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 <asm/semaphore.h>
26 #include "ops_address.h"
34 * gfs2_get_block - Fills in a buffer head with details about a block
36 * @lblock: The block number to look up
37 * @bh_result: The buffer head to return the result in
38 * @create: Non-zero if we may add block to the file
43 int gfs2_get_block(struct inode *inode, sector_t lblock,
44 struct buffer_head *bh_result, int create)
46 struct gfs2_inode *ip = get_v2ip(inode);
51 error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
58 map_bh(bh_result, inode->i_sb, dblock);
60 set_buffer_new(bh_result);
66 * get_block_noalloc - Fills in a buffer head with details about a block
68 * @lblock: The block number to look up
69 * @bh_result: The buffer head to return the result in
70 * @create: Non-zero if we may add block to the file
75 static int get_block_noalloc(struct inode *inode, sector_t lblock,
76 struct buffer_head *bh_result, int create)
78 struct gfs2_inode *ip = get_v2ip(inode);
83 error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
88 map_bh(bh_result, inode->i_sb, dblock);
89 else if (gfs2_assert_withdraw(ip->i_sbd, !create))
95 static int get_blocks(struct inode *inode, sector_t lblock,
96 unsigned long max_blocks, struct buffer_head *bh_result,
99 struct gfs2_inode *ip = get_v2ip(inode);
105 error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
112 map_bh(bh_result, inode->i_sb, dblock);
114 set_buffer_new(bh_result);
116 if (extlen > max_blocks)
118 bh_result->b_size = extlen << inode->i_blkbits;
123 static int get_blocks_noalloc(struct inode *inode, sector_t lblock,
124 unsigned long max_blocks,
125 struct buffer_head *bh_result, int create)
127 struct gfs2_inode *ip = get_v2ip(inode);
133 error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
138 map_bh(bh_result, inode->i_sb, dblock);
139 if (extlen > max_blocks)
141 bh_result->b_size = extlen << inode->i_blkbits;
142 } else if (gfs2_assert_withdraw(ip->i_sbd, !create))
149 * gfs2_writepage - Write complete page
150 * @page: Page to write
154 * Some of this is copied from block_write_full_page() although we still
155 * call it to do most of the work.
158 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
160 struct inode *inode = page->mapping->host;
161 struct gfs2_inode *ip = get_v2ip(page->mapping->host);
162 struct gfs2_sbd *sdp = ip->i_sbd;
163 loff_t i_size = i_size_read(inode);
164 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
169 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
176 /* Is the page fully outside i_size? (truncate in progress) */
177 offset = i_size & (PAGE_CACHE_SIZE-1);
178 if (page->index >= end_index+1 || !offset) {
179 page->mapping->a_ops->invalidatepage(page, 0);
181 return 0; /* don't care */
184 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
185 error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
188 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
191 error = block_write_full_page(page, get_block_noalloc, wbc);
194 gfs2_meta_cache_flush(ip);
198 redirty_page_for_writepage(wbc, page);
204 * stuffed_readpage - Fill in a Linux page with stuffed file data
211 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
213 struct buffer_head *dibh;
217 error = gfs2_meta_inode_buffer(ip, &dibh);
221 kaddr = kmap_atomic(page, KM_USER0);
222 memcpy((char *)kaddr,
223 dibh->b_data + sizeof(struct gfs2_dinode),
225 memset((char *)kaddr + ip->i_di.di_size,
227 PAGE_CACHE_SIZE - ip->i_di.di_size);
228 kunmap_atomic(page, KM_USER0);
232 SetPageUptodate(page);
237 static int zero_readpage(struct page *page)
241 kaddr = kmap_atomic(page, KM_USER0);
242 memset(kaddr, 0, PAGE_CACHE_SIZE);
243 kunmap_atomic(page, KM_USER0);
245 SetPageUptodate(page);
252 * gfs2_readpage - readpage with locking
253 * @file: The file to read a page for. N.B. This may be NULL if we are
254 * reading an internal file.
255 * @page: The page to read
260 static int gfs2_readpage(struct file *file, struct page *page)
262 struct gfs2_inode *ip = get_v2ip(page->mapping->host);
263 struct gfs2_sbd *sdp = ip->i_sbd;
264 struct gfs2_holder gh;
267 if (file != &gfs2_internal_file_sentinal) {
268 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
269 error = gfs2_glock_nq_m_atime(1, &gh);
274 if (gfs2_is_stuffed(ip)) {
276 error = stuffed_readpage(ip, page);
279 error = zero_readpage(page);
281 error = mpage_readpage(page, gfs2_get_block);
283 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
286 if (file != &gfs2_internal_file_sentinal) {
287 gfs2_glock_dq_m(1, &gh);
288 gfs2_holder_uninit(&gh);
298 * gfs2_prepare_write - Prepare to write a page to a file
299 * @file: The file to write to
300 * @page: The page which is to be prepared for writing
301 * @from: From (byte range within page)
302 * @to: To (byte range within page)
307 static int gfs2_prepare_write(struct file *file, struct page *page,
308 unsigned from, unsigned to)
310 struct gfs2_inode *ip = get_v2ip(page->mapping->host);
311 struct gfs2_sbd *sdp = ip->i_sbd;
312 unsigned int data_blocks, ind_blocks, rblocks;
315 loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
316 loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
317 struct gfs2_alloc *al;
319 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
320 error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
324 gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);
326 error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
331 if (alloc_required) {
332 al = gfs2_alloc_get(ip);
334 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
338 error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
342 al->al_requested = data_blocks + ind_blocks;
343 error = gfs2_inplace_reserve(ip);
348 rblocks = RES_DINODE + ind_blocks;
349 if (gfs2_is_jdata(ip))
350 rblocks += data_blocks ? data_blocks : 1;
351 if (ind_blocks || data_blocks)
352 rblocks += RES_STATFS + RES_QUOTA;
354 error = gfs2_trans_begin(sdp, rblocks, 0);
358 if (gfs2_is_stuffed(ip)) {
359 if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
360 error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
364 } else if (!PageUptodate(page))
365 error = stuffed_readpage(ip, page);
370 error = block_prepare_write(page, from, to, gfs2_get_block);
375 if (alloc_required) {
376 gfs2_inplace_release(ip);
378 gfs2_quota_unlock(ip);
383 gfs2_glock_dq_m(1, &ip->i_gh);
385 gfs2_holder_uninit(&ip->i_gh);
392 * gfs2_commit_write - Commit write to a file
393 * @file: The file to write to
394 * @page: The page containing the data
395 * @from: From (byte range within page)
396 * @to: To (byte range within page)
401 static int gfs2_commit_write(struct file *file, struct page *page,
402 unsigned from, unsigned to)
404 struct inode *inode = page->mapping->host;
405 struct gfs2_inode *ip = get_v2ip(inode);
406 struct gfs2_sbd *sdp = ip->i_sbd;
407 int error = -EOPNOTSUPP;
408 struct buffer_head *dibh;
409 struct gfs2_alloc *al = &ip->i_alloc;;
411 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
414 error = gfs2_meta_inode_buffer(ip, &dibh);
418 gfs2_trans_add_bh(ip->i_gl, dibh, 1);
420 if (gfs2_is_stuffed(ip)) {
424 file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
426 kaddr = kmap_atomic(page, KM_USER0);
427 memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
428 (char *)kaddr + from, to - from);
429 kunmap_atomic(page, KM_USER0);
431 SetPageUptodate(page);
433 if (inode->i_size < file_size)
434 i_size_write(inode, file_size);
436 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
438 gfs2_page_add_databufs(ip, page, from, to);
439 error = generic_commit_write(file, page, from, to);
444 if (ip->i_di.di_size < inode->i_size)
445 ip->i_di.di_size = inode->i_size;
447 gfs2_dinode_out(&ip->i_di, dibh->b_data);
450 if (al->al_requested) {
451 gfs2_inplace_release(ip);
452 gfs2_quota_unlock(ip);
455 gfs2_glock_dq_m(1, &ip->i_gh);
456 gfs2_holder_uninit(&ip->i_gh);
463 if (al->al_requested) {
464 gfs2_inplace_release(ip);
465 gfs2_quota_unlock(ip);
468 gfs2_glock_dq_m(1, &ip->i_gh);
469 gfs2_holder_uninit(&ip->i_gh);
471 ClearPageUptodate(page);
476 * gfs2_bmap - Block map function
477 * @mapping: Address space info
478 * @lblock: The block to map
480 * Returns: The disk address for the block or 0 on hole or error
483 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
485 struct gfs2_inode *ip = get_v2ip(mapping->host);
486 struct gfs2_holder i_gh;
490 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
494 if (!gfs2_is_stuffed(ip))
495 dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
497 gfs2_glock_dq_uninit(&i_gh);
502 static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
504 struct gfs2_bufdata *bd;
511 gfs2_log_unlock(sdp);
514 gfs2_log_unlock(sdp);
517 clear_buffer_dirty(bh);
519 clear_buffer_mapped(bh);
520 clear_buffer_req(bh);
521 clear_buffer_new(bh);
522 clear_buffer_delay(bh);
526 static int gfs2_invalidatepage(struct page *page, unsigned long offset)
528 struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb);
529 struct buffer_head *head, *bh, *next;
530 unsigned int curr_off = 0;
533 BUG_ON(!PageLocked(page));
534 if (!page_has_buffers(page))
537 bh = head = page_buffers(page);
539 unsigned int next_off = curr_off + bh->b_size;
540 next = bh->b_this_page;
542 if (offset <= curr_off)
543 discard_buffer(sdp, bh);
547 } while (bh != head);
550 ret = try_to_release_page(page, 0);
555 static ssize_t gfs2_direct_IO_write(struct kiocb *iocb, const struct iovec *iov,
556 loff_t offset, unsigned long nr_segs)
558 struct file *file = iocb->ki_filp;
559 struct inode *inode = file->f_mapping->host;
560 struct gfs2_inode *ip = get_v2ip(inode);
561 struct gfs2_holder gh;
565 * Shared lock, even though its write, since we do no allocation
566 * on this path. All we need change is atime.
568 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
569 rv = gfs2_glock_nq_m_atime(1, &gh);
574 * Should we return an error here? I can't see that O_DIRECT for
575 * a journaled file makes any sense. For now we'll silently fall
576 * back to buffered I/O, likewise we do the same for stuffed
577 * files since they are (a) small and (b) unaligned.
579 if (gfs2_is_jdata(ip))
582 if (gfs2_is_stuffed(ip))
585 rv = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
586 iov, offset, nr_segs, get_blocks_noalloc,
587 NULL, DIO_OWN_LOCKING);
589 gfs2_glock_dq_m(1, &gh);
590 gfs2_holder_uninit(&gh);
598 * This is called with a shared lock already held for the read path.
599 * Currently, no locks are held when the write path is called.
601 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
602 const struct iovec *iov, loff_t offset,
603 unsigned long nr_segs)
605 struct file *file = iocb->ki_filp;
606 struct inode *inode = file->f_mapping->host;
607 struct gfs2_inode *ip = get_v2ip(inode);
608 struct gfs2_sbd *sdp = ip->i_sbd;
611 return gfs2_direct_IO_write(iocb, iov, offset, nr_segs);
613 if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
614 gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
617 return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
618 offset, nr_segs, get_blocks, NULL,
622 struct address_space_operations gfs2_file_aops = {
623 .writepage = gfs2_writepage,
624 .readpage = gfs2_readpage,
625 .sync_page = block_sync_page,
626 .prepare_write = gfs2_prepare_write,
627 .commit_write = gfs2_commit_write,
629 .invalidatepage = gfs2_invalidatepage,
630 .direct_IO = gfs2_direct_IO,