udf: finalize integrity descriptor before writeback

Make sure the CRC and tag checksum of the Logical Volume Integrity
Descriptor are valid before the structure is written out to disk.
Otherwise, unless the filesystem is unmounted gracefully, the on-disk
LVID will be invalid - which is unnecessary filesystem damage.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 2d87428010605eef7b0948ef19e4a260215bad9e..2cf435c8758363bf446084113c8635212fc5e529 100644 (file)
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -2046,8 +2046,8 @@ u64 lvid_get_unique_id(struct super_block *sb)
        if (!(++uniqueID & 0xFFFFFFFF))
                uniqueID += 16;
        lvhd->uniqueID = cpu_to_le64(uniqueID);
+       udf_updated_lvid(sb);
        mutex_unlock(&sbi->s_alloc_mutex);
-       mark_buffer_dirty(bh);
 
        return ret;
 }
@@ -2318,11 +2318,20 @@ static int udf_sync_fs(struct super_block *sb, int wait)
 
        mutex_lock(&sbi->s_alloc_mutex);
        if (sbi->s_lvid_dirty) {
+               struct buffer_head *bh = sbi->s_lvid_bh;
+
+               if (bh) {
+                       struct logicalVolIntegrityDesc *lvid;
+
+                       lvid = (struct logicalVolIntegrityDesc *)bh->b_data;
+                       udf_finalize_lvid(lvid);
+               }
+
                /*
                 * Blockdevice will be synced later so we don't have to submit
                 * the buffer for IO
                 */
-               mark_buffer_dirty(sbi->s_lvid_bh);
+               mark_buffer_dirty(bh);
                sbi->s_lvid_dirty = 0;
        }
        mutex_unlock(&sbi->s_alloc_mutex);