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 void afs_file_invalidatepage(struct page
*page
, unsigned long offset
);
32 static int afs_file_releasepage(struct page
*page
, gfp_t gfp_flags
);
34 struct inode_operations afs_file_inode_operations
= {
35 .getattr
= afs_inode_getattr
,
38 const struct address_space_operations afs_fs_aops
= {
39 .readpage
= afs_file_readpage
,
40 .set_page_dirty
= __set_page_dirty_nobuffers
,
41 .releasepage
= afs_file_releasepage
,
42 .invalidatepage
= afs_file_invalidatepage
,
45 /*****************************************************************************/
47 * deal with notification that a page was read from the cache
49 #ifdef AFS_CACHING_SUPPORT
50 static void afs_file_readpage_read_complete(void *cookie_data
,
55 _enter("%p,%p,%p,%d", cookie_data
, page
, data
, error
);
60 SetPageUptodate(page
);
63 } /* end afs_file_readpage_read_complete() */
66 /*****************************************************************************/
68 * deal with notification that a page was written to the cache
70 #ifdef AFS_CACHING_SUPPORT
71 static void afs_file_readpage_write_complete(void *cookie_data
,
76 _enter("%p,%p,%p,%d", cookie_data
, page
, data
, error
);
80 } /* end afs_file_readpage_write_complete() */
83 /*****************************************************************************/
85 * AFS read page from file (or symlink)
87 static int afs_file_readpage(struct file
*file
, struct page
*page
)
89 struct afs_rxfs_fetch_descriptor desc
;
90 #ifdef AFS_CACHING_SUPPORT
91 struct cachefs_page
*pageio
;
93 struct afs_vnode
*vnode
;
97 inode
= page
->mapping
->host
;
99 _enter("{%lu},{%lu}", inode
->i_ino
, page
->index
);
101 vnode
= AFS_FS_I(inode
);
103 BUG_ON(!PageLocked(page
));
106 if (vnode
->flags
& AFS_VNODE_DELETED
)
109 #ifdef AFS_CACHING_SUPPORT
110 ret
= cachefs_page_get_private(page
, &pageio
, GFP_NOIO
);
115 ret
= cachefs_read_or_alloc_page(vnode
->cache
,
117 afs_file_readpage_read_complete
,
125 /* read BIO submitted and wb-journal entry found */
127 BUG(); // TODO - handle wb-journal match
129 /* read BIO submitted (page in cache) */
133 /* no page available in cache */
137 desc
.fid
= vnode
->fid
;
138 desc
.offset
= page
->index
<< PAGE_CACHE_SHIFT
;
139 desc
.size
= min((size_t) (inode
->i_size
- desc
.offset
),
141 desc
.buffer
= kmap(page
);
143 clear_page(desc
.buffer
);
145 /* read the contents of the file from the server into the
147 ret
= afs_vnode_fetch_data(vnode
, &desc
);
151 _debug("got NOENT from server"
152 " - marking file deleted and stale");
153 vnode
->flags
|= AFS_VNODE_DELETED
;
157 #ifdef AFS_CACHING_SUPPORT
158 cachefs_uncache_page(vnode
->cache
, page
);
163 SetPageUptodate(page
);
165 #ifdef AFS_CACHING_SUPPORT
166 if (cachefs_write_page(vnode
->cache
,
168 afs_file_readpage_write_complete
,
172 cachefs_uncache_page(vnode
->cache
, page
);
187 _leave(" = %d", ret
);
190 } /* end afs_file_readpage() */
192 /*****************************************************************************/
194 * get a page cookie for the specified page
196 #ifdef AFS_CACHING_SUPPORT
197 int afs_cache_get_page_cookie(struct page
*page
,
198 struct cachefs_page
**_page_cookie
)
203 ret
= cachefs_page_get_private(page
,_page_cookie
, GFP_NOIO
);
205 _leave(" = %d", ret
);
207 } /* end afs_cache_get_page_cookie() */
210 /*****************************************************************************/
212 * invalidate part or all of a page
214 static void afs_file_invalidatepage(struct page
*page
, unsigned long offset
)
218 _enter("{%lu},%lu", page
->index
, offset
);
220 BUG_ON(!PageLocked(page
));
222 if (PagePrivate(page
)) {
223 #ifdef AFS_CACHING_SUPPORT
224 struct afs_vnode
*vnode
= AFS_FS_I(page
->mapping
->host
);
225 cachefs_uncache_page(vnode
->cache
,page
);
228 /* We release buffers only if the entire page is being
230 * The get_block cached value has been unconditionally
231 * invalidated, so real IO is not possible anymore.
234 BUG_ON(!PageLocked(page
));
237 if (!PageWriteback(page
))
238 ret
= page
->mapping
->a_ops
->releasepage(page
,
240 /* possibly should BUG_ON(!ret); - neilb */
244 _leave(" = %d", ret
);
245 } /* end afs_file_invalidatepage() */
247 /*****************************************************************************/
249 * release a page and cleanup its private data
251 static int afs_file_releasepage(struct page
*page
, gfp_t gfp_flags
)
253 struct cachefs_page
*pageio
;
255 _enter("{%lu},%x", page
->index
, gfp_flags
);
257 if (PagePrivate(page
)) {
258 #ifdef AFS_CACHING_SUPPORT
259 struct afs_vnode
*vnode
= AFS_FS_I(page
->mapping
->host
);
260 cachefs_uncache_page(vnode
->cache
, page
);
263 pageio
= (struct cachefs_page
*) page_private(page
);
264 set_page_private(page
, 0);
265 ClearPagePrivate(page
);
272 } /* end afs_file_releasepage() */