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scsi: explicitly release bidi buffers 

Instead of trying to guess when we have a BIDI buffer in scsi_release_buffers
add a function to explicitly free the BIDI ressoures in the one place that
handles them.  This avoids needing a special __scsi_release_buffers for the
case where we already have freed the request as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
This commit is contained in:
Christoph Hellwig 2014-05-01 16:51:02 +02:00
parent d6d211db37
commit c682adf3e1
1 changed files with 20 additions and 27 deletions
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47
drivers/scsi/scsi_lib.c
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@ -512,8 +512,6 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
scsi_run_queue(sdev->request_queue);
}
static void __scsi_release_buffers(struct scsi_cmnd *, int);
/*
* Function: scsi_end_request()
*
@ -569,7 +567,7 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
* This will goose the queue request function at the end, so we don't
* need to worry about launching another command.
*/
__scsi_release_buffers(cmd, 0);
scsi_release_buffers(cmd);
scsi_next_command(cmd);
return NULL;
}
@ -625,30 +623,10 @@ static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
__sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
}
static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
{
if (cmd->sdb.table.nents)
scsi_free_sgtable(&cmd->sdb);
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
if (do_bidi_check && scsi_bidi_cmnd(cmd)) {
struct scsi_data_buffer *bidi_sdb =
cmd->request->next_rq->special;
scsi_free_sgtable(bidi_sdb);
kmem_cache_free(scsi_sdb_cache, bidi_sdb);
cmd->request->next_rq->special = NULL;
}
if (scsi_prot_sg_count(cmd))
scsi_free_sgtable(cmd->prot_sdb);
}
/*
* Function: scsi_release_buffers()
*
* Purpose: Completion processing for block device I/O requests.
* Purpose: Free resources allocate for a scsi_command.
*
* Arguments: cmd - command that we are bailing.
*
@ -659,15 +637,29 @@ static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
* Notes: In the event that an upper level driver rejects a
* command, we must release resources allocated during
* the __init_io() function. Primarily this would involve
* the scatter-gather table, and potentially any bounce
* buffers.
* the scatter-gather table.
*/
void scsi_release_buffers(struct scsi_cmnd *cmd)
{
__scsi_release_buffers(cmd, 1);
if (cmd->sdb.table.nents)
scsi_free_sgtable(&cmd->sdb);
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
if (scsi_prot_sg_count(cmd))
scsi_free_sgtable(cmd->prot_sdb);
}
EXPORT_SYMBOL(scsi_release_buffers);
static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
{
struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
scsi_free_sgtable(bidi_sdb);
kmem_cache_free(scsi_sdb_cache, bidi_sdb);
cmd->request->next_rq->special = NULL;
}
/**
* __scsi_error_from_host_byte - translate SCSI error code into errno
* @cmd: SCSI command (unused)
@ -801,6 +793,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
req->next_rq->resid_len = scsi_in(cmd)->resid;
scsi_release_buffers(cmd);
scsi_release_bidi_buffers(cmd);
blk_end_request_all(req, 0);
scsi_next_command(cmd);