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2011-01-17xfs: Do not name variables "panic"Geert Uytterhoeven
On platforms that call panic() inside their BUG() macro (m68k/sun3, and all platforms that don't set HAVE_ARCH_BUG), compilation fails with: | fs/xfs/support/debug.c: In function ‘xfs_cmn_err’: | fs/xfs/support/debug.c:92: error: called object ‘panic’ is not a function as the local variable "panic" conflicts with the "panic()" function. Rename the local variable to resolve this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-17fallocate should be a file operationChristoph Hellwig
Currently all filesystems except XFS implement fallocate asynchronously, while XFS forced a commit. Both of these are suboptimal - in case of O_SYNC I/O we really want our allocation on disk, especially for the !KEEP_SIZE case where we actually grow the file with user-visible zeroes. On the other hand always commiting the transaction is a bad idea for fast-path uses of fallocate like for example in recent Samba versions. Given that block allocation is a data plane operation anyway change it from an inode operation to a file operation so that we have the file structure available that lets us check for O_SYNC. This also includes moving the code around for a few of the filesystems, and remove the already unnedded S_ISDIR checks given that we only wire up fallocate for regular files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-17make the feature checks in ->fallocate future proofChristoph Hellwig
Instead of various home grown checks that might need updates for new flags just check for any bit outside the mask of the features supported by the filesystem. This makes the check future proof for any newly added flag. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-14Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds
* 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: prevent NMI timeouts in cmn_err xfs: Add log level to assertion printk xfs: fix an assignment within an ASSERT() xfs: fix error handling for synchronous writes xfs: add FITRIM support xfs: ensure log covering transactions are synchronous xfs: serialise unaligned direct IOs xfs: factor common write setup code xfs: split buffered IO write path from xfs_file_aio_write xfs: split direct IO write path from xfs_file_aio_write xfs: introduce xfs_rw_lock() helpers for locking the inode xfs: factor post-write newsize updates xfs: factor common post-write isize handling code xfs: ensure sync write errors are returned
2011-01-13Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits) block: ensure that completion error gets properly traced blktrace: add missing probe argument to block_bio_complete block cfq: don't use atomic_t for cfq_group block cfq: don't use atomic_t for cfq_queue block: trace event block fix unassigned field block: add internal hd part table references block: fix accounting bug on cross partition merges kref: add kref_test_and_get bio-integrity: mark kintegrityd_wq highpri and CPU intensive block: make kblockd_workqueue smarter Revert "sd: implement sd_check_events()" block: Clean up exit_io_context() source code. Fix compile warnings due to missing removal of a 'ret' variable fs/block: type signature of major_to_index(int) to major_to_index(unsigned) block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p) cfq-iosched: don't check cfqg in choose_service_tree() fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors cdrom: export cdrom_check_events() sd: implement sd_check_events() sr: implement sr_check_events() ...
2011-01-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits) fs: add documentation on fallocate hole punching Gfs2: fail if we try to use hole punch Btrfs: fail if we try to use hole punch Ext4: fail if we try to use hole punch Ocfs2: handle hole punching via fallocate properly XFS: handle hole punching via fallocate properly fs: add hole punching to fallocate vfs: pass struct file to do_truncate on O_TRUNC opens (try #2) fix signedness mess in rw_verify_area() on 64bit architectures fs: fix kernel-doc for dcache::prepend_path fs: fix kernel-doc for dcache::d_validate sanitize ecryptfs ->mount() switch afs move internal-only parts of ncpfs headers to fs/ncpfs switch ncpfs switch 9p pass default dentry_operations to mount_pseudo() switch hostfs switch affs switch configfs ...
2011-01-13Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-12XFS: handle hole punching via fallocate properlyJosef Bacik
This patch simply allows XFS to handle the hole punching flag in fallocate properly. I've tested this with a little program that does a bunch of random hole punching with FL_KEEP_SIZE and without it to make sure it does the right thing. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12xfs: prevent NMI timeouts in cmn_errDave Chinner
We currently have a global error message buffer in cmn_err that is protected by a spin lock that disables interrupts. Recently there have been reports of NMI timeouts occurring when the console is being flooded by SCSI error reports due to cmn_err() getting stuck trying to print to the console while holding this lock (i.e. with interrupts disabled). The NMI watchdog is seeing this CPU as non-responding and so is triggering a panic. While the trigger for the reported case is SCSI errors, pretty much anything that spams the kernel log could cause this to occur. Realistically the only reason that we have the intemediate message buffer is to prepend the correct kernel log level prefix to the log message. The only reason we have the lock is to protect the global message buffer and the only reason the message buffer is global is to keep it off the stack. Hence if we can avoid needing a global message buffer we avoid needing the lock, and we can do this with a small amount of cleanup and some preprocessor tricks: 1. clean up xfs_cmn_err() panic mask functionality to avoid needing debug code in xfs_cmn_err() 2. remove the couple of "!" message prefixes that still exist that the existing cmn_err() code steps over. 3. redefine CE_* levels directly to KERN_* 4. redefine cmn_err() and friends to use printk() directly via variable argument length macros. By doing this, we can completely remove the cmn_err() code and the lock that is causing the problems, and rely solely on printk() serialisation to ensure that we don't get garbled messages. A series of followup patches is really needed to clean up all the cmn_err() calls and related messages properly, but that results in a series that is not easily back portable to enterprise kernels. Hence this initial fix is only to address the direct problem in the lowest impact way possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: Add log level to assertion printkAnton Blanchard
I received a ppc64 bug report involving xfs but the assertion was filtered out by the console log level. Use KERN_CRIT to ensure it makes it out. Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: fix an assignment within an ASSERT()Jesper Juhl
In fs/xfs/xfs_trans.c::xfs_trans_unreserve_and_mod_sb() at the out: label we have this: ASSERT(error = 0); I believe a comparison was intended, not an assignment. If I'm right, the patch below fixes that up. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: fix error handling for synchronous writesChristoph Hellwig
If we get an IO error on a synchronous superblock write, we attach an error release function to it so that when the last reference goes away the release function is called and the buffer is invalidated and unlocked. The buffer is left locked until the release function is called so that other concurrent users of the buffer will be locked out until the buffer error is fully processed. Unfortunately, for the superblock buffer the filesyetm itself holds a reference to the buffer which prevents the reference count from dropping to zero and the release function being called. As a result, once an IO error occurs on a sync write, the buffer will never be unlocked and all future attempts to lock the buffer will hang. To make matters worse, this problems is not unique to such buffers; if there is a concurrent _xfs_buf_find() running, the lookup will grab a reference to the buffer and then wait on the buffer lock, preventing the reference count from ever falling to zero and hence unlocking the buffer. As such, the whole b_relse function implementation is broken because it cannot rely on the buffer reference count falling to zero to unlock the errored buffer. The synchronous write error path is the only path that uses this callback - it is used to ensure that the synchronous waiter gets the buffer error before the error state is cleared from the buffer by the release function. Given that the only sychronous buffer writes now go through xfs_bwrite and the error path in question can only occur for a write of a dirty, logged buffer, we can move most of the b_relse processing to happen inline in xfs_buf_iodone_callbacks, just like a normal I/O completion. In addition to that we make sure the error is not cleared in xfs_buf_iodone_callbacks, so that xfs_bwrite can reliably check it. Given that xfs_bwrite keeps the buffer locked until it has waited for it and checked the error this allows to reliably propagate the error to the caller, and make sure that the buffer is reliably unlocked. Given that xfs_buf_iodone_callbacks was the only instance of the b_relse callback we can remove it entirely. Based on earlier patches by Dave Chinner and Ajeet Yadav. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Ajeet Yadav <ajeet.yadav.77@gmail.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: add FITRIM supportChristoph Hellwig
Allow manual discards from userspace using the FITRIM ioctl. This is not intended to be run during normal workloads, as the freepsace btree walks can cause large performance degradation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: ensure log covering transactions are synchronousDave Chinner
To ensure the log is covered and the filesystem idles correctly, we need to ensure that dummy transactions hit the disk and do not stay pinned in memory. If the superblock is pinned in memory, it can't be flushed so the log covering cannot make progress. The result is dependent on timing - more oftent han not we continue to issues a log covering transaction every 36s rather than idling after ~90s. Fix this by making the log covering transaction synchronous. To avoid additional log force from xfssyncd, make the log covering transaction take the place of the existing log force in the xfssyncd background sync process. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-10Merge branch 'master' into for-linus-mergedAlex Elder
This merge pulls the XFS master branch into the latest Linus master. This results in a merge conflict whose best fix is not obvious. I manually fixed the conflict, in "fs/xfs/xfs_iget.c". Dave Chinner had done work that resulted in RCU freeing of inodes separate from what Nick Piggin had done, and their results differed slightly in xfs_inode_free(). The fix updates Nick's call_rcu() with the use of VFS_I(), while incorporating needed updates to some XFS inode fields implemented in Dave's series. Dave's RCU callback function has also been removed. Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-11xfs: serialise unaligned direct IOsDave Chinner
When two concurrent unaligned, non-overlapping direct IOs are issued to the same block, the direct Io layer will race to zero the block. The result is that one of the concurrent IOs will overwrite data written by the other IO with zeros. This is demonstrated by the xfsqa test 240. To avoid this problem, serialise all unaligned direct IOs to an inode with a big hammer. We need a big hammer approach as we need to serialise AIO as well, so we can't just block writes on locks. Hence, the big hammer is calling xfs_ioend_wait() while holding out other unaligned direct IOs from starting. We don't bother trying to serialised aligned vs unaligned IOs as they are overlapping IO and the result of concurrent overlapping IOs is undefined - the result of either IO is a valid result so we let them race. Hence we only penalise unaligned IO, which already has a major overhead compared to aligned IO so this isn't a major problem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: factor common write setup codeDave Chinner
The buffered IO and direct IO write paths share a common set of checks and limiting code prior to issuing the write. Factor that into a common helper function. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: split buffered IO write path from xfs_file_aio_writeDave Chinner
Complete the split of the different write IO paths by splitting the buffered IO write path out of xfs_file_aio_write(). This makes the different mechanisms of the write patchs easier to follow. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: split direct IO write path from xfs_file_aio_writeDave Chinner
The current xfs_file_aio_write code is a mess of locking shenanigans to handle the different locking requirements of buffered and direct IO. Start to clean this up by disentangling the direct IO path from the mess. This also removes the failed direct IO fallback path to buffered IO. XFS handles all direct IO cases without needing to fall back to buffered IO, so we can safely remove this unused path. This greatly simplifies the logic and locking needed in the write path. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-12xfs: introduce xfs_rw_lock() helpers for locking the inodeDave Chinner
We need to obtain the i_mutex, i_iolock and i_ilock during the read and write paths. Add a set of wrapper functions to neatly encapsulate the lock ordering and shared/exclusive semantics to make the locking easier to follow and get right. Note that this changes some of the exclusive locking serialisation in that serialisation will occur against the i_mutex instead of the XFS_IOLOCK_EXCL. This does not change any behaviour, and it is arguably more efficient to use the mutex for such serialisation than the rw_sem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: factor post-write newsize updatesDave Chinner
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: factor common post-write isize handling codeDave Chinner
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-11xfs: ensure sync write errors are returnedDave Chinner
xfs_file_aio_write() only returns the error from synchronous flushing of the data and inode if error == 0. At the point where error is being checked, it is guaranteed to be > 0. Therefore any errors returned by the data or fsync flush will never be returned. Fix the checks so we overwrite the current error once and only if an error really occurred. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-01-07Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits) usb: don't use flush_scheduled_work() speedtch: don't abuse struct delayed_work media/video: don't use flush_scheduled_work() media/video: explicitly flush request_module work ioc4: use static work_struct for ioc4_load_modules() init: don't call flush_scheduled_work() from do_initcalls() s390: don't use flush_scheduled_work() rtc: don't use flush_scheduled_work() mmc: update workqueue usages mfd: update workqueue usages dvb: don't use flush_scheduled_work() leds-wm8350: don't use flush_scheduled_work() mISDN: don't use flush_scheduled_work() macintosh/ams: don't use flush_scheduled_work() vmwgfx: don't use flush_scheduled_work() tpm: don't use flush_scheduled_work() sonypi: don't use flush_scheduled_work() hvsi: don't use flush_scheduled_work() xen: don't use flush_scheduled_work() gdrom: don't use flush_scheduled_work() ... Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c as per Tejun.
2011-01-07xfs: provide simple rcu-walk ACL implementationNick Piggin
This simple implementation just checks for no ACLs on the inode, and if so, then the rcu-walk may proceed, otherwise fail it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: provide rcu-walk aware permission i_opsNick Piggin
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-12-22Merge branch 'master' into for-nextJiri Kosina
Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
2010-12-21xfs: convert grant head manipulations to lockless algorithmDave Chinner
The only thing that the grant lock remains to protect is the grant head manipulations when adding or removing space from the log. These calculations are already based on atomic variables, so we can already update them safely without locks. However, the grant head manpulations require atomic multi-step calculations to be executed, which the algorithms currently don't allow. To make these multi-step calculations atomic, convert the algorithms to compare-and-exchange loops on the atomic variables. That is, we sample the old value, perform the calculation and use atomic64_cmpxchg() to attempt to update the head with the new value. If the head has not changed since we sampled it, it will succeed and we are done. Otherwise, we rerun the calculation again from a new sample of the head. This allows us to remove the grant lock from around all the grant head space manipulations, and that effectively removes the grant lock from the log completely. Hence we can remove the grant lock completely from the log at this point. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: introduce new locks for the log grant ticket wait queuesDave Chinner
The log grant ticket wait queues are currently protected by the log grant lock. However, the queues are functionally independent from each other, and operations on them only require serialisation against other queue operations now that all of the other log variables they use are atomic values. Hence, we can make them independent of the grant lock by introducing new locks just to protect the lists operations. because the lists are independent, we can use a lock per list and ensure that reserve and write head queuing do not contend. To ensure forced shutdowns work correctly in conjunction with the new fast paths, ensure that we check whether the log has been shut down in the grant functions once we hold the relevant spin locks but before we go to sleep. This is needed to co-ordinate correctly with the wakeups that are issued on the ticket queues so we don't leave any processes sleeping on the queues during a shutdown. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-15workqueue: convert cancel_rearming_delayed_work[queue]() users to ↵Tejun Heo
cancel_delayed_work_sync() cancel_rearming_delayed_work[queue]() has been superceded by cancel_delayed_work_sync() quite some time ago. Convert all the in-kernel users. The conversions are completely equivalent and trivial. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: netdev@vger.kernel.org Cc: Anton Vorontsov <cbou@mail.ru> Cc: David Woodhouse <dwmw2@infradead.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: xfs-masters@oss.sgi.com Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: netfilter-devel@vger.kernel.org Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: linux-nfs@vger.kernel.org
2010-12-09xfs: log timestamp changes to the source inode in renameChristoph Hellwig
Now that we don't mark VFS inodes dirty anymore for internal timestamp changes, but rely on the transaction subsystem to push them out, we need to explicitly log the source inode in rename after updating it's timestamps to make sure the changes actually get forced out by sync/fsync or an AIL push. We already account for the fourth inode in the log reservation, as a rename of directories needs to update the nlink field, so just adding the xfs_trans_log_inode call is enough. This fixes the xfsqa 065 regression introduced by: "xfs: don't use vfs writeback for pure metadata modifications" Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2010-12-04xfs: convert log grant heads to atomic variablesDave Chinner
Convert the log grant heads to atomic64_t types in preparation for converting the accounting algorithms to atomic operations. his patch just converts the variables; the algorithmic changes are in a separate patch for clarity. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: convert l_tail_lsn to an atomic variable.Dave Chinner
log->l_tail_lsn is currently protected by the log grant lock. The lock is only needed for serialising readers against writers, so we don't really need the lock if we make the l_tail_lsn variable an atomic. Converting the l_tail_lsn variable to an atomic64_t means we can start to peel back the grant lock from various operations. Also, provide functions to safely crack an atomic LSN variable into it's component pieces and to recombined the components into an atomic variable. Use them where appropriate. This also removes the need for explicitly holding a spinlock to read the l_tail_lsn on 32 bit platforms. Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-12-03xfs: convert l_last_sync_lsn to an atomic variableDave Chinner
log->l_last_sync_lsn is updated in only one critical spot - log buffer Io completion - and is protected by the grant lock here. This requires the grant lock to be taken for every log buffer IO completion. Converting the l_last_sync_lsn variable to an atomic64_t means that we do not need to take the grant lock in log buffer IO completion to update it. This also removes the need for explicitly holding a spinlock to read the l_last_sync_lsn on 32 bit platforms. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: make AIL tail pushing independent of the grant lockDave Chinner
The xlog_grant_push_ail() currently takes the grant lock internally to sample the tail lsn, last sync lsn and the reserve grant head. Most of the callers already hold the grant lock but have to drop it before calling xlog_grant_push_ail(). This is a left over from when the AIL tail pushing was done in line and hence xlog_grant_push_ail had to drop the grant lock. AIL push is now done in another thread and hence we can safely hold the grant lock over the entire xlog_grant_push_ail call. Push the grant lock outside of xlog_grant_push_ail() to simplify the locking and synchronisation needed for tail pushing. This will reduce traffic on the grant lock by itself, but this is only one step in preparing for the complete removal of the grant lock. While there, clean up the formatting of xlog_grant_push_ail() to match the rest of the XFS code. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: use wait queues directly for the log wait queuesDave Chinner
The log grant queues are one of the few places left using sv_t constructs for waiting. Given we are touching this code, we should convert them to plain wait queues. While there, convert all the other sv_t users in the log code as well. Seeing as this removes the last users of the sv_t type, remove the header file defining the wrapper and the fragments that still reference it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: combine grant heads into a single 64 bit integerDave Chinner
Prepare for switching the grant heads to atomic variables by combining the two 32 bit values that make up the grant head into a single 64 bit variable. Provide wrapper functions to combine and split the grant heads appropriately for calculations and use them as necessary. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: rework log grant space calculationsDave Chinner
The log grant space calculations are repeated for both write and reserve grant heads. To make it simpler to convert the calculations toa different algorithm, factor them so both the gratn heads use the same calculation functions. Once this is done we can drop the wrappers that are used in only a couple of place to update both grant heads at once as they don't provide any particular value. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: fact out common grant head/log tail verification codeDave Chinner
Factor repeated debug code out of grant head manipulation functions into a separate function. This removes ifdef DEBUG spagetti from the code and makes the code easier to follow. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21xfs: convert log grant ticket queues to list headsDave Chinner
The grant write and reserve queues use a roll-your-own double linked list, so convert it to a standard list_head structure and convert all the list traversals to use list_for_each_entry(). We can also get rid of the XLOG_TIC_IN_Q flag as we can use the list_empty() check to tell if the ticket is in a list or not. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: use AIL bulk delete function to implement single deleteDave Chinner
We now have two copies of AIL delete operations that are mostly duplicate functionality. The single log item deletes can be implemented via the bulk updates by turning xfs_trans_ail_delete() into a simple wrapper. This removes all the duplicate delete functionality and associated helpers. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: use AIL bulk update function to implement single updatesDave Chinner
We now have two copies of AIL insert operations that are mostly duplicate functionality. The single log item updates can be implemented via the bulk updates by turning xfs_trans_ail_update() into a simple wrapper. This removes all the duplicate insert functionality and associated helpers. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: remove all the inodes on a buffer from the AIL in bulkDave Chinner
When inode buffer IO completes, usually all of the inodes are removed from the AIL. This involves processing them one at a time and taking the AIL lock once for every inode. When all CPUs are processing inode IO completions, this causes excessive amount sof contention on the AIL lock. Instead, change the way we process inode IO completion in the buffer IO done callback. Allow the inode IO done callback to walk the list of IO done callbacks and pull all the inodes off the buffer in one go and then process them as a batch. Once all the inodes for removal are collected, take the AIL lock once and do a bulk removal operation to minimise traffic on the AIL lock. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-03xfs: consume iodone callback items on buffers as they are processedDave Chinner
To allow buffer iodone callbacks to consume multiple items off the callback list, first we need to convert the xfs_buf_do_callbacks() to consume items and always pull the next item from the head of the list. The means the item list walk is never dependent on knowing the next item on the list and hence allows callbacks to remove items from the list as well. This allows callbacks to do bulk operations by scanning the list for identical callbacks, consuming them all and then processing them in bulk, negating the need for multiple callbacks of that type. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-17xfs: reduce the number of AIL push wakeupsDave Chinner
The xfaild often tries to rest to wait for congestion to pass of for IO to complete, but is regularly woken in tail-pushing situations. In severe cases, the xfsaild is getting woken tens of thousands of times a second. Reduce the number needless wakeups by only waking the xfsaild if the new target is larger than the old one. Further make short sleeps uninterruptible as they occur when the xfsaild has decided it needs to back off to allow some IO to complete and being woken early is counter-productive. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: bulk AIL insertion during transaction commitDave Chinner
When inserting items into the AIL from the transaction committed callbacks, we take the AIL lock for every single item that is to be inserted. For a CIL checkpoint commit, this can be tens of thousands of individual inserts, yet almost all of the items will be inserted at the same point in the AIL because they have the same index. To reduce the overhead and contention on the AIL lock for such operations, introduce a "bulk insert" operation which allows a list of log items with the same LSN to be inserted in a single operation via a list splice. To do this, we need to pre-sort the log items being committed into a temporary list for insertion. The complexity is that not every log item will end up with the same LSN, and not every item is actually inserted into the AIL. Items that don't match the commit LSN will be inserted and unpinned as per the current one-at-a-time method (relatively rare), while items that are not to be inserted will be unpinned and freed immediately. Items that are to be inserted at the given commit lsn are placed in a temporary array and inserted into the AIL in bulk each time the array fills up. As a result of this, we trade off AIL hold time for a significant reduction in traffic. lock_stat output shows that the worst case hold time is unchanged, but contention from AIL inserts drops by an order of magnitude and the number of lock traversal decreases significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-03xfs: clean up xfs_ail_delete()Dave Chinner
xfs_ail_delete() has a needlessly complex interface. It returns the log item that was passed in for deletion (which the callers then assert is identical to the one passed in), and callers of xfs_ail_delete() still need to invalidate current traversal cursors. Make xfs_ail_delete() return void, move the cursor invalidation inside it, and clean up the callers just to use the log item pointer they passed in. While cleaning up, remove the messy and unnecessary "/* ARGUSED */" comments around all these functions. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: Pull EFI/EFD handling out from under the AIL lockDave Chinner
EFI/EFD interactions are protected from races by the AIL lock. They are the only type of log items that require the the AIL lock to serialise internal state, so they need to be separated from the AIL lock before we can do bulk insert operations on the AIL. To acheive this, convert the counter of the number of extents in the EFI to an atomic so it can be safely manipulated by EFD processing without locks. Also, convert the EFI state flag manipulations to use atomic bit operations so no locks are needed to record state changes. Finally, use the state bits to determine when it is safe to free the EFI and clean up the code to do this neatly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-20xfs: fix EFI transaction cancellation.Dave Chinner
XFS_EFI_CANCELED has not been set in the code base since xfs_efi_cancel() was removed back in 2006 by commit 065d312e15902976d256ddaf396a7950ec0350a8 ("[XFS] Remove unused iop_abort log item operation), and even then xfs_efi_cancel() was never called. I haven't tracked it back further than that (beyond git history), but it indicates that the handling of EFIs in cancelled transactions has been broken for a long time. Basically, when we get an IOP_UNPIN(lip, 1); call from xfs_trans_uncommit() (i.e. remove == 1), if we don't free the log item descriptor we leak it. Fix the behviour to be correct and kill the XFS_EFI_CANCELED flag. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>