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>
30 #define MLOG_MASK_PREFIX ML_FILE_IO
31 #include <cluster/masklog.h>
38 #include "extent_map.h"
46 #include "buffer_head_io.h"
48 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
49 struct buffer_head *bh_result, int create)
53 struct ocfs2_dinode *fe = NULL;
54 struct buffer_head *bh = NULL;
55 struct buffer_head *buffer_cache_bh = NULL;
56 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
59 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
60 (unsigned long long)iblock, bh_result, create);
62 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
64 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
65 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
66 (unsigned long long)iblock);
70 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
71 OCFS2_I(inode)->ip_blkno,
72 &bh, OCFS2_BH_CACHED, inode);
77 fe = (struct ocfs2_dinode *) bh->b_data;
79 if (!OCFS2_IS_VALID_DINODE(fe)) {
80 mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
81 (unsigned long long)le64_to_cpu(fe->i_blkno), 7,
86 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
87 le32_to_cpu(fe->i_clusters))) {
88 mlog(ML_ERROR, "block offset is outside the allocated size: "
89 "%llu\n", (unsigned long long)iblock);
93 /* We don't use the page cache to create symlink data, so if
94 * need be, copy it over from the buffer cache. */
95 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
96 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
98 buffer_cache_bh = sb_getblk(osb->sb, blkno);
99 if (!buffer_cache_bh) {
100 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
104 /* we haven't locked out transactions, so a commit
105 * could've happened. Since we've got a reference on
106 * the bh, even if it commits while we're doing the
107 * copy, the data is still good. */
108 if (buffer_jbd(buffer_cache_bh)
109 && ocfs2_inode_is_new(inode)) {
110 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
112 mlog(ML_ERROR, "couldn't kmap!\n");
115 memcpy(kaddr + (bh_result->b_size * iblock),
116 buffer_cache_bh->b_data,
118 kunmap_atomic(kaddr, KM_USER0);
119 set_buffer_uptodate(bh_result);
121 brelse(buffer_cache_bh);
124 map_bh(bh_result, inode->i_sb,
125 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
137 static int ocfs2_get_block(struct inode *inode, sector_t iblock,
138 struct buffer_head *bh_result, int create)
141 unsigned int ext_flags;
142 u64 p_blkno, past_eof;
143 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
145 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
146 (unsigned long long)iblock, bh_result, create);
148 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
149 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
150 inode, inode->i_ino);
152 if (S_ISLNK(inode->i_mode)) {
153 /* this always does I/O for some reason. */
154 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
158 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL,
161 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
162 "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
163 (unsigned long long)p_blkno);
168 * ocfs2 never allocates in this function - the only time we
169 * need to use BH_New is when we're extending i_size on a file
170 * system which doesn't support holes, in which case BH_New
171 * allows block_prepare_write() to zero.
173 mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
174 "ino %lu, iblock %llu\n", inode->i_ino,
175 (unsigned long long)iblock);
177 /* Treat the unwritten extent as a hole for zeroing purposes. */
178 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
179 map_bh(bh_result, inode->i_sb, p_blkno);
181 if (!ocfs2_sparse_alloc(osb)) {
185 "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
186 (unsigned long long)iblock,
187 (unsigned long long)p_blkno,
188 (unsigned long long)OCFS2_I(inode)->ip_blkno);
189 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
193 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
194 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
195 (unsigned long long)past_eof);
197 if (create && (iblock >= past_eof))
198 set_buffer_new(bh_result);
209 static int ocfs2_readpage(struct file *file, struct page *page)
211 struct inode *inode = page->mapping->host;
212 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
215 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
217 ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page);
219 if (ret == AOP_TRUNCATED_PAGE)
225 if (down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem) == 0) {
226 ret = AOP_TRUNCATED_PAGE;
227 goto out_meta_unlock;
231 * i_size might have just been updated as we grabed the meta lock. We
232 * might now be discovering a truncate that hit on another node.
233 * block_read_full_page->get_block freaks out if it is asked to read
234 * beyond the end of a file, so we check here. Callers
235 * (generic_file_read, fault->nopage) are clever enough to check i_size
236 * and notice that the page they just read isn't needed.
238 * XXX sys_readahead() seems to get that wrong?
240 if (start >= i_size_read(inode)) {
241 zero_user_page(page, 0, PAGE_SIZE, KM_USER0);
242 SetPageUptodate(page);
247 ret = ocfs2_data_lock_with_page(inode, 0, page);
249 if (ret == AOP_TRUNCATED_PAGE)
255 ret = block_read_full_page(page, ocfs2_get_block);
258 ocfs2_data_unlock(inode, 0);
260 up_read(&OCFS2_I(inode)->ip_alloc_sem);
262 ocfs2_meta_unlock(inode, 0);
270 /* Note: Because we don't support holes, our allocation has
271 * already happened (allocation writes zeros to the file data)
272 * so we don't have to worry about ordered writes in
275 * ->writepage is called during the process of invalidating the page cache
276 * during blocked lock processing. It can't block on any cluster locks
277 * to during block mapping. It's relying on the fact that the block
278 * mapping can't have disappeared under the dirty pages that it is
279 * being asked to write back.
281 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
285 mlog_entry("(0x%p)\n", page);
287 ret = block_write_full_page(page, ocfs2_get_block, wbc);
295 * This is called from ocfs2_write_zero_page() which has handled it's
296 * own cluster locking and has ensured allocation exists for those
297 * blocks to be written.
299 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
300 unsigned from, unsigned to)
304 down_read(&OCFS2_I(inode)->ip_alloc_sem);
306 ret = block_prepare_write(page, from, to, ocfs2_get_block);
308 up_read(&OCFS2_I(inode)->ip_alloc_sem);
313 /* Taken from ext3. We don't necessarily need the full blown
314 * functionality yet, but IMHO it's better to cut and paste the whole
315 * thing so we can avoid introducing our own bugs (and easily pick up
316 * their fixes when they happen) --Mark */
317 int walk_page_buffers( handle_t *handle,
318 struct buffer_head *head,
322 int (*fn)( handle_t *handle,
323 struct buffer_head *bh))
325 struct buffer_head *bh;
326 unsigned block_start, block_end;
327 unsigned blocksize = head->b_size;
329 struct buffer_head *next;
331 for ( bh = head, block_start = 0;
332 ret == 0 && (bh != head || !block_start);
333 block_start = block_end, bh = next)
335 next = bh->b_this_page;
336 block_end = block_start + blocksize;
337 if (block_end <= from || block_start >= to) {
338 if (partial && !buffer_uptodate(bh))
342 err = (*fn)(handle, bh);
349 handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
354 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
355 handle_t *handle = NULL;
358 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
365 if (ocfs2_should_order_data(inode)) {
366 ret = walk_page_buffers(handle,
369 ocfs2_journal_dirty_data);
376 ocfs2_commit_trans(osb, handle);
377 handle = ERR_PTR(ret);
382 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
387 struct inode *inode = mapping->host;
389 mlog_entry("(block = %llu)\n", (unsigned long long)block);
391 /* We don't need to lock journal system files, since they aren't
392 * accessed concurrently from multiple nodes.
394 if (!INODE_JOURNAL(inode)) {
395 err = ocfs2_meta_lock(inode, NULL, 0);
401 down_read(&OCFS2_I(inode)->ip_alloc_sem);
404 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL);
406 if (!INODE_JOURNAL(inode)) {
407 up_read(&OCFS2_I(inode)->ip_alloc_sem);
408 ocfs2_meta_unlock(inode, 0);
412 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
413 (unsigned long long)block);
420 status = err ? 0 : p_blkno;
422 mlog_exit((int)status);
428 * TODO: Make this into a generic get_blocks function.
430 * From do_direct_io in direct-io.c:
431 * "So what we do is to permit the ->get_blocks function to populate
432 * bh.b_size with the size of IO which is permitted at this offset and
435 * This function is called directly from get_more_blocks in direct-io.c.
437 * called like this: dio->get_blocks(dio->inode, fs_startblk,
438 * fs_count, map_bh, dio->rw == WRITE);
440 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
441 struct buffer_head *bh_result, int create)
444 u64 p_blkno, inode_blocks, contig_blocks;
445 unsigned int ext_flags;
446 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
447 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
449 /* This function won't even be called if the request isn't all
450 * nicely aligned and of the right size, so there's no need
451 * for us to check any of that. */
453 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
456 * Any write past EOF is not allowed because we'd be extending.
458 if (create && (iblock + max_blocks) > inode_blocks) {
463 /* This figures out the size of the next contiguous block, and
464 * our logical offset */
465 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
466 &contig_blocks, &ext_flags);
468 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
469 (unsigned long long)iblock);
474 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) {
475 ocfs2_error(inode->i_sb,
476 "Inode %llu has a hole at block %llu\n",
477 (unsigned long long)OCFS2_I(inode)->ip_blkno,
478 (unsigned long long)iblock);
484 * get_more_blocks() expects us to describe a hole by clearing
485 * the mapped bit on bh_result().
487 * Consider an unwritten extent as a hole.
489 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
490 map_bh(bh_result, inode->i_sb, p_blkno);
493 * ocfs2_prepare_inode_for_write() should have caught
494 * the case where we'd be filling a hole and triggered
495 * a buffered write instead.
503 clear_buffer_mapped(bh_result);
506 /* make sure we don't map more than max_blocks blocks here as
507 that's all the kernel will handle at this point. */
508 if (max_blocks < contig_blocks)
509 contig_blocks = max_blocks;
510 bh_result->b_size = contig_blocks << blocksize_bits;
516 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
517 * particularly interested in the aio/dio case. Like the core uses
518 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
519 * truncation on another.
521 static void ocfs2_dio_end_io(struct kiocb *iocb,
526 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
529 /* this io's submitter should not have unlocked this before we could */
530 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
532 ocfs2_iocb_clear_rw_locked(iocb);
534 level = ocfs2_iocb_rw_locked_level(iocb);
536 up_read(&inode->i_alloc_sem);
537 ocfs2_rw_unlock(inode, level);
541 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
542 * from ext3. PageChecked() bits have been removed as OCFS2 does not
543 * do journalled data.
545 static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
547 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
549 journal_invalidatepage(journal, page, offset);
552 static int ocfs2_releasepage(struct page *page, gfp_t wait)
554 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
556 if (!page_has_buffers(page))
558 return journal_try_to_free_buffers(journal, page, wait);
561 static ssize_t ocfs2_direct_IO(int rw,
563 const struct iovec *iov,
565 unsigned long nr_segs)
567 struct file *file = iocb->ki_filp;
568 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
573 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
575 * We get PR data locks even for O_DIRECT. This
576 * allows concurrent O_DIRECT I/O but doesn't let
577 * O_DIRECT with extending and buffered zeroing writes
578 * race. If they did race then the buffered zeroing
579 * could be written back after the O_DIRECT I/O. It's
580 * one thing to tell people not to mix buffered and
581 * O_DIRECT writes, but expecting them to understand
582 * that file extension is also an implicit buffered
583 * write is too much. By getting the PR we force
584 * writeback of the buffered zeroing before
587 ret = ocfs2_data_lock(inode, 0);
592 ocfs2_data_unlock(inode, 0);
595 ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
596 inode->i_sb->s_bdev, iov, offset,
598 ocfs2_direct_IO_get_blocks,
605 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
610 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
612 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
615 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
617 cluster_start = cpos % cpp;
618 cluster_start = cluster_start << osb->s_clustersize_bits;
620 cluster_end = cluster_start + osb->s_clustersize;
623 BUG_ON(cluster_start > PAGE_SIZE);
624 BUG_ON(cluster_end > PAGE_SIZE);
627 *start = cluster_start;
633 * 'from' and 'to' are the region in the page to avoid zeroing.
635 * If pagesize > clustersize, this function will avoid zeroing outside
636 * of the cluster boundary.
638 * from == to == 0 is code for "zero the entire cluster region"
640 static void ocfs2_clear_page_regions(struct page *page,
641 struct ocfs2_super *osb, u32 cpos,
642 unsigned from, unsigned to)
645 unsigned int cluster_start, cluster_end;
647 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
649 kaddr = kmap_atomic(page, KM_USER0);
652 if (from > cluster_start)
653 memset(kaddr + cluster_start, 0, from - cluster_start);
654 if (to < cluster_end)
655 memset(kaddr + to, 0, cluster_end - to);
657 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
660 kunmap_atomic(kaddr, KM_USER0);
664 * Some of this taken from block_prepare_write(). We already have our
665 * mapping by now though, and the entire write will be allocating or
666 * it won't, so not much need to use BH_New.
668 * This will also skip zeroing, which is handled externally.
670 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
671 struct inode *inode, unsigned int from,
672 unsigned int to, int new)
675 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
676 unsigned int block_end, block_start;
677 unsigned int bsize = 1 << inode->i_blkbits;
679 if (!page_has_buffers(page))
680 create_empty_buffers(page, bsize, 0);
682 head = page_buffers(page);
683 for (bh = head, block_start = 0; bh != head || !block_start;
684 bh = bh->b_this_page, block_start += bsize) {
685 block_end = block_start + bsize;
687 clear_buffer_new(bh);
690 * Ignore blocks outside of our i/o range -
691 * they may belong to unallocated clusters.
693 if (block_start >= to || block_end <= from) {
694 if (PageUptodate(page))
695 set_buffer_uptodate(bh);
700 * For an allocating write with cluster size >= page
701 * size, we always write the entire page.
706 if (!buffer_mapped(bh)) {
707 map_bh(bh, inode->i_sb, *p_blkno);
708 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
711 if (PageUptodate(page)) {
712 if (!buffer_uptodate(bh))
713 set_buffer_uptodate(bh);
714 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
716 (block_start < from || block_end > to)) {
717 ll_rw_block(READ, 1, &bh);
721 *p_blkno = *p_blkno + 1;
725 * If we issued read requests - let them complete.
727 while(wait_bh > wait) {
728 wait_on_buffer(*--wait_bh);
729 if (!buffer_uptodate(*wait_bh))
733 if (ret == 0 || !new)
737 * If we get -EIO above, zero out any newly allocated blocks
738 * to avoid exposing stale data.
745 block_end = block_start + bsize;
746 if (block_end <= from)
748 if (block_start >= to)
751 kaddr = kmap_atomic(page, KM_USER0);
752 memset(kaddr+block_start, 0, bh->b_size);
753 flush_dcache_page(page);
754 kunmap_atomic(kaddr, KM_USER0);
755 set_buffer_uptodate(bh);
756 mark_buffer_dirty(bh);
759 block_start = block_end;
760 bh = bh->b_this_page;
761 } while (bh != head);
766 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
767 #define OCFS2_MAX_CTXT_PAGES 1
769 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
772 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
775 * Describe the state of a single cluster to be written to.
777 struct ocfs2_write_cluster_desc {
781 * Give this a unique field because c_phys eventually gets
785 unsigned c_unwritten;
788 static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d)
790 return d->c_new || d->c_unwritten;
793 struct ocfs2_write_ctxt {
794 /* Logical cluster position / len of write */
798 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
801 * This is true if page_size > cluster_size.
803 * It triggers a set of special cases during write which might
804 * have to deal with allocating writes to partial pages.
806 unsigned int w_large_pages;
809 * Pages involved in this write.
811 * w_target_page is the page being written to by the user.
813 * w_pages is an array of pages which always contains
814 * w_target_page, and in the case of an allocating write with
815 * page_size < cluster size, it will contain zero'd and mapped
816 * pages adjacent to w_target_page which need to be written
817 * out in so that future reads from that region will get
820 struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
821 unsigned int w_num_pages;
822 struct page *w_target_page;
825 * ocfs2_write_end() uses this to know what the real range to
826 * write in the target should be.
828 unsigned int w_target_from;
829 unsigned int w_target_to;
832 * We could use journal_current_handle() but this is cleaner,
837 struct buffer_head *w_di_bh;
839 struct ocfs2_cached_dealloc_ctxt w_dealloc;
842 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
846 for(i = 0; i < wc->w_num_pages; i++) {
847 if (wc->w_pages[i] == NULL)
850 unlock_page(wc->w_pages[i]);
851 mark_page_accessed(wc->w_pages[i]);
852 page_cache_release(wc->w_pages[i]);
859 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
860 struct ocfs2_super *osb, loff_t pos,
861 unsigned len, struct buffer_head *di_bh)
863 struct ocfs2_write_ctxt *wc;
865 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
869 wc->w_cpos = pos >> osb->s_clustersize_bits;
870 wc->w_clen = ocfs2_clusters_for_bytes(osb->sb, len);
874 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
875 wc->w_large_pages = 1;
877 wc->w_large_pages = 0;
879 ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
887 * If a page has any new buffers, zero them out here, and mark them uptodate
888 * and dirty so they'll be written out (in order to prevent uninitialised
889 * block data from leaking). And clear the new bit.
891 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
893 unsigned int block_start, block_end;
894 struct buffer_head *head, *bh;
896 BUG_ON(!PageLocked(page));
897 if (!page_has_buffers(page))
900 bh = head = page_buffers(page);
903 block_end = block_start + bh->b_size;
905 if (buffer_new(bh)) {
906 if (block_end > from && block_start < to) {
907 if (!PageUptodate(page)) {
911 start = max(from, block_start);
912 end = min(to, block_end);
914 kaddr = kmap_atomic(page, KM_USER0);
915 memset(kaddr+start, 0, end - start);
916 flush_dcache_page(page);
917 kunmap_atomic(kaddr, KM_USER0);
918 set_buffer_uptodate(bh);
921 clear_buffer_new(bh);
922 mark_buffer_dirty(bh);
926 block_start = block_end;
927 bh = bh->b_this_page;
928 } while (bh != head);
932 * Only called when we have a failure during allocating write to write
933 * zero's to the newly allocated region.
935 static void ocfs2_write_failure(struct inode *inode,
936 struct ocfs2_write_ctxt *wc,
937 loff_t user_pos, unsigned user_len)
941 struct page *tmppage;
943 ocfs2_zero_new_buffers(wc->w_target_page, user_pos, user_len);
945 if (wc->w_large_pages) {
946 from = wc->w_target_from;
947 to = wc->w_target_to;
950 to = PAGE_CACHE_SIZE;
953 for(i = 0; i < wc->w_num_pages; i++) {
954 tmppage = wc->w_pages[i];
956 if (ocfs2_should_order_data(inode))
957 walk_page_buffers(wc->w_handle, page_buffers(tmppage),
959 ocfs2_journal_dirty_data);
961 block_commit_write(tmppage, from, to);
965 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
966 struct ocfs2_write_ctxt *wc,
967 struct page *page, u32 cpos,
968 loff_t user_pos, unsigned user_len,
972 unsigned int map_from = 0, map_to = 0;
973 unsigned int cluster_start, cluster_end;
974 unsigned int user_data_from = 0, user_data_to = 0;
976 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
977 &cluster_start, &cluster_end);
979 if (page == wc->w_target_page) {
980 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
981 map_to = map_from + user_len;
984 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
985 cluster_start, cluster_end,
988 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
989 map_from, map_to, new);
995 user_data_from = map_from;
996 user_data_to = map_to;
998 map_from = cluster_start;
999 map_to = cluster_end;
1002 wc->w_target_from = map_from;
1003 wc->w_target_to = map_to;
1006 * If we haven't allocated the new page yet, we
1007 * shouldn't be writing it out without copying user
1008 * data. This is likely a math error from the caller.
1012 map_from = cluster_start;
1013 map_to = cluster_end;
1015 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1016 cluster_start, cluster_end, new);
1024 * Parts of newly allocated pages need to be zero'd.
1026 * Above, we have also rewritten 'to' and 'from' - as far as
1027 * the rest of the function is concerned, the entire cluster
1028 * range inside of a page needs to be written.
1030 * We can skip this if the page is up to date - it's already
1031 * been zero'd from being read in as a hole.
1033 if (new && !PageUptodate(page))
1034 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1035 cpos, user_data_from, user_data_to);
1037 flush_dcache_page(page);
1044 * This function will only grab one clusters worth of pages.
1046 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1047 struct ocfs2_write_ctxt *wc,
1048 u32 cpos, loff_t user_pos, int new,
1049 struct page *mmap_page)
1052 unsigned long start, target_index, index;
1053 struct inode *inode = mapping->host;
1055 target_index = user_pos >> PAGE_CACHE_SHIFT;
1058 * Figure out how many pages we'll be manipulating here. For
1059 * non allocating write, we just change the one
1060 * page. Otherwise, we'll need a whole clusters worth.
1063 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1064 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1066 wc->w_num_pages = 1;
1067 start = target_index;
1070 for(i = 0; i < wc->w_num_pages; i++) {
1073 if (index == target_index && mmap_page) {
1075 * ocfs2_pagemkwrite() is a little different
1076 * and wants us to directly use the page
1079 lock_page(mmap_page);
1081 if (mmap_page->mapping != mapping) {
1082 unlock_page(mmap_page);
1084 * Sanity check - the locking in
1085 * ocfs2_pagemkwrite() should ensure
1086 * that this code doesn't trigger.
1093 page_cache_get(mmap_page);
1094 wc->w_pages[i] = mmap_page;
1096 wc->w_pages[i] = find_or_create_page(mapping, index,
1098 if (!wc->w_pages[i]) {
1105 if (index == target_index)
1106 wc->w_target_page = wc->w_pages[i];
1113 * Prepare a single cluster for write one cluster into the file.
1115 static int ocfs2_write_cluster(struct address_space *mapping,
1116 u32 phys, unsigned int unwritten,
1117 struct ocfs2_alloc_context *data_ac,
1118 struct ocfs2_alloc_context *meta_ac,
1119 struct ocfs2_write_ctxt *wc, u32 cpos,
1120 loff_t user_pos, unsigned user_len)
1122 int ret, i, new, should_zero = 0;
1123 u64 v_blkno, p_blkno;
1124 struct inode *inode = mapping->host;
1126 new = phys == 0 ? 1 : 0;
1127 if (new || unwritten)
1134 * This is safe to call with the page locks - it won't take
1135 * any additional semaphores or cluster locks.
1138 ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
1139 &tmp_pos, 1, 0, wc->w_di_bh,
1140 wc->w_handle, data_ac,
1143 * This shouldn't happen because we must have already
1144 * calculated the correct meta data allocation required. The
1145 * internal tree allocation code should know how to increase
1146 * transaction credits itself.
1148 * If need be, we could handle -EAGAIN for a
1149 * RESTART_TRANS here.
1151 mlog_bug_on_msg(ret == -EAGAIN,
1152 "Inode %llu: EAGAIN return during allocation.\n",
1153 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1158 } else if (unwritten) {
1159 ret = ocfs2_mark_extent_written(inode, wc->w_di_bh,
1160 wc->w_handle, cpos, 1, phys,
1161 meta_ac, &wc->w_dealloc);
1169 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1171 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1174 * The only reason this should fail is due to an inability to
1175 * find the extent added.
1177 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1180 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1181 "at logical block %llu",
1182 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1183 (unsigned long long)v_blkno);
1187 BUG_ON(p_blkno == 0);
1189 for(i = 0; i < wc->w_num_pages; i++) {
1192 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1193 wc->w_pages[i], cpos,
1204 * We only have cleanup to do in case of allocating write.
1207 ocfs2_write_failure(inode, wc, user_pos, user_len);
1214 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1215 struct ocfs2_alloc_context *data_ac,
1216 struct ocfs2_alloc_context *meta_ac,
1217 struct ocfs2_write_ctxt *wc,
1218 loff_t pos, unsigned len)
1221 struct ocfs2_write_cluster_desc *desc;
1223 for (i = 0; i < wc->w_clen; i++) {
1224 desc = &wc->w_desc[i];
1226 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1227 desc->c_unwritten, data_ac, meta_ac,
1228 wc, desc->c_cpos, pos, len);
1241 * ocfs2_write_end() wants to know which parts of the target page it
1242 * should complete the write on. It's easiest to compute them ahead of
1243 * time when a more complete view of the write is available.
1245 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1246 struct ocfs2_write_ctxt *wc,
1247 loff_t pos, unsigned len, int alloc)
1249 struct ocfs2_write_cluster_desc *desc;
1251 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1252 wc->w_target_to = wc->w_target_from + len;
1258 * Allocating write - we may have different boundaries based
1259 * on page size and cluster size.
1261 * NOTE: We can no longer compute one value from the other as
1262 * the actual write length and user provided length may be
1266 if (wc->w_large_pages) {
1268 * We only care about the 1st and last cluster within
1269 * our range and whether they should be zero'd or not. Either
1270 * value may be extended out to the start/end of a
1271 * newly allocated cluster.
1273 desc = &wc->w_desc[0];
1274 if (ocfs2_should_zero_cluster(desc))
1275 ocfs2_figure_cluster_boundaries(osb,
1280 desc = &wc->w_desc[wc->w_clen - 1];
1281 if (ocfs2_should_zero_cluster(desc))
1282 ocfs2_figure_cluster_boundaries(osb,
1287 wc->w_target_from = 0;
1288 wc->w_target_to = PAGE_CACHE_SIZE;
1293 * Populate each single-cluster write descriptor in the write context
1294 * with information about the i/o to be done.
1296 * Returns the number of clusters that will have to be allocated, as
1297 * well as a worst case estimate of the number of extent records that
1298 * would have to be created during a write to an unwritten region.
1300 static int ocfs2_populate_write_desc(struct inode *inode,
1301 struct ocfs2_write_ctxt *wc,
1302 unsigned int *clusters_to_alloc,
1303 unsigned int *extents_to_split)
1306 struct ocfs2_write_cluster_desc *desc;
1307 unsigned int num_clusters = 0;
1308 unsigned int ext_flags = 0;
1312 *clusters_to_alloc = 0;
1313 *extents_to_split = 0;
1315 for (i = 0; i < wc->w_clen; i++) {
1316 desc = &wc->w_desc[i];
1317 desc->c_cpos = wc->w_cpos + i;
1319 if (num_clusters == 0) {
1321 * Need to look up the next extent record.
1323 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1324 &num_clusters, &ext_flags);
1331 * Assume worst case - that we're writing in
1332 * the middle of the extent.
1334 * We can assume that the write proceeds from
1335 * left to right, in which case the extent
1336 * insert code is smart enough to coalesce the
1337 * next splits into the previous records created.
1339 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1340 *extents_to_split = *extents_to_split + 2;
1343 * Only increment phys if it doesn't describe
1349 desc->c_phys = phys;
1352 *clusters_to_alloc = *clusters_to_alloc + 1;
1354 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1355 desc->c_unwritten = 1;
1365 int ocfs2_write_begin_nolock(struct address_space *mapping,
1366 loff_t pos, unsigned len, unsigned flags,
1367 struct page **pagep, void **fsdata,
1368 struct buffer_head *di_bh, struct page *mmap_page)
1370 int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
1371 unsigned int clusters_to_alloc, extents_to_split;
1372 struct ocfs2_write_ctxt *wc;
1373 struct inode *inode = mapping->host;
1374 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1375 struct ocfs2_dinode *di;
1376 struct ocfs2_alloc_context *data_ac = NULL;
1377 struct ocfs2_alloc_context *meta_ac = NULL;
1380 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1386 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1393 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1396 * We set w_target_from, w_target_to here so that
1397 * ocfs2_write_end() knows which range in the target page to
1398 * write out. An allocation requires that we write the entire
1401 if (clusters_to_alloc || extents_to_split) {
1403 * XXX: We are stretching the limits of
1404 * ocfs2_lock_allocators(). It greatly over-estimates
1405 * the work to be done.
1407 ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc,
1408 extents_to_split, &data_ac, &meta_ac);
1414 credits = ocfs2_calc_extend_credits(inode->i_sb, di,
1419 ocfs2_set_target_boundaries(osb, wc, pos, len,
1420 clusters_to_alloc + extents_to_split);
1422 handle = ocfs2_start_trans(osb, credits);
1423 if (IS_ERR(handle)) {
1424 ret = PTR_ERR(handle);
1429 wc->w_handle = handle;
1432 * We don't want this to fail in ocfs2_write_end(), so do it
1435 ret = ocfs2_journal_access(handle, inode, wc->w_di_bh,
1436 OCFS2_JOURNAL_ACCESS_WRITE);
1443 * Fill our page array first. That way we've grabbed enough so
1444 * that we can zero and flush if we error after adding the
1447 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
1448 clusters_to_alloc + extents_to_split,
1455 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1463 ocfs2_free_alloc_context(data_ac);
1465 ocfs2_free_alloc_context(meta_ac);
1467 *pagep = wc->w_target_page;
1471 ocfs2_commit_trans(osb, handle);
1474 ocfs2_free_write_ctxt(wc);
1477 ocfs2_free_alloc_context(data_ac);
1479 ocfs2_free_alloc_context(meta_ac);
1483 int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1484 loff_t pos, unsigned len, unsigned flags,
1485 struct page **pagep, void **fsdata)
1488 struct buffer_head *di_bh = NULL;
1489 struct inode *inode = mapping->host;
1491 ret = ocfs2_meta_lock(inode, &di_bh, 1);
1498 * Take alloc sem here to prevent concurrent lookups. That way
1499 * the mapping, zeroing and tree manipulation within
1500 * ocfs2_write() will be safe against ->readpage(). This
1501 * should also serve to lock out allocation from a shared
1504 down_write(&OCFS2_I(inode)->ip_alloc_sem);
1506 ret = ocfs2_data_lock(inode, 1);
1512 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
1513 fsdata, di_bh, NULL);
1524 ocfs2_data_unlock(inode, 1);
1526 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1529 ocfs2_meta_unlock(inode, 1);
1534 int ocfs2_write_end_nolock(struct address_space *mapping,
1535 loff_t pos, unsigned len, unsigned copied,
1536 struct page *page, void *fsdata)
1539 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1540 struct inode *inode = mapping->host;
1541 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1542 struct ocfs2_write_ctxt *wc = fsdata;
1543 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1544 handle_t *handle = wc->w_handle;
1545 struct page *tmppage;
1547 if (unlikely(copied < len)) {
1548 if (!PageUptodate(wc->w_target_page))
1551 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1554 flush_dcache_page(wc->w_target_page);
1556 for(i = 0; i < wc->w_num_pages; i++) {
1557 tmppage = wc->w_pages[i];
1559 if (tmppage == wc->w_target_page) {
1560 from = wc->w_target_from;
1561 to = wc->w_target_to;
1563 BUG_ON(from > PAGE_CACHE_SIZE ||
1564 to > PAGE_CACHE_SIZE ||
1568 * Pages adjacent to the target (if any) imply
1569 * a hole-filling write in which case we want
1570 * to flush their entire range.
1573 to = PAGE_CACHE_SIZE;
1576 if (ocfs2_should_order_data(inode))
1577 walk_page_buffers(wc->w_handle, page_buffers(tmppage),
1579 ocfs2_journal_dirty_data);
1581 block_commit_write(tmppage, from, to);
1585 if (pos > inode->i_size) {
1586 i_size_write(inode, pos);
1587 mark_inode_dirty(inode);
1589 inode->i_blocks = ocfs2_inode_sector_count(inode);
1590 di->i_size = cpu_to_le64((u64)i_size_read(inode));
1591 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1592 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
1593 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
1594 ocfs2_journal_dirty(handle, wc->w_di_bh);
1596 ocfs2_commit_trans(osb, handle);
1598 ocfs2_run_deallocs(osb, &wc->w_dealloc);
1600 ocfs2_free_write_ctxt(wc);
1605 int ocfs2_write_end(struct file *file, struct address_space *mapping,
1606 loff_t pos, unsigned len, unsigned copied,
1607 struct page *page, void *fsdata)
1610 struct inode *inode = mapping->host;
1612 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
1614 ocfs2_data_unlock(inode, 1);
1615 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1616 ocfs2_meta_unlock(inode, 1);
1621 const struct address_space_operations ocfs2_aops = {
1622 .readpage = ocfs2_readpage,
1623 .writepage = ocfs2_writepage,
1625 .sync_page = block_sync_page,
1626 .direct_IO = ocfs2_direct_IO,
1627 .invalidatepage = ocfs2_invalidatepage,
1628 .releasepage = ocfs2_releasepage,
1629 .migratepage = buffer_migrate_page,