2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/pagemap.h>
16 #include <linux/pagevec.h>
17 #include <linux/mpage.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/lm_interface.h>
29 #include "ops_address.h"
38 static void gfs2_page_add_databufs(struct gfs2_inode
*ip
, struct page
*page
,
39 unsigned int from
, unsigned int to
)
41 struct buffer_head
*head
= page_buffers(page
);
42 unsigned int bsize
= head
->b_size
;
43 struct buffer_head
*bh
;
44 unsigned int start
, end
;
46 for (bh
= head
, start
= 0; bh
!= head
|| !start
;
47 bh
= bh
->b_this_page
, start
= end
) {
49 if (end
<= from
|| start
>= to
)
51 gfs2_trans_add_bh(ip
->i_gl
, bh
, 0);
56 * gfs2_get_block - Fills in a buffer head with details about a block
58 * @lblock: The block number to look up
59 * @bh_result: The buffer head to return the result in
60 * @create: Non-zero if we may add block to the file
65 int gfs2_get_block(struct inode
*inode
, sector_t lblock
,
66 struct buffer_head
*bh_result
, int create
)
68 return gfs2_block_map(inode
, lblock
, create
, bh_result
, 32);
72 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
74 * @lblock: The block number to look up
75 * @bh_result: The buffer head to return the result in
76 * @create: Non-zero if we may add block to the file
81 static int gfs2_get_block_noalloc(struct inode
*inode
, sector_t lblock
,
82 struct buffer_head
*bh_result
, int create
)
86 error
= gfs2_block_map(inode
, lblock
, 0, bh_result
, 1);
89 if (bh_result
->b_blocknr
== 0)
94 static int gfs2_get_block_direct(struct inode
*inode
, sector_t lblock
,
95 struct buffer_head
*bh_result
, int create
)
97 return gfs2_block_map(inode
, lblock
, 0, bh_result
, 512);
101 * gfs2_writepage - Write complete page
102 * @page: Page to write
106 * Some of this is copied from block_write_full_page() although we still
107 * call it to do most of the work.
110 static int gfs2_writepage(struct page
*page
, struct writeback_control
*wbc
)
112 struct inode
*inode
= page
->mapping
->host
;
113 struct gfs2_inode
*ip
= GFS2_I(inode
);
114 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
115 loff_t i_size
= i_size_read(inode
);
116 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
121 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_held_excl(ip
->i_gl
))) {
125 if (current
->journal_info
)
128 /* Is the page fully outside i_size? (truncate in progress) */
129 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
130 if (page
->index
> end_index
|| (page
->index
== end_index
&& !offset
)) {
131 page
->mapping
->a_ops
->invalidatepage(page
, 0);
133 return 0; /* don't care */
136 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
|| gfs2_is_jdata(ip
)) {
137 error
= gfs2_trans_begin(sdp
, RES_DINODE
+ 1, 0);
140 if (!page_has_buffers(page
)) {
141 create_empty_buffers(page
, inode
->i_sb
->s_blocksize
,
142 (1 << BH_Dirty
)|(1 << BH_Uptodate
));
144 gfs2_page_add_databufs(ip
, page
, 0, sdp
->sd_vfs
->s_blocksize
-1);
147 error
= block_write_full_page(page
, gfs2_get_block_noalloc
, wbc
);
150 gfs2_meta_cache_flush(ip
);
154 redirty_page_for_writepage(wbc
, page
);
159 static int zero_readpage(struct page
*page
)
163 kaddr
= kmap_atomic(page
, KM_USER0
);
164 memset(kaddr
, 0, PAGE_CACHE_SIZE
);
165 kunmap_atomic(page
, KM_USER0
);
167 SetPageUptodate(page
);
173 * stuffed_readpage - Fill in a Linux page with stuffed file data
180 static int stuffed_readpage(struct gfs2_inode
*ip
, struct page
*page
)
182 struct buffer_head
*dibh
;
186 /* Only the first page of a stuffed file might contain data */
187 if (unlikely(page
->index
))
188 return zero_readpage(page
);
190 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
194 kaddr
= kmap_atomic(page
, KM_USER0
);
195 memcpy(kaddr
, dibh
->b_data
+ sizeof(struct gfs2_dinode
),
197 memset(kaddr
+ ip
->i_di
.di_size
, 0, PAGE_CACHE_SIZE
- ip
->i_di
.di_size
);
198 kunmap_atomic(page
, KM_USER0
);
202 SetPageUptodate(page
);
209 * gfs2_readpage - readpage with locking
210 * @file: The file to read a page for. N.B. This may be NULL if we are
211 * reading an internal file.
212 * @page: The page to read
217 static int gfs2_readpage(struct file
*file
, struct page
*page
)
219 struct gfs2_inode
*ip
= GFS2_I(page
->mapping
->host
);
220 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
221 struct gfs2_file
*gf
= NULL
;
222 struct gfs2_holder gh
;
226 if (likely(file
!= &gfs2_internal_file_sentinel
)) {
228 gf
= file
->private_data
;
229 if (test_bit(GFF_EXLOCK
, &gf
->f_flags
))
230 /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
233 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
|GL_AOP
, &gh
);
235 error
= gfs2_glock_nq_m_atime(1, &gh
);
241 if (gfs2_is_stuffed(ip
)) {
242 error
= stuffed_readpage(ip
, page
);
245 error
= mpage_readpage(page
, gfs2_get_block
);
247 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
251 gfs2_glock_dq_m(1, &gh
);
252 gfs2_holder_uninit(&gh
);
259 gfs2_holder_uninit(&gh
);
264 * gfs2_readpages - Read a bunch of pages at once
267 * 1. This is only for readahead, so we can simply ignore any things
268 * which are slightly inconvenient (such as locking conflicts between
269 * the page lock and the glock) and return having done no I/O. Its
270 * obviously not something we'd want to do on too regular a basis.
271 * Any I/O we ignore at this time will be done via readpage later.
272 * 2. We have to handle stuffed files here too.
273 * 3. mpage_readpages() does most of the heavy lifting in the common case.
274 * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
275 * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
276 * well as read-ahead.
278 static int gfs2_readpages(struct file
*file
, struct address_space
*mapping
,
279 struct list_head
*pages
, unsigned nr_pages
)
281 struct inode
*inode
= mapping
->host
;
282 struct gfs2_inode
*ip
= GFS2_I(inode
);
283 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
284 struct gfs2_holder gh
;
289 if (likely(file
!= &gfs2_internal_file_sentinel
)) {
291 struct gfs2_file
*gf
= file
->private_data
;
292 if (test_bit(GFF_EXLOCK
, &gf
->f_flags
))
295 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
,
296 LM_FLAG_TRY_1CB
|GL_ATIME
|GL_AOP
, &gh
);
298 ret
= gfs2_glock_nq_m_atime(1, &gh
);
299 if (ret
== GLR_TRYFAILED
)
305 if (gfs2_is_stuffed(ip
)) {
306 struct pagevec lru_pvec
;
307 pagevec_init(&lru_pvec
, 0);
308 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
309 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
310 prefetchw(&page
->flags
);
311 list_del(&page
->lru
);
312 if (!add_to_page_cache(page
, mapping
,
313 page
->index
, GFP_KERNEL
)) {
314 ret
= stuffed_readpage(ip
, page
);
316 if (!pagevec_add(&lru_pvec
, page
))
317 __pagevec_lru_add(&lru_pvec
);
319 page_cache_release(page
);
322 pagevec_lru_add(&lru_pvec
);
325 /* What we really want to do .... */
326 ret
= mpage_readpages(mapping
, pages
, nr_pages
, gfs2_get_block
);
330 gfs2_glock_dq_m(1, &gh
);
331 gfs2_holder_uninit(&gh
);
334 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
340 /* unlock all pages, we can't do any I/O right now */
341 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
342 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
343 list_del(&page
->lru
);
345 page_cache_release(page
);
348 gfs2_holder_uninit(&gh
);
353 * gfs2_prepare_write - Prepare to write a page to a file
354 * @file: The file to write to
355 * @page: The page which is to be prepared for writing
356 * @from: From (byte range within page)
357 * @to: To (byte range within page)
362 static int gfs2_prepare_write(struct file
*file
, struct page
*page
,
363 unsigned from
, unsigned to
)
365 struct gfs2_inode
*ip
= GFS2_I(page
->mapping
->host
);
366 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
367 unsigned int data_blocks
, ind_blocks
, rblocks
;
370 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + from
;
371 loff_t end
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
372 struct gfs2_alloc
*al
;
374 gfs2_holder_init(ip
->i_gl
, LM_ST_EXCLUSIVE
, GL_ATIME
|GL_AOP
, &ip
->i_gh
);
375 error
= gfs2_glock_nq_m_atime(1, &ip
->i_gh
);
379 gfs2_write_calc_reserv(ip
, to
- from
, &data_blocks
, &ind_blocks
);
381 error
= gfs2_write_alloc_required(ip
, pos
, from
- to
, &alloc_required
);
386 if (alloc_required
) {
387 al
= gfs2_alloc_get(ip
);
389 error
= gfs2_quota_lock(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
393 error
= gfs2_quota_check(ip
, ip
->i_di
.di_uid
, ip
->i_di
.di_gid
);
397 al
->al_requested
= data_blocks
+ ind_blocks
;
398 error
= gfs2_inplace_reserve(ip
);
403 rblocks
= RES_DINODE
+ ind_blocks
;
404 if (gfs2_is_jdata(ip
))
405 rblocks
+= data_blocks
? data_blocks
: 1;
406 if (ind_blocks
|| data_blocks
)
407 rblocks
+= RES_STATFS
+ RES_QUOTA
;
409 error
= gfs2_trans_begin(sdp
, rblocks
, 0);
413 if (gfs2_is_stuffed(ip
)) {
414 if (end
> sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
)) {
415 error
= gfs2_unstuff_dinode(ip
, page
);
418 } else if (!PageUptodate(page
))
419 error
= stuffed_readpage(ip
, page
);
424 error
= block_prepare_write(page
, from
, to
, gfs2_get_block
);
429 if (alloc_required
) {
430 gfs2_inplace_release(ip
);
432 gfs2_quota_unlock(ip
);
437 gfs2_glock_dq_m(1, &ip
->i_gh
);
439 gfs2_holder_uninit(&ip
->i_gh
);
446 * gfs2_commit_write - Commit write to a file
447 * @file: The file to write to
448 * @page: The page containing the data
449 * @from: From (byte range within page)
450 * @to: To (byte range within page)
455 static int gfs2_commit_write(struct file
*file
, struct page
*page
,
456 unsigned from
, unsigned to
)
458 struct inode
*inode
= page
->mapping
->host
;
459 struct gfs2_inode
*ip
= GFS2_I(inode
);
460 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
461 int error
= -EOPNOTSUPP
;
462 struct buffer_head
*dibh
;
463 struct gfs2_alloc
*al
= &ip
->i_alloc
;;
465 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_locked_by_me(ip
->i_gl
)))
468 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
472 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
474 if (gfs2_is_stuffed(ip
)) {
478 file_size
= ((u64
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
480 kaddr
= kmap_atomic(page
, KM_USER0
);
481 memcpy(dibh
->b_data
+ sizeof(struct gfs2_dinode
) + from
,
482 kaddr
+ from
, to
- from
);
483 kunmap_atomic(page
, KM_USER0
);
485 SetPageUptodate(page
);
487 if (inode
->i_size
< file_size
)
488 i_size_write(inode
, file_size
);
490 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
||
492 gfs2_page_add_databufs(ip
, page
, from
, to
);
493 error
= generic_commit_write(file
, page
, from
, to
);
498 if (ip
->i_di
.di_size
< inode
->i_size
)
499 ip
->i_di
.di_size
= inode
->i_size
;
501 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
504 if (al
->al_requested
) {
505 gfs2_inplace_release(ip
);
506 gfs2_quota_unlock(ip
);
509 gfs2_glock_dq_m(1, &ip
->i_gh
);
510 gfs2_holder_uninit(&ip
->i_gh
);
517 if (al
->al_requested
) {
518 gfs2_inplace_release(ip
);
519 gfs2_quota_unlock(ip
);
522 gfs2_glock_dq_m(1, &ip
->i_gh
);
523 gfs2_holder_uninit(&ip
->i_gh
);
525 ClearPageUptodate(page
);
530 * gfs2_bmap - Block map function
531 * @mapping: Address space info
532 * @lblock: The block to map
534 * Returns: The disk address for the block or 0 on hole or error
537 static sector_t
gfs2_bmap(struct address_space
*mapping
, sector_t lblock
)
539 struct gfs2_inode
*ip
= GFS2_I(mapping
->host
);
540 struct gfs2_holder i_gh
;
544 error
= gfs2_glock_nq_init(ip
->i_gl
, LM_ST_SHARED
, LM_FLAG_ANY
, &i_gh
);
548 if (!gfs2_is_stuffed(ip
))
549 dblock
= generic_block_bmap(mapping
, lblock
, gfs2_get_block
);
551 gfs2_glock_dq_uninit(&i_gh
);
556 static void discard_buffer(struct gfs2_sbd
*sdp
, struct buffer_head
*bh
)
558 struct gfs2_bufdata
*bd
;
564 bh
->b_private
= NULL
;
566 gfs2_log_unlock(sdp
);
569 clear_buffer_dirty(bh
);
571 clear_buffer_mapped(bh
);
572 clear_buffer_req(bh
);
573 clear_buffer_new(bh
);
574 clear_buffer_delay(bh
);
578 static void gfs2_invalidatepage(struct page
*page
, unsigned long offset
)
580 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
581 struct buffer_head
*head
, *bh
, *next
;
582 unsigned int curr_off
= 0;
584 BUG_ON(!PageLocked(page
));
585 if (!page_has_buffers(page
))
588 bh
= head
= page_buffers(page
);
590 unsigned int next_off
= curr_off
+ bh
->b_size
;
591 next
= bh
->b_this_page
;
593 if (offset
<= curr_off
)
594 discard_buffer(sdp
, bh
);
598 } while (bh
!= head
);
601 try_to_release_page(page
, 0);
606 static ssize_t
gfs2_direct_IO(int rw
, struct kiocb
*iocb
,
607 const struct iovec
*iov
, loff_t offset
,
608 unsigned long nr_segs
)
610 struct file
*file
= iocb
->ki_filp
;
611 struct inode
*inode
= file
->f_mapping
->host
;
612 struct gfs2_inode
*ip
= GFS2_I(inode
);
613 struct gfs2_holder gh
;
617 mutex_lock(&inode
->i_mutex
);
619 * Shared lock, even if its a write, since we do no allocation
620 * on this path. All we need change is atime.
622 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
, &gh
);
623 rv
= gfs2_glock_nq_m_atime(1, &gh
);
627 if (offset
> i_size_read(inode
))
631 * Should we return an error here? I can't see that O_DIRECT for
632 * a journaled file makes any sense. For now we'll silently fall
633 * back to buffered I/O, likewise we do the same for stuffed
634 * files since they are (a) small and (b) unaligned.
636 if (gfs2_is_jdata(ip
))
639 if (gfs2_is_stuffed(ip
))
642 rv
= blockdev_direct_IO_own_locking(rw
, iocb
, inode
,
644 iov
, offset
, nr_segs
,
645 gfs2_get_block_direct
, NULL
);
647 gfs2_glock_dq_m(1, &gh
);
648 gfs2_holder_uninit(&gh
);
650 mutex_unlock(&inode
->i_mutex
);
656 * stuck_releasepage - We're stuck in gfs2_releasepage(). Print stuff out.
657 * @bh: the buffer we're stuck on
661 static void stuck_releasepage(struct buffer_head
*bh
)
663 struct inode
*inode
= bh
->b_page
->mapping
->host
;
664 struct gfs2_sbd
*sdp
= inode
->i_sb
->s_fs_info
;
665 struct gfs2_bufdata
*bd
= bh
->b_private
;
666 struct gfs2_glock
*gl
;
667 static unsigned limit
= 0;
673 fs_warn(sdp
, "stuck in gfs2_releasepage() %p\n", inode
);
674 fs_warn(sdp
, "blkno = %llu, bh->b_count = %d\n",
675 (unsigned long long)bh
->b_blocknr
, atomic_read(&bh
->b_count
));
676 fs_warn(sdp
, "pinned = %u\n", buffer_pinned(bh
));
677 fs_warn(sdp
, "bh->b_private = %s\n", (bd
) ? "!NULL" : "NULL");
684 fs_warn(sdp
, "gl = (%u, %llu)\n",
685 gl
->gl_name
.ln_type
, (unsigned long long)gl
->gl_name
.ln_number
);
687 fs_warn(sdp
, "bd_list_tr = %s, bd_le.le_list = %s\n",
688 (list_empty(&bd
->bd_list_tr
)) ? "no" : "yes",
689 (list_empty(&bd
->bd_le
.le_list
)) ? "no" : "yes");
691 if (gl
->gl_ops
== &gfs2_inode_glops
) {
692 struct gfs2_inode
*ip
= gl
->gl_object
;
698 fs_warn(sdp
, "ip = %llu %llu\n",
699 (unsigned long long)ip
->i_num
.no_formal_ino
,
700 (unsigned long long)ip
->i_num
.no_addr
);
702 for (x
= 0; x
< GFS2_MAX_META_HEIGHT
; x
++)
703 fs_warn(sdp
, "ip->i_cache[%u] = %s\n",
704 x
, (ip
->i_cache
[x
]) ? "!NULL" : "NULL");
709 * gfs2_releasepage - free the metadata associated with a page
710 * @page: the page that's being released
711 * @gfp_mask: passed from Linux VFS, ignored by us
713 * Call try_to_free_buffers() if the buffers in this page can be
719 int gfs2_releasepage(struct page
*page
, gfp_t gfp_mask
)
721 struct inode
*aspace
= page
->mapping
->host
;
722 struct gfs2_sbd
*sdp
= aspace
->i_sb
->s_fs_info
;
723 struct buffer_head
*bh
, *head
;
724 struct gfs2_bufdata
*bd
;
725 unsigned long t
= jiffies
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
;
727 if (!page_has_buffers(page
))
730 head
= bh
= page_buffers(page
);
732 while (atomic_read(&bh
->b_count
)) {
733 if (!atomic_read(&aspace
->i_writecount
))
736 if (time_after_eq(jiffies
, t
)) {
737 stuck_releasepage(bh
);
738 /* should we withdraw here? */
745 gfs2_assert_warn(sdp
, !buffer_pinned(bh
));
746 gfs2_assert_warn(sdp
, !buffer_dirty(bh
));
751 gfs2_assert_warn(sdp
, bd
->bd_bh
== bh
);
752 gfs2_assert_warn(sdp
, list_empty(&bd
->bd_list_tr
));
753 gfs2_assert_warn(sdp
, !bd
->bd_ail
);
755 if (!list_empty(&bd
->bd_le
.le_list
))
757 bh
->b_private
= NULL
;
759 gfs2_log_unlock(sdp
);
761 kmem_cache_free(gfs2_bufdata_cachep
, bd
);
763 bh
= bh
->b_this_page
;
764 } while (bh
!= head
);
767 return try_to_free_buffers(page
);
770 const struct address_space_operations gfs2_file_aops
= {
771 .writepage
= gfs2_writepage
,
772 .readpage
= gfs2_readpage
,
773 .readpages
= gfs2_readpages
,
774 .sync_page
= block_sync_page
,
775 .prepare_write
= gfs2_prepare_write
,
776 .commit_write
= gfs2_commit_write
,
778 .invalidatepage
= gfs2_invalidatepage
,
779 .releasepage
= gfs2_releasepage
,
780 .direct_IO
= gfs2_direct_IO
,