1 files changed, 184 insertions, 0 deletions

diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
new file mode 100644
index 000000000000..5453d2947ab3
--- /dev/null
+++ b/fs/gfs2/ops_vm.c
@@ -0,0 +1,184 @@
+/*
+ * 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/mm.h>
+#include <linux/pagemap.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 "ops_vm.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+
+static void pfault_be_greedy(struct gfs2_inode *ip)
+{
+        unsigned int time;
+
+        spin_lock(&ip->i_spin);
+        time = ip->i_greedy;
+        ip->i_last_pfault = jiffies;
+        spin_unlock(&ip->i_spin);
+
+        igrab(&ip->i_inode);
+        if (gfs2_glock_be_greedy(ip->i_gl, time))
+                iput(&ip->i_inode);
+}
+
+static struct page *gfs2_private_nopage(struct vm_area_struct *area,
+                                        unsigned long address, int *type)
+{
+        struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
+        struct page *result;
+
+        set_bit(GIF_PAGED, &ip->i_flags);
+
+        result = filemap_nopage(area, address, type);
+
+        if (result && result != NOPAGE_OOM)
+                pfault_be_greedy(ip);
+
+        return result;
+}
+
+static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
+{
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+        unsigned long index = page->index;
+        u64 lblock = index << (PAGE_CACHE_SHIFT -
+                                    sdp->sd_sb.sb_bsize_shift);
+        unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
+        struct gfs2_alloc *al;
+        unsigned int data_blocks, ind_blocks;
+        unsigned int x;
+        int error;
+
+        al = gfs2_alloc_get(ip);
+
+        error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
+        if (error)
+                goto out;
+
+        error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
+        if (error)
+                goto out_gunlock_q;
+
+        gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
+
+        al->al_requested = data_blocks + ind_blocks;
+
+        error = gfs2_inplace_reserve(ip);
+        if (error)
+                goto out_gunlock_q;
+
+        error = gfs2_trans_begin(sdp, al->al_rgd->rd_ri.ri_length +
+                                 ind_blocks + RES_DINODE +
+                                 RES_STATFS + RES_QUOTA, 0);
+        if (error)
+                goto out_ipres;
+
+        if (gfs2_is_stuffed(ip)) {
+                error = gfs2_unstuff_dinode(ip, NULL);
+                if (error)
+                        goto out_trans;
+        }
+
+        for (x = 0; x < blocks; ) {
+                u64 dblock;
+                unsigned int extlen;
+                int new = 1;
+
+                error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);
+                if (error)
+                        goto out_trans;
+
+                lblock += extlen;
+                x += extlen;
+        }
+
+        gfs2_assert_warn(sdp, al->al_alloced);
+
+out_trans:
+        gfs2_trans_end(sdp);
+out_ipres:
+        gfs2_inplace_release(ip);
+out_gunlock_q:
+        gfs2_quota_unlock(ip);
+out:
+        gfs2_alloc_put(ip);
+        return error;
+}
+
+static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
+                                           unsigned long address, int *type)
+{
+        struct file *file = area->vm_file;
+        struct gfs2_file *gf = file->private_data;
+        struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+        struct gfs2_holder i_gh;
+        struct page *result = NULL;
+        unsigned long index = ((address - area->vm_start) >> PAGE_CACHE_SHIFT) +
+                              area->vm_pgoff;
+        int alloc_required;
+        int error;
+
+        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
+        if (error)
+                return NULL;
+
+        set_bit(GIF_PAGED, &ip->i_flags);
+        set_bit(GIF_SW_PAGED, &ip->i_flags);
+
+        error = gfs2_write_alloc_required(ip, (u64)index << PAGE_CACHE_SHIFT,
+                                          PAGE_CACHE_SIZE, &alloc_required);
+        if (error)
+                goto out;
+
+        set_bit(GFF_EXLOCK, &gf->f_flags);
+        result = filemap_nopage(area, address, type);
+        clear_bit(GFF_EXLOCK, &gf->f_flags);
+        if (!result || result == NOPAGE_OOM)
+                goto out;
+
+        if (alloc_required) {
+                error = alloc_page_backing(ip, result);
+                if (error) {
+                        page_cache_release(result);
+                        result = NULL;
+                        goto out;
+                }
+                set_page_dirty(result);
+        }
+
+        pfault_be_greedy(ip);
+out:
+        gfs2_glock_dq_uninit(&i_gh);
+
+        return result;
+}
+
+struct vm_operations_struct gfs2_vm_ops_private = {
+        .nopage = gfs2_private_nopage,
+};
+
+struct vm_operations_struct gfs2_vm_ops_sharewrite = {
+        .nopage = gfs2_sharewrite_nopage,
+};
+