1 files changed, 46 insertions, 64 deletions

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index d2e9c09b5215..4da7fa9bca1e 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -987,42 +987,50 @@ static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
         tape->chrdev_dir = IDETAPE_DIR_NONE;
 }
 
-static int idetape_init_read(ide_drive_t *drive)
+static int idetape_init_rw(ide_drive_t *drive, int dir)
 {
         idetape_tape_t *tape = drive->driver_data;
-        int bytes_read;
+        int rc;
 
-        /* Initialize read operation */
-        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
-                if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-                        ide_tape_flush_merge_buffer(drive);
-                        idetape_flush_tape_buffers(drive);
-                }
-                if (tape->buf || tape->valid) {
-                        printk(KERN_ERR "ide-tape: valid should be 0 now\n");
-                        tape->valid = 0;
-                }
-                tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
-                if (!tape->buf)
-                        return -ENOMEM;
-                tape->chrdev_dir = IDETAPE_DIR_READ;
-                tape->cur = tape->buf;
+        BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
 
-                /*
-                 * Issue a read 0 command to ensure that DSC handshake is
-                 * switched from completion mode to buffer available mode.
-                 * No point in issuing this if DSC overlap isn't supported, some
-                 * drives (Seagate STT3401A) will return an error.
-                 */
-                if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
-                        bytes_read = idetape_queue_rw_tail(drive,
-                                                        REQ_IDETAPE_READ, 0);
-                        if (bytes_read < 0) {
-                                kfree(tape->buf);
-                                tape->buf = NULL;
-                                tape->chrdev_dir = IDETAPE_DIR_NONE;
-                                return bytes_read;
-                        }
+        if (tape->chrdev_dir == dir)
+                return 0;
+
+        if (tape->chrdev_dir == IDETAPE_DIR_READ)
+                ide_tape_discard_merge_buffer(drive, 1);
+        else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
+                ide_tape_flush_merge_buffer(drive);
+                idetape_flush_tape_buffers(drive);
+        }
+
+        if (tape->buf || tape->valid) {
+                printk(KERN_ERR "ide-tape: valid should be 0 now\n");
+                tape->valid = 0;
+        }
+
+        tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
+        if (!tape->buf)
+                return -ENOMEM;
+        tape->chrdev_dir = dir;
+        tape->cur = tape->buf;
+
+        /*
+         * Issue a 0 rw command to ensure that DSC handshake is
+         * switched from completion mode to buffer available mode.  No
+         * point in issuing this if DSC overlap isn't supported, some
+         * drives (Seagate STT3401A) will return an error.
+         */
+        if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
+                int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
+                                                  : REQ_IDETAPE_WRITE;
+
+                rc = idetape_queue_rw_tail(drive, cmd, 0);
+                if (rc < 0) {
+                        kfree(tape->buf);
+                        tape->buf = NULL;
+                        tape->chrdev_dir = IDETAPE_DIR_NONE;
+                        return rc;
                 }
         }
 
@@ -1038,7 +1046,7 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
         if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
                 return 0;
 
-        idetape_init_read(drive);
+        idetape_init_rw(drive, IDETAPE_DIR_READ);
 
         return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks);
 }
@@ -1195,7 +1203,7 @@ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
                             (count % tape->blk_size) == 0)
                                 tape->user_bs_factor = count / tape->blk_size;
         }
-        rc = idetape_init_read(drive);
+        rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
         if (rc < 0)
                 return rc;
         if (count == 0)
@@ -1249,6 +1257,7 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
         ssize_t actually_written = 0;
         ssize_t ret = 0;
         u16 ctl = *(u16 *)&tape->caps[12];
+        int rc;
 
         /* The drive is write protected. */
         if (tape->write_prot)
@@ -1257,36 +1266,9 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
         debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
 
         /* Initialize write operation */
-        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
-                if (tape->chrdev_dir == IDETAPE_DIR_READ)
-                        ide_tape_discard_merge_buffer(drive, 1);
-                if (tape->buf || tape->valid) {
-                        printk(KERN_ERR "ide-tape: valid should be 0 now\n");
-                        tape->valid = 0;
-                }
-                tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
-                if (!tape->buf)
-                        return -ENOMEM;
-                tape->chrdev_dir = IDETAPE_DIR_WRITE;
-                tape->cur = tape->buf;
-
-                /*
-                 * Issue a write 0 command to ensure that DSC handshake is
-                 * switched from completion mode to buffer available mode. No
-                 * point in issuing this if DSC overlap isn't supported, some
-                 * drives (Seagate STT3401A) will return an error.
-                 */
-                if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
-                        ssize_t retval = idetape_queue_rw_tail(drive,
-                                                        REQ_IDETAPE_WRITE, 0);
-                        if (retval < 0) {
-                                kfree(tape->buf);
-                                tape->buf = NULL;
-                                tape->chrdev_dir = IDETAPE_DIR_NONE;
-                                return retval;
-                        }
-                }
-        }
+        rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
+        if (rc < 0)
+                return rc;
         if (count == 0)
                 return (0);
         if (tape->valid < tape->buffer_size) {