On 10.07.2018 09:33, Gu Jinxiang wrote:
> Instead of pointer to btrfs_fs_devices as an arg in
> btrfs_scan_one_device, better to make it as a return value.
>
> Signed-off-by: Gu Jinxiang <gujx@xxxxxxxxxxxxxx>
> ---
> fs/btrfs/super.c | 29 ++++++++++++++++++-----------
> fs/btrfs/volumes.c | 14 +++++++-------
> fs/btrfs/volumes.h | 4 ++--
> 3 files changed, 27 insertions(+), 20 deletions(-)
>
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 4ee082e96d51..a5ddeb6836e3 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -918,11 +918,13 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags,
> error = -ENOMEM;
> goto out;
> }
> - error = btrfs_scan_one_device(device_name,
> - flags, holder, &fs_devices);
> + fs_devices = btrfs_scan_one_device(device_name,
> + flags, holder);
> kfree(device_name);
> - if (error)
> + if (IS_ERR(fs_devices)) {
> + error = PTR_ERR(fs_devices);
> goto out;
> + }
> }
> }
>
> @@ -1539,9 +1541,11 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
> return ERR_PTR(error);
> }
>
> - error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
> - if (error)
> + fs_devices = btrfs_scan_one_device(device_name, mode, fs_type);
> + if (IS_ERR(fs_devices)) {
> + error = PTR_ERR(fs_devices);
> goto error_sec_opts;
> + }
>
> /*
> * Setup a dummy root and fs_info for test/set super. This is because
> @@ -2222,7 +2226,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
> unsigned long arg)
> {
> struct btrfs_ioctl_vol_args *vol;
> - struct btrfs_fs_devices *fs_devices;
> + struct btrfs_fs_devices *fs_devices = NULL;
> int ret = -ENOTTY;
>
> if (!capable(CAP_SYS_ADMIN))
> @@ -2234,14 +2238,17 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
>
> switch (cmd) {
> case BTRFS_IOC_SCAN_DEV:
> - ret = btrfs_scan_one_device(vol->name, FMODE_READ,
> - &btrfs_root_fs_type, &fs_devices);
> + fs_devices = btrfs_scan_one_device(vol->name, FMODE_READ,
> + &btrfs_root_fs_type);
> + ret = IS_ERR(fs_devices) ? PTR_ERR(fs_devices) : 0;
> break;
> case BTRFS_IOC_DEVICES_READY:
> - ret = btrfs_scan_one_device(vol->name, FMODE_READ,
> - &btrfs_root_fs_type, &fs_devices);
> - if (ret)
> + fs_devices = btrfs_scan_one_device(vol->name, FMODE_READ,
> + &btrfs_root_fs_type);
> + if (IS_ERR(fs_devices)) {
> + ret = PTR_ERR(fs_devices);
> break;
> + }
> ret = !(fs_devices->num_devices == fs_devices->total_devices);
> break;
> case BTRFS_IOC_GET_SUPPORTED_FEATURES:
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index b33bf29130b6..922c4ad6d421 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1215,14 +1215,14 @@ static int btrfs_read_disk_super(struct block_device *bdev, u64 bytenr,
> * and we are not allowed to call set_blocksize during the scan. The superblock
> * is read via pagecache
> */
> -int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
> - struct btrfs_fs_devices **fs_devices_ret)
> +struct btrfs_fs_devices *btrfs_scan_one_device(const char *path, fmode_t flags,
> + void *holder)
> {
> struct btrfs_super_block *disk_super;
> struct btrfs_device *device;
> struct block_device *bdev;
> struct page *page;
> - int ret = 0;
> + struct btrfs_fs_devices *ret = NULL;
> u64 bytenr;
>
> /*
> @@ -1236,19 +1236,19 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
>
> bdev = blkdev_get_by_path(path, flags, holder);
> if (IS_ERR(bdev))
> - return PTR_ERR(bdev);
> + return (struct btrfs_fs_devices *)bdev;
This makes my eyes bleed. There is already a construct which handles
this and it's called ERR_CAST so use it.
>
> if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) {
> - ret = -EINVAL;
> + ret = ERR_PTR(-EINVAL);
> goto error_bdev_put;
> }
>
> mutex_lock(&uuid_mutex);
> device = device_list_add(path, disk_super);
> if (IS_ERR(device))
> - ret = PTR_ERR(device);
> + ret = (struct btrfs_fs_devices *)device;
ERR_CAST
> else
> - *fs_devices_ret = device->fs_devices;
> + ret = device->fs_devices;
> mutex_unlock(&uuid_mutex);
>
> btrfs_release_disk_super(page);
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 77e6004b6cb9..f867f07be963 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -406,8 +406,8 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
> int mirror_num, int async_submit);
> int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
> fmode_t flags, void *holder);
> -int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
> - struct btrfs_fs_devices **fs_devices_ret);
> +struct btrfs_fs_devices *btrfs_scan_one_device(const char *path, fmode_t flags,
> + void *holder);
> int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
> void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
> void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
>
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
