1 files changed, 793 insertions, 0 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
new file mode 100644
index 000000000000..8d5963c7e123
--- /dev/null
+++ b/fs/gfs2/ops_address.c
@@ -0,0 +1,793 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/mpage.h>
+#include <linux/fs.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/lm_interface.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "bmap.h"
+#include "glock.h"
+#include "inode.h"
+#include "log.h"
+#include "meta_io.h"
+#include "ops_address.h"
+#include "quota.h"
+#include "trans.h"
+#include "rgrp.h"
+#include "ops_file.h"
+#include "util.h"
+#include "glops.h"
+
+
+static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
+				   unsigned int from, unsigned int to)
+{
+	struct buffer_head *head = page_buffers(page);
+	unsigned int bsize = head->b_size;
+	struct buffer_head *bh;
+	unsigned int start, end;
+
+	for (bh = head, start = 0; bh != head || !start;
+	     bh = bh->b_this_page, start = end) {
+		end = start + bsize;
+		if (end <= from || start >= to)
+			continue;
+		gfs2_trans_add_bh(ip->i_gl, bh, 0);
+	}
+}
+
+/**
+ * gfs2_get_block - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+int gfs2_get_block(struct inode *inode, sector_t lblock,
+	           struct buffer_head *bh_result, int create)
+{
+	return gfs2_block_map(inode, lblock, create, bh_result);
+}
+
+/**
+ * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
+				  struct buffer_head *bh_result, int create)
+{
+	int error;
+
+	error = gfs2_block_map(inode, lblock, 0, bh_result);
+	if (error)
+		return error;
+	if (bh_result->b_blocknr == 0)
+		return -EIO;
+	return 0;
+}
+
+static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
+				 struct buffer_head *bh_result, int create)
+{
+	return gfs2_block_map(inode, lblock, 0, bh_result);
+}
+
+/**
+ * gfs2_writepage - Write complete page
+ * @page: Page to write
+ *
+ * Returns: errno
+ *
+ * Some of this is copied from block_write_full_page() although we still
+ * call it to do most of the work.
+ */
+
+static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	loff_t i_size = i_size_read(inode);
+	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	unsigned offset;
+	int error;
+	int done_trans = 0;
+
+	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
+		unlock_page(page);
+		return -EIO;
+	}
+	if (current->journal_info)
+		goto out_ignore;
+
+	/* Is the page fully outside i_size? (truncate in progress) */
+        offset = i_size & (PAGE_CACHE_SIZE-1);
+	if (page->index > end_index || (page->index == end_index && !offset)) {
+		page->mapping->a_ops->invalidatepage(page, 0);
+		unlock_page(page);
+		return 0; /* don't care */
+	}
+
+	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
+		error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
+		if (error)
+			goto out_ignore;
+		if (!page_has_buffers(page)) {
+			create_empty_buffers(page, inode->i_sb->s_blocksize,
+					     (1 << BH_Dirty)|(1 << BH_Uptodate));
+		}
+		gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
+		done_trans = 1;
+	}
+	error = block_write_full_page(page, gfs2_get_block_noalloc, wbc);
+	if (done_trans)
+		gfs2_trans_end(sdp);
+	gfs2_meta_cache_flush(ip);
+	return error;
+
+out_ignore:
+	redirty_page_for_writepage(wbc, page);
+	unlock_page(page);
+	return 0;
+}
+
+static int zero_readpage(struct page *page)
+{
+	void *kaddr;
+
+	kaddr = kmap_atomic(page, KM_USER0);
+	memset(kaddr, 0, PAGE_CACHE_SIZE);
+	kunmap_atomic(kaddr, KM_USER0);
+
+	SetPageUptodate(page);
+
+	return 0;
+}
+
+/**
+ * stuffed_readpage - Fill in a Linux page with stuffed file data
+ * @ip: the inode
+ * @page: the page
+ *
+ * Returns: errno
+ */
+
+static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
+{
+	struct buffer_head *dibh;
+	void *kaddr;
+	int error;
+
+	/* Only the first page of a stuffed file might contain data */
+	if (unlikely(page->index))
+		return zero_readpage(page);
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	kaddr = kmap_atomic(page, KM_USER0);
+	memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
+	       ip->i_di.di_size);
+	memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
+	kunmap_atomic(kaddr, KM_USER0);
+
+	brelse(dibh);
+
+	SetPageUptodate(page);
+
+	return 0;
+}
+
+
+/**
+ * gfs2_readpage - readpage with locking
+ * @file: The file to read a page for. N.B. This may be NULL if we are
+ * reading an internal file.
+ * @page: The page to read
+ *
+ * Returns: errno
+ */
+
+static int gfs2_readpage(struct file *file, struct page *page)
+{
+	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
+	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+	struct gfs2_file *gf = NULL;
+	struct gfs2_holder gh;
+	int error;
+	int do_unlock = 0;
+
+	if (likely(file != &gfs2_internal_file_sentinel)) {
+		if (file) {
+			gf = file->private_data;
+			if (test_bit(GFF_EXLOCK, &gf->f_flags))
+				/* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
+				goto skip_lock;
+		}
+		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh);
+		do_unlock = 1;
+		error = gfs2_glock_nq_m_atime(1, &gh);
+		if (unlikely(error))
+			goto out_unlock;
+	}
+
+skip_lock:
+	if (gfs2_is_stuffed(ip)) {
+		error = stuffed_readpage(ip, page);
+		unlock_page(page);
+	} else
+		error = mpage_readpage(page, gfs2_get_block);
+
+	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+		error = -EIO;
+
+	if (do_unlock) {
+		gfs2_glock_dq_m(1, &gh);
+		gfs2_holder_uninit(&gh);
+	}
+out:
+	return error;
+out_unlock:
+	unlock_page(page);
+	if (do_unlock)
+		gfs2_holder_uninit(&gh);
+	goto out;
+}
+
+/**
+ * gfs2_readpages - Read a bunch of pages at once
+ *
+ * Some notes:
+ * 1. This is only for readahead, so we can simply ignore any things
+ *    which are slightly inconvenient (such as locking conflicts between
+ *    the page lock and the glock) and return having done no I/O. Its
+ *    obviously not something we'd want to do on too regular a basis.
+ *    Any I/O we ignore at this time will be done via readpage later.
+ * 2. We have to handle stuffed files here too.
+ * 3. mpage_readpages() does most of the heavy lifting in the common case.
+ * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
+ * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
+ *    well as read-ahead.
+ */
+static int gfs2_readpages(struct file *file, struct address_space *mapping,
+			  struct list_head *pages, unsigned nr_pages)
+{
+	struct inode *inode = mapping->host;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct gfs2_holder gh;
+	unsigned page_idx;
+	int ret;
+	int do_unlock = 0;
+
+	if (likely(file != &gfs2_internal_file_sentinel)) {
+		if (file) {
+			struct gfs2_file *gf = file->private_data;
+			if (test_bit(GFF_EXLOCK, &gf->f_flags))
+				goto skip_lock;
+		}
+		gfs2_holder_init(ip->i_gl, LM_ST_SHARED,
+				 LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh);
+		do_unlock = 1;
+		ret = gfs2_glock_nq_m_atime(1, &gh);
+		if (ret == GLR_TRYFAILED)
+			goto out_noerror;
+		if (unlikely(ret))
+			goto out_unlock;
+	}
+skip_lock:
+	if (gfs2_is_stuffed(ip)) {
+		struct pagevec lru_pvec;
+		pagevec_init(&lru_pvec, 0);
+		for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+			struct page *page = list_entry(pages->prev, struct page, lru);
+			prefetchw(&page->flags);
+			list_del(&page->lru);
+			if (!add_to_page_cache(page, mapping,
+					       page->index, GFP_KERNEL)) {
+				ret = stuffed_readpage(ip, page);
+				unlock_page(page);
+				if (!pagevec_add(&lru_pvec, page))
+					 __pagevec_lru_add(&lru_pvec);
+			} else {
+				page_cache_release(page);
+			}
+		}
+		pagevec_lru_add(&lru_pvec);
+		ret = 0;
+	} else {
+		/* What we really want to do .... */
+		ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);
+	}
+
+	if (do_unlock) {
+		gfs2_glock_dq_m(1, &gh);
+		gfs2_holder_uninit(&gh);
+	}
+out:
+	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+		ret = -EIO;
+	return ret;
+out_noerror:
+	ret = 0;
+out_unlock:
+	/* unlock all pages, we can't do any I/O right now */
+	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+		struct page *page = list_entry(pages->prev, struct page, lru);
+		list_del(&page->lru);
+		unlock_page(page);
+		page_cache_release(page);
+	}
+	if (do_unlock)
+		gfs2_holder_uninit(&gh);
+	goto out;
+}
+
+/**
+ * gfs2_prepare_write - Prepare to write a page to a file
+ * @file: The file to write to
+ * @page: The page which is to be prepared for writing
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_prepare_write(struct file *file, struct page *page,
+			      unsigned from, unsigned to)
+{
+	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
+	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+	unsigned int data_blocks, ind_blocks, rblocks;
+	int alloc_required;
+	int error = 0;
+	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
+	loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+	struct gfs2_alloc *al;
+	unsigned int write_len = to - from;
+
+
+	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh);
+	error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
+	if (error)
+		goto out_uninit;
+
+	gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks);
+
+	error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required);
+	if (error)
+		goto out_unlock;
+
+
+	ip->i_alloc.al_requested = 0;
+	if (alloc_required) {
+		al = gfs2_alloc_get(ip);
+
+		error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
+		if (error)
+			goto out_alloc_put;
+
+		error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
+		if (error)
+			goto out_qunlock;
+
+		al->al_requested = data_blocks + ind_blocks;
+		error = gfs2_inplace_reserve(ip);
+		if (error)
+			goto out_qunlock;
+	}
+
+	rblocks = RES_DINODE + ind_blocks;
+	if (gfs2_is_jdata(ip))
+		rblocks += data_blocks ? data_blocks : 1;
+	if (ind_blocks || data_blocks)
+		rblocks += RES_STATFS + RES_QUOTA;
+
+	error = gfs2_trans_begin(sdp, rblocks, 0);
+	if (error)
+		goto out;
+
+	if (gfs2_is_stuffed(ip)) {
+		if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
+			error = gfs2_unstuff_dinode(ip, page);
+			if (error == 0)
+				goto prepare_write;
+		} else if (!PageUptodate(page))
+			error = stuffed_readpage(ip, page);
+		goto out;
+	}
+
+prepare_write:
+	error = block_prepare_write(page, from, to, gfs2_get_block);
+
+out:
+	if (error) {
+		gfs2_trans_end(sdp);
+		if (alloc_required) {
+			gfs2_inplace_release(ip);
+out_qunlock:
+			gfs2_quota_unlock(ip);
+out_alloc_put:
+			gfs2_alloc_put(ip);
+		}
+out_unlock:
+		gfs2_glock_dq_m(1, &ip->i_gh);
+out_uninit:
+		gfs2_holder_uninit(&ip->i_gh);
+	}
+
+	return error;
+}
+
+/**
+ * gfs2_commit_write - Commit write to a file
+ * @file: The file to write to
+ * @page: The page containing the data
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_commit_write(struct file *file, struct page *page,
+			     unsigned from, unsigned to)
+{
+	struct inode *inode = page->mapping->host;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	int error = -EOPNOTSUPP;
+	struct buffer_head *dibh;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_dinode *di;
+
+	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
+                goto fail_nounlock;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		goto fail_endtrans;
+
+	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+	di = (struct gfs2_dinode *)dibh->b_data;
+
+	if (gfs2_is_stuffed(ip)) {
+		u64 file_size;
+		void *kaddr;
+
+		file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to;
+
+		kaddr = kmap_atomic(page, KM_USER0);
+		memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
+		       kaddr + from, to - from);
+		kunmap_atomic(kaddr, KM_USER0);
+
+		SetPageUptodate(page);
+
+		if (inode->i_size < file_size)
+			i_size_write(inode, file_size);
+	} else {
+		if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
+		    gfs2_is_jdata(ip))
+			gfs2_page_add_databufs(ip, page, from, to);
+		error = generic_commit_write(file, page, from, to);
+		if (error)
+			goto fail;
+	}
+
+	if (ip->i_di.di_size < inode->i_size) {
+		ip->i_di.di_size = inode->i_size;
+		di->di_size = cpu_to_be64(inode->i_size);
+	}
+
+	di->di_mode = cpu_to_be32(inode->i_mode);
+	di->di_atime = cpu_to_be64(inode->i_atime.tv_sec);
+	di->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec);
+	di->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec);
+
+	brelse(dibh);
+	gfs2_trans_end(sdp);
+	if (al->al_requested) {
+		gfs2_inplace_release(ip);
+		gfs2_quota_unlock(ip);
+		gfs2_alloc_put(ip);
+	}
+	gfs2_glock_dq_m(1, &ip->i_gh);
+	gfs2_holder_uninit(&ip->i_gh);
+	return 0;
+
+fail:
+	brelse(dibh);
+fail_endtrans:
+	gfs2_trans_end(sdp);
+	if (al->al_requested) {
+		gfs2_inplace_release(ip);
+		gfs2_quota_unlock(ip);
+		gfs2_alloc_put(ip);
+	}
+	gfs2_glock_dq_m(1, &ip->i_gh);
+	gfs2_holder_uninit(&ip->i_gh);
+fail_nounlock:
+	ClearPageUptodate(page);
+	return error;
+}
+
+/**
+ * gfs2_bmap - Block map function
+ * @mapping: Address space info
+ * @lblock: The block to map
+ *
+ * Returns: The disk address for the block or 0 on hole or error
+ */
+
+static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
+{
+	struct gfs2_inode *ip = GFS2_I(mapping->host);
+	struct gfs2_holder i_gh;
+	sector_t dblock = 0;
+	int error;
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
+	if (error)
+		return 0;
+
+	if (!gfs2_is_stuffed(ip))
+		dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
+
+	gfs2_glock_dq_uninit(&i_gh);
+
+	return dblock;
+}
+
+static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	struct gfs2_bufdata *bd;
+
+	gfs2_log_lock(sdp);
+	bd = bh->b_private;
+	if (bd) {
+		bd->bd_bh = NULL;
+		bh->b_private = NULL;
+	}
+	gfs2_log_unlock(sdp);
+
+	lock_buffer(bh);
+	clear_buffer_dirty(bh);
+	bh->b_bdev = NULL;
+	clear_buffer_mapped(bh);
+	clear_buffer_req(bh);
+	clear_buffer_new(bh);
+	clear_buffer_delay(bh);
+	unlock_buffer(bh);
+}
+
+static void gfs2_invalidatepage(struct page *page, unsigned long offset)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+	struct buffer_head *head, *bh, *next;
+	unsigned int curr_off = 0;
+
+	BUG_ON(!PageLocked(page));
+	if (!page_has_buffers(page))
+		return;
+
+	bh = head = page_buffers(page);
+	do {
+		unsigned int next_off = curr_off + bh->b_size;
+		next = bh->b_this_page;
+
+		if (offset <= curr_off)
+			discard_buffer(sdp, bh);
+
+		curr_off = next_off;
+		bh = next;
+	} while (bh != head);
+
+	if (!offset)
+		try_to_release_page(page, 0);
+
+	return;
+}
+
+static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
+			      const struct iovec *iov, loff_t offset,
+			      unsigned long nr_segs)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_mapping->host;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	struct gfs2_holder gh;
+	int rv;
+
+	if (rw == READ)
+		mutex_lock(&inode->i_mutex);
+	/*
+	 * Shared lock, even if its a write, since we do no allocation
+	 * on this path. All we need change is atime.
+	 */
+	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
+	rv = gfs2_glock_nq_m_atime(1, &gh);
+	if (rv)
+		goto out;
+
+	if (offset > i_size_read(inode))
+		goto out;
+
+	/*
+	 * Should we return an error here? I can't see that O_DIRECT for
+	 * a journaled file makes any sense. For now we'll silently fall
+	 * back to buffered I/O, likewise we do the same for stuffed
+	 * files since they are (a) small and (b) unaligned.
+	 */
+	if (gfs2_is_jdata(ip))
+		goto out;
+
+	if (gfs2_is_stuffed(ip))
+		goto out;
+
+	rv = blockdev_direct_IO_own_locking(rw, iocb, inode,
+					    inode->i_sb->s_bdev,
+					    iov, offset, nr_segs,
+					    gfs2_get_block_direct, NULL);
+out:
+	gfs2_glock_dq_m(1, &gh);
+	gfs2_holder_uninit(&gh);
+	if (rw == READ)
+		mutex_unlock(&inode->i_mutex);
+
+	return rv;
+}
+
+/**
+ * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
+ * @bh: the buffer we're stuck on
+ *
+ */
+
+static void stuck_releasepage(struct buffer_head *bh)
+{
+	struct inode *inode = bh->b_page->mapping->host;
+	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
+	struct gfs2_bufdata *bd = bh->b_private;
+	struct gfs2_glock *gl;
+static unsigned limit = 0;
+
+	if (limit > 3)
+		return;
+	limit++;
+
+	fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
+	fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
+		(unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count));
+	fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
+	fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");
+
+	if (!bd)
+		return;
+
+	gl = bd->bd_gl;
+
+	fs_warn(sdp, "gl = (%u, %llu)\n",
+		gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number);
+
+	fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
+		(list_empty(&bd->bd_list_tr)) ? "no" : "yes",
+		(list_empty(&bd->bd_le.le_list)) ? "no" : "yes");
+
+	if (gl->gl_ops == &gfs2_inode_glops) {
+		struct gfs2_inode *ip = gl->gl_object;
+		unsigned int x;
+
+		if (!ip)
+			return;
+
+		fs_warn(sdp, "ip = %llu %llu\n",
+			(unsigned long long)ip->i_num.no_formal_ino,
+			(unsigned long long)ip->i_num.no_addr);
+
+		for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
+			fs_warn(sdp, "ip->i_cache[%u] = %s\n",
+				x, (ip->i_cache[x]) ? "!NULL" : "NULL");
+	}
+}
+
+/**
+ * gfs2_releasepage - free the metadata associated with a page
+ * @page: the page that's being released
+ * @gfp_mask: passed from Linux VFS, ignored by us
+ *
+ * Call try_to_free_buffers() if the buffers in this page can be
+ * released.
+ *
+ * Returns: 0
+ */
+
+int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
+{
+	struct inode *aspace = page->mapping->host;
+	struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
+	struct buffer_head *bh, *head;
+	struct gfs2_bufdata *bd;
+	unsigned long t = jiffies + gfs2_tune_get(sdp, gt_stall_secs) * HZ;
+
+	if (!page_has_buffers(page))
+		goto out;
+
+	head = bh = page_buffers(page);
+	do {
+		while (atomic_read(&bh->b_count)) {
+			if (!atomic_read(&aspace->i_writecount))
+				return 0;
+
+			if (time_after_eq(jiffies, t)) {
+				stuck_releasepage(bh);
+				/* should we withdraw here? */
+				return 0;
+			}
+
+			yield();
+		}
+
+		gfs2_assert_warn(sdp, !buffer_pinned(bh));
+		gfs2_assert_warn(sdp, !buffer_dirty(bh));
+
+		gfs2_log_lock(sdp);
+		bd = bh->b_private;
+		if (bd) {
+			gfs2_assert_warn(sdp, bd->bd_bh == bh);
+			gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
+			gfs2_assert_warn(sdp, !bd->bd_ail);
+			bd->bd_bh = NULL;
+			if (!list_empty(&bd->bd_le.le_list))
+				bd = NULL;
+			bh->b_private = NULL;
+		}
+		gfs2_log_unlock(sdp);
+		if (bd)
+			kmem_cache_free(gfs2_bufdata_cachep, bd);
+
+		bh = bh->b_this_page;
+	} while (bh != head);
+
+out:
+	return try_to_free_buffers(page);
+}
+
+const struct address_space_operations gfs2_file_aops = {
+	.writepage = gfs2_writepage,
+	.readpage = gfs2_readpage,
+	.readpages = gfs2_readpages,
+	.sync_page = block_sync_page,
+	.prepare_write = gfs2_prepare_write,
+	.commit_write = gfs2_commit_write,
+	.bmap = gfs2_bmap,
+	.invalidatepage = gfs2_invalidatepage,
+	.releasepage = gfs2_releasepage,
+	.direct_IO = gfs2_direct_IO,
+};
+