The map APIs takes a request (blk_rq_map_user and
blk_rq_map_user_iov), the unmap API, blk_rq_unmap_user takes a bio.
Due to the asymmetry of the APIs, callers have to track a mapped bio
even if they aren't interested in a bio, the details of I/O
representation. The asymmetry leads to trouble easily. The symmetrical
APIs are nicer and easier to use.
This is based on an earlier patch by Mike Christie.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: Mike Christie <michaelc@xxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
---
block/blk-core.c | 4 ++--
block/blk-map.c | 16 +++++-----------
block/bsg.c | 32 ++++++++++----------------------
block/scsi_ioctl.c | 10 +++-------
drivers/cdrom/cdrom.c | 4 +---
drivers/scsi/scsi_tgt_lib.c | 5 +----
include/linux/blkdev.h | 5 ++++-
7 files changed, 26 insertions(+), 50 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 2a438a9..284863f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -119,7 +119,7 @@ void rq_init(struct request_queue *q, struct request *rq)
rq->sector = rq->hard_sector = (sector_t) -1;
rq->nr_sectors = rq->hard_nr_sectors = 0;
rq->current_nr_sectors = rq->hard_cur_sectors = 0;
- rq->bio = rq->biotail = NULL;
+ rq->bio = rq->biotail = rq->biohead = NULL;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);
rq->rq_disk = NULL;
@@ -2018,7 +2018,7 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
rq->buffer = bio_data(bio);
rq->data_len = bio->bi_size;
- rq->bio = rq->biotail = bio;
+ rq->bio = rq->biotail = rq->biohead = bio;
if (bio->bi_bdev)
rq->rq_disk = bio->bi_bdev->bd_disk;
diff --git a/block/blk-map.c b/block/blk-map.c
index e949969..be02969 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -107,7 +107,6 @@ int blk_rq_map_user(struct request_queue *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))
@@ -134,8 +133,6 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
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;
}
@@ -143,8 +140,7 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
rq->buffer = rq->data = NULL;
return 0;
unmap_rq:
- blk_rq_unmap_user(bio);
- rq->bio = NULL;
+ blk_rq_unmap_user(rq);
return ret;
}
EXPORT_SYMBOL(blk_rq_map_user);
@@ -200,16 +196,14 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
/**
* blk_rq_unmap_user - unmap a request with user data
- * @bio: start of bio list
+ * @req: a request previously mapped
*
* Description:
- * 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.
+ * Unmap a rq previously mapped by blk_rq_map_user().
*/
-int blk_rq_unmap_user(struct bio *bio)
+int blk_rq_unmap_user(struct request *rq)
{
- struct bio *mapped_bio;
+ struct bio *mapped_bio, *bio = rq->biohead;
int ret = 0, ret2;
while (bio) {
diff --git a/block/bsg.c b/block/bsg.c
index 8917c51..e62d226 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -81,8 +81,6 @@ struct bsg_command {
struct bsg_device *bd;
struct list_head list;
struct request *rq;
- struct bio *bio;
- struct bio *bidi_bio;
int err;
struct sg_io_v4 hdr;
char sense[SCSI_SENSE_BUFFERSIZE];
@@ -305,7 +303,7 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
out:
blk_put_request(rq);
if (next_rq) {
- blk_rq_unmap_user(next_rq->bio);
+ blk_rq_unmap_user(next_rq);
blk_put_request(next_rq);
}
return ERR_PTR(ret);
@@ -321,8 +319,8 @@ static void bsg_rq_end_io(struct request *rq, int uptodate)
struct bsg_device *bd = bc->bd;
unsigned long flags;
- dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
- bd->name, rq, bc, bc->bio, uptodate);
+ dprintk("%s: finished rq %p bc %p, stat %d\n",
+ bd->name, rq, bc, uptodate);
bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
@@ -348,9 +346,6 @@ static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
* add bc command to busy queue and submit rq for io
*/
bc->rq = rq;
- bc->bio = rq->bio;
- if (rq->next_rq)
- bc->bidi_bio = rq->next_rq->bio;
bc->hdr.duration = jiffies;
spin_lock_irq(&bd->lock);
list_add_tail(&bc->list, &bd->busy_list);
@@ -407,12 +402,11 @@ static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
return bc;
}
-static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
- struct bio *bio, struct bio *bidi_bio)
+static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr)
{
int ret = 0;
- dprintk("rq %p bio %p %u\n", rq, bio, rq->errors);
+ dprintk("rq %p %u\n", rq, rq->errors);
/*
* fill in all the output members
*/
@@ -439,7 +433,7 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
if (rq->next_rq) {
hdr->dout_resid = rq->data_len;
hdr->din_resid = rq->next_rq->data_len;
- blk_rq_unmap_user(bidi_bio);
+ blk_rq_unmap_user(rq->next_rq);
blk_put_request(rq->next_rq);
} else if (rq_data_dir(rq) == READ)
hdr->din_resid = rq->data_len;
@@ -455,7 +449,7 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
if (!ret && rq->errors < 0)
ret = rq->errors;
- blk_rq_unmap_user(bio);
+ blk_rq_unmap_user(rq);
blk_put_request(rq);
return ret;
@@ -501,8 +495,7 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
if (IS_ERR(bc))
break;
- tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
- bc->bidi_bio);
+ tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr);
if (!ret)
ret = tret;
@@ -536,8 +529,7 @@ __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
* after completing the request. so do that here,
* bsg_complete_work() cannot do that for us
*/
- ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
- bc->bidi_bio);
+ ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr);
if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
ret = -EFAULT;
@@ -886,7 +878,6 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
case SG_IO: {
struct request *rq;
- struct bio *bio, *bidi_bio = NULL;
struct sg_io_v4 hdr;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
@@ -896,11 +887,8 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
if (IS_ERR(rq))
return PTR_ERR(rq);
- bio = rq->bio;
- if (rq->next_rq)
- bidi_bio = rq->next_rq->bio;
blk_execute_rq(bd->queue, NULL, rq, 0);
- ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
+ ret = blk_complete_sgv4_hdr_rq(rq, &hdr);
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index a2c3a93..f6cf8ba 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -245,13 +245,12 @@ static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
*/
static int blk_unmap_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
{
- blk_rq_unmap_user(rq->bio);
+ blk_rq_unmap_user(rq);
blk_put_request(rq);
return 0;
}
-static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
- struct bio *bio)
+static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr)
{
int r, ret = 0;
@@ -278,7 +277,6 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
ret = -EFAULT;
}
- rq->bio = bio;
r = blk_unmap_sghdr_rq(rq, hdr);
if (ret)
r = ret;
@@ -293,7 +291,6 @@ static int sg_io(struct file *file, struct request_queue *q,
int writing = 0, ret = 0, has_write_perm = 0;
struct request *rq;
char sense[SCSI_SENSE_BUFFERSIZE];
- struct bio *bio;
if (hdr->interface_id != 'S')
return -EINVAL;
@@ -352,7 +349,6 @@ static int sg_io(struct file *file, struct request_queue *q,
if (ret)
goto out;
- bio = rq->bio;
memset(sense, 0, sizeof(sense));
rq->sense = sense;
rq->sense_len = 0;
@@ -368,7 +364,7 @@ static int sg_io(struct file *file, struct request_queue *q,
hdr->duration = jiffies_to_msecs(jiffies - start_time);
- return blk_complete_sghdr_rq(rq, hdr, bio);
+ return blk_complete_sghdr_rq(rq, hdr);
out:
blk_put_request(rq);
return ret;
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 12f5bae..3ccaa3d 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2101,7 +2101,6 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
{
struct request_queue *q = cdi->disk->queue;
struct request *rq;
- struct bio *bio;
unsigned int len;
int nr, ret = 0;
@@ -2142,7 +2141,6 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
rq->cmd_len = 12;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = 60 * HZ;
- bio = rq->bio;
if (blk_execute_rq(q, cdi->disk, rq, 0)) {
struct request_sense *s = rq->sense;
@@ -2150,7 +2148,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
cdi->last_sense = s->sense_key;
}
- if (blk_rq_unmap_user(bio))
+ if (blk_rq_unmap_user(rq))
ret = -EFAULT;
if (ret)
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index a0f308b..2f7793a 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -43,7 +43,6 @@ struct scsi_tgt_cmd {
/* TODO replace work with James b's code */
struct work_struct work;
/* TODO fix limits of some drivers */
- struct bio *bio;
struct list_head hash_list;
struct request *rq;
@@ -170,7 +169,7 @@ static void cmd_hashlist_del(struct scsi_cmnd *cmd)
static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd)
{
- blk_rq_unmap_user(tcmd->bio);
+ blk_rq_unmap_user(tcmd->rq);
}
static void scsi_tgt_cmd_destroy(struct work_struct *work)
@@ -194,7 +193,6 @@ static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,
tcmd->itn_id = itn_id;
tcmd->tag = tag;
- tcmd->bio = NULL;
INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy);
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
head = &qdata->cmd_hash[cmd_hashfn(tag)];
@@ -375,7 +373,6 @@ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
return err;
}
- tcmd->bio = rq->bio;
err = scsi_init_io(cmd, GFP_KERNEL);
if (err) {
scsi_release_buffers(cmd);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6f79d40..b7879ed 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -233,6 +233,9 @@ struct request {
/* for bidi */
struct request *next_rq;
+
+ /* for blk_rq_unmap_user */
+ struct bio *biohead;
};
/*
@@ -622,7 +625,7 @@ extern void __blk_stop_queue(struct request_queue *q);
extern void blk_run_queue(struct request_queue *);
extern void blk_start_queueing(struct request_queue *);
extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long);
-extern int blk_rq_unmap_user(struct bio *);
+extern int blk_rq_unmap_user(struct request *);
extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
struct sg_iovec *, int, unsigned int);
--
1.5.3.7
--
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