ide-tape: unify r/w init paths

Impact: cleanup

Read and write init paths are almost identical.  Unify them into
idetape_init_rw().

Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index d2e9c09..4da7fa9 100644 (file)
--- 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) {