rgrp.c

linux 内核源代码

	return NULL;
}

/**
 * gfs2_inplace_reserve_i - Reserve space in the filesystem
 * @ip: the inode to reserve space for
 *
 * Returns: errno
 */

int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_alloc *al = &ip->i_alloc;
	struct inode *inode;
	int error = 0;
	u64 last_unlinked = NO_BLOCK;

	if (gfs2_assert_warn(sdp, al->al_requested))
		return -EINVAL;

try_again:
	/* We need to hold the rindex unless the inode we're using is
	   the rindex itself, in which case it's already held. */
	if (ip != GFS2_I(sdp->sd_rindex))
		error = gfs2_rindex_hold(sdp, &al->al_ri_gh);
	else if (!sdp->sd_rgrps) /* We may not have the rindex read in, so: */
		error = gfs2_ri_update_special(ip);

	if (error)
		return error;

	inode = get_local_rgrp(ip, &last_unlinked);
	if (inode) {
		if (ip != GFS2_I(sdp->sd_rindex))
			gfs2_glock_dq_uninit(&al->al_ri_gh);
		if (IS_ERR(inode))
			return PTR_ERR(inode);
		iput(inode);
		gfs2_log_flush(sdp, NULL);
		goto try_again;
	}

	al->al_file = file;
	al->al_line = line;

	return 0;
}

/**
 * gfs2_inplace_release - release an inplace reservation
 * @ip: the inode the reservation was taken out on
 *
 * Release a reservation made by gfs2_inplace_reserve().
 */

void gfs2_inplace_release(struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_alloc *al = &ip->i_alloc;

	if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1)
		fs_warn(sdp, "al_alloced = %u, al_requested = %u "
			     "al_file = %s, al_line = %u\n",
		             al->al_alloced, al->al_requested, al->al_file,
			     al->al_line);

	al->al_rgd = NULL;
	gfs2_glock_dq_uninit(&al->al_rgd_gh);
	if (ip != GFS2_I(sdp->sd_rindex))
		gfs2_glock_dq_uninit(&al->al_ri_gh);
}

/**
 * gfs2_get_block_type - Check a block in a RG is of given type
 * @rgd: the resource group holding the block
 * @block: the block number
 *
 * Returns: The block type (GFS2_BLKST_*)
 */

unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block)
{
	struct gfs2_bitmap *bi = NULL;
	u32 length, rgrp_block, buf_block;
	unsigned int buf;
	unsigned char type;

	length = rgd->rd_length;
	rgrp_block = block - rgd->rd_data0;

	for (buf = 0; buf < length; buf++) {
		bi = rgd->rd_bits + buf;
		if (rgrp_block < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
			break;
	}

	gfs2_assert(rgd->rd_sbd, buf < length);
	buf_block = rgrp_block - bi->bi_start * GFS2_NBBY;

	type = gfs2_testbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
			   bi->bi_len, buf_block);

	return type;
}

/**
 * rgblk_search - find a block in @old_state, change allocation
 *           state to @new_state
 * @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
 *
 * Walk rgrp's bitmap to find bits that represent a block in @old_state.
 * Add the found bitmap buffer to the transaction.
 * Set the found bits to @new_state to change block's allocation state.
 *
 * This function never fails, because we wouldn't call it unless we
 * know (from reservation results, etc.) that a block is available.
 *
 * Scope of @goal and returned block is just within rgrp, not the whole
 * filesystem.
 *
 * Returns:  the block number allocated
 */

static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,
			unsigned char old_state, unsigned char new_state)
{
	struct gfs2_bitmap *bi = NULL;
	u32 length = rgd->rd_length;
	u32 blk = 0;
	unsigned int buf, x;

	/* Find bitmap block that contains bits for goal block */
	for (buf = 0; buf < length; buf++) {
		bi = rgd->rd_bits + buf;
		if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
			break;
	}

	gfs2_assert(rgd->rd_sbd, buf < length);

	/* Convert scope of "goal" from rgrp-wide to within found bit block */
	goal -= bi->bi_start * GFS2_NBBY;

	/* Search (up to entire) bitmap in this rgrp for allocatable block.
	   "x <= length", instead of "x < length", because we typically start
	   the search in the middle of a bit block, but if we can't find an
	   allocatable block anywhere else, we want to be able wrap around and
	   search in the first part of our first-searched bit block.  */
	for (x = 0; x <= length; x++) {
		/* The GFS2_BLKST_UNLINKED state doesn't apply to the clone
		   bitmaps, so we must search the originals for that. */
		if (old_state != GFS2_BLKST_UNLINKED && bi->bi_clone)
			blk = gfs2_bitfit(rgd, bi->bi_clone + bi->bi_offset,
					  bi->bi_len, goal, old_state);
		else
			blk = gfs2_bitfit(rgd,
					  bi->bi_bh->b_data + bi->bi_offset,
					  bi->bi_len, goal, old_state);
		if (blk != BFITNOENT)
			break;

		/* Try next bitmap block (wrap back to rgrp header if at end) */
		buf = (buf + 1) % length;
		bi = rgd->rd_bits + buf;
		goal = 0;
	}

	if (blk != BFITNOENT && old_state != new_state) {
		gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
		gfs2_setbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
			    bi->bi_len, blk, new_state);
		if (bi->bi_clone)
			gfs2_setbit(rgd, bi->bi_clone + bi->bi_offset,
				    bi->bi_len, blk, new_state);
	}

	return (blk == BFITNOENT) ? blk : (bi->bi_start * GFS2_NBBY) + blk;
}

/**
 * rgblk_free - Change alloc state of given block(s)
 * @sdp: the filesystem
 * @bstart: the start of a run of blocks to free
 * @blen: the length of the block run (all must lie within ONE RG!)
 * @new_state: GFS2_BLKST_XXX the after-allocation block state
 *
 * Returns:  Resource group containing the block(s)
 */

static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, u64 bstart,
				     u32 blen, unsigned char new_state)
{
	struct gfs2_rgrpd *rgd;
	struct gfs2_bitmap *bi = NULL;
	u32 length, rgrp_blk, buf_blk;
	unsigned int buf;

	rgd = gfs2_blk2rgrpd(sdp, bstart);
	if (!rgd) {
		if (gfs2_consist(sdp))
			fs_err(sdp, "block = %llu\n", (unsigned long long)bstart);
		return NULL;
	}

	length = rgd->rd_length;

	rgrp_blk = bstart - rgd->rd_data0;

	while (blen--) {
		for (buf = 0; buf < length; buf++) {
			bi = rgd->rd_bits + buf;
			if (rgrp_blk < (bi->bi_start + bi->bi_len) * GFS2_NBBY)
				break;
		}

		gfs2_assert(rgd->rd_sbd, buf < length);

		buf_blk = rgrp_blk - bi->bi_start * GFS2_NBBY;
		rgrp_blk++;

		if (!bi->bi_clone) {
			bi->bi_clone = kmalloc(bi->bi_bh->b_size,
					       GFP_NOFS | __GFP_NOFAIL);
			memcpy(bi->bi_clone + bi->bi_offset,
			       bi->bi_bh->b_data + bi->bi_offset,
			       bi->bi_len);
		}
		gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
		gfs2_setbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
			    bi->bi_len, buf_blk, new_state);
	}

	return rgd;
}

/**
 * gfs2_alloc_data - Allocate a data block
 * @ip: the inode to allocate the data block for
 *
 * Returns: the allocated block
 */

u64 gfs2_alloc_data(struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_alloc *al = &ip->i_alloc;
	struct gfs2_rgrpd *rgd = al->al_rgd;
	u32 goal, blk;
	u64 block;

	if (rgrp_contains_block(rgd, ip->i_di.di_goal_data))
		goal = ip->i_di.di_goal_data - rgd->rd_data0;
	else
		goal = rgd->rd_last_alloc_data;

	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
	BUG_ON(blk == BFITNOENT);
	rgd->rd_last_alloc_data = blk;

	block = rgd->rd_data0 + blk;
	ip->i_di.di_goal_data = block;

	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
	rgd->rd_rg.rg_free--;

	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	al->al_alloced++;

	gfs2_statfs_change(sdp, 0, -1, 0);
	gfs2_quota_change(ip, +1, ip->i_inode.i_uid, ip->i_inode.i_gid);

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone--;
	spin_unlock(&sdp->sd_rindex_spin);

	return block;
}

/**
 * gfs2_alloc_meta - Allocate a metadata block
 * @ip: the inode to allocate the metadata block for
 *
 * Returns: the allocated block
 */

u64 gfs2_alloc_meta(struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_alloc *al = &ip->i_alloc;
	struct gfs2_rgrpd *rgd = al->al_rgd;
	u32 goal, blk;
	u64 block;

	if (rgrp_contains_block(rgd, ip->i_di.di_goal_meta))
		goal = ip->i_di.di_goal_meta - rgd->rd_data0;
	else
		goal = rgd->rd_last_alloc_meta;

	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED);
	BUG_ON(blk == BFITNOENT);
	rgd->rd_last_alloc_meta = blk;

	block = rgd->rd_data0 + blk;
	ip->i_di.di_goal_meta = block;

	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
	rgd->rd_rg.rg_free--;

	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	al->al_alloced++;

	gfs2_statfs_change(sdp, 0, -1, 0);
	gfs2_quota_change(ip, +1, ip->i_inode.i_uid, ip->i_inode.i_gid);
	gfs2_trans_add_unrevoke(sdp, block);

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone--;
	spin_unlock(&sdp->sd_rindex_spin);

	return block;
}

/**
 * gfs2_alloc_di - Allocate a dinode
 * @dip: the directory that the inode is going in
 *
 * Returns: the block allocated
 */

u64 gfs2_alloc_di(struct gfs2_inode *dip, u64 *generation)
{
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_alloc *al = &dip->i_alloc;
	struct gfs2_rgrpd *rgd = al->al_rgd;
	u32 blk;
	u64 block;

	blk = rgblk_search(rgd, rgd->rd_last_alloc_meta,
			   GFS2_BLKST_FREE, GFS2_BLKST_DINODE);
	BUG_ON(blk == BFITNOENT);

	rgd->rd_last_alloc_meta = blk;

	block = rgd->rd_data0 + blk;

	gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free);
	rgd->rd_rg.rg_free--;
	rgd->rd_rg.rg_dinodes++;
	*generation = rgd->rd_rg.rg_igeneration++;
	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	al->al_alloced++;

	gfs2_statfs_change(sdp, 0, -1, +1);
	gfs2_trans_add_unrevoke(sdp, block);

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone--;
	spin_unlock(&sdp->sd_rindex_spin);

	return block;
}

/**
 * gfs2_free_data - free a contiguous run of data block(s)
 * @ip: the inode these blocks are being freed from
 * @bstart: first block of a run of contiguous blocks
 * @blen: the length of the block run
 *
 */

void gfs2_free_data(struct gfs2_inode *ip, u64 bstart, u32 blen)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_rgrpd *rgd;

	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
	if (!rgd)
		return;

	rgd->rd_rg.rg_free += blen;

	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	gfs2_trans_add_rg(rgd);

	gfs2_statfs_change(sdp, 0, +blen, 0);
	gfs2_quota_change(ip, -(s64)blen, ip->i_inode.i_uid, ip->i_inode.i_gid);
}

/**
 * gfs2_free_meta - free a contiguous run of data block(s)
 * @ip: the inode these blocks are being freed from
 * @bstart: first block of a run of contiguous blocks
 * @blen: the length of the block run
 *
 */

void gfs2_free_meta(struct gfs2_inode *ip, u64 bstart, u32 blen)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_rgrpd *rgd;

	rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
	if (!rgd)
		return;

	rgd->rd_rg.rg_free += blen;

	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	gfs2_trans_add_rg(rgd);

	gfs2_statfs_change(sdp, 0, +blen, 0);
	gfs2_quota_change(ip, -(s64)blen, ip->i_inode.i_uid, ip->i_inode.i_gid);
	gfs2_meta_wipe(ip, bstart, blen);
}

void gfs2_unlink_di(struct inode *inode)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_rgrpd *rgd;
	u64 blkno = ip->i_no_addr;

	rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_UNLINKED);
	if (!rgd)
		return;
	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
	gfs2_trans_add_rg(rgd);
}

static void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, u64 blkno)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	struct gfs2_rgrpd *tmp_rgd;

	tmp_rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_FREE);
	if (!tmp_rgd)
		return;
	gfs2_assert_withdraw(sdp, rgd == tmp_rgd);

	if (!rgd->rd_rg.rg_dinodes)
		gfs2_consist_rgrpd(rgd);
	rgd->rd_rg.rg_dinodes--;
	rgd->rd_rg.rg_free++;

	gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
	gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);

	gfs2_statfs_change(sdp, 0, +1, -1);
	gfs2_trans_add_rg(rgd);
}


void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
{
	gfs2_free_uninit_di(rgd, ip->i_no_addr);
	gfs2_quota_change(ip, -1, ip->i_inode.i_uid, ip->i_inode.i_gid);
	gfs2_meta_wipe(ip, ip->i_no_addr, 1);
}

/**
 * gfs2_rlist_add - add a RG to a list of RGs
 * @sdp: the filesystem
 * @rlist: the list of resource groups
 * @block: the block
 *
 * Figure out what RG a block belongs to and add that RG to the list
 *
 * FIXME: Don't use NOFAIL
 *
 */

void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist,
		    u64 block)
{
	struct gfs2_rgrpd *rgd;
	struct gfs2_rgrpd **tmp;
	unsigned int new_space;
	unsigned int x;

	if (gfs2_assert_warn(sdp, !rlist->rl_ghs))
		return;

	rgd = gfs2_blk2rgrpd(sdp, block);
	if (!rgd) {
		if (gfs2_consist(sdp))
			fs_err(sdp, "block = %llu\n", (unsigned long long)block);
		return;
	}

	for (x = 0; x < rlist->rl_rgrps; x++)
		if (rlist->rl_rgd[x] == rgd)
			return;

	if (rlist->rl_rgrps == rlist->rl_space) {
		new_space = rlist->rl_space + 10;

		tmp = kcalloc(new_space, sizeof(struct gfs2_rgrpd *),
			      GFP_NOFS | __GFP_NOFAIL);

		if (rlist->rl_rgd) {
			memcpy(tmp, rlist->rl_rgd,
			       rlist->rl_space * sizeof(struct gfs2_rgrpd *));
			kfree(rlist->rl_rgd);
		}

		rlist->rl_space = new_space;
		rlist->rl_rgd = tmp;
	}

	rlist->rl_rgd[rlist->rl_rgrps++] = rgd;
}

/**
 * gfs2_rlist_alloc - all RGs have been added to the rlist, now allocate
 *      and initialize an array of glock holders for them
 * @rlist: the list of resource groups
 * @state: the lock state to acquire the RG lock in
 * @flags: the modifier flags for the holder structures
 *
 * FIXME: Don't use NOFAIL
 *
 */

void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state,
		      int flags)
{
	unsigned int x;

	rlist->rl_ghs = kcalloc(rlist->rl_rgrps, sizeof(struct gfs2_holder),
				GFP_NOFS | __GFP_NOFAIL);
	for (x = 0; x < rlist->rl_rgrps; x++)
		gfs2_holder_init(rlist->rl_rgd[x]->rd_gl,
				state, flags,
				&rlist->rl_ghs[x]);
}

/**
 * gfs2_rlist_free - free a resource group list
 * @list: the list of resource groups
 *
 */

void gfs2_rlist_free(struct gfs2_rgrp_list *rlist)
{
	unsigned int x;

	kfree(rlist->rl_rgd);

	if (rlist->rl_ghs) {
		for (x = 0; x < rlist->rl_rgrps; x++)
			gfs2_holder_uninit(&rlist->rl_ghs[x]);
		kfree(rlist->rl_ghs);
	}
}