ext4: enable quota enforcement based on mount options

When quota information is stored in quota files, we enable only quota
accounting on mount and enforcement is enabled only in response to
Q_QUOTAON quotactl. To make ext4 behavior consistent with XFS, we add a
possibility to enable quota enforcement on mount by specifying
corresponding quota mount option (usrquota, grpquota, prjquota).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

2 files changed, 33 insertions, 13 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ea31931386ec..0c2bf4444548 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1117,9 +1117,15 @@ struct ext4_inode_info {
 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
-#define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
-#define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
-#define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
+#define EXT4_MOUNT_QUOTA                0x40000 /* Some quota option set */
+#define EXT4_MOUNT_USRQUOTA             0x80000 /* "old" user quota,
+                                                 * enable enforcement for hidden
+                                                 * quota files */
+#define EXT4_MOUNT_GRPQUOTA             0x100000 /* "old" group quota, enable
+                                                  * enforcement for hidden quota
+                                                  * files */
+#define EXT4_MOUNT_PRJQUOTA             0x200000 /* Enable project quota
+                                                  * enforcement */
 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3ec8708989ca..5819b0e8ff66 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1267,7 +1267,7 @@ enum {
         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
-        Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_dax,
+        Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
         Opt_lazytime, Opt_nolazytime,
         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
@@ -1327,6 +1327,7 @@ static const match_table_t tokens = {
         {Opt_noquota, "noquota"},
         {Opt_quota, "quota"},
         {Opt_usrquota, "usrquota"},
+        {Opt_prjquota, "prjquota"},
         {Opt_barrier, "barrier=%u"},
         {Opt_barrier, "barrier"},
         {Opt_nobarrier, "nobarrier"},
@@ -1546,8 +1547,11 @@ static const struct mount_opts {
                                                         MOPT_SET | MOPT_Q},
         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
                                                         MOPT_SET | MOPT_Q},
+        {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
+                                                        MOPT_SET | MOPT_Q},
         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
-                       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
+                       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
+                                                        MOPT_CLEAR | MOPT_Q},
         {Opt_usrjquota, 0, MOPT_Q},
         {Opt_grpjquota, 0, MOPT_Q},
         {Opt_offusrjquota, 0, MOPT_Q},
@@ -1836,13 +1840,17 @@ static int parse_options(char *options, struct super_block *sb,
                         return 0;
         }
 #ifdef CONFIG_QUOTA
-        if (ext4_has_feature_quota(sb) &&
-            (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
-                ext4_msg(sb, KERN_INFO, "Quota feature enabled, usrquota and grpquota "
-                         "mount options ignored.");
-                clear_opt(sb, USRQUOTA);
-                clear_opt(sb, GRPQUOTA);
-        } else if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
+        /*
+         * We do the test below only for project quotas. 'usrquota' and
+         * 'grpquota' mount options are allowed even without quota feature
+         * to support legacy quotas in quota files.
+         */
+        if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
+                ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
+                         "Cannot enable project quota enforcement.");
+                return 0;
+        }
+        if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
                         clear_opt(sb, USRQUOTA);
 
@@ -5250,12 +5258,18 @@ static int ext4_enable_quotas(struct super_block *sb)
                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
         };
+        bool quota_mopt[EXT4_MAXQUOTAS] = {
+                test_opt(sb, USRQUOTA),
+                test_opt(sb, GRPQUOTA),
+                test_opt(sb, PRJQUOTA),
+        };
 
         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
                 if (qf_inums[type]) {
                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
-                                                DQUOT_USAGE_ENABLED);
+                                DQUOT_USAGE_ENABLED |
+                                (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
                         if (err) {
                                 ext4_warning(sb,
                                         "Failed to enable quota tracking "