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..bdd4d6b48721
--- /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 v.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 "gfs2.h"
+#include "lm_interface.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)
+{
+        int new = create;
+        uint64_t dblock;
+        int error;
+        int boundary;
+
+        error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary);
+        if (error)
+                return error;
+
+        if (!dblock)
+                return 0;
+
+        map_bh(bh_result, inode->i_sb, dblock);
+        if (new)
+                set_buffer_new(bh_result);
+        if (boundary)
+                set_buffer_boundary(bh_result);
+
+        return 0;
+}
+
+/**
+ * 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 get_block_noalloc(struct inode *inode, sector_t lblock,
+                             struct buffer_head *bh_result, int create)
+{
+        int new = 0;
+        uint64_t dblock;
+        int error;
+        int boundary;
+
+        error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary);
+        if (error)
+                return error;
+
+        if (dblock)
+                map_bh(bh_result, inode->i_sb, dblock);
+        else if (gfs2_assert_withdraw(GFS2_SB(inode), !create))
+                error = -EIO;
+        if (boundary)
+                set_buffer_boundary(bh_result);
+
+        return error;
+}
+
+/**
+ * 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(page->mapping->host);
+        struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+        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;
+                gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
+                done_trans = 1;
+        }
+        error = block_write_full_page(page, 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(page, 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(page, 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_holder gh;
+        int error;
+        int do_unlock = 0;
+
+        if (likely(file != &gfs2_internal_file_sentinal)) {
+                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, 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 (file != &gfs2_internal_file_sentinal) {
+                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_sentinal)) {
+                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;
+
+        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, to - from, &data_blocks, &ind_blocks);
+
+        error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
+        if (error)
+                goto out_unlock;
+
+
+        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;;
+
+        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);
+
+        if (gfs2_is_stuffed(ip)) {
+                uint64_t file_size;
+                void *kaddr;
+
+                file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+                kaddr = kmap_atomic(page, KM_USER0);
+                memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
+                       (char *)kaddr + from, to - from);
+                kunmap_atomic(page, 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;
+
+        gfs2_dinode_out(&ip->i_di, dibh->b_data);
+        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);
+                brelse(bh);
+        } else
+                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 = page->mapping->host->i_sb->s_fs_info;
+        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, 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;
+
+        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_aspace_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;
+
+        if (!page_has_buffers(page))
+                goto out;
+
+        head = bh = page_buffers(page);
+        do {
+                t = jiffies;
+
+                while (atomic_read(&bh->b_count)) {
+                        if (atomic_read(&aspace->i_writecount)) {
+                                if (time_after_eq(jiffies, t +
+                                    gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
+                                        stuck_releasepage(bh);
+                                        t = jiffies;
+                                }
+
+                                yield();
+                                continue;
+                        }
+
+                        return 0;
+                }
+
+                gfs2_assert_warn(sdp, !buffer_pinned(bh));
+
+                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, list_empty(&bd->bd_le.le_list));
+                        gfs2_assert_warn(sdp, !bd->bd_ail);
+                        kmem_cache_free(gfs2_bufdata_cachep, bd);
+                        bh->b_private = NULL;
+                }
+
+                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,
+};
+