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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | // SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2017 Red Hat, Inc. * Copyright (c) 2018-2021 Christoph Hellwig. */ #include <linux/module.h> #include <linux/compiler.h> #include <linux/fs.h> #include <linux/iomap.h> #include <linux/pagemap.h> #include <linux/pagevec.h> static loff_t iomap_seek_hole_iter(const struct iomap_iter *iter, loff_t *hole_pos) { loff_t length = iomap_length(iter); switch (iter->iomap.type) { case IOMAP_UNWRITTEN: *hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, iter->pos, iter->pos + length, SEEK_HOLE); if (*hole_pos == iter->pos + length) return length; return 0; case IOMAP_HOLE: *hole_pos = iter->pos; return 0; default: return length; } } loff_t iomap_seek_hole(struct inode *inode, loff_t pos, const struct iomap_ops *ops) { loff_t size = i_size_read(inode); struct iomap_iter iter = { .inode = inode, .pos = pos, .flags = IOMAP_REPORT, }; int ret; /* Nothing to be found before or beyond the end of the file. */ if (pos < 0 || pos >= size) return -ENXIO; iter.len = size - pos; while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = iomap_seek_hole_iter(&iter, &pos); if (ret < 0) return ret; if (iter.len) /* found hole before EOF */ return pos; return size; } EXPORT_SYMBOL_GPL(iomap_seek_hole); static loff_t iomap_seek_data_iter(const struct iomap_iter *iter, loff_t *hole_pos) { loff_t length = iomap_length(iter); switch (iter->iomap.type) { case IOMAP_HOLE: return length; case IOMAP_UNWRITTEN: *hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, iter->pos, iter->pos + length, SEEK_DATA); if (*hole_pos < 0) return length; return 0; default: *hole_pos = iter->pos; return 0; } } loff_t iomap_seek_data(struct inode *inode, loff_t pos, const struct iomap_ops *ops) { loff_t size = i_size_read(inode); struct iomap_iter iter = { .inode = inode, .pos = pos, .flags = IOMAP_REPORT, }; int ret; /* Nothing to be found before or beyond the end of the file. */ if (pos < 0 || pos >= size) return -ENXIO; iter.len = size - pos; while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = iomap_seek_data_iter(&iter, &pos); if (ret < 0) return ret; if (iter.len) /* found data before EOF */ return pos; /* We've reached the end of the file without finding data */ return -ENXIO; } EXPORT_SYMBOL_GPL(iomap_seek_data); |