[XFS] Revert to using a separate inode for metadata buffers once more.

SGI Modid: xfs-linux:xfs-kern:174253a
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/linux-2.6/xfs_buf.c

@@ -1484,6 +1484,7 @@ xfs_free_buftarg(
 	xfs_flush_buftarg(btp, 1);
 	if (external)
 		xfs_blkdev_put(btp->pbr_bdev);
+	iput(btp->pbr_mapping->host);
 	kmem_free(btp, sizeof(*btp));
 }
 
@@ -1497,7 +1498,7 @@ xfs_incore_relse(
 	truncate_inode_pages(btp->pbr_mapping, 0LL);
 }
 
-void
+int
 xfs_setsize_buftarg(
 	xfs_buftarg_t		*btp,
 	unsigned int		blocksize,
@@ -1511,7 +1512,38 @@ xfs_setsize_buftarg(
 		printk(KERN_WARNING
 			"XFS: Cannot set_blocksize to %u on device %s\n",
 			sectorsize, XFS_BUFTARG_NAME(btp));
+		return EINVAL;
 	}
+	return 0;
+}
+
+STATIC int
+xfs_mapping_buftarg(
+	xfs_buftarg_t		*btp,
+	struct block_device	*bdev)
+{
+	struct inode		*inode;
+	struct address_space	*mapping;
+	struct backing_dev_info	*bdi;
+
+	inode = new_inode(bdev->bd_inode->i_sb);
+	if (!inode) {
+		printk(KERN_WARNING
+			"XFS: Cannot allocate mapping inode for device %s\n",
+			XFS_BUFTARG_NAME(btp));
+		return ENOMEM;
+	}
+	inode->i_mode = S_IFBLK;
+	inode->i_bdev = bdev;
+	inode->i_rdev = bdev->bd_dev;
+	mapping = &inode->i_data;
+	bdi = blk_get_backing_dev_info(bdev);
+	if (!bdi)
+		bdi = &default_backing_dev_info;
+	mapping->backing_dev_info = bdi;
+	mapping_set_gfp_mask(mapping, GFP_KERNEL);
+	btp->pbr_mapping = mapping;
+	return 0;
 }
 
 xfs_buftarg_t *
@@ -1524,10 +1556,15 @@ xfs_alloc_buftarg(
 
 	btp->pbr_dev =  bdev->bd_dev;
 	btp->pbr_bdev = bdev;
-	btp->pbr_mapping = bdev->bd_inode->i_mapping;
-	xfs_setsize_buftarg(btp, PAGE_CACHE_SIZE, bdev_hardsect_size(bdev));
-
+	if (xfs_setsize_buftarg(btp, PAGE_CACHE_SIZE, bdev_hardsect_size(bdev)))
+		goto error;
+	if (xfs_mapping_buftarg(btp, bdev))
+		goto error;
 	return btp;
+
+error:
+	kmem_free(btp, sizeof(*btp));
+	return NULL;
 }
 
 

fs/xfs/linux-2.6/xfs_buf.h

@@ -566,7 +566,7 @@ static inline int xfs_bdwrite(void *mp, xfs_buf_t *bp)
 
 extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *);
 extern void xfs_free_buftarg(xfs_buftarg_t *, int);
-extern void xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
+extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
 extern void xfs_incore_relse(xfs_buftarg_t *, int, int);
 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
 

fs/xfs/xfs_vfsops.c

@@ -430,6 +430,16 @@ xfs_mount(
 	ddev = vfsp->vfs_super->s_bdev;
 	logdev = rtdev = NULL;
 
+	/*
+	 * Setup xfs_mount function vectors from available behaviors
+	 */
+	p = vfs_bhv_lookup(vfsp, VFS_POSITION_DM);
+	mp->m_dm_ops = p ? *(xfs_dmops_t *) vfs_bhv_custom(p) : xfs_dmcore_stub;
+	p = vfs_bhv_lookup(vfsp, VFS_POSITION_QM);
+	mp->m_qm_ops = p ? *(xfs_qmops_t *) vfs_bhv_custom(p) : xfs_qmcore_stub;
+	p = vfs_bhv_lookup(vfsp, VFS_POSITION_IO);
+	mp->m_io_ops = p ? *(xfs_ioops_t *) vfs_bhv_custom(p) : xfs_iocore_xfs;
+
 	/*
 	 * Open real time and log devices - order is important.
 	 */
@@ -454,69 +464,74 @@ xfs_mount(
 		}
 	}
 
-	/*
-	 * Setup xfs_mount function vectors from available behaviors
-	 */
-	p = vfs_bhv_lookup(vfsp, VFS_POSITION_DM);
-	mp->m_dm_ops = p ? *(xfs_dmops_t *) vfs_bhv_custom(p) : xfs_dmcore_stub;
-	p = vfs_bhv_lookup(vfsp, VFS_POSITION_QM);
-	mp->m_qm_ops = p ? *(xfs_qmops_t *) vfs_bhv_custom(p) : xfs_qmcore_stub;
-	p = vfs_bhv_lookup(vfsp, VFS_POSITION_IO);
-	mp->m_io_ops = p ? *(xfs_ioops_t *) vfs_bhv_custom(p) : xfs_iocore_xfs;
-
 	/*
 	 * Setup xfs_mount buffer target pointers
 	 */
+	error = ENOMEM;
 	mp->m_ddev_targp = xfs_alloc_buftarg(ddev);
-	if (rtdev)
+	if (!mp->m_ddev_targp) {
+		xfs_blkdev_put(logdev);
+		xfs_blkdev_put(rtdev);
+		return error;
+	}
+	if (rtdev) {
 		mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev);
+		if (!mp->m_rtdev_targp)
+			goto error0;
+	}
 	mp->m_logdev_targp = (logdev && logdev != ddev) ?
 				xfs_alloc_buftarg(logdev) : mp->m_ddev_targp;
+	if (!mp->m_logdev_targp)
+		goto error0;
 
 	/*
 	 * Setup flags based on mount(2) options and then the superblock
 	 */
 	error = xfs_start_flags(vfsp, args, mp);
 	if (error)
-		goto error;
+		goto error1;
 	error = xfs_readsb(mp);
 	if (error)
-		goto error;
+		goto error1;
 	error = xfs_finish_flags(vfsp, args, mp);
-	if (error) {
-		xfs_freesb(mp);
-		goto error;
-	}
+	if (error)
+		goto error2;
 
 	/*
 	 * Setup xfs_mount buffer target pointers based on superblock
 	 */
-	xfs_setsize_buftarg(mp->m_ddev_targp, mp->m_sb.sb_blocksize,
-			    mp->m_sb.sb_sectsize);
-	if (logdev && logdev != ddev) {
+	error = xfs_setsize_buftarg(mp->m_ddev_targp, mp->m_sb.sb_blocksize,
+				    mp->m_sb.sb_sectsize);
+	if (!error && logdev && logdev != ddev) {
 		unsigned int	log_sector_size = BBSIZE;
 
 		if (XFS_SB_VERSION_HASSECTOR(&mp->m_sb))
 			log_sector_size = mp->m_sb.sb_logsectsize;
-		xfs_setsize_buftarg(mp->m_logdev_targp, mp->m_sb.sb_blocksize,
-				    log_sector_size);
+		error = xfs_setsize_buftarg(mp->m_logdev_targp,
+					    mp->m_sb.sb_blocksize,
+					    log_sector_size);
 	}
-	if (rtdev)
-		xfs_setsize_buftarg(mp->m_rtdev_targp, mp->m_sb.sb_blocksize,
-				    mp->m_sb.sb_blocksize);
+	if (!error && rtdev)
+		error = xfs_setsize_buftarg(mp->m_rtdev_targp,
+					    mp->m_sb.sb_blocksize,
+					    mp->m_sb.sb_sectsize);
+	if (error)
+		goto error2;
 
-	if (!(error = XFS_IOINIT(vfsp, args, flags)))
+	error = XFS_IOINIT(vfsp, args, flags);
+	if (!error)
 		return 0;
-
- error:
+error2:
+	if (mp->m_sb_bp)
+		xfs_freesb(mp);
+error1:
 	xfs_binval(mp->m_ddev_targp);
-	if (logdev != NULL && logdev != ddev) {
+	if (logdev && logdev != ddev)
 		xfs_binval(mp->m_logdev_targp);
-	}
-	if (rtdev != NULL) {
+	if (rtdev)
 		xfs_binval(mp->m_rtdev_targp);
-	}
-	xfs_unmountfs_close(mp, NULL);
+error0:
+	xfs_unmountfs_close(mp, credp);
 	return error;
 }