1 files changed, 280 insertions, 0 deletions

diff --git a/fs/gfs2/page.c b/fs/gfs2/page.c
new file mode 100644
index 000000000000..cd93644c7d70
--- /dev/null
+++ b/fs/gfs2/page.c
@@ -0,0 +1,280 @@
+/*
+ * 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/mm.h>
+#include <linux/gfs2_ondisk.h>
+
+#include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
+#include "bmap.h"
+#include "inode.h"
+#include "page.h"
+#include "trans.h"
+#include "ops_address.h"
+#include "util.h"
+
+/**
+ * gfs2_pte_inval - Sync and invalidate all PTEs associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_pte_inval(struct gfs2_glock *gl)
+{
+        struct gfs2_inode *ip;
+        struct inode *inode;
+
+        ip = gl->gl_object;
+        if (!ip || !S_ISREG(ip->i_di.di_mode))
+                return;
+
+        if (!test_bit(GIF_PAGED, &ip->i_flags))
+                return;
+
+        inode = gfs2_ip2v_lookup(ip);
+        if (inode) {
+                unmap_shared_mapping_range(inode->i_mapping, 0, 0);
+                iput(inode);
+
+                if (test_bit(GIF_SW_PAGED, &ip->i_flags))
+                        set_bit(GLF_DIRTY, &gl->gl_flags);
+        }
+
+        clear_bit(GIF_SW_PAGED, &ip->i_flags);
+}
+
+/**
+ * gfs2_page_inval - Invalidate all pages associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_page_inval(struct gfs2_glock *gl)
+{
+        struct gfs2_inode *ip;
+        struct inode *inode;
+
+        ip = gl->gl_object;
+        if (!ip || !S_ISREG(ip->i_di.di_mode))
+                return;
+
+        inode = gfs2_ip2v_lookup(ip);
+        if (inode) {
+                struct address_space *mapping = inode->i_mapping;
+
+                truncate_inode_pages(mapping, 0);
+                gfs2_assert_withdraw(ip->i_sbd, !mapping->nrpages);
+
+                iput(inode);
+        }
+
+        clear_bit(GIF_PAGED, &ip->i_flags);
+}
+
+/**
+ * gfs2_page_sync - Sync the data pages (not metadata) associated with a glock
+ * @gl: the glock
+ * @flags: DIO_START | DIO_WAIT
+ *
+ * Syncs data (not metadata) for a regular file.
+ * No-op for all other types.
+ */
+
+void gfs2_page_sync(struct gfs2_glock *gl, int flags)
+{
+        struct gfs2_inode *ip;
+        struct inode *inode;
+
+        ip = gl->gl_object;
+        if (!ip || !S_ISREG(ip->i_di.di_mode))
+                return;
+
+        inode = gfs2_ip2v_lookup(ip);
+        if (inode) {
+                struct address_space *mapping = inode->i_mapping;
+                int error = 0;
+
+                if (flags & DIO_START)
+                        filemap_fdatawrite(mapping);
+                if (!error && (flags & DIO_WAIT))
+                        error = filemap_fdatawait(mapping);
+
+                /* Put back any errors cleared by filemap_fdatawait()
+                   so they can be caught by someone who can pass them
+                   up to user space. */
+
+                if (error == -ENOSPC)
+                        set_bit(AS_ENOSPC, &mapping->flags);
+                else if (error)
+                        set_bit(AS_EIO, &mapping->flags);
+
+                iput(inode);
+        }
+}
+
+/**
+ * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
+ * @ip: the inode
+ * @dibh: the dinode buffer
+ * @block: the block number that was allocated
+ * @private: any locked page held by the caller process
+ *
+ * Returns: errno
+ */
+
+int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
+                        uint64_t block, void *private)
+{
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct inode *inode = ip->i_vnode;
+        struct page *page = (struct page *)private;
+        struct buffer_head *bh;
+        int release = 0;
+
+        if (!page || page->index) {
+                page = grab_cache_page(inode->i_mapping, 0);
+                if (!page)
+                        return -ENOMEM;
+                release = 1;
+        }
+
+        if (!PageUptodate(page)) {
+                void *kaddr = kmap(page);
+
+                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(page);
+
+                SetPageUptodate(page);
+        }
+
+        if (!page_has_buffers(page))
+                create_empty_buffers(page, 1 << inode->i_blkbits,
+                                     (1 << BH_Uptodate));
+
+        bh = page_buffers(page);
+
+        if (!buffer_mapped(bh))
+                map_bh(bh, inode->i_sb, block);
+
+        set_buffer_uptodate(bh);
+        if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED) || gfs2_is_jdata(ip))
+                gfs2_trans_add_bh(ip->i_gl, bh, 0);
+        mark_buffer_dirty(bh);
+
+        if (release) {
+                unlock_page(page);
+                page_cache_release(page);
+        }
+
+        return 0;
+}
+
+/**
+ * gfs2_block_truncate_page - Deal with zeroing out data for truncate
+ *
+ * This is partly borrowed from ext3.
+ */
+int gfs2_block_truncate_page(struct address_space *mapping)
+{
+        struct inode *inode = mapping->host;
+        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        loff_t from = inode->i_size;
+        unsigned long index = from >> PAGE_CACHE_SHIFT;
+        unsigned offset = from & (PAGE_CACHE_SIZE-1);
+        unsigned blocksize, iblock, length, pos;
+        struct buffer_head *bh;
+        struct page *page;
+        void *kaddr;
+        int err;
+
+        page = grab_cache_page(mapping, index);
+        if (!page)
+                return 0;
+
+        blocksize = inode->i_sb->s_blocksize;
+        length = blocksize - (offset & (blocksize - 1));
+        iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+
+        if (!page_has_buffers(page))
+                create_empty_buffers(page, blocksize, 0);
+
+        /* Find the buffer that contains "offset" */
+        bh = page_buffers(page);
+        pos = blocksize;
+        while (offset >= pos) {
+                bh = bh->b_this_page;
+                iblock++;
+                pos += blocksize;
+        }
+
+        err = 0;
+
+        if (!buffer_mapped(bh)) {
+                gfs2_get_block(inode, iblock, bh, 0);
+                /* unmapped? It's a hole - nothing to do */
+                if (!buffer_mapped(bh))
+                        goto unlock;
+        }
+
+        /* Ok, it's mapped. Make sure it's up-to-date */
+        if (PageUptodate(page))
+                set_buffer_uptodate(bh);
+
+        if (!buffer_uptodate(bh)) {
+                err = -EIO;
+                ll_rw_block(READ, 1, &bh);
+                wait_on_buffer(bh);
+                /* Uhhuh. Read error. Complain and punt. */
+                if (!buffer_uptodate(bh))
+                        goto unlock;
+        }
+
+        if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
+                gfs2_trans_add_bh(ip->i_gl, bh, 0);
+
+        kaddr = kmap_atomic(page, KM_USER0);
+        memset(kaddr + offset, 0, length);
+        flush_dcache_page(page);
+        kunmap_atomic(kaddr, KM_USER0);
+
+unlock:
+        unlock_page(page);
+        page_cache_release(page);
+        return err;
+}
+
+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);
+        }
+}
+