Commit 350bb48b authored by Kemeng Shi's avatar Kemeng Shi Committed by Theodore Ts'o
Browse files

ext4: remove unnecessary check to avoid repeat update_backups for the same gdb 



The sbi->s_group_desc contains array of bh's for block group descriptors
and continuous EXT4_DESC_PER_BLOCK(sb) bg descriptors in single block
share the same bh.
Simply call update_backups for each gdb_bh in sbi->s_group_desc will not
update same group descriptors block for multiple times.

Commit 0acdb887 ("ext4: don't call update_backups() multiple times for
the same bg") wrongly assumed each block group descriptor in the same block
has a individual bh and unnecessary check was added.

Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230826174712.4059355-13-shikemeng@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 9dca529b

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -1494,6 +1494,7 @@ struct ext4_sb_info { 
	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */

	struct buffer_head * s_sbh;	/* Buffer containing the super block */

	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */

	/* Array of bh's for the block group descriptors */

	struct buffer_head * __rcu *s_group_desc;

	unsigned int s_mount_opt;

	unsigned int s_mount_opt2;

fs/ext4/resize.c

+0 −4
Original line number Diff line number Diff line
@@ -1588,7 +1588,6 @@ static int ext4_flex_group_add(struct super_block *sb, 
		int meta_bg = ext4_has_feature_meta_bg(sb);

		sector_t padding_blocks = meta_bg ? 0 : sbi->s_sbh->b_blocknr -

					 ext4_group_first_block_no(sb, 0);

		sector_t old_gdb = 0;



		update_backups(sb, ext4_group_first_block_no(sb, 0),

			       (char *)es, sizeof(struct ext4_super_block), 0);
@@ -1597,11 +1596,8 @@ static int ext4_flex_group_add(struct super_block *sb, 


			gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,

						     gdb_num);

			if (old_gdb == gdb_bh->b_blocknr)

				continue;

			update_backups(sb, gdb_bh->b_blocknr - padding_blocks,

				       gdb_bh->b_data, gdb_bh->b_size, meta_bg);

			old_gdb = gdb_bh->b_blocknr;

		}

	}

exit: