Fix _fat_bmap() locking
authorOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Wed, 11 Mar 2009 17:03:23 +0000 (02:03 +0900)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Mar 2009 19:04:18 +0000 (12:04 -0700)
On swapon() path, it has already i_mutex. So, this uses i_alloc_sem
instead of it.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Laurent GUERBY <laurent@guerby.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/fat/inode.c

index 6b74d09adbe5fa34d425f7b2c07a8271ddcd8e14..de0004fe6e0049c8a09a494444d19831313da64c 100644 (file)
@@ -202,9 +202,9 @@ static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
        sector_t blocknr;
 
        /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
-       mutex_lock(&mapping->host->i_mutex);
+       down_read(&mapping->host->i_alloc_sem);
        blocknr = generic_block_bmap(mapping, block, fat_get_block);
-       mutex_unlock(&mapping->host->i_mutex);
+       up_read(&mapping->host->i_alloc_sem);
 
        return blocknr;
 }