Commit b27f7c0c authored by David Sterba's avatar David Sterba Committed by Chris Mason
Browse files

btrfs: join DEV_STATS ioctls to one 

Commit c11d2c23 (Btrfs: add ioctl to get and reset the device
stats) introduced two ioctls doing almost the same thing distinguished
by just the ioctl number which encodes "do reset after read". I have
suggested

http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg16604.html



to implement it via the ioctl args. This hasn't happen, and I think we
should use a more clean way to pass flags and should not waste ioctl
numbers.

CC: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
parent a43a2111

fs/btrfs/ioctl.c

+8 −8
Original line number Diff line number Diff line
@@ -3065,19 +3065,21 @@ static long btrfs_ioctl_scrub_progress(struct btrfs_root *root, 
}



static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,

				      void __user *arg, int reset_after_read)

				      void __user *arg)

{

	struct btrfs_ioctl_get_dev_stats *sa;

	int ret;



	if (reset_after_read && !capable(CAP_SYS_ADMIN))

		return -EPERM;



	sa = memdup_user(arg, sizeof(*sa));

	if (IS_ERR(sa))

		return PTR_ERR(sa);



	ret = btrfs_get_dev_stats(root, sa, reset_after_read);

	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {

		kfree(sa);

		return -EPERM;

	}



	ret = btrfs_get_dev_stats(root, sa);



	if (copy_to_user(arg, sa, sizeof(*sa)))

		ret = -EFAULT;
@@ -3475,9 +3477,7 @@ long btrfs_ioctl(struct file *file, unsigned int 
	case BTRFS_IOC_BALANCE_PROGRESS:

		return btrfs_ioctl_balance_progress(root, argp);

	case BTRFS_IOC_GET_DEV_STATS:

		return btrfs_ioctl_get_dev_stats(root, argp, 0);

	case BTRFS_IOC_GET_AND_RESET_DEV_STATS:

		return btrfs_ioctl_get_dev_stats(root, argp, 1);

		return btrfs_ioctl_get_dev_stats(root, argp);

	}



	return -ENOTTY;

fs/btrfs/ioctl.h

+4 −2
Original line number Diff line number Diff line
@@ -285,9 +285,13 @@ enum btrfs_dev_stat_values { 
	BTRFS_DEV_STAT_VALUES_MAX

};



/* Reset statistics after reading; needs SYS_ADMIN capability */

#define	BTRFS_DEV_STATS_RESET		(1ULL << 0)



struct btrfs_ioctl_get_dev_stats {

	__u64 devid;				/* in */

	__u64 nr_items;				/* in/out */

	__u64 flags;				/* in/out */



	/* out values: */

	__u64 values[BTRFS_DEV_STAT_VALUES_MAX];
@@ -361,7 +365,5 @@ struct btrfs_ioctl_get_dev_stats { 
					struct btrfs_ioctl_ino_path_args)

#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \

				      struct btrfs_ioctl_get_dev_stats)

#define BTRFS_IOC_GET_AND_RESET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 53, \

					struct btrfs_ioctl_get_dev_stats)



#endif

fs/btrfs/volumes.c

+2 −3
Original line number Diff line number Diff line
@@ -4890,8 +4890,7 @@ static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev) 
}



int btrfs_get_dev_stats(struct btrfs_root *root,

			struct btrfs_ioctl_get_dev_stats *stats,

			int reset_after_read)

			struct btrfs_ioctl_get_dev_stats *stats)

{

	struct btrfs_device *dev;

	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
@@ -4909,7 +4908,7 @@ int btrfs_get_dev_stats(struct btrfs_root *root, 
		printk(KERN_WARNING

		       "btrfs: get dev_stats failed, not yet valid\n");

		return -ENODEV;

	} else if (reset_after_read) {

	} else if (stats->flags & BTRFS_DEV_STATS_RESET) {

		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {

			if (stats->nr_items > i)

				stats->values[i] =

fs/btrfs/volumes.h

+1 −2
Original line number Diff line number Diff line
@@ -293,8 +293,7 @@ struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root, 
void btrfs_dev_stat_print_on_error(struct btrfs_device *device);

void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);

int btrfs_get_dev_stats(struct btrfs_root *root,

			struct btrfs_ioctl_get_dev_stats *stats,

			int reset_after_read);

			struct btrfs_ioctl_get_dev_stats *stats);

int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);

int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,

			struct btrfs_fs_info *fs_info);

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