Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* file.c: AFS filesystem file handling |
| 2 | * |
| 3 | * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 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. |
| 10 | */ |
| 11 | |
| 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> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/buffer_head.h> |
| 20 | #include "volume.h" |
| 21 | #include "vnode.h" |
| 22 | #include <rxrpc/call.h> |
| 23 | #include "internal.h" |
| 24 | |
| 25 | #if 0 |
| 26 | static int afs_file_open(struct inode *inode, struct file *file); |
| 27 | static int afs_file_release(struct inode *inode, struct file *file); |
| 28 | #endif |
| 29 | |
| 30 | static int afs_file_readpage(struct file *file, struct page *page); |
NeilBrown | 2ff28e2 | 2006-03-26 01:37:18 -0800 | [diff] [blame] | 31 | static void afs_file_invalidatepage(struct page *page, unsigned long offset); |
Al Viro | 27496a8 | 2005-10-21 03:20:48 -0400 | [diff] [blame] | 32 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | struct inode_operations afs_file_inode_operations = { |
| 35 | .getattr = afs_inode_getattr, |
| 36 | }; |
| 37 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 38 | const struct address_space_operations afs_fs_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | .readpage = afs_file_readpage, |
| 40 | .sync_page = block_sync_page, |
| 41 | .set_page_dirty = __set_page_dirty_nobuffers, |
| 42 | .releasepage = afs_file_releasepage, |
| 43 | .invalidatepage = afs_file_invalidatepage, |
| 44 | }; |
| 45 | |
| 46 | /*****************************************************************************/ |
| 47 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | * deal with notification that a page was read from the cache |
| 49 | */ |
| 50 | #ifdef AFS_CACHING_SUPPORT |
| 51 | static void afs_file_readpage_read_complete(void *cookie_data, |
| 52 | struct page *page, |
| 53 | void *data, |
| 54 | int error) |
| 55 | { |
| 56 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); |
| 57 | |
| 58 | if (error) |
| 59 | SetPageError(page); |
| 60 | else |
| 61 | SetPageUptodate(page); |
| 62 | unlock_page(page); |
| 63 | |
| 64 | } /* end afs_file_readpage_read_complete() */ |
| 65 | #endif |
| 66 | |
| 67 | /*****************************************************************************/ |
| 68 | /* |
| 69 | * deal with notification that a page was written to the cache |
| 70 | */ |
| 71 | #ifdef AFS_CACHING_SUPPORT |
| 72 | static void afs_file_readpage_write_complete(void *cookie_data, |
| 73 | struct page *page, |
| 74 | void *data, |
| 75 | int error) |
| 76 | { |
| 77 | _enter("%p,%p,%p,%d", cookie_data, page, data, error); |
| 78 | |
| 79 | unlock_page(page); |
| 80 | |
| 81 | } /* end afs_file_readpage_write_complete() */ |
| 82 | #endif |
| 83 | |
| 84 | /*****************************************************************************/ |
| 85 | /* |
| 86 | * AFS read page from file (or symlink) |
| 87 | */ |
| 88 | static int afs_file_readpage(struct file *file, struct page *page) |
| 89 | { |
| 90 | struct afs_rxfs_fetch_descriptor desc; |
| 91 | #ifdef AFS_CACHING_SUPPORT |
| 92 | struct cachefs_page *pageio; |
| 93 | #endif |
| 94 | struct afs_vnode *vnode; |
| 95 | struct inode *inode; |
| 96 | int ret; |
| 97 | |
| 98 | inode = page->mapping->host; |
| 99 | |
| 100 | _enter("{%lu},{%lu}", inode->i_ino, page->index); |
| 101 | |
| 102 | vnode = AFS_FS_I(inode); |
| 103 | |
Matt Mackall | cd7619d | 2005-05-01 08:59:01 -0700 | [diff] [blame] | 104 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | |
| 106 | ret = -ESTALE; |
| 107 | if (vnode->flags & AFS_VNODE_DELETED) |
| 108 | goto error; |
| 109 | |
| 110 | #ifdef AFS_CACHING_SUPPORT |
| 111 | ret = cachefs_page_get_private(page, &pageio, GFP_NOIO); |
| 112 | if (ret < 0) |
| 113 | goto error; |
| 114 | |
| 115 | /* is it cached? */ |
| 116 | ret = cachefs_read_or_alloc_page(vnode->cache, |
| 117 | page, |
| 118 | afs_file_readpage_read_complete, |
| 119 | NULL, |
| 120 | GFP_KERNEL); |
| 121 | #else |
| 122 | ret = -ENOBUFS; |
| 123 | #endif |
| 124 | |
| 125 | switch (ret) { |
| 126 | /* read BIO submitted and wb-journal entry found */ |
| 127 | case 1: |
| 128 | BUG(); // TODO - handle wb-journal match |
| 129 | |
| 130 | /* read BIO submitted (page in cache) */ |
| 131 | case 0: |
| 132 | break; |
| 133 | |
| 134 | /* no page available in cache */ |
| 135 | case -ENOBUFS: |
| 136 | case -ENODATA: |
| 137 | default: |
| 138 | desc.fid = vnode->fid; |
| 139 | desc.offset = page->index << PAGE_CACHE_SHIFT; |
| 140 | desc.size = min((size_t) (inode->i_size - desc.offset), |
| 141 | (size_t) PAGE_SIZE); |
| 142 | desc.buffer = kmap(page); |
| 143 | |
| 144 | clear_page(desc.buffer); |
| 145 | |
| 146 | /* read the contents of the file from the server into the |
| 147 | * page */ |
| 148 | ret = afs_vnode_fetch_data(vnode, &desc); |
| 149 | kunmap(page); |
| 150 | if (ret < 0) { |
| 151 | if (ret==-ENOENT) { |
| 152 | _debug("got NOENT from server" |
| 153 | " - marking file deleted and stale"); |
| 154 | vnode->flags |= AFS_VNODE_DELETED; |
| 155 | ret = -ESTALE; |
| 156 | } |
| 157 | |
| 158 | #ifdef AFS_CACHING_SUPPORT |
| 159 | cachefs_uncache_page(vnode->cache, page); |
| 160 | #endif |
| 161 | goto error; |
| 162 | } |
| 163 | |
| 164 | SetPageUptodate(page); |
| 165 | |
| 166 | #ifdef AFS_CACHING_SUPPORT |
| 167 | if (cachefs_write_page(vnode->cache, |
| 168 | page, |
| 169 | afs_file_readpage_write_complete, |
| 170 | NULL, |
| 171 | GFP_KERNEL) != 0 |
| 172 | ) { |
| 173 | cachefs_uncache_page(vnode->cache, page); |
| 174 | unlock_page(page); |
| 175 | } |
| 176 | #else |
| 177 | unlock_page(page); |
| 178 | #endif |
| 179 | } |
| 180 | |
| 181 | _leave(" = 0"); |
| 182 | return 0; |
| 183 | |
| 184 | error: |
| 185 | SetPageError(page); |
| 186 | unlock_page(page); |
| 187 | |
| 188 | _leave(" = %d", ret); |
| 189 | return ret; |
| 190 | |
| 191 | } /* end afs_file_readpage() */ |
| 192 | |
| 193 | /*****************************************************************************/ |
| 194 | /* |
| 195 | * get a page cookie for the specified page |
| 196 | */ |
| 197 | #ifdef AFS_CACHING_SUPPORT |
| 198 | int afs_cache_get_page_cookie(struct page *page, |
| 199 | struct cachefs_page **_page_cookie) |
| 200 | { |
| 201 | int ret; |
| 202 | |
| 203 | _enter(""); |
| 204 | ret = cachefs_page_get_private(page,_page_cookie, GFP_NOIO); |
| 205 | |
| 206 | _leave(" = %d", ret); |
| 207 | return ret; |
| 208 | } /* end afs_cache_get_page_cookie() */ |
| 209 | #endif |
| 210 | |
| 211 | /*****************************************************************************/ |
| 212 | /* |
| 213 | * invalidate part or all of a page |
| 214 | */ |
NeilBrown | 2ff28e2 | 2006-03-26 01:37:18 -0800 | [diff] [blame] | 215 | static void afs_file_invalidatepage(struct page *page, unsigned long offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | { |
| 217 | int ret = 1; |
| 218 | |
| 219 | _enter("{%lu},%lu", page->index, offset); |
| 220 | |
| 221 | BUG_ON(!PageLocked(page)); |
| 222 | |
| 223 | if (PagePrivate(page)) { |
| 224 | #ifdef AFS_CACHING_SUPPORT |
| 225 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
| 226 | cachefs_uncache_page(vnode->cache,page); |
| 227 | #endif |
| 228 | |
| 229 | /* We release buffers only if the entire page is being |
| 230 | * invalidated. |
| 231 | * The get_block cached value has been unconditionally |
| 232 | * invalidated, so real IO is not possible anymore. |
| 233 | */ |
| 234 | if (offset == 0) { |
| 235 | BUG_ON(!PageLocked(page)); |
| 236 | |
| 237 | ret = 0; |
| 238 | if (!PageWriteback(page)) |
| 239 | ret = page->mapping->a_ops->releasepage(page, |
| 240 | 0); |
NeilBrown | 2ff28e2 | 2006-03-26 01:37:18 -0800 | [diff] [blame] | 241 | /* possibly should BUG_ON(!ret); - neilb */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | } |
| 243 | } |
| 244 | |
| 245 | _leave(" = %d", ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | } /* end afs_file_invalidatepage() */ |
| 247 | |
| 248 | /*****************************************************************************/ |
| 249 | /* |
| 250 | * release a page and cleanup its private data |
| 251 | */ |
Al Viro | 27496a8 | 2005-10-21 03:20:48 -0400 | [diff] [blame] | 252 | static int afs_file_releasepage(struct page *page, gfp_t gfp_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | { |
| 254 | struct cachefs_page *pageio; |
| 255 | |
| 256 | _enter("{%lu},%x", page->index, gfp_flags); |
| 257 | |
| 258 | if (PagePrivate(page)) { |
| 259 | #ifdef AFS_CACHING_SUPPORT |
| 260 | struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); |
| 261 | cachefs_uncache_page(vnode->cache, page); |
| 262 | #endif |
| 263 | |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 264 | pageio = (struct cachefs_page *) page_private(page); |
| 265 | set_page_private(page, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | ClearPagePrivate(page); |
| 267 | |
Jesper Juhl | f99d49a | 2005-11-07 01:01:34 -0800 | [diff] [blame] | 268 | kfree(pageio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | } |
| 270 | |
| 271 | _leave(" = 0"); |
| 272 | return 0; |
| 273 | } /* end afs_file_releasepage() */ |