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authorAl Viro <viro@zeniv.linux.org.uk>2018-11-04 15:18:51 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2019-01-31 01:44:25 +0300
commita0c9a8b8fd9fd572b0d60276beb2142c8f59f9b8 (patch)
tree240a81dae063cbcabc8c8b0d28af7e343dbf20b2 /fs/namespace.c
parent8f2918898eb5fe25845dde7f4a77bda0e2966e05 (diff)
downloadlinux-a0c9a8b8fd9fd572b0d60276beb2142c8f59f9b8.tar.xz
teach vfs_get_tree() to handle subtype, switch do_new_mount() to it
Roll the handling of subtypes into do_new_mount() and vfs_get_tree(). The former determines any subtype string and hangs it off the fs_context; the latter applies it. Make do_new_mount() create, parameterise and commit an fs_context and create a mount for itself rather than calling vfs_kern_mount(). [AV -- missing kstrdup()] [AV -- ... and no kstrdup() if we get to setting ->s_submount - we simply transfer it from fc, leaving NULL behind] [AV -- constify ->s_submount, while we are at it] Reviewed-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.c77
1 files changed, 46 insertions, 31 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 156771f5745a..0354cb6ac2d3 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2479,29 +2479,6 @@ out:
return err;
}
-static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
-{
- int err;
- const char *subtype = strchr(fstype, '.');
- if (subtype) {
- subtype++;
- err = -EINVAL;
- if (!subtype[0])
- goto err;
- } else
- subtype = "";
-
- mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
- err = -ENOMEM;
- if (!mnt->mnt_sb->s_subtype)
- goto err;
- return mnt;
-
- err:
- mntput(mnt);
- return ERR_PTR(err);
-}
-
/*
* add a mount into a namespace's mount tree
*/
@@ -2557,7 +2534,9 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
{
struct file_system_type *type;
struct vfsmount *mnt;
- int err;
+ struct fs_context *fc;
+ const char *subtype = NULL;
+ int err = 0;
if (!fstype)
return -EINVAL;
@@ -2566,23 +2545,59 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
if (!type)
return -ENODEV;
- mnt = vfs_kern_mount(type, sb_flags, name, data);
- if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
- !mnt->mnt_sb->s_subtype)
- mnt = fs_set_subtype(mnt, fstype);
+ if (type->fs_flags & FS_HAS_SUBTYPE) {
+ subtype = strchr(fstype, '.');
+ if (subtype) {
+ subtype++;
+ if (!*subtype) {
+ put_filesystem(type);
+ return -EINVAL;
+ }
+ } else {
+ subtype = "";
+ }
+ }
+ fc = fs_context_for_mount(type, sb_flags);
put_filesystem(type);
- if (IS_ERR(mnt))
- return PTR_ERR(mnt);
+ 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 (!err)
+ err = parse_monolithic_mount_data(fc, data);
+ if (!err)
+ err = vfs_get_tree(fc);
+ if (err)
+ goto out;
+
+ up_write(&fc->root->d_sb->s_umount);
+ mnt = vfs_create_mount(fc);
+ if (IS_ERR(mnt)) {
+ err = PTR_ERR(mnt);
+ goto out;
+ }
if (mount_too_revealing(mnt, &mnt_flags)) {
mntput(mnt);
- return -EPERM;
+ err = -EPERM;
+ goto out;
}
err = do_add_mount(real_mount(mnt), path, mnt_flags);
if (err)
mntput(mnt);
+out:
+ put_fs_context(fc);
return err;
}