From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: linux-fsdevel@vger.kernel.org, dhowells@redhat.com,
torvalds@linux-foundation.org, ebiederm@xmission.com,
linux-security-module@vger.kernel.org
Subject: [PATCH 08/43] teach vfs_get_tree() to handle subtype, switch do_new_mount() to it
Date: Tue, 19 Feb 2019 16:29:30 +0000 [thread overview]
Message-ID: <155059377086.12449.48912929800325479.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155059366914.12449.4669870128936536848.stgit@warthog.procyon.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
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>
---
fs/namespace.c | 77 +++++++++++++++++++++++++++++++---------------------
fs/super.c | 5 +++
include/linux/fs.h | 2 +
3 files changed, 52 insertions(+), 32 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 @@ static int do_move_mount(struct path *path, const char *old_name)
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;
}
diff --git a/fs/super.c b/fs/super.c
index fc3887277ad1..b91b6df05b67 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1262,6 +1262,11 @@ int vfs_get_tree(struct fs_context *fc)
sb = fc->root->d_sb;
WARN_ON(!sb->s_bdi);
+ if (fc->subtype && !sb->s_subtype) {
+ sb->s_subtype = fc->subtype;
+ fc->subtype = NULL;
+ }
+
/*
* Write barrier is for super_cache_count(). We place it before setting
* SB_BORN as the data dependency between the two functions is the
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 811c77743dad..36fff12ab890 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1447,7 +1447,7 @@ struct super_block {
* Filesystem subtype. If non-empty the filesystem type field
* in /proc/mounts will be "type.subtype"
*/
- char *s_subtype;
+ const char *s_subtype;
const struct dentry_operations *s_d_op; /* default d_op for dentries */
next prev parent reply other threads:[~2019-02-19 16:29 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-19 16:27 [PATCH 00/43] VFS: Introduce filesystem context David Howells
2019-02-19 16:28 ` [PATCH 01/43] fix cgroup_do_mount() handling of failure exits David Howells
2019-02-19 16:28 ` [PATCH 02/43] cgroup: saner refcounting for cgroup_root David Howells
2019-02-19 16:28 ` [PATCH 03/43] kill kernfs_pin_sb() David Howells
2019-02-19 16:28 ` [PATCH 04/43] separate copying and locking mount tree on cross-userns copies David Howells
2019-02-20 18:55 ` Alan Jenkins
2019-02-26 15:44 ` David Howells
2019-02-26 17:45 ` Alan Jenkins
2019-02-19 16:29 ` [PATCH 05/43] saner handling of temporary namespaces David Howells
2019-02-19 16:29 ` [PATCH 06/43] vfs: Introduce fs_context, switch vfs_kern_mount() to it David Howells
2019-02-19 16:29 ` [PATCH 07/43] new helpers: vfs_create_mount(), fc_mount() David Howells
2019-02-19 16:29 ` David Howells [this message]
2019-02-19 16:29 ` [PATCH 09/43] new helper: do_new_mount_fc() David Howells
2019-02-19 16:29 ` [PATCH 10/43] vfs_get_tree(): evict the call of security_sb_kern_mount() David Howells
2019-02-19 16:29 ` [PATCH 11/43] convert do_remount_sb() to fs_context David Howells
2019-03-22 11:19 ` Andreas Schwab
2019-03-22 11:25 ` David Howells
2019-03-22 13:28 ` Andreas Schwab
2019-03-22 14:00 ` Andreas Schwab
2019-02-19 16:30 ` [PATCH 12/43] fs_context flavour for submounts David Howells
2019-02-19 16:30 ` [PATCH 13/43] introduce fs_context methods David Howells
2019-02-19 16:30 ` [PATCH 14/43] vfs: Introduce logging functions David Howells
2019-02-19 16:30 ` [PATCH 15/43] vfs: Add configuration parser helpers David Howells
2019-03-03 2:53 ` Al Viro
2019-02-19 16:30 ` [PATCH 16/43] vfs: Add LSM hooks for the new mount API David Howells
2019-02-19 16:30 ` [PATCH 17/43] selinux: Implement the new mount API LSM hooks David Howells
2019-02-19 16:30 ` [PATCH 18/43] smack: Implement filesystem context security hooks David Howells
2019-02-19 16:30 ` [PATCH 19/43] vfs: Put security flags into the fs_context struct David Howells
2019-02-19 16:31 ` [PATCH 20/43] vfs: Implement a filesystem superblock creation/configuration context David Howells
2019-02-19 16:31 ` [PATCH 21/43] convenience helpers: vfs_get_super() and sget_fc() David Howells
2019-02-19 16:31 ` [PATCH 22/43] introduce cloning of fs_context David Howells
2019-02-19 16:31 ` [PATCH 23/43] procfs: Move proc_fill_super() to fs/proc/root.c David Howells
2019-02-19 16:31 ` [PATCH 24/43] proc: Add fs_context support to procfs David Howells
2019-02-19 16:31 ` [PATCH 25/43] ipc: Convert mqueue fs to fs_context David Howells
2019-02-19 16:31 ` [PATCH 26/43] cgroup: start switching " David Howells
2019-02-19 16:32 ` [PATCH 27/43] cgroup: fold cgroup1_mount() into cgroup1_get_tree() David Howells
2019-02-19 16:32 ` [PATCH 28/43] cgroup: take options parsing into ->parse_monolithic() David Howells
2019-02-19 16:32 ` [PATCH 29/43] cgroup1: switch to option-by-option parsing David Howells
2019-02-19 16:32 ` [PATCH 30/43] cgroup2: " David Howells
2019-02-19 16:32 ` [PATCH 31/43] cgroup: stash cgroup_root reference into cgroup_fs_context David Howells
2019-02-19 16:32 ` [PATCH 32/43] cgroup_do_mount(): massage calling conventions David Howells
2019-02-19 16:32 ` [PATCH 33/43] cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper David Howells
2019-02-19 16:33 ` [PATCH 34/43] cgroup: store a reference to cgroup_ns into cgroup_fs_context David Howells
2019-02-19 16:33 ` [PATCH 35/43] kernfs, sysfs, cgroup, intel_rdt: Support fs_context David Howells
2019-02-19 16:33 ` [PATCH 36/43] cpuset: Use fs_context David Howells
2019-02-19 16:33 ` [PATCH 37/43] hugetlbfs: Convert to fs_context David Howells
2019-02-19 16:33 ` [PATCH 38/43] vfs: Remove kern_mount_data() David Howells
2019-02-19 16:33 ` [PATCH 39/43] vfs: Provide documentation for new mount API David Howells
2019-02-19 16:34 ` [PATCH 40/43] vfs: Implement logging through fs_context David Howells
2019-02-19 16:34 ` [PATCH 41/43] vfs: Add some logging to the core users of the fs_context log David Howells
2019-02-19 16:34 ` [PATCH 42/43] afs: Add fs_context support David Howells
2019-02-19 16:34 ` [PATCH 43/43] afs: Use fs_context to pass parameters over automount David Howells
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