Review-not-tested-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
brassow
On Feb 4, 2009, at 8:47 PM, Mikulas Patocka wrote:
Hi
This patch should fix bug 472796 in upstream kernel.
---
Bio layer modifies the vector list when the request partially
succeeds.
Device mapper saves and restores various fields in the bio, but it
doesn't save
the vector. So, when the block driver modifies the vector on
partially succeeded
request, dm-raid1 and dm-multipath will attempt to resubmit a bio
that has
mismatching bi_size and the size of vector. That will cause BUG() in
the block
layer.
To make requests resubmittable in dm-raid1 and dm-multipath, we must
save
and restore the bio vector as well.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-bio-record.h | 3 +++
1 file changed, 3 insertions(+)
Index: linux-2.6.29-rc3-devel/drivers/md/dm-bio-record.h
===================================================================
--- linux-2.6.29-rc3-devel.orig/drivers/md/dm-bio-record.h
2009-02-05 03:10:49.000000000 +0100
+++ linux-2.6.29-rc3-devel/drivers/md/dm-bio-record.h 2009-02-05
03:12:52.000000000 +0100
@@ -22,6 +22,7 @@ struct dm_bio_details {
unsigned int bi_size;
unsigned short bi_idx;
unsigned long bi_flags;
+ struct bio_vec bi_io_vec[BIO_MAX_PAGES];
};
static inline void dm_bio_record(struct dm_bio_details *bd, struct
bio *bio)
@@ -31,6 +32,7 @@ static inline void dm_bio_record(struct
bd->bi_size = bio->bi_size;
bd->bi_idx = bio->bi_idx;
bd->bi_flags = bio->bi_flags;
+ memcpy(bd->bi_io_vec, bio->bi_io_vec, bio->bi_vcnt * sizeof(struct
bio_vec));
}
static inline void dm_bio_restore(struct dm_bio_details *bd, struct
bio *bio)
@@ -40,6 +42,7 @@ static inline void dm_bio_restore(struct
bio->bi_size = bd->bi_size;
bio->bi_idx = bd->bi_idx;
bio->bi_flags = bd->bi_flags;
+ memcpy(bio->bi_io_vec, bd->bi_io_vec, bio->bi_vcnt * sizeof(struct
bio_vec));
}
#endif
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