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-rw-r--r--drivers/ide/ide-tape.c110
1 files changed, 46 insertions, 64 deletions
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index d2e9c09b521..4da7fa9bca1 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) {