xfs: condense symbolic links after a mapping exchange operation

The previous commit added a new file mapping exchange flag that enables
us to perform post-exchange processing on file2 once we're done
exchanging the extent mappings.  Now add this ability for symlinks.

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online symlink repair feature can
salvage the remote target in a temporary link and exchange the data fork
mappings when ready.  If one file is in extents format and the other is
inline, we will have to promote both to extents format to perform the
exchange.  After the exchange, we can try to condense the fixed symlink
down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 7 insertions, 44 deletions

diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 3e376d24c7c1..3daeebff4bb4 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -250,19 +250,12 @@ out_release_dquots:
  */
 STATIC int
 xfs_inactive_symlink_rmt(
-	struct xfs_inode *ip)
+	struct xfs_inode	*ip)
 {
-	struct xfs_buf	*bp;
-	int		done;
-	int		error;
-	int		i;
-	xfs_mount_t	*mp;
-	xfs_bmbt_irec_t	mval[XFS_SYMLINK_MAPS];
-	int		nmaps;
-	int		size;
-	xfs_trans_t	*tp;
-
-	mp = ip->i_mount;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_trans	*tp;
+	int			error;
+
 	ASSERT(!xfs_need_iread_extents(&ip->i_df));
 	/*
 	 * We're freeing a symlink that has some
@@ -286,44 +279,14 @@ xfs_inactive_symlink_rmt(
 	 * locked for the second transaction.  In the error paths we need it
 	 * held so the cancel won't rele it, see below.
 	 */
-	size = (int)ip->i_disk_size;
 	ip->i_disk_size = 0;
 	VFS_I(ip)->i_mode = (VFS_I(ip)->i_mode & ~S_IFMT) | S_IFREG;
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-	/*
-	 * Find the block(s) so we can inval and unmap them.
-	 */
-	done = 0;
-	nmaps = ARRAY_SIZE(mval);
-	error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
-				mval, &nmaps, 0);
-	if (error)
-		goto error_trans_cancel;
-	/*
-	 * Invalidate the block(s). No validation is done.
-	 */
-	for (i = 0; i < nmaps; i++) {
-		error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
-				XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
-				XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0,
-				&bp);
-		if (error)
-			goto error_trans_cancel;
-		xfs_trans_binval(tp, bp);
-	}
-	/*
-	 * Unmap the dead block(s) to the dfops.
-	 */
-	error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps, &done);
+
+	error = xfs_symlink_remote_truncate(tp, ip);
 	if (error)
 		goto error_trans_cancel;
-	ASSERT(done);
 
-	/*
-	 * Commit the transaction. This first logs the EFI and the inode, then
-	 * rolls and commits the transaction that frees the extents.
-	 */
-	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 	error = xfs_trans_commit(tp);
 	if (error) {
 		ASSERT(xfs_is_shutdown(mp));