btrfs: join DEV_STATS ioctls to one
Commit c11d2c236cc260b36 (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: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index e440aa6..021c55e 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -285,9 +285,13 @@
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_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