Btrfs: Fix extent replacment race

[net-next-2.6.git] / fs / btrfs / file.c

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ef66c3d989b9a967fe6cc431cc7bf23a58e6eff0..4123db9d51410b9de5e68724af45b0069d3ef76a 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -177,10 +177,10 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                }
                flags = em->flags;
                if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
-                       write_unlock(&em_tree->lock);
                        if (em->start <= start &&
                            (!testend || em->start + em->len >= start + len)) {
                                free_extent_map(em);
+                               write_unlock(&em_tree->lock);
                                break;
                        }
                        if (start < em->start) {
@@ -190,6 +190,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
                                start = em->start + em->len;
                        }
                        free_extent_map(em);
+                       write_unlock(&em_tree->lock);
                        continue;
                }
                compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
@@ -269,7 +270,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
 noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root, struct inode *inode,
                       u64 start, u64 end, u64 locked_end,
-                      u64 inline_limit, u64 *hint_byte)
+                      u64 inline_limit, u64 *hint_byte, int drop_cache)
 {
        u64 extent_end = 0;
        u64 search_start = start;
@@ -294,7 +295,8 @@ noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
        int ret;
 
        inline_limit = 0;
-       btrfs_drop_extent_cache(inode, start, end - 1, 0);
+       if (drop_cache)
+               btrfs_drop_extent_cache(inode, start, end - 1, 0);
 
        path = btrfs_alloc_path();
        if (!path)