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2011-01-28xfs: xfs_bmap_add_extent_delay_real should init br_startblockbpm@sgi.com1-8/+25
When filling in the middle of a previous delayed allocation in xfs_bmap_add_extent_delay_real, set br_startblock of the new delay extent to the right to nullstartblock instead of 0 before inserting the extent into the ifork (xfs_iext_insert), rather than setting br_startblock afterward. Adding the extent into the ifork with br_startblock=0 can lead to the extent being copied into the btree by xfs_bmap_extent_to_btree if we happen to convert from extents format to btree format before updating br_startblock with the correct value. The unexpected addition of this delay extent to the btree can cause subsequent XFS_WANT_CORRUPTED_GOTO filesystem shutdown in several xfs_bmap_add_extent_delay_real cases where we are converting a delay extent to real and unexpectedly find an extent already inserted. For example: 911 case BMAP_LEFT_FILLING: 912 /* 913 * Filling in the first part of a previous delayed allocation. 914 * The left neighbor is not contiguous. 915 */ 916 trace_xfs_bmap_pre_update(ip, idx, state, _THIS_IP_); 917 xfs_bmbt_set_startoff(ep, new_endoff); 918 temp = PREV.br_blockcount - new->br_blockcount; 919 xfs_bmbt_set_blockcount(ep, temp); 920 xfs_iext_insert(ip, idx, 1, new, state); 921 ip->i_df.if_lastex = idx; 922 ip->i_d.di_nextents++; 923 if (cur == NULL) 924 rval = XFS_ILOG_CORE | XFS_ILOG_DEXT; 925 else { 926 rval = XFS_ILOG_CORE; 927 if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff, 928 new->br_startblock, new->br_blockcount, 929 &i))) 930 goto done; 931 XFS_WANT_CORRUPTED_GOTO(i == 0, done); With the bogus extent in the btree we shutdown the filesystem at 931. The conversion from extents to btree format happens when the number of extents in the inode increases above ip->i_df.if_ext_max. xfs_bmap_extent_to_btree copies extents from the ifork into the btree, ignoring all delalloc extents which are denoted by br_startblock having some value of nullstartblock. SGI-PV: 1013221 Signed-off-by: Ben Myers <bpm@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: fix dquot shaker deadlockDave Chinner1-25/+21
Commit 368e136 ("xfs: remove duplicate code from dquot reclaim") fails to unlock the dquot freelist when the number of loop restarts is exceeded in xfs_qm_dqreclaim_one(). This causes hangs in memory reclaim. Rework the loop control logic into an unwind stack that all the different cases jump into. This means there is only one set of code that processes the loop exit criteria, and simplifies the unlocking of all the items from different points in the loop. It also fixes a double increment of the restart counter from the qi_dqlist_lock case. Reported-by: Malcolm Scott <lkml@malc.org.uk> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: handle CIl transaction commit failures correctlyDave Chinner3-12/+3
Failure to commit a transaction into the CIL is not handled correctly. This currently can only happen when racing with a shutdown and requires an explicit shutdown check, so it rare and can be avoided. Remove the shutdown check and make the CIL commit a void function to indicate it will always succeed, thereby removing the incorrectly handled failure case. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: limit extsize to size of AGs and/or MAXEXTLENDave Chinner1-2/+18
The extent size hint can be set to larger than an AG. This means that the alignment process can push the range to be allocated outside the bounds of the AG, resulting in assert failures or corrupted bmbt records. Similarly, if the extsize is larger than the maximum extent size supported, the alignment process will produce extents that are too large to fit into the bmbt records, resulting in a different type of assert/corruption failure. Fix this by limiting extsize at the time іt is set firstly to be less than MAXEXTLEN, then to be a maximum of half the size of the AGs in the filesystem for non-realtime inodes. Realtime inodes do not allocate out of AGs, so don't have to be restricted by the size of AGs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: prevent extsize alignment from exceeding maximum extent sizeDave Chinner1-0/+10
When doing delayed allocation, if the allocation size is for a maximally sized extent, extent size alignment can push it over this limit. This results in an assert failure in xfs_bmbt_set_allf() as the extent length is too large to find in the extent record. Fix this by ensuring that we allow for space that extent size alignment requires (up to 2 * (extsize -1) blocks as we have to handle both head and tail alignment) when limiting the maximum size of the extent. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: limit extent length for allocation to AG sizeDave Chinner2-8/+26
Delayed allocation extents can be larger than AGs, so when trying to convert a large range we may scan every AG inside xfs_bmap_alloc_nullfb() trying to find an AG with a size larger than an AG. We should stop when we find the first AG with a maximum possible allocation size. This causes excessive CPU usage when there are lots of AGs. The same problem occurs when doing preallocation of a range larger than an AG. Fix the problem by limiting real allocation lengths to the maximum that an AG can support. This means if we have empty AGs, we'll stop the search at the first of them. If there are no empty AGs, we'll still scan them all, but that is a different problem.... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: speculative delayed allocation uses rounddown_power_of_2 badlyDave Chinner1-1/+6
rounddown_power_of_2() returns an undefined result when passed a value of zero. The specualtive delayed allocation code is doing this when the inode is zero length. Hence occasionally the preallocation is much, much larger than is necessary (e.g. 8GB for a 270 _byte_ file). Ensure we don't even pass a zero value to this function so the result of preallocation is always the desired size. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-28xfs: fix efi item leak on forced shutdownDave Chinner3-13/+38
After test 139, kmemleak shows: unreferenced object 0xffff880078b405d8 (size 400): comm "xfs_io", pid 4904, jiffies 4294909383 (age 1186.728s) hex dump (first 32 bytes): 60 c1 17 79 00 88 ff ff 60 c1 17 79 00 88 ff ff `..y....`..y.... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff81afb04d>] kmemleak_alloc+0x2d/0x60 [<ffffffff8115c6cf>] kmem_cache_alloc+0x13f/0x2b0 [<ffffffff814aaa97>] kmem_zone_alloc+0x77/0xf0 [<ffffffff814aab2e>] kmem_zone_zalloc+0x1e/0x50 [<ffffffff8147cd6b>] xfs_efi_init+0x4b/0xb0 [<ffffffff814a4ee8>] xfs_trans_get_efi+0x58/0x90 [<ffffffff81455fab>] xfs_bmap_finish+0x8b/0x1d0 [<ffffffff814851b4>] xfs_itruncate_finish+0x2c4/0x5d0 [<ffffffff814a970f>] xfs_setattr+0x8df/0xa70 [<ffffffff814b5c7b>] xfs_vn_setattr+0x1b/0x20 [<ffffffff8117dc00>] notify_change+0x170/0x2e0 [<ffffffff81163bf6>] do_truncate+0x66/0xa0 [<ffffffff81163d0b>] sys_ftruncate+0xdb/0xe0 [<ffffffff8103a002>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff The cause of the leak is that the "remove" parameter of IOP_UNPIN() is never set when a CIL push is aborted. This means that the EFI item is never freed if it was in the push being cancelled. The problem is specific to delayed logging, but has uncovered a couple of problems with the handling of IOP_UNPIN(remove). Firstly, we cannot safely call xfs_trans_del_item() from IOP_UNPIN() in the CIL commit failure path or the iclog write failure path because for delayed loging we have no transaction context. Hence we must only call xfs_trans_del_item() if the log item being unpinned has an active log item descriptor. Secondly, xfs_trans_uncommit() does not handle log item descriptor freeing during the traversal of log items on a transaction. It can reference a freed log item descriptor when unpinning an EFI item. Hence it needs to use a safe list traversal method to allow items to be removed from the transaction during IOP_UNPIN(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-27xfs: fix log ticket leak on forced shutdown.Dave Chinner1-2/+5
The kmemleak detector shows this after test 139: unreferenced object 0xffff880079b88bb0 (size 264): comm "xfs_io", pid 4904, jiffies 4294909382 (age 276.824s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 48 7b c9 82 ff ff ff ff ........H{...... backtrace: [<ffffffff81afb04d>] kmemleak_alloc+0x2d/0x60 [<ffffffff8115c6cf>] kmem_cache_alloc+0x13f/0x2b0 [<ffffffff814aaa97>] kmem_zone_alloc+0x77/0xf0 [<ffffffff814aab2e>] kmem_zone_zalloc+0x1e/0x50 [<ffffffff8148f394>] xlog_ticket_alloc+0x34/0x170 [<ffffffff81494444>] xlog_cil_push+0xa4/0x3f0 [<ffffffff81494eca>] xlog_cil_force_lsn+0x15a/0x160 [<ffffffff814933a5>] _xfs_log_force_lsn+0x75/0x2d0 [<ffffffff814a264d>] _xfs_trans_commit+0x2bd/0x2f0 [<ffffffff8148bfdd>] xfs_iomap_write_allocate+0x1ad/0x350 [<ffffffff814ac17f>] xfs_map_blocks+0x21f/0x370 [<ffffffff814ad1b7>] xfs_vm_writepage+0x1c7/0x550 [<ffffffff8112200a>] __writepage+0x1a/0x50 [<ffffffff81122df2>] write_cache_pages+0x1c2/0x4c0 [<ffffffff81123117>] generic_writepages+0x27/0x30 [<ffffffff814aba5d>] xfs_vm_writepages+0x5d/0x80 By inspection, the leak occurs when xlog_write() returns and error and we jump to the abort path without dropping the reference on the active ticket. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-17xfs: Do not name variables "panic"Geert Uytterhoeven1-3/+3
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 Hellwig2-60/+56
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 Hellwig1-0/+3
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>
2011-01-15Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds23-482/+729
* '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 Torvalds1-2/+3
* '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 Torvalds1-2/+5
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 Torvalds1-1/+1
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.
2011-01-13XFS: handle hole punching via fallocate properlyJosef Bacik1-2/+5
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 Chinner7-114/+96
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>
2011-01-12xfs: Add log level to assertion printkAnton Blanchard1-1/+2
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>
2011-01-12xfs: fix an assignment within an ASSERT()Jesper Juhl1-1/+1
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>
2011-01-12xfs: fix error handling for synchronous writesChristoph Hellwig3-114/+51
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>
2011-01-12xfs: add FITRIM supportChristoph Hellwig7-12/+259
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>
2011-01-12xfs: ensure log covering transactions are synchronousDave Chinner4-12/+13
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>
2011-01-11Merge branch 'master' into for-linus-mergedAlex Elder38-1920/+1997
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 Chinner1-10/+28
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 Chinner1-67/+56
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 Chinner1-77/+69
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 Chinner1-63/+116
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 Chinner1-51/+80
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 Chinner1-22/+21
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 Chinner1-26/+28
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 Chinner1-26/+23
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>
2011-01-08Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-1/+1
* '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 Piggin1-3/+6
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 Piggin2-3/+7
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin1-1/+12
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 Kosina16-97/+222
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 Chinner2-77/+49
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 Chinner3-60/+97
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 Heo1-1/+1
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
2010-12-10xfs: log timestamp changes to the source inode in renameChristoph Hellwig1-0/+1
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>
2010-12-03xfs: convert log grant heads to atomic variablesDave Chinner2-10/+10
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 Chinner4-46/+63
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 Chinner3-34/+36
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 Chinner1-57/+54
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 Chinner6-106/+52
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 Chinner4-91/+119
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 Chinner1-47/+48
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 Chinner1-29/+22
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 Chinner3-97/+53
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>