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authorBernd Schubert <bernd.schubert@itwm.fraunhofer.de>2012-05-11 16:36:44 +0200
committerJens Axboe <axboe@kernel.dk>2012-05-11 16:45:12 +0200
commitf908ee9463b09ddd05e1c1a0111132212dc05fac (patch)
treeaf80b227ec2049aa23fc3a8867e70fd685a4d34a
parent080399aaaf3531f5b8761ec0ac30ff98891e8686 (diff)
downloadblackbird-op-linux-f908ee9463b09ddd05e1c1a0111132212dc05fac.tar.gz
blackbird-op-linux-f908ee9463b09ddd05e1c1a0111132212dc05fac.zip
bio allocation failure due to bio_get_nr_vecs()
The number of bio_get_nr_vecs() is passed down via bio_alloc() to bvec_alloc_bs(), which fails the bio allocation if nr_iovecs > BIO_MAX_PAGES. For the underlying caller this causes an unexpected bio allocation failure. Limiting to queue_max_segments() is not sufficient, as max_segments also might be very large. bvec_alloc_bs(gfp_mask, nr_iovecs, ) => NULL when nr_iovecs > BIO_MAX_PAGES bio_alloc_bioset(gfp_mask, nr_iovecs, ...) bio_alloc(GFP_NOIO, nvecs) xfs_alloc_ioend_bio() Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/bio.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/bio.c b/fs/bio.c
index e453924036e9..84da88539046 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -505,9 +505,14 @@ EXPORT_SYMBOL(bio_clone);
int bio_get_nr_vecs(struct block_device *bdev)
{
struct request_queue *q = bdev_get_queue(bdev);
- return min_t(unsigned,
+ int nr_pages;
+
+ nr_pages = min_t(unsigned,
queue_max_segments(q),
queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1);
+
+ return min_t(unsigned, nr_pages, BIO_MAX_PAGES);
+
}
EXPORT_SYMBOL(bio_get_nr_vecs);
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