diff options
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_file.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index b9c88497e8f0..94383a56bd74 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -190,6 +190,11 @@ static int fd_configure_device(struct se_device *dev) fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++; fd_dev->fd_queue_depth = dev->queue_depth; + /* + * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB) + * based upon struct iovec limit for vfs_writev() + */ + dev->dev_attrib.max_write_same_len = 0x1000; pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s," " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id, @@ -328,6 +333,114 @@ fd_execute_sync_cache(struct se_cmd *cmd) 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 = spc_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; + + if (!nolb) { + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; + } + sg = &cmd->t_data_sg[0]; + + if (cmd->t_data_nents > 1 || + sg->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, + 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) + 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; + } + + old_fs = get_fs(); + set_fs(get_ds()); + rc = vfs_writev(f, &iov[0], iov_num, &pos); + set_fs(old_fs); + + vfree(iov); + kfree(buf); + + if (rc < 0 || rc != len) { + pr_err("vfs_writev() returned %d for write same\n", rc); + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + + target_complete_cmd(cmd, SAM_STAT_GOOD); + return 0; +} + static sense_reason_t fd_execute_rw(struct se_cmd *cmd) { @@ -486,6 +599,7 @@ static sector_t fd_get_blocks(struct se_device *dev) static struct sbc_ops fd_sbc_ops = { .execute_rw = fd_execute_rw, .execute_sync_cache = fd_execute_sync_cache, + .execute_write_same = fd_execute_write_same, }; static sense_reason_t |