1 files changed, 305 insertions, 0 deletions

diff --git a/fs/afs/file.c b/fs/afs/file.c
new file mode 100644
index 000000000000..6b6bb7c8abf6
--- /dev/null
+++ b/fs/afs/file.c
@@ -0,0 +1,305 @@
+/* file.c: AFS filesystem file handling
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include "volume.h"
+#include "vnode.h"
+#include <rxrpc/call.h>
+#include "internal.h"
+
+#if 0
+static int afs_file_open(struct inode *inode, struct file *file);
+static int afs_file_release(struct inode *inode, struct file *file);
+#endif
+
+static int afs_file_readpage(struct file *file, struct page *page);
+static int afs_file_invalidatepage(struct page *page, unsigned long offset);
+static int afs_file_releasepage(struct page *page, int gfp_flags);
+
+static ssize_t afs_file_write(struct file *file, const char __user *buf,
+                              size_t size, loff_t *off);
+
+struct inode_operations afs_file_inode_operations = {
+        .getattr        = afs_inode_getattr,
+};
+
+struct file_operations afs_file_file_operations = {
+        .read           = generic_file_read,
+        .write          = afs_file_write,
+        .mmap           = generic_file_mmap,
+#if 0
+        .open           = afs_file_open,
+        .release        = afs_file_release,
+        .fsync          = afs_file_fsync,
+#endif
+};
+
+struct address_space_operations afs_fs_aops = {
+        .readpage       = afs_file_readpage,
+        .sync_page      = block_sync_page,
+        .set_page_dirty = __set_page_dirty_nobuffers,
+        .releasepage    = afs_file_releasepage,
+        .invalidatepage = afs_file_invalidatepage,
+};
+
+/*****************************************************************************/
+/*
+ * AFS file write
+ */
+static ssize_t afs_file_write(struct file *file, const char __user *buf,
+                              size_t size, loff_t *off)
+{
+        struct afs_vnode *vnode;
+
+        vnode = AFS_FS_I(file->f_dentry->d_inode);
+        if (vnode->flags & AFS_VNODE_DELETED)
+                return -ESTALE;
+
+        return -EIO;
+} /* end afs_file_write() */
+
+/*****************************************************************************/
+/*
+ * deal with notification that a page was read from the cache
+ */
+#ifdef AFS_CACHING_SUPPORT
+static void afs_file_readpage_read_complete(void *cookie_data,
+                                            struct page *page,
+                                            void *data,
+                                            int error)
+{
+        _enter("%p,%p,%p,%d", cookie_data, page, data, error);
+
+        if (error)
+                SetPageError(page);
+        else
+                SetPageUptodate(page);
+        unlock_page(page);
+
+} /* end afs_file_readpage_read_complete() */
+#endif
+
+/*****************************************************************************/
+/*
+ * deal with notification that a page was written to the cache
+ */
+#ifdef AFS_CACHING_SUPPORT
+static void afs_file_readpage_write_complete(void *cookie_data,
+                                             struct page *page,
+                                             void *data,
+                                             int error)
+{
+        _enter("%p,%p,%p,%d", cookie_data, page, data, error);
+
+        unlock_page(page);
+
+} /* end afs_file_readpage_write_complete() */
+#endif
+
+/*****************************************************************************/
+/*
+ * AFS read page from file (or symlink)
+ */
+static int afs_file_readpage(struct file *file, struct page *page)
+{
+        struct afs_rxfs_fetch_descriptor desc;
+#ifdef AFS_CACHING_SUPPORT
+        struct cachefs_page *pageio;
+#endif
+        struct afs_vnode *vnode;
+        struct inode *inode;
+        int ret;
+
+        inode = page->mapping->host;
+
+        _enter("{%lu},{%lu}", inode->i_ino, page->index);
+
+        vnode = AFS_FS_I(inode);
+
+        if (!PageLocked(page))
+                PAGE_BUG(page);
+
+        ret = -ESTALE;
+        if (vnode->flags & AFS_VNODE_DELETED)
+                goto error;
+
+#ifdef AFS_CACHING_SUPPORT
+        ret = cachefs_page_get_private(page, &pageio, GFP_NOIO);
+        if (ret < 0)
+                goto error;
+
+        /* is it cached? */
+        ret = cachefs_read_or_alloc_page(vnode->cache,
+                                         page,
+                                         afs_file_readpage_read_complete,
+                                         NULL,
+                                         GFP_KERNEL);
+#else
+        ret = -ENOBUFS;
+#endif
+
+        switch (ret) {
+                /* read BIO submitted and wb-journal entry found */
+        case 1:
+                BUG(); // TODO - handle wb-journal match
+
+                /* read BIO submitted (page in cache) */
+        case 0:
+                break;
+
+                /* no page available in cache */
+        case -ENOBUFS:
+        case -ENODATA:
+        default:
+                desc.fid        = vnode->fid;
+                desc.offset     = page->index << PAGE_CACHE_SHIFT;
+                desc.size       = min((size_t) (inode->i_size - desc.offset),
+                                      (size_t) PAGE_SIZE);
+                desc.buffer     = kmap(page);
+
+                clear_page(desc.buffer);
+
+                /* read the contents of the file from the server into the
+                 * page */
+                ret = afs_vnode_fetch_data(vnode, &desc);
+                kunmap(page);
+                if (ret < 0) {
+                        if (ret==-ENOENT) {
+                                _debug("got NOENT from server"
+                                       " - marking file deleted and stale");
+                                vnode->flags |= AFS_VNODE_DELETED;
+                                ret = -ESTALE;
+                        }
+
+#ifdef AFS_CACHING_SUPPORT
+                        cachefs_uncache_page(vnode->cache, page);
+#endif
+                        goto error;
+                }
+
+                SetPageUptodate(page);
+
+#ifdef AFS_CACHING_SUPPORT
+                if (cachefs_write_page(vnode->cache,
+                                       page,
+                                       afs_file_readpage_write_complete,
+                                       NULL,
+                                       GFP_KERNEL) != 0
+                    ) {
+                        cachefs_uncache_page(vnode->cache, page);
+                        unlock_page(page);
+                }
+#else
+                unlock_page(page);
+#endif
+        }
+
+        _leave(" = 0");
+        return 0;
+
+ error:
+        SetPageError(page);
+        unlock_page(page);
+
+        _leave(" = %d", ret);
+        return ret;
+
+} /* end afs_file_readpage() */
+
+/*****************************************************************************/
+/*
+ * get a page cookie for the specified page
+ */
+#ifdef AFS_CACHING_SUPPORT
+int afs_cache_get_page_cookie(struct page *page,
+                              struct cachefs_page **_page_cookie)
+{
+        int ret;
+
+        _enter("");
+        ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO);
+
+        _leave(" = %d", ret);
+        return ret;
+} /* end afs_cache_get_page_cookie() */
+#endif
+
+/*****************************************************************************/
+/*
+ * invalidate part or all of a page
+ */
+static int afs_file_invalidatepage(struct page *page, unsigned long offset)
+{
+        int ret = 1;
+
+        _enter("{%lu},%lu", page->index, offset);
+
+        BUG_ON(!PageLocked(page));
+
+        if (PagePrivate(page)) {
+#ifdef AFS_CACHING_SUPPORT
+                struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+                cachefs_uncache_page(vnode->cache,page);
+#endif
+
+                /* We release buffers only if the entire page is being
+                 * invalidated.
+                 * The get_block cached value has been unconditionally
+                 * invalidated, so real IO is not possible anymore.
+                 */
+                if (offset == 0) {
+                        BUG_ON(!PageLocked(page));
+
+                        ret = 0;
+                        if (!PageWriteback(page))
+                                ret = page->mapping->a_ops->releasepage(page,
+                                                                        0);
+                }
+        }
+
+        _leave(" = %d", ret);
+        return ret;
+} /* end afs_file_invalidatepage() */
+
+/*****************************************************************************/
+/*
+ * release a page and cleanup its private data
+ */
+static int afs_file_releasepage(struct page *page, int gfp_flags)
+{
+        struct cachefs_page *pageio;
+
+        _enter("{%lu},%x", page->index, gfp_flags);
+
+        if (PagePrivate(page)) {
+#ifdef AFS_CACHING_SUPPORT
+                struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+                cachefs_uncache_page(vnode->cache, page);
+#endif
+
+                pageio = (struct cachefs_page *) page->private;
+                page->private = 0;
+                ClearPagePrivate(page);
+
+                if (pageio)
+                        kfree(pageio);
+        }
+
+        _leave(" = 0");
+        return 0;
+} /* end afs_file_releasepage() */