- 11 Apr, 2018 2 commits
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Carlos Maiolino authored
Forcing the log to disk after reading the agf is wrong, we might be calling xfs_log_force with XFS_LOG_SYNC with a metadata lock held. This can cause a deadlock when racing a fstrim with a filesystem shutdown. The deadlock has been identified due a miscalculation bug in device-mapper dm-thin, which returns lack of space to its users earlier than the device itself really runs out of space, changing the device-mapper volume into an error state. The problem happened while filling the filesystem with a single file, triggering the bug in device-mapper, consequently causing an IO error and shutting down the filesystem. If such file is removed, and fstrim executed before the XFS finishes the shut down process, the fstrim process will end up holding the buffer lock, and going to sleep on the cil wait queue. At this point, the shut down process will try to wake up all the threads waiting on the cil wait queue, but for this, it will try to hold the same buffer log already held my the fstrim, locking up the filesystem. Signed-off-by:
Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by:
Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:
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Matthew Wilcox authored
XFS currently contains a copy-and-paste of __set_page_dirty(). Export it from buffer.c instead. Signed-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Acked-by:
Jeff Layton <jlayton@kernel.org> Reviewed-by:
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- 10 Apr, 2018 1 commit
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Darrick J. Wong authored
In xfs_itruncate_extents, only cancel cow blocks and clear the reflink flag if we were asked to truncate the data fork. Attr fork blocks cannot be shared, so this makes no sense. Signed-off-by:
Christoph Hellwig <hch@lst.de>
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- 09 Apr, 2018 2 commits
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Eric Sandeen authored
Signed-off-by:
Eric Sandeen <sandeen@redhat.com> Reviewed-by:
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Christoph Hellwig authored
The filestreams allocator stores an xfs_fstrm_item structure in the MRU to cache inode number to agno mappings for a particular length of time. Each xfs_fstrm_item contains the internal MRU structure, an inode pointer and agno value. The inode pointer stored in the xfs_fstrm_item is not referenced, however, which means the inode itself can be removed and reclaimed before the MRU item is freed. If this occurs, xfs_fstrm_free_func() can access freed or unrelated memory through xfs_fstrm_item->ip and crash. The obvious solution is to grab an inode reference for xfs_fstrm_item. The filestream mechanism only actually uses the inode pointer as a means to access the xfs_mount, however. Rather than add unnecessary complexity, simplify the implementation to store an xfs_mount pointer in struct xfs_mru_cache, and pass it to the free callback. This also requires updates to the tracepoint class to provide the associated data via parameters rather than the inode and a minor hack to peek at the MRU key to establish the inode number at free time. Based on debugging work and an earlier patch from Brian Foster, who also wrote most of this changelog. Reported-by:
Brian Foster <bfoster@redhat.com> Signed-off-by:
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- 03 Apr, 2018 1 commit
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Dave Chinner authored
When an intent is aborted during it's initial commit through xfs_defer_trans_abort(), there is a use after free. The current report is for a RUI through this path in generic/388: Freed by task 6274: __kasan_slab_free+0x136/0x180 kmem_cache_free+0xe7/0x4b0 xfs_trans_free_items+0x198/0x2e0 __xfs_trans_commit+0x27f/0xcc0 xfs_trans_roll+0x17b/0x2a0 xfs_defer_trans_roll+0x6ad/0xe60 xfs_defer_finish+0x2a6/0x2140 xfs_alloc_file_space+0x53a/0xf90 xfs_file_fallocate+0x5c6/0xac0 vfs_fallocate+0x2f5/0x930 ioctl_preallocate+0x1dc/0x320 do_vfs_ioctl+0xfe4/0x1690 The problem is that the RUI has two active references - one in the current transaction, and another held by the defer_ops structure that is passed to the RUD (intent done) so that both the intent and the intent done structures are freed on commit of the intent done. Hence during abort, we need to release the intent item, because the defer_ops reference is released separately via ->abort_intent callback. Fix all the intent code to do this correctly. Signed-Off-By:
Dave Chinner <dchinner@redhat.com> Reviewed-by:
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- 02 Apr, 2018 1 commit
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Chandan Rajendra authored
xfs_dir_ialloc() rolls the current transaction when allocation of a new inode required the space manager to perform an allocation and replinish the Inode btree. None of the callers of xfs_dir_ialloc() need to know if the transaction was committed. Hence this commit removes the "committed" argument of xfs_dir_ialloc. Signed-off-by:
Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by:
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- 29 Mar, 2018 1 commit
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Eric Sandeen authored
Today if we run xfs_fsr and crash[1], log replay can fail because the recovery code tries to instantiate the donor inode from disk to replay the swapext, but it's been deleted and we get verifier failures when we try to read the inode off disk with i_mode == 0. This fixes both sides: We don't log the swapext change if the inode has been deleted, and we don't try to recover it either. [1] or if systemd doesn't cleanly unmount root, as it is wont to do ... Signed-off-by:
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- 26 Mar, 2018 1 commit
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Brian Foster authored
Most of the generic data structures embedded in xfs_mount are dynamically initialized immediately after mp is allocated. A few fields are left out and initialized during the xfs_mountfs() sequence, after mp has been attached to the superblock. To clean this up and help prevent premature access of associated fields, refactor xfs_mount allocation and all dependent init calls into a new helper. This self-documents that all low level data structures (i.e., locks, trees, etc.) should be initialized before xfs_mount is attached to the superblock. Signed-off-by:
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- 24 Mar, 2018 17 commits
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Dave Chinner authored
We can only get into the branch if CRCs are enabled, so there's no need to check inside the branch for CRCs being enabled.... Signed-Off-By:
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Dave Chinner authored
We recently came across a V4 filesystem causing memory corruption due to a newly allocated inode being setup twice and being added to the superblock inode list twice. From code inspection, the only way this could happen is if a newly allocated inode was not marked as free on disk (i.e. di_mode wasn't zero). Running the metadump on an upstream debug kernel fails during inode allocation like so: XFS: Assertion failed: ip->i_d.di_nblocks == 0, file: fs/xfs/xfs_inod= e.c, line: 838 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:114! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 11 PID: 3496 Comm: mkdir Not tainted 4.16.0-rc5-dgc #442 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/0= 1/2014 RIP: 0010:assfail+0x28/0x30 RSP: 0018:ffffc9000236fc80 EFLAGS: 00010202 RAX: 00000000ffffffea RBX: 0000000000004000 RCX: 0000000000000000 RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff8227211b RBP: ffffc9000236fce8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000bec R11: f000000000000000 R12: ffffc9000236fd30 R13: ffff8805c76bab80 R14: ffff8805c77ac800 R15: ffff88083fb12e10 FS: 00007fac8cbff040(0000) GS:ffff88083fd00000(0000) knlGS:0000000000000= 000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffa6783ff8 CR3: 00000005c6e2b003 CR4: 00000000000606e0 Call Trace: xfs_ialloc+0x383/0x570 xfs_dir_ialloc+0x6a/0x2a0 xfs_create+0x412/0x670 xfs_generic_create+0x1f7/0x2c0 ? capable_wrt_inode_uidgid+0x3f/0x50 vfs_mkdir+0xfb/0x1b0 SyS_mkdir+0xcf/0xf0 do_syscall_64+0x73/0x1a0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Extracting the inode number we crashed on from an event trace and looking at it with xfs_db: xfs_db> inode 184452204 xfs_db> p core.magic = 0x494e core.mode = 0100644 core.version = 2 core.format = 2 (extents) core.nlinkv2 = 1 core.onlink = 0 ..... Confirms that it is not a free inode on disk. xfs_repair also trips over this inode: ..... zero length extent (off = 0, fsbno = 0) in ino 184452204 correcting nextents for inode 184452204 bad attribute fork in inode 184452204, would clear attr fork bad nblocks 1 for inode 184452204, would reset to 0 bad anextents 1 for inode 184452204, would reset to 0 imap claims in-use inode 184452204 is free, would correct imap would have cleared inode 184452204 ..... disconnected inode 184452204, would move to lost+found And so we have a situation where the directory structure and the inobt thinks the inode is free, but the inode on disk thinks it is still in use. Where this corruption came from is not possible to diagnose, but we can detect it and prevent the kernel from oopsing on lookup. The reproducer now results in: $ sudo mkdir /mnt/scratch/{0,1,2,3,4,5}{0,1,2,3,4,5} mkdir: cannot create directory =E2=80=98/mnt/scratch/00=E2=80=99: File ex= ists mkdir: cannot create directory =E2=80=98/mnt/scratch/01=E2=80=99: File ex= ists mkdir: cannot create directory =E2=80=98/mnt/scratch/03=E2=80=99: Structu= re needs cleaning mkdir: cannot create directory =E2=80=98/mnt/scratch/04=E2=80=99: Input/o= utput error mkdir: cannot create directory =E2=80=98/mnt/scratch/05=E2=80=99: Input/o= utput error .... And this corruption shutdown: [ 54.843517] XFS (loop0): Corruption detected! Free inode 0xafe846c not= marked free on disk [ 54.845885] XFS (loop0): Internal error xfs_trans_cancel at line 1023 = of file fs/xfs/xfs_trans.c. Caller xfs_create+0x425/0x670 [ 54.848994] CPU: 10 PID: 3541 Comm: mkdir Not tainted 4.16.0-rc5-dgc #= 443 [ 54.850753] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIO= S 1.10.2-1 04/01/2014 [ 54.852859] Call Trace: [ 54.853531] dump_stack+0x85/0xc5 [ 54.854385] xfs_trans_cancel+0x197/0x1c0 [ 54.855421] xfs_create+0x425/0x670 [ 54.856314] xfs_generic_create+0x1f7/0x2c0 [ 54.857390] ? capable_wrt_inode_uidgid+0x3f/0x50 [ 54.858586] vfs_mkdir+0xfb/0x1b0 [ 54.859458] SyS_mkdir+0xcf/0xf0 [ 54.860254] do_syscall_64+0x73/0x1a0 [ 54.861193] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 54.862492] RIP: 0033:0x7fb73bddf547 [ 54.863358] RSP: 002b:00007ffdaa553338 EFLAGS: 00000246 ORIG_RAX: 0000= 000000000053 [ 54.865133] RAX: ffffffffffffffda RBX: 00007ffdaa55449a RCX: 00007fb73= bddf547 [ 54.866766] RDX: 0000000000000001 RSI: 00000000000001ff RDI: 00007ffda= a55449a [ 54.868432] RBP: 00007ffdaa55449a R08: 00000000000001ff R09: 00005623a= 8670dd0 [ 54.870110] R10: 00007fb73be72d5b R11: 0000000000000246 R12: 000000000= 00001ff [ 54.871752] R13: 00007ffdaa5534b0 R14: 0000000000000000 R15: 00007ffda= a553500 [ 54.873429] XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1= 024 of file fs/xfs/xfs_trans.c. Return address = ffffffff814cd050 [ 54.882790] XFS (loop0): Corruption of in-memory data detected. Shutt= ing down filesystem [ 54.884597] XFS (loop0): Please umount the filesystem and rectify the = problem(s) Note that this crash is only possible on v4 filesystemsi or v5 filesystems mounted with the ikeep mount option. For all other V5 filesystems, this problem cannot occur because we don't read inodes we are allocating from disk - we simply overwrite them with the new inode information. Signed-Off-By: -
Darrick J. Wong authored
In xfs_scrub_iallocbt_xref_rmap_inodes we're checking inodes against rmap records, so we should use xfs_scrub_btree_xref_set_corrupt if we encounter discrepancies here so that we know that it's a cross referencing error, not necessarily a corruption in the inobt itself. The userspace xfs_scrub program will try to repair outright corruptions in the agi/inobt prior to phase 3 so that the inode scan will proceed. If only a cross-referencing error is noted, the repair program defers the repair attempt until it can check the other space metadata at least once. It is therefore essential that the inobt scrubber can correctly distinguish between corruptions and "unable to cross-reference something else with this inobt". The same reasoning applies to "xfs: record inode buf errors as a xref error in inobt scrubber". Signed-off-by:
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Darrick J. Wong authored
If a directory's parent inode pointer doesn't point to an inode, the directory should be flagged as corrupt. Enable IGET_UNTRUSTED here so that _iget will return -EINVAL if the inobt does not confirm that the inode is present and allocated and we can flag the directory corruption. Signed-off-by:
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Darrick J. Wong authored
When we're verifying inode buffers, sanity-check the unlinked pointer. We don't want to run the risk of trying to purge something that's obviously broken. Signed-off-by:
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Darrick J. Wong authored
Extent size hint validation is used by scrub to decide if there's an error, and it will be used by repair to decide to remove the hint. Since these use the same validation functions, move them to libxfs. Signed-off-by:
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Darrick J. Wong authored
During the inode btree scrubs we try to confirm the freemask bits against the inode records. If the inode buffer read fails, this is a cross-referencing error, not a corruption of the inode btree itself. Use the xref_process_error call here. Found via core.version middlebit fuzz in xfs/415. The userspace xfs_scrub program will try to repair outright corruptions in the agi/inobt prior to phase 3 so that the inode scan will proceed. If only a cross-referencing error is noted, the repair program defers the repair attempt until it can check the other space metadata at least once. It is therefore essential that the inobt scrubber can correctly distinguish between corruptions and "unable to cross-reference something else with this inobt". Signed-off-by:
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Darrick J. Wong authored
Now that we no longer do raw inode buffer scrubbing, the bp parameter is no longer used anywhere we're dealing with an inode, so remove it and all the useless NULL parameters that go with it. Signed-off-by:
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Darrick J. Wong authored
The inode scrubber tries to _iget the inode prior to running checks. If that _iget call fails with corruption errors that's an automatic fail, regardless of whether it was the inode buffer read verifier, the ifork verifier, or the ifork formatter that errored out. Therefore, get rid of the raw mode scrub code because it's not needed. Found by trying to fix some test failures in xfs/379 and xfs/415. Signed-off-by:
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Darrick J. Wong authored
When we're scanning an extent mapping inode fork, ensure that every rmap record for this ifork has a corresponding bmbt record too. This (mostly) provides the ability to cross-reference rmap records with bmap data. The rmap scrubber cannot do the xref on its own because that requires taking an ilock with the agf lock held, which violates our locking order rules (inode, then agf). Note that we only do this for forks that are in btree format due to the increased complexity; or forks that should have data but suspiciously have zero extents because the inode could have just had its iforks zapped by the inode repair code and now we need to reclaim the old extents. Signed-off-by:
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Darrick J. Wong authored
When the inode buffer verifier encounters an error, it's much more helpful to print a buffer from the offending inode instead of just the start of the inode chunk buffer. Signed-off-by:
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Darrick J. Wong authored
Refactor some of the inode verifier failure logging call sites to use the new xfs_inode_verifier_error method which dumps the offending buffer as well as the code location of the failed check. This trims the output, makes it clearer to the admin that repair must be run, and gives the developers more details to work from. Signed-off-by:
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Darrick J. Wong authored
Refactor the bmap validator into a more complete helper that looks for extents that run off the end of the device, overflow into the next AG, or have invalid flag states. Signed-off-by:
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Darrick J. Wong authored
In xfs_dir2_data_use_free, we examine on-disk metadata and ASSERT if it doesn't make sense. Since a carefully crafted fuzzed image can cause the kernel to crash after blowing a bunch of assertions, let's move those checks into a validator function and rig everything up to return EFSCORRUPTED to userspace. Found by lastbit fuzzing ltail.bestcount via xfs/391. Signed-off-by:
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Brian Foster authored
The struct xfs_agfl v5 header was originally introduced with unexpected padding that caused the AGFL to operate with one less slot than intended. The header has since been packed, but the fix left an incompatibility for users who upgrade from an old kernel with the unpacked header to a newer kernel with the packed header while the AGFL happens to wrap around the end. The newer kernel recognizes one extra slot at the physical end of the AGFL that the previous kernel did not. The new kernel will eventually attempt to allocate a block from that slot, which contains invalid data, and cause a crash. This condition can be detected by comparing the active range of the AGFL to the count. While this detects a padding mismatch, it can also trigger false positives for unrelated flcount corruption. Since we cannot distinguish a size mismatch due to padding from unrelated corruption, we can't trust the AGFL enough to simply repopulate the empty slot. Instead, avoid unnecessarily complex detection logic and and use a solution that can handle any form of flcount corruption that slips through read verifiers: distrust the entire AGFL and reset it to an empty state. Any valid blocks within the AGFL are intentionally leaked. This requires xfs_repair to rectify (which was already necessary based on the state the AGFL was found in). The reset mitigates the side effect of the padding mismatch problem from a filesystem crash to a free space accounting inconsistency. The generic approach also means that this patch can be safely backported to kernels with or without a packed struct xfs_agfl. Check the AGF for an invalid freelist count on initial read from disk. If detected, set a flag on the xfs_perag to indicate that a reset is required before the AGFL can be used. In the first transaction that attempts to use a flagged AGFL, reset it to empty, warn the user about the inconsistency and allow the freelist fixup code to repopulate the AGFL with new blocks. The xfs_perag flag is cleared to eliminate the need for repeated checks on each block allocation operation. This allows kernels that include the packing fix commit 96f859d5 ("libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct") to handle older unpacked AGFL formats without a filesystem crash. Suggested-by:
Dave Chinner <david@fromorbit.com> Signed-off-by:
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Christoph Hellwig authored
Instead split out a __xfs_log_fore_lsn helper that gets called again with the already_slept flag set to true in case we had to sleep. This prepares for aio_fsync support. Signed-off-by:
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Christoph Hellwig authored
Use the the smallest possible loop as preable to find the correct iclog buffer, and then use gotos for unwinding to straighten the code. Also fix the top of function comment while we're at it. Signed-off-by:
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- 15 Mar, 2018 6 commits
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Christoph Hellwig authored
Use xfs_iext_prev_extent to skip to the previous extent instead of opencoding it. Signed-off-by:
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Christoph Hellwig authored
Simplify the control flow a bit in preparation for O_ATOMIC-related changes. Signed-off-by:
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Christoph Hellwig authored
This helper doesn't add any real value over just calling iomap_zero_range directly, so remove it. Signed-off-by:
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Christoph Hellwig authored
Now that we convert COW preallocations from unwritten to real on every call this function needs to be called with the ilock held exclusively. Fortunately we already do that, but update the assert to match. Signed-off-by:
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Christoph Hellwig authored
There is no reason to get a mapping bigger than what we were asked for. Signed-off-by:
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Christoph Hellwig authored
i_cnextents does not include delayed allocated extents, so switch to the inode fork size check that we already use in other places instead. Signed-off-by:
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- 14 Mar, 2018 6 commits
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Christoph Hellwig authored
Streamline the conditionals so that it is more obvious which specific case form the top of the function comments is being handled. Use gotos only for early returns. Signed-off-by:
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Christoph Hellwig authored
Switch to a single interface for flushing the log to a specific LSN, which gives consistent trace point coverage and a less confusing interface. The was only a single user of the previous xfs_log_force_lsn function, which now also passes a NULL log_flushed argument. Signed-off-by:
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Christoph Hellwig authored
Switch to a single interface for flushing the whole log, which gives consistent trace point coverage, and removes the unused log_flushed argument for the previous _xfs_log_force callers. Signed-off-by:
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Christoph Hellwig authored
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Christoph Hellwig authored
The function now does something, and that something is central to our inode logging scheme. Signed-off-by:
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Christoph Hellwig authored
Signed-off-by:
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- 12 Mar, 2018 2 commits
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Brian Foster authored
The rmapbt perag metadata reservation reserves blocks for the reverse mapping btree (rmapbt). Since the rmapbt uses blocks from the agfl and perag accounting is updated as blocks are allocated from the allocation btrees, the reservation actually accounts blocks as they are allocated to (or freed from) the agfl rather than the rmapbt itself. While this works for blocks that are eventually used for the rmapbt, not all agfl blocks are destined for the rmapbt. Blocks that are allocated to the agfl (and thus "reserved" for the rmapbt) but then used by another structure leads to a growing inconsistency over time between the runtime tracking of rmapbt usage vs. actual rmapbt usage. Since the runtime tracking thinks all agfl blocks are rmapbt blocks, it essentially believes that less future reservation is required to satisfy the rmapbt than what is actually necessary. The inconsistency is rectified across mount cycles because the perag reservation is initialized based on the actual rmapbt usage at mount time. The problem, however, is that the excessive drain of the reservation at runtime opens a window to allocate blocks for other purposes that might be required for the rmapbt on a subsequent mount. This problem can be demonstrated by a simple test that runs an allocation workload to consume agfl blocks over time and then observe the difference in the agfl reservation requirement across an unmount/mount cycle: mount ...: xfs_ag_resv_init: ... resv 3193 ask 3194 len 3194 ... ... : xfs_ag_resv_alloc_extent: ... resv 2957 ask 3194 len 1 umount...: xfs_ag_resv_free: ... resv 2956 ask 3194 len 0 mount ...: xfs_ag_resv_init: ... resv 3052 ask 3194 len 3194 As the above tracepoints show, the reservation requirement reduces from 3194 blocks to 2956 blocks as the workload runs. Without any other changes in the filesystem, the same reservation requirement jumps from 2956 to 3052 blocks over a umount/mount cycle. To address this divergence, update the RMAPBT reservation to account blocks used for the rmapbt only rather than all blocks filled into the agfl. This patch makes several high-level changes toward that end: 1.) Reintroduce an AGFL reservation type to serve as an accounting no-op for blocks allocated to (or freed from) the AGFL. 2.) Invoke RMAPBT usage accounting from the actual rmapbt block allocation path rather than the AGFL allocation path. The first change is required because agfl blocks are considered free blocks throughout their lifetime. The perag reservation subsystem is invoked unconditionally by the allocation subsystem, so we need a way to tell the perag subsystem (via the allocation subsystem) to not make any accounting changes for blocks filled into the AGFL. The second change causes the in-core RMAPBT reservation usage accounting to remain consistent with the on-disk state at all times and eliminates the risk of leaving the rmapbt reservation underfilled. Signed-off-by: -
Brian Foster authored
The AGFL perag reservation type accounts all allocations that feed into (or are released from) the allocation group free list (agfl). The purpose of the reservation is to support worst case conditions for the reverse mapping btree (rmapbt). As such, the agfl reservation usage accounting only considers rmapbt usage when the in-core counters are initialized at mount time. This implementation inconsistency leads to divergence of the in-core and on-disk usage accounting over time. In preparation to resolve this inconsistency and adjust the AGFL reservation into an rmapbt specific reservation, rename the AGFL reservation type and associated accounting fields to something more rmapbt-specific. Also fix up a couple tracepoints that incorrectly use the AGFL reservation type to pass the agfl state of the associated extent where the raw reservation type is expected. Note that this patch does not change perag reservation behavior. Signed-off-by:
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