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102 lines
2.3 KiB
102 lines
2.3 KiB
// 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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