nilfs2: reject incompatible filesystem

This forces nilfs to check compatibility of feature flags so as to reject a filesystem with unknown features when it mounts or remounts the filesystem. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs2: reject incompatible filesystem
This forces nilfs to check compatibility of feature flags so as to reject a filesystem with unknown features when it mounts or remounts the filesystem. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Ryusuke Konishi
1 parent 1a80a1763f
Showing 3 changed files with 61 additions and 0 deletions Side-by-side Diff
fs/nilfs2/nilfs.h
fs/nilfs2/super.c
fs/nilfs2/the_nilfs.c
@@ -275,6 +275,8 @@
 nilfs_read_super_block(struct super_block *, u64, int, struct buffer_head **);
 extern int nilfs_store_magic_and_option(struct super_block *,
 					struct nilfs_super_block *, char *);
+extern int nilfs_check_feature_compatibility(struct super_block *,
+					     struct nilfs_super_block *);
 extern void nilfs_set_log_cursor(struct nilfs_super_block *,
 				 struct the_nilfs *);
 extern struct nilfs_super_block **nilfs_prepare_super(struct nilfs_sb_info *,
@@ -790,6 +790,30 @@
 	return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
 }
  
+int nilfs_check_feature_compatibility(struct super_block *sb,
+				      struct nilfs_super_block *sbp)
+{
+	__u64 features;
+
+	features = le64_to_cpu(sbp->s_feature_incompat) &
+		~NILFS_FEATURE_INCOMPAT_SUPP;
+	if (features) {
+		printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
+		       "optional features (%llx)\n",
+		       (unsigned long long)features);
+		return -EINVAL;
+	}
+	features = le64_to_cpu(sbp->s_feature_compat_ro) &
+		~NILFS_FEATURE_COMPAT_RO_SUPP;
+	if (!(sb->s_flags & MS_RDONLY) && features) {
+		printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
+		       "unsupported optional features (%llx)\n",
+		       (unsigned long long)features);
+		return -EINVAL;
+	}
+	return 0;
+}
+
 /**
  * nilfs_fill_super() - initialize a super block instance
  * @sb: super_block
  
@@ -984,11 +1008,26 @@
 		nilfs_cleanup_super(sbi);
 		up_write(&nilfs->ns_sem);
 	} else {
+		__u64 features;
+
 		/*
 		 * Mounting a RDONLY partition read-write, so reread and
 		 * store the current valid flag.  (It may have been changed
 		 * by fsck since we originally mounted the partition.)
 		 */
+		down_read(&nilfs->ns_sem);
+		features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
+			~NILFS_FEATURE_COMPAT_RO_SUPP;
+		up_read(&nilfs->ns_sem);
+		if (features) {
+			printk(KERN_WARNING "NILFS (device %s): couldn't "
+			       "remount RDWR because of unsupported optional "
+			       "features (%llx)\n",
+			       sb->s_id, (unsigned long long)features);
+			err = -EROFS;
+			goto restore_opts;
+		}
+
 		sb->s_flags &= ~MS_RDONLY;
  
 		err = nilfs_attach_segment_constructor(sbi);
@@ -385,11 +385,23 @@
 		goto skip_recovery;
  
 	if (s_flags & MS_RDONLY) {
+		__u64 features;
+
 		if (nilfs_test_opt(sbi, NORECOVERY)) {
 			printk(KERN_INFO "NILFS: norecovery option specified. "
 			       "skipping roll-forward recovery\n");
 			goto skip_recovery;
 		}
+		features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
+			~NILFS_FEATURE_COMPAT_RO_SUPP;
+		if (features) {
+			printk(KERN_ERR "NILFS: couldn't proceed with "
+			       "recovery because of unsupported optional "
+			       "features (%llx)\n",
+			       (unsigned long long)features);
+			err = -EROFS;
+			goto failed_unload;
+		}
 		if (really_read_only) {
 			printk(KERN_ERR "NILFS: write access "
 			       "unavailable, cannot proceed.\n");
@@ -644,6 +656,10 @@
 		if (err)
 			goto out;
  
+		err = nilfs_check_feature_compatibility(sb, sbp);
+		if (err)
+			goto out;
+
 		blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
 		if (sb->s_blocksize != blocksize &&
 		    !sb_set_blocksize(sb, blocksize)) {
@@ -666,6 +682,10 @@
 		goto out;
  
 	err = nilfs_store_magic_and_option(sb, sbp, data);
+	if (err)
+		goto failed_sbh;
+
+	err = nilfs_check_feature_compatibility(sb, sbp);
 	if (err)
 		goto failed_sbh;
...	...	@@ -275,6 +275,8 @@
275	275	nilfs_read_super_block(struct super_block , u64, int, struct buffer_head *);
276	276	extern int nilfs_store_magic_and_option(struct super_block *,
277	277	struct nilfs_super_block , char );
	278	+extern int nilfs_check_feature_compatibility(struct super_block *,
	279	+ struct nilfs_super_block *);
278	280	extern void nilfs_set_log_cursor(struct nilfs_super_block *,
279	281	struct the_nilfs *);
280	282	extern struct nilfs_super_block *nilfs_prepare_super(struct nilfs_sb_info ,
...	...	@@ -790,6 +790,30 @@
790	790	return !parse_options(data, sb, 0) ? -EINVAL : 0 ;
791	791	}
792	792
	793	+int nilfs_check_feature_compatibility(struct super_block *sb,
	794	+ struct nilfs_super_block *sbp)
	795	+{
	796	+ __u64 features;
	797	+
	798	+ features = le64_to_cpu(sbp->s_feature_incompat) &
	799	+ ~NILFS_FEATURE_INCOMPAT_SUPP;
	800	+ if (features) {
	801	+ printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
	802	+ "optional features (%llx)\n",
	803	+ (unsigned long long)features);
	804	+ return -EINVAL;
	805	+ }
	806	+ features = le64_to_cpu(sbp->s_feature_compat_ro) &
	807	+ ~NILFS_FEATURE_COMPAT_RO_SUPP;
	808	+ if (!(sb->s_flags & MS_RDONLY) && features) {
	809	+ printk(KERN_ERR "NILFS: couldn't mount RDWR because of "
	810	+ "unsupported optional features (%llx)\n",
	811	+ (unsigned long long)features);
	812	+ return -EINVAL;
	813	+ }
	814	+ return 0;
	815	+}
	816	+
793	817	/**
794	818	* nilfs_fill_super() - initialize a super block instance
795	819	* @sb: super_block
796	820
...	...	@@ -984,11 +1008,26 @@
984	1008	nilfs_cleanup_super(sbi);
985	1009	up_write(&nilfs->ns_sem);
986	1010	} else {
	1011	+ __u64 features;
	1012	+
987	1013	/*
988	1014	* Mounting a RDONLY partition read-write, so reread and
989	1015	* store the current valid flag. (It may have been changed
990	1016	* by fsck since we originally mounted the partition.)
991	1017	*/
	1018	+ down_read(&nilfs->ns_sem);
	1019	+ features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
	1020	+ ~NILFS_FEATURE_COMPAT_RO_SUPP;
	1021	+ up_read(&nilfs->ns_sem);
	1022	+ if (features) {
	1023	+ printk(KERN_WARNING "NILFS (device %s): couldn't "
	1024	+ "remount RDWR because of unsupported optional "
	1025	+ "features (%llx)\n",
	1026	+ sb->s_id, (unsigned long long)features);
	1027	+ err = -EROFS;
	1028	+ goto restore_opts;
	1029	+ }
	1030	+
992	1031	sb->s_flags &= ~MS_RDONLY;
993	1032
994	1033	err = nilfs_attach_segment_constructor(sbi);
...	...	@@ -385,11 +385,23 @@
385	385	goto skip_recovery;
386	386
387	387	if (s_flags & MS_RDONLY) {
	388	+ __u64 features;
	389	+
388	390	if (nilfs_test_opt(sbi, NORECOVERY)) {
389	391	printk(KERN_INFO "NILFS: norecovery option specified. "
390	392	"skipping roll-forward recovery\n");
391	393	goto skip_recovery;
392	394	}
	395	+ features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
	396	+ ~NILFS_FEATURE_COMPAT_RO_SUPP;
	397	+ if (features) {
	398	+ printk(KERN_ERR "NILFS: couldn't proceed with "
	399	+ "recovery because of unsupported optional "
	400	+ "features (%llx)\n",
	401	+ (unsigned long long)features);
	402	+ err = -EROFS;
	403	+ goto failed_unload;
	404	+ }
393	405	if (really_read_only) {
394	406	printk(KERN_ERR "NILFS: write access "
395	407	"unavailable, cannot proceed.\n");
...	...	@@ -644,6 +656,10 @@
644	656	if (err)
645	657	goto out;
646	658
	659	+ err = nilfs_check_feature_compatibility(sb, sbp);
	660	+ if (err)
	661	+ goto out;
	662	+
647	663	blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
648	664	if (sb->s_blocksize != blocksize &&
649	665	!sb_set_blocksize(sb, blocksize)) {
...	...	@@ -666,6 +682,10 @@
666	682	goto out;
667	683
668	684	err = nilfs_store_magic_and_option(sb, sbp, data);
	685	+ if (err)
	686	+ goto failed_sbh;
	687	+
	688	+ err = nilfs_check_feature_compatibility(sb, sbp);
669	689	if (err)
670	690	goto failed_sbh;
671	691