Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits)
  fs: avoid I_NEW inodes
  Merge code for single and multiple-instance mounts
  Remove get_init_pts_sb()
  Move common mknod_ptmx() calls into caller
  Parse mount options just once and copy them to super block
  Unroll essentials of do_remount_sb() into devpts
  vfs: simple_set_mnt() should return void
  fs: move bdev code out of buffer.c
  constify dentry_operations: rest
  constify dentry_operations: configfs
  constify dentry_operations: sysfs
  constify dentry_operations: JFS
  constify dentry_operations: OCFS2
  constify dentry_operations: GFS2
  constify dentry_operations: FAT
  constify dentry_operations: FUSE
  constify dentry_operations: procfs
  constify dentry_operations: ecryptfs
  constify dentry_operations: CIFS
  constify dentry_operations: AFS
  ...

1 files changed, 46 insertions, 142 deletions

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index bff4052b05e7..63a4a59e4148 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -322,177 +322,81 @@ static int compare_init_pts_sb(struct super_block *s, void *p)
 }
 
 /*
- * Safely parse the mount options in @data and update @opts.
+ * devpts_get_sb()
  *
- * devpts ends up parsing options two times during mount, due to the
- * two modes of operation it supports. The first parse occurs in
- * devpts_get_sb() when determining the mode (single-instance or
- * multi-instance mode). The second parse happens in devpts_remount()
- * or new_pts_mount() depending on the mode.
+ *     If the '-o newinstance' mount option was specified, mount a new
+ *     (private) instance of devpts.  PTYs created in this instance are
+ *     independent of the PTYs in other devpts instances.
  *
- * Parsing of options modifies the @data making subsequent parsing
- * incorrect. So make a local copy of @data and parse it.
+ *     If the '-o newinstance' option was not specified, mount/remount the
+ *     initial kernel mount of devpts.  This type of mount gives the
+ *     legacy, single-instance semantics.
  *
- * Return: 0 On success, -errno on error
- */
-static int safe_parse_mount_options(void *data, struct pts_mount_opts *opts)
-{
-        int rc;
-        void *datacp;
-
-        if (!data)
-                return 0;
-
-        /* Use kstrdup() ?  */
-        datacp = kmalloc(PAGE_SIZE, GFP_KERNEL);
-        if (!datacp)
-                return -ENOMEM;
-
-        memcpy(datacp, data, PAGE_SIZE);
-        rc = parse_mount_options((char *)datacp, PARSE_MOUNT, opts);
-        kfree(datacp);
-
-        return rc;
-}
-
-/*
- * Mount a new (private) instance of devpts.  PTYs created in this
- * instance are independent of the PTYs in other devpts instances.
- */
-static int new_pts_mount(struct file_system_type *fs_type, int flags,
-                void *data, struct vfsmount *mnt)
-{
-        int err;
-        struct pts_fs_info *fsi;
-        struct pts_mount_opts *opts;
-
-        err = get_sb_nodev(fs_type, flags, data, devpts_fill_super, mnt);
-        if (err)
-                return err;
-
-        fsi = DEVPTS_SB(mnt->mnt_sb);
-        opts = &fsi->mount_opts;
-
-        err = parse_mount_options(data, PARSE_MOUNT, opts);
-        if (err)
-                goto fail;
-
-        err = mknod_ptmx(mnt->mnt_sb);
-        if (err)
-                goto fail;
-
-        return 0;
-
-fail:
-        dput(mnt->mnt_sb->s_root);
-        deactivate_super(mnt->mnt_sb);
-        return err;
-}
-
-/*
- * Check if 'newinstance' mount option was specified in @data.
+ *     The 'newinstance' option is needed to support multiple namespace
+ *     semantics in devpts while preserving backward compatibility of the
+ *     current 'single-namespace' semantics. i.e all mounts of devpts
+ *     without the 'newinstance' mount option should bind to the initial
+ *     kernel mount, like get_sb_single().
  *
- * Return: -errno       on error (eg: invalid mount options specified)
- *       : 1            if 'newinstance' mount option was specified
- *       : 0            if 'newinstance' mount option was NOT specified
- */
-static int is_new_instance_mount(void *data)
-{
-        int rc;
-        struct pts_mount_opts opts;
-
-        if (!data)
-                return 0;
-
-        rc = safe_parse_mount_options(data, &opts);
-        if (!rc)
-                rc = opts.newinstance;
-
-        return rc;
-}
-
-/*
- * get_init_pts_sb()
- *
- *     This interface is needed to support multiple namespace semantics in
- *     devpts while preserving backward compatibility of the current 'single-
- *     namespace' semantics. i.e all mounts of devpts without the 'newinstance'
- *     mount option should bind to the initial kernel mount, like
- *     get_sb_single().
+ *     Mounts with 'newinstance' option create a new, private namespace.
  *
- *     Mounts with 'newinstance' option create a new private namespace.
+ *     NOTE:
  *
- *     But for single-mount semantics, devpts cannot use get_sb_single(),
+ *     For single-mount semantics, devpts cannot use get_sb_single(),
  *     because get_sb_single()/sget() find and use the super-block from
  *     the most recent mount of devpts. But that recent mount may be a
  *     'newinstance' mount and get_sb_single() would pick the newinstance
  *     super-block instead of the initial super-block.
- *
- *     This interface is identical to get_sb_single() except that it
- *     consistently selects the 'single-namespace' superblock even in the
- *     presence of the private namespace (i.e 'newinstance') super-blocks.
  */
-static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
-                void *data, struct vfsmount *mnt)
+static int devpts_get_sb(struct file_system_type *fs_type,
+        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 {
-        struct super_block *s;
         int error;
+        struct pts_mount_opts opts;
+        struct super_block *s;
+
+        memset(&opts, 0, sizeof(opts));
+        if (data) {
+                error = parse_mount_options(data, PARSE_MOUNT, &opts);
+                if (error)
+                        return error;
+        }
+
+        if (opts.newinstance)
+                s = sget(fs_type, NULL, set_anon_super, NULL);
+        else
+                s = sget(fs_type, compare_init_pts_sb, set_anon_super, NULL);
 
-        s = sget(fs_type, compare_init_pts_sb, set_anon_super, NULL);
         if (IS_ERR(s))
                 return PTR_ERR(s);
 
         if (!s->s_root) {
                 s->s_flags = flags;
                 error = devpts_fill_super(s, data, flags & MS_SILENT ? 1 : 0);
-                if (error) {
-                        up_write(&s->s_umount);
-                        deactivate_super(s);
-                        return error;
-                }
+                if (error)
+                        goto out_undo_sget;
                 s->s_flags |= MS_ACTIVE;
         }
-        do_remount_sb(s, flags, data, 0);
-        return simple_set_mnt(mnt, s);
-}
 
-/*
- * Mount or remount the initial kernel mount of devpts. This type of
- * mount maintains the legacy, single-instance semantics, while the
- * kernel still allows multiple-instances.
- */
-static int init_pts_mount(struct file_system_type *fs_type, int flags,
-                void *data, struct vfsmount *mnt)
-{
-        int err;
+        simple_set_mnt(mnt, s);
 
-        err = get_init_pts_sb(fs_type, flags, data, mnt);
-        if (err)
-                return err;
+        memcpy(&(DEVPTS_SB(s))->mount_opts, &opts, sizeof(opts));
 
-        err = mknod_ptmx(mnt->mnt_sb);
-        if (err) {
-                dput(mnt->mnt_sb->s_root);
-                deactivate_super(mnt->mnt_sb);
-        }
+        error = mknod_ptmx(s);
+        if (error)
+                goto out_dput;
 
-        return err;
-}
-
-static int devpts_get_sb(struct file_system_type *fs_type,
-        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
-{
-        int new;
-
-        new = is_new_instance_mount(data);
-        if (new < 0)
-                return new;
+        return 0;
 
-        if (new)
-                return new_pts_mount(fs_type, flags, data, mnt);
+out_dput:
+        dput(s->s_root);
 
-        return init_pts_mount(fs_type, flags, data, mnt);
+out_undo_sget:
+        up_write(&s->s_umount);
+        deactivate_super(s);
+        return error;
 }
+
 #else
 /*
  * This supports only the legacy single-instance semantics (no