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* xfs: log timestamp changes to the source inode in renameChristoph Hellwig2010-12-091-0/+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>
* xfs: only run xfs_error_test if error injection is activeDave Chinner2010-12-012-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent tests writing lots of small files showed the flusher thread being CPU bound and taking a long time to do allocations on a debug kernel. perf showed this as the prime reason: samples pcnt function DSO _______ _____ ___________________________ _________________ 224648.00 36.8% xfs_error_test [kernel.kallsyms] 86045.00 14.1% xfs_btree_check_sblock [kernel.kallsyms] 39778.00 6.5% prandom32 [kernel.kallsyms] 37436.00 6.1% xfs_btree_increment [kernel.kallsyms] 29278.00 4.8% xfs_btree_get_rec [kernel.kallsyms] 27717.00 4.5% random32 [kernel.kallsyms] Walking btree blocks during allocation checking them requires each block (a cache hit, so no I/O) call xfs_error_test(), which then does a random32() call as the first operation. IOWs, ~50% of the CPU is being consumed just testing whether we need to inject an error, even though error injection is not active. Kill this overhead when error injection is not active by adding a global counter of active error traps and only calling into xfs_error_test when fault injection is active. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: avoid moving stale inodes in the AILDave Chinner2010-12-011-6/+25
| | | | | | | | | | | | | | | | | | | | | | | | | When an inode has been marked stale because the cluster is being freed, we don't want to (re-)insert this inode into the AIL. There is a race condition where the cluster buffer may be unpinned before the inode is inserted into the AIL during transaction committed processing. If the buffer is unpinned before the inode item has been committed and inserted, then it is possible for the buffer to be released and hence processthe stale inode callbacks before the inode is inserted into the AIL. In this case, we then insert a clean, stale inode into the AIL which will never get removed by an IO completion. It will, however, get reclaimed and that triggers an assert in xfs_inode_free() complaining about freeing an inode still in the AIL. This race can be avoided by not moving stale inodes forward in the AIL during transaction commit completion processing. This closes the race condition by ensuring we never insert clean stale inodes into the AIL. It is safe to do this because a dirty stale inode, by definition, must already be in the AIL. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: delayed alloc blocks beyond EOF are valid after writebackDave Chinner2010-12-012-2/+20
| | | | | | | | | | | | | | | | | | | | | There is an assumption in the parts of XFS that flushing a dirty file will make all the delayed allocation blocks disappear from an inode. That is, that after calling xfs_flush_pages() then ip->i_delayed_blks will be zero. This is an invalid assumption as we may have specualtive preallocation beyond EOF and they are recorded in ip->i_delayed_blks. A flush of the dirty pages of an inode will not change the state of these blocks beyond EOF, so a non-zero deeelalloc block count after a flush is valid. The bmap code has an invalid ASSERT() that needs to be removed, and the swapext code has a bug in that while it swaps the data forks around, it fails to swap the i_delayed_blks counter associated with the fork and hence can get the block accounting wrong. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: push stale, pinned buffers on trylock failuresDave Chinner2010-12-011-19/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | As reported by Nick Piggin, XFS is suffering from long pauses under highly concurrent workloads when hosted on ramdisks. The problem is that an inode buffer is stuck in the pinned state in memory and as a result either the inode buffer or one of the inodes within the buffer is stopping the tail of the log from being moved forward. The system remains in this state until a periodic log force issued by xfssyncd causes the buffer to be unpinned. The main problem is that these are stale buffers, and are hence held locked until the transaction/checkpoint that marked them state has been committed to disk. When the filesystem gets into this state, only the xfssyncd can cause the async transactions to be committed to disk and hence unpin the inode buffer. This problem was encountered when scaling the busy extent list, but only the blocking lock interface was fixed to solve the problem. Extend the same fix to the buffer trylock operations - if we fail to lock a pinned, stale buffer, then force the log immediately so that when the next attempt to lock it comes around, it will have been unpinned. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: fix failed write truncation handling.Dave Chinner2010-12-013-54/+121
| | | | | | | | | | | | | | | | | | | | | | | | | Since the move to the new truncate sequence we call xfs_setattr to truncate down excessively instanciated blocks. As shown by the testcase in kernel.org BZ #22452 that doesn't work too well. Due to the confusion of the internal inode size, and the VFS inode i_size it zeroes data that it shouldn't. But full blown truncate seems like overkill here. We only instanciate delayed allocations in the write path, and given that we never released the iolock we can't have converted them to real allocations yet either. The only nasty case is pre-existing preallocation which we need to skip. We already do this for page discard during writeback, so make the delayed allocation block punching a generic function and call it from the failed write path as well as xfs_aops_discard_page. The callers are responsible for ensuring that partial blocks are not truncated away, and that they hold the ilock. Based on a fix originally from Christoph Hellwig. This version used filesystem blocks as the range unit. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
* xfs: remove incorrect assert in xfs_vm_writepageChristoph Hellwig2010-11-101-3/+4
| | | | | | | | | | | | | | | In commit 20cb52ebd1b5ca6fa8a5d9b6b1392292f5ca8a45, titled "xfs: simplify xfs_vm_writepage" I added an assert that any !mapped and uptodate buffers are not dirty. That asserts turns out to trigger a lot when running fsx on filesystems with small block sizes. The reason for that is that the assert is simply incorrect. !mapped and uptodate just mean this buffer covers a hole, and whenever we do a set_page_dirty we mark all blocks in the page dirty, no matter if they have data or not. So remove the assert, and update the comment above the condition to match reality. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: use hlist_add_fakeChristoph Hellwig2010-11-101-1/+2
| | | | | | | | | | | | | | | XFS does not need it's inodes to actuall be hashed in the VFS inode cache, but we require the inode to be marked hashed for the writeback code to work. Insted of using insert_inode_hash, which requires a second inode_lock roundtrip after the partial merge of the inode scalability patches in 2.6.37-rc simply use the new hlist_add_fake helper to mark it hashed without requiring a lock or touching a global cache line. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: fix a few compiler warnings with CONFIG_XFS_QUOTA=nChristoph Hellwig2010-11-101-4/+16
| | | | | | | | | | Andi Kleen reported that gcc-4.5 gives lots of warnings for him inside the XFS code. It turned out most of them are due to the quota stubs beeing macros, and gcc now complaining about macros evaluating to 0 that are not assigned to variables. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: tell lockdep about parent iolock usage in filestreamsChristoph Hellwig2010-11-101-1/+7
| | | | | | | | | | | The filestreams code may take the iolock on the parent inode while holding it on a child. This is the only place in XFS where we take both the child and parent iolock, so just telling lockdep about it is enough. The lock flag required for that was already added as part of the ilock lockdep annotations and unused so far. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: move delayed write buffer traceDave Chinner2010-11-101-1/+1
| | | | | | | | | | | | | | The delayed write buffer split trace currently issues a trace for every buffer it scans. These buffers are not necessarily queued for delayed write. Indeed, when buffers are pinned, there can be thousands of traces of buffers that aren't actually queued for delayed write and the ones that are are lost in the noise. Move the trace point to record only buffers that are split out for IO to be issued on. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: fix per-ag reference counting in inode reclaim tree walkingDave Chinner2010-11-102-0/+2
| | | | | | | | | | The walk fails to decrement the per-ag reference count when the non-blocking walk fails to obtain the per-ag reclaim lock, leading to an assert failure on debug kernels when unmounting a filesystem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: xfs_ioctl: fix information leak to userlandKulikov Vasiliy2010-11-101-1/+1
| | | | | | | | | al_hreq is copied from userland. If al_hreq.buflen is not properly aligned then xfs_attr_list will ignore the last bytes of kbuf. These bytes are unitialized. It leads to leaking of contents of kernel stack memory. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* xfs: remove experimental tag from the delaylog optionChristoph Hellwig2010-11-101-3/+0
| | | | | | | | | We promised to do this for 2.6.37, and the code looks stable enough to keep that promise. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
* new helper: mount_bdev()Al Viro2010-10-291-7/+5
| | | | | | ... and switch of the obvious get_sb_bdev() users to ->mount() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for_linus' of ↵Linus Torvalds2010-10-271-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (24 commits) quota: Fix possible oops in __dquot_initialize() ext3: Update kernel-doc comments jbd/2: fixed typos ext2: fixed typo. ext3: Fix debug messages in ext3_group_extend() jbd: Convert atomic_inc() to get_bh() ext3: Remove misplaced BUFFER_TRACE() in ext3_truncate() jbd: Fix debug message in do_get_write_access() jbd: Check return value of __getblk() ext3: Use DIV_ROUND_UP() on group desc block counting ext3: Return proper error code on ext3_fill_super() ext3: Remove unnecessary casts on bh->b_data ext3: Cleanup ext3_setup_super() quota: Fix issuing of warnings from dquot_transfer quota: fix dquot_disable vs dquot_transfer race v2 jbd: Convert bitops to buffer fns ext3/jbd: Avoid WARN() messages when failing to write the superblock jbd: Use offset_in_page() instead of manual calculation jbd: Remove unnecessary goto statement jbd: Use printk_ratelimited() in journal_alloc_journal_head() ...
| * quota: Make QUOTACTL config be selected by its usersJan Kara2010-10-051-0/+1
| | | | | | | | | | | | | | | | | | Remove "depends on" line from QUOTACTL config option and rather select the option explicitely from config options which need it. It makes more sense this way and also fixes Kconfig warning due to GFS2 selecting QUOTACTL but QUOTACTL not depending on it. Signed-off-by: Jan Kara <jack@suse.cz>
* | Merge branch 'for-linus' of ↵Linus Torvalds2010-10-264-4/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: (52 commits) split invalidate_inodes() fs: skip I_FREEING inodes in writeback_sb_inodes fs: fold invalidate_list into invalidate_inodes fs: do not drop inode_lock in dispose_list fs: inode split IO and LRU lists fs: switch bdev inode bdi's correctly fs: fix buffer invalidation in invalidate_list fsnotify: use dget_parent smbfs: use dget_parent exportfs: use dget_parent fs: use RCU read side protection in d_validate fs: clean up dentry lru modification fs: split __shrink_dcache_sb fs: improve DCACHE_REFERENCED usage fs: use percpu counter for nr_dentry and nr_dentry_unused fs: simplify __d_free fs: take dcache_lock inside __d_path fs: do not assign default i_ino in new_inode fs: introduce a per-cpu last_ino allocator new helper: ihold() ...
| * | fs: do not assign default i_ino in new_inodeChristoph Hellwig2010-10-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | new helper: ihold()Al Viro2010-10-252-2/+2
| | | | | | | | | | | | | | | | | | Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | fs: remove inode_add_to_list/__inode_add_to_listChristoph Hellwig2010-10-251-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split up inode_add_to_list/__inode_add_to_list. Locking for the two lists will be split soon so these helpers really don't buy us much anymore. The __ prefixes for the sb list helpers will go away soon, but until inode_lock is gone we'll need them to distinguish between the locked and unlocked variants. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | fs: kill block_prepare_writeChristoph Hellwig2010-10-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | __block_write_begin and block_prepare_write are identical except for slightly different calling conventions. Convert all callers to the __block_write_begin calling conventions and drop block_prepare_write. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | writeback: remove nonblocking/encountered_congestion referencesWu Fengguang2010-10-261-2/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes more dead code that was somehow missed by commit 0d99519efef (writeback: remove unused nonblocking and congestion checks). There are no behavior change except for the removal of two entries from one of the ext4 tracing interface. The nonblocking checks in ->writepages are no longer used because the flusher now prefer to block on get_request_wait() than to skip inodes on IO congestion. The latter will lead to more seeky IO. The nonblocking checks in ->writepage are no longer used because it's redundant with the WB_SYNC_NONE check. We no long set ->nonblocking in VM page out and page migration, because a) it's effectively redundant with WB_SYNC_NONE in current code b) it's old semantic of "Don't get stuck on request queues" is mis-behavior: that would skip some dirty inodes on congestion and page out others, which is unfair in terms of LRU age. Inspired by Christoph Hellwig. Thanks! Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: David Howells <dhowells@redhat.com> Cc: Sage Weil <sage@newdream.net> Cc: Steve French <sfrench@samba.org> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds2010-10-2260-1375/+1185
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://oss.sgi.com/xfs/xfs: (36 commits) xfs: semaphore cleanup xfs: Extend project quotas to support 32bit project ids xfs: remove xfs_buf wrappers xfs: remove xfs_cred.h xfs: remove xfs_globals.h xfs: remove xfs_version.h xfs: remove xfs_refcache.h xfs: fix the xfs_trans_committed xfs: remove unused t_callback field in struct xfs_trans xfs: fix bogus m_maxagi check in xfs_iget xfs: do not use xfs_mod_incore_sb_batch for per-cpu counters xfs: do not use xfs_mod_incore_sb for per-cpu counters xfs: remove XFS_MOUNT_NO_PERCPU_SB xfs: pack xfs_buf structure more tightly xfs: convert buffer cache hash to rbtree xfs: serialise inode reclaim within an AG xfs: batch inode reclaim lookup xfs: implement batched inode lookups for AG walking xfs: split out inode walk inode grabbing xfs: split inode AG walking into separate code for reclaim ...
| * | xfs: semaphore cleanupThomas Gleixner2010-10-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Get rid of init_MUTEX[_LOCKED]() and use sema_init() instead. (Ported to current XFS code by <aelder@sgi.com>.) Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: Extend project quotas to support 32bit project idsArkadiusz Mi?kiewicz2010-10-1816-44/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for 32bit project quota identifiers. On disk format is backward compatible with 16bit projid numbers. projid on disk is now kept in two 16bit values - di_projid_lo (which holds the same position as old 16bit projid value) and new di_projid_hi (takes existing padding) and converts from/to 32bit value on the fly. xfs_admin (for existing fs), mkfs.xfs (for new fs) needs to be used to enable PROJID32BIT support. Signed-off-by: Arkadiusz Miśkiewicz <arekm@maven.pl> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove xfs_buf wrappersChristoph Hellwig2010-10-1816-48/+33
| | | | | | | | | | | | | | | | | | | | | | | | Stop having two different names for many buffer functions and use the more descriptive xfs_buf_* names directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove xfs_cred.hChristoph Hellwig2010-10-1812-58/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | We're not actually passing around credentials inside XFS for a while now, so remove all xfs_cred.h with it's cred_t typedef and all instances of it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove xfs_globals.hChristoph Hellwig2010-10-182-24/+0
| | | | | | | | | | | | | | | | | | | | | | | | This header only provides one extern that isn't actually declared anywhere, and shadowed by a macro. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove xfs_version.hChristoph Hellwig2010-10-183-30/+1
| | | | | | | | | | | | | | | | | | | | | | | | It used to have a place when it contained an automatically generated CVS version, but these days it's entirely superflous. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove xfs_refcache.hChristoph Hellwig2010-10-181-52/+0
| | | | | | | | | | | | | | | | | | | | | This header has been completely unused for a couple of years. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: fix the xfs_trans_committedChristoph Hellwig2010-10-181-2/+3
| | | | | | | | | | | | | | | | | | | | | Use the correct prototype for xfs_trans_committed instead of casting it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove unused t_callback field in struct xfs_transChristoph Hellwig2010-10-182-6/+0
| | | | | | | | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: fix bogus m_maxagi check in xfs_igetChristoph Hellwig2010-10-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These days inode64 should only control which AGs we allocate new inodes from, while we still try to support reading all existing inodes. To make this actually work the check ontop of xfs_iget needs to be relaxed to allow inodes in all allocation groups instead of just those that we allow allocating inodes from. Note that we can't simply remove the check - it prevents us from accessing invalid data when fed invalid inode numbers from NFS or bulkstat. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: do not use xfs_mod_incore_sb_batch for per-cpu countersChristoph Hellwig2010-10-182-107/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the per-cpu counters manually in xfs_trans_unreserve_and_mod_sb and remove support for per-cpu counters from xfs_mod_incore_sb_batch to simplify it. And added benefit is that we don't have to take m_sb_lock for transactions that only modify per-cpu counters. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: do not use xfs_mod_incore_sb for per-cpu countersChristoph Hellwig2010-10-185-40/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | Export xfs_icsb_modify_counters and always use it for modifying the per-cpu counters. Remove support for per-cpu counters from xfs_mod_incore_sb to simplify it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove XFS_MOUNT_NO_PERCPU_SBChristoph Hellwig2010-10-183-29/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | Fail the mount if we can't allocate memory for the per-CPU counters. This is consistent with how we handle everything else in the mount path and makes the superblock counter modification a lot simpler. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * | xfs: pack xfs_buf structure more tightlyDave Chinner2010-10-181-11/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pahole reports the struct xfs_buf has quite a few holes in it, so packing the structure better will reduce the size of it by 16 bytes. Also, move all the fields used in cache lookups into the first cacheline. Before on x86_64: /* size: 320, cachelines: 5 */ /* sum members: 298, holes: 6, sum holes: 22 */ After on x86_64: /* size: 304, cachelines: 5 */ /* padding: 6 */ /* last cacheline: 48 bytes */ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: convert buffer cache hash to rbtreeDave Chinner2010-10-184-76/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The buffer cache hash is showing typical hash scalability problems. In large scale testing the number of cached items growing far larger than the hash can efficiently handle. Hence we need to move to a self-scaling cache indexing mechanism. I have selected rbtrees for indexing becuse they can have O(log n) search scalability, and insert and remove cost is not excessive, even on large trees. Hence we should be able to cache large numbers of buffers without incurring the excessive cache miss search penalties that the hash is imposing on us. To ensure we still have parallel access to the cache, we need multiple trees. Rather than hashing the buffers by disk address to select a tree, it seems more sensible to separate trees by typical access patterns. Most operations use buffers from within a single AG at a time, so rather than searching lots of different lists, separate the buffer indexes out into per-AG rbtrees. This means that searches during metadata operation have a much higher chance of hitting cache resident nodes, and that updates of the tree are less likely to disturb trees being accessed on other CPUs doing independent operations. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: serialise inode reclaim within an AGDave Chinner2010-10-183-0/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memory reclaim via shrinkers has a terrible habit of having N+M concurrent shrinker executions (N = num CPUs, M = num kswapds) all trying to shrink the same cache. When the cache they are all working on is protected by a single spinlock, massive contention an slowdowns occur. Wrap the per-ag inode caches with a reclaim mutex to serialise reclaim access to the AG. This will block concurrent reclaim in each AG but still allow reclaim to scan multiple AGs concurrently. Allow shrinkers to move on to the next AG if it can't get the lock, and if we can't get any AG, then start blocking on locks. To prevent reclaimers from continually scanning the same inodes in each AG, add a cursor that tracks where the last reclaim got up to and start from that point on the next reclaim. This should avoid only ever scanning a small number of inodes at the satart of each AG and not making progress. If we have a non-shrinker based reclaim pass, ignore the cursor and reset it to zero once we are done. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: batch inode reclaim lookupDave Chinner2010-10-181-33/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Batch and optimise the per-ag inode lookup for reclaim to minimise scanning overhead. This involves gang lookups on the radix trees to get multiple inodes during each tree walk, and tighter validation of what inodes can be reclaimed without blocking befor we take any locks. This is based on ideas suggested in a proof-of-concept patch posted by Nick Piggin. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: implement batched inode lookups for AG walkingDave Chinner2010-10-182-23/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the reclaim code separated from the generic walking code, it is simple to implement batched lookups for the generic walk code. Separate out the inode validation from the execute operations and modify the tree lookups to get a batch of inodes at a time. Reclaim operations will be optimised separately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: split out inode walk inode grabbingDave Chinner2010-10-182-54/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing read side inode cache walks, the code to validate and grab an inode is common to all callers. Split it out of the execute callbacks in preparation for batching lookups. Similarly, split out the inode reference dropping from the execute callbacks into the main lookup look to be symmetric with the grab. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: split inode AG walking into separate code for reclaimDave Chinner2010-10-186-115/+122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reclaim walk requires different locking and has a slightly different walk algorithm, so separate it out so that it can be optimised separately. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: remove buftarg hash for external devicesDave Chinner2010-10-181-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | For RT and external log devices, we never use hashed buffers on them now. Remove the buftarg hash tables that are set up for them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: use unhashed buffers for size checksDave Chinner2010-10-183-45/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are checking we can access the last block of each device, we do not need to use cached buffers as they will be tossed away immediately. Use uncached buffers for size checks so that all IO prior to full in-memory structure initialisation does not use the buffer cache. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: kill XBF_FS_MANAGED buffersDave Chinner2010-10-183-59/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Filesystem level managed buffers are buffers that have their lifecycle controlled by the filesystem layer, not the buffer cache. We currently cache these buffers, which makes cleanup and cache walking somewhat troublesome. Convert the fs managed buffers to uncached buffers obtained by via xfs_buf_get_uncached(), and remove the XBF_FS_MANAGED special cases from the buffer cache. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: store xfs_mount in the buftarg instead of in the xfs_bufDave Chinner2010-10-185-21/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each buffer contains both a buftarg pointer and a mount pointer. If we add a mount pointer into the buftarg, we can avoid needing the b_mount field in every buffer and grab it from the buftarg when needed instead. This shrinks the xfs_buf by 8 bytes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: introduced uncached buffer read primitveDave Chinner2010-10-182-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid the need to use cached buffers for single-shot or buffers cached at the filesystem level, introduce a new buffer read primitive that bypasses the cache an reads directly from disk. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
| * | xfs: rename xfs_buf_get_nodaddr to be more appropriateDave Chinner2010-10-186-11/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xfs_buf_get_nodaddr() is really used to allocate a buffer that is uncached. While it is not directly assigned a disk address, the fact that they are not cached is a more important distinction. With the upcoming uncached buffer read primitive, we should be consistent with this disctinction. While there, make page allocation in xfs_buf_get_nodaddr() safe against memory reclaim re-entrancy into the filesystem by allowing a flags parameter to be passed. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
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