diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2023-09-11 17:09:27 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2024-03-05 13:40:36 +0100 |
| commit | 44350256ab943d424d70aa60a34f45060b3a36e8 (patch) | |
| tree | 65567a0a2cf44561b25f201f1e81540af1ed69af /fs/fuse/fuse_i.h | |
| parent | 7dc4e97a4f9a55bae6ed6ab3f96c92921259d59f (diff) | |
fuse: implement ioctls to manage backing files
FUSE server calls the FUSE_DEV_IOC_BACKING_OPEN ioctl with a backing file
descriptor. If the call succeeds, a backing file identifier is returned.
A later change will be using this backing file id in a reply to OPEN
request with the flag FOPEN_PASSTHROUGH to setup passthrough of file
operations on the open FUSE file to the backing file.
The FUSE server should call FUSE_DEV_IOC_BACKING_CLOSE ioctl to close the
backing file by its id.
This can be done at any time, but if an open reply with FOPEN_PASSTHROUGH
flag is still in progress, the open may fail if the backing file is
closed before the fuse file was opened.
Setting up backing files requires a server with CAP_SYS_ADMIN privileges.
For the backing file to be successfully setup, the backing file must
implement both read_iter and write_iter file operations.
The limitation on the level of filesystem stacking allowed for the
backing file is enforced before setting up the backing file.
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse/fuse_i.h')
| -rw-r--r-- | fs/fuse/fuse_i.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 19a86acc9dd0..4f1681650f57 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -79,6 +79,7 @@ struct fuse_submount_lookup { /** Container for data related to mapping to backing file */ struct fuse_backing { struct file *file; + struct cred *cred; /** refcount */ refcount_t count; @@ -897,6 +898,11 @@ struct fuse_conn { /* New writepages go into this bucket */ struct fuse_sync_bucket __rcu *curr_bucket; + +#ifdef CONFIG_FUSE_PASSTHROUGH + /** IDR for backing files ids */ + struct idr backing_files_map; +#endif }; /* @@ -1409,5 +1415,9 @@ static inline struct fuse_backing *fuse_inode_backing_set(struct fuse_inode *fi, struct fuse_backing *fuse_backing_get(struct fuse_backing *fb); void fuse_backing_put(struct fuse_backing *fb); +void fuse_backing_files_init(struct fuse_conn *fc); +void fuse_backing_files_free(struct fuse_conn *fc); +int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map); +int fuse_backing_close(struct fuse_conn *fc, int backing_id); #endif /* _FS_FUSE_I_H */ |