From: Andreas Dilger Subject: Re: [PATCH 2/2] ext4: remove ext4_free_blocks_after_init() Date: Wed, 20 Jul 2011 09:41:24 -0600 Message-ID: References: <1311168774-26378-1-git-send-email-xiaoqiangnk@gmail.com> <1311168774-26378-3-git-send-email-xiaoqiangnk@gmail.com> Mime-Version: 1.0 (iPhone Mail 8J2) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Cc: "linux-ext4@vger.kernel.org" , "tytso@mit.edu" , Yongqiang Yang To: Yongqiang Yang Return-path: Received: from mail-pv0-f174.google.com ([74.125.83.174]:60214 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751752Ab1GTPlk convert rfc822-to-8bit (ORCPT ); Wed, 20 Jul 2011 11:41:40 -0400 Received: by pvg12 with SMTP id 12so277908pvg.19 for ; Wed, 20 Jul 2011 08:41:40 -0700 (PDT) In-Reply-To: <1311168774-26378-3-git-send-email-xiaoqiangnk@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2011-07-20, at 7:32 AM, Yongqiang Yang wrote: > This patch removes ext4_free_blocks_after_init() and simplifies > ext4_init_block_bitmap() a lot. Why not use the ext4_set_bits() function, exported in another patch, to set multiple bits? > Signed-off-by: Yongqiang Yang > --- > fs/ext4/balloc.c | 122 ++++++++++++++++++----------------------------------- > fs/ext4/ext4.h | 4 +- > 2 files changed, 43 insertions(+), 83 deletions(-) > > diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c > index f8224ad..2dd9820 100644 > --- a/fs/ext4/balloc.c > +++ b/fs/ext4/balloc.c > @@ -55,60 +55,31 @@ static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block, > return 0; > } > > -static int ext4_group_used_meta_blocks(struct super_block *sb, > - ext4_group_t block_group, > - struct ext4_group_desc *gdp) > -{ > - ext4_fsblk_t tmp; > - struct ext4_sb_info *sbi = EXT4_SB(sb); > - /* block bitmap, inode bitmap, and inode table blocks */ > - int used_blocks = sbi->s_itb_per_group + 2; > - > - if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) { > - if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), > - block_group)) > - used_blocks--; > - > - if (!ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), > - block_group)) > - used_blocks--; > - > - tmp = ext4_inode_table(sb, gdp); > - for (; tmp < ext4_inode_table(sb, gdp) + > - sbi->s_itb_per_group; tmp++) { > - if (!ext4_block_in_group(sb, tmp, block_group)) > - used_blocks -= 1; > - } > - } > - return used_blocks; > -} > - > -/* Initializes an uninitialized block bitmap if given, and returns the > - * number of blocks free in the group. */ > -unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, > +/* Initializes an uninitialized block bitmap */ > +void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, > ext4_group_t block_group, struct ext4_group_desc *gdp) > { > + ext4_fsblk_t start, tmp; > int bit, bit_max; > ext4_group_t ngroups = ext4_get_groups_count(sb); > - unsigned free_blocks, group_blocks; > + unsigned group_blocks; > struct ext4_sb_info *sbi = EXT4_SB(sb); > - > - if (bh) { > - J_ASSERT_BH(bh, buffer_locked(bh)); > - > - /* If checksum is bad mark all blocks used to prevent allocation > - * essentially implementing a per-group read-only flag. */ > - if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { > - ext4_error(sb, "Checksum bad for group %u", > - block_group); > - ext4_free_blks_set(sb, gdp, 0); > - ext4_free_inodes_set(sb, gdp, 0); > - ext4_itable_unused_set(sb, gdp, 0); > - memset(bh->b_data, 0xff, sb->s_blocksize); > - return 0; > - } > - memset(bh->b_data, 0, sb->s_blocksize); > + int flex_bg = 0; > + > + J_ASSERT_BH(bh, bh && buffer_locked(bh)); > + > + /* If checksum is bad mark all blocks used to prevent allocation > + * essentially implementing a per-group read-only flag. */ > + if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { > + ext4_error(sb, "Checksum bad for group %u", > + block_group); > + ext4_free_blks_set(sb, gdp, 0); > + ext4_free_inodes_set(sb, gdp, 0); > + ext4_itable_unused_set(sb, gdp, 0); > + memset(bh->b_data, 0xff, sb->s_blocksize); > + return; > } > + memset(bh->b_data, 0, sb->s_blocksize); > > /* Check for superblock and gdt backups in this group */ > bit_max = ext4_bg_has_super(sb, block_group); > @@ -137,46 +108,37 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, > group_blocks = EXT4_BLOCKS_PER_GROUP(sb); > } > > - free_blocks = group_blocks - bit_max; > > - if (bh) { > - ext4_fsblk_t start, tmp; > - int flex_bg = 0; > + for (bit = 0; bit < bit_max; bit++) > + ext4_set_bit(bit, bh->b_data); > > - for (bit = 0; bit < bit_max; bit++) > - ext4_set_bit(bit, bh->b_data); > + start = ext4_group_first_block_no(sb, block_group); > > - start = ext4_group_first_block_no(sb, block_group); > + flex_bg = EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG); > > - if (EXT4_HAS_INCOMPAT_FEATURE(sb, > - EXT4_FEATURE_INCOMPAT_FLEX_BG)) > - flex_bg = 1; > + /* Set bits for block and inode bitmaps, and inode table */ > + tmp = ext4_block_bitmap(sb, gdp); > + if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) > + ext4_set_bit(tmp - start, bh->b_data); > > - /* Set bits for block and inode bitmaps, and inode table */ > - tmp = ext4_block_bitmap(sb, gdp); > - if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) > - ext4_set_bit(tmp - start, bh->b_data); > + tmp = ext4_inode_bitmap(sb, gdp); > + if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) > + ext4_set_bit(tmp - start, bh->b_data); > > - tmp = ext4_inode_bitmap(sb, gdp); > - if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) > + tmp = ext4_inode_table(sb, gdp); > + for (; tmp < ext4_inode_table(sb, gdp) + > + sbi->s_itb_per_group; tmp++) { > + if (!flex_bg || > + ext4_block_in_group(sb, tmp, block_group)) > ext4_set_bit(tmp - start, bh->b_data); > - > - tmp = ext4_inode_table(sb, gdp); > - for (; tmp < ext4_inode_table(sb, gdp) + > - sbi->s_itb_per_group; tmp++) { > - if (!flex_bg || > - ext4_block_in_group(sb, tmp, block_group)) > - ext4_set_bit(tmp - start, bh->b_data); > - } > - /* > - * Also if the number of blocks within the group is > - * less than the blocksize * 8 ( which is the size > - * of bitmap ), set rest of the block bitmap to 1 > - */ > - ext4_mark_bitmap_end(group_blocks, sb->s_blocksize * 8, > - bh->b_data); > } > - return free_blocks - ext4_group_used_meta_blocks(sb, block_group, gdp); > + /* > + * Also if the number of blocks within the group is > + * less than the blocksize * 8 ( which is the size > + * of bitmap ), set rest of the block bitmap to 1 > + */ > + ext4_mark_bitmap_end(group_blocks, sb->s_blocksize * 8, > + bh->b_data); > } > > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 62cee2b..eacaad2 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1741,12 +1741,10 @@ extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, > extern int ext4_should_retry_alloc(struct super_block *sb, int *retries); > struct buffer_head *ext4_read_block_bitmap(struct super_block *sb, > ext4_group_t block_group); > -extern unsigned ext4_init_block_bitmap(struct super_block *sb, > +extern void ext4_init_block_bitmap(struct super_block *sb, > struct buffer_head *bh, > ext4_group_t group, > struct ext4_group_desc *desc); > -#define ext4_free_blocks_after_init(sb, group, desc) \ > - ext4_init_block_bitmap(sb, NULL, group, desc) > ext4_fsblk_t ext4_inode_to_goal_block(struct inode *); 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