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authorYan <yanzheng@21cn.com>2008-01-22 12:46:56 -0500
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:03:59 -0400
commitb17854275cd297d40c6c5562fa44a472314c6c7f (patch)
treea8056de7cbc45dd927cf1220ff2dfc8f4e15dd17 /fs/btrfs/inode-map.c
parente18e4809b10e6c9efb5fe10c1ddcb4ebb690d517 (diff)
Fix for btrfs_find_free_objectid
btrfs_find_free_objectid may return a used objectid due to arithmetic underflow. This bug may happen when parameter 'root' is tree root, so it may cause serious problems when creating snapshot or sub-volume. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/inode-map.c')
-rw-r--r--fs/btrfs/inode-map.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index ab74977adf5c..a0925eabdaa2 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -62,7 +62,6 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
62 struct btrfs_path *path; 62 struct btrfs_path *path;
63 struct btrfs_key key; 63 struct btrfs_key key;
64 int ret; 64 int ret;
65 u64 hole_size = 0;
66 int slot = 0; 65 int slot = 0;
67 u64 last_ino = 0; 66 u64 last_ino = 0;
68 int start_found; 67 int start_found;
@@ -109,8 +108,7 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
109 if (start_found) { 108 if (start_found) {
110 if (last_ino < search_start) 109 if (last_ino < search_start)
111 last_ino = search_start; 110 last_ino = search_start;
112 hole_size = key.objectid - last_ino; 111 if (key.objectid > last_ino) {
113 if (hole_size > 0) {
114 *objectid = last_ino; 112 *objectid = last_ino;
115 goto found; 113 goto found;
116 } 114 }