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author | Boaz Harrosh <bharrosh@panasas.com> | 2007-12-13 12:47:40 +0100 |
---|---|---|
committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2008-01-30 20:03:40 +0100 |
commit | 30b0c37b27485a9cb897bfe3824f6f517b8c80d6 (patch) | |
tree | 22643da8e175ff7badf2413dc8c84b2e99613a6f /drivers/scsi/scsi_lib.c | |
parent | [SCSI] tgt: use scsi_init_io instead of scsi_alloc_sgtable (diff) | |
download | linux-30b0c37b27485a9cb897bfe3824f6f517b8c80d6.tar.xz linux-30b0c37b27485a9cb897bfe3824f6f517b8c80d6.zip |
[SCSI] implement scsi_data_buffer
In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.
- Group all IO members of scsi_cmnd into a scsi_data_buffer
structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
scsi_cmnd. And work on it.
- Adjust scsi_init_io() and scsi_release_buffers() for above
change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
accessors where appropriate.
- fix Documentation about scsi_cmnd in scsi_host.h
- scsi_error.c
* Changed needed members of struct scsi_eh_save.
* Careful considerations in scsi_eh_prep/restore_cmnd.
- sd.c and sr.c
* sd and sr would adjust IO size to align on device's block
size so code needs to change once we move to scsi_data_buff
implementation.
* Convert code to use scsi_for_each_sg
* Use data accessors where appropriate.
- tgt: convert libsrp to use scsi_data_buffer
- isd200: This driver still bangs on scsi_cmnd IO members,
so need changing
[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 63 |
1 files changed, 25 insertions, 38 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 69fd62183bab..d5e77e9b3a9c 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -440,7 +440,7 @@ EXPORT_SYMBOL_GPL(scsi_execute_async); static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) { cmd->serial_number = 0; - cmd->resid = 0; + scsi_set_resid(cmd, 0); memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); if (cmd->cmd_len == 0) cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); @@ -746,25 +746,25 @@ static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) return mempool_alloc(sgp->pool, gfp_mask); } -static int scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) +static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, + gfp_t gfp_mask) { int ret; - BUG_ON(!cmd->use_sg); + BUG_ON(!nents); - ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg, - SCSI_MAX_SG_SEGMENTS, gfp_mask, scsi_sg_alloc); + ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, + gfp_mask, scsi_sg_alloc); if (unlikely(ret)) - __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, + __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); - cmd->request_buffer = cmd->sg_table.sgl; return ret; } -static void scsi_free_sgtable(struct scsi_cmnd *cmd) +static void scsi_free_sgtable(struct scsi_data_buffer *sdb) { - __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); + __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); } /* @@ -786,15 +786,10 @@ static void scsi_free_sgtable(struct scsi_cmnd *cmd) */ void scsi_release_buffers(struct scsi_cmnd *cmd) { - if (cmd->use_sg) - scsi_free_sgtable(cmd); + if (cmd->sdb.table.nents) + scsi_free_sgtable(&cmd->sdb); - /* - * Zero these out. They now point to freed memory, and it is - * dangerous to hang onto the pointers. - */ - cmd->request_buffer = NULL; - cmd->request_bufflen = 0; + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); } EXPORT_SYMBOL(scsi_release_buffers); @@ -829,7 +824,7 @@ EXPORT_SYMBOL(scsi_release_buffers); void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) { int result = cmd->result; - int this_count = cmd->request_bufflen; + int this_count = scsi_bufflen(cmd); struct request_queue *q = cmd->device->request_queue; struct request *req = cmd->request; int clear_errors = 1; @@ -837,8 +832,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) int sense_valid = 0; int sense_deferred = 0; - scsi_release_buffers(cmd); - if (result) { sense_valid = scsi_command_normalize_sense(cmd, &sshdr); if (sense_valid) @@ -861,9 +854,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) req->sense_len = len; } } - req->data_len = cmd->resid; + req->data_len = scsi_get_resid(cmd); } + scsi_release_buffers(cmd); + /* * Next deal with any sectors which we were able to correctly * handle. @@ -871,7 +866,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, " "%d bytes done.\n", req->nr_sectors, good_bytes)); - SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg)); if (clear_errors) req->errors = 0; @@ -1002,35 +996,30 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { struct request *req = cmd->request; int count; - - /* - * We used to not use scatter-gather for single segment request, - * but now we do (it makes highmem I/O easier to support without - * kmapping pages) - */ - cmd->use_sg = req->nr_phys_segments; + struct scsi_data_buffer *sdb = &cmd->sdb; /* * If sg table allocation fails, requeue request later. */ - if (unlikely(scsi_alloc_sgtable(cmd, gfp_mask))) { + if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, + gfp_mask))) { scsi_unprep_request(req); return BLKPREP_DEFER; } req->buffer = NULL; if (blk_pc_request(req)) - cmd->request_bufflen = req->data_len; + sdb->length = req->data_len; else - cmd->request_bufflen = req->nr_sectors << 9; + sdb->length = req->nr_sectors << 9; /* * Next, walk the list, and fill in the addresses and sizes of * each segment. */ - count = blk_rq_map_sg(req->q, req, cmd->request_buffer); - BUG_ON(count > cmd->use_sg); - cmd->use_sg = count; + count = blk_rq_map_sg(req->q, req, sdb->table.sgl); + BUG_ON(count > sdb->table.nents); + sdb->table.nents = count; return BLKPREP_OK; } EXPORT_SYMBOL(scsi_init_io); @@ -1086,9 +1075,7 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) BUG_ON(req->data_len); BUG_ON(req->data); - cmd->request_bufflen = 0; - cmd->request_buffer = NULL; - cmd->use_sg = 0; + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); req->buffer = NULL; } |