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commit bd5ff862ec7855cc7a110891443e7dc6deeb6b84
parent adcbc921d3dff0bf1657d4d31beee68f92f51538
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri,  8 Feb 2019 10:46:14 -0800

Merge tag 'xfs-5.0-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
 "Here are a handful of XFS fixes to fix a data corruption problem, a
  crasher bug, and a deadlock.

  Summary:

   - Fix cache coherency problem with writeback mappings

   - Fix buffer deadlock when shutting fs down

   - Fix a null pointer dereference when running online repair"

* tag 'xfs-5.0-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: set buffer ops when repair probes for btree type
  xfs: end sync buffer I/O properly on shutdown error
  xfs: eof trim writeback mapping as soon as it is cached

Diffstat:
Mfs/xfs/scrub/repair.c | 11++++++++---
Mfs/xfs/xfs_aops.c | 2++
Mfs/xfs/xfs_buf.c | 19+++++++++++++++++--
3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c @@ -768,18 +768,23 @@ xrep_findroot_block( if (!uuid_equal(&btblock->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) goto out; + /* + * Read verifiers can reference b_ops, so we set the pointer + * here. If the verifier fails we'll reset the buffer state + * to what it was before we touched the buffer. + */ + bp->b_ops = fab->buf_ops; fab->buf_ops->verify_read(bp); if (bp->b_error) { + bp->b_ops = NULL; bp->b_error = 0; goto out; } /* * Some read verifiers will (re)set b_ops, so we must be - * careful not to blow away any such assignment. + * careful not to change b_ops after running the verifier. */ - if (!bp->b_ops) - bp->b_ops = fab->buf_ops; } /* diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c @@ -449,6 +449,7 @@ xfs_map_blocks( } wpc->imap = imap; + xfs_trim_extent_eof(&wpc->imap, ip); trace_xfs_map_blocks_found(ip, offset, count, wpc->io_type, &imap); return 0; allocate_blocks: @@ -459,6 +460,7 @@ allocate_blocks: ASSERT(whichfork == XFS_COW_FORK || cow_fsb == NULLFILEOFF || imap.br_startoff + imap.br_blockcount <= cow_fsb); wpc->imap = imap; + xfs_trim_extent_eof(&wpc->imap, ip); trace_xfs_map_blocks_alloc(ip, offset, count, wpc->io_type, &imap); return 0; } diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c @@ -776,10 +776,26 @@ _xfs_buf_read( } /* + * Set buffer ops on an unchecked buffer and validate it, if possible. + * * If the caller passed in an ops structure and the buffer doesn't have ops * assigned, set the ops and use them to verify the contents. If the contents * cannot be verified, we'll clear XBF_DONE. We assume the buffer has no * recorded errors and is already in XBF_DONE state. + * + * Under normal operations, every in-core buffer must have buffer ops assigned + * to them when the buffer is read in from disk so that we can validate the + * metadata. + * + * However, there are two scenarios where one can encounter in-core buffers + * that don't have buffer ops. The first is during log recovery of buffers on + * a V4 filesystem, though these buffers are purged at the end of recovery. + * + * The other is online repair, which tries to match arbitrary metadata blocks + * with btree types in order to find the root. If online repair doesn't match + * the buffer with /any/ btree type, the buffer remains in memory in DONE state + * with no ops, and a subsequent read_buf call from elsewhere will not set the + * ops. This function helps us fix this situation. */ int xfs_buf_ensure_ops( @@ -1536,8 +1552,7 @@ __xfs_buf_submit( xfs_buf_ioerror(bp, -EIO); bp->b_flags &= ~XBF_DONE; xfs_buf_stale(bp); - if (bp->b_flags & XBF_ASYNC) - xfs_buf_ioend(bp); + xfs_buf_ioend(bp); return -EIO; }