summaryrefslogtreecommitdiff
path: root/drivers/staging/dst/trans.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/staging/dst/trans.c')
-rw-r--r--drivers/staging/dst/trans.c337
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 1c36a6bc31d..00000000000
--- 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;
-}