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| author | Greg Kurz <groug@kaod.org> | 2021-06-04 19:11:53 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2021-06-22 10:15:35 +0300 |
| commit | fe0a7bd81bfefe5eb73bce55682586c6c266e21e (patch) | |
| tree | b9e84e157d8022a19153d1833e562a5a86f95f17 /fs/fuse | |
| parent | 2d82ab251ef0f6e7716279b04e9b5a01a86ca530 (diff) | |
| download | linux-fe0a7bd81bfefe5eb73bce55682586c6c266e21e.tar.xz | |
fuse: add dedicated filesystem context ops for submounts
The creation of a submount is open-coded in fuse_dentry_automount().
This brings a lot of complexity and we recently had to fix bugs
because we weren't setting SB_BORN or because we were unlocking
sb->s_umount before sb was fully configured. Most of these could
have been avoided by using the mount API instead of open-coding.
Basically, this means coming up with a proper ->get_tree()
implementation for submounts and call vfs_get_tree(), or better
fc_mount().
The creation of the superblock for submounts is quite different from
the root mount. Especially, it doesn't require to allocate a FUSE
filesystem context, nor to parse parameters.
Introduce a dedicated context ops for submounts to make this clear.
This is just a placeholder for now, fuse_get_tree_submount() will
be populated in a subsequent patch.
Only visible change is that we stop allocating/freeing a useless FUSE
filesystem context with submounts.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
| -rw-r--r-- | fs/fuse/fuse_i.h | 5 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 16 | ||||
| -rw-r--r-- | fs/fuse/virtio_fs.c | 3 |
3 files changed, 24 insertions, 0 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index f48dd7ff32af..b5957c8274dd 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1101,6 +1101,11 @@ int fuse_fill_super_submount(struct super_block *sb, bool fuse_mount_remove(struct fuse_mount *fm); /* + * Setup context ops for submounts + */ +int fuse_init_fs_context_submount(struct fs_context *fsc); + +/* * Shut down the connection (possibly sending DESTROY request). */ void fuse_conn_destroy(struct fuse_mount *fm); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 93d28dc1f572..a0a8228979a2 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1353,6 +1353,22 @@ int fuse_fill_super_submount(struct super_block *sb, return 0; } +static int fuse_get_tree_submount(struct fs_context *fsc) +{ + return 0; +} + +static const struct fs_context_operations fuse_context_submount_ops = { + .get_tree = fuse_get_tree_submount, +}; + +int fuse_init_fs_context_submount(struct fs_context *fsc) +{ + fsc->ops = &fuse_context_submount_ops; + return 0; +} +EXPORT_SYMBOL_GPL(fuse_init_fs_context_submount); + int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx) { struct fuse_dev *fud = NULL; diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index f9809b1b82f0..8f52cdaa8445 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -1497,6 +1497,9 @@ static int virtio_fs_init_fs_context(struct fs_context *fsc) { struct fuse_fs_context *ctx; + if (fsc->purpose == FS_CONTEXT_FOR_SUBMOUNT) + return fuse_init_fs_context_submount(fsc); + ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL); if (!ctx) return -ENOMEM; |