xfs: Print name and pid when memory allocation loops

This patch adds comm name and pid to warning messages printed by
kmem_alloc(), kmem_zone_alloc() and xfs_buf_allocate_memory().
This will help telling which memory allocations (e.g. kernel worker
threads, OOM victim tasks, neither) are stalling because these functions
are passing __GFP_NOWARN which suppresses not only backtrace but comm name
and pid.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
index a7a3a63..535c136 100644
--- a/fs/xfs/kmem.c
+++ b/fs/xfs/kmem.c
@@ -55,8 +55,9 @@
 			return ptr;
 		if (!(++retries % 100))
 			xfs_err(NULL,
-		"possible memory allocation deadlock in %s (mode:0x%x)",
-					__func__, lflags);
+		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
+				current->comm, current->pid,
+				__func__, lflags);
 		congestion_wait(BLK_RW_ASYNC, HZ/50);
 	} while (1);
 }
@@ -120,8 +121,9 @@
 			return ptr;
 		if (!(++retries % 100))
 			xfs_err(NULL,
-		"possible memory allocation deadlock in %s (mode:0x%x)",
-					__func__, lflags);
+		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
+				current->comm, current->pid,
+				__func__, lflags);
 		congestion_wait(BLK_RW_ASYNC, HZ/50);
 	} while (1);
 }
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 8ecffb3..cac62e1 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -354,7 +354,8 @@
 			 */
 			if (!(++retries % 100))
 				xfs_err(NULL,
-		"possible memory allocation deadlock in %s (mode:0x%x)",
+		"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
+					current->comm, current->pid,
 					__func__, gfp_mask);
 
 			XFS_STATS_INC(xb_page_retries);