mirror of https://gitee.com/openkylin/linux.git
103 lines
2.3 KiB
C
103 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2017 Red Hat, Inc.
|
|
* Copyright (c) 2018 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_actor(struct inode *inode, loff_t start, loff_t length,
|
|
void *data, struct iomap *iomap, struct iomap *srcmap)
|
|
{
|
|
loff_t offset = start;
|
|
|
|
switch (iomap->type) {
|
|
case IOMAP_UNWRITTEN:
|
|
offset = mapping_seek_hole_data(inode->i_mapping, start,
|
|
start + length, SEEK_HOLE);
|
|
if (offset == start + length)
|
|
return length;
|
|
fallthrough;
|
|
case IOMAP_HOLE:
|
|
*(loff_t *)data = offset;
|
|
return 0;
|
|
default:
|
|
return length;
|
|
}
|
|
}
|
|
|
|
loff_t
|
|
iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
loff_t ret;
|
|
|
|
/* Nothing to be found before or beyond the end of the file. */
|
|
if (offset < 0 || offset >= size)
|
|
return -ENXIO;
|
|
|
|
while (offset < size) {
|
|
ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
|
|
ops, &offset, iomap_seek_hole_actor);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
break;
|
|
offset += ret;
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_seek_hole);
|
|
|
|
static loff_t
|
|
iomap_seek_data_actor(struct inode *inode, loff_t start, loff_t length,
|
|
void *data, struct iomap *iomap, struct iomap *srcmap)
|
|
{
|
|
loff_t offset = start;
|
|
|
|
switch (iomap->type) {
|
|
case IOMAP_HOLE:
|
|
return length;
|
|
case IOMAP_UNWRITTEN:
|
|
offset = mapping_seek_hole_data(inode->i_mapping, start,
|
|
start + length, SEEK_DATA);
|
|
if (offset < 0)
|
|
return length;
|
|
fallthrough;
|
|
default:
|
|
*(loff_t *)data = offset;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
loff_t
|
|
iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
loff_t ret;
|
|
|
|
/* Nothing to be found before or beyond the end of the file. */
|
|
if (offset < 0 || offset >= size)
|
|
return -ENXIO;
|
|
|
|
while (offset < size) {
|
|
ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
|
|
ops, &offset, iomap_seek_data_actor);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (ret == 0)
|
|
return offset;
|
|
offset += ret;
|
|
}
|
|
|
|
/* We've reached the end of the file without finding data */
|
|
return -ENXIO;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iomap_seek_data);
|