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2017-09-20xfs: fix multi-AG deadlock in xfs_bunmapiChristoph Hellwig
commit 5b094d6dac0451ad89b1dc088395c7b399b7e9e8 upstream. Just like in the allocator we must avoid touching multiple AGs out of order when freeing blocks, as freeing still locks the AGF and can cause the same AB-BA deadlocks as in the allocation path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: fix quotacheck dquot id overflow infinite loopBrian Foster
commit cfaf2d034360166e569a4929dd83ae9698bed856 upstream. If a dquot has an id of U32_MAX, the next lookup index increment overflows the uint32_t back to 0. This starts the lookup sequence over from the beginning, repeats indefinitely and results in a livelock. Update xfs_qm_dquot_walk() to explicitly check for the lookup overflow and exit the loop. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: check _alloc_read_agf buffer pointer before usingDarrick J. Wong
commit 10479e2dea83d4c421ad05dfc55d918aa8dfc0cd upstream. In some circumstances, _alloc_read_agf can return an error code of zero but also a null AGF buffer pointer. Check for this and jump out. Fixes-coverity-id: 1415250 Fixes-coverity-id: 1415320 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: set firstfsb to NULLFSBLOCK before feeding it to _bmapi_writeDarrick J. Wong
commit 4c1a67bd3606540b9b42caff34a1d5cd94b1cf65 upstream. We must initialize the firstfsb parameter to _bmapi_write so that it doesn't incorrectly treat stack garbage as a restriction on which AGs it can search for free space. Fixes-coverity-id: 1402025 Fixes-coverity-id: 1415167 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: check _btree_check_block valueDarrick J. Wong
commit 1e86eabe73b73c82e1110c746ed3ec6d5e1c0a0d upstream. Check the _btree_check_block return value for the firstrec and lastrec functions, since we have the ability to signal that the repositioning did not succeed. Fixes-coverity-id: 114067 Fixes-coverity-id: 114068 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: don't crash on unexpected holes in dir/attr btreesDarrick J. Wong
commit cd87d867920155911d0d2e6485b769d853547750 upstream. In quite a few places we call xfs_da_read_buf with a mappedbno that we don't control, then assume that the function passes back either an error code or a buffer pointer. Unfortunately, if mappedbno == -2 and bno maps to a hole, we get a return code of zero and a NULL buffer, which means that we crash if we actually try to use that buffer pointer. This happens immediately when we set the buffer type for transaction context. Therefore, check that we have no error code and a non-NULL bp before trying to use bp. This patch is a follow-up to an incomplete fix in 96a3aefb8ffde231 ("xfs: don't crash if reading a directory results in an unexpected hole"). Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: free cowblocks and retry on buffered write ENOSPCBrian Foster
commit cf2cb7845d6e101cb17bd62f8aa08cd514fc8988 upstream. XFS runs an eofblocks reclaim scan before returning an ENOSPC error to userspace for buffered writes. This facilitates aggressive speculative preallocation without causing user visible side effects such as premature ENOSPC. Run a cowblocks scan in the same situation to reclaim lingering COW fork preallocation throughout the filesystem. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: free uncommitted transactions during log recoveryBrian Foster
commit 39775431f82f890f4aaa08860a30883d081bffc7 upstream. Log recovery allocates in-core transaction and member item data structures on-demand as it processes the on-disk log. Transactions are allocated on first encounter on-disk and stored in a hash table structure where they are easily accessible for subsequent lookups. Transaction items are also allocated on demand and are attached to the associated transactions. When a commit record is encountered in the log, the transaction is committed to the fs and the in-core structures are freed. If a filesystem crashes or shuts down before all in-core log buffers are flushed to the log, however, not all transactions may have commit records in the log. As expected, the modifications in such an incomplete transaction are not replayed to the fs. The in-core data structures for the partial transaction are never freed, however, resulting in a memory leak. Update xlog_do_recovery_pass() to first correctly initialize the hash table array so empty lists can be distinguished from populated lists on function exit. Update xlog_recover_free_trans() to always remove the transaction from the list prior to freeing the associated memory. Finally, walk the hash table of transaction lists as the last step before it goes out of scope and free any transactions that may remain on the lists. This prevents a memory leak of partial transactions in the log. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: don't allow bmap on rt filesDarrick J. Wong
commit 61d819e7bcb7f33da710bf3f5dcb2bcf1e48203c upstream. bmap returns a dumb LBA address but not the block device that goes with that LBA. Swapfiles don't care about this and will blindly assume that the data volume is the correct blockdev, which is totally bogus for files on the rt subvolume. This results in the swap code doing IOs to arbitrary locations on the data device(!) if the passed in mapping is a realtime file, so just turn off bmap for rt files. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: remove bli from AIL before release on transaction abortBrian Foster
commit 3d4b4a3e30ae7a949c31e1e10268a3da4723d290 upstream. When a buffer is modified, logged and committed, it ultimately ends up sitting on the AIL with a dirty bli waiting for metadata writeback. If another transaction locks and invalidates the buffer (freeing an inode chunk, for example) in the meantime, the bli is flagged as stale, the dirty state is cleared and the bli remains in the AIL. If a shutdown occurs before the transaction that has invalidated the buffer is committed, the transaction is ultimately aborted. The log items are flagged as such and ->iop_unlock() handles the aborted items. Because the bli is clean (due to the invalidation), ->iop_unlock() unconditionally releases it. The log item may still reside in the AIL, however, which means the I/O completion handler may still run and attempt to access it. This results in assert failure due to the release of the bli while still present in the AIL and a subsequent NULL dereference and panic in the buffer I/O completion handling. This can be reproduced by running generic/388 in repetition. To avoid this problem, update xfs_buf_item_unlock() to first check whether the bli is aborted and if so, remove it from the AIL before it is released. This ensures that the bli is no longer accessed during the shutdown sequence after it has been freed. Signed-off-by: Brian Foster <bfoster@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: release bli from transaction properly on fs shutdownBrian Foster
commit 79e641ce29cfae5b8fc55fb77ac62d11d2d849c0 upstream. If a filesystem shutdown occurs with a buffer log item in the CIL and a log force occurs, the ->iop_unpin() handler is generally expected to tear down the bli properly. This entails freeing the bli memory and releasing the associated hold on the buffer so it can be released and the filesystem unmounted. If this sequence occurs while ->bli_refcount is elevated (i.e., another transaction is open and attempting to modify the buffer), however, ->iop_unpin() may not be responsible for releasing the bli. Instead, the transaction may release the final ->bli_refcount reference and thus xfs_trans_brelse() is responsible for tearing down the bli. While xfs_trans_brelse() does drop the reference count, it only attempts to release the bli if it is clean (i.e., not in the CIL/AIL). If the filesystem is shutdown and the bli is sitting dirty in the CIL as noted above, this ends up skipping the last opportunity to release the bli. In turn, this leaves the hold on the buffer and causes an unmount hang. This can be reproduced by running generic/388 in repetition. Update xfs_trans_brelse() to handle this shutdown corner case correctly. If the final bli reference is dropped and the filesystem is shutdown, remove the bli from the AIL (if necessary) and release the bli to drop the buffer hold and ensure an unmount does not hang. Signed-off-by: Brian Foster <bfoster@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: try to avoid blowing out the transaction reservation when bunmaping a ↵Darrick J. Wong
shared extent commit e1a4e37cc7b665b6804fba812aca2f4d7402c249 upstream. In a pathological scenario where we are trying to bunmapi a single extent in which every other block is shared, it's possible that trying to unmap the entire large extent in a single transaction can generate so many EFIs that we overflow the transaction reservation. Therefore, use a heuristic to guess at the number of blocks we can safely unmap from a reflink file's data fork in an single transaction. This should prevent problems such as the log head slamming into the tail and ASSERTs that trigger because we've exceeded the transaction reservation. Note that since bunmapi can fail to unmap the entire range, we must also teach the deferred unmap code to roll into a new transaction whenever we get low on reservation. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: random edits, all bugs are my fault] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: push buffer of flush locked dquot to avoid quotacheck deadlockBrian Foster
commit 7912e7fef2aebe577f0b46d3cba261f2783c5695 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: fix spurious spin_is_locked() assert failures on non-smp kernelsBrian Foster
commit 95989c46d2a156365867b1d795fdefce71bce378 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-20xfs: Move handling of missing page into one place in ↵Jan Kara
xfs_find_get_desired_pgoff() commit a54fba8f5a0dc36161cacdf2aa90f007f702ec1a upstream. Currently several places in xfs_find_get_desired_pgoff() handle the case of a missing page. Make them all handled in one place after the loop has terminated. Signed-off-by: Jan Kara <jack@suse.cz> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-13xfs: XFS_IS_REALTIME_INODE() should be false if no rt device presentRichard Wareing
commit b31ff3cdf540110da4572e3e29bd172087af65cc upstream. If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on a directory in a filesystem that does not have a realtime device and create a new file in that directory, it gets marked as a real time file. When data is written and a fsync is issued, the filesystem attempts to flush a non-existent rt device during the fsync process. This results in a crash dereferencing a null buftarg pointer in xfs_blkdev_issue_flush(): BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: xfs_blkdev_issue_flush+0xd/0x20 ..... Call Trace: xfs_file_fsync+0x188/0x1c0 vfs_fsync_range+0x3b/0xa0 do_fsync+0x3d/0x70 SyS_fsync+0x10/0x20 do_syscall_64+0x4d/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 Setting RT inode flags does not require special privileges so any unprivileged user can cause this oops to occur. To reproduce, confirm kernel is compiled with CONFIG_XFS_RT=y and run: # mkfs.xfs -f /dev/pmem0 # mount /dev/pmem0 /mnt/test # mkdir /mnt/test/foo # xfs_io -c 'chattr +t' /mnt/test/foo # xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait. Kernels built with CONFIG_XFS_RT=n are not exposed to this bug. Fixes: f538d4da8d52 ("[XFS] write barrier support") Signed-off-by: Richard Wareing <rwareing@fb.com> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-27xfs: Don't clear SGID when inheriting ACLsJan Kara
commit 8ba358756aa08414fa9e65a1a41d28304ed6fd7f upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by calling __xfs_set_acl() instead of xfs_set_acl() when setting up inode in xfs_generic_create(). That prevents SGID bit clearing and mode is properly set by posix_acl_create() anyway. We also reorder arguments of __xfs_set_acl() to match the ordering of xfs_set_acl() to make things consistent. Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: Darrick J. Wong <darrick.wong@oracle.com> CC: linux-xfs@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14fs: add i_blocksize()Fabian Frederick
commit 93407472a21b82f39c955ea7787e5bc7da100642 upstream. Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs branch. This patch also fixes multiple checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Thanks to Andrew Morton for suggesting more appropriate function instead of macro. [geliangtang@gmail.com: truncate: use i_blocksize()] Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: Fix off-by-in in loop termination in xfs_find_get_desired_pgoff()Jan Kara
commit d7fd24257aa60316bf81093f7f909dc9475ae974 upstream. There is an off-by-one error in loop termination conditions in xfs_find_get_desired_pgoff() since 'end' may index a page beyond end of desired range if 'endoff' is page aligned. It doesn't have any visible effects but still it is good to fix it. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix unaligned access in xfs_btree_visit_blocksEric Sandeen
commit a4d768e702de224cc85e0c8eac9311763403b368 upstream. This structure copy was throwing unaligned access warnings on sparc64: Kernel unaligned access at TPC[1043c088] xfs_btree_visit_blocks+0x88/0xe0 [xfs] xfs_btree_copy_ptrs does a memcpy, which avoids it. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: avoid mount-time deadlock in CoW extent recoveryDarrick J. Wong
commit 3ecb3ac7b950ff8f6c6a61e8b7b0d6e3546429a0 upstream. If a malicious user corrupts the refcount btree to cause a cycle between different levels of the tree, the next mount attempt will deadlock in the CoW recovery routine while grabbing buffer locks. We can use the ability to re-grab a buffer that was previous locked to a transaction to avoid deadlocks, so do that here. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: xfs_trans_alloc_emptyChristoph Hellwig
This is a partial cherry-pick of commit e89c041338 ("xfs: implement the GETFSMAP ioctl"), which also adds this helper, and a great example of why feature patches should be properly split into their parts. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: split from the larger patch for -stable] Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-07xfs: bad assertion for delalloc an extent that start at i_sizeZorro Lang
commit 892d2a5f705723b2cb488bfb38bcbdcf83273184 upstream. By run fsstress long enough time enough in RHEL-7, I find an assertion failure (harder to reproduce on linux-4.11, but problem is still there): XFS: Assertion failed: (iflags & BMV_IF_DELALLOC) != 0, file: fs/xfs/xfs_bmap_util.c The assertion is in xfs_getbmap() funciton: if (map[i].br_startblock == DELAYSTARTBLOCK && --> map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip))) ASSERT((iflags & BMV_IF_DELALLOC) != 0); When map[i].br_startoff == XFS_B_TO_FSB(mp, XFS_ISIZE(ip)), the startoff is just at EOF. But we only need to make sure delalloc extents that are within EOF, not include EOF. Signed-off-by: Zorro Lang <zlang@redhat.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: BMAPX shouldn't barf on inline-format directoriesDarrick J. Wong
commit 6eadbf4c8ba816c10d1c97bed9aa861d9fd17809 upstream. When we're fulfilling a BMAPX request, jump out early if the data fork is in local format. This prevents us from hitting a debugging check in bmapi_read and barfing errors back to userspace. The on-disk extent count check later isn't sufficient for IF_DELALLOC mode because da extents are in memory and not on disk. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix indlen accounting error on partial delalloc conversionBrian Foster
commit 0daaecacb83bc6b656a56393ab77a31c28139bc7 upstream. The delalloc -> real block conversion path uses an incorrect calculation in the case where the middle part of a delalloc extent is being converted. This is documented as a rare situation because XFS generally attempts to maximize contiguity by converting as much of a delalloc extent as possible. If this situation does occur, the indlen reservation for the two new delalloc extents left behind by the conversion of the middle range is calculated and compared with the original reservation. If more blocks are required, the delta is allocated from the global block pool. This delta value can be characterized as the difference between the new total requirement (temp + temp2) and the currently available reservation minus those blocks that have already been allocated (startblockval(PREV.br_startblock) - allocated). The problem is that the current code does not account for previously allocated blocks correctly. It subtracts the current allocation count from the (new - old) delta rather than the old indlen reservation. This means that more indlen blocks than have been allocated end up stashed in the remaining extents and free space accounting is broken as a result. Fix up the calculation to subtract the allocated block count from the original extent indlen and thus correctly allocate the reservation delta based on the difference between the new total requirement and the unused blocks from the original reservation. Also remove a bogus assert that contradicts the fact that the new indlen reservation can be larger than the original indlen reservation. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix use-after-free in xfs_finish_page_writebackEryu Guan
commit 161f55efba5ddccc690139fae9373cafc3447a97 upstream. Commit 28b783e47ad7 ("xfs: bufferhead chains are invalid after end_page_writeback") fixed one use-after-free issue by pre-calculating the loop conditionals before calling bh->b_end_io() in the end_io processing loop, but it assigned 'next' pointer before checking end offset boundary & breaking the loop, at which point the bh might be freed already, and caused use-after-free. This is caught by KASAN when running fstests generic/127 on sub-page block size XFS. [ 2517.244502] run fstests generic/127 at 2017-04-27 07:30:50 [ 2747.868840] ================================================================== [ 2747.876949] BUG: KASAN: use-after-free in xfs_destroy_ioend+0x3d3/0x4e0 [xfs] at addr ffff8801395ae698 ... [ 2747.918245] Call Trace: [ 2747.920975] dump_stack+0x63/0x84 [ 2747.924673] kasan_object_err+0x21/0x70 [ 2747.928950] kasan_report+0x271/0x530 [ 2747.933064] ? xfs_destroy_ioend+0x3d3/0x4e0 [xfs] [ 2747.938409] ? end_page_writeback+0xce/0x110 [ 2747.943171] __asan_report_load8_noabort+0x19/0x20 [ 2747.948545] xfs_destroy_ioend+0x3d3/0x4e0 [xfs] [ 2747.953724] xfs_end_io+0x1af/0x2b0 [xfs] [ 2747.958197] process_one_work+0x5ff/0x1000 [ 2747.962766] worker_thread+0xe4/0x10e0 [ 2747.966946] kthread+0x2d3/0x3d0 [ 2747.970546] ? process_one_work+0x1000/0x1000 [ 2747.975405] ? kthread_create_on_node+0xc0/0xc0 [ 2747.980457] ? syscall_return_slowpath+0xe6/0x140 [ 2747.985706] ? do_page_fault+0x30/0x80 [ 2747.989887] ret_from_fork+0x2c/0x40 [ 2747.993874] Object at ffff8801395ae690, in cache buffer_head size: 104 [ 2748.001155] Allocated: [ 2748.003782] PID = 8327 [ 2748.006411] save_stack_trace+0x1b/0x20 [ 2748.010688] save_stack+0x46/0xd0 [ 2748.014383] kasan_kmalloc+0xad/0xe0 [ 2748.018370] kasan_slab_alloc+0x12/0x20 [ 2748.022648] kmem_cache_alloc+0xb8/0x1b0 [ 2748.027024] alloc_buffer_head+0x22/0xc0 [ 2748.031399] alloc_page_buffers+0xd1/0x250 [ 2748.035968] create_empty_buffers+0x30/0x410 [ 2748.040730] create_page_buffers+0x120/0x1b0 [ 2748.045493] __block_write_begin_int+0x17a/0x1800 [ 2748.050740] iomap_write_begin+0x100/0x2f0 [ 2748.055308] iomap_zero_range_actor+0x253/0x5c0 [ 2748.060362] iomap_apply+0x157/0x270 [ 2748.064347] iomap_zero_range+0x5a/0x80 [ 2748.068624] iomap_truncate_page+0x6b/0xa0 [ 2748.073227] xfs_setattr_size+0x1f7/0xa10 [xfs] [ 2748.078312] xfs_vn_setattr_size+0x68/0x140 [xfs] [ 2748.083589] xfs_file_fallocate+0x4ac/0x820 [xfs] [ 2748.088838] vfs_fallocate+0x2cf/0x780 [ 2748.093021] SyS_fallocate+0x48/0x80 [ 2748.097006] do_syscall_64+0x18a/0x430 [ 2748.101186] return_from_SYSCALL_64+0x0/0x6a [ 2748.105948] Freed: [ 2748.108189] PID = 8327 [ 2748.110816] save_stack_trace+0x1b/0x20 [ 2748.115093] save_stack+0x46/0xd0 [ 2748.118788] kasan_slab_free+0x73/0xc0 [ 2748.122969] kmem_cache_free+0x7a/0x200 [ 2748.127247] free_buffer_head+0x41/0x80 [ 2748.131524] try_to_free_buffers+0x178/0x250 [ 2748.136316] xfs_vm_releasepage+0x2e9/0x3d0 [xfs] [ 2748.141563] try_to_release_page+0x100/0x180 [ 2748.146325] invalidate_inode_pages2_range+0x7da/0xcf0 [ 2748.152087] xfs_shift_file_space+0x37d/0x6e0 [xfs] [ 2748.157557] xfs_collapse_file_space+0x49/0x120 [xfs] [ 2748.163223] xfs_file_fallocate+0x2a7/0x820 [xfs] [ 2748.168462] vfs_fallocate+0x2cf/0x780 [ 2748.172642] SyS_fallocate+0x48/0x80 [ 2748.176629] do_syscall_64+0x18a/0x430 [ 2748.180810] return_from_SYSCALL_64+0x0/0x6a Fixed it by checking on offset against end & breaking out first, dereference bh only if there're still bufferheads to process. Signed-off-by: Eryu Guan <eguan@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: reserve enough blocks to handle btree splits when remappingDarrick J. Wong
commit fe0be23e68200573de027de9b8cc2b27e7fce35e upstream. In xfs_reflink_end_cow, we erroneously reserve only enough blocks to handle adding 1 extent. This is problematic if we fragment free space, have to do CoW, and then have to perform multiple bmap btree expansions. Furthermore, the BUI recovery routine doesn't reserve /any/ blocks to handle btree splits, so log recovery fails after our first error causes the filesystem to go down. Therefore, refactor the transaction block reservation macros until we have a macro that works for our deferred (re)mapping activities, and fix both problems by using that macro. With 1k blocks we can hit this fairly often in g/187 if the scratch fs is big enough. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: wait on new inodes during quotaoff dquot releaseBrian Foster
commit e20c8a517f259cb4d258e10b0cd5d4b30d4167a0 upstream. The quotaoff operation has a race with inode allocation that results in a livelock. An inode allocation that occurs before the quota status flags are updated acquires the appropriate dquots for the inode via xfs_qm_vop_dqalloc(). It then inserts the XFS_INEW inode into the perag radix tree, sometime later attaches the dquots to the inode and finally clears the XFS_INEW flag. Quotaoff expects to release the dquots from all inodes in the filesystem via xfs_qm_dqrele_all_inodes(). This invokes the AG inode iterator, which skips inodes in the XFS_INEW state because they are not fully constructed. If the scan occurs after dquots have been attached to an inode, but before XFS_INEW is cleared, the newly allocated inode will continue to hold a reference to the applicable dquots. When quotaoff invokes xfs_qm_dqpurge_all(), the reference count of those dquot(s) remain elevated and the dqpurge scan spins indefinitely. To address this problem, update the xfs_qm_dqrele_all_inodes() scan to wait on inodes marked on the XFS_INEW state. We wait on the inodes explicitly rather than skip and retry to avoid continuous retry loops due to a parallel inode allocation workload. Since quotaoff updates the quota state flags and uses a synchronous transaction before the dqrele scan, and dquots are attached to inodes after radix tree insertion iff quota is enabled, one INEW waiting pass through the AG guarantees that the scan has processed all inodes that could possibly hold dquot references. Reported-by: Eryu Guan <eguan@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: update ag iterator to support wait on new inodesBrian Foster
commit ae2c4ac2dd39b23a87ddb14ceddc3f2872c6aef5 upstream. The AG inode iterator currently skips new inodes as such inodes are inserted into the inode radix tree before they are fully constructed. Certain contexts require the ability to wait on the construction of new inodes, however. The fs-wide dquot release from the quotaoff sequence is an example of this. Update the AG inode iterator to support the ability to wait on inodes flagged with XFS_INEW upon request. Create a new xfs_inode_ag_iterator_flags() interface and support a set of iteration flags to modify the iteration behavior. When the XFS_AGITER_INEW_WAIT flag is set, include XFS_INEW flags in the radix tree inode lookup and wait on them before the callback is executed. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: support ability to wait on new inodesBrian Foster
commit 756baca27fff3ecaeab9dbc7a5ee35a1d7bc0c7f upstream. Inodes that are inserted into the perag tree but still under construction are flagged with the XFS_INEW bit. Most contexts either skip such inodes when they are encountered or have the ability to handle them. The runtime quotaoff sequence introduces a context that must wait for construction of such inodes to correctly ensure that all dquots in the fs are released. In anticipation of this, support the ability to wait on new inodes. Wake the appropriate bit when XFS_INEW is cleared. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix up quotacheck buffer list error handlingBrian Foster
commit 20e8a063786050083fe05b4f45be338c60b49126 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: prevent multi-fsb dir readahead from reading random blocksBrian Foster
commit cb52ee334a45ae6c78a3999e4b473c43ddc528f4 upstream. Directory block readahead uses a complex iteration mechanism to map between high-level directory blocks and underlying physical extents. This mechanism attempts to traverse the higher-level dir blocks in a manner that handles multi-fsb directory blocks and simultaneously maintains a reference to the corresponding physical blocks. This logic doesn't handle certain (discontiguous) physical extent layouts correctly with multi-fsb directory blocks. For example, consider the case of a 4k FSB filesystem with a 2 FSB (8k) directory block size and a directory with the following extent layout: EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL 0: [0..7]: 88..95 0 (88..95) 8 1: [8..15]: 80..87 0 (80..87) 8 2: [16..39]: 168..191 0 (168..191) 24 3: [40..63]: 5242952..5242975 1 (72..95) 24 Directory block 0 spans physical extents 0 and 1, dirblk 1 lies entirely within extent 2 and dirblk 2 spans extents 2 and 3. Because extent 2 is larger than the directory block size, the readahead code erroneously assumes the block is contiguous and issues a readahead based on the physical mapping of the first fsb of the dirblk. This results in read verifier failure and a spurious corruption or crc failure, depending on the filesystem format. Further, the subsequent readahead code responsible for walking through the physical table doesn't correctly advance the physical block reference for dirblk 2. Instead of advancing two physical filesystem blocks, the first iteration of the loop advances 1 block (correctly), but the subsequent iteration advances 2 more physical blocks because the next physical extent (extent 3, above) happens to cover more than dirblk 2. At this point, the higher-level directory block walking is completely off the rails of the actual physical layout of the directory for the respective mapping table. Update the contiguous dirblock logic to consider the current offset in the physical extent to avoid issuing directory readahead to unrelated blocks. Also, update the mapping table advancing code to consider the current offset within the current dirblock to avoid advancing the mapping reference too far beyond the dirblock. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: handle array index overrun in xfs_dir2_leaf_readbuf()Eric Sandeen
commit 023cc840b40fad95c6fe26fff1d380a8c9d45939 upstream. Carlos had a case where "find" seemed to start spinning forever and never return. This was on a filesystem with non-default multi-fsb (8k) directory blocks, and a fragmented directory with extents like this: 0:[0,133646,2,0] 1:[2,195888,1,0] 2:[3,195890,1,0] 3:[4,195892,1,0] 4:[5,195894,1,0] 5:[6,195896,1,0] 6:[7,195898,1,0] 7:[8,195900,1,0] 8:[9,195902,1,0] 9:[10,195908,1,0] 10:[11,195910,1,0] 11:[12,195912,1,0] 12:[13,195914,1,0] ... i.e. the first extent is a contiguous 2-fsb dir block, but after that it is fragmented into 1 block extents. At the top of the readdir path, we allocate a mapping array which (for this filesystem geometry) can hold 10 extents; see the assignment to map_info->map_size. During readdir, we are therefore able to map extents 0 through 9 above into the array for readahead purposes. If we count by 2, we see that the last mapped index (9) is the first block of a 2-fsb directory block. At the end of xfs_dir2_leaf_readbuf() we have 2 loops to fill more readahead; the outer loop assumes one full dir block is processed each loop iteration, and an inner loop that ensures that this is so by advancing to the next extent until a full directory block is mapped. The problem is that this inner loop may step past the last extent in the mapping array as it tries to reach the end of the directory block. This will read garbage for the extent length, and as a result the loop control variable 'j' may become corrupted and never fail the loop conditional. The number of valid mappings we have in our array is stored in map->map_valid, so stop this inner loop based on that limit. There is an ASSERT at the top of the outer loop for this same condition, but we never made it out of the inner loop, so the ASSERT never fired. Huge appreciation for Carlos for debugging and isolating the problem. Debugged-and-analyzed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Tested-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix integer truncation in xfs_bmap_remap_allocChristoph Hellwig
commit 52813fb13ff90bd9c39a93446cbf1103c290b6e9 upstream. bno should be a xfs_fsblock_t, which is 64-bit wides instead of a xfs_aglock_t, which truncates the value to 32 bits. Signed-off-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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: drop iolock from reclaim context to appease lockdepBrian Foster
commit 3b4683c294095b5f777c03307ef8c60f47320e12 upstream. Lockdep complains about use of the iolock in inode reclaim context because it doesn't understand that reclaim has the last reference to the inode, and thus an iolock->reclaim->iolock deadlock is not possible. The iolock is technically not necessary in xfs_inactive() and was only added to appease an assert in xfs_free_eofblocks(), which can be called from other non-reclaim contexts. Therefore, just kill the assert and drop the use of the iolock from reclaim context to quiet lockdep. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: actually report xattr extents via iomapDarrick J. Wong
commit 84358536dc355a9c8978ee425f87e116186bed16 upstream. Apparently FIEMAP for xattrs has been broken since we switched to the iomap backend because of an incorrect check for xattr presence. Also fix the broken locking. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix over-copying of getbmap parameters from userspaceDarrick J. Wong
commit be6324c00c4d1e0e665f03ed1fc18863a88da119 upstream. In xfs_ioc_getbmap, we should only copy the fields of struct getbmap from userspace, or else we end up copying random stack contents into the kernel. struct getbmap is a strict subset of getbmapx, so a partial structure copy should work fine. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: use dedicated log worker wq to avoid deadlock with cil wqBrian Foster
commit 696a562072e3c14bcd13ae5acc19cdf27679e865 upstream. The log covering background task used to be part of the xfssyncd workqueue. That workqueue was removed as of commit 5889608df ("xfs: syncd workqueue is no more") and the associated work item scheduled to the xfs-log wq. The latter is used for log buffer I/O completion. Since xfs_log_worker() can invoke a log flush, a deadlock is possible between the xfs-log and xfs-cil workqueues. Consider the following codepath from xfs_log_worker(): xfs_log_worker() xfs_log_force() _xfs_log_force() xlog_cil_force() xlog_cil_force_lsn() xlog_cil_push_now() flush_work() The above is in xfs-log wq context and blocked waiting on the completion of an xfs-cil work item. Concurrently, the cil push in progress can end up blocked here: xlog_cil_push_work() xlog_cil_push() xlog_write() xlog_state_get_iclog_space() xlog_wait(&log->l_flush_wait, ...) The above is in xfs-cil context waiting on log buffer I/O completion, which executes in xfs-log wq context. In this scenario both workqueues are deadlocked waiting on eachother. Add a new workqueue specifically for the high level log covering and ail pushing worker, as was the case prior to commit 5889608df. Diagnosed-by: David Jeffery <djeffery@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix kernel memory exposure problemsDarrick J. Wong
commit bf9216f922612d2db7666aae01e65064da2ffb3a upstream. Fix a memory exposure problems in inumbers where we allocate an array of structures with holes, fail to zero the holes, then blindly copy the kernel memory contents (junk and all) into userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: rework the inline directory verifiersDarrick J. Wong
commit 78420281a9d74014af7616958806c3aba056319e upstream. The inline directory verifiers should be called on the inode fork data, which means after iformat_local on the read side, and prior to ifork_flush on the write side. This makes the fork verifier more consistent with the way buffer verifiers work -- i.e. they will operate on the memory buffer that the code will be reading and writing directly. Furthermore, revise the verifier function to return -EFSCORRUPTED so that we don't flood the logs with corruption messages and assert notices. This has been a particular problem with xfs/348, which triggers the XFS_WANT_CORRUPTED_RETURN assertions, which halts the kernel when CONFIG_XFS_DEBUG=y. Disk corruption isn't supposed to do that, at least not in a verifier. Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: verify inline directory data forksDarrick J. Wong
commit 630a04e79dd41ff746b545d4fc052e0abb836120 upstream. When we're reading or writing the data fork of an inline directory, check the contents to make sure we're not overflowing buffers or eating garbage data. xfs/348 corrupts an inline symlink into an inline directory, triggering a buffer overflow bug. v2: add more checks consistent with _dir2_sf_check and make the verifier usable from anywhere. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: fix off-by-one on max nr_pages in xfs_find_get_desired_pgoff()Eryu Guan
commit 8affebe16d79ebefb1d9d6d56a46dc89716f9453 upstream. xfs_find_get_desired_pgoff() is used to search for offset of hole or data in page range [index, end] (both inclusive), and the max number of pages to search should be at least one, if end == index. Otherwise the only page is missed and no hole or data is found, which is not correct. When block size is smaller than page size, this can be demonstrated by preallocating a file with size smaller than page size and writing data to the last block. E.g. run this xfs_io command on a 1k block size XFS on x86_64 host. # xfs_io -fc "falloc 0 3k" -c "pwrite 2k 1k" \ -c "seek -d 0" /mnt/xfs/testfile wrote 1024/1024 bytes at offset 2048 1 KiB, 1 ops; 0.0000 sec (33.675 MiB/sec and 34482.7586 ops/sec) Whence Result DATA EOF Data at offset 2k was missed, and lseek(2) returned ENXIO. This is uncovered by generic/285 subtest 07 and 08 on ppc64 host, where pagesize is 64k. Because a recent change to generic/285 reduced the preallocated file size to smaller than 64k. Signed-off-by: Eryu Guan <eguan@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: use ->b_state to fix buffer I/O accounting release raceBrian Foster
commit 63db7c815bc0997c29e484d2409684fdd9fcd93b upstream. 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") 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07xfs: Fix missed holes in SEEK_HOLE implementationJan Kara
commit 5375023ae1266553a7baa0845e82917d8803f48c upstream. XFS SEEK_HOLE implementation could miss a hole in an unwritten extent as can be seen by the following command: xfs_io -c "falloc 0 256k" -c "pwrite 0 56k" -c "pwrite 128k 8k" -c "seek -h 0" file wrote 57344/57344 bytes at offset 0 56 KiB, 14 ops; 0.0000 sec (49.312 MiB/sec and 12623.9856 ops/sec) wrote 8192/8192 bytes at offset 131072 8 KiB, 2 ops; 0.0000 sec (70.383 MiB/sec and 18018.0180 ops/sec) Whence Result HOLE 139264 Where we can see that hole at offset 56k was just ignored by SEEK_HOLE implementation. The bug is in xfs_find_get_desired_pgoff() which does not properly detect the case when pages are not contiguous. Fix the problem by properly detecting when found page has larger offset than expected. Fixes: d126d43f631f996daeee5006714fed914be32368 Signed-off-by: Jan Kara <jack@suse.cz> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-12xfs: Honor FALLOC_FL_KEEP_SIZE when punching ends of filesCalvin Owens
commit 3dd09d5a8589c640abb49cfcf92b4ed669eafad1 upstream. When punching past EOF on XFS, fallocate(mode=PUNCH_HOLE|KEEP_SIZE) will round the file size up to the nearest multiple of PAGE_SIZE: calvinow@vm-disks/generic-xfs-1 ~$ dd if=/dev/urandom of=test bs=2048 count=1 calvinow@vm-disks/generic-xfs-1 ~$ stat test Size: 2048 Blocks: 8 IO Block: 4096 regular file calvinow@vm-disks/generic-xfs-1 ~$ fallocate -n -l 2048 -o 2048 -p test calvinow@vm-disks/generic-xfs-1 ~$ stat test Size: 4096 Blocks: 8 IO Block: 4096 regular file Commit 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") replaced xfs_zero_remaining_bytes() with calls to iomap helpers. The new helpers don't enforce that [pos,offset) lies strictly on [0,i_size) when being called from xfs_free_file_space(), so by "leaking" these ranges into xfs_zero_range() we get this buggy behavior. Fix this by reintroducing the checks xfs_zero_remaining_bytes() did against i_size at the bottom of xfs_free_file_space(). Reported-by: Aaron Gao <gzh@fb.com> Fixes: 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") Cc: Christoph Hellwig <hch@lst.de> Cc: Brian Foster <bfoster@redhat.com> Signed-off-by: Calvin Owens <calvinowens@fb.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08xfs: try any AG when allocating the first btree block when reflinkingChristoph Hellwig
commit 2fcc319d2467a5f5b78f35f79fd6e22741a31b1e upstream. When a reflink operation causes the bmap code to allocate a btree block we're currently doing single-AG allocations due to having ->firstblock set and then try any higher AG due a little reflink quirk we've put in when adding the reflink code. But given that we do not have a minleft reservation of any kind in this AG we can still not have any space in the same or higher AG even if the file system has enough free space. To fix this use a XFS_ALLOCTYPE_FIRST_AG allocation in this fall back path instead. [And yes, we need to redo this properly instead of piling hacks over hacks. I'm working on that, but it's not going to be a small series. In the meantime this fixes the customer reported issue] Also add a warning for failing allocations to make it easier to debug. Signed-off-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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08xfs: use iomap new flag for newly allocated delalloc blocksBrian Foster
commit f65e6fad293b3a5793b7fa2044800506490e7a2e upstream. Commit fa7f138 ("xfs: clear delalloc and cache on buffered write failure") fixed one regression in the iomap error handling code and exposed another. The fundamental problem is that if a buffered write is a rewrite of preexisting delalloc blocks and the write fails, the failure handling code can punch out preexisting blocks with valid file data. This was reproduced directly by sub-block writes in the LTP kernel/syscalls/write/write03 test. A first 100 byte write allocates a single block in a file. A subsequent 100 byte write fails and punches out the block, including the data successfully written by the previous write. To address this problem, update the ->iomap_begin() handler to distinguish newly allocated delalloc blocks from preexisting delalloc blocks via the IOMAP_F_NEW flag. Use this flag in the ->iomap_end() handler to decide when a failed or short write should punch out delalloc blocks. This introduces the subtle requirement that ->iomap_begin() should never combine newly allocated delalloc blocks with existing blocks in the resulting iomap descriptor. This can occur when a new delalloc reservation merges with a neighboring extent that is part of the current write, for example. Therefore, drop the post-allocation extent lookup from xfs_bmapi_reserve_delalloc() and just return the record inserted into the fork. This ensures only new blocks are returned and thus that preexisting delalloc blocks are always handled as "found" blocks and not punched out on a failed rewrite. Reported-by: Xiong Zhou <xzhou@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08xfs: Use xfs_icluster_size_fsb() to calculate inode alignment maskChandan Rajendra
commit d5825712ee98d68a2c17bc89dad2c30276894cba upstream. When block size is larger than inode cluster size, the call to XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size) returns 0. Also, mkfs.xfs would have set xfs_sb->sb_inoalignmt to 0. Hence in xfs_set_inoalignment(), xfs_mount->m_inoalign_mask gets initialized to -1 instead of 0. However, xfs_mount->m_sinoalign would get correctly intialized to 0 because for every positive value of xfs_mount->m_dalign, the condition "!(mp->m_dalign & mp->m_inoalign_mask)" would evaluate to false. Also, xfs_imap() worked fine even with xfs_mount->m_inoalign_mask having -1 as the value because blks_per_cluster variable would have the value 1 and hence we would never have a need to use xfs_mount->m_inoalign_mask to compute the inode chunk's agbno and offset within the chunk. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08xfs: fix and streamline error handling in xfs_end_ioChristoph Hellwig
commit 787eb485509f9d58962bd8b4dbc6a5ac6e2034fe upstream. There are two different cases of buffered I/O errors: - first we can have an already shutdown fs. In that case we should skip any on-disk operations and just clean up the appen transaction if present and destroy the ioend - a real I/O error. In that case we should cleanup any lingering COW blocks. This gets skipped in the current code and is fixed by this patch. Signed-off-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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08xfs: only reclaim unwritten COW extents periodicallyChristoph Hellwig
commit 3802a345321a08093ba2ddb1849e736f84e8d450 upstream. We only want to reclaim preallocations from our periodic work item. Currently this is archived by looking for a dirty inode, but that check is rather fragile. Instead add a flag to xfs_reflink_cancel_cow_* so that the caller can ask for just cancelling unwritten extents in the COW fork. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: fix typos in commit message] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>