reiserfs: check kstrdup failure

Check out-of-memory failure of the kstrdup option. Note that the argument
"arg" may be NULL (in that case kstrup returns NULL), so out of memory
condition happened if arg was non-NULL and kstrdup returned NULL.

The patch also changes the call to replace_mount_options - if we didn't
pass any filesystem-specific options, we don't call replace_mount_options
(thus we don't erase existing reported options).

Note that to properly report options after remount, the reiserfs
filesystem should implement the show_options method. Without the
show_options method, options changed with remount replace existing
options.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index b8f2d1e8c645..c72c16c5a60f 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -1393,7 +1393,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
         unsigned long safe_mask = 0;
         unsigned int commit_max_age = (unsigned int)-1;
         struct reiserfs_journal *journal = SB_JOURNAL(s);
-        char *new_opts = kstrdup(arg, GFP_KERNEL);
+        char *new_opts;
         int err;
         char *qf_names[REISERFS_MAXQUOTAS];
         unsigned int qfmt = 0;
@@ -1401,6 +1401,10 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
         int i;
 #endif
 
+        new_opts = kstrdup(arg, GFP_KERNEL);
+        if (arg && !new_opts)
+                return -ENOMEM;
+
         sync_filesystem(s);
         reiserfs_write_lock(s);
 
@@ -1546,7 +1550,8 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
         }
 
 out_ok_unlocked:
-        replace_mount_options(s, new_opts);
+        if (new_opts)
+                replace_mount_options(s, new_opts);
         return 0;
 
 out_err_unlock: