path: root/fs/fuse/file.c

/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/compat.h>

static const struct file_operations fuse_direct_io_file_operations;

static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
			  int opcode, struct fuse_open_out *outargp)
{
	struct fuse_open_in inarg;
	struct fuse_req *req;
	int err;

	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);

	memset(&inarg, 0, sizeof(inarg));
	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
	if (!fc->atomic_o_trunc)
		inarg.flags &= ~O_TRUNC;
	req->in.h.opcode = opcode;
	req->in.h.nodeid = nodeid;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(*outargp);
	req->out.args[0].value = outargp;
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);

	return err;
}

struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
{
	struct fuse_file *ff;

	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	if (unlikely(!ff))
		return NULL;

	ff->fc = fc;
	ff->reserved_req = fuse_request_alloc();
	if (unlikely(!ff->reserved_req)) {
		kfree(ff);
		return NULL;
	}

	INIT_LIST_HEAD(&ff->write_entry);
	atomic_set(&ff->count, 0);
	RB_CLEAR_NODE(&ff->polled_node);
	init_waitqueue_head(&ff->poll_wait);

	spin_lock(&fc->lock);
	ff->kh = ++fc->khctr;
	spin_unlock(&fc->lock);

	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
	fuse_request_free(ff->reserved_req);
	kfree(ff);
}

struct fuse_file *fuse_file_get(struct fuse_file *ff)
{
	atomic_inc(&ff->count);
	return ff;
}

static void fuse_release_async(struct work_struct *work)
{
	struct fuse_req *req;
	struct fuse_conn *fc;
	struct path path;

	req = container_of(work, struct fuse_req, misc.release.work);
	path = req->misc.release.path;
	fc = get_fuse_conn(path.dentry->d_inode);

	fuse_put_request(fc, req);
	path_put(&path);
}

static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
	if (fc->destroy_req) {
		/*
		 * If this is a fuseblk mount, then it's possible that
		 * releasing the path will result in releasing the
		 * super block and sending the DESTROY request.  If
		 * the server is single threaded, this would hang.
		 * For this reason do the path_put() in a separate
		 * thread.
		 */
		atomic_inc(&req->count);
		INIT_WORK(&req->misc.release.work, fuse_release_async);
		schedule_work(&req->misc.release.work);
	} else {
		path_put(&req->misc.release.path);
	}
}

static void fuse_file_put(struct fuse_file *ff, bool sync)
{
	if (atomic_dec_and_test(&ff->count)) {
		struct fuse_req *req = ff->reserved_req;

		if (sync) {
			fuse_request_send(ff->fc, req);
			path_put(&req->misc.release.path);
			fuse_put_request(ff->fc, req);
		} else {
			req->end = fuse_release_end;
			fuse_request_send_background(ff->fc, req);
		}
		kfree(ff);
	}
}

int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
		 bool isdir)
{
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;
	int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;

	ff = fuse_file_alloc(fc);
	if (!ff)
		return -ENOMEM;

	err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
	if (err) {
		fuse_file_free(ff);
		return err;
	}

	if (isdir)
		outarg.open_flags &= ~FOPEN_DIRECT_IO;

	ff->fh = outarg.fh;
	ff->nodeid = nodeid;
	ff->open_flags = outarg.open_flags;
	file->private_data = fuse_file_get(ff);

	return 0;
}
EXPORT_SYMBOL_GPL(fuse_do_open);

void fuse_finish_open(struct inode *inode, struct file *file)
{
	struct fuse_file *ff = file->private_data;
	struct fuse_conn *fc = get_fuse_conn(inode);

	if (ff->open_flags & FOPEN_DIRECT_IO)
		file->f_op = &fuse_direct_io_file_operations;
	if (!(ff->open_flags & FOPEN_KEEP_CACHE))
		invalidate_inode_pages2(inode->i_mapping);
	if (ff->open_flags & FOPEN_NONSEEKABLE)
		nonseekable_open(inode, file);
	if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
		struct fuse_inode *fi = get_fuse_inode(inode);

		spin_lock(&fc->lock);
		fi->attr_version = ++fc->attr_version;
		i_size_write(inode, 0);
		spin_unlock(&fc->lock);
		fuse_invalidate_attr(inode);
	}
}

int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	int err;

	/* VFS checks this, but only _after_ ->open() */
	if (file->f_flags & O_DIRECT)
		return -EINVAL;

	err = generic_file_open(inode, file);
	if (err)
		return err;

	err = fuse_do_open(fc, get_node_id(inode), file, isdir);
	if (err)
		return err;

	fuse_finish_open(inode, file);

	return 0;
}

static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode)
{
	struct fuse_conn *fc = ff->fc;
	struct fuse_req *req = ff->reserved_req;
	struct fuse_release_in *inarg = &req->misc.release.in;

	spin_lock(&fc->lock);
	list_del(&ff->write_entry);
	if (!RB_EMPTY_NODE(&ff->polled_node))
		rb_erase(&ff->polled_node, &fc->polled_files);
	spin_unlock(&fc->lock);

	wake_up_interruptible_all(&ff->poll_wait);

	inarg->fh = ff->fh;
	inarg->flags = flags;
	req->in.h.opcode = opcode;
	req->in.h.nodeid = ff->nodeid;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
}

void fuse_release_common(struct file *file, int opcode)
{
	struct fuse_file *ff;
	struct fuse_req *req;

	ff = file->private_data;
	if (unlikely(!ff))
		return;

	req = ff->reserved_req;
	fuse_prepare_release(ff, file->f_flags, opcode);

	/* Hold vfsmount and dentry until release is finished */
	path_get(&file->f_path);
	req->misc.release.path = file->f_path;

	/*
	 * Normally this will send the RELEASE request, however if
	 * some asynchronous READ or WRITE requests are outstanding,
	 * the sending will be delayed.
	 *
	 * Make the release synchronous if this is a fuseblk mount,
	 * synchronous RELEASE is allowed (and desirable) in this case
	 * because the server can be trusted not to screw up.
	 */
	fuse_file_put(ff, ff->fc->destroy_req != NULL);
}

static int fuse_open(struct inode *inode, struct file *file)
{
	return fuse_open_common(inode, file, false);
}

static int fuse_release(struct inode *inode, struct file *file)
{
	fuse_release_common(file, FUSE_RELEASE);

	/* return value is ignored by VFS */
	return 0;
}

void fuse_sync_release(struct fuse_file *ff, int flags)
{
	WARN_ON(atomic_read(&ff->count) > 1);
	fuse_prepare_release(ff, flags, FUSE_RELEASE);
	ff->reserved_req->force = 1;
	fuse_request_send(ff->fc, ff->reserved_req);
	fuse_put_request(ff->fc, ff->reserved_req);
	kfree(ff);
}
EXPORT_SYMBOL_GPL(fuse_sync_release);

/*
 * Scramble the ID space with XTEA, so that the value of the files_struct
 * pointer is not exposed to userspace.
 */
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
{
	u32 *k = fc->scramble_key;
	u64 v = (unsigned long) id;
	u32 v0 = v;
	u32 v1 = v >> 32;
	u32 sum = 0;
	int i;

	for (i = 0; i < 32; i++) {
		v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
		sum += 0x9E3779B9;
		v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
	}

	return (u64) v0 + ((u64) v1 << 32);
}

/*
 * Check if page is under writeback
 *
 * This is currently done by walking the list of writepage requests
 * for the inode, which can be pretty inefficient.
 */
static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	struct fuse_req *req;
	bool found = false;

	spin_lock(&fc->lock);
	list_for_each_entry(req, &fi->writepages, writepages_entry) {
		pgoff_t curr_index;

		BUG_ON(req->inode != inode);
		curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT;
		if (curr_index == index) {
			found = true;
			break;
		}
	}
	spin_unlock(&fc->lock);

	return found;
}

/*
 * Wait for page writeback to be completed.
 *
 * Since fuse doesn't rely on the VM writeback tracking, this has to
 * use some other means.
 */
static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
{
	struct fuse_inode *fi = get_fuse_inode(inode);

	wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
	return 0;
}

static int fuse_flush(struct file *file, fl_owner_t id)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_flush_in inarg;
	int err;

	if (is_bad_inode(inode))
		return -EIO;

	if (fc->no_flush)
		return 0;

	req = fuse_get_req_nofail(fc, file);
	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.lock_owner = fuse_lock_owner_id(fc, id);
	req->in.h.opcode = FUSE_FLUSH;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->force = 1;
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_flush = 1;
		err = 0;
	}
	return err;
}

/*
 * Wait for all pending writepages on the inode to finish.
 *
 * This is currently done by blocking further writes with FUSE_NOWRITE
 * and waiting for all sent writes to complete.
 *
 * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
 * could conflict with truncation.
 */
static void fuse_sync_writes(struct inode *inode)
{
	fuse_set_nowrite(inode);
	fuse_release_nowrite(inode);
}

int fuse_fsync_common(struct file *file, int datasync, int isdir)
{
	struct inode *inode = file->f_mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_fsync_in inarg;
	int err;

	if (is_bad_inode(inode))
		return -EIO;

	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
		return 0;

	/*
	 * Start writeback against all dirty pages of the inode, then
	 * wait for all outstanding writes, before sending the FSYNC
	 * request.
	 */
	err = write_inode_now(inode, 0);
	if (err)
		return err;

	fuse_sync_writes(inode);

	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
	req->in.h.nodeid = get_node_id(inode);
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
		err = 0;
	}
	return err;
}

static int fuse_fsync(struct file *file, int datasync)
{
	return fuse_fsync_common(file, datasync, 0);
}

void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos,
		    size_t count, int opcode)
{
	struct fuse_read_in *inarg = &req->misc.read.in;
	struct fuse_file *ff = file->private_data;

	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;ate ra_state;
	u64 rgrp_count = i_size_read(inode);
	struct gfs2_rgrpd *rgd;
	unsigned int max_data = 0;
	int error;

	do_div(rgrp_count, sizeof(struct gfs2_rindex));
	clear_rgrpdi(sdp);

	file_ra_state_init(&ra_state, inode->i_mapping);
	for (sdp->sd_rgrps = 0; sdp->sd_rgrps < rgrp_count; sdp->sd_rgrps++) {
		error = read_rindex_entry(ip, &ra_state);
		if (error) {
			clear_rgrpdi(sdp);
			return error;
		}
	}

	list_for_each_entry(rgd, &sdp->sd_rindex_list, rd_list)
		if (rgd->rd_data > max_data)
			max_data = rgd->rd_data;
	sdp->sd_max_rg_data = max_data;
	sdp->sd_rindex_uptodate = 1;
	return 0;
}

/**
 * gfs2_rindex_hold - Grab a lock on the rindex
 * @sdp: The GFS2 superblock
 * @ri_gh: the glock holder
 *
 * We grab a lock on the rindex inode to make sure that it doesn't
 * change whilst we are performing an operation. We keep this lock
 * for quite long periods of time compared to other locks. This
 * doesn't matter, since it is shared and it is very, very rarely
 * accessed in the exclusive mode (i.e. only when expanding the filesystem).
 *
 * This makes sure that we're using the latest copy of the resource index
 * special file, which might have been updated if someone expanded the
 * filesystem (via gfs2_grow utility), which adds new resource groups.
 *
 * Returns: 0 on success, error code otherwise
 */

int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh)
{
	struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
	struct gfs2_glock *gl = ip->i_gl;
	int error;

	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, ri_gh);
	if (error)
		return error;

	/* Read new copy from disk if we don't have the latest */
	if (!sdp->sd_rindex_uptodate) {
		mutex_lock(&sdp->sd_rindex_mutex);
		if (!sdp->sd_rindex_uptodate) {
			error = gfs2_ri_update(ip);
			if (error)
				gfs2_glock_dq_uninit(ri_gh);
		}
		mutex_unlock(&sdp->sd_rindex_mutex);
	}

	return error;
}

static void gfs2_rgrp_in(struct gfs2_rgrpd *rgd, const void *buf)
{
	const struct gfs2_rgrp *str = buf;
	u32 rg_flags;

	rg_flags = be32_to_cpu(str->rg_flags);
	rg_flags &= ~GFS2_RDF_MASK;
	rgd->rd_flags &= GFS2_RDF_MASK;
	rgd->rd_flags |= rg_flags;
	rgd->rd_free = be32_to_cpu(str->rg_free);
	rgd->rd_dinodes = be32_to_cpu(str->rg_dinodes);
	rgd->rd_igeneration = be64_to_cpu(str->rg_igeneration);
}

static void gfs2_rgrp_out(struct gfs2_rgrpd *rgd, void *buf)
{
	struct gfs2_rgrp *str = buf;

	str->rg_flags = cpu_to_be32(rgd->rd_flags & ~GFS2_RDF_MASK);
	str->rg_free = cpu_to_be32(rgd->rd_free);
	str->rg_dinodes = cpu_to_be32(rgd->rd_dinodes);
	str->__pad = cpu_to_be32(0);
	str->rg_igeneration = cpu_to_be64(rgd->rd_igeneration);
	memset(&str->rg_reserved, 0, sizeof(str->rg_reserved));
}

/**
 * gfs2_rgrp_bh_get - Read in a RG's header and bitmaps
 * @rgd: the struct gfs2_rgrpd describing the RG to read in
 *
 * Read in all of a Resource Group's header and bitmap blocks.
 * Caller must eventually call gfs2_rgrp_relse() to free the bitmaps.
 *
 * Returns: errno
 */

int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	struct gfs2_glock *gl = rgd->rd_gl;
	unsigned int length = rgd->rd_length;
	struct gfs2_bitmap *bi;
	unsigned int x, y;
	int error;

	mutex_lock(&rgd->rd_mutex);

	spin_lock(&sdp->sd_rindex_spin);
	if (rgd->rd_bh_count) {
		rgd->rd_bh_count++;
		spin_unlock(&sdp->sd_rindex_spin);
		mutex_unlock(&rgd->rd_mutex);
		return 0;
	}
	spin_unlock(&sdp->sd_rindex_spin);

	for (x = 0; x < length; x++) {
		bi = rgd->rd_bits + x;
		error = gfs2_meta_read(gl, rgd->rd_addr + x, 0, &bi->bi_bh);
		if (error)
			goto fail;
	}

	for (y = length; y--;) {
		bi = rgd->rd_bits + y;
		error = gfs2_meta_wait(sdp, bi->bi_bh);
		if (error)
			goto fail;
		if (gfs2_metatype_check(sdp, bi->bi_bh, y ? GFS2_METATYPE_RB :
					      GFS2_METATYPE_RG)) {
			error = -EIO;
			goto fail;
		}
	}

	if (!(rgd->rd_flags & GFS2_RDF_UPTODATE)) {
		for (x = 0; x < length; x++)
			clear_bit(GBF_FULL, &rgd->rd_bits[x].bi_flags);
		gfs2_rgrp_in(rgd, (rgd->rd_bits[0].bi_bh)->b_data);
		rgd->rd_flags |= (GFS2_RDF_UPTODATE | GFS2_RDF_CHECK);
	}

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone = rgd->rd_free;
	rgd->rd_bh_count++;
	spin_unlock(&sdp->sd_rindex_spin);

	mutex_unlock(&rgd->rd_mutex);

	return 0;

fail:
	while (x--) {
		bi = rgd->rd_bits + x;
		brelse(bi->bi_bh);
		bi->bi_bh = NULL;
		gfs2_assert_warn(sdp, !bi->bi_clone);
	}
	mutex_unlock(&rgd->rd_mutex);

	return error;
}

void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;

	spin_lock(&sdp->sd_rindex_spin);
	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
	rgd->rd_bh_count++;
	spin_unlock(&sdp->sd_rindex_spin);
}

/**
 * gfs2_rgrp_bh_put - Release RG bitmaps read in with gfs2_rgrp_bh_get()
 * @rgd: the struct gfs2_rgrpd describing the RG to read in
 *
 */

void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	int x, length = rgd->rd_length;

	spin_lock(&sdp->sd_rindex_spin);
	gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count);
	if (--rgd->rd_bh_count) {
		spin_unlock(&sdp->sd_rindex_spin);
		return;
	}

	for (x = 0; x < length; x++) {
		struct gfs2_bitmap *bi = rgd->rd_bits + x;
		kfree(bi->bi_clone);
		bi->bi_clone = NULL;
		brelse(bi->bi_bh);
		bi->bi_bh = NULL;
	}

	spin_unlock(&sdp->sd_rindex_spin);
}

static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
				    const struct gfs2_bitmap *bi)
{
	struct super_block *sb = sdp->sd_vfs;
	struct block_device *bdev = sb->s_bdev;
	const unsigned int sects_per_blk = sdp->sd_sb.sb_bsize /
					   bdev_logical_block_size(sb->s_bdev);
	u64 blk;
	sector_t start = 0;
	sector_t nr_sects = 0;
	int rv;
	unsigned int x;

	for (x = 0; x < bi->bi_len; x++) {
		const u8 *orig = bi->bi_bh->b_data + bi->bi_offset + x;
		const u8 *clone = bi->bi_clone + bi->bi_offset + x;
		u8 diff = ~(*orig | (*orig >> 1)) & (*clone | (*clone >> 1));
		diff &= 0x55;
		if (diff == 0)
			continue;
		blk = offset + ((bi->bi_start + x) * GFS2_NBBY);
		blk *= sects_per_blk; /* convert to sectors */
		while(diff) {
			if (diff & 1) {
				if (nr_sects == 0)
					goto start_new_extent;
				if ((start + nr_sects) != blk) {
					rv = blkdev_issue_discard(bdev, start,
							    nr_sects, GFP_NOFS,
							    0);
					if (rv)
						goto fail;
					nr_sects = 0;
start_new_extent:
					start = blk;
				}
				nr_sects += sects_per_blk;
			}
			diff >>= 2;
			blk += sects_per_blk;
		}
	}
	if (nr_sects) {
		rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS, 0);
		if (rv)
			goto fail;
	}
	return;
fail:
	fs_warn(sdp, "error %d on discard request, turning discards off for this filesystem", rv);
	sdp->sd_args.ar_discard = 0;
}

void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	unsigned int length = rgd->rd_length;
	unsigned int x;

	for (x = 0; x < length; x++) {
		struct gfs2_bitmap *bi = rgd->rd_bits + x;
		if (!bi->bi_clone)
			continue;
		if (sdp->sd_args.ar_discard)
			gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bi);
		clear_bit(GBF_FULL, &bi->bi_flags);
		memcpy(bi->bi_clone + bi->bi_offset,
		       bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
	}

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

/**
 * gfs2_alloc_get - get the struct gfs2_alloc structure for an inode
 * @ip: the incore GFS2 inode structure
 *
 * Returns: the struct gfs2_alloc
 */

struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip)
{
	BUG_ON(ip->i_alloc != NULL);
	ip->i_alloc = kzalloc(sizeof(struct gfs2_alloc), GFP_NOFS);
	return ip->i_alloc;
}

/**
 * try_rgrp_fit - See if a given reservation will fit in a given RG
 * @rgd: the RG data
 * @al: the struct gfs2_alloc structure describing the reservation
 *
 * If there's room for the requested blocks to be allocated from the RG:
 *   Sets the $al_rgd field in @al.
 *
 * Returns: 1 on success (it fits), 0 on failure (it doesn't fit)
 */

static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	int ret = 0;

	if (rgd->rd_flags & (GFS2_RGF_NOALLOC | GFS2_RDF_ERROR))
		return 0;

	spin_lock(&sdp->sd_rindex_spin);
	if (rgd->rd_free_clone >= al->al_requested) {
		al->al_rgd = rgd;
		ret = 1;
	}
	spin_unlock(&sdp->sd_rindex_spin);

	return ret;
}

/**
 * try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes
 * @rgd: The rgrp
 *
 * Returns: 0 if no error
 *          The inode, if one has been found, in inode.
 */

static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip)
{
	u32 goal = 0, block;
	u64 no_addr;
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	unsigned int n;
	struct gfs2_glock *gl;
	struct gfs2_inode *ip;
	int error;
	int found = 0;

	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);
		up_write(&sdp->sd_log_flush_lock);
		if (block == BFITNOENT)
			break;
		/* rgblk_search can return a block < goal, so we need to
		   keep it marching forward. */
		no_addr = block + rgd->rd_data0;
		goal = max(block + 1, goal + 1);
		if (*last_unlinked != NO_BLOCK && no_addr <= *last_unlinked)
			continue;
		if (no_addr == skip)
			continue;
		*last_unlinked = no_addr;

		error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &gl);
		if (error)
			continue;

		/* If the inode is already in cache, we can ignore it here
		 * because the existing inode disposal code will deal with
		 * it when all refs have gone away. Accessing gl_object like
		 * this is not safe in general. Here it is ok because we do
		 * not dereference the pointer, and we only need an approx
		 * answer to whether it is NULL or not.
		 */
		ip = gl->gl_object;

		if (ip || queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 0)
			gfs2_glock_put(gl);
		else
			found++;

		/* Limit reclaim to sensible number of tasks */
		if (found > NR_CPUS)
			return;
	}

	rgd->rd_flags &= ~GFS2_RDF_CHECK;
	return;
}

/**
 * recent_rgrp_next - get next RG from "recent" list
 * @cur_rgd: current rgrp
 *
 * Returns: The next rgrp in the recent list
 */

static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd)
{
	struct gfs2_sbd *sdp = cur_rgd->rd_sbd;
	struct list_head *head;
	struct gfs2_rgrpd *rgd;

	spin_lock(&sdp->sd_rindex_spin);
	head = &sdp->sd_rindex_mru_list;
	if (unlikely(cur_rgd->rd_list_mru.next == head)) {
		spin_unlock(&sdp->sd_rindex_spin);
		return NULL;
	}
	rgd = list_entry(cur_rgd->rd_list_mru.next, struct gfs2_rgrpd, rd_list_mru);
	spin_unlock(&sdp->sd_rindex_spin);
	return rgd;
}

/**
 * forward_rgrp_get - get an rgrp to try next from full list
 * @sdp: The GFS2 superblock
 *
 * Returns: The rgrp to try next
 */

static struct gfs2_rgrpd *forward_rgrp_get(struct gfs2_sbd *sdp)
{
	struct gfs2_rgrpd *rgd;
	unsigned int journals = gfs2_jindex_size(sdp);
	unsigned int rg = 0, x;

	spin_lock(&sdp->sd_rindex_spin);

	rgd = sdp->sd_rindex_forward;
	if (!rgd) {
		if (sdp->sd_rgrps >= journals)
			rg = sdp->sd_rgrps * sdp->sd_jdesc->jd_jid / journals;

		for (x = 0, rgd = gfs2_rgrpd_get_first(sdp); x < rg;
		     x++, rgd = gfs2_rgrpd_get_next(rgd))
			/* Do Nothing */;

		sdp->sd_rindex_forward = rgd;
	}

	spin_unlock(&sdp->sd_rindex_spin);

	return rgd;
}

/**
 * forward_rgrp_set - set the forward rgrp pointer
 * @sdp: the filesystem
 * @rgd: The new forward rgrp
 *
 */

static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd)
{
	spin_lock(&sdp->sd_rindex_spin);
	sdp->sd_rindex_forward = rgd;
	spin_unlock(&sdp->sd_rindex_spin);
}

/**
 * get_local_rgrp - Choose and lock a rgrp for allocation
 * @ip: the inode to reserve space for
 * @rgp: the chosen and locked rgrp
 *
 * Try to acquire rgrp in way which avoids contending with others.
 *
 * Returns: errno
 */

static int get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct gfs2_rgrpd *rgd, *begin = NULL;
	struct gfs2_alloc *al = ip->i_alloc;
	int flags = LM_FLAG_TRY;
	int skipped = 0;
	int loops = 0;
	int error, rg_locked;

	rgd = gfs2_blk2rgrpd(sdp, ip->i_goal);

	while (rgd) {
		rg_locked = 0;

		if (gfs2_glock_is_locked_by_me(rgd->rd_gl)) {
			rg_locked = 1;
			error = 0;
		} else {
			error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
						   LM_FLAG_TRY, &al->al_rgd_gh);
		}
		switch (error) {
		case 0:
			if (try_rgrp_fit(rgd, al))
				goto out;
			if (rgd->rd_flags & GFS2_RDF_CHECK)
				try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr);
			if (!rg_locked)
				gfs2_glock_dq_uninit(&al->al_rgd_gh);
			/* fall through */
		case GLR_TRYFAILED:
			rgd = recent_rgrp_next(rgd);
			break;

		default:
			return error;
		}
	}

	/* Go through full list of rgrps */

	begin = rgd = forward_rgrp_get(sdp);

	for (;;) {
		rg_locked = 0;

		if (gfs2_glock_is_locked_by_me(rgd->rd_gl)) {
			rg_locked = 1;
			error = 0;
		} else {
			error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, flags,
						   &al->al_rgd_gh);
		}
		switch (error) {
		case 0:
			if (try_rgrp_fit(rgd, al))
				goto out;
			if (rgd->rd_flags & GFS2_RDF_CHECK)
				try_rgrp_unlink(rgd, last_unlinked, ip->i_no_addr);
			if (!rg_locked)
				gfs2_glock_dq_uninit(&al->al_rgd_gh);
			break;

		case GLR_TRYFAILED:
			skipped++;
			break;

		default:
			return error;
		}

		rgd = gfs2_rgrpd_get_next(rgd);
		if (!rgd)
			rgd = gfs2_rgrpd_get_first(sdp);

		if (rgd == begin) {
			if (++loops >= 3)
				return -ENOSPC;
			if (!skipped)
				loops++;
			flags = 0;
			if (loops == 2)
				gfs2_log_flush(sdp, NULL);
		}
	}

out:
	if (begin) {
		spin_lock(&sdp->sd_rindex_spin);
		list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
		spin_unlock(&sdp->sd_rindex_spin);
		rgd = gfs2_rgrpd_get_next(rgd);
		if (!rgd)
			rgd = gfs2_rgrpd_get_first(sdp);
		forward_rgrp_set(sdp, rgd);
	}

	return 0;
}

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

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

	if (hold_rindex) {
		/* 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(ip);
		if (error)
			return error;
	}

try_again:
	do {
		error = get_local_rgrp(ip, &last_unlinked);
		/* If there is no space, flushing the log may release some */
		if (error) {
			if (ip == GFS2_I(sdp->sd_rindex) &&
			    !sdp->sd_rindex_uptodate) {
				error = gfs2_ri_update(ip);
				if (error)
					return error;
				goto try_again;
			}
			gfs2_log_flush(sdp, NULL);
		}
	} while (error && tries++ < 3);

	if (error) {
		if (hold_rindex && ip != GFS2_I(sdp->sd_rindex))
			gfs2_glock_dq_uninit(&al->al_ri_gh);
		return error;
	}

	/* no error, so we have the rgrp set in the inode's allocation. */
	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;
	if (al->al_rgd_gh.gh_gl)
		gfs2_glock_dq_uninit(&al->al_rgd_gh);
	if (ip != GFS2_I(sdp->sd_rindex) && al->al_ri_gh.gh_gl)
		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_*)
 */

static 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
 * @n: The extent length
 *
 * 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,
			unsigned int *n)
{
	struct gfs2_bitmap *bi = NULL;
	const u32 length = rgd->rd_length;
	u32 blk = BFITNOENT;
	unsigned int buf, x;
	const unsigned int elen = *n;
	const u8 *buffer = NULL;

	*n = 0;
	/* Find bitmap block that contains bits for goal block */
	for (buf = 0; buf < length; buf++) {
		bi = rgd->rd_bits + buf;
		/* Convert scope of "goal" from rgrp-wide to within found bit block */
		if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY) {
			goal -= bi->bi_start * GFS2_NBBY;
			goto do_search;
		}
	}
	buf = 0;
	goal = 0;

do_search:
	/* 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++) {
		bi = rgd->rd_bits + buf;

		if (test_bit(GBF_FULL, &bi->bi_flags) &&
		    (old_state == GFS2_BLKST_FREE))
			goto skip;

		/* The GFS2_BLKST_UNLINKED state doesn't apply to the clone
		   bitmaps, so we must search the originals for that. */
		buffer = bi->bi_bh->b_data + bi->bi_offset;
		if (old_state != GFS2_BLKST_UNLINKED && bi->bi_clone)
			buffer = bi->bi_clone + bi->bi_offset;

		blk = gfs2_bitfit(buffer, bi->bi_len, goal, old_state);
		if (blk != BFITNOENT)
			break;

		if ((goal == 0) && (old_state == GFS2_BLKST_FREE))
			set_bit(GBF_FULL, &bi->bi_flags);

		/* Try next bitmap block (wrap back to rgrp header if at end) */
skip:
		buf++;
		buf %= length;
		goal = 0;
	}

	if (blk == BFITNOENT)
		return blk;
	*n = 1;
	if (old_state == new_state)
		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);
	goal = blk;
	while (*n < elen) {
		goal++;
		if (goal >= (bi->bi_len * GFS2_NBBY))
			break;
		if (gfs2_testbit(rgd, buffer, bi->bi_len, goal) !=
		    GFS2_BLKST_FREE)
			break;
		gfs2_setbit(rgd, bi->bi_bh->b_data, bi->bi_clone, bi->bi_offset,
			    bi, goal, new_state);
		(*n)++;
	}
out:
	return (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, NULL, bi->bi_offset,
			    bi, buf_blk, new_state);
	}

	return rgd;
}

/**
 * gfs2_rgrp_dump - print out an rgrp
 * @seq: The iterator
 * @gl: The glock in question
 *
 */

int gfs2_rgrp_dump(struct seq_file *seq, const struct gfs2_glock *gl)
{
	const struct gfs2_rgrpd *rgd = gl->gl_object;
	if (rgd == NULL)
		return 0;
	gfs2_print_dbg(seq, " R: n:%llu f:%02x b:%u/%u i:%u\n",
		       (unsigned long long)rgd->rd_addr, rgd->rd_flags,
		       rgd->rd_free, rgd->rd_free_clone, rgd->rd_dinodes);
	return 0;
}

static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd)
{
	struct gfs2_sbd *sdp = rgd->rd_sbd;
	fs_warn(sdp, "rgrp %llu has an error, marking it readonly until umount\n",
		(unsigned long long)rgd->rd_addr);
	fs_warn(sdp, "umount on all nodes and run fsck.gfs2 to fix the error\n");
	gfs2_rgrp_dump(NULL, rgd->rd_gl);
	rgd->rd_flags |= GFS2_RDF_ERROR;
}

/**
 * gfs2_alloc_block - Allocate one or more blocks
 * @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)
 *
 * Returns: 0 or error
 */

int gfs2_alloc_block(struct gfs2_inode *ip, u64 *bn, unsigned int *n)
{
	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;
	u64 block;
	int error;

	/* Only happens if there is a bug in gfs2, return something distinctive
	 * to ensure that it is noticed.
	 */
	if (al == NULL)
		return -ECANCELED;

	rgd = al->al_rgd;

	if (rgrp_contains_block(rgd, ip->i_goal))
		goal = ip->i_goal - rgd->rd_data0;
	else
		goal = rgd->rd_last_alloc;

	blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, GFS2_BLKST_USED, n);

	/* Since all blocks are reserved in advance, this shouldn't happen */
	if (blk == BFITNOENT)
		goto rgrp_error;

	rgd->rd_last_alloc = blk;
	block = rgd->rd_data0 + blk;
	ip->i_goal = block;
	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error == 0) {
		struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		di->di_goal_meta = di->di_goal_data = cpu_to_be64(ip->i_goal);
		brelse(dibh);
	}
	if (rgd->rd_free < *n)
		goto rgrp_error;

	rgd->rd_free -= *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);

	al->al_alloced += *n;

	gfs2_statfs_change(sdp, 0, -(s64)*n, 0);
	gfs2_quota_change(ip, *n, ip->i_inode.i_uid, ip->i_inode.i_gid);

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone -= *n;
	spin_unlock(&sdp->sd_rindex_spin);
	trace_gfs2_block_alloc(ip, block, *n, GFS2_BLKST_USED);
	*bn = block;
	return 0;

rgrp_error:
	gfs2_rgrp_error(rgd);
	return -EIO;
}

/**
 * gfs2_alloc_di - Allocate a dinode
 * @dip: the directory that the inode is going in
 * @bn: the block number which is allocated
 * @generation: the generation number of the inode
 *
 * Returns: 0 on success or error
 */

int gfs2_alloc_di(struct gfs2_inode *dip, u64 *bn, 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;
	unsigned int n = 1;

	blk = rgblk_search(rgd, rgd->rd_last_alloc,
			   GFS2_BLKST_FREE, GFS2_BLKST_DINODE, &n);

	/* Since all blocks are reserved in advance, this shouldn't happen */
	if (blk == BFITNOENT)
		goto rgrp_error;

	rgd->rd_last_alloc = blk;
	block = rgd->rd_data0 + blk;
	if (rgd->rd_free == 0)
		goto rgrp_error;

	rgd->rd_free--;
	rgd->rd_dinodes++;
	*generation = rgd->rd_igeneration++;
	if (*generation == 0)
		*generation = rgd->rd_igeneration++;
	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);

	al->al_alloced++;

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

	spin_lock(&sdp->sd_rindex_spin);
	rgd->rd_free_clone--;
	spin_unlock(&sdp->sd_rindex_spin);
	trace_gfs2_block_alloc(dip, block, 1, GFS2_BLKST_DINODE);
	*bn = block;
	return 0;

rgrp_error:
	gfs2_rgrp_error(rgd);
	return -EIO;
}

/**
 * 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;
	trace_gfs2_block_alloc(ip, bstart, blen, GFS2_BLKST_FREE);
	rgd->rd_free += blen;

	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_trans_add_rg(rgd);

	/* Directories keep their data in the metadata address space */
	if (ip->i_depth)
		gfs2_meta_wipe(ip, bstart, blen);
}

/**
 * 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);

	__gfs2_free_data(ip, bstart, blen);
	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;
	trace_gfs2_block_alloc(ip, bstart, blen, GFS2_BLKST_FREE);
	rgd->rd_free += blen;

	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_trans_add_rg(rgd);
	gfs2_meta_wipe(ip, bstart, blen);
}

/**
 * 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);

	__gfs2_free_meta(ip, bstart, blen);
	gfs2_statfs_change(sdp, 0, +blen, 0);
	gfs2_quota_change(ip, -(s64)blen, ip->i_inode.i_uid, ip->i_inode.i_gid);
}

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;
	trace_gfs2_block_alloc(ip, blkno, 1, GFS2_BLKST_UNLINKED);
	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_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_dinodes)
		gfs2_consist_rgrpd(rgd);
	rgd->rd_dinodes--;
	rgd->rd_free++;

	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, +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);
	trace_gfs2_block_alloc(ip, ip->i_no_addr, 1, GFS2_BLKST_FREE);
	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_check_blk_type - Check the type of a block
 * @sdp: The superblock
 * @no_addr: The block number to check
 * @type: The block type we are looking for
 *
 * Returns: 0 if the block type matches the expected type
 *          -ESTALE if it doesn't match
 *          or -ve errno if something went wrong while checking
 */

int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr, unsigned int type)
{
	struct gfs2_rgrpd *rgd;
	struct gfs2_holder ri_gh, rgd_gh;
	struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
	int ri_locked = 0;
	int error;

	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
		error = gfs2_rindex_hold(sdp, &ri_gh);
		if (error)
			goto fail;
		ri_locked = 1;
	}

	error = -EINVAL;
	rgd = gfs2_blk2rgrpd(sdp, no_addr);
	if (!rgd)
		goto fail_rindex;

	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	if (error)
		goto fail_rindex;

	if (gfs2_get_block_type(rgd, no_addr) != type)
		error = -ESTALE;

	gfs2_glock_dq_uninit(&rgd_gh);
fail_rindex:
	if (ri_locked)
		gfs2_glock_dq_uninit(&ri_gh);
fail:
	return error;
}

/**
 * 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)
{
	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, 0,
				&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);
	}
}