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>
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30c00eda73
Коммит
62858dacc8
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@ -673,24 +673,20 @@ fail:
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static void get_sectorsize(struct scsi_cd *cd)
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{
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unsigned char cmd[10];
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unsigned char *buffer;
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unsigned char buffer[8];
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int the_result, retries = 3;
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int sector_size;
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struct request_queue *queue;
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buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
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if (!buffer)
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goto Enomem;
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do {
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cmd[0] = READ_CAPACITY;
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memset((void *) &cmd[1], 0, 9);
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memset(buffer, 0, 8);
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memset(buffer, 0, sizeof(buffer));
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/* Do the command and wait.. */
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the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
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buffer, 8, NULL, SR_TIMEOUT,
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MAX_RETRIES);
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buffer, sizeof(buffer), NULL,
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SR_TIMEOUT, MAX_RETRIES);
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retries--;
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@ -745,14 +741,8 @@ static void get_sectorsize(struct scsi_cd *cd)
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queue = cd->device->request_queue;
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blk_queue_hardsect_size(queue, sector_size);
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out:
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kfree(buffer);
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return;
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Enomem:
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cd->capacity = 0x1fffff;
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cd->device->sector_size = 2048; /* A guess, just in case */
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goto out;
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return;
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}
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static void get_capabilities(struct scsi_cd *cd)
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