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authorJens Axboe <jens.axboe@oracle.com>2006-12-19 11:12:46 +0100
committerJens Axboe <jens.axboe@oracle.com>2006-12-19 11:12:46 +0100
commit8e5cfc45e7527eb5c8a9a22d56a7b9227e7c0913 (patch)
tree7be7c45168af77518bd6a47601e2f9e31b967dba /block/ll_rw_blk.c
parent48785bb9fa39415d7553e234946442579dfcf591 (diff)
downloadlinux-2.6.34-ux500-8e5cfc45e7527eb5c8a9a22d56a7b9227e7c0913.tar.gz
[PATCH] Fixup blk_rq_unmap_user() API
The blk_rq_unmap_user() API is not very nice. It expects the caller to know that rq->bio has to be reset to the original bio, and it will silently do nothing if that is not done. Instead make it explicit that we need to pass in the first bio, by expecting a bio argument. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/ll_rw_blk.c')
-rw-r--r--block/ll_rw_blk.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index a66ec30855d..e07c079e07e 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2405,6 +2405,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
unsigned long len)
{
unsigned long bytes_read = 0;
+ struct bio *bio = NULL;
int ret;
if (len > (q->max_hw_sectors << 9))
@@ -2431,6 +2432,8 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
ret = __blk_rq_map_user(q, rq, ubuf, map_len);
if (ret < 0)
goto unmap_rq;
+ if (!bio)
+ bio = rq->bio;
bytes_read += ret;
ubuf += ret;
}
@@ -2438,7 +2441,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
rq->buffer = rq->data = NULL;
return 0;
unmap_rq:
- blk_rq_unmap_user(rq);
+ blk_rq_unmap_user(bio);
return ret;
}
@@ -2495,29 +2498,30 @@ EXPORT_SYMBOL(blk_rq_map_user_iov);
/**
* blk_rq_unmap_user - unmap a request with user data
- * @rq: rq to be unmapped
+ * @bio: start of bio list
*
* Description:
- * Unmap a rq previously mapped by blk_rq_map_user().
- * rq->bio must be set to the original head of the request.
+ * Unmap a rq previously mapped by blk_rq_map_user(). The caller must
+ * supply the original rq->bio from the blk_rq_map_user() return, since
+ * the io completion may have changed rq->bio.
*/
-int blk_rq_unmap_user(struct request *rq)
+int blk_rq_unmap_user(struct bio *bio)
{
- struct bio *bio, *mapped_bio;
+ struct bio *mapped_bio;
int ret = 0, ret2;
- while ((bio = rq->bio)) {
- if (bio_flagged(bio, BIO_BOUNCED))
+ while (bio) {
+ mapped_bio = bio;
+ if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
mapped_bio = bio->bi_private;
- else
- mapped_bio = bio;
ret2 = __blk_rq_unmap_user(mapped_bio);
if (ret2 && !ret)
ret = ret2;
- rq->bio = bio->bi_next;
- bio_put(bio);
+ mapped_bio = bio;
+ bio = bio->bi_next;
+ bio_put(mapped_bio);
}
return ret;