1. 06 Nov, 2017 13 commits
  2. 03 Nov, 2017 2 commits
    • Darrick J. Wong's avatar
      xfs: scrub: avoid uninitialized return code · 0dca060c
      Darrick J. Wong authored
      The newly added xfs_scrub_da_btree_block() function has one code path
      that returns the 'error' variable without initializing it first, as
      shown by this compiler warning:
      
      fs/xfs/scrub/dabtree.c: In function 'xfs_scrub_da_btree_block':
      fs/xfs/scrub/dabtree.c:462:9: error: 'error' may be used uninitialized in this function [-Werror=maybe-uninitialized]
      
      Return zero since the caller will exit the scrub code if we don't produce a
      buffer pointer.
      
      Fixes: 7c4a07a4 ("xfs: scrub directory/attribute btrees")
      Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      0dca060c
    • Eryu Guan's avatar
      xfs: truncate pagecache before writeback in xfs_setattr_size() · 350976ae
      Eryu Guan authored
      On truncate down, if new size is not block size aligned, we zero the
      rest of block to avoid exposing stale data to user, and
      iomap_truncate_page() skips zeroing if the range is already in
      unwritten state or a hole. Then we writeback from on-disk i_size to
      the new size if this range hasn't been written to disk yet, and
      truncate page cache beyond new EOF and set in-core i_size.
      
      The problem is that we could write data between di_size and newsize
      before removing the page cache beyond newsize, as the extents may
      still be in unwritten state right after a buffer write. As such, the
      page of data that newsize lies in has not been zeroed by page cache
      invalidation before it is written, and xfs_do_writepage() hasn't
      triggered it's "zero data beyond EOF" case because we haven't
      updated in-core i_size yet. Then a subsequent mmap read could see
      non-zeros past EOF.
      
      I occasionally see this in fsx runs in fstests generic/112, a
      simplified fsx operation sequence is like (assuming 4k block size
      xfs):
      
        fallocate 0x0 0x1000 0x0 keep_size
        write 0x0 0x1000 0x0
        truncate 0x0 0x800 0x1000
        punch_hole 0x0 0x800 0x800
        mapread 0x0 0x800 0x800
      
      where fallocate allocates unwritten extent but doesn't update
      i_size, buffer write populates the page cache and extent is still
      unwritten, truncate skips zeroing page past new EOF and writes the
      page to disk, punch_hole invalidates the page cache, at last mapread
      reads the block back and sees non-zero beyond EOF.
      
      Fix it by moving truncate_setsize() to before writeback so the page
      cache invalidation zeros the partial page at the new EOF. This also
      triggers "zero data beyond EOF" in xfs_do_writepage() at writeback
      time, because newsize has been set and page straddles the newsize.
      
      Also fixed the wrong 'end' param of filemap_write_and_wait_range()
      call while we're at it, the 'end' is inclusive and should be
      'newsize - 1'.
      Suggested-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarEryu Guan <eguan@redhat.com>
      Acked-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      350976ae
  3. 01 Nov, 2017 4 commits
  4. 31 Oct, 2017 1 commit
  5. 27 Oct, 2017 4 commits
  6. 26 Oct, 2017 16 commits