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2020-06-22xfs: reset buffer write failure state on successful completionBrian Foster
[ Upstream commit b6983e80b03bd4fd42de71993b3ac7403edac758 ] The buffer write failure flag is intended to control the internal write retry that XFS has historically implemented to help mitigate the severity of transient I/O errors. The flag is set when a buffer is resubmitted from the I/O completion path due to a previous failure. It is checked on subsequent I/O completions to skip the internal retry and fall through to the higher level configurable error handling mechanism. The flag is cleared in the synchronous and delwri submission paths and also checked in various places to log write failure messages. There are a couple minor problems with the current usage of this flag. One is that we issue an internal retry after every submission from xfsaild due to how delwri submission clears the flag. This results in double the expected or configured number of write attempts when under sustained failures. Another more subtle issue is that the flag is never cleared on successful I/O completion. This can cause xfs_wait_buftarg() to suggest that dirty buffers are being thrown away due to the existence of the flag, when the reality is that the flag might still be set because the write succeeded on the retry. Clear the write failure flag on successful I/O completion to address both of these problems. This means that the internal retry attempt occurs once since the last time a buffer write failed and that various other contexts only see the flag set when the immediately previous write attempt has failed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05xfs: end sync buffer I/O properly on shutdown errorBrian Foster
[ Upstream commit 465fa17f4a303d9fdff9eac4d45f91ece92e96ca ] As of commit e339dd8d8b ("xfs: use sync buffer I/O for sync delwri queue submission"), the delwri submission code uses sync buffer I/O for sync delwri I/O. Instead of waiting on async I/O to unlock the buffer, it uses the underlying sync I/O completion mechanism. If delwri buffer submission fails due to a shutdown scenario, an error is set on the buffer and buffer completion never occurs. This can cause xfs_buf_delwri_submit() to deadlock waiting on a completion event. We could check the error state before waiting on such buffers, but that doesn't serialize against the case of an error set via a racing I/O completion. Instead, invoke I/O completion in the shutdown case regardless of buffer I/O type. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01xfs: clear ail delwri queued bufs on unmount of shutdown fsBrian Foster
[ Upstream commit efc3289cf8d39c34502a7cc9695ca2fa125aad0c ] In the typical unmount case, the AIL is forced out by the unmount sequence before the xfsaild task is stopped. Since AIL items are removed on writeback completion, this means that the AIL ->ail_buf_list delwri queue has been drained. This is not always true in the shutdown case, however. It's possible for buffers to sit on a delwri queue for a period of time across submission attempts if said items are locked or have been relogged and pinned since first added to the queue. If the attempt to log such an item results in a log I/O error, the error processing can shutdown the fs, remove the item from the AIL, stale the buffer (dropping the LRU reference) and clear its delwri queue state. The latter bit means the buffer will be released from a delwri queue on the next submission attempt, but this might never occur if the filesystem has shutdown and the AIL is empty. This means that such buffers are held indefinitely by the AIL delwri queue across destruction of the AIL. Aside from being a memory leak, these buffers can also hold references to in-core perag structures. The latter problem manifests as a generic/475 failure, reproducing the following asserts at unmount time: XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 151 XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 132 To prevent this problem, clear the AIL delwri queue as a final step before xfsaild() exit. The !empty state should never occur in the normal case, so add an assert to catch unexpected problems going forward. [dgc: add comment explaining need for xfs_buf_delwri_cancel() after calling xfs_buf_delwri_submit_nowait().] Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01xfs: fix use-after-free race in xfs_buf_releDave Chinner
[ Upstream commit 37fd1678245f7a5898c1b05128bc481fb403c290 ] When looking at a 4.18 based KASAN use after free report, I noticed that racing xfs_buf_rele() may race on dropping the last reference to the buffer and taking the buffer lock. This was the symptom displayed by the KASAN report, but the actual issue that was reported had already been fixed in 4.19-rc1 by commit e339dd8d8b04 ("xfs: use sync buffer I/O for sync delwri queue submission"). Despite this, I think there is still an issue with xfs_buf_rele() in this code: release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock); spin_lock(&bp->b_lock); if (!release) { ..... If two threads race on the b_lock after both dropping a reference and one getting dropping the last reference so release = true, we end up with: CPU 0 CPU 1 atomic_dec_and_lock() atomic_dec_and_lock() spin_lock(&bp->b_lock) spin_lock(&bp->b_lock) <spins> <release = true bp->b_lru_ref = 0> <remove from lists> freebuf = true spin_unlock(&bp->b_lock) xfs_buf_free(bp) <gets lock, reading and writing freed memory> <accesses freed memory> spin_unlock(&bp->b_lock) <reads/writes freed memory> IOWs, we can't safely take bp->b_lock after dropping the hold reference because the buffer may go away at any time after we drop that reference. However, this can be fixed simply by taking the bp->b_lock before we drop the reference. It is safe to nest the pag_buf_lock inside bp->b_lock as the pag_buf_lock is only used to serialise against lookup in xfs_buf_find() and no other locks are held over or under the pag_buf_lock there. Make this clear by documenting the buffer lock orders at the top of the file. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-08-12xfs: remove b_last_holder & associated macrosEric Sandeen
The old lock tracking infrastructure in xfs using the b_last_holder field seems to only be useful if you can get into the system with a debugger; it seems that the existing tracepoints would be the way to go these days, and this old infrastructure can be removed. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: kill __xfs_buf_submit_common()Brian Foster
Now that there is only one caller, fold the common submission helper into __xfs_buf_submit(). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: combine [a]sync buffer submission apisBrian Foster
The buffer I/O submission path consists of separate function calls per type. The buffer I/O type is already controlled via buffer state (XBF_ASYNC), however, so there is no real need for separate submission functions. Combine the buffer submission functions into a single function that processes the buffer appropriately based on XBF_ASYNC. Retain an internal helper with a conditional wait parameter to continue to support batched !XBF_ASYNC submission/completion required by delwri queues. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: use sync buffer I/O for sync delwri queue submissionBrian Foster
If a delwri queue occurs of a buffer that sits on a delwri queue wait list, the queue sets _XBF_DELWRI_Q without changing the state of ->b_list. This occurs, for example, if another thread beats the current delwri waiter thread to the buffer lock after I/O completion. Once the waiter acquires the lock, it removes the buffer from the wait list and leaves a buffer with _XBF_DELWRI_Q set but not populated on a list. This results in a lost buffer submission and in turn can result in assert failures due to _XBF_DELWRI_Q being set on buffer reclaim or filesystem lockups if the buffer happens to cover an item in the AIL. This problem has been reproduced by repeated iterations of xfs/305 on high CPU count (28xcpu) systems with limited memory (~1GB). Dirty dquot reclaim races with an xfsaild push of a separate dquot backed by the same buffer such that the buffer sits on the reclaim wait list at the time xfsaild attempts to queue it. Since the latter dquot has been flush locked but the underlying buffer not submitted for I/O, the dquot pins the AIL and causes the filesystem to livelock. This race is essentially made possible by the buffer lock cycle involved with waiting on a synchronous delwri queue submission. Close the race by using synchronous buffer I/O for respective delwri queue submission. This means the buffer remains locked across the I/O and so is inaccessible from other contexts while in the intermediate wait list state. The sync buffer I/O wait mechanism is factored into a helper such that sync delwri buffer submission and serialization are batched operations. Designed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: refactor buffer submission into a common helperBrian Foster
Sync and async buffer submission both do generally similar things with a couple odd exceptions. Refactor the core buffer submission code into a common helper to isolate buffer submission from completion handling of synchronous buffer I/O. This patch does not change behavior. It is a step towards support for using synchronous buffer I/O via synchronous delwri queue submission. Designed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-08xfs: xfs_reflink_convert_cow() memory allocation deadlockDave Chinner
xfs_reflink_convert_cow() manipulates the incore extent list in GFP_KERNEL context in the IO submission path whilst holding locked pages under writeback. This is a memory reclaim deadlock vector. This code is not in a transaction, so any memory allocations it makes aren't protected via the memalloc_nofs_save() context that transactions carry. Hence we need to run this call under memalloc_nofs_save() context to prevent potential memory allocations from being run as GFP_KERNEL and deadlocking. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-06xfs: convert to SPDX license tagsDave Chinner
Remove the verbose license text from XFS files and replace them with SPDX tags. This does not change the license of any of the code, merely refers to the common, up-to-date license files in LICENSES/ This change was mostly scripted. fs/xfs/Makefile and fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected and modified by the following command: for f in `git grep -l "GNU General" fs/xfs/` ; do echo $f cat $f | awk -f hdr.awk > $f.new mv -f $f.new $f done And the hdr.awk script that did the modification (including detecting the difference between GPL-2.0 and GPL-2.0+ licenses) is as follows: $ cat hdr.awk BEGIN { hdr = 1.0 tag = "GPL-2.0" str = "" } /^ \* This program is free software/ { hdr = 2.0; next } /any later version./ { tag = "GPL-2.0+" next } /^ \*\// { if (hdr > 0.0) { print "// SPDX-License-Identifier: " tag print str print $0 str="" hdr = 0.0 next } print $0 next } /^ \* / { if (hdr > 1.0) next if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 next } /^ \*/ { if (hdr > 0.0) next print $0 next } // { if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 } END { } $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-09xfs: don't retry xfs_buf_find on XBF_TRYLOCK failureDave Chinner
When looking at an event trace recently, I noticed that non-blocking buffer lookup attempts would fail on cached locked buffers and then run the slow cache-miss path. This means we are doing an xfs_buf allocation, lookup and free unnecessarily every time we avoid blocking on a locked buffer. Fix this by changing _xfs_buf_find() to return an error status to the caller to indicate that we failed the lock attempt rather than just returning a NULL. This allows the higher level code to discriminate between a cache miss and an cache hit that we failed to lock. This also allows us to return a -EFSCORRUPTED state if we are asked to look up a block number outside the range of the filesystem in _xfs_buf_find(), which moves us one step closer to being able to handle such errors in a more graceful manner at the higher levels. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-09xfs: make xfs_buf_incore out of lineDave Chinner
Move xfs_buf_incore out of line and make it the only way to look up a buffer in the buffer cache from outside the buffer cache. Convert the external users of _xfs_buf_find() to xfs_buf_incore() and make _xfs_buf_find() static. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: actually rename xfs_incore -> xfs_buf_incore] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-04-09xfs: non-scrub - remove unused function parametersEric Sandeen
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-11xfs: Correctly invert xfs_buftarg LRU isolation logicVratislav Bendel
Due to an inverted logic mistake in xfs_buftarg_isolate() the xfs_buffers with zero b_lru_ref will take another trip around LRU, while isolating buffers with non-zero b_lru_ref. Additionally those isolated buffers end up right back on the LRU once they are released, because b_lru_ref remains elevated. Fix that circuitous route by leaving them on the LRU as originally intended. Signed-off-by: Vratislav Bendel <vbendel@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-29Use list_head infra-structure for buffer's log items listCarlos Maiolino
Now that buffer's b_fspriv has been split, just replace the current singly linked list of xfs_log_items, by the list_head infrastructure. Also, remove the xfs_log_item argument from xfs_buf_resubmit_failed_buffers(), there is no need for this argument, once the log items can be walked through the list_head in the buffer. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: minor style cleanups] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-09xfs: clarify units in the failed metadata io messageDarrick J. Wong
If a metadata IO error happens, we report the location of the failed IO request in units of daddrs. However, the printk message misleads people into thinking that the units are fs blocks, so fix the reported units. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-01-08xfs: dump the first 128 bytes of any corrupt bufferDarrick J. Wong
Increase the corrupt buffer dump to the first 128 bytes since v5 filesystems have larger block headers than before. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-01-08xfs: refactor xfs_verifier_error and xfs_buf_ioerrorDarrick J. Wong
Since all verification errors also mark the buffer as having an error, we can combine these two calls. Later we'll add a xfs_failaddr_t parameter to promote the idea of reporting corruption errors and the address of the failing check to enable better debugging reports. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-28xfs: fortify xfs_alloc_buftarg error handlingMichal Hocko
percpu_counter_init failure path doesn't clean up &btp->bt_lru list. Call list_lru_destroy in that error path. Similarly register_shrinker error path is not handled. While it is unlikely to trigger these error path, it is not impossible especially the later might fail with large NUMAs. Let's handle the failure to make the code more robust. Noticed-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-01xfs: move error injection tags into their own fileDarrick J. Wong
Move the error injection tag names into a libxfs header so that we can share it between kernel and userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-27xfs: fix unused variable warning in xfs_buf_set_ref()Brian Foster
Fix an unused variable warning on non-DEBUG builds introduced by commit 7561d27e90 ("xfs: buffer lru reference count error injection tag"). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-10-26xfs: buffer lru reference count error injection tagBrian Foster
XFS uses a fixed reference count for certain types of buffers in the internal LRU cache. These reference counts dictate how aggressively certain buffers are reclaimed vs. others. While the reference counts implements priority across different buffer types, all buffers (other than uncached buffers) are typically cached for at least one reclaim cycle. We've had at least one bug recently that has been hidden by a released buffer sitting around in the LRU. Users hitting the problem were able to reproduce under enough memory pressure to cause aggressive reclaim in a particular window of time. To support future xfstests cases, add an error injection tag to hardcode the buffer reference count to zero. When enabled, this bypasses caching of associated buffers and facilitates test cases that depend on this behavior. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-25xfs: remove redundant re-initialization of total_nr_pagesColin Ian King
Variable total_nr_pages is being initialized and then updated with the same value, this latter assignment is redundant and can be removed. Cleans up clang build warning: Value stored to 'total_nr_pages' during its initialization is never read Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-11Merge tag 'libnvdimm-for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm from Dan Williams: "A rework of media error handling in the BTT driver and other updates. It has appeared in a few -next releases and collected some late- breaking build-error and warning fixups as a result. Summary: - Media error handling support in the Block Translation Table (BTT) driver is reworked to address sleeping-while-atomic locking and memory-allocation-context conflicts. - The dax_device lookup overhead for xfs and ext4 is moved out of the iomap hot-path to a mount-time lookup. - A new 'ecc_unit_size' sysfs attribute is added to advertise the read-modify-write boundary property of a persistent memory range. - Preparatory fix-ups for arm and powerpc pmem support are included along with other miscellaneous fixes" * tag 'libnvdimm-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (26 commits) libnvdimm, btt: fix format string warnings libnvdimm, btt: clean up warning and error messages ext4: fix null pointer dereference on sbi libnvdimm, nfit: move the check on nd_reserved2 to the endpoint dax: fix FS_DAX=n BLOCK=y compilation libnvdimm: fix integer overflow static analysis warning libnvdimm, nd_blk: remove mmio_flush_range() libnvdimm, btt: rework error clearing libnvdimm: fix potential deadlock while clearing errors libnvdimm, btt: cache sector_size in arena_info libnvdimm, btt: ensure that flags were also unchanged during a map_read libnvdimm, btt: refactor map entry operations with macros libnvdimm, btt: fix a missed NVDIMM_IO_ATOMIC case in the write path libnvdimm, nfit: export an 'ecc_unit_size' sysfs attribute ext4: perform dax_device lookup at mount ext2: perform dax_device lookup at mount xfs: perform dax_device lookup at mount dax: introduce a fs_dax_get_by_bdev() helper libnvdimm, btt: check memory allocation failure libnvdimm, label: fix index block size calculation ...
2017-08-31xfs: perform dax_device lookup at mountDan Williams
The ->iomap_begin() operation is a hot path, so cache the fs_dax_get_by_host() result at mount time to avoid the incurring the hash lookup overhead on a per-i/o basis. Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-10Merge tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull XFS updates from Darrick Wong: "Here are some changes for you for 4.13. For the most part it's fixes for bugs and deadlock problems, and preparation for online fsck in some future merge window. - Avoid quotacheck deadlocks - Fix transaction overflows when bunmapping fragmented files - Refactor directory readahead - Allow admin to configure if ASSERT is fatal - Improve transaction usage detail logging during overflows - Minor cleanups - Don't leak log items when the log shuts down - Remove double-underscore typedefs - Various preparation for online scrubbing - Introduce new error injection configuration sysfs knobs - Refactor dq_get_next to use extent map directly - Fix problems with iterating the page cache for unwritten data - Implement SEEK_{HOLE,DATA} via iomap - Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA - Don't use MAXPATHLEN to check on-disk symlink target lengths" * tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (48 commits) xfs: don't crash on unexpected holes in dir/attr btrees xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN xfs: fix contiguous dquot chunk iteration livelock xfs: Switch to iomap for SEEK_HOLE / SEEK_DATA vfs: Add iomap_seek_hole and iomap_seek_data helpers vfs: Add page_cache_seek_hole_data helper xfs: remove a whitespace-only line from xfs_fs_get_nextdqblk xfs: rewrite xfs_dq_get_next_id using xfs_iext_lookup_extent xfs: Check for m_errortag initialization in xfs_errortag_test xfs: grab dquots without taking the ilock xfs: fix semicolon.cocci warnings xfs: Don't clear SGID when inheriting ACLs xfs: free cowblocks and retry on buffered write ENOSPC xfs: replace log_badcrc_factor knob with error injection tag xfs: convert drop_writes to use the errortag mechanism xfs: remove unneeded parameter from XFS_TEST_ERROR xfs: expose errortag knobs via sysfs xfs: make errortag a per-mountpoint structure xfs: free uncommitted transactions during log recovery xfs: don't allow bmap on rt files ...
2017-07-03Merge branch 'for-4.13/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block/IO updates from Jens Axboe: "This is the main pull request for the block layer for 4.13. Not a huge round in terms of features, but there's a lot of churn related to some core cleanups. Note this depends on the UUID tree pull request, that Christoph already sent out. This pull request contains: - A series from Christoph, unifying the error/stats codes in the block layer. We now use blk_status_t everywhere, instead of using different schemes for different places. - Also from Christoph, some cleanups around request allocation and IO scheduler interactions in blk-mq. - And yet another series from Christoph, cleaning up how we handle and do bounce buffering in the block layer. - A blk-mq debugfs series from Bart, further improving on the support we have for exporting internal information to aid debugging IO hangs or stalls. - Also from Bart, a series that cleans up the request initialization differences across types of devices. - A series from Goldwyn Rodrigues, allowing the block layer to return failure if we will block and the user asked for non-blocking. - Patch from Hannes for supporting setting loop devices block size to that of the underlying device. - Two series of patches from Javier, fixing various issues with lightnvm, particular around pblk. - A series from me, adding support for write hints. This comes with NVMe support as well, so applications can help guide data placement on flash to improve performance, latencies, and write amplification. - A series from Ming, improving and hardening blk-mq support for stopping/starting and quiescing hardware queues. - Two pull requests for NVMe updates. Nothing major on the feature side, but lots of cleanups and bug fixes. From the usual crew. - A series from Neil Brown, greatly improving the bio rescue set support. Most notably, this kills the bio rescue work queues, if we don't really need them. - Lots of other little bug fixes that are all over the place" * 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits) lightnvm: pblk: set line bitmap check under debug lightnvm: pblk: verify that cache read is still valid lightnvm: pblk: add initialization check lightnvm: pblk: remove target using async. I/Os lightnvm: pblk: use vmalloc for GC data buffer lightnvm: pblk: use right metadata buffer for recovery lightnvm: pblk: schedule if data is not ready lightnvm: pblk: remove unused return variable lightnvm: pblk: fix double-free on pblk init lightnvm: pblk: fix bad le64 assignations nvme: Makefile: remove dead build rule blk-mq: map all HWQ also in hyperthreaded system nvmet-rdma: register ib_client to not deadlock in device removal nvme_fc: fix error recovery on link down. nvmet_fc: fix crashes on bad opcodes nvme_fc: Fix crash when nvme controller connection fails. nvme_fc: replace ioabort msleep loop with completion nvme_fc: fix double calls to nvme_cleanup_cmd() nvme-fabrics: verify that a controller returns the correct NQN nvme: simplify nvme_dev_attrs_are_visible ...
2017-06-19xfs: remove double-underscore integer typesDarrick J. Wong
This is a purely mechanical patch that removes the private __{u,}int{8,16,32,64}_t typedefs in favor of using the system {u,}int{8,16,32,64}_t typedefs. This is the sed script used to perform the transformation and fix the resulting whitespace and indentation errors: s/typedef\t__uint8_t/typedef __uint8_t\t/g s/typedef\t__uint/typedef __uint/g s/typedef\t__int\([0-9]*\)_t/typedef int\1_t\t/g s/__uint8_t\t/__uint8_t\t\t/g s/__uint/uint/g s/__int\([0-9]*\)_t\t/__int\1_t\t\t/g s/__int/int/g /^typedef.*int[0-9]*_t;$/d Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-06-19xfs: push buffer of flush locked dquot to avoid quotacheck deadlockBrian Foster
Reclaim during quotacheck can lead to deadlocks on the dquot flush lock: - Quotacheck populates a local delwri queue with the physical dquot buffers. - Quotacheck performs the xfs_qm_dqusage_adjust() bulkstat and dirties all of the dquots. - Reclaim kicks in and attempts to flush a dquot whose buffer is already queud on the quotacheck queue. The flush succeeds but queueing to the reclaim delwri queue fails as the backing buffer is already queued. The flush unlock is now deferred to I/O completion of the buffer from the quotacheck queue. - The dqadjust bulkstat continues and dirties the recently flushed dquot once again. - Quotacheck proceeds to the xfs_qm_flush_one() walk which requires the flush lock to update the backing buffers with the in-core recalculated values. It deadlocks on the redirtied dquot as the flush lock was already acquired by reclaim, but the buffer resides on the local delwri queue which isn't submitted until the end of quotacheck. This is reproduced by running quotacheck on a filesystem with a couple million inodes in low memory (512MB-1GB) situations. This is a regression as of commit 43ff2122e6 ("xfs: on-stack delayed write buffer lists"), which removed a trylock and buffer I/O submission from the quotacheck dquot flush sequence. Quotacheck first resets and collects the physical dquot buffers in a delwri queue. Then, it traverses the filesystem inodes via bulkstat, updates the in-core dquots, flushes the corrected dquots to the backing buffers and finally submits the delwri queue for I/O. Since the backing buffers are queued across the entire quotacheck operation, dquot reclaim cannot possibly complete a dquot flush before quotacheck completes. Therefore, quotacheck must submit the buffer for I/O in order to cycle the flush lock and flush the dirty in-core dquot to the buffer. Add a delwri queue buffer push mechanism to submit an individual buffer for I/O without losing the delwri queue status and use it from quotacheck to avoid the deadlock. This restores quotacheck behavior to as before the regression was introduced. Reported-by: Martin Svec <martin.svec@zoner.cz> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-12Merge tag 'v4.12-rc5' into for-4.13/blockJens Axboe
We've already got a few conflicts and upcoming work depends on some of the changes that have gone into mainline as regression fixes for this series. Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream trees to continue working on 4.13 changes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-08xfs: fix spurious spin_is_locked() assert failures on non-smp kernelsBrian Foster
The 0-day kernel test robot reports assertion failures on !CONFIG_SMP kernels due to failed spin_is_locked() checks. As it turns out, spin_is_locked() is hardcoded to return zero on !CONFIG_SMP kernels and so this function cannot be relied on to verify spinlock state in this configuration. To avoid this problem, replace the associated asserts with lockdep variants that do the right thing regardless of kernel configuration. Drop the one assert that checks for an unlocked lock as there is no suitable lockdep variant for that case. This moves the spinlock checks from XFS debug code to lockdep, but generally provides the same level of protection. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-31xfs: use ->b_state to fix buffer I/O accounting release raceBrian Foster
We've had user reports of unmount hangs in xfs_wait_buftarg() that analysis shows is due to btp->bt_io_count == -1. bt_io_count represents the count of in-flight asynchronous buffers and thus should always be >= 0. xfs_wait_buftarg() waits for this value to stabilize to zero in order to ensure that all untracked (with respect to the lru) buffers have completed I/O processing before unmount proceeds to tear down in-core data structures. The value of -1 implies an I/O accounting decrement race. Indeed, the fact that xfs_buf_ioacct_dec() is called from xfs_buf_rele() (where the buffer lock is no longer held) means that bp->b_flags can be updated from an unsafe context. While a user-level reproducer is currently not available, some intrusive hacks to run racing buffer lookups/ioacct/releases from multiple threads was used to successfully manufacture this problem. Existing callers do not expect to acquire the buffer lock from xfs_buf_rele(). Therefore, we can not safely update ->b_flags from this context. It turns out that we already have separate buffer state bits and associated serialization for dealing with buffer LRU state in the form of ->b_state and ->b_lock. Therefore, replace the _XBF_IN_FLIGHT flag with a ->b_state variant, update the I/O accounting wrappers appropriately and make sure they are used with the correct locking. This ensures that buffer in-flight state can be modified at buffer release time without racing with modifications from a buffer lock holder. Fixes: 9c7504aa72b6 ("xfs: track and serialize in-flight async buffers against unmount") Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Libor Pechacek <lpechacek@suse.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-06Merge tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs updates from Darrick Wong: "Here are the XFS changes for 4.12. The big new feature for this release is the new space mapping ioctl that we've been discussing since LSF2016, but other than that most of the patches are larger bug fixes, memory corruption prevention, and other cleanups. Summary: - various code cleanups - introduce GETFSMAP ioctl - various refactoring - avoid dio reads past eof - fix memory corruption and other errors with fragmented directory blocks - fix accidental userspace memory corruptions - publish fs uuid in superblock - make fstrim terminatable - fix race between quotaoff and in-core inode creation - avoid use-after-free when finishing up w/ buffer heads - reserve enough space to handle bmap tree resizing during cow remap" * tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (53 commits) xfs: fix use-after-free in xfs_finish_page_writeback xfs: reserve enough blocks to handle btree splits when remapping xfs: wait on new inodes during quotaoff dquot release xfs: update ag iterator to support wait on new inodes xfs: support ability to wait on new inodes xfs: publish UUID in struct super_block xfs: Allow user to kill fstrim process xfs: better log intent item refcount checking xfs: fix up quotacheck buffer list error handling xfs: remove xfs_trans_ail_delete_bulk xfs: don't use bool values in trace buffers xfs: fix getfsmap userspace memory corruption while setting OF_LAST xfs: fix __user annotations for xfs_ioc_getfsmap xfs: corruption needs to respect endianess too! xfs: use NULL instead of 0 to initialize a pointer in xfs_ioc_getfsmap xfs: use NULL instead of 0 to initialize a pointer in xfs_getfsmap xfs: simplify validation of the unwritten extent bit xfs: remove unused values from xfs_exntst_t xfs: remove the unused XFS_MAXLINK_1 define xfs: more do_div cleanups ...
2017-05-03xfs: use memalloc_nofs_{save,restore} instead of memalloc_noio*Michal Hocko
kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} API to prevent from reclaim recursion into the fs because vmalloc can invoke unconditional GFP_KERNEL allocations and these functions might be called from the NOFS contexts. The memalloc_noio_save will enforce GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should provide exactly what we need here - implicit GFP_NOFS context. Link: http://lkml.kernel.org/r/20170306131408.9828-6-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <clm@fb.com> Cc: David Sterba <dsterba@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Nikolay Borisov <nborisov@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-25xfs: fix up quotacheck buffer list error handlingBrian Foster
The quotacheck error handling of the delwri buffer list assumes the resident buffers are locked and doesn't clear the _XBF_DELWRI_Q flag on the buffers that are dequeued. This can lead to assert failures on buffer release and possibly other locking problems. Move this code to a delwri queue cancel helper function to encapsulate the logic required to properly release buffers from a delwri queue. Update the helper to clear the delwri queue flag and call it from quotacheck. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-03-02sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h>Ingo Molnar
Update the .c files that depend on these APIs. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-17Merge branch 'for-4.11/next' into for-4.11/linus-mergeJens Axboe
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02block: Get rid of blk_get_backing_dev_info()Jan Kara
blk_get_backing_dev_info() is now a simple dereference. Remove that function and simplify some code around that. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-25xfs: clear _XBF_PAGES from buffers when readahead pageDarrick J. Wong
If we try to allocate memory pages to back an xfs_buf that we're trying to read, it's possible that we'll be so short on memory that the page allocation fails. For a blocking read we'll just wait, but for readahead we simply dump all the pages we've collected so far. Unfortunately, after dumping the pages we neglect to clear the _XBF_PAGES state, which means that the subsequent call to xfs_buf_free thinks that b_pages still points to pages we own. It then double-frees the b_pages pages. This results in screaming about negative page refcounts from the memory manager, which xfs oughtn't be triggering. To reproduce this case, mount a filesystem where the size of the inodes far outweighs the availalble memory (a ~500M inode filesystem on a VM with 300MB memory did the trick here) and run bulkstat in parallel with other memory eating processes to put a huge load on the system. The "check summary" phase of xfs_scrub also works for this purpose. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2016-12-14Merge tag 'xfs-for-linus-4.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "There is quite a varied bunch of stuff in this update, and some of it you will have already merged through the ext4 tree which imported the dax-4.10-iomap-pmd topic branch from the XFS tree. There is also a new direct IO implementation that uses the iomap infrastructure. It's much simpler, faster, and has lower IO latency than the existing direct IO infrastructure. Summary: - DAX PMD faults via iomap infrastructure - Direct-io support in iomap infrastructure - removal of now-redundant XFS inode iolock, replaced with VFS i_rwsem - synchronisation with fixes and changes in userspace libxfs code - extent tree lookup helpers - lots of little corruption detection improvements to verifiers - optimised CRC calculations - faster buffer cache lookups - deprecation of barrier/nobarrier mount options - we always use REQ_FUA/REQ_FLUSH where appropriate for data integrity now - cleanups to speculative preallocation - miscellaneous minor bug fixes and cleanups" * tag 'xfs-for-linus-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (63 commits) xfs: nuke unused tracepoint definitions xfs: use GPF_NOFS when allocating btree cursors xfs: use xfs_vn_setattr_size to check on new size xfs: deprecate barrier/nobarrier mount option xfs: Always flush caches when integrity is required xfs: ignore leaf attr ichdr.count in verifier during log replay xfs: use rhashtable to track buffer cache xfs: optimise CRC updates xfs: make xfs btree stats less huge xfs: don't cap maximum dedupe request length xfs: don't allow di_size with high bit set xfs: error out if trying to add attrs and anextents > 0 xfs: don't crash if reading a directory results in an unexpected hole xfs: complain if we don't get nextents bmap records xfs: check for bogus values in btree block headers xfs: forbid AG btrees with level == 0 xfs: several xattr functions can be void xfs: handle cow fork in xfs_bmap_trace_exlist xfs: pass state not whichfork to trace_xfs_extlist xfs: Move AGI buffer type setting to xfs_read_agi ...
2016-12-09Merge branch 'xfs-4.10-misc-fixes-4' into for-nextDave Chinner
2016-12-09xfs: Always flush caches when integrity is requiredDave Chinner
There is no reason anymore for not issuing device integrity operations when teh filesystem requires ordering or data integrity guarantees. We should always issue cache flushes and FUA writes where necessary and let the underlying storage optimise them as necessary for correct integrity operation. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-07xfs: use rhashtable to track buffer cacheLucas Stach
On filesystems with a lot of metadata and in metadata intensive workloads xfs_buf_find() is showing up at the top of the CPU cycles trace. Most of the CPU time is spent on CPU cache misses while traversing the rbtree. As the buffer cache does not need any kind of ordering, but fast lookups a hashtable is the natural data structure to use. The rhashtable infrastructure provides a self-scaling hashtable implementation and allows lookups to proceed while the table is going through a resize operation. This reduces the CPU-time spent for the lookups to 1/3 even for small filesystems with a relatively small number of cached buffers, with possibly much larger gains on higher loaded filesystems. [dchinner: reduce minimum hash size to an acceptable size for large filesystems with many AGs with no active use.] [dchinner: remove stale rbtree asserts.] [dchinner: use xfs_buf_map for compare function argument.] [dchinner: make functions static.] [dchinner: remove redundant comments.] Signed-off-by: Lucas Stach <dev@lynxeye.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-26xfs: prevent dropping ioend completions during buftarg waitBrian Foster
xfs_wait_buftarg() waits for all pending I/O, drains the ioend completion workqueue and walks the LRU until all buffers in the cache have been released. This is traditionally an unmount operation` but the mechanism is also reused during filesystem freeze. xfs_wait_buftarg() invokes drain_workqueue() as part of the quiesce, which is intended more for a shutdown sequence in that it indicates to the queue that new operations are not expected once the drain has begun. New work jobs after this point result in a WARN_ON_ONCE() and are otherwise dropped. With filesystem freeze, however, read operations are allowed and can proceed during or after the workqueue drain. If such a read occurs during the drain sequence, the workqueue infrastructure complains about the queued ioend completion work item and drops it on the floor. As a result, the buffer remains on the LRU and the freeze never completes. Despite the fact that the overall buffer cache cleanup is not necessary during freeze, fix up this operation such that it is safe to invoke during non-unmount quiesce operations. Replace the drain_workqueue() call with flush_workqueue(), which runs a similar serialization on pending workqueue jobs without causing new jobs to be dropped. This is safe for unmount as unmount independently locks out new operations by the time xfs_wait_buftarg() is invoked. cc: <stable@vger.kernel.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17xfs: don't assert fail on non-async buffers on ioacct decrementBrian Foster
The buffer I/O accounting mechanism tracks async buffers under I/O. As an optimization, the buffer I/O count is incremented only once on the first async I/O for a given hold cycle of a buffer and decremented once the buffer is released to the LRU (or freed). xfs_buf_ioacct_dec() has an ASSERT() check for an XBF_ASYNC buffer, but we have one or two corner cases where a buffer can be submitted for I/O multiple times via different methods in a single hold cycle. If an async I/O occurs first, the I/O count is incremented. If a sync I/O occurs before the hold count drops, XBF_ASYNC is cleared by the time the I/O count is decremented. Remove the async assert check from xfs_buf_ioacct_dec() as this is a perfectly valid scenario. For the purposes of I/O accounting, we really only care about the buffer async state at I/O submission time. Discovered-and-analyzed-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-27Merge tag 'xfs-for-linus-4.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "The major addition is the new iomap based block mapping infrastructure. We've been kicking this about locally for years, but there are other filesystems want to use it too (e.g. gfs2). Now it is fully working, reviewed and ready for merge and be used by other filesystems. There are a lot of other fixes and cleanups in the tree, but those are XFS internal things and none are of the scale or visibility of the iomap changes. See below for details. I am likely to send another pull request next week - we're just about ready to merge some new functionality (on disk block->owner reverse mapping infrastructure), but that's a huge chunk of code (74 files changed, 7283 insertions(+), 1114 deletions(-)) so I'm keeping that separate to all the "normal" pull request changes so they don't get lost in the noise. Summary of changes in this update: - generic iomap based IO path infrastructure - generic iomap based fiemap implementation - xfs iomap based Io path implementation - buffer error handling fixes - tracking of in flight buffer IO for unmount serialisation - direct IO and DAX io path separation and simplification - shortform directory format definition changes for wider platform compatibility - various buffer cache fixes - cleanups in preparation for rmap merge - error injection cleanups and fixes - log item format buffer memory allocation restructuring to prevent rare OOM reclaim deadlocks - sparse inode chunks are now fully supported" * tag 'xfs-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (53 commits) xfs: remove EXPERIMENTAL tag from sparse inode feature xfs: bufferhead chains are invalid after end_page_writeback xfs: allocate log vector buffers outside CIL context lock libxfs: directory node splitting does not have an extra block xfs: remove dax code from object file when disabled xfs: skip dirty pages in ->releasepage() xfs: remove __arch_pack xfs: kill xfs_dir2_inou_t xfs: kill xfs_dir2_sf_off_t xfs: split direct I/O and DAX path xfs: direct calls in the direct I/O path xfs: stop using generic_file_read_iter for direct I/O xfs: split xfs_file_read_iter into buffered and direct I/O helpers xfs: remove s_maxbytes enforcement in xfs_file_read_iter xfs: kill ioflags xfs: don't pass ioflags around in the ioctl path xfs: track and serialize in-flight async buffers against unmount xfs: exclude never-released buffers from buftarg I/O accounting xfs: don't reset b_retries to 0 on every failure xfs: remove extraneous buffer flag changes ...