This forces nilfs to check compatibility of feature flags when it
mounts or remounts the filesystem so that it rejects the filesystem
with unknown features.
Signed-off-by: Ryusuke Konishi <konishi.ryus...@lab.ntt.co.jp>
---
fs/nilfs2/nilfs.h | 2 ++
fs/nilfs2/super.c | 39 +++++++++++++++++++++++++++++++++++++++
fs/nilfs2/the_nilfs.c | 8 ++++++++
3 files changed, 49 insertions(+), 0 deletions(-)
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index cfedc48..0842d77 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -275,6 +275,8 @@ extern struct nilfs_super_block *
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 *,
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 1644573..26078b3 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -790,6 +790,30 @@ int nilfs_store_magic_and_option(struct super_block *sb,
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 @@ static int nilfs_remount(struct super_block *sb, int
*flags, char *data)
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);
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index f2efc8c..45d58f0 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -644,6 +644,10 @@ int init_nilfs(struct the_nilfs *nilfs, struct
nilfs_sb_info *sbi, char *data)
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)) {
@@ -669,6 +673,10 @@ int init_nilfs(struct the_nilfs *nilfs, struct
nilfs_sb_info *sbi, char *data)
if (err)
goto failed_sbh;
+ err = nilfs_check_feature_compatibility(sb, sbp);
+ if (err)
+ goto failed_sbh;
+
blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
if (sb->s_blocksize != blocksize) {
int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
--
1.6.6.2
--
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