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| author | Miklos Szeredi <mszeredi@redhat.com> | 2025-08-22 13:10:44 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2025-09-02 11:14:15 +0200 |
| commit | dfb84c33079497bf27058b15780e1c7bba4c371b (patch) | |
| tree | e45caf557d5bcfc1dcd6cc81e8de84a5531e570a /include/uapi | |
| parent | fuse: zero initialize inode private data (diff) | |
| download | linux-dfb84c33079497bf27058b15780e1c7bba4c371b.tar.gz linux-dfb84c33079497bf27058b15780e1c7bba4c371b.zip | |
fuse: allow synchronous FUSE_INIT
FUSE_INIT has always been asynchronous with mount. That means that the
server processed this request after the mount syscall returned.
This means that FUSE_INIT can't supply the root inode's ID, hence it
currently has a hardcoded value. There are other limitations such as not
being able to perform getxattr during mount, which is needed by selinux.
To remove these limitations allow server to process FUSE_INIT while
initializing the in-core super block for the fuse filesystem. This can
only be done if the server is prepared to handle this, so add
FUSE_DEV_IOC_SYNC_INIT ioctl, which
a) lets the server know whether this feature is supported, returning
ENOTTY othewrwise.
b) lets the kernel know to perform a synchronous initialization
The implementation is slightly tricky, since fuse_dev/fuse_conn are set up
only during super block creation. This is solved by setting the private
data of the fuse device file to a special value ((struct fuse_dev *) 1) and
waiting for this to be turned into a proper fuse_dev before commecing with
operations on the device file.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/fuse.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 94621f68a5cc..6b9fb8b08768 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -1131,6 +1131,7 @@ struct fuse_backing_map { #define FUSE_DEV_IOC_BACKING_OPEN _IOW(FUSE_DEV_IOC_MAGIC, 1, \ struct fuse_backing_map) #define FUSE_DEV_IOC_BACKING_CLOSE _IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t) +#define FUSE_DEV_IOC_SYNC_INIT _IO(FUSE_DEV_IOC_MAGIC, 3) struct fuse_lseek_in { uint64_t fh; |