1afc51aaaSDarrick J. Wong // SPDX-License-Identifier: GPL-2.0 2afc51aaaSDarrick J. Wong /* 3afc51aaaSDarrick J. Wong * Copyright (C) 2010 Red Hat, Inc. 4598ecfbaSChristoph Hellwig * Copyright (C) 2016-2019 Christoph Hellwig. 5afc51aaaSDarrick J. Wong */ 6afc51aaaSDarrick J. Wong #include <linux/module.h> 7afc51aaaSDarrick J. Wong #include <linux/compiler.h> 8afc51aaaSDarrick J. Wong #include <linux/fs.h> 9afc51aaaSDarrick J. Wong #include <linux/iomap.h> 10afc51aaaSDarrick J. Wong #include <linux/pagemap.h> 11afc51aaaSDarrick J. Wong #include <linux/uio.h> 12afc51aaaSDarrick J. Wong #include <linux/buffer_head.h> 13afc51aaaSDarrick J. Wong #include <linux/dax.h> 14afc51aaaSDarrick J. Wong #include <linux/writeback.h> 15598ecfbaSChristoph Hellwig #include <linux/list_sort.h> 16afc51aaaSDarrick J. Wong #include <linux/swap.h> 17afc51aaaSDarrick J. Wong #include <linux/bio.h> 18afc51aaaSDarrick J. Wong #include <linux/sched/signal.h> 19afc51aaaSDarrick J. Wong #include <linux/migrate.h> 209e91c572SChristoph Hellwig #include "trace.h" 21afc51aaaSDarrick J. Wong 22afc51aaaSDarrick J. Wong #include "../internal.h" 23afc51aaaSDarrick J. Wong 24ab08b01eSChristoph Hellwig /* 250a195b91SMatthew Wilcox (Oracle) * Structure allocated for each page or THP when block size < page size 260a195b91SMatthew Wilcox (Oracle) * to track sub-page uptodate status and I/O completions. 27ab08b01eSChristoph Hellwig */ 28ab08b01eSChristoph Hellwig struct iomap_page { 297d636676SMatthew Wilcox (Oracle) atomic_t read_bytes_pending; 300fb2d720SMatthew Wilcox (Oracle) atomic_t write_bytes_pending; 311cea335dSChristoph Hellwig spinlock_t uptodate_lock; 320a195b91SMatthew Wilcox (Oracle) unsigned long uptodate[]; 33ab08b01eSChristoph Hellwig }; 34ab08b01eSChristoph Hellwig 35ab08b01eSChristoph Hellwig static inline struct iomap_page *to_iomap_page(struct page *page) 36ab08b01eSChristoph Hellwig { 370a195b91SMatthew Wilcox (Oracle) /* 380a195b91SMatthew Wilcox (Oracle) * per-block data is stored in the head page. Callers should 390a195b91SMatthew Wilcox (Oracle) * not be dealing with tail pages (and if they are, they can 400a195b91SMatthew Wilcox (Oracle) * call thp_head() first. 410a195b91SMatthew Wilcox (Oracle) */ 420a195b91SMatthew Wilcox (Oracle) VM_BUG_ON_PGFLAGS(PageTail(page), page); 430a195b91SMatthew Wilcox (Oracle) 44ab08b01eSChristoph Hellwig if (page_has_private(page)) 45ab08b01eSChristoph Hellwig return (struct iomap_page *)page_private(page); 46ab08b01eSChristoph Hellwig return NULL; 47ab08b01eSChristoph Hellwig } 48ab08b01eSChristoph Hellwig 49598ecfbaSChristoph Hellwig static struct bio_set iomap_ioend_bioset; 50598ecfbaSChristoph Hellwig 51afc51aaaSDarrick J. Wong static struct iomap_page * 52afc51aaaSDarrick J. Wong iomap_page_create(struct inode *inode, struct page *page) 53afc51aaaSDarrick J. Wong { 54afc51aaaSDarrick J. Wong struct iomap_page *iop = to_iomap_page(page); 550a195b91SMatthew Wilcox (Oracle) unsigned int nr_blocks = i_blocks_per_page(inode, page); 56afc51aaaSDarrick J. Wong 570a195b91SMatthew Wilcox (Oracle) if (iop || nr_blocks <= 1) 58afc51aaaSDarrick J. Wong return iop; 59afc51aaaSDarrick J. Wong 600a195b91SMatthew Wilcox (Oracle) iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)), 610a195b91SMatthew Wilcox (Oracle) GFP_NOFS | __GFP_NOFAIL); 621cea335dSChristoph Hellwig spin_lock_init(&iop->uptodate_lock); 634595a298SMatthew Wilcox (Oracle) if (PageUptodate(page)) 644595a298SMatthew Wilcox (Oracle) bitmap_fill(iop->uptodate, nr_blocks); 6558aeb731SGuoqing Jiang attach_page_private(page, iop); 66afc51aaaSDarrick J. Wong return iop; 67afc51aaaSDarrick J. Wong } 68afc51aaaSDarrick J. Wong 69afc51aaaSDarrick J. Wong static void 70afc51aaaSDarrick J. Wong iomap_page_release(struct page *page) 71afc51aaaSDarrick J. Wong { 7258aeb731SGuoqing Jiang struct iomap_page *iop = detach_page_private(page); 730a195b91SMatthew Wilcox (Oracle) unsigned int nr_blocks = i_blocks_per_page(page->mapping->host, page); 74afc51aaaSDarrick J. Wong 75afc51aaaSDarrick J. Wong if (!iop) 76afc51aaaSDarrick J. Wong return; 777d636676SMatthew Wilcox (Oracle) WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending)); 780fb2d720SMatthew Wilcox (Oracle) WARN_ON_ONCE(atomic_read(&iop->write_bytes_pending)); 790a195b91SMatthew Wilcox (Oracle) WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) != 800a195b91SMatthew Wilcox (Oracle) PageUptodate(page)); 81afc51aaaSDarrick J. Wong kfree(iop); 82afc51aaaSDarrick J. Wong } 83afc51aaaSDarrick J. Wong 84afc51aaaSDarrick J. Wong /* 85afc51aaaSDarrick J. Wong * Calculate the range inside the page that we actually need to read. 86afc51aaaSDarrick J. Wong */ 87afc51aaaSDarrick J. Wong static void 88afc51aaaSDarrick J. Wong iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, 89afc51aaaSDarrick J. Wong loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp) 90afc51aaaSDarrick J. Wong { 91afc51aaaSDarrick J. Wong loff_t orig_pos = *pos; 92afc51aaaSDarrick J. Wong loff_t isize = i_size_read(inode); 93afc51aaaSDarrick J. Wong unsigned block_bits = inode->i_blkbits; 94afc51aaaSDarrick J. Wong unsigned block_size = (1 << block_bits); 95afc51aaaSDarrick J. Wong unsigned poff = offset_in_page(*pos); 96afc51aaaSDarrick J. Wong unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length); 97afc51aaaSDarrick J. Wong unsigned first = poff >> block_bits; 98afc51aaaSDarrick J. Wong unsigned last = (poff + plen - 1) >> block_bits; 99afc51aaaSDarrick J. Wong 100afc51aaaSDarrick J. Wong /* 101afc51aaaSDarrick J. Wong * If the block size is smaller than the page size we need to check the 102afc51aaaSDarrick J. Wong * per-block uptodate status and adjust the offset and length if needed 103afc51aaaSDarrick J. Wong * to avoid reading in already uptodate ranges. 104afc51aaaSDarrick J. Wong */ 105afc51aaaSDarrick J. Wong if (iop) { 106afc51aaaSDarrick J. Wong unsigned int i; 107afc51aaaSDarrick J. Wong 108afc51aaaSDarrick J. Wong /* move forward for each leading block marked uptodate */ 109afc51aaaSDarrick J. Wong for (i = first; i <= last; i++) { 110afc51aaaSDarrick J. Wong if (!test_bit(i, iop->uptodate)) 111afc51aaaSDarrick J. Wong break; 112afc51aaaSDarrick J. Wong *pos += block_size; 113afc51aaaSDarrick J. Wong poff += block_size; 114afc51aaaSDarrick J. Wong plen -= block_size; 115afc51aaaSDarrick J. Wong first++; 116afc51aaaSDarrick J. Wong } 117afc51aaaSDarrick J. Wong 118afc51aaaSDarrick J. Wong /* truncate len if we find any trailing uptodate block(s) */ 119afc51aaaSDarrick J. Wong for ( ; i <= last; i++) { 120afc51aaaSDarrick J. Wong if (test_bit(i, iop->uptodate)) { 121afc51aaaSDarrick J. Wong plen -= (last - i + 1) * block_size; 122afc51aaaSDarrick J. Wong last = i - 1; 123afc51aaaSDarrick J. Wong break; 124afc51aaaSDarrick J. Wong } 125afc51aaaSDarrick J. Wong } 126afc51aaaSDarrick J. Wong } 127afc51aaaSDarrick J. Wong 128afc51aaaSDarrick J. Wong /* 129afc51aaaSDarrick J. Wong * If the extent spans the block that contains the i_size we need to 130afc51aaaSDarrick J. Wong * handle both halves separately so that we properly zero data in the 131afc51aaaSDarrick J. Wong * page cache for blocks that are entirely outside of i_size. 132afc51aaaSDarrick J. Wong */ 133afc51aaaSDarrick J. Wong if (orig_pos <= isize && orig_pos + length > isize) { 134afc51aaaSDarrick J. Wong unsigned end = offset_in_page(isize - 1) >> block_bits; 135afc51aaaSDarrick J. Wong 136afc51aaaSDarrick J. Wong if (first <= end && last > end) 137afc51aaaSDarrick J. Wong plen -= (last - end) * block_size; 138afc51aaaSDarrick J. Wong } 139afc51aaaSDarrick J. Wong 140afc51aaaSDarrick J. Wong *offp = poff; 141afc51aaaSDarrick J. Wong *lenp = plen; 142afc51aaaSDarrick J. Wong } 143afc51aaaSDarrick J. Wong 144afc51aaaSDarrick J. Wong static void 1451cea335dSChristoph Hellwig iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len) 146afc51aaaSDarrick J. Wong { 147afc51aaaSDarrick J. Wong struct iomap_page *iop = to_iomap_page(page); 148afc51aaaSDarrick J. Wong struct inode *inode = page->mapping->host; 149afc51aaaSDarrick J. Wong unsigned first = off >> inode->i_blkbits; 150afc51aaaSDarrick J. Wong unsigned last = (off + len - 1) >> inode->i_blkbits; 1511cea335dSChristoph Hellwig unsigned long flags; 152afc51aaaSDarrick J. Wong 1531cea335dSChristoph Hellwig spin_lock_irqsave(&iop->uptodate_lock, flags); 154b21866f5SMatthew Wilcox (Oracle) bitmap_set(iop->uptodate, first, last - first + 1); 155b21866f5SMatthew Wilcox (Oracle) if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page))) 1561cea335dSChristoph Hellwig SetPageUptodate(page); 1571cea335dSChristoph Hellwig spin_unlock_irqrestore(&iop->uptodate_lock, flags); 158afc51aaaSDarrick J. Wong } 159afc51aaaSDarrick J. Wong 1601cea335dSChristoph Hellwig static void 1611cea335dSChristoph Hellwig iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len) 1621cea335dSChristoph Hellwig { 1631cea335dSChristoph Hellwig if (PageError(page)) 1641cea335dSChristoph Hellwig return; 1651cea335dSChristoph Hellwig 1661cea335dSChristoph Hellwig if (page_has_private(page)) 1671cea335dSChristoph Hellwig iomap_iop_set_range_uptodate(page, off, len); 1681cea335dSChristoph Hellwig else 169afc51aaaSDarrick J. Wong SetPageUptodate(page); 170afc51aaaSDarrick J. Wong } 171afc51aaaSDarrick J. Wong 172afc51aaaSDarrick J. Wong static void 173afc51aaaSDarrick J. Wong iomap_read_page_end_io(struct bio_vec *bvec, int error) 174afc51aaaSDarrick J. Wong { 175afc51aaaSDarrick J. Wong struct page *page = bvec->bv_page; 176afc51aaaSDarrick J. Wong struct iomap_page *iop = to_iomap_page(page); 177afc51aaaSDarrick J. Wong 178afc51aaaSDarrick J. Wong if (unlikely(error)) { 179afc51aaaSDarrick J. Wong ClearPageUptodate(page); 180afc51aaaSDarrick J. Wong SetPageError(page); 181afc51aaaSDarrick J. Wong } else { 182afc51aaaSDarrick J. Wong iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len); 183afc51aaaSDarrick J. Wong } 184afc51aaaSDarrick J. Wong 1857d636676SMatthew Wilcox (Oracle) if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) 1867d636676SMatthew Wilcox (Oracle) unlock_page(page); 187afc51aaaSDarrick J. Wong } 188afc51aaaSDarrick J. Wong 189afc51aaaSDarrick J. Wong static void 190afc51aaaSDarrick J. Wong iomap_read_end_io(struct bio *bio) 191afc51aaaSDarrick J. Wong { 192afc51aaaSDarrick J. Wong int error = blk_status_to_errno(bio->bi_status); 193afc51aaaSDarrick J. Wong struct bio_vec *bvec; 194afc51aaaSDarrick J. Wong struct bvec_iter_all iter_all; 195afc51aaaSDarrick J. Wong 196afc51aaaSDarrick J. Wong bio_for_each_segment_all(bvec, bio, iter_all) 197afc51aaaSDarrick J. Wong iomap_read_page_end_io(bvec, error); 198afc51aaaSDarrick J. Wong bio_put(bio); 199afc51aaaSDarrick J. Wong } 200afc51aaaSDarrick J. Wong 201afc51aaaSDarrick J. Wong struct iomap_readpage_ctx { 202afc51aaaSDarrick J. Wong struct page *cur_page; 203afc51aaaSDarrick J. Wong bool cur_page_in_bio; 204afc51aaaSDarrick J. Wong struct bio *bio; 2059d24a13aSMatthew Wilcox (Oracle) struct readahead_control *rac; 206afc51aaaSDarrick J. Wong }; 207afc51aaaSDarrick J. Wong 208afc51aaaSDarrick J. Wong static void 209afc51aaaSDarrick J. Wong iomap_read_inline_data(struct inode *inode, struct page *page, 210afc51aaaSDarrick J. Wong struct iomap *iomap) 211afc51aaaSDarrick J. Wong { 212afc51aaaSDarrick J. Wong size_t size = i_size_read(inode); 213afc51aaaSDarrick J. Wong void *addr; 214afc51aaaSDarrick J. Wong 215afc51aaaSDarrick J. Wong if (PageUptodate(page)) 216afc51aaaSDarrick J. Wong return; 217afc51aaaSDarrick J. Wong 218afc51aaaSDarrick J. Wong BUG_ON(page->index); 219afc51aaaSDarrick J. Wong BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data)); 220afc51aaaSDarrick J. Wong 221afc51aaaSDarrick J. Wong addr = kmap_atomic(page); 222afc51aaaSDarrick J. Wong memcpy(addr, iomap->inline_data, size); 223afc51aaaSDarrick J. Wong memset(addr + size, 0, PAGE_SIZE - size); 224afc51aaaSDarrick J. Wong kunmap_atomic(addr); 225afc51aaaSDarrick J. Wong SetPageUptodate(page); 226afc51aaaSDarrick J. Wong } 227afc51aaaSDarrick J. Wong 228009d8d84SChristoph Hellwig static inline bool iomap_block_needs_zeroing(struct inode *inode, 229009d8d84SChristoph Hellwig struct iomap *iomap, loff_t pos) 230009d8d84SChristoph Hellwig { 231009d8d84SChristoph Hellwig return iomap->type != IOMAP_MAPPED || 232009d8d84SChristoph Hellwig (iomap->flags & IOMAP_F_NEW) || 233009d8d84SChristoph Hellwig pos >= i_size_read(inode); 234009d8d84SChristoph Hellwig } 235009d8d84SChristoph Hellwig 236afc51aaaSDarrick J. Wong static loff_t 237afc51aaaSDarrick J. Wong iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 238c039b997SGoldwyn Rodrigues struct iomap *iomap, struct iomap *srcmap) 239afc51aaaSDarrick J. Wong { 240afc51aaaSDarrick J. Wong struct iomap_readpage_ctx *ctx = data; 241afc51aaaSDarrick J. Wong struct page *page = ctx->cur_page; 242afc51aaaSDarrick J. Wong struct iomap_page *iop = iomap_page_create(inode, page); 243afc51aaaSDarrick J. Wong bool same_page = false, is_contig = false; 244afc51aaaSDarrick J. Wong loff_t orig_pos = pos; 245afc51aaaSDarrick J. Wong unsigned poff, plen; 246afc51aaaSDarrick J. Wong sector_t sector; 247afc51aaaSDarrick J. Wong 248afc51aaaSDarrick J. Wong if (iomap->type == IOMAP_INLINE) { 249afc51aaaSDarrick J. Wong WARN_ON_ONCE(pos); 250afc51aaaSDarrick J. Wong iomap_read_inline_data(inode, page, iomap); 251afc51aaaSDarrick J. Wong return PAGE_SIZE; 252afc51aaaSDarrick J. Wong } 253afc51aaaSDarrick J. Wong 254afc51aaaSDarrick J. Wong /* zero post-eof blocks as the page may be mapped */ 255afc51aaaSDarrick J. Wong iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); 256afc51aaaSDarrick J. Wong if (plen == 0) 257afc51aaaSDarrick J. Wong goto done; 258afc51aaaSDarrick J. Wong 259009d8d84SChristoph Hellwig if (iomap_block_needs_zeroing(inode, iomap, pos)) { 260afc51aaaSDarrick J. Wong zero_user(page, poff, plen); 261afc51aaaSDarrick J. Wong iomap_set_range_uptodate(page, poff, plen); 262afc51aaaSDarrick J. Wong goto done; 263afc51aaaSDarrick J. Wong } 264afc51aaaSDarrick J. Wong 265afc51aaaSDarrick J. Wong ctx->cur_page_in_bio = true; 2667d636676SMatthew Wilcox (Oracle) if (iop) 2677d636676SMatthew Wilcox (Oracle) atomic_add(plen, &iop->read_bytes_pending); 268afc51aaaSDarrick J. Wong 2697d636676SMatthew Wilcox (Oracle) /* Try to merge into a previous segment if we can */ 270afc51aaaSDarrick J. Wong sector = iomap_sector(iomap, pos); 2717d636676SMatthew Wilcox (Oracle) if (ctx->bio && bio_end_sector(ctx->bio) == sector) { 2727d636676SMatthew Wilcox (Oracle) if (__bio_try_merge_page(ctx->bio, page, plen, poff, 2737d636676SMatthew Wilcox (Oracle) &same_page)) 274afc51aaaSDarrick J. Wong goto done; 2757d636676SMatthew Wilcox (Oracle) is_contig = true; 276afc51aaaSDarrick J. Wong } 277afc51aaaSDarrick J. Wong 2787d636676SMatthew Wilcox (Oracle) if (!is_contig || bio_full(ctx->bio, plen)) { 279afc51aaaSDarrick J. Wong gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL); 280457df33eSMatthew Wilcox (Oracle) gfp_t orig_gfp = gfp; 2815f7136dbSMatthew Wilcox (Oracle) unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE); 282afc51aaaSDarrick J. Wong 283afc51aaaSDarrick J. Wong if (ctx->bio) 284afc51aaaSDarrick J. Wong submit_bio(ctx->bio); 285afc51aaaSDarrick J. Wong 2869d24a13aSMatthew Wilcox (Oracle) if (ctx->rac) /* same as readahead_gfp_mask */ 287afc51aaaSDarrick J. Wong gfp |= __GFP_NORETRY | __GFP_NOWARN; 2885f7136dbSMatthew Wilcox (Oracle) ctx->bio = bio_alloc(gfp, bio_max_segs(nr_vecs)); 289457df33eSMatthew Wilcox (Oracle) /* 290457df33eSMatthew Wilcox (Oracle) * If the bio_alloc fails, try it again for a single page to 291457df33eSMatthew Wilcox (Oracle) * avoid having to deal with partial page reads. This emulates 292457df33eSMatthew Wilcox (Oracle) * what do_mpage_readpage does. 293457df33eSMatthew Wilcox (Oracle) */ 294457df33eSMatthew Wilcox (Oracle) if (!ctx->bio) 295457df33eSMatthew Wilcox (Oracle) ctx->bio = bio_alloc(orig_gfp, 1); 296afc51aaaSDarrick J. Wong ctx->bio->bi_opf = REQ_OP_READ; 2979d24a13aSMatthew Wilcox (Oracle) if (ctx->rac) 298afc51aaaSDarrick J. Wong ctx->bio->bi_opf |= REQ_RAHEAD; 299afc51aaaSDarrick J. Wong ctx->bio->bi_iter.bi_sector = sector; 300afc51aaaSDarrick J. Wong bio_set_dev(ctx->bio, iomap->bdev); 301afc51aaaSDarrick J. Wong ctx->bio->bi_end_io = iomap_read_end_io; 302afc51aaaSDarrick J. Wong } 303afc51aaaSDarrick J. Wong 304afc51aaaSDarrick J. Wong bio_add_page(ctx->bio, page, plen, poff); 305afc51aaaSDarrick J. Wong done: 306afc51aaaSDarrick J. Wong /* 307afc51aaaSDarrick J. Wong * Move the caller beyond our range so that it keeps making progress. 308afc51aaaSDarrick J. Wong * For that we have to include any leading non-uptodate ranges, but 309afc51aaaSDarrick J. Wong * we can skip trailing ones as they will be handled in the next 310afc51aaaSDarrick J. Wong * iteration. 311afc51aaaSDarrick J. Wong */ 312afc51aaaSDarrick J. Wong return pos - orig_pos + plen; 313afc51aaaSDarrick J. Wong } 314afc51aaaSDarrick J. Wong 315afc51aaaSDarrick J. Wong int 316afc51aaaSDarrick J. Wong iomap_readpage(struct page *page, const struct iomap_ops *ops) 317afc51aaaSDarrick J. Wong { 318afc51aaaSDarrick J. Wong struct iomap_readpage_ctx ctx = { .cur_page = page }; 319afc51aaaSDarrick J. Wong struct inode *inode = page->mapping->host; 320afc51aaaSDarrick J. Wong unsigned poff; 321afc51aaaSDarrick J. Wong loff_t ret; 322afc51aaaSDarrick J. Wong 3239e91c572SChristoph Hellwig trace_iomap_readpage(page->mapping->host, 1); 3249e91c572SChristoph Hellwig 325afc51aaaSDarrick J. Wong for (poff = 0; poff < PAGE_SIZE; poff += ret) { 326afc51aaaSDarrick J. Wong ret = iomap_apply(inode, page_offset(page) + poff, 327afc51aaaSDarrick J. Wong PAGE_SIZE - poff, 0, ops, &ctx, 328afc51aaaSDarrick J. Wong iomap_readpage_actor); 329afc51aaaSDarrick J. Wong if (ret <= 0) { 330afc51aaaSDarrick J. Wong WARN_ON_ONCE(ret == 0); 331afc51aaaSDarrick J. Wong SetPageError(page); 332afc51aaaSDarrick J. Wong break; 333afc51aaaSDarrick J. Wong } 334afc51aaaSDarrick J. Wong } 335afc51aaaSDarrick J. Wong 336afc51aaaSDarrick J. Wong if (ctx.bio) { 337afc51aaaSDarrick J. Wong submit_bio(ctx.bio); 338afc51aaaSDarrick J. Wong WARN_ON_ONCE(!ctx.cur_page_in_bio); 339afc51aaaSDarrick J. Wong } else { 340afc51aaaSDarrick J. Wong WARN_ON_ONCE(ctx.cur_page_in_bio); 341afc51aaaSDarrick J. Wong unlock_page(page); 342afc51aaaSDarrick J. Wong } 343afc51aaaSDarrick J. Wong 344afc51aaaSDarrick J. Wong /* 345d4388340SMatthew Wilcox (Oracle) * Just like mpage_readahead and block_read_full_page we always 346afc51aaaSDarrick J. Wong * return 0 and just mark the page as PageError on errors. This 347afc51aaaSDarrick J. Wong * should be cleaned up all through the stack eventually. 348afc51aaaSDarrick J. Wong */ 349afc51aaaSDarrick J. Wong return 0; 350afc51aaaSDarrick J. Wong } 351afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_readpage); 352afc51aaaSDarrick J. Wong 353afc51aaaSDarrick J. Wong static loff_t 3549d24a13aSMatthew Wilcox (Oracle) iomap_readahead_actor(struct inode *inode, loff_t pos, loff_t length, 355c039b997SGoldwyn Rodrigues void *data, struct iomap *iomap, struct iomap *srcmap) 356afc51aaaSDarrick J. Wong { 357afc51aaaSDarrick J. Wong struct iomap_readpage_ctx *ctx = data; 358afc51aaaSDarrick J. Wong loff_t done, ret; 359afc51aaaSDarrick J. Wong 360afc51aaaSDarrick J. Wong for (done = 0; done < length; done += ret) { 361afc51aaaSDarrick J. Wong if (ctx->cur_page && offset_in_page(pos + done) == 0) { 362afc51aaaSDarrick J. Wong if (!ctx->cur_page_in_bio) 363afc51aaaSDarrick J. Wong unlock_page(ctx->cur_page); 364afc51aaaSDarrick J. Wong put_page(ctx->cur_page); 365afc51aaaSDarrick J. Wong ctx->cur_page = NULL; 366afc51aaaSDarrick J. Wong } 367afc51aaaSDarrick J. Wong if (!ctx->cur_page) { 3689d24a13aSMatthew Wilcox (Oracle) ctx->cur_page = readahead_page(ctx->rac); 369afc51aaaSDarrick J. Wong ctx->cur_page_in_bio = false; 370afc51aaaSDarrick J. Wong } 371afc51aaaSDarrick J. Wong ret = iomap_readpage_actor(inode, pos + done, length - done, 372c039b997SGoldwyn Rodrigues ctx, iomap, srcmap); 373afc51aaaSDarrick J. Wong } 374afc51aaaSDarrick J. Wong 375afc51aaaSDarrick J. Wong return done; 376afc51aaaSDarrick J. Wong } 377afc51aaaSDarrick J. Wong 3789d24a13aSMatthew Wilcox (Oracle) /** 3799d24a13aSMatthew Wilcox (Oracle) * iomap_readahead - Attempt to read pages from a file. 3809d24a13aSMatthew Wilcox (Oracle) * @rac: Describes the pages to be read. 3819d24a13aSMatthew Wilcox (Oracle) * @ops: The operations vector for the filesystem. 3829d24a13aSMatthew Wilcox (Oracle) * 3839d24a13aSMatthew Wilcox (Oracle) * This function is for filesystems to call to implement their readahead 3849d24a13aSMatthew Wilcox (Oracle) * address_space operation. 3859d24a13aSMatthew Wilcox (Oracle) * 3869d24a13aSMatthew Wilcox (Oracle) * Context: The @ops callbacks may submit I/O (eg to read the addresses of 3879d24a13aSMatthew Wilcox (Oracle) * blocks from disc), and may wait for it. The caller may be trying to 3889d24a13aSMatthew Wilcox (Oracle) * access a different page, and so sleeping excessively should be avoided. 3899d24a13aSMatthew Wilcox (Oracle) * It may allocate memory, but should avoid costly allocations. This 3909d24a13aSMatthew Wilcox (Oracle) * function is called with memalloc_nofs set, so allocations will not cause 3919d24a13aSMatthew Wilcox (Oracle) * the filesystem to be reentered. 3929d24a13aSMatthew Wilcox (Oracle) */ 3939d24a13aSMatthew Wilcox (Oracle) void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops) 394afc51aaaSDarrick J. Wong { 3959d24a13aSMatthew Wilcox (Oracle) struct inode *inode = rac->mapping->host; 3969d24a13aSMatthew Wilcox (Oracle) loff_t pos = readahead_pos(rac); 3979d24a13aSMatthew Wilcox (Oracle) loff_t length = readahead_length(rac); 398afc51aaaSDarrick J. Wong struct iomap_readpage_ctx ctx = { 3999d24a13aSMatthew Wilcox (Oracle) .rac = rac, 400afc51aaaSDarrick J. Wong }; 401afc51aaaSDarrick J. Wong 4029d24a13aSMatthew Wilcox (Oracle) trace_iomap_readahead(inode, readahead_count(rac)); 4039e91c572SChristoph Hellwig 404afc51aaaSDarrick J. Wong while (length > 0) { 4059d24a13aSMatthew Wilcox (Oracle) loff_t ret = iomap_apply(inode, pos, length, 0, ops, 4069d24a13aSMatthew Wilcox (Oracle) &ctx, iomap_readahead_actor); 407afc51aaaSDarrick J. Wong if (ret <= 0) { 408afc51aaaSDarrick J. Wong WARN_ON_ONCE(ret == 0); 4099d24a13aSMatthew Wilcox (Oracle) break; 410afc51aaaSDarrick J. Wong } 411afc51aaaSDarrick J. Wong pos += ret; 412afc51aaaSDarrick J. Wong length -= ret; 413afc51aaaSDarrick J. Wong } 4149d24a13aSMatthew Wilcox (Oracle) 415afc51aaaSDarrick J. Wong if (ctx.bio) 416afc51aaaSDarrick J. Wong submit_bio(ctx.bio); 417afc51aaaSDarrick J. Wong if (ctx.cur_page) { 418afc51aaaSDarrick J. Wong if (!ctx.cur_page_in_bio) 419afc51aaaSDarrick J. Wong unlock_page(ctx.cur_page); 420afc51aaaSDarrick J. Wong put_page(ctx.cur_page); 421afc51aaaSDarrick J. Wong } 422afc51aaaSDarrick J. Wong } 4239d24a13aSMatthew Wilcox (Oracle) EXPORT_SYMBOL_GPL(iomap_readahead); 424afc51aaaSDarrick J. Wong 425afc51aaaSDarrick J. Wong /* 426afc51aaaSDarrick J. Wong * iomap_is_partially_uptodate checks whether blocks within a page are 427afc51aaaSDarrick J. Wong * uptodate or not. 428afc51aaaSDarrick J. Wong * 429afc51aaaSDarrick J. Wong * Returns true if all blocks which correspond to a file portion 430afc51aaaSDarrick J. Wong * we want to read within the page are uptodate. 431afc51aaaSDarrick J. Wong */ 432afc51aaaSDarrick J. Wong int 433afc51aaaSDarrick J. Wong iomap_is_partially_uptodate(struct page *page, unsigned long from, 434afc51aaaSDarrick J. Wong unsigned long count) 435afc51aaaSDarrick J. Wong { 436afc51aaaSDarrick J. Wong struct iomap_page *iop = to_iomap_page(page); 437afc51aaaSDarrick J. Wong struct inode *inode = page->mapping->host; 438afc51aaaSDarrick J. Wong unsigned len, first, last; 439afc51aaaSDarrick J. Wong unsigned i; 440afc51aaaSDarrick J. Wong 441afc51aaaSDarrick J. Wong /* Limit range to one page */ 442afc51aaaSDarrick J. Wong len = min_t(unsigned, PAGE_SIZE - from, count); 443afc51aaaSDarrick J. Wong 444afc51aaaSDarrick J. Wong /* First and last blocks in range within page */ 445afc51aaaSDarrick J. Wong first = from >> inode->i_blkbits; 446afc51aaaSDarrick J. Wong last = (from + len - 1) >> inode->i_blkbits; 447afc51aaaSDarrick J. Wong 448afc51aaaSDarrick J. Wong if (iop) { 449afc51aaaSDarrick J. Wong for (i = first; i <= last; i++) 450afc51aaaSDarrick J. Wong if (!test_bit(i, iop->uptodate)) 451afc51aaaSDarrick J. Wong return 0; 452afc51aaaSDarrick J. Wong return 1; 453afc51aaaSDarrick J. Wong } 454afc51aaaSDarrick J. Wong 455afc51aaaSDarrick J. Wong return 0; 456afc51aaaSDarrick J. Wong } 457afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate); 458afc51aaaSDarrick J. Wong 459afc51aaaSDarrick J. Wong int 460afc51aaaSDarrick J. Wong iomap_releasepage(struct page *page, gfp_t gfp_mask) 461afc51aaaSDarrick J. Wong { 4621ac99452SMatthew Wilcox (Oracle) trace_iomap_releasepage(page->mapping->host, page_offset(page), 4631ac99452SMatthew Wilcox (Oracle) PAGE_SIZE); 4649e91c572SChristoph Hellwig 465afc51aaaSDarrick J. Wong /* 466afc51aaaSDarrick J. Wong * mm accommodates an old ext3 case where clean pages might not have had 467afc51aaaSDarrick J. Wong * the dirty bit cleared. Thus, it can send actual dirty pages to 468afc51aaaSDarrick J. Wong * ->releasepage() via shrink_active_list(), skip those here. 469afc51aaaSDarrick J. Wong */ 470afc51aaaSDarrick J. Wong if (PageDirty(page) || PageWriteback(page)) 471afc51aaaSDarrick J. Wong return 0; 472afc51aaaSDarrick J. Wong iomap_page_release(page); 473afc51aaaSDarrick J. Wong return 1; 474afc51aaaSDarrick J. Wong } 475afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_releasepage); 476afc51aaaSDarrick J. Wong 477afc51aaaSDarrick J. Wong void 478afc51aaaSDarrick J. Wong iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len) 479afc51aaaSDarrick J. Wong { 4801ac99452SMatthew Wilcox (Oracle) trace_iomap_invalidatepage(page->mapping->host, offset, len); 4819e91c572SChristoph Hellwig 482afc51aaaSDarrick J. Wong /* 483afc51aaaSDarrick J. Wong * If we are invalidating the entire page, clear the dirty state from it 484afc51aaaSDarrick J. Wong * and release it to avoid unnecessary buildup of the LRU. 485afc51aaaSDarrick J. Wong */ 486afc51aaaSDarrick J. Wong if (offset == 0 && len == PAGE_SIZE) { 487afc51aaaSDarrick J. Wong WARN_ON_ONCE(PageWriteback(page)); 488afc51aaaSDarrick J. Wong cancel_dirty_page(page); 489afc51aaaSDarrick J. Wong iomap_page_release(page); 490afc51aaaSDarrick J. Wong } 491afc51aaaSDarrick J. Wong } 492afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_invalidatepage); 493afc51aaaSDarrick J. Wong 494afc51aaaSDarrick J. Wong #ifdef CONFIG_MIGRATION 495afc51aaaSDarrick J. Wong int 496afc51aaaSDarrick J. Wong iomap_migrate_page(struct address_space *mapping, struct page *newpage, 497afc51aaaSDarrick J. Wong struct page *page, enum migrate_mode mode) 498afc51aaaSDarrick J. Wong { 499afc51aaaSDarrick J. Wong int ret; 500afc51aaaSDarrick J. Wong 50126473f83SLinus Torvalds ret = migrate_page_move_mapping(mapping, newpage, page, 0); 502afc51aaaSDarrick J. Wong if (ret != MIGRATEPAGE_SUCCESS) 503afc51aaaSDarrick J. Wong return ret; 504afc51aaaSDarrick J. Wong 50558aeb731SGuoqing Jiang if (page_has_private(page)) 50658aeb731SGuoqing Jiang attach_page_private(newpage, detach_page_private(page)); 507afc51aaaSDarrick J. Wong 508afc51aaaSDarrick J. Wong if (mode != MIGRATE_SYNC_NO_COPY) 509afc51aaaSDarrick J. Wong migrate_page_copy(newpage, page); 510afc51aaaSDarrick J. Wong else 511afc51aaaSDarrick J. Wong migrate_page_states(newpage, page); 512afc51aaaSDarrick J. Wong return MIGRATEPAGE_SUCCESS; 513afc51aaaSDarrick J. Wong } 514afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_migrate_page); 515afc51aaaSDarrick J. Wong #endif /* CONFIG_MIGRATION */ 516afc51aaaSDarrick J. Wong 51732a38a49SChristoph Hellwig enum { 51832a38a49SChristoph Hellwig IOMAP_WRITE_F_UNSHARE = (1 << 0), 51932a38a49SChristoph Hellwig }; 52032a38a49SChristoph Hellwig 521afc51aaaSDarrick J. Wong static void 522afc51aaaSDarrick J. Wong iomap_write_failed(struct inode *inode, loff_t pos, unsigned len) 523afc51aaaSDarrick J. Wong { 524afc51aaaSDarrick J. Wong loff_t i_size = i_size_read(inode); 525afc51aaaSDarrick J. Wong 526afc51aaaSDarrick J. Wong /* 527afc51aaaSDarrick J. Wong * Only truncate newly allocated pages beyoned EOF, even if the 528afc51aaaSDarrick J. Wong * write started inside the existing inode size. 529afc51aaaSDarrick J. Wong */ 530afc51aaaSDarrick J. Wong if (pos + len > i_size) 531afc51aaaSDarrick J. Wong truncate_pagecache_range(inode, max(pos, i_size), pos + len); 532afc51aaaSDarrick J. Wong } 533afc51aaaSDarrick J. Wong 534afc51aaaSDarrick J. Wong static int 535d3b40439SChristoph Hellwig iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, 536d3b40439SChristoph Hellwig unsigned plen, struct iomap *iomap) 537afc51aaaSDarrick J. Wong { 538afc51aaaSDarrick J. Wong struct bio_vec bvec; 539afc51aaaSDarrick J. Wong struct bio bio; 540afc51aaaSDarrick J. Wong 541afc51aaaSDarrick J. Wong bio_init(&bio, &bvec, 1); 542afc51aaaSDarrick J. Wong bio.bi_opf = REQ_OP_READ; 543afc51aaaSDarrick J. Wong bio.bi_iter.bi_sector = iomap_sector(iomap, block_start); 544afc51aaaSDarrick J. Wong bio_set_dev(&bio, iomap->bdev); 545afc51aaaSDarrick J. Wong __bio_add_page(&bio, page, plen, poff); 546afc51aaaSDarrick J. Wong return submit_bio_wait(&bio); 547afc51aaaSDarrick J. Wong } 548afc51aaaSDarrick J. Wong 549afc51aaaSDarrick J. Wong static int 55032a38a49SChristoph Hellwig __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, 551c039b997SGoldwyn Rodrigues struct page *page, struct iomap *srcmap) 552afc51aaaSDarrick J. Wong { 553afc51aaaSDarrick J. Wong struct iomap_page *iop = iomap_page_create(inode, page); 554afc51aaaSDarrick J. Wong loff_t block_size = i_blocksize(inode); 5556cc19c5fSNikolay Borisov loff_t block_start = round_down(pos, block_size); 5566cc19c5fSNikolay Borisov loff_t block_end = round_up(pos + len, block_size); 557afc51aaaSDarrick J. Wong unsigned from = offset_in_page(pos), to = from + len, poff, plen; 558afc51aaaSDarrick J. Wong 559afc51aaaSDarrick J. Wong if (PageUptodate(page)) 560afc51aaaSDarrick J. Wong return 0; 561e6e7ca92SMatthew Wilcox (Oracle) ClearPageError(page); 562afc51aaaSDarrick J. Wong 563afc51aaaSDarrick J. Wong do { 564afc51aaaSDarrick J. Wong iomap_adjust_read_range(inode, iop, &block_start, 565afc51aaaSDarrick J. Wong block_end - block_start, &poff, &plen); 566afc51aaaSDarrick J. Wong if (plen == 0) 567afc51aaaSDarrick J. Wong break; 568afc51aaaSDarrick J. Wong 56932a38a49SChristoph Hellwig if (!(flags & IOMAP_WRITE_F_UNSHARE) && 57032a38a49SChristoph Hellwig (from <= poff || from >= poff + plen) && 571d3b40439SChristoph Hellwig (to <= poff || to >= poff + plen)) 572d3b40439SChristoph Hellwig continue; 573d3b40439SChristoph Hellwig 574c039b997SGoldwyn Rodrigues if (iomap_block_needs_zeroing(inode, srcmap, block_start)) { 57532a38a49SChristoph Hellwig if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) 57632a38a49SChristoph Hellwig return -EIO; 577d3b40439SChristoph Hellwig zero_user_segments(page, poff, from, to, poff + plen); 57814284fedSMatthew Wilcox (Oracle) } else { 57914284fedSMatthew Wilcox (Oracle) int status = iomap_read_page_sync(block_start, page, 58014284fedSMatthew Wilcox (Oracle) poff, plen, srcmap); 581d3b40439SChristoph Hellwig if (status) 582d3b40439SChristoph Hellwig return status; 58314284fedSMatthew Wilcox (Oracle) } 58414284fedSMatthew Wilcox (Oracle) iomap_set_range_uptodate(page, poff, plen); 585afc51aaaSDarrick J. Wong } while ((block_start += plen) < block_end); 586afc51aaaSDarrick J. Wong 587d3b40439SChristoph Hellwig return 0; 588afc51aaaSDarrick J. Wong } 589afc51aaaSDarrick J. Wong 590afc51aaaSDarrick J. Wong static int 591afc51aaaSDarrick J. Wong iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, 592c039b997SGoldwyn Rodrigues struct page **pagep, struct iomap *iomap, struct iomap *srcmap) 593afc51aaaSDarrick J. Wong { 594afc51aaaSDarrick J. Wong const struct iomap_page_ops *page_ops = iomap->page_ops; 595afc51aaaSDarrick J. Wong struct page *page; 596afc51aaaSDarrick J. Wong int status = 0; 597afc51aaaSDarrick J. Wong 598afc51aaaSDarrick J. Wong BUG_ON(pos + len > iomap->offset + iomap->length); 599c039b997SGoldwyn Rodrigues if (srcmap != iomap) 600c039b997SGoldwyn Rodrigues BUG_ON(pos + len > srcmap->offset + srcmap->length); 601afc51aaaSDarrick J. Wong 602afc51aaaSDarrick J. Wong if (fatal_signal_pending(current)) 603afc51aaaSDarrick J. Wong return -EINTR; 604afc51aaaSDarrick J. Wong 605afc51aaaSDarrick J. Wong if (page_ops && page_ops->page_prepare) { 606afc51aaaSDarrick J. Wong status = page_ops->page_prepare(inode, pos, len, iomap); 607afc51aaaSDarrick J. Wong if (status) 608afc51aaaSDarrick J. Wong return status; 609afc51aaaSDarrick J. Wong } 610afc51aaaSDarrick J. Wong 611dcd6158dSChristoph Hellwig page = grab_cache_page_write_begin(inode->i_mapping, pos >> PAGE_SHIFT, 612dcd6158dSChristoph Hellwig AOP_FLAG_NOFS); 613afc51aaaSDarrick J. Wong if (!page) { 614afc51aaaSDarrick J. Wong status = -ENOMEM; 615afc51aaaSDarrick J. Wong goto out_no_page; 616afc51aaaSDarrick J. Wong } 617afc51aaaSDarrick J. Wong 618c039b997SGoldwyn Rodrigues if (srcmap->type == IOMAP_INLINE) 619c039b997SGoldwyn Rodrigues iomap_read_inline_data(inode, page, srcmap); 620afc51aaaSDarrick J. Wong else if (iomap->flags & IOMAP_F_BUFFER_HEAD) 621c039b997SGoldwyn Rodrigues status = __block_write_begin_int(page, pos, len, NULL, srcmap); 622afc51aaaSDarrick J. Wong else 62332a38a49SChristoph Hellwig status = __iomap_write_begin(inode, pos, len, flags, page, 624c039b997SGoldwyn Rodrigues srcmap); 625afc51aaaSDarrick J. Wong 626afc51aaaSDarrick J. Wong if (unlikely(status)) 627afc51aaaSDarrick J. Wong goto out_unlock; 628afc51aaaSDarrick J. Wong 629afc51aaaSDarrick J. Wong *pagep = page; 630afc51aaaSDarrick J. Wong return 0; 631afc51aaaSDarrick J. Wong 632afc51aaaSDarrick J. Wong out_unlock: 633afc51aaaSDarrick J. Wong unlock_page(page); 634afc51aaaSDarrick J. Wong put_page(page); 635afc51aaaSDarrick J. Wong iomap_write_failed(inode, pos, len); 636afc51aaaSDarrick J. Wong 637afc51aaaSDarrick J. Wong out_no_page: 638afc51aaaSDarrick J. Wong if (page_ops && page_ops->page_done) 639afc51aaaSDarrick J. Wong page_ops->page_done(inode, pos, 0, NULL, iomap); 640afc51aaaSDarrick J. Wong return status; 641afc51aaaSDarrick J. Wong } 642afc51aaaSDarrick J. Wong 643afc51aaaSDarrick J. Wong int 644afc51aaaSDarrick J. Wong iomap_set_page_dirty(struct page *page) 645afc51aaaSDarrick J. Wong { 646afc51aaaSDarrick J. Wong struct address_space *mapping = page_mapping(page); 647afc51aaaSDarrick J. Wong int newly_dirty; 648afc51aaaSDarrick J. Wong 649afc51aaaSDarrick J. Wong if (unlikely(!mapping)) 650afc51aaaSDarrick J. Wong return !TestSetPageDirty(page); 651afc51aaaSDarrick J. Wong 652afc51aaaSDarrick J. Wong /* 653bcfe06bfSRoman Gushchin * Lock out page's memcg migration to keep PageDirty 654afc51aaaSDarrick J. Wong * synchronized with per-memcg dirty page counters. 655afc51aaaSDarrick J. Wong */ 656afc51aaaSDarrick J. Wong lock_page_memcg(page); 657afc51aaaSDarrick J. Wong newly_dirty = !TestSetPageDirty(page); 658afc51aaaSDarrick J. Wong if (newly_dirty) 659afc51aaaSDarrick J. Wong __set_page_dirty(page, mapping, 0); 660afc51aaaSDarrick J. Wong unlock_page_memcg(page); 661afc51aaaSDarrick J. Wong 662afc51aaaSDarrick J. Wong if (newly_dirty) 663afc51aaaSDarrick J. Wong __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); 664afc51aaaSDarrick J. Wong return newly_dirty; 665afc51aaaSDarrick J. Wong } 666afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_set_page_dirty); 667afc51aaaSDarrick J. Wong 668e25ba8cbSMatthew Wilcox (Oracle) static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, 669e25ba8cbSMatthew Wilcox (Oracle) size_t copied, struct page *page) 670afc51aaaSDarrick J. Wong { 671afc51aaaSDarrick J. Wong flush_dcache_page(page); 672afc51aaaSDarrick J. Wong 673afc51aaaSDarrick J. Wong /* 674afc51aaaSDarrick J. Wong * The blocks that were entirely written will now be uptodate, so we 675afc51aaaSDarrick J. Wong * don't have to worry about a readpage reading them and overwriting a 676afc51aaaSDarrick J. Wong * partial write. However if we have encountered a short write and only 677afc51aaaSDarrick J. Wong * partially written into a block, it will not be marked uptodate, so a 678afc51aaaSDarrick J. Wong * readpage might come in and destroy our partial write. 679afc51aaaSDarrick J. Wong * 680afc51aaaSDarrick J. Wong * Do the simplest thing, and just treat any short write to a non 681afc51aaaSDarrick J. Wong * uptodate page as a zero-length write, and force the caller to redo 682afc51aaaSDarrick J. Wong * the whole thing. 683afc51aaaSDarrick J. Wong */ 684afc51aaaSDarrick J. Wong if (unlikely(copied < len && !PageUptodate(page))) 685afc51aaaSDarrick J. Wong return 0; 686afc51aaaSDarrick J. Wong iomap_set_range_uptodate(page, offset_in_page(pos), len); 687afc51aaaSDarrick J. Wong iomap_set_page_dirty(page); 688afc51aaaSDarrick J. Wong return copied; 689afc51aaaSDarrick J. Wong } 690afc51aaaSDarrick J. Wong 691e25ba8cbSMatthew Wilcox (Oracle) static size_t iomap_write_end_inline(struct inode *inode, struct page *page, 692e25ba8cbSMatthew Wilcox (Oracle) struct iomap *iomap, loff_t pos, size_t copied) 693afc51aaaSDarrick J. Wong { 694afc51aaaSDarrick J. Wong void *addr; 695afc51aaaSDarrick J. Wong 696afc51aaaSDarrick J. Wong WARN_ON_ONCE(!PageUptodate(page)); 697afc51aaaSDarrick J. Wong BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data)); 698afc51aaaSDarrick J. Wong 6997ed3cd1aSMatthew Wilcox (Oracle) flush_dcache_page(page); 700afc51aaaSDarrick J. Wong addr = kmap_atomic(page); 701afc51aaaSDarrick J. Wong memcpy(iomap->inline_data + pos, addr + pos, copied); 702afc51aaaSDarrick J. Wong kunmap_atomic(addr); 703afc51aaaSDarrick J. Wong 704afc51aaaSDarrick J. Wong mark_inode_dirty(inode); 705afc51aaaSDarrick J. Wong return copied; 706afc51aaaSDarrick J. Wong } 707afc51aaaSDarrick J. Wong 708e25ba8cbSMatthew Wilcox (Oracle) /* Returns the number of bytes copied. May be 0. Cannot be an errno. */ 709e25ba8cbSMatthew Wilcox (Oracle) static size_t iomap_write_end(struct inode *inode, loff_t pos, size_t len, 710e25ba8cbSMatthew Wilcox (Oracle) size_t copied, struct page *page, struct iomap *iomap, 711e25ba8cbSMatthew Wilcox (Oracle) struct iomap *srcmap) 712afc51aaaSDarrick J. Wong { 713afc51aaaSDarrick J. Wong const struct iomap_page_ops *page_ops = iomap->page_ops; 714afc51aaaSDarrick J. Wong loff_t old_size = inode->i_size; 715e25ba8cbSMatthew Wilcox (Oracle) size_t ret; 716afc51aaaSDarrick J. Wong 717c039b997SGoldwyn Rodrigues if (srcmap->type == IOMAP_INLINE) { 718afc51aaaSDarrick J. Wong ret = iomap_write_end_inline(inode, page, iomap, pos, copied); 719c039b997SGoldwyn Rodrigues } else if (srcmap->flags & IOMAP_F_BUFFER_HEAD) { 720afc51aaaSDarrick J. Wong ret = block_write_end(NULL, inode->i_mapping, pos, len, copied, 721afc51aaaSDarrick J. Wong page, NULL); 722afc51aaaSDarrick J. Wong } else { 723c12d6fa8SChristoph Hellwig ret = __iomap_write_end(inode, pos, len, copied, page); 724afc51aaaSDarrick J. Wong } 725afc51aaaSDarrick J. Wong 726afc51aaaSDarrick J. Wong /* 727afc51aaaSDarrick J. Wong * Update the in-memory inode size after copying the data into the page 728afc51aaaSDarrick J. Wong * cache. It's up to the file system to write the updated size to disk, 729afc51aaaSDarrick J. Wong * preferably after I/O completion so that no stale data is exposed. 730afc51aaaSDarrick J. Wong */ 731afc51aaaSDarrick J. Wong if (pos + ret > old_size) { 732afc51aaaSDarrick J. Wong i_size_write(inode, pos + ret); 733afc51aaaSDarrick J. Wong iomap->flags |= IOMAP_F_SIZE_CHANGED; 734afc51aaaSDarrick J. Wong } 735afc51aaaSDarrick J. Wong unlock_page(page); 736afc51aaaSDarrick J. Wong 737afc51aaaSDarrick J. Wong if (old_size < pos) 738afc51aaaSDarrick J. Wong pagecache_isize_extended(inode, old_size, pos); 739afc51aaaSDarrick J. Wong if (page_ops && page_ops->page_done) 740afc51aaaSDarrick J. Wong page_ops->page_done(inode, pos, ret, page, iomap); 741afc51aaaSDarrick J. Wong put_page(page); 742afc51aaaSDarrick J. Wong 743afc51aaaSDarrick J. Wong if (ret < len) 744afc51aaaSDarrick J. Wong iomap_write_failed(inode, pos, len); 745afc51aaaSDarrick J. Wong return ret; 746afc51aaaSDarrick J. Wong } 747afc51aaaSDarrick J. Wong 748afc51aaaSDarrick J. Wong static loff_t 749afc51aaaSDarrick J. Wong iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 750c039b997SGoldwyn Rodrigues struct iomap *iomap, struct iomap *srcmap) 751afc51aaaSDarrick J. Wong { 752afc51aaaSDarrick J. Wong struct iov_iter *i = data; 753afc51aaaSDarrick J. Wong long status = 0; 754afc51aaaSDarrick J. Wong ssize_t written = 0; 755afc51aaaSDarrick J. Wong 756afc51aaaSDarrick J. Wong do { 757afc51aaaSDarrick J. Wong struct page *page; 758afc51aaaSDarrick J. Wong unsigned long offset; /* Offset into pagecache page */ 759afc51aaaSDarrick J. Wong unsigned long bytes; /* Bytes to write to page */ 760afc51aaaSDarrick J. Wong size_t copied; /* Bytes copied from user */ 761afc51aaaSDarrick J. Wong 762afc51aaaSDarrick J. Wong offset = offset_in_page(pos); 763afc51aaaSDarrick J. Wong bytes = min_t(unsigned long, PAGE_SIZE - offset, 764afc51aaaSDarrick J. Wong iov_iter_count(i)); 765afc51aaaSDarrick J. Wong again: 766afc51aaaSDarrick J. Wong if (bytes > length) 767afc51aaaSDarrick J. Wong bytes = length; 768afc51aaaSDarrick J. Wong 769afc51aaaSDarrick J. Wong /* 770afc51aaaSDarrick J. Wong * Bring in the user page that we will copy from _first_. 771afc51aaaSDarrick J. Wong * Otherwise there's a nasty deadlock on copying from the 772afc51aaaSDarrick J. Wong * same page as we're writing to, without it being marked 773afc51aaaSDarrick J. Wong * up-to-date. 774afc51aaaSDarrick J. Wong */ 775afc51aaaSDarrick J. Wong if (unlikely(iov_iter_fault_in_readable(i, bytes))) { 776afc51aaaSDarrick J. Wong status = -EFAULT; 777afc51aaaSDarrick J. Wong break; 778afc51aaaSDarrick J. Wong } 779afc51aaaSDarrick J. Wong 780c039b997SGoldwyn Rodrigues status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, 781c039b997SGoldwyn Rodrigues srcmap); 782afc51aaaSDarrick J. Wong if (unlikely(status)) 783afc51aaaSDarrick J. Wong break; 784afc51aaaSDarrick J. Wong 785afc51aaaSDarrick J. Wong if (mapping_writably_mapped(inode->i_mapping)) 786afc51aaaSDarrick J. Wong flush_dcache_page(page); 787afc51aaaSDarrick J. Wong 788*f0b65f39SAl Viro copied = copy_page_from_iter_atomic(page, offset, bytes, i); 789afc51aaaSDarrick J. Wong 790bc1bb416SAl Viro status = iomap_write_end(inode, pos, bytes, copied, page, iomap, 791c039b997SGoldwyn Rodrigues srcmap); 792afc51aaaSDarrick J. Wong 793*f0b65f39SAl Viro if (unlikely(copied != status)) 794*f0b65f39SAl Viro iov_iter_revert(i, copied - status); 795afc51aaaSDarrick J. Wong 796*f0b65f39SAl Viro cond_resched(); 797bc1bb416SAl Viro if (unlikely(status == 0)) { 798afc51aaaSDarrick J. Wong /* 799bc1bb416SAl Viro * A short copy made iomap_write_end() reject the 800bc1bb416SAl Viro * thing entirely. Might be memory poisoning 801bc1bb416SAl Viro * halfway through, might be a race with munmap, 802bc1bb416SAl Viro * might be severe memory pressure. 803afc51aaaSDarrick J. Wong */ 804bc1bb416SAl Viro if (copied) 805bc1bb416SAl Viro bytes = copied; 806afc51aaaSDarrick J. Wong goto again; 807afc51aaaSDarrick J. Wong } 808*f0b65f39SAl Viro pos += status; 809*f0b65f39SAl Viro written += status; 810*f0b65f39SAl Viro length -= status; 811afc51aaaSDarrick J. Wong 812afc51aaaSDarrick J. Wong balance_dirty_pages_ratelimited(inode->i_mapping); 813afc51aaaSDarrick J. Wong } while (iov_iter_count(i) && length); 814afc51aaaSDarrick J. Wong 815afc51aaaSDarrick J. Wong return written ? written : status; 816afc51aaaSDarrick J. Wong } 817afc51aaaSDarrick J. Wong 818afc51aaaSDarrick J. Wong ssize_t 819afc51aaaSDarrick J. Wong iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter, 820afc51aaaSDarrick J. Wong const struct iomap_ops *ops) 821afc51aaaSDarrick J. Wong { 822afc51aaaSDarrick J. Wong struct inode *inode = iocb->ki_filp->f_mapping->host; 823afc51aaaSDarrick J. Wong loff_t pos = iocb->ki_pos, ret = 0, written = 0; 824afc51aaaSDarrick J. Wong 825afc51aaaSDarrick J. Wong while (iov_iter_count(iter)) { 826afc51aaaSDarrick J. Wong ret = iomap_apply(inode, pos, iov_iter_count(iter), 827afc51aaaSDarrick J. Wong IOMAP_WRITE, ops, iter, iomap_write_actor); 828afc51aaaSDarrick J. Wong if (ret <= 0) 829afc51aaaSDarrick J. Wong break; 830afc51aaaSDarrick J. Wong pos += ret; 831afc51aaaSDarrick J. Wong written += ret; 832afc51aaaSDarrick J. Wong } 833afc51aaaSDarrick J. Wong 834afc51aaaSDarrick J. Wong return written ? written : ret; 835afc51aaaSDarrick J. Wong } 836afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_file_buffered_write); 837afc51aaaSDarrick J. Wong 838afc51aaaSDarrick J. Wong static loff_t 8393590c4d8SChristoph Hellwig iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 840c039b997SGoldwyn Rodrigues struct iomap *iomap, struct iomap *srcmap) 841afc51aaaSDarrick J. Wong { 842afc51aaaSDarrick J. Wong long status = 0; 843d4ff3b2eSMatthew Wilcox (Oracle) loff_t written = 0; 844afc51aaaSDarrick J. Wong 8453590c4d8SChristoph Hellwig /* don't bother with blocks that are not shared to start with */ 8463590c4d8SChristoph Hellwig if (!(iomap->flags & IOMAP_F_SHARED)) 8473590c4d8SChristoph Hellwig return length; 8483590c4d8SChristoph Hellwig /* don't bother with holes or unwritten extents */ 849c039b997SGoldwyn Rodrigues if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) 8503590c4d8SChristoph Hellwig return length; 8513590c4d8SChristoph Hellwig 852afc51aaaSDarrick J. Wong do { 85332a38a49SChristoph Hellwig unsigned long offset = offset_in_page(pos); 85432a38a49SChristoph Hellwig unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length); 85532a38a49SChristoph Hellwig struct page *page; 856afc51aaaSDarrick J. Wong 85732a38a49SChristoph Hellwig status = iomap_write_begin(inode, pos, bytes, 858c039b997SGoldwyn Rodrigues IOMAP_WRITE_F_UNSHARE, &page, iomap, srcmap); 859afc51aaaSDarrick J. Wong if (unlikely(status)) 860afc51aaaSDarrick J. Wong return status; 861afc51aaaSDarrick J. Wong 862c039b997SGoldwyn Rodrigues status = iomap_write_end(inode, pos, bytes, bytes, page, iomap, 863c039b997SGoldwyn Rodrigues srcmap); 864afc51aaaSDarrick J. Wong if (WARN_ON_ONCE(status == 0)) 865afc51aaaSDarrick J. Wong return -EIO; 866afc51aaaSDarrick J. Wong 867afc51aaaSDarrick J. Wong cond_resched(); 868afc51aaaSDarrick J. Wong 869afc51aaaSDarrick J. Wong pos += status; 870afc51aaaSDarrick J. Wong written += status; 871afc51aaaSDarrick J. Wong length -= status; 872afc51aaaSDarrick J. Wong 873afc51aaaSDarrick J. Wong balance_dirty_pages_ratelimited(inode->i_mapping); 874afc51aaaSDarrick J. Wong } while (length); 875afc51aaaSDarrick J. Wong 876afc51aaaSDarrick J. Wong return written; 877afc51aaaSDarrick J. Wong } 878afc51aaaSDarrick J. Wong 879afc51aaaSDarrick J. Wong int 8803590c4d8SChristoph Hellwig iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, 881afc51aaaSDarrick J. Wong const struct iomap_ops *ops) 882afc51aaaSDarrick J. Wong { 883afc51aaaSDarrick J. Wong loff_t ret; 884afc51aaaSDarrick J. Wong 885afc51aaaSDarrick J. Wong while (len) { 886afc51aaaSDarrick J. Wong ret = iomap_apply(inode, pos, len, IOMAP_WRITE, ops, NULL, 8873590c4d8SChristoph Hellwig iomap_unshare_actor); 888afc51aaaSDarrick J. Wong if (ret <= 0) 889afc51aaaSDarrick J. Wong return ret; 890afc51aaaSDarrick J. Wong pos += ret; 891afc51aaaSDarrick J. Wong len -= ret; 892afc51aaaSDarrick J. Wong } 893afc51aaaSDarrick J. Wong 894afc51aaaSDarrick J. Wong return 0; 895afc51aaaSDarrick J. Wong } 8963590c4d8SChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_file_unshare); 897afc51aaaSDarrick J. Wong 89881ee8e52SMatthew Wilcox (Oracle) static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length, 89981ee8e52SMatthew Wilcox (Oracle) struct iomap *iomap, struct iomap *srcmap) 900afc51aaaSDarrick J. Wong { 901afc51aaaSDarrick J. Wong struct page *page; 902afc51aaaSDarrick J. Wong int status; 90381ee8e52SMatthew Wilcox (Oracle) unsigned offset = offset_in_page(pos); 90481ee8e52SMatthew Wilcox (Oracle) unsigned bytes = min_t(u64, PAGE_SIZE - offset, length); 905afc51aaaSDarrick J. Wong 906c039b997SGoldwyn Rodrigues status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap); 907afc51aaaSDarrick J. Wong if (status) 908afc51aaaSDarrick J. Wong return status; 909afc51aaaSDarrick J. Wong 910afc51aaaSDarrick J. Wong zero_user(page, offset, bytes); 911afc51aaaSDarrick J. Wong mark_page_accessed(page); 912afc51aaaSDarrick J. Wong 913c039b997SGoldwyn Rodrigues return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); 914afc51aaaSDarrick J. Wong } 915afc51aaaSDarrick J. Wong 91681ee8e52SMatthew Wilcox (Oracle) static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos, 91781ee8e52SMatthew Wilcox (Oracle) loff_t length, void *data, struct iomap *iomap, 91881ee8e52SMatthew Wilcox (Oracle) struct iomap *srcmap) 919afc51aaaSDarrick J. Wong { 920afc51aaaSDarrick J. Wong bool *did_zero = data; 921afc51aaaSDarrick J. Wong loff_t written = 0; 922afc51aaaSDarrick J. Wong 923afc51aaaSDarrick J. Wong /* already zeroed? we're done. */ 924c039b997SGoldwyn Rodrigues if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) 92581ee8e52SMatthew Wilcox (Oracle) return length; 926afc51aaaSDarrick J. Wong 927afc51aaaSDarrick J. Wong do { 92881ee8e52SMatthew Wilcox (Oracle) s64 bytes; 929afc51aaaSDarrick J. Wong 930afc51aaaSDarrick J. Wong if (IS_DAX(inode)) 93181ee8e52SMatthew Wilcox (Oracle) bytes = dax_iomap_zero(pos, length, iomap); 932afc51aaaSDarrick J. Wong else 93381ee8e52SMatthew Wilcox (Oracle) bytes = iomap_zero(inode, pos, length, iomap, srcmap); 93481ee8e52SMatthew Wilcox (Oracle) if (bytes < 0) 93581ee8e52SMatthew Wilcox (Oracle) return bytes; 936afc51aaaSDarrick J. Wong 937afc51aaaSDarrick J. Wong pos += bytes; 93881ee8e52SMatthew Wilcox (Oracle) length -= bytes; 939afc51aaaSDarrick J. Wong written += bytes; 940afc51aaaSDarrick J. Wong if (did_zero) 941afc51aaaSDarrick J. Wong *did_zero = true; 94281ee8e52SMatthew Wilcox (Oracle) } while (length > 0); 943afc51aaaSDarrick J. Wong 944afc51aaaSDarrick J. Wong return written; 945afc51aaaSDarrick J. Wong } 946afc51aaaSDarrick J. Wong 947afc51aaaSDarrick J. Wong int 948afc51aaaSDarrick J. Wong iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero, 949afc51aaaSDarrick J. Wong const struct iomap_ops *ops) 950afc51aaaSDarrick J. Wong { 951afc51aaaSDarrick J. Wong loff_t ret; 952afc51aaaSDarrick J. Wong 953afc51aaaSDarrick J. Wong while (len > 0) { 954afc51aaaSDarrick J. Wong ret = iomap_apply(inode, pos, len, IOMAP_ZERO, 955afc51aaaSDarrick J. Wong ops, did_zero, iomap_zero_range_actor); 956afc51aaaSDarrick J. Wong if (ret <= 0) 957afc51aaaSDarrick J. Wong return ret; 958afc51aaaSDarrick J. Wong 959afc51aaaSDarrick J. Wong pos += ret; 960afc51aaaSDarrick J. Wong len -= ret; 961afc51aaaSDarrick J. Wong } 962afc51aaaSDarrick J. Wong 963afc51aaaSDarrick J. Wong return 0; 964afc51aaaSDarrick J. Wong } 965afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_zero_range); 966afc51aaaSDarrick J. Wong 967afc51aaaSDarrick J. Wong int 968afc51aaaSDarrick J. Wong iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 969afc51aaaSDarrick J. Wong const struct iomap_ops *ops) 970afc51aaaSDarrick J. Wong { 971afc51aaaSDarrick J. Wong unsigned int blocksize = i_blocksize(inode); 972afc51aaaSDarrick J. Wong unsigned int off = pos & (blocksize - 1); 973afc51aaaSDarrick J. Wong 974afc51aaaSDarrick J. Wong /* Block boundary? Nothing to do */ 975afc51aaaSDarrick J. Wong if (!off) 976afc51aaaSDarrick J. Wong return 0; 977afc51aaaSDarrick J. Wong return iomap_zero_range(inode, pos, blocksize - off, did_zero, ops); 978afc51aaaSDarrick J. Wong } 979afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_truncate_page); 980afc51aaaSDarrick J. Wong 981afc51aaaSDarrick J. Wong static loff_t 982afc51aaaSDarrick J. Wong iomap_page_mkwrite_actor(struct inode *inode, loff_t pos, loff_t length, 983c039b997SGoldwyn Rodrigues void *data, struct iomap *iomap, struct iomap *srcmap) 984afc51aaaSDarrick J. Wong { 985afc51aaaSDarrick J. Wong struct page *page = data; 986afc51aaaSDarrick J. Wong int ret; 987afc51aaaSDarrick J. Wong 988afc51aaaSDarrick J. Wong if (iomap->flags & IOMAP_F_BUFFER_HEAD) { 989afc51aaaSDarrick J. Wong ret = __block_write_begin_int(page, pos, length, NULL, iomap); 990afc51aaaSDarrick J. Wong if (ret) 991afc51aaaSDarrick J. Wong return ret; 992afc51aaaSDarrick J. Wong block_commit_write(page, 0, length); 993afc51aaaSDarrick J. Wong } else { 994afc51aaaSDarrick J. Wong WARN_ON_ONCE(!PageUptodate(page)); 995afc51aaaSDarrick J. Wong iomap_page_create(inode, page); 996afc51aaaSDarrick J. Wong set_page_dirty(page); 997afc51aaaSDarrick J. Wong } 998afc51aaaSDarrick J. Wong 999afc51aaaSDarrick J. Wong return length; 1000afc51aaaSDarrick J. Wong } 1001afc51aaaSDarrick J. Wong 1002afc51aaaSDarrick J. Wong vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops) 1003afc51aaaSDarrick J. Wong { 1004afc51aaaSDarrick J. Wong struct page *page = vmf->page; 1005afc51aaaSDarrick J. Wong struct inode *inode = file_inode(vmf->vma->vm_file); 1006afc51aaaSDarrick J. Wong unsigned long length; 1007243145bcSAndreas Gruenbacher loff_t offset; 1008afc51aaaSDarrick J. Wong ssize_t ret; 1009afc51aaaSDarrick J. Wong 1010afc51aaaSDarrick J. Wong lock_page(page); 1011243145bcSAndreas Gruenbacher ret = page_mkwrite_check_truncate(page, inode); 1012243145bcSAndreas Gruenbacher if (ret < 0) 1013afc51aaaSDarrick J. Wong goto out_unlock; 1014243145bcSAndreas Gruenbacher length = ret; 1015afc51aaaSDarrick J. Wong 1016243145bcSAndreas Gruenbacher offset = page_offset(page); 1017afc51aaaSDarrick J. Wong while (length > 0) { 1018afc51aaaSDarrick J. Wong ret = iomap_apply(inode, offset, length, 1019afc51aaaSDarrick J. Wong IOMAP_WRITE | IOMAP_FAULT, ops, page, 1020afc51aaaSDarrick J. Wong iomap_page_mkwrite_actor); 1021afc51aaaSDarrick J. Wong if (unlikely(ret <= 0)) 1022afc51aaaSDarrick J. Wong goto out_unlock; 1023afc51aaaSDarrick J. Wong offset += ret; 1024afc51aaaSDarrick J. Wong length -= ret; 1025afc51aaaSDarrick J. Wong } 1026afc51aaaSDarrick J. Wong 1027afc51aaaSDarrick J. Wong wait_for_stable_page(page); 1028afc51aaaSDarrick J. Wong return VM_FAULT_LOCKED; 1029afc51aaaSDarrick J. Wong out_unlock: 1030afc51aaaSDarrick J. Wong unlock_page(page); 1031afc51aaaSDarrick J. Wong return block_page_mkwrite_return(ret); 1032afc51aaaSDarrick J. Wong } 1033afc51aaaSDarrick J. Wong EXPORT_SYMBOL_GPL(iomap_page_mkwrite); 1034598ecfbaSChristoph Hellwig 1035598ecfbaSChristoph Hellwig static void 103648d64cd1SChristoph Hellwig iomap_finish_page_writeback(struct inode *inode, struct page *page, 10370fb2d720SMatthew Wilcox (Oracle) int error, unsigned int len) 1038598ecfbaSChristoph Hellwig { 103948d64cd1SChristoph Hellwig struct iomap_page *iop = to_iomap_page(page); 1040598ecfbaSChristoph Hellwig 1041598ecfbaSChristoph Hellwig if (error) { 104248d64cd1SChristoph Hellwig SetPageError(page); 1043598ecfbaSChristoph Hellwig mapping_set_error(inode->i_mapping, -EIO); 1044598ecfbaSChristoph Hellwig } 1045598ecfbaSChristoph Hellwig 104624addd84SMatthew Wilcox (Oracle) WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop); 10470fb2d720SMatthew Wilcox (Oracle) WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) <= 0); 1048598ecfbaSChristoph Hellwig 10490fb2d720SMatthew Wilcox (Oracle) if (!iop || atomic_sub_and_test(len, &iop->write_bytes_pending)) 105048d64cd1SChristoph Hellwig end_page_writeback(page); 1051598ecfbaSChristoph Hellwig } 1052598ecfbaSChristoph Hellwig 1053598ecfbaSChristoph Hellwig /* 1054598ecfbaSChristoph Hellwig * We're now finished for good with this ioend structure. Update the page 1055598ecfbaSChristoph Hellwig * state, release holds on bios, and finally free up memory. Do not use the 1056598ecfbaSChristoph Hellwig * ioend after this. 1057598ecfbaSChristoph Hellwig */ 1058598ecfbaSChristoph Hellwig static void 1059598ecfbaSChristoph Hellwig iomap_finish_ioend(struct iomap_ioend *ioend, int error) 1060598ecfbaSChristoph Hellwig { 1061598ecfbaSChristoph Hellwig struct inode *inode = ioend->io_inode; 1062598ecfbaSChristoph Hellwig struct bio *bio = &ioend->io_inline_bio; 1063598ecfbaSChristoph Hellwig struct bio *last = ioend->io_bio, *next; 1064598ecfbaSChristoph Hellwig u64 start = bio->bi_iter.bi_sector; 1065c275779fSZorro Lang loff_t offset = ioend->io_offset; 1066598ecfbaSChristoph Hellwig bool quiet = bio_flagged(bio, BIO_QUIET); 1067598ecfbaSChristoph Hellwig 1068598ecfbaSChristoph Hellwig for (bio = &ioend->io_inline_bio; bio; bio = next) { 1069598ecfbaSChristoph Hellwig struct bio_vec *bv; 1070598ecfbaSChristoph Hellwig struct bvec_iter_all iter_all; 1071598ecfbaSChristoph Hellwig 1072598ecfbaSChristoph Hellwig /* 1073598ecfbaSChristoph Hellwig * For the last bio, bi_private points to the ioend, so we 1074598ecfbaSChristoph Hellwig * need to explicitly end the iteration here. 1075598ecfbaSChristoph Hellwig */ 1076598ecfbaSChristoph Hellwig if (bio == last) 1077598ecfbaSChristoph Hellwig next = NULL; 1078598ecfbaSChristoph Hellwig else 1079598ecfbaSChristoph Hellwig next = bio->bi_private; 1080598ecfbaSChristoph Hellwig 1081598ecfbaSChristoph Hellwig /* walk each page on bio, ending page IO on them */ 1082598ecfbaSChristoph Hellwig bio_for_each_segment_all(bv, bio, iter_all) 10830fb2d720SMatthew Wilcox (Oracle) iomap_finish_page_writeback(inode, bv->bv_page, error, 10840fb2d720SMatthew Wilcox (Oracle) bv->bv_len); 1085598ecfbaSChristoph Hellwig bio_put(bio); 1086598ecfbaSChristoph Hellwig } 1087c275779fSZorro Lang /* The ioend has been freed by bio_put() */ 1088598ecfbaSChristoph Hellwig 1089598ecfbaSChristoph Hellwig if (unlikely(error && !quiet)) { 1090598ecfbaSChristoph Hellwig printk_ratelimited(KERN_ERR 10919cd0ed63SDarrick J. Wong "%s: writeback error on inode %lu, offset %lld, sector %llu", 1092c275779fSZorro Lang inode->i_sb->s_id, inode->i_ino, offset, start); 1093598ecfbaSChristoph Hellwig } 1094598ecfbaSChristoph Hellwig } 1095598ecfbaSChristoph Hellwig 1096598ecfbaSChristoph Hellwig void 1097598ecfbaSChristoph Hellwig iomap_finish_ioends(struct iomap_ioend *ioend, int error) 1098598ecfbaSChristoph Hellwig { 1099598ecfbaSChristoph Hellwig struct list_head tmp; 1100598ecfbaSChristoph Hellwig 1101598ecfbaSChristoph Hellwig list_replace_init(&ioend->io_list, &tmp); 1102598ecfbaSChristoph Hellwig iomap_finish_ioend(ioend, error); 1103598ecfbaSChristoph Hellwig 1104598ecfbaSChristoph Hellwig while (!list_empty(&tmp)) { 1105598ecfbaSChristoph Hellwig ioend = list_first_entry(&tmp, struct iomap_ioend, io_list); 1106598ecfbaSChristoph Hellwig list_del_init(&ioend->io_list); 1107598ecfbaSChristoph Hellwig iomap_finish_ioend(ioend, error); 1108598ecfbaSChristoph Hellwig } 1109598ecfbaSChristoph Hellwig } 1110598ecfbaSChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_finish_ioends); 1111598ecfbaSChristoph Hellwig 1112598ecfbaSChristoph Hellwig /* 1113598ecfbaSChristoph Hellwig * We can merge two adjacent ioends if they have the same set of work to do. 1114598ecfbaSChristoph Hellwig */ 1115598ecfbaSChristoph Hellwig static bool 1116598ecfbaSChristoph Hellwig iomap_ioend_can_merge(struct iomap_ioend *ioend, struct iomap_ioend *next) 1117598ecfbaSChristoph Hellwig { 1118598ecfbaSChristoph Hellwig if (ioend->io_bio->bi_status != next->io_bio->bi_status) 1119598ecfbaSChristoph Hellwig return false; 1120598ecfbaSChristoph Hellwig if ((ioend->io_flags & IOMAP_F_SHARED) ^ 1121598ecfbaSChristoph Hellwig (next->io_flags & IOMAP_F_SHARED)) 1122598ecfbaSChristoph Hellwig return false; 1123598ecfbaSChristoph Hellwig if ((ioend->io_type == IOMAP_UNWRITTEN) ^ 1124598ecfbaSChristoph Hellwig (next->io_type == IOMAP_UNWRITTEN)) 1125598ecfbaSChristoph Hellwig return false; 1126598ecfbaSChristoph Hellwig if (ioend->io_offset + ioend->io_size != next->io_offset) 1127598ecfbaSChristoph Hellwig return false; 1128598ecfbaSChristoph Hellwig return true; 1129598ecfbaSChristoph Hellwig } 1130598ecfbaSChristoph Hellwig 1131598ecfbaSChristoph Hellwig void 11326e552494SBrian Foster iomap_ioend_try_merge(struct iomap_ioend *ioend, struct list_head *more_ioends) 1133598ecfbaSChristoph Hellwig { 1134598ecfbaSChristoph Hellwig struct iomap_ioend *next; 1135598ecfbaSChristoph Hellwig 1136598ecfbaSChristoph Hellwig INIT_LIST_HEAD(&ioend->io_list); 1137598ecfbaSChristoph Hellwig 1138598ecfbaSChristoph Hellwig while ((next = list_first_entry_or_null(more_ioends, struct iomap_ioend, 1139598ecfbaSChristoph Hellwig io_list))) { 1140598ecfbaSChristoph Hellwig if (!iomap_ioend_can_merge(ioend, next)) 1141598ecfbaSChristoph Hellwig break; 1142598ecfbaSChristoph Hellwig list_move_tail(&next->io_list, &ioend->io_list); 1143598ecfbaSChristoph Hellwig ioend->io_size += next->io_size; 1144598ecfbaSChristoph Hellwig } 1145598ecfbaSChristoph Hellwig } 1146598ecfbaSChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_ioend_try_merge); 1147598ecfbaSChristoph Hellwig 1148598ecfbaSChristoph Hellwig static int 11494f0f586bSSami Tolvanen iomap_ioend_compare(void *priv, const struct list_head *a, 11504f0f586bSSami Tolvanen const struct list_head *b) 1151598ecfbaSChristoph Hellwig { 1152b3d423ecSChristoph Hellwig struct iomap_ioend *ia = container_of(a, struct iomap_ioend, io_list); 1153b3d423ecSChristoph Hellwig struct iomap_ioend *ib = container_of(b, struct iomap_ioend, io_list); 1154598ecfbaSChristoph Hellwig 1155598ecfbaSChristoph Hellwig if (ia->io_offset < ib->io_offset) 1156598ecfbaSChristoph Hellwig return -1; 1157b3d423ecSChristoph Hellwig if (ia->io_offset > ib->io_offset) 1158598ecfbaSChristoph Hellwig return 1; 1159598ecfbaSChristoph Hellwig return 0; 1160598ecfbaSChristoph Hellwig } 1161598ecfbaSChristoph Hellwig 1162598ecfbaSChristoph Hellwig void 1163598ecfbaSChristoph Hellwig iomap_sort_ioends(struct list_head *ioend_list) 1164598ecfbaSChristoph Hellwig { 1165598ecfbaSChristoph Hellwig list_sort(NULL, ioend_list, iomap_ioend_compare); 1166598ecfbaSChristoph Hellwig } 1167598ecfbaSChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_sort_ioends); 1168598ecfbaSChristoph Hellwig 1169598ecfbaSChristoph Hellwig static void iomap_writepage_end_bio(struct bio *bio) 1170598ecfbaSChristoph Hellwig { 1171598ecfbaSChristoph Hellwig struct iomap_ioend *ioend = bio->bi_private; 1172598ecfbaSChristoph Hellwig 1173598ecfbaSChristoph Hellwig iomap_finish_ioend(ioend, blk_status_to_errno(bio->bi_status)); 1174598ecfbaSChristoph Hellwig } 1175598ecfbaSChristoph Hellwig 1176598ecfbaSChristoph Hellwig /* 1177598ecfbaSChristoph Hellwig * Submit the final bio for an ioend. 1178598ecfbaSChristoph Hellwig * 1179598ecfbaSChristoph Hellwig * If @error is non-zero, it means that we have a situation where some part of 1180598ecfbaSChristoph Hellwig * the submission process has failed after we have marked paged for writeback 1181598ecfbaSChristoph Hellwig * and unlocked them. In this situation, we need to fail the bio instead of 1182598ecfbaSChristoph Hellwig * submitting it. This typically only happens on a filesystem shutdown. 1183598ecfbaSChristoph Hellwig */ 1184598ecfbaSChristoph Hellwig static int 1185598ecfbaSChristoph Hellwig iomap_submit_ioend(struct iomap_writepage_ctx *wpc, struct iomap_ioend *ioend, 1186598ecfbaSChristoph Hellwig int error) 1187598ecfbaSChristoph Hellwig { 1188598ecfbaSChristoph Hellwig ioend->io_bio->bi_private = ioend; 1189598ecfbaSChristoph Hellwig ioend->io_bio->bi_end_io = iomap_writepage_end_bio; 1190598ecfbaSChristoph Hellwig 1191598ecfbaSChristoph Hellwig if (wpc->ops->prepare_ioend) 1192598ecfbaSChristoph Hellwig error = wpc->ops->prepare_ioend(ioend, error); 1193598ecfbaSChristoph Hellwig if (error) { 1194598ecfbaSChristoph Hellwig /* 1195598ecfbaSChristoph Hellwig * If we are failing the IO now, just mark the ioend with an 1196598ecfbaSChristoph Hellwig * error and finish it. This will run IO completion immediately 1197598ecfbaSChristoph Hellwig * as there is only one reference to the ioend at this point in 1198598ecfbaSChristoph Hellwig * time. 1199598ecfbaSChristoph Hellwig */ 1200598ecfbaSChristoph Hellwig ioend->io_bio->bi_status = errno_to_blk_status(error); 1201598ecfbaSChristoph Hellwig bio_endio(ioend->io_bio); 1202598ecfbaSChristoph Hellwig return error; 1203598ecfbaSChristoph Hellwig } 1204598ecfbaSChristoph Hellwig 1205598ecfbaSChristoph Hellwig submit_bio(ioend->io_bio); 1206598ecfbaSChristoph Hellwig return 0; 1207598ecfbaSChristoph Hellwig } 1208598ecfbaSChristoph Hellwig 1209598ecfbaSChristoph Hellwig static struct iomap_ioend * 1210598ecfbaSChristoph Hellwig iomap_alloc_ioend(struct inode *inode, struct iomap_writepage_ctx *wpc, 1211598ecfbaSChristoph Hellwig loff_t offset, sector_t sector, struct writeback_control *wbc) 1212598ecfbaSChristoph Hellwig { 1213598ecfbaSChristoph Hellwig struct iomap_ioend *ioend; 1214598ecfbaSChristoph Hellwig struct bio *bio; 1215598ecfbaSChristoph Hellwig 1216a8affc03SChristoph Hellwig bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_VECS, &iomap_ioend_bioset); 1217598ecfbaSChristoph Hellwig bio_set_dev(bio, wpc->iomap.bdev); 1218598ecfbaSChristoph Hellwig bio->bi_iter.bi_sector = sector; 1219598ecfbaSChristoph Hellwig bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc); 1220598ecfbaSChristoph Hellwig bio->bi_write_hint = inode->i_write_hint; 1221598ecfbaSChristoph Hellwig wbc_init_bio(wbc, bio); 1222598ecfbaSChristoph Hellwig 1223598ecfbaSChristoph Hellwig ioend = container_of(bio, struct iomap_ioend, io_inline_bio); 1224598ecfbaSChristoph Hellwig INIT_LIST_HEAD(&ioend->io_list); 1225598ecfbaSChristoph Hellwig ioend->io_type = wpc->iomap.type; 1226598ecfbaSChristoph Hellwig ioend->io_flags = wpc->iomap.flags; 1227598ecfbaSChristoph Hellwig ioend->io_inode = inode; 1228598ecfbaSChristoph Hellwig ioend->io_size = 0; 1229598ecfbaSChristoph Hellwig ioend->io_offset = offset; 1230598ecfbaSChristoph Hellwig ioend->io_bio = bio; 1231598ecfbaSChristoph Hellwig return ioend; 1232598ecfbaSChristoph Hellwig } 1233598ecfbaSChristoph Hellwig 1234598ecfbaSChristoph Hellwig /* 1235598ecfbaSChristoph Hellwig * Allocate a new bio, and chain the old bio to the new one. 1236598ecfbaSChristoph Hellwig * 1237598ecfbaSChristoph Hellwig * Note that we have to do perform the chaining in this unintuitive order 1238598ecfbaSChristoph Hellwig * so that the bi_private linkage is set up in the right direction for the 1239598ecfbaSChristoph Hellwig * traversal in iomap_finish_ioend(). 1240598ecfbaSChristoph Hellwig */ 1241598ecfbaSChristoph Hellwig static struct bio * 1242598ecfbaSChristoph Hellwig iomap_chain_bio(struct bio *prev) 1243598ecfbaSChristoph Hellwig { 1244598ecfbaSChristoph Hellwig struct bio *new; 1245598ecfbaSChristoph Hellwig 1246a8affc03SChristoph Hellwig new = bio_alloc(GFP_NOFS, BIO_MAX_VECS); 1247598ecfbaSChristoph Hellwig bio_copy_dev(new, prev);/* also copies over blkcg information */ 1248598ecfbaSChristoph Hellwig new->bi_iter.bi_sector = bio_end_sector(prev); 1249598ecfbaSChristoph Hellwig new->bi_opf = prev->bi_opf; 1250598ecfbaSChristoph Hellwig new->bi_write_hint = prev->bi_write_hint; 1251598ecfbaSChristoph Hellwig 1252598ecfbaSChristoph Hellwig bio_chain(prev, new); 1253598ecfbaSChristoph Hellwig bio_get(prev); /* for iomap_finish_ioend */ 1254598ecfbaSChristoph Hellwig submit_bio(prev); 1255598ecfbaSChristoph Hellwig return new; 1256598ecfbaSChristoph Hellwig } 1257598ecfbaSChristoph Hellwig 1258598ecfbaSChristoph Hellwig static bool 1259598ecfbaSChristoph Hellwig iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t offset, 1260598ecfbaSChristoph Hellwig sector_t sector) 1261598ecfbaSChristoph Hellwig { 1262598ecfbaSChristoph Hellwig if ((wpc->iomap.flags & IOMAP_F_SHARED) != 1263598ecfbaSChristoph Hellwig (wpc->ioend->io_flags & IOMAP_F_SHARED)) 1264598ecfbaSChristoph Hellwig return false; 1265598ecfbaSChristoph Hellwig if (wpc->iomap.type != wpc->ioend->io_type) 1266598ecfbaSChristoph Hellwig return false; 1267598ecfbaSChristoph Hellwig if (offset != wpc->ioend->io_offset + wpc->ioend->io_size) 1268598ecfbaSChristoph Hellwig return false; 1269598ecfbaSChristoph Hellwig if (sector != bio_end_sector(wpc->ioend->io_bio)) 1270598ecfbaSChristoph Hellwig return false; 1271598ecfbaSChristoph Hellwig return true; 1272598ecfbaSChristoph Hellwig } 1273598ecfbaSChristoph Hellwig 1274598ecfbaSChristoph Hellwig /* 1275598ecfbaSChristoph Hellwig * Test to see if we have an existing ioend structure that we could append to 1276598ecfbaSChristoph Hellwig * first, otherwise finish off the current ioend and start another. 1277598ecfbaSChristoph Hellwig */ 1278598ecfbaSChristoph Hellwig static void 1279598ecfbaSChristoph Hellwig iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page, 1280598ecfbaSChristoph Hellwig struct iomap_page *iop, struct iomap_writepage_ctx *wpc, 1281598ecfbaSChristoph Hellwig struct writeback_control *wbc, struct list_head *iolist) 1282598ecfbaSChristoph Hellwig { 1283598ecfbaSChristoph Hellwig sector_t sector = iomap_sector(&wpc->iomap, offset); 1284598ecfbaSChristoph Hellwig unsigned len = i_blocksize(inode); 1285598ecfbaSChristoph Hellwig unsigned poff = offset & (PAGE_SIZE - 1); 1286598ecfbaSChristoph Hellwig bool merged, same_page = false; 1287598ecfbaSChristoph Hellwig 1288598ecfbaSChristoph Hellwig if (!wpc->ioend || !iomap_can_add_to_ioend(wpc, offset, sector)) { 1289598ecfbaSChristoph Hellwig if (wpc->ioend) 1290598ecfbaSChristoph Hellwig list_add(&wpc->ioend->io_list, iolist); 1291598ecfbaSChristoph Hellwig wpc->ioend = iomap_alloc_ioend(inode, wpc, offset, sector, wbc); 1292598ecfbaSChristoph Hellwig } 1293598ecfbaSChristoph Hellwig 1294598ecfbaSChristoph Hellwig merged = __bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, 1295598ecfbaSChristoph Hellwig &same_page); 12960fb2d720SMatthew Wilcox (Oracle) if (iop) 12970fb2d720SMatthew Wilcox (Oracle) atomic_add(len, &iop->write_bytes_pending); 1298598ecfbaSChristoph Hellwig 1299598ecfbaSChristoph Hellwig if (!merged) { 1300598ecfbaSChristoph Hellwig if (bio_full(wpc->ioend->io_bio, len)) { 1301598ecfbaSChristoph Hellwig wpc->ioend->io_bio = 1302598ecfbaSChristoph Hellwig iomap_chain_bio(wpc->ioend->io_bio); 1303598ecfbaSChristoph Hellwig } 1304598ecfbaSChristoph Hellwig bio_add_page(wpc->ioend->io_bio, page, len, poff); 1305598ecfbaSChristoph Hellwig } 1306598ecfbaSChristoph Hellwig 1307598ecfbaSChristoph Hellwig wpc->ioend->io_size += len; 1308598ecfbaSChristoph Hellwig wbc_account_cgroup_owner(wbc, page, len); 1309598ecfbaSChristoph Hellwig } 1310598ecfbaSChristoph Hellwig 1311598ecfbaSChristoph Hellwig /* 1312598ecfbaSChristoph Hellwig * We implement an immediate ioend submission policy here to avoid needing to 1313598ecfbaSChristoph Hellwig * chain multiple ioends and hence nest mempool allocations which can violate 1314598ecfbaSChristoph Hellwig * forward progress guarantees we need to provide. The current ioend we are 1315598ecfbaSChristoph Hellwig * adding blocks to is cached on the writepage context, and if the new block 1316598ecfbaSChristoph Hellwig * does not append to the cached ioend it will create a new ioend and cache that 1317598ecfbaSChristoph Hellwig * instead. 1318598ecfbaSChristoph Hellwig * 1319598ecfbaSChristoph Hellwig * If a new ioend is created and cached, the old ioend is returned and queued 1320598ecfbaSChristoph Hellwig * locally for submission once the entire page is processed or an error has been 1321598ecfbaSChristoph Hellwig * detected. While ioends are submitted immediately after they are completed, 1322598ecfbaSChristoph Hellwig * batching optimisations are provided by higher level block plugging. 1323598ecfbaSChristoph Hellwig * 1324598ecfbaSChristoph Hellwig * At the end of a writeback pass, there will be a cached ioend remaining on the 1325598ecfbaSChristoph Hellwig * writepage context that the caller will need to submit. 1326598ecfbaSChristoph Hellwig */ 1327598ecfbaSChristoph Hellwig static int 1328598ecfbaSChristoph Hellwig iomap_writepage_map(struct iomap_writepage_ctx *wpc, 1329598ecfbaSChristoph Hellwig struct writeback_control *wbc, struct inode *inode, 1330598ecfbaSChristoph Hellwig struct page *page, u64 end_offset) 1331598ecfbaSChristoph Hellwig { 1332598ecfbaSChristoph Hellwig struct iomap_page *iop = to_iomap_page(page); 1333598ecfbaSChristoph Hellwig struct iomap_ioend *ioend, *next; 1334598ecfbaSChristoph Hellwig unsigned len = i_blocksize(inode); 1335598ecfbaSChristoph Hellwig u64 file_offset; /* file offset of page */ 1336598ecfbaSChristoph Hellwig int error = 0, count = 0, i; 1337598ecfbaSChristoph Hellwig LIST_HEAD(submit_list); 1338598ecfbaSChristoph Hellwig 133924addd84SMatthew Wilcox (Oracle) WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop); 13400fb2d720SMatthew Wilcox (Oracle) WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0); 1341598ecfbaSChristoph Hellwig 1342598ecfbaSChristoph Hellwig /* 1343598ecfbaSChristoph Hellwig * Walk through the page to find areas to write back. If we run off the 1344598ecfbaSChristoph Hellwig * end of the current map or find the current map invalid, grab a new 1345598ecfbaSChristoph Hellwig * one. 1346598ecfbaSChristoph Hellwig */ 1347598ecfbaSChristoph Hellwig for (i = 0, file_offset = page_offset(page); 1348598ecfbaSChristoph Hellwig i < (PAGE_SIZE >> inode->i_blkbits) && file_offset < end_offset; 1349598ecfbaSChristoph Hellwig i++, file_offset += len) { 1350598ecfbaSChristoph Hellwig if (iop && !test_bit(i, iop->uptodate)) 1351598ecfbaSChristoph Hellwig continue; 1352598ecfbaSChristoph Hellwig 1353598ecfbaSChristoph Hellwig error = wpc->ops->map_blocks(wpc, inode, file_offset); 1354598ecfbaSChristoph Hellwig if (error) 1355598ecfbaSChristoph Hellwig break; 13563e19e6f3SChristoph Hellwig if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) 13573e19e6f3SChristoph Hellwig continue; 1358598ecfbaSChristoph Hellwig if (wpc->iomap.type == IOMAP_HOLE) 1359598ecfbaSChristoph Hellwig continue; 1360598ecfbaSChristoph Hellwig iomap_add_to_ioend(inode, file_offset, page, iop, wpc, wbc, 1361598ecfbaSChristoph Hellwig &submit_list); 1362598ecfbaSChristoph Hellwig count++; 1363598ecfbaSChristoph Hellwig } 1364598ecfbaSChristoph Hellwig 1365598ecfbaSChristoph Hellwig WARN_ON_ONCE(!wpc->ioend && !list_empty(&submit_list)); 1366598ecfbaSChristoph Hellwig WARN_ON_ONCE(!PageLocked(page)); 1367598ecfbaSChristoph Hellwig WARN_ON_ONCE(PageWriteback(page)); 136850e7d6c7SBrian Foster WARN_ON_ONCE(PageDirty(page)); 1369598ecfbaSChristoph Hellwig 1370598ecfbaSChristoph Hellwig /* 1371598ecfbaSChristoph Hellwig * We cannot cancel the ioend directly here on error. We may have 1372598ecfbaSChristoph Hellwig * already set other pages under writeback and hence we have to run I/O 1373598ecfbaSChristoph Hellwig * completion to mark the error state of the pages under writeback 1374598ecfbaSChristoph Hellwig * appropriately. 1375598ecfbaSChristoph Hellwig */ 1376598ecfbaSChristoph Hellwig if (unlikely(error)) { 1377598ecfbaSChristoph Hellwig /* 1378763e4cdcSBrian Foster * Let the filesystem know what portion of the current page 1379763e4cdcSBrian Foster * failed to map. If the page wasn't been added to ioend, it 1380763e4cdcSBrian Foster * won't be affected by I/O completion and we must unlock it 1381763e4cdcSBrian Foster * now. 1382598ecfbaSChristoph Hellwig */ 1383598ecfbaSChristoph Hellwig if (wpc->ops->discard_page) 1384763e4cdcSBrian Foster wpc->ops->discard_page(page, file_offset); 1385763e4cdcSBrian Foster if (!count) { 1386598ecfbaSChristoph Hellwig ClearPageUptodate(page); 1387598ecfbaSChristoph Hellwig unlock_page(page); 1388598ecfbaSChristoph Hellwig goto done; 1389598ecfbaSChristoph Hellwig } 1390598ecfbaSChristoph Hellwig } 1391598ecfbaSChristoph Hellwig 139250e7d6c7SBrian Foster set_page_writeback(page); 1393598ecfbaSChristoph Hellwig unlock_page(page); 1394598ecfbaSChristoph Hellwig 1395598ecfbaSChristoph Hellwig /* 1396598ecfbaSChristoph Hellwig * Preserve the original error if there was one, otherwise catch 1397598ecfbaSChristoph Hellwig * submission errors here and propagate into subsequent ioend 1398598ecfbaSChristoph Hellwig * submissions. 1399598ecfbaSChristoph Hellwig */ 1400598ecfbaSChristoph Hellwig list_for_each_entry_safe(ioend, next, &submit_list, io_list) { 1401598ecfbaSChristoph Hellwig int error2; 1402598ecfbaSChristoph Hellwig 1403598ecfbaSChristoph Hellwig list_del_init(&ioend->io_list); 1404598ecfbaSChristoph Hellwig error2 = iomap_submit_ioend(wpc, ioend, error); 1405598ecfbaSChristoph Hellwig if (error2 && !error) 1406598ecfbaSChristoph Hellwig error = error2; 1407598ecfbaSChristoph Hellwig } 1408598ecfbaSChristoph Hellwig 1409598ecfbaSChristoph Hellwig /* 1410598ecfbaSChristoph Hellwig * We can end up here with no error and nothing to write only if we race 1411598ecfbaSChristoph Hellwig * with a partial page truncate on a sub-page block sized filesystem. 1412598ecfbaSChristoph Hellwig */ 1413598ecfbaSChristoph Hellwig if (!count) 1414598ecfbaSChristoph Hellwig end_page_writeback(page); 1415598ecfbaSChristoph Hellwig done: 1416598ecfbaSChristoph Hellwig mapping_set_error(page->mapping, error); 1417598ecfbaSChristoph Hellwig return error; 1418598ecfbaSChristoph Hellwig } 1419598ecfbaSChristoph Hellwig 1420598ecfbaSChristoph Hellwig /* 1421598ecfbaSChristoph Hellwig * Write out a dirty page. 1422598ecfbaSChristoph Hellwig * 1423598ecfbaSChristoph Hellwig * For delalloc space on the page we need to allocate space and flush it. 1424598ecfbaSChristoph Hellwig * For unwritten space on the page we need to start the conversion to 1425598ecfbaSChristoph Hellwig * regular allocated space. 1426598ecfbaSChristoph Hellwig */ 1427598ecfbaSChristoph Hellwig static int 1428598ecfbaSChristoph Hellwig iomap_do_writepage(struct page *page, struct writeback_control *wbc, void *data) 1429598ecfbaSChristoph Hellwig { 1430598ecfbaSChristoph Hellwig struct iomap_writepage_ctx *wpc = data; 1431598ecfbaSChristoph Hellwig struct inode *inode = page->mapping->host; 1432598ecfbaSChristoph Hellwig pgoff_t end_index; 1433598ecfbaSChristoph Hellwig u64 end_offset; 1434598ecfbaSChristoph Hellwig loff_t offset; 1435598ecfbaSChristoph Hellwig 14361ac99452SMatthew Wilcox (Oracle) trace_iomap_writepage(inode, page_offset(page), PAGE_SIZE); 1437598ecfbaSChristoph Hellwig 1438598ecfbaSChristoph Hellwig /* 1439598ecfbaSChristoph Hellwig * Refuse to write the page out if we are called from reclaim context. 1440598ecfbaSChristoph Hellwig * 1441598ecfbaSChristoph Hellwig * This avoids stack overflows when called from deeply used stacks in 1442598ecfbaSChristoph Hellwig * random callers for direct reclaim or memcg reclaim. We explicitly 1443598ecfbaSChristoph Hellwig * allow reclaim from kswapd as the stack usage there is relatively low. 1444598ecfbaSChristoph Hellwig * 1445598ecfbaSChristoph Hellwig * This should never happen except in the case of a VM regression so 1446598ecfbaSChristoph Hellwig * warn about it. 1447598ecfbaSChristoph Hellwig */ 1448598ecfbaSChristoph Hellwig if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == 1449598ecfbaSChristoph Hellwig PF_MEMALLOC)) 1450598ecfbaSChristoph Hellwig goto redirty; 1451598ecfbaSChristoph Hellwig 1452598ecfbaSChristoph Hellwig /* 1453598ecfbaSChristoph Hellwig * Is this page beyond the end of the file? 1454598ecfbaSChristoph Hellwig * 1455598ecfbaSChristoph Hellwig * The page index is less than the end_index, adjust the end_offset 1456598ecfbaSChristoph Hellwig * to the highest offset that this page should represent. 1457598ecfbaSChristoph Hellwig * ----------------------------------------------------- 1458598ecfbaSChristoph Hellwig * | file mapping | <EOF> | 1459598ecfbaSChristoph Hellwig * ----------------------------------------------------- 1460598ecfbaSChristoph Hellwig * | Page ... | Page N-2 | Page N-1 | Page N | | 1461598ecfbaSChristoph Hellwig * ^--------------------------------^----------|-------- 1462598ecfbaSChristoph Hellwig * | desired writeback range | see else | 1463598ecfbaSChristoph Hellwig * ---------------------------------^------------------| 1464598ecfbaSChristoph Hellwig */ 1465598ecfbaSChristoph Hellwig offset = i_size_read(inode); 1466598ecfbaSChristoph Hellwig end_index = offset >> PAGE_SHIFT; 1467598ecfbaSChristoph Hellwig if (page->index < end_index) 1468598ecfbaSChristoph Hellwig end_offset = (loff_t)(page->index + 1) << PAGE_SHIFT; 1469598ecfbaSChristoph Hellwig else { 1470598ecfbaSChristoph Hellwig /* 1471598ecfbaSChristoph Hellwig * Check whether the page to write out is beyond or straddles 1472598ecfbaSChristoph Hellwig * i_size or not. 1473598ecfbaSChristoph Hellwig * ------------------------------------------------------- 1474598ecfbaSChristoph Hellwig * | file mapping | <EOF> | 1475598ecfbaSChristoph Hellwig * ------------------------------------------------------- 1476598ecfbaSChristoph Hellwig * | Page ... | Page N-2 | Page N-1 | Page N | Beyond | 1477598ecfbaSChristoph Hellwig * ^--------------------------------^-----------|--------- 1478598ecfbaSChristoph Hellwig * | | Straddles | 1479598ecfbaSChristoph Hellwig * ---------------------------------^-----------|--------| 1480598ecfbaSChristoph Hellwig */ 1481598ecfbaSChristoph Hellwig unsigned offset_into_page = offset & (PAGE_SIZE - 1); 1482598ecfbaSChristoph Hellwig 1483598ecfbaSChristoph Hellwig /* 1484598ecfbaSChristoph Hellwig * Skip the page if it is fully outside i_size, e.g. due to a 1485598ecfbaSChristoph Hellwig * truncate operation that is in progress. We must redirty the 1486598ecfbaSChristoph Hellwig * page so that reclaim stops reclaiming it. Otherwise 1487598ecfbaSChristoph Hellwig * iomap_vm_releasepage() is called on it and gets confused. 1488598ecfbaSChristoph Hellwig * 1489598ecfbaSChristoph Hellwig * Note that the end_index is unsigned long, it would overflow 1490598ecfbaSChristoph Hellwig * if the given offset is greater than 16TB on 32-bit system 1491598ecfbaSChristoph Hellwig * and if we do check the page is fully outside i_size or not 1492598ecfbaSChristoph Hellwig * via "if (page->index >= end_index + 1)" as "end_index + 1" 1493598ecfbaSChristoph Hellwig * will be evaluated to 0. Hence this page will be redirtied 1494598ecfbaSChristoph Hellwig * and be written out repeatedly which would result in an 1495598ecfbaSChristoph Hellwig * infinite loop, the user program that perform this operation 1496598ecfbaSChristoph Hellwig * will hang. Instead, we can verify this situation by checking 1497598ecfbaSChristoph Hellwig * if the page to write is totally beyond the i_size or if it's 1498598ecfbaSChristoph Hellwig * offset is just equal to the EOF. 1499598ecfbaSChristoph Hellwig */ 1500598ecfbaSChristoph Hellwig if (page->index > end_index || 1501598ecfbaSChristoph Hellwig (page->index == end_index && offset_into_page == 0)) 1502598ecfbaSChristoph Hellwig goto redirty; 1503598ecfbaSChristoph Hellwig 1504598ecfbaSChristoph Hellwig /* 1505598ecfbaSChristoph Hellwig * The page straddles i_size. It must be zeroed out on each 1506598ecfbaSChristoph Hellwig * and every writepage invocation because it may be mmapped. 1507598ecfbaSChristoph Hellwig * "A file is mapped in multiples of the page size. For a file 1508598ecfbaSChristoph Hellwig * that is not a multiple of the page size, the remaining 1509598ecfbaSChristoph Hellwig * memory is zeroed when mapped, and writes to that region are 1510598ecfbaSChristoph Hellwig * not written out to the file." 1511598ecfbaSChristoph Hellwig */ 1512598ecfbaSChristoph Hellwig zero_user_segment(page, offset_into_page, PAGE_SIZE); 1513598ecfbaSChristoph Hellwig 1514598ecfbaSChristoph Hellwig /* Adjust the end_offset to the end of file */ 1515598ecfbaSChristoph Hellwig end_offset = offset; 1516598ecfbaSChristoph Hellwig } 1517598ecfbaSChristoph Hellwig 1518598ecfbaSChristoph Hellwig return iomap_writepage_map(wpc, wbc, inode, page, end_offset); 1519598ecfbaSChristoph Hellwig 1520598ecfbaSChristoph Hellwig redirty: 1521598ecfbaSChristoph Hellwig redirty_page_for_writepage(wbc, page); 1522598ecfbaSChristoph Hellwig unlock_page(page); 1523598ecfbaSChristoph Hellwig return 0; 1524598ecfbaSChristoph Hellwig } 1525598ecfbaSChristoph Hellwig 1526598ecfbaSChristoph Hellwig int 1527598ecfbaSChristoph Hellwig iomap_writepage(struct page *page, struct writeback_control *wbc, 1528598ecfbaSChristoph Hellwig struct iomap_writepage_ctx *wpc, 1529598ecfbaSChristoph Hellwig const struct iomap_writeback_ops *ops) 1530598ecfbaSChristoph Hellwig { 1531598ecfbaSChristoph Hellwig int ret; 1532598ecfbaSChristoph Hellwig 1533598ecfbaSChristoph Hellwig wpc->ops = ops; 1534598ecfbaSChristoph Hellwig ret = iomap_do_writepage(page, wbc, wpc); 1535598ecfbaSChristoph Hellwig if (!wpc->ioend) 1536598ecfbaSChristoph Hellwig return ret; 1537598ecfbaSChristoph Hellwig return iomap_submit_ioend(wpc, wpc->ioend, ret); 1538598ecfbaSChristoph Hellwig } 1539598ecfbaSChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_writepage); 1540598ecfbaSChristoph Hellwig 1541598ecfbaSChristoph Hellwig int 1542598ecfbaSChristoph Hellwig iomap_writepages(struct address_space *mapping, struct writeback_control *wbc, 1543598ecfbaSChristoph Hellwig struct iomap_writepage_ctx *wpc, 1544598ecfbaSChristoph Hellwig const struct iomap_writeback_ops *ops) 1545598ecfbaSChristoph Hellwig { 1546598ecfbaSChristoph Hellwig int ret; 1547598ecfbaSChristoph Hellwig 1548598ecfbaSChristoph Hellwig wpc->ops = ops; 1549598ecfbaSChristoph Hellwig ret = write_cache_pages(mapping, wbc, iomap_do_writepage, wpc); 1550598ecfbaSChristoph Hellwig if (!wpc->ioend) 1551598ecfbaSChristoph Hellwig return ret; 1552598ecfbaSChristoph Hellwig return iomap_submit_ioend(wpc, wpc->ioend, ret); 1553598ecfbaSChristoph Hellwig } 1554598ecfbaSChristoph Hellwig EXPORT_SYMBOL_GPL(iomap_writepages); 1555598ecfbaSChristoph Hellwig 1556598ecfbaSChristoph Hellwig static int __init iomap_init(void) 1557598ecfbaSChristoph Hellwig { 1558598ecfbaSChristoph Hellwig return bioset_init(&iomap_ioend_bioset, 4 * (PAGE_SIZE / SECTOR_SIZE), 1559598ecfbaSChristoph Hellwig offsetof(struct iomap_ioend, io_inline_bio), 1560598ecfbaSChristoph Hellwig BIOSET_NEED_BVECS); 1561598ecfbaSChristoph Hellwig } 1562598ecfbaSChristoph Hellwig fs_initcall(iomap_init); 1563