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  1. 05 6月, 2009 1 次提交
    • C
      Btrfs: Fix oops and use after free during space balancing · 44fb5511
      由 Chris Mason 提交于 
      The btrfs allocator uses list_for_each to walk the available block
groups when searching for free blocks.  It starts off with a hint
to help find the best block group for a given allocation.

The hint is resolved into a block group, but we don't properly check
to make sure the block group we find isn't in the middle of being
freed due to filesystem shrinking or balancing.  If it is being
freed, the list pointers in it are bogus and can't be trusted.  But,
the code happily goes along and uses them in the list_for_each loop,
leading to all kinds of fun.

The fix used here is to check to make sure the block group we find really
is on the list before we use it.  list_del_init is used when removing
it from the list, so we can do a proper check.

The allocation clustering code has a similar bug where it will trust
the block group in the current free space cluster.  If our allocation
flags have changed (going from single spindle dup to raid1 for example)
because the drives in the FS have changed, we're not allowed to use
the old block group any more.

The fix used here is to check the current cluster against the
current allocation flags.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      44fb5511
  3. 04 6月, 2009 1 次提交
  5. 15 5月, 2009 6 次提交
  7. 28 4月, 2009 2 次提交
    • C
      Btrfs: look for acls during btrfs_read_locked_inode · 46a53cca
      由 Chris Mason 提交于 
      This changes btrfs_read_locked_inode() to peek ahead in the btree for acl items.
If it is certain a given inode has no acls, it will set the in memory acl
fields to null to avoid acl lookups completely.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      46a53cca
    • C
      Btrfs: fix acl caching · 7b1a14bb
      由 Chris Mason 提交于 
      Linus noticed the btrfs code to cache acls wasn't properly caching
a NULL acl when the inode didn't have any acls.  This meant the common
case of no acls resulted in expensive btree searches every time the
kernel checked permissions (which is quite often).

This is a modified version of Linus' original patch:

Properly set initial acl fields to BTRFS_ACL_NOT_CACHED in the inode.
This forces an acl lookup when permission checks are done.

Fix btrfs_get_acl to avoid lookups and locking when the inode acls fields
are set to null.

Fix btrfs_get_acl to use the right return value from __btrfs_getxattr
when deciding to cache a NULL acl.  It was storing a NULL acl when
__btrfs_getxattr return -ENOENT, but __btrfs_getxattr was actually returning
-ENODATA for this case.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      7b1a14bb
  9. 27 4月, 2009 6 次提交
  11. 25 4月, 2009 6 次提交
  13. 22 4月, 2009 1 次提交
    • C
      Btrfs: fix btrfs fallocate oops and deadlock · 546888da
      由 Chris Mason 提交于 
      Btrfs fallocate was incorrectly starting a transaction with a lock held
on the extent_io tree for the file, which could deadlock.  Strictly
speaking it was using join_transaction which would be safe, but it is better
to move the transaction outside of the lock.

When preallocated extents are overwritten, btrfs_mark_buffer_dirty was
being called on an unlocked buffer.  This was triggering an assertion and
oops because the lock is supposed to be held.

The bug was calling btrfs_mark_buffer_dirty on a leaf after btrfs_del_item had
been run.  btrfs_del_item takes care of dirtying things, so the solution is a
to skip the btrfs_mark_buffer_dirty call in this case.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      546888da
  15. 21 4月, 2009 4 次提交
    • C
      Btrfs: use the right node in reada_for_balance · 8c594ea8
      由 Chris Mason 提交于 
      reada_for_balance was using the wrong index into the path node array,
so it wasn't reading the right blocks.  We never directly used the
results of the read done by this function because the btree search is
started over at the end.

This fixes reada_for_balance to reada in the correct node and to
avoid searching past the last slot in the node.  It also makes sure to
hold the parent lock while we are finding the nodes to read.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      8c594ea8
    • C
      Btrfs: fix oops on page->mapping->host during writepage · 11c8349b
      由 Chris Mason 提交于 
      The extent_io writepage call updates the writepage index in the inode
as it makes progress.  But, it was doing the update after unlocking the page,
which isn't legal because page->mapping can't be trusted once the page
is unlocked.

This lead to an oops, especially common with compression turned on.  The
fix here is to update the writeback index before unlocking the page.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      11c8349b
    • C
      Btrfs: add a priority queue to the async thread helpers · d313d7a3
      由 Chris Mason 提交于 
      Btrfs is using WRITE_SYNC_PLUG to send down synchronous IOs with a
higher priority.  But, the checksumming helper threads prevent it
from being fully effective.

There are two problems.  First, a big queue of pending checksumming
will delay the synchronous IO behind other lower priority writes.  Second,
the checksumming uses an ordered async work queue.  The ordering makes sure
that IOs are sent to the block layer in the same order they are sent
to the checksumming threads.  Usually this gives us less seeky IO.

But, when we start mixing IO priorities, the lower priority IO can delay
the higher priority IO.

This patch solves both problems by adding a high priority list to the async
helper threads, and a new btrfs_set_work_high_prio(), which is used
to make put a new async work item onto the higher priority list.

The ordering is still done on high priority IO, but all of the high
priority bios are ordered separately from the low priority bios.  This
ordering is purely an IO optimization, it is not involved in data
or metadata integrity.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      d313d7a3
    • C
      Btrfs: use WRITE_SYNC for synchronous writes · ffbd517d
      由 Chris Mason 提交于 
      Part of reducing fsync/O_SYNC/O_DIRECT latencies is using WRITE_SYNC for
writes we plan on waiting on in the near future.  This patch
mirrors recent changes in other filesystems and the generic code to
use WRITE_SYNC when WB_SYNC_ALL is passed and to use WRITE_SYNC for
other latency critical writes.

Btrfs uses async worker threads for checksumming before the write is done,
and then again to actually submit the bios.  The bio submission code just
runs a per-device list of bios that need to be sent down the pipe.

This list is split into low priority and high priority lists so the
WRITE_SYNC IO happens first.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      ffbd517d
  17. 15 4月, 2009 10 次提交
  19. 14 4月, 2009 3 次提交