From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:45002 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726854AbeGLGkF (ORCPT ); Thu, 12 Jul 2018 02:40:05 -0400 Subject: Re: [PATCH v4 2/2] btrfs: get device pointer from btrfs_scan_one_device To: Gu Jinxiang , linux-btrfs@vger.kernel.org Cc: anand.jain@oracle.com References: <1531376596-26333-1-git-send-email-gujx@cn.fujitsu.com> <1531376596-26333-2-git-send-email-gujx@cn.fujitsu.com> From: Nikolay Borisov Message-ID: <92d4454c-319c-2269-dc5d-941355fa5ec1@suse.com> Date: Thu, 12 Jul 2018 09:31:55 +0300 MIME-Version: 1.0 In-Reply-To: <1531376596-26333-2-git-send-email-gujx@cn.fujitsu.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 12.07.2018 09:23, 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. > > And since btrfs_fs_devices can be get by btrfs_device, > better to return btrfs_device than fs_btrfs_devices. > > Signed-off-by: Gu Jinxiang Reviewed-by: Nikolay Borisov > --- > > Changelog: > v4: as suggested by Anand, change return value of > btrfs_scan_one_device from btrfs_fs_devices to btrfs_device. > v3: as comment by robot, use PTR_ERR_OR_ZERO, and rebase to misc-next. > v2: as comment by Nikolay, use ERR_CAST instead of cast type manually. > > fs/btrfs/super.c | 37 ++++++++++++++++++++++++------------- > fs/btrfs/volumes.c | 17 ++++++----------- > fs/btrfs/volumes.h | 4 ++-- > 3 files changed, 32 insertions(+), 26 deletions(-) > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index 44f58bdb5fa6..e73d547eacff 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -888,7 +888,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, > { > substring_t args[MAX_OPT_ARGS]; > char *device_name, *opts, *orig, *p; > - struct btrfs_fs_devices *fs_devices = NULL; > + struct btrfs_device *device = NULL; > int error = 0; > > if (!options) > @@ -916,11 +916,13 @@ 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); > + device = btrfs_scan_one_device(device_name, > + flags, holder); > kfree(device_name); > - if (error) > + if (IS_ERR(device)) { > + error = PTR_ERR(device); > goto out; > + } > } > } > > @@ -1516,6 +1518,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, > { > struct block_device *bdev = NULL; > struct super_block *s; > + struct btrfs_device *device = NULL; > struct btrfs_fs_devices *fs_devices = NULL; > struct btrfs_fs_info *fs_info = NULL; > struct security_mnt_opts new_sec_opts; > @@ -1537,9 +1540,13 @@ 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) > + device = btrfs_scan_one_device(device_name, mode, fs_type); > + if (IS_ERR(device)) { > + error = PTR_ERR(device); > goto error_sec_opts; > + } > + > + fs_devices = device->fs_devices; > > /* > * Setup a dummy root and fs_info for test/set super. This is because > @@ -2220,7 +2227,7 @@ 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_device *device = NULL; > int ret = -ENOTTY; > > if (!capable(CAP_SYS_ADMIN)) > @@ -2232,15 +2239,19 @@ 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); > + device = btrfs_scan_one_device(vol->name, FMODE_READ, > + &btrfs_root_fs_type); > + ret = PTR_ERR_OR_ZERO(device); > break; > case BTRFS_IOC_DEVICES_READY: > - ret = btrfs_scan_one_device(vol->name, FMODE_READ, > - &btrfs_root_fs_type, &fs_devices); > - if (ret) > + device = btrfs_scan_one_device(vol->name, FMODE_READ, > + &btrfs_root_fs_type); > + if (IS_ERR(device)) { > + ret = PTR_ERR(device); > break; > - ret = !(fs_devices->num_devices == fs_devices->total_devices); > + } > + ret = !(device->fs_devices->num_devices == > + device->fs_devices->total_devices); > break; > case BTRFS_IOC_GET_SUPPORTED_FEATURES: > ret = btrfs_ioctl_get_supported_features((void __user*)arg); > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 52abada5c789..3bc479e8cc22 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -1212,14 +1212,13 @@ 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_device *btrfs_scan_one_device(const char *path, fmode_t flags, > + void *holder) > { > struct btrfs_super_block *disk_super; > - struct btrfs_device *device; > + struct btrfs_device *ret = NULL; > struct block_device *bdev; > struct page *page; > - int ret = 0; > u64 bytenr; > > /* > @@ -1233,19 +1232,15 @@ 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 ERR_CAST(bdev); > > 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); > - else > - *fs_devices_ret = device->fs_devices; > + ret = device_list_add(path, disk_super); > mutex_unlock(&uuid_mutex); > > btrfs_release_disk_super(page); > diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h > index 9665b84b1026..06d8bb7dd557 100644 > --- a/fs/btrfs/volumes.h > +++ b/fs/btrfs/volumes.h > @@ -403,8 +403,8 @@ 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_device *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, >