Commit 2237498f authored by Nicholas Bellinger's avatar Nicholas Bellinger

target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout

The people who are actively using iblock_execute_write_same_direct() are
doing so in the context of ESX VAAI BlockZero, together with
EXTENDED_COPY and COMPARE_AND_WRITE primitives.

In practice though I've not seen any users of IBLOCK WRITE_SAME for
anything other than VAAI BlockZero, so just using blkdev_issue_zeroout()
when available, and falling back to iblock_execute_write_same() if the
WRITE_SAME buffer contains anything other than zeros should be OK.

(Hook up max_write_zeroes_sectors to signal LBPRZ feature bit in
 target_configure_unmap_from_queue - nab)
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 464fd641
...@@ -851,7 +851,7 @@ bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib, ...@@ -851,7 +851,7 @@ bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
attrib->unmap_granularity = q->limits.discard_granularity / block_size; attrib->unmap_granularity = q->limits.discard_granularity / block_size;
attrib->unmap_granularity_alignment = q->limits.discard_alignment / attrib->unmap_granularity_alignment = q->limits.discard_alignment /
block_size; block_size;
attrib->unmap_zeroes_data = 0; attrib->unmap_zeroes_data = (q->limits.max_write_zeroes_sectors);
return true; return true;
} }
EXPORT_SYMBOL(target_configure_unmap_from_queue); EXPORT_SYMBOL(target_configure_unmap_from_queue);
......
...@@ -86,6 +86,7 @@ static int iblock_configure_device(struct se_device *dev) ...@@ -86,6 +86,7 @@ static int iblock_configure_device(struct se_device *dev)
struct block_device *bd = NULL; struct block_device *bd = NULL;
struct blk_integrity *bi; struct blk_integrity *bi;
fmode_t mode; fmode_t mode;
unsigned int max_write_zeroes_sectors;
int ret = -ENOMEM; int ret = -ENOMEM;
if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) { if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
...@@ -129,7 +130,11 @@ static int iblock_configure_device(struct se_device *dev) ...@@ -129,7 +130,11 @@ static int iblock_configure_device(struct se_device *dev)
* Enable write same emulation for IBLOCK and use 0xFFFF as * Enable write same emulation for IBLOCK and use 0xFFFF as
* the smaller WRITE_SAME(10) only has a two-byte block count. * the smaller WRITE_SAME(10) only has a two-byte block count.
*/ */
dev->dev_attrib.max_write_same_len = 0xFFFF; max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
if (max_write_zeroes_sectors)
dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
else
dev->dev_attrib.max_write_same_len = 0xFFFF;
if (blk_queue_nonrot(q)) if (blk_queue_nonrot(q))
dev->dev_attrib.is_nonrot = 1; dev->dev_attrib.is_nonrot = 1;
...@@ -415,28 +420,31 @@ iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) ...@@ -415,28 +420,31 @@ iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
} }
static sense_reason_t static sense_reason_t
iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd) iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
{ {
struct se_device *dev = cmd->se_dev; struct se_device *dev = cmd->se_dev;
struct scatterlist *sg = &cmd->t_data_sg[0]; struct scatterlist *sg = &cmd->t_data_sg[0];
struct page *page = NULL; unsigned char *buf, zero = 0x00, *p = &zero;
int ret; int rc, ret;
if (sg->offset) { buf = kmap(sg_page(sg)) + sg->offset;
page = alloc_page(GFP_KERNEL); if (!buf)
if (!page) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
return TCM_OUT_OF_RESOURCES; /*
sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page), * Fall back to block_execute_write_same() slow-path if
dev->dev_attrib.block_size); * incoming WRITE_SAME payload does not contain zeros.
} */
rc = memcmp(buf, p, cmd->data_length);
kunmap(sg_page(sg));
if (rc)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
ret = blkdev_issue_write_same(bdev, ret = blkdev_issue_zeroout(bdev,
target_to_linux_sector(dev, cmd->t_task_lba), target_to_linux_sector(dev, cmd->t_task_lba),
target_to_linux_sector(dev, target_to_linux_sector(dev,
sbc_get_write_same_sectors(cmd)), sbc_get_write_same_sectors(cmd)),
GFP_KERNEL, page ? page : sg_page(sg)); GFP_KERNEL, false);
if (page)
__free_page(page);
if (ret) if (ret)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
...@@ -472,8 +480,10 @@ iblock_execute_write_same(struct se_cmd *cmd) ...@@ -472,8 +480,10 @@ iblock_execute_write_same(struct se_cmd *cmd)
return TCM_INVALID_CDB_FIELD; return TCM_INVALID_CDB_FIELD;
} }
if (bdev_write_same(bdev)) if (bdev_write_zeroes_sectors(bdev)) {
return iblock_execute_write_same_direct(bdev, cmd); if (!iblock_execute_zero_out(bdev, cmd))
return 0;
}
ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
if (!ibr) if (!ibr)
......
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