1 files changed, 13 insertions, 0 deletions

diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c
index 1563d5ce5764..5fd51a5833ff 100644
--- a/fs/hfs/mdb.c
+++ b/fs/hfs/mdb.c
@@ -260,6 +260,10 @@ void hfs_mdb_commit(struct super_block *sb)
 {
         struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
 
+        if (sb->s_flags & MS_RDONLY)
+                return;
+
+        lock_buffer(HFS_SB(sb)->mdb_bh);
         if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
                 /* These parameters may have been modified, so write them back */
                 mdb->drLsMod = hfs_mtime();
@@ -283,9 +287,13 @@ void hfs_mdb_commit(struct super_block *sb)
                                      &mdb->drXTFlSize, NULL);
                 hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
                                      &mdb->drCTFlSize, NULL);
+
+                lock_buffer(HFS_SB(sb)->alt_mdb_bh);
                 memcpy(HFS_SB(sb)->alt_mdb, HFS_SB(sb)->mdb, HFS_SECTOR_SIZE);
                 HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
                 HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+                unlock_buffer(HFS_SB(sb)->alt_mdb_bh);
+
                 mark_buffer_dirty(HFS_SB(sb)->alt_mdb_bh);
                 sync_dirty_buffer(HFS_SB(sb)->alt_mdb_bh);
         }
@@ -308,7 +316,11 @@ void hfs_mdb_commit(struct super_block *sb)
                                 break;
                         }
                         len = min((int)sb->s_blocksize - off, size);
+
+                        lock_buffer(bh);
                         memcpy(bh->b_data + off, ptr, len);
+                        unlock_buffer(bh);
+
                         mark_buffer_dirty(bh);
                         brelse(bh);
                         block++;
@@ -317,6 +329,7 @@ void hfs_mdb_commit(struct super_block *sb)
                         size -= len;
                 }
         }
+        unlock_buffer(HFS_SB(sb)->mdb_bh);
 }
 
 void hfs_mdb_close(struct super_block *sb)