+++ /dev/null
-/*
- * linux/drivers/block/cfq-iosched.c
- *
- * CFQ, or complete fairness queueing, disk scheduler.
- *
- * Based on ideas from a previously unfinished io
- * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
- *
- * Copyright (C) 2003 Jens Axboe <axboe@suse.de>
- */
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/blkdev.h>
-#include <linux/elevator.h>
-#include <linux/bio.h>
-#include <linux/config.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/compiler.h>
-#include <linux/hash.h>
-#include <linux/rbtree.h>
-#include <linux/mempool.h>
-
-/*
- * tunables
- */
-static int cfq_quantum = 4;
-static int cfq_queued = 8;
-
-#define CFQ_QHASH_SHIFT 6
-#define CFQ_QHASH_ENTRIES (1 << CFQ_QHASH_SHIFT)
-#define list_entry_qhash(entry) list_entry((entry), struct cfq_queue, cfq_hash)
-
-#define CFQ_MHASH_SHIFT 8
-#define CFQ_MHASH_BLOCK(sec) ((sec) >> 3)
-#define CFQ_MHASH_ENTRIES (1 << CFQ_MHASH_SHIFT)
-#define CFQ_MHASH_FN(sec) (hash_long(CFQ_MHASH_BLOCK((sec)),CFQ_MHASH_SHIFT))
-#define ON_MHASH(crq) !list_empty(&(crq)->hash)
-#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
-#define list_entry_hash(ptr) list_entry((ptr), struct cfq_rq, hash)
-
-#define list_entry_cfqq(ptr) list_entry((ptr), struct cfq_queue, cfq_list)
-
-#define RQ_DATA(rq) ((struct cfq_rq *) (rq)->elevator_private)
-
-static kmem_cache_t *crq_pool;
-static kmem_cache_t *cfq_pool;
-static mempool_t *cfq_mpool;
-
-struct cfq_data {
- struct list_head rr_list;
- struct list_head *dispatch;
- struct list_head *cfq_hash;
-
- struct list_head *crq_hash;
-
- unsigned int busy_queues;
- unsigned int max_queued;
-
- mempool_t *crq_pool;
-
- request_queue_t *queue;
-
- /*
- * tunables
- */
- unsigned int cfq_quantum;
- unsigned int cfq_queued;
-};
-
-struct cfq_queue {
- struct list_head cfq_hash;
- struct list_head cfq_list;
- struct rb_root sort_list;
- int pid;
- int queued[2];
-#if 0
- /*
- * with a simple addition like this, we can do io priorities. almost.
- * does need a split request free list, too.
- */
- int io_prio
-#endif
-};
-
-struct cfq_rq {
- struct rb_node rb_node;
- sector_t rb_key;
-
- struct request *request;
-
- struct cfq_queue *cfq_queue;
-
- struct list_head hash;
-};
-
-static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq);
-static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid);
-static void cfq_dispatch_sort(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_rq *crq);
-
-/*
- * lots of deadline iosched dupes, can be abstracted later...
- */
-static inline void __cfq_del_crq_hash(struct cfq_rq *crq)
-{
- list_del_init(&crq->hash);
-}
-
-static inline void cfq_del_crq_hash(struct cfq_rq *crq)
-{
- if (ON_MHASH(crq))
- __cfq_del_crq_hash(crq);
-}
-
-static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
-{
- cfq_del_crq_hash(crq);
-
- if (q->last_merge == crq->request)
- q->last_merge = NULL;
-}
-
-static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
-{
- struct request *rq = crq->request;
-
- BUG_ON(ON_MHASH(crq));
-
- list_add(&crq->hash, &cfqd->crq_hash[CFQ_MHASH_FN(rq_hash_key(rq))]);
-}
-
-static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
-{
- struct list_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)];
- struct list_head *entry, *next = hash_list->next;
-
- while ((entry = next) != hash_list) {
- struct cfq_rq *crq = list_entry_hash(entry);
- struct request *__rq = crq->request;
-
- next = entry->next;
-
- BUG_ON(!ON_MHASH(crq));
-
- if (!rq_mergeable(__rq)) {
- __cfq_del_crq_hash(crq);
- continue;
- }
-
- if (rq_hash_key(__rq) == offset)
- return __rq;
- }
-
- return NULL;
-}
-
-/*
- * rb tree support functions
- */
-#define RB_NONE (2)
-#define RB_EMPTY(node) ((node)->rb_node == NULL)
-#define RB_CLEAR(node) ((node)->rb_color = RB_NONE)
-#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
-#define ON_RB(node) ((node)->rb_color != RB_NONE)
-#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
-#define rq_rb_key(rq) (rq)->sector
-
-static inline void cfq_del_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
-{
- if (ON_RB(&crq->rb_node)) {
- cfqq->queued[rq_data_dir(crq->request)]--;
- rb_erase(&crq->rb_node, &cfqq->sort_list);
- crq->cfq_queue = NULL;
- }
-}
-
-static struct cfq_rq *
-__cfq_add_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
-{
- struct rb_node **p = &cfqq->sort_list.rb_node;
- struct rb_node *parent = NULL;
- struct cfq_rq *__crq;
-
- while (*p) {
- parent = *p;
- __crq = rb_entry_crq(parent);
-
- if (crq->rb_key < __crq->rb_key)
- p = &(*p)->rb_left;
- else if (crq->rb_key > __crq->rb_key)
- p = &(*p)->rb_right;
- else
- return __crq;
- }
-
- rb_link_node(&crq->rb_node, parent, p);
- return NULL;
-}
-
-static void
-cfq_add_crq_rb(struct cfq_data *cfqd, struct cfq_queue *cfqq,struct cfq_rq *crq)
-{
- struct request *rq = crq->request;
- struct cfq_rq *__alias;
-
- crq->rb_key = rq_rb_key(rq);
- cfqq->queued[rq_data_dir(rq)]++;
-retry:
- __alias = __cfq_add_crq_rb(cfqq, crq);
- if (!__alias) {
- rb_insert_color(&crq->rb_node, &cfqq->sort_list);
- crq->cfq_queue = cfqq;
- return;
- }
-
- cfq_dispatch_sort(cfqd, cfqq, __alias);
- goto retry;
-}
-
-static struct request *
-cfq_find_rq_rb(struct cfq_data *cfqd, sector_t sector)
-{
- struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, current->tgid);
- struct rb_node *n;
-
- if (!cfqq)
- goto out;
-
- n = cfqq->sort_list.rb_node;
- while (n) {
- struct cfq_rq *crq = rb_entry_crq(n);
-
- if (sector < crq->rb_key)
- n = n->rb_left;
- else if (sector > crq->rb_key)
- n = n->rb_right;
- else
- return crq->request;
- }
-
-out:
- return NULL;
-}
-
-static void cfq_remove_request(request_queue_t *q, struct request *rq)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
-
- if (crq) {
- struct cfq_queue *cfqq = crq->cfq_queue;
-
- cfq_remove_merge_hints(q, crq);
- list_del_init(&rq->queuelist);
-
- if (cfqq) {
- cfq_del_crq_rb(cfqq, crq);
-
- if (RB_EMPTY(&cfqq->sort_list))
- cfq_put_queue(cfqd, cfqq);
- }
- }
-}
-
-static int
-cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct request *__rq;
- int ret;
-
- ret = elv_try_last_merge(q, bio);
- if (ret != ELEVATOR_NO_MERGE) {
- __rq = q->last_merge;
- goto out_insert;
- }
-
- __rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
- if (__rq) {
- BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector);
-
- if (elv_rq_merge_ok(__rq, bio)) {
- ret = ELEVATOR_BACK_MERGE;
- goto out;
- }
- }
-
- __rq = cfq_find_rq_rb(cfqd, bio->bi_sector + bio_sectors(bio));
- if (__rq) {
- if (elv_rq_merge_ok(__rq, bio)) {
- ret = ELEVATOR_FRONT_MERGE;
- goto out;
- }
- }
-
- return ELEVATOR_NO_MERGE;
-out:
- q->last_merge = __rq;
-out_insert:
- *req = __rq;
- return ret;
-}
-
-static void cfq_merged_request(request_queue_t *q, struct request *req)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(req);
-
- cfq_del_crq_hash(crq);
- cfq_add_crq_hash(cfqd, crq);
-
- if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) {
- struct cfq_queue *cfqq = crq->cfq_queue;
-
- cfq_del_crq_rb(cfqq, crq);
- cfq_add_crq_rb(cfqd, cfqq, crq);
- }
-
- q->last_merge = req;
-}
-
-static void
-cfq_merged_requests(request_queue_t *q, struct request *req,
- struct request *next)
-{
- cfq_merged_request(q, req);
- cfq_remove_request(q, next);
-}
-
-static void
-cfq_dispatch_sort(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_rq *crq)
-{
- struct list_head *head = cfqd->dispatch, *entry = head;
- struct request *__rq;
-
- cfq_del_crq_rb(cfqq, crq);
- cfq_remove_merge_hints(cfqd->queue, crq);
-
- if (!list_empty(head)) {
- __rq = list_entry_rq(head->next);
-
- if (crq->request->sector < __rq->sector) {
- entry = head->prev;
- goto link;
- }
- }
-
- while ((entry = entry->prev) != head) {
- __rq = list_entry_rq(entry);
-
- if (crq->request->sector <= __rq->sector)
- break;
- }
-
-link:
- list_add_tail(&crq->request->queuelist, entry);
-}
-
-static inline void
-__cfq_dispatch_requests(request_queue_t *q, struct cfq_data *cfqd,
- struct cfq_queue *cfqq)
-{
- struct cfq_rq *crq = rb_entry_crq(rb_first(&cfqq->sort_list));
-
- cfq_dispatch_sort(cfqd, cfqq, crq);
-}
-
-static int cfq_dispatch_requests(request_queue_t *q, struct cfq_data *cfqd)
-{
- struct cfq_queue *cfqq;
- struct list_head *entry, *tmp;
- int ret, queued, good_queues;
-
- if (list_empty(&cfqd->rr_list))
- return 0;
-
- queued = ret = 0;
-restart:
- good_queues = 0;
- list_for_each_safe(entry, tmp, &cfqd->rr_list) {
- cfqq = list_entry_cfqq(cfqd->rr_list.next);
-
- BUG_ON(RB_EMPTY(&cfqq->sort_list));
-
- __cfq_dispatch_requests(q, cfqd, cfqq);
-
- if (RB_EMPTY(&cfqq->sort_list))
- cfq_put_queue(cfqd, cfqq);
- else
- good_queues++;
-
- queued++;
- ret = 1;
- }
-
- if ((queued < cfqd->cfq_quantum) && good_queues)
- goto restart;
-
- return ret;
-}
-
-static struct request *cfq_next_request(request_queue_t *q)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct request *rq;
-
- if (!list_empty(cfqd->dispatch)) {
- struct cfq_rq *crq;
-dispatch:
- rq = list_entry_rq(cfqd->dispatch->next);
-
- crq = RQ_DATA(rq);
- if (crq)
- cfq_remove_merge_hints(q, crq);
-
- return rq;
- }
-
- if (cfq_dispatch_requests(q, cfqd))
- goto dispatch;
-
- return NULL;
-}
-
-static inline struct cfq_queue *
-__cfq_find_cfq_hash(struct cfq_data *cfqd, int pid, const int hashval)
-{
- struct list_head *hash_list = &cfqd->cfq_hash[hashval];
- struct list_head *entry;
-
- list_for_each(entry, hash_list) {
- struct cfq_queue *__cfqq = list_entry_qhash(entry);
-
- if (__cfqq->pid == pid)
- return __cfqq;
- }
-
- return NULL;
-}
-
-static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid)
-{
- const int hashval = hash_long(current->tgid, CFQ_QHASH_SHIFT);
-
- return __cfq_find_cfq_hash(cfqd, pid, hashval);
-}
-
-static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
-{
- cfqd->busy_queues--;
- list_del(&cfqq->cfq_list);
- list_del(&cfqq->cfq_hash);
- mempool_free(cfqq, cfq_mpool);
-}
-
-static struct cfq_queue *__cfq_get_queue(struct cfq_data *cfqd, int pid,
- int gfp_mask)
-{
- const int hashval = hash_long(current->tgid, CFQ_QHASH_SHIFT);
- struct cfq_queue *cfqq, *new_cfqq = NULL;
- request_queue_t *q = cfqd->queue;
-
-retry:
- cfqq = __cfq_find_cfq_hash(cfqd, pid, hashval);
-
- if (!cfqq) {
- if (new_cfqq) {
- cfqq = new_cfqq;
- new_cfqq = NULL;
- } else if (gfp_mask & __GFP_WAIT) {
- spin_unlock_irq(q->queue_lock);
- new_cfqq = mempool_alloc(cfq_mpool, gfp_mask);
- spin_lock_irq(q->queue_lock);
- goto retry;
- } else
- return NULL;
-
- INIT_LIST_HEAD(&cfqq->cfq_hash);
- INIT_LIST_HEAD(&cfqq->cfq_list);
- RB_CLEAR_ROOT(&cfqq->sort_list);
-
- cfqq->pid = pid;
- cfqq->queued[0] = cfqq->queued[1] = 0;
- list_add(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]);
- }
-
- if (new_cfqq)
- mempool_free(new_cfqq, cfq_mpool);
-
- return cfqq;
-}
-
-static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, int pid,
- int gfp_mask)
-{
- request_queue_t *q = cfqd->queue;
- struct cfq_queue *cfqq;
-
- spin_lock_irq(q->queue_lock);
- cfqq = __cfq_get_queue(cfqd, pid, gfp_mask);
- spin_unlock_irq(q->queue_lock);
-
- return cfqq;
-}
-
-static void cfq_enqueue(struct cfq_data *cfqd, struct cfq_rq *crq)
-{
- struct cfq_queue *cfqq;
-
- cfqq = __cfq_get_queue(cfqd, current->tgid, GFP_ATOMIC);
- if (cfqq) {
- cfq_add_crq_rb(cfqd, cfqq, crq);
-
- if (list_empty(&cfqq->cfq_list)) {
- list_add(&cfqq->cfq_list, &cfqd->rr_list);
- cfqd->busy_queues++;
- }
- } else {
- /*
- * should can only happen if the request wasn't allocated
- * through blk_alloc_request(), eg stack requests from ide-cd
- * (those should be removed) _and_ we are in OOM.
- */
- list_add_tail(&crq->request->queuelist, cfqd->dispatch);
- }
-}
-
-static void
-cfq_insert_request(request_queue_t *q, struct request *rq, int where)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
-
- switch (where) {
- case ELEVATOR_INSERT_BACK:
- while (cfq_dispatch_requests(q, cfqd))
- ;
- list_add_tail(&rq->queuelist, cfqd->dispatch);
- break;
- case ELEVATOR_INSERT_FRONT:
- list_add(&rq->queuelist, cfqd->dispatch);
- break;
- case ELEVATOR_INSERT_SORT:
- BUG_ON(!blk_fs_request(rq));
- cfq_enqueue(cfqd, crq);
- break;
- default:
- printk("%s: bad insert point %d\n", __FUNCTION__,where);
- return;
- }
-
- if (rq_mergeable(rq)) {
- cfq_add_crq_hash(cfqd, crq);
-
- if (!q->last_merge)
- q->last_merge = rq;
- }
-}
-
-static int cfq_queue_empty(request_queue_t *q)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
-
- if (list_empty(cfqd->dispatch) && list_empty(&cfqd->rr_list))
- return 1;
-
- return 0;
-}
-
-static struct request *
-cfq_former_request(request_queue_t *q, struct request *rq)
-{
- struct cfq_rq *crq = RQ_DATA(rq);
- struct rb_node *rbprev = rb_prev(&crq->rb_node);
-
- if (rbprev)
- return rb_entry_crq(rbprev)->request;
-
- return NULL;
-}
-
-static struct request *
-cfq_latter_request(request_queue_t *q, struct request *rq)
-{
- struct cfq_rq *crq = RQ_DATA(rq);
- struct rb_node *rbnext = rb_next(&crq->rb_node);
-
- if (rbnext)
- return rb_entry_crq(rbnext)->request;
-
- return NULL;
-}
-
-static int cfq_may_queue(request_queue_t *q, int rw)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_queue *cfqq;
- int ret = 1;
-
- if (!cfqd->busy_queues)
- goto out;
-
- cfqq = cfq_find_cfq_hash(cfqd, current->tgid);
- if (cfqq) {
- int limit = (q->nr_requests - cfqd->cfq_queued) / cfqd->busy_queues;
-
- if (limit < 3)
- limit = 3;
- else if (limit > cfqd->max_queued)
- limit = cfqd->max_queued;
-
- if (cfqq->queued[rw] > limit)
- ret = 0;
- }
-out:
- return ret;
-}
-
-static void cfq_put_request(request_queue_t *q, struct request *rq)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
- struct request_list *rl;
- int other_rw;
-
- if (crq) {
- BUG_ON(q->last_merge == rq);
- BUG_ON(ON_MHASH(crq));
-
- mempool_free(crq, cfqd->crq_pool);
- rq->elevator_private = NULL;
- }
-
- /*
- * work-around for may_queue "bug": if a read gets issued and refused
- * to queue because writes ate all the allowed slots and no other
- * reads are pending for this queue, it could get stuck infinitely
- * since freed_request() only checks the waitqueue for writes when
- * freeing them. or vice versa for a single write vs many reads.
- * so check here whether "the other" data direction might be able
- * to queue and wake them
- */
- rl = &q->rq;
- other_rw = rq_data_dir(rq) ^ 1;
- if (rl->count[other_rw] <= q->nr_requests) {
- smp_mb();
- if (waitqueue_active(&rl->wait[other_rw]))
- wake_up(&rl->wait[other_rw]);
- }
-}
-
-static int cfq_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
-{
- struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_queue *cfqq;
- struct cfq_rq *crq;
-
- /*
- * prepare a queue up front, so cfq_enqueue() doesn't have to
- */
- cfqq = cfq_get_queue(cfqd, current->tgid, gfp_mask);
- if (!cfqq)
- return 1;
-
- crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
- if (crq) {
- memset(crq, 0, sizeof(*crq));
- RB_CLEAR(&crq->rb_node);
- crq->request = rq;
- crq->cfq_queue = NULL;
- INIT_LIST_HEAD(&crq->hash);
- rq->elevator_private = crq;
- return 0;
- }
-
- return 1;
-}
-
-static void cfq_exit(request_queue_t *q, elevator_t *e)
-{
- struct cfq_data *cfqd = e->elevator_data;
-
- e->elevator_data = NULL;
- mempool_destroy(cfqd->crq_pool);
- kfree(cfqd->crq_hash);
- kfree(cfqd->cfq_hash);
- kfree(cfqd);
-}
-
-static int cfq_init(request_queue_t *q, elevator_t *e)
-{
- struct cfq_data *cfqd;
- int i;
-
- cfqd = kmalloc(sizeof(*cfqd), GFP_KERNEL);
- if (!cfqd)
- return -ENOMEM;
-
- memset(cfqd, 0, sizeof(*cfqd));
- INIT_LIST_HEAD(&cfqd->rr_list);
-
- cfqd->crq_hash = kmalloc(sizeof(struct list_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL);
- if (!cfqd->crq_hash)
- goto out_crqhash;
-
- cfqd->cfq_hash = kmalloc(sizeof(struct list_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL);
- if (!cfqd->cfq_hash)
- goto out_cfqhash;
-
- cfqd->crq_pool = mempool_create(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, crq_pool);
- if (!cfqd->crq_pool)
- goto out_crqpool;
-
- for (i = 0; i < CFQ_MHASH_ENTRIES; i++)
- INIT_LIST_HEAD(&cfqd->crq_hash[i]);
- for (i = 0; i < CFQ_QHASH_ENTRIES; i++)
- INIT_LIST_HEAD(&cfqd->cfq_hash[i]);
-
- cfqd->dispatch = &q->queue_head;
- e->elevator_data = cfqd;
- cfqd->queue = q;
-
- /*
- * just set it to some high value, we want anyone to be able to queue
- * some requests. fairness is handled differently
- */
- cfqd->max_queued = q->nr_requests;
- q->nr_requests = 8192;
-
- cfqd->cfq_queued = cfq_queued;
- cfqd->cfq_quantum = cfq_quantum;
-
- return 0;
-out_crqpool:
- kfree(cfqd->cfq_hash);
-out_cfqhash:
- kfree(cfqd->crq_hash);
-out_crqhash:
- kfree(cfqd);
- return -ENOMEM;
-}
-
-static int __init cfq_slab_setup(void)
-{
- crq_pool = kmem_cache_create("crq_pool", sizeof(struct cfq_rq), 0, 0,
- NULL, NULL);
-
- if (!crq_pool)
- panic("cfq_iosched: can't init crq pool\n");
-
- cfq_pool = kmem_cache_create("cfq_pool", sizeof(struct cfq_queue), 0, 0,
- NULL, NULL);
-
- if (!cfq_pool)
- panic("cfq_iosched: can't init cfq pool\n");
-
- cfq_mpool = mempool_create(64, mempool_alloc_slab, mempool_free_slab, cfq_pool);
-
- if (!cfq_mpool)
- panic("cfq_iosched: can't init cfq mpool\n");
-
- return 0;
-}
-
-subsys_initcall(cfq_slab_setup);
-
-/*
- * sysfs parts below -->
- */
-struct cfq_fs_entry {
- struct attribute attr;
- ssize_t (*show)(struct cfq_data *, char *);
- ssize_t (*store)(struct cfq_data *, const char *, size_t);
-};
-
-static ssize_t
-cfq_var_show(unsigned int var, char *page)
-{
- return sprintf(page, "%d\n", var);
-}
-
-static ssize_t
-cfq_var_store(unsigned int *var, const char *page, size_t count)
-{
- char *p = (char *) page;
-
- *var = simple_strtoul(p, &p, 10);
- return count;
-}
-
-#define SHOW_FUNCTION(__FUNC, __VAR) \
-static ssize_t __FUNC(struct cfq_data *cfqd, char *page) \
-{ \
- return cfq_var_show(__VAR, (page)); \
-}
-SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum);
-SHOW_FUNCTION(cfq_queued_show, cfqd->cfq_queued);
-#undef SHOW_FUNCTION
-
-#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
-static ssize_t __FUNC(struct cfq_data *cfqd, const char *page, size_t count) \
-{ \
- int ret = cfq_var_store(__PTR, (page), count); \
- if (*(__PTR) < (MIN)) \
- *(__PTR) = (MIN); \
- else if (*(__PTR) > (MAX)) \
- *(__PTR) = (MAX); \
- return ret; \
-}
-STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, INT_MAX);
-STORE_FUNCTION(cfq_queued_store, &cfqd->cfq_queued, 1, INT_MAX);
-#undef STORE_FUNCTION
-
-static struct cfq_fs_entry cfq_quantum_entry = {
- .attr = {.name = "quantum", .mode = S_IRUGO | S_IWUSR },
- .show = cfq_quantum_show,
- .store = cfq_quantum_store,
-};
-static struct cfq_fs_entry cfq_queued_entry = {
- .attr = {.name = "queued", .mode = S_IRUGO | S_IWUSR },
- .show = cfq_queued_show,
- .store = cfq_queued_store,
-};
-
-static struct attribute *default_attrs[] = {
- &cfq_quantum_entry.attr,
- &cfq_queued_entry.attr,
- NULL,
-};
-
-#define to_cfq(atr) container_of((atr), struct cfq_fs_entry, attr)
-
-static ssize_t
-cfq_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
-{
- elevator_t *e = container_of(kobj, elevator_t, kobj);
- struct cfq_fs_entry *entry = to_cfq(attr);
-
- if (!entry->show)
- return 0;
-
- return entry->show(e->elevator_data, page);
-}
-
-static ssize_t
-cfq_attr_store(struct kobject *kobj, struct attribute *attr,
- const char *page, size_t length)
-{
- elevator_t *e = container_of(kobj, elevator_t, kobj);
- struct cfq_fs_entry *entry = to_cfq(attr);
-
- if (!entry->store)
- return -EINVAL;
-
- return entry->store(e->elevator_data, page, length);
-}
-
-static struct sysfs_ops cfq_sysfs_ops = {
- .show = cfq_attr_show,
- .store = cfq_attr_store,
-};
-
-struct kobj_type cfq_ktype = {
- .sysfs_ops = &cfq_sysfs_ops,
- .default_attrs = default_attrs,
-};
-
-elevator_t iosched_cfq = {
- .elevator_name = "cfq",
- .elevator_ktype = &cfq_ktype,
- .elevator_merge_fn = cfq_merge,
- .elevator_merged_fn = cfq_merged_request,
- .elevator_merge_req_fn = cfq_merged_requests,
- .elevator_next_req_fn = cfq_next_request,
- .elevator_add_req_fn = cfq_insert_request,
- .elevator_remove_req_fn = cfq_remove_request,
- .elevator_queue_empty_fn = cfq_queue_empty,
- .elevator_former_req_fn = cfq_former_request,
- .elevator_latter_req_fn = cfq_latter_request,
- .elevator_set_req_fn = cfq_set_request,
- .elevator_put_req_fn = cfq_put_request,
- .elevator_may_queue_fn = cfq_may_queue,
- .elevator_init_fn = cfq_init,
- .elevator_exit_fn = cfq_exit,
-};
-
-EXPORT_SYMBOL(iosched_cfq);
+++ /dev/null
-/*
- * linux/kernel/exit.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
-
-#include <linux/config.h>
-#include <linux/mm.h>
-#include <linux/slab.h>
-#include <linux/interrupt.h>
-#include <linux/smp_lock.h>
-#include <linux/module.h>
-#include <linux/completion.h>
-#include <linux/personality.h>
-#include <linux/tty.h>
-#include <linux/namespace.h>
-#include <linux/security.h>
-#include <linux/acct.h>
-#include <linux/file.h>
-#include <linux/binfmts.h>
-#include <linux/ptrace.h>
-#include <linux/profile.h>
-#include <linux/mount.h>
-#include <linux/proc_fs.h>
-#include <linux/mempolicy.h>
-#include <linux/ckrm.h>
-#include <linux/ckrm_tsk.h>
-
-#include <asm/uaccess.h>
-#include <asm/unistd.h>
-#include <asm/pgtable.h>
-#include <asm/mmu_context.h>
-
-extern void sem_exit (void);
-extern struct task_struct *child_reaper;
-
-int getrusage(struct task_struct *, int, struct rusage __user *);
-
-static void __unhash_process(struct task_struct *p)
-{
- nr_threads--;
- detach_pid(p, PIDTYPE_PID);
- detach_pid(p, PIDTYPE_TGID);
- if (thread_group_leader(p)) {
- detach_pid(p, PIDTYPE_PGID);
- detach_pid(p, PIDTYPE_SID);
- if (p->pid)
- __get_cpu_var(process_counts)--;
- }
-
- REMOVE_LINKS(p);
-}
-
-void release_task(struct task_struct * p)
-{
- int zap_leader;
- task_t *leader;
- struct dentry *proc_dentry;
-
-repeat:
- BUG_ON(p->state < TASK_ZOMBIE);
-
- atomic_dec(&p->user->processes);
- spin_lock(&p->proc_lock);
- proc_dentry = proc_pid_unhash(p);
- write_lock_irq(&tasklist_lock);
- if (unlikely(p->ptrace))
- __ptrace_unlink(p);
- BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
- __exit_signal(p);
- __exit_sighand(p);
- __unhash_process(p);
-
- /*
- * If we are the last non-leader member of the thread
- * group, and the leader is zombie, then notify the
- * group leader's parent process. (if it wants notification.)
- */
- zap_leader = 0;
- leader = p->group_leader;
- if (leader != p && thread_group_empty(leader) && leader->state == TASK_ZOMBIE) {
- BUG_ON(leader->exit_signal == -1);
- do_notify_parent(leader, leader->exit_signal);
- /*
- * If we were the last child thread and the leader has
- * exited already, and the leader's parent ignores SIGCHLD,
- * then we are the one who should release the leader.
- *
- * do_notify_parent() will have marked it self-reaping in
- * that case.
- */
- zap_leader = (leader->exit_signal == -1);
- }
-
- p->parent->cutime += p->utime + p->cutime;
- p->parent->cstime += p->stime + p->cstime;
- p->parent->cmin_flt += p->min_flt + p->cmin_flt;
- p->parent->cmaj_flt += p->maj_flt + p->cmaj_flt;
- p->parent->cnvcsw += p->nvcsw + p->cnvcsw;
- p->parent->cnivcsw += p->nivcsw + p->cnivcsw;
- sched_exit(p);
- write_unlock_irq(&tasklist_lock);
- spin_unlock(&p->proc_lock);
- proc_pid_flush(proc_dentry);
- release_thread(p);
- put_task_struct(p);
-
- p = leader;
- if (unlikely(zap_leader))
- goto repeat;
-}
-
-/* we are using it only for SMP init */
-
-void unhash_process(struct task_struct *p)
-{
- struct dentry *proc_dentry;
-
- spin_lock(&p->proc_lock);
- proc_dentry = proc_pid_unhash(p);
- write_lock_irq(&tasklist_lock);
- __unhash_process(p);
- write_unlock_irq(&tasklist_lock);
- spin_unlock(&p->proc_lock);
- proc_pid_flush(proc_dentry);
-}
-
-/*
- * This checks not only the pgrp, but falls back on the pid if no
- * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
- * without this...
- */
-int session_of_pgrp(int pgrp)
-{
- struct task_struct *p;
- struct list_head *l;
- struct pid *pid;
- int sid = -1;
-
- read_lock(&tasklist_lock);
- for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid)
- if (p->signal->session > 0) {
- sid = p->signal->session;
- goto out;
- }
- p = find_task_by_pid(pgrp);
- if (p)
- sid = p->signal->session;
-out:
- read_unlock(&tasklist_lock);
-
- return sid;
-}
-
-/*
- * Determine if a process group is "orphaned", according to the POSIX
- * definition in 2.2.2.52. Orphaned process groups are not to be affected
- * by terminal-generated stop signals. Newly orphaned process groups are
- * to receive a SIGHUP and a SIGCONT.
- *
- * "I ask you, have you ever known what it is to be an orphan?"
- */
-static int will_become_orphaned_pgrp(int pgrp, task_t *ignored_task)
-{
- struct task_struct *p;
- struct list_head *l;
- struct pid *pid;
- int ret = 1;
-
- for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid) {
- if (p == ignored_task
- || p->state >= TASK_ZOMBIE
- || p->real_parent->pid == 1)
- continue;
- if (process_group(p->real_parent) != pgrp
- && p->real_parent->signal->session == p->signal->session) {
- ret = 0;
- break;
- }
- }
- return ret; /* (sighing) "Often!" */
-}
-
-int is_orphaned_pgrp(int pgrp)
-{
- int retval;
-
- read_lock(&tasklist_lock);
- retval = will_become_orphaned_pgrp(pgrp, NULL);
- read_unlock(&tasklist_lock);
-
- return retval;
-}
-
-static inline int has_stopped_jobs(int pgrp)
-{
- int retval = 0;
- struct task_struct *p;
- struct list_head *l;
- struct pid *pid;
-
- for_each_task_pid(pgrp, PIDTYPE_PGID, p, l, pid) {
- if (p->state != TASK_STOPPED)
- continue;
-
- /* If p is stopped by a debugger on a signal that won't
- stop it, then don't count p as stopped. This isn't
- perfect but it's a good approximation. */
- if (unlikely (p->ptrace)
- && p->exit_code != SIGSTOP
- && p->exit_code != SIGTSTP
- && p->exit_code != SIGTTOU
- && p->exit_code != SIGTTIN)
- continue;
-
- retval = 1;
- break;
- }
- return retval;
-}
-
-/**
- * reparent_to_init() - Reparent the calling kernel thread to the init task.
- *
- * If a kernel thread is launched as a result of a system call, or if
- * it ever exits, it should generally reparent itself to init so that
- * it is correctly cleaned up on exit.
- *
- * The various task state such as scheduling policy and priority may have
- * been inherited from a user process, so we reset them to sane values here.
- *
- * NOTE that reparent_to_init() gives the caller full capabilities.
- */
-void reparent_to_init(void)
-{
- write_lock_irq(&tasklist_lock);
-
- ptrace_unlink(current);
- /* Reparent to init */
- REMOVE_LINKS(current);
- current->parent = child_reaper;
- current->real_parent = child_reaper;
- SET_LINKS(current);
-
- /* Set the exit signal to SIGCHLD so we signal init on exit */
- current->exit_signal = SIGCHLD;
-
- if ((current->policy == SCHED_NORMAL) && (task_nice(current) < 0))
- set_user_nice(current, 0);
- /* cpus_allowed? */
- /* rt_priority? */
- /* signals? */
- security_task_reparent_to_init(current);
- memcpy(current->rlim, init_task.rlim, sizeof(*(current->rlim)));
- atomic_inc(&(INIT_USER->__count));
- switch_uid(INIT_USER);
-
- write_unlock_irq(&tasklist_lock);
-}
-
-void __set_special_pids(pid_t session, pid_t pgrp)
-{
- struct task_struct *curr = current;
-
- if (curr->signal->session != session) {
- detach_pid(curr, PIDTYPE_SID);
- curr->signal->session = session;
- attach_pid(curr, PIDTYPE_SID, session);
- }
- if (process_group(curr) != pgrp) {
- detach_pid(curr, PIDTYPE_PGID);
- curr->signal->pgrp = pgrp;
- attach_pid(curr, PIDTYPE_PGID, pgrp);
- }
-}
-
-void set_special_pids(pid_t session, pid_t pgrp)
-{
- write_lock_irq(&tasklist_lock);
- __set_special_pids(session, pgrp);
- write_unlock_irq(&tasklist_lock);
-}
-
-/*
- * Let kernel threads use this to say that they
- * allow a certain signal (since daemonize() will
- * have disabled all of them by default).
- */
-int allow_signal(int sig)
-{
- if (sig < 1 || sig > _NSIG)
- return -EINVAL;
-
- spin_lock_irq(¤t->sighand->siglock);
- sigdelset(¤t->blocked, sig);
- if (!current->mm) {
- /* Kernel threads handle their own signals.
- Let the signal code know it'll be handled, so
- that they don't get converted to SIGKILL or
- just silently dropped */
- current->sighand->action[(sig)-1].sa.sa_handler = (void *)2;
- }
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
- return 0;
-}
-
-EXPORT_SYMBOL(allow_signal);
-
-int disallow_signal(int sig)
-{
- if (sig < 1 || sig > _NSIG)
- return -EINVAL;
-
- spin_lock_irq(¤t->sighand->siglock);
- sigaddset(¤t->blocked, sig);
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
- return 0;
-}
-
-EXPORT_SYMBOL(disallow_signal);
-
-/*
- * Put all the gunge required to become a kernel thread without
- * attached user resources in one place where it belongs.
- */
-
-void daemonize(const char *name, ...)
-{
- va_list args;
- struct fs_struct *fs;
- sigset_t blocked;
-
- va_start(args, name);
- vsnprintf(current->comm, sizeof(current->comm), name, args);
- va_end(args);
-
- /*
- * If we were started as result of loading a module, close all of the
- * user space pages. We don't need them, and if we didn't close them
- * they would be locked into memory.
- */
- exit_mm(current);
-
- set_special_pids(1, 1);
- current->signal->tty = NULL;
-
- /* Block and flush all signals */
- sigfillset(&blocked);
- sigprocmask(SIG_BLOCK, &blocked, NULL);
- flush_signals(current);
-
- /* Become as one with the init task */
-
- exit_fs(current); /* current->fs->count--; */
- fs = init_task.fs;
- current->fs = fs;
- atomic_inc(&fs->count);
- exit_files(current);
- current->files = init_task.files;
- atomic_inc(¤t->files->count);
-
- reparent_to_init();
-}
-
-EXPORT_SYMBOL(daemonize);
-
-static inline void close_files(struct files_struct * files)
-{
- int i, j;
-
- j = 0;
- for (;;) {
- unsigned long set;
- i = j * __NFDBITS;
- if (i >= files->max_fdset || i >= files->max_fds)
- break;
- set = files->open_fds->fds_bits[j++];
- while (set) {
- if (set & 1) {
- struct file * file = xchg(&files->fd[i], NULL);
- if (file)
- filp_close(file, files);
- }
- i++;
- set >>= 1;
- }
- }
-}
-
-struct files_struct *get_files_struct(struct task_struct *task)
-{
- struct files_struct *files;
-
- task_lock(task);
- files = task->files;
- if (files)
- atomic_inc(&files->count);
- task_unlock(task);
-
- return files;
-}
-
-void fastcall put_files_struct(struct files_struct *files)
-{
- if (atomic_dec_and_test(&files->count)) {
- close_files(files);
- /*
- * Free the fd and fdset arrays if we expanded them.
- */
- if (files->fd != &files->fd_array[0])
- free_fd_array(files->fd, files->max_fds);
- if (files->max_fdset > __FD_SETSIZE) {
- free_fdset(files->open_fds, files->max_fdset);
- free_fdset(files->close_on_exec, files->max_fdset);
- }
- kmem_cache_free(files_cachep, files);
- }
-}
-
-EXPORT_SYMBOL(put_files_struct);
-
-static inline void __exit_files(struct task_struct *tsk)
-{
- struct files_struct * files = tsk->files;
-
- if (files) {
- task_lock(tsk);
- tsk->files = NULL;
- task_unlock(tsk);
- put_files_struct(files);
- }
-}
-
-void exit_files(struct task_struct *tsk)
-{
- __exit_files(tsk);
-}
-
-static inline void __put_fs_struct(struct fs_struct *fs)
-{
- /* No need to hold fs->lock if we are killing it */
- if (atomic_dec_and_test(&fs->count)) {
- dput(fs->root);
- mntput(fs->rootmnt);
- dput(fs->pwd);
- mntput(fs->pwdmnt);
- if (fs->altroot) {
- dput(fs->altroot);
- mntput(fs->altrootmnt);
- }
- kmem_cache_free(fs_cachep, fs);
- }
-}
-
-void put_fs_struct(struct fs_struct *fs)
-{
- __put_fs_struct(fs);
-}
-
-static inline void __exit_fs(struct task_struct *tsk)
-{
- struct fs_struct * fs = tsk->fs;
-
- if (fs) {
- task_lock(tsk);
- tsk->fs = NULL;
- task_unlock(tsk);
- __put_fs_struct(fs);
- }
-}
-
-void exit_fs(struct task_struct *tsk)
-{
- __exit_fs(tsk);
-}
-
-EXPORT_SYMBOL_GPL(exit_fs);
-
-/*
- * Turn us into a lazy TLB process if we
- * aren't already..
- */
-static inline void __exit_mm(struct task_struct * tsk)
-{
- struct mm_struct *mm = tsk->mm;
-
- mm_release(tsk, mm);
- if (!mm)
- return;
- /*
- * Serialize with any possible pending coredump.
- * We must hold mmap_sem around checking core_waiters
- * and clearing tsk->mm. The core-inducing thread
- * will increment core_waiters for each thread in the
- * group with ->mm != NULL.
- */
- down_read(&mm->mmap_sem);
- if (mm->core_waiters) {
- up_read(&mm->mmap_sem);
- down_write(&mm->mmap_sem);
- if (!--mm->core_waiters)
- complete(mm->core_startup_done);
- up_write(&mm->mmap_sem);
-
- wait_for_completion(&mm->core_done);
- down_read(&mm->mmap_sem);
- }
- atomic_inc(&mm->mm_count);
- if (mm != tsk->active_mm) BUG();
- /* more a memory barrier than a real lock */
- task_lock(tsk);
- tsk->mm = NULL;
- up_read(&mm->mmap_sem);
- enter_lazy_tlb(mm, current);
- task_unlock(tsk);
- mmput(mm);
-}
-
-void exit_mm(struct task_struct *tsk)
-{
- __exit_mm(tsk);
-}
-
-EXPORT_SYMBOL(exit_mm);
-
-static inline void choose_new_parent(task_t *p, task_t *reaper, task_t *child_reaper)
-{
- /*
- * Make sure we're not reparenting to ourselves and that
- * the parent is not a zombie.
- */
- if (p == reaper || reaper->state >= TASK_ZOMBIE)
- p->real_parent = child_reaper;
- else
- p->real_parent = reaper;
- if (p->parent == p->real_parent)
- BUG();
-}
-
-static inline void reparent_thread(task_t *p, task_t *father, int traced)
-{
- /* We don't want people slaying init. */
- if (p->exit_signal != -1)
- p->exit_signal = SIGCHLD;
- p->self_exec_id++;
-
- if (p->pdeath_signal)
- /* We already hold the tasklist_lock here. */
- group_send_sig_info(p->pdeath_signal, (void *) 0, p);
-
- /* Move the child from its dying parent to the new one. */
- if (unlikely(traced)) {
- /* Preserve ptrace links if someone else is tracing this child. */
- list_del_init(&p->ptrace_list);
- if (p->parent != p->real_parent)
- list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
- } else {
- /* If this child is being traced, then we're the one tracing it
- * anyway, so let go of it.
- */
- p->ptrace = 0;
- list_del_init(&p->sibling);
- p->parent = p->real_parent;
- list_add_tail(&p->sibling, &p->parent->children);
-
- /* If we'd notified the old parent about this child's death,
- * also notify the new parent.
- */
- if (p->state == TASK_ZOMBIE && p->exit_signal != -1 &&
- thread_group_empty(p))
- do_notify_parent(p, p->exit_signal);
- }
-
- /*
- * process group orphan check
- * Case ii: Our child is in a different pgrp
- * than we are, and it was the only connection
- * outside, so the child pgrp is now orphaned.
- */
- if ((process_group(p) != process_group(father)) &&
- (p->signal->session == father->signal->session)) {
- int pgrp = process_group(p);
-
- if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
- __kill_pg_info(SIGHUP, (void *)1, pgrp);
- __kill_pg_info(SIGCONT, (void *)1, pgrp);
- }
- }
-}
-
-/*
- * When we die, we re-parent all our children.
- * Try to give them to another thread in our thread
- * group, and if no such member exists, give it to
- * the global child reaper process (ie "init")
- */
-static inline void forget_original_parent(struct task_struct * father)
-{
- struct task_struct *p, *reaper = father;
- struct list_head *_p, *_n;
-
- reaper = father->group_leader;
- if (reaper == father)
- reaper = child_reaper;
-
- /*
- * There are only two places where our children can be:
- *
- * - in our child list
- * - in our ptraced child list
- *
- * Search them and reparent children.
- */
- list_for_each_safe(_p, _n, &father->children) {
- p = list_entry(_p,struct task_struct,sibling);
- if (father == p->real_parent) {
- choose_new_parent(p, reaper, child_reaper);
- reparent_thread(p, father, 0);
- } else {
- ptrace_unlink (p);
- if (p->state == TASK_ZOMBIE && p->exit_signal != -1 &&
- thread_group_empty(p))
- do_notify_parent(p, p->exit_signal);
- }
- }
- list_for_each_safe(_p, _n, &father->ptrace_children) {
- p = list_entry(_p,struct task_struct,ptrace_list);
- choose_new_parent(p, reaper, child_reaper);
- reparent_thread(p, father, 1);
- }
-}
-
-/*
- * Send signals to all our closest relatives so that they know
- * to properly mourn us..
- */
-static void exit_notify(struct task_struct *tsk)
-{
- int state;
- struct task_struct *t;
-
- ckrm_cb_exit(tsk);
-
- if (signal_pending(tsk) && !tsk->signal->group_exit
- && !thread_group_empty(tsk)) {
- /*
- * This occurs when there was a race between our exit
- * syscall and a group signal choosing us as the one to
- * wake up. It could be that we are the only thread
- * alerted to check for pending signals, but another thread
- * should be woken now to take the signal since we will not.
- * Now we'll wake all the threads in the group just to make
- * sure someone gets all the pending signals.
- */
- read_lock(&tasklist_lock);
- spin_lock_irq(&tsk->sighand->siglock);
- for (t = next_thread(tsk); t != tsk; t = next_thread(t))
- if (!signal_pending(t) && !(t->flags & PF_EXITING)) {
- recalc_sigpending_tsk(t);
- if (signal_pending(t))
- signal_wake_up(t, 0);
- }
- spin_unlock_irq(&tsk->sighand->siglock);
- read_unlock(&tasklist_lock);
- }
-
- write_lock_irq(&tasklist_lock);
-
- /*
- * This does two things:
- *
- * A. Make init inherit all the child processes
- * B. Check to see if any process groups have become orphaned
- * as a result of our exiting, and if they have any stopped
- * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
- */
-
- forget_original_parent(tsk);
- BUG_ON(!list_empty(&tsk->children));
-
- /*
- * Check to see if any process groups have become orphaned
- * as a result of our exiting, and if they have any stopped
- * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
- *
- * Case i: Our father is in a different pgrp than we are
- * and we were the only connection outside, so our pgrp
- * is about to become orphaned.
- */
-
- t = tsk->real_parent;
-
- if ((process_group(t) != process_group(tsk)) &&
- (t->signal->session == tsk->signal->session) &&
- will_become_orphaned_pgrp(process_group(tsk), tsk) &&
- has_stopped_jobs(process_group(tsk))) {
- __kill_pg_info(SIGHUP, (void *)1, process_group(tsk));
- __kill_pg_info(SIGCONT, (void *)1, process_group(tsk));
- }
-
- /* Let father know we died
- *
- * Thread signals are configurable, but you aren't going to use
- * that to send signals to arbitary processes.
- * That stops right now.
- *
- * If the parent exec id doesn't match the exec id we saved
- * when we started then we know the parent has changed security
- * domain.
- *
- * If our self_exec id doesn't match our parent_exec_id then
- * we have changed execution domain as these two values started
- * the same after a fork.
- *
- */
-
- if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&
- ( tsk->parent_exec_id != t->self_exec_id ||
- tsk->self_exec_id != tsk->parent_exec_id)
- && !capable(CAP_KILL))
- tsk->exit_signal = SIGCHLD;
-
-
- /* If something other than our normal parent is ptracing us, then
- * send it a SIGCHLD instead of honoring exit_signal. exit_signal
- * only has special meaning to our real parent.
- */
- if (tsk->exit_signal != -1 && thread_group_empty(tsk)) {
- int signal = tsk->parent == tsk->real_parent ? tsk->exit_signal : SIGCHLD;
- do_notify_parent(tsk, signal);
- } else if (tsk->ptrace) {
- do_notify_parent(tsk, SIGCHLD);
- }
-
- state = TASK_ZOMBIE;
- if (tsk->exit_signal == -1 && tsk->ptrace == 0)
- state = TASK_DEAD;
- tsk->state = state;
- tsk->flags |= PF_DEAD;
-
- /*
- * Clear these here so that update_process_times() won't try to deliver
- * itimer, profile or rlimit signals to this task while it is in late exit.
- */
- tsk->it_virt_value = 0;
- tsk->it_prof_value = 0;
- tsk->rlim[RLIMIT_CPU].rlim_cur = RLIM_INFINITY;
-
- /*
- * In the preemption case it must be impossible for the task
- * to get runnable again, so use "_raw_" unlock to keep
- * preempt_count elevated until we schedule().
- *
- * To avoid deadlock on SMP, interrupts must be unmasked. If we
- * don't, subsequently called functions (e.g, wait_task_inactive()
- * via release_task()) will spin, with interrupt flags
- * unwittingly blocked, until the other task sleeps. That task
- * may itself be waiting for smp_call_function() to answer and
- * complete, and with interrupts blocked that will never happen.
- */
- _raw_write_unlock(&tasklist_lock);
- local_irq_enable();
-
- /* If the process is dead, release it - nobody will wait for it */
- if (state == TASK_DEAD)
- release_task(tsk);
-
-}
-
-asmlinkage NORET_TYPE void do_exit(long code)
-{
- struct task_struct *tsk = current;
-
- if (unlikely(in_interrupt()))
- panic("Aiee, killing interrupt handler!");
- if (unlikely(!tsk->pid))
- panic("Attempted to kill the idle task!");
- if (unlikely(tsk->pid == 1))
- panic("Attempted to kill init!");
- if (tsk->io_context)
- exit_io_context();
- tsk->flags |= PF_EXITING;
- del_timer_sync(&tsk->real_timer);
-
- if (unlikely(in_atomic()))
- printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
- current->comm, current->pid,
- preempt_count());
-
- profile_exit_task(tsk);
-
- if (unlikely(current->ptrace & PT_TRACE_EXIT)) {
- current->ptrace_message = code;
- ptrace_notify((PTRACE_EVENT_EXIT << 8) | SIGTRAP);
- }
-
- acct_process(code);
- __exit_mm(tsk);
-
- exit_sem(tsk);
- __exit_files(tsk);
- __exit_fs(tsk);
- exit_namespace(tsk);
- exit_thread();
-#ifdef CONFIG_NUMA
- mpol_free(tsk->mempolicy);
-#endif
-
- if (tsk->signal->leader)
- disassociate_ctty(1);
-
- module_put(tsk->thread_info->exec_domain->module);
- if (tsk->binfmt)
- module_put(tsk->binfmt->module);
-
- tsk->exit_code = code;
-#ifdef CONFIG_CKRM_TYPE_TASKCLASS
- numtasks_put_ref(tsk->taskclass);
-#endif
- exit_notify(tsk);
- schedule();
- BUG();
- /* Avoid "noreturn function does return". */
- for (;;) ;
-}
-
-NORET_TYPE void complete_and_exit(struct completion *comp, long code)
-{
- if (comp)
- complete(comp);
-
- do_exit(code);
-}
-
-EXPORT_SYMBOL(complete_and_exit);
-
-asmlinkage long sys_exit(int error_code)
-{
- do_exit((error_code&0xff)<<8);
-}
-
-task_t fastcall *next_thread(task_t *p)
-{
- struct pid_link *link = p->pids + PIDTYPE_TGID;
- struct list_head *tmp, *head = &link->pidptr->task_list;
-
-#ifdef CONFIG_SMP
- if (!p->sighand)
- BUG();
- if (!spin_is_locked(&p->sighand->siglock) &&
- !rwlock_is_locked(&tasklist_lock))
- BUG();
-#endif
- tmp = link->pid_chain.next;
- if (tmp == head)
- tmp = head->next;
-
- return pid_task(tmp, PIDTYPE_TGID);
-}
-
-EXPORT_SYMBOL(next_thread);
-
-/*
- * Take down every thread in the group. This is called by fatal signals
- * as well as by sys_exit_group (below).
- */
-NORET_TYPE void
-do_group_exit(int exit_code)
-{
- BUG_ON(exit_code & 0x80); /* core dumps don't get here */
-
- if (current->signal->group_exit)
- exit_code = current->signal->group_exit_code;
- else if (!thread_group_empty(current)) {
- struct signal_struct *const sig = current->signal;
- struct sighand_struct *const sighand = current->sighand;
- read_lock(&tasklist_lock);
- spin_lock_irq(&sighand->siglock);
- if (sig->group_exit)
- /* Another thread got here before we took the lock. */
- exit_code = sig->group_exit_code;
- else {
- sig->group_exit = 1;
- sig->group_exit_code = exit_code;
- zap_other_threads(current);
- }
- spin_unlock_irq(&sighand->siglock);
- read_unlock(&tasklist_lock);
- }
-
- do_exit(exit_code);
- /* NOTREACHED */
-}
-
-/*
- * this kills every thread in the thread group. Note that any externally
- * wait4()-ing process will get the correct exit code - even if this
- * thread is not the thread group leader.
- */
-asmlinkage void sys_exit_group(int error_code)
-{
- do_group_exit((error_code & 0xff) << 8);
-}
-
-static int eligible_child(pid_t pid, int options, task_t *p)
-{
- if (pid > 0) {
- if (p->pid != pid)
- return 0;
- } else if (!pid) {
- if (process_group(p) != process_group(current))
- return 0;
- } else if (pid != -1) {
- if (process_group(p) != -pid)
- return 0;
- }
-
- /*
- * Do not consider detached threads that are
- * not ptraced:
- */
- if (p->exit_signal == -1 && !p->ptrace)
- return 0;
-
- /* Wait for all children (clone and not) if __WALL is set;
- * otherwise, wait for clone children *only* if __WCLONE is
- * set; otherwise, wait for non-clone children *only*. (Note:
- * A "clone" child here is one that reports to its parent
- * using a signal other than SIGCHLD.) */
- if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
- && !(options & __WALL))
- return 0;
- /*
- * Do not consider thread group leaders that are
- * in a non-empty thread group:
- */
- if (current->tgid != p->tgid && delay_group_leader(p))
- return 2;
-
- if (security_task_wait(p))
- return 0;
-
- return 1;
-}
-
-/*
- * Handle sys_wait4 work for one task in state TASK_ZOMBIE. We hold
- * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
- * the lock and this task is uninteresting. If we return nonzero, we have
- * released the lock and the system call should return.
- */
-static int wait_task_zombie(task_t *p, unsigned int __user *stat_addr, struct rusage __user *ru)
-{
- unsigned long state;
- int retval;
-
- /*
- * Try to move the task's state to DEAD
- * only one thread is allowed to do this:
- */
- state = xchg(&p->state, TASK_DEAD);
- if (state != TASK_ZOMBIE) {
- BUG_ON(state != TASK_DEAD);
- return 0;
- }
- if (unlikely(p->exit_signal == -1 && p->ptrace == 0))
- /*
- * This can only happen in a race with a ptraced thread
- * dying on another processor.
- */
- return 0;
-
- /*
- * Now we are sure this task is interesting, and no other
- * thread can reap it because we set its state to TASK_DEAD.
- */
- read_unlock(&tasklist_lock);
-
- retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
- if (!retval && stat_addr) {
- if (p->signal->group_exit)
- retval = put_user(p->signal->group_exit_code, stat_addr);
- else
- retval = put_user(p->exit_code, stat_addr);
- }
- if (retval) {
- p->state = TASK_ZOMBIE;
- return retval;
- }
- retval = p->pid;
- if (p->real_parent != p->parent) {
- write_lock_irq(&tasklist_lock);
- /* Double-check with lock held. */
- if (p->real_parent != p->parent) {
- __ptrace_unlink(p);
- p->state = TASK_ZOMBIE;
- /* If this is a detached thread, this is where it goes away. */
- if (p->exit_signal == -1) {
- /* release_task takes the lock itself. */
- write_unlock_irq(&tasklist_lock);
- release_task (p);
- }
- else {
- do_notify_parent(p, p->exit_signal);
- write_unlock_irq(&tasklist_lock);
- }
- p = NULL;
- }
- else
- write_unlock_irq(&tasklist_lock);
- }
- if (p != NULL)
- release_task(p);
- BUG_ON(!retval);
- return retval;
-}
-
-/*
- * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold
- * read_lock(&tasklist_lock) on entry. If we return zero, we still hold
- * the lock and this task is uninteresting. If we return nonzero, we have
- * released the lock and the system call should return.
- */
-static int wait_task_stopped(task_t *p, int delayed_group_leader,
- unsigned int __user *stat_addr,
- struct rusage __user *ru)
-{
- int retval, exit_code;
-
- if (!p->exit_code)
- return 0;
- if (delayed_group_leader && !(p->ptrace & PT_PTRACED) &&
- p->signal && p->signal->group_stop_count > 0)
- /*
- * A group stop is in progress and this is the group leader.
- * We won't report until all threads have stopped.
- */
- return 0;
-
- /*
- * Now we are pretty sure this task is interesting.
- * Make sure it doesn't get reaped out from under us while we
- * give up the lock and then examine it below. We don't want to
- * keep holding onto the tasklist_lock while we call getrusage and
- * possibly take page faults for user memory.
- */
- get_task_struct(p);
- read_unlock(&tasklist_lock);
- write_lock_irq(&tasklist_lock);
-
- /*
- * This uses xchg to be atomic with the thread resuming and setting
- * it. It must also be done with the write lock held to prevent a
- * race with the TASK_ZOMBIE case.
- */
- exit_code = xchg(&p->exit_code, 0);
- if (unlikely(p->state > TASK_STOPPED)) {
- /*
- * The task resumed and then died. Let the next iteration
- * catch it in TASK_ZOMBIE. Note that exit_code might
- * already be zero here if it resumed and did _exit(0).
- * The task itself is dead and won't touch exit_code again;
- * other processors in this function are locked out.
- */
- p->exit_code = exit_code;
- exit_code = 0;
- }
- if (unlikely(exit_code == 0)) {
- /*
- * Another thread in this function got to it first, or it
- * resumed, or it resumed and then died.
- */
- write_unlock_irq(&tasklist_lock);
- put_task_struct(p);
- read_lock(&tasklist_lock);
- return 0;
- }
-
- /* move to end of parent's list to avoid starvation */
- remove_parent(p);
- add_parent(p, p->parent);
-
- write_unlock_irq(&tasklist_lock);
-
- retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
- if (!retval && stat_addr)
- retval = put_user((exit_code << 8) | 0x7f, stat_addr);
- if (!retval)
- retval = p->pid;
- put_task_struct(p);
-
- BUG_ON(!retval);
- return retval;
-}
-
-asmlinkage long sys_wait4(pid_t pid,unsigned int __user *stat_addr, int options, struct rusage __user *ru)
-{
- DECLARE_WAITQUEUE(wait, current);
- struct task_struct *tsk;
- int flag, retval;
-
- if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
- return -EINVAL;
-
- add_wait_queue(¤t->wait_chldexit,&wait);
-repeat:
- flag = 0;
- current->state = TASK_INTERRUPTIBLE;
- read_lock(&tasklist_lock);
- tsk = current;
- do {
- struct task_struct *p;
- struct list_head *_p;
- int ret;
-
- list_for_each(_p,&tsk->children) {
- p = list_entry(_p,struct task_struct,sibling);
-
- ret = eligible_child(pid, options, p);
- if (!ret)
- continue;
- flag = 1;
-
- switch (p->state) {
- case TASK_STOPPED:
- if (!(options & WUNTRACED) &&
- !(p->ptrace & PT_PTRACED))
- continue;
- retval = wait_task_stopped(p, ret == 2,
- stat_addr, ru);
- if (retval != 0) /* He released the lock. */
- goto end_wait4;
- break;
- case TASK_ZOMBIE:
- /*
- * Eligible but we cannot release it yet:
- */
- if (ret == 2)
- continue;
- retval = wait_task_zombie(p, stat_addr, ru);
- if (retval != 0) /* He released the lock. */
- goto end_wait4;
- break;
- }
- }
- if (!flag) {
- list_for_each (_p,&tsk->ptrace_children) {
- p = list_entry(_p,struct task_struct,ptrace_list);
- if (!eligible_child(pid, options, p))
- continue;
- flag = 1;
- break;
- }
- }
- if (options & __WNOTHREAD)
- break;
- tsk = next_thread(tsk);
- if (tsk->signal != current->signal)
- BUG();
- } while (tsk != current);
- read_unlock(&tasklist_lock);
- if (flag) {
- retval = 0;
- if (options & WNOHANG)
- goto end_wait4;
- retval = -ERESTARTSYS;
- if (signal_pending(current))
- goto end_wait4;
- schedule();
- goto repeat;
- }
- retval = -ECHILD;
-end_wait4:
- current->state = TASK_RUNNING;
- remove_wait_queue(¤t->wait_chldexit,&wait);
- return retval;
-}
-
-#ifdef __ARCH_WANT_SYS_WAITPID
-
-/*
- * sys_waitpid() remains for compatibility. waitpid() should be
- * implemented by calling sys_wait4() from libc.a.
- */
-asmlinkage long sys_waitpid(pid_t pid, unsigned __user *stat_addr, int options)
-{
- return sys_wait4(pid, stat_addr, options, NULL);
-}
-
-#endif
git://git.onelab.eu / linux-2.6.git / commitdiff