Enable multigrain timestamps, which should ensure that there is an
apparent change to the timestamp whenever it has been written after
being actively observed via getattr.
Beyond enabling the FS_MGTIME flag, this patch eliminates
update_time_for_write, which goes to great pains to avoid in-memory
stores. Just have it overwrite the timestamps unconditionally.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/btrfs/file.c | 24 ++++--------------------
fs/btrfs/super.c | 5 +++--
2 files changed, 7 insertions(+), 22 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index d7a9ece7a40b..b9e75c9f95ac 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1106,25 +1106,6 @@ void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
btrfs_drew_write_unlock(&inode->root->snapshot_lock);
}
-static void update_time_for_write(struct inode *inode)
-{
- struct timespec64 now, ctime;
-
- if (IS_NOCMTIME(inode))
- return;
-
- now = current_time(inode);
- if (!timespec64_equal(&inode->i_mtime, &now))
- inode->i_mtime = now;
-
- ctime = inode_get_ctime(inode);
- if (!timespec64_equal(&ctime, &now))
- inode_set_ctime_to_ts(inode, now);
-
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
-}
-
static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from,
size_t count)
{
@@ -1156,7 +1137,10 @@ static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from,
* need to start yet another transaction to update the inode as we will
* update the inode when we finish writing whatever data we write.
*/
- update_time_for_write(inode);
+ if (!IS_NOCMTIME(inode)) {
+ inode->i_mtime = inode_set_ctime_current(inode);
+ inode_inc_iversion(inode);
+ }
start_pos = round_down(pos, fs_info->sectorsize);
oldsize = i_size_read(inode);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f1dd172d8d5b..8eda51b095c9 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2144,7 +2144,7 @@ static struct file_system_type btrfs_fs_type = {
.name = "btrfs",
.mount = btrfs_mount,
.kill_sb = btrfs_kill_super,
- .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
+ .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_MGTIME,
};
static struct file_system_type btrfs_root_fs_type = {
@@ -2152,7 +2152,8 @@ static struct file_system_type btrfs_root_fs_type = {
.name = "btrfs",
.mount = btrfs_mount_root,
.kill_sb = btrfs_kill_super,
- .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
+ .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA |
+ FS_ALLOW_IDMAP | FS_MGTIME,
};
MODULE_ALIAS_FS("btrfs");
--
2.41.0
