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author | Christoph Hellwig <hch@lst.de> | 2014-09-05 18:23:07 -0700 |
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committer | Christoph Hellwig <hch@lst.de> | 2014-11-24 19:57:03 +0100 |
commit | 82042a2cdb55cd8402207f14a6e2c24d7a5febe8 (patch) | |
tree | 3c1e9660a193d895ddd736775305acc668c8576c /drivers/scsi/scsi_lib.c | |
parent | 3c356bde19e9a728b26a231a23099c8057dbe881 (diff) | |
download | linux-82042a2cdb55cd8402207f14a6e2c24d7a5febe8.tar.gz linux-82042a2cdb55cd8402207f14a6e2c24d7a5febe8.tar.bz2 linux-82042a2cdb55cd8402207f14a6e2c24d7a5febe8.zip |
scsi: move scsi_dispatch_cmd to scsi_lib.c
scsi_lib.c is where the rest of the I/O submission path lives, so move
scsi_dispatch_cmd there and mark it static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index fcdc585278bf..7e3d954c9cac 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1641,6 +1641,87 @@ static void scsi_softirq_done(struct request *rq) } /** + * scsi_dispatch_command - Dispatch a command to the low-level driver. + * @cmd: command block we are dispatching. + * + * Return: nonzero return request was rejected and device's queue needs to be + * plugged. + */ +static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) +{ + struct Scsi_Host *host = cmd->device->host; + int rtn = 0; + + atomic_inc(&cmd->device->iorequest_cnt); + + /* check if the device is still usable */ + if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { + /* in SDEV_DEL we error all commands. DID_NO_CONNECT + * returns an immediate error upwards, and signals + * that the device is no longer present */ + cmd->result = DID_NO_CONNECT << 16; + goto done; + } + + /* Check to see if the scsi lld made this device blocked. */ + if (unlikely(scsi_device_blocked(cmd->device))) { + /* + * in blocked state, the command is just put back on + * the device queue. The suspend state has already + * blocked the queue so future requests should not + * occur until the device transitions out of the + * suspend state. + */ + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : device blocked\n")); + return SCSI_MLQUEUE_DEVICE_BUSY; + } + + /* Store the LUN value in cmnd, if needed. */ + if (cmd->device->lun_in_cdb) + cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | + (cmd->device->lun << 5 & 0xe0); + + scsi_log_send(cmd); + + /* + * Before we queue this command, check if the command + * length exceeds what the host adapter can handle. + */ + if (cmd->cmd_len > cmd->device->host->max_cmd_len) { + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : command too long. " + "cdb_size=%d host->max_cmd_len=%d\n", + cmd->cmd_len, cmd->device->host->max_cmd_len)); + cmd->result = (DID_ABORT << 16); + goto done; + } + + if (unlikely(host->shost_state == SHOST_DEL)) { + cmd->result = (DID_NO_CONNECT << 16); + goto done; + + } + + trace_scsi_dispatch_cmd_start(cmd); + rtn = host->hostt->queuecommand(host, cmd); + if (rtn) { + trace_scsi_dispatch_cmd_error(cmd, rtn); + if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && + rtn != SCSI_MLQUEUE_TARGET_BUSY) + rtn = SCSI_MLQUEUE_HOST_BUSY; + + SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, + "queuecommand : request rejected\n")); + } + + return rtn; + done: + cmd->scsi_done(cmd); + return 0; +} + +/** * scsi_done - Invoke completion on finished SCSI command. * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives * ownership back to SCSI Core -- i.e. the LLDD has finished with it. |