block: disallow FS recursion from sb_issue_discard allocation

Filesystems can call sb_issue_discard on a memory reclaim path
(e.g. ext4 calls sb_issue_discard during journal commit).

Use GFP_NOFS in sb_issue_discard to avoid recursing back into the FS.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Mike Snitzer 2010-08-03 12:54:51 +02:00 коммит произвёл Jens Axboe
Родитель f6c4c8e19a
Коммит edca4a3805
1 изменённых файлов: 1 добавлений и 1 удалений

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@ -933,7 +933,7 @@ static inline int sb_issue_discard(struct super_block *sb,
{
block <<= (sb->s_blocksize_bits - 9);
nr_blocks <<= (sb->s_blocksize_bits - 9);
return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL,
return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
}