1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2010 Red Hat, Inc.
4 * Copyright (c) 2016-2018 Christoph Hellwig.
6 #include <linux/module.h>
7 #include <linux/compiler.h>
9 #include <linux/iomap.h>
10 #include <linux/pagemap.h>
11 #include <linux/uio.h>
12 #include <linux/buffer_head.h>
13 #include <linux/dax.h>
14 #include <linux/writeback.h>
15 #include <linux/swap.h>
16 #include <linux/bio.h>
17 #include <linux/sched/signal.h>
18 #include <linux/migrate.h>
20 #include "../internal.h"
22 static struct iomap_page *
23 iomap_page_create(struct inode *inode, struct page *page)
25 struct iomap_page *iop = to_iomap_page(page);
27 if (iop || i_blocksize(inode) == PAGE_SIZE)
30 iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
31 atomic_set(&iop->read_count, 0);
32 atomic_set(&iop->write_count, 0);
33 bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
36 * migrate_page_move_mapping() assumes that pages with private data have
37 * their count elevated by 1.
40 set_page_private(page, (unsigned long)iop);
46 iomap_page_release(struct page *page)
48 struct iomap_page *iop = to_iomap_page(page);
52 WARN_ON_ONCE(atomic_read(&iop->read_count));
53 WARN_ON_ONCE(atomic_read(&iop->write_count));
54 ClearPagePrivate(page);
55 set_page_private(page, 0);
61 * Calculate the range inside the page that we actually need to read.
64 iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
65 loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp)
67 loff_t orig_pos = *pos;
68 loff_t isize = i_size_read(inode);
69 unsigned block_bits = inode->i_blkbits;
70 unsigned block_size = (1 << block_bits);
71 unsigned poff = offset_in_page(*pos);
72 unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length);
73 unsigned first = poff >> block_bits;
74 unsigned last = (poff + plen - 1) >> block_bits;
77 * If the block size is smaller than the page size we need to check the
78 * per-block uptodate status and adjust the offset and length if needed
79 * to avoid reading in already uptodate ranges.
84 /* move forward for each leading block marked uptodate */
85 for (i = first; i <= last; i++) {
86 if (!test_bit(i, iop->uptodate))
94 /* truncate len if we find any trailing uptodate block(s) */
95 for ( ; i <= last; i++) {
96 if (test_bit(i, iop->uptodate)) {
97 plen -= (last - i + 1) * block_size;
105 * If the extent spans the block that contains the i_size we need to
106 * handle both halves separately so that we properly zero data in the
107 * page cache for blocks that are entirely outside of i_size.
109 if (orig_pos <= isize && orig_pos + length > isize) {
110 unsigned end = offset_in_page(isize - 1) >> block_bits;
112 if (first <= end && last > end)
113 plen -= (last - end) * block_size;
121 iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
123 struct iomap_page *iop = to_iomap_page(page);
124 struct inode *inode = page->mapping->host;
125 unsigned first = off >> inode->i_blkbits;
126 unsigned last = (off + len - 1) >> inode->i_blkbits;
128 bool uptodate = true;
131 for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
132 if (i >= first && i <= last)
133 set_bit(i, iop->uptodate);
134 else if (!test_bit(i, iop->uptodate))
139 if (uptodate && !PageError(page))
140 SetPageUptodate(page);
144 iomap_read_finish(struct iomap_page *iop, struct page *page)
146 if (!iop || atomic_dec_and_test(&iop->read_count))
151 iomap_read_page_end_io(struct bio_vec *bvec, int error)
153 struct page *page = bvec->bv_page;
154 struct iomap_page *iop = to_iomap_page(page);
156 if (unlikely(error)) {
157 ClearPageUptodate(page);
160 iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
163 iomap_read_finish(iop, page);
167 iomap_read_end_io(struct bio *bio)
169 int error = blk_status_to_errno(bio->bi_status);
170 struct bio_vec *bvec;
171 struct bvec_iter_all iter_all;
173 bio_for_each_segment_all(bvec, bio, iter_all)
174 iomap_read_page_end_io(bvec, error);
178 struct iomap_readpage_ctx {
179 struct page *cur_page;
180 bool cur_page_in_bio;
183 struct list_head *pages;
187 iomap_read_inline_data(struct inode *inode, struct page *page,
190 size_t size = i_size_read(inode);
193 if (PageUptodate(page))
197 BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
199 addr = kmap_atomic(page);
200 memcpy(addr, iomap->inline_data, size);
201 memset(addr + size, 0, PAGE_SIZE - size);
203 SetPageUptodate(page);
207 iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
210 struct iomap_readpage_ctx *ctx = data;
211 struct page *page = ctx->cur_page;
212 struct iomap_page *iop = iomap_page_create(inode, page);
213 bool same_page = false, is_contig = false;
214 loff_t orig_pos = pos;
218 if (iomap->type == IOMAP_INLINE) {
220 iomap_read_inline_data(inode, page, iomap);
224 /* zero post-eof blocks as the page may be mapped */
225 iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
229 if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) {
230 zero_user(page, poff, plen);
231 iomap_set_range_uptodate(page, poff, plen);
235 ctx->cur_page_in_bio = true;
238 * Try to merge into a previous segment if we can.
240 sector = iomap_sector(iomap, pos);
241 if (ctx->bio && bio_end_sector(ctx->bio) == sector)
245 __bio_try_merge_page(ctx->bio, page, plen, poff, &same_page)) {
246 if (!same_page && iop)
247 atomic_inc(&iop->read_count);
252 * If we start a new segment we need to increase the read count, and we
253 * need to do so before submitting any previous full bio to make sure
254 * that we don't prematurely unlock the page.
257 atomic_inc(&iop->read_count);
259 if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {
260 gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
261 int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
264 submit_bio(ctx->bio);
266 if (ctx->is_readahead) /* same as readahead_gfp_mask */
267 gfp |= __GFP_NORETRY | __GFP_NOWARN;
268 ctx->bio = bio_alloc(gfp, min(BIO_MAX_PAGES, nr_vecs));
269 ctx->bio->bi_opf = REQ_OP_READ;
270 if (ctx->is_readahead)
271 ctx->bio->bi_opf |= REQ_RAHEAD;
272 ctx->bio->bi_iter.bi_sector = sector;
273 bio_set_dev(ctx->bio, iomap->bdev);
274 ctx->bio->bi_end_io = iomap_read_end_io;
277 bio_add_page(ctx->bio, page, plen, poff);
280 * Move the caller beyond our range so that it keeps making progress.
281 * For that we have to include any leading non-uptodate ranges, but
282 * we can skip trailing ones as they will be handled in the next
285 return pos - orig_pos + plen;
289 iomap_readpage(struct page *page, const struct iomap_ops *ops)
291 struct iomap_readpage_ctx ctx = { .cur_page = page };
292 struct inode *inode = page->mapping->host;
296 for (poff = 0; poff < PAGE_SIZE; poff += ret) {
297 ret = iomap_apply(inode, page_offset(page) + poff,
298 PAGE_SIZE - poff, 0, ops, &ctx,
299 iomap_readpage_actor);
301 WARN_ON_ONCE(ret == 0);
309 WARN_ON_ONCE(!ctx.cur_page_in_bio);
311 WARN_ON_ONCE(ctx.cur_page_in_bio);
316 * Just like mpage_readpages and block_read_full_page we always
317 * return 0 and just mark the page as PageError on errors. This
318 * should be cleaned up all through the stack eventually.
322 EXPORT_SYMBOL_GPL(iomap_readpage);
325 iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos,
326 loff_t length, loff_t *done)
328 while (!list_empty(pages)) {
329 struct page *page = lru_to_page(pages);
331 if (page_offset(page) >= (u64)pos + length)
334 list_del(&page->lru);
335 if (!add_to_page_cache_lru(page, inode->i_mapping, page->index,
340 * If we already have a page in the page cache at index we are
341 * done. Upper layers don't care if it is uptodate after the
342 * readpages call itself as every page gets checked again once
353 iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
354 void *data, struct iomap *iomap)
356 struct iomap_readpage_ctx *ctx = data;
359 for (done = 0; done < length; done += ret) {
360 if (ctx->cur_page && offset_in_page(pos + done) == 0) {
361 if (!ctx->cur_page_in_bio)
362 unlock_page(ctx->cur_page);
363 put_page(ctx->cur_page);
364 ctx->cur_page = NULL;
366 if (!ctx->cur_page) {
367 ctx->cur_page = iomap_next_page(inode, ctx->pages,
371 ctx->cur_page_in_bio = false;
373 ret = iomap_readpage_actor(inode, pos + done, length - done,
381 iomap_readpages(struct address_space *mapping, struct list_head *pages,
382 unsigned nr_pages, const struct iomap_ops *ops)
384 struct iomap_readpage_ctx ctx = {
386 .is_readahead = true,
388 loff_t pos = page_offset(list_entry(pages->prev, struct page, lru));
389 loff_t last = page_offset(list_entry(pages->next, struct page, lru));
390 loff_t length = last - pos + PAGE_SIZE, ret = 0;
393 ret = iomap_apply(mapping->host, pos, length, 0, ops,
394 &ctx, iomap_readpages_actor);
396 WARN_ON_ONCE(ret == 0);
407 if (!ctx.cur_page_in_bio)
408 unlock_page(ctx.cur_page);
409 put_page(ctx.cur_page);
413 * Check that we didn't lose a page due to the arcance calling
416 WARN_ON_ONCE(!ret && !list_empty(ctx.pages));
419 EXPORT_SYMBOL_GPL(iomap_readpages);
422 * iomap_is_partially_uptodate checks whether blocks within a page are
425 * Returns true if all blocks which correspond to a file portion
426 * we want to read within the page are uptodate.
429 iomap_is_partially_uptodate(struct page *page, unsigned long from,
432 struct iomap_page *iop = to_iomap_page(page);
433 struct inode *inode = page->mapping->host;
434 unsigned len, first, last;
437 /* Limit range to one page */
438 len = min_t(unsigned, PAGE_SIZE - from, count);
440 /* First and last blocks in range within page */
441 first = from >> inode->i_blkbits;
442 last = (from + len - 1) >> inode->i_blkbits;
445 for (i = first; i <= last; i++)
446 if (!test_bit(i, iop->uptodate))
453 EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
456 iomap_releasepage(struct page *page, gfp_t gfp_mask)
459 * mm accommodates an old ext3 case where clean pages might not have had
460 * the dirty bit cleared. Thus, it can send actual dirty pages to
461 * ->releasepage() via shrink_active_list(), skip those here.
463 if (PageDirty(page) || PageWriteback(page))
465 iomap_page_release(page);
468 EXPORT_SYMBOL_GPL(iomap_releasepage);
471 iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len)
474 * If we are invalidating the entire page, clear the dirty state from it
475 * and release it to avoid unnecessary buildup of the LRU.
477 if (offset == 0 && len == PAGE_SIZE) {
478 WARN_ON_ONCE(PageWriteback(page));
479 cancel_dirty_page(page);
480 iomap_page_release(page);
483 EXPORT_SYMBOL_GPL(iomap_invalidatepage);
485 #ifdef CONFIG_MIGRATION
487 iomap_migrate_page(struct address_space *mapping, struct page *newpage,
488 struct page *page, enum migrate_mode mode)
492 ret = migrate_page_move_mapping(mapping, newpage, page, 0);
493 if (ret != MIGRATEPAGE_SUCCESS)
496 if (page_has_private(page)) {
497 ClearPagePrivate(page);
499 set_page_private(newpage, page_private(page));
500 set_page_private(page, 0);
502 SetPagePrivate(newpage);
505 if (mode != MIGRATE_SYNC_NO_COPY)
506 migrate_page_copy(newpage, page);
508 migrate_page_states(newpage, page);
509 return MIGRATEPAGE_SUCCESS;
511 EXPORT_SYMBOL_GPL(iomap_migrate_page);
512 #endif /* CONFIG_MIGRATION */
515 iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
517 loff_t i_size = i_size_read(inode);
520 * Only truncate newly allocated pages beyoned EOF, even if the
521 * write started inside the existing inode size.
523 if (pos + len > i_size)
524 truncate_pagecache_range(inode, max(pos, i_size), pos + len);
528 iomap_read_page_sync(struct inode *inode, loff_t block_start, struct page *page,
529 unsigned poff, unsigned plen, unsigned from, unsigned to,
535 if (iomap->type != IOMAP_MAPPED || block_start >= i_size_read(inode)) {
536 zero_user_segments(page, poff, from, to, poff + plen);
537 iomap_set_range_uptodate(page, poff, plen);
541 bio_init(&bio, &bvec, 1);
542 bio.bi_opf = REQ_OP_READ;
543 bio.bi_iter.bi_sector = iomap_sector(iomap, block_start);
544 bio_set_dev(&bio, iomap->bdev);
545 __bio_add_page(&bio, page, plen, poff);
546 return submit_bio_wait(&bio);
550 __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
551 struct page *page, struct iomap *iomap)
553 struct iomap_page *iop = iomap_page_create(inode, page);
554 loff_t block_size = i_blocksize(inode);
555 loff_t block_start = pos & ~(block_size - 1);
556 loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1);
557 unsigned from = offset_in_page(pos), to = from + len, poff, plen;
560 if (PageUptodate(page))
564 iomap_adjust_read_range(inode, iop, &block_start,
565 block_end - block_start, &poff, &plen);
569 if ((from > poff && from < poff + plen) ||
570 (to > poff && to < poff + plen)) {
571 status = iomap_read_page_sync(inode, block_start, page,
572 poff, plen, from, to, iomap);
577 } while ((block_start += plen) < block_end);
583 iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
584 struct page **pagep, struct iomap *iomap)
586 const struct iomap_page_ops *page_ops = iomap->page_ops;
587 pgoff_t index = pos >> PAGE_SHIFT;
591 BUG_ON(pos + len > iomap->offset + iomap->length);
593 if (fatal_signal_pending(current))
596 if (page_ops && page_ops->page_prepare) {
597 status = page_ops->page_prepare(inode, pos, len, iomap);
602 page = grab_cache_page_write_begin(inode->i_mapping, index, flags);
608 if (iomap->type == IOMAP_INLINE)
609 iomap_read_inline_data(inode, page, iomap);
610 else if (iomap->flags & IOMAP_F_BUFFER_HEAD)
611 status = __block_write_begin_int(page, pos, len, NULL, iomap);
613 status = __iomap_write_begin(inode, pos, len, page, iomap);
615 if (unlikely(status))
624 iomap_write_failed(inode, pos, len);
627 if (page_ops && page_ops->page_done)
628 page_ops->page_done(inode, pos, 0, NULL, iomap);
633 iomap_set_page_dirty(struct page *page)
635 struct address_space *mapping = page_mapping(page);
638 if (unlikely(!mapping))
639 return !TestSetPageDirty(page);
642 * Lock out page->mem_cgroup migration to keep PageDirty
643 * synchronized with per-memcg dirty page counters.
645 lock_page_memcg(page);
646 newly_dirty = !TestSetPageDirty(page);
648 __set_page_dirty(page, mapping, 0);
649 unlock_page_memcg(page);
652 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
655 EXPORT_SYMBOL_GPL(iomap_set_page_dirty);
658 __iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
659 unsigned copied, struct page *page, struct iomap *iomap)
661 flush_dcache_page(page);
664 * The blocks that were entirely written will now be uptodate, so we
665 * don't have to worry about a readpage reading them and overwriting a
666 * partial write. However if we have encountered a short write and only
667 * partially written into a block, it will not be marked uptodate, so a
668 * readpage might come in and destroy our partial write.
670 * Do the simplest thing, and just treat any short write to a non
671 * uptodate page as a zero-length write, and force the caller to redo
674 if (unlikely(copied < len && !PageUptodate(page)))
676 iomap_set_range_uptodate(page, offset_in_page(pos), len);
677 iomap_set_page_dirty(page);
682 iomap_write_end_inline(struct inode *inode, struct page *page,
683 struct iomap *iomap, loff_t pos, unsigned copied)
687 WARN_ON_ONCE(!PageUptodate(page));
688 BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
690 addr = kmap_atomic(page);
691 memcpy(iomap->inline_data + pos, addr + pos, copied);
694 mark_inode_dirty(inode);
699 iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
700 unsigned copied, struct page *page, struct iomap *iomap)
702 const struct iomap_page_ops *page_ops = iomap->page_ops;
703 loff_t old_size = inode->i_size;
706 if (iomap->type == IOMAP_INLINE) {
707 ret = iomap_write_end_inline(inode, page, iomap, pos, copied);
708 } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
709 ret = block_write_end(NULL, inode->i_mapping, pos, len, copied,
712 ret = __iomap_write_end(inode, pos, len, copied, page, iomap);
716 * Update the in-memory inode size after copying the data into the page
717 * cache. It's up to the file system to write the updated size to disk,
718 * preferably after I/O completion so that no stale data is exposed.
720 if (pos + ret > old_size) {
721 i_size_write(inode, pos + ret);
722 iomap->flags |= IOMAP_F_SIZE_CHANGED;
727 pagecache_isize_extended(inode, old_size, pos);
728 if (page_ops && page_ops->page_done)
729 page_ops->page_done(inode, pos, ret, page, iomap);
733 iomap_write_failed(inode, pos, len);
738 iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
741 struct iov_iter *i = data;
744 unsigned int flags = AOP_FLAG_NOFS;
748 unsigned long offset; /* Offset into pagecache page */
749 unsigned long bytes; /* Bytes to write to page */
750 size_t copied; /* Bytes copied from user */
752 offset = offset_in_page(pos);
753 bytes = min_t(unsigned long, PAGE_SIZE - offset,
760 * Bring in the user page that we will copy from _first_.
761 * Otherwise there's a nasty deadlock on copying from the
762 * same page as we're writing to, without it being marked
765 * Not only is this an optimisation, but it is also required
766 * to check that the address is actually valid, when atomic
767 * usercopies are used, below.
769 if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
774 status = iomap_write_begin(inode, pos, bytes, flags, &page,
776 if (unlikely(status))
779 if (mapping_writably_mapped(inode->i_mapping))
780 flush_dcache_page(page);
782 copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
784 flush_dcache_page(page);
786 status = iomap_write_end(inode, pos, bytes, copied, page,
788 if (unlikely(status < 0))
794 iov_iter_advance(i, copied);
795 if (unlikely(copied == 0)) {
797 * If we were unable to copy any data at all, we must
798 * fall back to a single segment length write.
800 * If we didn't fallback here, we could livelock
801 * because not all segments in the iov can be copied at
802 * once without a pagefault.
804 bytes = min_t(unsigned long, PAGE_SIZE - offset,
805 iov_iter_single_seg_count(i));
812 balance_dirty_pages_ratelimited(inode->i_mapping);
813 } while (iov_iter_count(i) && length);
815 return written ? written : status;
819 iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter,
820 const struct iomap_ops *ops)
822 struct inode *inode = iocb->ki_filp->f_mapping->host;
823 loff_t pos = iocb->ki_pos, ret = 0, written = 0;
825 while (iov_iter_count(iter)) {
826 ret = iomap_apply(inode, pos, iov_iter_count(iter),
827 IOMAP_WRITE, ops, iter, iomap_write_actor);
834 return written ? written : ret;
836 EXPORT_SYMBOL_GPL(iomap_file_buffered_write);
839 __iomap_read_page(struct inode *inode, loff_t offset)
841 struct address_space *mapping = inode->i_mapping;
844 page = read_mapping_page(mapping, offset >> PAGE_SHIFT, NULL);
847 if (!PageUptodate(page)) {
849 return ERR_PTR(-EIO);
855 iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
862 struct page *page, *rpage;
863 unsigned long offset; /* Offset into pagecache page */
864 unsigned long bytes; /* Bytes to write to page */
866 offset = offset_in_page(pos);
867 bytes = min_t(loff_t, PAGE_SIZE - offset, length);
869 rpage = __iomap_read_page(inode, pos);
871 return PTR_ERR(rpage);
873 status = iomap_write_begin(inode, pos, bytes,
874 AOP_FLAG_NOFS, &page, iomap);
876 if (unlikely(status))
879 WARN_ON_ONCE(!PageUptodate(page));
881 status = iomap_write_end(inode, pos, bytes, bytes, page, iomap);
882 if (unlikely(status <= 0)) {
883 if (WARN_ON_ONCE(status == 0))
894 balance_dirty_pages_ratelimited(inode->i_mapping);
901 iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
902 const struct iomap_ops *ops)
907 ret = iomap_apply(inode, pos, len, IOMAP_WRITE, ops, NULL,
917 EXPORT_SYMBOL_GPL(iomap_file_dirty);
919 static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
920 unsigned bytes, struct iomap *iomap)
925 status = iomap_write_begin(inode, pos, bytes, AOP_FLAG_NOFS, &page,
930 zero_user(page, offset, bytes);
931 mark_page_accessed(page);
933 return iomap_write_end(inode, pos, bytes, bytes, page, iomap);
936 static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
939 return __dax_zero_page_range(iomap->bdev, iomap->dax_dev,
940 iomap_sector(iomap, pos & PAGE_MASK), offset, bytes);
944 iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
945 void *data, struct iomap *iomap)
947 bool *did_zero = data;
951 /* already zeroed? we're done. */
952 if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN)
956 unsigned offset, bytes;
958 offset = offset_in_page(pos);
959 bytes = min_t(loff_t, PAGE_SIZE - offset, count);
962 status = iomap_dax_zero(pos, offset, bytes, iomap);
964 status = iomap_zero(inode, pos, offset, bytes, iomap);
979 iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
980 const struct iomap_ops *ops)
985 ret = iomap_apply(inode, pos, len, IOMAP_ZERO,
986 ops, did_zero, iomap_zero_range_actor);
996 EXPORT_SYMBOL_GPL(iomap_zero_range);
999 iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
1000 const struct iomap_ops *ops)
1002 unsigned int blocksize = i_blocksize(inode);
1003 unsigned int off = pos & (blocksize - 1);
1005 /* Block boundary? Nothing to do */
1008 return iomap_zero_range(inode, pos, blocksize - off, did_zero, ops);
1010 EXPORT_SYMBOL_GPL(iomap_truncate_page);
1013 iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length,
1014 void *data, struct iomap *iomap)
1016 struct page *page = data;
1019 if (iomap->flags & IOMAP_F_BUFFER_HEAD) {
1020 ret = __block_write_begin_int(page, pos, length, NULL, iomap);
1023 block_commit_write(page, 0, length);
1025 WARN_ON_ONCE(!PageUptodate(page));
1026 iomap_page_create(inode, page);
1027 set_page_dirty(page);
1033 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
1035 struct page *page = vmf->page;
1036 struct inode *inode = file_inode(vmf->vma->vm_file);
1037 unsigned long length;
1038 loff_t offset, size;
1042 size = i_size_read(inode);
1043 if ((page->mapping != inode->i_mapping) ||
1044 (page_offset(page) > size)) {
1045 /* We overload EFAULT to mean page got truncated */
1050 /* page is wholly or partially inside EOF */
1051 if (((page->index + 1) << PAGE_SHIFT) > size)
1052 length = offset_in_page(size);
1056 offset = page_offset(page);
1057 while (length > 0) {
1058 ret = iomap_apply(inode, offset, length,
1059 IOMAP_WRITE | IOMAP_FAULT, ops, page,
1060 iomap_page_mkwrite_actor);
1061 if (unlikely(ret <= 0))
1067 wait_for_stable_page(page);
1068 return VM_FAULT_LOCKED;
1071 return block_page_mkwrite_return(ret);
1073 EXPORT_SYMBOL_GPL(iomap_page_mkwrite);