1 /* file.c: AFS filesystem file handling
3 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
18 #include <linux/pagemap.h>
19 #include <linux/buffer_head.h>
22 #include <rxrpc/call.h>
26 static int afs_file_open(struct inode *inode, struct file *file);
27 static int afs_file_release(struct inode *inode, struct file *file);
30 static int afs_file_readpage(struct file *file, struct page *page);
31 static int afs_file_invalidatepage(struct page *page, unsigned long offset);
32 static int afs_file_releasepage(struct page *page, int gfp_flags);
34 static ssize_t afs_file_write(struct file *file, const char __user *buf,
35 size_t size, loff_t *off);
37 struct inode_operations afs_file_inode_operations = {
38 .getattr = afs_inode_getattr,
41 struct file_operations afs_file_file_operations = {
42 .read = generic_file_read,
43 .write = afs_file_write,
44 .mmap = generic_file_mmap,
46 .open = afs_file_open,
47 .release = afs_file_release,
48 .fsync = afs_file_fsync,
52 struct address_space_operations afs_fs_aops = {
53 .readpage = afs_file_readpage,
54 .sync_page = block_sync_page,
55 .set_page_dirty = __set_page_dirty_nobuffers,
56 .releasepage = afs_file_releasepage,
57 .invalidatepage = afs_file_invalidatepage,
60 /*****************************************************************************/
64 static ssize_t afs_file_write(struct file *file, const char __user *buf,
65 size_t size, loff_t *off)
67 struct afs_vnode *vnode;
69 vnode = AFS_FS_I(file->f_dentry->d_inode);
70 if (vnode->flags & AFS_VNODE_DELETED)
74 } /* end afs_file_write() */
76 /*****************************************************************************/
78 * deal with notification that a page was read from the cache
80 #ifdef AFS_CACHING_SUPPORT
81 static void afs_file_readpage_read_complete(void *cookie_data,
86 _enter("%p,%p,%p,%d", cookie_data, page, data, error);
91 SetPageUptodate(page);
94 } /* end afs_file_readpage_read_complete() */
97 /*****************************************************************************/
99 * deal with notification that a page was written to the cache
101 #ifdef AFS_CACHING_SUPPORT
102 static void afs_file_readpage_write_complete(void *cookie_data,
107 _enter("%p,%p,%p,%d", cookie_data, page, data, error);
111 } /* end afs_file_readpage_write_complete() */
114 /*****************************************************************************/
116 * AFS read page from file (or symlink)
118 static int afs_file_readpage(struct file *file, struct page *page)
120 struct afs_rxfs_fetch_descriptor desc;
121 #ifdef AFS_CACHING_SUPPORT
122 struct cachefs_page *pageio;
124 struct afs_vnode *vnode;
128 inode = page->mapping->host;
130 _enter("{%lu},{%lu}", inode->i_ino, page->index);
132 vnode = AFS_FS_I(inode);
134 if (!PageLocked(page))
138 if (vnode->flags & AFS_VNODE_DELETED)
141 #ifdef AFS_CACHING_SUPPORT
142 ret = cachefs_page_get_private(page, &pageio, GFP_NOIO);
147 ret = cachefs_read_or_alloc_page(vnode->cache,
149 afs_file_readpage_read_complete,
157 /* read BIO submitted and wb-journal entry found */
159 BUG(); // TODO - handle wb-journal match
161 /* read BIO submitted (page in cache) */
165 /* no page available in cache */
169 desc.fid = vnode->fid;
170 desc.offset = page->index << PAGE_CACHE_SHIFT;
171 desc.size = min((size_t) (inode->i_size - desc.offset),
173 desc.buffer = kmap(page);
175 clear_page(desc.buffer);
177 /* read the contents of the file from the server into the
179 ret = afs_vnode_fetch_data(vnode, &desc);
183 _debug("got NOENT from server"
184 " - marking file deleted and stale");
185 vnode->flags |= AFS_VNODE_DELETED;
189 #ifdef AFS_CACHING_SUPPORT
190 cachefs_uncache_page(vnode->cache, page);
195 SetPageUptodate(page);
197 #ifdef AFS_CACHING_SUPPORT
198 if (cachefs_write_page(vnode->cache,
200 afs_file_readpage_write_complete,
204 cachefs_uncache_page(vnode->cache, page);
219 _leave(" = %d", ret);
222 } /* end afs_file_readpage() */
224 /*****************************************************************************/
226 * get a page cookie for the specified page
228 #ifdef AFS_CACHING_SUPPORT
229 int afs_cache_get_page_cookie(struct page *page,
230 struct cachefs_page **_page_cookie)
235 ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO);
237 _leave(" = %d", ret);
239 } /* end afs_cache_get_page_cookie() */
242 /*****************************************************************************/
244 * invalidate part or all of a page
246 static int afs_file_invalidatepage(struct page *page, unsigned long offset)
250 _enter("{%lu},%lu", page->index, offset);
252 BUG_ON(!PageLocked(page));
254 if (PagePrivate(page)) {
255 #ifdef AFS_CACHING_SUPPORT
256 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
257 cachefs_uncache_page(vnode->cache,page);
260 /* We release buffers only if the entire page is being
262 * The get_block cached value has been unconditionally
263 * invalidated, so real IO is not possible anymore.
266 BUG_ON(!PageLocked(page));
269 if (!PageWriteback(page))
270 ret = page->mapping->a_ops->releasepage(page,
275 _leave(" = %d", ret);
277 } /* end afs_file_invalidatepage() */
279 /*****************************************************************************/
281 * release a page and cleanup its private data
283 static int afs_file_releasepage(struct page *page, int gfp_flags)
285 struct cachefs_page *pageio;
287 _enter("{%lu},%x", page->index, gfp_flags);
289 if (PagePrivate(page)) {
290 #ifdef AFS_CACHING_SUPPORT
291 struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
292 cachefs_uncache_page(vnode->cache, page);
295 pageio = (struct cachefs_page *) page->private;
297 ClearPagePrivate(page);
305 } /* end afs_file_releasepage() */