1. 07 2月, 2008 7 次提交
  2. 16 10月, 2007 2 次提交
  3. 15 10月, 2007 2 次提交
  4. 05 9月, 2007 1 次提交
  5. 14 7月, 2007 4 次提交
    • D
      [XFS] Lazy Superblock Counters · 92821e2b
      David Chinner 提交于
      When we have a couple of hundred transactions on the fly at once, they all
      typically modify the on disk superblock in some way.
      create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
      free block counts.
      
      When these counts are modified in a transaction, they must eventually lock
      the superblock buffer and apply the mods. The buffer then remains locked
      until the transaction is committed into the incore log buffer. The result
      of this is that with enough transactions on the fly the incore superblock
      buffer becomes a bottleneck.
      
      The result of contention on the incore superblock buffer is that
      transaction rates fall - the more pressure that is put on the superblock
      buffer, the slower things go.
      
      The key to removing the contention is to not require the superblock fields
      in question to be locked. We do that by not marking the superblock dirty
      in the transaction. IOWs, we modify the incore superblock but do not
      modify the cached superblock buffer. In short, we do not log superblock
      modifications to critical fields in the superblock on every transaction.
      In fact we only do it just before we write the superblock to disk every
      sync period or just before unmount.
      
      This creates an interesting problem - if we don't log or write out the
      fields in every transaction, then how do the values get recovered after a
      crash? the answer is simple - we keep enough duplicate, logged information
      in other structures that we can reconstruct the correct count after log
      recovery has been performed.
      
      It is the AGF and AGI structures that contain the duplicate information;
      after recovery, we walk every AGI and AGF and sum their individual
      counters to get the correct value, and we do a transaction into the log to
      correct them. An optimisation of this is that if we have a clean unmount
      record, we know the value in the superblock is correct, so we can avoid
      the summation walk under normal conditions and so mount/recovery times do
      not change under normal operation.
      
      One wrinkle that was discovered during development was that the blocks
      used in the freespace btrees are never accounted for in the AGF counters.
      This was once a valid optimisation to make; when the filesystem is full,
      the free space btrees are empty and consume no space. Hence when it
      matters, the "accounting" is correct. But that means the when we do the
      AGF summations, we would not have a correct count and xfs_check would
      complain. Hence a new counter was added to track the number of blocks used
      by the free space btrees. This is an *on-disk format change*.
      
      As a result of this, lazy superblock counters are a mkfs option and at the
      moment on linux there is no way to convert an old filesystem. This is
      possible - xfs_db can be used to twiddle the right bits and then
      xfs_repair will do the format conversion for you. Similarly, you can
      convert backwards as well. At some point we'll add functionality to
      xfs_admin to do the bit twiddling easily....
      
      SGI-PV: 964999
      SGI-Modid: xfs-linux-melb:xfs-kern:28652a
      Signed-off-by: NDavid Chinner <dgc@sgi.com>
      Signed-off-by: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NTim Shimmin <tes@sgi.com>
      92821e2b
    • D
      [XFS] Fix vmalloc leak on mount/unmount. · 511105b3
      David Chinner 提交于
      When setting the length of the iclogbuf to write out we should just be
      changing the desired byte count rather completely reassociating the buffer
      memory with the buffer. Reassociating the buffer memory changes the
      apparent length of the buffer and hence when we free the buffer, we don't
      free all the vmap()d space we originally allocated.
      
      SGI-PV: 964983
      SGI-Modid: xfs-linux-melb:xfs-kern:28640a
      Signed-off-by: NDavid Chinner <dgc@sgi.com>
      Signed-off-by: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NTim Shimmin <tes@sgi.com>
      511105b3
    • D
      [XFS] Fix use-after-free during log unmount. · 3db296f3
      David Chinner 提交于
      Don't reference the log buffer after running the callbacks as the callback
      can trigger the log buffers to be freed during unmount.
      
      SGI-PV: 964545
      SGI-Modid: xfs-linux-melb:xfs-kern:28567a
      Signed-off-by: NDavid Chinner <dgc@sgi.com>
      Signed-off-by: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NTim Shimmin <tes@sgi.com>
      3db296f3
    • C
      [XFS] Only use refcounted pages for I/O · 1fa40b01
      Christoph Hellwig 提交于
      Many block drivers (aoe, iscsi) really want refcountable pages in bios,
      which is what almost everyone send down. XFS unfortunately has a few
      places where it sends down buffers that may come from kmalloc, which
      breaks them.
      
      Fix the places that use kmalloc()d buffers.
      
      SGI-PV: 964546
      SGI-Modid: xfs-linux-melb:xfs-kern:28562a
      Signed-Off-By: NChristoph Hellwig <hch@infradead.org>
      Signed-off-by: NDavid Chinner <dgc@sgi.com>
      Signed-off-by: NTim Shimmin <tes@sgi.com>
      1fa40b01
  6. 28 9月, 2006 3 次提交
  7. 28 7月, 2006 1 次提交
  8. 28 6月, 2006 1 次提交
  9. 20 6月, 2006 1 次提交
  10. 09 6月, 2006 3 次提交
  11. 29 3月, 2006 1 次提交
  12. 15 1月, 2006 1 次提交
  13. 11 1月, 2006 3 次提交
  14. 02 11月, 2005 6 次提交
  15. 02 9月, 2005 2 次提交
  16. 21 6月, 2005 1 次提交
  17. 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