blob: bcb59425a21ccf5946cf19efaaa0c22665557e7c [file] [log] [blame]
/*
* 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: %zu, 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: %zu, 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: %zu, 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: %zu, 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: %zu.\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);
}