[GFS2] fix GFP_KERNEL misuses

There are several places where GFP_KERNEL allocations happen under a glock,
which will result in hangs if we're under memory pressure and go to re-enter the
fs in order to flush stuff out.  This patch changes the culprits to GFS_NOFS to
keep this problem from happening.  Thank you,

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 94070ad..eed040d 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -1089,7 +1089,7 @@
 
 	/*  Allocate both the "from" and "to" buffers in one big chunk  */
 
-	buf = kcalloc(3, sdp->sd_hash_bsize, GFP_KERNEL | __GFP_NOFAIL);
+	buf = kcalloc(3, sdp->sd_hash_bsize, GFP_NOFS | __GFP_NOFAIL);
 
 	for (block = dip->i_di.di_size >> sdp->sd_hash_bsize_shift; block--;) {
 		error = gfs2_dir_read_data(dip, (char *)buf,
@@ -1378,7 +1378,7 @@
 	hash = gfs2_dir_offset2hash(*offset);
 	index = hash >> (32 - dip->i_depth);
 
-	lp = kmalloc(sdp->sd_hash_bsize, GFP_KERNEL);
+	lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
 	if (!lp)
 		return -ENOMEM;
 
@@ -1443,7 +1443,7 @@
 
 	error = -ENOMEM;
 	/* 96 is max number of dirents which can be stuffed into an inode */
-	darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_KERNEL);
+	darr = kmalloc(96 * sizeof(struct gfs2_dirent *), GFP_NOFS);
 	if (darr) {
 		g.pdent = darr;
 		g.offset = 0;
@@ -1789,7 +1789,7 @@
 		return -EIO;
 	}
 
-	lp = kmalloc(sdp->sd_hash_bsize, GFP_KERNEL);
+	lp = kmalloc(sdp->sd_hash_bsize, GFP_NOFS);
 	if (!lp)
 		return -ENOMEM;
 
@@ -1864,7 +1864,7 @@
 
 	memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
 
-	ht = kzalloc(size, GFP_KERNEL);
+	ht = kzalloc(size, GFP_NOFS);
 	if (!ht)
 		return -ENOMEM;