From: Theodore Ts'o <tytso@mit.edu>
To: Ext4 Developers List <linux-ext4@vger.kernel.org>
Cc: xiaoqiangnk@gmail.com, "Theodore Ts'o" <tytso@mit.edu>,
stable@vger.kernel.org
Subject: [PATCH 2/5] ext4: avoid duplicate writes of the backup bg descriptor blocks
Date: Sun, 2 Sep 2012 00:51:22 -0400 [thread overview]
Message-ID: <1346561485-6413-3-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1346561485-6413-1-git-send-email-tytso@mit.edu>
From: Yongqiang Yang <xiaoqiangnk@gmail.com>
The resize code was needlessly writing the backup block group
descriptor blocks multiple times (once per block group) during an
online resize.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
---
fs/ext4/resize.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 724e250..e3f5f53 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1353,13 +1353,15 @@ exit_journal:
err = err2;
if (!err) {
- int i;
+ int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
+ int gdb_num_end = ((group + flex_gd->count - 1) /
+ EXT4_DESC_PER_BLOCK(sb));
+
update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
sizeof(struct ext4_super_block));
- for (i = 0; i < flex_gd->count; i++, group++) {
+ for (; gdb_num <= gdb_num_end; gdb_num++) {
struct buffer_head *gdb_bh;
- int gdb_num;
- gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
+
gdb_bh = sbi->s_group_desc[gdb_num];
update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
gdb_bh->b_size);
--
1.7.12.rc0.22.gcdd159b
next prev parent reply other threads:[~2012-09-02 5:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-02 4:51 [PATCH 0/5] meta_bg online resize patches Theodore Ts'o
2012-09-02 4:51 ` [PATCH 1/5] ext4: when resizing, do not copy gdt blocks for groups that do not have them Theodore Ts'o
2012-09-02 4:51 ` Theodore Ts'o [this message]
2012-09-02 4:51 ` [PATCH 3/5] ext4: grow the s_flex_groups array as needed when resizing Theodore Ts'o
2012-09-02 4:51 ` [PATCH 4/5] ext4: grow the s_group_info array as needed Theodore Ts'o
2012-09-02 4:51 ` [PATCH 5/5] ext4: add online resizing support for meta_bg and bit64 Theodore Ts'o
2012-09-03 16:33 ` [PATCH 5/5 -v2] ext4: add online resizing support for meta_bg and 64-bit file systems Theodore Ts'o
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