hfsplus: avoid deadlock on file truncation

[linux-2.6-microblaze.git] / fs / hfsplus / extents.c

diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
index e877093..8e0f597 100644 (file)
--- a/fs/hfsplus/extents.c
+++ b/fs/hfsplus/extents.c
@@ -336,6 +336,9 @@ static int hfsplus_free_extents(struct super_block *sb,
        int i;
        int err = 0;
 
+       /* Mapping the allocation file may lock the extent tree */
+       WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock));
+
        hfsplus_dump_extent(extent);
        for (i = 0; i < 8; extent++, i++) {
                count = be32_to_cpu(extent->block_count);
@@ -415,11 +418,13 @@ int hfsplus_free_fork(struct super_block *sb, u32 cnid,
                if (res)
                        break;
                start = be32_to_cpu(fd.key->ext.start_block);
-               hfsplus_free_extents(sb, ext_entry,
-                                    total_blocks - start,
-                                    total_blocks);
                hfs_brec_remove(&fd);
+
+               mutex_unlock(&fd.tree->tree_lock);
+               hfsplus_free_extents(sb, ext_entry, total_blocks - start,
+                                    total_blocks);
                total_blocks = start;
+               mutex_lock(&fd.tree->tree_lock);
        } while (total_blocks > blocks);
        hfs_find_exit(&fd);
 
@@ -576,15 +581,20 @@ void hfsplus_file_truncate(struct inode *inode)
        }
        while (1) {
                if (alloc_cnt == hip->first_blocks) {
+                       mutex_unlock(&fd.tree->tree_lock);
                        hfsplus_free_extents(sb, hip->first_extents,
                                             alloc_cnt, alloc_cnt - blk_cnt);
                        hfsplus_dump_extent(hip->first_extents);
                        hip->first_blocks = blk_cnt;
+                       mutex_lock(&fd.tree->tree_lock);
                        break;
                }
                res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
                if (res)
                        break;
+               hfs_brec_remove(&fd);
+
+               mutex_unlock(&fd.tree->tree_lock);
                start = hip->cached_start;
                hfsplus_free_extents(sb, hip->cached_extents,
                                     alloc_cnt - start, alloc_cnt - blk_cnt);
@@ -596,7 +606,7 @@ void hfsplus_file_truncate(struct inode *inode)
                alloc_cnt = start;
                hip->cached_start = hip->cached_blocks = 0;
                hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
-               hfs_brec_remove(&fd);
+               mutex_lock(&fd.tree->tree_lock);
        }
        hfs_find_exit(&fd);