1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2010 Red Hat, Inc. 4 * Copyright (C) 2016-2023 Christoph Hellwig. 5 */ 6 #include <linux/bio-integrity.h> 7 #include <linux/iomap.h> 8 #include <linux/pagemap.h> 9 #include "internal.h" 10 #include "trace.h" 11 12 static DEFINE_SPINLOCK(failed_read_lock); 13 static struct bio_list failed_read_list = BIO_EMPTY_LIST; 14 15 static u32 __iomap_read_end_io(struct bio *bio, int error) 16 { 17 struct folio_iter fi; 18 u32 folio_count = 0; 19 20 bio_for_each_folio_all(fi, bio) { 21 iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error); 22 folio_count++; 23 } 24 if (bio_integrity(bio)) 25 fs_bio_integrity_free(bio); 26 bio_put(bio); 27 return folio_count; 28 } 29 30 static void 31 iomap_fail_reads( 32 struct work_struct *work) 33 { 34 struct bio *bio; 35 struct bio_list tmp = BIO_EMPTY_LIST; 36 unsigned long flags; 37 38 spin_lock_irqsave(&failed_read_lock, flags); 39 bio_list_merge_init(&tmp, &failed_read_list); 40 spin_unlock_irqrestore(&failed_read_lock, flags); 41 42 while ((bio = bio_list_pop(&tmp)) != NULL) { 43 __iomap_read_end_io(bio, blk_status_to_errno(bio->bi_status)); 44 cond_resched(); 45 } 46 } 47 48 static DECLARE_WORK(failed_read_work, iomap_fail_reads); 49 50 static void iomap_fail_buffered_read(struct bio *bio) 51 { 52 unsigned long flags; 53 54 /* 55 * Bounce I/O errors to a workqueue to avoid nested i_lock acquisitions 56 * in the fserror code. The caller no longer owns the bio reference 57 * after the spinlock drops. 58 */ 59 spin_lock_irqsave(&failed_read_lock, flags); 60 if (bio_list_empty(&failed_read_list)) 61 WARN_ON_ONCE(!schedule_work(&failed_read_work)); 62 bio_list_add(&failed_read_list, bio); 63 spin_unlock_irqrestore(&failed_read_lock, flags); 64 } 65 66 static void iomap_read_end_io(struct bio *bio) 67 { 68 if (bio->bi_status) { 69 iomap_fail_buffered_read(bio); 70 return; 71 } 72 73 __iomap_read_end_io(bio, 0); 74 } 75 76 u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend) 77 { 78 return __iomap_read_end_io(&ioend->io_bio, ioend->io_error); 79 } 80 81 static void iomap_bio_submit_read(const struct iomap_iter *iter, 82 struct iomap_read_folio_ctx *ctx) 83 { 84 struct bio *bio = ctx->read_ctx; 85 86 if (iter->iomap.flags & IOMAP_F_INTEGRITY) 87 fs_bio_integrity_alloc(bio); 88 submit_bio(bio); 89 } 90 91 static struct bio_set *iomap_read_bio_set(struct iomap_read_folio_ctx *ctx) 92 { 93 if (ctx->ops && ctx->ops->bio_set) 94 return ctx->ops->bio_set; 95 return &fs_bio_set; 96 } 97 98 static void iomap_read_alloc_bio(const struct iomap_iter *iter, 99 struct iomap_read_folio_ctx *ctx, size_t plen) 100 { 101 const struct iomap *iomap = &iter->iomap; 102 unsigned int nr_vecs = DIV_ROUND_UP(iomap_length(iter), PAGE_SIZE); 103 struct bio_set *bio_set = iomap_read_bio_set(ctx); 104 struct folio *folio = ctx->cur_folio; 105 gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL); 106 gfp_t orig_gfp = gfp; 107 struct bio *bio; 108 109 /* Submit the existing range if there was one. */ 110 if (ctx->read_ctx) 111 ctx->ops->submit_read(iter, ctx); 112 113 /* Same as readahead_gfp_mask: */ 114 if (ctx->rac) 115 gfp |= __GFP_NORETRY | __GFP_NOWARN; 116 117 /* 118 * If the bio_alloc fails, try it again for a single page to avoid 119 * having to deal with partial page reads. This emulates what 120 * do_mpage_read_folio does. 121 */ 122 bio = bio_alloc_bioset(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ, 123 gfp, bio_set); 124 if (!bio) 125 bio = bio_alloc_bioset(iomap->bdev, 1, REQ_OP_READ, orig_gfp, 126 bio_set); 127 if (ctx->rac) 128 bio->bi_opf |= REQ_RAHEAD; 129 bio->bi_iter.bi_sector = iomap_sector(iomap, iter->pos); 130 bio->bi_end_io = iomap_read_end_io; 131 bio_add_folio_nofail(bio, folio, plen, 132 offset_in_folio(folio, iter->pos)); 133 ctx->read_ctx = bio; 134 ctx->read_ctx_file_offset = iter->pos; 135 } 136 137 int iomap_bio_read_folio_range(const struct iomap_iter *iter, 138 struct iomap_read_folio_ctx *ctx, size_t plen) 139 { 140 struct folio *folio = ctx->cur_folio; 141 struct bio *bio = ctx->read_ctx; 142 143 if (!bio || 144 bio_end_sector(bio) != iomap_sector(&iter->iomap, iter->pos) || 145 bio->bi_iter.bi_size > iomap_max_bio_size(&iter->iomap) - plen || 146 !bio_add_folio(bio, folio, plen, offset_in_folio(folio, iter->pos))) 147 iomap_read_alloc_bio(iter, ctx, plen); 148 return 0; 149 } 150 EXPORT_SYMBOL_GPL(iomap_bio_read_folio_range); 151 152 const struct iomap_read_ops iomap_bio_read_ops = { 153 .read_folio_range = iomap_bio_read_folio_range, 154 .submit_read = iomap_bio_submit_read, 155 }; 156 EXPORT_SYMBOL_GPL(iomap_bio_read_ops); 157 158 int iomap_bio_read_folio_range_sync(const struct iomap_iter *iter, 159 struct folio *folio, loff_t pos, size_t len) 160 { 161 const struct iomap *srcmap = iomap_iter_srcmap(iter); 162 sector_t sector = iomap_sector(srcmap, pos); 163 struct bio_vec bvec; 164 struct bio bio; 165 int error; 166 167 bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ); 168 bio.bi_iter.bi_sector = sector; 169 bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos)); 170 if (srcmap->flags & IOMAP_F_INTEGRITY) 171 fs_bio_integrity_alloc(&bio); 172 error = submit_bio_wait(&bio); 173 if (srcmap->flags & IOMAP_F_INTEGRITY) { 174 if (!error) 175 error = fs_bio_integrity_verify(&bio, sector, len); 176 fs_bio_integrity_free(&bio); 177 } 178 return error; 179 } 180