diff options
Diffstat (limited to 'drivers/staging/dst/trans.c')
-rw-r--r-- | drivers/staging/dst/trans.c | 337 |
1 files changed, 0 insertions, 337 deletions
diff --git a/drivers/staging/dst/trans.c b/drivers/staging/dst/trans.c deleted file mode 100644 index 1c36a6b..0000000 --- a/drivers/staging/dst/trans.c +++ /dev/null @@ -1,337 +0,0 @@ -/* - * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net> - * All rights reserved. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - */ - -#include <linux/bio.h> -#include <linux/dst.h> -#include <linux/slab.h> -#include <linux/mempool.h> - -/* - * Transaction memory pool size. - */ -static int dst_mempool_num = 32; -module_param(dst_mempool_num, int, 0644); - -/* - * Transaction tree management. - */ -static inline int dst_trans_cmp(dst_gen_t gen, dst_gen_t new) -{ - if (gen < new) - return 1; - if (gen > new) - return -1; - return 0; -} - -struct dst_trans *dst_trans_search(struct dst_node *node, dst_gen_t gen) -{ - struct rb_root *root = &node->trans_root; - struct rb_node *n = root->rb_node; - struct dst_trans *t, *ret = NULL; - int cmp; - - while (n) { - t = rb_entry(n, struct dst_trans, trans_entry); - - cmp = dst_trans_cmp(t->gen, gen); - if (cmp < 0) - n = n->rb_left; - else if (cmp > 0) - n = n->rb_right; - else { - ret = t; - break; - } - } - - dprintk("%s: %s transaction: id: %llu.\n", __func__, - (ret) ? "found" : "not found", gen); - - return ret; -} - -static int dst_trans_insert(struct dst_trans *new) -{ - struct rb_root *root = &new->n->trans_root; - struct rb_node **n = &root->rb_node, *parent = NULL; - struct dst_trans *ret = NULL, *t; - int cmp; - - while (*n) { - parent = *n; - - t = rb_entry(parent, struct dst_trans, trans_entry); - - cmp = dst_trans_cmp(t->gen, new->gen); - if (cmp < 0) - n = &parent->rb_left; - else if (cmp > 0) - n = &parent->rb_right; - else { - ret = t; - break; - } - } - - new->send_time = jiffies; - if (ret) { - printk(KERN_DEBUG "%s: exist: old: gen: %llu, bio: %llu/%u, " - "send_time: %lu, new: gen: %llu, bio: %llu/%u, " - "send_time: %lu.\n", __func__, - ret->gen, (u64)ret->bio->bi_sector, - ret->bio->bi_size, ret->send_time, - new->gen, (u64)new->bio->bi_sector, - new->bio->bi_size, new->send_time); - return -EEXIST; - } - - rb_link_node(&new->trans_entry, parent, n); - rb_insert_color(&new->trans_entry, root); - - dprintk("%s: inserted: gen: %llu, bio: %llu/%u, send_time: %lu.\n", - __func__, new->gen, (u64)new->bio->bi_sector, - new->bio->bi_size, new->send_time); - - return 0; -} - -int dst_trans_remove_nolock(struct dst_trans *t) -{ - struct dst_node *n = t->n; - - if (t->trans_entry.rb_parent_color) { - rb_erase(&t->trans_entry, &n->trans_root); - t->trans_entry.rb_parent_color = 0; - } - return 0; -} - -int dst_trans_remove(struct dst_trans *t) -{ - int ret; - struct dst_node *n = t->n; - - mutex_lock(&n->trans_lock); - ret = dst_trans_remove_nolock(t); - mutex_unlock(&n->trans_lock); - - return ret; -} - -/* - * When transaction is completed and there are no more users, - * we complete appriate block IO request with given error status. - */ -void dst_trans_put(struct dst_trans *t) -{ - if (atomic_dec_and_test(&t->refcnt)) { - struct bio *bio = t->bio; - - dprintk("%s: completed t: %p, gen: %llu, bio: %p.\n", - __func__, t, t->gen, bio); - - bio_endio(bio, t->error); - bio_put(bio); - - dst_node_put(t->n); - mempool_free(t, t->n->trans_pool); - } -} - -/* - * Process given block IO request: allocate transaction, insert it into the tree - * and send/schedule crypto processing. - */ -int dst_process_bio(struct dst_node *n, struct bio *bio) -{ - struct dst_trans *t; - int err = -ENOMEM; - - t = mempool_alloc(n->trans_pool, GFP_NOFS); - if (!t) - goto err_out_exit; - - t->n = dst_node_get(n); - t->bio = bio; - t->error = 0; - t->retries = 0; - atomic_set(&t->refcnt, 1); - t->gen = atomic_long_inc_return(&n->gen); - - t->enc = bio_data_dir(bio); - dst_bio_to_cmd(bio, &t->cmd, DST_IO, t->gen); - - mutex_lock(&n->trans_lock); - err = dst_trans_insert(t); - mutex_unlock(&n->trans_lock); - if (err) - goto err_out_free; - - dprintk("%s: gen: %llu, bio: %llu/%u, dir/enc: %d, need_crypto: %d.\n", - __func__, t->gen, (u64)bio->bi_sector, - bio->bi_size, t->enc, dst_need_crypto(n)); - - if (dst_need_crypto(n) && t->enc) - dst_trans_crypto(t); - else - dst_trans_send(t); - - return 0; - -err_out_free: - dst_node_put(n); - mempool_free(t, n->trans_pool); -err_out_exit: - bio_endio(bio, err); - bio_put(bio); - return err; -} - -/* - * Scan for timeout/stale transactions. - * Each transaction is being resent multiple times before error completion. - */ -static void dst_trans_scan(struct work_struct *work) -{ - struct dst_node *n = container_of(work, struct dst_node, - trans_work.work); - struct rb_node *rb_node; - struct dst_trans *t; - unsigned long timeout = n->trans_scan_timeout; - int num = 10 * n->trans_max_retries; - - mutex_lock(&n->trans_lock); - - for (rb_node = rb_first(&n->trans_root); rb_node; ) { - t = rb_entry(rb_node, struct dst_trans, trans_entry); - - if (timeout && time_after(t->send_time + timeout, jiffies) - && t->retries == 0) - break; -#if 0 - dprintk("%s: t: %p, gen: %llu, n: %s, retries: %u, max: %u.\n", - __func__, t, t->gen, n->name, - t->retries, n->trans_max_retries); -#endif - if (--num == 0) - break; - - dst_trans_get(t); - - rb_node = rb_next(rb_node); - - if (timeout && (++t->retries < n->trans_max_retries)) { - dst_trans_send(t); - } else { - t->error = -ETIMEDOUT; - dst_trans_remove_nolock(t); - dst_trans_put(t); - } - - dst_trans_put(t); - } - - mutex_unlock(&n->trans_lock); - - /* - * If no timeout specified then system is in the middle of exiting - * process, so no need to reschedule scanning process again. - */ - if (timeout) { - if (!num) - timeout = HZ; - schedule_delayed_work(&n->trans_work, timeout); - } -} - -/* - * Flush all transactions and mark them as timed out. - * Destroy transaction pools. - */ -void dst_node_trans_exit(struct dst_node *n) -{ - struct dst_trans *t; - struct rb_node *rb_node; - - if (!n->trans_cache) - return; - - dprintk("%s: n: %p, cancelling the work.\n", __func__, n); - cancel_delayed_work_sync(&n->trans_work); - flush_scheduled_work(); - dprintk("%s: n: %p, work has been cancelled.\n", __func__, n); - - for (rb_node = rb_first(&n->trans_root); rb_node; ) { - t = rb_entry(rb_node, struct dst_trans, trans_entry); - - dprintk("%s: t: %p, gen: %llu, n: %s.\n", - __func__, t, t->gen, n->name); - - rb_node = rb_next(rb_node); - - t->error = -ETIMEDOUT; - dst_trans_remove_nolock(t); - dst_trans_put(t); - } - - mempool_destroy(n->trans_pool); - kmem_cache_destroy(n->trans_cache); -} - -/* - * Initialize transaction storage for given node. - * Transaction stores not only control information, - * but also network command and crypto data (if needed) - * to reduce number of allocations. Thus transaction size - * differs from node to node. - */ -int dst_node_trans_init(struct dst_node *n, unsigned int size) -{ - /* - * We need this, since node with given name can be dropped from the - * hash table, but be still alive, so subsequent creation of the node - * with the same name may collide with existing cache name. - */ - - snprintf(n->cache_name, sizeof(n->cache_name), "%s-%p", n->name, n); - - n->trans_cache = kmem_cache_create(n->cache_name, - size + n->crypto.crypto_attached_size, - 0, 0, NULL); - if (!n->trans_cache) - goto err_out_exit; - - n->trans_pool = mempool_create_slab_pool(dst_mempool_num, - n->trans_cache); - if (!n->trans_pool) - goto err_out_cache_destroy; - - mutex_init(&n->trans_lock); - n->trans_root = RB_ROOT; - - INIT_DELAYED_WORK(&n->trans_work, dst_trans_scan); - schedule_delayed_work(&n->trans_work, n->trans_scan_timeout); - - dprintk("%s: n: %p, size: %u, crypto: %u.\n", - __func__, n, size, n->crypto.crypto_attached_size); - - return 0; - -err_out_cache_destroy: - kmem_cache_destroy(n->trans_cache); -err_out_exit: - return -ENOMEM; -} |