Re: [PATCH 19/20] ext2: Add ext2_sb_info s_lock spinlock

OGAWA Hirofumi
2009-11-18T12:31:20Z

Jan Blunck <jblunck@suse.de> writes:

> +static void ext2_sync_super(struct super_block *sb,
> + struct ext2_super_block *es)
> {
> + spin_lock(&EXT2_SB(sb)->s_lock);
> es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
> es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
> es->s_wtime = cpu_to_le32(get_seconds());
> + /* unlock before we do IO */
> + spin_unlock(&EXT2_SB(sb)->s_lock);
> mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
> sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
> sb->s_dirt = 0;

[...]

> static int ext2_sync_fs(struct super_block *sb, int wait)
> {
> - struct ext2_super_block *es = EXT2_SB(sb)->s_es;
> + struct ext2_sb_info *sbi = EXT2_SB(sb);
> + struct ext2_super_block *es = sbi->s_es;
>
> lock_kernel();
> + spin_lock(&sbi->s_lock);
> if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
> ext2_debug("setting valid to 0\n");
> es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
> @@ -1137,9 +1159,11 @@ static int ext2_sync_fs(struct super_block *sb, int wait)
> es->s_free_inodes_count =
> cpu_to_le32(ext2_count_free_inodes(sb));
> es->s_mtime = cpu_to_le32(get_seconds());
> + spin_unlock(&EXT2_SB(sb)->s_lock);
> ext2_sync_super(sb, es);
> } else {
> ext2_commit_super(sb, es);
> + spin_unlock(&sbi->s_lock);
> }
> sb->s_dirt = 0;

[...]

> @@ -1237,6 +1264,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
> if (!ext2_setup_super (sb, es, 0))
> sb->s_flags &= ~MS_RDONLY;
> }
> + spin_unlock(&EXT2_SB(sb)->s_lock);
> ext2_sync_super(sb, es);
> unlock_kernel();
> return 0;

ext2_setup_super() will call ext2_sync_fs(), so ->s_lock seems to be
recursive in here.

Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>