diff options
| author | David Dillow <dillowda@ornl.gov> | 2011-01-20 23:44:22 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-21 02:02:05 +0100 |
| commit | 20d9600cb407b0b55fef6ee814b60345c6f58264 (patch) | |
| tree | a023082339b33c55e8def552abecd441ffe92fb5 /fs | |
| parent | mm: compaction: prevent division-by-zero during user-requested compaction (diff) | |
| download | linux-20d9600cb407b0b55fef6ee814b60345c6f58264.tar.xz linux-20d9600cb407b0b55fef6ee814b60345c6f58264.zip | |
fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
When using devices that support max_segments > BIO_MAX_PAGES (256), direct
IO tries to allocate a bio with more pages than allowed, which leads to an
oops in dio_bio_alloc(). Clamp the request to the supported maximum, and
change dio_bio_alloc() to reflect that bio_alloc() will always return a
bio when called with __GFP_WAIT and a valid number of vectors.
[akpm@linux-foundation.org: remove redundant BUG_ON()]
Signed-off-by: David Dillow <dillowda@ornl.gov>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/direct-io.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index 85882f6ba5f7..b044705eedd4 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -325,12 +325,16 @@ void dio_end_io(struct bio *bio, int error) } EXPORT_SYMBOL_GPL(dio_end_io); -static int +static void dio_bio_alloc(struct dio *dio, struct block_device *bdev, sector_t first_sector, int nr_vecs) { struct bio *bio; + /* + * bio_alloc() is guaranteed to return a bio when called with + * __GFP_WAIT and we request a valid number of vectors. + */ bio = bio_alloc(GFP_KERNEL, nr_vecs); bio->bi_bdev = bdev; @@ -342,7 +346,6 @@ dio_bio_alloc(struct dio *dio, struct block_device *bdev, dio->bio = bio; dio->logical_offset_in_bio = dio->cur_page_fs_offset; - return 0; } /* @@ -583,8 +586,9 @@ static int dio_new_bio(struct dio *dio, sector_t start_sector) goto out; sector = start_sector << (dio->blkbits - 9); nr_pages = min(dio->pages_in_io, bio_get_nr_vecs(dio->map_bh.b_bdev)); + nr_pages = min(nr_pages, BIO_MAX_PAGES); BUG_ON(nr_pages <= 0); - ret = dio_bio_alloc(dio, dio->map_bh.b_bdev, sector, nr_pages); + dio_bio_alloc(dio, dio->map_bh.b_bdev, sector, nr_pages); dio->boundary = 0; out: return ret; |