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214 lines
6.9 KiB
214 lines
6.9 KiB
#ifndef _LINUX_ELEVATOR_H |
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#define _LINUX_ELEVATOR_H |
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#include <linux/percpu.h> |
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#include <linux/hashtable.h> |
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#ifdef CONFIG_BLOCK |
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struct io_cq; |
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struct elevator_type; |
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typedef int (elevator_merge_fn) (struct request_queue *, struct request **, |
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struct bio *); |
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typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *); |
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typedef void (elevator_merged_fn) (struct request_queue *, struct request *, int); |
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typedef int (elevator_allow_merge_fn) (struct request_queue *, struct request *, struct bio *); |
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typedef void (elevator_bio_merged_fn) (struct request_queue *, |
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struct request *, struct bio *); |
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typedef int (elevator_dispatch_fn) (struct request_queue *, int); |
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typedef void (elevator_add_req_fn) (struct request_queue *, struct request *); |
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typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *); |
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typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *); |
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typedef int (elevator_may_queue_fn) (struct request_queue *, int); |
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typedef void (elevator_init_icq_fn) (struct io_cq *); |
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typedef void (elevator_exit_icq_fn) (struct io_cq *); |
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typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, |
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struct bio *, gfp_t); |
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typedef void (elevator_put_req_fn) (struct request *); |
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typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); |
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typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); |
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typedef int (elevator_init_fn) (struct request_queue *, |
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struct elevator_type *e); |
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typedef void (elevator_exit_fn) (struct elevator_queue *); |
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typedef void (elevator_registered_fn) (struct request_queue *); |
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struct elevator_ops |
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{ |
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elevator_merge_fn *elevator_merge_fn; |
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elevator_merged_fn *elevator_merged_fn; |
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elevator_merge_req_fn *elevator_merge_req_fn; |
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elevator_allow_merge_fn *elevator_allow_merge_fn; |
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elevator_bio_merged_fn *elevator_bio_merged_fn; |
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elevator_dispatch_fn *elevator_dispatch_fn; |
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elevator_add_req_fn *elevator_add_req_fn; |
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elevator_activate_req_fn *elevator_activate_req_fn; |
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elevator_deactivate_req_fn *elevator_deactivate_req_fn; |
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elevator_completed_req_fn *elevator_completed_req_fn; |
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elevator_request_list_fn *elevator_former_req_fn; |
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elevator_request_list_fn *elevator_latter_req_fn; |
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elevator_init_icq_fn *elevator_init_icq_fn; /* see iocontext.h */ |
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elevator_exit_icq_fn *elevator_exit_icq_fn; /* ditto */ |
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elevator_set_req_fn *elevator_set_req_fn; |
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elevator_put_req_fn *elevator_put_req_fn; |
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elevator_may_queue_fn *elevator_may_queue_fn; |
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elevator_init_fn *elevator_init_fn; |
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elevator_exit_fn *elevator_exit_fn; |
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elevator_registered_fn *elevator_registered_fn; |
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}; |
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#define ELV_NAME_MAX (16) |
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struct elv_fs_entry { |
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struct attribute attr; |
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ssize_t (*show)(struct elevator_queue *, char *); |
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ssize_t (*store)(struct elevator_queue *, const char *, size_t); |
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}; |
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/* |
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* identifies an elevator type, such as AS or deadline |
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*/ |
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struct elevator_type |
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{ |
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/* managed by elevator core */ |
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struct kmem_cache *icq_cache; |
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/* fields provided by elevator implementation */ |
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struct elevator_ops ops; |
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size_t icq_size; /* see iocontext.h */ |
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size_t icq_align; /* ditto */ |
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struct elv_fs_entry *elevator_attrs; |
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char elevator_name[ELV_NAME_MAX]; |
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struct module *elevator_owner; |
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/* managed by elevator core */ |
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char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */ |
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struct list_head list; |
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}; |
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#define ELV_HASH_BITS 6 |
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/* |
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* each queue has an elevator_queue associated with it |
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*/ |
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struct elevator_queue |
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{ |
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struct elevator_type *type; |
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void *elevator_data; |
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struct kobject kobj; |
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struct mutex sysfs_lock; |
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unsigned int registered:1; |
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DECLARE_HASHTABLE(hash, ELV_HASH_BITS); |
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}; |
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/* |
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* block elevator interface |
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*/ |
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extern void elv_dispatch_sort(struct request_queue *, struct request *); |
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extern void elv_dispatch_add_tail(struct request_queue *, struct request *); |
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extern void elv_add_request(struct request_queue *, struct request *, int); |
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extern void __elv_add_request(struct request_queue *, struct request *, int); |
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extern int elv_merge(struct request_queue *, struct request **, struct bio *); |
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extern void elv_merge_requests(struct request_queue *, struct request *, |
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struct request *); |
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extern void elv_merged_request(struct request_queue *, struct request *, int); |
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extern void elv_bio_merged(struct request_queue *q, struct request *, |
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struct bio *); |
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extern void elv_requeue_request(struct request_queue *, struct request *); |
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extern struct request *elv_former_request(struct request_queue *, struct request *); |
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extern struct request *elv_latter_request(struct request_queue *, struct request *); |
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extern int elv_register_queue(struct request_queue *q); |
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extern void elv_unregister_queue(struct request_queue *q); |
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extern int elv_may_queue(struct request_queue *, int); |
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extern void elv_completed_request(struct request_queue *, struct request *); |
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extern int elv_set_request(struct request_queue *q, struct request *rq, |
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struct bio *bio, gfp_t gfp_mask); |
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extern void elv_put_request(struct request_queue *, struct request *); |
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extern void elv_drain_elevator(struct request_queue *); |
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/* |
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* io scheduler registration |
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*/ |
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extern void __init load_default_elevator_module(void); |
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extern int elv_register(struct elevator_type *); |
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extern void elv_unregister(struct elevator_type *); |
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/* |
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* io scheduler sysfs switching |
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*/ |
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extern ssize_t elv_iosched_show(struct request_queue *, char *); |
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extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); |
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extern int elevator_init(struct request_queue *, char *); |
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extern void elevator_exit(struct elevator_queue *); |
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extern int elevator_change(struct request_queue *, const char *); |
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extern bool elv_rq_merge_ok(struct request *, struct bio *); |
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extern struct elevator_queue *elevator_alloc(struct request_queue *, |
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struct elevator_type *); |
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/* |
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* Helper functions. |
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*/ |
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extern struct request *elv_rb_former_request(struct request_queue *, struct request *); |
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extern struct request *elv_rb_latter_request(struct request_queue *, struct request *); |
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/* |
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* rb support functions. |
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*/ |
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extern void elv_rb_add(struct rb_root *, struct request *); |
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extern void elv_rb_del(struct rb_root *, struct request *); |
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extern struct request *elv_rb_find(struct rb_root *, sector_t); |
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/* |
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* Return values from elevator merger |
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*/ |
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#define ELEVATOR_NO_MERGE 0 |
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#define ELEVATOR_FRONT_MERGE 1 |
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#define ELEVATOR_BACK_MERGE 2 |
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/* |
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* Insertion selection |
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*/ |
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#define ELEVATOR_INSERT_FRONT 1 |
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#define ELEVATOR_INSERT_BACK 2 |
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#define ELEVATOR_INSERT_SORT 3 |
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#define ELEVATOR_INSERT_REQUEUE 4 |
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#define ELEVATOR_INSERT_FLUSH 5 |
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#define ELEVATOR_INSERT_SORT_MERGE 6 |
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/* |
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* return values from elevator_may_queue_fn |
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*/ |
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enum { |
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ELV_MQUEUE_MAY, |
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ELV_MQUEUE_NO, |
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ELV_MQUEUE_MUST, |
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}; |
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#define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq)) |
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#define rb_entry_rq(node) rb_entry((node), struct request, rb_node) |
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#define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist) |
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#define rq_fifo_clear(rq) list_del_init(&(rq)->queuelist) |
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#else /* CONFIG_BLOCK */ |
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static inline void load_default_elevator_module(void) { } |
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#endif /* CONFIG_BLOCK */ |
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#endif
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