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80 lines
2.4 KiB
80 lines
2.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2010 Red Hat, Inc. |
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* Copyright (c) 2016-2021 Christoph Hellwig. |
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*/ |
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#include <linux/fs.h> |
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#include <linux/iomap.h> |
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#include "trace.h" |
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static inline int iomap_iter_advance(struct iomap_iter *iter) |
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{ |
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/* handle the previous iteration (if any) */ |
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if (iter->iomap.length) { |
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if (iter->processed <= 0) |
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return iter->processed; |
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if (WARN_ON_ONCE(iter->processed > iomap_length(iter))) |
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return -EIO; |
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iter->pos += iter->processed; |
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iter->len -= iter->processed; |
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if (!iter->len) |
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return 0; |
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} |
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/* clear the state for the next iteration */ |
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iter->processed = 0; |
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memset(&iter->iomap, 0, sizeof(iter->iomap)); |
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memset(&iter->srcmap, 0, sizeof(iter->srcmap)); |
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return 1; |
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} |
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static inline void iomap_iter_done(struct iomap_iter *iter) |
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{ |
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WARN_ON_ONCE(iter->iomap.offset > iter->pos); |
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WARN_ON_ONCE(iter->iomap.length == 0); |
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WARN_ON_ONCE(iter->iomap.offset + iter->iomap.length <= iter->pos); |
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trace_iomap_iter_dstmap(iter->inode, &iter->iomap); |
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if (iter->srcmap.type != IOMAP_HOLE) |
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trace_iomap_iter_srcmap(iter->inode, &iter->srcmap); |
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} |
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/** |
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* iomap_iter - iterate over a ranges in a file |
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* @iter: iteration structue |
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* @ops: iomap ops provided by the file system |
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* |
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* Iterate over filesystem-provided space mappings for the provided file range. |
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* |
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* This function handles cleanup of resources acquired for iteration when the |
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* filesystem indicates there are no more space mappings, which means that this |
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* function must be called in a loop that continues as long it returns a |
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* positive value. If 0 or a negative value is returned, the caller must not |
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* return to the loop body. Within a loop body, there are two ways to break out |
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* of the loop body: leave @iter.processed unchanged, or set it to a negative |
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* errno. |
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*/ |
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int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) |
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{ |
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int ret; |
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if (iter->iomap.length && ops->iomap_end) { |
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ret = ops->iomap_end(iter->inode, iter->pos, iomap_length(iter), |
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iter->processed > 0 ? iter->processed : 0, |
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iter->flags, &iter->iomap); |
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if (ret < 0 && !iter->processed) |
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return ret; |
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} |
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trace_iomap_iter(iter, ops, _RET_IP_); |
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ret = iomap_iter_advance(iter); |
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if (ret <= 0) |
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return ret; |
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ret = ops->iomap_begin(iter->inode, iter->pos, iter->len, iter->flags, |
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&iter->iomap, &iter->srcmap); |
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if (ret < 0) |
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return ret; |
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iomap_iter_done(iter); |
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return 1; |
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}
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