cgroup: fix subsys bitops
[linux-2.6/kmemtrace.git] / fs / ocfs2 / aops.c
blob82243127eebf6b81d80acd239609bdc1fd26ae43
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
22 #include <linux/fs.h>
23 #include <linux/slab.h>
24 #include <linux/highmem.h>
25 #include <linux/pagemap.h>
26 #include <asm/byteorder.h>
27 #include <linux/swap.h>
28 #include <linux/pipe_fs_i.h>
29 #include <linux/mpage.h>
31 #define MLOG_MASK_PREFIX ML_FILE_IO
32 #include <cluster/masklog.h>
34 #include "ocfs2.h"
36 #include "alloc.h"
37 #include "aops.h"
38 #include "dlmglue.h"
39 #include "extent_map.h"
40 #include "file.h"
41 #include "inode.h"
42 #include "journal.h"
43 #include "suballoc.h"
44 #include "super.h"
45 #include "symlink.h"
47 #include "buffer_head_io.h"
49 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
50 struct buffer_head *bh_result, int create)
52 int err = -EIO;
53 int status;
54 struct ocfs2_dinode *fe = NULL;
55 struct buffer_head *bh = NULL;
56 struct buffer_head *buffer_cache_bh = NULL;
57 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
58 void *kaddr;
60 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
61 (unsigned long long)iblock, bh_result, create);
63 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
65 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
66 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
67 (unsigned long long)iblock);
68 goto bail;
71 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
72 OCFS2_I(inode)->ip_blkno,
73 &bh, OCFS2_BH_CACHED, inode);
74 if (status < 0) {
75 mlog_errno(status);
76 goto bail;
78 fe = (struct ocfs2_dinode *) bh->b_data;
80 if (!OCFS2_IS_VALID_DINODE(fe)) {
81 mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
82 (unsigned long long)le64_to_cpu(fe->i_blkno), 7,
83 fe->i_signature);
84 goto bail;
87 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
88 le32_to_cpu(fe->i_clusters))) {
89 mlog(ML_ERROR, "block offset is outside the allocated size: "
90 "%llu\n", (unsigned long long)iblock);
91 goto bail;
94 /* We don't use the page cache to create symlink data, so if
95 * need be, copy it over from the buffer cache. */
96 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
97 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
98 iblock;
99 buffer_cache_bh = sb_getblk(osb->sb, blkno);
100 if (!buffer_cache_bh) {
101 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
102 goto bail;
105 /* we haven't locked out transactions, so a commit
106 * could've happened. Since we've got a reference on
107 * the bh, even if it commits while we're doing the
108 * copy, the data is still good. */
109 if (buffer_jbd(buffer_cache_bh)
110 && ocfs2_inode_is_new(inode)) {
111 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
112 if (!kaddr) {
113 mlog(ML_ERROR, "couldn't kmap!\n");
114 goto bail;
116 memcpy(kaddr + (bh_result->b_size * iblock),
117 buffer_cache_bh->b_data,
118 bh_result->b_size);
119 kunmap_atomic(kaddr, KM_USER0);
120 set_buffer_uptodate(bh_result);
122 brelse(buffer_cache_bh);
125 map_bh(bh_result, inode->i_sb,
126 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
128 err = 0;
130 bail:
131 if (bh)
132 brelse(bh);
134 mlog_exit(err);
135 return err;
138 static int ocfs2_get_block(struct inode *inode, sector_t iblock,
139 struct buffer_head *bh_result, int create)
141 int err = 0;
142 unsigned int ext_flags;
143 u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
144 u64 p_blkno, count, past_eof;
145 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
147 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
148 (unsigned long long)iblock, bh_result, create);
150 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
151 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
152 inode, inode->i_ino);
154 if (S_ISLNK(inode->i_mode)) {
155 /* this always does I/O for some reason. */
156 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
157 goto bail;
160 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
161 &ext_flags);
162 if (err) {
163 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
164 "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
165 (unsigned long long)p_blkno);
166 goto bail;
169 if (max_blocks < count)
170 count = max_blocks;
173 * ocfs2 never allocates in this function - the only time we
174 * need to use BH_New is when we're extending i_size on a file
175 * system which doesn't support holes, in which case BH_New
176 * allows block_prepare_write() to zero.
178 mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
179 "ino %lu, iblock %llu\n", inode->i_ino,
180 (unsigned long long)iblock);
182 /* Treat the unwritten extent as a hole for zeroing purposes. */
183 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
184 map_bh(bh_result, inode->i_sb, p_blkno);
186 bh_result->b_size = count << inode->i_blkbits;
188 if (!ocfs2_sparse_alloc(osb)) {
189 if (p_blkno == 0) {
190 err = -EIO;
191 mlog(ML_ERROR,
192 "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
193 (unsigned long long)iblock,
194 (unsigned long long)p_blkno,
195 (unsigned long long)OCFS2_I(inode)->ip_blkno);
196 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
197 dump_stack();
200 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
201 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
202 (unsigned long long)past_eof);
204 if (create && (iblock >= past_eof))
205 set_buffer_new(bh_result);
208 bail:
209 if (err < 0)
210 err = -EIO;
212 mlog_exit(err);
213 return err;
216 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
217 struct buffer_head *di_bh)
219 void *kaddr;
220 loff_t size;
221 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
223 if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
224 ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
225 (unsigned long long)OCFS2_I(inode)->ip_blkno);
226 return -EROFS;
229 size = i_size_read(inode);
231 if (size > PAGE_CACHE_SIZE ||
232 size > ocfs2_max_inline_data(inode->i_sb)) {
233 ocfs2_error(inode->i_sb,
234 "Inode %llu has with inline data has bad size: %Lu",
235 (unsigned long long)OCFS2_I(inode)->ip_blkno,
236 (unsigned long long)size);
237 return -EROFS;
240 kaddr = kmap_atomic(page, KM_USER0);
241 if (size)
242 memcpy(kaddr, di->id2.i_data.id_data, size);
243 /* Clear the remaining part of the page */
244 memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
245 flush_dcache_page(page);
246 kunmap_atomic(kaddr, KM_USER0);
248 SetPageUptodate(page);
250 return 0;
253 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
255 int ret;
256 struct buffer_head *di_bh = NULL;
257 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
259 BUG_ON(!PageLocked(page));
260 BUG_ON(!OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL);
262 ret = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &di_bh,
263 OCFS2_BH_CACHED, inode);
264 if (ret) {
265 mlog_errno(ret);
266 goto out;
269 ret = ocfs2_read_inline_data(inode, page, di_bh);
270 out:
271 unlock_page(page);
273 brelse(di_bh);
274 return ret;
277 static int ocfs2_readpage(struct file *file, struct page *page)
279 struct inode *inode = page->mapping->host;
280 struct ocfs2_inode_info *oi = OCFS2_I(inode);
281 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
282 int ret, unlock = 1;
284 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
286 ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
287 if (ret != 0) {
288 if (ret == AOP_TRUNCATED_PAGE)
289 unlock = 0;
290 mlog_errno(ret);
291 goto out;
294 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
295 ret = AOP_TRUNCATED_PAGE;
296 goto out_inode_unlock;
300 * i_size might have just been updated as we grabed the meta lock. We
301 * might now be discovering a truncate that hit on another node.
302 * block_read_full_page->get_block freaks out if it is asked to read
303 * beyond the end of a file, so we check here. Callers
304 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
305 * and notice that the page they just read isn't needed.
307 * XXX sys_readahead() seems to get that wrong?
309 if (start >= i_size_read(inode)) {
310 zero_user(page, 0, PAGE_SIZE);
311 SetPageUptodate(page);
312 ret = 0;
313 goto out_alloc;
316 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
317 ret = ocfs2_readpage_inline(inode, page);
318 else
319 ret = block_read_full_page(page, ocfs2_get_block);
320 unlock = 0;
322 out_alloc:
323 up_read(&OCFS2_I(inode)->ip_alloc_sem);
324 out_inode_unlock:
325 ocfs2_inode_unlock(inode, 0);
326 out:
327 if (unlock)
328 unlock_page(page);
329 mlog_exit(ret);
330 return ret;
334 * This is used only for read-ahead. Failures or difficult to handle
335 * situations are safe to ignore.
337 * Right now, we don't bother with BH_Boundary - in-inode extent lists
338 * are quite large (243 extents on 4k blocks), so most inodes don't
339 * grow out to a tree. If need be, detecting boundary extents could
340 * trivially be added in a future version of ocfs2_get_block().
342 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
343 struct list_head *pages, unsigned nr_pages)
345 int ret, err = -EIO;
346 struct inode *inode = mapping->host;
347 struct ocfs2_inode_info *oi = OCFS2_I(inode);
348 loff_t start;
349 struct page *last;
352 * Use the nonblocking flag for the dlm code to avoid page
353 * lock inversion, but don't bother with retrying.
355 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
356 if (ret)
357 return err;
359 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
360 ocfs2_inode_unlock(inode, 0);
361 return err;
365 * Don't bother with inline-data. There isn't anything
366 * to read-ahead in that case anyway...
368 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
369 goto out_unlock;
372 * Check whether a remote node truncated this file - we just
373 * drop out in that case as it's not worth handling here.
375 last = list_entry(pages->prev, struct page, lru);
376 start = (loff_t)last->index << PAGE_CACHE_SHIFT;
377 if (start >= i_size_read(inode))
378 goto out_unlock;
380 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
382 out_unlock:
383 up_read(&oi->ip_alloc_sem);
384 ocfs2_inode_unlock(inode, 0);
386 return err;
389 /* Note: Because we don't support holes, our allocation has
390 * already happened (allocation writes zeros to the file data)
391 * so we don't have to worry about ordered writes in
392 * ocfs2_writepage.
394 * ->writepage is called during the process of invalidating the page cache
395 * during blocked lock processing. It can't block on any cluster locks
396 * to during block mapping. It's relying on the fact that the block
397 * mapping can't have disappeared under the dirty pages that it is
398 * being asked to write back.
400 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
402 int ret;
404 mlog_entry("(0x%p)\n", page);
406 ret = block_write_full_page(page, ocfs2_get_block, wbc);
408 mlog_exit(ret);
410 return ret;
414 * This is called from ocfs2_write_zero_page() which has handled it's
415 * own cluster locking and has ensured allocation exists for those
416 * blocks to be written.
418 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
419 unsigned from, unsigned to)
421 int ret;
423 ret = block_prepare_write(page, from, to, ocfs2_get_block);
425 return ret;
428 /* Taken from ext3. We don't necessarily need the full blown
429 * functionality yet, but IMHO it's better to cut and paste the whole
430 * thing so we can avoid introducing our own bugs (and easily pick up
431 * their fixes when they happen) --Mark */
432 int walk_page_buffers( handle_t *handle,
433 struct buffer_head *head,
434 unsigned from,
435 unsigned to,
436 int *partial,
437 int (*fn)( handle_t *handle,
438 struct buffer_head *bh))
440 struct buffer_head *bh;
441 unsigned block_start, block_end;
442 unsigned blocksize = head->b_size;
443 int err, ret = 0;
444 struct buffer_head *next;
446 for ( bh = head, block_start = 0;
447 ret == 0 && (bh != head || !block_start);
448 block_start = block_end, bh = next)
450 next = bh->b_this_page;
451 block_end = block_start + blocksize;
452 if (block_end <= from || block_start >= to) {
453 if (partial && !buffer_uptodate(bh))
454 *partial = 1;
455 continue;
457 err = (*fn)(handle, bh);
458 if (!ret)
459 ret = err;
461 return ret;
464 handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
465 struct page *page,
466 unsigned from,
467 unsigned to)
469 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
470 handle_t *handle = NULL;
471 int ret = 0;
473 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
474 if (!handle) {
475 ret = -ENOMEM;
476 mlog_errno(ret);
477 goto out;
480 if (ocfs2_should_order_data(inode)) {
481 ret = walk_page_buffers(handle,
482 page_buffers(page),
483 from, to, NULL,
484 ocfs2_journal_dirty_data);
485 if (ret < 0)
486 mlog_errno(ret);
488 out:
489 if (ret) {
490 if (handle)
491 ocfs2_commit_trans(osb, handle);
492 handle = ERR_PTR(ret);
494 return handle;
497 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
499 sector_t status;
500 u64 p_blkno = 0;
501 int err = 0;
502 struct inode *inode = mapping->host;
504 mlog_entry("(block = %llu)\n", (unsigned long long)block);
506 /* We don't need to lock journal system files, since they aren't
507 * accessed concurrently from multiple nodes.
509 if (!INODE_JOURNAL(inode)) {
510 err = ocfs2_inode_lock(inode, NULL, 0);
511 if (err) {
512 if (err != -ENOENT)
513 mlog_errno(err);
514 goto bail;
516 down_read(&OCFS2_I(inode)->ip_alloc_sem);
519 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
520 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
521 NULL);
523 if (!INODE_JOURNAL(inode)) {
524 up_read(&OCFS2_I(inode)->ip_alloc_sem);
525 ocfs2_inode_unlock(inode, 0);
528 if (err) {
529 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
530 (unsigned long long)block);
531 mlog_errno(err);
532 goto bail;
535 bail:
536 status = err ? 0 : p_blkno;
538 mlog_exit((int)status);
540 return status;
544 * TODO: Make this into a generic get_blocks function.
546 * From do_direct_io in direct-io.c:
547 * "So what we do is to permit the ->get_blocks function to populate
548 * bh.b_size with the size of IO which is permitted at this offset and
549 * this i_blkbits."
551 * This function is called directly from get_more_blocks in direct-io.c.
553 * called like this: dio->get_blocks(dio->inode, fs_startblk,
554 * fs_count, map_bh, dio->rw == WRITE);
556 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
557 struct buffer_head *bh_result, int create)
559 int ret;
560 u64 p_blkno, inode_blocks, contig_blocks;
561 unsigned int ext_flags;
562 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
563 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
565 /* This function won't even be called if the request isn't all
566 * nicely aligned and of the right size, so there's no need
567 * for us to check any of that. */
569 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
572 * Any write past EOF is not allowed because we'd be extending.
574 if (create && (iblock + max_blocks) > inode_blocks) {
575 ret = -EIO;
576 goto bail;
579 /* This figures out the size of the next contiguous block, and
580 * our logical offset */
581 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
582 &contig_blocks, &ext_flags);
583 if (ret) {
584 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
585 (unsigned long long)iblock);
586 ret = -EIO;
587 goto bail;
590 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) {
591 ocfs2_error(inode->i_sb,
592 "Inode %llu has a hole at block %llu\n",
593 (unsigned long long)OCFS2_I(inode)->ip_blkno,
594 (unsigned long long)iblock);
595 ret = -EROFS;
596 goto bail;
600 * get_more_blocks() expects us to describe a hole by clearing
601 * the mapped bit on bh_result().
603 * Consider an unwritten extent as a hole.
605 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
606 map_bh(bh_result, inode->i_sb, p_blkno);
607 else {
609 * ocfs2_prepare_inode_for_write() should have caught
610 * the case where we'd be filling a hole and triggered
611 * a buffered write instead.
613 if (create) {
614 ret = -EIO;
615 mlog_errno(ret);
616 goto bail;
619 clear_buffer_mapped(bh_result);
622 /* make sure we don't map more than max_blocks blocks here as
623 that's all the kernel will handle at this point. */
624 if (max_blocks < contig_blocks)
625 contig_blocks = max_blocks;
626 bh_result->b_size = contig_blocks << blocksize_bits;
627 bail:
628 return ret;
632 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
633 * particularly interested in the aio/dio case. Like the core uses
634 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
635 * truncation on another.
637 static void ocfs2_dio_end_io(struct kiocb *iocb,
638 loff_t offset,
639 ssize_t bytes,
640 void *private)
642 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
643 int level;
645 /* this io's submitter should not have unlocked this before we could */
646 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
648 ocfs2_iocb_clear_rw_locked(iocb);
650 level = ocfs2_iocb_rw_locked_level(iocb);
651 if (!level)
652 up_read(&inode->i_alloc_sem);
653 ocfs2_rw_unlock(inode, level);
657 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
658 * from ext3. PageChecked() bits have been removed as OCFS2 does not
659 * do journalled data.
661 static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
663 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
665 journal_invalidatepage(journal, page, offset);
668 static int ocfs2_releasepage(struct page *page, gfp_t wait)
670 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
672 if (!page_has_buffers(page))
673 return 0;
674 return journal_try_to_free_buffers(journal, page, wait);
677 static ssize_t ocfs2_direct_IO(int rw,
678 struct kiocb *iocb,
679 const struct iovec *iov,
680 loff_t offset,
681 unsigned long nr_segs)
683 struct file *file = iocb->ki_filp;
684 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
685 int ret;
687 mlog_entry_void();
690 * Fallback to buffered I/O if we see an inode without
691 * extents.
693 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
694 return 0;
696 ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
697 inode->i_sb->s_bdev, iov, offset,
698 nr_segs,
699 ocfs2_direct_IO_get_blocks,
700 ocfs2_dio_end_io);
702 mlog_exit(ret);
703 return ret;
706 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
707 u32 cpos,
708 unsigned int *start,
709 unsigned int *end)
711 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
713 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
714 unsigned int cpp;
716 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
718 cluster_start = cpos % cpp;
719 cluster_start = cluster_start << osb->s_clustersize_bits;
721 cluster_end = cluster_start + osb->s_clustersize;
724 BUG_ON(cluster_start > PAGE_SIZE);
725 BUG_ON(cluster_end > PAGE_SIZE);
727 if (start)
728 *start = cluster_start;
729 if (end)
730 *end = cluster_end;
734 * 'from' and 'to' are the region in the page to avoid zeroing.
736 * If pagesize > clustersize, this function will avoid zeroing outside
737 * of the cluster boundary.
739 * from == to == 0 is code for "zero the entire cluster region"
741 static void ocfs2_clear_page_regions(struct page *page,
742 struct ocfs2_super *osb, u32 cpos,
743 unsigned from, unsigned to)
745 void *kaddr;
746 unsigned int cluster_start, cluster_end;
748 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
750 kaddr = kmap_atomic(page, KM_USER0);
752 if (from || to) {
753 if (from > cluster_start)
754 memset(kaddr + cluster_start, 0, from - cluster_start);
755 if (to < cluster_end)
756 memset(kaddr + to, 0, cluster_end - to);
757 } else {
758 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
761 kunmap_atomic(kaddr, KM_USER0);
765 * Nonsparse file systems fully allocate before we get to the write
766 * code. This prevents ocfs2_write() from tagging the write as an
767 * allocating one, which means ocfs2_map_page_blocks() might try to
768 * read-in the blocks at the tail of our file. Avoid reading them by
769 * testing i_size against each block offset.
771 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
772 unsigned int block_start)
774 u64 offset = page_offset(page) + block_start;
776 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
777 return 1;
779 if (i_size_read(inode) > offset)
780 return 1;
782 return 0;
786 * Some of this taken from block_prepare_write(). We already have our
787 * mapping by now though, and the entire write will be allocating or
788 * it won't, so not much need to use BH_New.
790 * This will also skip zeroing, which is handled externally.
792 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
793 struct inode *inode, unsigned int from,
794 unsigned int to, int new)
796 int ret = 0;
797 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
798 unsigned int block_end, block_start;
799 unsigned int bsize = 1 << inode->i_blkbits;
801 if (!page_has_buffers(page))
802 create_empty_buffers(page, bsize, 0);
804 head = page_buffers(page);
805 for (bh = head, block_start = 0; bh != head || !block_start;
806 bh = bh->b_this_page, block_start += bsize) {
807 block_end = block_start + bsize;
809 clear_buffer_new(bh);
812 * Ignore blocks outside of our i/o range -
813 * they may belong to unallocated clusters.
815 if (block_start >= to || block_end <= from) {
816 if (PageUptodate(page))
817 set_buffer_uptodate(bh);
818 continue;
822 * For an allocating write with cluster size >= page
823 * size, we always write the entire page.
825 if (new)
826 set_buffer_new(bh);
828 if (!buffer_mapped(bh)) {
829 map_bh(bh, inode->i_sb, *p_blkno);
830 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
833 if (PageUptodate(page)) {
834 if (!buffer_uptodate(bh))
835 set_buffer_uptodate(bh);
836 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
837 !buffer_new(bh) &&
838 ocfs2_should_read_blk(inode, page, block_start) &&
839 (block_start < from || block_end > to)) {
840 ll_rw_block(READ, 1, &bh);
841 *wait_bh++=bh;
844 *p_blkno = *p_blkno + 1;
848 * If we issued read requests - let them complete.
850 while(wait_bh > wait) {
851 wait_on_buffer(*--wait_bh);
852 if (!buffer_uptodate(*wait_bh))
853 ret = -EIO;
856 if (ret == 0 || !new)
857 return ret;
860 * If we get -EIO above, zero out any newly allocated blocks
861 * to avoid exposing stale data.
863 bh = head;
864 block_start = 0;
865 do {
866 block_end = block_start + bsize;
867 if (block_end <= from)
868 goto next_bh;
869 if (block_start >= to)
870 break;
872 zero_user(page, block_start, bh->b_size);
873 set_buffer_uptodate(bh);
874 mark_buffer_dirty(bh);
876 next_bh:
877 block_start = block_end;
878 bh = bh->b_this_page;
879 } while (bh != head);
881 return ret;
884 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
885 #define OCFS2_MAX_CTXT_PAGES 1
886 #else
887 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
888 #endif
890 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
893 * Describe the state of a single cluster to be written to.
895 struct ocfs2_write_cluster_desc {
896 u32 c_cpos;
897 u32 c_phys;
899 * Give this a unique field because c_phys eventually gets
900 * filled.
902 unsigned c_new;
903 unsigned c_unwritten;
906 static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d)
908 return d->c_new || d->c_unwritten;
911 struct ocfs2_write_ctxt {
912 /* Logical cluster position / len of write */
913 u32 w_cpos;
914 u32 w_clen;
916 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
919 * This is true if page_size > cluster_size.
921 * It triggers a set of special cases during write which might
922 * have to deal with allocating writes to partial pages.
924 unsigned int w_large_pages;
927 * Pages involved in this write.
929 * w_target_page is the page being written to by the user.
931 * w_pages is an array of pages which always contains
932 * w_target_page, and in the case of an allocating write with
933 * page_size < cluster size, it will contain zero'd and mapped
934 * pages adjacent to w_target_page which need to be written
935 * out in so that future reads from that region will get
936 * zero's.
938 struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
939 unsigned int w_num_pages;
940 struct page *w_target_page;
943 * ocfs2_write_end() uses this to know what the real range to
944 * write in the target should be.
946 unsigned int w_target_from;
947 unsigned int w_target_to;
950 * We could use journal_current_handle() but this is cleaner,
951 * IMHO -Mark
953 handle_t *w_handle;
955 struct buffer_head *w_di_bh;
957 struct ocfs2_cached_dealloc_ctxt w_dealloc;
960 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
962 int i;
964 for(i = 0; i < num_pages; i++) {
965 if (pages[i]) {
966 unlock_page(pages[i]);
967 mark_page_accessed(pages[i]);
968 page_cache_release(pages[i]);
973 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
975 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
977 brelse(wc->w_di_bh);
978 kfree(wc);
981 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
982 struct ocfs2_super *osb, loff_t pos,
983 unsigned len, struct buffer_head *di_bh)
985 u32 cend;
986 struct ocfs2_write_ctxt *wc;
988 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
989 if (!wc)
990 return -ENOMEM;
992 wc->w_cpos = pos >> osb->s_clustersize_bits;
993 cend = (pos + len - 1) >> osb->s_clustersize_bits;
994 wc->w_clen = cend - wc->w_cpos + 1;
995 get_bh(di_bh);
996 wc->w_di_bh = di_bh;
998 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
999 wc->w_large_pages = 1;
1000 else
1001 wc->w_large_pages = 0;
1003 ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
1005 *wcp = wc;
1007 return 0;
1011 * If a page has any new buffers, zero them out here, and mark them uptodate
1012 * and dirty so they'll be written out (in order to prevent uninitialised
1013 * block data from leaking). And clear the new bit.
1015 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
1017 unsigned int block_start, block_end;
1018 struct buffer_head *head, *bh;
1020 BUG_ON(!PageLocked(page));
1021 if (!page_has_buffers(page))
1022 return;
1024 bh = head = page_buffers(page);
1025 block_start = 0;
1026 do {
1027 block_end = block_start + bh->b_size;
1029 if (buffer_new(bh)) {
1030 if (block_end > from && block_start < to) {
1031 if (!PageUptodate(page)) {
1032 unsigned start, end;
1034 start = max(from, block_start);
1035 end = min(to, block_end);
1037 zero_user_segment(page, start, end);
1038 set_buffer_uptodate(bh);
1041 clear_buffer_new(bh);
1042 mark_buffer_dirty(bh);
1046 block_start = block_end;
1047 bh = bh->b_this_page;
1048 } while (bh != head);
1052 * Only called when we have a failure during allocating write to write
1053 * zero's to the newly allocated region.
1055 static void ocfs2_write_failure(struct inode *inode,
1056 struct ocfs2_write_ctxt *wc,
1057 loff_t user_pos, unsigned user_len)
1059 int i;
1060 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
1061 to = user_pos + user_len;
1062 struct page *tmppage;
1064 ocfs2_zero_new_buffers(wc->w_target_page, from, to);
1066 for(i = 0; i < wc->w_num_pages; i++) {
1067 tmppage = wc->w_pages[i];
1069 if (ocfs2_should_order_data(inode))
1070 walk_page_buffers(wc->w_handle, page_buffers(tmppage),
1071 from, to, NULL,
1072 ocfs2_journal_dirty_data);
1074 block_commit_write(tmppage, from, to);
1078 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1079 struct ocfs2_write_ctxt *wc,
1080 struct page *page, u32 cpos,
1081 loff_t user_pos, unsigned user_len,
1082 int new)
1084 int ret;
1085 unsigned int map_from = 0, map_to = 0;
1086 unsigned int cluster_start, cluster_end;
1087 unsigned int user_data_from = 0, user_data_to = 0;
1089 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1090 &cluster_start, &cluster_end);
1092 if (page == wc->w_target_page) {
1093 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1094 map_to = map_from + user_len;
1096 if (new)
1097 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1098 cluster_start, cluster_end,
1099 new);
1100 else
1101 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1102 map_from, map_to, new);
1103 if (ret) {
1104 mlog_errno(ret);
1105 goto out;
1108 user_data_from = map_from;
1109 user_data_to = map_to;
1110 if (new) {
1111 map_from = cluster_start;
1112 map_to = cluster_end;
1114 } else {
1116 * If we haven't allocated the new page yet, we
1117 * shouldn't be writing it out without copying user
1118 * data. This is likely a math error from the caller.
1120 BUG_ON(!new);
1122 map_from = cluster_start;
1123 map_to = cluster_end;
1125 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1126 cluster_start, cluster_end, new);
1127 if (ret) {
1128 mlog_errno(ret);
1129 goto out;
1134 * Parts of newly allocated pages need to be zero'd.
1136 * Above, we have also rewritten 'to' and 'from' - as far as
1137 * the rest of the function is concerned, the entire cluster
1138 * range inside of a page needs to be written.
1140 * We can skip this if the page is up to date - it's already
1141 * been zero'd from being read in as a hole.
1143 if (new && !PageUptodate(page))
1144 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1145 cpos, user_data_from, user_data_to);
1147 flush_dcache_page(page);
1149 out:
1150 return ret;
1154 * This function will only grab one clusters worth of pages.
1156 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1157 struct ocfs2_write_ctxt *wc,
1158 u32 cpos, loff_t user_pos, int new,
1159 struct page *mmap_page)
1161 int ret = 0, i;
1162 unsigned long start, target_index, index;
1163 struct inode *inode = mapping->host;
1165 target_index = user_pos >> PAGE_CACHE_SHIFT;
1168 * Figure out how many pages we'll be manipulating here. For
1169 * non allocating write, we just change the one
1170 * page. Otherwise, we'll need a whole clusters worth.
1172 if (new) {
1173 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1174 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1175 } else {
1176 wc->w_num_pages = 1;
1177 start = target_index;
1180 for(i = 0; i < wc->w_num_pages; i++) {
1181 index = start + i;
1183 if (index == target_index && mmap_page) {
1185 * ocfs2_pagemkwrite() is a little different
1186 * and wants us to directly use the page
1187 * passed in.
1189 lock_page(mmap_page);
1191 if (mmap_page->mapping != mapping) {
1192 unlock_page(mmap_page);
1194 * Sanity check - the locking in
1195 * ocfs2_pagemkwrite() should ensure
1196 * that this code doesn't trigger.
1198 ret = -EINVAL;
1199 mlog_errno(ret);
1200 goto out;
1203 page_cache_get(mmap_page);
1204 wc->w_pages[i] = mmap_page;
1205 } else {
1206 wc->w_pages[i] = find_or_create_page(mapping, index,
1207 GFP_NOFS);
1208 if (!wc->w_pages[i]) {
1209 ret = -ENOMEM;
1210 mlog_errno(ret);
1211 goto out;
1215 if (index == target_index)
1216 wc->w_target_page = wc->w_pages[i];
1218 out:
1219 return ret;
1223 * Prepare a single cluster for write one cluster into the file.
1225 static int ocfs2_write_cluster(struct address_space *mapping,
1226 u32 phys, unsigned int unwritten,
1227 struct ocfs2_alloc_context *data_ac,
1228 struct ocfs2_alloc_context *meta_ac,
1229 struct ocfs2_write_ctxt *wc, u32 cpos,
1230 loff_t user_pos, unsigned user_len)
1232 int ret, i, new, should_zero = 0;
1233 u64 v_blkno, p_blkno;
1234 struct inode *inode = mapping->host;
1236 new = phys == 0 ? 1 : 0;
1237 if (new || unwritten)
1238 should_zero = 1;
1240 if (new) {
1241 u32 tmp_pos;
1244 * This is safe to call with the page locks - it won't take
1245 * any additional semaphores or cluster locks.
1247 tmp_pos = cpos;
1248 ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
1249 &tmp_pos, 1, 0, wc->w_di_bh,
1250 wc->w_handle, data_ac,
1251 meta_ac, NULL);
1253 * This shouldn't happen because we must have already
1254 * calculated the correct meta data allocation required. The
1255 * internal tree allocation code should know how to increase
1256 * transaction credits itself.
1258 * If need be, we could handle -EAGAIN for a
1259 * RESTART_TRANS here.
1261 mlog_bug_on_msg(ret == -EAGAIN,
1262 "Inode %llu: EAGAIN return during allocation.\n",
1263 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1264 if (ret < 0) {
1265 mlog_errno(ret);
1266 goto out;
1268 } else if (unwritten) {
1269 ret = ocfs2_mark_extent_written(inode, wc->w_di_bh,
1270 wc->w_handle, cpos, 1, phys,
1271 meta_ac, &wc->w_dealloc);
1272 if (ret < 0) {
1273 mlog_errno(ret);
1274 goto out;
1278 if (should_zero)
1279 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1280 else
1281 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1284 * The only reason this should fail is due to an inability to
1285 * find the extent added.
1287 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1288 NULL);
1289 if (ret < 0) {
1290 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1291 "at logical block %llu",
1292 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1293 (unsigned long long)v_blkno);
1294 goto out;
1297 BUG_ON(p_blkno == 0);
1299 for(i = 0; i < wc->w_num_pages; i++) {
1300 int tmpret;
1302 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1303 wc->w_pages[i], cpos,
1304 user_pos, user_len,
1305 should_zero);
1306 if (tmpret) {
1307 mlog_errno(tmpret);
1308 if (ret == 0)
1309 tmpret = ret;
1314 * We only have cleanup to do in case of allocating write.
1316 if (ret && new)
1317 ocfs2_write_failure(inode, wc, user_pos, user_len);
1319 out:
1321 return ret;
1324 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1325 struct ocfs2_alloc_context *data_ac,
1326 struct ocfs2_alloc_context *meta_ac,
1327 struct ocfs2_write_ctxt *wc,
1328 loff_t pos, unsigned len)
1330 int ret, i;
1331 loff_t cluster_off;
1332 unsigned int local_len = len;
1333 struct ocfs2_write_cluster_desc *desc;
1334 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1336 for (i = 0; i < wc->w_clen; i++) {
1337 desc = &wc->w_desc[i];
1340 * We have to make sure that the total write passed in
1341 * doesn't extend past a single cluster.
1343 local_len = len;
1344 cluster_off = pos & (osb->s_clustersize - 1);
1345 if ((cluster_off + local_len) > osb->s_clustersize)
1346 local_len = osb->s_clustersize - cluster_off;
1348 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1349 desc->c_unwritten, data_ac, meta_ac,
1350 wc, desc->c_cpos, pos, local_len);
1351 if (ret) {
1352 mlog_errno(ret);
1353 goto out;
1356 len -= local_len;
1357 pos += local_len;
1360 ret = 0;
1361 out:
1362 return ret;
1366 * ocfs2_write_end() wants to know which parts of the target page it
1367 * should complete the write on. It's easiest to compute them ahead of
1368 * time when a more complete view of the write is available.
1370 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1371 struct ocfs2_write_ctxt *wc,
1372 loff_t pos, unsigned len, int alloc)
1374 struct ocfs2_write_cluster_desc *desc;
1376 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1377 wc->w_target_to = wc->w_target_from + len;
1379 if (alloc == 0)
1380 return;
1383 * Allocating write - we may have different boundaries based
1384 * on page size and cluster size.
1386 * NOTE: We can no longer compute one value from the other as
1387 * the actual write length and user provided length may be
1388 * different.
1391 if (wc->w_large_pages) {
1393 * We only care about the 1st and last cluster within
1394 * our range and whether they should be zero'd or not. Either
1395 * value may be extended out to the start/end of a
1396 * newly allocated cluster.
1398 desc = &wc->w_desc[0];
1399 if (ocfs2_should_zero_cluster(desc))
1400 ocfs2_figure_cluster_boundaries(osb,
1401 desc->c_cpos,
1402 &wc->w_target_from,
1403 NULL);
1405 desc = &wc->w_desc[wc->w_clen - 1];
1406 if (ocfs2_should_zero_cluster(desc))
1407 ocfs2_figure_cluster_boundaries(osb,
1408 desc->c_cpos,
1409 NULL,
1410 &wc->w_target_to);
1411 } else {
1412 wc->w_target_from = 0;
1413 wc->w_target_to = PAGE_CACHE_SIZE;
1418 * Populate each single-cluster write descriptor in the write context
1419 * with information about the i/o to be done.
1421 * Returns the number of clusters that will have to be allocated, as
1422 * well as a worst case estimate of the number of extent records that
1423 * would have to be created during a write to an unwritten region.
1425 static int ocfs2_populate_write_desc(struct inode *inode,
1426 struct ocfs2_write_ctxt *wc,
1427 unsigned int *clusters_to_alloc,
1428 unsigned int *extents_to_split)
1430 int ret;
1431 struct ocfs2_write_cluster_desc *desc;
1432 unsigned int num_clusters = 0;
1433 unsigned int ext_flags = 0;
1434 u32 phys = 0;
1435 int i;
1437 *clusters_to_alloc = 0;
1438 *extents_to_split = 0;
1440 for (i = 0; i < wc->w_clen; i++) {
1441 desc = &wc->w_desc[i];
1442 desc->c_cpos = wc->w_cpos + i;
1444 if (num_clusters == 0) {
1446 * Need to look up the next extent record.
1448 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1449 &num_clusters, &ext_flags);
1450 if (ret) {
1451 mlog_errno(ret);
1452 goto out;
1456 * Assume worst case - that we're writing in
1457 * the middle of the extent.
1459 * We can assume that the write proceeds from
1460 * left to right, in which case the extent
1461 * insert code is smart enough to coalesce the
1462 * next splits into the previous records created.
1464 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1465 *extents_to_split = *extents_to_split + 2;
1466 } else if (phys) {
1468 * Only increment phys if it doesn't describe
1469 * a hole.
1471 phys++;
1474 desc->c_phys = phys;
1475 if (phys == 0) {
1476 desc->c_new = 1;
1477 *clusters_to_alloc = *clusters_to_alloc + 1;
1479 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1480 desc->c_unwritten = 1;
1482 num_clusters--;
1485 ret = 0;
1486 out:
1487 return ret;
1490 static int ocfs2_write_begin_inline(struct address_space *mapping,
1491 struct inode *inode,
1492 struct ocfs2_write_ctxt *wc)
1494 int ret;
1495 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1496 struct page *page;
1497 handle_t *handle;
1498 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1500 page = find_or_create_page(mapping, 0, GFP_NOFS);
1501 if (!page) {
1502 ret = -ENOMEM;
1503 mlog_errno(ret);
1504 goto out;
1507 * If we don't set w_num_pages then this page won't get unlocked
1508 * and freed on cleanup of the write context.
1510 wc->w_pages[0] = wc->w_target_page = page;
1511 wc->w_num_pages = 1;
1513 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1514 if (IS_ERR(handle)) {
1515 ret = PTR_ERR(handle);
1516 mlog_errno(ret);
1517 goto out;
1520 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh,
1521 OCFS2_JOURNAL_ACCESS_WRITE);
1522 if (ret) {
1523 ocfs2_commit_trans(osb, handle);
1525 mlog_errno(ret);
1526 goto out;
1529 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1530 ocfs2_set_inode_data_inline(inode, di);
1532 if (!PageUptodate(page)) {
1533 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1534 if (ret) {
1535 ocfs2_commit_trans(osb, handle);
1537 goto out;
1541 wc->w_handle = handle;
1542 out:
1543 return ret;
1546 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1548 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1550 if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1551 return 1;
1552 return 0;
1555 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1556 struct inode *inode, loff_t pos,
1557 unsigned len, struct page *mmap_page,
1558 struct ocfs2_write_ctxt *wc)
1560 int ret, written = 0;
1561 loff_t end = pos + len;
1562 struct ocfs2_inode_info *oi = OCFS2_I(inode);
1564 mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n",
1565 (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos,
1566 oi->ip_dyn_features);
1569 * Handle inodes which already have inline data 1st.
1571 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1572 if (mmap_page == NULL &&
1573 ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1574 goto do_inline_write;
1577 * The write won't fit - we have to give this inode an
1578 * inline extent list now.
1580 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1581 if (ret)
1582 mlog_errno(ret);
1583 goto out;
1587 * Check whether the inode can accept inline data.
1589 if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1590 return 0;
1593 * Check whether the write can fit.
1595 if (mmap_page || end > ocfs2_max_inline_data(inode->i_sb))
1596 return 0;
1598 do_inline_write:
1599 ret = ocfs2_write_begin_inline(mapping, inode, wc);
1600 if (ret) {
1601 mlog_errno(ret);
1602 goto out;
1606 * This signals to the caller that the data can be written
1607 * inline.
1609 written = 1;
1610 out:
1611 return written ? written : ret;
1615 * This function only does anything for file systems which can't
1616 * handle sparse files.
1618 * What we want to do here is fill in any hole between the current end
1619 * of allocation and the end of our write. That way the rest of the
1620 * write path can treat it as an non-allocating write, which has no
1621 * special case code for sparse/nonsparse files.
1623 static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,
1624 unsigned len,
1625 struct ocfs2_write_ctxt *wc)
1627 int ret;
1628 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1629 loff_t newsize = pos + len;
1631 if (ocfs2_sparse_alloc(osb))
1632 return 0;
1634 if (newsize <= i_size_read(inode))
1635 return 0;
1637 ret = ocfs2_extend_no_holes(inode, newsize, newsize - len);
1638 if (ret)
1639 mlog_errno(ret);
1641 return ret;
1644 int ocfs2_write_begin_nolock(struct address_space *mapping,
1645 loff_t pos, unsigned len, unsigned flags,
1646 struct page **pagep, void **fsdata,
1647 struct buffer_head *di_bh, struct page *mmap_page)
1649 int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
1650 unsigned int clusters_to_alloc, extents_to_split;
1651 struct ocfs2_write_ctxt *wc;
1652 struct inode *inode = mapping->host;
1653 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1654 struct ocfs2_dinode *di;
1655 struct ocfs2_alloc_context *data_ac = NULL;
1656 struct ocfs2_alloc_context *meta_ac = NULL;
1657 handle_t *handle;
1659 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1660 if (ret) {
1661 mlog_errno(ret);
1662 return ret;
1665 if (ocfs2_supports_inline_data(osb)) {
1666 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1667 mmap_page, wc);
1668 if (ret == 1) {
1669 ret = 0;
1670 goto success;
1672 if (ret < 0) {
1673 mlog_errno(ret);
1674 goto out;
1678 ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);
1679 if (ret) {
1680 mlog_errno(ret);
1681 goto out;
1684 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1685 &extents_to_split);
1686 if (ret) {
1687 mlog_errno(ret);
1688 goto out;
1691 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1694 * We set w_target_from, w_target_to here so that
1695 * ocfs2_write_end() knows which range in the target page to
1696 * write out. An allocation requires that we write the entire
1697 * cluster range.
1699 if (clusters_to_alloc || extents_to_split) {
1701 * XXX: We are stretching the limits of
1702 * ocfs2_lock_allocators(). It greatly over-estimates
1703 * the work to be done.
1705 ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc,
1706 extents_to_split, &data_ac, &meta_ac);
1707 if (ret) {
1708 mlog_errno(ret);
1709 goto out;
1712 credits = ocfs2_calc_extend_credits(inode->i_sb, di,
1713 clusters_to_alloc);
1717 ocfs2_set_target_boundaries(osb, wc, pos, len,
1718 clusters_to_alloc + extents_to_split);
1720 handle = ocfs2_start_trans(osb, credits);
1721 if (IS_ERR(handle)) {
1722 ret = PTR_ERR(handle);
1723 mlog_errno(ret);
1724 goto out;
1727 wc->w_handle = handle;
1730 * We don't want this to fail in ocfs2_write_end(), so do it
1731 * here.
1733 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh,
1734 OCFS2_JOURNAL_ACCESS_WRITE);
1735 if (ret) {
1736 mlog_errno(ret);
1737 goto out_commit;
1741 * Fill our page array first. That way we've grabbed enough so
1742 * that we can zero and flush if we error after adding the
1743 * extent.
1745 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
1746 clusters_to_alloc + extents_to_split,
1747 mmap_page);
1748 if (ret) {
1749 mlog_errno(ret);
1750 goto out_commit;
1753 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1754 len);
1755 if (ret) {
1756 mlog_errno(ret);
1757 goto out_commit;
1760 if (data_ac)
1761 ocfs2_free_alloc_context(data_ac);
1762 if (meta_ac)
1763 ocfs2_free_alloc_context(meta_ac);
1765 success:
1766 *pagep = wc->w_target_page;
1767 *fsdata = wc;
1768 return 0;
1769 out_commit:
1770 ocfs2_commit_trans(osb, handle);
1772 out:
1773 ocfs2_free_write_ctxt(wc);
1775 if (data_ac)
1776 ocfs2_free_alloc_context(data_ac);
1777 if (meta_ac)
1778 ocfs2_free_alloc_context(meta_ac);
1779 return ret;
1782 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1783 loff_t pos, unsigned len, unsigned flags,
1784 struct page **pagep, void **fsdata)
1786 int ret;
1787 struct buffer_head *di_bh = NULL;
1788 struct inode *inode = mapping->host;
1790 ret = ocfs2_inode_lock(inode, &di_bh, 1);
1791 if (ret) {
1792 mlog_errno(ret);
1793 return ret;
1797 * Take alloc sem here to prevent concurrent lookups. That way
1798 * the mapping, zeroing and tree manipulation within
1799 * ocfs2_write() will be safe against ->readpage(). This
1800 * should also serve to lock out allocation from a shared
1801 * writeable region.
1803 down_write(&OCFS2_I(inode)->ip_alloc_sem);
1805 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
1806 fsdata, di_bh, NULL);
1807 if (ret) {
1808 mlog_errno(ret);
1809 goto out_fail;
1812 brelse(di_bh);
1814 return 0;
1816 out_fail:
1817 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1819 brelse(di_bh);
1820 ocfs2_inode_unlock(inode, 1);
1822 return ret;
1825 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1826 unsigned len, unsigned *copied,
1827 struct ocfs2_dinode *di,
1828 struct ocfs2_write_ctxt *wc)
1830 void *kaddr;
1832 if (unlikely(*copied < len)) {
1833 if (!PageUptodate(wc->w_target_page)) {
1834 *copied = 0;
1835 return;
1839 kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
1840 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1841 kunmap_atomic(kaddr, KM_USER0);
1843 mlog(0, "Data written to inode at offset %llu. "
1844 "id_count = %u, copied = %u, i_dyn_features = 0x%x\n",
1845 (unsigned long long)pos, *copied,
1846 le16_to_cpu(di->id2.i_data.id_count),
1847 le16_to_cpu(di->i_dyn_features));
1850 int ocfs2_write_end_nolock(struct address_space *mapping,
1851 loff_t pos, unsigned len, unsigned copied,
1852 struct page *page, void *fsdata)
1854 int i;
1855 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1856 struct inode *inode = mapping->host;
1857 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1858 struct ocfs2_write_ctxt *wc = fsdata;
1859 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1860 handle_t *handle = wc->w_handle;
1861 struct page *tmppage;
1863 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1864 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1865 goto out_write_size;
1868 if (unlikely(copied < len)) {
1869 if (!PageUptodate(wc->w_target_page))
1870 copied = 0;
1872 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1873 start+len);
1875 flush_dcache_page(wc->w_target_page);
1877 for(i = 0; i < wc->w_num_pages; i++) {
1878 tmppage = wc->w_pages[i];
1880 if (tmppage == wc->w_target_page) {
1881 from = wc->w_target_from;
1882 to = wc->w_target_to;
1884 BUG_ON(from > PAGE_CACHE_SIZE ||
1885 to > PAGE_CACHE_SIZE ||
1886 to < from);
1887 } else {
1889 * Pages adjacent to the target (if any) imply
1890 * a hole-filling write in which case we want
1891 * to flush their entire range.
1893 from = 0;
1894 to = PAGE_CACHE_SIZE;
1897 if (ocfs2_should_order_data(inode))
1898 walk_page_buffers(wc->w_handle, page_buffers(tmppage),
1899 from, to, NULL,
1900 ocfs2_journal_dirty_data);
1902 block_commit_write(tmppage, from, to);
1905 out_write_size:
1906 pos += copied;
1907 if (pos > inode->i_size) {
1908 i_size_write(inode, pos);
1909 mark_inode_dirty(inode);
1911 inode->i_blocks = ocfs2_inode_sector_count(inode);
1912 di->i_size = cpu_to_le64((u64)i_size_read(inode));
1913 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1914 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
1915 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
1916 ocfs2_journal_dirty(handle, wc->w_di_bh);
1918 ocfs2_commit_trans(osb, handle);
1920 ocfs2_run_deallocs(osb, &wc->w_dealloc);
1922 ocfs2_free_write_ctxt(wc);
1924 return copied;
1927 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
1928 loff_t pos, unsigned len, unsigned copied,
1929 struct page *page, void *fsdata)
1931 int ret;
1932 struct inode *inode = mapping->host;
1934 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
1936 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1937 ocfs2_inode_unlock(inode, 1);
1939 return ret;
1942 const struct address_space_operations ocfs2_aops = {
1943 .readpage = ocfs2_readpage,
1944 .readpages = ocfs2_readpages,
1945 .writepage = ocfs2_writepage,
1946 .write_begin = ocfs2_write_begin,
1947 .write_end = ocfs2_write_end,
1948 .bmap = ocfs2_bmap,
1949 .sync_page = block_sync_page,
1950 .direct_IO = ocfs2_direct_IO,
1951 .invalidatepage = ocfs2_invalidatepage,
1952 .releasepage = ocfs2_releasepage,
1953 .migratepage = buffer_migrate_page,