path: root/fs
diff options
authorSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>2009-05-14 19:38:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-15 08:03:23 -0700
commit1f71ebedb3f8ce9108978168759c8551d873a912 (patch)
tree604f633fa092872f8b70873780c36e024de3677a /fs
parentbd67ce0f661482bd073f94144dd7e5a093ef012f (diff)
devpts: correctly set default options
devpts_get_sb() calls memset(0) to clear mount options and calls parse_mount_options() if user specified any mount options. The memset(0) is bogus since the 'mode' and 'ptmxmode' options are non-zero by default. parse_mount_options() restores options to default anyway and can properly deal with NULL mount options. So in devpts_get_sb() remove memset(0) and call parse_mount_options() even for NULL mount options. Bug reported by Eric Paris: http://lkml.org/lkml/2009/5/7/448. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Tested-by: Marc Dionne <marc.c.dionne@gmail.com> Reported-by: Eric Paris <eparis@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Reviewed-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 21165cf934f..c68edb96944 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -90,6 +90,15 @@ static inline struct super_block *pts_sb_from_inode(struct inode *inode)
#define PARSE_MOUNT 0
+ * parse_mount_options():
+ * Set @opts to mount options specified in @data. If an option is not
+ * specified in @data, set it to its default value. The exception is
+ * 'newinstance' option which can only be set/cleared on a mount (i.e.
+ * cannot be changed during remount).
+ *
+ * Note: @data may be NULL (in which case all options are set to default).
+ */
static int parse_mount_options(char *data, int op, struct pts_mount_opts *opts)
char *p;
@@ -355,12 +364,9 @@ static int devpts_get_sb(struct file_system_type *fs_type,
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;
- }
+ error = parse_mount_options(data, PARSE_MOUNT, &opts);
+ if (error)
+ return error;
if (opts.newinstance)
s = sget(fs_type, NULL, set_anon_super, NULL);