Commit a3e713b5 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 727a53bd
......@@ -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;
}
......
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