[Cluster-devel] [fsck.gfs2 PATCH] fsck.gfs2: Make pass2 go by directory rbtree for performance

[Andrew Price]

On 13/07/16 13:47, Bob Peterson wrote:
> Hi,
>
> I posted this fsck.gfs2 performance patch previously on 22 June
> as part of the same multi-patch set.
>
> Pass2 went from 21m53.031s to 17m10.214s with the previous patch.
>
> With this patch pass2 went from 17m10.214s to 12m38.876s, a
> savings of 4.52 minutes: a 26 percent speedup.

Another nice improvement...

>
> Regards,
>
> Bob Peterson
> Red Hat File Systems
> ---
> This patch speeds up pass2 of fsck.gfs2 for large file systems.
> Before, pass2 was checking the bitmap for every block in the file
> system. If the file system is 15TB, that means looping 15 trillion
> times. With this patch, it merely traverses the inode tree, since
> it needs that information anyway, and already ignores any blocks
> that don't have it. Traversing an empty 15TB file system goes from
> 13.5 minutes to 0.00 seconds for pass2.
>
> Signed-off-by: Bob Peterson <rpeterso at redhat.com>
> ---
> diff --git a/gfs2/fsck/pass2.c b/gfs2/fsck/pass2.c
> index 808cf21..abc2b96 100644
> --- a/gfs2/fsck/pass2.c
> +++ b/gfs2/fsck/pass2.c
> @@ -2203,8 +2203,11 @@ static int pass2_check_dir(struct gfs2_sbd *sdp, struct gfs2_inode *ip)
>   */
>  int pass2(struct gfs2_sbd *sdp)
>  {
> +	struct osi_node *tmp, *next = NULL;
> +	struct gfs2_inode *ip;
> +	struct dir_info *dt;
>  	uint64_t dirblk;
> -	int q;
> +	int error;
>
>  	/* Check all the system directory inodes. */
>  	if (!sdp->gfs1 &&
> @@ -2236,11 +2239,11 @@ int pass2(struct gfs2_sbd *sdp)
>  		return FSCK_OK;
>  	log_info( _("Checking directory inodes.\n"));
>  	/* Grab each directory inode, and run checks on it */
> -	for (dirblk = 0; dirblk < last_fs_block; dirblk++) {
> -		struct gfs2_inode *ip;
> -		struct dir_info *dt;
> -		int error;
> +	for (tmp = osi_first(&dirtree); tmp; tmp = next) {
> +		next = osi_next(tmp);

Why not 'for (next = osi_first(&dirtree); next; next = osi_next(next)) {' ?

ACK

Andy

>
> +		dt = (struct dir_info *)tmp;
> +		dirblk = dt->dinode.no_addr;
>  		warm_fuzzy_stuff(dirblk);
>  		if (skip_this_pass || fsck_abort) /* if asked to skip the rest */
>  			return FSCK_OK;
> @@ -2249,14 +2252,6 @@ int pass2(struct gfs2_sbd *sdp)
>  		if (is_system_dir(sdp, dirblk))
>  			continue;
>
> -		q = bitmap_type(sdp, dirblk);
> -		if (q != GFS2_BLKST_DINODE)
> -			continue;
> -
> -		dt = dirtree_find(dirblk);
> -		if (dt == NULL)
> -			continue;
> -
>  		/* If we created lost+found, its links should have been
>  		   properly adjusted, so don't check it. */
>  		if (lf_was_created &&
>