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| author | Tao Ma <boyu.mt@taobao.com> | 2012-09-26 00:08:57 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-09-26 00:08:57 -0400 |
| commit | 0acdb8876fead922c9ffa6768c5675a37485c48c (patch) | |
| tree | b4cca27cf1cff13e704e5eed85a8248a38da8ec7 /fs/ext4/resize.c | |
| parent | 7f1468d1d50d368097ab13596dc08eaba7eace7f (diff) | |
| download | lwn-0acdb8876fead922c9ffa6768c5675a37485c48c.tar.gz lwn-0acdb8876fead922c9ffa6768c5675a37485c48c.zip | |
ext4: don't call update_backups() multiple times for the same bg
When performing an online resize, we add a bunch of groups at one time
in ext4_flex_group_add, so in most cases a lot of group descriptors
will be in the same group block. But in the end of this function,
update_backups will be called for every group descriptor and the same
block will be copied and journalled again and again. It is really a
waste.
Fix things so we only update a particular bg descriptor block once and
skip subsequent updates of the same block.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/resize.c')
| -rw-r--r-- | fs/ext4/resize.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index f21fdbf5c75d..7a75e1086961 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1460,6 +1460,7 @@ exit_journal: EXT4_DESC_PER_BLOCK(sb)); int meta_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG); + sector_t old_gdb = 0; update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, sizeof(struct ext4_super_block), 0); @@ -1467,8 +1468,11 @@ exit_journal: struct buffer_head *gdb_bh; gdb_bh = sbi->s_group_desc[gdb_num]; + if (old_gdb == gdb_bh->b_blocknr) + continue; update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, gdb_bh->b_size, meta_bg); + old_gdb = gdb_bh->b_blocknr; } } exit: |