From 50e9ceef1d4f644ee0049e82e360058a64ec284c Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 7 Aug 2023 15:38:44 -0400 Subject: [PATCH] btrfs: convert to multigrain timestamps 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 Acked-by: David Sterba Reviewed-by: Jan Kara Message-Id: <20230807-mgctime-v7-13-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner --- 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 d7a9ece7a40b4..b9e75c9f95acf 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 f1dd172d8d5bd..8eda51b095c91 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"); -- 2.30.2