[XFS] Only use refcounted pages for I/O

Many block drivers (aoe, iscsi) really want refcountable pages in bios,
which is what almost everyone send down. XFS unfortunately has a few
places where it sends down buffers that may come from kmalloc, which
breaks them.

Fix the places that use kmalloc()d buffers.

SGI-PV: 964546
SGI-Modid: xfs-linux-melb:xfs-kern:28562a

Signed-Off-By: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index c48bf61..635f99e 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1199,11 +1199,18 @@
 		*iclogp = (xlog_in_core_t *)
 			  kmem_zalloc(sizeof(xlog_in_core_t), KM_SLEEP);
 		iclog = *iclogp;
-		iclog->hic_data = (xlog_in_core_2_t *)
-			  kmem_zalloc(iclogsize, KM_SLEEP | KM_LARGE);
-
 		iclog->ic_prev = prev_iclog;
 		prev_iclog = iclog;
+
+		bp = xfs_buf_get_noaddr(log->l_iclog_size, mp->m_logdev_targp);
+		if (!XFS_BUF_CPSEMA(bp))
+			ASSERT(0);
+		XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
+		XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);
+		XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
+		iclog->ic_bp = bp;
+		iclog->hic_data = bp->b_addr;
+
 		log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);
 
 		head = &iclog->ic_header;
@@ -1216,11 +1223,6 @@
 		INT_SET(head->h_fmt, ARCH_CONVERT, XLOG_FMT);
 		memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
 
-		bp = xfs_buf_get_empty(log->l_iclog_size, mp->m_logdev_targp);
-		XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
-		XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);
-		XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
-		iclog->ic_bp = bp;
 
 		iclog->ic_size = XFS_BUF_SIZE(bp) - log->l_iclog_hsize;
 		iclog->ic_state = XLOG_STATE_ACTIVE;
@@ -1528,7 +1530,6 @@
 		}
 #endif
 		next_iclog = iclog->ic_next;
-		kmem_free(iclog->hic_data, log->l_iclog_size);
 		kmem_free(iclog, sizeof(xlog_in_core_t));
 		iclog = next_iclog;
 	}