btrfs: set inode flag BTRFS_INODE_COPY_EVERYTHING when logging new name

[ Upstream commit 953902e4fb4c373c81a977f78e40f9f93a79e20f ]

If we are logging a new name make sure our inode has the runtime flag
BTRFS_INODE_COPY_EVERYTHING set so that at btrfs_log_inode() we will find
new inode refs/extrefs in the subvolume tree and copy them into the log
tree.

We are currently doing it when adding a new link but we are missing it
when renaming.

An example where this makes a new name not persisted:

  1) create symlink with name foo in directory A
  2) fsync directory A, which persists the symlink
  3) rename the symlink from foo to bar
  4) fsync directory A to persist the new symlink name

Step 4 isn't working correctly as it's not logging the new name and also
leaving the old inode ref in the log tree, so after a power failure the
symlink still has the old name of "foo". This is because when we first
fsync directoy A we log the symlink's inode (as it's a new entry) and at
btrfs_log_inode() we set the log mode to LOG_INODE_ALL and then because
we are using that mode and the inode has the runtime flag
BTRFS_INODE_NEEDS_FULL_SYNC set, we clear that flag as well as the flag
BTRFS_INODE_COPY_EVERYTHING. That means the next time we log the inode,
during the rename through the call to btrfs_log_new_name() (calling
btrfs_log_inode_parent() and then btrfs_log_inode()), we will not search
the subvolume tree for new refs/extrefs and jump directory to the
'log_extents' label.

Fix this by making sure we set BTRFS_INODE_COPY_EVERYTHING on an inode
when we are about to log a new name. A test case for fstests will follow
soon.

Reported-by: Vyacheslav Kovalevsky <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Reviewed-by: Boris Burkov <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

Author: fdmanana

fs/btrfs/inode.c

@@ -6850,7 +6850,6 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 	BTRFS_I(inode)->dir_index = 0ULL;
 	inode_inc_iversion(inode);
 	inode_set_ctime_current(inode);
-	set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
 
 	ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
 			     &fname.disk_name, 1, index);

fs/btrfs/tree-log.c

@@ -7608,6 +7608,9 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	bool log_pinned = false;
 	int ret;
 
+	/* The inode has a new name (ref/extref), so make sure we log it. */
+	set_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
+
 	btrfs_init_log_ctx(&ctx, inode);
 	ctx.logging_new_name = true;