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2012-05-14xfs: clean up xfs_bit.h includesDave Chinner
With the removal of xfs_rw.h and other changes over time, xfs_bit.h is being included in many files that don't actually need it. Clean up the includes as necessary. Also move the only-used-once xfs_ialloc_find_free() static inline function out of a header file that is widely included to reduce the number of needless dependencies on xfs_bit.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move xfs_get_extsz_hint() and kill xfs_rw.hDave Chinner
The only thing left in xfs_rw.h is a function prototype for an inode function. Move that to xfs_inode.h, and kill xfs_rw.h. Also move the function implementing the prototype from xfs_rw.c to xfs_inode.c so we only have one function left in xfs_rw.c Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move xfsagino_t to xfs_types.hDave Chinner
Untangle the header file includes a bit by moving the definition of xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include xfs_ag.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: Use preallocation for inodes with extsz hintsDave Chinner
xfstest 229 exposes a problem with buffered IO, delayed allocation and extent size hints. That is when we do delayed allocation during buffered IO, we reserve space for the extent size hint alignment and allocate the physical space to align the extent, but we do not zero the regions of the extent that aren't written by the write(2) syscall. The result is that we expose stale data in unwritten regions of the extent size hints. There are two ways to fix this. The first is to detect that we are doing unaligned writes, check if there is already a mapping or data over the extent size hint range, and if not zero the page cache first before then doing the real write. This can be very expensive for large extent size hints, especially if the subsequent writes fill then entire extent size before the data is written to disk. The second, and simpler way, is simply to turn off delayed allocation when the extent size hint is set and use preallocation instead. This results in unwritten extents being laid down on disk and so only the written portions will be converted. This matches the behaviour for direct IO, and will also work for the real time device. The disadvantage of this approach is that for small extent size hints we can get file fragmentation, but in general extent size hints are fairly large (e.g. stripe width sized) so this isn't a big deal. Implement the second approach as it is simple and effective. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: punch new delalloc blocks out of failed writes inside EOF.Dave Chinner
When a partial write inside EOF fails, it can leave delayed allocation blocks lying around because they don't get punched back out. This leads to assert failures like: XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 847 when evicting inodes from the cache. This can be trivially triggered by xfstests 083, which takes between 5 and 15 executions on a 512 byte block size filesystem to trip over this. Debugging shows a failed write due to ENOSPC calling xfs_vm_write_failed such as: [ 5012.329024] ino 0xa0026: vwf to 0x17000, sze 0x1c85ae and no action is taken on it. This leaves behind a delayed allocation extent that has no page covering it and no data in it: [ 5015.867162] ino 0xa0026: blks: 0x83 delay blocks 0x1, size 0x2538c0 [ 5015.868293] ext 0: off 0x4a, fsb 0x50306, len 0x1 [ 5015.869095] ext 1: off 0x4b, fsb 0x7899, len 0x6b [ 5015.869900] ext 2: off 0xb6, fsb 0xffffffffe0008, len 0x1 ^^^^^^^^^^^^^^^ [ 5015.871027] ext 3: off 0x36e, fsb 0x7a27, len 0xd [ 5015.872206] ext 4: off 0x4cf, fsb 0x7a1d, len 0xa So the delayed allocation extent is one block long at offset 0x16c00. Tracing shows that a bigger write: xfs_file_buffered_write: size 0x1c85ae offset 0x959d count 0x1ca3f ioflags allocates the block, and then fails with ENOSPC trying to allocate the last block on the page, leading to a failed write with stale delalloc blocks on it. Because we've had an ENOSPC when trying to allocate 0x16e00, it means that we are never goinge to call ->write_end on the page and so the allocated new buffer will not get marked dirty or have the buffer_new state cleared. In other works, what the above write is supposed to end up with is this mapping for the page: +------+------+------+------+------+------+------+------+ UMA UMA UMA UMA UMA UMA UND FAIL where: U = uptodate M = mapped N = new A = allocated D = delalloc FAIL = block we ENOSPC'd on. and the key point being the buffer_new() state for the newly allocated delayed allocation block. Except it doesn't - we're not marking buffers new correctly. That buffer_new() problem goes back to the xfs_iomap removal days, where xfs_iomap() used to return a "new" status for any map with newly allocated blocks, so that __xfs_get_blocks() could call set_buffer_new() on it. We still have the "new" variable and the check for it in the set_buffer_new() logic - except we never set it now! Hence that newly allocated delalloc block doesn't have the new flag set on it, so when the write fails we cannot tell which blocks we are supposed to punch out. WHy do we need the buffer_new flag? Well, that's because we can have this case: +------+------+------+------+------+------+------+------+ UMD UMD UMD UMD UMD UMD UND FAIL where all the UMD buffers contain valid data from a previously successful write() system call. We only want to punch the UND buffer because that's the only one that we added in this write and it was only this write that failed. That implies that even the old buffer_new() logic was wrong - because it would result in all those UMD buffers on the page having set_buffer_new() called on them even though they aren't new. Hence we shoul donly be calling set_buffer_new() for delalloc buffers that were allocated (i.e. were a hole before xfs_iomap_write_delay() was called). So, fix this set_buffer_new logic according to how we need it to work for handling failed writes correctly. Also, restore the new buffer logic handling for blocks allocated via xfs_iomap_write_direct(), because it should still set the buffer_new flag appropriately for newly allocated blocks, too. SO, now we have the buffer_new() being set appropriately in __xfs_get_blocks(), we can detect the exact delalloc ranges that we allocated in a failed write, and hence can now do a walk of the buffers on a page to find them. Except, it's not that easy. When block_write_begin() fails, it unlocks and releases the page that we just had an error on, so we can't use that page to handle errors anymore. We have to get access to the page while it is still locked to walk the buffers. Hence we have to open code block_write_begin() in xfs_vm_write_begin() to be able to insert xfs_vm_write_failed() is the right place. With that, we can pass the page and write range to xfs_vm_write_failed() and walk the buffers on the page, looking for delalloc buffers that are either new or beyond EOF and punch them out. Handling buffers beyond EOF ensures we still handle the existing case that xfs_vm_write_failed() handles. Of special note is the truncate_pagecache() handling - that only should be done for pages outside EOF - pages within EOF can still contain valid, dirty data so we must not punch them out of the cache. That just leaves the xfs_vm_write_end() failure handling. The only failure case here is that we didn't copy the entire range, and generic_write_end() handles that by zeroing the region of the page that wasn't copied, we don't have to punch out blocks within the file because they are guaranteed to contain zeros. Hence we only have to handle the existing "beyond EOF" case and don't need access to the buffers on the page. Hence it remains largely unchanged. Note that xfs_getbmap() can still trip over delalloc blocks beyond EOF that are left there by speculative delayed allocation. Hence this bug fix does not solve all known issues with bmap vs delalloc, but it does fix all the the known accidental occurances of the problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: page type check in writeback only checks last bufferDave Chinner
xfs_is_delayed_page() checks to see if a page has buffers matching the given IO type passed in. It does so by walking the buffer heads on the page and checking if the state flags match the IO type. However, the "acceptable" variable that is calculated is overwritten every time a new buffer is checked. Hence if the first buffer on the page is of the right type, this state is lost if the second buffer is not of the correct type. This means that xfs_aops_discard_page() may not discard delalloc regions when it is supposed to, and xfs_convert_page() may not cluster IO as efficiently as possible. This problem only occurs on filesystems with a block size smaller than page size. Also, rename xfs_is_delayed_page() to xfs_check_page_type() to better describe what it is doing - it is not delalloc specific anymore. The problem was first noticed by Peter Watkins. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: punch all delalloc blocks beyond EOF on write failure.Dave Chinner
I've been seeing regular ASSERT failures in xfstests when running fsstress based tests over the past month. xfs_getbmap() has been failing this test: XFS: Assertion failed: ((iflags & BMV_IF_DELALLOC) != 0) || (map[i].br_startblock != DELAYSTARTBLOCK), file: fs/xfs/xfs_bmap.c, line: 5650 where it is encountering a delayed allocation extent after writing all the dirty data to disk and then walking the extent map atomically by holding the XFS_IOLOCK_SHARED to prevent new delayed allocation extents from being created. Test 083 on a 512 byte block size filesystem was used to reproduce the problem, because it only had a 5s run timeand would usually fail every 3-4 runs. This test is exercising ENOSPC behaviour by running fsstress on a nearly full filesystem. The following trace extract shows the final few events on the inode that tripped the assert: xfs_ilock: flags ILOCK_EXCL caller xfs_setfilesize xfs_setfilesize: isize 0x180000 disize 0x12d400 offset 0x17e200 count 7680 file size updated to 0x180000 by IO completion xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay xfs_iext_insert: state idx 3 offset 3072 block 4503599627239432 count 1 flag 0 caller xfs_bmap_add_extent_hole_delay xfs_get_blocks_alloc: size 0x180000 offset 0x180000 count 512 type startoff 0xc00 startblock -1 blockcount 0x1 xfs_ilock: flags ILOCK_EXCL caller __xfs_get_blocks delalloc write, adding a single block at offset 0x180000 xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180200 count 512 ENOSPC trying to allocate a dellalloc block at offset 0x180200 xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay xfs_get_blocks_alloc: size 0x180000 offset 0x180200 count 512 type startoff 0xc00 startblock -1 blockcount 0x2 And succeeding on retry after flushing dirty inodes. xfs_ilock: flags ILOCK_EXCL caller __xfs_get_blocks xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180400 count 512 ENOSPC trying to allocate a dellalloc block at offset 0x180400 xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180400 count 512 And failing the retry, giving a real ENOSPC error. xfs_ilock: flags ILOCK_EXCL caller xfs_vm_write_failed ^^^^^^^^^^^^^^^^^^^ The smoking gun - the write being failed and cleaning up delalloc blocks beyond EOF allocated by the failed write. xfs_getattr: xfs_ilock: flags IOLOCK_SHARED caller xfs_getbmap xfs_ilock: flags ILOCK_SHARED caller xfs_ilock_map_shared And that's where we died almost immediately afterwards. xfs_bmapi_read() found delalloc extent beyond current file in memory file size. Some debug I added to xfs_getbmap() showed the state just before the assert failure: ino 0x80e48: off 0xc00, fsb 0xffffffffffffffff, len 0x1, size 0x180000 start_fsb 0x106, end_fsb 0x638 ino flags 0x2 nex 0xd bmvcnt 0x555, len 0x3c58a6f23c0bf1, start 0xc00 ext 0: off 0x1fc, fsb 0x24782, len 0x254 ext 1: off 0x450, fsb 0x40851, len 0x30 ext 2: off 0x480, fsb 0xd99, len 0x1b8 ext 3: off 0x92f, fsb 0x4099a, len 0x3b ext 4: off 0x96d, fsb 0x41844, len 0x98 ext 5: off 0xbf1, fsb 0x408ab, len 0xf which shows that we found a single delalloc block beyond EOF (first line of output) when we were returning the map for a length somewhere around 10^16 bytes long (second line), and the on-disk extents showed they didn't go past EOF (last lines). Further debug added to xfs_vm_write_failed() showed this happened when punching out delalloc blocks beyond the end of the file after the failed write: [ 132.606693] ino 0x80e48: vwf to 0x181000, sze 0x180000 [ 132.609573] start_fsb 0xc01, end_fsb 0xc08 It punched the range 0xc01 -> 0xc08, but the range we really need to punch is 0xc00 -> 0xc07 (8 blocks from 0xc00) as this testing was run on a 512 byte block size filesystem (8 blocks per page). the punch from is 0xc00. So end_fsb is correct, but start_fsb is wrong as we punch from start_fsb for (end_fsb - start_fsb) blocks. Hence we are not punching the delalloc block beyond EOF in the case. The fix is simple - it's a silly off-by-one mistake in calculating the range. It's especially silly because the macro used to calculate the start_fsb already takes into account the case where the inode size is an exact multiple of the filesystem block size... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: use shared ilock mode for direct IO writes by defaultDave Chinner
For the direct IO write path, we only really need the ilock to be taken in exclusive mode during IO submission if we need to do extent allocation instead of all the time. Change the block mapping code to take the ilock in shared mode for the initial block mapping, and only retake it exclusively when we actually have to perform extent allocations. We were already dropping the ilock for the transaction allocation, so this doesn't introduce new race windows. Based on an earlier patch from Dave Chinner. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-13xfs: log file size updates at I/O completion timeChristoph Hellwig
Do not use unlogged metadata updates and the VFS dirty bit for updating the file size after writeback. In addition to causing various problems with updates getting delayed for far too long this also drags in the unscalable VFS dirty tracking, and is one of the few remaining unlogged metadata updates. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-05xfs: log file size updates as part of unwritten extent conversionChristoph Hellwig
If we convert and unwritten extent past the current i_size log the size update as part of the extent manipulation transactions instead of doing an unlogged metadata update later. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-05xfs: do not require an ioend for new EOF calculationChristoph Hellwig
Replace xfs_ioend_new_eof with a new inline xfs_new_eof helper that doesn't require and ioend, and is available also outside of xfs_aops.c. Also make the code a bit more clear by using a normal if statement instead of a slightly misleading MIN(). Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-05xfs: use per-filesystem I/O completion workqueuesChristoph Hellwig
The new concurrency managed workqueues are cheap enough that we can create per-filesystem instead of global workqueues. This allows us to remove the trylock or defer scheme on the ilock, which is not helpful once we have outstanding log reservations until finishing a size update. Also allow the default concurrency on this workqueues so that I/O completions blocking on the ilock for one inode do not block process for another inode. Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: remove the i_new_size field in struct xfs_inodeChristoph Hellwig
Now that we use the VFS i_size field throughout XFS there is no need for the i_new_size field any more given that the VFS i_size field gets updated in ->write_end before unlocking the page, and thus is always uptodate when writeback could see a page. Removing i_new_size also has the advantage that we will never have to trim back di_size during a failed buffered write, given that it never gets updated past i_size. Note that currently the generic direct I/O code only updates i_size after calling our end_io handler, which requires a small workaround to make sure di_size actually makes it to disk. I hope to fix this properly in the generic code. A downside is that we lose the support for parallel non-overlapping O_DIRECT appending writes that recently was added. I don't think keeping the complex and fragile i_new_size infrastructure for this is a good tradeoff - if we really care about parallel appending writers we should investigate turning the iolock into a range lock, which would also allow for parallel non-overlapping buffered writers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: remove the i_size field in struct xfs_inodeChristoph Hellwig
There is no fundamental need to keep an in-memory inode size copy in the XFS inode. We already have the on-disk value in the dinode, and the separate in-memory copy that we need for regular files only in the XFS inode. Remove the xfs_inode i_size field and change the XFS_ISIZE macro to use the VFS inode i_size field for regular files. Switch code that was directly accessing the i_size field in the xfs_inode to XFS_ISIZE, or in cases where we are limited to regular files direct access of the VFS inode i_size field. This also allows dropping some fairly complicated code in the write path which dealt with keeping the xfs_inode i_size uptodate with the VFS i_size that is getting updated inside ->write_end. Note that we do not bother resetting the VFS i_size when truncating a file that gets freed to zero as there is no point in doing so because the VFS inode is no longer in use at this point. Just relax the assert in xfs_ifree to only check the on-disk size instead. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-11-08xfs: fix force shutdown handling in xfs_end_ioChristoph Hellwig
Ensure ioend->io_error gets propagated back to e.g. AIO completions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alex Elder <aelder@sgi.com>
2011-11-01xfs: warn if direct reclaim tries to writeback pagesMel Gorman
Direct reclaim should never writeback pages. For now, handle the situation and warn about it. Ultimately, this will be a BUG_ON. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-12xfs: introduce xfs_bmapi_read()Dave Chinner
xfs_bmapi() currently handles both extent map reading and allocation. As a result, the code is littered with "if (wr)" branches to conditionally do allocation operations if required. This makes the code much harder to follow and causes significant indent issues with the code. Given that read mapping is much simpler than allocation, we can split out read mapping from xfs_bmapi() and reuse the logic that we have already factored out do do all the hard work of handling the extent map manipulations. The results in a much simpler function for the common extent read operations, and will allow the allocation code to be simplified in another commit. Once xfs_bmapi_read() is implemented, convert all the callers of xfs_bmapi() that are only reading extents to use the new function. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-12xfs: improve ioend error handlingChristoph Hellwig
Return unwritten extent conversion errors to aio_complete. Skip both unwritten extent conversion and size updates if we had an I/O error or the filesystem has been shut down. Return -EIO to the aio/buffer completion handlers in case of a forced shutdown. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-12xfs: remove i_iocountChristoph Hellwig
We now have an i_dio_count filed and surrounding infrastructure to wait for direct I/O completion instead of i_icount, and we have never needed to iocount waits for buffered I/O given that we only set the page uptodate after finishing all required work. Thus remove i_iocount, and replace the actually needed waits with calls to inode_dio_wait. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-12xfs: reduce ioend latencyChristoph Hellwig
There is no reason to queue up ioends for processing in user context unless we actually need it. Just complete ioends that do not convert unwritten extents or need a size update from the end_io context. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-12xfs: defer AIO/DIO completionsChristoph Hellwig
We really shouldn't complete AIO or DIO requests until we have finished the unwritten extent conversion and size update. This means fsync never has to pick up any ioends as all work has been completed when signalling I/O completion. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-12xfs: remove dead ENODEV handling in xfs_destroy_ioendChristoph Hellwig
No driver returns ENODEV from it bio completion handler, not has this ever been documented. Remove the dead code dealing with it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-09-14xfs: fix a use after free in xfs_end_io_direct_writeChristoph Hellwig
There is a window in which the ioend that we call inode_dio_wake on in xfs_end_io_direct_write is already free. Fix this by storing the inode pointer in a local variable. This is a fix for the regression introduced in 3.1-rc by "fs: move inode_dio_done to the end_io handler". Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-08-12xfs: remove subdirectoriesChristoph Hellwig
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the annoying subdirectories in the XFS source code. Besides the large amount of file rename the only changes are to the Makefile, a few files including headers with the subdirectory prefix, and the binary sysctl compat code that includes a header under fs/xfs/ from kernel/. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>