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// 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);
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