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authorVladimir Saveliev <vs@namesys.com>2007-10-16 04:25:12 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 12:42:56 -0400
commit797b4cffdf79b9ed66759b8d2d5252eba965fb18 (patch)
tree5704fe75e0e9ff45ccd078d0b34420ad71f242a8 /fs/reiserfs/file.c
parentf87061842877cf822251c65b39cc624cc94046da (diff)
reiserfs: use generic write
Make reiserfs to write via generic routines. Original reiserfs write optimized for big writes is deadlock rone Signed-off-by: Vladimir Saveliev <vs@namesys.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/reiserfs/file.c')
-rw-r--r--fs/reiserfs/file.c1240
1 files changed, 1 insertions, 1239 deletions
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 2070aeee2a52..a804903d31d1 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -153,608 +153,6 @@ static int reiserfs_sync_file(struct file *p_s_filp,
153 return (n_err < 0) ? -EIO : 0; 153 return (n_err < 0) ? -EIO : 0;
154} 154}
155 155
156/* I really do not want to play with memory shortage right now, so
157 to simplify the code, we are not going to write more than this much pages at
158 a time. This still should considerably improve performance compared to 4k
159 at a time case. This is 32 pages of 4k size. */
160#define REISERFS_WRITE_PAGES_AT_A_TIME (128 * 1024) / PAGE_CACHE_SIZE
161
162/* Allocates blocks for a file to fulfil write request.
163 Maps all unmapped but prepared pages from the list.
164 Updates metadata with newly allocated blocknumbers as needed */
165static int reiserfs_allocate_blocks_for_region(struct reiserfs_transaction_handle *th, struct inode *inode, /* Inode we work with */
166 loff_t pos, /* Writing position */
167 int num_pages, /* number of pages write going
168 to touch */
169 int write_bytes, /* amount of bytes to write */
170 struct page **prepared_pages, /* array of
171 prepared pages
172 */
173 int blocks_to_allocate /* Amount of blocks we
174 need to allocate to
175 fit the data into file
176 */
177 )
178{
179 struct cpu_key key; // cpu key of item that we are going to deal with
180 struct item_head *ih; // pointer to item head that we are going to deal with
181 struct buffer_head *bh; // Buffer head that contains items that we are going to deal with
182 __le32 *item; // pointer to item we are going to deal with
183 INITIALIZE_PATH(path); // path to item, that we are going to deal with.
184 b_blocknr_t *allocated_blocks; // Pointer to a place where allocated blocknumbers would be stored.
185 reiserfs_blocknr_hint_t hint; // hint structure for block allocator.
186 size_t res; // return value of various functions that we call.
187 int curr_block; // current block used to keep track of unmapped blocks.
188 int i; // loop counter
189 int itempos; // position in item
190 unsigned int from = (pos & (PAGE_CACHE_SIZE - 1)); // writing position in
191 // first page
192 unsigned int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1; /* last modified byte offset in last page */
193 __u64 hole_size; // amount of blocks for a file hole, if it needed to be created.
194 int modifying_this_item = 0; // Flag for items traversal code to keep track
195 // of the fact that we already prepared
196 // current block for journal
197 int will_prealloc = 0;
198 RFALSE(!blocks_to_allocate,
199 "green-9004: tried to allocate zero blocks?");
200
201 /* only preallocate if this is a small write */
202 if (REISERFS_I(inode)->i_prealloc_count ||
203 (!(write_bytes & (inode->i_sb->s_blocksize - 1)) &&
204 blocks_to_allocate <
205 REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize))
206 will_prealloc =
207 REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize;
208
209 allocated_blocks = kmalloc((blocks_to_allocate + will_prealloc) *
210 sizeof(b_blocknr_t), GFP_NOFS);
211 if (!allocated_blocks)
212 return -ENOMEM;
213
214 /* First we compose a key to point at the writing position, we want to do
215 that outside of any locking region. */
216 make_cpu_key(&key, inode, pos + 1, TYPE_ANY, 3 /*key length */ );
217
218 /* If we came here, it means we absolutely need to open a transaction,
219 since we need to allocate some blocks */
220 reiserfs_write_lock(inode->i_sb); // Journaling stuff and we need that.
221 res = journal_begin(th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3 + 1 + 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb)); // Wish I know if this number enough
222 if (res)
223 goto error_exit;
224 reiserfs_update_inode_transaction(inode);
225
226 /* Look for the in-tree position of our write, need path for block allocator */
227 res = search_for_position_by_key(inode->i_sb, &key, &path);
228 if (res == IO_ERROR) {
229 res = -EIO;
230 goto error_exit;
231 }
232
233 /* Allocate blocks */
234 /* First fill in "hint" structure for block allocator */
235 hint.th = th; // transaction handle.
236 hint.path = &path; // Path, so that block allocator can determine packing locality or whatever it needs to determine.
237 hint.inode = inode; // Inode is needed by block allocator too.
238 hint.search_start = 0; // We have no hint on where to search free blocks for block allocator.
239 hint.key = key.on_disk_key; // on disk key of file.
240 hint.block = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); // Number of disk blocks this file occupies already.
241 hint.formatted_node = 0; // We are allocating blocks for unformatted node.
242 hint.preallocate = will_prealloc;
243
244 /* Call block allocator to allocate blocks */
245 res =
246 reiserfs_allocate_blocknrs(&hint, allocated_blocks,
247 blocks_to_allocate, blocks_to_allocate);
248 if (res != CARRY_ON) {
249 if (res == NO_DISK_SPACE) {
250 /* We flush the transaction in case of no space. This way some
251 blocks might become free */
252 SB_JOURNAL(inode->i_sb)->j_must_wait = 1;
253 res = restart_transaction(th, inode, &path);
254 if (res)
255 goto error_exit;
256
257 /* We might have scheduled, so search again */
258 res =
259 search_for_position_by_key(inode->i_sb, &key,
260 &path);
261 if (res == IO_ERROR) {
262 res = -EIO;
263 goto error_exit;
264 }
265
266 /* update changed info for hint structure. */
267 res =
268 reiserfs_allocate_blocknrs(&hint, allocated_blocks,
269 blocks_to_allocate,
270 blocks_to_allocate);
271 if (res != CARRY_ON) {
272 res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC;
273 pathrelse(&path);
274 goto error_exit;
275 }
276 } else {
277 res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC;
278 pathrelse(&path);
279 goto error_exit;
280 }
281 }
282#ifdef __BIG_ENDIAN
283 // Too bad, I have not found any way to convert a given region from
284 // cpu format to little endian format
285 {
286 int i;
287 for (i = 0; i < blocks_to_allocate; i++)
288 allocated_blocks[i] = cpu_to_le32(allocated_blocks[i]);
289 }
290#endif
291
292 /* Blocks allocating well might have scheduled and tree might have changed,
293 let's search the tree again */
294 /* find where in the tree our write should go */
295 res = search_for_position_by_key(inode->i_sb, &key, &path);
296 if (res == IO_ERROR) {
297 res = -EIO;
298 goto error_exit_free_blocks;
299 }
300
301 bh = get_last_bh(&path); // Get a bufferhead for last element in path.
302 ih = get_ih(&path); // Get a pointer to last item head in path.
303 item = get_item(&path); // Get a pointer to last item in path
304
305 /* Let's see what we have found */
306 if (res != POSITION_FOUND) { /* position not found, this means that we
307 might need to append file with holes
308 first */
309 // Since we are writing past the file's end, we need to find out if
310 // there is a hole that needs to be inserted before our writing
311 // position, and how many blocks it is going to cover (we need to
312 // populate pointers to file blocks representing the hole with zeros)
313
314 {
315 int item_offset = 1;
316 /*
317 * if ih is stat data, its offset is 0 and we don't want to
318 * add 1 to pos in the hole_size calculation
319 */
320 if (is_statdata_le_ih(ih))
321 item_offset = 0;
322 hole_size = (pos + item_offset -
323 (le_key_k_offset
324 (get_inode_item_key_version(inode),
325 &(ih->ih_key)) + op_bytes_number(ih,
326 inode->
327 i_sb->
328 s_blocksize)))
329 >> inode->i_sb->s_blocksize_bits;
330 }
331
332 if (hole_size > 0) {
333 int to_paste = min_t(__u64, hole_size, MAX_ITEM_LEN(inode->i_sb->s_blocksize) / UNFM_P_SIZE); // How much data to insert first time.
334 /* area filled with zeroes, to supply as list of zero blocknumbers
335 We allocate it outside of loop just in case loop would spin for
336 several iterations. */
337 char *zeros = kzalloc(to_paste * UNFM_P_SIZE, GFP_ATOMIC); // We cannot insert more than MAX_ITEM_LEN bytes anyway.
338 if (!zeros) {
339 res = -ENOMEM;
340 goto error_exit_free_blocks;
341 }
342 do {
343 to_paste =
344 min_t(__u64, hole_size,
345 MAX_ITEM_LEN(inode->i_sb->
346 s_blocksize) /
347 UNFM_P_SIZE);
348 if (is_indirect_le_ih(ih)) {
349 /* Ok, there is existing indirect item already. Need to append it */
350 /* Calculate position past inserted item */
351 make_cpu_key(&key, inode,
352 le_key_k_offset
353 (get_inode_item_key_version
354 (inode),
355 &(ih->ih_key)) +
356 op_bytes_number(ih,
357 inode->
358 i_sb->
359 s_blocksize),
360 TYPE_INDIRECT, 3);
361 res =
362 reiserfs_paste_into_item(th, &path,
363 &key,
364 inode,
365 (char *)
366 zeros,
367 UNFM_P_SIZE
368 *
369 to_paste);
370 if (res) {
371 kfree(zeros);
372 goto error_exit_free_blocks;
373 }
374 } else if (is_statdata_le_ih(ih)) {
375 /* No existing item, create it */
376 /* item head for new item */
377 struct item_head ins_ih;
378
379 /* create a key for our new item */
380 make_cpu_key(&key, inode, 1,
381 TYPE_INDIRECT, 3);
382
383 /* Create new item head for our new item */
384 make_le_item_head(&ins_ih, &key,
385 key.version, 1,
386 TYPE_INDIRECT,
387 to_paste *
388 UNFM_P_SIZE,
389 0 /* free space */ );
390
391 /* Find where such item should live in the tree */
392 res =
393 search_item(inode->i_sb, &key,
394 &path);
395 if (res != ITEM_NOT_FOUND) {
396 /* item should not exist, otherwise we have error */
397 if (res != -ENOSPC) {
398 reiserfs_warning(inode->
399 i_sb,
400 "green-9008: search_by_key (%K) returned %d",
401 &key,
402 res);
403 }
404 res = -EIO;
405 kfree(zeros);
406 goto error_exit_free_blocks;
407 }
408 res =
409 reiserfs_insert_item(th, &path,
410 &key, &ins_ih,
411 inode,
412 (char *)zeros);
413 } else {
414 reiserfs_panic(inode->i_sb,
415 "green-9011: Unexpected key type %K\n",
416 &key);
417 }
418 if (res) {
419 kfree(zeros);
420 goto error_exit_free_blocks;
421 }
422 /* Now we want to check if transaction is too full, and if it is
423 we restart it. This will also free the path. */
424 if (journal_transaction_should_end
425 (th, th->t_blocks_allocated)) {
426 inode->i_size = cpu_key_k_offset(&key) +
427 (to_paste << inode->i_blkbits);
428 res =
429 restart_transaction(th, inode,
430 &path);
431 if (res) {
432 pathrelse(&path);
433 kfree(zeros);
434 goto error_exit;
435 }
436 }
437
438 /* Well, need to recalculate path and stuff */
439 set_cpu_key_k_offset(&key,
440 cpu_key_k_offset(&key) +
441 (to_paste << inode->
442 i_blkbits));
443 res =
444 search_for_position_by_key(inode->i_sb,
445 &key, &path);
446 if (res == IO_ERROR) {
447 res = -EIO;
448 kfree(zeros);
449 goto error_exit_free_blocks;
450 }
451 bh = get_last_bh(&path);
452 ih = get_ih(&path);
453 item = get_item(&path);
454 hole_size -= to_paste;
455 } while (hole_size);
456 kfree(zeros);
457 }
458 }
459 // Go through existing indirect items first
460 // replace all zeroes with blocknumbers from list
461 // Note that if no corresponding item was found, by previous search,
462 // it means there are no existing in-tree representation for file area
463 // we are going to overwrite, so there is nothing to scan through for holes.
464 for (curr_block = 0, itempos = path.pos_in_item;
465 curr_block < blocks_to_allocate && res == POSITION_FOUND;) {
466 retry:
467
468 if (itempos >= ih_item_len(ih) / UNFM_P_SIZE) {
469 /* We run out of data in this indirect item, let's look for another
470 one. */
471 /* First if we are already modifying current item, log it */
472 if (modifying_this_item) {
473 journal_mark_dirty(th, inode->i_sb, bh);
474 modifying_this_item = 0;
475 }
476 /* Then set the key to look for a new indirect item (offset of old
477 item is added to old item length */
478 set_cpu_key_k_offset(&key,
479 le_key_k_offset
480 (get_inode_item_key_version(inode),
481 &(ih->ih_key)) +
482 op_bytes_number(ih,
483 inode->i_sb->
484 s_blocksize));
485 /* Search ofor position of new key in the tree. */
486 res =
487 search_for_position_by_key(inode->i_sb, &key,
488 &path);
489 if (res == IO_ERROR) {
490 res = -EIO;
491 goto error_exit_free_blocks;
492 }
493 bh = get_last_bh(&path);
494 ih = get_ih(&path);
495 item = get_item(&path);
496 itempos = path.pos_in_item;
497 continue; // loop to check all kinds of conditions and so on.
498 }
499 /* Ok, we have correct position in item now, so let's see if it is
500 representing file hole (blocknumber is zero) and fill it if needed */
501 if (!item[itempos]) {
502 /* Ok, a hole. Now we need to check if we already prepared this
503 block to be journaled */
504 while (!modifying_this_item) { // loop until succeed
505 /* Well, this item is not journaled yet, so we must prepare
506 it for journal first, before we can change it */
507 struct item_head tmp_ih; // We copy item head of found item,
508 // here to detect if fs changed under
509 // us while we were preparing for
510 // journal.
511 int fs_gen; // We store fs generation here to find if someone
512 // changes fs under our feet
513
514 copy_item_head(&tmp_ih, ih); // Remember itemhead
515 fs_gen = get_generation(inode->i_sb); // remember fs generation
516 reiserfs_prepare_for_journal(inode->i_sb, bh, 1); // Prepare a buffer within which indirect item is stored for changing.
517 if (fs_changed(fs_gen, inode->i_sb)
518 && item_moved(&tmp_ih, &path)) {
519 // Sigh, fs was changed under us, we need to look for new
520 // location of item we are working with
521
522 /* unmark prepaerd area as journaled and search for it's
523 new position */
524 reiserfs_restore_prepared_buffer(inode->
525 i_sb,
526 bh);
527 res =
528 search_for_position_by_key(inode->
529 i_sb,
530 &key,
531 &path);
532 if (res == IO_ERROR) {
533 res = -EIO;
534 goto error_exit_free_blocks;
535 }
536 bh = get_last_bh(&path);
537 ih = get_ih(&path);
538 item = get_item(&path);
539 itempos = path.pos_in_item;
540 goto retry;
541 }
542 modifying_this_item = 1;
543 }
544 item[itempos] = allocated_blocks[curr_block]; // Assign new block
545 curr_block++;
546 }
547 itempos++;
548 }
549
550 if (modifying_this_item) { // We need to log last-accessed block, if it
551 // was modified, but not logged yet.
552 journal_mark_dirty(th, inode->i_sb, bh);
553 }
554
555 if (curr_block < blocks_to_allocate) {
556 // Oh, well need to append to indirect item, or to create indirect item
557 // if there weren't any
558 if (is_indirect_le_ih(ih)) {
559 // Existing indirect item - append. First calculate key for append
560 // position. We do not need to recalculate path as it should
561 // already point to correct place.
562 make_cpu_key(&key, inode,
563 le_key_k_offset(get_inode_item_key_version
564 (inode),
565 &(ih->ih_key)) +
566 op_bytes_number(ih,
567 inode->i_sb->s_blocksize),
568 TYPE_INDIRECT, 3);
569 res =
570 reiserfs_paste_into_item(th, &path, &key, inode,
571 (char *)(allocated_blocks +
572 curr_block),
573 UNFM_P_SIZE *
574 (blocks_to_allocate -
575 curr_block));
576 if (res) {
577 goto error_exit_free_blocks;
578 }
579 } else if (is_statdata_le_ih(ih)) {
580 // Last found item was statdata. That means we need to create indirect item.
581 struct item_head ins_ih; /* itemhead for new item */
582
583 /* create a key for our new item */
584 make_cpu_key(&key, inode, 1, TYPE_INDIRECT, 3); // Position one,
585 // because that's
586 // where first
587 // indirect item
588 // begins
589 /* Create new item head for our new item */
590 make_le_item_head(&ins_ih, &key, key.version, 1,
591 TYPE_INDIRECT,
592 (blocks_to_allocate -
593 curr_block) * UNFM_P_SIZE,
594 0 /* free space */ );
595 /* Find where such item should live in the tree */
596 res = search_item(inode->i_sb, &key, &path);
597 if (res != ITEM_NOT_FOUND) {
598 /* Well, if we have found such item already, or some error
599 occured, we need to warn user and return error */
600 if (res != -ENOSPC) {
601 reiserfs_warning(inode->i_sb,
602 "green-9009: search_by_key (%K) "
603 "returned %d", &key,
604 res);
605 }
606 res = -EIO;
607 goto error_exit_free_blocks;
608 }
609 /* Insert item into the tree with the data as its body */
610 res =
611 reiserfs_insert_item(th, &path, &key, &ins_ih,
612 inode,
613 (char *)(allocated_blocks +
614 curr_block));
615 } else {
616 reiserfs_panic(inode->i_sb,
617 "green-9010: unexpected item type for key %K\n",
618 &key);
619 }
620 }
621 // the caller is responsible for closing the transaction
622 // unless we return an error, they are also responsible for logging
623 // the inode.
624 //
625 pathrelse(&path);
626 /*
627 * cleanup prellocation from previous writes
628 * if this is a partial block write
629 */
630 if (write_bytes & (inode->i_sb->s_blocksize - 1))
631 reiserfs_discard_prealloc(th, inode);
632 reiserfs_write_unlock(inode->i_sb);
633
634 // go through all the pages/buffers and map the buffers to newly allocated
635 // blocks (so that system knows where to write these pages later).
636 curr_block = 0;
637 for (i = 0; i < num_pages; i++) {
638 struct page *page = prepared_pages[i]; //current page
639 struct buffer_head *head = page_buffers(page); // first buffer for a page
640 int block_start, block_end; // in-page offsets for buffers.
641
642 if (!page_buffers(page))
643 reiserfs_panic(inode->i_sb,
644 "green-9005: No buffers for prepared page???");
645
646 /* For each buffer in page */
647 for (bh = head, block_start = 0; bh != head || !block_start;
648 block_start = block_end, bh = bh->b_this_page) {
649 if (!bh)
650 reiserfs_panic(inode->i_sb,
651 "green-9006: Allocated but absent buffer for a page?");
652 block_end = block_start + inode->i_sb->s_blocksize;
653 if (i == 0 && block_end <= from)
654 /* if this buffer is before requested data to map, skip it */
655 continue;
656 if (i == num_pages - 1 && block_start >= to)
657 /* If this buffer is after requested data to map, abort
658 processing of current page */
659 break;
660
661 if (!buffer_mapped(bh)) { // Ok, unmapped buffer, need to map it
662 map_bh(bh, inode->i_sb,
663 le32_to_cpu(allocated_blocks
664 [curr_block]));
665 curr_block++;
666 set_buffer_new(bh);
667 }
668 }
669 }
670
671 RFALSE(curr_block > blocks_to_allocate,
672 "green-9007: Used too many blocks? weird");
673
674 kfree(allocated_blocks);
675 return 0;
676
677// Need to deal with transaction here.
678 error_exit_free_blocks:
679 pathrelse(&path);
680 // free blocks
681 for (i = 0; i < blocks_to_allocate; i++)
682 reiserfs_free_block(th, inode, le32_to_cpu(allocated_blocks[i]),
683 1);
684
685 error_exit:
686 if (th->t_trans_id) {
687 int err;
688 // update any changes we made to blk count
689 mark_inode_dirty(inode);
690 err =
691 journal_end(th, inode->i_sb,
692 JOURNAL_PER_BALANCE_CNT * 3 + 1 +
693 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb));
694 if (err)
695 res = err;
696 }
697 reiserfs_write_unlock(inode->i_sb);
698 kfree(allocated_blocks);
699
700 return res;
701}
702
703/* Unlock pages prepared by reiserfs_prepare_file_region_for_write */
704static void reiserfs_unprepare_pages(struct page **prepared_pages, /* list of locked pages */
705 size_t num_pages /* amount of pages */ )
706{
707 int i; // loop counter
708
709 for (i = 0; i < num_pages; i++) {
710 struct page *page = prepared_pages[i];
711
712 try_to_free_buffers(page);
713 unlock_page(page);
714 page_cache_release(page);
715 }
716}
717
718/* This function will copy data from userspace to specified pages within
719 supplied byte range */
720static int reiserfs_copy_from_user_to_file_region(loff_t pos, /* In-file position */
721 int num_pages, /* Number of pages affected */
722 int write_bytes, /* Amount of bytes to write */
723 struct page **prepared_pages, /* pointer to
724 array to
725 prepared pages
726 */
727 const char __user * buf /* Pointer to user-supplied
728 data */
729 )
730{
731 long page_fault = 0; // status of copy_from_user.
732 int i; // loop counter.
733 int offset; // offset in page
734
735 for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages;
736 i++, offset = 0) {
737 size_t count = min_t(size_t, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page
738 struct page *page = prepared_pages[i]; // Current page we process.
739
740 fault_in_pages_readable(buf, count);
741
742 /* Copy data from userspace to the current page */
743 kmap(page);
744 page_fault = __copy_from_user(page_address(page) + offset, buf, count); // Copy the data.
745 /* Flush processor's dcache for this page */
746 flush_dcache_page(page);
747 kunmap(page);
748 buf += count;
749 write_bytes -= count;
750
751 if (page_fault)
752 break; // Was there a fault? abort.
753 }
754
755 return page_fault ? -EFAULT : 0;
756}
757
758/* taken fs/buffer.c:__block_commit_write */ 156/* taken fs/buffer.c:__block_commit_write */
759int reiserfs_commit_page(struct inode *inode, struct page *page, 157int reiserfs_commit_page(struct inode *inode, struct page *page,
760 unsigned from, unsigned to) 158 unsigned from, unsigned to)
@@ -824,432 +222,6 @@ int reiserfs_commit_page(struct inode *inode, struct page *page,
824 return ret; 222 return ret;
825} 223}
826 224
827/* Submit pages for write. This was separated from actual file copying
828 because we might want to allocate block numbers in-between.
829 This function assumes that caller will adjust file size to correct value. */
830static int reiserfs_submit_file_region_for_write(struct reiserfs_transaction_handle *th, struct inode *inode, loff_t pos, /* Writing position offset */
831 size_t num_pages, /* Number of pages to write */
832 size_t write_bytes, /* number of bytes to write */
833 struct page **prepared_pages /* list of pages */
834 )
835{
836 int status; // return status of block_commit_write.
837 int retval = 0; // Return value we are going to return.
838 int i; // loop counter
839 int offset; // Writing offset in page.
840 int orig_write_bytes = write_bytes;
841 int sd_update = 0;
842
843 for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages;
844 i++, offset = 0) {
845 int count = min_t(int, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page
846 struct page *page = prepared_pages[i]; // Current page we process.
847
848 status =
849 reiserfs_commit_page(inode, page, offset, offset + count);
850 if (status)
851 retval = status; // To not overcomplicate matters We are going to
852 // submit all the pages even if there was error.
853 // we only remember error status to report it on
854 // exit.
855 write_bytes -= count;
856 }
857 /* now that we've gotten all the ordered buffers marked dirty,
858 * we can safely update i_size and close any running transaction
859 */
860 if (pos + orig_write_bytes > inode->i_size) {
861 inode->i_size = pos + orig_write_bytes; // Set new size
862 /* If the file have grown so much that tail packing is no
863 * longer possible, reset "need to pack" flag */
864 if ((have_large_tails(inode->i_sb) &&
865 inode->i_size > i_block_size(inode) * 4) ||
866 (have_small_tails(inode->i_sb) &&
867 inode->i_size > i_block_size(inode)))
868 REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
869 else if ((have_large_tails(inode->i_sb) &&
870 inode->i_size < i_block_size(inode) * 4) ||
871 (have_small_tails(inode->i_sb) &&
872 inode->i_size < i_block_size(inode)))
873 REISERFS_I(inode)->i_flags |= i_pack_on_close_mask;
874
875 if (th->t_trans_id) {
876 reiserfs_write_lock(inode->i_sb);
877 // this sets the proper flags for O_SYNC to trigger a commit
878 mark_inode_dirty(inode);
879 reiserfs_write_unlock(inode->i_sb);
880 } else {
881 reiserfs_write_lock(inode->i_sb);
882 reiserfs_update_inode_transaction(inode);
883 mark_inode_dirty(inode);
884 reiserfs_write_unlock(inode->i_sb);
885 }
886
887 sd_update = 1;
888 }
889 if (th->t_trans_id) {
890 reiserfs_write_lock(inode->i_sb);
891 if (!sd_update)
892 mark_inode_dirty(inode);
893 status = journal_end(th, th->t_super, th->t_blocks_allocated);
894 if (status)
895 retval = status;
896 reiserfs_write_unlock(inode->i_sb);
897 }
898 th->t_trans_id = 0;
899
900 /*
901 * we have to unlock the pages after updating i_size, otherwise
902 * we race with writepage
903 */
904 for (i = 0; i < num_pages; i++) {
905 struct page *page = prepared_pages[i];
906 unlock_page(page);
907 mark_page_accessed(page);
908 page_cache_release(page);
909 }
910 return retval;
911}
912
913/* Look if passed writing region is going to touch file's tail
914 (if it is present). And if it is, convert the tail to unformatted node */
915static int reiserfs_check_for_tail_and_convert(struct inode *inode, /* inode to deal with */
916 loff_t pos, /* Writing position */
917 int write_bytes /* amount of bytes to write */
918 )
919{
920 INITIALIZE_PATH(path); // needed for search_for_position
921 struct cpu_key key; // Key that would represent last touched writing byte.
922 struct item_head *ih; // item header of found block;
923 int res; // Return value of various functions we call.
924 int cont_expand_offset; // We will put offset for generic_cont_expand here
925 // This can be int just because tails are created
926 // only for small files.
927
928/* this embodies a dependency on a particular tail policy */
929 if (inode->i_size >= inode->i_sb->s_blocksize * 4) {
930 /* such a big files do not have tails, so we won't bother ourselves
931 to look for tails, simply return */
932 return 0;
933 }
934
935 reiserfs_write_lock(inode->i_sb);
936 /* find the item containing the last byte to be written, or if
937 * writing past the end of the file then the last item of the
938 * file (and then we check its type). */
939 make_cpu_key(&key, inode, pos + write_bytes + 1, TYPE_ANY,
940 3 /*key length */ );
941 res = search_for_position_by_key(inode->i_sb, &key, &path);
942 if (res == IO_ERROR) {
943 reiserfs_write_unlock(inode->i_sb);
944 return -EIO;
945 }
946 ih = get_ih(&path);
947 res = 0;
948 if (is_direct_le_ih(ih)) {
949 /* Ok, closest item is file tail (tails are stored in "direct"
950 * items), so we need to unpack it. */
951 /* To not overcomplicate matters, we just call generic_cont_expand
952 which will in turn call other stuff and finally will boil down to
953 reiserfs_get_block() that would do necessary conversion. */
954 cont_expand_offset =
955 le_key_k_offset(get_inode_item_key_version(inode),
956 &(ih->ih_key));
957 pathrelse(&path);
958 res = generic_cont_expand(inode, cont_expand_offset);
959 } else
960 pathrelse(&path);
961
962 reiserfs_write_unlock(inode->i_sb);
963 return res;
964}
965
966/* This function locks pages starting from @pos for @inode.
967 @num_pages pages are locked and stored in
968 @prepared_pages array. Also buffers are allocated for these pages.
969 First and last page of the region is read if it is overwritten only
970 partially. If last page did not exist before write (file hole or file
971 append), it is zeroed, then.
972 Returns number of unallocated blocks that should be allocated to cover
973 new file data.*/
974static int reiserfs_prepare_file_region_for_write(struct inode *inode
975 /* Inode of the file */ ,
976 loff_t pos, /* position in the file */
977 size_t num_pages, /* number of pages to
978 prepare */
979 size_t write_bytes, /* Amount of bytes to be
980 overwritten from
981 @pos */
982 struct page **prepared_pages /* pointer to array
983 where to store
984 prepared pages */
985 )
986{
987 int res = 0; // Return values of different functions we call.
988 unsigned long index = pos >> PAGE_CACHE_SHIFT; // Offset in file in pages.
989 int from = (pos & (PAGE_CACHE_SIZE - 1)); // Writing offset in first page
990 int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1;
991 /* offset of last modified byte in last
992 page */
993 struct address_space *mapping = inode->i_mapping; // Pages are mapped here.
994 int i; // Simple counter
995 int blocks = 0; /* Return value (blocks that should be allocated) */
996 struct buffer_head *bh, *head; // Current bufferhead and first bufferhead
997 // of a page.
998 unsigned block_start, block_end; // Starting and ending offsets of current
999 // buffer in the page.
1000 struct buffer_head *wait[2], **wait_bh = wait; // Buffers for page, if
1001 // Page appeared to be not up
1002 // to date. Note how we have
1003 // at most 2 buffers, this is
1004 // because we at most may
1005 // partially overwrite two
1006 // buffers for one page. One at // the beginning of write area
1007 // and one at the end.
1008 // Everything inthe middle gets // overwritten totally.
1009
1010 struct cpu_key key; // cpu key of item that we are going to deal with
1011 struct item_head *ih = NULL; // pointer to item head that we are going to deal with
1012 struct buffer_head *itembuf = NULL; // Buffer head that contains items that we are going to deal with
1013 INITIALIZE_PATH(path); // path to item, that we are going to deal with.
1014 __le32 *item = NULL; // pointer to item we are going to deal with
1015 int item_pos = -1; /* Position in indirect item */
1016
1017 if (num_pages < 1) {
1018 reiserfs_warning(inode->i_sb,
1019 "green-9001: reiserfs_prepare_file_region_for_write "
1020 "called with zero number of pages to process");
1021 return -EFAULT;
1022 }
1023
1024 /* We have 2 loops for pages. In first loop we grab and lock the pages, so
1025 that nobody would touch these until we release the pages. Then
1026 we'd start to deal with mapping buffers to blocks. */
1027 for (i = 0; i < num_pages; i++) {
1028 prepared_pages[i] = grab_cache_page(mapping, index + i); // locks the page
1029 if (!prepared_pages[i]) {
1030 res = -ENOMEM;
1031 goto failed_page_grabbing;
1032 }
1033 if (!page_has_buffers(prepared_pages[i]))
1034 create_empty_buffers(prepared_pages[i],
1035 inode->i_sb->s_blocksize, 0);
1036 }
1037
1038 /* Let's count amount of blocks for a case where all the blocks
1039 overwritten are new (we will substract already allocated blocks later) */
1040 if (num_pages > 2)
1041 /* These are full-overwritten pages so we count all the blocks in
1042 these pages are counted as needed to be allocated */
1043 blocks =
1044 (num_pages - 2) << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1045
1046 /* count blocks needed for first page (possibly partially written) */
1047 blocks += ((PAGE_CACHE_SIZE - from) >> inode->i_blkbits) + !!(from & (inode->i_sb->s_blocksize - 1)); /* roundup */
1048
1049 /* Now we account for last page. If last page == first page (we
1050 overwrite only one page), we substract all the blocks past the
1051 last writing position in a page out of already calculated number
1052 of blocks */
1053 blocks += ((num_pages > 1) << (PAGE_CACHE_SHIFT - inode->i_blkbits)) -
1054 ((PAGE_CACHE_SIZE - to) >> inode->i_blkbits);
1055 /* Note how we do not roundup here since partial blocks still
1056 should be allocated */
1057
1058 /* Now if all the write area lies past the file end, no point in
1059 maping blocks, since there is none, so we just zero out remaining
1060 parts of first and last pages in write area (if needed) */
1061 if ((pos & ~((loff_t) PAGE_CACHE_SIZE - 1)) > inode->i_size) {
1062 if (from != 0) /* First page needs to be partially zeroed */
1063 zero_user_page(prepared_pages[0], 0, from, KM_USER0);
1064
1065 if (to != PAGE_CACHE_SIZE) /* Last page needs to be partially zeroed */
1066 zero_user_page(prepared_pages[num_pages-1], to,
1067 PAGE_CACHE_SIZE - to, KM_USER0);
1068
1069 /* Since all blocks are new - use already calculated value */
1070 return blocks;
1071 }
1072
1073 /* Well, since we write somewhere into the middle of a file, there is
1074 possibility we are writing over some already allocated blocks, so
1075 let's map these blocks and substract number of such blocks out of blocks
1076 we need to allocate (calculated above) */
1077 /* Mask write position to start on blocksize, we do it out of the
1078 loop for performance reasons */
1079 pos &= ~((loff_t) inode->i_sb->s_blocksize - 1);
1080 /* Set cpu key to the starting position in a file (on left block boundary) */
1081 make_cpu_key(&key, inode,
1082 1 + ((pos) & ~((loff_t) inode->i_sb->s_blocksize - 1)),
1083 TYPE_ANY, 3 /*key length */ );
1084
1085 reiserfs_write_lock(inode->i_sb); // We need that for at least search_by_key()
1086 for (i = 0; i < num_pages; i++) {
1087
1088 head = page_buffers(prepared_pages[i]);
1089 /* For each buffer in the page */
1090 for (bh = head, block_start = 0; bh != head || !block_start;
1091 block_start = block_end, bh = bh->b_this_page) {
1092 if (!bh)
1093 reiserfs_panic(inode->i_sb,
1094 "green-9002: Allocated but absent buffer for a page?");
1095 /* Find where this buffer ends */
1096 block_end = block_start + inode->i_sb->s_blocksize;
1097 if (i == 0 && block_end <= from)
1098 /* if this buffer is before requested data to map, skip it */
1099 continue;
1100
1101 if (i == num_pages - 1 && block_start >= to) {
1102 /* If this buffer is after requested data to map, abort
1103 processing of current page */
1104 break;
1105 }
1106
1107 if (buffer_mapped(bh) && bh->b_blocknr != 0) {
1108 /* This is optimisation for a case where buffer is mapped
1109 and have blocknumber assigned. In case significant amount
1110 of such buffers are present, we may avoid some amount
1111 of search_by_key calls.
1112 Probably it would be possible to move parts of this code
1113 out of BKL, but I afraid that would overcomplicate code
1114 without any noticeable benefit.
1115 */
1116 item_pos++;
1117 /* Update the key */
1118 set_cpu_key_k_offset(&key,
1119 cpu_key_k_offset(&key) +
1120 inode->i_sb->s_blocksize);
1121 blocks--; // Decrease the amount of blocks that need to be
1122 // allocated
1123 continue; // Go to the next buffer
1124 }
1125
1126 if (!itembuf || /* if first iteration */
1127 item_pos >= ih_item_len(ih) / UNFM_P_SIZE) { /* or if we progressed past the
1128 current unformatted_item */
1129 /* Try to find next item */
1130 res =
1131 search_for_position_by_key(inode->i_sb,
1132 &key, &path);
1133 /* Abort if no more items */
1134 if (res != POSITION_FOUND) {
1135 /* make sure later loops don't use this item */
1136 itembuf = NULL;
1137 item = NULL;
1138 break;
1139 }
1140
1141 /* Update information about current indirect item */
1142 itembuf = get_last_bh(&path);
1143 ih = get_ih(&path);
1144 item = get_item(&path);
1145 item_pos = path.pos_in_item;
1146
1147 RFALSE(!is_indirect_le_ih(ih),
1148 "green-9003: indirect item expected");
1149 }
1150
1151 /* See if there is some block associated with the file
1152 at that position, map the buffer to this block */
1153 if (get_block_num(item, item_pos)) {
1154 map_bh(bh, inode->i_sb,
1155 get_block_num(item, item_pos));
1156 blocks--; // Decrease the amount of blocks that need to be
1157 // allocated
1158 }
1159 item_pos++;
1160 /* Update the key */
1161 set_cpu_key_k_offset(&key,
1162 cpu_key_k_offset(&key) +
1163 inode->i_sb->s_blocksize);
1164 }
1165 }
1166 pathrelse(&path); // Free the path
1167 reiserfs_write_unlock(inode->i_sb);
1168
1169 /* Now zero out unmappend buffers for the first and last pages of
1170 write area or issue read requests if page is mapped. */
1171 /* First page, see if it is not uptodate */
1172 if (!PageUptodate(prepared_pages[0])) {
1173 head = page_buffers(prepared_pages[0]);
1174
1175 /* For each buffer in page */
1176 for (bh = head, block_start = 0; bh != head || !block_start;
1177 block_start = block_end, bh = bh->b_this_page) {
1178
1179 if (!bh)
1180 reiserfs_panic(inode->i_sb,
1181 "green-9002: Allocated but absent buffer for a page?");
1182 /* Find where this buffer ends */
1183 block_end = block_start + inode->i_sb->s_blocksize;
1184 if (block_end <= from)
1185 /* if this buffer is before requested data to map, skip it */
1186 continue;
1187 if (block_start < from) { /* Aha, our partial buffer */
1188 if (buffer_mapped(bh)) { /* If it is mapped, we need to
1189 issue READ request for it to
1190 not loose data */
1191 ll_rw_block(READ, 1, &bh);
1192 *wait_bh++ = bh;
1193 } else { /* Not mapped, zero it */
1194 zero_user_page(prepared_pages[0],
1195 block_start,
1196 from - block_start, KM_USER0);
1197 set_buffer_uptodate(bh);
1198 }
1199 }
1200 }
1201 }
1202
1203 /* Last page, see if it is not uptodate, or if the last page is past the end of the file. */
1204 if (!PageUptodate(prepared_pages[num_pages - 1]) ||
1205 ((pos + write_bytes) >> PAGE_CACHE_SHIFT) >
1206 (inode->i_size >> PAGE_CACHE_SHIFT)) {
1207 head = page_buffers(prepared_pages[num_pages - 1]);
1208
1209 /* for each buffer in page */
1210 for (bh = head, block_start = 0; bh != head || !block_start;
1211 block_start = block_end, bh = bh->b_this_page) {
1212
1213 if (!bh)
1214 reiserfs_panic(inode->i_sb,
1215 "green-9002: Allocated but absent buffer for a page?");
1216 /* Find where this buffer ends */
1217 block_end = block_start + inode->i_sb->s_blocksize;
1218 if (block_start >= to)
1219 /* if this buffer is after requested data to map, skip it */
1220 break;
1221 if (block_end > to) { /* Aha, our partial buffer */
1222 if (buffer_mapped(bh)) { /* If it is mapped, we need to
1223 issue READ request for it to
1224 not loose data */
1225 ll_rw_block(READ, 1, &bh);
1226 *wait_bh++ = bh;
1227 } else { /* Not mapped, zero it */
1228 zero_user_page(prepared_pages[num_pages-1],
1229 to, block_end - to, KM_USER0);
1230 set_buffer_uptodate(bh);
1231 }
1232 }
1233 }
1234 }
1235
1236 /* Wait for read requests we made to happen, if necessary */
1237 while (wait_bh > wait) {
1238 wait_on_buffer(*--wait_bh);
1239 if (!buffer_uptodate(*wait_bh)) {
1240 res = -EIO;
1241 goto failed_read;
1242 }
1243 }
1244
1245 return blocks;
1246 failed_page_grabbing:
1247 num_pages = i;
1248 failed_read:
1249 reiserfs_unprepare_pages(prepared_pages, num_pages);
1250 return res;
1251}
1252
1253/* Write @count bytes at position @ppos in a file indicated by @file 225/* Write @count bytes at position @ppos in a file indicated by @file
1254 from the buffer @buf. 226 from the buffer @buf.
1255 227
@@ -1284,14 +256,9 @@ static ssize_t reiserfs_file_write(struct file *file, /* the file we are going t
1284 * new current position before returning. */ 256 * new current position before returning. */
1285 ) 257 )
1286{ 258{
1287 size_t already_written = 0; // Number of bytes already written to the file.
1288 loff_t pos; // Current position in the file.
1289 ssize_t res; // return value of various functions that we call.
1290 int err = 0;
1291 struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to. 259 struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to.
1292 /* To simplify coding at this time, we store 260 /* To simplify coding at this time, we store
1293 locked pages in array for now */ 261 locked pages in array for now */
1294 struct page *prepared_pages[REISERFS_WRITE_PAGES_AT_A_TIME];
1295 struct reiserfs_transaction_handle th; 262 struct reiserfs_transaction_handle th;
1296 th.t_trans_id = 0; 263 th.t_trans_id = 0;
1297 264
@@ -1311,212 +278,7 @@ static ssize_t reiserfs_file_write(struct file *file, /* the file we are going t
1311 count = MAX_NON_LFS - (unsigned long)*ppos; 278 count = MAX_NON_LFS - (unsigned long)*ppos;
1312 } 279 }
1313 280
1314 if (file->f_flags & O_DIRECT) 281 return do_sync_write(file, buf, count, ppos);
1315 return do_sync_write(file, buf, count, ppos);
1316
1317 if (unlikely((ssize_t) count < 0))
1318 return -EINVAL;
1319
1320 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
1321 return -EFAULT;
1322
1323 mutex_lock(&inode->i_mutex); // locks the entire file for just us
1324
1325 pos = *ppos;
1326
1327 /* Check if we can write to specified region of file, file
1328 is not overly big and this kind of stuff. Adjust pos and
1329 count, if needed */
1330 res = generic_write_checks(file, &pos, &count, 0);
1331 if (res)
1332 goto out;
1333
1334 if (count == 0)
1335 goto out;
1336
1337 res = remove_suid(file->f_path.dentry);
1338 if (res)
1339 goto out;
1340
1341 file_update_time(file);
1342
1343 // Ok, we are done with all the checks.
1344
1345 // Now we should start real work
1346
1347 /* If we are going to write past the file's packed tail or if we are going
1348 to overwrite part of the tail, we need that tail to be converted into
1349 unformatted node */
1350 res = reiserfs_check_for_tail_and_convert(inode, pos, count);
1351 if (res)
1352 goto out;
1353
1354 while (count > 0) {
1355 /* This is the main loop in which we running until some error occures
1356 or until we write all of the data. */
1357 size_t num_pages; /* amount of pages we are going to write this iteration */
1358 size_t write_bytes; /* amount of bytes to write during this iteration */
1359 size_t blocks_to_allocate; /* how much blocks we need to allocate for this iteration */
1360
1361 /* (pos & (PAGE_CACHE_SIZE-1)) is an idiom for offset into a page of pos */
1362 num_pages = !!((pos + count) & (PAGE_CACHE_SIZE - 1)) + /* round up partial
1363 pages */
1364 ((count +
1365 (pos & (PAGE_CACHE_SIZE - 1))) >> PAGE_CACHE_SHIFT);
1366 /* convert size to amount of
1367 pages */
1368 reiserfs_write_lock(inode->i_sb);
1369 if (num_pages > REISERFS_WRITE_PAGES_AT_A_TIME
1370 || num_pages > reiserfs_can_fit_pages(inode->i_sb)) {
1371 /* If we were asked to write more data than we want to or if there
1372 is not that much space, then we shorten amount of data to write
1373 for this iteration. */
1374 num_pages =
1375 min_t(size_t, REISERFS_WRITE_PAGES_AT_A_TIME,
1376 reiserfs_can_fit_pages(inode->i_sb));
1377 /* Also we should not forget to set size in bytes accordingly */
1378 write_bytes = (num_pages << PAGE_CACHE_SHIFT) -
1379 (pos & (PAGE_CACHE_SIZE - 1));
1380 /* If position is not on the
1381 start of the page, we need
1382 to substract the offset
1383 within page */
1384 } else
1385 write_bytes = count;
1386
1387 /* reserve the blocks to be allocated later, so that later on
1388 we still have the space to write the blocks to */
1389 reiserfs_claim_blocks_to_be_allocated(inode->i_sb,
1390 num_pages <<
1391 (PAGE_CACHE_SHIFT -
1392 inode->i_blkbits));
1393 reiserfs_write_unlock(inode->i_sb);
1394
1395 if (!num_pages) { /* If we do not have enough space even for a single page... */
1396 if (pos >
1397 inode->i_size + inode->i_sb->s_blocksize -
1398 (pos & (inode->i_sb->s_blocksize - 1))) {
1399 res = -ENOSPC;
1400 break; // In case we are writing past the end of the last file block, break.
1401 }
1402 // Otherwise we are possibly overwriting the file, so
1403 // let's set write size to be equal or less than blocksize.
1404 // This way we get it correctly for file holes.
1405 // But overwriting files on absolutelly full volumes would not
1406 // be very efficient. Well, people are not supposed to fill
1407 // 100% of disk space anyway.
1408 write_bytes =
1409 min_t(size_t, count,
1410 inode->i_sb->s_blocksize -
1411 (pos & (inode->i_sb->s_blocksize - 1)));
1412 num_pages = 1;
1413 // No blocks were claimed before, so do it now.
1414 reiserfs_claim_blocks_to_be_allocated(inode->i_sb,
1415 1 <<
1416 (PAGE_CACHE_SHIFT
1417 -
1418 inode->
1419 i_blkbits));
1420 }
1421
1422 /* Prepare for writing into the region, read in all the
1423 partially overwritten pages, if needed. And lock the pages,
1424 so that nobody else can access these until we are done.
1425 We get number of actual blocks needed as a result. */
1426 res = reiserfs_prepare_file_region_for_write(inode, pos,
1427 num_pages,
1428 write_bytes,
1429 prepared_pages);
1430 if (res < 0) {
1431 reiserfs_release_claimed_blocks(inode->i_sb,
1432 num_pages <<
1433 (PAGE_CACHE_SHIFT -
1434 inode->i_blkbits));
1435 break;
1436 }
1437
1438 blocks_to_allocate = res;
1439
1440 /* First we correct our estimate of how many blocks we need */
1441 reiserfs_release_claimed_blocks(inode->i_sb,
1442 (num_pages <<
1443 (PAGE_CACHE_SHIFT -
1444 inode->i_sb->
1445 s_blocksize_bits)) -
1446 blocks_to_allocate);
1447
1448 if (blocks_to_allocate > 0) { /*We only allocate blocks if we need to */
1449 /* Fill in all the possible holes and append the file if needed */
1450 res =
1451 reiserfs_allocate_blocks_for_region(&th, inode, pos,
1452 num_pages,
1453 write_bytes,
1454 prepared_pages,
1455 blocks_to_allocate);
1456 }
1457
1458 /* well, we have allocated the blocks, so it is time to free
1459 the reservation we made earlier. */
1460 reiserfs_release_claimed_blocks(inode->i_sb,
1461 blocks_to_allocate);
1462 if (res) {
1463 reiserfs_unprepare_pages(prepared_pages, num_pages);
1464 break;
1465 }
1466
1467/* NOTE that allocating blocks and filling blocks can be done in reverse order
1468 and probably we would do that just to get rid of garbage in files after a
1469 crash */
1470
1471 /* Copy data from user-supplied buffer to file's pages */
1472 res =
1473 reiserfs_copy_from_user_to_file_region(pos, num_pages,
1474 write_bytes,
1475 prepared_pages, buf);
1476 if (res) {
1477 reiserfs_unprepare_pages(prepared_pages, num_pages);
1478 break;
1479 }
1480
1481 /* Send the pages to disk and unlock them. */
1482 res =
1483 reiserfs_submit_file_region_for_write(&th, inode, pos,
1484 num_pages,
1485 write_bytes,
1486 prepared_pages);
1487 if (res)
1488 break;
1489
1490 already_written += write_bytes;
1491 buf += write_bytes;
1492 *ppos = pos += write_bytes;
1493 count -= write_bytes;
1494 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
1495 }
1496
1497 /* this is only true on error */
1498 if (th.t_trans_id) {
1499 reiserfs_write_lock(inode->i_sb);
1500 err = journal_end(&th, th.t_super, th.t_blocks_allocated);
1501 reiserfs_write_unlock(inode->i_sb);
1502 if (err) {
1503 res = err;
1504 goto out;
1505 }
1506 }
1507
1508 if (likely(res >= 0) &&
1509 (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode))))
1510 res = generic_osync_inode(inode, file->f_mapping,
1511 OSYNC_METADATA | OSYNC_DATA);
1512
1513 mutex_unlock(&inode->i_mutex);
1514 reiserfs_async_progress_wait(inode->i_sb);
1515 return (already_written != 0) ? already_written : res;
1516
1517 out:
1518 mutex_unlock(&inode->i_mutex); // unlock the file on exit.
1519 return res;
1520} 282}
1521 283
1522const struct file_operations reiserfs_file_operations = { 284const struct file_operations reiserfs_file_operations = {
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-28 13:37:16 -0500