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49694d14ff
The length variable is rather pointless given that it can be trivially deduced from offset and size. Also the initial calculation can lead to KASAN warnings. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Leizhen (ThunderTown) <thunder.leizhen@huawei.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
103 lines
2.3 KiB
C
103 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2017 Red Hat, Inc.
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* Copyright (c) 2018 Christoph Hellwig.
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*/
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#include <linux/module.h>
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#include <linux/compiler.h>
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#include <linux/fs.h>
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#include <linux/iomap.h>
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#include <linux/pagemap.h>
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#include <linux/pagevec.h>
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static loff_t
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iomap_seek_hole_actor(struct inode *inode, loff_t start, loff_t length,
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void *data, struct iomap *iomap, struct iomap *srcmap)
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{
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loff_t offset = start;
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switch (iomap->type) {
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case IOMAP_UNWRITTEN:
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offset = mapping_seek_hole_data(inode->i_mapping, start,
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start + length, SEEK_HOLE);
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if (offset == start + length)
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return length;
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fallthrough;
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case IOMAP_HOLE:
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*(loff_t *)data = offset;
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return 0;
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default:
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return length;
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}
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}
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loff_t
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iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
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{
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loff_t size = i_size_read(inode);
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loff_t ret;
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/* Nothing to be found before or beyond the end of the file. */
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if (offset < 0 || offset >= size)
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return -ENXIO;
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while (offset < size) {
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ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
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ops, &offset, iomap_seek_hole_actor);
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if (ret < 0)
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return ret;
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if (ret == 0)
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break;
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offset += ret;
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}
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return offset;
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}
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EXPORT_SYMBOL_GPL(iomap_seek_hole);
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static loff_t
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iomap_seek_data_actor(struct inode *inode, loff_t start, loff_t length,
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void *data, struct iomap *iomap, struct iomap *srcmap)
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{
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loff_t offset = start;
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switch (iomap->type) {
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case IOMAP_HOLE:
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return length;
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case IOMAP_UNWRITTEN:
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offset = mapping_seek_hole_data(inode->i_mapping, start,
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start + length, SEEK_DATA);
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if (offset < 0)
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return length;
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fallthrough;
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default:
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*(loff_t *)data = offset;
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return 0;
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}
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}
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loff_t
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iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
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{
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loff_t size = i_size_read(inode);
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loff_t ret;
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/* Nothing to be found before or beyond the end of the file. */
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if (offset < 0 || offset >= size)
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return -ENXIO;
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while (offset < size) {
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ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
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ops, &offset, iomap_seek_data_actor);
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if (ret < 0)
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return ret;
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if (ret == 0)
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return offset;
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offset += ret;
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}
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/* We've reached the end of the file without finding data */
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return -ENXIO;
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}
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EXPORT_SYMBOL_GPL(iomap_seek_data);
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