Doug / smarc-fsl-linux-kernel

06 May, 2011

1 commit

  • f2a97a9db   btrfs: remove all unused functions ... Browse Code »

    Remove static and global declarations and/or definitions. Reduces size
    of btrfs.ko by ~3.4kB.

    text data bss dec hex filename
    402081 7464 200 409745 64091 btrfs.ko.base
    398620 7144 200 405964 631cc btrfs.ko.remove-all

    Signed-off-by: David Sterba

    David Sterba
     

09 Mar, 2010

1 commit

  • 6bef4d317   Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULL ... Browse Code »

    btrfs inialize rb trees in quite a number of places by settin rb_node =
    NULL; The problem with this is that 17d9ddc72fb8bba0d4f678 in the
    linux-next tree adds a new field to that struct which needs to be NULL for
    the new rbtree library code to work properly. This patch uses RB_ROOT as
    the intializer so all of the relevant fields will be NULL'd. Without the
    patch I get a panic.

    Signed-off-by: Eric Paris
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Chris Mason

    Eric Paris
     

04 Feb, 2009

1 commit

  • bd56b3020   Btrfs: Make btrfs_drop_snapshot work in larger and more efficient chunks ... Browse Code »

    Every transaction in btrfs creates a new snapshot, and then schedules the
    snapshot from the last transaction for deletion. Snapshot deletion
    works by walking down the btree and dropping the reference counts
    on each btree block during the walk.

    If if a given leaf or node has a reference count greater than one,
    the reference count is decremented and the subtree pointed to by that
    node is ignored.

    If the reference count is one, walking continues down into that node
    or leaf, and the references of everything it points to are decremented.

    The old code would try to work in small pieces, walking down the tree
    until it found the lowest leaf or node to free and then returning. This
    was very friendly to the rest of the FS because it didn't have a huge
    impact on other operations.

    But it wouldn't always keep up with the rate that new commits added new
    snapshots for deletion, and it wasn't very optimal for the extent
    allocation tree because it wasn't finding leaves that were close together
    on disk and processing them at the same time.

    This changes things to walk down to a level 1 node and then process it
    in bulk. All the leaf pointers are sorted and the leaves are dropped
    in order based on their extent number.

    The extent allocation tree and commit code are now fast enough for
    this kind of bulk processing to work without slowing the rest of the FS
    down. Overall it does less IO and is better able to keep up with
    snapshot deletions under high load.

    Signed-off-by: Chris Mason

    Chris Mason
     

30 Sep, 2008

1 commit

  • d352ac681   Btrfs: add and improve comments ... Browse Code »

    This improves the comments at the top of many functions. It didn't
    dive into the guts of functions because I was trying to
    avoid merging problems with the new allocator and back reference work.

    extent-tree.c and volumes.c were both skipped, and there is definitely
    more work todo in cleaning and commenting the code.

    Signed-off-by: Chris Mason

    Chris Mason
     

26 Sep, 2008

1 commit

  • e46576893   Btrfs: Add shared reference cache ... Browse Code »

    Btrfs has a cache of reference counts in leaves, allowing it to
    avoid reading tree leaves while deleting snapshots. To reduce
    contention with multiple subvolumes, this cache is private to each
    subvolume.

    This patch adds shared reference cache support. The new space
    balancing code plays with multiple subvols at the same time, So
    the old per-subvol reference cache is not well suited.

    Signed-off-by: Chris Mason

    Zheng Yan
     

25 Sep, 2008

3 commits

  • bcc63abbf   Btrfs: implement memory reclaim for leaf reference cache ... Browse Code »

    The memory reclaiming issue happens when snapshot exists. In that
    case, some cache entries may not be used during old snapshot dropping,
    so they will remain in the cache until umount.

    The patch adds a field to struct btrfs_leaf_ref to record create time. Besides,
    the patch makes all dead roots of a given snapshot linked together in order of
    create time. After a old snapshot was completely dropped, we check the dead
    root list and remove all cache entries created before the oldest dead root in
    the list.

    Signed-off-by: Chris Mason

    Yan
     
  • 017e5369e   Btrfs: Leaf reference cache update ... Browse Code »

    This changes the reference cache to make a single cache per root
    instead of one cache per transaction, and to key by the byte number
    of the disk block instead of the keys inside.

    This makes it much less likely to have cache misses if a snapshot
    or something has an extra reference on a higher node or a leaf while
    the first transaction that added the leaf into the cache is dropping.

    Some throttling is added to functions that free blocks heavily so they
    wait for old transactions to drop.

    Signed-off-by: Chris Mason

    Chris Mason
     
  • 31153d812   Btrfs: Add a leaf reference cache ... Browse Code »

    Much of the IO done while dropping snapshots is done looking up
    leaves in the filesystem trees to see if they point to any extents and
    to drop the references on any extents found.

    This creates a cache so that IO isn't required.

    Signed-off-by: Chris Mason

    Yan Zheng