f2fs: checkpoint disabling
Note that, it requires "f2fs: return correct errno in f2fs_gc".
This adds a lightweight non-persistent snapshotting scheme to f2fs.
To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5b6c420..f947f57 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -212,7 +212,8 @@
};
unsigned int seq_id = 0;
- if (unlikely(f2fs_readonly(inode->i_sb)))
+ if (unlikely(f2fs_readonly(inode->i_sb) ||
+ is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
return 0;
trace_f2fs_sync_file_enter(inode);
@@ -2153,6 +2154,12 @@
if (f2fs_readonly(sbi->sb))
return -EROFS;
+ if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
+ f2fs_msg(sbi->sb, KERN_INFO,
+ "Skipping Checkpoint. Checkpoints currently disabled.");
+ return -EINVAL;
+ }
+
ret = mnt_want_write_file(filp);
if (ret)
return ret;
@@ -2524,6 +2531,9 @@
if (f2fs_readonly(sbi->sb))
return -EROFS;
+ if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
+ return -EINVAL;
+
if (copy_from_user(&range, (struct f2fs_flush_device __user *)arg,
sizeof(range)))
return -EFAULT;