Re: [PATCH v4 2/2] btrfs: get device pointer from btrfs_scan_one_device
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, _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, _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,
> - _root_fs_type, _devices);
> + device = btrfs_scan_one_device(vol->name, FMODE_READ,
> + _root_fs_type);
> + ret = PTR_ERR_OR_ZERO(device);
> break;
> case BTRFS_IOC_DEVICES_READY:
> - ret = btrfs_scan_one_device(vol->name, FMODE_READ,
> - _root_fs_type, _devices);
> - if (ret)
> + device = btrfs_scan_one_device(vol->name, FMODE_READ,
> + _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
[PATCH v4 2/2] btrfs: get device pointer from btrfs_scan_one_device
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
---
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, _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, _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,
- _root_fs_type, _devices);
+ device = btrfs_scan_one_device(vol->name, FMODE_READ,
+ _root_fs_type);
+ ret = PTR_ERR_OR_ZERO(device);
break;
case BTRFS_IOC_DEVICES_READY:
- ret = btrfs_scan_one_device(vol->name, FMODE_READ,
- _root_fs_type, _devices);
- if (ret)
+ device = btrfs_scan_one_device(vol->name, FMODE_READ,
+ _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
