[PATCH] __bread oops fix

If a filesystem passes an idiotic blocksize into bread(), __getblk_slow() will
warn and will return NULL.  We have a report (from Hubert Tonneau
<hubert.tonneau@fullpliant.org>) of isofs_fill_super() doing this (passing in
a silly block size) against an unplugged CDROM drive.

But a couple of __getblk_slow() callers forgot to check for the NULL bh, hence
oops.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andrew Morton 2005-10-30 15:03:15 -08:00 committed by Linus Torvalds
parent 727a53bd53
commit a3e713b5fd

View File

@ -1478,8 +1478,10 @@ EXPORT_SYMBOL(__getblk);
void __breadahead(struct block_device *bdev, sector_t block, int size)
{
struct buffer_head *bh = __getblk(bdev, block, size);
ll_rw_block(READA, 1, &bh);
brelse(bh);
if (likely(bh)) {
ll_rw_block(READA, 1, &bh);
brelse(bh);
}
}
EXPORT_SYMBOL(__breadahead);
@ -1497,7 +1499,7 @@ __bread(struct block_device *bdev, sector_t block, int size)
{
struct buffer_head *bh = __getblk(bdev, block, size);
if (!buffer_uptodate(bh))
if (likely(bh) && !buffer_uptodate(bh))
bh = __bread_slow(bh);
return bh;
}