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  1. 27 10月, 2017 22 次提交
  3. 24 10月, 2017 1 次提交
  5. 19 10月, 2017 1 次提交
  7. 17 10月, 2017 3 次提交
    • A
      xfs: move two more RT specific functions into CONFIG_XFS_RT · 785545c8
      由 Arnd Bergmann 提交于 
      The last cleanup introduced two harmless warnings:

fs/xfs/xfs_fsmap.c:480:1: warning: '__xfs_getfsmap_rtdev' defined but not used
fs/xfs/xfs_fsmap.c:372:1: warning: 'xfs_getfsmap_rtdev_rtbitmap_helper' defined but not used

This moves those two functions as well.

Fixes: bb9c2e54 ("xfs: move more RT specific code under CONFIG_XFS_RT")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      785545c8
    • B
      xfs: trim writepage mapping to within eof · 40214d12
      由 Brian Foster 提交于 
      The writeback rework in commit fbcc0256 ("xfs: Introduce
writeback context for writepages") introduced a subtle change in
behavior with regard to the block mapping used across the
->writepages() sequence. The previous xfs_cluster_write() code would
only flush pages up to EOF at the time of the writepage, thus
ensuring that any pages due to file-extending writes would be
handled on a separate cycle and with a new, updated block mapping.

The updated code establishes a block mapping in xfs_writepage_map()
that could extend beyond EOF if the file has post-eof preallocation.
Because we now use the generic writeback infrastructure and pass the
cached mapping to each writepage call, there is no implicit EOF
limit in place. If eofblocks trimming occurs during ->writepages(),
any post-eof portion of the cached mapping becomes invalid. The
eofblocks code has no means to serialize against writeback because
there are no pages associated with post-eof blocks. Therefore if an
eofblocks trim occurs and is followed by a file-extending buffered
write, not only has the mapping become invalid, but we could end up
writing a page to disk based on the invalid mapping.

Consider the following sequence of events:

- A buffered write creates a delalloc extent and post-eof
  speculative preallocation.
- Writeback starts and on the first writepage cycle, the delalloc
  extent is converted to real blocks (including the post-eof blocks)
  and the mapping is cached.
- The file is closed and xfs_release() trims post-eof blocks. The
  cached writeback mapping is now invalid.
- Another buffered write appends the file with a delalloc extent.
- The concurrent writeback cycle picks up the just written page
  because the writeback range end is LLONG_MAX. xfs_writepage_map()
  attributes it to the (now invalid) cached mapping and writes the
  data to an incorrect location on disk (and where the file offset is
  still backed by a delalloc extent).

This problem is reproduced by xfstests test generic/464, which
triggers racing writes, appends, open/closes and writeback requests.

To address this problem, trim the mapping used during writeback to
within EOF when the mapping is validated. This ensures the mapping
is revalidated for any pages encountered beyond EOF as of the time
the current mapping was cached or last validated.
Reported-by: NEryu Guan <eguan@redhat.com>
Diagnosed-by: NEryu Guan <eguan@redhat.com>
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      40214d12
    • D
      xfs: cancel dirty pages on invalidation · 793d7dbe
      由 Dave Chinner 提交于 
      Recently we've had warnings arise from the vm handing us pages
without bufferheads attached to them. This should not ever occur
in XFS, but we don't defend against it properly if it does. The only
place where we remove bufferheads from a page is in
xfs_vm_releasepage(), but we can't tell the difference here between
"page is dirty so don't release" and "page is dirty but is being
invalidated so release it".

In some places that are invalidating pages ask for pages to be
released and follow up afterward calling ->releasepage by checking
whether the page was dirty and then aborting the invalidation. This
is a possible vector for releasing buffers from a page but then
leaving it in the mapping, so we really do need to avoid dirty pages
in xfs_vm_releasepage().

To differentiate between invalidated pages and normal pages, we need
to clear the page dirty flag when invalidating the pages. This can
be done through xfs_vm_invalidatepage(), and will result
xfs_vm_releasepage() seeing the page as clean which matches the
bufferhead state on the page after calling block_invalidatepage().

Hence we can re-add the page dirty check in xfs_vm_releasepage to
catch the case where we might be releasing a page that is actually
dirty and so should not have the bufferheads on it removed. This
will remove one possible vector of "dirty page with no bufferheads"
and so help narrow down the search for the root cause of that
problem.
Signed-Off-By: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      793d7dbe
  9. 12 10月, 2017 6 次提交
  11. 04 10月, 2017 2 次提交
  13. 27 9月, 2017 5 次提交