This is against Jens' sg chaining branch. http://git.kernel.org/?p=linux/kernel/git/axboe/linux-2.6-block.git;a=commitdiff;h=d6beb57f48231f5c012fb7d55b369bc0af6b0c41 The sg chaining patchset adds __use_sg to save the length of sg list before dma mapping. The sg chaining patchset also uses sglist_len but we can live without it. So let's remove sglist_len since we can add something to scsi_cmnd structure only when we definitely need to do. Now the sg chaining provides a way to decrease memory consumption and doesn't add anything to scsi_cmnd structure. James, do you want to change more about the sg chaining's scsi_lib.c? -- >From b887de7c48a674ace622544addd70ebc8ae31fd2 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Date: Thu, 6 Sep 2007 08:41:33 +0100 Subject: [PATCH] remove sglist_len Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 11 ++++------- include/scsi/scsi_cmnd.h | 1 - 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 2fc2380..1e0f691 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -774,10 +774,8 @@ struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) /* * first loop through, set initial index and return value */ - if (!ret) { - cmd->sglist_len = index; + if (!ret) ret = sgl; - } /* * chain previous sglist, if any. we know the previous @@ -830,8 +828,6 @@ void scsi_free_sgtable(struct scsi_cmnd *cmd) struct scatterlist *sgl = cmd->request_buffer; struct scsi_host_sg_pool *sgp; - BUG_ON(cmd->sglist_len >= SG_MEMPOOL_NR); - /* * if this is the biggest size sglist, check if we have * chained parts we need to free @@ -866,9 +862,10 @@ void scsi_free_sgtable(struct scsi_cmnd *cmd) * Restore original, will be freed below */ sgl = cmd->request_buffer; - } + sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1; + } else + sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg); - sgp = scsi_sg_pools + cmd->sglist_len; mempool_free(sgl, sgp->pool); } diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index 6263c4e..bb6358a 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -72,7 +72,6 @@ struct scsi_cmnd { /* These elements define the operation we ultimately want to perform */ unsigned short use_sg; /* Number of pieces of scatter-gather */ - unsigned short sglist_len; /* size of malloc'd scatter-gather list */ unsigned short __use_sg; unsigned underflow; /* Return error if less than -- 1.5.2.4 - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
