On Thu, 2012-11-15 at 20:13 +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
>
> This patch adds support for emulation of WRITE_SAME w/ UNMAP=0 within
> iblock_execute_write_same() backend code.
>
> The emulation uses a bio_add_page() call for each sector, and by default
> enforces a limit of max_write_same_len=0xFFFF (65536) sectors following
> what scsi_debug reports per default for MAXIMUM WRITE SAME LENGTH.
>
> It also sets max_write_same_len to the operational default at setup ->
> iblock_configure_device() time.
>
> (hch: Move unmap logic into iblock_execute_write_same_unmap + add
> check for single sector SGLs in iblock_execute_write_same)
> (mkp: Update comment for 0xFFFF magic constant)
>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
> ---
> drivers/target/target_core_iblock.c | 91 ++++++++++++++++++++++++++++++++---
> 1 files changed, 84 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
> index 53f4501..5abbd55 100644
> --- a/drivers/target/target_core_iblock.c
> +++ b/drivers/target/target_core_iblock.c
> +static sense_reason_t
> +iblock_execute_write_same(struct se_cmd *cmd)
> +{
> + struct iblock_req *ibr;
> + struct scatterlist *sg;
> + struct bio *bio;
> + struct bio_list list;
> + sector_t block_lba = cmd->t_task_lba;
> + unsigned int sectors = spc_get_write_same_sectors(cmd);
> +
> + if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
> + pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
> + sectors, cmd->se_dev->dev_attrib.max_write_same_len);
> + return TCM_INVALID_CDB_FIELD;
> + }
<SNIP>
Forgot to remove this now redundant check for max_write_same_len.
Dropping now..
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