This patch simplifies "good_bytes" computation in sd_rw_intr().
sd: "good_bytes" computation is always done in terms of the resolution
of the device's medium, since after that it is the number of good bytes
we pass around and other layers/contexts (as opposed ot sd) can translate
that to their own resolution (block layer:512). It also makes
scsi_io_completion() processing more straightforward, eliminating the
3rd argument to the function.
It also fixes a couple of bugs like not checking return value,
using "break" instead of "return;", etc.
I've been running with this patch for some time now on a
test (do-it-all) system.
Signed-off-by: Luben Tuikov <ltuikov@xxxxxxxxx>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e23522e..ec843b2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -855,8 +855,7 @@ static void scsi_release_buffers(struct
* b) We can just use scsi_requeue_command() here. This would
* be used if we just wanted to retry, for example.
*/
-void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
- unsigned int block_bytes)
+void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
{
int result = cmd->result;
int this_count = cmd->bufflen;
@@ -921,87 +920,72 @@ void scsi_io_completion(struct scsi_cmnd
* Next deal with any sectors which we were able to correctly
* handle.
*/
- if (good_bytes >= 0) {
- SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d bytes done.\n",
+ if (good_bytes > 0) {
+ 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;
- /*
- * If multiple sectors are requested in one buffer, then
- * they will have been finished off by the first command.
- * If not, then we have a multi-buffer command.
- *
- * If block_bytes != 0, it means we had a medium error
- * of some sort, and that we want to mark some number of
- * sectors as not uptodate. Thus we want to inhibit
- * requeueing right here - we will requeue down below
- * when we handle the bad sectors.
- */
- /*
- * If the command completed without error, then either
- * finish off the rest of the command, or start a new one.
+ /* A number of bytes were successfully read. If there
+ * is leftovers and there is some kind of error
+ * (result != 0), retry the rest.
*/
- if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
+ if (scsi_end_request(cmd, 1, good_bytes, !!result) == NULL)
return;
}
- /*
- * Now, if we were good little boys and girls, Santa left us a request
- * sense buffer. We can extract information from this, so we
- * can choose a block to remap, etc.
+
+ /* good_bytes = 0, or (inclusive) there were leftovers and
+ * result = 0, so scsi_end_request couldn't retry.
*/
if (sense_valid && !sense_deferred) {
switch (sshdr.sense_key) {
case UNIT_ATTENTION:
if (cmd->device->removable) {
- /* detected disc change. set a bit
+ /* Detected disc change. Set a bit
* and quietly refuse further access.
*/
cmd->device->changed = 1;
- scsi_end_request(cmd, 0,
- this_count, 1);
+ scsi_end_request(cmd, 0, this_count, 1);
return;
} else {
- /*
- * Must have been a power glitch, or a
- * bus reset. Could not have been a
- * media change, so we just retry the
- * request and see what happens.
- */
+ /* Must have been a power glitch, or a
+ * bus reset. Could not have been a
+ * media change, so we just retry the
+ * request and see what happens.
+ */
scsi_requeue_command(q, cmd);
return;
}
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 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)) {
cmd->device->use_10_for_rw = 0;
- /*
- * This will cause a retry with a 6-byte
- * command.
+ /* This will cause a retry with a
+ * 6-byte command.
*/
scsi_requeue_command(q, cmd);
- result = 0;
+ return;
} else {
scsi_end_request(cmd, 0, this_count, 1);
return;
}
break;
case NOT_READY:
- /*
- * If the device is in the process of becoming
+ /* If the device is in the process of becoming
* ready, or has a temporary blockage, retry.
*/
if (sshdr.asc == 0x04) {
@@ -1021,7 +1005,7 @@ void scsi_io_completion(struct scsi_cmnd
}
if (!(req->flags & REQ_QUIET)) {
scmd_printk(KERN_INFO, cmd,
- "Device not ready: ");
+ "Device not ready: ");
scsi_print_sense_hdr("", &sshdr);
}
scsi_end_request(cmd, 0, this_count, 1);
@@ -1029,21 +1013,21 @@ void scsi_io_completion(struct scsi_cmnd
case VOLUME_OVERFLOW:
if (!(req->flags & REQ_QUIET)) {
scmd_printk(KERN_INFO, cmd,
- "Volume overflow, CDB: ");
+ "Volume overflow, CDB: ");
__scsi_print_command(cmd->data_cmnd);
scsi_print_sense("", cmd);
}
- scsi_end_request(cmd, 0, block_bytes, 1);
+ /* See SSC3rXX or current. */
+ scsi_end_request(cmd, 0, this_count, 1);
return;
default:
break;
}
- } /* driver byte != 0 */
+ }
if (host_byte(result) == DID_RESET) {
- /*
- * Third party bus reset or reset for error
- * recovery reasons. Just retry the request
- * and see what happens.
+ /* Third party bus reset or reset for error recovery
+ * reasons. Just retry the request and see what
+ * happens.
*/
scsi_requeue_command(q, cmd);
return;
@@ -1051,21 +1035,13 @@ void scsi_io_completion(struct scsi_cmnd
if (result) {
if (!(req->flags & REQ_QUIET)) {
scmd_printk(KERN_INFO, cmd,
- "SCSI error: return code = 0x%x\n", result);
-
+ "SCSI error: return code = 0x%08x\n",
+ result);
if (driver_byte(result) & DRIVER_SENSE)
scsi_print_sense("", cmd);
}
- /*
- * Mark a single buffer as not uptodate. Queue the remainder.
- * We sometimes get this cruft in the event that a medium error
- * isn't properly reported.
- */
- block_bytes = req->hard_cur_sectors << 9;
- if (!block_bytes)
- block_bytes = req->data_len;
- scsi_end_request(cmd, 0, block_bytes, 1);
}
+ scsi_end_request(cmd, 0, this_count, !result);
}
EXPORT_SYMBOL(scsi_io_completion);
@@ -1169,7 +1145,7 @@ static void scsi_blk_pc_done(struct scsi
* successfully. Since this is a REQ_BLOCK_PC command the
* caller should check the request's errors value
*/
- scsi_io_completion(cmd, cmd->bufflen, 0);
+ scsi_io_completion(cmd, cmd->bufflen);
}
static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 01f0cae..0522b05 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -891,11 +891,10 @@ #endif
static void sd_rw_intr(struct scsi_cmnd * SCpnt)
{
int result = SCpnt->result;
- int this_count = SCpnt->request_bufflen;
- int good_bytes = (result == 0 ? this_count : 0);
- sector_t block_sectors = 1;
- u64 first_err_block;
- sector_t error_sector;
+ unsigned int xfer_size = SCpnt->request_bufflen;
+ unsigned int good_bytes = result ? 0 : xfer_size;
+ u64 start_lba = SCpnt->request->sector;
+ u64 bad_lba;
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
int sense_deferred = 0;
@@ -906,7 +905,6 @@ static void sd_rw_intr(struct scsi_cmnd
if (sense_valid)
sense_deferred = scsi_sense_is_deferred(&sshdr);
}
-
#ifdef CONFIG_SCSI_LOGGING
SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n",
SCpnt->request->rq_disk->disk_name, result));
@@ -916,89 +914,72 @@ #ifdef CONFIG_SCSI_LOGGING
sshdr.sense_key, sshdr.asc, sshdr.ascq));
}
#endif
- /*
- Handle MEDIUM ERRORs that indicate partial success. Since this is a
- relatively rare error condition, no care is taken to avoid
- unnecessary additional work such as memcpy's that could be avoided.
- */
- if (driver_byte(result) != 0 &&
- sense_valid && !sense_deferred) {
- switch (sshdr.sense_key) {
- case MEDIUM_ERROR:
- if (!blk_fs_request(SCpnt->request))
- break;
- info_valid = scsi_get_sense_info_fld(
- SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE,
- &first_err_block);
- /*
- * May want to warn and skip if following cast results
- * in actual truncation (if sector_t < 64 bits)
- */
- error_sector = (sector_t)first_err_block;
- if (SCpnt->request->bio != NULL)
- block_sectors = bio_sectors(SCpnt->request->bio);
- switch (SCpnt->device->sector_size) {
- case 1024:
- error_sector <<= 1;
- if (block_sectors < 2)
- block_sectors = 2;
- break;
- case 2048:
- error_sector <<= 2;
- if (block_sectors < 4)
- block_sectors = 4;
- break;
- case 4096:
- error_sector <<=3;
- if (block_sectors < 8)
- block_sectors = 8;
- break;
- case 256:
- error_sector >>= 1;
- break;
- default:
- break;
- }
+ if (driver_byte(result) != DRIVER_SENSE &&
+ (!sense_valid || sense_deferred))
+ goto out;
- error_sector &= ~(block_sectors - 1);
- good_bytes = (error_sector - SCpnt->request->sector) << 9;
- if (good_bytes < 0 || good_bytes >= this_count)
- good_bytes = 0;
+ switch (sshdr.sense_key) {
+ case HARDWARE_ERROR:
+ case MEDIUM_ERROR:
+ if (!blk_fs_request(SCpnt->request))
+ goto out;
+ info_valid = scsi_get_sense_info_fld(SCpnt->sense_buffer,
+ SCSI_SENSE_BUFFERSIZE,
+ &bad_lba);
+ if (!info_valid)
+ goto out;
+ if (xfer_size <= SCpnt->device->sector_size)
+ goto out;
+ switch (SCpnt->device->sector_size) {
+ case 256:
+ start_lba <<= 1;
break;
-
- case RECOVERED_ERROR: /* an error occurred, but it recovered */
- case NO_SENSE: /* LLDD got sense data */
- /*
- * Inform the user, but make sure that it's not treated
- * as a hard error.
- */
- scsi_print_sense("sd", SCpnt);
- SCpnt->result = 0;
- memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
- good_bytes = this_count;
+ case 512:
break;
-
- case ILLEGAL_REQUEST:
- if (SCpnt->device->use_10_for_rw &&
- (SCpnt->cmnd[0] == READ_10 ||
- SCpnt->cmnd[0] == WRITE_10))
- SCpnt->device->use_10_for_rw = 0;
- if (SCpnt->device->use_10_for_ms &&
- (SCpnt->cmnd[0] == MODE_SENSE_10 ||
- SCpnt->cmnd[0] == MODE_SELECT_10))
- SCpnt->device->use_10_for_ms = 0;
+ case 1024:
+ start_lba >>= 1;
+ break;
+ case 2048:
+ start_lba >>= 2;
+ break;
+ case 4096:
+ start_lba >>= 3;
break;
-
default:
+ /* Print something here with limiting frequency. */
+ goto out;
break;
}
+ /* This computation should always be done in terms of
+ * the resolution of the device's medium.
+ */
+ good_bytes = (bad_lba - start_lba)*SCpnt->device->sector_size;
+ break;
+ case RECOVERED_ERROR:
+ case NO_SENSE:
+ /* Inform the user, but make sure that it's not treated
+ * as a hard error.
+ */
+ scsi_print_sense("sd", SCpnt);
+ SCpnt->result = 0;
+ memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+ good_bytes = xfer_size;
+ break;
+ case ILLEGAL_REQUEST:
+ if (SCpnt->device->use_10_for_rw &&
+ (SCpnt->cmnd[0] == READ_10 ||
+ SCpnt->cmnd[0] == WRITE_10))
+ SCpnt->device->use_10_for_rw = 0;
+ if (SCpnt->device->use_10_for_ms &&
+ (SCpnt->cmnd[0] == MODE_SENSE_10 ||
+ SCpnt->cmnd[0] == MODE_SELECT_10))
+ SCpnt->device->use_10_for_ms = 0;
+ break;
+ default:
+ break;
}
- /*
- * This calls the generic completion function, now that we know
- * how many actual sectors finished, and how many sectors we need
- * to say have failed.
- */
- scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
+ out:
+ scsi_io_completion(SCpnt, good_bytes);
}
static int media_not_present(struct scsi_disk *sdkp,
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index ebf6579..fd94408 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -292,7 +292,7 @@ #endif
* how many actual sectors finished, and how many sectors we need
* to say have failed.
*/
- scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
+ scsi_io_completion(SCpnt, good_bytes);
}
static int sr_init_command(struct scsi_cmnd * SCpnt)
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index e46cd40..371f70d 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -143,7 +143,7 @@ #define SCSI_STATE_MLQUEUE 0x100
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
-extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
+extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
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