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, vm_ops->fault) 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.
743 block_end
= block_start
+ bsize
;
744 if (block_end
<= from
)
746 if (block_start
>= to
)
749 zero_user_page(page
, block_start
, bh
->b_size
, KM_USER0
);
750 set_buffer_uptodate(bh
);
751 mark_buffer_dirty(bh
);
754 block_start
= block_end
;
755 bh
= bh
->b_this_page
;
756 } while (bh
!= head
);
761 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
762 #define OCFS2_MAX_CTXT_PAGES 1
764 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
767 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
770 * Describe the state of a single cluster to be written to.
772 struct ocfs2_write_cluster_desc
{
776 * Give this a unique field because c_phys eventually gets
780 unsigned c_unwritten
;
783 static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc
*d
)
785 return d
->c_new
|| d
->c_unwritten
;
788 struct ocfs2_write_ctxt
{
789 /* Logical cluster position / len of write */
793 struct ocfs2_write_cluster_desc w_desc
[OCFS2_MAX_CLUSTERS_PER_PAGE
];
796 * This is true if page_size > cluster_size.
798 * It triggers a set of special cases during write which might
799 * have to deal with allocating writes to partial pages.
801 unsigned int w_large_pages
;
804 * Pages involved in this write.
806 * w_target_page is the page being written to by the user.
808 * w_pages is an array of pages which always contains
809 * w_target_page, and in the case of an allocating write with
810 * page_size < cluster size, it will contain zero'd and mapped
811 * pages adjacent to w_target_page which need to be written
812 * out in so that future reads from that region will get
815 struct page
*w_pages
[OCFS2_MAX_CTXT_PAGES
];
816 unsigned int w_num_pages
;
817 struct page
*w_target_page
;
820 * ocfs2_write_end() uses this to know what the real range to
821 * write in the target should be.
823 unsigned int w_target_from
;
824 unsigned int w_target_to
;
827 * We could use journal_current_handle() but this is cleaner,
832 struct buffer_head
*w_di_bh
;
834 struct ocfs2_cached_dealloc_ctxt w_dealloc
;
837 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt
*wc
)
841 for(i
= 0; i
< wc
->w_num_pages
; i
++) {
842 if (wc
->w_pages
[i
] == NULL
)
845 unlock_page(wc
->w_pages
[i
]);
846 mark_page_accessed(wc
->w_pages
[i
]);
847 page_cache_release(wc
->w_pages
[i
]);
854 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt
**wcp
,
855 struct ocfs2_super
*osb
, loff_t pos
,
856 unsigned len
, struct buffer_head
*di_bh
)
859 struct ocfs2_write_ctxt
*wc
;
861 wc
= kzalloc(sizeof(struct ocfs2_write_ctxt
), GFP_NOFS
);
865 wc
->w_cpos
= pos
>> osb
->s_clustersize_bits
;
866 cend
= (pos
+ len
- 1) >> osb
->s_clustersize_bits
;
867 wc
->w_clen
= cend
- wc
->w_cpos
+ 1;
871 if (unlikely(PAGE_CACHE_SHIFT
> osb
->s_clustersize_bits
))
872 wc
->w_large_pages
= 1;
874 wc
->w_large_pages
= 0;
876 ocfs2_init_dealloc_ctxt(&wc
->w_dealloc
);
884 * If a page has any new buffers, zero them out here, and mark them uptodate
885 * and dirty so they'll be written out (in order to prevent uninitialised
886 * block data from leaking). And clear the new bit.
888 static void ocfs2_zero_new_buffers(struct page
*page
, unsigned from
, unsigned to
)
890 unsigned int block_start
, block_end
;
891 struct buffer_head
*head
, *bh
;
893 BUG_ON(!PageLocked(page
));
894 if (!page_has_buffers(page
))
897 bh
= head
= page_buffers(page
);
900 block_end
= block_start
+ bh
->b_size
;
902 if (buffer_new(bh
)) {
903 if (block_end
> from
&& block_start
< to
) {
904 if (!PageUptodate(page
)) {
907 start
= max(from
, block_start
);
908 end
= min(to
, block_end
);
910 zero_user_page(page
, start
, end
- start
, KM_USER0
);
911 set_buffer_uptodate(bh
);
914 clear_buffer_new(bh
);
915 mark_buffer_dirty(bh
);
919 block_start
= block_end
;
920 bh
= bh
->b_this_page
;
921 } while (bh
!= head
);
925 * Only called when we have a failure during allocating write to write
926 * zero's to the newly allocated region.
928 static void ocfs2_write_failure(struct inode
*inode
,
929 struct ocfs2_write_ctxt
*wc
,
930 loff_t user_pos
, unsigned user_len
)
933 unsigned from
= user_pos
& (PAGE_CACHE_SIZE
- 1),
934 to
= user_pos
+ user_len
;
935 struct page
*tmppage
;
937 ocfs2_zero_new_buffers(wc
->w_target_page
, from
, to
);
939 for(i
= 0; i
< wc
->w_num_pages
; i
++) {
940 tmppage
= wc
->w_pages
[i
];
942 if (ocfs2_should_order_data(inode
))
943 walk_page_buffers(wc
->w_handle
, page_buffers(tmppage
),
945 ocfs2_journal_dirty_data
);
947 block_commit_write(tmppage
, from
, to
);
951 static int ocfs2_prepare_page_for_write(struct inode
*inode
, u64
*p_blkno
,
952 struct ocfs2_write_ctxt
*wc
,
953 struct page
*page
, u32 cpos
,
954 loff_t user_pos
, unsigned user_len
,
958 unsigned int map_from
= 0, map_to
= 0;
959 unsigned int cluster_start
, cluster_end
;
960 unsigned int user_data_from
= 0, user_data_to
= 0;
962 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode
->i_sb
), cpos
,
963 &cluster_start
, &cluster_end
);
965 if (page
== wc
->w_target_page
) {
966 map_from
= user_pos
& (PAGE_CACHE_SIZE
- 1);
967 map_to
= map_from
+ user_len
;
970 ret
= ocfs2_map_page_blocks(page
, p_blkno
, inode
,
971 cluster_start
, cluster_end
,
974 ret
= ocfs2_map_page_blocks(page
, p_blkno
, inode
,
975 map_from
, map_to
, new);
981 user_data_from
= map_from
;
982 user_data_to
= map_to
;
984 map_from
= cluster_start
;
985 map_to
= cluster_end
;
989 * If we haven't allocated the new page yet, we
990 * shouldn't be writing it out without copying user
991 * data. This is likely a math error from the caller.
995 map_from
= cluster_start
;
996 map_to
= cluster_end
;
998 ret
= ocfs2_map_page_blocks(page
, p_blkno
, inode
,
999 cluster_start
, cluster_end
, new);
1007 * Parts of newly allocated pages need to be zero'd.
1009 * Above, we have also rewritten 'to' and 'from' - as far as
1010 * the rest of the function is concerned, the entire cluster
1011 * range inside of a page needs to be written.
1013 * We can skip this if the page is up to date - it's already
1014 * been zero'd from being read in as a hole.
1016 if (new && !PageUptodate(page
))
1017 ocfs2_clear_page_regions(page
, OCFS2_SB(inode
->i_sb
),
1018 cpos
, user_data_from
, user_data_to
);
1020 flush_dcache_page(page
);
1027 * This function will only grab one clusters worth of pages.
1029 static int ocfs2_grab_pages_for_write(struct address_space
*mapping
,
1030 struct ocfs2_write_ctxt
*wc
,
1031 u32 cpos
, loff_t user_pos
, int new,
1032 struct page
*mmap_page
)
1035 unsigned long start
, target_index
, index
;
1036 struct inode
*inode
= mapping
->host
;
1038 target_index
= user_pos
>> PAGE_CACHE_SHIFT
;
1041 * Figure out how many pages we'll be manipulating here. For
1042 * non allocating write, we just change the one
1043 * page. Otherwise, we'll need a whole clusters worth.
1046 wc
->w_num_pages
= ocfs2_pages_per_cluster(inode
->i_sb
);
1047 start
= ocfs2_align_clusters_to_page_index(inode
->i_sb
, cpos
);
1049 wc
->w_num_pages
= 1;
1050 start
= target_index
;
1053 for(i
= 0; i
< wc
->w_num_pages
; i
++) {
1056 if (index
== target_index
&& mmap_page
) {
1058 * ocfs2_pagemkwrite() is a little different
1059 * and wants us to directly use the page
1062 lock_page(mmap_page
);
1064 if (mmap_page
->mapping
!= mapping
) {
1065 unlock_page(mmap_page
);
1067 * Sanity check - the locking in
1068 * ocfs2_pagemkwrite() should ensure
1069 * that this code doesn't trigger.
1076 page_cache_get(mmap_page
);
1077 wc
->w_pages
[i
] = mmap_page
;
1079 wc
->w_pages
[i
] = find_or_create_page(mapping
, index
,
1081 if (!wc
->w_pages
[i
]) {
1088 if (index
== target_index
)
1089 wc
->w_target_page
= wc
->w_pages
[i
];
1096 * Prepare a single cluster for write one cluster into the file.
1098 static int ocfs2_write_cluster(struct address_space
*mapping
,
1099 u32 phys
, unsigned int unwritten
,
1100 struct ocfs2_alloc_context
*data_ac
,
1101 struct ocfs2_alloc_context
*meta_ac
,
1102 struct ocfs2_write_ctxt
*wc
, u32 cpos
,
1103 loff_t user_pos
, unsigned user_len
)
1105 int ret
, i
, new, should_zero
= 0;
1106 u64 v_blkno
, p_blkno
;
1107 struct inode
*inode
= mapping
->host
;
1109 new = phys
== 0 ? 1 : 0;
1110 if (new || unwritten
)
1117 * This is safe to call with the page locks - it won't take
1118 * any additional semaphores or cluster locks.
1121 ret
= ocfs2_do_extend_allocation(OCFS2_SB(inode
->i_sb
), inode
,
1122 &tmp_pos
, 1, 0, wc
->w_di_bh
,
1123 wc
->w_handle
, data_ac
,
1126 * This shouldn't happen because we must have already
1127 * calculated the correct meta data allocation required. The
1128 * internal tree allocation code should know how to increase
1129 * transaction credits itself.
1131 * If need be, we could handle -EAGAIN for a
1132 * RESTART_TRANS here.
1134 mlog_bug_on_msg(ret
== -EAGAIN
,
1135 "Inode %llu: EAGAIN return during allocation.\n",
1136 (unsigned long long)OCFS2_I(inode
)->ip_blkno
);
1141 } else if (unwritten
) {
1142 ret
= ocfs2_mark_extent_written(inode
, wc
->w_di_bh
,
1143 wc
->w_handle
, cpos
, 1, phys
,
1144 meta_ac
, &wc
->w_dealloc
);
1152 v_blkno
= ocfs2_clusters_to_blocks(inode
->i_sb
, cpos
);
1154 v_blkno
= user_pos
>> inode
->i_sb
->s_blocksize_bits
;
1157 * The only reason this should fail is due to an inability to
1158 * find the extent added.
1160 ret
= ocfs2_extent_map_get_blocks(inode
, v_blkno
, &p_blkno
, NULL
,
1163 ocfs2_error(inode
->i_sb
, "Corrupting extend for inode %llu, "
1164 "at logical block %llu",
1165 (unsigned long long)OCFS2_I(inode
)->ip_blkno
,
1166 (unsigned long long)v_blkno
);
1170 BUG_ON(p_blkno
== 0);
1172 for(i
= 0; i
< wc
->w_num_pages
; i
++) {
1175 tmpret
= ocfs2_prepare_page_for_write(inode
, &p_blkno
, wc
,
1176 wc
->w_pages
[i
], cpos
,
1187 * We only have cleanup to do in case of allocating write.
1190 ocfs2_write_failure(inode
, wc
, user_pos
, user_len
);
1197 static int ocfs2_write_cluster_by_desc(struct address_space
*mapping
,
1198 struct ocfs2_alloc_context
*data_ac
,
1199 struct ocfs2_alloc_context
*meta_ac
,
1200 struct ocfs2_write_ctxt
*wc
,
1201 loff_t pos
, unsigned len
)
1205 unsigned int local_len
= len
;
1206 struct ocfs2_write_cluster_desc
*desc
;
1207 struct ocfs2_super
*osb
= OCFS2_SB(mapping
->host
->i_sb
);
1209 for (i
= 0; i
< wc
->w_clen
; i
++) {
1210 desc
= &wc
->w_desc
[i
];
1213 * We have to make sure that the total write passed in
1214 * doesn't extend past a single cluster.
1217 cluster_off
= pos
& (osb
->s_clustersize
- 1);
1218 if ((cluster_off
+ local_len
) > osb
->s_clustersize
)
1219 local_len
= osb
->s_clustersize
- cluster_off
;
1221 ret
= ocfs2_write_cluster(mapping
, desc
->c_phys
,
1222 desc
->c_unwritten
, data_ac
, meta_ac
,
1223 wc
, desc
->c_cpos
, pos
, local_len
);
1239 * ocfs2_write_end() wants to know which parts of the target page it
1240 * should complete the write on. It's easiest to compute them ahead of
1241 * time when a more complete view of the write is available.
1243 static void ocfs2_set_target_boundaries(struct ocfs2_super
*osb
,
1244 struct ocfs2_write_ctxt
*wc
,
1245 loff_t pos
, unsigned len
, int alloc
)
1247 struct ocfs2_write_cluster_desc
*desc
;
1249 wc
->w_target_from
= pos
& (PAGE_CACHE_SIZE
- 1);
1250 wc
->w_target_to
= wc
->w_target_from
+ len
;
1256 * Allocating write - we may have different boundaries based
1257 * on page size and cluster size.
1259 * NOTE: We can no longer compute one value from the other as
1260 * the actual write length and user provided length may be
1264 if (wc
->w_large_pages
) {
1266 * We only care about the 1st and last cluster within
1267 * our range and whether they should be zero'd or not. Either
1268 * value may be extended out to the start/end of a
1269 * newly allocated cluster.
1271 desc
= &wc
->w_desc
[0];
1272 if (ocfs2_should_zero_cluster(desc
))
1273 ocfs2_figure_cluster_boundaries(osb
,
1278 desc
= &wc
->w_desc
[wc
->w_clen
- 1];
1279 if (ocfs2_should_zero_cluster(desc
))
1280 ocfs2_figure_cluster_boundaries(osb
,
1285 wc
->w_target_from
= 0;
1286 wc
->w_target_to
= PAGE_CACHE_SIZE
;
1291 * Populate each single-cluster write descriptor in the write context
1292 * with information about the i/o to be done.
1294 * Returns the number of clusters that will have to be allocated, as
1295 * well as a worst case estimate of the number of extent records that
1296 * would have to be created during a write to an unwritten region.
1298 static int ocfs2_populate_write_desc(struct inode
*inode
,
1299 struct ocfs2_write_ctxt
*wc
,
1300 unsigned int *clusters_to_alloc
,
1301 unsigned int *extents_to_split
)
1304 struct ocfs2_write_cluster_desc
*desc
;
1305 unsigned int num_clusters
= 0;
1306 unsigned int ext_flags
= 0;
1310 *clusters_to_alloc
= 0;
1311 *extents_to_split
= 0;
1313 for (i
= 0; i
< wc
->w_clen
; i
++) {
1314 desc
= &wc
->w_desc
[i
];
1315 desc
->c_cpos
= wc
->w_cpos
+ i
;
1317 if (num_clusters
== 0) {
1319 * Need to look up the next extent record.
1321 ret
= ocfs2_get_clusters(inode
, desc
->c_cpos
, &phys
,
1322 &num_clusters
, &ext_flags
);
1329 * Assume worst case - that we're writing in
1330 * the middle of the extent.
1332 * We can assume that the write proceeds from
1333 * left to right, in which case the extent
1334 * insert code is smart enough to coalesce the
1335 * next splits into the previous records created.
1337 if (ext_flags
& OCFS2_EXT_UNWRITTEN
)
1338 *extents_to_split
= *extents_to_split
+ 2;
1341 * Only increment phys if it doesn't describe
1347 desc
->c_phys
= phys
;
1350 *clusters_to_alloc
= *clusters_to_alloc
+ 1;
1352 if (ext_flags
& OCFS2_EXT_UNWRITTEN
)
1353 desc
->c_unwritten
= 1;
1363 int ocfs2_write_begin_nolock(struct address_space
*mapping
,
1364 loff_t pos
, unsigned len
, unsigned flags
,
1365 struct page
**pagep
, void **fsdata
,
1366 struct buffer_head
*di_bh
, struct page
*mmap_page
)
1368 int ret
, credits
= OCFS2_INODE_UPDATE_CREDITS
;
1369 unsigned int clusters_to_alloc
, extents_to_split
;
1370 struct ocfs2_write_ctxt
*wc
;
1371 struct inode
*inode
= mapping
->host
;
1372 struct ocfs2_super
*osb
= OCFS2_SB(inode
->i_sb
);
1373 struct ocfs2_dinode
*di
;
1374 struct ocfs2_alloc_context
*data_ac
= NULL
;
1375 struct ocfs2_alloc_context
*meta_ac
= NULL
;
1378 ret
= ocfs2_alloc_write_ctxt(&wc
, osb
, pos
, len
, di_bh
);
1384 ret
= ocfs2_populate_write_desc(inode
, wc
, &clusters_to_alloc
,
1391 di
= (struct ocfs2_dinode
*)wc
->w_di_bh
->b_data
;
1394 * We set w_target_from, w_target_to here so that
1395 * ocfs2_write_end() knows which range in the target page to
1396 * write out. An allocation requires that we write the entire
1399 if (clusters_to_alloc
|| extents_to_split
) {
1401 * XXX: We are stretching the limits of
1402 * ocfs2_lock_allocators(). It greatly over-estimates
1403 * the work to be done.
1405 ret
= ocfs2_lock_allocators(inode
, di
, clusters_to_alloc
,
1406 extents_to_split
, &data_ac
, &meta_ac
);
1412 credits
= ocfs2_calc_extend_credits(inode
->i_sb
, di
,
1417 ocfs2_set_target_boundaries(osb
, wc
, pos
, len
,
1418 clusters_to_alloc
+ extents_to_split
);
1420 handle
= ocfs2_start_trans(osb
, credits
);
1421 if (IS_ERR(handle
)) {
1422 ret
= PTR_ERR(handle
);
1427 wc
->w_handle
= handle
;
1430 * We don't want this to fail in ocfs2_write_end(), so do it
1433 ret
= ocfs2_journal_access(handle
, inode
, wc
->w_di_bh
,
1434 OCFS2_JOURNAL_ACCESS_WRITE
);
1441 * Fill our page array first. That way we've grabbed enough so
1442 * that we can zero and flush if we error after adding the
1445 ret
= ocfs2_grab_pages_for_write(mapping
, wc
, wc
->w_cpos
, pos
,
1446 clusters_to_alloc
+ extents_to_split
,
1453 ret
= ocfs2_write_cluster_by_desc(mapping
, data_ac
, meta_ac
, wc
, pos
,
1461 ocfs2_free_alloc_context(data_ac
);
1463 ocfs2_free_alloc_context(meta_ac
);
1465 *pagep
= wc
->w_target_page
;
1469 ocfs2_commit_trans(osb
, handle
);
1472 ocfs2_free_write_ctxt(wc
);
1475 ocfs2_free_alloc_context(data_ac
);
1477 ocfs2_free_alloc_context(meta_ac
);
1481 int ocfs2_write_begin(struct file
*file
, struct address_space
*mapping
,
1482 loff_t pos
, unsigned len
, unsigned flags
,
1483 struct page
**pagep
, void **fsdata
)
1486 struct buffer_head
*di_bh
= NULL
;
1487 struct inode
*inode
= mapping
->host
;
1489 ret
= ocfs2_meta_lock(inode
, &di_bh
, 1);
1496 * Take alloc sem here to prevent concurrent lookups. That way
1497 * the mapping, zeroing and tree manipulation within
1498 * ocfs2_write() will be safe against ->readpage(). This
1499 * should also serve to lock out allocation from a shared
1502 down_write(&OCFS2_I(inode
)->ip_alloc_sem
);
1504 ret
= ocfs2_data_lock(inode
, 1);
1510 ret
= ocfs2_write_begin_nolock(mapping
, pos
, len
, flags
, pagep
,
1511 fsdata
, di_bh
, NULL
);
1522 ocfs2_data_unlock(inode
, 1);
1524 up_write(&OCFS2_I(inode
)->ip_alloc_sem
);
1527 ocfs2_meta_unlock(inode
, 1);
1532 int ocfs2_write_end_nolock(struct address_space
*mapping
,
1533 loff_t pos
, unsigned len
, unsigned copied
,
1534 struct page
*page
, void *fsdata
)
1537 unsigned from
, to
, start
= pos
& (PAGE_CACHE_SIZE
- 1);
1538 struct inode
*inode
= mapping
->host
;
1539 struct ocfs2_super
*osb
= OCFS2_SB(inode
->i_sb
);
1540 struct ocfs2_write_ctxt
*wc
= fsdata
;
1541 struct ocfs2_dinode
*di
= (struct ocfs2_dinode
*)wc
->w_di_bh
->b_data
;
1542 handle_t
*handle
= wc
->w_handle
;
1543 struct page
*tmppage
;
1545 if (unlikely(copied
< len
)) {
1546 if (!PageUptodate(wc
->w_target_page
))
1549 ocfs2_zero_new_buffers(wc
->w_target_page
, start
+copied
,
1552 flush_dcache_page(wc
->w_target_page
);
1554 for(i
= 0; i
< wc
->w_num_pages
; i
++) {
1555 tmppage
= wc
->w_pages
[i
];
1557 if (tmppage
== wc
->w_target_page
) {
1558 from
= wc
->w_target_from
;
1559 to
= wc
->w_target_to
;
1561 BUG_ON(from
> PAGE_CACHE_SIZE
||
1562 to
> PAGE_CACHE_SIZE
||
1566 * Pages adjacent to the target (if any) imply
1567 * a hole-filling write in which case we want
1568 * to flush their entire range.
1571 to
= PAGE_CACHE_SIZE
;
1574 if (ocfs2_should_order_data(inode
))
1575 walk_page_buffers(wc
->w_handle
, page_buffers(tmppage
),
1577 ocfs2_journal_dirty_data
);
1579 block_commit_write(tmppage
, from
, to
);
1583 if (pos
> inode
->i_size
) {
1584 i_size_write(inode
, pos
);
1585 mark_inode_dirty(inode
);
1587 inode
->i_blocks
= ocfs2_inode_sector_count(inode
);
1588 di
->i_size
= cpu_to_le64((u64
)i_size_read(inode
));
1589 inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME
;
1590 di
->i_mtime
= di
->i_ctime
= cpu_to_le64(inode
->i_mtime
.tv_sec
);
1591 di
->i_mtime_nsec
= di
->i_ctime_nsec
= cpu_to_le32(inode
->i_mtime
.tv_nsec
);
1592 ocfs2_journal_dirty(handle
, wc
->w_di_bh
);
1594 ocfs2_commit_trans(osb
, handle
);
1596 ocfs2_run_deallocs(osb
, &wc
->w_dealloc
);
1598 ocfs2_free_write_ctxt(wc
);
1603 int ocfs2_write_end(struct file
*file
, struct address_space
*mapping
,
1604 loff_t pos
, unsigned len
, unsigned copied
,
1605 struct page
*page
, void *fsdata
)
1608 struct inode
*inode
= mapping
->host
;
1610 ret
= ocfs2_write_end_nolock(mapping
, pos
, len
, copied
, page
, fsdata
);
1612 ocfs2_data_unlock(inode
, 1);
1613 up_write(&OCFS2_I(inode
)->ip_alloc_sem
);
1614 ocfs2_meta_unlock(inode
, 1);
1619 const struct address_space_operations ocfs2_aops
= {
1620 .readpage
= ocfs2_readpage
,
1621 .writepage
= ocfs2_writepage
,
1623 .sync_page
= block_sync_page
,
1624 .direct_IO
= ocfs2_direct_IO
,
1625 .invalidatepage
= ocfs2_invalidatepage
,
1626 .releasepage
= ocfs2_releasepage
,
1627 .migratepage
= buffer_migrate_page
,