kill-the-bkl/reiserfs: turn GFP_ATOMIC flag to GFP_NOFS in reiserfs_get_block()

GFP_ATOMIC was used in reiserfs_get_block to not lose the Bkl so that
nobody can modify the tree in the middle of its work. Now that we
kicked out the bkl, we can use a more friendly flag. We use GFP_NOFS
here because we already hold the reiserfs lock.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Laurent Riffard <laurent.riffard@free.fr>
Cc: Thomas Gleixner <tglx@linutronix.de>

fs/reiserfs/inode.c

@@ -932,7 +932,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
 			if (blocks_needed == 1) {
 				un = &unf_single;
 			} else {
-				un = kzalloc(min(blocks_needed, max_to_insert) * UNFM_P_SIZE, GFP_ATOMIC);	// We need to avoid scheduling.
+				un = kzalloc(min(blocks_needed, max_to_insert) * UNFM_P_SIZE, GFP_NOFS);
 				if (!un) {
 					un = &unf_single;
 					blocks_needed = 1;