ext4: trivial quota cleanup

The patch is aimed to reorganize and simplify quota code a bit.
Quota code is itself complex enough, but we can make it more readable
in some places:
- Move quota option parsing to separate functions.
- Simplify old-quota and journaled-quota mix check.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 69 insertions, 54 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7e8b1b4236d3..79937e921988 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1206,6 +1206,64 @@ static ext4_fsblk_t get_sb_block(void **data)
 
 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
 
+#ifdef CONFIG_QUOTA
+static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        char *qname;
+
+        if (sb_any_quota_loaded(sb) &&
+                !sbi->s_qf_names[qtype]) {
+                ext4_msg(sb, KERN_ERR,
+                        "Cannot change journaled "
+                        "quota options when quota turned on");
+                return 0;
+        }
+        qname = match_strdup(args);
+        if (!qname) {
+                ext4_msg(sb, KERN_ERR,
+                        "Not enough memory for storing quotafile name");
+                return 0;
+        }
+        if (sbi->s_qf_names[qtype] &&
+                strcmp(sbi->s_qf_names[qtype], qname)) {
+                ext4_msg(sb, KERN_ERR,
+                        "%s quota file already specified", QTYPE2NAME(qtype));
+                kfree(qname);
+                return 0;
+        }
+        sbi->s_qf_names[qtype] = qname;
+        if (strchr(sbi->s_qf_names[qtype], '/')) {
+                ext4_msg(sb, KERN_ERR,
+                        "quotafile must be on filesystem root");
+                kfree(sbi->s_qf_names[qtype]);
+                sbi->s_qf_names[qtype] = NULL;
+                return 0;
+        }
+        set_opt(sbi->s_mount_opt, QUOTA);
+        return 1;
+}
+
+static int clear_qf_name(struct super_block *sb, int qtype)
+{
+
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+        if (sb_any_quota_loaded(sb) &&
+                sbi->s_qf_names[qtype]) {
+                ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
+                        " when quota turned on");
+                return 0;
+        }
+        /*
+         * The space will be released later when all options are confirmed
+         * to be correct
+         */
+        sbi->s_qf_names[qtype] = NULL;
+        return 1;
+}
+#endif
+
 static int parse_options(char *options, struct super_block *sb,
                          unsigned long *journal_devnum,
                          unsigned int *journal_ioprio,
@@ -1217,8 +1275,7 @@ static int parse_options(char *options, struct super_block *sb,
         int data_opt = 0;
         int option;
 #ifdef CONFIG_QUOTA
-        int qtype, qfmt;
-        char *qname;
+        int qfmt;
 #endif
 
         if (!options)
@@ -1401,63 +1458,22 @@ static int parse_options(char *options, struct super_block *sb,
                         break;
 #ifdef CONFIG_QUOTA
                 case Opt_usrjquota:
-                        qtype = USRQUOTA;
-                        goto set_qf_name;
-                case Opt_grpjquota:
-                        qtype = GRPQUOTA;
-set_qf_name:
-                        if (sb_any_quota_loaded(sb) &&
-                            !sbi->s_qf_names[qtype]) {
-                                ext4_msg(sb, KERN_ERR,
-                                       "Cannot change journaled "
-                                       "quota options when quota turned on");
+                        if (!set_qf_name(sb, USRQUOTA, &args[0]))
                                 return 0;
-                        }
-                        qname = match_strdup(&args[0]);
-                        if (!qname) {
-                                ext4_msg(sb, KERN_ERR,
-                                        "Not enough memory for "
-                                        "storing quotafile name");
-                                return 0;
-                        }
-                        if (sbi->s_qf_names[qtype] &&
-                            strcmp(sbi->s_qf_names[qtype], qname)) {
-                                ext4_msg(sb, KERN_ERR,
-                                        "%s quota file already "
-                                        "specified", QTYPE2NAME(qtype));
-                                kfree(qname);
-                                return 0;
-                        }
-                        sbi->s_qf_names[qtype] = qname;
-                        if (strchr(sbi->s_qf_names[qtype], '/')) {
-                                ext4_msg(sb, KERN_ERR,
-                                        "quotafile must be on "
-                                        "filesystem root");
-                                kfree(sbi->s_qf_names[qtype]);
-                                sbi->s_qf_names[qtype] = NULL;
+                        break;
+                case Opt_grpjquota:
+                        if (!set_qf_name(sb, GRPQUOTA, &args[0]))
                                 return 0;
-                        }
-                        set_opt(sbi->s_mount_opt, QUOTA);
                         break;
                 case Opt_offusrjquota:
-                        qtype = USRQUOTA;
-                        goto clear_qf_name;
+                        if (!clear_qf_name(sb, USRQUOTA))
+                                return 0;
+                        break;
                 case Opt_offgrpjquota:
-                        qtype = GRPQUOTA;
-clear_qf_name:
-                        if (sb_any_quota_loaded(sb) &&
-                            sbi->s_qf_names[qtype]) {
-                                ext4_msg(sb, KERN_ERR, "Cannot change "
-                                        "journaled quota options when "
-                                        "quota turned on");
+                        if (!clear_qf_name(sb, GRPQUOTA))
                                 return 0;
-                        }
-                        /*
-                         * 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:
                         qfmt = QFMT_VFS_OLD;
                         goto set_qf_format;
@@ -1630,8 +1646,7 @@ set_qf_format:
                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
                         clear_opt(sbi->s_mount_opt, GRPQUOTA);
 
-                if ((sbi->s_qf_names[USRQUOTA] && test_opt(sb, GRPQUOTA)) ||
-                        (sbi->s_qf_names[GRPQUOTA] && test_opt(sb, USRQUOTA))) {
+                if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
                         ext4_msg(sb, KERN_ERR, "old and new quota "
                                         "format mixing");
                         return 0;