Merge remote-tracking branch 'xfs/for-next'

19 files changed, 290 insertions, 325 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 4bffffe038a1..eff34218f405 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2209,6 +2209,10 @@ xfs_agf_verify(
 	      be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
 		return false;
 
+	if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS ||
+	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
+		return false;
+
 	/*
 	 * during growfs operations, the perag is not fully initialised,
 	 * so we can't use it for any useful checking. growfs ensures we can't
diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
index 6cef22152fd6..7075aaf131f4 100644
--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -237,7 +237,8 @@ xfs_dir_init(
 }
 
 /*
-  Enter a name in a directory.
+ * Enter a name in a directory, or check for available space.
+ * If inum is 0, only the available space test is performed.
  */
 int
 xfs_dir_createname(
@@ -254,10 +255,12 @@ xfs_dir_createname(
 	int			v;		/* type-checking value */
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
-	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
-	if (rval)
-		return rval;
-	XFS_STATS_INC(xs_dir_create);
+	if (inum) {
+		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
+		if (rval)
+			return rval;
+		XFS_STATS_INC(xs_dir_create);
+	}
 
 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
 	if (!args)
@@ -276,6 +279,8 @@ xfs_dir_createname(
 	args->whichfork = XFS_DATA_FORK;
 	args->trans = tp;
 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
+	if (!inum)
+		args->op_flags |= XFS_DA_OP_JUSTCHECK;
 
 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
 		rval = xfs_dir2_sf_addname(args);
@@ -535,62 +540,14 @@ out_free:
 
 /*
  * See if this entry can be added to the directory without allocating space.
- * First checks that the caller couldn't reserve enough space (resblks = 0).
  */
 int
 xfs_dir_canenter(
 	xfs_trans_t	*tp,
 	xfs_inode_t	*dp,
-	struct xfs_name	*name,		/* name of entry to add */
-	uint		resblks)
+	struct xfs_name	*name)		/* name of entry to add */
 {
-	struct xfs_da_args *args;
-	int		rval;
-	int		v;		/* type-checking value */
-
-	if (resblks)
-		return 0;
-
-	ASSERT(S_ISDIR(dp->i_d.di_mode));
-
-	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
-	if (!args)
-		return -ENOMEM;
-
-	args->geo = dp->i_mount->m_dir_geo;
-	args->name = name->name;
-	args->namelen = name->len;
-	args->filetype = name->type;
-	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args->dp = dp;
-	args->whichfork = XFS_DATA_FORK;
-	args->trans = tp;
-	args->op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
-							XFS_DA_OP_OKNOENT;
-
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
-		rval = xfs_dir2_sf_addname(args);
-		goto out_free;
-	}
-
-	rval = xfs_dir2_isblock(args, &v);
-	if (rval)
-		goto out_free;
-	if (v) {
-		rval = xfs_dir2_block_addname(args);
-		goto out_free;
-	}
-
-	rval = xfs_dir2_isleaf(args, &v);
-	if (rval)
-		goto out_free;
-	if (v)
-		rval = xfs_dir2_leaf_addname(args);
-	else
-		rval = xfs_dir2_node_addname(args);
-out_free:
-	kmem_free(args);
-	return rval;
+	return xfs_dir_createname(tp, dp, name, 0, NULL, NULL, 0);
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index c8e86b0b5e99..4dff261e6ed5 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -136,7 +136,7 @@ extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
 				xfs_fsblock_t *first,
 				struct xfs_bmap_free *flist, xfs_extlen_t tot);
 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
-				struct xfs_name *name, uint resblks);
+				struct xfs_name *name);
 
 /*
  * Direct call from the bmap code, bypassing the generic directory layer.
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index b62771f1f4b5..d213a2eae95e 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -2051,6 +2051,8 @@ xfs_agi_verify(
 	if (!XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)))
 		return false;
 
+	if (be32_to_cpu(agi->agi_level) > XFS_BTREE_MAXLEVELS)
+		return false;
 	/*
 	 * during growfs operations, the perag is not fully initialised,
 	 * so we can't use it for any useful checking. growfs ensures we can't
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index f4dd697cac08..7c818f1e4484 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -424,20 +424,24 @@ xfs_rtfind_forw(
 }
 
 /*
- * Read and modify the summary information for a given extent size,
+ * Read and/or modify the summary information for a given extent size,
  * bitmap block combination.
  * Keeps track of a current summary block, so we don't keep reading
  * it from the buffer cache.
+ *
+ * Summary information is returned in *sum if specified.
+ * If no delta is specified, returns summary only.
  */
 int
-xfs_rtmodify_summary(
-	xfs_mount_t	*mp,		/* file system mount point */
+xfs_rtmodify_summary_int(
+	xfs_mount_t	*mp,		/* file system mount structure */
 	xfs_trans_t	*tp,		/* transaction pointer */
 	int		log,		/* log2 of extent size */
 	xfs_rtblock_t	bbno,		/* bitmap block number */
 	int		delta,		/* change to make to summary info */
 	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
+	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	xfs_suminfo_t	*sum)		/* out: summary info for this block */
 {
 	xfs_buf_t	*bp;		/* buffer for the summary block */
 	int		error;		/* error value */
@@ -456,7 +460,7 @@ xfs_rtmodify_summary(
 	/*
 	 * If we have an old buffer, and the block number matches, use that.
 	 */
-	if (rbpp && *rbpp && *rsb == sb)
+	if (*rbpp && *rsb == sb)
 		bp = *rbpp;
 	/*
 	 * Otherwise we have to get the buffer.
@@ -465,7 +469,7 @@ xfs_rtmodify_summary(
 		/*
 		 * If there was an old one, get rid of it first.
 		 */
-		if (rbpp && *rbpp)
+		if (*rbpp)
 			xfs_trans_brelse(tp, *rbpp);
 		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
 		if (error) {
@@ -474,21 +478,38 @@ xfs_rtmodify_summary(
 		/*
 		 * Remember this buffer and block for the next call.
 		 */
-		if (rbpp) {
-			*rbpp = bp;
-			*rsb = sb;
-		}
+		*rbpp = bp;
+		*rsb = sb;
 	}
 	/*
-	 * Point to the summary information, modify and log it.
+	 * Point to the summary information, modify/log it, and/or copy it out.
 	 */
 	sp = XFS_SUMPTR(mp, bp, so);
-	*sp += delta;
-	xfs_trans_log_buf(tp, bp, (uint)((char *)sp - (char *)bp->b_addr),
-		(uint)((char *)sp - (char *)bp->b_addr + sizeof(*sp) - 1));
+	if (delta) {
+		uint first = (uint)((char *)sp - (char *)bp->b_addr);
+
+		*sp += delta;
+		xfs_trans_log_buf(tp, bp, first, first + sizeof(*sp) - 1);
+	}
+	if (sum)
+		*sum = *sp;
 	return 0;
 }
 
+int
+xfs_rtmodify_summary(
+	xfs_mount_t	*mp,		/* file system mount structure */
+	xfs_trans_t	*tp,		/* transaction pointer */
+	int		log,		/* log2 of extent size */
+	xfs_rtblock_t	bbno,		/* bitmap block number */
+	int		delta,		/* change to make to summary info */
+	xfs_buf_t	**rbpp,		/* in/out: summary block buffer */
+	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
+{
+	return xfs_rtmodify_summary_int(mp, tp, log, bbno,
+					delta, rbpp, rsb, NULL);
+}
+
 /*
  * Set the given range of bitmap bits to the given value.
  * Do whatever I/O and logging is required.
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index ad525a5623a4..8426e5e2682e 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -279,11 +279,13 @@ xfs_mount_validate_sb(
 	    sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG			||
 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
 	    sbp->sb_blocksize != (1 << sbp->sb_blocklog)		||
+	    sbp->sb_dirblklog > XFS_MAX_BLOCKSIZE_LOG			||
 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
 	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
 	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
 	    sbp->sb_inodesize != (1 << sbp->sb_inodelog)		||
+	    sbp->sb_logsunit > XLOG_MAX_RECORD_BSIZE			||
 	    sbp->sb_inopblock != howmany(sbp->sb_blocksize,sbp->sb_inodesize) ||
 	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index cd7b8ca9b064..ec6505056b2c 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1884,7 +1884,7 @@ xfs_buf_init(void)
 		goto out;
 
 	xfslogd_workqueue = alloc_workqueue("xfslogd",
-					WQ_MEM_RECLAIM | WQ_HIGHPRI, 1);
+				WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_FREEZABLE, 1);
 	if (!xfslogd_workqueue)
 		goto out_free_buf_zone;
 
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index de5368c803f9..eb596b419942 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -983,7 +983,7 @@ xfs_vm_page_mkwrite(
 
 /*
  * This type is designed to indicate the type of offset we would like
- * to search from page cache for either xfs_seek_data() or xfs_seek_hole().
+ * to search from page cache for xfs_seek_hole_data().
  */
 enum {
 	HOLE_OFF = 0,
@@ -1040,7 +1040,7 @@ xfs_lookup_buffer_offset(
 /*
  * This routine is called to find out and return a data or hole offset
  * from the page cache for unwritten extents according to the desired
- * type for xfs_seek_data() or xfs_seek_hole().
+ * type for xfs_seek_hole_data().
  *
  * The argument offset is used to tell where we start to search from the
  * page cache.  Map is used to figure out the end points of the range to
@@ -1200,9 +1200,10 @@ out:
 }
 
 STATIC loff_t
-xfs_seek_data(
+xfs_seek_hole_data(
 	struct file		*file,
-	loff_t			start)
+	loff_t			start,
+	int			whence)
 {
 	struct inode		*inode = file->f_mapping->host;
 	struct xfs_inode	*ip = XFS_I(inode);
@@ -1214,6 +1215,9 @@ xfs_seek_data(
 	uint			lock;
 	int			error;
 
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
 	lock = xfs_ilock_data_map_shared(ip);
 
 	isize = i_size_read(inode);
@@ -1228,6 +1232,7 @@ xfs_seek_data(
 	 */
 	fsbno = XFS_B_TO_FSBT(mp, start);
 	end = XFS_B_TO_FSB(mp, isize);
+
 	for (;;) {
 		struct xfs_bmbt_irec	map[2];
 		int			nmap = 2;
@@ -1248,29 +1253,48 @@ xfs_seek_data(
 			offset = max_t(loff_t, start,
 				       XFS_FSB_TO_B(mp, map[i].br_startoff));
 
-			/* Landed in a data extent */
-			if (map[i].br_startblock == DELAYSTARTBLOCK ||
-			    (map[i].br_state == XFS_EXT_NORM &&
-			     !isnullstartblock(map[i].br_startblock)))
+			/* Landed in the hole we wanted? */
+			if (whence == SEEK_HOLE &&
+			    map[i].br_startblock == HOLESTARTBLOCK)
+				goto out;
+
+			/* Landed in the data extent we wanted? */
+			if (whence == SEEK_DATA &&
+			    (map[i].br_startblock == DELAYSTARTBLOCK ||
+			     (map[i].br_state == XFS_EXT_NORM &&
+			      !isnullstartblock(map[i].br_startblock))))
 				goto out;
 
 			/*
-			 * Landed in an unwritten extent, try to search data
-			 * from page cache.
+			 * Landed in an unwritten extent, try to search
+			 * for hole or data from page cache.
 			 */
 			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
 				if (xfs_find_get_desired_pgoff(inode, &map[i],
-							DATA_OFF, &offset))
+				      whence == SEEK_HOLE ? HOLE_OFF : DATA_OFF,
+							&offset))
 					goto out;
 			}
 		}
 
 		/*
-		 * map[0] is hole or its an unwritten extent but
-		 * without data in page cache.  Probably means that
-		 * we are reading after EOF if nothing in map[1].
+		 * We only received one extent out of the two requested. This
+		 * means we've hit EOF and didn't find what we are looking for.
 		 */
 		if (nmap == 1) {
+			/*
+			 * If we were looking for a hole, set offset to
+			 * the end of the file (i.e., there is an implicit
+			 * hole at the end of any file).
+		 	 */
+			if (whence == SEEK_HOLE) {
+				offset = isize;
+				break;
+			}
+			/*
+			 * If we were looking for data, it's nowhere to be found
+			 */
+			ASSERT(whence == SEEK_DATA);
 			error = -ENXIO;
 			goto out_unlock;
 		}
@@ -1279,125 +1303,30 @@ xfs_seek_data(
 
 		/*
 		 * Nothing was found, proceed to the next round of search
-		 * if reading offset not beyond or hit EOF.
+		 * if the next reading offset is not at or beyond EOF.
 		 */
 		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
 		start = XFS_FSB_TO_B(mp, fsbno);
 		if (start >= isize) {
+			if (whence == SEEK_HOLE) {
+				offset = isize;
+				break;
+			}
+			ASSERT(whence == SEEK_DATA);
 			error = -ENXIO;
 			goto out_unlock;
 		}
 	}
 
 out:
-	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
-
-out_unlock:
-	xfs_iunlock(ip, lock);
-
-	if (error)
-		return error;
-	return offset;
-}
-
-STATIC loff_t
-xfs_seek_hole(
-	struct file		*file,
-	loff_t			start)
-{
-	struct inode		*inode = file->f_mapping->host;
-	struct xfs_inode	*ip = XFS_I(inode);
-	struct xfs_mount	*mp = ip->i_mount;
-	loff_t			uninitialized_var(offset);
-	xfs_fsize_t		isize;
-	xfs_fileoff_t		fsbno;
-	xfs_filblks_t		end;
-	uint			lock;
-	int			error;
-
-	if (XFS_FORCED_SHUTDOWN(mp))
-		return -EIO;
-
-	lock = xfs_ilock_data_map_shared(ip);
-
-	isize = i_size_read(inode);
-	if (start >= isize) {
-		error = -ENXIO;
-		goto out_unlock;
-	}
-
-	fsbno = XFS_B_TO_FSBT(mp, start);
-	end = XFS_B_TO_FSB(mp, isize);
-
-	for (;;) {
-		struct xfs_bmbt_irec	map[2];
-		int			nmap = 2;
-		unsigned int		i;
-
-		error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
-				       XFS_BMAPI_ENTIRE);
-		if (error)
-			goto out_unlock;
-
-		/* No extents at given offset, must be beyond EOF */
-		if (nmap == 0) {
-			error = -ENXIO;
-			goto out_unlock;
-		}
-
-		for (i = 0; i < nmap; i++) {
-			offset = max_t(loff_t, start,
-				       XFS_FSB_TO_B(mp, map[i].br_startoff));
-
-			/* Landed in a hole */
-			if (map[i].br_startblock == HOLESTARTBLOCK)
-				goto out;
-
-			/*
-			 * Landed in an unwritten extent, try to search hole
-			 * from page cache.
-			 */
-			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
-				if (xfs_find_get_desired_pgoff(inode, &map[i],
-							HOLE_OFF, &offset))
-					goto out;
-			}
-		}
-
-		/*
-		 * map[0] contains data or its unwritten but contains
-		 * data in page cache, probably means that we are
-		 * reading after EOF.  We should fix offset to point
-		 * to the end of the file(i.e., there is an implicit
-		 * hole at the end of any file).
-		 */
-		if (nmap == 1) {
-			offset = isize;
-			break;
-		}
-
-		ASSERT(i > 1);
-
-		/*
-		 * Both mappings contains data, proceed to the next round of
-		 * search if the current reading offset not beyond or hit EOF.
-		 */
-		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
-		start = XFS_FSB_TO_B(mp, fsbno);
-		if (start >= isize) {
-			offset = isize;
-			break;
-		}
-	}
-
-out:
 	/*
-	 * At this point, we must have found a hole.  However, the returned
+	 * If at this point we have found the hole we wanted, the returned
 	 * offset may be bigger than the file size as it may be aligned to
-	 * page boundary for unwritten extents, we need to deal with this
+	 * page boundary for unwritten extents.  We need to deal with this
 	 * situation in particular.
 	 */
-	offset = min_t(loff_t, offset, isize);
+	if (whence == SEEK_HOLE)
+		offset = min_t(loff_t, offset, isize);
 	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
 
 out_unlock:
@@ -1412,17 +1341,16 @@ STATIC loff_t
 xfs_file_llseek(
 	struct file	*file,
 	loff_t		offset,
-	int		origin)
+	int		whence)
 {
-	switch (origin) {
+	switch (whence) {
 	case SEEK_END:
 	case SEEK_CUR:
 	case SEEK_SET:
-		return generic_file_llseek(file, offset, origin);
-	case SEEK_DATA:
-		return xfs_seek_data(file, offset);
+		return generic_file_llseek(file, offset, whence);
 	case SEEK_HOLE:
-		return xfs_seek_hole(file, offset);
+	case SEEK_DATA:
+		return xfs_seek_hole_data(file, offset, whence);
 	default:
 		return -EINVAL;
 	}
diff --git a/fs/xfs/xfs_globals.c b/fs/xfs/xfs_globals.c
index 5399ef222dd7..4d41b241298f 100644
--- a/fs/xfs/xfs_globals.c
+++ b/fs/xfs/xfs_globals.c
@@ -43,3 +43,7 @@ xfs_param_t xfs_params = {
 	.fstrm_timer	= {	1,		30*100,		3600*100},
 	.eofb_timer	= {	1,		300,		3600*24},
 };
+
+struct xfs_globals xfs_globals = {
+	.log_recovery_delay	=	0,	/* no delay by default */
+};
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index fea3c92fb3f0..c92cb48617d1 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1153,9 +1153,11 @@ xfs_create(
 	if (error)
 		goto out_trans_cancel;
 
-	error = xfs_dir_canenter(tp, dp, name, resblks);
-	if (error)
-		goto out_trans_cancel;
+	if (!resblks) {
+		error = xfs_dir_canenter(tp, dp, name);
+		if (error)
+			goto out_trans_cancel;
+	}
 
 	/*
 	 * A newly created regular or special file just has one directory
@@ -1421,9 +1423,11 @@ xfs_link(
 		goto error_return;
 	}
 
-	error = xfs_dir_canenter(tp, tdp, target_name, resblks);
-	if (error)
-		goto error_return;
+	if (!resblks) {
+		error = xfs_dir_canenter(tp, tdp, target_name);
+		if (error)
+			goto error_return;
+	}
 
 	xfs_bmap_init(&free_list, &first_block);
 
@@ -2759,9 +2763,11 @@ xfs_rename(
 		 * If there's no space reservation, check the entry will
 		 * fit before actually inserting it.
 		 */
-		error = xfs_dir_canenter(tp, target_dp, target_name, spaceres);
-		if (error)
-			goto error_return;
+		if (!spaceres) {
+			error = xfs_dir_canenter(tp, target_dp, target_name);
+			if (error)
+				goto error_return;
+		}
 		/*
 		 * If target does not exist and the rename crosses
 		 * directories, adjust the target directory link count
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 1fd5787add99..29e101fc32c5 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -4132,41 +4132,13 @@ xlog_do_recovery_pass(
 	}
 
 	memset(rhash, 0, sizeof(rhash));
-	if (tail_blk <= head_blk) {
-		for (blk_no = tail_blk; blk_no < head_blk; ) {
-			error = xlog_bread(log, blk_no, hblks, hbp, &offset);
-			if (error)
-				goto bread_err2;
-
-			rhead = (xlog_rec_header_t *)offset;
-			error = xlog_valid_rec_header(log, rhead, blk_no);
-			if (error)
-				goto bread_err2;
-
-			/* blocks in data section */
-			bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
-			error = xlog_bread(log, blk_no + hblks, bblks, dbp,
-					   &offset);
-			if (error)
-				goto bread_err2;
-
-			error = xlog_unpack_data(rhead, offset, log);
-			if (error)
-				goto bread_err2;
-
-			error = xlog_recover_process_data(log,
-						rhash, rhead, offset, pass);
-			if (error)
-				goto bread_err2;
-			blk_no += bblks + hblks;
-		}
-	} else {
+	blk_no = tail_blk;
+	if (tail_blk > head_blk) {
 		/*
 		 * Perform recovery around the end of the physical log.
 		 * When the head is not on the same cycle number as the tail,
-		 * we can't do a sequential recovery as above.
+		 * we can't do a sequential recovery.
 		 */
-		blk_no = tail_blk;
 		while (blk_no < log->l_logBBsize) {
 			/*
 			 * Check for header wrapping around physical end-of-log
@@ -4280,34 +4252,35 @@ xlog_do_recovery_pass(
 
 		ASSERT(blk_no >= log->l_logBBsize);
 		blk_no -= log->l_logBBsize;
+	}
 
-		/* read first part of physical log */
-		while (blk_no < head_blk) {
-			error = xlog_bread(log, blk_no, hblks, hbp, &offset);
-			if (error)
-				goto bread_err2;
+	/* read first part of physical log */
+	while (blk_no < head_blk) {
+		error = xlog_bread(log, blk_no, hblks, hbp, &offset);
+		if (error)
+			goto bread_err2;
 
-			rhead = (xlog_rec_header_t *)offset;
-			error = xlog_valid_rec_header(log, rhead, blk_no);
-			if (error)
-				goto bread_err2;
+		rhead = (xlog_rec_header_t *)offset;
+		error = xlog_valid_rec_header(log, rhead, blk_no);
+		if (error)
+			goto bread_err2;
 
-			bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
-			error = xlog_bread(log, blk_no+hblks, bblks, dbp,
-					   &offset);
-			if (error)
-				goto bread_err2;
+		/* blocks in data section */
+		bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
+		error = xlog_bread(log, blk_no+hblks, bblks, dbp,
+				   &offset);
+		if (error)
+			goto bread_err2;
 
-			error = xlog_unpack_data(rhead, offset, log);
-			if (error)
-				goto bread_err2;
+		error = xlog_unpack_data(rhead, offset, log);
+		if (error)
+			goto bread_err2;
 
-			error = xlog_recover_process_data(log, rhash,
-							rhead, offset, pass);
-			if (error)
-				goto bread_err2;
-			blk_no += bblks + hblks;
-		}
+		error = xlog_recover_process_data(log, rhash,
+						rhead, offset, pass);
+		if (error)
+			goto bread_err2;
+		blk_no += bblks + hblks;
 	}
 
  bread_err2:
@@ -4509,6 +4482,18 @@ xlog_recover(
 			return -EINVAL;
 		}
 
+		/*
+		 * Delay log recovery if the debug hook is set. This is debug
+		 * instrumention to coordinate simulation of I/O failures with
+		 * log recovery.
+		 */
+		if (xfs_globals.log_recovery_delay) {
+			xfs_notice(log->l_mp,
+				"Delaying log recovery for %d seconds.",
+				xfs_globals.log_recovery_delay);
+			msleep(xfs_globals.log_recovery_delay * 1000);
+		}
+
 		xfs_notice(log->l_mp, "Starting recovery (logdev: %s)",
 				log->l_mp->m_logname ? log->l_mp->m_logname
 						     : "internal");
diff --git a/fs/xfs/xfs_mru_cache.c b/fs/xfs/xfs_mru_cache.c
index 1eb6f3df698c..30ecca3037e3 100644
--- a/fs/xfs/xfs_mru_cache.c
+++ b/fs/xfs/xfs_mru_cache.c
@@ -304,7 +304,8 @@ _xfs_mru_cache_reap(
 int
 xfs_mru_cache_init(void)
 {
-	xfs_mru_reap_wq = alloc_workqueue("xfs_mru_cache", WQ_MEM_RECLAIM, 1);
+	xfs_mru_reap_wq = alloc_workqueue("xfs_mru_cache",
+				WQ_MEM_RECLAIM|WQ_FREEZABLE, 1);
 	if (!xfs_mru_reap_wq)
 		return -ENOMEM;
 	return 0;
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 909e143b87ae..d1160cce5dad 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -46,7 +46,7 @@
  * Keeps track of a current summary block, so we don't keep reading
  * it from the buffer cache.
  */
-STATIC int				/* error */
+int
 xfs_rtget_summary(
 	xfs_mount_t	*mp,		/* file system mount structure */
 	xfs_trans_t	*tp,		/* transaction pointer */
@@ -56,60 +56,9 @@ xfs_rtget_summary(
 	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 	xfs_suminfo_t	*sum)		/* out: summary info for this block */
 {
-	xfs_buf_t	*bp;		/* buffer for summary block */
-	int		error;		/* error value */
-	xfs_fsblock_t	sb;		/* summary fsblock */
-	int		so;		/* index into the summary file */
-	xfs_suminfo_t	*sp;		/* pointer to returned data */
-
-	/*
-	 * Compute entry number in the summary file.
-	 */
-	so = XFS_SUMOFFS(mp, log, bbno);
-	/*
-	 * Compute the block number in the summary file.
-	 */
-	sb = XFS_SUMOFFSTOBLOCK(mp, so);
-	/*
-	 * If we have an old buffer, and the block number matches, use that.
-	 */
-	if (rbpp && *rbpp && *rsb == sb)
-		bp = *rbpp;
-	/*
-	 * Otherwise we have to get the buffer.
-	 */
-	else {
-		/*
-		 * If there was an old one, get rid of it first.
-		 */
-		if (rbpp && *rbpp)
-			xfs_trans_brelse(tp, *rbpp);
-		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
-		if (error) {
-			return error;
-		}
-		/*
-		 * Remember this buffer and block for the next call.
-		 */
-		if (rbpp) {
-			*rbpp = bp;
-			*rsb = sb;
-		}
-	}
-	/*
-	 * Point to the summary information & copy it out.
-	 */
-	sp = XFS_SUMPTR(mp, bp, so);
-	*sum = *sp;
-	/*
-	 * Drop the buffer if we're not asked to remember it.
-	 */
-	if (!rbpp)
-		xfs_trans_brelse(tp, bp);
-	return 0;
+	return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rbpp, rsb, sum);
 }
 
-
 /*
  * Return whether there are any free extents in the size range given
  * by low and high, for the bitmap block bbno.
diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index c642795324af..76c0a4a9bb17 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -111,6 +111,10 @@ int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
 		    xfs_rtblock_t *rtblock);
 int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
 		       xfs_rtblock_t start, xfs_extlen_t len, int val);
+int xfs_rtmodify_summary_int(struct xfs_mount *mp, struct xfs_trans *tp,
+			     int log, xfs_rtblock_t bbno, int delta,
+			     xfs_buf_t **rbpp, xfs_fsblock_t *rsb,
+			     xfs_suminfo_t *sum);
 int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
 			 xfs_rtblock_t bbno, int delta, xfs_buf_t **rbpp,
 			 xfs_fsblock_t *rsb);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index b194652033cd..dcd4b93dccdc 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -47,6 +47,7 @@
 #include "xfs_dinode.h"
 #include "xfs_filestream.h"
 #include "xfs_quota.h"
+#include "xfs_sysfs.h"
 
 #include <linux/namei.h>
 #include <linux/init.h>
@@ -61,7 +62,11 @@
 static const struct super_operations xfs_super_operations;
 static kmem_zone_t *xfs_ioend_zone;
 mempool_t *xfs_ioend_pool;
-struct kset *xfs_kset;
+
+struct kset *xfs_kset;			/* top-level xfs sysfs dir */
+#ifdef DEBUG
+static struct xfs_kobj xfs_dbg_kobj;	/* global debug sysfs attrs */
+#endif
 
 #define MNTOPT_LOGBUFS	"logbufs"	/* number of XFS log buffers */
 #define MNTOPT_LOGBSIZE	"logbsize"	/* size of XFS log buffers */
@@ -838,32 +843,32 @@ xfs_init_mount_workqueues(
 	struct xfs_mount	*mp)
 {
 	mp->m_data_workqueue = alloc_workqueue("xfs-data/%s",
-			WQ_MEM_RECLAIM, 0, mp->m_fsname);
+			WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_data_workqueue)
 		goto out;
 
 	mp->m_unwritten_workqueue = alloc_workqueue("xfs-conv/%s",
-			WQ_MEM_RECLAIM, 0, mp->m_fsname);
+			WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_unwritten_workqueue)
 		goto out_destroy_data_iodone_queue;
 
 	mp->m_cil_workqueue = alloc_workqueue("xfs-cil/%s",
-			WQ_MEM_RECLAIM, 0, mp->m_fsname);
+			WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_cil_workqueue)
 		goto out_destroy_unwritten;
 
 	mp->m_reclaim_workqueue = alloc_workqueue("xfs-reclaim/%s",
-			0, 0, mp->m_fsname);
+			WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_reclaim_workqueue)
 		goto out_destroy_cil;
 
 	mp->m_log_workqueue = alloc_workqueue("xfs-log/%s",
-			0, 0, mp->m_fsname);
+			WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_log_workqueue)
 		goto out_destroy_reclaim;
 
 	mp->m_eofblocks_workqueue = alloc_workqueue("xfs-eofblocks/%s",
-			0, 0, mp->m_fsname);
+			WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_eofblocks_workqueue)
 		goto out_destroy_log;
 
@@ -1715,7 +1720,8 @@ xfs_init_workqueues(void)
 	 * AGs in all the filesystems mounted. Hence use the default large
 	 * max_active value for this workqueue.
 	 */
-	xfs_alloc_wq = alloc_workqueue("xfsalloc", WQ_MEM_RECLAIM, 0);
+	xfs_alloc_wq = alloc_workqueue("xfsalloc",
+			WQ_MEM_RECLAIM|WQ_FREEZABLE, 0);
 	if (!xfs_alloc_wq)
 		return -ENOMEM;
 
@@ -1768,9 +1774,16 @@ init_xfs_fs(void)
 		goto out_sysctl_unregister;;
 	}
 
-	error = xfs_qm_init();
+#ifdef DEBUG
+	xfs_dbg_kobj.kobject.kset = xfs_kset;
+	error = xfs_sysfs_init(&xfs_dbg_kobj, &xfs_dbg_ktype, NULL, "debug");
 	if (error)
 		goto out_kset_unregister;
+#endif
+
+	error = xfs_qm_init();
+	if (error)
+		goto out_remove_kobj;
 
 	error = register_filesystem(&xfs_fs_type);
 	if (error)
@@ -1779,7 +1792,11 @@ init_xfs_fs(void)
 
  out_qm_exit:
 	xfs_qm_exit();
+ out_remove_kobj:
+#ifdef DEBUG
+	xfs_sysfs_del(&xfs_dbg_kobj);
  out_kset_unregister:
+#endif
 	kset_unregister(xfs_kset);
  out_sysctl_unregister:
 	xfs_sysctl_unregister();
@@ -1802,6 +1819,9 @@ exit_xfs_fs(void)
 {
 	xfs_qm_exit();
 	unregister_filesystem(&xfs_fs_type);
+#ifdef DEBUG
+	xfs_sysfs_del(&xfs_dbg_kobj);
+#endif
 	kset_unregister(xfs_kset);
 	xfs_sysctl_unregister();
 	xfs_cleanup_procfs();
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 6a944a2cd36f..02ae62a998e0 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -269,9 +269,11 @@ xfs_symlink(
 	/*
 	 * Check for ability to enter directory entry, if no space reserved.
 	 */
-	error = xfs_dir_canenter(tp, dp, link_name, resblks);
-	if (error)
-		goto error_return;
+	if (!resblks) {
+		error = xfs_dir_canenter(tp, dp, link_name);
+		if (error)
+			goto error_return;
+	}
 	/*
 	 * Initialize the bmap freelist prior to calling either
 	 * bmapi or the directory create code.
diff --git a/fs/xfs/xfs_sysctl.h b/fs/xfs/xfs_sysctl.h
index bd8e157c20ef..ffef45375754 100644
--- a/fs/xfs/xfs_sysctl.h
+++ b/fs/xfs/xfs_sysctl.h
@@ -92,6 +92,11 @@ enum {
 
 extern xfs_param_t	xfs_params;
 
+struct xfs_globals {
+	int	log_recovery_delay;	/* log recovery delay (secs) */
+};
+extern struct xfs_globals	xfs_globals;
+
 #ifdef CONFIG_SYSCTL
 extern int xfs_sysctl_register(void);
 extern void xfs_sysctl_unregister(void);
diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c
index 9835139ce1ec..aa03670851d8 100644
--- a/fs/xfs/xfs_sysfs.c
+++ b/fs/xfs/xfs_sysfs.c
@@ -51,6 +51,80 @@ struct kobj_type xfs_mp_ktype = {
 	.release = xfs_sysfs_release,
 };
 
+#ifdef DEBUG
+/* debug */
+
+STATIC ssize_t
+log_recovery_delay_store(
+	const char	*buf,
+	size_t		count,
+	void		*data)
+{
+	int		ret;
+	int		val;
+
+	ret = kstrtoint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val < 0 || val > 60)
+		return -EINVAL;
+
+	xfs_globals.log_recovery_delay = val;
+
+	return count;
+}
+
+STATIC ssize_t
+log_recovery_delay_show(
+	char	*buf,
+	void	*data)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.log_recovery_delay);
+}
+XFS_SYSFS_ATTR_RW(log_recovery_delay);
+
+static struct attribute *xfs_dbg_attrs[] = {
+	ATTR_LIST(log_recovery_delay),
+	NULL,
+};
+
+STATIC ssize_t
+xfs_dbg_show(
+	struct kobject		*kobject,
+	struct attribute	*attr,
+	char			*buf)
+{
+	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
+
+	return xfs_attr->show ? xfs_attr->show(buf, NULL) : 0;
+}
+
+STATIC ssize_t
+xfs_dbg_store(
+	struct kobject		*kobject,
+	struct attribute	*attr,
+	const char		*buf,
+	size_t			count)
+{
+	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
+
+	return xfs_attr->store ? xfs_attr->store(buf, count, NULL) : 0;
+}
+
+static struct sysfs_ops xfs_dbg_ops = {
+	.show = xfs_dbg_show,
+	.store = xfs_dbg_store,
+};
+
+struct kobj_type xfs_dbg_ktype = {
+	.release = xfs_sysfs_release,
+	.sysfs_ops = &xfs_dbg_ops,
+	.default_attrs = xfs_dbg_attrs,
+};
+
+#endif /* DEBUG */
+
 /* xlog */
 
 STATIC ssize_t
diff --git a/fs/xfs/xfs_sysfs.h b/fs/xfs/xfs_sysfs.h
index 54a2091183c0..240eee35f342 100644
--- a/fs/xfs/xfs_sysfs.h
+++ b/fs/xfs/xfs_sysfs.h
@@ -20,6 +20,7 @@
 #define __XFS_SYSFS_H__
 
 extern struct kobj_type xfs_mp_ktype;	/* xfs_mount */
+extern struct kobj_type xfs_dbg_ktype;	/* debug */
 extern struct kobj_type xfs_log_ktype;	/* xlog */
 
 static inline struct xfs_kobj *