1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/slab.h> 11 #include <linux/spinlock.h> 12 #include <linux/completion.h> 13 #include <linux/buffer_head.h> 14 #include <linux/pagemap.h> 15 #include <linux/uio.h> 16 #include <linux/blkdev.h> 17 #include <linux/mm.h> 18 #include <linux/mount.h> 19 #include <linux/fs.h> 20 #include <linux/gfs2_ondisk.h> 21 #include <linux/falloc.h> 22 #include <linux/swap.h> 23 #include <linux/crc32.h> 24 #include <linux/writeback.h> 25 #include <linux/uaccess.h> 26 #include <linux/dlm.h> 27 #include <linux/dlm_plock.h> 28 #include <linux/delay.h> 29 30 #include "gfs2.h" 31 #include "incore.h" 32 #include "bmap.h" 33 #include "dir.h" 34 #include "glock.h" 35 #include "glops.h" 36 #include "inode.h" 37 #include "log.h" 38 #include "meta_io.h" 39 #include "quota.h" 40 #include "rgrp.h" 41 #include "trans.h" 42 #include "util.h" 43 44 /** 45 * gfs2_llseek - seek to a location in a file 46 * @file: the file 47 * @offset: the offset 48 * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END) 49 * 50 * SEEK_END requires the glock for the file because it references the 51 * file's size. 52 * 53 * Returns: The new offset, or errno 54 */ 55 56 static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence) 57 { 58 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); 59 struct gfs2_holder i_gh; 60 loff_t error; 61 62 switch (whence) { 63 case SEEK_END: /* These reference inode->i_size */ 64 case SEEK_DATA: 65 case SEEK_HOLE: 66 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, 67 &i_gh); 68 if (!error) { 69 error = generic_file_llseek(file, offset, whence); 70 gfs2_glock_dq_uninit(&i_gh); 71 } 72 break; 73 case SEEK_CUR: 74 case SEEK_SET: 75 error = generic_file_llseek(file, offset, whence); 76 break; 77 default: 78 error = -EINVAL; 79 } 80 81 return error; 82 } 83 84 /** 85 * gfs2_readdir - Iterator for a directory 86 * @file: The directory to read from 87 * @ctx: What to feed directory entries to 88 * 89 * Returns: errno 90 */ 91 92 static int gfs2_readdir(struct file *file, struct dir_context *ctx) 93 { 94 struct inode *dir = file->f_mapping->host; 95 struct gfs2_inode *dip = GFS2_I(dir); 96 struct gfs2_holder d_gh; 97 int error; 98 99 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh); 100 if (error) 101 return error; 102 103 error = gfs2_dir_read(dir, ctx, &file->f_ra); 104 105 gfs2_glock_dq_uninit(&d_gh); 106 107 return error; 108 } 109 110 /** 111 * fsflags_cvt 112 * @table: A table of 32 u32 flags 113 * @val: a 32 bit value to convert 114 * 115 * This function can be used to convert between fsflags values and 116 * GFS2's own flags values. 117 * 118 * Returns: the converted flags 119 */ 120 static u32 fsflags_cvt(const u32 *table, u32 val) 121 { 122 u32 res = 0; 123 while(val) { 124 if (val & 1) 125 res |= *table; 126 table++; 127 val >>= 1; 128 } 129 return res; 130 } 131 132 static const u32 fsflags_to_gfs2[32] = { 133 [3] = GFS2_DIF_SYNC, 134 [4] = GFS2_DIF_IMMUTABLE, 135 [5] = GFS2_DIF_APPENDONLY, 136 [7] = GFS2_DIF_NOATIME, 137 [12] = GFS2_DIF_EXHASH, 138 [14] = GFS2_DIF_INHERIT_JDATA, 139 [17] = GFS2_DIF_TOPDIR, 140 }; 141 142 static const u32 gfs2_to_fsflags[32] = { 143 [gfs2fl_Sync] = FS_SYNC_FL, 144 [gfs2fl_Immutable] = FS_IMMUTABLE_FL, 145 [gfs2fl_AppendOnly] = FS_APPEND_FL, 146 [gfs2fl_NoAtime] = FS_NOATIME_FL, 147 [gfs2fl_ExHash] = FS_INDEX_FL, 148 [gfs2fl_TopLevel] = FS_TOPDIR_FL, 149 [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL, 150 }; 151 152 static int gfs2_get_flags(struct file *filp, u32 __user *ptr) 153 { 154 struct inode *inode = file_inode(filp); 155 struct gfs2_inode *ip = GFS2_I(inode); 156 struct gfs2_holder gh; 157 int error; 158 u32 fsflags; 159 160 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 161 error = gfs2_glock_nq(&gh); 162 if (error) 163 goto out_uninit; 164 165 fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags); 166 if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA) 167 fsflags |= FS_JOURNAL_DATA_FL; 168 if (put_user(fsflags, ptr)) 169 error = -EFAULT; 170 171 gfs2_glock_dq(&gh); 172 out_uninit: 173 gfs2_holder_uninit(&gh); 174 return error; 175 } 176 177 void gfs2_set_inode_flags(struct inode *inode) 178 { 179 struct gfs2_inode *ip = GFS2_I(inode); 180 unsigned int flags = inode->i_flags; 181 182 flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC); 183 if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode)) 184 flags |= S_NOSEC; 185 if (ip->i_diskflags & GFS2_DIF_IMMUTABLE) 186 flags |= S_IMMUTABLE; 187 if (ip->i_diskflags & GFS2_DIF_APPENDONLY) 188 flags |= S_APPEND; 189 if (ip->i_diskflags & GFS2_DIF_NOATIME) 190 flags |= S_NOATIME; 191 if (ip->i_diskflags & GFS2_DIF_SYNC) 192 flags |= S_SYNC; 193 inode->i_flags = flags; 194 } 195 196 /* Flags that can be set by user space */ 197 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \ 198 GFS2_DIF_IMMUTABLE| \ 199 GFS2_DIF_APPENDONLY| \ 200 GFS2_DIF_NOATIME| \ 201 GFS2_DIF_SYNC| \ 202 GFS2_DIF_SYSTEM| \ 203 GFS2_DIF_TOPDIR| \ 204 GFS2_DIF_INHERIT_JDATA) 205 206 /** 207 * do_gfs2_set_flags - set flags on an inode 208 * @filp: file pointer 209 * @reqflags: The flags to set 210 * @mask: Indicates which flags are valid 211 * 212 */ 213 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask) 214 { 215 struct inode *inode = file_inode(filp); 216 struct gfs2_inode *ip = GFS2_I(inode); 217 struct gfs2_sbd *sdp = GFS2_SB(inode); 218 struct buffer_head *bh; 219 struct gfs2_holder gh; 220 int error; 221 u32 new_flags, flags; 222 223 error = mnt_want_write_file(filp); 224 if (error) 225 return error; 226 227 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); 228 if (error) 229 goto out_drop_write; 230 231 error = -EACCES; 232 if (!inode_owner_or_capable(inode)) 233 goto out; 234 235 error = 0; 236 flags = ip->i_diskflags; 237 new_flags = (flags & ~mask) | (reqflags & mask); 238 if ((new_flags ^ flags) == 0) 239 goto out; 240 241 error = -EINVAL; 242 if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET) 243 goto out; 244 245 error = -EPERM; 246 if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE)) 247 goto out; 248 if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY)) 249 goto out; 250 if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) && 251 !capable(CAP_LINUX_IMMUTABLE)) 252 goto out; 253 if (!IS_IMMUTABLE(inode)) { 254 error = gfs2_permission(inode, MAY_WRITE); 255 if (error) 256 goto out; 257 } 258 if ((flags ^ new_flags) & GFS2_DIF_JDATA) { 259 if (flags & GFS2_DIF_JDATA) 260 gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH); 261 error = filemap_fdatawrite(inode->i_mapping); 262 if (error) 263 goto out; 264 error = filemap_fdatawait(inode->i_mapping); 265 if (error) 266 goto out; 267 } 268 error = gfs2_trans_begin(sdp, RES_DINODE, 0); 269 if (error) 270 goto out; 271 error = gfs2_meta_inode_buffer(ip, &bh); 272 if (error) 273 goto out_trans_end; 274 gfs2_trans_add_meta(ip->i_gl, bh); 275 ip->i_diskflags = new_flags; 276 gfs2_dinode_out(ip, bh->b_data); 277 brelse(bh); 278 gfs2_set_inode_flags(inode); 279 gfs2_set_aops(inode); 280 out_trans_end: 281 gfs2_trans_end(sdp); 282 out: 283 gfs2_glock_dq_uninit(&gh); 284 out_drop_write: 285 mnt_drop_write_file(filp); 286 return error; 287 } 288 289 static int gfs2_set_flags(struct file *filp, u32 __user *ptr) 290 { 291 struct inode *inode = file_inode(filp); 292 u32 fsflags, gfsflags; 293 294 if (get_user(fsflags, ptr)) 295 return -EFAULT; 296 297 gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags); 298 if (!S_ISDIR(inode->i_mode)) { 299 gfsflags &= ~GFS2_DIF_TOPDIR; 300 if (gfsflags & GFS2_DIF_INHERIT_JDATA) 301 gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA); 302 return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_SYSTEM); 303 } 304 return do_gfs2_set_flags(filp, gfsflags, ~(GFS2_DIF_SYSTEM | GFS2_DIF_JDATA)); 305 } 306 307 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 308 { 309 switch(cmd) { 310 case FS_IOC_GETFLAGS: 311 return gfs2_get_flags(filp, (u32 __user *)arg); 312 case FS_IOC_SETFLAGS: 313 return gfs2_set_flags(filp, (u32 __user *)arg); 314 case FITRIM: 315 return gfs2_fitrim(filp, (void __user *)arg); 316 } 317 return -ENOTTY; 318 } 319 320 /** 321 * gfs2_size_hint - Give a hint to the size of a write request 322 * @filep: The struct file 323 * @offset: The file offset of the write 324 * @size: The length of the write 325 * 326 * When we are about to do a write, this function records the total 327 * write size in order to provide a suitable hint to the lower layers 328 * about how many blocks will be required. 329 * 330 */ 331 332 static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size) 333 { 334 struct inode *inode = file_inode(filep); 335 struct gfs2_sbd *sdp = GFS2_SB(inode); 336 struct gfs2_inode *ip = GFS2_I(inode); 337 size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift; 338 int hint = min_t(size_t, INT_MAX, blks); 339 340 if (hint > atomic_read(&ip->i_res.rs_sizehint)) 341 atomic_set(&ip->i_res.rs_sizehint, hint); 342 } 343 344 /** 345 * gfs2_allocate_page_backing - Use bmap to allocate blocks 346 * @page: The (locked) page to allocate backing for 347 * 348 * We try to allocate all the blocks required for the page in 349 * one go. This might fail for various reasons, so we keep 350 * trying until all the blocks to back this page are allocated. 351 * If some of the blocks are already allocated, thats ok too. 352 */ 353 354 static int gfs2_allocate_page_backing(struct page *page) 355 { 356 struct inode *inode = page->mapping->host; 357 struct buffer_head bh; 358 unsigned long size = PAGE_SIZE; 359 u64 lblock = page->index << (PAGE_SHIFT - inode->i_blkbits); 360 361 do { 362 bh.b_state = 0; 363 bh.b_size = size; 364 gfs2_block_map(inode, lblock, &bh, 1); 365 if (!buffer_mapped(&bh)) 366 return -EIO; 367 size -= bh.b_size; 368 lblock += (bh.b_size >> inode->i_blkbits); 369 } while(size > 0); 370 return 0; 371 } 372 373 /** 374 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable 375 * @vma: The virtual memory area 376 * @vmf: The virtual memory fault containing the page to become writable 377 * 378 * When the page becomes writable, we need to ensure that we have 379 * blocks allocated on disk to back that page. 380 */ 381 382 static int gfs2_page_mkwrite(struct vm_fault *vmf) 383 { 384 struct page *page = vmf->page; 385 struct inode *inode = file_inode(vmf->vma->vm_file); 386 struct gfs2_inode *ip = GFS2_I(inode); 387 struct gfs2_sbd *sdp = GFS2_SB(inode); 388 struct gfs2_alloc_parms ap = { .aflags = 0, }; 389 unsigned long last_index; 390 u64 pos = page->index << PAGE_SHIFT; 391 unsigned int data_blocks, ind_blocks, rblocks; 392 struct gfs2_holder gh; 393 loff_t size; 394 int ret; 395 396 sb_start_pagefault(inode->i_sb); 397 398 ret = gfs2_rsqa_alloc(ip); 399 if (ret) 400 goto out; 401 402 gfs2_size_hint(vmf->vma->vm_file, pos, PAGE_SIZE); 403 404 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); 405 ret = gfs2_glock_nq(&gh); 406 if (ret) 407 goto out_uninit; 408 409 /* Update file times before taking page lock */ 410 file_update_time(vmf->vma->vm_file); 411 412 set_bit(GLF_DIRTY, &ip->i_gl->gl_flags); 413 set_bit(GIF_SW_PAGED, &ip->i_flags); 414 415 if (!gfs2_write_alloc_required(ip, pos, PAGE_SIZE)) { 416 lock_page(page); 417 if (!PageUptodate(page) || page->mapping != inode->i_mapping) { 418 ret = -EAGAIN; 419 unlock_page(page); 420 } 421 goto out_unlock; 422 } 423 424 ret = gfs2_rindex_update(sdp); 425 if (ret) 426 goto out_unlock; 427 428 gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks); 429 ap.target = data_blocks + ind_blocks; 430 ret = gfs2_quota_lock_check(ip, &ap); 431 if (ret) 432 goto out_unlock; 433 ret = gfs2_inplace_reserve(ip, &ap); 434 if (ret) 435 goto out_quota_unlock; 436 437 rblocks = RES_DINODE + ind_blocks; 438 if (gfs2_is_jdata(ip)) 439 rblocks += data_blocks ? data_blocks : 1; 440 if (ind_blocks || data_blocks) { 441 rblocks += RES_STATFS + RES_QUOTA; 442 rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks); 443 } 444 ret = gfs2_trans_begin(sdp, rblocks, 0); 445 if (ret) 446 goto out_trans_fail; 447 448 lock_page(page); 449 ret = -EINVAL; 450 size = i_size_read(inode); 451 last_index = (size - 1) >> PAGE_SHIFT; 452 /* Check page index against inode size */ 453 if (size == 0 || (page->index > last_index)) 454 goto out_trans_end; 455 456 ret = -EAGAIN; 457 /* If truncated, we must retry the operation, we may have raced 458 * with the glock demotion code. 459 */ 460 if (!PageUptodate(page) || page->mapping != inode->i_mapping) 461 goto out_trans_end; 462 463 /* Unstuff, if required, and allocate backing blocks for page */ 464 ret = 0; 465 if (gfs2_is_stuffed(ip)) 466 ret = gfs2_unstuff_dinode(ip, page); 467 if (ret == 0) 468 ret = gfs2_allocate_page_backing(page); 469 470 out_trans_end: 471 if (ret) 472 unlock_page(page); 473 gfs2_trans_end(sdp); 474 out_trans_fail: 475 gfs2_inplace_release(ip); 476 out_quota_unlock: 477 gfs2_quota_unlock(ip); 478 out_unlock: 479 gfs2_glock_dq(&gh); 480 out_uninit: 481 gfs2_holder_uninit(&gh); 482 if (ret == 0) { 483 set_page_dirty(page); 484 wait_for_stable_page(page); 485 } 486 out: 487 sb_end_pagefault(inode->i_sb); 488 return block_page_mkwrite_return(ret); 489 } 490 491 static const struct vm_operations_struct gfs2_vm_ops = { 492 .fault = filemap_fault, 493 .map_pages = filemap_map_pages, 494 .page_mkwrite = gfs2_page_mkwrite, 495 }; 496 497 /** 498 * gfs2_mmap - 499 * @file: The file to map 500 * @vma: The VMA which described the mapping 501 * 502 * There is no need to get a lock here unless we should be updating 503 * atime. We ignore any locking errors since the only consequence is 504 * a missed atime update (which will just be deferred until later). 505 * 506 * Returns: 0 507 */ 508 509 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma) 510 { 511 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); 512 513 if (!(file->f_flags & O_NOATIME) && 514 !IS_NOATIME(&ip->i_inode)) { 515 struct gfs2_holder i_gh; 516 int error; 517 518 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, 519 &i_gh); 520 if (error) 521 return error; 522 /* grab lock to update inode */ 523 gfs2_glock_dq_uninit(&i_gh); 524 file_accessed(file); 525 } 526 vma->vm_ops = &gfs2_vm_ops; 527 528 return 0; 529 } 530 531 /** 532 * gfs2_open_common - This is common to open and atomic_open 533 * @inode: The inode being opened 534 * @file: The file being opened 535 * 536 * This maybe called under a glock or not depending upon how it has 537 * been called. We must always be called under a glock for regular 538 * files, however. For other file types, it does not matter whether 539 * we hold the glock or not. 540 * 541 * Returns: Error code or 0 for success 542 */ 543 544 int gfs2_open_common(struct inode *inode, struct file *file) 545 { 546 struct gfs2_file *fp; 547 int ret; 548 549 if (S_ISREG(inode->i_mode)) { 550 ret = generic_file_open(inode, file); 551 if (ret) 552 return ret; 553 } 554 555 fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS); 556 if (!fp) 557 return -ENOMEM; 558 559 mutex_init(&fp->f_fl_mutex); 560 561 gfs2_assert_warn(GFS2_SB(inode), !file->private_data); 562 file->private_data = fp; 563 return 0; 564 } 565 566 /** 567 * gfs2_open - open a file 568 * @inode: the inode to open 569 * @file: the struct file for this opening 570 * 571 * After atomic_open, this function is only used for opening files 572 * which are already cached. We must still get the glock for regular 573 * files to ensure that we have the file size uptodate for the large 574 * file check which is in the common code. That is only an issue for 575 * regular files though. 576 * 577 * Returns: errno 578 */ 579 580 static int gfs2_open(struct inode *inode, struct file *file) 581 { 582 struct gfs2_inode *ip = GFS2_I(inode); 583 struct gfs2_holder i_gh; 584 int error; 585 bool need_unlock = false; 586 587 if (S_ISREG(ip->i_inode.i_mode)) { 588 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, 589 &i_gh); 590 if (error) 591 return error; 592 need_unlock = true; 593 } 594 595 error = gfs2_open_common(inode, file); 596 597 if (need_unlock) 598 gfs2_glock_dq_uninit(&i_gh); 599 600 return error; 601 } 602 603 /** 604 * gfs2_release - called to close a struct file 605 * @inode: the inode the struct file belongs to 606 * @file: the struct file being closed 607 * 608 * Returns: errno 609 */ 610 611 static int gfs2_release(struct inode *inode, struct file *file) 612 { 613 struct gfs2_inode *ip = GFS2_I(inode); 614 615 kfree(file->private_data); 616 file->private_data = NULL; 617 618 if (!(file->f_mode & FMODE_WRITE)) 619 return 0; 620 621 gfs2_rsqa_delete(ip, &inode->i_writecount); 622 return 0; 623 } 624 625 /** 626 * gfs2_fsync - sync the dirty data for a file (across the cluster) 627 * @file: the file that points to the dentry 628 * @start: the start position in the file to sync 629 * @end: the end position in the file to sync 630 * @datasync: set if we can ignore timestamp changes 631 * 632 * We split the data flushing here so that we don't wait for the data 633 * until after we've also sent the metadata to disk. Note that for 634 * data=ordered, we will write & wait for the data at the log flush 635 * stage anyway, so this is unlikely to make much of a difference 636 * except in the data=writeback case. 637 * 638 * If the fdatawrite fails due to any reason except -EIO, we will 639 * continue the remainder of the fsync, although we'll still report 640 * the error at the end. This is to match filemap_write_and_wait_range() 641 * behaviour. 642 * 643 * Returns: errno 644 */ 645 646 static int gfs2_fsync(struct file *file, loff_t start, loff_t end, 647 int datasync) 648 { 649 struct address_space *mapping = file->f_mapping; 650 struct inode *inode = mapping->host; 651 int sync_state = inode->i_state & I_DIRTY_ALL; 652 struct gfs2_inode *ip = GFS2_I(inode); 653 int ret = 0, ret1 = 0; 654 655 if (mapping->nrpages) { 656 ret1 = filemap_fdatawrite_range(mapping, start, end); 657 if (ret1 == -EIO) 658 return ret1; 659 } 660 661 if (!gfs2_is_jdata(ip)) 662 sync_state &= ~I_DIRTY_PAGES; 663 if (datasync) 664 sync_state &= ~(I_DIRTY_SYNC | I_DIRTY_TIME); 665 666 if (sync_state) { 667 ret = sync_inode_metadata(inode, 1); 668 if (ret) 669 return ret; 670 if (gfs2_is_jdata(ip)) 671 filemap_write_and_wait(mapping); 672 gfs2_ail_flush(ip->i_gl, 1); 673 } 674 675 if (mapping->nrpages) 676 ret = filemap_fdatawait_range(mapping, start, end); 677 678 return ret ? ret : ret1; 679 } 680 681 /** 682 * gfs2_file_write_iter - Perform a write to a file 683 * @iocb: The io context 684 * @iov: The data to write 685 * @nr_segs: Number of @iov segments 686 * @pos: The file position 687 * 688 * We have to do a lock/unlock here to refresh the inode size for 689 * O_APPEND writes, otherwise we can land up writing at the wrong 690 * offset. There is still a race, but provided the app is using its 691 * own file locking, this will make O_APPEND work as expected. 692 * 693 */ 694 695 static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 696 { 697 struct file *file = iocb->ki_filp; 698 struct gfs2_inode *ip = GFS2_I(file_inode(file)); 699 int ret; 700 701 ret = gfs2_rsqa_alloc(ip); 702 if (ret) 703 return ret; 704 705 gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from)); 706 707 if (iocb->ki_flags & IOCB_APPEND) { 708 struct gfs2_holder gh; 709 710 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh); 711 if (ret) 712 return ret; 713 gfs2_glock_dq_uninit(&gh); 714 } 715 716 return generic_file_write_iter(iocb, from); 717 } 718 719 static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, 720 int mode) 721 { 722 struct gfs2_inode *ip = GFS2_I(inode); 723 struct buffer_head *dibh; 724 int error; 725 unsigned int nr_blks; 726 sector_t lblock = offset >> inode->i_blkbits; 727 728 error = gfs2_meta_inode_buffer(ip, &dibh); 729 if (unlikely(error)) 730 return error; 731 732 gfs2_trans_add_meta(ip->i_gl, dibh); 733 734 if (gfs2_is_stuffed(ip)) { 735 error = gfs2_unstuff_dinode(ip, NULL); 736 if (unlikely(error)) 737 goto out; 738 } 739 740 while (len) { 741 struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 }; 742 bh_map.b_size = len; 743 set_buffer_zeronew(&bh_map); 744 745 error = gfs2_block_map(inode, lblock, &bh_map, 1); 746 if (unlikely(error)) 747 goto out; 748 len -= bh_map.b_size; 749 nr_blks = bh_map.b_size >> inode->i_blkbits; 750 lblock += nr_blks; 751 if (!buffer_new(&bh_map)) 752 continue; 753 if (unlikely(!buffer_zeronew(&bh_map))) { 754 error = -EIO; 755 goto out; 756 } 757 } 758 out: 759 brelse(dibh); 760 return error; 761 } 762 /** 763 * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of 764 * blocks, determine how many bytes can be written. 765 * @ip: The inode in question. 766 * @len: Max cap of bytes. What we return in *len must be <= this. 767 * @data_blocks: Compute and return the number of data blocks needed 768 * @ind_blocks: Compute and return the number of indirect blocks needed 769 * @max_blocks: The total blocks available to work with. 770 * 771 * Returns: void, but @len, @data_blocks and @ind_blocks are filled in. 772 */ 773 static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len, 774 unsigned int *data_blocks, unsigned int *ind_blocks, 775 unsigned int max_blocks) 776 { 777 loff_t max = *len; 778 const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 779 unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1); 780 781 for (tmp = max_data; tmp > sdp->sd_diptrs;) { 782 tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs); 783 max_data -= tmp; 784 } 785 786 *data_blocks = max_data; 787 *ind_blocks = max_blocks - max_data; 788 *len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift; 789 if (*len > max) { 790 *len = max; 791 gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks); 792 } 793 } 794 795 static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 796 { 797 struct inode *inode = file_inode(file); 798 struct gfs2_sbd *sdp = GFS2_SB(inode); 799 struct gfs2_inode *ip = GFS2_I(inode); 800 struct gfs2_alloc_parms ap = { .aflags = 0, }; 801 unsigned int data_blocks = 0, ind_blocks = 0, rblocks; 802 loff_t bytes, max_bytes, max_blks = UINT_MAX; 803 int error; 804 const loff_t pos = offset; 805 const loff_t count = len; 806 loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1); 807 loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift; 808 loff_t max_chunk_size = UINT_MAX & bsize_mask; 809 810 next = (next + 1) << sdp->sd_sb.sb_bsize_shift; 811 812 offset &= bsize_mask; 813 814 len = next - offset; 815 bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2; 816 if (!bytes) 817 bytes = UINT_MAX; 818 bytes &= bsize_mask; 819 if (bytes == 0) 820 bytes = sdp->sd_sb.sb_bsize; 821 822 gfs2_size_hint(file, offset, len); 823 824 gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks); 825 ap.min_target = data_blocks + ind_blocks; 826 827 while (len > 0) { 828 if (len < bytes) 829 bytes = len; 830 if (!gfs2_write_alloc_required(ip, offset, bytes)) { 831 len -= bytes; 832 offset += bytes; 833 continue; 834 } 835 836 /* We need to determine how many bytes we can actually 837 * fallocate without exceeding quota or going over the 838 * end of the fs. We start off optimistically by assuming 839 * we can write max_bytes */ 840 max_bytes = (len > max_chunk_size) ? max_chunk_size : len; 841 842 /* Since max_bytes is most likely a theoretical max, we 843 * calculate a more realistic 'bytes' to serve as a good 844 * starting point for the number of bytes we may be able 845 * to write */ 846 gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks); 847 ap.target = data_blocks + ind_blocks; 848 849 error = gfs2_quota_lock_check(ip, &ap); 850 if (error) 851 return error; 852 /* ap.allowed tells us how many blocks quota will allow 853 * us to write. Check if this reduces max_blks */ 854 if (ap.allowed && ap.allowed < max_blks) 855 max_blks = ap.allowed; 856 857 error = gfs2_inplace_reserve(ip, &ap); 858 if (error) 859 goto out_qunlock; 860 861 /* check if the selected rgrp limits our max_blks further */ 862 if (ap.allowed && ap.allowed < max_blks) 863 max_blks = ap.allowed; 864 865 /* Almost done. Calculate bytes that can be written using 866 * max_blks. We also recompute max_bytes, data_blocks and 867 * ind_blocks */ 868 calc_max_reserv(ip, &max_bytes, &data_blocks, 869 &ind_blocks, max_blks); 870 871 rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA + 872 RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks); 873 if (gfs2_is_jdata(ip)) 874 rblocks += data_blocks ? data_blocks : 1; 875 876 error = gfs2_trans_begin(sdp, rblocks, 877 PAGE_SIZE/sdp->sd_sb.sb_bsize); 878 if (error) 879 goto out_trans_fail; 880 881 error = fallocate_chunk(inode, offset, max_bytes, mode); 882 gfs2_trans_end(sdp); 883 884 if (error) 885 goto out_trans_fail; 886 887 len -= max_bytes; 888 offset += max_bytes; 889 gfs2_inplace_release(ip); 890 gfs2_quota_unlock(ip); 891 } 892 893 if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size) { 894 i_size_write(inode, pos + count); 895 file_update_time(file); 896 mark_inode_dirty(inode); 897 } 898 899 if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host)) 900 return vfs_fsync_range(file, pos, pos + count - 1, 901 (file->f_flags & __O_SYNC) ? 0 : 1); 902 return 0; 903 904 out_trans_fail: 905 gfs2_inplace_release(ip); 906 out_qunlock: 907 gfs2_quota_unlock(ip); 908 return error; 909 } 910 911 static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 912 { 913 struct inode *inode = file_inode(file); 914 struct gfs2_inode *ip = GFS2_I(inode); 915 struct gfs2_holder gh; 916 int ret; 917 918 if ((mode & ~FALLOC_FL_KEEP_SIZE) || gfs2_is_jdata(ip)) 919 return -EOPNOTSUPP; 920 921 inode_lock(inode); 922 923 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); 924 ret = gfs2_glock_nq(&gh); 925 if (ret) 926 goto out_uninit; 927 928 if (!(mode & FALLOC_FL_KEEP_SIZE) && 929 (offset + len) > inode->i_size) { 930 ret = inode_newsize_ok(inode, offset + len); 931 if (ret) 932 goto out_unlock; 933 } 934 935 ret = get_write_access(inode); 936 if (ret) 937 goto out_unlock; 938 939 ret = gfs2_rsqa_alloc(ip); 940 if (ret) 941 goto out_putw; 942 943 ret = __gfs2_fallocate(file, mode, offset, len); 944 if (ret) 945 gfs2_rs_deltree(&ip->i_res); 946 947 out_putw: 948 put_write_access(inode); 949 out_unlock: 950 gfs2_glock_dq(&gh); 951 out_uninit: 952 gfs2_holder_uninit(&gh); 953 inode_unlock(inode); 954 return ret; 955 } 956 957 static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe, 958 struct file *out, loff_t *ppos, 959 size_t len, unsigned int flags) 960 { 961 int error; 962 struct gfs2_inode *ip = GFS2_I(out->f_mapping->host); 963 964 error = gfs2_rsqa_alloc(ip); 965 if (error) 966 return (ssize_t)error; 967 968 gfs2_size_hint(out, *ppos, len); 969 970 return iter_file_splice_write(pipe, out, ppos, len, flags); 971 } 972 973 #ifdef CONFIG_GFS2_FS_LOCKING_DLM 974 975 /** 976 * gfs2_lock - acquire/release a posix lock on a file 977 * @file: the file pointer 978 * @cmd: either modify or retrieve lock state, possibly wait 979 * @fl: type and range of lock 980 * 981 * Returns: errno 982 */ 983 984 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl) 985 { 986 struct gfs2_inode *ip = GFS2_I(file->f_mapping->host); 987 struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host); 988 struct lm_lockstruct *ls = &sdp->sd_lockstruct; 989 990 if (!(fl->fl_flags & FL_POSIX)) 991 return -ENOLCK; 992 if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK) 993 return -ENOLCK; 994 995 if (cmd == F_CANCELLK) { 996 /* Hack: */ 997 cmd = F_SETLK; 998 fl->fl_type = F_UNLCK; 999 } 1000 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) { 1001 if (fl->fl_type == F_UNLCK) 1002 locks_lock_file_wait(file, fl); 1003 return -EIO; 1004 } 1005 if (IS_GETLK(cmd)) 1006 return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl); 1007 else if (fl->fl_type == F_UNLCK) 1008 return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl); 1009 else 1010 return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl); 1011 } 1012 1013 static int do_flock(struct file *file, int cmd, struct file_lock *fl) 1014 { 1015 struct gfs2_file *fp = file->private_data; 1016 struct gfs2_holder *fl_gh = &fp->f_fl_gh; 1017 struct gfs2_inode *ip = GFS2_I(file_inode(file)); 1018 struct gfs2_glock *gl; 1019 unsigned int state; 1020 u16 flags; 1021 int error = 0; 1022 int sleeptime; 1023 1024 state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; 1025 flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT; 1026 1027 mutex_lock(&fp->f_fl_mutex); 1028 1029 gl = fl_gh->gh_gl; 1030 if (gl) { 1031 if (fl_gh->gh_state == state) 1032 goto out; 1033 locks_lock_file_wait(file, 1034 &(struct file_lock) { 1035 .fl_type = F_UNLCK, 1036 .fl_flags = FL_FLOCK 1037 }); 1038 gfs2_glock_dq(fl_gh); 1039 gfs2_holder_reinit(state, flags, fl_gh); 1040 } else { 1041 error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr, 1042 &gfs2_flock_glops, CREATE, &gl); 1043 if (error) 1044 goto out; 1045 gfs2_holder_init(gl, state, flags, fl_gh); 1046 gfs2_glock_put(gl); 1047 } 1048 for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) { 1049 error = gfs2_glock_nq(fl_gh); 1050 if (error != GLR_TRYFAILED) 1051 break; 1052 fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT; 1053 fl_gh->gh_error = 0; 1054 msleep(sleeptime); 1055 } 1056 if (error) { 1057 gfs2_holder_uninit(fl_gh); 1058 if (error == GLR_TRYFAILED) 1059 error = -EAGAIN; 1060 } else { 1061 error = locks_lock_file_wait(file, fl); 1062 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error); 1063 } 1064 1065 out: 1066 mutex_unlock(&fp->f_fl_mutex); 1067 return error; 1068 } 1069 1070 static void do_unflock(struct file *file, struct file_lock *fl) 1071 { 1072 struct gfs2_file *fp = file->private_data; 1073 struct gfs2_holder *fl_gh = &fp->f_fl_gh; 1074 1075 mutex_lock(&fp->f_fl_mutex); 1076 locks_lock_file_wait(file, fl); 1077 if (gfs2_holder_initialized(fl_gh)) { 1078 gfs2_glock_dq(fl_gh); 1079 gfs2_holder_uninit(fl_gh); 1080 } 1081 mutex_unlock(&fp->f_fl_mutex); 1082 } 1083 1084 /** 1085 * gfs2_flock - acquire/release a flock lock on a file 1086 * @file: the file pointer 1087 * @cmd: either modify or retrieve lock state, possibly wait 1088 * @fl: type and range of lock 1089 * 1090 * Returns: errno 1091 */ 1092 1093 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl) 1094 { 1095 if (!(fl->fl_flags & FL_FLOCK)) 1096 return -ENOLCK; 1097 if (fl->fl_type & LOCK_MAND) 1098 return -EOPNOTSUPP; 1099 1100 if (fl->fl_type == F_UNLCK) { 1101 do_unflock(file, fl); 1102 return 0; 1103 } else { 1104 return do_flock(file, cmd, fl); 1105 } 1106 } 1107 1108 const struct file_operations gfs2_file_fops = { 1109 .llseek = gfs2_llseek, 1110 .read_iter = generic_file_read_iter, 1111 .write_iter = gfs2_file_write_iter, 1112 .unlocked_ioctl = gfs2_ioctl, 1113 .mmap = gfs2_mmap, 1114 .open = gfs2_open, 1115 .release = gfs2_release, 1116 .fsync = gfs2_fsync, 1117 .lock = gfs2_lock, 1118 .flock = gfs2_flock, 1119 .splice_read = generic_file_splice_read, 1120 .splice_write = gfs2_file_splice_write, 1121 .setlease = simple_nosetlease, 1122 .fallocate = gfs2_fallocate, 1123 }; 1124 1125 const struct file_operations gfs2_dir_fops = { 1126 .iterate_shared = gfs2_readdir, 1127 .unlocked_ioctl = gfs2_ioctl, 1128 .open = gfs2_open, 1129 .release = gfs2_release, 1130 .fsync = gfs2_fsync, 1131 .lock = gfs2_lock, 1132 .flock = gfs2_flock, 1133 .llseek = default_llseek, 1134 }; 1135 1136 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */ 1137 1138 const struct file_operations gfs2_file_fops_nolock = { 1139 .llseek = gfs2_llseek, 1140 .read_iter = generic_file_read_iter, 1141 .write_iter = gfs2_file_write_iter, 1142 .unlocked_ioctl = gfs2_ioctl, 1143 .mmap = gfs2_mmap, 1144 .open = gfs2_open, 1145 .release = gfs2_release, 1146 .fsync = gfs2_fsync, 1147 .splice_read = generic_file_splice_read, 1148 .splice_write = gfs2_file_splice_write, 1149 .setlease = generic_setlease, 1150 .fallocate = gfs2_fallocate, 1151 }; 1152 1153 const struct file_operations gfs2_dir_fops_nolock = { 1154 .iterate_shared = gfs2_readdir, 1155 .unlocked_ioctl = gfs2_ioctl, 1156 .open = gfs2_open, 1157 .release = gfs2_release, 1158 .fsync = gfs2_fsync, 1159 .llseek = default_llseek, 1160 }; 1161 1162