[Cluster-devel] [GFS2 PATCH] GFS2: combine gfs2_alloc_block and gfs2_alloc_di

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Wed, 2011-11-16 at 09:18 -0500, Bob Peterson wrote:
> ----- Original Message -----
> | Hi,
> | 
> | As a follow up to this patch, I'd quite like to see rgblk_search
> | split
> | into two functions. One to do the search and another to actually make
> | changes to the bitmap when a block is found. That should help
> | development of further alloc changes on top.
> | 
> | Also, if someone requests allocation of an extent > 1 block with an
> | inode type, then only the first block should be set to being an
> | inode,
> | the others should be set to "used" and the various stats should be
> | updated accordingly. Otherwise it will never be possible to ask for
> | more
> | than a single block when an inode is being allocated,
> | 
> | Steve.
> 
> Hi,
> 
> Good suggestions. Hopefully I'll post a patch or two soon.
> In the meantime, here's a clean-up for one of the patches.
> I should have done this in the first place.
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> --
> commit e5091d2b20b98424cb6924ec499bdf5c5bc5827d
> Author: Bob Peterson <rpeterso@redhat.com>
> Date:   Wed Nov 16 08:17:33 2011 -0600
> 
>     GFS2: Clean up gfs2_block_alloc by passing in block type
>     
>     This patch simplifies function gfs2_block_alloc by making its
>     callers pass in the requested block type rather than a flag to be
>     translated as a block type.
> 
> diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
> index b69235b..491e1f2 100644
> --- a/fs/gfs2/bmap.c
> +++ b/fs/gfs2/bmap.c
> @@ -133,7 +133,7 @@ int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page)
>  		   and write it out to disk */
>  
>  		unsigned int n = 1;
> -		error = gfs2_alloc_block(ip, &block, &n, 0, NULL);
> +		error = gfs2_alloc_block(ip, &block, &n, GFS2_BLKST_USED, NULL);
>  		if (error)
>  			goto out_brelse;
>  		if (isdir) {
> @@ -503,7 +503,7 @@ static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock,
>  	do {
>  		int error;
>  		n = blks - alloced;
> -		error = gfs2_alloc_block(ip, &bn, &n, 0, NULL);
> +		error = gfs2_alloc_block(ip, &bn, &n, GFS2_BLKST_USED, NULL);
>  		if (error)
>  			return error;
>  		alloced += n;
> diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
> index ae75319..c38b32c 100644
> --- a/fs/gfs2/dir.c
> +++ b/fs/gfs2/dir.c
> @@ -823,7 +823,7 @@ static struct gfs2_leaf *new_leaf(struct inode *inode, struct buffer_head **pbh,
>  	struct gfs2_dirent *dent;
>  	struct qstr name = { .name = "", .len = 0, .hash = 0 };
>  
> -	error = gfs2_alloc_block(ip, &bn, &n, 0, NULL);
> +	error = gfs2_alloc_block(ip, &bn, &n, GFS2_BLKST_USED, NULL);
>  	if (error)
>  		return NULL;
>  	bh = gfs2_meta_new(ip->i_gl, bn);
> diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
> index de2668f..25b6657 100644
> --- a/fs/gfs2/inode.c
> +++ b/fs/gfs2/inode.c
> @@ -402,7 +402,8 @@ static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation)
>  	if (error)
>  		goto out_ipreserv;
>  
> -	error = gfs2_alloc_block(dip, no_addr, NULL, 1, generation);
> +	error = gfs2_alloc_block(dip, no_addr, NULL, GFS2_BLKST_DINODE,
> +				 generation);
>  
>  	gfs2_trans_end(sdp);
>  
> diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
> index 995f4e6..abac4bd 100644
> --- a/fs/gfs2/rgrp.c
> +++ b/fs/gfs2/rgrp.c
> @@ -1311,7 +1311,7 @@ static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd)
>   */
>  
>  int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
> -		     int dinode, u64 *generation)
> +		     unsigned char blk_type, u64 *generation)
>  {
>  	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
>  	struct buffer_head *dibh;
> @@ -1321,7 +1321,6 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
>  	u64 block; /* block, within the file system scope */
>  	unsigned int extn = 1;
>  	int error;
> -	unsigned char blk_type = dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED;
>  
>  	/* Only happens if there is a bug in gfs2, return something distinctive
>  	 * to ensure that it is noticed.
> @@ -1333,7 +1332,7 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
>  		n = &extn;
>  	rgd = ip->i_rgd;
>  
> -	if (!dinode && rgrp_contains_block(rgd, ip->i_goal))
> +	if (blk_type == GFS2_BLKST_USED && rgrp_contains_block(rgd, ip->i_goal))
>  		goal = ip->i_goal - rgd->rd_data0;
>  	else
>  		goal = rgd->rd_last_alloc;
> @@ -1346,7 +1345,7 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
>  
>  	rgd->rd_last_alloc = blk;
>  	block = rgd->rd_data0 + blk;
> -	if (!dinode) {
> +	if (blk_type == GFS2_BLKST_USED) {
>  		ip->i_goal = block + *n - 1;
>  		error = gfs2_meta_inode_buffer(ip, &dibh);
>  		if (error == 0) {
> @@ -1362,7 +1361,7 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
>  		goto rgrp_error;
>  
>  	rgd->rd_free -= *n;
> -	if (dinode) {
> +	if (blk_type == GFS2_BLKST_DINODE) {
>  		rgd->rd_dinodes++;
>  		*generation = rgd->rd_igeneration++;
>  		if (*generation == 0)
> @@ -1374,8 +1373,8 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
>  
>  	al->al_alloced += *n;
>  
> -	gfs2_statfs_change(sdp, 0, -(s64)*n, dinode ? 1 : 0);
> -	if (dinode)
> +	gfs2_statfs_change(sdp, 0, -(s64)*n, (blk_type == GFS2_BLKST_DINODE));
It is not a good plan to rely on this to give us 0 and 1 inode counts.
Using the ?: as before would be better. I suspect that if you maintain
separate counts of inodes (which can be 0 or 1 only) and other blocks
(any number) calculated at the start of the function then a number of
the tests you need to do will just become 0 or non-zero on one or other
other of these.

Also, it would be a good plan to always pass the extent size in, even if
the caller is requesting only a single block, then there is no need for
a NULL test,

Steve.


> +	if (blk_type == GFS2_BLKST_DINODE)
>  		gfs2_trans_add_unrevoke(sdp, block, 1);
>  	else
>  		gfs2_quota_change(ip, *n, ip->i_inode.i_uid,
> diff --git a/fs/gfs2/rgrp.h b/fs/gfs2/rgrp.h
> index 4cb5608..6a81011 100644
> --- a/fs/gfs2/rgrp.h
> +++ b/fs/gfs2/rgrp.h
> @@ -40,7 +40,7 @@ extern int gfs2_inplace_reserve(struct gfs2_inode *ip);
>  extern void gfs2_inplace_release(struct gfs2_inode *ip);
>  
>  extern int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,
> -			    int dinode, u64 *generation);
> +			    unsigned char blk_type, u64 *generation);
>  
>  extern void __gfs2_free_blocks(struct gfs2_inode *ip, u64 bstart, u32 blen, int meta);
>  extern void gfs2_free_meta(struct gfs2_inode *ip, u64 bstart, u32 blen);
> diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
> index e4794a5..f2b77b4 100644
> --- a/fs/gfs2/xattr.c
> +++ b/fs/gfs2/xattr.c
> @@ -610,7 +610,7 @@ static int ea_alloc_blk(struct gfs2_inode *ip, struct buffer_head **bhp)
>  	u64 block;
>  	int error;
>  
> -	error = gfs2_alloc_block(ip, &block, &n, 0, NULL);
> +	error = gfs2_alloc_block(ip, &block, &n, GFS2_BLKST_USED, NULL);
>  	if (error)
>  		return error;
>  	gfs2_trans_add_unrevoke(sdp, block, 1);
> @@ -672,7 +672,8 @@ static int ea_write(struct gfs2_inode *ip, struct gfs2_ea_header *ea,
>  			int mh_size = sizeof(struct gfs2_meta_header);
>  			unsigned int n = 1;
>  
> -			error = gfs2_alloc_block(ip, &block, &n, 0, NULL);
> +			error = gfs2_alloc_block(ip, &block, &n,
> +						 GFS2_BLKST_USED, NULL);
>  			if (error)
>  				return error;
>  			gfs2_trans_add_unrevoke(sdp, block, 1);
> @@ -992,7 +993,7 @@ static int ea_set_block(struct gfs2_inode *ip, struct gfs2_ea_request *er,
>  	} else {
>  		u64 blk;
>  		unsigned int n = 1;
> -		error = gfs2_alloc_block(ip, &blk, &n, 0, NULL);
> +		error = gfs2_alloc_block(ip, &blk, &n, GFS2_BLKST_USED, NULL);
>  		if (error)
>  			return error;
>  		gfs2_trans_add_unrevoke(sdp, blk, 1);