This is a note to let you know that I've just added the patch titled
bio allocation failure due to bio_get_nr_vecs()
to the 3.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bio-allocation-failure-due-to-bio_get_nr_vecs.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f908ee9463b09ddd05e1c1a0111132212dc05fac Mon Sep 17 00:00:00 2001
From: Bernd Schubert <[email protected]>
Date: Fri, 11 May 2012 16:36:44 +0200
Subject: bio allocation failure due to bio_get_nr_vecs()
From: Bernd Schubert <[email protected]>
commit f908ee9463b09ddd05e1c1a0111132212dc05fac upstream.
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 <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/bio.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- 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);
Patches currently in stable-queue which might be from
[email protected] are
queue-3.3/bio-allocation-failure-due-to-bio_get_nr_vecs.patch
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