[SCSI] scsi_debug: remove the duplicated code in resp_read and resp_write

resp_read and resp_write performs READ_* and WRITE_* commands
respectively. This sweeps up the similar code in them.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 70bcee6..c98559e 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1468,25 +1468,53 @@ static int resp_log_sense(struct scsi_cmnd * scp,
                    min(len, SDEBUG_MAX_INQ_ARR_SZ));
 }
 
-static int resp_read(struct scsi_cmnd * SCpnt, unsigned long long lba,
-                    unsigned int num, struct sdebug_dev_info * devip)
+static int check_device_access_params(struct sdebug_dev_info *devi,
+                                     unsigned long long lba, unsigned int num)
 {
-       unsigned long iflags;
-       unsigned int block, from_bottom;
-       unsigned long long u;
-       int ret;
-
        if (lba + num > sdebug_capacity) {
-               mk_sense_buffer(devip, ILLEGAL_REQUEST, ADDR_OUT_OF_RANGE,
-                               0);
+               mk_sense_buffer(devi, ILLEGAL_REQUEST, ADDR_OUT_OF_RANGE, 0);
                return check_condition_result;
        }
        /* transfer length excessive (tie in to block limits VPD page) */
        if (num > sdebug_store_sectors) {
-               mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
-                               0);
+               mk_sense_buffer(devi, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                return check_condition_result;
        }
+       return 0;
+}
+
+static int do_device_access(struct scsi_cmnd *scmd,
+                           struct sdebug_dev_info *devi,
+                           unsigned long long lba, unsigned int num, int write)
+{
+       int ret;
+       unsigned int block, rest = 0;
+       int (*func)(struct scsi_cmnd *, unsigned char *, int);
+
+       func = write ? fetch_to_dev_buffer : fill_from_dev_buffer;
+
+       block = do_div(lba, sdebug_store_sectors);
+       if (block + num > sdebug_store_sectors)
+               rest = block + num - sdebug_store_sectors;
+
+       ret = func(scmd, fake_storep + (block * SECT_SIZE),
+                  (num - rest) * SECT_SIZE);
+       if (!ret && rest)
+               ret = func(scmd, fake_storep, rest * SECT_SIZE);
+
+       return ret;
+}
+
+static int resp_read(struct scsi_cmnd *SCpnt, unsigned long long lba,
+                    unsigned int num, struct sdebug_dev_info *devip)
+{
+       unsigned long iflags;
+       int ret;
+
+       ret = check_device_access_params(devip, lba, num);
+       if (ret)
+               return ret;
+
        if ((SCSI_DEBUG_OPT_MEDIUM_ERR & scsi_debug_opts) &&
            (lba <= OPT_MEDIUM_ERR_ADDR) &&
            ((lba + num) > OPT_MEDIUM_ERR_ADDR)) {
@@ -1505,74 +1533,30 @@ static int resp_read(struct scsi_cmnd * SCpnt, unsigned long long lba,
                return check_condition_result;
        }
        read_lock_irqsave(&atomic_rw, iflags);
-       if ((lba + num) <= sdebug_store_sectors)
-               ret = fill_from_dev_buffer(SCpnt,
-                                          fake_storep + (lba * SECT_SIZE),
-                                          num * SECT_SIZE);
-       else {
-               /* modulo when one arg is 64 bits needs do_div() */
-               u = lba;
-               block = do_div(u, sdebug_store_sectors);
-               from_bottom = 0;
-               if ((block + num) > sdebug_store_sectors)
-                       from_bottom = (block + num) - sdebug_store_sectors;
-               ret = fill_from_dev_buffer(SCpnt,
-                                          fake_storep + (block * SECT_SIZE),
-                                          (num - from_bottom) * SECT_SIZE);
-               if ((0 == ret) && (from_bottom > 0))
-                       ret = fill_from_dev_buffer(SCpnt, fake_storep,
-                                                  from_bottom * SECT_SIZE);
-       }
+       ret = do_device_access(SCpnt, devip, lba, num, 0);
        read_unlock_irqrestore(&atomic_rw, iflags);
        return ret;
 }
 
-static int resp_write(struct scsi_cmnd * SCpnt, unsigned long long lba,
-                     unsigned int num, struct sdebug_dev_info * devip)
+static int resp_write(struct scsi_cmnd *SCpnt, unsigned long long lba,
+                     unsigned int num, struct sdebug_dev_info *devip)
 {
        unsigned long iflags;
-       unsigned int block, to_bottom;
-       unsigned long long u;
-       int res;
+       int ret;
 
-       if (lba + num > sdebug_capacity) {
-               mk_sense_buffer(devip, ILLEGAL_REQUEST, ADDR_OUT_OF_RANGE,
-                               0);
-               return check_condition_result;
-       }
-       /* transfer length excessive (tie in to block limits VPD page) */
-       if (num > sdebug_store_sectors) {
-               mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
-                               0);
-               return check_condition_result;
-       }
+       ret = check_device_access_params(devip, lba, num);
+       if (ret)
+               return ret;
 
        write_lock_irqsave(&atomic_rw, iflags);
-       if ((lba + num) <= sdebug_store_sectors)
-               res = fetch_to_dev_buffer(SCpnt,
-                                         fake_storep + (lba * SECT_SIZE),
-                                         num * SECT_SIZE);
-       else {
-               /* modulo when one arg is 64 bits needs do_div() */
-               u = lba;
-               block = do_div(u, sdebug_store_sectors);
-               to_bottom = 0;
-               if ((block + num) > sdebug_store_sectors)
-                       to_bottom = (block + num) - sdebug_store_sectors;
-               res = fetch_to_dev_buffer(SCpnt,
-                                         fake_storep + (block * SECT_SIZE),
-                                         (num - to_bottom) * SECT_SIZE);
-               if ((0 == res) && (to_bottom > 0))
-                       res = fetch_to_dev_buffer(SCpnt, fake_storep,
-                                                 to_bottom * SECT_SIZE);
-       }
+       ret = do_device_access(SCpnt, devip, lba, num, 1);
        write_unlock_irqrestore(&atomic_rw, iflags);
-       if (-1 == res)
+       if (-1 == ret)
                return (DID_ERROR << 16);
-       else if ((res < (num * SECT_SIZE)) &&
+       else if ((ret < (num * SECT_SIZE)) &&
                 (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts))
                printk(KERN_INFO "scsi_debug: write: cdb indicated=%u, "
-                      " IO sent=%d bytes\n", num * SECT_SIZE, res);
+                      " IO sent=%d bytes\n", num * SECT_SIZE, ret);
        return 0;
 }