tree ce664010089283f464d88cd89c11a60d35923851
parent 8e6401187ef7fb1edc2740832b48bf47ed2c90f2
author James Bottomley <[EMAIL PROTECTED](none)> Thu, 16 Jun 2005 04:48:29 -0500
committer James Bottomley <[EMAIL PROTECTED](none)> Sun, 28 Aug 2005 20:46:40 
-0500

[SCSI] use scatter lists for all block pc requests and simplify hw handlers

Original From: Mike Christie <[EMAIL PROTECTED]>

Add scsi_execute_req() as a replacement for scsi_wait_req()

Fixed up various pieces (added REQ_SPECIAL and caught req use after
free)

Signed-off-by: James Bottomley <[EMAIL PROTECTED]>
 drivers/scsi/scsi_lib.c     |   51 +++++++++++++++++++-
 drivers/scsi/scsi_scan.c    |  112 +++++++++++++++++++-------------------------
 include/scsi/scsi_request.h |    3 +
 3 files changed, 102 insertions(+), 64 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -246,7 +246,7 @@ void scsi_wait_req(struct scsi_request *
                   unsigned bufflen, int timeout, int retries)
 {
        DECLARE_COMPLETION(wait);
-       int write = sreq->sr_data_direction == DMA_TO_DEVICE;
+       int write = (sreq->sr_data_direction == DMA_TO_DEVICE);
        struct request *req;
 
        req = blk_get_request(sreq->sr_device->request_queue, write,
@@ -281,6 +281,55 @@ void scsi_wait_req(struct scsi_request *
 
 EXPORT_SYMBOL(scsi_wait_req);
 
+/**
+ * scsi_execute_req - insert request and wait for the result
+ * @sdev:      scsi device
+ * @cmd:       scsi command
+ * @data_direction: data direction
+ * @buffer:    data buffer
+ * @bufflen:   len of buffer
+ * @sense:     optional sense buffer
+ * @timeout:   request timeout in seconds
+ * @retries:   number of times to retry request
+ *
+ * scsi_execute_req returns the req->errors value which is the
+ * the scsi_cmnd result field.
+ **/
+int scsi_execute_req(struct scsi_device *sdev, unsigned char *cmd,
+                    int data_direction, void *buffer, unsigned bufflen,
+                    unsigned char *sense, int timeout, int retries)
+{
+       struct request *req;
+       int write = (data_direction == DMA_TO_DEVICE);
+       int ret = DRIVER_ERROR << 24;
+
+       req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
+
+       if (bufflen &&  blk_rq_map_kern(sdev->request_queue, req,
+                                       buffer, bufflen, __GFP_WAIT))
+               goto out;
+
+       req->cmd_len = COMMAND_SIZE(cmd[0]);
+       memcpy(req->cmd, cmd, req->cmd_len);
+       req->sense = sense;
+       req->sense_len = 0;
+       req->timeout = timeout;
+       req->flags |= REQ_BLOCK_PC | REQ_SPECIAL;
+
+       /*
+        * head injection *required* here otherwise quiesce won't work
+        */
+       blk_execute_rq(req->q, NULL, req, 1);
+
+       ret = req->errors;
+ out:
+       blk_put_request(req);
+
+       return ret;
+}
+
+EXPORT_SYMBOL(scsi_execute_req);
+
 /*
  * Function:    scsi_init_cmd_errh()
  *
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -111,15 +111,14 @@ MODULE_PARM_DESC(inq_timeout, 
 
 /**
  * scsi_unlock_floptical - unlock device via a special MODE SENSE command
- * @sreq:      used to send the command
+ * @sdev:      scsi device to send command to
  * @result:    area to store the result of the MODE SENSE
  *
  * Description:
- *     Send a vendor specific MODE SENSE (not a MODE SELECT) command using
- *     @sreq to unlock a device, storing the (unused) results into result.
+ *     Send a vendor specific MODE SENSE (not a MODE SELECT) command.
  *     Called for BLIST_KEY devices.
  **/
-static void scsi_unlock_floptical(struct scsi_request *sreq,
+static void scsi_unlock_floptical(struct scsi_device *sdev,
                                  unsigned char *result)
 {
        unsigned char scsi_cmd[MAX_COMMAND_SIZE];
@@ -129,11 +128,10 @@ static void scsi_unlock_floptical(struct
        scsi_cmd[1] = 0;
        scsi_cmd[2] = 0x2e;
        scsi_cmd[3] = 0;
-       scsi_cmd[4] = 0x2a;     /* size */
+       scsi_cmd[4] = 0x2a;     /* size */
        scsi_cmd[5] = 0;
-       sreq->sr_cmd_len = 0;
-       sreq->sr_data_direction = DMA_FROM_DEVICE;
-       scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
+       scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
+                        SCSI_TIMEOUT, 3);
 }
 
 /**
@@ -433,26 +431,26 @@ void scsi_target_reap(struct scsi_target
 
 /**
  * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
- * @sreq:      used to send the INQUIRY
+ * @sdev:      scsi_device to probe
  * @inq_result:        area to store the INQUIRY result
+ * @result_len: len of inq_result
  * @bflags:    store any bflags found here
  *
  * Description:
- *     Probe the lun associated with @sreq using a standard SCSI INQUIRY;
+ *     Probe the lun associated with @req using a standard SCSI INQUIRY;
  *
- *     If the INQUIRY is successful, sreq->sr_result is zero and: the
+ *     If the INQUIRY is successful, zero is returned and the
  *     INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
- *     are copied to the Scsi_Device at @sreq->sr_device (sdev);
- *     any flags value is stored in [EMAIL PROTECTED]
+ *     are copied to the Scsi_Device any flags value is stored in [EMAIL 
PROTECTED]
  **/
-static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
-                          int *bflags)
+static int scsi_probe_lun(struct scsi_device *sdev, char *inq_result,
+                         int result_len, int *bflags)
 {
-       struct scsi_device *sdev = sreq->sr_device;     /* a bit ugly */
+       char sense[SCSI_SENSE_BUFFERSIZE];
        unsigned char scsi_cmd[MAX_COMMAND_SIZE];
        int first_inquiry_len, try_inquiry_len, next_inquiry_len;
        int response_len = 0;
-       int pass, count;
+       int pass, count, result;
        struct scsi_sense_hdr sshdr;
 
        *bflags = 0;
@@ -475,28 +473,28 @@ static void scsi_probe_lun(struct scsi_r
                memset(scsi_cmd, 0, 6);
                scsi_cmd[0] = INQUIRY;
                scsi_cmd[4] = (unsigned char) try_inquiry_len;
-               sreq->sr_cmd_len = 0;
-               sreq->sr_data_direction = DMA_FROM_DEVICE;
 
+               memset(sense, 0, sizeof(sense));
                memset(inq_result, 0, try_inquiry_len);
-               scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result,
-                               try_inquiry_len,
-                               HZ/2 + HZ*scsi_inq_timeout, 3);
+
+               result = scsi_execute_req(sdev,  scsi_cmd, DMA_FROM_DEVICE,
+                                         inq_result, try_inquiry_len, sense,
+                                         HZ / 2 + HZ * scsi_inq_timeout, 3);
 
                SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
                                "with code 0x%x\n",
-                               sreq->sr_result ? "failed" : "successful",
-                               sreq->sr_result));
+                               result ? "failed" : "successful", result));
 
-               if (sreq->sr_result) {
+               if (result) {
                        /*
                         * not-ready to ready transition [asc/ascq=0x28/0x0]
                         * or power-on, reset [asc/ascq=0x29/0x0], continue.
                         * INQUIRY should not yield UNIT_ATTENTION
                         * but many buggy devices do so anyway. 
                         */
-                       if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
-                           scsi_request_normalize_sense(sreq, &sshdr)) {
+                       if ((driver_byte(result) & DRIVER_SENSE) &&
+                           scsi_normalize_sense(sense, sizeof(sense),
+                                                &sshdr)) {
                                if ((sshdr.sense_key == UNIT_ATTENTION) &&
                                    ((sshdr.asc == 0x28) ||
                                     (sshdr.asc == 0x29)) &&
@@ -507,7 +505,7 @@ static void scsi_probe_lun(struct scsi_r
                break;
        }
 
-       if (sreq->sr_result == 0) {
+       if (result == 0) {
                response_len = (unsigned char) inq_result[4] + 5;
                if (response_len > 255)
                        response_len = first_inquiry_len;       /* sanity */
@@ -556,8 +554,8 @@ static void scsi_probe_lun(struct scsi_r
 
        /* If the last transfer attempt got an error, assume the
         * peripheral doesn't exist or is dead. */
-       if (sreq->sr_result)
-               return;
+       if (result)
+               return -EIO;
 
        /* Don't report any more data than the device says is valid */
        sdev->inquiry_len = min(try_inquiry_len, response_len);
@@ -593,7 +591,7 @@ static void scsi_probe_lun(struct scsi_r
            (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
                sdev->scsi_level++;
 
-       return;
+       return 0;
 }
 
 /**
@@ -800,9 +798,8 @@ static int scsi_probe_and_add_lun(struct
                                  void *hostdata)
 {
        struct scsi_device *sdev;
-       struct scsi_request *sreq;
        unsigned char *result;
-       int bflags, res = SCSI_SCAN_NO_RESPONSE;
+       int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 
        /*
@@ -831,16 +828,13 @@ static int scsi_probe_and_add_lun(struct
        sdev = scsi_alloc_sdev(starget, lun, hostdata);
        if (!sdev)
                goto out;
-       sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
-       if (!sreq)
-               goto out_free_sdev;
-       result = kmalloc(256, GFP_ATOMIC |
+
+       result = kmalloc(result_len, GFP_ATOMIC |
                        ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
        if (!result)
-               goto out_free_sreq;
+               goto out_free_sdev;
 
-       scsi_probe_lun(sreq, result, &bflags);
-       if (sreq->sr_result)
+       if (scsi_probe_lun(sdev, result, result_len, &bflags))
                goto out_free_result;
 
        /*
@@ -868,7 +862,7 @@ static int scsi_probe_and_add_lun(struct
        if (res == SCSI_SCAN_LUN_PRESENT) {
                if (bflags & BLIST_KEY) {
                        sdev->lockable = 0;
-                       scsi_unlock_floptical(sreq, result);
+                       scsi_unlock_floptical(sdev, result);
                }
                if (bflagsp)
                        *bflagsp = bflags;
@@ -876,8 +870,6 @@ static int scsi_probe_and_add_lun(struct
 
  out_free_result:
        kfree(result);
- out_free_sreq:
-       scsi_release_request(sreq);
  out_free_sdev:
        if (res == SCSI_SCAN_LUN_PRESENT) {
                if (sdevp) {
@@ -1065,13 +1057,14 @@ static int scsi_report_lun_scan(struct s
                                int rescan)
 {
        char devname[64];
+       char sense[SCSI_SENSE_BUFFERSIZE];
        unsigned char scsi_cmd[MAX_COMMAND_SIZE];
        unsigned int length;
        unsigned int lun;
        unsigned int num_luns;
        unsigned int retries;
+       int result;
        struct scsi_lun *lunp, *lun_data;
-       struct scsi_request *sreq;
        u8 *data;
        struct scsi_sense_hdr sshdr;
        struct scsi_target *starget = scsi_target(sdev);
@@ -1089,10 +1082,6 @@ static int scsi_report_lun_scan(struct s
        if (bflags & BLIST_NOLUN)
                return 0;
 
-       sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
-       if (!sreq)
-               goto out;
-
        sprintf(devname, "host %d channel %d id %d",
                sdev->host->host_no, sdev->channel, sdev->id);
 
@@ -1110,7 +1099,7 @@ static int scsi_report_lun_scan(struct s
        lun_data = kmalloc(length, GFP_ATOMIC |
                           (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
        if (!lun_data)
-               goto out_release_request;
+               goto out;
 
        scsi_cmd[0] = REPORT_LUNS;
 
@@ -1129,8 +1118,6 @@ static int scsi_report_lun_scan(struct s
 
        scsi_cmd[10] = 0;       /* reserved */
        scsi_cmd[11] = 0;       /* control */
-       sreq->sr_cmd_len = 0;
-       sreq->sr_data_direction = DMA_FROM_DEVICE;
 
        /*
         * We can get a UNIT ATTENTION, for example a power on/reset, so
@@ -1146,29 +1133,30 @@ static int scsi_report_lun_scan(struct s
                SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
                                " REPORT LUNS to %s (try %d)\n", devname,
                                retries));
-               scsi_wait_req(sreq, scsi_cmd, lun_data, length,
-                               SCSI_TIMEOUT + 4*HZ, 3);
+
+               memset(sense, 0, sizeof(sense));
+               result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
+                                         lun_data, length, sense,
+                                         SCSI_TIMEOUT + 4 * HZ, 3);
+
                SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
-                               " %s (try %d) result 0x%x\n", sreq->sr_result
-                               ?  "failed" : "successful", retries,
-                               sreq->sr_result));
-               if (sreq->sr_result == 0)
+                               " %s (try %d) result 0x%x\n", result
+                               ?  "failed" : "successful", retries, result));
+               if (result == 0)
                        break;
-               else if (scsi_request_normalize_sense(sreq, &sshdr)) {
+               else if (scsi_normalize_sense(sense, sizeof(sense), &sshdr)) {
                        if (sshdr.sense_key != UNIT_ATTENTION)
                                break;
                }
        }
 
-       if (sreq->sr_result) {
+       if (result) {
                /*
                 * The device probably does not support a REPORT LUN command
                 */
                kfree(lun_data);
-               scsi_release_request(sreq);
                return 1;
        }
-       scsi_release_request(sreq);
 
        /*
         * Get the length from the first four bytes of lun_data.
@@ -1242,8 +1230,6 @@ static int scsi_report_lun_scan(struct s
        kfree(lun_data);
        return 0;
 
- out_release_request:
-       scsi_release_request(sreq);
  out:
        /*
         * We are out of memory, don't try scanning any further.
diff --git a/include/scsi/scsi_request.h b/include/scsi/scsi_request.h
--- a/include/scsi/scsi_request.h
+++ b/include/scsi/scsi_request.h
@@ -54,6 +54,9 @@ extern void scsi_do_req(struct scsi_requ
                        void *buffer, unsigned bufflen,
                        void (*done) (struct scsi_cmnd *),
                        int timeout, int retries);
+extern int scsi_execute_req(struct scsi_device *sdev, unsigned char *cmd,
+                           int data_direction, void *buffer, unsigned bufflen,
+                           unsigned char *sense, int timeout, int retries);
 
 struct scsi_mode_data {
        __u32   length;
-
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