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  1. 27 7月, 2010 2 次提交
  3. 24 6月, 2010 3 次提交
    • D
      xfs: remove block number from inode lookup code · 7b6259e7
      由 Dave Chinner 提交于 
      The block number comes from bulkstat based inode lookups to shortcut
the mapping calculations. We ar enot able to trust anything from
bulkstat, so drop the block number as well so that the correct
lookups and mappings are always done.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
      7b6259e7
    • D
      xfs: rename XFS_IGET_BULKSTAT to XFS_IGET_UNTRUSTED · 1920779e
      由 Dave Chinner 提交于 
      Inode numbers may come from somewhere external to the filesystem
(e.g. file handles, bulkstat information) and so are inherently
untrusted. Rename the flag we use for these lookups to make it
obvious we are doing a lookup of an untrusted inode number and need
to verify it completely before trying to read it from disk.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
      1920779e
    • D
      xfs: validate untrusted inode numbers during lookup · 7124fe0a
      由 Dave Chinner 提交于 
      When we decode a handle or do a bulkstat lookup, we are using an
inode number we cannot trust to be valid. If we are deleting inode
chunks from disk (default noikeep mode), then we cannot trust the on
disk inode buffer for any given inode number to correctly reflect
whether the inode has been unlinked as the di_mode nor the
generation number may have been updated on disk.

This is due to the fact that when we delete an inode chunk, we do
not write the clusters back to disk when they are removed - instead
we mark them stale to avoid them being written back potentially over
the top of something that has been subsequently allocated at that
location. The result is that we can have locations of disk that look
like they contain valid inodes but in reality do not. Hence we
cannot simply convert the inode number to a block number and read
the location from disk to determine if the inode is valid or not.

As a result, and XFS_IGET_BULKSTAT lookup needs to actually look the
inode up in the inode allocation btree to determine if the inode
number is valid or not.

It should be noted even on ikeep filesystems, there is the
possibility that blocks on disk may look like valid inode clusters.
e.g. if there are filesystem images hosted on the filesystem. Hence
even for ikeep filesystems we really need to validate that the inode
number is valid before issuing the inode buffer read.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
      7124fe0a
  5. 22 1月, 2010 1 次提交
  7. 16 1月, 2010 2 次提交
    • D
      xfs: Replace per-ag array with a radix tree · 1c1c6ebc
      由 Dave Chinner 提交于 
      The use of an array for the per-ag structures requires reallocation
of the array when growing the filesystem. This requires locking
access to the array to avoid use after free situations, and the
locking is difficult to get right. To avoid needing to reallocate an
array, change the per-ag structures to an allocated object per ag
and index them using a tree structure.

The AGs are always densely indexed (hence the use of an array), but
the number supported is 2^32 and lookups tend to be random and hence
indexing needs to scale. A simple choice is a radix tree - it works
well with this sort of index.  This change also removes another
large contiguous allocation from the mount/growfs path in XFS.

The growing process now needs to change to only initialise the new
AGs required for the extra space, and as such only needs to
exclusively lock the tree for inserts. The rest of the code only
needs to lock the tree while doing lookups, and hence this will
remove all the deadlocks that currently occur on the m_perag_lock as
it is now an innermost lock. The lock is also changed to a spinlock
from a read/write lock as the hold time is now extremely short.

To complete the picture, the per-ag structures will need to be
reference counted to ensure that we don't free/modify them while
they are still in use.  This will be done in subsequent patch.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>
      1c1c6ebc
    • D
      xfs: convert remaining direct references to m_perag · 44b56e0a
      由 Dave Chinner 提交于 
      Convert the remaining direct lookups of the per ag structures to use
get/put accesses. Ensure that the loops across AGs and prior users
of the interface balance gets and puts correctly.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>
      44b56e0a
  9. 12 12月, 2009 1 次提交
  11. 30 10月, 2009 1 次提交
    • E
      xfs: free temporary cursor in xfs_dialloc · 3b826386
      由 Eric Sandeen 提交于 
      Commit bd169565 seems
to have a slight regression where this code path:

    if (!--searchdistance) {
        /*
         * Not in range - save last search
         * location and allocate a new inode
         */
        ...
        goto newino;
    }

doesn't free the temporary cursor (tcur) that got dup'd in
this function.

This leaks an item in the xfs_btree_cur zone, and it's caught
on module unload:

===========================================================
BUG xfs_btree_cur: Objects remaining on kmem_cache_close()
-----------------------------------------------------------

It seems like maybe a single free at the end of the function might
be cleaner, but for now put a del_cursor right in this code block
similar to the handling in the rest of the function.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
      3b826386
  13. 02 9月, 2009 8 次提交
  15. 29 3月, 2009 1 次提交
  17. 09 2月, 2009 1 次提交
  19. 19 1月, 2009 1 次提交
  21. 16 1月, 2009 1 次提交
  23. 01 12月, 2008 8 次提交
  25. 30 10月, 2008 8 次提交
  27. 29 4月, 2008 1 次提交
    • D
      [XFS] Don't initialise new inode generation numbers to zero · 359346a9
      由 David Chinner 提交于 
      When we allocation new inode chunks, we initialise the generation numbers
to zero. This works fine until we delete a chunk and then reallocate it,
resulting in the same inode numbers but with a reset generation count.
This can result in inode/generation pairs of different inodes occurring
relatively close together.

Given that the inode/gen pair makes up the "unique" portion of an NFS
filehandle on XFS, this can result in file handles cached on clients being
seen on the wire from the server but refer to a different file. This
causes .... issues for NFS clients.

Hence we need a unique generation number initialisation for each inode to
prevent reuse of a small portion of the generation number space. Use a
random number to initialise the generation number so we don't need to keep
any new state on disk whilst making the new number difficult to guess from
previous allocations.

SGI-PV: 979416
SGI-Modid: xfs-linux-melb:xfs-kern:31001a
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
      359346a9
  29. 18 4月, 2008 1 次提交
    • D
      [XFS] Account for inode cluster alignment in all allocations · 75de2a91
      由 David Chinner 提交于 
      At ENOSPC, we can get a filesystem shutdown due to a cancelling a dirty
transaction in xfs_mkdir or xfs_create. This is due to the initial
allocation attempt not taking into account inode alignment and hence we
can prepare the AGF freelist for allocation when it's not actually
possible to do an allocation. This results in inode allocation returning
ENOSPC with a dirty transaction, and hence we shut down the filesystem.

Because the first allocation is an exact allocation attempt, we must tell
the allocator that the alignment does not affect the allocation attempt.
i.e. we will accept any extent alignment as long as the extent starts at
the block we want. Unfortunately, this means that if the longest free
extent is less than the length + alignment necessary for fallback
allocation attempts but is long enough to attempt a non-aligned
allocation, we will modify the free list.

If we then have the exact allocation fail, all other allocation attempts
will also fail due to the alignment constraint being taken into account.
Hence the initial attempt needs to set the "alignment slop" field so that
alignment, while not required, must be taken into account when determining
if there is enough space left in the AG to do the allocation.

That means if the exact allocation fails, we will not dirty the freelist
if there is not enough space available fo a subsequent allocation to
succeed. Hence we get an ENOSPC error back to userspace without shutting
down the filesystem.

SGI-PV: 978886
SGI-Modid: xfs-linux-melb:xfs-kern:30699a
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
      75de2a91