Hi Chris, please consider this patch for 3.5-rc before it goes final. Thanks.
From: David Sterba <dste...@suse.cz> 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 <sbehr...@giantdisaster.de> Signed-off-by: David Sterba <dste...@suse.cz> --- fs/btrfs/ioctl.c | 16 ++++++++-------- fs/btrfs/ioctl.h | 6 ++++-- fs/btrfs/volumes.c | 5 ++--- fs/btrfs/volumes.h | 3 +-- 4 files changed, 15 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 0e92e57..670c5d2 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3063,19 +3063,21 @@ 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; @@ -3473,9 +3475,7 @@ 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; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 497c530..c4089c5 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -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 diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 8a3d259..661e6ca 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4871,8 +4871,7 @@ 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; @@ -4890,7 +4889,7 @@ 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] = diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 74366f2..e673589 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -292,8 +292,7 @@ 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); -- 1.7.9 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
