fiemap.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2016-2021 Christoph Hellwig.
  4 */
  5#include <linux/iomap.h>
  6#include <linux/fiemap.h>
  7#include <linux/pagemap.h>
  8
  9static int iomap_to_fiemap(struct fiemap_extent_info *fi,
 10		const struct iomap *iomap, u32 flags)
 11{
 12	switch (iomap->type) {
 13	case IOMAP_HOLE:
 14		/* skip holes */
 15		return 0;
 16	case IOMAP_DELALLOC:
 17		flags |= FIEMAP_EXTENT_DELALLOC | FIEMAP_EXTENT_UNKNOWN;
 18		break;
 19	case IOMAP_MAPPED:
 20		break;
 21	case IOMAP_UNWRITTEN:
 22		flags |= FIEMAP_EXTENT_UNWRITTEN;
 23		break;
 24	case IOMAP_INLINE:
 25		flags |= FIEMAP_EXTENT_DATA_INLINE;
 26		break;
 27	}
 28
 29	if (iomap->flags & IOMAP_F_MERGED)
 30		flags |= FIEMAP_EXTENT_MERGED;
 31	if (iomap->flags & IOMAP_F_SHARED)
 32		flags |= FIEMAP_EXTENT_SHARED;
 33
 34	return fiemap_fill_next_extent(fi, iomap->offset,
 35			iomap->addr != IOMAP_NULL_ADDR ? iomap->addr : 0,
 36			iomap->length, flags);
 37}
 38
 39static int iomap_fiemap_iter(struct iomap_iter *iter,
 40		struct fiemap_extent_info *fi, struct iomap *prev)
 41{
 42	int ret;
 43
 44	if (iter->iomap.type == IOMAP_HOLE)
 45		goto advance;
 46
 47	ret = iomap_to_fiemap(fi, prev, 0);
 48	*prev = iter->iomap;
 49	if (ret < 0)
 50		return ret;
 51	if (ret == 1)	/* extent array full */
 52		return 0;
 53
 54advance:
 55	return iomap_iter_advance_full(iter);
 56}
 57
 58int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
 59		u64 start, u64 len, const struct iomap_ops *ops)
 60{
 61	struct iomap_iter iter = {
 62		.inode		= inode,
 63		.pos		= start,
 64		.len		= len,
 65		.flags		= IOMAP_REPORT,
 66	};
 67	struct iomap prev = {
 68		.type		= IOMAP_HOLE,
 69	};
 70	int ret;
 71
 72	ret = fiemap_prep(inode, fi, start, &iter.len, 0);
 73	if (ret)
 74		return ret;
 75
 76	while ((ret = iomap_iter(&iter, ops)) > 0)
 77		iter.status = iomap_fiemap_iter(&iter, fi, &prev);
 78
 79	if (prev.type != IOMAP_HOLE) {
 80		ret = iomap_to_fiemap(fi, &prev, FIEMAP_EXTENT_LAST);
 81		if (ret < 0)
 82			return ret;
 83	}
 84
 85	/* inode with no (attribute) mapping will give ENOENT */
 86	if (ret < 0 && ret != -ENOENT)
 87		return ret;
 88	return 0;
 89}
 90EXPORT_SYMBOL_GPL(iomap_fiemap);
 91
 92/* legacy ->bmap interface.  0 is the error return (!) */
 93sector_t
 94iomap_bmap(struct address_space *mapping, sector_t bno,
 95		const struct iomap_ops *ops)
 96{
 97	struct iomap_iter iter = {
 98		.inode	= mapping->host,
 99		.pos	= (loff_t)bno << mapping->host->i_blkbits,
100		.len	= i_blocksize(mapping->host),
101		.flags	= IOMAP_REPORT,
102	};
103	const unsigned int blkshift = mapping->host->i_blkbits - SECTOR_SHIFT;
104	int ret;
105
106	if (filemap_write_and_wait(mapping))
107		return 0;
108
109	bno = 0;
110	while ((ret = iomap_iter(&iter, ops)) > 0) {
111		if (iter.iomap.type == IOMAP_MAPPED)
112			bno = iomap_sector(&iter.iomap, iter.pos) >> blkshift;
113		/* leave iter.status unset to abort loop */
114	}
115	if (ret)
116		return 0;
117
118	return bno;
119}
120EXPORT_SYMBOL_GPL(iomap_bmap);