From: Mike Christie <[email protected]> bc core and the rbd backend driver want seperate scatterlists for the write phase of COMPARE_AND_WRITE. This moves the sbc code to a helper function.
Signed-off-by: Mike Christie <[email protected]> --- drivers/target/target_core_sbc.c | 73 ++++++++++++++++++++++++------------ include/target/target_core_backend.h | 1 + 2 files changed, 49 insertions(+), 25 deletions(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 9a001e6..f803068 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -428,12 +428,58 @@ static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success) return TCM_NO_SENSE; } +/** + * sbc_create_compare_and_write_sg - alloc and prep a sg for the write phase + * @cmd: se_cmd to copy scatterlist from. + * + * Takes the cmd's scatterlist and creates a new sg with only the write + * portion. +*/ +struct scatterlist *sbc_create_compare_and_write_sg(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + unsigned int block_size = dev->dev_attrib.block_size; + unsigned int len = cmd->t_task_nolb * block_size; + struct scatterlist *write_sg; + struct sg_mapping_iter m; + int i = 0; + + write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents, + GFP_KERNEL); + if (!write_sg) { + pr_err("Unable to allocate compare_and_write sg\n"); + return NULL; + } + sg_init_table(write_sg, cmd->t_data_nents); + + sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG); + /* + * Currently assumes NoLB=1 and SGLs are PAGE_SIZE.. + */ + while (len) { + sg_miter_next(&m); + + if (block_size < PAGE_SIZE) { + sg_set_page(&write_sg[i], m.page, block_size, + block_size); + } else { + sg_miter_next(&m); + sg_set_page(&write_sg[i], m.page, block_size, 0); + } + len -= block_size; + i++; + } + sg_miter_stop(&m); + + return write_sg; +} +EXPORT_SYMBOL(sbc_create_compare_and_write_sg); + static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success) { struct se_device *dev = cmd->se_dev; struct scatterlist *write_sg = NULL, *sg; unsigned char *buf = NULL, *addr; - struct sg_mapping_iter m; unsigned int offset = 0, len; unsigned int nlbas = cmd->t_task_nolb; unsigned int block_size = dev->dev_attrib.block_size; @@ -469,14 +515,12 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes goto out; } - write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents, - GFP_KERNEL); + write_sg = sbc_create_compare_and_write_sg(cmd); if (!write_sg) { pr_err("Unable to allocate compare_and_write sg\n"); ret = TCM_OUT_OF_RESOURCES; goto out; } - sg_init_table(write_sg, cmd->t_data_nents); /* * Setup verify and write data payloads from total NumberLBAs. */ @@ -513,27 +557,6 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes break; } - i = 0; - len = cmd->t_task_nolb * block_size; - sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG); - /* - * Currently assumes NoLB=1 and SGLs are PAGE_SIZE.. - */ - while (len) { - sg_miter_next(&m); - - if (block_size < PAGE_SIZE) { - sg_set_page(&write_sg[i], m.page, block_size, - block_size); - } else { - sg_miter_next(&m); - sg_set_page(&write_sg[i], m.page, block_size, - 0); - } - len -= block_size; - i++; - } - sg_miter_stop(&m); /* * Save the original SGL + nents values before updating to new * assignments, to be released in transport_free_pages() -> diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index c98f6e6..d8895e2 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -61,6 +61,7 @@ void target_complete_cmd(struct se_cmd *, u8); void target_complete_cmd_with_sense(struct se_cmd *, sense_reason_t); void target_complete_cmd_with_length(struct se_cmd *, u8, int); +struct scatterlist *sbc_create_compare_and_write_sg(struct se_cmd *); sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size); sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd); sense_reason_t spc_emulate_inquiry_std(struct se_cmd *, unsigned char *); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
