1. 23 2月, 2017 17 次提交
  2. 29 1月, 2017 15 次提交
  3. 28 1月, 2017 1 次提交
    • B
      xfs: prevent quotacheck from overloading inode lru · e0d76fa4
      Brian Foster 提交于
      Quotacheck runs at mount time in situations where quota accounting must
      be recalculated. In doing so, it uses bulkstat to visit every inode in
      the filesystem. Historically, every inode processed during quotacheck
      was released and immediately tagged for reclaim because quotacheck runs
      before the superblock is marked active by the VFS. In other words,
      the final iput() lead to an immediate ->destroy_inode() call, which
      allowed the XFS background reclaim worker to start reclaiming inodes.
      
      Commit 17c12bcd ("xfs: when replaying bmap operations, don't let
      unlinked inodes get reaped") marks the XFS superblock active sooner as
      part of the mount process to support caching inodes processed during log
      recovery. This occurs before quotacheck and thus means all inodes
      processed by quotacheck are inserted to the LRU on release.  The
      s_umount lock is held until the mount has completed and thus prevents
      the shrinkers from operating on the sb. This means that quotacheck can
      excessively populate the inode LRU and lead to OOM conditions on systems
      without sufficient RAM.
      
      Update the quotacheck bulkstat handler to set XFS_IGET_DONTCACHE on
      inodes processed by quotacheck. This causes ->drop_inode() to return 1
      and in turn causes iput_final() to evict the inode. This preserves the
      original quotacheck behavior and prevents it from overloading the LRU
      and running out of memory.
      
      CC: stable@vger.kernel.org # v4.9
      Reported-by: NMartin Svec <martin.svec@zoner.cz>
      Signed-off-by: NBrian Foster <bfoster@redhat.com>
      Reviewed-by: NEric Sandeen <sandeen@redhat.com>
      Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      e0d76fa4
  4. 27 1月, 2017 6 次提交
  5. 26 1月, 2017 1 次提交
    • D
      xfs: clear _XBF_PAGES from buffers when readahead page · 2aa6ba7b
      Darrick J. Wong 提交于
      If we try to allocate memory pages to back an xfs_buf that we're trying
      to read, it's possible that we'll be so short on memory that the page
      allocation fails.  For a blocking read we'll just wait, but for
      readahead we simply dump all the pages we've collected so far.
      
      Unfortunately, after dumping the pages we neglect to clear the
      _XBF_PAGES state, which means that the subsequent call to xfs_buf_free
      thinks that b_pages still points to pages we own.  It then double-frees
      the b_pages pages.
      
      This results in screaming about negative page refcounts from the memory
      manager, which xfs oughtn't be triggering.  To reproduce this case,
      mount a filesystem where the size of the inodes far outweighs the
      availalble memory (a ~500M inode filesystem on a VM with 300MB memory
      did the trick here) and run bulkstat in parallel with other memory
      eating processes to put a huge load on the system.  The "check summary"
      phase of xfs_scrub also works for this purpose.
      Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      Reviewed-by: NEric Sandeen <sandeen@redhat.com>
      2aa6ba7b