05-02 09:14:36 +01:00
Steven Whitehouse 144a4c2ff7 GFS2: Log code fixes
This patch removes a log lock from around atomic operation where
it is not needed, removes an unused variable, and also changes
a void pointer used incorrectly to a struct page pointer.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:38 +01:00
Steven Whitehouse c50b91c4bd GFS2: Remove bd_list_tr
This is another clean up in the logging code. This per-transaction
list was largely unused. Its main function was to ensure that the
number of buffers in a transaction was correct, however that counter
was only used to check the number of buffers in the bd_list_tr, plus
an assert at the end of each transaction. With the assert now changed
to use the calculated buffer counts, we can remove both bd_list_tr and
its associated counter.

This should make the code easier to understand as well as shrinking
a couple of structures.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:36 +01:00
Steven Whitehouse e8c92ed769 GFS2: Clean up log write code path
Prior to this patch, we have two ways of sending i/o to the log.
One of those is used when we need to allocate both the data
to be written itself and also a buffer head to submit it. This
is done via sb_getblk and friends. This is used mostly for writing
log headers.

The other method is used when writing blocks which have some
in-place counterpart. This is the case for all the metadata
blocks which are journalled, and when journaled data is in use,
for unescaped journalled data blocks.

This patch replaces both of those two methods, and about half
a dozen separate i/o submission points with a single i/o
submission function. We also go direct to bio rather than
using buffer heads, since this allows us to build i/o
requests of the maximum size for the block device in
question. It also reduces the memory required for flushing
the log, which can be very useful in low memory situations.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:34 +01:00
Steven Whitehouse fdb76a4228 GFS2: Drop "pull" argument from log_write_header()
The "pull" argument to log_write_header() is only used
for debug purposes and it is not really needed any more. There
are other tests for this particular problem, so I think we can
dispose of it in order to simplify the code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-24 16:44:24 +01:00
Steven Whitehouse 34cc1781c2 GFS2: Clean up log flush header writing
We already send both a pre and post flush to the block device
when writing a journal header. There is no need to wait for
the previous I/O specifically when we do this, unless we've
turned "barriers" off.

As a side effect, this also cleans up the code path for flushing
the journal and makes it more readable.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-03-09 14:07:06 +00:00
Steven Whitehouse 08728f2d8b GFS2: Make bd_cmp() static
Add missing static to bd_cmp()

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 17:11:27 +00:00
Bob Peterson 4a36d08d0d GFS2: Sort the ordered write list
This patch sorts the ordered write list for GFS2 writes.
This increases the throughput for simultaneous writes.
For example, if you have ten processes, all doing:
dd if=/dev/zero of=/mnt/gfs2/fileX
on different files, the throughput will be much better.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 17:10:53 +00:00
Steven Whitehouse 47ac5537a7 GFS2: Move two functions from log.c to lops.c
gfs2_log_get_buf() and gfs2_log_fake_buf() are both used
only in lops.c, so move them next to their callers and they
can then become static.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 17:09:59 +00:00
Linus Torvalds eb59c505f8 Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
  PM / Hibernate: Implement compat_ioctl for /dev/snapshot
  PM / Freezer: fix return value of freezable_schedule_timeout_killable()
  PM / shmobile: Allow the A4R domain to be turned off at run time
  PM / input / touchscreen: Make st1232 use device PM QoS constraints
  PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
  PM / shmobile: Remove the stay_on flag from SH7372's PM domains
  PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
  PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
  PM: Drop generic_subsys_pm_ops
  PM / Sleep: Remove forward-only callbacks from AMBA bus type
  PM / Sleep: Remove forward-only callbacks from platform bus type
  PM: Run the driver callback directly if the subsystem one is not there
  PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
  PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
  PM / Sleep: Merge internal functions in generic_ops.c
  PM / Sleep: Simplify generic system suspend callbacks
  PM / Hibernate: Remove deprecated hibernation snapshot ioctls
  PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
  ARM: S3C64XX: Implement basic power domain support
  PM / shmobile: Use common always on power domain governor
  ...

Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
2012-01-08 13:10:57 -08:00
Tejun Heo a0acae0e88 freezer: unexport refrigerator() and update try_to_freeze() slightly
There is no reason to export two functions for entering the
refrigerator.  Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.

* Rename refrigerator() to __refrigerator() and make it return bool
  indicating whether it scheduled out for freezing.

* Update try_to_freeze() to return bool and relay the return value of
  __refrigerator() if freezing().

* Convert all refrigerator() users to try_to_freeze().

* Update documentation accordingly.

* While at it, add might_sleep() to try_to_freeze().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
2011-11-21 12:32:22 -08:00
Steven Whitehouse 20ed0535d3 GFS2: Fix up REQ flags
Christoph has split up REQ_PRIO from REQ_META. That means that
we can drop REQ_PRIO from places where is it not needed. I'm
not at all sure that the combination WRITE_FLUSH_FUA | REQ_PRIO
makes any kind of sense, anyway.

In addition, I've added REQ_META to one place in the code where
it was missing. REQ_PRIO has been left for read/writes triggered
by glock acquisition and writeback only. We can adjust it again
if required, but these are the most important points from a
performance perspective.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
2011-11-08 09:51:53 +00:00
Christoph Hellwig 65299a3b78 block: separate priority boosting from REQ_META
Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule,
and lave REQ_META purely for marking requests as metadata in blktrace.

All existing callers of REQ_META except for XFS are updated to also
set REQ_PRIO for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-23 14:50:29 +02:00
Steven Whitehouse 380f7c65a7 GFS2: Resolve inode eviction and ail list interaction bug
This patch contains a few misc fixes which resolve a recently
reported issue. This patch has been a real team effort and has
received a lot of testing.

The first issue is that the ail lock needs to be held over a few
more operations. The lock thats added into gfs2_releasepage() may
possibly be a candidate for replacing with RCU at some future
point, but at this stage we've gone for the obvious fix.

The second issue is that gfs2_write_inode() can end up calling
a glock recursively when called from gfs2_evict_inode() via the
syncing code, so it needs a guard added.

The third issue is that we either need to not truncate the metadata
pages of inodes which have zero link count, but which we cannot
deallocate due to them still being in use by other nodes, or we need
to ensure that those pages have all made it through the journal and
ail lists first. This patch takes the former approach, but the
latter has also been tested and there is nothing to choose between
them performance-wise. So again, we could revise that decision
in the future.

Also, the inode eviction process is now better documented.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Tested-by: Abhijith Das <adas@redhat.com>
Reported-by: Barry J. Marson <bmarson@redhat.com>
Reported-by: David Teigland <teigland@redhat.com>
2011-07-14 08:59:44 +01:00
Steven Whitehouse 26b06a6958 GFS2: Wait properly when flushing the ail list
The ail flush code has always relied upon log flushing to prevent
it from spinning needlessly. This fixes it to wait on the last
I/O request submitted (we don't need to wait for all of it)
instead of either spinning with io_schedule or sleeping.

As a result cpu usage of gfs2_logd is much reduced with certain
workloads.

Reported-by: Abhijith Das <adas@redhat.com>
Tested-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-21 19:21:07 +01:00
Steven Whitehouse 4f1de01821 GFS2: Fix ail list traversal
In the recent patches to update the AIL list code, I managed to
forget that the ail list lock got dropped, even though I
added a comment specifically to remind myself :(

Reported-by: Barry Marson <bmarson@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-03 11:48:07 +01:00
Steven Whitehouse c83ae9cad8 GFS2: Add an AIL writeback tracepoint
Add a tracepoint for monitoring writeback of the AIL.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20 09:01:58 +01:00
Steven Whitehouse 4667a0ec32 GFS2: Make writeback more responsive to system conditions
This patch adds writeback_control to writing back the AIL
list. This means that we can then take advantage of the
information we get in ->write_inode() in order to set off
some pre-emptive writeback.

In addition, the AIL code is cleaned up a bit to make it
a bit simpler to understand.

There is still more which can usefully be done in this area,
but this is a good start at least.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20 09:01:37 +01:00
Steven Whitehouse 5ac048bb7e GFS2: Use filemap_fdatawrite() to write back the AIL
In order to ensure that the mapping stats (and thus the bdi) are correctly
updated, this patch changes the AIL writeback to use the filemap_datawrite
function. This helps prevent stalls in balance_dirty_pages() due to
large amounts of dirty metadata when there is little or no dirty data
around.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20 08:59:25 +01:00
Linus Torvalds 6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Steven Whitehouse c618e87a5f GFS2: Update to AIL list locking
The previous patch missed a couple of places where the AIL list
needed locking, so this fixes up those places, plus a comment
is corrected too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Chinner <dchinner@redhat.com>
2011-03-14 12:40:29 +00:00
Dave Chinner d6a079e82e GFS2: introduce AIL lock
The log lock is currently used to protect the AIL lists and
the movements of buffers into and out of them. The lists
are self contained and no log specific items outside the
lists are accessed when starting or emptying the AIL lists.

Hence the operation of the AIL does not require the protection
of the log lock so split them out into a new AIL specific lock
to reduce the amount of traffic on the log lock. This will
also reduce the amount of serialisation that occurs when
the gfs2_logd pushes on the AIL to move it forward.

This reduces the impact of log pushing on sequential write
throughput.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-11 11:52:25 +00:00
Jens Axboe 721a9602e6 block: kill off REQ_UNPLUG
With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:27 +01:00
Jens Axboe fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Steven Whitehouse 5f4874903d GFS2: gfs2_logd should be using interruptible waits
Looks like this crept in, in a recent update.

Reported-by:  Krzysztof Urbaniak <urban@bash.org.pl>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-17 14:00:10 +01:00
Christoph Hellwig f1e4d518c3 gfs2: replace barriers with explicit flush / FUA usage
Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:39 +02:00
Christoph Hellwig 7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00