From: Amir Goldstein <amir73il@xxxxxxxxxxxx>
Enable readwrite mount of filesystem with has_snapshot feature only
if ext4 was compiled with snapshot support.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxxxxx>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@xxxxxxxxx>
---
fs/ext4/ext4.h | 1 +
fs/ext4/super.c | 10 ++++++++++
2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 92d75c2..633a835 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1483,6 +1483,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
EXT4_FEATURE_INCOMPAT_FLEX_BG)
#define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT| \
EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7f15983..9a81828 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2693,6 +2693,16 @@ static int ext4_feature_set_ok(struct super_block *sb, int readonly)
"must run fsck -xy to make it writable.");
return 0;
}
+ } else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT)) {
+ /*
+ * We get here when CONFIG_EXT4_FS_SNAPSHOT is not defined
+ * so EXT4_SNAPSHOTS(sb) is defined to (0)
+ */
+ ext4_msg(sb, KERN_ERR,
+ "Filesystem with has_snapshot feature cannot be "
+ "mounted RDWR without CONFIG_EXT4_FS_SNAPSHOT");
+ return 0;
}
return 1;
}
--
1.7.4.1
--
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