[PATCH] ext3: fix options parsing

Fix a problem with ext3 mount option parsing.  When remount of a filesystem
fails, old options are now restored.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 60 insertions, 10 deletions

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index a6d1779d7de4..3c3c6e399fb3 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -890,7 +890,10 @@ clear_qf_name:
                                         "quota turned on.\n");
                                 return 0;
                         }
-                        kfree(sbi->s_qf_names[qtype]);
+                        /*
+                         * The space will be released later when all options
+                         * are confirmed to be correct
+                         */
                         sbi->s_qf_names[qtype] = NULL;
                         break;
                 case Opt_jqfmt_vfsold:
@@ -939,7 +942,7 @@ clear_qf_name:
                 case Opt_ignore:
                         break;
                 case Opt_resize:
-                        if (!n_blocks_count) {
+                        if (!is_remount) {
                                 printk("EXT3-fs: resize option only available "
                                         "for remount\n");
                                 return 0;
@@ -2109,14 +2112,33 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
 {
         struct ext3_super_block * es;
         struct ext3_sb_info *sbi = EXT3_SB(sb);
-        unsigned long tmp;
         unsigned long n_blocks_count = 0;
+        unsigned long old_sb_flags;
+        struct ext3_mount_options old_opts;
+        int err;
+#ifdef CONFIG_QUOTA
+        int i;
+#endif
+
+        /* Store the original options */
+        old_sb_flags = sb->s_flags;
+        old_opts.s_mount_opt = sbi->s_mount_opt;
+        old_opts.s_resuid = sbi->s_resuid;
+        old_opts.s_resgid = sbi->s_resgid;
+        old_opts.s_commit_interval = sbi->s_commit_interval;
+#ifdef CONFIG_QUOTA
+        old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
+        for (i = 0; i < MAXQUOTAS; i++)
+                old_opts.s_qf_names[i] = sbi->s_qf_names[i];
+#endif
 
         /*
          * Allow the "check" option to be passed as a remount option.
          */
-        if (!parse_options(data, sb, &tmp, &n_blocks_count, 1))
-                return -EINVAL;
+        if (!parse_options(data, sb, NULL, &n_blocks_count, 1)) {
+                err = -EINVAL;
+                goto restore_opts;
+        }
 
         if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
                 ext3_abort(sb, __FUNCTION__, "Abort forced by user");
@@ -2130,8 +2152,10 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
 
         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
                 n_blocks_count > le32_to_cpu(es->s_blocks_count)) {
-                if (sbi->s_mount_opt & EXT3_MOUNT_ABORT)
-                        return -EROFS;
+                if (sbi->s_mount_opt & EXT3_MOUNT_ABORT) {
+                        err = -EROFS;
+                        goto restore_opts;
+                }
 
                 if (*flags & MS_RDONLY) {
                         /*
@@ -2158,7 +2182,8 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
                                        "remount RDWR because of unsupported "
                                        "optional features (%x).\n",
                                        sb->s_id, le32_to_cpu(ret));
-                                return -EROFS;
+                                err = -EROFS;
+                                goto restore_opts;
                         }
                         /*
                          * Mounting a RDONLY partition read-write, so reread
@@ -2168,13 +2193,38 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
                          */
                         ext3_clear_journal_err(sb, es);
                         sbi->s_mount_state = le16_to_cpu(es->s_state);
-                        if ((ret = ext3_group_extend(sb, es, n_blocks_count)))
-                                return ret;
+                        if ((ret = ext3_group_extend(sb, es, n_blocks_count))) {
+                                err = ret;
+                                goto restore_opts;
+                        }
                         if (!ext3_setup_super (sb, es, 0))
                                 sb->s_flags &= ~MS_RDONLY;
                 }
         }
+#ifdef CONFIG_QUOTA
+        /* Release old quota file names */
+        for (i = 0; i < MAXQUOTAS; i++)
+                if (old_opts.s_qf_names[i] &&
+                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
+                        kfree(old_opts.s_qf_names[i]);
+#endif
         return 0;
+restore_opts:
+        sb->s_flags = old_sb_flags;
+        sbi->s_mount_opt = old_opts.s_mount_opt;
+        sbi->s_resuid = old_opts.s_resuid;
+        sbi->s_resgid = old_opts.s_resgid;
+        sbi->s_commit_interval = old_opts.s_commit_interval;
+#ifdef CONFIG_QUOTA
+        sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
+        for (i = 0; i < MAXQUOTAS; i++) {
+                if (sbi->s_qf_names[i] &&
+                    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
+                        kfree(sbi->s_qf_names[i]);
+                sbi->s_qf_names[i] = old_opts.s_qf_names[i];
+        }
+#endif
+        return err;
 }
 
 static int ext3_statfs (struct super_block * sb, struct kstatfs * buf)