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2017-08-25GFS2: Withdraw for IO errors writing to the journal or statfsBob Peterson
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 Therefore, any IO errors that would previously go unnoticed are now noticed and the file system is withdrawn as early as possible, thus preventing further file system damage.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>
2017-08-10gfs2: forcibly flush ail to relieve memory pressureAbhi Das
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>
2017-07-05Merge tag 'gfs2-4.13.fixes' of ↵Linus Torvalds
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
2017-06-20GFS2: Eliminate vestigial sd_log_flush_wrappedBob Peterson
Superblock variable sd_log_flush_wrapped is set, but never referenced, so this patch eliminates it. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2017-05-24gfs2: Make flush bios explicitely syncJan Kara
Commit b685d3d65ac7 "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: b685d3d65ac791406e0dfd8779cc9b3707fea5a3 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>
2017-02-21Merge tag 'gfs2-4.11.fixes' of ↵Linus Torvalds
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
2017-01-27GFS2: Switch tr_touched to flag in transactionBob Peterson
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>
2017-01-06GFS2: Wake up io waiters whenever a flush is doneBob Peterson
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>
2017-01-05GFS2: Made logd daemon take into account log demandBob Peterson
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>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig
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>
2016-06-07gfs2: use bio op accessorsMike Christie
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>
2015-12-14gfs2: clear journal live bit in gfs2_log_flushBenjamin Marzinski
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>
2014-11-17GFS2: update freeze code to use freeze/thaw_super on all nodesBenjamin Marzinski
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>
2014-05-14GFS2: remove transaction glockBenjamin Marzinski
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>
2014-03-12GFS2: Re-add a call to log_flush_wait when flushing the journalBob Peterson
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>
2014-02-25GFS2: Remove extra "if" in gfs2_log_flush()Steven Whitehouse
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>
2014-02-24GFS2: Move log buffer accounting to transactionSteven Whitehouse
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>
2014-02-24GFS2: Move log buffer lists into transactionSteven Whitehouse
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>
2014-02-03GFS2: Plug on AIL flushSteven Whitehouse
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>
2013-12-13GFS2: Fix use-after-free race when calling gfs2_remove_from_ailBob Peterson
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>
2013-06-19GFS2: aggressively issue revokes in gfs2_log_flushBenjamin Marzinski
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>
2013-04-08GFS2: replace gfs2_ail structure with gfs2_transBenjamin Marzinski
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>
2013-01-29GFS2: Use ->writepages for ordered writesSteven Whitehouse
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>
2012-05-02GFS2: eliminate log elements and simplifyBob Peterson
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>
2012-04-24GFS2: Log code fixesSteven Whitehouse
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>
2012-04-24GFS2: Remove bd_list_trSteven Whitehouse
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>
2012-04-24GFS2: Clean up log write code pathSteven Whitehouse
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>
2012-04-24GFS2: Drop "pull" argument from log_write_header()Steven Whitehouse
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>
2012-03-09GFS2: Clean up log flush header writingSteven Whitehouse
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>
2012-02-28GFS2: Make bd_cmp() staticSteven Whitehouse
Add missing static to bd_cmp() Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28GFS2: Sort the ordered write listBob Peterson
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>
2012-02-28GFS2: Move two functions from log.c to lops.cSteven Whitehouse
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>
2012-01-08Merge branch 'pm-for-linus' of ↵Linus Torvalds
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
2011-11-21freezer: unexport refrigerator() and update try_to_freeze() slightlyTejun Heo
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>
2011-11-08GFS2: Fix up REQ flagsSteven Whitehouse
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>
2011-08-23block: separate priority boosting from REQ_METAChristoph Hellwig
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>
2011-07-14GFS2: Resolve inode eviction and ail list interaction bugSteven Whitehouse
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>
2011-05-21GFS2: Wait properly when flushing the ail listSteven Whitehouse
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>
2011-05-03GFS2: Fix ail list traversalSteven Whitehouse
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>
2011-04-20GFS2: Add an AIL writeback tracepointSteven Whitehouse
Add a tracepoint for monitoring writeback of the AIL. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20GFS2: Make writeback more responsive to system conditionsSteven Whitehouse
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>
2011-04-20GFS2: Use filemap_fdatawrite() to write back the AILSteven Whitehouse
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>
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* '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}
2011-03-14GFS2: Update to AIL list lockingSteven Whitehouse
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>
2011-03-11GFS2: introduce AIL lockDave Chinner
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>
2011-03-10block: kill off REQ_UNPLUGJens Axboe
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>
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-17GFS2: gfs2_logd should be using interruptible waitsSteven Whitehouse
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>
2010-09-10gfs2: replace barriers with explicit flush / FUA usageChristoph Hellwig
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>
2010-08-07block: unify flags for struct bio and struct requestChristoph Hellwig
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>