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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-07-04 09:31:50 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-07-04 09:52:14 +0200 |
| commit | 62858dacc8dea55c5bdb474ccd8acb0657e23dd0 (patch) | |
| tree | d7678ade2e3e47b041b58fd5ea8ad02a4019ea88 | |
| parent | block: blk_rq_map_kern uses the bounce buffers for stack buffers (diff) | |
| download | linux-62858dacc8dea55c5bdb474ccd8acb0657e23dd0.tar.xz linux-62858dacc8dea55c5bdb474ccd8acb0657e23dd0.zip | |
scsi: sr avoids useless buffer allocation
blk_rq_map_kern can handle the stack buffers correctly (avoid DMA
from/to the stack buffers by using the bounce buffer) so we don't need
to complicate the code by allocating just 8 bytes.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| -rw-r--r-- | drivers/scsi/sr.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index c82df8bd4d89..27f5bfd1def3 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -673,24 +673,20 @@ fail: static void get_sectorsize(struct scsi_cd *cd) { unsigned char cmd[10]; - unsigned char *buffer; + unsigned char buffer[8]; int the_result, retries = 3; int sector_size; struct request_queue *queue; - buffer = kmalloc(512, GFP_KERNEL | GFP_DMA); - if (!buffer) - goto Enomem; - do { cmd[0] = READ_CAPACITY; memset((void *) &cmd[1], 0, 9); - memset(buffer, 0, 8); + memset(buffer, 0, sizeof(buffer)); /* Do the command and wait.. */ the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE, - buffer, 8, NULL, SR_TIMEOUT, - MAX_RETRIES); + buffer, sizeof(buffer), NULL, + SR_TIMEOUT, MAX_RETRIES); retries--; @@ -745,14 +741,8 @@ static void get_sectorsize(struct scsi_cd *cd) queue = cd->device->request_queue; blk_queue_hardsect_size(queue, sector_size); -out: - kfree(buffer); - return; -Enomem: - cd->capacity = 0x1fffff; - cd->device->sector_size = 2048; /* A guess, just in case */ - goto out; + return; } static void get_capabilities(struct scsi_cd *cd) |