target: rewrite fd_execute_write_same
With the new bio_vec backed iov_iter helpers we can simply set up
on bio_vec per LBA, all pointing to the same initiator-supplied
buffer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index ea6e14e..8800d54 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -433,59 +433,17 @@
return 0;
}
-static unsigned char *
-fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
- unsigned int len)
-{
- struct se_device *se_dev = cmd->se_dev;
- unsigned int block_size = se_dev->dev_attrib.block_size;
- unsigned int i = 0, end;
- unsigned char *buf, *p, *kmap_buf;
-
- buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
- if (!buf) {
- pr_err("Unable to allocate fd_execute_write_same buf\n");
- return NULL;
- }
-
- kmap_buf = kmap(sg_page(sg)) + sg->offset;
- if (!kmap_buf) {
- pr_err("kmap() failed in fd_setup_write_same\n");
- kfree(buf);
- return NULL;
- }
- /*
- * Fill local *buf to contain multiple WRITE_SAME blocks up to
- * min(len, PAGE_SIZE)
- */
- p = buf;
- end = min_t(unsigned int, len, PAGE_SIZE);
-
- while (i < end) {
- memcpy(p, kmap_buf, block_size);
-
- i += block_size;
- p += block_size;
- }
- kunmap(sg_page(sg));
-
- return buf;
-}
-
static sense_reason_t
fd_execute_write_same(struct se_cmd *cmd)
{
struct se_device *se_dev = cmd->se_dev;
struct fd_dev *fd_dev = FD_DEV(se_dev);
- struct file *f = fd_dev->fd_file;
- struct scatterlist *sg;
- struct iovec *iov;
- mm_segment_t old_fs;
- sector_t nolb = sbc_get_write_same_sectors(cmd);
loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
- unsigned int len, len_tmp, iov_num;
- int i, rc;
- unsigned char *buf;
+ sector_t nolb = sbc_get_write_same_sectors(cmd);
+ struct iov_iter iter;
+ struct bio_vec *bvec;
+ unsigned int len = 0, i;
+ ssize_t ret;
if (!nolb) {
target_complete_cmd(cmd, SAM_STAT_GOOD);
@@ -496,49 +454,35 @@
" backends not supported\n");
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
- sg = &cmd->t_data_sg[0];
if (cmd->t_data_nents > 1 ||
- sg->length != cmd->se_dev->dev_attrib.block_size) {
+ cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
- " block_size: %u\n", cmd->t_data_nents, sg->length,
+ " block_size: %u\n",
+ cmd->t_data_nents,
+ cmd->t_data_sg[0].length,
cmd->se_dev->dev_attrib.block_size);
return TCM_INVALID_CDB_FIELD;
}
- len = len_tmp = nolb * se_dev->dev_attrib.block_size;
- iov_num = DIV_ROUND_UP(len, PAGE_SIZE);
-
- buf = fd_setup_write_same_buf(cmd, sg, len);
- if (!buf)
+ bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
+ if (!bvec)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- iov = vzalloc(sizeof(struct iovec) * iov_num);
- if (!iov) {
- pr_err("Unable to allocate fd_execute_write_same iovecs\n");
- kfree(buf);
- return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- }
- /*
- * Map the single fabric received scatterlist block now populated
- * in *buf into each iovec for I/O submission.
- */
- for (i = 0; i < iov_num; i++) {
- iov[i].iov_base = buf;
- iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
- len_tmp -= iov[i].iov_len;
+ for (i = 0; i < nolb; i++) {
+ bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
+ bvec[i].bv_len = cmd->t_data_sg[0].length;
+ bvec[i].bv_offset = cmd->t_data_sg[0].offset;
+
+ len += se_dev->dev_attrib.block_size;
}
- old_fs = get_fs();
- set_fs(get_ds());
- rc = vfs_writev(f, &iov[0], iov_num, &pos);
- set_fs(old_fs);
+ iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
+ ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
- vfree(iov);
- kfree(buf);
-
- if (rc < 0 || rc != len) {
- pr_err("vfs_writev() returned %d for write same\n", rc);
+ kfree(bvec);
+ if (ret < 0 || ret != len) {
+ pr_err("vfs_iter_write() returned %zd for write same\n", ret);
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
