[v7,06/39] btrfs: disallow NODATACOW in ZONED mode

Commit Message

Naohiro Aota Sept. 11, 2020, 12:32 p.m. UTC

NODATACOW implies overwriting the file data on a device, which is
impossible in sequential required zones. Disable NODATACOW globally with
mount option and per-file NODATACOW attribute by masking FS_NOCOW_FL.

Reviewed-by: Johannes Thumshirn <[e-mail]>
Reviewed-by: Josef Bacik <[e-mail]>
Signed-off-by: Naohiro Aota <[e-mail]>
---
 fs/btrfs/ioctl.c | 3 +++
 fs/btrfs/zoned.c | 6 ++++++
 2 files changed, 9 insertions(+)

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ac45f022b495..548692cdc5df 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -91,6 +91,9 @@  struct btrfs_ioctl_send_args_32 {
 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
 		unsigned int flags)
 {
+	if (btrfs_fs_incompat(btrfs_sb(inode->i_sb), ZONED))
+		flags &= ~FS_NOCOW_FL;
+
 	if (S_ISDIR(inode->i_mode))
 		return flags;
 	else if (S_ISREG(inode->i_mode))
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 1629e585ba8c..6bce654bb0e8 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -284,5 +284,11 @@  int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info)
 		return -EOPNOTSUPP;
 	}
 
+	if (btrfs_test_opt(info, NODATACOW)) {
+		btrfs_err(info,
+		  "cannot enable nodatacow with ZONED mode");
+		return -EOPNOTSUPP;
+	}
+
 	return 0;
 }