From patchwork Tue Mar  1 10:14:34 2011
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From: "Zhong, Xin" <xin.zhong@intel.com>
To: Mitch Harder <mitch.harder@sabayonlinux.org>,
	=?iso-8859-1?Q?Maria_Wikstr=F6m?= <maria@ponstudios.se>
CC: Josef Bacik <josef@redhat.com>,
	Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>,
	Chris Mason <chris.mason@oracle.com>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Date: Tue, 1 Mar 2011 18:14:34 +0800
Subject: RE: [PATCH] btrfs file write debugging patch
Thread-Topic: [PATCH] btrfs file write debugging patch
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--- fs/btrfs/file.c	2011-02-28 10:13:45.000000000 -0600
+++ /usr/src/linux/fs/btrfs/file.c	2011-02-28 13:07:11.000000000 -0600
@@ -53,12 +53,14 @@
 	int offset = pos & (PAGE_CACHE_SIZE - 1);
 	int total_copied = 0;

+	/***************************
 	if ((jiffies % 10) == 0)
 		return 0;

 	if ((jiffies % 25) == 0) {
 		write_bytes /= 2;
 	}
+	**************************/

 	while (write_bytes > 0) {
 		size_t count = min_t(size_t,
@@ -82,10 +84,13 @@

 		/* Return to btrfs_file_aio_write to fault page */
 		if (unlikely(copied == 0)) {
+			trace_printk("TPK: unlikely copied == 0 in btrfs_copy_from_user
(total_copied=%i)\n",
+				     total_copied);
 			break;
 		}

 		if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
+			trace_printk("TPK: unlikely copied < PAGE_CACHE_SIZE - offset in
btrfs_copy_from_user\n");
 			offset += copied;