diff options
author | David Howells <dhowells@redhat.com> | 2018-11-02 02:07:25 +0300 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-02-28 11:29:26 +0300 |
commit | 3e1aeb00e6d132efc151dacc062b38269bc9eccc (patch) | |
tree | d6cb75c4e0540cdd94e381c2afcacd6d7142fb30 /fs/namespace.c | |
parent | 846e56621897a63966b7f03a70be29060394c363 (diff) | |
download | linux-3e1aeb00e6d132efc151dacc062b38269bc9eccc.tar.xz |
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 'fs/namespace.c')
-rw-r--r-- | fs/namespace.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 931228d8518a..1a1ed2528f47 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -997,17 +997,15 @@ struct vfsmount *vfs_kern_mount(struct file_system_type *type, int ret = 0; if (!type) - return ERR_PTR(-ENODEV); + return ERR_PTR(-EINVAL); fc = fs_context_for_mount(type, flags); if (IS_ERR(fc)) return ERR_CAST(fc); - if (name) { - fc->source = kstrdup(name, GFP_KERNEL); - if (!fc->source) - ret = -ENOMEM; - } + if (name) + ret = vfs_parse_fs_string(fc, "source", + name, strlen(name)); if (!ret) ret = parse_monolithic_mount_data(fc, data); if (!ret) @@ -2611,16 +2609,11 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags, if (IS_ERR(fc)) return PTR_ERR(fc); - if (subtype) { - fc->subtype = kstrdup(subtype, GFP_KERNEL); - if (!fc->subtype) - err = -ENOMEM; - } - if (!err && name) { - fc->source = kstrdup(name, GFP_KERNEL); - if (!fc->source) - err = -ENOMEM; - } + if (subtype) + err = vfs_parse_fs_string(fc, "subtype", + subtype, strlen(subtype)); + if (!err && name) + err = vfs_parse_fs_string(fc, "source", name, strlen(name)); if (!err) err = parse_monolithic_mount_data(fc, data); if (!err) |