#include <linux/hardirq.h>
#include <scsi/scsi.h>
-#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
+#include <scsi/scsi_request.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
-#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
+#define SG_MEMPOOL_NR (sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool))
#define SG_MEMPOOL_SIZE 32
struct scsi_host_sg_pool {
struct scsi_cmnd *cmd = req->special;
req->flags &= ~REQ_DONTPREP;
- req->special = NULL;
+ req->special = (req->flags & REQ_SPECIAL) ? cmd->sc_request : NULL;
scsi_put_command(cmd);
}
return 0;
}
+/*
+ * Function: scsi_do_req
+ *
+ * Purpose: Queue a SCSI request
+ *
+ * Arguments: sreq - command descriptor.
+ * cmnd - actual SCSI command to be performed.
+ * buffer - data buffer.
+ * bufflen - size of data buffer.
+ * done - completion function to be run.
+ * timeout - how long to let it run before timeout.
+ * retries - number of retries we allow.
+ *
+ * Lock status: No locks held upon entry.
+ *
+ * Returns: Nothing.
+ *
+ * Notes: This function is only used for queueing requests for things
+ * like ioctls and character device requests - this is because
+ * we essentially just inject a request into the queue for the
+ * device.
+ *
+ * In order to support the scsi_device_quiesce function, we
+ * now inject requests on the *head* of the device queue
+ * rather than the tail.
+ */
+void scsi_do_req(struct scsi_request *sreq, const void *cmnd,
+ void *buffer, unsigned bufflen,
+ void (*done)(struct scsi_cmnd *),
+ int timeout, int retries)
+{
+ /*
+ * If the upper level driver is reusing these things, then
+ * we should release the low-level block now. Another one will
+ * be allocated later when this request is getting queued.
+ */
+ __scsi_release_request(sreq);
+
+ /*
+ * Our own function scsi_done (which marks the host as not busy,
+ * disables the timeout counter, etc) will be called by us or by the
+ * scsi_hosts[host].queuecommand() function needs to also call
+ * the completion function for the high level driver.
+ */
+ memcpy(sreq->sr_cmnd, cmnd, sizeof(sreq->sr_cmnd));
+ sreq->sr_bufflen = bufflen;
+ sreq->sr_buffer = buffer;
+ sreq->sr_allowed = retries;
+ sreq->sr_done = done;
+ sreq->sr_timeout_per_command = timeout;
+
+ if (sreq->sr_cmd_len == 0)
+ sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
+
+ /*
+ * head injection *required* here otherwise quiesce won't work
+ *
+ * Because users of this function are apt to reuse requests with no
+ * modification, we have to sanitise the request flags here
+ */
+ sreq->sr_request->flags &= ~REQ_DONTPREP;
+ blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request,
+ 1, sreq);
+}
+EXPORT_SYMBOL(scsi_do_req);
+
/**
* scsi_execute - insert request and wait for the result
* @sdev: scsi device
*
* Arguments: cmd - command that is ready to be queued.
*
+ * Returns: Nothing
+ *
* Notes: This function has the job of initializing a number of
* fields related to error handling. Typically this will
* be called once for each command, as required.
*/
-static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
+static int scsi_init_cmd_errh(struct scsi_cmnd *cmd)
{
cmd->serial_number = 0;
+
memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
+
if (cmd->cmd_len == 0)
cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
+
+ /*
+ * We need saved copies of a number of fields - this is because
+ * error handling may need to overwrite these with different values
+ * to run different commands, and once error handling is complete,
+ * we will need to restore these values prior to running the actual
+ * command.
+ */
+ cmd->old_use_sg = cmd->use_sg;
+ cmd->old_cmd_len = cmd->cmd_len;
+ cmd->sc_old_data_direction = cmd->sc_data_direction;
+ cmd->old_underflow = cmd->underflow;
+ memcpy(cmd->data_cmnd, cmd->cmnd, sizeof(cmd->cmnd));
+ cmd->buffer = cmd->request_buffer;
+ cmd->bufflen = cmd->request_bufflen;
+
+ return 1;
+}
+
+/*
+ * Function: scsi_setup_cmd_retry()
+ *
+ * Purpose: Restore the command state for a retry
+ *
+ * Arguments: cmd - command to be restored
+ *
+ * Returns: Nothing
+ *
+ * Notes: Immediately prior to retrying a command, we need
+ * to restore certain fields that we saved above.
+ */
+void scsi_setup_cmd_retry(struct scsi_cmnd *cmd)
+{
+ memcpy(cmd->cmnd, cmd->data_cmnd, sizeof(cmd->data_cmnd));
+ cmd->request_buffer = cmd->buffer;
+ cmd->request_bufflen = cmd->bufflen;
+ cmd->use_sg = cmd->old_use_sg;
+ cmd->cmd_len = cmd->old_cmd_len;
+ cmd->sc_data_direction = cmd->sc_old_data_direction;
+ cmd->underflow = cmd->old_underflow;
}
void scsi_device_unbusy(struct scsi_device *sdev)
spin_lock_irqsave(shost->host_lock, flags);
shost->host_busy--;
if (unlikely(scsi_host_in_recovery(shost) &&
- (shost->host_failed || shost->host_eh_scheduled)))
+ shost->host_failed))
scsi_eh_wakeup(shost);
spin_unlock(shost->host_lock);
spin_lock(sdev->request_queue->queue_lock);
*/
static void scsi_release_buffers(struct scsi_cmnd *cmd)
{
+ struct request *req = cmd->request;
+
+ /*
+ * Free up any indirection buffers we allocated for DMA purposes.
+ */
if (cmd->use_sg)
scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+ else if (cmd->request_buffer != req->buffer)
+ kfree(cmd->request_buffer);
/*
* Zero these out. They now point to freed memory, and it is
* dangerous to hang onto the pointers.
*/
+ cmd->buffer = NULL;
+ cmd->bufflen = 0;
cmd->request_buffer = NULL;
cmd->request_bufflen = 0;
}
* 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)
+void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
+ unsigned int block_bytes)
{
int result = cmd->result;
- int this_count = cmd->request_bufflen;
+ int this_count = cmd->bufflen;
request_queue_t *q = cmd->device->request_queue;
struct request *req = cmd->request;
int clear_errors = 1;
int sense_valid = 0;
int sense_deferred = 0;
- scsi_release_buffers(cmd);
+ /*
+ * Free up any indirection buffers we allocated for DMA purposes.
+ * For the case of a READ, we need to copy the data out of the
+ * bounce buffer and into the real buffer.
+ */
+ if (cmd->use_sg)
+ scsi_free_sgtable(cmd->buffer, cmd->sglist_len);
+ else if (cmd->buffer != req->buffer) {
+ if (rq_data_dir(req) == READ) {
+ unsigned long flags;
+ char *to = bio_kmap_irq(req->bio, &flags);
+ memcpy(to, cmd->buffer, cmd->bufflen);
+ bio_kunmap_irq(to, &flags);
+ }
+ kfree(cmd->buffer);
+ }
if (result) {
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
if (sense_valid)
sense_deferred = scsi_sense_is_deferred(&sshdr);
}
-
if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
req->errors = result;
if (result) {
req->data_len = cmd->resid;
}
+ /*
+ * Zero these out. They now point to freed memory, and it is
+ * dangerous to hang onto the pointers.
+ */
+ cmd->buffer = NULL;
+ cmd->bufflen = 0;
+ cmd->request_buffer = NULL;
+ cmd->request_bufflen = 0;
+
/*
* Next deal with any sectors which we were able to correctly
* handle.
*/
- 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 (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;
-
- /* A number of bytes were successfully read. If there
- * are leftovers and there is some kind of error
- * (result != 0), retry the rest.
- */
- if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
- return;
+ 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.
+ */
- /* good_bytes = 0, or (inclusive) there were leftovers and
- * result = 0, so scsi_end_request couldn't retry.
+ /*
+ * If the command completed without error, then either
+ * finish off the rest of the command, or start a new one.
+ */
+ if (scsi_end_request(cmd, 1, good_bytes, result == 0) == 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.
*/
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);
- return;
+ result = 0;
} 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) {
}
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);
case VOLUME_OVERFLOW:
if (!(req->flags & REQ_QUIET)) {
scmd_printk(KERN_INFO, cmd,
- "Volume overflow, CDB: ");
- __scsi_print_command(cmd->cmnd);
+ "Volume overflow, CDB: ");
+ __scsi_print_command(cmd->data_cmnd);
scsi_print_sense("", cmd);
}
- /* See SSC3rXX or current. */
- scsi_end_request(cmd, 0, this_count, 1);
+ scsi_end_request(cmd, 0, block_bytes, 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;
if (result) {
if (!(req->flags & REQ_QUIET)) {
scmd_printk(KERN_INFO, cmd,
- "SCSI error: return code = 0x%08x\n",
- result);
+ "SCSI error: return code = 0x%x\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);
* successfully. Since this is a REQ_BLOCK_PC command the
* caller should check the request's errors value
*/
- scsi_io_completion(cmd, cmd->request_bufflen);
+ scsi_io_completion(cmd, cmd->bufflen, 0);
}
static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
* at request->cmd, as this tells us the real story.
*/
if (req->flags & REQ_SPECIAL && req->special) {
- cmd = req->special;
+ struct scsi_request *sreq = req->special;
+
+ if (sreq->sr_magic == SCSI_REQ_MAGIC) {
+ cmd = scsi_get_command(sreq->sr_device, GFP_ATOMIC);
+ if (unlikely(!cmd))
+ goto defer;
+ scsi_init_cmd_from_req(cmd, sreq);
+ } else
+ cmd = req->special;
} else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) {
switch (oldstate) {
case SDEV_CREATED:
case SDEV_RUNNING:
- case SDEV_QUIESCE:
case SDEV_OFFLINE:
case SDEV_BLOCK:
break;
case SDEV_DEL:
switch (oldstate) {
- case SDEV_CREATED:
- case SDEV_RUNNING:
- case SDEV_OFFLINE:
case SDEV_CANCEL:
break;
default:
device_for_each_child(dev, NULL, target_unblock);
}
EXPORT_SYMBOL_GPL(scsi_target_unblock);
-
-/**
- * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
- * @sg: scatter-gather list
- * @sg_count: number of segments in sg
- * @offset: offset in bytes into sg, on return offset into the mapped area
- * @len: bytes to map, on return number of bytes mapped
- *
- * Returns virtual address of the start of the mapped page
- */
-void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
- size_t *offset, size_t *len)
-{
- int i;
- size_t sg_len = 0, len_complete = 0;
- struct page *page;
-
- for (i = 0; i < sg_count; i++) {
- len_complete = sg_len; /* Complete sg-entries */
- sg_len += sg[i].length;
- if (sg_len > *offset)
- break;
- }
-
- if (unlikely(i == sg_count)) {
- printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
- "elements %d\n",
- __FUNCTION__, sg_len, *offset, sg_count);
- WARN_ON(1);
- return NULL;
- }
-
- /* Offset starting from the beginning of first page in this sg-entry */
- *offset = *offset - len_complete + sg[i].offset;
-
- /* Assumption: contiguous pages can be accessed as "page + i" */
- page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
- *offset &= ~PAGE_MASK;
-
- /* Bytes in this sg-entry from *offset to the end of the page */
- sg_len = PAGE_SIZE - *offset;
- if (*len > sg_len)
- *len = sg_len;
-
- return kmap_atomic(page, KM_BIO_SRC_IRQ);
-}
-EXPORT_SYMBOL(scsi_kmap_atomic_sg);
-
-/**
- * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
- * mapped with scsi_kmap_atomic_sg
- * @virt: virtual address to be unmapped
- */
-void scsi_kunmap_atomic_sg(void *virt)
-{
- kunmap_atomic(virt, KM_BIO_SRC_IRQ);
-}
-EXPORT_SYMBOL(scsi_kunmap_atomic_sg);