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Commit | Line | Data |
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a195d12b GKH |
1 | From 2ebd1704ded88a8ae29b5f3998b13959c715c4be Mon Sep 17 00:00:00 2001 |
2 | From: Yongqiang Yang <xiaoqiangnk@gmail.com> | |
3 | Date: Wed, 5 Sep 2012 01:27:50 -0400 | |
4 | Subject: ext4: avoid duplicate writes of the backup bg descriptor blocks | |
5 | ||
6 | From: Yongqiang Yang <xiaoqiangnk@gmail.com> | |
7 | ||
8 | commit 2ebd1704ded88a8ae29b5f3998b13959c715c4be upstream. | |
9 | ||
10 | The resize code was needlessly writing the backup block group | |
11 | descriptor blocks multiple times (once per block group) during an | |
12 | online resize. | |
13 | ||
14 | Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> | |
15 | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> | |
16 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
17 | ||
18 | --- | |
19 | fs/ext4/resize.c | 10 ++++++---- | |
20 | 1 file changed, 6 insertions(+), 4 deletions(-) | |
21 | ||
22 | --- a/fs/ext4/resize.c | |
23 | +++ b/fs/ext4/resize.c | |
24 | @@ -1358,13 +1358,15 @@ exit_journal: | |
25 | err = err2; | |
26 | ||
27 | if (!err) { | |
28 | - int i; | |
29 | + int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); | |
30 | + int gdb_num_end = ((group + flex_gd->count - 1) / | |
31 | + EXT4_DESC_PER_BLOCK(sb)); | |
32 | + | |
33 | update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, | |
34 | sizeof(struct ext4_super_block)); | |
35 | - for (i = 0; i < flex_gd->count; i++, group++) { | |
36 | + for (; gdb_num <= gdb_num_end; gdb_num++) { | |
37 | struct buffer_head *gdb_bh; | |
38 | - int gdb_num; | |
39 | - gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb); | |
40 | + | |
41 | gdb_bh = sbi->s_group_desc[gdb_num]; | |
42 | update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, | |
43 | gdb_bh->b_size); |