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-rw-r--r--fs/devpts/inode.c100
1 files changed, 22 insertions, 78 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index fb4da9d8913..70013dd8ec7 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