[PATCH 08/14] xfs: make xfs_buf_get_uncached return an error code

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

Source kernel commit: 2842b6db3d539bec08d080b22635b6e8acaa30ec

Convert xfs_buf_get_uncached() 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>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 libxfs/libxfs_io.h        |    4 ++--
 libxfs/rdwr.c             |    8 +++++---
 libxfs/xfs_ag.c           |   21 ++++++++++++---------
 libxlog/xfs_log_recover.c |    7 +++++--
 mkfs/xfs_mkfs.c           |    8 +++++++-
 5 files changed, 31 insertions(+), 17 deletions(-)


diff --git a/libxfs/libxfs_io.h b/libxfs/libxfs_io.h
index 064587a6..6fbf976b 100644
--- a/libxfs/libxfs_io.h
+++ b/libxfs/libxfs_io.h
@@ -256,8 +256,8 @@ xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t len)
 	return 0;
 }
 
-struct xfs_buf *libxfs_buf_get_uncached(struct xfs_buftarg *targ, size_t bblen,
-		int flags);
+int libxfs_buf_get_uncached(struct xfs_buftarg *targ, size_t bblen, int flags,
+		struct xfs_buf **bpp);
 int libxfs_buf_read_uncached(struct xfs_buftarg *targ, xfs_daddr_t daddr,
 		size_t bblen, int flags, struct xfs_buf **bpp,
 		const struct xfs_buf_ops *ops);
diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
index a05e0fee..0bfe46f3 100644
--- a/libxfs/rdwr.c
+++ b/libxfs/rdwr.c
@@ -1128,13 +1128,15 @@ libxfs_getbufr_uncached(
  * Allocate an uncached buffer that points nowhere.  The refcount will be 1,
  * and the cache node hash list will be empty to indicate that it's uncached.
  */
-struct xfs_buf *
+int
 libxfs_buf_get_uncached(
 	struct xfs_buftarg	*targ,
 	size_t			bblen,
-	int			flags)
+	int			flags,
+	struct xfs_buf		**bpp)
 {
-	return libxfs_getbufr_uncached(targ, XFS_BUF_DADDR_NULL, bblen);
+	*bpp = libxfs_getbufr_uncached(targ, XFS_BUF_DADDR_NULL, bblen);
+	return *bpp != NULL ? 0 : -ENOMEM;
 }
 
 /*
diff --git a/libxfs/xfs_ag.c b/libxfs/xfs_ag.c
index 5bf6975d..73fb30cb 100644
--- a/libxfs/xfs_ag.c
+++ b/libxfs/xfs_ag.c
@@ -23,25 +23,28 @@
 #include "xfs_ag_resv.h"
 #include "xfs_health.h"
 
-static struct xfs_buf *
+static int
 xfs_get_aghdr_buf(
 	struct xfs_mount	*mp,
 	xfs_daddr_t		blkno,
 	size_t			numblks,
+	struct xfs_buf		**bpp,
 	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
+	int			error;
 
-	bp = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, 0);
-	if (!bp)
-		return NULL;
+	error = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, 0, &bp);
+	if (error)
+		return error;
 
 	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
 	bp->b_bn = blkno;
 	bp->b_maps[0].bm_bn = blkno;
 	bp->b_ops = ops;
 
-	return bp;
+	*bpp = bp;
+	return 0;
 }
 
 static inline bool is_log_ag(struct xfs_mount *mp, struct aghdr_init_data *id)
@@ -340,13 +343,13 @@ xfs_ag_init_hdr(
 	struct aghdr_init_data	*id,
 	aghdr_init_work_f	work,
 	const struct xfs_buf_ops *ops)
-
 {
 	struct xfs_buf		*bp;
+	int			error;
 
-	bp = xfs_get_aghdr_buf(mp, id->daddr, id->numblks, ops);
-	if (!bp)
-		return -ENOMEM;
+	error = xfs_get_aghdr_buf(mp, id->daddr, id->numblks, &bp, ops);
+	if (error)
+		return error;
 
 	(*work)(mp, bp, id);
 
diff --git a/libxlog/xfs_log_recover.c b/libxlog/xfs_log_recover.c
index e7e57bd2..78fbafab 100644
--- a/libxlog/xfs_log_recover.c
+++ b/libxlog/xfs_log_recover.c
@@ -35,11 +35,13 @@ xlog_buf_bbcount_valid(
  * to map to a range of nbblks basic blocks at any valid (basic
  * block) offset within the log.
  */
-xfs_buf_t *
+struct xfs_buf *
 xlog_get_bp(
 	struct xlog	*log,
 	int		nbblks)
 {
+	struct xfs_buf	*bp;
+
 	if (!xlog_buf_bbcount_valid(log, nbblks)) {
 		xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",
 			nbblks);
@@ -67,7 +69,8 @@ xlog_get_bp(
 		nbblks += log->l_sectBBsize;
 	nbblks = round_up(nbblks, log->l_sectBBsize);
 
-	return libxfs_buf_get_uncached(log->l_dev, nbblks, 0);
+	libxfs_buf_get_uncached(log->l_dev, nbblks, 0, &bp);
+	return bp;
 }
 
 /*
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index b50b8b3a..e6b44575 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -3404,8 +3404,14 @@ get_write_buf(
 	int			bblen)
 {
 	struct xfs_buf		*bp;
+	int			error;
 
-	bp = libxfs_buf_get_uncached(btp, bblen, 0);
+	error = -libxfs_buf_get_uncached(btp, bblen, 0, &bp);
+	if (error) {
+		fprintf(stderr, _("Could not get memory for buffer, err=%d\n"),
+				error);
+		exit(1);
+	}
 	bp->b_bn = daddr;
 	bp->b_maps[0].bm_bn = daddr;
 	return bp;