xfs: push down inactive transaction mgmt for remote symlinks

Push down the transaction management for remote symlinks from
xfs_inactive() down to xfs_inactive_symlink_rmt(). The latter is
cleaned up to avoid transaction management intended for the
calling context (i.e., trans duplication, reservation, item
attachment).

Signed-off-by: Brian Foster <[e-mail]>
Reviewed-by: Dave Chinner <[e-mail]>
Signed-off-by: Ben Myers <[e-mail]>

fs/xfs/xfs_inode.c

···
 	if (error)
 		return VN_INACTIVE_CACHE;
 
+	if (S_ISLNK(ip->i_d.di_mode)) {
+		error = xfs_inactive_symlink(ip);
+		if (error)
+			goto out;
+	}
+
 	tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
-	resp = (truncate || S_ISLNK(ip->i_d.di_mode)) ?
-		&M_RES(mp)->tr_itruncate : &M_RES(mp)->tr_ifree;
+	resp = truncate ? &M_RES(mp)->tr_itruncate : &M_RES(mp)->tr_ifree;
 
 	error = xfs_trans_reserve(tp, resp, 0, 0);
 	if (error) {
···
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	if (S_ISLNK(ip->i_d.di_mode)) {
-		error = xfs_inactive_symlink(ip, &tp);
-		if (error)
-			goto out_cancel;
-	} else if (truncate) {
+	if (truncate) {
 		ip->i_d.di_size = 0;
 		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 

fs/xfs/xfs_symlink.c

···
  */
 STATIC int
 xfs_inactive_symlink_rmt(
-	xfs_inode_t	*ip,
-	xfs_trans_t	**tpp)
+	struct xfs_inode *ip)
 {
 	xfs_buf_t	*bp;
 	int		committed;
···
 	xfs_mount_t	*mp;
 	xfs_bmbt_irec_t	mval[XFS_SYMLINK_MAPS];
 	int		nmaps;
-	xfs_trans_t	*ntp;
 	int		size;
 	xfs_trans_t	*tp;
 
-	tp = *tpp;
 	mp = ip->i_mount;
 	ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
 	/*
···
 	 * free them all in one bunmapi call.
 	 */
 	ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
+
+	tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
+	if (error) {
+		xfs_trans_cancel(tp, 0);
+		return error;
+	}
+
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	xfs_trans_ijoin(tp, ip, 0);
 
 	/*
 	 * Lock the inode, fix the size, and join it to the transaction.
···
 	error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
 				mval, &nmaps, 0);
 	if (error)
-		goto error0;
+		goto error_trans_cancel;
 	/*
 	 * Invalidate the block(s). No validation is done.
 	 */
···
 			XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
 		if (!bp) {
 			error = ENOMEM;
-			goto error1;
+			goto error_bmap_cancel;
 		}
 		xfs_trans_binval(tp, bp);
 	}
 	/*
 	 * Unmap the dead block(s) to the free_list.
 	 */
-	if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
-			&first_block, &free_list, &done)))
-		goto error1;
+	error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
+			    &first_block, &free_list, &done);
+	if (error)
+		goto error_bmap_cancel;
 	ASSERT(done);
 	/*
 	 * Commit the first transaction.  This logs the EFI and the inode.
 	 */
-	if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
-		goto error1;
+	error = xfs_bmap_finish(&tp, &free_list, &committed);
+	if (error)
+		goto error_bmap_cancel;
 	/*
 	 * The transaction must have been committed, since there were
 	 * actually extents freed by xfs_bunmapi.  See xfs_bmap_finish.
···
 	xfs_trans_ijoin(tp, ip, 0);
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 	/*
-	 * Get a new, empty transaction to return to our caller.
-	 */
-	ntp = xfs_trans_dup(tp);
-	/*
 	 * Commit the transaction containing extent freeing and EFDs.
-	 * If we get an error on the commit here or on the reserve below,
-	 * we need to unlock the inode since the new transaction doesn't
-	 * have the inode attached.
 	 */
-	error = xfs_trans_commit(tp, 0);
-	tp = ntp;
+	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 	if (error) {
 		ASSERT(XFS_FORCED_SHUTDOWN(mp));
-		goto error0;
+		goto error_unlock;
 	}
-	/*
-	 * transaction commit worked ok so we can drop the extra ticket
-	 * reference that we gained in xfs_trans_dup()
-	 */
-	xfs_log_ticket_put(tp->t_ticket);
 
 	/*
 	 * Remove the memory for extent descriptions (just bookkeeping).
···
 	if (ip->i_df.if_bytes)
 		xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
 	ASSERT(ip->i_df.if_bytes == 0);
-	/*
-	 * Put an itruncate log reservation in the new transaction
-	 * for our caller.
-	 */
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
-	if (error) {
-		ASSERT(XFS_FORCED_SHUTDOWN(mp));
-		goto error0;
-	}
 
-	xfs_trans_ijoin(tp, ip, 0);
-	*tpp = tp;
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	return 0;
 
- error1:
+error_bmap_cancel:
 	xfs_bmap_cancel(&free_list);
- error0:
+error_trans_cancel:
+	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+error_unlock:
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	return error;
 }
 
···
  */
 int
 xfs_inactive_symlink(
-	struct xfs_inode	*ip,
-	struct xfs_trans	**tp)
+	struct xfs_inode	*ip)
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	int			pathlen;
 
 	trace_xfs_inactive_symlink(ip);
 
-	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-
 	if (XFS_FORCED_SHUTDOWN(mp))
 		return XFS_ERROR(EIO);
+
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
 
 	/*
 	 * Zero length symlinks _can_ exist.
 	 */
 	pathlen = (int)ip->i_d.di_size;
-	if (!pathlen)
+	if (!pathlen) {
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 		return 0;
+	}
 
 	if (pathlen < 0 || pathlen > MAXPATHLEN) {
 		xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
 			 __func__, (unsigned long long)ip->i_ino, pathlen);
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 		ASSERT(0);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 
 	if (ip->i_df.if_flags & XFS_IFINLINE) {
-		if (ip->i_df.if_bytes > 0)
+		if (ip->i_df.if_bytes > 0) 
 			xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
 					  XFS_DATA_FORK);
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 		ASSERT(ip->i_df.if_bytes == 0);
 		return 0;
 	}
 
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
 	/* remove the remote symlink */
-	return xfs_inactive_symlink_rmt(ip, tp);
+	return xfs_inactive_symlink_rmt(ip);
 }

fs/xfs/xfs_symlink.h

···
 int xfs_symlink(struct xfs_inode *dp, struct xfs_name *link_name,
 		const char *target_path, umode_t mode, struct xfs_inode **ipp);
 int xfs_readlink(struct xfs_inode *ip, char *link);
-int xfs_inactive_symlink(struct xfs_inode *ip, struct xfs_trans **tpp);
+int xfs_inactive_symlink(struct xfs_inode *ip);
 
 #endif /* __XFS_SYMLINK_H */