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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-07-22 03:22:20 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2010-07-23 10:02:16 +0900
commitc5ca48aabe8b11674bf1102abe52d17ecc053f9c (patch)
tree18c7647b42981d457c59cd4a842ca342a239770d /fs/nilfs2/super.c
parent1a80a1763fb760b3a84a28df87515f7cdc07a4f4 (diff)
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>
Diffstat (limited to 'fs/nilfs2/super.c')
-rw-r--r--fs/nilfs2/super.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 164457316df..26078b3407c 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);