1 files changed, 22 insertions, 78 deletions

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index fb4da9d89130..70013dd8ec70 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -322,60 +322,21 @@ static int compare_init_pts_sb(struct super_block *s, void *p)
 }
 
 /*
- * Safely parse the mount options in @data and update @opts.
- *
- * 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.
- *
- * Parsing of options modifies the @data making subsequent parsing
- * incorrect. So make a local copy of @data and parse it.
- *
- * 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)
+                void *data, struct pts_mount_opts *opts, 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;
+        memcpy(&fsi->mount_opts, opts, sizeof(opts));
 
         err = mknod_ptmx(mnt->mnt_sb);
         if (err)
@@ -391,28 +352,6 @@ fail:
 }
 
 /*
- * Check if 'newinstance' mount option was specified in @data.
- *
- * 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
@@ -434,10 +373,9 @@ static int is_new_instance_mount(void *data)
  *     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)
+                void *data, struct pts_mount_opts *opts, struct vfsmount *mnt)
 {
         struct super_block *s;
-        struct pts_mount_opts *opts;
         struct pts_fs_info *fsi;
         int error;
 
@@ -455,11 +393,12 @@ static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
                 }
                 s->s_flags |= MS_ACTIVE;
         }
-        fsi = DEVPTS_SB(s);
-        opts = &fsi->mount_opts;
-        parse_mount_options(data, PARSE_REMOUNT, opts);
 
         simple_set_mnt(mnt, s);
+
+        fsi = DEVPTS_SB(mnt->mnt_sb);
+        memcpy(&fsi->mount_opts, opts, sizeof(opts));
+
         return 0;
 }
 
@@ -469,11 +408,11 @@ static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
  * kernel still allows multiple-instances.
  */
 static int init_pts_mount(struct file_system_type *fs_type, int flags,
-                void *data, struct vfsmount *mnt)
+                void *data, struct pts_mount_opts *opts, struct vfsmount *mnt)
 {
         int err;
 
-        err = get_init_pts_sb(fs_type, flags, data, mnt);
+        err = get_init_pts_sb(fs_type, flags, data, opts, mnt);
         if (err)
                 return err;
 
@@ -490,17 +429,22 @@ static int init_pts_mount(struct file_system_type *fs_type, int flags,
 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;
+        int error;
+        struct pts_mount_opts opts;
 
-        if (new)
-                return new_pts_mount(fs_type, flags, data, mnt);
+        memset(&opts, 0, sizeof(opts));
+        if (data) {
+                error = parse_mount_options(data, PARSE_MOUNT, &opts);
+                if (error)
+                        return error;
+        }
 
-        return init_pts_mount(fs_type, flags, data, mnt);
+        if (opts.newinstance)
+                return new_pts_mount(fs_type, flags, data, &opts, mnt);
+        else
+                return init_pts_mount(fs_type, flags, data, &opts, mnt);
 }
+
 #else
 /*
  * This supports only the legacy single-instance semantics (no