| 1 | /* |
| 2 | * linux/fs/nfs/file.c |
| 3 | * |
| 4 | * Copyright (C) 1992 Rick Sladkey |
| 5 | * |
| 6 | * Changes Copyright (C) 1994 by Florian La Roche |
| 7 | * - Do not copy data too often around in the kernel. |
| 8 | * - In nfs_file_read the return value of kmalloc wasn't checked. |
| 9 | * - Put in a better version of read look-ahead buffering. Original idea |
| 10 | * and implementation by Wai S Kok elekokws@ee.nus.sg. |
| 11 | * |
| 12 | * Expire cache on write to a file by Wai S Kok (Oct 1994). |
| 13 | * |
| 14 | * Total rewrite of read side for new NFS buffer cache.. Linus. |
| 15 | * |
| 16 | * nfs regular file handling functions |
| 17 | */ |
| 18 | |
| 19 | #include <linux/time.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/fcntl.h> |
| 23 | #include <linux/stat.h> |
| 24 | #include <linux/nfs_fs.h> |
| 25 | #include <linux/nfs_mount.h> |
| 26 | #include <linux/mm.h> |
| 27 | #include <linux/slab.h> |
| 28 | #include <linux/pagemap.h> |
| 29 | #include <linux/smp_lock.h> |
| 30 | #include <linux/aio.h> |
| 31 | |
| 32 | #include <asm/uaccess.h> |
| 33 | #include <asm/system.h> |
| 34 | |
| 35 | #include "delegation.h" |
| 36 | #include "internal.h" |
| 37 | #include "iostat.h" |
| 38 | |
| 39 | #define NFSDBG_FACILITY NFSDBG_FILE |
| 40 | |
| 41 | static int nfs_file_open(struct inode *, struct file *); |
| 42 | static int nfs_file_release(struct inode *, struct file *); |
| 43 | static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin); |
| 44 | static int nfs_file_mmap(struct file *, struct vm_area_struct *); |
| 45 | static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| 46 | struct pipe_inode_info *pipe, |
| 47 | size_t count, unsigned int flags); |
| 48 | static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov, |
| 49 | unsigned long nr_segs, loff_t pos); |
| 50 | static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov, |
| 51 | unsigned long nr_segs, loff_t pos); |
| 52 | static int nfs_file_flush(struct file *, fl_owner_t id); |
| 53 | static int nfs_fsync(struct file *, struct dentry *dentry, int datasync); |
| 54 | static int nfs_check_flags(int flags); |
| 55 | static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl); |
| 56 | static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl); |
| 57 | static int nfs_setlease(struct file *file, long arg, struct file_lock **fl); |
| 58 | |
| 59 | static struct vm_operations_struct nfs_file_vm_ops; |
| 60 | |
| 61 | const struct file_operations nfs_file_operations = { |
| 62 | .llseek = nfs_file_llseek, |
| 63 | .read = do_sync_read, |
| 64 | .write = do_sync_write, |
| 65 | .aio_read = nfs_file_read, |
| 66 | .aio_write = nfs_file_write, |
| 67 | #ifdef CONFIG_MMU |
| 68 | .mmap = nfs_file_mmap, |
| 69 | #else |
| 70 | .mmap = generic_file_mmap, |
| 71 | #endif |
| 72 | .open = nfs_file_open, |
| 73 | .flush = nfs_file_flush, |
| 74 | .release = nfs_file_release, |
| 75 | .fsync = nfs_fsync, |
| 76 | .lock = nfs_lock, |
| 77 | .flock = nfs_flock, |
| 78 | .splice_read = nfs_file_splice_read, |
| 79 | .check_flags = nfs_check_flags, |
| 80 | .setlease = nfs_setlease, |
| 81 | }; |
| 82 | |
| 83 | const struct inode_operations nfs_file_inode_operations = { |
| 84 | .permission = nfs_permission, |
| 85 | .getattr = nfs_getattr, |
| 86 | .setattr = nfs_setattr, |
| 87 | }; |
| 88 | |
| 89 | #ifdef CONFIG_NFS_V3 |
| 90 | const struct inode_operations nfs3_file_inode_operations = { |
| 91 | .permission = nfs_permission, |
| 92 | .getattr = nfs_getattr, |
| 93 | .setattr = nfs_setattr, |
| 94 | .listxattr = nfs3_listxattr, |
| 95 | .getxattr = nfs3_getxattr, |
| 96 | .setxattr = nfs3_setxattr, |
| 97 | .removexattr = nfs3_removexattr, |
| 98 | }; |
| 99 | #endif /* CONFIG_NFS_v3 */ |
| 100 | |
| 101 | /* Hack for future NFS swap support */ |
| 102 | #ifndef IS_SWAPFILE |
| 103 | # define IS_SWAPFILE(inode) (0) |
| 104 | #endif |
| 105 | |
| 106 | static int nfs_check_flags(int flags) |
| 107 | { |
| 108 | if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) |
| 109 | return -EINVAL; |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | /* |
| 115 | * Open file |
| 116 | */ |
| 117 | static int |
| 118 | nfs_file_open(struct inode *inode, struct file *filp) |
| 119 | { |
| 120 | int res; |
| 121 | |
| 122 | res = nfs_check_flags(filp->f_flags); |
| 123 | if (res) |
| 124 | return res; |
| 125 | |
| 126 | nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
| 127 | lock_kernel(); |
| 128 | res = NFS_PROTO(inode)->file_open(inode, filp); |
| 129 | unlock_kernel(); |
| 130 | return res; |
| 131 | } |
| 132 | |
| 133 | static int |
| 134 | nfs_file_release(struct inode *inode, struct file *filp) |
| 135 | { |
| 136 | /* Ensure that dirty pages are flushed out with the right creds */ |
| 137 | if (filp->f_mode & FMODE_WRITE) |
| 138 | nfs_wb_all(filp->f_path.dentry->d_inode); |
| 139 | nfs_inc_stats(inode, NFSIOS_VFSRELEASE); |
| 140 | return NFS_PROTO(inode)->file_release(inode, filp); |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * nfs_revalidate_size - Revalidate the file size |
| 145 | * @inode - pointer to inode struct |
| 146 | * @file - pointer to struct file |
| 147 | * |
| 148 | * Revalidates the file length. This is basically a wrapper around |
| 149 | * nfs_revalidate_inode() that takes into account the fact that we may |
| 150 | * have cached writes (in which case we don't care about the server's |
| 151 | * idea of what the file length is), or O_DIRECT (in which case we |
| 152 | * shouldn't trust the cache). |
| 153 | */ |
| 154 | static int nfs_revalidate_file_size(struct inode *inode, struct file *filp) |
| 155 | { |
| 156 | struct nfs_server *server = NFS_SERVER(inode); |
| 157 | struct nfs_inode *nfsi = NFS_I(inode); |
| 158 | |
| 159 | if (server->flags & NFS_MOUNT_NOAC) |
| 160 | goto force_reval; |
| 161 | if (filp->f_flags & O_DIRECT) |
| 162 | goto force_reval; |
| 163 | if (nfsi->npages != 0) |
| 164 | return 0; |
| 165 | if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode)) |
| 166 | return 0; |
| 167 | force_reval: |
| 168 | return __nfs_revalidate_inode(server, inode); |
| 169 | } |
| 170 | |
| 171 | static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin) |
| 172 | { |
| 173 | /* origin == SEEK_END => we must revalidate the cached file length */ |
| 174 | if (origin == SEEK_END) { |
| 175 | struct inode *inode = filp->f_mapping->host; |
| 176 | int retval = nfs_revalidate_file_size(inode, filp); |
| 177 | if (retval < 0) |
| 178 | return (loff_t)retval; |
| 179 | } |
| 180 | return remote_llseek(filp, offset, origin); |
| 181 | } |
| 182 | |
| 183 | /* |
| 184 | * Helper for nfs_file_flush() and nfs_fsync() |
| 185 | * |
| 186 | * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to |
| 187 | * disk, but it retrieves and clears ctx->error after synching, despite |
| 188 | * the two being set at the same time in nfs_context_set_write_error(). |
| 189 | * This is because the former is used to notify the _next_ call to |
| 190 | * nfs_file_write() that a write error occured, and hence cause it to |
| 191 | * fall back to doing a synchronous write. |
| 192 | */ |
| 193 | static int nfs_do_fsync(struct nfs_open_context *ctx, struct inode *inode) |
| 194 | { |
| 195 | int have_error, status; |
| 196 | int ret = 0; |
| 197 | |
| 198 | have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); |
| 199 | status = nfs_wb_all(inode); |
| 200 | have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); |
| 201 | if (have_error) |
| 202 | ret = xchg(&ctx->error, 0); |
| 203 | if (!ret) |
| 204 | ret = status; |
| 205 | return ret; |
| 206 | } |
| 207 | |
| 208 | /* |
| 209 | * Flush all dirty pages, and check for write errors. |
| 210 | * |
| 211 | */ |
| 212 | static int |
| 213 | nfs_file_flush(struct file *file, fl_owner_t id) |
| 214 | { |
| 215 | struct nfs_open_context *ctx = nfs_file_open_context(file); |
| 216 | struct inode *inode = file->f_path.dentry->d_inode; |
| 217 | int status; |
| 218 | |
| 219 | dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino); |
| 220 | |
| 221 | if ((file->f_mode & FMODE_WRITE) == 0) |
| 222 | return 0; |
| 223 | nfs_inc_stats(inode, NFSIOS_VFSFLUSH); |
| 224 | |
| 225 | /* Ensure that data+attribute caches are up to date after close() */ |
| 226 | status = nfs_do_fsync(ctx, inode); |
| 227 | if (!status) |
| 228 | nfs_revalidate_inode(NFS_SERVER(inode), inode); |
| 229 | return status; |
| 230 | } |
| 231 | |
| 232 | static ssize_t |
| 233 | nfs_file_read(struct kiocb *iocb, const struct iovec *iov, |
| 234 | unsigned long nr_segs, loff_t pos) |
| 235 | { |
| 236 | struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| 237 | struct inode * inode = dentry->d_inode; |
| 238 | ssize_t result; |
| 239 | size_t count = iov_length(iov, nr_segs); |
| 240 | |
| 241 | if (iocb->ki_filp->f_flags & O_DIRECT) |
| 242 | return nfs_file_direct_read(iocb, iov, nr_segs, pos); |
| 243 | |
| 244 | dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n", |
| 245 | dentry->d_parent->d_name.name, dentry->d_name.name, |
| 246 | (unsigned long) count, (unsigned long) pos); |
| 247 | |
| 248 | result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping); |
| 249 | nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count); |
| 250 | if (!result) |
| 251 | result = generic_file_aio_read(iocb, iov, nr_segs, pos); |
| 252 | return result; |
| 253 | } |
| 254 | |
| 255 | static ssize_t |
| 256 | nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| 257 | struct pipe_inode_info *pipe, size_t count, |
| 258 | unsigned int flags) |
| 259 | { |
| 260 | struct dentry *dentry = filp->f_path.dentry; |
| 261 | struct inode *inode = dentry->d_inode; |
| 262 | ssize_t res; |
| 263 | |
| 264 | dfprintk(VFS, "nfs: splice_read(%s/%s, %lu@%Lu)\n", |
| 265 | dentry->d_parent->d_name.name, dentry->d_name.name, |
| 266 | (unsigned long) count, (unsigned long long) *ppos); |
| 267 | |
| 268 | res = nfs_revalidate_mapping(inode, filp->f_mapping); |
| 269 | if (!res) |
| 270 | res = generic_file_splice_read(filp, ppos, pipe, count, flags); |
| 271 | return res; |
| 272 | } |
| 273 | |
| 274 | static int |
| 275 | nfs_file_mmap(struct file * file, struct vm_area_struct * vma) |
| 276 | { |
| 277 | struct dentry *dentry = file->f_path.dentry; |
| 278 | struct inode *inode = dentry->d_inode; |
| 279 | int status; |
| 280 | |
| 281 | dfprintk(VFS, "nfs: mmap(%s/%s)\n", |
| 282 | dentry->d_parent->d_name.name, dentry->d_name.name); |
| 283 | |
| 284 | status = nfs_revalidate_mapping(inode, file->f_mapping); |
| 285 | if (!status) { |
| 286 | vma->vm_ops = &nfs_file_vm_ops; |
| 287 | vma->vm_flags |= VM_CAN_NONLINEAR; |
| 288 | file_accessed(file); |
| 289 | } |
| 290 | return status; |
| 291 | } |
| 292 | |
| 293 | /* |
| 294 | * Flush any dirty pages for this process, and check for write errors. |
| 295 | * The return status from this call provides a reliable indication of |
| 296 | * whether any write errors occurred for this process. |
| 297 | */ |
| 298 | static int |
| 299 | nfs_fsync(struct file *file, struct dentry *dentry, int datasync) |
| 300 | { |
| 301 | struct nfs_open_context *ctx = nfs_file_open_context(file); |
| 302 | struct inode *inode = dentry->d_inode; |
| 303 | |
| 304 | dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino); |
| 305 | |
| 306 | nfs_inc_stats(inode, NFSIOS_VFSFSYNC); |
| 307 | return nfs_do_fsync(ctx, inode); |
| 308 | } |
| 309 | |
| 310 | /* |
| 311 | * This does the "real" work of the write. We must allocate and lock the |
| 312 | * page to be sent back to the generic routine, which then copies the |
| 313 | * data from user space. |
| 314 | * |
| 315 | * If the writer ends up delaying the write, the writer needs to |
| 316 | * increment the page use counts until he is done with the page. |
| 317 | */ |
| 318 | static int nfs_write_begin(struct file *file, struct address_space *mapping, |
| 319 | loff_t pos, unsigned len, unsigned flags, |
| 320 | struct page **pagep, void **fsdata) |
| 321 | { |
| 322 | int ret; |
| 323 | pgoff_t index; |
| 324 | struct page *page; |
| 325 | index = pos >> PAGE_CACHE_SHIFT; |
| 326 | |
| 327 | page = __grab_cache_page(mapping, index); |
| 328 | if (!page) |
| 329 | return -ENOMEM; |
| 330 | *pagep = page; |
| 331 | |
| 332 | ret = nfs_flush_incompatible(file, page); |
| 333 | if (ret) { |
| 334 | unlock_page(page); |
| 335 | page_cache_release(page); |
| 336 | } |
| 337 | return ret; |
| 338 | } |
| 339 | |
| 340 | static int nfs_write_end(struct file *file, struct address_space *mapping, |
| 341 | loff_t pos, unsigned len, unsigned copied, |
| 342 | struct page *page, void *fsdata) |
| 343 | { |
| 344 | unsigned offset = pos & (PAGE_CACHE_SIZE - 1); |
| 345 | int status; |
| 346 | |
| 347 | lock_kernel(); |
| 348 | status = nfs_updatepage(file, page, offset, copied); |
| 349 | unlock_kernel(); |
| 350 | |
| 351 | unlock_page(page); |
| 352 | page_cache_release(page); |
| 353 | |
| 354 | if (status < 0) |
| 355 | return status; |
| 356 | return copied; |
| 357 | } |
| 358 | |
| 359 | static void nfs_invalidate_page(struct page *page, unsigned long offset) |
| 360 | { |
| 361 | if (offset != 0) |
| 362 | return; |
| 363 | /* Cancel any unstarted writes on this page */ |
| 364 | nfs_wb_page_cancel(page->mapping->host, page); |
| 365 | } |
| 366 | |
| 367 | static int nfs_release_page(struct page *page, gfp_t gfp) |
| 368 | { |
| 369 | /* If PagePrivate() is set, then the page is not freeable */ |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | static int nfs_launder_page(struct page *page) |
| 374 | { |
| 375 | return nfs_wb_page(page->mapping->host, page); |
| 376 | } |
| 377 | |
| 378 | const struct address_space_operations nfs_file_aops = { |
| 379 | .readpage = nfs_readpage, |
| 380 | .readpages = nfs_readpages, |
| 381 | .set_page_dirty = __set_page_dirty_nobuffers, |
| 382 | .writepage = nfs_writepage, |
| 383 | .writepages = nfs_writepages, |
| 384 | .write_begin = nfs_write_begin, |
| 385 | .write_end = nfs_write_end, |
| 386 | .invalidatepage = nfs_invalidate_page, |
| 387 | .releasepage = nfs_release_page, |
| 388 | .direct_IO = nfs_direct_IO, |
| 389 | .launder_page = nfs_launder_page, |
| 390 | }; |
| 391 | |
| 392 | static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page) |
| 393 | { |
| 394 | struct file *filp = vma->vm_file; |
| 395 | unsigned pagelen; |
| 396 | int ret = -EINVAL; |
| 397 | struct address_space *mapping; |
| 398 | |
| 399 | lock_page(page); |
| 400 | mapping = page->mapping; |
| 401 | if (mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping) |
| 402 | goto out_unlock; |
| 403 | |
| 404 | ret = 0; |
| 405 | pagelen = nfs_page_length(page); |
| 406 | if (pagelen == 0) |
| 407 | goto out_unlock; |
| 408 | |
| 409 | ret = nfs_flush_incompatible(filp, page); |
| 410 | if (ret != 0) |
| 411 | goto out_unlock; |
| 412 | |
| 413 | ret = nfs_updatepage(filp, page, 0, pagelen); |
| 414 | if (ret == 0) |
| 415 | ret = pagelen; |
| 416 | out_unlock: |
| 417 | unlock_page(page); |
| 418 | return ret; |
| 419 | } |
| 420 | |
| 421 | static struct vm_operations_struct nfs_file_vm_ops = { |
| 422 | .fault = filemap_fault, |
| 423 | .page_mkwrite = nfs_vm_page_mkwrite, |
| 424 | }; |
| 425 | |
| 426 | static int nfs_need_sync_write(struct file *filp, struct inode *inode) |
| 427 | { |
| 428 | struct nfs_open_context *ctx; |
| 429 | |
| 430 | if (IS_SYNC(inode) || (filp->f_flags & O_SYNC)) |
| 431 | return 1; |
| 432 | ctx = nfs_file_open_context(filp); |
| 433 | if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags)) |
| 434 | return 1; |
| 435 | return 0; |
| 436 | } |
| 437 | |
| 438 | static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, |
| 439 | unsigned long nr_segs, loff_t pos) |
| 440 | { |
| 441 | struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| 442 | struct inode * inode = dentry->d_inode; |
| 443 | ssize_t result; |
| 444 | size_t count = iov_length(iov, nr_segs); |
| 445 | |
| 446 | if (iocb->ki_filp->f_flags & O_DIRECT) |
| 447 | return nfs_file_direct_write(iocb, iov, nr_segs, pos); |
| 448 | |
| 449 | dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%Ld)\n", |
| 450 | dentry->d_parent->d_name.name, dentry->d_name.name, |
| 451 | inode->i_ino, (unsigned long) count, (long long) pos); |
| 452 | |
| 453 | result = -EBUSY; |
| 454 | if (IS_SWAPFILE(inode)) |
| 455 | goto out_swapfile; |
| 456 | /* |
| 457 | * O_APPEND implies that we must revalidate the file length. |
| 458 | */ |
| 459 | if (iocb->ki_filp->f_flags & O_APPEND) { |
| 460 | result = nfs_revalidate_file_size(inode, iocb->ki_filp); |
| 461 | if (result) |
| 462 | goto out; |
| 463 | } |
| 464 | |
| 465 | result = count; |
| 466 | if (!count) |
| 467 | goto out; |
| 468 | |
| 469 | nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); |
| 470 | result = generic_file_aio_write(iocb, iov, nr_segs, pos); |
| 471 | /* Return error values for O_SYNC and IS_SYNC() */ |
| 472 | if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) { |
| 473 | int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode); |
| 474 | if (err < 0) |
| 475 | result = err; |
| 476 | } |
| 477 | out: |
| 478 | return result; |
| 479 | |
| 480 | out_swapfile: |
| 481 | printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); |
| 482 | goto out; |
| 483 | } |
| 484 | |
| 485 | static int do_getlk(struct file *filp, int cmd, struct file_lock *fl) |
| 486 | { |
| 487 | struct inode *inode = filp->f_mapping->host; |
| 488 | int status = 0; |
| 489 | |
| 490 | lock_kernel(); |
| 491 | /* Try local locking first */ |
| 492 | posix_test_lock(filp, fl); |
| 493 | if (fl->fl_type != F_UNLCK) { |
| 494 | /* found a conflict */ |
| 495 | goto out; |
| 496 | } |
| 497 | |
| 498 | if (nfs_have_delegation(inode, FMODE_READ)) |
| 499 | goto out_noconflict; |
| 500 | |
| 501 | if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM) |
| 502 | goto out_noconflict; |
| 503 | |
| 504 | status = NFS_PROTO(inode)->lock(filp, cmd, fl); |
| 505 | out: |
| 506 | unlock_kernel(); |
| 507 | return status; |
| 508 | out_noconflict: |
| 509 | fl->fl_type = F_UNLCK; |
| 510 | goto out; |
| 511 | } |
| 512 | |
| 513 | static int do_vfs_lock(struct file *file, struct file_lock *fl) |
| 514 | { |
| 515 | int res = 0; |
| 516 | switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { |
| 517 | case FL_POSIX: |
| 518 | res = posix_lock_file_wait(file, fl); |
| 519 | break; |
| 520 | case FL_FLOCK: |
| 521 | res = flock_lock_file_wait(file, fl); |
| 522 | break; |
| 523 | default: |
| 524 | BUG(); |
| 525 | } |
| 526 | if (res < 0) |
| 527 | dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager" |
| 528 | " - error %d!\n", |
| 529 | __func__, res); |
| 530 | return res; |
| 531 | } |
| 532 | |
| 533 | static int do_unlk(struct file *filp, int cmd, struct file_lock *fl) |
| 534 | { |
| 535 | struct inode *inode = filp->f_mapping->host; |
| 536 | int status; |
| 537 | |
| 538 | /* |
| 539 | * Flush all pending writes before doing anything |
| 540 | * with locks.. |
| 541 | */ |
| 542 | nfs_sync_mapping(filp->f_mapping); |
| 543 | |
| 544 | /* NOTE: special case |
| 545 | * If we're signalled while cleaning up locks on process exit, we |
| 546 | * still need to complete the unlock. |
| 547 | */ |
| 548 | lock_kernel(); |
| 549 | /* Use local locking if mounted with "-onolock" */ |
| 550 | if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) |
| 551 | status = NFS_PROTO(inode)->lock(filp, cmd, fl); |
| 552 | else |
| 553 | status = do_vfs_lock(filp, fl); |
| 554 | unlock_kernel(); |
| 555 | return status; |
| 556 | } |
| 557 | |
| 558 | static int do_setlk(struct file *filp, int cmd, struct file_lock *fl) |
| 559 | { |
| 560 | struct inode *inode = filp->f_mapping->host; |
| 561 | int status; |
| 562 | |
| 563 | /* |
| 564 | * Flush all pending writes before doing anything |
| 565 | * with locks.. |
| 566 | */ |
| 567 | status = nfs_sync_mapping(filp->f_mapping); |
| 568 | if (status != 0) |
| 569 | goto out; |
| 570 | |
| 571 | lock_kernel(); |
| 572 | /* Use local locking if mounted with "-onolock" */ |
| 573 | if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) |
| 574 | status = NFS_PROTO(inode)->lock(filp, cmd, fl); |
| 575 | else |
| 576 | status = do_vfs_lock(filp, fl); |
| 577 | unlock_kernel(); |
| 578 | if (status < 0) |
| 579 | goto out; |
| 580 | /* |
| 581 | * Make sure we clear the cache whenever we try to get the lock. |
| 582 | * This makes locking act as a cache coherency point. |
| 583 | */ |
| 584 | nfs_sync_mapping(filp->f_mapping); |
| 585 | nfs_zap_caches(inode); |
| 586 | out: |
| 587 | return status; |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * Lock a (portion of) a file |
| 592 | */ |
| 593 | static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl) |
| 594 | { |
| 595 | struct inode * inode = filp->f_mapping->host; |
| 596 | int ret = -ENOLCK; |
| 597 | |
| 598 | dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n", |
| 599 | inode->i_sb->s_id, inode->i_ino, |
| 600 | fl->fl_type, fl->fl_flags, |
| 601 | (long long)fl->fl_start, (long long)fl->fl_end); |
| 602 | nfs_inc_stats(inode, NFSIOS_VFSLOCK); |
| 603 | |
| 604 | /* No mandatory locks over NFS */ |
| 605 | if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) |
| 606 | goto out_err; |
| 607 | |
| 608 | if (NFS_PROTO(inode)->lock_check_bounds != NULL) { |
| 609 | ret = NFS_PROTO(inode)->lock_check_bounds(fl); |
| 610 | if (ret < 0) |
| 611 | goto out_err; |
| 612 | } |
| 613 | |
| 614 | if (IS_GETLK(cmd)) |
| 615 | ret = do_getlk(filp, cmd, fl); |
| 616 | else if (fl->fl_type == F_UNLCK) |
| 617 | ret = do_unlk(filp, cmd, fl); |
| 618 | else |
| 619 | ret = do_setlk(filp, cmd, fl); |
| 620 | out_err: |
| 621 | return ret; |
| 622 | } |
| 623 | |
| 624 | /* |
| 625 | * Lock a (portion of) a file |
| 626 | */ |
| 627 | static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl) |
| 628 | { |
| 629 | dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n", |
| 630 | filp->f_path.dentry->d_inode->i_sb->s_id, |
| 631 | filp->f_path.dentry->d_inode->i_ino, |
| 632 | fl->fl_type, fl->fl_flags); |
| 633 | |
| 634 | /* |
| 635 | * No BSD flocks over NFS allowed. |
| 636 | * Note: we could try to fake a POSIX lock request here by |
| 637 | * using ((u32) filp | 0x80000000) or some such as the pid. |
| 638 | * Not sure whether that would be unique, though, or whether |
| 639 | * that would break in other places. |
| 640 | */ |
| 641 | if (!(fl->fl_flags & FL_FLOCK)) |
| 642 | return -ENOLCK; |
| 643 | |
| 644 | /* We're simulating flock() locks using posix locks on the server */ |
| 645 | fl->fl_owner = (fl_owner_t)filp; |
| 646 | fl->fl_start = 0; |
| 647 | fl->fl_end = OFFSET_MAX; |
| 648 | |
| 649 | if (fl->fl_type == F_UNLCK) |
| 650 | return do_unlk(filp, cmd, fl); |
| 651 | return do_setlk(filp, cmd, fl); |
| 652 | } |
| 653 | |
| 654 | static int nfs_setlease(struct file *file, long arg, struct file_lock **fl) |
| 655 | { |
| 656 | /* |
| 657 | * There is no protocol support for leases, so we have no way |
| 658 | * to implement them correctly in the face of opens by other |
| 659 | * clients. |
| 660 | */ |
| 661 | return -EINVAL; |
| 662 | } |