On 10.01.2018 07:16, Anand Jain wrote: > Instead of pointer to btrfs_fs_devices as an arg in device_list_add() > better to get pointer to btrfs_device as return value, then we have > both, pointer to btrfs_device and btrfs_fs_devices. btrfs_device is > needed to handle reappearing missing device. > > Signed-off-by: Anand Jain <anand.j...@oracle.com> > --- > fs/btrfs/volumes.c | 34 ++++++++++++++++++---------------- > 1 file changed, 18 insertions(+), 16 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 4e5b82976455..b5305bd48338 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -726,12 +726,11 @@ static int btrfs_open_one_device(struct > btrfs_fs_devices *fs_devices, > * Add new device to list of registered devices > * > * Returns: > - * 0 - device already known or newly added > - * < 0 - error > + * device pointer which was just added or updated when successful > + * error pointer when failed > */ > -static noinline int device_list_add(const char *path, > - struct btrfs_super_block *disk_super, > - u64 devid, struct btrfs_fs_devices **fs_devices_ret) > +static noinline struct btrfs_device *device_list_add(const char *path, > + struct btrfs_super_block *disk_super, u64 devid) > { > struct btrfs_device *device; > struct btrfs_fs_devices *fs_devices; > @@ -742,7 +741,7 @@ static noinline int device_list_add(const char *path, > if (!fs_devices) { > fs_devices = alloc_fs_devices(disk_super->fsid); > if (IS_ERR(fs_devices)) > - return PTR_ERR(fs_devices); > + return ERR_PTR(PTR_ERR(fs_devices));
No need to do any conversion, alloc_fs_devices already returns ERR_PTR value so plain return fs_devices suffices. > > list_add(&fs_devices->list, &fs_uuids); > > @@ -754,19 +753,19 @@ static noinline int device_list_add(const char *path, > > if (!device) { > if (fs_devices->opened) > - return -EBUSY; > + return ERR_PTR(-EBUSY); > > device = btrfs_alloc_device(NULL, &devid, > disk_super->dev_item.uuid); > if (IS_ERR(device)) { > /* we can safely leave the fs_devices entry around */ > - return PTR_ERR(device); > + return ERR_PTR(PTR_ERR(device)); Ditto > } > > name = rcu_string_strdup(path, GFP_NOFS); > if (!name) { > free_device(device); > - return -ENOMEM; > + return ERR_PTR(-ENOMEM); > } > rcu_assign_pointer(device->name, name); > > @@ -820,12 +819,12 @@ static noinline int device_list_add(const char *path, > * with larger generation number or the last-in if > * generation are equal. > */ > - return -EEXIST; > + return ERR_PTR(-EEXIST); > } > > name = rcu_string_strdup(path, GFP_NOFS); > if (!name) > - return -ENOMEM; > + return ERR_PTR(-ENOMEM); > rcu_string_free(device->name); > rcu_assign_pointer(device->name, name); > if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { > @@ -845,9 +844,7 @@ static noinline int device_list_add(const char *path, > > fs_devices->total_devices = btrfs_super_num_devices(disk_super); > > - *fs_devices_ret = fs_devices; > - > - return 0; > + return device; > } > > static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices > *orig) > @@ -1182,9 +1179,10 @@ int btrfs_scan_one_device(const char *path, fmode_t > flags, void *holder, > struct btrfs_fs_devices **fs_devices_ret) > { > struct btrfs_super_block *disk_super; > + struct btrfs_device *device; > struct block_device *bdev; > struct page *page; > - int ret; > + int ret = 0; > u64 devid; > u64 bytenr; > > @@ -1209,8 +1207,12 @@ int btrfs_scan_one_device(const char *path, fmode_t > flags, void *holder, > devid = btrfs_stack_device_id(&disk_super->dev_item); > > mutex_lock(&uuid_mutex); > - ret = device_list_add(path, disk_super, devid, fs_devices_ret); > + device = device_list_add(path, disk_super, devid); > mutex_unlock(&uuid_mutex); > + if (IS_ERR(device)) > + ret = PTR_ERR(device); > + > + *fs_devices_ret = device->fs_devices; > > btrfs_release_disk_super(page); > > -- 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