1. 13 8月, 2013 1 次提交
  2. 06 4月, 2013 1 次提交
    • D
      xfs: don't free EFIs before the EFDs are committed · 666d644c
      Dave Chinner 提交于
      Filesystems are occasionally being shut down with this error:
      
      xfs_trans_ail_delete_bulk: attempting to delete a log item that is
      not in the AIL.
      
      It was diagnosed to be related to the EFI/EFD commit order when the
      EFI and EFD are in different checkpoints and the EFD is committed
      before the EFI here:
      
      http://oss.sgi.com/archives/xfs/2013-01/msg00082.html
      
      The real problem is that a single bit cannot fully describe the
      states that the EFI/EFD processing can be in. These completion
      states are:
      
      EFI			EFI in AIL	EFD		Result
      committed/unpinned	Yes		committed	OK
      committed/pinned	No		committed	Shutdown
      uncommitted		No		committed	Shutdown
      
      
      Note that the "result" field is what should happen, not what does
      happen. The current logic is broken and handles the first two cases
      correctly by luck.  That is, the code will free the EFI if the
      XFS_EFI_COMMITTED bit is *not* set, rather than if it is set. The
      inverted logic "works" because if both EFI and EFD are committed,
      then the first __xfs_efi_release() call clears the XFS_EFI_COMMITTED
      bit, and the second frees the EFI item. Hence as long as
      xfs_efi_item_committed() has been called, everything appears to be
      fine.
      
      It is the third case where the logic fails - where
      xfs_efd_item_committed() is called before xfs_efi_item_committed(),
      and that results in the EFI being freed before it has been
      committed. That is the bug that triggered the shutdown, and hence
      keeping track of whether the EFI has been committed or not is
      insufficient to correctly order the EFI/EFD operations w.r.t. the
      AIL.
      
      What we really want is this: the EFI is always placed into the
      AIL before the last reference goes away. The only way to guarantee
      that is that the EFI is not freed until after it has been unpinned
      *and* the EFD has been committed. That is, restructure the logic so
      that the only case that can occur is the first case.
      
      This can be done easily by replacing the XFS_EFI_COMMITTED with an
      EFI reference count. The EFI is initialised with it's own count, and
      that is not released until it is unpinned. However, there is a
      complication to this method - the high level EFI/EFD code in
      xfs_bmap_finish() does not hold direct references to the EFI
      structure, and runs a transaction commit between the EFI and EFD
      processing. Hence the EFI can be freed even before the EFD is
      created using such a method.
      
      Further, log recovery uses the AIL for tracking EFI/EFDs that need
      to be recovered, but it uses the AIL *differently* to the EFI
      transaction commit. Hence log recovery never pins or unpins EFIs, so
      we can't drop the EFI reference count indirectly to free the EFI.
      
      However, this doesn't prevent us from using a reference count here.
      There is a 1:1 relationship between EFIs and EFDs, so when we
      initialise the EFI we can take a reference count for the EFD as
      well. This solves the xfs_bmap_finish() issue - the EFI will never
      be freed until the EFD is processed. In terms of log recovery,
      during the committing of the EFD we can look for the
      XFS_EFI_RECOVERED bit being set and drop the EFI reference as well,
      thereby ensuring everything works correctly there as well.
      Signed-off-by: NDave Chinner <dchinner@redhat.com>
      Reviewed-by: NMark Tinguely <tinguely@sgi.com>
      Signed-off-by: NBen Myers <bpm@sgi.com>
      666d644c
  3. 20 12月, 2010 2 次提交
    • D
      xfs: Pull EFI/EFD handling out from under the AIL lock · b199c8a4
      Dave Chinner 提交于
      EFI/EFD interactions are protected from races by the AIL lock. They
      are the only type of log items that require the the AIL lock to
      serialise internal state, so they need to be separated from the AIL
      lock before we can do bulk insert operations on the AIL.
      
      To acheive this, convert the counter of the number of extents in the
      EFI to an atomic so it can be safely manipulated by EFD processing
      without locks. Also, convert the EFI state flag manipulations to use
      atomic bit operations so no locks are needed to record state
      changes. Finally, use the state bits to determine when it is safe to
      free the EFI and clean up the code to do this neatly.
      Signed-off-by: NDave Chinner <dchinner@redhat.com>
      Reviewed-by: NChristoph Hellwig <hch@lst.de>
      b199c8a4
    • D
      xfs: fix EFI transaction cancellation. · 9c5f8414
      Dave Chinner 提交于
      XFS_EFI_CANCELED has not been set in the code base since
      xfs_efi_cancel() was removed back in 2006 by commit
      065d312e ("[XFS] Remove unused
      iop_abort log item operation), and even then xfs_efi_cancel() was
      never called. I haven't tracked it back further than that (beyond
      git history), but it indicates that the handling of EFIs in
      cancelled transactions has been broken for a long time.
      
      Basically, when we get an IOP_UNPIN(lip, 1); call from
      xfs_trans_uncommit() (i.e. remove == 1), if we don't free the log
      item descriptor we leak it. Fix the behviour to be correct and kill
      the XFS_EFI_CANCELED flag.
      Signed-off-by: NDave Chinner <dchinner@redhat.com>
      Reviewed-by: NChristoph Hellwig <hch@lst.de>
      9c5f8414
  4. 22 1月, 2009 1 次提交
  5. 28 9月, 2006 1 次提交
  6. 09 6月, 2006 1 次提交
  7. 02 11月, 2005 1 次提交
  8. 21 6月, 2005 1 次提交
  9. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4