2a842acab1
Currently we use nornal Linux errno values in the block layer, and while we accept any error a few have overloaded magic meanings. This patch instead introduces a new blk_status_t value that holds block layer specific status codes and explicitly explains their meaning. Helpers to convert from and to the previous special meanings are provided for now, but I suspect we want to get rid of them in the long run - those drivers that have a errno input (e.g. networking) usually get errnos that don't know about the special block layer overloads, and similarly returning them to userspace will usually return somethings that strictly speaking isn't correct for file system operations, but that's left as an exercise for later. For now the set of errors is a very limited set that closely corresponds to the previous overloaded errno values, but there is some low hanging fruite to improve it. blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse typechecking, so that we can easily catch places passing the wrong values. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
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* Internal header file for device mapper
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*
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* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the LGPL.
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*/
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#ifndef DM_RQ_INTERNAL_H
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#define DM_RQ_INTERNAL_H
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#include <linux/bio.h>
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#include <linux/kthread.h>
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#include "dm-stats.h"
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struct mapped_device;
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/*
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* One of these is allocated per request.
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*/
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struct dm_rq_target_io {
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struct mapped_device *md;
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struct dm_target *ti;
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struct request *orig, *clone;
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struct kthread_work work;
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blk_status_t error;
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union map_info info;
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struct dm_stats_aux stats_aux;
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unsigned long duration_jiffies;
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unsigned n_sectors;
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};
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/*
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* For request-based dm - the bio clones we allocate are embedded in these
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* structs.
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*
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* We allocate these with bio_alloc_bioset, using the front_pad parameter when
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* the bioset is created - this means the bio has to come at the end of the
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* struct.
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*/
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struct dm_rq_clone_bio_info {
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struct bio *orig;
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struct dm_rq_target_io *tio;
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struct bio clone;
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};
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bool dm_use_blk_mq_default(void);
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bool dm_use_blk_mq(struct mapped_device *md);
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int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t);
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int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t);
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void dm_mq_cleanup_mapped_device(struct mapped_device *md);
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void dm_start_queue(struct request_queue *q);
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void dm_stop_queue(struct request_queue *q);
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void dm_mq_kick_requeue_list(struct mapped_device *md);
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unsigned dm_get_reserved_rq_based_ios(void);
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ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
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ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
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const char *buf, size_t count);
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#endif
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