Revert "btrfs: convert to multigrain timestamps"

This reverts commit 50e9ceef1d4f644ee0049e82e360058a64ec284c.

Users reported regressions due to enabling multi-grained timestamps
unconditionally. As no clear consensus on a solution has come up and the
discussion has gone back to the drawing board revert the infrastructure
changes for. If it isn't code that's here to stay, make it go away.

Message-ID: <20230920-keine-eile-c9755b5825db@brauner>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ca46a52..ad6f401 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1106,6 +1106,25 @@ 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)
 {
@@ -1137,10 +1156,7 @@ 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.
         */
-       if (!IS_NOCMTIME(inode)) {
-               inode->i_mtime = inode_set_ctime_current(inode);
-               inode_inc_iversion(inode);
-       }
+       update_time_for_write(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 09bfe68..cffdd6f 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2150,7 +2150,7 @@ 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_MGTIME,
+       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
 };
 
 static struct file_system_type btrfs_root_fs_type = {
@@ -2158,8 +2158,7 @@ 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_MGTIME,
+       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
 };
 
 MODULE_ALIAS_FS("btrfs");