summaryrefslogtreecommitdiff
path: root/fs/reiserfs/bitmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/reiserfs/bitmap.c')
-rw-r--r--fs/reiserfs/bitmap.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index a6f39fe2b664..edc8ef78b63f 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -513,9 +513,17 @@ static void __discard_prealloc(struct reiserfs_transaction_handle *th,
"inode has negative prealloc blocks count.");
#endif
while (ei->i_prealloc_count > 0) {
- reiserfs_free_prealloc_block(th, inode, ei->i_prealloc_block);
- ei->i_prealloc_block++;
+ b_blocknr_t block_to_free;
+
+ /*
+ * reiserfs_free_prealloc_block can drop the write lock,
+ * which could allow another caller to free the same block.
+ * We can protect against it by modifying the prealloc
+ * state before calling it.
+ */
+ block_to_free = ei->i_prealloc_block++;
ei->i_prealloc_count--;
+ reiserfs_free_prealloc_block(th, inode, block_to_free);
dirty = 1;
}
if (dirty)