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.
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>
39 #include "extent_map.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)
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);
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);
74 status = ocfs2_read_inode_block(inode, &bh);
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);
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) +
93 buffer_cache_bh = sb_getblk(osb->sb, blkno);
94 if (!buffer_cache_bh) {
95 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
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);
107 mlog(ML_ERROR, "couldn't kmap!\n");
110 memcpy(kaddr + (bh_result->b_size * iblock),
111 buffer_cache_bh->b_data,
113 kunmap_atomic(kaddr);
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);
130 int ocfs2_get_block(struct inode *inode, sector_t iblock,
131 struct buffer_head *bh_result, int create)
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);
152 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
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);
161 if (max_blocks < count)
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);
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)) {
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);
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);
215 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
216 struct buffer_head *di_bh)
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);
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);
239 kaddr = kmap_atomic(page);
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);
247 SetPageUptodate(page);
252 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
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);
266 ret = ocfs2_read_inline_data(inode, page, di_bh);
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;
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);
286 if (ret == AOP_TRUNCATED_PAGE)
292 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
294 * Unlock the page and cycle ip_alloc_sem so that we don't
295 * busyloop waiting for ip_alloc_sem to unlock
297 ret = AOP_TRUNCATED_PAGE;
300 down_read(&oi->ip_alloc_sem);
301 up_read(&oi->ip_alloc_sem);
302 goto out_inode_unlock;
306 * i_size might have just been updated as we grabed the meta lock. We
307 * might now be discovering a truncate that hit on another node.
308 * block_read_full_page->get_block freaks out if it is asked to read
309 * beyond the end of a file, so we check here. Callers
310 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
311 * and notice that the page they just read isn't needed.
313 * XXX sys_readahead() seems to get that wrong?
315 if (start >= i_size_read(inode)) {
316 zero_user(page, 0, PAGE_SIZE);
317 SetPageUptodate(page);
322 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
323 ret = ocfs2_readpage_inline(inode, page);
325 ret = block_read_full_page(page, ocfs2_get_block);
329 up_read(&OCFS2_I(inode)->ip_alloc_sem);
331 ocfs2_inode_unlock(inode, 0);
339 * This is used only for read-ahead. Failures or difficult to handle
340 * situations are safe to ignore.
342 * Right now, we don't bother with BH_Boundary - in-inode extent lists
343 * are quite large (243 extents on 4k blocks), so most inodes don't
344 * grow out to a tree. If need be, detecting boundary extents could
345 * trivially be added in a future version of ocfs2_get_block().
347 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
348 struct list_head *pages, unsigned nr_pages)
351 struct inode *inode = mapping->host;
352 struct ocfs2_inode_info *oi = OCFS2_I(inode);
357 * Use the nonblocking flag for the dlm code to avoid page
358 * lock inversion, but don't bother with retrying.
360 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
364 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
365 ocfs2_inode_unlock(inode, 0);
370 * Don't bother with inline-data. There isn't anything
371 * to read-ahead in that case anyway...
373 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
377 * Check whether a remote node truncated this file - we just
378 * drop out in that case as it's not worth handling here.
380 last = list_entry(pages->prev, struct page, lru);
381 start = (loff_t)last->index << PAGE_CACHE_SHIFT;
382 if (start >= i_size_read(inode))
385 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
388 up_read(&oi->ip_alloc_sem);
389 ocfs2_inode_unlock(inode, 0);
394 /* Note: Because we don't support holes, our allocation has
395 * already happened (allocation writes zeros to the file data)
396 * so we don't have to worry about ordered writes in
399 * ->writepage is called during the process of invalidating the page cache
400 * during blocked lock processing. It can't block on any cluster locks
401 * to during block mapping. It's relying on the fact that the block
402 * mapping can't have disappeared under the dirty pages that it is
403 * being asked to write back.
405 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
407 trace_ocfs2_writepage(
408 (unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno,
411 return block_write_full_page(page, ocfs2_get_block, wbc);
414 /* Taken from ext3. We don't necessarily need the full blown
415 * functionality yet, but IMHO it's better to cut and paste the whole
416 * thing so we can avoid introducing our own bugs (and easily pick up
417 * their fixes when they happen) --Mark */
418 int walk_page_buffers( handle_t *handle,
419 struct buffer_head *head,
423 int (*fn)( handle_t *handle,
424 struct buffer_head *bh))
426 struct buffer_head *bh;
427 unsigned block_start, block_end;
428 unsigned blocksize = head->b_size;
430 struct buffer_head *next;
432 for ( bh = head, block_start = 0;
433 ret == 0 && (bh != head || !block_start);
434 block_start = block_end, bh = next)
436 next = bh->b_this_page;
437 block_end = block_start + blocksize;
438 if (block_end <= from || block_start >= to) {
439 if (partial && !buffer_uptodate(bh))
443 err = (*fn)(handle, bh);
450 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
455 struct inode *inode = mapping->host;
457 trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno,
458 (unsigned long long)block);
460 /* We don't need to lock journal system files, since they aren't
461 * accessed concurrently from multiple nodes.
463 if (!INODE_JOURNAL(inode)) {
464 err = ocfs2_inode_lock(inode, NULL, 0);
470 down_read(&OCFS2_I(inode)->ip_alloc_sem);
473 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
474 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
477 if (!INODE_JOURNAL(inode)) {
478 up_read(&OCFS2_I(inode)->ip_alloc_sem);
479 ocfs2_inode_unlock(inode, 0);
483 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
484 (unsigned long long)block);
490 status = err ? 0 : p_blkno;
496 * TODO: Make this into a generic get_blocks function.
498 * From do_direct_io in direct-io.c:
499 * "So what we do is to permit the ->get_blocks function to populate
500 * bh.b_size with the size of IO which is permitted at this offset and
503 * This function is called directly from get_more_blocks in direct-io.c.
505 * called like this: dio->get_blocks(dio->inode, fs_startblk,
506 * fs_count, map_bh, dio->rw == WRITE);
508 * Note that we never bother to allocate blocks here, and thus ignore the
511 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
512 struct buffer_head *bh_result, int create)
515 u64 p_blkno, inode_blocks, contig_blocks;
516 unsigned int ext_flags;
517 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
518 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
520 /* This function won't even be called if the request isn't all
521 * nicely aligned and of the right size, so there's no need
522 * for us to check any of that. */
524 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
526 /* This figures out the size of the next contiguous block, and
527 * our logical offset */
528 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
529 &contig_blocks, &ext_flags);
531 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
532 (unsigned long long)iblock);
537 /* We should already CoW the refcounted extent in case of create. */
538 BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
541 * get_more_blocks() expects us to describe a hole by clearing
542 * the mapped bit on bh_result().
544 * Consider an unwritten extent as a hole.
546 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
547 map_bh(bh_result, inode->i_sb, p_blkno);
549 clear_buffer_mapped(bh_result);
551 /* make sure we don't map more than max_blocks blocks here as
552 that's all the kernel will handle at this point. */
553 if (max_blocks < contig_blocks)
554 contig_blocks = max_blocks;
555 bh_result->b_size = contig_blocks << blocksize_bits;
561 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
562 * particularly interested in the aio/dio case. We use the rw_lock DLM lock
563 * to protect io on one node from truncation on another.
565 static void ocfs2_dio_end_io(struct kiocb *iocb,
570 struct inode *inode = file_inode(iocb->ki_filp);
572 wait_queue_head_t *wq = ocfs2_ioend_wq(inode);
574 /* this io's submitter should not have unlocked this before we could */
575 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
577 if (ocfs2_iocb_is_sem_locked(iocb))
578 ocfs2_iocb_clear_sem_locked(iocb);
580 if (ocfs2_iocb_is_unaligned_aio(iocb)) {
581 ocfs2_iocb_clear_unaligned_aio(iocb);
583 if (atomic_dec_and_test(&OCFS2_I(inode)->ip_unaligned_aio) &&
584 waitqueue_active(wq)) {
589 ocfs2_iocb_clear_rw_locked(iocb);
591 level = ocfs2_iocb_rw_locked_level(iocb);
592 ocfs2_rw_unlock(inode, level);
596 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
597 * from ext3. PageChecked() bits have been removed as OCFS2 does not
598 * do journalled data.
600 static void ocfs2_invalidatepage(struct page *page, unsigned int offset,
603 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
605 jbd2_journal_invalidatepage(journal, page, offset, length);
608 static int ocfs2_releasepage(struct page *page, gfp_t wait)
610 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
612 if (!page_has_buffers(page))
614 return jbd2_journal_try_to_free_buffers(journal, page, wait);
617 static ssize_t ocfs2_direct_IO(int rw,
619 struct iov_iter *iter,
622 struct file *file = iocb->ki_filp;
623 struct inode *inode = file_inode(file)->i_mapping->host;
626 * Fallback to buffered I/O if we see an inode without
629 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
632 /* Fallback to buffered I/O if we are appending. */
633 if (i_size_read(inode) <= offset)
636 return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
637 iter, offset, ocfs2_direct_IO_get_blocks,
638 ocfs2_dio_end_io, NULL, 0);
641 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
646 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
648 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
651 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
653 cluster_start = cpos % cpp;
654 cluster_start = cluster_start << osb->s_clustersize_bits;
656 cluster_end = cluster_start + osb->s_clustersize;
659 BUG_ON(cluster_start > PAGE_SIZE);
660 BUG_ON(cluster_end > PAGE_SIZE);
663 *start = cluster_start;
669 * 'from' and 'to' are the region in the page to avoid zeroing.
671 * If pagesize > clustersize, this function will avoid zeroing outside
672 * of the cluster boundary.
674 * from == to == 0 is code for "zero the entire cluster region"
676 static void ocfs2_clear_page_regions(struct page *page,
677 struct ocfs2_super *osb, u32 cpos,
678 unsigned from, unsigned to)
681 unsigned int cluster_start, cluster_end;
683 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
685 kaddr = kmap_atomic(page);
688 if (from > cluster_start)
689 memset(kaddr + cluster_start, 0, from - cluster_start);
690 if (to < cluster_end)
691 memset(kaddr + to, 0, cluster_end - to);
693 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
696 kunmap_atomic(kaddr);
700 * Nonsparse file systems fully allocate before we get to the write
701 * code. This prevents ocfs2_write() from tagging the write as an
702 * allocating one, which means ocfs2_map_page_blocks() might try to
703 * read-in the blocks at the tail of our file. Avoid reading them by
704 * testing i_size against each block offset.
706 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
707 unsigned int block_start)
709 u64 offset = page_offset(page) + block_start;
711 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
714 if (i_size_read(inode) > offset)
721 * Some of this taken from __block_write_begin(). We already have our
722 * mapping by now though, and the entire write will be allocating or
723 * it won't, so not much need to use BH_New.
725 * This will also skip zeroing, which is handled externally.
727 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
728 struct inode *inode, unsigned int from,
729 unsigned int to, int new)
732 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
733 unsigned int block_end, block_start;
734 unsigned int bsize = 1 << inode->i_blkbits;
736 if (!page_has_buffers(page))
737 create_empty_buffers(page, bsize, 0);
739 head = page_buffers(page);
740 for (bh = head, block_start = 0; bh != head || !block_start;
741 bh = bh->b_this_page, block_start += bsize) {
742 block_end = block_start + bsize;
744 clear_buffer_new(bh);
747 * Ignore blocks outside of our i/o range -
748 * they may belong to unallocated clusters.
750 if (block_start >= to || block_end <= from) {
751 if (PageUptodate(page))
752 set_buffer_uptodate(bh);
757 * For an allocating write with cluster size >= page
758 * size, we always write the entire page.
763 if (!buffer_mapped(bh)) {
764 map_bh(bh, inode->i_sb, *p_blkno);
765 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
768 if (PageUptodate(page)) {
769 if (!buffer_uptodate(bh))
770 set_buffer_uptodate(bh);
771 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
773 ocfs2_should_read_blk(inode, page, block_start) &&
774 (block_start < from || block_end > to)) {
775 ll_rw_block(READ, 1, &bh);
779 *p_blkno = *p_blkno + 1;
783 * If we issued read requests - let them complete.
785 while(wait_bh > wait) {
786 wait_on_buffer(*--wait_bh);
787 if (!buffer_uptodate(*wait_bh))
791 if (ret == 0 || !new)
795 * If we get -EIO above, zero out any newly allocated blocks
796 * to avoid exposing stale data.
801 block_end = block_start + bsize;
802 if (block_end <= from)
804 if (block_start >= to)
807 zero_user(page, block_start, bh->b_size);
808 set_buffer_uptodate(bh);
809 mark_buffer_dirty(bh);
812 block_start = block_end;
813 bh = bh->b_this_page;
814 } while (bh != head);
819 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
820 #define OCFS2_MAX_CTXT_PAGES 1
822 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
825 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
828 * Describe the state of a single cluster to be written to.
830 struct ocfs2_write_cluster_desc {
834 * Give this a unique field because c_phys eventually gets
838 unsigned c_unwritten;
839 unsigned c_needs_zero;
842 struct ocfs2_write_ctxt {
843 /* Logical cluster position / len of write */
847 /* First cluster allocated in a nonsparse extend */
848 u32 w_first_new_cpos;
850 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
853 * This is true if page_size > cluster_size.
855 * It triggers a set of special cases during write which might
856 * have to deal with allocating writes to partial pages.
858 unsigned int w_large_pages;
861 * Pages involved in this write.
863 * w_target_page is the page being written to by the user.
865 * w_pages is an array of pages which always contains
866 * w_target_page, and in the case of an allocating write with
867 * page_size < cluster size, it will contain zero'd and mapped
868 * pages adjacent to w_target_page which need to be written
869 * out in so that future reads from that region will get
872 unsigned int w_num_pages;
873 struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
874 struct page *w_target_page;
877 * w_target_locked is used for page_mkwrite path indicating no unlocking
878 * against w_target_page in ocfs2_write_end_nolock.
880 unsigned int w_target_locked:1;
883 * ocfs2_write_end() uses this to know what the real range to
884 * write in the target should be.
886 unsigned int w_target_from;
887 unsigned int w_target_to;
890 * We could use journal_current_handle() but this is cleaner,
895 struct buffer_head *w_di_bh;
897 struct ocfs2_cached_dealloc_ctxt w_dealloc;
900 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
904 for(i = 0; i < num_pages; i++) {
906 unlock_page(pages[i]);
907 mark_page_accessed(pages[i]);
908 page_cache_release(pages[i]);
913 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
918 * w_target_locked is only set to true in the page_mkwrite() case.
919 * The intent is to allow us to lock the target page from write_begin()
920 * to write_end(). The caller must hold a ref on w_target_page.
922 if (wc->w_target_locked) {
923 BUG_ON(!wc->w_target_page);
924 for (i = 0; i < wc->w_num_pages; i++) {
925 if (wc->w_target_page == wc->w_pages[i]) {
926 wc->w_pages[i] = NULL;
930 mark_page_accessed(wc->w_target_page);
931 page_cache_release(wc->w_target_page);
933 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
939 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
940 struct ocfs2_super *osb, loff_t pos,
941 unsigned len, struct buffer_head *di_bh)
944 struct ocfs2_write_ctxt *wc;
946 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
950 wc->w_cpos = pos >> osb->s_clustersize_bits;
951 wc->w_first_new_cpos = UINT_MAX;
952 cend = (pos + len - 1) >> osb->s_clustersize_bits;
953 wc->w_clen = cend - wc->w_cpos + 1;
957 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
958 wc->w_large_pages = 1;
960 wc->w_large_pages = 0;
962 ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
970 * If a page has any new buffers, zero them out here, and mark them uptodate
971 * and dirty so they'll be written out (in order to prevent uninitialised
972 * block data from leaking). And clear the new bit.
974 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
976 unsigned int block_start, block_end;
977 struct buffer_head *head, *bh;
979 BUG_ON(!PageLocked(page));
980 if (!page_has_buffers(page))
983 bh = head = page_buffers(page);
986 block_end = block_start + bh->b_size;
988 if (buffer_new(bh)) {
989 if (block_end > from && block_start < to) {
990 if (!PageUptodate(page)) {
993 start = max(from, block_start);
994 end = min(to, block_end);
996 zero_user_segment(page, start, end);
997 set_buffer_uptodate(bh);
1000 clear_buffer_new(bh);
1001 mark_buffer_dirty(bh);
1005 block_start = block_end;
1006 bh = bh->b_this_page;
1007 } while (bh != head);
1011 * Only called when we have a failure during allocating write to write
1012 * zero's to the newly allocated region.
1014 static void ocfs2_write_failure(struct inode *inode,
1015 struct ocfs2_write_ctxt *wc,
1016 loff_t user_pos, unsigned user_len)
1019 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
1020 to = user_pos + user_len;
1021 struct page *tmppage;
1023 ocfs2_zero_new_buffers(wc->w_target_page, from, to);
1025 for(i = 0; i < wc->w_num_pages; i++) {
1026 tmppage = wc->w_pages[i];
1028 if (page_has_buffers(tmppage)) {
1029 if (ocfs2_should_order_data(inode))
1030 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1032 block_commit_write(tmppage, from, to);
1037 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1038 struct ocfs2_write_ctxt *wc,
1039 struct page *page, u32 cpos,
1040 loff_t user_pos, unsigned user_len,
1044 unsigned int map_from = 0, map_to = 0;
1045 unsigned int cluster_start, cluster_end;
1046 unsigned int user_data_from = 0, user_data_to = 0;
1048 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1049 &cluster_start, &cluster_end);
1051 /* treat the write as new if the a hole/lseek spanned across
1052 * the page boundary.
1054 new = new | ((i_size_read(inode) <= page_offset(page)) &&
1055 (page_offset(page) <= user_pos));
1057 if (page == wc->w_target_page) {
1058 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1059 map_to = map_from + user_len;
1062 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1063 cluster_start, cluster_end,
1066 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1067 map_from, map_to, new);
1073 user_data_from = map_from;
1074 user_data_to = map_to;
1076 map_from = cluster_start;
1077 map_to = cluster_end;
1081 * If we haven't allocated the new page yet, we
1082 * shouldn't be writing it out without copying user
1083 * data. This is likely a math error from the caller.
1087 map_from = cluster_start;
1088 map_to = cluster_end;
1090 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1091 cluster_start, cluster_end, new);
1099 * Parts of newly allocated pages need to be zero'd.
1101 * Above, we have also rewritten 'to' and 'from' - as far as
1102 * the rest of the function is concerned, the entire cluster
1103 * range inside of a page needs to be written.
1105 * We can skip this if the page is up to date - it's already
1106 * been zero'd from being read in as a hole.
1108 if (new && !PageUptodate(page))
1109 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1110 cpos, user_data_from, user_data_to);
1112 flush_dcache_page(page);
1119 * This function will only grab one clusters worth of pages.
1121 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1122 struct ocfs2_write_ctxt *wc,
1123 u32 cpos, loff_t user_pos,
1124 unsigned user_len, int new,
1125 struct page *mmap_page)
1128 unsigned long start, target_index, end_index, index;
1129 struct inode *inode = mapping->host;
1132 target_index = user_pos >> PAGE_CACHE_SHIFT;
1135 * Figure out how many pages we'll be manipulating here. For
1136 * non allocating write, we just change the one
1137 * page. Otherwise, we'll need a whole clusters worth. If we're
1138 * writing past i_size, we only need enough pages to cover the
1139 * last page of the write.
1142 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1143 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1145 * We need the index *past* the last page we could possibly
1146 * touch. This is the page past the end of the write or
1147 * i_size, whichever is greater.
1149 last_byte = max(user_pos + user_len, i_size_read(inode));
1150 BUG_ON(last_byte < 1);
1151 end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1;
1152 if ((start + wc->w_num_pages) > end_index)
1153 wc->w_num_pages = end_index - start;
1155 wc->w_num_pages = 1;
1156 start = target_index;
1159 for(i = 0; i < wc->w_num_pages; i++) {
1162 if (index == target_index && mmap_page) {
1164 * ocfs2_pagemkwrite() is a little different
1165 * and wants us to directly use the page
1168 lock_page(mmap_page);
1170 /* Exit and let the caller retry */
1171 if (mmap_page->mapping != mapping) {
1172 WARN_ON(mmap_page->mapping);
1173 unlock_page(mmap_page);
1178 page_cache_get(mmap_page);
1179 wc->w_pages[i] = mmap_page;
1180 wc->w_target_locked = true;
1182 wc->w_pages[i] = find_or_create_page(mapping, index,
1184 if (!wc->w_pages[i]) {
1190 wait_for_stable_page(wc->w_pages[i]);
1192 if (index == target_index)
1193 wc->w_target_page = wc->w_pages[i];
1197 wc->w_target_locked = false;
1202 * Prepare a single cluster for write one cluster into the file.
1204 static int ocfs2_write_cluster(struct address_space *mapping,
1205 u32 phys, unsigned int unwritten,
1206 unsigned int should_zero,
1207 struct ocfs2_alloc_context *data_ac,
1208 struct ocfs2_alloc_context *meta_ac,
1209 struct ocfs2_write_ctxt *wc, u32 cpos,
1210 loff_t user_pos, unsigned user_len)
1213 u64 v_blkno, p_blkno;
1214 struct inode *inode = mapping->host;
1215 struct ocfs2_extent_tree et;
1217 new = phys == 0 ? 1 : 0;
1222 * This is safe to call with the page locks - it won't take
1223 * any additional semaphores or cluster locks.
1226 ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1227 &tmp_pos, 1, 0, wc->w_di_bh,
1228 wc->w_handle, data_ac,
1231 * This shouldn't happen because we must have already
1232 * calculated the correct meta data allocation required. The
1233 * internal tree allocation code should know how to increase
1234 * transaction credits itself.
1236 * If need be, we could handle -EAGAIN for a
1237 * RESTART_TRANS here.
1239 mlog_bug_on_msg(ret == -EAGAIN,
1240 "Inode %llu: EAGAIN return during allocation.\n",
1241 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1246 } else if (unwritten) {
1247 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1249 ret = ocfs2_mark_extent_written(inode, &et,
1250 wc->w_handle, cpos, 1, phys,
1251 meta_ac, &wc->w_dealloc);
1259 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1261 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1264 * The only reason this should fail is due to an inability to
1265 * find the extent added.
1267 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1270 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1271 "at logical block %llu",
1272 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1273 (unsigned long long)v_blkno);
1277 BUG_ON(p_blkno == 0);
1279 for(i = 0; i < wc->w_num_pages; i++) {
1282 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1283 wc->w_pages[i], cpos,
1294 * We only have cleanup to do in case of allocating write.
1297 ocfs2_write_failure(inode, wc, user_pos, user_len);
1304 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1305 struct ocfs2_alloc_context *data_ac,
1306 struct ocfs2_alloc_context *meta_ac,
1307 struct ocfs2_write_ctxt *wc,
1308 loff_t pos, unsigned len)
1312 unsigned int local_len = len;
1313 struct ocfs2_write_cluster_desc *desc;
1314 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1316 for (i = 0; i < wc->w_clen; i++) {
1317 desc = &wc->w_desc[i];
1320 * We have to make sure that the total write passed in
1321 * doesn't extend past a single cluster.
1324 cluster_off = pos & (osb->s_clustersize - 1);
1325 if ((cluster_off + local_len) > osb->s_clustersize)
1326 local_len = osb->s_clustersize - cluster_off;
1328 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1332 wc, desc->c_cpos, pos, local_len);
1348 * ocfs2_write_end() wants to know which parts of the target page it
1349 * should complete the write on. It's easiest to compute them ahead of
1350 * time when a more complete view of the write is available.
1352 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1353 struct ocfs2_write_ctxt *wc,
1354 loff_t pos, unsigned len, int alloc)
1356 struct ocfs2_write_cluster_desc *desc;
1358 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1359 wc->w_target_to = wc->w_target_from + len;
1365 * Allocating write - we may have different boundaries based
1366 * on page size and cluster size.
1368 * NOTE: We can no longer compute one value from the other as
1369 * the actual write length and user provided length may be
1373 if (wc->w_large_pages) {
1375 * We only care about the 1st and last cluster within
1376 * our range and whether they should be zero'd or not. Either
1377 * value may be extended out to the start/end of a
1378 * newly allocated cluster.
1380 desc = &wc->w_desc[0];
1381 if (desc->c_needs_zero)
1382 ocfs2_figure_cluster_boundaries(osb,
1387 desc = &wc->w_desc[wc->w_clen - 1];
1388 if (desc->c_needs_zero)
1389 ocfs2_figure_cluster_boundaries(osb,
1394 wc->w_target_from = 0;
1395 wc->w_target_to = PAGE_CACHE_SIZE;
1400 * Populate each single-cluster write descriptor in the write context
1401 * with information about the i/o to be done.
1403 * Returns the number of clusters that will have to be allocated, as
1404 * well as a worst case estimate of the number of extent records that
1405 * would have to be created during a write to an unwritten region.
1407 static int ocfs2_populate_write_desc(struct inode *inode,
1408 struct ocfs2_write_ctxt *wc,
1409 unsigned int *clusters_to_alloc,
1410 unsigned int *extents_to_split)
1413 struct ocfs2_write_cluster_desc *desc;
1414 unsigned int num_clusters = 0;
1415 unsigned int ext_flags = 0;
1419 *clusters_to_alloc = 0;
1420 *extents_to_split = 0;
1422 for (i = 0; i < wc->w_clen; i++) {
1423 desc = &wc->w_desc[i];
1424 desc->c_cpos = wc->w_cpos + i;
1426 if (num_clusters == 0) {
1428 * Need to look up the next extent record.
1430 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1431 &num_clusters, &ext_flags);
1437 /* We should already CoW the refcountd extent. */
1438 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1441 * Assume worst case - that we're writing in
1442 * the middle of the extent.
1444 * We can assume that the write proceeds from
1445 * left to right, in which case the extent
1446 * insert code is smart enough to coalesce the
1447 * next splits into the previous records created.
1449 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1450 *extents_to_split = *extents_to_split + 2;
1453 * Only increment phys if it doesn't describe
1460 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1461 * file that got extended. w_first_new_cpos tells us
1462 * where the newly allocated clusters are so we can
1465 if (desc->c_cpos >= wc->w_first_new_cpos) {
1467 desc->c_needs_zero = 1;
1470 desc->c_phys = phys;
1473 desc->c_needs_zero = 1;
1474 *clusters_to_alloc = *clusters_to_alloc + 1;
1477 if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1478 desc->c_unwritten = 1;
1479 desc->c_needs_zero = 1;
1490 static int ocfs2_write_begin_inline(struct address_space *mapping,
1491 struct inode *inode,
1492 struct ocfs2_write_ctxt *wc)
1495 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1498 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1500 page = find_or_create_page(mapping, 0, GFP_NOFS);
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);
1520 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1521 OCFS2_JOURNAL_ACCESS_WRITE);
1523 ocfs2_commit_trans(osb, handle);
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);
1535 ocfs2_commit_trans(osb, handle);
1541 wc->w_handle = handle;
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))
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);
1563 struct ocfs2_dinode *di = NULL;
1565 trace_ocfs2_try_to_write_inline_data((unsigned long long)oi->ip_blkno,
1566 len, (unsigned long long)pos,
1567 oi->ip_dyn_features);
1570 * Handle inodes which already have inline data 1st.
1572 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1573 if (mmap_page == NULL &&
1574 ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1575 goto do_inline_write;
1578 * The write won't fit - we have to give this inode an
1579 * inline extent list now.
1581 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1588 * Check whether the inode can accept inline data.
1590 if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1594 * Check whether the write can fit.
1596 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1598 end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1602 ret = ocfs2_write_begin_inline(mapping, inode, wc);
1609 * This signals to the caller that the data can be written
1614 return written ? written : ret;
1618 * This function only does anything for file systems which can't
1619 * handle sparse files.
1621 * What we want to do here is fill in any hole between the current end
1622 * of allocation and the end of our write. That way the rest of the
1623 * write path can treat it as an non-allocating write, which has no
1624 * special case code for sparse/nonsparse files.
1626 static int ocfs2_expand_nonsparse_inode(struct inode *inode,
1627 struct buffer_head *di_bh,
1628 loff_t pos, unsigned len,
1629 struct ocfs2_write_ctxt *wc)
1632 loff_t newsize = pos + len;
1634 BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1636 if (newsize <= i_size_read(inode))
1639 ret = ocfs2_extend_no_holes(inode, di_bh, newsize, pos);
1643 wc->w_first_new_cpos =
1644 ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1649 static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
1654 BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)));
1655 if (pos > i_size_read(inode))
1656 ret = ocfs2_zero_extend(inode, di_bh, pos);
1662 * Try to flush truncate logs if we can free enough clusters from it.
1663 * As for return value, "< 0" means error, "0" no space and "1" means
1664 * we have freed enough spaces and let the caller try to allocate again.
1666 static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
1667 unsigned int needed)
1671 unsigned int truncated_clusters;
1673 mutex_lock(&osb->osb_tl_inode->i_mutex);
1674 truncated_clusters = osb->truncated_clusters;
1675 mutex_unlock(&osb->osb_tl_inode->i_mutex);
1678 * Check whether we can succeed in allocating if we free
1681 if (truncated_clusters < needed)
1684 ret = ocfs2_flush_truncate_log(osb);
1690 if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
1691 jbd2_log_wait_commit(osb->journal->j_journal, target);
1698 int ocfs2_write_begin_nolock(struct file *filp,
1699 struct address_space *mapping,
1700 loff_t pos, unsigned len, unsigned flags,
1701 struct page **pagep, void **fsdata,
1702 struct buffer_head *di_bh, struct page *mmap_page)
1704 int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1705 unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
1706 struct ocfs2_write_ctxt *wc;
1707 struct inode *inode = mapping->host;
1708 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1709 struct ocfs2_dinode *di;
1710 struct ocfs2_alloc_context *data_ac = NULL;
1711 struct ocfs2_alloc_context *meta_ac = NULL;
1713 struct ocfs2_extent_tree et;
1714 int try_free = 1, ret1;
1717 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1723 if (ocfs2_supports_inline_data(osb)) {
1724 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1736 if (ocfs2_sparse_alloc(osb))
1737 ret = ocfs2_zero_tail(inode, di_bh, pos);
1739 ret = ocfs2_expand_nonsparse_inode(inode, di_bh, pos, len,
1746 ret = ocfs2_check_range_for_refcount(inode, pos, len);
1750 } else if (ret == 1) {
1751 clusters_need = wc->w_clen;
1752 ret = ocfs2_refcount_cow(inode, di_bh,
1753 wc->w_cpos, wc->w_clen, UINT_MAX);
1760 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1766 clusters_need += clusters_to_alloc;
1768 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1770 trace_ocfs2_write_begin_nolock(
1771 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1772 (long long)i_size_read(inode),
1773 le32_to_cpu(di->i_clusters),
1774 pos, len, flags, mmap_page,
1775 clusters_to_alloc, extents_to_split);
1778 * We set w_target_from, w_target_to here so that
1779 * ocfs2_write_end() knows which range in the target page to
1780 * write out. An allocation requires that we write the entire
1783 if (clusters_to_alloc || extents_to_split) {
1785 * XXX: We are stretching the limits of
1786 * ocfs2_lock_allocators(). It greatly over-estimates
1787 * the work to be done.
1789 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1791 ret = ocfs2_lock_allocators(inode, &et,
1792 clusters_to_alloc, extents_to_split,
1793 &data_ac, &meta_ac);
1800 data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
1802 credits = ocfs2_calc_extend_credits(inode->i_sb,
1809 * We have to zero sparse allocated clusters, unwritten extent clusters,
1810 * and non-sparse clusters we just extended. For non-sparse writes,
1811 * we know zeros will only be needed in the first and/or last cluster.
1813 if (clusters_to_alloc || extents_to_split ||
1814 (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1815 wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1816 cluster_of_pages = 1;
1818 cluster_of_pages = 0;
1820 ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1822 handle = ocfs2_start_trans(osb, credits);
1823 if (IS_ERR(handle)) {
1824 ret = PTR_ERR(handle);
1829 wc->w_handle = handle;
1831 if (clusters_to_alloc) {
1832 ret = dquot_alloc_space_nodirty(inode,
1833 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1838 * We don't want this to fail in ocfs2_write_end(), so do it
1841 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1842 OCFS2_JOURNAL_ACCESS_WRITE);
1849 * Fill our page array first. That way we've grabbed enough so
1850 * that we can zero and flush if we error after adding the
1853 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, len,
1854 cluster_of_pages, mmap_page);
1855 if (ret && ret != -EAGAIN) {
1861 * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock
1862 * the target page. In this case, we exit with no error and no target
1863 * page. This will trigger the caller, page_mkwrite(), to re-try
1866 if (ret == -EAGAIN) {
1867 BUG_ON(wc->w_target_page);
1872 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1880 ocfs2_free_alloc_context(data_ac);
1882 ocfs2_free_alloc_context(meta_ac);
1885 *pagep = wc->w_target_page;
1889 if (clusters_to_alloc)
1890 dquot_free_space(inode,
1891 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1893 ocfs2_commit_trans(osb, handle);
1896 ocfs2_free_write_ctxt(wc);
1899 ocfs2_free_alloc_context(data_ac);
1901 ocfs2_free_alloc_context(meta_ac);
1903 if (ret == -ENOSPC && try_free) {
1905 * Try to free some truncate log so that we can have enough
1906 * clusters to allocate.
1910 ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
1921 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1922 loff_t pos, unsigned len, unsigned flags,
1923 struct page **pagep, void **fsdata)
1926 struct buffer_head *di_bh = NULL;
1927 struct inode *inode = mapping->host;
1929 ret = ocfs2_inode_lock(inode, &di_bh, 1);
1936 * Take alloc sem here to prevent concurrent lookups. That way
1937 * the mapping, zeroing and tree manipulation within
1938 * ocfs2_write() will be safe against ->readpage(). This
1939 * should also serve to lock out allocation from a shared
1942 down_write(&OCFS2_I(inode)->ip_alloc_sem);
1944 ret = ocfs2_write_begin_nolock(file, mapping, pos, len, flags, pagep,
1945 fsdata, di_bh, NULL);
1956 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1959 ocfs2_inode_unlock(inode, 1);
1964 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1965 unsigned len, unsigned *copied,
1966 struct ocfs2_dinode *di,
1967 struct ocfs2_write_ctxt *wc)
1971 if (unlikely(*copied < len)) {
1972 if (!PageUptodate(wc->w_target_page)) {
1978 kaddr = kmap_atomic(wc->w_target_page);
1979 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1980 kunmap_atomic(kaddr);
1982 trace_ocfs2_write_end_inline(
1983 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1984 (unsigned long long)pos, *copied,
1985 le16_to_cpu(di->id2.i_data.id_count),
1986 le16_to_cpu(di->i_dyn_features));
1989 int ocfs2_write_end_nolock(struct address_space *mapping,
1990 loff_t pos, unsigned len, unsigned copied,
1991 struct page *page, void *fsdata)
1994 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1995 struct inode *inode = mapping->host;
1996 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1997 struct ocfs2_write_ctxt *wc = fsdata;
1998 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1999 handle_t *handle = wc->w_handle;
2000 struct page *tmppage;
2002 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
2003 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
2004 goto out_write_size;
2007 if (unlikely(copied < len)) {
2008 if (!PageUptodate(wc->w_target_page))
2011 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
2014 flush_dcache_page(wc->w_target_page);
2016 for(i = 0; i < wc->w_num_pages; i++) {
2017 tmppage = wc->w_pages[i];
2019 if (tmppage == wc->w_target_page) {
2020 from = wc->w_target_from;
2021 to = wc->w_target_to;
2023 BUG_ON(from > PAGE_CACHE_SIZE ||
2024 to > PAGE_CACHE_SIZE ||
2028 * Pages adjacent to the target (if any) imply
2029 * a hole-filling write in which case we want
2030 * to flush their entire range.
2033 to = PAGE_CACHE_SIZE;
2036 if (page_has_buffers(tmppage)) {
2037 if (ocfs2_should_order_data(inode))
2038 ocfs2_jbd2_file_inode(wc->w_handle, inode);
2039 block_commit_write(tmppage, from, to);
2045 if (pos > i_size_read(inode)) {
2046 i_size_write(inode, pos);
2047 mark_inode_dirty(inode);
2049 inode->i_blocks = ocfs2_inode_sector_count(inode);
2050 di->i_size = cpu_to_le64((u64)i_size_read(inode));
2051 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2052 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
2053 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
2054 ocfs2_journal_dirty(handle, wc->w_di_bh);
2056 ocfs2_commit_trans(osb, handle);
2058 ocfs2_run_deallocs(osb, &wc->w_dealloc);
2060 ocfs2_free_write_ctxt(wc);
2065 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
2066 loff_t pos, unsigned len, unsigned copied,
2067 struct page *page, void *fsdata)
2070 struct inode *inode = mapping->host;
2072 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
2074 up_write(&OCFS2_I(inode)->ip_alloc_sem);
2075 ocfs2_inode_unlock(inode, 1);
2080 const struct address_space_operations ocfs2_aops = {
2081 .readpage = ocfs2_readpage,
2082 .readpages = ocfs2_readpages,
2083 .writepage = ocfs2_writepage,
2084 .write_begin = ocfs2_write_begin,
2085 .write_end = ocfs2_write_end,
2087 .direct_IO = ocfs2_direct_IO,
2088 .invalidatepage = ocfs2_invalidatepage,
2089 .releasepage = ocfs2_releasepage,
2090 .migratepage = buffer_migrate_page,
2091 .is_partially_uptodate = block_is_partially_uptodate,
2092 .error_remove_page = generic_error_remove_page,