2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 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/mpage.h>
18 #include <linux/gfs2_ondisk.h>
19 #include <asm/semaphore.h>
22 #include "lm_interface.h"
29 #include "ops_address.h"
38 * gfs2_get_block - Fills in a buffer head with details about a block
40 * @lblock: The block number to look up
41 * @bh_result: The buffer head to return the result in
42 * @create: Non-zero if we may add block to the file
47 int gfs2_get_block(struct inode
*inode
, sector_t lblock
,
48 struct buffer_head
*bh_result
, int create
)
50 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
55 error
= gfs2_block_map(ip
, lblock
, &new, &dblock
, NULL
);
62 map_bh(bh_result
, inode
->i_sb
, dblock
);
64 set_buffer_new(bh_result
);
70 * get_block_noalloc - Fills in a buffer head with details about a block
72 * @lblock: The block number to look up
73 * @bh_result: The buffer head to return the result in
74 * @create: Non-zero if we may add block to the file
79 static int get_block_noalloc(struct inode
*inode
, sector_t lblock
,
80 struct buffer_head
*bh_result
, int create
)
82 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
87 error
= gfs2_block_map(ip
, lblock
, &new, &dblock
, NULL
);
92 map_bh(bh_result
, inode
->i_sb
, dblock
);
93 else if (gfs2_assert_withdraw(ip
->i_sbd
, !create
))
99 static int get_blocks(struct inode
*inode
, sector_t lblock
,
100 unsigned long max_blocks
, struct buffer_head
*bh_result
,
103 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
109 error
= gfs2_block_map(ip
, lblock
, &new, &dblock
, &extlen
);
116 map_bh(bh_result
, inode
->i_sb
, dblock
);
118 set_buffer_new(bh_result
);
120 if (extlen
> max_blocks
)
122 bh_result
->b_size
= extlen
<< inode
->i_blkbits
;
127 static int get_blocks_noalloc(struct inode
*inode
, sector_t lblock
,
128 unsigned long max_blocks
,
129 struct buffer_head
*bh_result
, int create
)
131 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
137 error
= gfs2_block_map(ip
, lblock
, &new, &dblock
, &extlen
);
142 map_bh(bh_result
, inode
->i_sb
, dblock
);
143 if (extlen
> max_blocks
)
145 bh_result
->b_size
= extlen
<< inode
->i_blkbits
;
146 } else if (gfs2_assert_withdraw(ip
->i_sbd
, !create
))
153 * gfs2_writepage - Write complete page
154 * @page: Page to write
158 * Some of this is copied from block_write_full_page() although we still
159 * call it to do most of the work.
162 static int gfs2_writepage(struct page
*page
, struct writeback_control
*wbc
)
164 struct inode
*inode
= page
->mapping
->host
;
165 struct gfs2_inode
*ip
= page
->mapping
->host
->u
.generic_ip
;
166 struct gfs2_sbd
*sdp
= ip
->i_sbd
;
167 loff_t i_size
= i_size_read(inode
);
168 pgoff_t end_index
= i_size
>> PAGE_CACHE_SHIFT
;
173 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_held_excl(ip
->i_gl
))) {
177 if (current
->journal_info
)
180 /* Is the page fully outside i_size? (truncate in progress) */
181 offset
= i_size
& (PAGE_CACHE_SIZE
-1);
182 if (page
->index
>= end_index
+1 || !offset
) {
183 page
->mapping
->a_ops
->invalidatepage(page
, 0);
185 return 0; /* don't care */
188 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
|| gfs2_is_jdata(ip
)) {
189 error
= gfs2_trans_begin(sdp
, RES_DINODE
+ 1, 0);
192 gfs2_page_add_databufs(ip
, page
, 0, sdp
->sd_vfs
->s_blocksize
-1);
195 error
= block_write_full_page(page
, get_block_noalloc
, wbc
);
198 gfs2_meta_cache_flush(ip
);
202 redirty_page_for_writepage(wbc
, page
);
208 * stuffed_readpage - Fill in a Linux page with stuffed file data
215 static int stuffed_readpage(struct gfs2_inode
*ip
, struct page
*page
)
217 struct buffer_head
*dibh
;
221 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
225 kaddr
= kmap_atomic(page
, KM_USER0
);
226 memcpy((char *)kaddr
,
227 dibh
->b_data
+ sizeof(struct gfs2_dinode
),
229 memset((char *)kaddr
+ ip
->i_di
.di_size
,
231 PAGE_CACHE_SIZE
- ip
->i_di
.di_size
);
232 kunmap_atomic(page
, KM_USER0
);
236 SetPageUptodate(page
);
241 static int zero_readpage(struct page
*page
)
245 kaddr
= kmap_atomic(page
, KM_USER0
);
246 memset(kaddr
, 0, PAGE_CACHE_SIZE
);
247 kunmap_atomic(page
, KM_USER0
);
249 SetPageUptodate(page
);
256 * gfs2_readpage - readpage with locking
257 * @file: The file to read a page for. N.B. This may be NULL if we are
258 * reading an internal file.
259 * @page: The page to read
264 static int gfs2_readpage(struct file
*file
, struct page
*page
)
266 struct gfs2_inode
*ip
= page
->mapping
->host
->u
.generic_ip
;
267 struct gfs2_sbd
*sdp
= ip
->i_sbd
;
268 struct gfs2_holder gh
;
271 if (file
!= &gfs2_internal_file_sentinal
) {
272 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
, &gh
);
273 error
= gfs2_glock_nq_m_atime(1, &gh
);
278 if (gfs2_is_stuffed(ip
)) {
280 error
= stuffed_readpage(ip
, page
);
283 error
= zero_readpage(page
);
285 error
= mpage_readpage(page
, gfs2_get_block
);
287 if (unlikely(test_bit(SDF_SHUTDOWN
, &sdp
->sd_flags
)))
290 if (file
!= &gfs2_internal_file_sentinal
) {
291 gfs2_glock_dq_m(1, &gh
);
292 gfs2_holder_uninit(&gh
);
302 * gfs2_prepare_write - Prepare to write a page to a file
303 * @file: The file to write to
304 * @page: The page which is to be prepared for writing
305 * @from: From (byte range within page)
306 * @to: To (byte range within page)
311 static int gfs2_prepare_write(struct file
*file
, struct page
*page
,
312 unsigned from
, unsigned to
)
314 struct gfs2_inode
*ip
= page
->mapping
->host
->u
.generic_ip
;
315 struct gfs2_sbd
*sdp
= ip
->i_sbd
;
316 unsigned int data_blocks
, ind_blocks
, rblocks
;
319 loff_t pos
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + from
;
320 loff_t end
= ((loff_t
)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
321 struct gfs2_alloc
*al
;
323 gfs2_holder_init(ip
->i_gl
, LM_ST_EXCLUSIVE
, GL_ATIME
, &ip
->i_gh
);
324 error
= gfs2_glock_nq_m_atime(1, &ip
->i_gh
);
328 gfs2_write_calc_reserv(ip
, to
- from
, &data_blocks
, &ind_blocks
);
330 error
= gfs2_write_alloc_required(ip
, pos
, from
- to
, &alloc_required
);
335 if (alloc_required
) {
336 al
= gfs2_alloc_get(ip
);
338 error
= gfs2_quota_lock(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
342 error
= gfs2_quota_check(ip
, ip
->i_di
.di_uid
, ip
->i_di
.di_gid
);
346 al
->al_requested
= data_blocks
+ ind_blocks
;
347 error
= gfs2_inplace_reserve(ip
);
352 rblocks
= RES_DINODE
+ ind_blocks
;
353 if (gfs2_is_jdata(ip
))
354 rblocks
+= data_blocks
? data_blocks
: 1;
355 if (ind_blocks
|| data_blocks
)
356 rblocks
+= RES_STATFS
+ RES_QUOTA
;
358 error
= gfs2_trans_begin(sdp
, rblocks
, 0);
362 if (gfs2_is_stuffed(ip
)) {
363 if (end
> sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
)) {
364 error
= gfs2_unstuff_dinode(ip
, gfs2_unstuffer_page
,
368 } else if (!PageUptodate(page
))
369 error
= stuffed_readpage(ip
, page
);
374 error
= block_prepare_write(page
, from
, to
, gfs2_get_block
);
379 if (alloc_required
) {
380 gfs2_inplace_release(ip
);
382 gfs2_quota_unlock(ip
);
387 gfs2_glock_dq_m(1, &ip
->i_gh
);
389 gfs2_holder_uninit(&ip
->i_gh
);
396 * gfs2_commit_write - Commit write to a file
397 * @file: The file to write to
398 * @page: The page containing the data
399 * @from: From (byte range within page)
400 * @to: To (byte range within page)
405 static int gfs2_commit_write(struct file
*file
, struct page
*page
,
406 unsigned from
, unsigned to
)
408 struct inode
*inode
= page
->mapping
->host
;
409 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
410 struct gfs2_sbd
*sdp
= ip
->i_sbd
;
411 int error
= -EOPNOTSUPP
;
412 struct buffer_head
*dibh
;
413 struct gfs2_alloc
*al
= &ip
->i_alloc
;;
415 if (gfs2_assert_withdraw(sdp
, gfs2_glock_is_locked_by_me(ip
->i_gl
)))
418 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
422 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
424 if (gfs2_is_stuffed(ip
)) {
428 file_size
= ((uint64_t)page
->index
<< PAGE_CACHE_SHIFT
) + to
;
430 kaddr
= kmap_atomic(page
, KM_USER0
);
431 memcpy(dibh
->b_data
+ sizeof(struct gfs2_dinode
) + from
,
432 (char *)kaddr
+ from
, to
- from
);
433 kunmap_atomic(page
, KM_USER0
);
435 SetPageUptodate(page
);
437 if (inode
->i_size
< file_size
)
438 i_size_write(inode
, file_size
);
440 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
||
442 gfs2_page_add_databufs(ip
, page
, from
, to
);
443 error
= generic_commit_write(file
, page
, from
, to
);
448 if (ip
->i_di
.di_size
< inode
->i_size
)
449 ip
->i_di
.di_size
= inode
->i_size
;
451 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
454 if (al
->al_requested
) {
455 gfs2_inplace_release(ip
);
456 gfs2_quota_unlock(ip
);
459 gfs2_glock_dq_m(1, &ip
->i_gh
);
460 gfs2_holder_uninit(&ip
->i_gh
);
467 if (al
->al_requested
) {
468 gfs2_inplace_release(ip
);
469 gfs2_quota_unlock(ip
);
472 gfs2_glock_dq_m(1, &ip
->i_gh
);
473 gfs2_holder_uninit(&ip
->i_gh
);
475 ClearPageUptodate(page
);
480 * gfs2_bmap - Block map function
481 * @mapping: Address space info
482 * @lblock: The block to map
484 * Returns: The disk address for the block or 0 on hole or error
487 static sector_t
gfs2_bmap(struct address_space
*mapping
, sector_t lblock
)
489 struct gfs2_inode
*ip
= mapping
->host
->u
.generic_ip
;
490 struct gfs2_holder i_gh
;
494 error
= gfs2_glock_nq_init(ip
->i_gl
, LM_ST_SHARED
, LM_FLAG_ANY
, &i_gh
);
498 if (!gfs2_is_stuffed(ip
))
499 dblock
= generic_block_bmap(mapping
, lblock
, gfs2_get_block
);
501 gfs2_glock_dq_uninit(&i_gh
);
506 static void discard_buffer(struct gfs2_sbd
*sdp
, struct buffer_head
*bh
)
508 struct gfs2_bufdata
*bd
;
514 bh
->b_private
= NULL
;
515 gfs2_log_unlock(sdp
);
518 gfs2_log_unlock(sdp
);
521 clear_buffer_dirty(bh
);
523 clear_buffer_mapped(bh
);
524 clear_buffer_req(bh
);
525 clear_buffer_new(bh
);
526 clear_buffer_delay(bh
);
530 static int gfs2_invalidatepage(struct page
*page
, unsigned long offset
)
532 struct gfs2_sbd
*sdp
= page
->mapping
->host
->i_sb
->s_fs_info
;
533 struct buffer_head
*head
, *bh
, *next
;
534 unsigned int curr_off
= 0;
537 BUG_ON(!PageLocked(page
));
538 if (!page_has_buffers(page
))
541 bh
= head
= page_buffers(page
);
543 unsigned int next_off
= curr_off
+ bh
->b_size
;
544 next
= bh
->b_this_page
;
546 if (offset
<= curr_off
)
547 discard_buffer(sdp
, bh
);
551 } while (bh
!= head
);
554 ret
= try_to_release_page(page
, 0);
559 static ssize_t
gfs2_direct_IO_write(struct kiocb
*iocb
, const struct iovec
*iov
,
560 loff_t offset
, unsigned long nr_segs
)
562 struct file
*file
= iocb
->ki_filp
;
563 struct inode
*inode
= file
->f_mapping
->host
;
564 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
565 struct gfs2_holder gh
;
569 * Shared lock, even though its write, since we do no allocation
570 * on this path. All we need change is atime.
572 gfs2_holder_init(ip
->i_gl
, LM_ST_SHARED
, GL_ATIME
, &gh
);
573 rv
= gfs2_glock_nq_m_atime(1, &gh
);
578 * Should we return an error here? I can't see that O_DIRECT for
579 * a journaled file makes any sense. For now we'll silently fall
580 * back to buffered I/O, likewise we do the same for stuffed
581 * files since they are (a) small and (b) unaligned.
583 if (gfs2_is_jdata(ip
))
586 if (gfs2_is_stuffed(ip
))
589 rv
= __blockdev_direct_IO(WRITE
, iocb
, inode
, inode
->i_sb
->s_bdev
,
590 iov
, offset
, nr_segs
, get_blocks_noalloc
,
591 NULL
, DIO_OWN_LOCKING
);
593 gfs2_glock_dq_m(1, &gh
);
594 gfs2_holder_uninit(&gh
);
602 * This is called with a shared lock already held for the read path.
603 * Currently, no locks are held when the write path is called.
605 static ssize_t
gfs2_direct_IO(int rw
, struct kiocb
*iocb
,
606 const struct iovec
*iov
, loff_t offset
,
607 unsigned long nr_segs
)
609 struct file
*file
= iocb
->ki_filp
;
610 struct inode
*inode
= file
->f_mapping
->host
;
611 struct gfs2_inode
*ip
= inode
->u
.generic_ip
;
612 struct gfs2_sbd
*sdp
= ip
->i_sbd
;
615 return gfs2_direct_IO_write(iocb
, iov
, offset
, nr_segs
);
617 if (gfs2_assert_warn(sdp
, gfs2_glock_is_locked_by_me(ip
->i_gl
)) ||
618 gfs2_assert_warn(sdp
, !gfs2_is_stuffed(ip
)))
621 return __blockdev_direct_IO(READ
, iocb
, inode
, inode
->i_sb
->s_bdev
, iov
,
622 offset
, nr_segs
, get_blocks
, NULL
,
626 struct address_space_operations gfs2_file_aops
= {
627 .writepage
= gfs2_writepage
,
628 .readpage
= gfs2_readpage
,
629 .sync_page
= block_sync_page
,
630 .prepare_write
= gfs2_prepare_write
,
631 .commit_write
= gfs2_commit_write
,
633 .invalidatepage
= gfs2_invalidatepage
,
634 .direct_IO
= gfs2_direct_IO
,