From: Christophe Saout <christophe@saout.de>
The intent of these are to clarify the meaning of the bio fields in the
bi_end_io function (since we are already mostly there). After these small
modifications bio->bi_idx and the corresponding bio_iovec(bio)->bv_offset
point to the beginning of the completed data, together with the nr_bytes
argument you know exactly what data was finished, e.g. when you can't
track it otherwise (or it would be unnecessary expensive). Apart from that
it's a nice-to-have.
The first mini-patch moves the update of bio_iovec(bio)->bv_offset and
->bv_len after the call of bi_end_io where bi_idx gets updated so they get
updated together. Ok with Jens.
The second part of the patch modifies the multwrite hack in PIO non-
taskfile ide disk code. It modifies the bi_idx field to walk the bios and
doesn't reset it correctly before ending the request. The patch uses the
segment counter in the request field to correctly restore the bi_idx field
before ending the request. Can't possibly break anything since it's
working on the local request copy ("scratchpad") anyway. Also does this in
legacy/pdc4030.c (similar code). The code modified here is going to die
anyway any trying to fix it would be too invasive. Ok with Bartlomiej.
drivers/block/ll_rw_blk.c | 6 +++---
drivers/ide/ide-disk.c | 25 ++++++++++---------------
drivers/ide/legacy/pdc4030.c | 18 ++++++++++++++++--
3 files changed, 29 insertions(+), 20 deletions(-)
diff -puN drivers/block/ll_rw_blk.c~bio_endio-clarifications drivers/block/ll_rw_blk.c
--- 25/drivers/block/ll_rw_blk.c~bio_endio-clarifications 2004-01-06 09:26:05.000000000 -0800
+++ 25-akpm/drivers/block/ll_rw_blk.c 2004-01-06 09:26:05.000000000 -0800
@@ -2505,8 +2505,6 @@ static int __end_that_request_first(stru
* not a complete bvec done
*/
if (unlikely(nbytes > nr_bytes)) {
- bio_iovec_idx(bio, idx)->bv_offset += nr_bytes;
- bio_iovec_idx(bio, idx)->bv_len -= nr_bytes;
bio_nbytes += nr_bytes;
total_bytes += nr_bytes;
break;
@@ -2542,7 +2540,9 @@ static int __end_that_request_first(stru
*/
if (bio_nbytes) {
bio_endio(bio, bio_nbytes, error);
- req->bio->bi_idx += next_idx;
+ bio->bi_idx += next_idx;
+ bio_iovec(bio)->bv_offset += nr_bytes;
+ bio_iovec(bio)->bv_len -= nr_bytes;
}
blk_recalc_rq_sectors(req, total_bytes >> 9);
diff -puN drivers/ide/ide-disk.c~bio_endio-clarifications drivers/ide/ide-disk.c
--- 25/drivers/ide/ide-disk.c~bio_endio-clarifications 2004-01-06 09:26:05.000000000 -0800
+++ 25-akpm/drivers/ide/ide-disk.c 2004-01-06 09:26:05.000000000 -0800
@@ -251,7 +251,7 @@ static ide_startstop_t write_intr (ide_d
* is shorter or smaller than the BH segment then we should be OKAY.
* This is only valid if we can rewind the rq->current_nr_sectors counter.
*/
-int ide_multwrite (ide_drive_t *drive, unsigned int mcount)
+void ide_multwrite (ide_drive_t *drive, unsigned int mcount)
{
ide_hwgroup_t *hwgroup = HWGROUP(drive);
struct request *rq = &hwgroup->wrq;
@@ -279,7 +279,7 @@ int ide_multwrite (ide_drive_t *drive, u
* all bvecs in this one.
*/
if (++bio->bi_idx >= bio->bi_vcnt) {
- bio->bi_idx = 0;
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
bio = bio->bi_next;
}
@@ -288,7 +288,8 @@ int ide_multwrite (ide_drive_t *drive, u
mcount = 0;
} else {
rq->bio = bio;
- rq->current_nr_sectors = bio_iovec(bio)->bv_len >> 9;
+ rq->nr_cbio_segments = bio_segments(bio);
+ rq->current_nr_sectors = bio_cur_sectors(bio);
rq->hard_cur_sectors = rq->current_nr_sectors;
}
}
@@ -300,8 +301,6 @@ int ide_multwrite (ide_drive_t *drive, u
taskfile_output_data(drive, buffer, nsect<<7);
ide_unmap_buffer(rq, buffer, &flags);
} while (mcount);
-
- return 0;
}
/*
@@ -312,6 +311,7 @@ static ide_startstop_t multwrite_intr (i
ide_hwgroup_t *hwgroup = HWGROUP(drive);
ide_hwif_t *hwif = HWIF(drive);
struct request *rq = &hwgroup->wrq;
+ struct bio *bio = rq->bio;
u8 stat;
stat = hwif->INB(IDE_STATUS_REG);
@@ -322,8 +322,7 @@ static ide_startstop_t multwrite_intr (i
* of the request
*/
if (rq->nr_sectors) {
- if (ide_multwrite(drive, drive->mult_count))
- return ide_stopped;
+ ide_multwrite(drive, drive->mult_count);
ide_set_handler(drive, &multwrite_intr, WAIT_CMD, NULL);
return ide_started;
}
@@ -333,14 +332,17 @@ static ide_startstop_t multwrite_intr (i
* we can end the original request.
*/
if (!rq->nr_sectors) { /* all done? */
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
rq = hwgroup->rq;
ide_end_request(drive, 1, rq->nr_sectors);
return ide_stopped;
}
}
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
/* the original code did this here (?) */
return ide_stopped;
}
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
return DRIVER(drive)->error(drive, "multwrite_intr", stat);
}
@@ -519,14 +521,7 @@ ide_startstop_t __ide_do_rw_disk (ide_dr
*/
hwgroup->wrq = *rq; /* scratchpad */
ide_set_handler(drive, &multwrite_intr, WAIT_CMD, NULL);
- if (ide_multwrite(drive, drive->mult_count)) {
- unsigned long flags;
- spin_lock_irqsave(&ide_lock, flags);
- hwgroup->handler = NULL;
- del_timer(&hwgroup->timer);
- spin_unlock_irqrestore(&ide_lock, flags);
- return ide_stopped;
- }
+ ide_multwrite(drive, drive->mult_count);
} else {
unsigned long flags;
char *to = ide_map_buffer(rq, &flags);
diff -puN drivers/ide/legacy/pdc4030.c~bio_endio-clarifications drivers/ide/legacy/pdc4030.c
--- 25/drivers/ide/legacy/pdc4030.c~bio_endio-clarifications 2004-01-06 09:26:05.000000000 -0800
+++ 25-akpm/drivers/ide/legacy/pdc4030.c 2004-01-06 09:26:05.000000000 -0800
@@ -443,7 +443,12 @@ read_next:
static ide_startstop_t promise_complete_pollfunc(ide_drive_t *drive)
{
ide_hwgroup_t *hwgroup = HWGROUP(drive);
+#ifdef CONFIG_IDE_TASKFILE_IO
struct request *rq = hwgroup->rq;
+#else
+ struct request *rq = &hwgroup->wrq;
+ struct bio *bio = rq->bio;
+#endif
if ((HWIF(drive)->INB(IDE_STATUS_REG)) & BUSY_STAT) {
if (time_before(jiffies, hwgroup->poll_timeout)) {
@@ -472,6 +477,8 @@ static ide_startstop_t promise_complete_
while (rq->bio != rq->cbio)
(void) DRIVER(drive)->end_request(drive, 1, bio_sectors(rq->bio));
#else
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
+ rq = hwgroup->rq;
DRIVER(drive)->end_request(drive, 1, rq->hard_nr_sectors);
#endif
return ide_stopped;
@@ -530,7 +537,7 @@ static void promise_multwrite (ide_drive
* all bvecs in this one.
*/
if (++bio->bi_idx >= bio->bi_vcnt) {
- bio->bi_idx = 0;
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
bio = bio->bi_next;
}
@@ -539,7 +546,8 @@ static void promise_multwrite (ide_drive
mcount = 0;
} else {
rq->bio = bio;
- rq->current_nr_sectors = bio_iovec(bio)->bv_len >> 9;
+ rq->nr_cbio_segments = bio_segments(bio);
+ rq->current_nr_sectors = bio_cur_sectors(bio);
rq->hard_cur_sectors = rq->current_nr_sectors;
}
}
@@ -561,6 +569,9 @@ static ide_startstop_t promise_write_pol
ide_hwgroup_t *hwgroup = HWGROUP(drive);
#ifdef CONFIG_IDE_TASKFILE_IO
struct request *rq = hwgroup->rq;
+#else
+ struct request *rq = &hwgroup->wrq;
+ struct bio *bio = rq->bio;
#endif
if (HWIF(drive)->INB(IDE_NSECTOR_REG) != 0) {
@@ -575,6 +586,9 @@ static ide_startstop_t promise_write_pol
}
hwgroup->poll_timeout = 0;
printk(KERN_ERR "%s: write timed-out!\n",drive->name);
+#ifndef CONFIG_IDE_TASKFILE_IO
+ bio->bi_idx = bio->bi_vcnt - rq->nr_cbio_segments;
+#endif
return DRIVER(drive)->error(drive, "write timeout",
HWIF(drive)->INB(IDE_STATUS_REG));
}
_