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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-10-17 19:34:11 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-17 19:34:11 +0200 |
| commit | ba951841ceb7fa5b06ad48caa5270cc2ae17941e (patch) | |
| tree | fda194f4506fb2af93895d3aac1902051678e8e0 /block | |
| parent | a3bec5c5aea0da263111c4d8f8eabc1f8560d7bf (diff) | |
| download | lwn-ba951841ceb7fa5b06ad48caa5270cc2ae17941e.tar.gz lwn-ba951841ceb7fa5b06ad48caa5270cc2ae17941e.zip | |
[BLOCK] blk_rq_map_sg() next_sg fixup
Don't ever use sg_next() on the last entry, it may not be valid!
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/ll_rw_blk.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 9e3f3cc85d0d..3935469e3662 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -1322,8 +1322,8 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, struct scatterlist *sglist) { struct bio_vec *bvec, *bvprv; - struct scatterlist *next_sg, *sg; struct req_iterator iter; + struct scatterlist *sg; int nsegs, cluster; nsegs = 0; @@ -1333,7 +1333,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, * for each bio in rq */ bvprv = NULL; - sg = next_sg = &sglist[0]; + sg = NULL; rq_for_each_segment(bvec, rq, iter) { int nbytes = bvec->bv_len; @@ -1349,8 +1349,10 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, sg->length += nbytes; } else { new_segment: - sg = next_sg; - next_sg = sg_next(sg); + if (!sg) + sg = sglist; + else + sg = sg_next(sg); memset(sg, 0, sizeof(*sg)); sg->page = bvec->bv_page; |