Commit 6e87ed0f authored by Bob Peterson's avatar Bob Peterson Committed by Steven Whitehouse
Browse files

GFS2: move toward a generic multi-block allocator 



This patch is a revision of the one I previously posted.
I tried to integrate all the suggestions Steve gave.
The purpose of the patch is to change function gfs2_alloc_block
(allocate either a dinode block or an extent of data blocks)
to a more generic gfs2_alloc_blocks function that can
allocate both a dinode _and_ an extent of data blocks in the
same call. This will ultimately help us create a multi-block
reservation scheme to reduce file fragmentation.

This patch moves more toward a generic multi-block allocator that
takes a pointer to the number of data blocks to allocate, plus whether
or not to allocate a dinode. In theory, it could be called to allocate
(1) a single dinode block, (2) a group of one or more data blocks, or
(3) a dinode plus several data blocks.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 4442f2e0

fs/gfs2/bmap.c

+2 −2
Original line number Diff line number Diff line
@@ -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_blocks(ip, &block, &n, 0, 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_blocks(ip, &bn, &n, 0, NULL);

		if (error)

			return error;

		alloced += n;

fs/gfs2/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -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_blocks(ip, &bn, &n, 0, NULL);

	if (error)

		return NULL;

	bh = gfs2_meta_new(ip->i_gl, bn);

fs/gfs2/inode.c

+2 −1
Original line number Diff line number Diff line
@@ -389,6 +389,7 @@ static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation) 
{

	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);

	int error;

	int dblocks = 0;



	if (gfs2_alloc_get(dip) == NULL)

		return -ENOMEM;
@@ -402,7 +403,7 @@ 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_blocks(dip, no_addr, &dblocks, 1, generation);



	gfs2_trans_end(sdp);

fs/gfs2/rgrp.c

+29 −30
Original line number Diff line number Diff line
@@ -65,8 +65,8 @@ static const char valid_change[16] = { 
};



static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,

                        unsigned char old_state, unsigned char new_state,

			unsigned int *n);

                        unsigned char old_state, bool dinode,

			unsigned int *ndata);



/**

 * gfs2_setbit - Set a bit in the bitmaps
@@ -921,8 +921,7 @@ static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip 
	while (goal < rgd->rd_data) {

		down_write(&sdp->sd_log_flush_lock);

		n = 1;

		block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED,

				     GFS2_BLKST_UNLINKED, &n);

		block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED, 0, &n);

		up_write(&sdp->sd_log_flush_lock);

		if (block == BFITNOENT)

			break;
@@ -1115,7 +1114,7 @@ static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block) 
 * @rgd: the resource group descriptor

 * @goal: the goal block within the RG (start here to search for avail block)

 * @old_state: GFS2_BLKST_XXX the before-allocation state to find

 * @new_state: GFS2_BLKST_XXX the after-allocation block state

 * @dinode: TRUE if the first block we allocate is for a dinode

 * @n: The extent length

 *

 * Walk rgrp's bitmap to find bits that represent a block in @old_state.
@@ -1132,8 +1131,7 @@ static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block) 
 */



static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,

			unsigned char old_state, unsigned char new_state,

			unsigned int *n)

			unsigned char old_state, bool dinode, unsigned int *n)

{

	struct gfs2_bitmap *bi = NULL;

	const u32 length = rgd->rd_length;
@@ -1192,13 +1190,14 @@ skip: 
	if (blk == BFITNOENT)

		return blk;



	*n = 1;

	if (old_state == new_state)

	if (old_state == GFS2_BLKST_UNLINKED)

		goto out;



	gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);

	gfs2_setbit(rgd, bi->bi_bh->b_data, bi->bi_clone, bi->bi_offset,

		    bi, blk, new_state);

		    bi, blk, dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);

	if (!dinode)

		(*n)++;

	goal = blk;

	while (*n < elen) {

		goal++;
@@ -1208,7 +1207,7 @@ skip: 
		    GFS2_BLKST_FREE)

			break;

		gfs2_setbit(rgd, bi->bi_bh->b_data, bi->bi_clone, bi->bi_offset,

			    bi, goal, new_state);

			    bi, goal, GFS2_BLKST_USED);

		(*n)++;

	}

out:
@@ -1300,28 +1299,26 @@ static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd) 
}



/**

 * gfs2_alloc_block - Allocate one or more blocks

 * gfs2_alloc_blocks - Allocate one or more blocks of data and/or a dinode

 * @ip: the inode to allocate the block for

 * @bn: Used to return the starting block number

 * @n: requested number of blocks/extent length (value/result)

 * dinode: 1 if we're allocating a dinode, 0 if it's a data block

 * @ndata: requested number of data blocks/extent length (value/result)

 * @dinode: 1 if we're allocating a dinode block, else 0

 * @generation: the generation number of the inode

 *

 * Returns: 0 or error

 */



int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n,

		     int dinode, u64 *generation)

int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *ndata,

		      bool dinode, u64 *generation)

{

	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

	struct buffer_head *dibh;

	struct gfs2_alloc *al = ip->i_alloc;

	struct gfs2_rgrpd *rgd;

	u32 goal, blk; /* block, within the rgrp scope */

	u32 goal, extlen, blk; /* block, within the rgrp scope */

	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.
@@ -1329,8 +1326,6 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n, 
	if (al == NULL)

		return -ECANCELED;



	if (n == NULL)

		n = &extn;

	rgd = ip->i_rgd;



	if (!dinode && rgrp_contains_block(rgd, ip->i_goal))
@@ -1338,7 +1333,7 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n, 
	else

		goal = rgd->rd_last_alloc;



	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, blk_type, n);

	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, dinode, ndata);



	/* Since all blocks are reserved in advance, this shouldn't happen */

	if (blk == BFITNOENT)
@@ -1347,7 +1342,7 @@ 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) {

		ip->i_goal = block + *n - 1;

		ip->i_goal = block + *ndata - 1;

		error = gfs2_meta_inode_buffer(ip, &dibh);

		if (error == 0) {

			struct gfs2_dinode *di =
@@ -1358,10 +1353,13 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n, 
			brelse(dibh);

		}

	}

	if (rgd->rd_free < *n)

	extlen = *ndata;

	if (dinode)

		extlen++;

	if (rgd->rd_free < extlen)

		goto rgrp_error;



	rgd->rd_free -= *n;

	rgd->rd_free -= extlen;

	if (dinode) {

		rgd->rd_dinodes++;

		*generation = rgd->rd_igeneration++;
@@ -1372,15 +1370,16 @@ int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n, 
	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);

	gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);



	gfs2_statfs_change(sdp, 0, -(s64)*n, dinode ? 1 : 0);

	gfs2_statfs_change(sdp, 0, -(s64)extlen, dinode ? 1 : 0);

	if (dinode)

		gfs2_trans_add_unrevoke(sdp, block, 1);

	else

		gfs2_quota_change(ip, *n, ip->i_inode.i_uid,

	if (*ndata)

		gfs2_quota_change(ip, *ndata, ip->i_inode.i_uid,

				  ip->i_inode.i_gid);



	rgd->rd_free_clone -= *n;

	trace_gfs2_block_alloc(ip, block, *n, blk_type);

	rgd->rd_free_clone -= extlen;

	trace_gfs2_block_alloc(ip, block, *ndata,

			       dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);

	*bn = block;

	return 0;

fs/gfs2/rgrp.h

+2 −2
Original line number Diff line number Diff line
@@ -39,8 +39,8 @@ static inline void gfs2_alloc_put(struct gfs2_inode *ip) 
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);

extern int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *n,

			     bool dinode, 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);

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