nfs41: implement DESTROY_CLIENTID operation
[linux-btrfs-devel.git] / fs / ocfs2 / aops.c
blobc1efe939c774e2c9b909892f6c95434d6da760ee
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>
30 #include <linux/quotaops.h>
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"
46 #include "refcounttree.h"
47 #include "ocfs2_trace.h"
49 #include "buffer_head_io.h"
51 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
52 struct buffer_head *bh_result, int create)
54 int err = -EIO;
55 int status;
56 struct ocfs2_dinode *fe = NULL;
57 struct buffer_head *bh = NULL;
58 struct buffer_head *buffer_cache_bh = NULL;
59 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
60 void *kaddr;
62 trace_ocfs2_symlink_get_block(
63 (unsigned long long)OCFS2_I(inode)->ip_blkno,
64 (unsigned long long)iblock, bh_result, create);
66 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
68 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
69 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
70 (unsigned long long)iblock);
71 goto bail;
74 status = ocfs2_read_inode_block(inode, &bh);
75 if (status < 0) {
76 mlog_errno(status);
77 goto bail;
79 fe = (struct ocfs2_dinode *) bh->b_data;
81 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
82 le32_to_cpu(fe->i_clusters))) {
83 mlog(ML_ERROR, "block offset is outside the allocated size: "
84 "%llu\n", (unsigned long long)iblock);
85 goto bail;
88 /* We don't use the page cache to create symlink data, so if
89 * need be, copy it over from the buffer cache. */
90 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
91 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
92 iblock;
93 buffer_cache_bh = sb_getblk(osb->sb, blkno);
94 if (!buffer_cache_bh) {
95 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
96 goto bail;
99 /* we haven't locked out transactions, so a commit
100 * could've happened. Since we've got a reference on
101 * the bh, even if it commits while we're doing the
102 * copy, the data is still good. */
103 if (buffer_jbd(buffer_cache_bh)
104 && ocfs2_inode_is_new(inode)) {
105 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
106 if (!kaddr) {
107 mlog(ML_ERROR, "couldn't kmap!\n");
108 goto bail;
110 memcpy(kaddr + (bh_result->b_size * iblock),
111 buffer_cache_bh->b_data,
112 bh_result->b_size);
113 kunmap_atomic(kaddr, KM_USER0);
114 set_buffer_uptodate(bh_result);
116 brelse(buffer_cache_bh);
119 map_bh(bh_result, inode->i_sb,
120 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
122 err = 0;
124 bail:
125 brelse(bh);
127 return err;
130 int ocfs2_get_block(struct inode *inode, sector_t iblock,
131 struct buffer_head *bh_result, int create)
133 int err = 0;
134 unsigned int ext_flags;
135 u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
136 u64 p_blkno, count, past_eof;
137 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
139 trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno,
140 (unsigned long long)iblock, bh_result, create);
142 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
143 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
144 inode, inode->i_ino);
146 if (S_ISLNK(inode->i_mode)) {
147 /* this always does I/O for some reason. */
148 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
149 goto bail;
152 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
153 &ext_flags);
154 if (err) {
155 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
156 "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
157 (unsigned long long)p_blkno);
158 goto bail;
161 if (max_blocks < count)
162 count = max_blocks;
165 * ocfs2 never allocates in this function - the only time we
166 * need to use BH_New is when we're extending i_size on a file
167 * system which doesn't support holes, in which case BH_New
168 * allows __block_write_begin() to zero.
170 * If we see this on a sparse file system, then a truncate has
171 * raced us and removed the cluster. In this case, we clear
172 * the buffers dirty and uptodate bits and let the buffer code
173 * ignore it as a hole.
175 if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
176 clear_buffer_dirty(bh_result);
177 clear_buffer_uptodate(bh_result);
178 goto bail;
181 /* Treat the unwritten extent as a hole for zeroing purposes. */
182 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
183 map_bh(bh_result, inode->i_sb, p_blkno);
185 bh_result->b_size = count << inode->i_blkbits;
187 if (!ocfs2_sparse_alloc(osb)) {
188 if (p_blkno == 0) {
189 err = -EIO;
190 mlog(ML_ERROR,
191 "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
192 (unsigned long long)iblock,
193 (unsigned long long)p_blkno,
194 (unsigned long long)OCFS2_I(inode)->ip_blkno);
195 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
196 dump_stack();
197 goto bail;
201 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
203 trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno,
204 (unsigned long long)past_eof);
205 if (create && (iblock >= past_eof))
206 set_buffer_new(bh_result);
208 bail:
209 if (err < 0)
210 err = -EIO;
212 return err;
215 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
216 struct buffer_head *di_bh)
218 void *kaddr;
219 loff_t size;
220 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
222 if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
223 ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
224 (unsigned long long)OCFS2_I(inode)->ip_blkno);
225 return -EROFS;
228 size = i_size_read(inode);
230 if (size > PAGE_CACHE_SIZE ||
231 size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
232 ocfs2_error(inode->i_sb,
233 "Inode %llu has with inline data has bad size: %Lu",
234 (unsigned long long)OCFS2_I(inode)->ip_blkno,
235 (unsigned long long)size);
236 return -EROFS;
239 kaddr = kmap_atomic(page, KM_USER0);
240 if (size)
241 memcpy(kaddr, di->id2.i_data.id_data, size);
242 /* Clear the remaining part of the page */
243 memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
244 flush_dcache_page(page);
245 kunmap_atomic(kaddr, KM_USER0);
247 SetPageUptodate(page);
249 return 0;
252 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
254 int ret;
255 struct buffer_head *di_bh = NULL;
257 BUG_ON(!PageLocked(page));
258 BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
260 ret = ocfs2_read_inode_block(inode, &di_bh);
261 if (ret) {
262 mlog_errno(ret);
263 goto out;
266 ret = ocfs2_read_inline_data(inode, page, di_bh);
267 out:
268 unlock_page(page);
270 brelse(di_bh);
271 return ret;
274 static int ocfs2_readpage(struct file *file, struct page *page)
276 struct inode *inode = page->mapping->host;
277 struct ocfs2_inode_info *oi = OCFS2_I(inode);
278 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
279 int ret, unlock = 1;
281 trace_ocfs2_readpage((unsigned long long)oi->ip_blkno,
282 (page ? page->index : 0));
284 ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
285 if (ret != 0) {
286 if (ret == AOP_TRUNCATED_PAGE)
287 unlock = 0;
288 mlog_errno(ret);
289 goto out;
292 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
293 ret = AOP_TRUNCATED_PAGE;
294 goto out_inode_unlock;
298 * i_size might have just been updated as we grabed the meta lock. We
299 * might now be discovering a truncate that hit on another node.
300 * block_read_full_page->get_block freaks out if it is asked to read
301 * beyond the end of a file, so we check here. Callers
302 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
303 * and notice that the page they just read isn't needed.
305 * XXX sys_readahead() seems to get that wrong?
307 if (start >= i_size_read(inode)) {
308 zero_user(page, 0, PAGE_SIZE);
309 SetPageUptodate(page);
310 ret = 0;
311 goto out_alloc;
314 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
315 ret = ocfs2_readpage_inline(inode, page);
316 else
317 ret = block_read_full_page(page, ocfs2_get_block);
318 unlock = 0;
320 out_alloc:
321 up_read(&OCFS2_I(inode)->ip_alloc_sem);
322 out_inode_unlock:
323 ocfs2_inode_unlock(inode, 0);
324 out:
325 if (unlock)
326 unlock_page(page);
327 return ret;
331 * This is used only for read-ahead. Failures or difficult to handle
332 * situations are safe to ignore.
334 * Right now, we don't bother with BH_Boundary - in-inode extent lists
335 * are quite large (243 extents on 4k blocks), so most inodes don't
336 * grow out to a tree. If need be, detecting boundary extents could
337 * trivially be added in a future version of ocfs2_get_block().
339 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
340 struct list_head *pages, unsigned nr_pages)
342 int ret, err = -EIO;
343 struct inode *inode = mapping->host;
344 struct ocfs2_inode_info *oi = OCFS2_I(inode);
345 loff_t start;
346 struct page *last;
349 * Use the nonblocking flag for the dlm code to avoid page
350 * lock inversion, but don't bother with retrying.
352 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
353 if (ret)
354 return err;
356 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
357 ocfs2_inode_unlock(inode, 0);
358 return err;
362 * Don't bother with inline-data. There isn't anything
363 * to read-ahead in that case anyway...
365 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
366 goto out_unlock;
369 * Check whether a remote node truncated this file - we just
370 * drop out in that case as it's not worth handling here.
372 last = list_entry(pages->prev, struct page, lru);
373 start = (loff_t)last->index << PAGE_CACHE_SHIFT;
374 if (start >= i_size_read(inode))
375 goto out_unlock;
377 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
379 out_unlock:
380 up_read(&oi->ip_alloc_sem);
381 ocfs2_inode_unlock(inode, 0);
383 return err;
386 /* Note: Because we don't support holes, our allocation has
387 * already happened (allocation writes zeros to the file data)
388 * so we don't have to worry about ordered writes in
389 * ocfs2_writepage.
391 * ->writepage is called during the process of invalidating the page cache
392 * during blocked lock processing. It can't block on any cluster locks
393 * to during block mapping. It's relying on the fact that the block
394 * mapping can't have disappeared under the dirty pages that it is
395 * being asked to write back.
397 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
399 trace_ocfs2_writepage(
400 (unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
401 page->index);
403 return block_write_full_page(page, ocfs2_get_block, wbc);
406 /* Taken from ext3. We don't necessarily need the full blown
407 * functionality yet, but IMHO it's better to cut and paste the whole
408 * thing so we can avoid introducing our own bugs (and easily pick up
409 * their fixes when they happen) --Mark */
410 int walk_page_buffers( handle_t *handle,
411 struct buffer_head *head,
412 unsigned from,
413 unsigned to,
414 int *partial,
415 int (*fn)( handle_t *handle,
416 struct buffer_head *bh))
418 struct buffer_head *bh;
419 unsigned block_start, block_end;
420 unsigned blocksize = head->b_size;
421 int err, ret = 0;
422 struct buffer_head *next;
424 for ( bh = head, block_start = 0;
425 ret == 0 && (bh != head || !block_start);
426 block_start = block_end, bh = next)
428 next = bh->b_this_page;
429 block_end = block_start + blocksize;
430 if (block_end <= from || block_start >= to) {
431 if (partial && !buffer_uptodate(bh))
432 *partial = 1;
433 continue;
435 err = (*fn)(handle, bh);
436 if (!ret)
437 ret = err;
439 return ret;
442 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
444 sector_t status;
445 u64 p_blkno = 0;
446 int err = 0;
447 struct inode *inode = mapping->host;
449 trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
450 (unsigned long long)block);
452 /* We don't need to lock journal system files, since they aren't
453 * accessed concurrently from multiple nodes.
455 if (!INODE_JOURNAL(inode)) {
456 err = ocfs2_inode_lock(inode, NULL, 0);
457 if (err) {
458 if (err != -ENOENT)
459 mlog_errno(err);
460 goto bail;
462 down_read(&OCFS2_I(inode)->ip_alloc_sem);
465 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
466 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
467 NULL);
469 if (!INODE_JOURNAL(inode)) {
470 up_read(&OCFS2_I(inode)->ip_alloc_sem);
471 ocfs2_inode_unlock(inode, 0);
474 if (err) {
475 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
476 (unsigned long long)block);
477 mlog_errno(err);
478 goto bail;
481 bail:
482 status = err ? 0 : p_blkno;
484 return status;
488 * TODO: Make this into a generic get_blocks function.
490 * From do_direct_io in direct-io.c:
491 * "So what we do is to permit the ->get_blocks function to populate
492 * bh.b_size with the size of IO which is permitted at this offset and
493 * this i_blkbits."
495 * This function is called directly from get_more_blocks in direct-io.c.
497 * called like this: dio->get_blocks(dio->inode, fs_startblk,
498 * fs_count, map_bh, dio->rw == WRITE);
500 * Note that we never bother to allocate blocks here, and thus ignore the
501 * create argument.
503 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
504 struct buffer_head *bh_result, int create)
506 int ret;
507 u64 p_blkno, inode_blocks, contig_blocks;
508 unsigned int ext_flags;
509 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
510 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
512 /* This function won't even be called if the request isn't all
513 * nicely aligned and of the right size, so there's no need
514 * for us to check any of that. */
516 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
518 /* This figures out the size of the next contiguous block, and
519 * our logical offset */
520 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
521 &contig_blocks, &ext_flags);
522 if (ret) {
523 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
524 (unsigned long long)iblock);
525 ret = -EIO;
526 goto bail;
529 /* We should already CoW the refcounted extent in case of create. */
530 BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
533 * get_more_blocks() expects us to describe a hole by clearing
534 * the mapped bit on bh_result().
536 * Consider an unwritten extent as a hole.
538 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
539 map_bh(bh_result, inode->i_sb, p_blkno);
540 else
541 clear_buffer_mapped(bh_result);
543 /* make sure we don't map more than max_blocks blocks here as
544 that's all the kernel will handle at this point. */
545 if (max_blocks < contig_blocks)
546 contig_blocks = max_blocks;
547 bh_result->b_size = contig_blocks << blocksize_bits;
548 bail:
549 return ret;
553 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
554 * particularly interested in the aio/dio case. We use the rw_lock DLM lock
555 * to protect io on one node from truncation on another.
557 static void ocfs2_dio_end_io(struct kiocb *iocb,
558 loff_t offset,
559 ssize_t bytes,
560 void *private,
561 int ret,
562 bool is_async)
564 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
565 int level;
567 /* this io's submitter should not have unlocked this before we could */
568 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
570 if (ocfs2_iocb_is_sem_locked(iocb))
571 ocfs2_iocb_clear_sem_locked(iocb);
573 ocfs2_iocb_clear_rw_locked(iocb);
575 level = ocfs2_iocb_rw_locked_level(iocb);
576 ocfs2_rw_unlock(inode, level);
578 if (is_async)
579 aio_complete(iocb, ret, 0);
580 inode_dio_done(inode);
584 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
585 * from ext3. PageChecked() bits have been removed as OCFS2 does not
586 * do journalled data.
588 static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
590 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
592 jbd2_journal_invalidatepage(journal, page, offset);
595 static int ocfs2_releasepage(struct page *page, gfp_t wait)
597 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
599 if (!page_has_buffers(page))
600 return 0;
601 return jbd2_journal_try_to_free_buffers(journal, page, wait);
604 static ssize_t ocfs2_direct_IO(int rw,
605 struct kiocb *iocb,
606 const struct iovec *iov,
607 loff_t offset,
608 unsigned long nr_segs)
610 struct file *file = iocb->ki_filp;
611 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
614 * Fallback to buffered I/O if we see an inode without
615 * extents.
617 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
618 return 0;
620 /* Fallback to buffered I/O if we are appending. */
621 if (i_size_read(inode) <= offset)
622 return 0;
624 return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
625 iov, offset, nr_segs,
626 ocfs2_direct_IO_get_blocks,
627 ocfs2_dio_end_io, NULL, 0);
630 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
631 u32 cpos,
632 unsigned int *start,
633 unsigned int *end)
635 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
637 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
638 unsigned int cpp;
640 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
642 cluster_start = cpos % cpp;
643 cluster_start = cluster_start << osb->s_clustersize_bits;
645 cluster_end = cluster_start + osb->s_clustersize;
648 BUG_ON(cluster_start > PAGE_SIZE);
649 BUG_ON(cluster_end > PAGE_SIZE);
651 if (start)
652 *start = cluster_start;
653 if (end)
654 *end = cluster_end;
658 * 'from' and 'to' are the region in the page to avoid zeroing.
660 * If pagesize > clustersize, this function will avoid zeroing outside
661 * of the cluster boundary.
663 * from == to == 0 is code for "zero the entire cluster region"
665 static void ocfs2_clear_page_regions(struct page *page,
666 struct ocfs2_super *osb, u32 cpos,
667 unsigned from, unsigned to)
669 void *kaddr;
670 unsigned int cluster_start, cluster_end;
672 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
674 kaddr = kmap_atomic(page, KM_USER0);
676 if (from || to) {
677 if (from > cluster_start)
678 memset(kaddr + cluster_start, 0, from - cluster_start);
679 if (to < cluster_end)
680 memset(kaddr + to, 0, cluster_end - to);
681 } else {
682 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
685 kunmap_atomic(kaddr, KM_USER0);
689 * Nonsparse file systems fully allocate before we get to the write
690 * code. This prevents ocfs2_write() from tagging the write as an
691 * allocating one, which means ocfs2_map_page_blocks() might try to
692 * read-in the blocks at the tail of our file. Avoid reading them by
693 * testing i_size against each block offset.
695 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
696 unsigned int block_start)
698 u64 offset = page_offset(page) + block_start;
700 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
701 return 1;
703 if (i_size_read(inode) > offset)
704 return 1;
706 return 0;
710 * Some of this taken from __block_write_begin(). We already have our
711 * mapping by now though, and the entire write will be allocating or
712 * it won't, so not much need to use BH_New.
714 * This will also skip zeroing, which is handled externally.
716 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
717 struct inode *inode, unsigned int from,
718 unsigned int to, int new)
720 int ret = 0;
721 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
722 unsigned int block_end, block_start;
723 unsigned int bsize = 1 << inode->i_blkbits;
725 if (!page_has_buffers(page))
726 create_empty_buffers(page, bsize, 0);
728 head = page_buffers(page);
729 for (bh = head, block_start = 0; bh != head || !block_start;
730 bh = bh->b_this_page, block_start += bsize) {
731 block_end = block_start + bsize;
733 clear_buffer_new(bh);
736 * Ignore blocks outside of our i/o range -
737 * they may belong to unallocated clusters.
739 if (block_start >= to || block_end <= from) {
740 if (PageUptodate(page))
741 set_buffer_uptodate(bh);
742 continue;
746 * For an allocating write with cluster size >= page
747 * size, we always write the entire page.
749 if (new)
750 set_buffer_new(bh);
752 if (!buffer_mapped(bh)) {
753 map_bh(bh, inode->i_sb, *p_blkno);
754 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
757 if (PageUptodate(page)) {
758 if (!buffer_uptodate(bh))
759 set_buffer_uptodate(bh);
760 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
761 !buffer_new(bh) &&
762 ocfs2_should_read_blk(inode, page, block_start) &&
763 (block_start < from || block_end > to)) {
764 ll_rw_block(READ, 1, &bh);
765 *wait_bh++=bh;
768 *p_blkno = *p_blkno + 1;
772 * If we issued read requests - let them complete.
774 while(wait_bh > wait) {
775 wait_on_buffer(*--wait_bh);
776 if (!buffer_uptodate(*wait_bh))
777 ret = -EIO;
780 if (ret == 0 || !new)
781 return ret;
784 * If we get -EIO above, zero out any newly allocated blocks
785 * to avoid exposing stale data.
787 bh = head;
788 block_start = 0;
789 do {
790 block_end = block_start + bsize;
791 if (block_end <= from)
792 goto next_bh;
793 if (block_start >= to)
794 break;
796 zero_user(page, block_start, bh->b_size);
797 set_buffer_uptodate(bh);
798 mark_buffer_dirty(bh);
800 next_bh:
801 block_start = block_end;
802 bh = bh->b_this_page;
803 } while (bh != head);
805 return ret;
808 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
809 #define OCFS2_MAX_CTXT_PAGES 1
810 #else
811 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
812 #endif
814 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
817 * Describe the state of a single cluster to be written to.
819 struct ocfs2_write_cluster_desc {
820 u32 c_cpos;
821 u32 c_phys;
823 * Give this a unique field because c_phys eventually gets
824 * filled.
826 unsigned c_new;
827 unsigned c_unwritten;
828 unsigned c_needs_zero;
831 struct ocfs2_write_ctxt {
832 /* Logical cluster position / len of write */
833 u32 w_cpos;
834 u32 w_clen;
836 /* First cluster allocated in a nonsparse extend */
837 u32 w_first_new_cpos;
839 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
842 * This is true if page_size > cluster_size.
844 * It triggers a set of special cases during write which might
845 * have to deal with allocating writes to partial pages.
847 unsigned int w_large_pages;
850 * Pages involved in this write.
852 * w_target_page is the page being written to by the user.
854 * w_pages is an array of pages which always contains
855 * w_target_page, and in the case of an allocating write with
856 * page_size < cluster size, it will contain zero'd and mapped
857 * pages adjacent to w_target_page which need to be written
858 * out in so that future reads from that region will get
859 * zero's.
861 unsigned int w_num_pages;
862 struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
863 struct page *w_target_page;
866 * ocfs2_write_end() uses this to know what the real range to
867 * write in the target should be.
869 unsigned int w_target_from;
870 unsigned int w_target_to;
873 * We could use journal_current_handle() but this is cleaner,
874 * IMHO -Mark
876 handle_t *w_handle;
878 struct buffer_head *w_di_bh;
880 struct ocfs2_cached_dealloc_ctxt w_dealloc;
883 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
885 int i;
887 for(i = 0; i < num_pages; i++) {
888 if (pages[i]) {
889 unlock_page(pages[i]);
890 mark_page_accessed(pages[i]);
891 page_cache_release(pages[i]);
896 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
898 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
900 brelse(wc->w_di_bh);
901 kfree(wc);
904 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
905 struct ocfs2_super *osb, loff_t pos,
906 unsigned len, struct buffer_head *di_bh)
908 u32 cend;
909 struct ocfs2_write_ctxt *wc;
911 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
912 if (!wc)
913 return -ENOMEM;
915 wc->w_cpos = pos >> osb->s_clustersize_bits;
916 wc->w_first_new_cpos = UINT_MAX;
917 cend = (pos + len - 1) >> osb->s_clustersize_bits;
918 wc->w_clen = cend - wc->w_cpos + 1;
919 get_bh(di_bh);
920 wc->w_di_bh = di_bh;
922 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
923 wc->w_large_pages = 1;
924 else
925 wc->w_large_pages = 0;
927 ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
929 *wcp = wc;
931 return 0;
935 * If a page has any new buffers, zero them out here, and mark them uptodate
936 * and dirty so they'll be written out (in order to prevent uninitialised
937 * block data from leaking). And clear the new bit.
939 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
941 unsigned int block_start, block_end;
942 struct buffer_head *head, *bh;
944 BUG_ON(!PageLocked(page));
945 if (!page_has_buffers(page))
946 return;
948 bh = head = page_buffers(page);
949 block_start = 0;
950 do {
951 block_end = block_start + bh->b_size;
953 if (buffer_new(bh)) {
954 if (block_end > from && block_start < to) {
955 if (!PageUptodate(page)) {
956 unsigned start, end;
958 start = max(from, block_start);
959 end = min(to, block_end);
961 zero_user_segment(page, start, end);
962 set_buffer_uptodate(bh);
965 clear_buffer_new(bh);
966 mark_buffer_dirty(bh);
970 block_start = block_end;
971 bh = bh->b_this_page;
972 } while (bh != head);
976 * Only called when we have a failure during allocating write to write
977 * zero's to the newly allocated region.
979 static void ocfs2_write_failure(struct inode *inode,
980 struct ocfs2_write_ctxt *wc,
981 loff_t user_pos, unsigned user_len)
983 int i;
984 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
985 to = user_pos + user_len;
986 struct page *tmppage;
988 ocfs2_zero_new_buffers(wc->w_target_page, from, to);
990 for(i = 0; i < wc->w_num_pages; i++) {
991 tmppage = wc->w_pages[i];
993 if (page_has_buffers(tmppage)) {
994 if (ocfs2_should_order_data(inode))
995 ocfs2_jbd2_file_inode(wc->w_handle, inode);
997 block_commit_write(tmppage, from, to);
1002 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1003 struct ocfs2_write_ctxt *wc,
1004 struct page *page, u32 cpos,
1005 loff_t user_pos, unsigned user_len,
1006 int new)
1008 int ret;
1009 unsigned int map_from = 0, map_to = 0;
1010 unsigned int cluster_start, cluster_end;
1011 unsigned int user_data_from = 0, user_data_to = 0;
1013 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1014 &cluster_start, &cluster_end);
1016 /* treat the write as new if the a hole/lseek spanned across
1017 * the page boundary.
1019 new = new | ((i_size_read(inode) <= page_offset(page)) &&
1020 (page_offset(page) <= user_pos));
1022 if (page == wc->w_target_page) {
1023 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1024 map_to = map_from + user_len;
1026 if (new)
1027 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1028 cluster_start, cluster_end,
1029 new);
1030 else
1031 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1032 map_from, map_to, new);
1033 if (ret) {
1034 mlog_errno(ret);
1035 goto out;
1038 user_data_from = map_from;
1039 user_data_to = map_to;
1040 if (new) {
1041 map_from = cluster_start;
1042 map_to = cluster_end;
1044 } else {
1046 * If we haven't allocated the new page yet, we
1047 * shouldn't be writing it out without copying user
1048 * data. This is likely a math error from the caller.
1050 BUG_ON(!new);
1052 map_from = cluster_start;
1053 map_to = cluster_end;
1055 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1056 cluster_start, cluster_end, new);
1057 if (ret) {
1058 mlog_errno(ret);
1059 goto out;
1064 * Parts of newly allocated pages need to be zero'd.
1066 * Above, we have also rewritten 'to' and 'from' - as far as
1067 * the rest of the function is concerned, the entire cluster
1068 * range inside of a page needs to be written.
1070 * We can skip this if the page is up to date - it's already
1071 * been zero'd from being read in as a hole.
1073 if (new && !PageUptodate(page))
1074 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1075 cpos, user_data_from, user_data_to);
1077 flush_dcache_page(page);
1079 out:
1080 return ret;
1084 * This function will only grab one clusters worth of pages.
1086 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1087 struct ocfs2_write_ctxt *wc,
1088 u32 cpos, loff_t user_pos,
1089 unsigned user_len, int new,
1090 struct page *mmap_page)
1092 int ret = 0, i;
1093 unsigned long start, target_index, end_index, index;
1094 struct inode *inode = mapping->host;
1095 loff_t last_byte;
1097 target_index = user_pos >> PAGE_CACHE_SHIFT;
1100 * Figure out how many pages we'll be manipulating here. For
1101 * non allocating write, we just change the one
1102 * page. Otherwise, we'll need a whole clusters worth. If we're
1103 * writing past i_size, we only need enough pages to cover the
1104 * last page of the write.
1106 if (new) {
1107 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1108 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1110 * We need the index *past* the last page we could possibly
1111 * touch. This is the page past the end of the write or
1112 * i_size, whichever is greater.
1114 last_byte = max(user_pos + user_len, i_size_read(inode));
1115 BUG_ON(last_byte < 1);
1116 end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1;
1117 if ((start + wc->w_num_pages) > end_index)
1118 wc->w_num_pages = end_index - start;
1119 } else {
1120 wc->w_num_pages = 1;
1121 start = target_index;
1124 for(i = 0; i < wc->w_num_pages; i++) {
1125 index = start + i;
1127 if (index == target_index && mmap_page) {
1129 * ocfs2_pagemkwrite() is a little different
1130 * and wants us to directly use the page
1131 * passed in.
1133 lock_page(mmap_page);
1135 if (mmap_page->mapping != mapping) {
1136 unlock_page(mmap_page);
1138 * Sanity check - the locking in
1139 * ocfs2_pagemkwrite() should ensure
1140 * that this code doesn't trigger.
1142 ret = -EINVAL;
1143 mlog_errno(ret);
1144 goto out;
1147 page_cache_get(mmap_page);
1148 wc->w_pages[i] = mmap_page;
1149 } else {
1150 wc->w_pages[i] = find_or_create_page(mapping, index,
1151 GFP_NOFS);
1152 if (!wc->w_pages[i]) {
1153 ret = -ENOMEM;
1154 mlog_errno(ret);
1155 goto out;
1159 if (index == target_index)
1160 wc->w_target_page = wc->w_pages[i];
1162 out:
1163 return ret;
1167 * Prepare a single cluster for write one cluster into the file.
1169 static int ocfs2_write_cluster(struct address_space *mapping,
1170 u32 phys, unsigned int unwritten,
1171 unsigned int should_zero,
1172 struct ocfs2_alloc_context *data_ac,
1173 struct ocfs2_alloc_context *meta_ac,
1174 struct ocfs2_write_ctxt *wc, u32 cpos,
1175 loff_t user_pos, unsigned user_len)
1177 int ret, i, new;
1178 u64 v_blkno, p_blkno;
1179 struct inode *inode = mapping->host;
1180 struct ocfs2_extent_tree et;
1182 new = phys == 0 ? 1 : 0;
1183 if (new) {
1184 u32 tmp_pos;
1187 * This is safe to call with the page locks - it won't take
1188 * any additional semaphores or cluster locks.
1190 tmp_pos = cpos;
1191 ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1192 &tmp_pos, 1, 0, wc->w_di_bh,
1193 wc->w_handle, data_ac,
1194 meta_ac, NULL);
1196 * This shouldn't happen because we must have already
1197 * calculated the correct meta data allocation required. The
1198 * internal tree allocation code should know how to increase
1199 * transaction credits itself.
1201 * If need be, we could handle -EAGAIN for a
1202 * RESTART_TRANS here.
1204 mlog_bug_on_msg(ret == -EAGAIN,
1205 "Inode %llu: EAGAIN return during allocation.\n",
1206 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1207 if (ret < 0) {
1208 mlog_errno(ret);
1209 goto out;
1211 } else if (unwritten) {
1212 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1213 wc->w_di_bh);
1214 ret = ocfs2_mark_extent_written(inode, &et,
1215 wc->w_handle, cpos, 1, phys,
1216 meta_ac, &wc->w_dealloc);
1217 if (ret < 0) {
1218 mlog_errno(ret);
1219 goto out;
1223 if (should_zero)
1224 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1225 else
1226 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1229 * The only reason this should fail is due to an inability to
1230 * find the extent added.
1232 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1233 NULL);
1234 if (ret < 0) {
1235 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1236 "at logical block %llu",
1237 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1238 (unsigned long long)v_blkno);
1239 goto out;
1242 BUG_ON(p_blkno == 0);
1244 for(i = 0; i < wc->w_num_pages; i++) {
1245 int tmpret;
1247 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1248 wc->w_pages[i], cpos,
1249 user_pos, user_len,
1250 should_zero);
1251 if (tmpret) {
1252 mlog_errno(tmpret);
1253 if (ret == 0)
1254 ret = tmpret;
1259 * We only have cleanup to do in case of allocating write.
1261 if (ret && new)
1262 ocfs2_write_failure(inode, wc, user_pos, user_len);
1264 out:
1266 return ret;
1269 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1270 struct ocfs2_alloc_context *data_ac,
1271 struct ocfs2_alloc_context *meta_ac,
1272 struct ocfs2_write_ctxt *wc,
1273 loff_t pos, unsigned len)
1275 int ret, i;
1276 loff_t cluster_off;
1277 unsigned int local_len = len;
1278 struct ocfs2_write_cluster_desc *desc;
1279 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1281 for (i = 0; i < wc->w_clen; i++) {
1282 desc = &wc->w_desc[i];
1285 * We have to make sure that the total write passed in
1286 * doesn't extend past a single cluster.
1288 local_len = len;
1289 cluster_off = pos & (osb->s_clustersize - 1);
1290 if ((cluster_off + local_len) > osb->s_clustersize)
1291 local_len = osb->s_clustersize - cluster_off;
1293 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1294 desc->c_unwritten,
1295 desc->c_needs_zero,
1296 data_ac, meta_ac,
1297 wc, desc->c_cpos, pos, local_len);
1298 if (ret) {
1299 mlog_errno(ret);
1300 goto out;
1303 len -= local_len;
1304 pos += local_len;
1307 ret = 0;
1308 out:
1309 return ret;
1313 * ocfs2_write_end() wants to know which parts of the target page it
1314 * should complete the write on. It's easiest to compute them ahead of
1315 * time when a more complete view of the write is available.
1317 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1318 struct ocfs2_write_ctxt *wc,
1319 loff_t pos, unsigned len, int alloc)
1321 struct ocfs2_write_cluster_desc *desc;
1323 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1324 wc->w_target_to = wc->w_target_from + len;
1326 if (alloc == 0)
1327 return;
1330 * Allocating write - we may have different boundaries based
1331 * on page size and cluster size.
1333 * NOTE: We can no longer compute one value from the other as
1334 * the actual write length and user provided length may be
1335 * different.
1338 if (wc->w_large_pages) {
1340 * We only care about the 1st and last cluster within
1341 * our range and whether they should be zero'd or not. Either
1342 * value may be extended out to the start/end of a
1343 * newly allocated cluster.
1345 desc = &wc->w_desc[0];
1346 if (desc->c_needs_zero)
1347 ocfs2_figure_cluster_boundaries(osb,
1348 desc->c_cpos,
1349 &wc->w_target_from,
1350 NULL);
1352 desc = &wc->w_desc[wc->w_clen - 1];
1353 if (desc->c_needs_zero)
1354 ocfs2_figure_cluster_boundaries(osb,
1355 desc->c_cpos,
1356 NULL,
1357 &wc->w_target_to);
1358 } else {
1359 wc->w_target_from = 0;
1360 wc->w_target_to = PAGE_CACHE_SIZE;
1365 * Populate each single-cluster write descriptor in the write context
1366 * with information about the i/o to be done.
1368 * Returns the number of clusters that will have to be allocated, as
1369 * well as a worst case estimate of the number of extent records that
1370 * would have to be created during a write to an unwritten region.
1372 static int ocfs2_populate_write_desc(struct inode *inode,
1373 struct ocfs2_write_ctxt *wc,
1374 unsigned int *clusters_to_alloc,
1375 unsigned int *extents_to_split)
1377 int ret;
1378 struct ocfs2_write_cluster_desc *desc;
1379 unsigned int num_clusters = 0;
1380 unsigned int ext_flags = 0;
1381 u32 phys = 0;
1382 int i;
1384 *clusters_to_alloc = 0;
1385 *extents_to_split = 0;
1387 for (i = 0; i < wc->w_clen; i++) {
1388 desc = &wc->w_desc[i];
1389 desc->c_cpos = wc->w_cpos + i;
1391 if (num_clusters == 0) {
1393 * Need to look up the next extent record.
1395 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1396 &num_clusters, &ext_flags);
1397 if (ret) {
1398 mlog_errno(ret);
1399 goto out;
1402 /* We should already CoW the refcountd extent. */
1403 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1406 * Assume worst case - that we're writing in
1407 * the middle of the extent.
1409 * We can assume that the write proceeds from
1410 * left to right, in which case the extent
1411 * insert code is smart enough to coalesce the
1412 * next splits into the previous records created.
1414 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1415 *extents_to_split = *extents_to_split + 2;
1416 } else if (phys) {
1418 * Only increment phys if it doesn't describe
1419 * a hole.
1421 phys++;
1425 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1426 * file that got extended. w_first_new_cpos tells us
1427 * where the newly allocated clusters are so we can
1428 * zero them.
1430 if (desc->c_cpos >= wc->w_first_new_cpos) {
1431 BUG_ON(phys == 0);
1432 desc->c_needs_zero = 1;
1435 desc->c_phys = phys;
1436 if (phys == 0) {
1437 desc->c_new = 1;
1438 desc->c_needs_zero = 1;
1439 *clusters_to_alloc = *clusters_to_alloc + 1;
1442 if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1443 desc->c_unwritten = 1;
1444 desc->c_needs_zero = 1;
1447 num_clusters--;
1450 ret = 0;
1451 out:
1452 return ret;
1455 static int ocfs2_write_begin_inline(struct address_space *mapping,
1456 struct inode *inode,
1457 struct ocfs2_write_ctxt *wc)
1459 int ret;
1460 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1461 struct page *page;
1462 handle_t *handle;
1463 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1465 page = find_or_create_page(mapping, 0, GFP_NOFS);
1466 if (!page) {
1467 ret = -ENOMEM;
1468 mlog_errno(ret);
1469 goto out;
1472 * If we don't set w_num_pages then this page won't get unlocked
1473 * and freed on cleanup of the write context.
1475 wc->w_pages[0] = wc->w_target_page = page;
1476 wc->w_num_pages = 1;
1478 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1479 if (IS_ERR(handle)) {
1480 ret = PTR_ERR(handle);
1481 mlog_errno(ret);
1482 goto out;
1485 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1486 OCFS2_JOURNAL_ACCESS_WRITE);
1487 if (ret) {
1488 ocfs2_commit_trans(osb, handle);
1490 mlog_errno(ret);
1491 goto out;
1494 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1495 ocfs2_set_inode_data_inline(inode, di);
1497 if (!PageUptodate(page)) {
1498 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1499 if (ret) {
1500 ocfs2_commit_trans(osb, handle);
1502 goto out;
1506 wc->w_handle = handle;
1507 out:
1508 return ret;
1511 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1513 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1515 if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1516 return 1;
1517 return 0;
1520 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1521 struct inode *inode, loff_t pos,
1522 unsigned len, struct page *mmap_page,
1523 struct ocfs2_write_ctxt *wc)
1525 int ret, written = 0;
1526 loff_t end = pos + len;
1527 struct ocfs2_inode_info *oi = OCFS2_I(inode);
1528 struct ocfs2_dinode *di = NULL;
1530 trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1531 len, (unsigned long long)pos,
1532 oi->ip_dyn_features);
1535 * Handle inodes which already have inline data 1st.
1537 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1538 if (mmap_page == NULL &&
1539 ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1540 goto do_inline_write;
1543 * The write won't fit - we have to give this inode an
1544 * inline extent list now.
1546 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1547 if (ret)
1548 mlog_errno(ret);
1549 goto out;
1553 * Check whether the inode can accept inline data.
1555 if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1556 return 0;
1559 * Check whether the write can fit.
1561 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1562 if (mmap_page ||
1563 end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1564 return 0;
1566 do_inline_write:
1567 ret = ocfs2_write_begin_inline(mapping, inode, wc);
1568 if (ret) {
1569 mlog_errno(ret);
1570 goto out;
1574 * This signals to the caller that the data can be written
1575 * inline.
1577 written = 1;
1578 out:
1579 return written ? written : ret;
1583 * This function only does anything for file systems which can't
1584 * handle sparse files.
1586 * What we want to do here is fill in any hole between the current end
1587 * of allocation and the end of our write. That way the rest of the
1588 * write path can treat it as an non-allocating write, which has no
1589 * special case code for sparse/nonsparse files.
1591 static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1592 struct buffer_head *di_bh,
1593 loff_t pos, unsigned len,
1594 struct ocfs2_write_ctxt *wc)
1596 int ret;
1597 loff_t newsize = pos + len;
1599 BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1601 if (newsize <= i_size_read(inode))
1602 return 0;
1604 ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1605 if (ret)
1606 mlog_errno(ret);
1608 wc->w_first_new_cpos =
1609 ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1611 return ret;
1614 static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1615 loff_t pos)
1617 int ret = 0;
1619 BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1620 if (pos > i_size_read(inode))
1621 ret = ocfs2_zero_extend(inode, di_bh, pos);
1623 return ret;
1627 * Try to flush truncate logs if we can free enough clusters from it.
1628 * As for return value, "< 0" means error, "0" no space and "1" means
1629 * we have freed enough spaces and let the caller try to allocate again.
1631 static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
1632 unsigned int needed)
1634 tid_t target;
1635 int ret = 0;
1636 unsigned int truncated_clusters;
1638 mutex_lock(&osb->osb_tl_inode->i_mutex);
1639 truncated_clusters = osb->truncated_clusters;
1640 mutex_unlock(&osb->osb_tl_inode->i_mutex);
1643 * Check whether we can succeed in allocating if we free
1644 * the truncate log.
1646 if (truncated_clusters < needed)
1647 goto out;
1649 ret = ocfs2_flush_truncate_log(osb);
1650 if (ret) {
1651 mlog_errno(ret);
1652 goto out;
1655 if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
1656 jbd2_log_wait_commit(osb->journal->j_journal, target);
1657 ret = 1;
1659 out:
1660 return ret;
1663 int ocfs2_write_begin_nolock(struct file *filp,
1664 struct address_space *mapping,
1665 loff_t pos, unsigned len, unsigned flags,
1666 struct page **pagep, void **fsdata,
1667 struct buffer_head *di_bh, struct page *mmap_page)
1669 int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1670 unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1671 struct ocfs2_write_ctxt *wc;
1672 struct inode *inode = mapping->host;
1673 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1674 struct ocfs2_dinode *di;
1675 struct ocfs2_alloc_context *data_ac = NULL;
1676 struct ocfs2_alloc_context *meta_ac = NULL;
1677 handle_t *handle;
1678 struct ocfs2_extent_tree et;
1679 int try_free = 1, ret1;
1681 try_again:
1682 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1683 if (ret) {
1684 mlog_errno(ret);
1685 return ret;
1688 if (ocfs2_supports_inline_data(osb)) {
1689 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1690 mmap_page, wc);
1691 if (ret == 1) {
1692 ret = 0;
1693 goto success;
1695 if (ret < 0) {
1696 mlog_errno(ret);
1697 goto out;
1701 if (ocfs2_sparse_alloc(osb))
1702 ret = ocfs2_zero_tail(inode, di_bh, pos);
1703 else
1704 ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos, len,
1705 wc);
1706 if (ret) {
1707 mlog_errno(ret);
1708 goto out;
1711 ret = ocfs2_check_range_for_refcount(inode, pos, len);
1712 if (ret < 0) {
1713 mlog_errno(ret);
1714 goto out;
1715 } else if (ret == 1) {
1716 clusters_need = wc->w_clen;
1717 ret = ocfs2_refcount_cow(inode, filp, di_bh,
1718 wc->w_cpos, wc->w_clen, UINT_MAX);
1719 if (ret) {
1720 mlog_errno(ret);
1721 goto out;
1725 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1726 &extents_to_split);
1727 if (ret) {
1728 mlog_errno(ret);
1729 goto out;
1731 clusters_need += clusters_to_alloc;
1733 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1735 trace_ocfs2_write_begin_nolock(
1736 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1737 (long long)i_size_read(inode),
1738 le32_to_cpu(di->i_clusters),
1739 pos, len, flags, mmap_page,
1740 clusters_to_alloc, extents_to_split);
1743 * We set w_target_from, w_target_to here so that
1744 * ocfs2_write_end() knows which range in the target page to
1745 * write out. An allocation requires that we write the entire
1746 * cluster range.
1748 if (clusters_to_alloc || extents_to_split) {
1750 * XXX: We are stretching the limits of
1751 * ocfs2_lock_allocators(). It greatly over-estimates
1752 * the work to be done.
1754 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1755 wc->w_di_bh);
1756 ret = ocfs2_lock_allocators(inode, &et,
1757 clusters_to_alloc, extents_to_split,
1758 &data_ac, &meta_ac);
1759 if (ret) {
1760 mlog_errno(ret);
1761 goto out;
1764 if (data_ac)
1765 data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1767 credits = ocfs2_calc_extend_credits(inode->i_sb,
1768 &di->id2.i_list,
1769 clusters_to_alloc);
1774 * We have to zero sparse allocated clusters, unwritten extent clusters,
1775 * and non-sparse clusters we just extended. For non-sparse writes,
1776 * we know zeros will only be needed in the first and/or last cluster.
1778 if (clusters_to_alloc || extents_to_split ||
1779 (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1780 wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1781 cluster_of_pages = 1;
1782 else
1783 cluster_of_pages = 0;
1785 ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1787 handle = ocfs2_start_trans(osb, credits);
1788 if (IS_ERR(handle)) {
1789 ret = PTR_ERR(handle);
1790 mlog_errno(ret);
1791 goto out;
1794 wc->w_handle = handle;
1796 if (clusters_to_alloc) {
1797 ret = dquot_alloc_space_nodirty(inode,
1798 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1799 if (ret)
1800 goto out_commit;
1803 * We don't want this to fail in ocfs2_write_end(), so do it
1804 * here.
1806 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1807 OCFS2_JOURNAL_ACCESS_WRITE);
1808 if (ret) {
1809 mlog_errno(ret);
1810 goto out_quota;
1814 * Fill our page array first. That way we've grabbed enough so
1815 * that we can zero and flush if we error after adding the
1816 * extent.
1818 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1819 cluster_of_pages, mmap_page);
1820 if (ret) {
1821 mlog_errno(ret);
1822 goto out_quota;
1825 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1826 len);
1827 if (ret) {
1828 mlog_errno(ret);
1829 goto out_quota;
1832 if (data_ac)
1833 ocfs2_free_alloc_context(data_ac);
1834 if (meta_ac)
1835 ocfs2_free_alloc_context(meta_ac);
1837 success:
1838 *pagep = wc->w_target_page;
1839 *fsdata = wc;
1840 return 0;
1841 out_quota:
1842 if (clusters_to_alloc)
1843 dquot_free_space(inode,
1844 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1845 out_commit:
1846 ocfs2_commit_trans(osb, handle);
1848 out:
1849 ocfs2_free_write_ctxt(wc);
1851 if (data_ac)
1852 ocfs2_free_alloc_context(data_ac);
1853 if (meta_ac)
1854 ocfs2_free_alloc_context(meta_ac);
1856 if (ret == -ENOSPC && try_free) {
1858 * Try to free some truncate log so that we can have enough
1859 * clusters to allocate.
1861 try_free = 0;
1863 ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1864 if (ret1 == 1)
1865 goto try_again;
1867 if (ret1 < 0)
1868 mlog_errno(ret1);
1871 return ret;
1874 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1875 loff_t pos, unsigned len, unsigned flags,
1876 struct page **pagep, void **fsdata)
1878 int ret;
1879 struct buffer_head *di_bh = NULL;
1880 struct inode *inode = mapping->host;
1882 ret = ocfs2_inode_lock(inode, &di_bh, 1);
1883 if (ret) {
1884 mlog_errno(ret);
1885 return ret;
1889 * Take alloc sem here to prevent concurrent lookups. That way
1890 * the mapping, zeroing and tree manipulation within
1891 * ocfs2_write() will be safe against ->readpage(). This
1892 * should also serve to lock out allocation from a shared
1893 * writeable region.
1895 down_write(&OCFS2_I(inode)->ip_alloc_sem);
1897 ret = ocfs2_write_begin_nolock(file, mapping, pos, len, flags, pagep,
1898 fsdata, di_bh, NULL);
1899 if (ret) {
1900 mlog_errno(ret);
1901 goto out_fail;
1904 brelse(di_bh);
1906 return 0;
1908 out_fail:
1909 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1911 brelse(di_bh);
1912 ocfs2_inode_unlock(inode, 1);
1914 return ret;
1917 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1918 unsigned len, unsigned *copied,
1919 struct ocfs2_dinode *di,
1920 struct ocfs2_write_ctxt *wc)
1922 void *kaddr;
1924 if (unlikely(*copied < len)) {
1925 if (!PageUptodate(wc->w_target_page)) {
1926 *copied = 0;
1927 return;
1931 kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
1932 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1933 kunmap_atomic(kaddr, KM_USER0);
1935 trace_ocfs2_write_end_inline(
1936 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1937 (unsigned long long)pos, *copied,
1938 le16_to_cpu(di->id2.i_data.id_count),
1939 le16_to_cpu(di->i_dyn_features));
1942 int ocfs2_write_end_nolock(struct address_space *mapping,
1943 loff_t pos, unsigned len, unsigned copied,
1944 struct page *page, void *fsdata)
1946 int i;
1947 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1948 struct inode *inode = mapping->host;
1949 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1950 struct ocfs2_write_ctxt *wc = fsdata;
1951 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1952 handle_t *handle = wc->w_handle;
1953 struct page *tmppage;
1955 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1956 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1957 goto out_write_size;
1960 if (unlikely(copied < len)) {
1961 if (!PageUptodate(wc->w_target_page))
1962 copied = 0;
1964 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1965 start+len);
1967 flush_dcache_page(wc->w_target_page);
1969 for(i = 0; i < wc->w_num_pages; i++) {
1970 tmppage = wc->w_pages[i];
1972 if (tmppage == wc->w_target_page) {
1973 from = wc->w_target_from;
1974 to = wc->w_target_to;
1976 BUG_ON(from > PAGE_CACHE_SIZE ||
1977 to > PAGE_CACHE_SIZE ||
1978 to < from);
1979 } else {
1981 * Pages adjacent to the target (if any) imply
1982 * a hole-filling write in which case we want
1983 * to flush their entire range.
1985 from = 0;
1986 to = PAGE_CACHE_SIZE;
1989 if (page_has_buffers(tmppage)) {
1990 if (ocfs2_should_order_data(inode))
1991 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1992 block_commit_write(tmppage, from, to);
1996 out_write_size:
1997 pos += copied;
1998 if (pos > inode->i_size) {
1999 i_size_write(inode, pos);
2000 mark_inode_dirty(inode);
2002 inode->i_blocks = ocfs2_inode_sector_count(inode);
2003 di->i_size = cpu_to_le64((u64)i_size_read(inode));
2004 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2005 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2006 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2007 ocfs2_journal_dirty(handle, wc->w_di_bh);
2009 ocfs2_commit_trans(osb, handle);
2011 ocfs2_run_deallocs(osb, &wc->w_dealloc);
2013 ocfs2_free_write_ctxt(wc);
2015 return copied;
2018 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2019 loff_t pos, unsigned len, unsigned copied,
2020 struct page *page, void *fsdata)
2022 int ret;
2023 struct inode *inode = mapping->host;
2025 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
2027 up_write(&OCFS2_I(inode)->ip_alloc_sem);
2028 ocfs2_inode_unlock(inode, 1);
2030 return ret;
2033 const struct address_space_operations ocfs2_aops = {
2034 .readpage = ocfs2_readpage,
2035 .readpages = ocfs2_readpages,
2036 .writepage = ocfs2_writepage,
2037 .write_begin = ocfs2_write_begin,
2038 .write_end = ocfs2_write_end,
2039 .bmap = ocfs2_bmap,
2040 .direct_IO = ocfs2_direct_IO,
2041 .invalidatepage = ocfs2_invalidatepage,
2042 .releasepage = ocfs2_releasepage,
2043 .migratepage = buffer_migrate_page,
2044 .is_partially_uptodate = block_is_partially_uptodate,
2045 .error_remove_page = generic_error_remove_page,