Move the error handling path out of scsi_io_completion and into an
out of line helper.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/scsi/scsi_lib.c | 263 +++++++++++++++++++++++++-----------------------
1 file changed, 136 insertions(+), 127 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2221bf1..cc5d404 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -742,6 +742,132 @@ static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
return error;
}
+static noinline bool
+scsi_handle_ioerror(struct scsi_cmnd *cmd, int result,
+ struct scsi_sense_hdr *sshdr)
+{
+ struct request *req = cmd->request;
+ unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
+ int error = 0;
+ enum {
+ ACTION_FAIL,
+ ACTION_REPREP,
+ ACTION_RETRY,
+ ACTION_DELAYED_RETRY,
+ } action = ACTION_FAIL;
+
+ error = __scsi_error_from_host_byte(cmd, result);
+
+ if (host_byte(result) == DID_RESET) {
+ /* Third party bus reset or reset for error recovery
+ * reasons. Just retry the command and see what
+ * happens.
+ */
+ action = ACTION_RETRY;
+ } else if (sshdr) {
+ switch (sshdr->sense_key) {
+ case UNIT_ATTENTION:
+ if (cmd->device->removable) {
+ /* Detected disc change. Set a bit
+ * and quietly refuse further access.
+ */
+ cmd->device->changed = 1;
+ } else {
+ /* Must have been a power glitch, or a
+ * bus reset. Could not have been a
+ * media change, so we just retry the
+ * command and see what happens.
+ */
+ action = ACTION_RETRY;
+ }
+ break;
+ case ILLEGAL_REQUEST:
+ /* If we had an ILLEGAL REQUEST returned, then
+ * we may have performed an unsupported
+ * command. The only thing this should be
+ * would be a ten byte read where only a six
+ * byte read was supported. Also, on a system
+ * where READ CAPACITY failed, we may have
+ * read past the end of the disk.
+ */
+ if ((cmd->device->use_10_for_rw &&
+ sshdr->asc == 0x20 && sshdr->ascq == 0x00) &&
+ (cmd->cmnd[0] == READ_10 ||
+ cmd->cmnd[0] == WRITE_10)) {
+ /* This will issue a new 6-byte command. */
+ cmd->device->use_10_for_rw = 0;
+ action = ACTION_REPREP;
+ } else if (sshdr->asc == 0x10) /* DIX */ {
+ error = -EILSEQ;
+ /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
+ } else if (sshdr->asc == 0x20 || sshdr->asc == 0x24) {
+ error = -EREMOTEIO;
+ }
+ break;
+ case ABORTED_COMMAND:
+ if (sshdr->asc == 0x10) /* DIF */
+ error = -EILSEQ;
+ break;
+ case NOT_READY:
+ /* If the device is in the process of becoming
+ * ready, or has a temporary blockage, retry.
+ */
+ if (sshdr->asc == 0x04) {
+ switch (sshdr->ascq) {
+ case 0x01: /* becoming ready */
+ case 0x04: /* format in progress */
+ case 0x05: /* rebuild in progress */
+ case 0x06: /* recalculation in progress */
+ case 0x07: /* operation in progress */
+ case 0x08: /* Long write in progress */
+ case 0x09: /* self test in progress */
+ case 0x14: /* space allocation in progress */
+ action = ACTION_DELAYED_RETRY;
+ break;
+ default:
+ break;
+ }
+ }
+ break;
+ case VOLUME_OVERFLOW:
+ /* See SSC3rXX or current. */
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (action != ACTION_FAIL &&
+ time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
+ action = ACTION_FAIL;
+
+ switch (action) {
+ case ACTION_FAIL:
+ /* Give up and fail the remainder of the request */
+ if (!(req->cmd_flags & REQ_QUIET)) {
+ scsi_print_result(cmd);
+ if (driver_byte(result) & DRIVER_SENSE)
+ scsi_print_sense("", cmd);
+ scsi_print_command(cmd);
+ }
+ if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0))
+ break;
+ /*FALLTHRU*/
+ case ACTION_REPREP:
+ return false;
+ case ACTION_RETRY:
+ /* Retry the same command immediately */
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
+ break;
+ case ACTION_DELAYED_RETRY:
+ /* Retry the same command after a delay */
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
+ break;
+ }
+
+ return true;
+}
+
/*
* Function: scsi_io_completion()
*
@@ -779,9 +905,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
int sense_deferred = 0;
- enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
- ACTION_DELAYED_RETRY} action;
- unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
if (result) {
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
@@ -867,7 +990,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
/*
* If we finished all bytes in the request we are done now.
*/
- if (!scsi_end_request(req, error, good_bytes, 0))
+ if (likely(!scsi_end_request(req, error, good_bytes, 0)))
return;
/*
@@ -880,132 +1003,18 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
}
/*
- * If there had been no error, but we have leftover bytes in the
- * requeues just queue the command up again.
+ * Try to handle errors if we got a non-zero result.
*/
- if (result == 0)
- goto requeue;
-
- error = __scsi_error_from_host_byte(cmd, result);
-
- if (host_byte(result) == DID_RESET) {
- /* Third party bus reset or reset for error recovery
- * reasons. Just retry the command and see what
- * happens.
- */
- action = ACTION_RETRY;
- } else if (sense_valid && !sense_deferred) {
- switch (sshdr.sense_key) {
- case UNIT_ATTENTION:
- if (cmd->device->removable) {
- /* Detected disc change. Set a bit
- * and quietly refuse further access.
- */
- cmd->device->changed = 1;
- action = ACTION_FAIL;
- } else {
- /* Must have been a power glitch, or a
- * bus reset. Could not have been a
- * media change, so we just retry the
- * command and see what happens.
- */
- action = ACTION_RETRY;
- }
- break;
- case ILLEGAL_REQUEST:
- /* If we had an ILLEGAL REQUEST returned, then
- * we may have performed an unsupported
- * command. The only thing this should be
- * would be a ten byte read where only a six
- * byte read was supported. Also, on a system
- * where READ CAPACITY failed, we may have
- * read past the end of the disk.
- */
- if ((cmd->device->use_10_for_rw &&
- sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
- (cmd->cmnd[0] == READ_10 ||
- cmd->cmnd[0] == WRITE_10)) {
- /* This will issue a new 6-byte command. */
- cmd->device->use_10_for_rw = 0;
- action = ACTION_REPREP;
- } else if (sshdr.asc == 0x10) /* DIX */ {
- action = ACTION_FAIL;
- error = -EILSEQ;
- /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
- } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
- action = ACTION_FAIL;
- error = -EREMOTEIO;
- } else
- action = ACTION_FAIL;
- break;
- case ABORTED_COMMAND:
- action = ACTION_FAIL;
- if (sshdr.asc == 0x10) /* DIF */
- error = -EILSEQ;
- break;
- case NOT_READY:
- /* If the device is in the process of becoming
- * ready, or has a temporary blockage, retry.
- */
- if (sshdr.asc == 0x04) {
- switch (sshdr.ascq) {
- case 0x01: /* becoming ready */
- case 0x04: /* format in progress */
- case 0x05: /* rebuild in progress */
- case 0x06: /* recalculation in progress */
- case 0x07: /* operation in progress */
- case 0x08: /* Long write in progress */
- case 0x09: /* self test in progress */
- case 0x14: /* space allocation in progress */
- action = ACTION_DELAYED_RETRY;
- break;
- default:
- action = ACTION_FAIL;
- break;
- }
- } else
- action = ACTION_FAIL;
- break;
- case VOLUME_OVERFLOW:
- /* See SSC3rXX or current. */
- action = ACTION_FAIL;
- break;
- default:
- action = ACTION_FAIL;
- break;
- }
- } else
- action = ACTION_FAIL;
-
- if (action != ACTION_FAIL &&
- time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
- action = ACTION_FAIL;
-
- switch (action) {
- case ACTION_FAIL:
- /* Give up and fail the remainder of the request */
- if (!(req->cmd_flags & REQ_QUIET)) {
- scsi_print_result(cmd);
- if (driver_byte(result) & DRIVER_SENSE)
- scsi_print_sense("", cmd);
- scsi_print_command(cmd);
- }
- if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0))
+ if (result != 0) {
+ if (scsi_handle_ioerror(cmd, result,
+ sense_valid && !sense_deferred ? &sshdr : NULL))
return;
- /*FALLTHRU*/
- case ACTION_REPREP:
- requeue:
- scsi_requeue_command(cmd);
- break;
- case ACTION_RETRY:
- /* Retry the same command immediately */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
- break;
- case ACTION_DELAYED_RETRY:
- /* Retry the same command after a delay */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
- break;
}
+
+ /*
+ * Queue up the leftovers again.
+ */
+ scsi_requeue_command(cmd);
}
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
--
1.9.1
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