diff options
| -rw-r--r-- | drivers/staging/pohmelfs/trans.c | 715 |
1 files changed, 715 insertions, 0 deletions
diff --git a/drivers/staging/pohmelfs/trans.c b/drivers/staging/pohmelfs/trans.c new file mode 100644 index 000000000000..92054bdc154c --- /dev/null +++ b/drivers/staging/pohmelfs/trans.c @@ -0,0 +1,715 @@ +/* + * 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/module.h> +#include <linux/crypto.h> +#include <linux/fs.h> +#include <linux/jhash.h> +#include <linux/hash.h> +#include <linux/ktime.h> +#include <linux/mempool.h> +#include <linux/mm.h> +#include <linux/mount.h> +#include <linux/pagemap.h> +#include <linux/parser.h> +#include <linux/poll.h> +#include <linux/swap.h> +#include <linux/slab.h> +#include <linux/statfs.h> +#include <linux/writeback.h> + +#include "netfs.h" + +static struct kmem_cache *netfs_trans_dst; +static mempool_t *netfs_trans_dst_pool; + +static void netfs_trans_init_static(struct netfs_trans *t, int num, int size) +{ + t->page_num = num; + t->total_size = size; + atomic_set(&t->refcnt, 1); + + spin_lock_init(&t->dst_lock); + INIT_LIST_HEAD(&t->dst_list); +} + +static int netfs_trans_send_pages(struct netfs_trans *t, struct netfs_state *st) +{ + int err = 0; + unsigned int i, attached_pages = t->attached_pages, ci; + struct msghdr msg; + struct page **pages = (t->eng)?t->eng->pages:t->pages; + struct page *p; + unsigned int size; + + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = MSG_WAITALL | MSG_MORE; + + ci = 0; + for (i=0; i<t->page_num; ++i) { + struct page *page = pages[ci]; + struct netfs_cmd cmd; + struct iovec io; + + p = t->pages[i]; + + if (!p) + continue; + + size = page_private(p); + + io.iov_base = &cmd; + io.iov_len = sizeof(struct netfs_cmd); + + cmd.cmd = NETFS_WRITE_PAGE; + cmd.ext = 0; + cmd.id = 0; + cmd.size = size; + cmd.start = p->index; + cmd.start <<= PAGE_CACHE_SHIFT; + cmd.csize = 0; + cmd.cpad = 0; + cmd.iv = pohmelfs_gen_iv(t); + + netfs_convert_cmd(&cmd); + + msg.msg_iov = &io; + msg.msg_iovlen = 1; + msg.msg_flags = MSG_WAITALL | MSG_MORE; + + err = kernel_sendmsg(st->socket, &msg, (struct kvec *)msg.msg_iov, 1, sizeof(struct netfs_cmd)); + if (err <= 0) { + printk("%s: %d/%d failed to send transaction header: t: %p, gen: %u, err: %d.\n", + __func__, i, t->page_num, t, t->gen, err); + if (err == 0) + err = -ECONNRESET; + goto err_out; + } + + msg.msg_flags = MSG_WAITALL|(attached_pages == 1)?0:MSG_MORE; + + err = kernel_sendpage(st->socket, page, 0, size, msg.msg_flags); + if (err <= 0) { + printk("%s: %d/%d failed to send transaction page: t: %p, gen: %u, size: %u, err: %d.\n", + __func__, i, t->page_num, t, t->gen, size, err); + if (err == 0) + err = -ECONNRESET; + goto err_out; + } + + dprintk("%s: %d/%d sent t: %p, gen: %u, page: %p/%p, size: %u.\n", + __func__, i, t->page_num, t, t->gen, page, p, size); + + err = 0; + attached_pages--; + if (!attached_pages) + break; + ci++; + + continue; + +err_out: + printk("%s: t: %p, gen: %u, err: %d.\n", __func__, t, t->gen, err); + netfs_state_exit(st); + break; + } + + return err; +} + +int netfs_trans_send(struct netfs_trans *t, struct netfs_state *st) +{ + int err; + struct msghdr msg; + + BUG_ON(!t->iovec.iov_len); + BUG_ON(t->iovec.iov_len > 1024*1024*1024); + + netfs_state_lock_send(st); + if (!st->socket) { + err = netfs_state_init(st); + if (err) + goto err_out_unlock_return; + } + + msg.msg_iov = &t->iovec; + msg.msg_iovlen = 1; + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = MSG_WAITALL; + + if (t->attached_pages) + msg.msg_flags |= MSG_MORE; + + err = kernel_sendmsg(st->socket, &msg, (struct kvec *)msg.msg_iov, 1, t->iovec.iov_len); + if (err <= 0) { + printk("%s: failed to send contig transaction: t: %p, gen: %u, size: %u, err: %d.\n", + __func__, t, t->gen, t->iovec.iov_len, err); + if (err == 0) + err = -ECONNRESET; + goto err_out_unlock_return; + } + + dprintk("%s: sent %s transaction: t: %p, gen: %u, size: %u, page_num: %u.\n", + __func__, (t->page_num)?"partial":"full", + t, t->gen, t->iovec.iov_len, t->page_num); + + err = 0; + if (t->attached_pages) + err = netfs_trans_send_pages(t, st); + +err_out_unlock_return: + + if (st->need_reset) { + netfs_state_exit(st); + } + netfs_state_unlock_send(st); + + dprintk("%s: t: %p, gen: %u, err: %d.\n", + __func__, t, t->gen, err); + + t->result = err; + return err; +} + +static inline int netfs_trans_cmp(unsigned int gen, unsigned int new) +{ + if (gen < new) + return 1; + if (gen > new) + return -1; + return 0; +} + +struct netfs_trans_dst *netfs_trans_search(struct netfs_state *st, unsigned int gen) +{ + struct rb_root *root = &st->trans_root; + struct rb_node *n = root->rb_node; + struct netfs_trans_dst *tmp, *ret = NULL; + struct netfs_trans *t; + int cmp; + + while (n) { + tmp = rb_entry(n, struct netfs_trans_dst, state_entry); + t = tmp->trans; + + cmp = netfs_trans_cmp(t->gen, gen); + if (cmp < 0) + n = n->rb_left; + else if (cmp > 0) + n = n->rb_right; + else { + ret = tmp; + break; + } + } + + return ret; +} + +static int netfs_trans_insert(struct netfs_trans_dst *ndst, struct netfs_state *st) +{ + struct rb_root *root = &st->trans_root; + struct rb_node **n = &root->rb_node, *parent = NULL; + struct netfs_trans_dst *ret = NULL, *tmp; + struct netfs_trans *t = NULL, *new = ndst->trans; + int cmp; + + while (*n) { + parent = *n; + + tmp = rb_entry(parent, struct netfs_trans_dst, state_entry); + t = tmp->trans; + + cmp = netfs_trans_cmp(t->gen, new->gen); + if (cmp < 0) + n = &parent->rb_left; + else if (cmp > 0) + n = &parent->rb_right; + else { + ret = tmp; + break; + } + } + + if (ret) { + printk("%s: exist: old: gen: %u, flags: %x, send_time: %lu, " + "new: gen: %u, flags: %x, send_time: %lu.\n", + __func__, t->gen, t->flags, ret->send_time, + new->gen, new->flags, ndst->send_time); + return -EEXIST; + } + + rb_link_node(&ndst->state_entry, parent, n); + rb_insert_color(&ndst->state_entry, root); + ndst->send_time = jiffies; + + return 0; +} + +int netfs_trans_remove_nolock(struct netfs_trans_dst *dst, struct netfs_state *st) +{ + if (dst && dst->state_entry.rb_parent_color) { + rb_erase(&dst->state_entry, &st->trans_root); + dst->state_entry.rb_parent_color = 0; + return 1; + } + return 0; +} + +static int netfs_trans_remove_state(struct netfs_trans_dst *dst) +{ + int ret; + struct netfs_state *st = dst->state; + + mutex_lock(&st->trans_lock); + ret = netfs_trans_remove_nolock(dst, st); + mutex_unlock(&st->trans_lock); + + return ret; +} + +/* + * Create new destination for given transaction associated with given network state. + * Transaction's reference counter is bumped and will be dropped when either + * reply is received or when async timeout detection task will fail resending + * and drop transaction. + */ +static int netfs_trans_push_dst(struct netfs_trans *t, struct netfs_state *st) +{ + struct netfs_trans_dst *dst; + int err; + + dst = mempool_alloc(netfs_trans_dst_pool, GFP_KERNEL); + if (!dst) + return -ENOMEM; + + dst->retries = 0; + dst->send_time = 0; + dst->state = st; + dst->trans = t; + netfs_trans_get(t); + + mutex_lock(&st->trans_lock); + err = netfs_trans_insert(dst, st); + mutex_unlock(&st->trans_lock); + + if (err) + goto err_out_free; + + spin_lock(&t->dst_lock); + list_add_tail(&dst->trans_entry, &t->dst_list); + spin_unlock(&t->dst_lock); + + return 0; + +err_out_free: + t->result = err; + netfs_trans_put(t); + mempool_free(dst, netfs_trans_dst_pool); + return err; +} + +static void netfs_trans_free_dst(struct netfs_trans_dst *dst) +{ + netfs_trans_put(dst->trans); + mempool_free(dst, netfs_trans_dst_pool); +} + +static void netfs_trans_remove_dst(struct netfs_trans_dst *dst) +{ + if (netfs_trans_remove_state(dst)) + netfs_trans_free_dst(dst); +} + +/* + * Drop destination transaction entry when we know it. + */ +void netfs_trans_drop_dst(struct netfs_trans_dst *dst) +{ + struct netfs_trans *t = dst->trans; + + spin_lock(&t->dst_lock); + list_del_init(&dst->trans_entry); + spin_unlock(&t->dst_lock); + + netfs_trans_remove_dst(dst); +} + +/* + * Drop destination transaction entry when we know it and when we + * already removed dst from state tree. + */ +void netfs_trans_drop_dst_nostate(struct netfs_trans_dst *dst) +{ + struct netfs_trans *t = dst->trans; + + spin_lock(&t->dst_lock); + list_del_init(&dst->trans_entry); + spin_unlock(&t->dst_lock); + + netfs_trans_free_dst(dst); +} + +/* + * This drops destination transaction entry from appropriate network state + * tree and drops related reference counter. It is possible that transaction + * will be freed here if its reference counter hits zero. + * Destination transaction entry will be freed. + */ +void netfs_trans_drop_trans(struct netfs_trans *t, struct netfs_state *st) +{ + struct netfs_trans_dst *dst, *tmp, *ret = NULL; + + spin_lock(&t->dst_lock); + list_for_each_entry_safe(dst, tmp, &t->dst_list, trans_entry) { + if (dst->state == st) { + ret = dst; + list_del(&dst->trans_entry); + break; + } + } + spin_unlock(&t->dst_lock); + + if (ret) + netfs_trans_remove_dst(ret); +} + +/* + * This drops destination transaction entry from appropriate network state + * tree and drops related reference counter. It is possible that transaction + * will be freed here if its reference counter hits zero. + * Destination transaction entry will be freed. + */ +void netfs_trans_drop_last(struct netfs_trans *t, struct netfs_state *st) +{ + struct netfs_trans_dst *dst, *tmp, *ret; + + spin_lock(&t->dst_lock); + ret = list_entry(t->dst_list.prev, struct netfs_trans_dst, trans_entry); + if (ret->state != st) { + ret = NULL; + list_for_each_entry_safe(dst, tmp, &t->dst_list, trans_entry) { + if (dst->state == st) { + ret = dst; + list_del_init(&dst->trans_entry); + break; + } + } + } else { + list_del(&ret->trans_entry); + } + spin_unlock(&t->dst_lock); + + if (ret) + netfs_trans_remove_dst(ret); +} + +static int netfs_trans_push(struct netfs_trans *t, struct netfs_state *st) +{ + int err; + + err = netfs_trans_push_dst(t, st); + if (err) + return err; + + err = netfs_trans_send(t, st); + if (err) + goto err_out_free; + + if (t->flags & NETFS_TRANS_SINGLE_DST) + pohmelfs_switch_active(st->psb); + + return 0; + +err_out_free: + t->result = err; + netfs_trans_drop_last(t, st); + + return err; +} + +int netfs_trans_finish_send(struct netfs_trans *t, struct pohmelfs_sb *psb) +{ + struct pohmelfs_config *c; + int err = -ENODEV; + struct netfs_state *st; +#if 0 + dprintk("%s: t: %p, gen: %u, size: %u, page_num: %u, active: %p.\n", + __func__, t, t->gen, t->iovec.iov_len, t->page_num, psb->active_state); +#endif + mutex_lock(&psb->state_lock); + + if ((t->flags & NETFS_TRANS_SINGLE_DST) && psb->active_state) { + st = &psb->active_state->state; + + err = -EPIPE; + if (netfs_state_poll(st) & POLLOUT) { + err = netfs_trans_push_dst(t, st); + if (!err) { + err = netfs_trans_send(t, st); + if (err) { + netfs_trans_drop_last(t, st); + } else { + pohmelfs_switch_active(psb); + goto out; + } + } + } + pohmelfs_switch_active(psb); + } + + list_for_each_entry(c, &psb->state_list, config_entry) { + st = &c->state; + + err = netfs_trans_push(t, st); + if (!err && (t->flags & NETFS_TRANS_SINGLE_DST)) + break; + } +out: + mutex_unlock(&psb->state_lock); +#if 0 + dprintk("%s: fully sent t: %p, gen: %u, size: %u, page_num: %u, err: %d.\n", + __func__, t, t->gen, t->iovec.iov_len, t->page_num, err); +#endif + if (err) + t->result = err; + return err; +} + +int netfs_trans_finish(struct netfs_trans *t, struct pohmelfs_sb *psb) +{ + int err; + struct netfs_cmd *cmd = t->iovec.iov_base; + + t->gen = atomic_inc_return(&psb->trans_gen); + + pohmelfs_ftrans_clean(t->gen); + + cmd->size = t->iovec.iov_len - sizeof(struct netfs_cmd) + + t->attached_size + t->attached_pages * sizeof(struct netfs_cmd); + cmd->cmd = NETFS_TRANS; + cmd->start = t->gen; + cmd->id = 0; + + if (psb->perform_crypto) { + cmd->ext = psb->crypto_attached_size; + cmd->csize = psb->crypto_attached_size; + } + + dprintk("%s: t: %u, size: %u, iov_len: %u, attached_size: %u, attached_pages: %u.\n", + __func__, t->gen, cmd->size, t->iovec.iov_len, t->attached_size, t->attached_pages); + err = pohmelfs_trans_crypt(t, psb); + if (err) { + t->result = err; + netfs_convert_cmd(cmd); + dprintk("%s: trans: %llu, crypto_attached_size: %u, attached_size: %u, attached_pages: %d, trans_size: %u, err: %d.\n", + __func__, cmd->start, psb->crypto_attached_size, t->attached_size, t->attached_pages, cmd->size, err); + } + netfs_trans_put(t); + return err; +} + +/* + * Resend transaction to remote server(s). + * If new servers were added into superblock, we can try to send data + * to them too. + * + * It is called under superblock's state_lock, so we can safely + * dereference psb->state_list. Also, transaction's reference counter is + * bumped, so it can not go away under us, thus we can safely access all + * its members. State is locked. + * + * This function returns 0 if transaction was successfully sent to at + * least one destination target. + */ +int netfs_trans_resend(struct netfs_trans *t, struct pohmelfs_sb *psb) +{ + struct netfs_trans_dst *dst; + struct netfs_state *st; + struct pohmelfs_config *c; + int err, exist, error = -ENODEV; + + list_for_each_entry(c, &psb->state_list, config_entry) { + st = &c->state; + + exist = 0; + spin_lock(&t->dst_lock); + list_for_each_entry(dst, &t->dst_list, trans_entry) { + if (st == dst->state) { + exist = 1; + break; + } + } + spin_unlock(&t->dst_lock); + + if (exist) { + if (!(t->flags & NETFS_TRANS_SINGLE_DST) || + (c->config_entry.next == &psb->state_list)) { + dprintk("%s: resending st: %p, t: %p, gen: %u.\n", + __func__, st, t, t->gen); + err = netfs_trans_send(t, st); + if (!err) + error = 0; + } + continue; + } + + dprintk("%s: pushing/resending st: %p, t: %p, gen: %u.\n", + __func__, st, t, t->gen); + err = netfs_trans_push(t, st); + if (err) + continue; + error = 0; + if (t->flags & NETFS_TRANS_SINGLE_DST) + break; + } + + t->result = error; + return error; +} + +void *netfs_trans_add(struct netfs_trans *t, unsigned int size) +{ + struct iovec *io = &t->iovec; + void *ptr; + + if (size > t->total_size) { + ptr = ERR_PTR(-EINVAL); + goto out; + } + + if (io->iov_len + size > t->total_size) { + dprintk("%s: too big size t: %p, gen: %u, iov_len: %u, size: %u, total: %u.\n", + __func__, t, t->gen, io->iov_len, size, t->total_size); + ptr = ERR_PTR(-E2BIG); + goto out; + } + + ptr = io->iov_base + io->iov_len; + io->iov_len += size; + +out: + dprintk("%s: t: %p, gen: %u, size: %u, total: %u.\n", + __func__, t, t->gen, size, io->iov_len); + return ptr; +} + +void netfs_trans_free(struct netfs_trans *t) +{ + if (t->eng) + pohmelfs_crypto_thread_make_ready(t->eng->thread); + kfree(t); +} + +struct netfs_trans *netfs_trans_alloc(struct pohmelfs_sb *psb, unsigned int size, + unsigned int flags, unsigned int nr) +{ + struct netfs_trans *t; + unsigned int num, cont, pad, size_no_trans; + unsigned int crypto_added = 0; + struct netfs_cmd *cmd; + + if (psb->perform_crypto) + crypto_added = psb->crypto_attached_size; + + /* + * |sizeof(struct netfs_trans)| + * |sizeof(struct netfs_cmd)| - transaction header + * |size| - buffer with requested size + * |padding| - crypto padding, zero bytes + * |nr * sizeof(struct page *)| - array of page pointers + * + * Overall size should be less than PAGE_SIZE for guaranteed allocation. + */ + + cont = size; + size = ALIGN(size, psb->crypto_align_size); + pad = size - cont; + + size_no_trans = size + sizeof(struct netfs_cmd) * 2 + crypto_added; + + cont = sizeof(struct netfs_trans) + size_no_trans; + + num = (PAGE_SIZE - cont)/sizeof(struct page *); + + if (nr > num) + nr = num; + + t = kzalloc(cont + nr*sizeof(struct page *), GFP_NOIO); + if (!t) + goto err_out_exit; + + t->iovec.iov_base = (void *)(t + 1); + t->pages = (struct page **)(t->iovec.iov_base + size_no_trans); + + /* + * Reserving space for transaction header. + */ + t->iovec.iov_len = sizeof(struct netfs_cmd) + crypto_added; + + netfs_trans_init_static(t, nr, size_no_trans); + + t->flags = flags; + t->psb = psb; + + cmd = (struct netfs_cmd *)t->iovec.iov_base; + + cmd->size = size; + cmd->cpad = pad; + cmd->csize = crypto_added; + + dprintk("%s: t: %p, gen: %u, size: %u, padding: %u, align_size: %u, flags: %x, " + "page_num: %u, base: %p, pages: %p.\n", + __func__, t, t->gen, size, pad, psb->crypto_align_size, flags, nr, + t->iovec.iov_base, t->pages); + + return t; + +err_out_exit: + return NULL; +} + +int netfs_trans_init(void) +{ + int err = -ENOMEM; + + netfs_trans_dst = kmem_cache_create("netfs_trans_dst", sizeof(struct netfs_trans_dst), + 0, 0, NULL); + if (!netfs_trans_dst) + goto err_out_exit; + + netfs_trans_dst_pool = mempool_create_slab_pool(256, netfs_trans_dst); + if (!netfs_trans_dst_pool) + goto err_out_free; + + return 0; + +err_out_free: + kmem_cache_destroy(netfs_trans_dst); +err_out_exit: + return err; +} + +void netfs_trans_exit(void) +{ + mempool_destroy(netfs_trans_dst_pool); + kmem_cache_destroy(netfs_trans_dst); +} |