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104 lines
2.3 KiB
104 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) 2018-2021 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 iomap_seek_hole_iter(const struct iomap_iter *iter, |
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loff_t *hole_pos) |
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{ |
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loff_t length = iomap_length(iter); |
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switch (iter->iomap.type) { |
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case IOMAP_UNWRITTEN: |
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*hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, |
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iter->pos, iter->pos + length, SEEK_HOLE); |
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if (*hole_pos == iter->pos + length) |
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return length; |
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return 0; |
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case IOMAP_HOLE: |
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*hole_pos = iter->pos; |
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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 pos, const struct iomap_ops *ops) |
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{ |
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loff_t size = i_size_read(inode); |
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struct iomap_iter iter = { |
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.inode = inode, |
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.pos = pos, |
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.flags = IOMAP_REPORT, |
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}; |
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int ret; |
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/* Nothing to be found before or beyond the end of the file. */ |
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if (pos < 0 || pos >= size) |
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return -ENXIO; |
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iter.len = size - pos; |
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while ((ret = iomap_iter(&iter, ops)) > 0) |
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iter.processed = iomap_seek_hole_iter(&iter, &pos); |
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if (ret < 0) |
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return ret; |
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if (iter.len) /* found hole before EOF */ |
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return pos; |
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return size; |
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} |
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EXPORT_SYMBOL_GPL(iomap_seek_hole); |
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static loff_t iomap_seek_data_iter(const struct iomap_iter *iter, |
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loff_t *hole_pos) |
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{ |
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loff_t length = iomap_length(iter); |
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switch (iter->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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*hole_pos = mapping_seek_hole_data(iter->inode->i_mapping, |
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iter->pos, iter->pos + length, SEEK_DATA); |
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if (*hole_pos < 0) |
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return length; |
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return 0; |
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default: |
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*hole_pos = iter->pos; |
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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 pos, const struct iomap_ops *ops) |
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{ |
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loff_t size = i_size_read(inode); |
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struct iomap_iter iter = { |
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.inode = inode, |
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.pos = pos, |
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.flags = IOMAP_REPORT, |
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}; |
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int ret; |
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/* Nothing to be found before or beyond the end of the file. */ |
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if (pos < 0 || pos >= size) |
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return -ENXIO; |
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iter.len = size - pos; |
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while ((ret = iomap_iter(&iter, ops)) > 0) |
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iter.processed = iomap_seek_data_iter(&iter, &pos); |
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if (ret < 0) |
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return ret; |
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if (iter.len) /* found data before EOF */ |
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return pos; |
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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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