From 9a790ba1ec02bbae0933e7ebd576c0bc329e9796 Mon Sep 17 00:00:00 2001
From: Tristan Ye <tristan.ye@oracle.com>
Date: Thu, 12 May 2011 20:47:07 +0800
Subject: ocfs2: skip existing hole when removing the last extent_rec in
punching-hole codes.
In the case of removing a partial extent record which covers a hole, current
punching-hole logic will try to remove more than the length of whole extent
record, which leads to the failure of following assert(fs/ocfs2/alloc.c):
5507 BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);
This patch tries to skip existing hole at the last attempt of removing a partial
extent record, what's more, it also adds some necessary comments for better
understanding of punching-hole codes.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
---
fs/ocfs2/file.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 41565ae52856..89659d6dc206 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1607,6 +1607,9 @@ static void ocfs2_calc_trunc_pos(struct inode *inode,
range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
if (le32_to_cpu(rec->e_cpos) >= trunc_start) {
+ /*
+ * remove an entire extent record.
+ */
*trunc_cpos = le32_to_cpu(rec->e_cpos);
/*
* Skip holes if any.
@@ -1617,7 +1620,16 @@ static void ocfs2_calc_trunc_pos(struct inode *inode,
*blkno = le64_to_cpu(rec->e_blkno);
*trunc_end = le32_to_cpu(rec->e_cpos);
} else if (range > trunc_start) {
+ /*
+ * remove a partial extent record, which means we're
+ * removing the last extent record.
+ */
*trunc_cpos = trunc_start;
+ /*
+ * skip hole if any.
+ */
+ if (range < *trunc_end)
+ *trunc_end = range;
*trunc_len = *trunc_end - trunc_start;
coff = trunc_start - le32_to_cpu(rec->e_cpos);
*blkno = le64_to_cpu(rec->e_blkno) +
--
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