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> Acked-by: David Sterba <dsterba@xxxxxxxx> --- 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