xfs: make xfs_trans_get_buf return an error code

Convert xfs_trans_get_buf() to return numeric error codes like most
everywhere else in xfs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_btree.c

@@ -688,11 +688,16 @@ xfs_btree_get_bufl(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_fsblock_t	fsbno)		/* file system block number */
 {
+	struct xfs_buf		*bp;
 	xfs_daddr_t		d;		/* real disk block address */
+	int			error;
 
 	ASSERT(fsbno != NULLFSBLOCK);
 	d = XFS_FSB_TO_DADDR(mp, fsbno);
-	return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0);
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0, &bp);
+	if (error)
+		return NULL;
+	return bp;
 }
 
 /*
@@ -706,12 +711,17 @@ xfs_btree_get_bufs(
 	xfs_agnumber_t	agno,		/* allocation group number */
 	xfs_agblock_t	agbno)		/* allocation group block number */
 {
+	struct xfs_buf		*bp;
 	xfs_daddr_t		d;		/* real disk block address */
+	int			error;
 
 	ASSERT(agno != NULLAGNUMBER);
 	ASSERT(agbno != NULLAGBLOCK);
 	d = XFS_AGB_TO_DADDR(mp, agno, agbno);
-	return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0);
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0, &bp);
+	if (error)
+		return NULL;
+	return bp;
 }
 
 /*
@@ -1270,11 +1280,10 @@ xfs_btree_get_buf_block(
 	error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
 	if (error)
 		return error;
-	*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
-				 mp->m_bsize, 0);
-
-	if (!*bpp)
-		return -ENOMEM;
+	error = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize,
+			0, bpp);
+	if (error)
+		return error;
 
 	(*bpp)->b_ops = cur->bc_ops->buf_ops;
 	*block = XFS_BUF_TO_BLOCK(*bpp);

fs/xfs/libxfs/xfs_ialloc.c

@@ -276,6 +276,7 @@ xfs_ialloc_inode_init(
 	int			i, j;
 	xfs_daddr_t		d;
 	xfs_ino_t		ino = 0;
+	int			error;
 
 	/*
 	 * Loop over the new block(s), filling in the inodes.  For small block
@@ -327,12 +328,11 @@ xfs_ialloc_inode_init(
 		 */
 		d = XFS_AGB_TO_DADDR(mp, agno, agbno +
 				(j * M_IGEO(mp)->blocks_per_cluster));
-		fbuf = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
-					 mp->m_bsize *
-					 M_IGEO(mp)->blocks_per_cluster,
-					 XBF_UNMAPPED);
-		if (!fbuf)
-			return -ENOMEM;
+		error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
+				mp->m_bsize * M_IGEO(mp)->blocks_per_cluster,
+				XBF_UNMAPPED, &fbuf);
+		if (error)
+			return error;
 
 		/* Initialize the inode buffers and log them appropriately. */
 		fbuf->b_ops = &xfs_inode_buf_ops;

fs/xfs/libxfs/xfs_sb.c

@@ -1185,13 +1185,14 @@ xfs_sb_get_secondary(
 	struct xfs_buf		**bpp)
 {
 	struct xfs_buf		*bp;
+	int			error;
 
 	ASSERT(agno != 0 && agno != NULLAGNUMBER);
-	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
 			XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
-			XFS_FSS_TO_BB(mp, 1), 0);
-	if (!bp)
-		return -ENOMEM;
+			XFS_FSS_TO_BB(mp, 1), 0, &bp);
+	if (error)
+		return error;
 	bp->b_ops = &xfs_sb_buf_ops;
 	xfs_buf_oneshot(bp);
 	*bpp = bp;

fs/xfs/scrub/repair.c

@@ -341,13 +341,17 @@ xrep_init_btblock(
 	struct xfs_trans		*tp = sc->tp;
 	struct xfs_mount		*mp = sc->mp;
 	struct xfs_buf			*bp;
+	int				error;
 
 	trace_xrep_init_btblock(mp, XFS_FSB_TO_AGNO(mp, fsb),
 			XFS_FSB_TO_AGBNO(mp, fsb), btnum);
 
 	ASSERT(XFS_FSB_TO_AGNO(mp, fsb) == sc->sa.agno);
-	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, fsb),
-			XFS_FSB_TO_BB(mp, 1), 0);
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+			XFS_FSB_TO_DADDR(mp, fsb), XFS_FSB_TO_BB(mp, 1), 0,
+			&bp);
+	if (error)
+		return error;
 	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
 	xfs_btree_init_block(mp, bp, btnum, 0, 0, sc->sa.agno);
 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_BTREE_BUF);

fs/xfs/xfs_attr_inactive.c

@@ -205,11 +205,12 @@ xfs_attr3_node_inactive(
 		/*
 		 * Remove the subsidiary block from the cache and from the log.
 		 */
-		child_bp = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
+		error = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
 				child_blkno,
-				XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0);
-		if (!child_bp)
-			return -EIO;
+				XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0,
+				&child_bp);
+		if (error)
+			return error;
 		error = bp->b_error;
 		if (error) {
 			xfs_trans_brelse(*trans, child_bp);
@@ -298,10 +299,10 @@ xfs_attr3_root_inactive(
 	/*
 	 * Invalidate the incore copy of the root block.
 	 */
-	bp = xfs_trans_get_buf(*trans, mp->m_ddev_targp, blkno,
-			XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0);
-	if (!bp)
-		return -EIO;
+	error = xfs_trans_get_buf(*trans, mp->m_ddev_targp, blkno,
+			XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0, &bp);
+	if (error)
+		return error;
 	error = bp->b_error;
 	if (error) {
 		xfs_trans_brelse(*trans, bp);

fs/xfs/xfs_dquot.c

@@ -320,10 +320,10 @@ xfs_dquot_disk_alloc(
 	dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 
 	/* now we can just get the buffer (there's nothing to read yet) */
-	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, dqp->q_blkno,
-			mp->m_quotainfo->qi_dqchunklen, 0);
-	if (!bp)
-		return -ENOMEM;
+	error = xfs_trans_get_buf(tp, mp->m_ddev_targp, dqp->q_blkno,
+			mp->m_quotainfo->qi_dqchunklen, 0, &bp);
+	if (error)
+		return error;
 	bp->b_ops = &xfs_dquot_buf_ops;
 
 	/*

fs/xfs/xfs_inode.c

@@ -2546,6 +2546,7 @@ xfs_ifree_cluster(
 	struct xfs_perag	*pag;
 	struct xfs_ino_geometry	*igeo = M_IGEO(mp);
 	xfs_ino_t		inum;
+	int			error;
 
 	inum = xic->first_ino;
 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
@@ -2574,12 +2575,11 @@ xfs_ifree_cluster(
 		 * complete before we get a lock on it, and hence we may fail
 		 * to mark all the active inodes on the buffer stale.
 		 */
-		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
-					mp->m_bsize * igeo->blocks_per_cluster,
-					XBF_UNMAPPED);
-
-		if (!bp)
-			return -ENOMEM;
+		error = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
+				mp->m_bsize * igeo->blocks_per_cluster,
+				XBF_UNMAPPED, &bp);
+		if (error)
+			return error;
 
 		/*
 		 * This buffer may not have been correctly initialised as we

fs/xfs/xfs_rtalloc.c

@@ -826,12 +826,10 @@ xfs_growfs_rt_alloc(
 			 * Get a buffer for the block.
 			 */
 			d = XFS_FSB_TO_DADDR(mp, fsbno);
-			bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
-				mp->m_bsize, 0);
-			if (bp == NULL) {
-				error = -EIO;
+			error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
+					mp->m_bsize, 0, &bp);
+			if (error)
 				goto out_trans_cancel;
-			}
 			memset(bp->b_addr, 0, mp->m_sb.sb_blocksize);
 			xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 			/*

fs/xfs/xfs_symlink.c

@@ -280,12 +280,10 @@ xfs_symlink(
 
 			d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
 			byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
-			bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
-					       BTOBB(byte_cnt), 0);
-			if (!bp) {
-				error = -ENOMEM;
+			error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
+					       BTOBB(byte_cnt), 0, &bp);
+			if (error)
 				goto out_trans_cancel;
-			}
 			bp->b_ops = &xfs_symlink_buf_ops;
 
 			byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
@@ -423,13 +421,12 @@ xfs_inactive_symlink_rmt(
 	 * Invalidate the block(s). No validation is done.
 	 */
 	for (i = 0; i < nmaps; i++) {
-		bp = 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);
-		if (!bp) {
-			error = -ENOMEM;
+		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);
 	}
 	/*

fs/xfs/xfs_trans.h

@@ -173,22 +173,17 @@ int xfs_trans_get_buf_map(struct xfs_trans *tp, struct xfs_buftarg *target,
 		struct xfs_buf_map *map, int nmaps, xfs_buf_flags_t flags,
 		struct xfs_buf **bpp);
 
-static inline struct xfs_buf *
+static inline int
 xfs_trans_get_buf(
 	struct xfs_trans	*tp,
 	struct xfs_buftarg	*target,
 	xfs_daddr_t		blkno,
 	int			numblks,
-	uint			flags)
+	uint			flags,
+	struct xfs_buf		**bpp)
 {
-	struct xfs_buf		*bp;
-	int			error;
-
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
-	error = xfs_trans_get_buf_map(tp, target, &map, 1, flags, &bp);
-	if (error)
-		return NULL;
-	return bp;
+	return xfs_trans_get_buf_map(tp, target, &map, 1, flags, bpp);
 }
 
 int		xfs_trans_read_buf_map(struct xfs_mount *mp,