diff options
| author | David Howells <dhowells@redhat.com> | 2018-11-01 23:07:25 +0000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-02-28 03:29:26 -0500 |
| commit | 3e1aeb00e6d132efc151dacc062b38269bc9eccc (patch) | |
| tree | d6cb75c4e0540cdd94e381c2afcacd6d7142fb30 /include/linux/fs_context.h | |
| parent | 846e56621897a63966b7f03a70be29060394c363 (diff) | |
| download | lwn-3e1aeb00e6d132efc151dacc062b38269bc9eccc.tar.gz lwn-3e1aeb00e6d132efc151dacc062b38269bc9eccc.zip | |
vfs: Implement a filesystem superblock creation/configuration context
[AV - unfuck kern_mount_data(); we want non-NULL ->mnt_ns on long-living
mounts]
[AV - reordering fs/namespace.c is badly overdue, but let's keep it
separate from that series]
[AV - drop simple_pin_fs() change]
[AV - clean vfs_kern_mount() failure exits up]
Implement a filesystem context concept to be used during superblock
creation for mount and superblock reconfiguration for remount.
The mounting procedure then becomes:
(1) Allocate new fs_context context.
(2) Configure the context.
(3) Create superblock.
(4) Query the superblock.
(5) Create a mount for the superblock.
(6) Destroy the context.
Rather than calling fs_type->mount(), an fs_context struct is created and
fs_type->init_fs_context() is called to set it up. Pointers exist for the
filesystem and LSM to hang their private data off.
A set of operations has to be set by ->init_fs_context() to provide
freeing, duplication, option parsing, binary data parsing, validation,
mounting and superblock filling.
Legacy filesystems are supported by the provision of a set of legacy
fs_context operations that build up a list of mount options and then invoke
fs_type->mount() from within the fs_context ->get_tree() operation. This
allows all filesystems to be accessed using fs_context.
It should be noted that, whilst this patch adds a lot of lines of code,
there is quite a bit of duplication with existing code that can be
eliminated should all filesystems be converted over.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/fs_context.h')
| -rw-r--r-- | include/linux/fs_context.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h index d5ff3b0bc28d..d794b04e9fbb 100644 --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -92,6 +92,7 @@ struct fs_context { struct fs_context_operations { void (*free)(struct fs_context *fc); + int (*parse_param)(struct fs_context *fc, struct fs_parameter *param); int (*parse_monolithic)(struct fs_context *fc, void *data); int (*get_tree)(struct fs_context *fc); int (*reconfigure)(struct fs_context *fc); @@ -108,6 +109,10 @@ extern struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, extern struct fs_context *fs_context_for_submount(struct file_system_type *fs_type, struct dentry *reference); +extern int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param); +extern int vfs_parse_fs_string(struct fs_context *fc, const char *key, + const char *value, size_t v_size); +extern int generic_parse_monolithic(struct fs_context *fc, void *data); extern int vfs_get_tree(struct fs_context *fc); extern void put_fs_context(struct fs_context *fc); |