[PATCH 4.9 09/39] btrfs: export helpers for subvolume name/id resolution

From: Greg Kroah-Hartman
Date: Mon Aug 24 2020 - 05:27:51 EST


From: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>

[ Upstream commit c0c907a47dccf2cf26251a8fb4a8e7a3bf79ce84 ]

The functions will be used outside of export.c and super.c to allow
resolving subvolume name from a given id, eg. for subvolume deletion by
id ioctl.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
[ split from the next patch ]
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/btrfs/ctree.h | 2 ++
fs/btrfs/export.c | 8 ++++----
fs/btrfs/export.h | 5 +++++
fs/btrfs/super.c | 8 ++++----
4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2bc37d03d4075..abfc090510480 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3261,6 +3261,8 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
int btrfs_parse_options(struct btrfs_root *root, char *options,
unsigned long new_flags);
int btrfs_sync_fs(struct super_block *sb, int wait);
+char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
+ u64 subvol_objectid);

static inline __printf(2, 3)
void btrfs_no_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 2513a7f533342..92f80ed642194 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -55,9 +55,9 @@ static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
return type;
}

-static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
- u64 root_objectid, u32 generation,
- int check_generation)
+struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
+ u64 root_objectid, u32 generation,
+ int check_generation)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_root *root;
@@ -150,7 +150,7 @@ static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}

-static struct dentry *btrfs_get_parent(struct dentry *child)
+struct dentry *btrfs_get_parent(struct dentry *child)
{
struct inode *dir = d_inode(child);
struct btrfs_root *root = BTRFS_I(dir)->root;
diff --git a/fs/btrfs/export.h b/fs/btrfs/export.h
index 074348a95841f..7a305e5549991 100644
--- a/fs/btrfs/export.h
+++ b/fs/btrfs/export.h
@@ -16,4 +16,9 @@ struct btrfs_fid {
u64 parent_root_objectid;
} __attribute__ ((packed));

+struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
+ u64 root_objectid, u32 generation,
+ int check_generation);
+struct dentry *btrfs_get_parent(struct dentry *child);
+
#endif
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9286603a6a98b..af5be060c651f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -948,8 +948,8 @@ out:
return error;
}

-static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
- u64 subvol_objectid)
+char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
+ u64 subvol_objectid)
{
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_root *fs_root;
@@ -1430,8 +1430,8 @@ static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
goto out;
}
}
- subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb),
- subvol_objectid);
+ subvol_name = btrfs_get_subvol_name_from_objectid(
+ btrfs_sb(mnt->mnt_sb), subvol_objectid);
if (IS_ERR(subvol_name)) {
root = ERR_CAST(subvol_name);
subvol_name = NULL;
--
2.25.1