Commit dcd96379 authored by Daniel Walker's avatar Daniel Walker Committed by Linus Torvalds
Browse files

[PATCH] idetape gcc 4.1 warning fix 



In both the read and write cases it will return an error if
copy_{from/to}_user faults.  However, I let the driver try to read/write as
much as it can just as it normally would , then finally it returns an error
if there was one.  This was the most straight forward way to handle the
error , since there isn't a clear way to clean up the buffers on error .

I moved retval in idetape_chrdev_write() down into the actual code blocks
since it's really once used there, and it conflicted with my ret variable.

Fixes the following warning,

drivers/ide/ide-tape.c: In function ‘idetape_copy_stage_from_user’:
drivers/ide/ide-tape.c:2662: warning: ignoring return value of ‘copy_from_user’, declared with attribute warn_unused_result
drivers/ide/ide-tape.c: In function ‘idetape_copy_stage_to_user’:
drivers/ide/ide-tape.c:2689: warning: ignoring return value of ‘copy_to_user’, declared with attribute warn_unused_result

Signed-off-by: default avatarDaniel Walker <dwalker@mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a04ee146

drivers/ide/ide-tape.c

+33 −16
Original line number Diff line number Diff line
@@ -2646,21 +2646,23 @@ static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape) 
	return __idetape_kmalloc_stage(tape, 0, 0);

}



static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)

static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)

{

	struct idetape_bh *bh = tape->bh;

	int count;

	int ret = 0;



	while (n) {

#if IDETAPE_DEBUG_BUGS

		if (bh == NULL) {

			printk(KERN_ERR "ide-tape: bh == NULL in "

				"idetape_copy_stage_from_user\n");

			return;

			return 1;

		}

#endif /* IDETAPE_DEBUG_BUGS */

		count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);

		copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);

		if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))

			ret = 1;

		n -= count;

		atomic_add(count, &bh->b_count);

		buf += count;
@@ -2671,23 +2673,26 @@ static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t 
		}

	}

	tape->bh = bh;

	return ret;

}



static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)

static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)

{

	struct idetape_bh *bh = tape->bh;

	int count;

	int ret = 0;



	while (n) {

#if IDETAPE_DEBUG_BUGS

		if (bh == NULL) {

			printk(KERN_ERR "ide-tape: bh == NULL in "

				"idetape_copy_stage_to_user\n");

			return;

			return 1;

		}

#endif /* IDETAPE_DEBUG_BUGS */

		count = min(tape->b_count, n);

		copy_to_user(buf, tape->b_data, count);

		if  (copy_to_user(buf, tape->b_data, count))

			ret = 1;

		n -= count;

		tape->b_data += count;

		tape->b_count -= count;
@@ -2700,6 +2705,7 @@ static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, 
			}

		}

	}

	return ret;

}



static void idetape_init_merge_stage (idetape_tape_t *tape)
@@ -3719,6 +3725,7 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf, 
	struct ide_tape_obj *tape = ide_tape_f(file);

	ide_drive_t *drive = tape->drive;

	ssize_t bytes_read,temp, actually_read = 0, rc;

	ssize_t ret = 0;



#if IDETAPE_DEBUG_LOG

	if (tape->debug_level >= 3)
@@ -3737,7 +3744,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf, 
		return (0);

	if (tape->merge_stage_size) {

		actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);

		idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read);

		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))

			ret = -EFAULT;

		buf += actually_read;

		tape->merge_stage_size -= actually_read;

		count -= actually_read;
@@ -3746,7 +3754,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf, 
		bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);

		if (bytes_read <= 0)

			goto finish;

		idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read);

		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))

			ret = -EFAULT;

		buf += bytes_read;

		count -= bytes_read;

		actually_read += bytes_read;
@@ -3756,7 +3765,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf, 
		if (bytes_read <= 0)

			goto finish;

		temp = min((unsigned long)count, (unsigned long)bytes_read);

		idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp);

		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))

			ret = -EFAULT;

		actually_read += temp;

		tape->merge_stage_size = bytes_read-temp;

	}
@@ -3769,7 +3779,8 @@ finish: 
		idetape_space_over_filemarks(drive, MTFSF, 1);

		return 0;

	}

	return actually_read;



	return (ret) ? ret : actually_read;

}



static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
@@ -3777,7 +3788,8 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, 
{

	struct ide_tape_obj *tape = ide_tape_f(file);

	ide_drive_t *drive = tape->drive;

	ssize_t retval, actually_written = 0;

	ssize_t actually_written = 0;

	ssize_t ret = 0;



	/* The drive is write protected. */

	if (tape->write_prot)
@@ -3813,7 +3825,7 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, 
		 *	some drives (Seagate STT3401A) will return an error.

		 */

		if (drive->dsc_overlap) {

			retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);

			ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);

			if (retval < 0) {

				__idetape_kfree_stage(tape->merge_stage);

				tape->merge_stage = NULL;
@@ -3834,12 +3846,14 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, 
		}

#endif /* IDETAPE_DEBUG_BUGS */

		actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);

		idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written);

		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))

				ret = -EFAULT;

		buf += actually_written;

		tape->merge_stage_size += actually_written;

		count -= actually_written;



		if (tape->merge_stage_size == tape->stage_size) {

			ssize_t retval;

			tape->merge_stage_size = 0;

			retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);

			if (retval <= 0)
@@ -3847,7 +3861,9 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, 
		}

	}

	while (count >= tape->stage_size) {

		idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size);

		ssize_t retval;

		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))

			ret = -EFAULT;

		buf += tape->stage_size;

		count -= tape->stage_size;

		retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
@@ -3857,10 +3873,11 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, 
	}

	if (count) {

		actually_written += count;

		idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count);

		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))

			ret = -EFAULT;

		tape->merge_stage_size += count;

	}

	return (actually_written);

	return (ret) ? ret : actually_written;

}



static int idetape_write_filemark (ide_drive_t *drive)

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