[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>

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index a6d1779..3c3c6e3 100644 (file)
--- 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)

diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 4b6e1ab..c166628 100644 (file)
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -238,6 +238,20 @@ struct ext3_new_group_data {
 #define EXT3_IOC_GETRSVSZ              _IOR('f', 5, long)
 #define EXT3_IOC_SETRSVSZ              _IOW('f', 6, long)
 
+/*
+ *  Mount options
+ */
+struct ext3_mount_options {
+       unsigned long s_mount_opt;
+       uid_t s_resuid;
+       gid_t s_resgid;
+       unsigned long s_commit_interval;
+#ifdef CONFIG_QUOTA
+       int s_jquota_fmt;
+       char *s_qf_names[MAXQUOTAS];
+#endif
+};
+
 /*
  * Structure of an inode on the disk
  */