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2018-11-21xfs: delalloc -> unwritten COW fork allocation can go wrongDave Chinner1-1/+4
Long saga. There have been days spent following this through dead end after dead end in multi-GB event traces. This morning, after writing a trace-cmd wrapper that enabled me to be more selective about XFS trace points, I discovered that I could get just enough essential tracepoints enabled that there was a 50:50 chance the fsx config would fail at ~115k ops. If it didn't fail at op 115547, I stopped fsx at op 115548 anyway. That gave me two traces - one where the problem manifested, and one where it didn't. After refining the traces to have the necessary information, I found that in the failing case there was a real extent in the COW fork compared to an unwritten extent in the working case. Walking back through the two traces to the point where the CWO fork extents actually diverged, I found that the bad case had an extra unwritten extent in it. This is likely because the bug it led me to had triggered multiple times in those 115k ops, leaving stray COW extents around. What I saw was a COW delalloc conversion to an unwritten extent (as they should always be through xfs_iomap_write_allocate()) resulted in a /written extent/: xfs_writepage: dev 259:0 ino 0x83 pgoff 0x17000 size 0x79a00 offset 0 length 0 xfs_iext_remove: dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/2 offset 32 block 152 count 20 flag 1 caller xfs_bmap_add_extent_delay_real xfs_bmap_pre_update: dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/1 offset 1 block 4503599627239429 count 31 flag 0 caller xfs_bmap_add_extent_delay_real xfs_bmap_post_update: dev 259:0 ino 0x83 state RC|LF|RF|COW cur 0xffff888247b899c0/1 offset 1 block 121 count 51 flag 0 caller xfs_bmap_add_ex Basically, Cow fork before: 0 1 32 52 +H+DDDDDDDDDDDD+UUUUUUUUUUU+ PREV RIGHT COW delalloc conversion allocates: 1 32 +uuuuuuuuuuuu+ NEW And the result according to the xfs_bmap_post_update trace was: 0 1 32 52 +H+wwwwwwwwwwwwwwwwwwwwwwww+ PREV Which is clearly wrong - it should be a merged unwritten extent, not an unwritten extent. That lead me to look at the LEFT_FILLING|RIGHT_FILLING|RIGHT_CONTIG case in xfs_bmap_add_extent_delay_real(), and sure enough, there's the bug. It takes the old delalloc extent (PREV) and adds the length of the RIGHT extent to it, takes the start block from NEW, removes the RIGHT extent and then updates PREV with the new extent. What it fails to do is update PREV.br_state. For delalloc, this is always XFS_EXT_NORM, while in this case we are converting the delayed allocation to unwritten, so it needs to be updated to XFS_EXT_UNWRITTEN. This LF|RF|RC case does not do this, and so the resultant extent is always written. And that's the bug I've been chasing for a week - a bmap btree bug, not a reflink/dedupe/copy_file_range bug, but a BMBT bug introduced with the recent in core extent tree scalability enhancements. Signed-off-by: Dave Chinner <dchinner@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>
2018-11-21xfs: flush removing page cache in xfs_reflink_remap_prepDave Chinner3-5/+17
On a sub-page block size filesystem, fsx is failing with a data corruption after a series of operations involving copying a file with the destination offset beyond EOF of the destination of the file: 8093(157 mod 256): TRUNCATE DOWN from 0x7a120 to 0x50000 ******WWWW 8094(158 mod 256): INSERT 0x25000 thru 0x25fff (0x1000 bytes) 8095(159 mod 256): COPY 0x18000 thru 0x1afff (0x3000 bytes) to 0x2f400 8096(160 mod 256): WRITE 0x5da00 thru 0x651ff (0x7800 bytes) HOLE 8097(161 mod 256): COPY 0x2000 thru 0x5fff (0x4000 bytes) to 0x6fc00 The second copy here is beyond EOF, and it is to sub-page (4k) but block aligned (1k) offset. The clone runs the EOF zeroing, landing in a pre-existing post-eof delalloc extent. This zeroes the post-eof extents in the page cache just fine, dirtying the pages correctly. The problem is that xfs_reflink_remap_prep() now truncates the page cache over the range that it is copying it to, and rounds that down to cover the entire start page. This removes the dirty page over the delalloc extent from the page cache without having written it back. Hence later, when the page cache is flushed, the page at offset 0x6f000 has not been written back and hence exposes stale data, which fsx trips over less than 10 operations later. Fix this by changing xfs_reflink_remap_prep() to use xfs_flush_unmap_range(). Signed-off-by: Dave Chinner <dchinner@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>
2018-11-20xfs: extent shifting doesn't fully invalidate page cacheDave Chinner1-7/+1
The extent shifting code uses a flush and invalidate mechainsm prior to shifting extents around. This is similar to what xfs_free_file_space() does, but it doesn't take into account things like page cache vs block size differences, and it will fail if there is a page that it currently busy. xfs_flush_unmap_range() handles all of these cases, so just convert xfs_prepare_shift() to us that mechanism rather than having it's own special sauce. Signed-off-by: Dave Chinner <dchinner@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>
2018-11-20xfs: finobt AG reserves don't consider last AG can be a runtDave Chinner1-4/+7
The last AG may be very small comapred to all other AGs, and hence AG reservations based on the superblock AG size may actually consume more space than the AG actually has. This results on assert failures like: XFS: Assertion failed: xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= pag->pagf_freeblks + pag->pagf_flcount, file: fs/xfs/libxfs/xfs_ag_resv.c, line: 319 [ 48.932891] xfs_ag_resv_init+0x1bd/0x1d0 [ 48.933853] xfs_fs_reserve_ag_blocks+0x37/0xb0 [ 48.934939] xfs_mountfs+0x5b3/0x920 [ 48.935804] xfs_fs_fill_super+0x462/0x640 [ 48.936784] ? xfs_test_remount_options+0x60/0x60 [ 48.937908] mount_bdev+0x178/0x1b0 [ 48.938751] mount_fs+0x36/0x170 [ 48.939533] vfs_kern_mount.part.43+0x54/0x130 [ 48.940596] do_mount+0x20e/0xcb0 [ 48.941396] ? memdup_user+0x3e/0x70 [ 48.942249] ksys_mount+0xba/0xd0 [ 48.943046] __x64_sys_mount+0x21/0x30 [ 48.943953] do_syscall_64+0x54/0x170 [ 48.944835] entry_SYSCALL_64_after_hwframe+0x49/0xbe Hence we need to ensure the finobt per-ag space reservations take into account the size of the last AG rather than treat it like all the other full size AGs. Note that both refcountbt and rmapbt already take the size of the AG into account via reading the AGF length directly. Signed-off-by: Dave Chinner <dchinner@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>
2018-11-20xfs: fix transient reference count error in xfs_buf_resubmit_failed_buffersDave Chinner1-7/+21
When retrying a failed inode or dquot buffer, xfs_buf_resubmit_failed_buffers() clears all the failed flags from the inde/dquot log items. In doing so, it also drops all the reference counts on the buffer that the failed log items hold. This means it can drop all the active references on the buffer and hence free the buffer before it queues it for write again. Putting the buffer on the delwri queue takes a reference to the buffer (so that it hangs around until it has been written and completed), but this goes bang if the buffer has already been freed. Hence we need to add the buffer to the delwri queue before we remove the failed flags from the log items attached to the buffer to ensure it always remains referenced during the resubmit process. Reported-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dave Chinner <dchinner@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>
2018-11-20xfs: uncached buffer tracing needs to print bnoDave Chinner1-1/+4
Useless: xfs_buf_get_uncached: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_unlock: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_submit: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_hold: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_iowait: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_iodone: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_iowait_done: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_rele: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... Useful: xfs_buf_get_uncached: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_unlock: dev 253:32 bno 0xffffffffffffffff nblks 0x1 ... xfs_buf_submit: dev 253:32 bno 0x200b5 nblks 0x1 ... xfs_buf_hold: dev 253:32 bno 0x200b5 nblks 0x1 ... xfs_buf_iowait: dev 253:32 bno 0x200b5 nblks 0x1 ... xfs_buf_iodone: dev 253:32 bno 0x200b5 nblks 0x1 ... xfs_buf_iowait_done: dev 253:32 bno 0x200b5 nblks 0x1 ... xfs_buf_rele: dev 253:32 bno 0x200b5 nblks 0x1 ... Signed-off-by: Dave Chinner <dchinner@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>
2018-11-19xfs: make xfs_file_remap_range() staticEric Biggers1-1/+1
xfs_file_remap_range() is only used in fs/xfs/xfs_file.c, so make it static. This addresses a gcc warning when -Wmissing-prototypes is enabled. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-19xfs: fix shared extent data corruption due to missing cow reservationBrian Foster1-0/+1
Page writeback indirectly handles shared extents via the existence of overlapping COW fork blocks. If COW fork blocks exist, writeback always performs the associated copy-on-write regardless if the underlying blocks are actually shared. If the blocks are shared, then overlapping COW fork blocks must always exist. fstests shared/010 reproduces a case where a buffered write occurs over a shared block without performing the requisite COW fork reservation. This ultimately causes writeback to the shared extent and data corruption that is detected across md5 checks of the filesystem across a mount cycle. The problem occurs when a buffered write lands over a shared extent that crosses an extent size hint boundary and that also happens to have a partial COW reservation that doesn't cover the start and end blocks of the data fork extent. For example, a buffered write occurs across the file offset (in FSB units) range of [29, 57]. A shared extent exists at blocks [29, 35] and COW reservation already exists at blocks [32, 34]. After accommodating a COW extent size hint of 32 blocks and the existing reservation at offset 32, xfs_reflink_reserve_cow() allocates 32 blocks of reservation at offset 0 and returns with COW reservation across the range of [0, 34]. The associated data fork extent is still [29, 35], however, which isn't fully covered by the COW reservation. This leads to a buffered write at file offset 35 over a shared extent without associated COW reservation. Writeback eventually kicks in, performs an overwrite of the underlying shared block and causes the associated data corruption. Update xfs_reflink_reserve_cow() to accommodate the fact that a delalloc allocation request may not fully cover the extent in the data fork. Trim the data fork extent appropriately, just as is done for shared extent boundaries and/or existing COW reservations that happen to overlap the start of the data fork extent. This prevents shared/010 failures due to data corruption on reflink enabled filesystems. 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>
2018-11-06xfs: fix overflow in xfs_attr3_leaf_verifyDave Chinner1-2/+9
generic/070 on 64k block size filesystems is failing with a verifier corruption on writeback or an attribute leaf block: [ 94.973083] XFS (pmem0): Metadata corruption detected at xfs_attr3_leaf_verify+0x246/0x260, xfs_attr3_leaf block 0x811480 [ 94.975623] XFS (pmem0): Unmount and run xfs_repair [ 94.976720] XFS (pmem0): First 128 bytes of corrupted metadata buffer: [ 94.978270] 000000004b2e7b45: 00 00 00 00 00 00 00 00 3b ee 00 00 00 00 00 00 ........;....... [ 94.980268] 000000006b1db90b: 00 00 00 00 00 81 14 80 00 00 00 00 00 00 00 00 ................ [ 94.982251] 00000000433f2407: 22 7b 5c 82 2d 5c 47 4c bb 31 1c 37 fa a9 ce d6 "{\.-\GL.1.7.... [ 94.984157] 0000000010dc7dfb: 00 00 00 00 00 81 04 8a 00 0a 18 e8 dd 94 01 00 ................ [ 94.986215] 00000000d5a19229: 00 a0 dc f4 fe 98 01 68 f0 d8 07 e0 00 00 00 00 .......h........ [ 94.988171] 00000000521df36c: 0c 2d 32 e2 fe 20 01 00 0c 2d 58 65 fe 0c 01 00 .-2.. ...-Xe.... [ 94.990162] 000000008477ae06: 0c 2d 5b 66 fe 8c 01 00 0c 2d 71 35 fe 7c 01 00 .-[f.....-q5.|.. [ 94.992139] 00000000a4a6bca6: 0c 2d 72 37 fc d4 01 00 0c 2d d8 b8 f0 90 01 00 .-r7.....-...... [ 94.994789] XFS (pmem0): xfs_do_force_shutdown(0x8) called from line 1453 of file fs/xfs/xfs_buf.c. Return address = ffffffff815365f3 This is failing this check: end = ichdr.freemap[i].base + ichdr.freemap[i].size; if (end < ichdr.freemap[i].base) >>>>> return __this_address; if (end > mp->m_attr_geo->blksize) return __this_address; And from the buffer output above, the freemap array is: freemap[0].base = 0x00a0 freemap[0].size = 0xdcf4 end = 0xdd94 freemap[1].base = 0xfe98 freemap[1].size = 0x0168 end = 0x10000 freemap[2].base = 0xf0d8 freemap[2].size = 0x07e0 end = 0xf8b8 These all look valid - the block size is 0x10000 and so from the last check in the above verifier fragment we know that the end of freemap[1] is valid. The problem is that end is declared as: uint16_t end; And (uint16_t)0x10000 = 0. So we have a verifier bug here, not a corruption. Fix the verifier to use uint32_t types for the check and hence avoid the overflow. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=201577 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>
2018-11-06xfs: print buffer offsets when dumping corrupt buffersDarrick J. Wong1-1/+1
Use DUMP_PREFIX_OFFSET when printing hex dumps of corrupt buffers because modern Linux now prints a 32-bit hash of our 64-bit pointer when using DUMP_PREFIX_ADDRESS: 00000000b4bb4297: 00 00 00 00 00 00 00 00 3b ee 00 00 00 00 00 00 ........;....... 00000005ec77e26: 00 00 00 00 02 d0 5a 00 00 00 00 00 00 00 00 00 ......Z......... 000000015938018: 21 98 e8 b4 fd de 4c 07 bc ea 3c e5 ae b4 7c 48 !.....L...<...|H This is totally worthless for a sequential dump since we probably only care about tracking the buffer offsets and afaik there's no way to recover the actual pointer from the hashed value. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-11-06xfs: Fix error code in 'xfs_ioc_getbmap()'Christophe JAILLET1-1/+1
In this function, once 'buf' has been allocated, we unconditionally return 0. However, 'error' is set to some error codes in several error handling paths. Before commit 232b51948b99 ("xfs: simplify the xfs_getbmap interface") this was not an issue because all error paths were returning directly, but now that some cleanup at the end may be needed, we must propagate the error code. Fixes: 232b51948b99 ("xfs: simplify the xfs_getbmap interface") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> 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>
2018-11-02Merge tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds3-161/+109
Pull vfs dedup fixes from Dave Chinner: "This reworks the vfs data cloning infrastructure. We discovered many issues with these interfaces late in the 4.19 cycle - the worst of them (data corruption, setuid stripping) were fixed for XFS in 4.19-rc8, but a larger rework of the infrastructure fixing all the problems was needed. That rework is the contents of this pull request. Rework the vfs_clone_file_range and vfs_dedupe_file_range infrastructure to use a common .remap_file_range method and supply generic bounds and sanity checking functions that are shared with the data write path. The current VFS infrastructure has problems with rlimit, LFS file sizes, file time stamps, maximum filesystem file sizes, stripping setuid bits, etc and so they are addressed in these commits. We also introduce the ability for the ->remap_file_range methods to return short clones so that clones for vfs_copy_file_range() don't get rejected if the entire range can't be cloned. It also allows filesystems to sliently skip deduplication of partial EOF blocks if they are not capable of doing so without requiring errors to be thrown to userspace. Existing filesystems are converted to user the new remap_file_range method, and both XFS and ocfs2 are modified to make use of the new generic checking infrastructure" * tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits) xfs: remove [cm]time update from reflink calls xfs: remove xfs_reflink_remap_range xfs: remove redundant remap partial EOF block checks xfs: support returning partial reflink results xfs: clean up xfs_reflink_remap_blocks call site xfs: fix pagecache truncation prior to reflink ocfs2: remove ocfs2_reflink_remap_range ocfs2: support partial clone range and dedupe range ocfs2: fix pagecache truncation prior to reflink ocfs2: truncate page cache for clone destination file before remapping vfs: clean up generic_remap_file_range_prep return value vfs: hide file range comparison function vfs: enable remap callers that can handle short operations vfs: plumb remap flags through the vfs dedupe functions vfs: plumb remap flags through the vfs clone functions vfs: make remap_file_range functions take and return bytes completed vfs: remap helper should update destination inode metadata vfs: pass remap flags to generic_remap_checks vfs: pass remap flags to generic_remap_file_range_prep vfs: combine the clone and dedupe into a single remap_file_range ...
2018-10-30xfs: remove [cm]time update from reflink callsDarrick J. Wong1-6/+1
Now that the vfs remap helper dirties the inode [cm]time for us, xfs no longer needs to do that on its own. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30xfs: remove xfs_reflink_remap_rangeDarrick J. Wong3-75/+70
Since xfs_file_remap_range is a thin wrapper, move the contents of xfs_reflink_remap_range into the shell. This cuts down on the vfs calls being made from internal xfs code. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30xfs: remove redundant remap partial EOF block checksDarrick J. Wong1-19/+0
Now that we've moved the partial EOF block checks to the VFS helpers, we can remove the redundant functionality from XFS. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30xfs: support returning partial reflink resultsDarrick J. Wong3-10/+14
Back when the XFS reflink code only supported clone_file_range, we were only able to return zero or negative error codes to userspace. However, now that copy_file_range (which returns bytes copied) can use XFS' clone_file_range, we have the opportunity to return partial results. For example, if userspace sends a 1GB clone request and we run out of space halfway through, we at least can tell userspace that we completed 512M of that request like a regular write. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30xfs: clean up xfs_reflink_remap_blocks call siteDarrick J. Wong1-19/+18
Move the offset <-> blocks unit conversions into xfs_reflink_remap_blocks to make the call site less ugly. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30xfs: fix pagecache truncation prior to reflinkDarrick J. Wong1-2/+3
Prior to remapping blocks, it is necessary to remove pages from the destination file's page cache. Unfortunately, the truncation is not aggressive enough -- if page size > block size, we'll end up zeroing subpage blocks instead of removing them. So, round the start offset down and the end offset up to page boundaries. We already wrote all the dirty data so the larger range shouldn't be a problem. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: clean up generic_remap_file_range_prep return valueDarrick J. Wong1-2/+2
Since the remap prep function can update the length of the remap request, we can change this function to return the usual return status instead of the odd behavior it has now. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: make remap_file_range functions take and return bytes completedDarrick J. Wong3-6/+9
Change the remap_file_range functions to take a number of bytes to operate upon and return the number of bytes they operated on. This is a requirement for allowing fs implementations to return short clone/dedupe results to the user, which will enable us to obey resource limits in a graceful manner. A subsequent patch will enable copy_file_range to signal to the ->clone_file_range implementation that it can handle a short length, which will be returned in the function's return value. For now the short return is not implemented anywhere so the behavior won't change -- either copy_file_range manages to clone the entire range or it tries an alternative. Neither clone ioctl can take advantage of this, alas. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: remap helper should update destination inode metadataDarrick J. Wong1-23/+0
Extend generic_remap_file_range_prep to handle inode metadata updates when remapping into a file. If the operation can possibly alter the file contents, we must update the ctime and mtime and remove security privileges, just like we do for regular file writes. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: pass remap flags to generic_remap_file_range_prepDarrick J. Wong3-12/+14
Plumb the remap flags through the filesystem from the vfs function dispatcher all the way to the prep function to prepare for behavior changes in subsequent patches. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: combine the clone and dedupe into a single remap_file_rangeDarrick J. Wong1-16/+7
Combine the clone_file_range and dedupe_file_range operations into a single remap_file_range file operation dispatch since they're fundamentally the same operation. The differences between the two can be made in the prep functions. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: rename vfs_clone_file_prep to be more descriptiveDarrick J. Wong1-1/+1
The vfs_clone_file_prep is a generic function to be called by filesystem implementations only. Rename the prefix to generic_ and make it more clear that it applies to remap operations, not just clones. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-30vfs: check file ranges before cloning filesDarrick J. Wong1-1/+1
Move the file range checks from vfs_clone_file_prep into a separate generic_remap_checks function so that all the checks are collected in a central location. This forms the basis for adding more checks from generic_write_checks that will make cloning's input checking more consistent with write input checking. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: cancel COW blocks before swapextChristoph Hellwig1-0/+6
We need to make sure we have no outstanding COW blocks before we swap extents, as there is nothing preventing us from having preallocated COW delalloc on either inode that swapext is called on. That case can easily be reproduced by running generic/324 in always_cow mode: [ 620.760572] XFS: Assertion failed: tip->i_delayed_blks == 0, file: fs/xfs/xfs_bmap_util.c, line: 1669 [ 620.761608] ------------[ cut here ]------------ [ 620.762171] kernel BUG at fs/xfs/xfs_message.c:102! [ 620.762732] invalid opcode: 0000 [#1] SMP PTI [ 620.763272] CPU: 0 PID: 24153 Comm: xfs_fsr Tainted: G W 4.19.0-rc1+ #4182 [ 620.764203] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 [ 620.765202] RIP: 0010:assfail+0x20/0x28 [ 620.765646] Code: 31 ff e8 83 fc ff ff 0f 0b c3 48 89 f1 41 89 d0 48 c7 c6 48 ca 8d 82 48 89 fa 38 [ 620.767758] RSP: 0018:ffffc9000898bc10 EFLAGS: 00010202 [ 620.768359] RAX: 0000000000000000 RBX: ffff88012f14ba40 RCX: 0000000000000000 [ 620.769174] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828560d9 [ 620.769982] RBP: ffff88012f14b300 R08: 0000000000000000 R09: 0000000000000000 [ 620.770788] R10: 000000000000000a R11: f000000000000000 R12: ffffc9000898bc98 [ 620.771638] R13: ffffc9000898bc9c R14: ffff880130b5e2b8 R15: ffff88012a1fa2a8 [ 620.772504] FS: 00007fdc36e0fbc0(0000) GS:ffff88013ba00000(0000) knlGS:0000000000000000 [ 620.773475] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 620.774168] CR2: 00007fdc3604d000 CR3: 0000000132afc000 CR4: 00000000000006f0 [ 620.774978] Call Trace: [ 620.775274] xfs_swap_extent_forks+0x2a0/0x2e0 [ 620.775792] xfs_swap_extents+0x38b/0xab0 [ 620.776256] xfs_ioc_swapext+0x121/0x140 [ 620.776709] xfs_file_ioctl+0x328/0xc90 [ 620.777154] ? rcu_read_lock_sched_held+0x50/0x60 [ 620.777694] ? xfs_iunlock+0x233/0x260 [ 620.778127] ? xfs_setattr_nonsize+0x3be/0x6a0 [ 620.778647] do_vfs_ioctl+0x9d/0x680 [ 620.779071] ? ksys_fchown+0x47/0x80 [ 620.779552] ksys_ioctl+0x35/0x70 [ 620.780040] __x64_sys_ioctl+0x11/0x20 [ 620.780530] do_syscall_64+0x4b/0x190 [ 620.780927] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 620.781467] RIP: 0033:0x7fdc364d0f07 [ 620.781900] Code: b3 66 90 48 8b 05 81 5f 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 28 [ 620.784044] RSP: 002b:00007ffe2a766038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 620.784896] RAX: ffffffffffffffda RBX: 0000000000000025 RCX: 00007fdc364d0f07 [ 620.785667] RDX: 0000560296ca2fc0 RSI: 00000000c0c0586d RDI: 0000000000000005 [ 620.786398] RBP: 0000000000000025 R08: 0000000000001200 R09: 0000000000000000 [ 620.787283] R10: 0000000000000432 R11: 0000000000000246 R12: 0000000000000005 [ 620.788051] R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000006 [ 620.788927] Modules linked in: [ 620.789340] ---[ end trace 9503b7417ffdbdb0 ]--- [ 620.790065] RIP: 0010:assfail+0x20/0x28 [ 620.790642] Code: 31 ff e8 83 fc ff ff 0f 0b c3 48 89 f1 41 89 d0 48 c7 c6 48 ca 8d 82 48 89 fa 38 [ 620.793038] RSP: 0018:ffffc9000898bc10 EFLAGS: 00010202 [ 620.793609] RAX: 0000000000000000 RBX: ffff88012f14ba40 RCX: 0000000000000000 [ 620.794317] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828560d9 [ 620.795025] RBP: ffff88012f14b300 R08: 0000000000000000 R09: 0000000000000000 [ 620.795778] R10: 000000000000000a R11: f000000000000000 R12: ffffc9000898bc98 [ 620.796675] R13: ffffc9000898bc9c R14: ffff880130b5e2b8 R15: ffff88012a1fa2a8 [ 620.797782] FS: 00007fdc36e0fbc0(0000) GS:ffff88013ba00000(0000) knlGS:0000000000000000 [ 620.798908] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 620.799594] CR2: 00007fdc3604d000 CR3: 0000000132afc000 CR4: 00000000000006f0 [ 620.800424] Kernel panic - not syncing: Fatal exception [ 620.801191] Kernel Offset: disabled [ 620.801597] ---[ end Kernel panic - not syncing: Fatal exception ]--- Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: clear ail delwri queued bufs on unmount of shutdown fsBrian Foster2-6/+29
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>
2018-10-18xfs: use offsetof() in place of offset macros for __xfsstatsCarlos Maiolino2-49/+31
Most offset macro mess is used in xfs_stats_format() only, and we can simply get the right offsets using offsetof(), instead of several macros to mark the offsets inside __xfsstats structure. Replace all XFSSTAT_END_* macros by a single helper macro to get the right offset into __xfsstats, and use this helper in xfs_stats_format() directly. The quota stats code, still looks a bit cleaner when using XFSSTAT_* macros, so, this patch also defines XFSSTAT_START_XQMSTAT and XFSSTAT_END_XQMSTAT locally to that code. This also should prevent offset mistakes when updates are done into __xfsstats. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: Fix xqmstats offsets in /proc/fs/xfs/xqmstatCarlos Maiolino1-1/+1
The addition of FIBT, RMAP and REFCOUNT changed the offsets into __xfssats structure. This caused xqmstat_proc_show() to display garbage data via /proc/fs/xfs/xqmstat, once it relies on the offsets marked via macros. Fix it. Fixes: 00f4e4f9 xfs: add rmap btree stats infrastructure Fixes: aafc3c24 xfs: support the XFS_BTNUM_FINOBT free inode btree type Fixes: 46eeb521 xfs: introduce refcount btree definitions Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: fix use-after-free race in xfs_buf_releDave Chinner1-1/+37
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>
2018-10-18xfs: Add attibute remove and helper functionsAllison Henderson2-11/+26
This patch adds xfs_attr_remove_args. These sub-routines remove the attributes specified in @args. We will use this later for setting parent pointers as a deferred attribute operation. Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: Add attibute set and helper functionsAllison Henderson4-87/+115
This patch adds xfs_attr_set_args and xfs_bmap_set_attrforkoff. These sub-routines set the attributes specified in @args. We will use this later for setting parent pointers as a deferred attribute operation. [dgc: remove attr fork init code from xfs_attr_set_args().] [dgc: xfs_attr_try_sf_addname() NULLs args.trans after commit.] [dgc: correct sf add error handling.] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: Add helper function xfs_attr_try_sf_addnameAllison Henderson1-23/+30
This patch adds a subroutine xfs_attr_try_sf_addname used by xfs_attr_set. This subrotine will attempt to add the attribute name specified in args in shortform, as well and perform error handling previously done in xfs_attr_set. This patch helps to pre-simplify xfs_attr_set for reviewing purposes and reduce indentation. New function will be added in the next patch. [dgc: moved commit to helper function, too.] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: Move fs/xfs/xfs_attr.h to fs/xfs/libxfs/xfs_attr.hAllison Henderson1-0/+0
This patch moves fs/xfs/xfs_attr.h to fs/xfs/libxfs/xfs_attr.h since xfs_attr.c is in libxfs. We will need these later in xfsprogs. Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: issue log message on user force shutdownDave Chinner1-25/+25
The kernel only issues a log message that it's been shut down when the filesystem triggers a shutdown itself. Hence there is no trace in the log when a shutdown is triggered manually from userspace. This can make it hard to see sequence of events in the log when things go wrong, so make sure we always log a message when a shutdown is run. While there, clean up the logic flow so we don't have to continually check if the shutdown trigger was user initiated before logging shutdown messages. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: fix buffer state management in xrep_findroot_blockDarrick J. Wong3-14/+71
We don't handle buffer state properly in online repair's findroot routine. If a buffer already has b_ops set, we don't ever want to touch that, and we don't want to call the read verifiers on a buffer that could be dirty (CRCs are only recomputed during log checkpoints). Therefore, be more careful about what we do with a buffer -- if someone else already attached ops that are not the ones for this btree type, just ignore the buffer. We only attach our btree type's buf ops if it matches the magic/uuid and structure checks. We also modify xfs_buf_read_map to allow callers to set buffer ops on a DONE buffer with NULL ops so that repair doesn't leave behind buffers which won't have buffers attached to them. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: always assign buffer verifiers when one is providedDarrick J. Wong3-17/+78
If a caller supplies buffer ops when trying to read a buffer and the buffer doesn't already have buf ops assigned, ensure that the ops are assigned to the buffer and the verifier is run on that buffer. Note that current XFS code is careful to assign buffer ops after a xfs_{trans_,}buf_read call in which ops were not supplied. However, we should apply ops defensively in case there is ever a coding mistake; and an upcoming repair patch will need to be able to read a buffer without assigning buf ops. 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: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: xrep_findroot_block should reject root blocks with siblingsDarrick J. Wong1-13/+48
In xrep_findroot_block, if we find a candidate root block with sibling pointers or sibling blocks on the same tree level, we should not return that block as a tree root because root blocks cannot have siblings. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: add a define for statfs magic to uapiAdam Borowski1-2/+3
Needed by userspace programs that call fstatfs(). It'd be natural to publish XFS_SB_MAGIC in uapi, but while these two have identical values, they have different semantic meaning: one is an enum cookie meant for statfs, the other a signature of the on-disk format. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: print dangling delalloc extentsChristoph Hellwig1-1/+32
Instead of just asserting that we have no delalloc space dangling in an inode that gets freed print the actual offenders for debug mode. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: fix fork selection in xfs_find_trim_cow_extentChristoph Hellwig1-2/+6
We should want to write directly into the data fork for blocks that don't have an extent in the COW fork covering them yet. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: remove the unused trimmed argument from xfs_reflink_trim_around_sharedChristoph Hellwig4-16/+10
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: remove the unused shared argument to xfs_reflink_reserve_cowChristoph Hellwig3-12/+8
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: handle zeroing in xfs_file_iomap_begin_delayChristoph Hellwig1-6/+38
We only need to allocate blocks for zeroing for reflink inodes, and for we currently have a special case for reflink files in the otherwise direct I/O path that I'd like to get rid of. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: remove suport for filesystems without unwritten extent flagChristoph Hellwig6-94/+12
The option to enable unwritten extents was made default in 2003, removed from mkfs in 2007, and cannot be disabled in v5. We also rely on it for a lot of common functionality, so filesystems without it will run a completely untested and buggy code path. Enabling the support also is a simple bit flip using xfs_db, so legacy file systems can still be brought forward. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18xfs: remove XFS_IO_INVALIDChristoph Hellwig2-10/+8
The invalid state isn't any different from a hole, so merge the two states. Use the more descriptive hole name, but keep it as the first value of the enum to catch uninitialized fields. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-06xfs: fix data corruption w/ unaligned reflink rangesDave Chinner1-13/+34
When reflinking sub-file ranges, a data corruption can occur when the source file range includes a partial EOF block. This shares the unknown data beyond EOF into the second file at a position inside EOF, exposing stale data in the second file. XFS only supports whole block sharing, but we still need to support whole file reflink correctly. Hence if the reflink request includes the last block of the souce file, only proceed with the reflink operation if it lands at or past the destination file's current EOF. If it lands within the destination file EOF, reject the entire request with -EINVAL and make the caller go the hard way. This avoids the data corruption vector, but also avoids disruption of returning EINVAL to userspace for the common case of whole file cloning. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-06xfs: fix data corruption w/ unaligned dedupe rangesDave Chinner1-0/+21
A deduplication data corruption is Exposed by fstests generic/505 on XFS. It is caused by extending the block match range to include the partial EOF block, but then allowing unknown data beyond EOF to be considered a "match" to data in the destination file because the comparison is only made to the end of the source file. This corrupts the destination file when the source extent is shared with it. XFS only supports whole block dedupe, but we still need to appear to support whole file dedupe correctly. Hence if the dedupe request includes the last block of the souce file, don't include it in the actual XFS dedupe operation. If the rest of the range dedupes successfully, then report the partial last block as deduped, too, so that userspace sees it as a successful dedupe rather than return EINVAL because we can't dedupe unaligned blocks. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-05xfs: update ctime and remove suid before cloning filesDarrick J. Wong1-0/+25
Before cloning into a file, update the ctime and remove sensitive attributes like suid, just like we'd do for a regular file write. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-05xfs: zero posteof blocks when cloning above eofDarrick J. Wong1-8/+25
When we're reflinking between two files and the destination file range is well beyond the destination file's EOF marker, zero any posteof speculative preallocations in the destination file so that we don't expose stale disk contents. The previous strategy of trying to clear the preallocations does not work if the destination file has the PREALLOC flag set. Uncovered by shared/010. Reported-by: Zorro Lang <zlang@redhat.com> Bugzilla-id: https://bugzilla.kernel.org/show_bug.cgi?id=201259 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>