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 v.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>
22 #include "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
)
73 error
= gfs2_block_map(inode
, lblock
, &new, &dblock
, &boundary
);
80 map_bh(bh_result
, inode
->i_sb
, dblock
);
82 set_buffer_new(bh_result
);
84 set_buffer_boundary(bh_result
);
90 * get_block_noalloc - Fills in a buffer head with details about a block
92 * @lblock: The block number to look up
93 * @bh_result: The buffer head to return the result in
94 * @create: Non-zero if we may add block to the file
99 static int get_block_noalloc(struct inode
*inode
, sector_t lblock
,
100 struct buffer_head
*bh_result
, int create
)
107 error
= gfs2_block_map(inode
, lblock
, &new, &dblock
, &boundary
);
112 map_bh(bh_result
, inode
->i_sb
, dblock
);
113 else if (gfs2_assert_withdraw(GFS2_SB(inode
), !create
))
116 set_buffer_boundary(bh_result
);
122 * gfs2_writepage - Write complete page
123 * @page: Page to write
127 * Some of this is copied from block_write_full_page() although we still
128 * call it to do most of the work.
131 static int gfs2_writepage(struct page
*page
, struct writeback_control
*wbc
)
133 struct inode
*inode
= page
->mapping
->host
;
134 struct gfs2_inode
*ip
= GFS2_I(inode
);
135 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
136 loff_t i_size
= i_size_read(inode
);
137 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
142 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_held_excl(ip
->i_gl
))) {
146 if (current
->journal_info
)
149 /* Is the page fully outside i_size? (truncate in progress) */
150 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
151 if (page
->index
> end_index
|| (page
->index
== end_index
&& !offset
)) {
152 page
->mapping
->a_ops
->invalidatepage(page
, 0);
154 return 0; /* don't care */
157 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
|| gfs2_is_jdata(ip
)) {
158 error
= gfs2_trans_begin(sdp
, RES_DINODE
+ 1, 0);
161 if (!page_has_buffers(page
)) {
162 create_empty_buffers(page
, inode
->i_sb
->s_blocksize
,
163 (1 << BH_Dirty
)|(1 << BH_Uptodate
));
165 gfs2_page_add_databufs(ip
, page
, 0, sdp
->sd_vfs
->s_blocksize
-1);
168 error
= block_write_full_page(page
, get_block_noalloc
, wbc
);
171 gfs2_meta_cache_flush(ip
);
175 redirty_page_for_writepage(wbc
, page
);
180 static int zero_readpage(struct page
*page
)
184 kaddr
= kmap_atomic(page
, KM_USER0
);
185 memset(kaddr
, 0, PAGE_CACHE_SIZE
);
186 kunmap_atomic(page
, KM_USER0
);
188 SetPageUptodate(page
);
194 * stuffed_readpage - Fill in a Linux page with stuffed file data
201 static int stuffed_readpage(struct gfs2_inode
*ip
, struct page
*page
)
203 struct buffer_head
*dibh
;
207 /* Only the first page of a stuffed file might contain data */
208 if (unlikely(page
->index
))
209 return zero_readpage(page
);
211 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
215 kaddr
= kmap_atomic(page
, KM_USER0
);
216 memcpy(kaddr
, dibh
->b_data
+ sizeof(struct gfs2_dinode
),
218 memset(kaddr
+ ip
->i_di
.di_size
, 0, PAGE_CACHE_SIZE
- ip
->i_di
.di_size
);
219 kunmap_atomic(page
, KM_USER0
);
223 SetPageUptodate(page
);
230 * gfs2_readpage - readpage with locking
231 * @file: The file to read a page for. N.B. This may be NULL if we are
232 * reading an internal file.
233 * @page: The page to read
238 static int gfs2_readpage(struct file
*file
, struct page
*page
)
240 struct gfs2_inode
*ip
= GFS2_I(page
->mapping
->host
);
241 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
242 struct gfs2_holder gh
;
246 if (likely(file
!= &gfs2_internal_file_sentinal
)) {
248 struct gfs2_file
*gf
= file
->private_data
;
249 if (test_bit(GFF_EXLOCK
, &gf
->f_flags
))
252 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
|GL_AOP
, &gh
);
254 error
= gfs2_glock_nq_m_atime(1, &gh
);
260 if (gfs2_is_stuffed(ip
)) {
261 error
= stuffed_readpage(ip
, page
);
264 error
= mpage_readpage(page
, gfs2_get_block
);
266 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
269 if (file
!= &gfs2_internal_file_sentinal
) {
270 gfs2_glock_dq_m(1, &gh
);
271 gfs2_holder_uninit(&gh
);
278 gfs2_holder_uninit(&gh
);
283 * gfs2_readpages - Read a bunch of pages at once
286 * 1. This is only for readahead, so we can simply ignore any things
287 * which are slightly inconvenient (such as locking conflicts between
288 * the page lock and the glock) and return having done no I/O. Its
289 * obviously not something we'd want to do on too regular a basis.
290 * Any I/O we ignore at this time will be done via readpage later.
291 * 2. We have to handle stuffed files here too.
292 * 3. mpage_readpages() does most of the heavy lifting in the common case.
293 * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
294 * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
295 * well as read-ahead.
297 static int gfs2_readpages(struct file
*file
, struct address_space
*mapping
,
298 struct list_head
*pages
, unsigned nr_pages
)
300 struct inode
*inode
= mapping
->host
;
301 struct gfs2_inode
*ip
= GFS2_I(inode
);
302 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
303 struct gfs2_holder gh
;
308 if (likely(file
!= &gfs2_internal_file_sentinal
)) {
310 struct gfs2_file
*gf
= file
->private_data
;
311 if (test_bit(GFF_EXLOCK
, &gf
->f_flags
))
314 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
,
315 LM_FLAG_TRY_1CB
|GL_ATIME
|GL_AOP
, &gh
);
317 ret
= gfs2_glock_nq_m_atime(1, &gh
);
318 if (ret
== GLR_TRYFAILED
)
324 if (gfs2_is_stuffed(ip
)) {
325 struct pagevec lru_pvec
;
326 pagevec_init(&lru_pvec
, 0);
327 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
328 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
329 prefetchw(&page
->flags
);
330 list_del(&page
->lru
);
331 if (!add_to_page_cache(page
, mapping
,
332 page
->index
, GFP_KERNEL
)) {
333 ret
= stuffed_readpage(ip
, page
);
335 if (!pagevec_add(&lru_pvec
, page
))
336 __pagevec_lru_add(&lru_pvec
);
338 page_cache_release(page
);
341 pagevec_lru_add(&lru_pvec
);
344 /* What we really want to do .... */
345 ret
= mpage_readpages(mapping
, pages
, nr_pages
, gfs2_get_block
);
349 gfs2_glock_dq_m(1, &gh
);
350 gfs2_holder_uninit(&gh
);
353 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
359 /* unlock all pages, we can't do any I/O right now */
360 for (page_idx
= 0; page_idx
< nr_pages
; page_idx
++) {
361 struct page
*page
= list_entry(pages
->prev
, struct page
, lru
);
362 list_del(&page
->lru
);
364 page_cache_release(page
);
367 gfs2_holder_uninit(&gh
);
372 * gfs2_prepare_write - Prepare to write a page to a file
373 * @file: The file to write to
374 * @page: The page which is to be prepared for writing
375 * @from: From (byte range within page)
376 * @to: To (byte range within page)
381 static int gfs2_prepare_write(struct file
*file
, struct page
*page
,
382 unsigned from
, unsigned to
)
384 struct gfs2_inode
*ip
= GFS2_I(page
->mapping
->host
);
385 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
386 unsigned int data_blocks
, ind_blocks
, rblocks
;
389 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + from
;
390 loff_t end
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
391 struct gfs2_alloc
*al
;
393 gfs2_holder_init(ip
->i_gl
, LM_ST_EXCLUSIVE
, GL_ATIME
|GL_AOP
, &ip
->i_gh
);
394 error
= gfs2_glock_nq_m_atime(1, &ip
->i_gh
);
398 gfs2_write_calc_reserv(ip
, to
- from
, &data_blocks
, &ind_blocks
);
400 error
= gfs2_write_alloc_required(ip
, pos
, from
- to
, &alloc_required
);
405 if (alloc_required
) {
406 al
= gfs2_alloc_get(ip
);
408 error
= gfs2_quota_lock(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
412 error
= gfs2_quota_check(ip
, ip
->i_di
.di_uid
, ip
->i_di
.di_gid
);
416 al
->al_requested
= data_blocks
+ ind_blocks
;
417 error
= gfs2_inplace_reserve(ip
);
422 rblocks
= RES_DINODE
+ ind_blocks
;
423 if (gfs2_is_jdata(ip
))
424 rblocks
+= data_blocks
? data_blocks
: 1;
425 if (ind_blocks
|| data_blocks
)
426 rblocks
+= RES_STATFS
+ RES_QUOTA
;
428 error
= gfs2_trans_begin(sdp
, rblocks
, 0);
432 if (gfs2_is_stuffed(ip
)) {
433 if (end
> sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
)) {
434 error
= gfs2_unstuff_dinode(ip
, page
);
437 } else if (!PageUptodate(page
))
438 error
= stuffed_readpage(ip
, page
);
443 error
= block_prepare_write(page
, from
, to
, gfs2_get_block
);
448 if (alloc_required
) {
449 gfs2_inplace_release(ip
);
451 gfs2_quota_unlock(ip
);
456 gfs2_glock_dq_m(1, &ip
->i_gh
);
458 gfs2_holder_uninit(&ip
->i_gh
);
465 * gfs2_commit_write - Commit write to a file
466 * @file: The file to write to
467 * @page: The page containing the data
468 * @from: From (byte range within page)
469 * @to: To (byte range within page)
474 static int gfs2_commit_write(struct file
*file
, struct page
*page
,
475 unsigned from
, unsigned to
)
477 struct inode
*inode
= page
->mapping
->host
;
478 struct gfs2_inode
*ip
= GFS2_I(inode
);
479 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
480 int error
= -EOPNOTSUPP
;
481 struct buffer_head
*dibh
;
482 struct gfs2_alloc
*al
= &ip
->i_alloc
;;
484 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_locked_by_me(ip
->i_gl
)))
487 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
491 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
493 if (gfs2_is_stuffed(ip
)) {
497 file_size
= ((uint64_t)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
499 kaddr
= kmap_atomic(page
, KM_USER0
);
500 memcpy(dibh
->b_data
+ sizeof(struct gfs2_dinode
) + from
,
501 (char *)kaddr
+ from
, to
- from
);
502 kunmap_atomic(page
, KM_USER0
);
504 SetPageUptodate(page
);
506 if (inode
->i_size
< file_size
)
507 i_size_write(inode
, file_size
);
509 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
||
511 gfs2_page_add_databufs(ip
, page
, from
, to
);
512 error
= generic_commit_write(file
, page
, from
, to
);
517 if (ip
->i_di
.di_size
< inode
->i_size
)
518 ip
->i_di
.di_size
= inode
->i_size
;
520 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
523 if (al
->al_requested
) {
524 gfs2_inplace_release(ip
);
525 gfs2_quota_unlock(ip
);
528 gfs2_glock_dq_m(1, &ip
->i_gh
);
529 gfs2_holder_uninit(&ip
->i_gh
);
536 if (al
->al_requested
) {
537 gfs2_inplace_release(ip
);
538 gfs2_quota_unlock(ip
);
541 gfs2_glock_dq_m(1, &ip
->i_gh
);
542 gfs2_holder_uninit(&ip
->i_gh
);
544 ClearPageUptodate(page
);
549 * gfs2_bmap - Block map function
550 * @mapping: Address space info
551 * @lblock: The block to map
553 * Returns: The disk address for the block or 0 on hole or error
556 static sector_t
gfs2_bmap(struct address_space
*mapping
, sector_t lblock
)
558 struct gfs2_inode
*ip
= GFS2_I(mapping
->host
);
559 struct gfs2_holder i_gh
;
563 error
= gfs2_glock_nq_init(ip
->i_gl
, LM_ST_SHARED
, LM_FLAG_ANY
, &i_gh
);
567 if (!gfs2_is_stuffed(ip
))
568 dblock
= generic_block_bmap(mapping
, lblock
, gfs2_get_block
);
570 gfs2_glock_dq_uninit(&i_gh
);
575 static void discard_buffer(struct gfs2_sbd
*sdp
, struct buffer_head
*bh
)
577 struct gfs2_bufdata
*bd
;
583 bh
->b_private
= NULL
;
585 gfs2_log_unlock(sdp
);
588 clear_buffer_dirty(bh
);
590 clear_buffer_mapped(bh
);
591 clear_buffer_req(bh
);
592 clear_buffer_new(bh
);
593 clear_buffer_delay(bh
);
597 static void gfs2_invalidatepage(struct page
*page
, unsigned long offset
)
599 struct gfs2_sbd
*sdp
= GFS2_SB(page
->mapping
->host
);
600 struct buffer_head
*head
, *bh
, *next
;
601 unsigned int curr_off
= 0;
603 BUG_ON(!PageLocked(page
));
604 if (!page_has_buffers(page
))
607 bh
= head
= page_buffers(page
);
609 unsigned int next_off
= curr_off
+ bh
->b_size
;
610 next
= bh
->b_this_page
;
612 if (offset
<= curr_off
)
613 discard_buffer(sdp
, bh
);
617 } while (bh
!= head
);
620 try_to_release_page(page
, 0);
625 static ssize_t
gfs2_direct_IO(int rw
, struct kiocb
*iocb
,
626 const struct iovec
*iov
, loff_t offset
,
627 unsigned long nr_segs
)
629 struct file
*file
= iocb
->ki_filp
;
630 struct inode
*inode
= file
->f_mapping
->host
;
631 struct gfs2_inode
*ip
= GFS2_I(inode
);
632 struct gfs2_holder gh
;
636 mutex_lock(&inode
->i_mutex
);
638 * Shared lock, even if its a write, since we do no allocation
639 * on this path. All we need change is atime.
641 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
, &gh
);
642 rv
= gfs2_glock_nq_m_atime(1, &gh
);
646 if (offset
> i_size_read(inode
))
650 * Should we return an error here? I can't see that O_DIRECT for
651 * a journaled file makes any sense. For now we'll silently fall
652 * back to buffered I/O, likewise we do the same for stuffed
653 * files since they are (a) small and (b) unaligned.
655 if (gfs2_is_jdata(ip
))
658 if (gfs2_is_stuffed(ip
))
661 rv
= blockdev_direct_IO_own_locking(rw
, iocb
, inode
,
663 iov
, offset
, nr_segs
,
664 gfs2_get_block
, NULL
);
666 gfs2_glock_dq_m(1, &gh
);
667 gfs2_holder_uninit(&gh
);
669 mutex_unlock(&inode
->i_mutex
);
675 * stuck_releasepage - We're stuck in gfs2_releasepage(). Print stuff out.
676 * @bh: the buffer we're stuck on
680 static void stuck_releasepage(struct buffer_head
*bh
)
682 struct inode
*inode
= bh
->b_page
->mapping
->host
;
683 struct gfs2_sbd
*sdp
= inode
->i_sb
->s_fs_info
;
684 struct gfs2_bufdata
*bd
= bh
->b_private
;
685 struct gfs2_glock
*gl
;
686 static unsigned limit
= 0;
691 fs_warn(sdp
, "stuck in gfs2_releasepage() %p\n", inode
);
692 fs_warn(sdp
, "blkno = %llu, bh->b_count = %d\n",
693 (unsigned long long)bh
->b_blocknr
, atomic_read(&bh
->b_count
));
694 fs_warn(sdp
, "pinned = %u\n", buffer_pinned(bh
));
695 fs_warn(sdp
, "bh->b_private = %s\n", (bd
) ? "!NULL" : "NULL");
702 fs_warn(sdp
, "gl = (%u, %llu)\n",
703 gl
->gl_name
.ln_type
, (unsigned long long)gl
->gl_name
.ln_number
);
705 fs_warn(sdp
, "bd_list_tr = %s, bd_le.le_list = %s\n",
706 (list_empty(&bd
->bd_list_tr
)) ? "no" : "yes",
707 (list_empty(&bd
->bd_le
.le_list
)) ? "no" : "yes");
709 if (gl
->gl_ops
== &gfs2_inode_glops
) {
710 struct gfs2_inode
*ip
= gl
->gl_object
;
716 fs_warn(sdp
, "ip = %llu %llu\n",
717 (unsigned long long)ip
->i_num
.no_formal_ino
,
718 (unsigned long long)ip
->i_num
.no_addr
);
720 for (x
= 0; x
< GFS2_MAX_META_HEIGHT
; x
++)
721 fs_warn(sdp
, "ip->i_cache[%u] = %s\n",
722 x
, (ip
->i_cache
[x
]) ? "!NULL" : "NULL");
727 * gfs2_aspace_releasepage - free the metadata associated with a page
728 * @page: the page that's being released
729 * @gfp_mask: passed from Linux VFS, ignored by us
731 * Call try_to_free_buffers() if the buffers in this page can be
737 int gfs2_releasepage(struct page
*page
, gfp_t gfp_mask
)
739 struct inode
*aspace
= page
->mapping
->host
;
740 struct gfs2_sbd
*sdp
= aspace
->i_sb
->s_fs_info
;
741 struct buffer_head
*bh
, *head
;
742 struct gfs2_bufdata
*bd
;
743 unsigned long t
= jiffies
+ gfs2_tune_get(sdp
, gt_stall_secs
) * HZ
;
745 if (!page_has_buffers(page
))
748 head
= bh
= page_buffers(page
);
750 while (atomic_read(&bh
->b_count
)) {
751 if (!atomic_read(&aspace
->i_writecount
))
754 if (time_after_eq(jiffies
, t
)) {
755 stuck_releasepage(bh
);
756 /* should we withdraw here? */
763 gfs2_assert_warn(sdp
, !buffer_pinned(bh
));
767 gfs2_assert_warn(sdp
, bd
->bd_bh
== bh
);
768 gfs2_assert_warn(sdp
, list_empty(&bd
->bd_list_tr
));
769 gfs2_assert_warn(sdp
, list_empty(&bd
->bd_le
.le_list
));
770 gfs2_assert_warn(sdp
, !bd
->bd_ail
);
771 kmem_cache_free(gfs2_bufdata_cachep
, bd
);
772 bh
->b_private
= NULL
;
775 bh
= bh
->b_this_page
;
776 } while (bh
!= head
);
779 return try_to_free_buffers(page
);
782 const struct address_space_operations gfs2_file_aops
= {
783 .writepage
= gfs2_writepage
,
784 .readpage
= gfs2_readpage
,
785 .readpages
= gfs2_readpages
,
786 .sync_page
= block_sync_page
,
787 .prepare_write
= gfs2_prepare_write
,
788 .commit_write
= gfs2_commit_write
,
790 .invalidatepage
= gfs2_invalidatepage
,
791 .releasepage
= gfs2_releasepage
,
792 .direct_IO
= gfs2_direct_IO
,