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Date: Fri, 13 Jun 2008 20:42:42 +0400
From: Evgeniy Polyakov <johnpol@....mipt.ru>
To: linux-kernel@...r.kernel.org
Cc: netdev@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: [3/3] POHMELFS high performance network filesystem.
POHMELFS client code.
Signed-off-by: Evgeniy Polyakov <johnpol@....mipt.ru>
diff --git a/fs/Kconfig b/fs/Kconfig
index c509123..59935cd 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1566,6 +1566,8 @@ menuconfig NETWORK_FILESYSTEMS
if NETWORK_FILESYSTEMS
+source "fs/pohmelfs/Kconfig"
+
config NFS_FS
tristate "NFS file system support"
depends on INET
diff --git a/fs/Makefile b/fs/Makefile
index 1e7a11b..6ce6a35 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -119,3 +119,4 @@ obj-$(CONFIG_HPPFS) += hppfs/
obj-$(CONFIG_DEBUG_FS) += debugfs/
obj-$(CONFIG_OCFS2_FS) += ocfs2/
obj-$(CONFIG_GFS2_FS) += gfs2/
+obj-$(CONFIG_POHMELFS) += pohmelfs/
diff --git a/fs/pohmelfs/Kconfig b/fs/pohmelfs/Kconfig
new file mode 100644
index 0000000..5178514
--- /dev/null
+++ b/fs/pohmelfs/Kconfig
@@ -0,0 +1,26 @@
+config POHMELFS
+ tristate "POHMELFS filesystem support"
+ select CONNECTOR
+ help
+ POHMELFS stands for Parallel Optimized Host Message Exchange Layered File System.
+ This is a network filesystem which supports coherent caching of data and metadata
+ on clients.
+
+config POHMELFS_DEBUG
+ bool "POHMELFS debugging"
+ depends on POHMELFS
+ default n
+ help
+ Turns on excessive POHMELFS debugging facilities.
+ You usually do not want to slow things down noticebly and get really lots of kernel
+ messages in syslog.
+
+config POHMELFS_CC_GROUP
+ bool "POHMELFS cache coherency protocol"
+ depends on POHMELFS
+ default y
+ help
+ This allows to broadcast data and metadata cache coherency messages between clients.
+ Usually you want this facility, although without locking you can get different from
+ POSIX expectation behaviour. For more details check POHMELFS homepage and development
+ section.
diff --git a/fs/pohmelfs/Makefile b/fs/pohmelfs/Makefile
new file mode 100644
index 0000000..aa415a3
--- /dev/null
+++ b/fs/pohmelfs/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_POHMELFS) += pohmelfs.o
+
+pohmelfs-y := inode.o config.o dir.o net.o path_entry.o trans.o
diff --git a/fs/pohmelfs/config.c b/fs/pohmelfs/config.c
new file mode 100644
index 0000000..4fa80fd
--- /dev/null
+++ b/fs/pohmelfs/config.c
@@ -0,0 +1,192 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/kernel.h>
+#include <linux/connector.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+
+#include "netfs.h"
+
+/*
+ * Global configuration list.
+ * Each client can be asked to get one of them.
+ *
+ * Allows to provide remote server address (ipv4/v6/whatever), port
+ * and so on via kernel connector.
+ */
+
+static struct cb_id pohmelfs_cn_id = {.idx = POHMELFS_CN_IDX, .val = POHMELFS_CN_VAL};
+static LIST_HEAD(pohmelfs_config_list);
+static DEFINE_MUTEX(pohmelfs_config_lock);
+
+static inline int pohmelfs_config_eql(struct pohmelfs_ctl *sc, struct pohmelfs_ctl *ctl)
+{
+ if (sc->idx == ctl->idx && sc->type == ctl->type &&
+ sc->proto == ctl->proto &&
+ sc->addrlen == ctl->addrlen &&
+ !memcmp(&sc->addr, &ctl->addr, ctl->addrlen))
+ return 1;
+
+ return 0;
+}
+
+int pohmelfs_copy_config(struct pohmelfs_sb *psb)
+{
+ struct pohmelfs_config *c, *dst;
+ int err = -ENODEV;
+
+ mutex_lock(&pohmelfs_config_lock);
+ list_for_each_entry(c, &pohmelfs_config_list, config_entry) {
+ if (c->state.ctl.idx != psb->idx)
+ continue;
+
+ err = 0;
+ list_for_each_entry(dst, &psb->state_list, config_entry) {
+ if (pohmelfs_config_eql(&dst->state.ctl, &c->state.ctl)) {
+ err = -EEXIST;
+ break;
+ }
+ }
+
+ if (err)
+ continue;
+
+ dst = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
+ if (!dst) {
+ err = -ENOMEM;
+ goto err_out_unlock;
+ }
+
+ memcpy(&dst->state.ctl, &c->state.ctl, sizeof(struct pohmelfs_ctl));
+
+ list_add_tail(&dst->config_entry, &psb->state_list);
+
+ err = pohmelfs_state_init_one(psb, dst);
+ if (err) {
+ list_del(&dst->config_entry);
+ kfree(dst);
+ }
+ }
+ mutex_unlock(&pohmelfs_config_lock);
+
+ return err;
+
+err_out_unlock:
+ mutex_unlock(&pohmelfs_config_lock);
+
+ mutex_lock(&psb->state_lock);
+ list_for_each_entry_safe(dst, c, &psb->state_list, config_entry) {
+ list_del(&dst->config_entry);
+ kfree(dst);
+ }
+ mutex_unlock(&psb->state_lock);
+
+ return err;
+}
+
+static void pohmelfs_cn_callback(void *data)
+{
+ struct cn_msg *msg = data;
+ struct pohmelfs_ctl *ctl;
+ struct pohmelfs_cn_ack *ack;
+ struct pohmelfs_config *c, *tmp;
+ int err;
+
+ if (msg->len < sizeof(struct pohmelfs_ctl)) {
+ err = -EBADMSG;
+ goto out;
+ }
+
+ ctl = (struct pohmelfs_ctl *)msg->data;
+
+ err = 0;
+ mutex_lock(&pohmelfs_config_lock);
+ list_for_each_entry_safe(c, tmp, &pohmelfs_config_list, config_entry) {
+ struct pohmelfs_ctl *sc = &c->state.ctl;
+
+ if (pohmelfs_config_eql(sc, ctl)) {
+ list_del(&c->config_entry);
+ err = -EEXIST;
+ break;
+ }
+ }
+ if (!err) {
+ c = kzalloc(sizeof(struct pohmelfs_config), GFP_KERNEL);
+ if (!c) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(&c->state.ctl, ctl, sizeof(struct pohmelfs_ctl));
+ list_add_tail(&c->config_entry, &pohmelfs_config_list);
+ }
+ mutex_unlock(&pohmelfs_config_lock);
+
+out:
+ ack = kmalloc(sizeof(struct pohmelfs_cn_ack), GFP_KERNEL);
+ if (!ack)
+ return;
+
+ memcpy(&ack->msg, msg, sizeof(struct cn_msg));
+
+ ack->msg.ack = msg->ack + 1;
+ ack->msg.len = sizeof(struct pohmelfs_cn_ack) - sizeof(struct cn_msg);
+
+ ack->error = err;
+
+ cn_netlink_send(&ack->msg, 0, GFP_KERNEL);
+ kfree(ack);
+}
+
+int pohmelfs_config_check(struct pohmelfs_config *config, int idx)
+{
+ struct pohmelfs_ctl *ctl = &config->state.ctl;
+ struct pohmelfs_config *tmp;
+ int err = -ENOENT;
+ struct pohmelfs_ctl *sc;
+
+ mutex_lock(&pohmelfs_config_lock);
+ list_for_each_entry(tmp, &pohmelfs_config_list, config_entry) {
+ sc = &tmp->state.ctl;
+
+ if (sc->idx == idx && pohmelfs_config_eql(sc, ctl)) {
+ err = 0;
+ break;
+ }
+ }
+ mutex_unlock(&pohmelfs_config_lock);
+
+ return err;
+}
+
+int __init pohmelfs_config_init(void)
+{
+ return cn_add_callback(&pohmelfs_cn_id, "pohmelfs", pohmelfs_cn_callback);
+}
+
+void __exit pohmelfs_config_exit(void)
+{
+ struct pohmelfs_config *c, *tmp;
+
+ cn_del_callback(&pohmelfs_cn_id);
+
+ mutex_lock(&pohmelfs_config_lock);
+ list_for_each_entry_safe(c, tmp, &pohmelfs_config_list, config_entry) {
+ list_del(&c->config_entry);
+ kfree(c);
+ }
+ mutex_unlock(&pohmelfs_config_lock);
+}
diff --git a/fs/pohmelfs/dir.c b/fs/pohmelfs/dir.c
new file mode 100644
index 0000000..522f969
--- /dev/null
+++ b/fs/pohmelfs/dir.c
@@ -0,0 +1,1180 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/kernel.h>
+#include <linux/fs.h>
+#include <linux/jhash.h>
+#include <linux/pagemap.h>
+
+#include "netfs.h"
+
+/*
+ * Each pohmelfs directory inode contains a tree of childrens indexed
+ * by offset (in the dir reading stream) and name hash and len. Entries
+ * of that hashes are called pohmelfs_name.
+ *
+ * This routings deal with it.
+ */
+static int pohmelfs_cmp_offset(struct pohmelfs_name *n, u64 offset)
+{
+ if (n->offset > offset)
+ return -1;
+ if (n->offset < offset)
+ return 1;
+ return 0;
+}
+
+static struct pohmelfs_name *pohmelfs_search_offset(struct pohmelfs_inode *pi, u64 offset)
+{
+ struct rb_node *n = pi->offset_root.rb_node;
+ struct pohmelfs_name *tmp;
+ int cmp;
+
+ while (n) {
+ tmp = rb_entry(n, struct pohmelfs_name, offset_node);
+
+ cmp = pohmelfs_cmp_offset(tmp, offset);
+ if (cmp < 0)
+ n = n->rb_left;
+ else if (cmp > 0)
+ n = n->rb_right;
+ else
+ return tmp;
+ }
+
+ return NULL;
+}
+
+static struct pohmelfs_name *pohmelfs_insert_offset(struct pohmelfs_inode *pi,
+ struct pohmelfs_name *new)
+{
+ struct rb_node **n = &pi->offset_root.rb_node, *parent = NULL;
+ struct pohmelfs_name *ret = NULL, *tmp;
+ int cmp;
+
+ while (*n) {
+ parent = *n;
+
+ tmp = rb_entry(parent, struct pohmelfs_name, offset_node);
+
+ cmp = pohmelfs_cmp_offset(tmp, new->offset);
+ if (cmp < 0)
+ n = &parent->rb_left;
+ else if (cmp > 0)
+ n = &parent->rb_right;
+ else {
+ ret = tmp;
+ break;
+ }
+ }
+
+ if (ret)
+ return ret;
+
+ rb_link_node(&new->offset_node, parent, n);
+ rb_insert_color(&new->offset_node, &pi->offset_root);
+
+ pi->total_len += new->len;
+
+ return NULL;
+}
+
+static int pohmelfs_cmp_hash(struct pohmelfs_name *n, u32 hash, u32 len)
+{
+ if (n->hash > hash)
+ return -1;
+ if (n->hash < hash)
+ return 1;
+
+ if (n->len > len)
+ return -1;
+ if (n->len < len)
+ return 1;
+
+ return 0;
+}
+
+static struct pohmelfs_name *pohmelfs_search_hash(struct pohmelfs_inode *pi, u32 hash, u32 len)
+{
+ struct rb_node *n = pi->hash_root.rb_node;
+ struct pohmelfs_name *tmp;
+ int cmp;
+
+ while (n) {
+ tmp = rb_entry(n, struct pohmelfs_name, hash_node);
+
+ cmp = pohmelfs_cmp_hash(tmp, hash, len);
+ if (cmp < 0)
+ n = n->rb_left;
+ else if (cmp > 0)
+ n = n->rb_right;
+ else
+ return tmp;
+ }
+
+ return NULL;
+}
+
+static void __pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
+{
+ rb_erase(&node->offset_node, &parent->offset_root);
+ rb_erase(&node->hash_node, &parent->hash_root);
+}
+
+/*
+ * Remove name cache entry from its caches and free it.
+ */
+static void pohmelfs_name_free(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
+{
+ __pohmelfs_name_del(parent, node);
+ list_del(&node->sync_del_entry);
+ list_del(&node->sync_create_entry);
+ kfree(node);
+}
+
+static struct pohmelfs_name *pohmelfs_insert_hash(struct pohmelfs_inode *pi,
+ struct pohmelfs_name *new)
+{
+ struct rb_node **n = &pi->hash_root.rb_node, *parent = NULL;
+ struct pohmelfs_name *ret = NULL, *tmp;
+ int cmp;
+
+ while (*n) {
+ parent = *n;
+
+ tmp = rb_entry(parent, struct pohmelfs_name, hash_node);
+
+ cmp = pohmelfs_cmp_hash(tmp, new->hash, new->len);
+ if (cmp < 0)
+ n = &parent->rb_left;
+ else if (cmp > 0)
+ n = &parent->rb_right;
+ else {
+ ret = tmp;
+ break;
+ }
+ }
+
+ if (ret) {
+ printk("%s: exist: ino: %llu, hash: %x, len: %u, data: '%s', new: ino: %llu, hash: %x, len: %u, data: '%s'.\n",
+ __func__, ret->ino, ret->hash, ret->len, ret->data,
+ new->ino, new->hash, new->len, new->data);
+ ret->ino = new->ino;
+ return ret;
+ }
+
+ rb_link_node(&new->hash_node, parent, n);
+ rb_insert_color(&new->hash_node, &pi->hash_root);
+
+ return NULL;
+}
+
+/*
+ * Free name cache for given inode.
+ */
+void pohmelfs_free_names(struct pohmelfs_inode *parent)
+{
+ struct rb_node *rb_node;
+ struct pohmelfs_name *n;
+
+ for (rb_node = rb_first(&parent->offset_root); rb_node;) {
+ n = rb_entry(rb_node, struct pohmelfs_name, offset_node);
+ rb_node = rb_next(rb_node);
+
+ pohmelfs_name_free(parent, n);
+ }
+}
+
+/*
+ * When name cache entry is removed (for example when object is removed),
+ * offset for all subsequent childrens has to be fixed to match new reality.
+ */
+static int pohmelfs_fix_offset(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
+{
+ struct rb_node *rb_node;
+ int decr = 0;
+
+ for (rb_node = rb_next(&node->offset_node); rb_node; rb_node = rb_next(rb_node)) {
+ struct pohmelfs_name *n = container_of(rb_node, struct pohmelfs_name, offset_node);
+
+ n->offset -= node->len;
+ decr++;
+ }
+
+ parent->total_len -= node->len;
+
+ return decr;
+}
+
+/*
+ * Fix offset and free name cache entry helper.
+ */
+void pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node)
+{
+ int decr;
+
+ decr = pohmelfs_fix_offset(parent, node);
+
+ dprintk("%s: parent: %llu, ino: %llu, decr: %d.\n",
+ __func__, parent->ino, node->ino, decr);
+
+ pohmelfs_name_free(parent, node);
+}
+
+/*
+ * Insert new name cache entry into all caches (offset and name hash).
+ */
+static int pohmelfs_insert_name(struct pohmelfs_inode *parent, struct pohmelfs_name *n)
+{
+ struct pohmelfs_name *name;
+
+ name = pohmelfs_insert_offset(parent, n);
+ if (name)
+ return -EEXIST;
+
+ name = pohmelfs_insert_hash(parent, n);
+ if (name) {
+ parent->total_len -= n->len;
+ rb_erase(&n->offset_node, &parent->offset_root);
+ return -EEXIST;
+ }
+
+ list_add_tail(&n->sync_create_entry, &parent->sync_create_list);
+
+ return 0;
+}
+
+/*
+ * Allocate new name cache entry.
+ */
+static struct pohmelfs_name *pohmelfs_name_clone(unsigned int len)
+{
+ struct pohmelfs_name *n;
+
+ n = kzalloc(sizeof(struct pohmelfs_name) + len, GFP_KERNEL);
+ if (!n)
+ return NULL;
+
+ INIT_LIST_HEAD(&n->sync_create_entry);
+ INIT_LIST_HEAD(&n->sync_del_entry);
+
+ n->data = (char *)(n+1);
+
+ return n;
+}
+
+/*
+ * Add new name entry into directory's cache.
+ */
+static int pohmelfs_add_dir(struct pohmelfs_sb *psb, struct pohmelfs_inode *parent,
+ struct pohmelfs_inode *npi, struct qstr *str, unsigned int mode, int link)
+{
+ int err = -ENOMEM;
+ struct pohmelfs_name *n;
+ struct pohmelfs_path_entry *e = NULL;
+
+ n = pohmelfs_name_clone(str->len + 1);
+ if (!n)
+ goto err_out_exit;
+
+ n->ino = npi->ino;
+ n->offset = parent->total_len;
+ n->mode = mode;
+ n->len = str->len;
+ n->hash = str->hash;
+ sprintf(n->data, str->name);
+
+ if (!(str->len == 1 && str->name[0] == '.') &&
+ !(str->len == 2 && str->name[0] == '.' && str->name[1] == '.')) {
+ mutex_lock(&psb->path_lock);
+ e = pohmelfs_add_path_entry(psb, parent->ino, npi->ino, str, link, mode);
+ mutex_unlock(&psb->path_lock);
+ if (IS_ERR(e)) {
+ err = PTR_ERR(e);
+ goto err_out_free;
+ }
+ }
+
+ mutex_lock(&parent->offset_lock);
+ err = pohmelfs_insert_name(parent, n);
+ mutex_unlock(&parent->offset_lock);
+
+ if (err) {
+ if (err != -EEXIST)
+ goto err_out_remove;
+ kfree(n);
+ }
+
+ return 0;
+
+err_out_remove:
+ if (e) {
+ mutex_lock(&psb->path_lock);
+ pohmelfs_remove_path_entry(psb, e);
+ mutex_unlock(&psb->path_lock);
+ }
+err_out_free:
+ kfree(n);
+err_out_exit:
+ return err;
+}
+
+/*
+ * Create new inode for given parameters (name, inode info, parent).
+ * This does not create object on the server, it will be synced there during writeback.
+ */
+struct pohmelfs_inode *pohmelfs_new_inode(struct pohmelfs_sb *psb,
+ struct pohmelfs_inode *parent, struct qstr *str,
+ struct netfs_inode_info *info, int link)
+{
+ struct inode *new = NULL;
+ struct pohmelfs_inode *npi;
+ int err = -EEXIST;
+
+ dprintk("%s: creating inode: parent: %llu, ino: %llu, str: %p.\n",
+ __func__, (parent)?parent->ino:0, info->ino, str);
+
+ err = -ENOMEM;
+ new = iget_locked(psb->sb, info->ino);
+ if (!new)
+ goto err_out_exit;
+
+ npi = POHMELFS_I(new);
+ npi->ino = info->ino;
+ err = 0;
+
+ if (new->i_state & I_NEW) {
+ dprintk("%s: filling VFS inode: %lu/%llu.\n",
+ __func__, new->i_ino, info->ino);
+ pohmelfs_fill_inode(new, info);
+
+ if (S_ISDIR(info->mode)) {
+ struct qstr s;
+
+ s.name = ".";
+ s.len = 1;
+ s.hash = jhash(s.name, s.len, 0);
+
+ err = pohmelfs_add_dir(psb, npi, npi, &s, info->mode, 0);
+ if (err)
+ goto err_out_put;
+
+ s.name = "..";
+ s.len = 2;
+ s.hash = jhash(s.name, s.len, 0);
+
+ err = pohmelfs_add_dir(psb, npi, (parent)?parent:npi, &s,
+ (parent)?parent->vfs_inode.i_mode:npi->vfs_inode.i_mode, 0);
+ if (err)
+ goto err_out_put;
+ }
+ }
+
+ if (str) {
+ if (parent) {
+ err = pohmelfs_add_dir(psb, parent, npi, str, info->mode, link);
+
+ dprintk("%s: %s inserted name: '%s', new_offset: %llu, ino: %llu, parent: %llu.\n",
+ __func__, (err)?"unsuccessfully":"successfully",
+ str->name, parent->total_len, info->ino, parent->ino);
+
+ if (err && err != -EEXIST)
+ goto err_out_put;
+ } else {
+ mutex_lock(&psb->path_lock);
+ pohmelfs_add_path_entry(psb, npi->ino, npi->ino, str, link, info->mode);
+ mutex_unlock(&psb->path_lock);
+ }
+ }
+
+ if (new->i_state & I_NEW) {
+ if (parent)
+ mark_inode_dirty(&parent->vfs_inode);
+ mark_inode_dirty(new);
+
+#ifdef POHMELFS_CC_GROUP
+ pohmelfs_meta_command(npi, NETFS_JOIN_GROUP, 0, NULL, NULL, 0);
+#endif
+ }
+ unlock_new_inode(new);
+
+ return npi;
+
+err_out_put:
+ printk("%s: putting inode: %p, npi: %p, error: %d.\n", __func__, new, npi, err);
+ iput(new);
+err_out_exit:
+ return ERR_PTR(err);
+}
+
+static int pohmelfs_remote_sync_complete(struct page **pages, unsigned int page_num,
+ void *private, int err)
+{
+ struct pohmelfs_inode *pi = private;
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+
+ dprintk("%s: ino: %llu, err: %d.\n", __func__, pi->ino, err);
+
+ if (err)
+ pi->error = err;
+ wake_up(&psb->wait);
+ pohmelfs_put_inode(pi);
+
+ return err;
+}
+
+/*
+ * Receive directory content from the server.
+ * This should be only done for objects, which were not created locally,
+ * and which were not synced previously.
+ */
+static int pohmelfs_sync_remote_dir(struct pohmelfs_inode *pi)
+{
+ struct inode *inode = &pi->vfs_inode;
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ long ret = msecs_to_jiffies(25000);
+ int err;
+
+ dprintk("%s: dir: %llu, state: %lx: created: %d, remote_synced: %d.\n",
+ __func__, pi->ino, pi->state, test_bit(NETFS_INODE_CREATED, &pi->state),
+ test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state));
+
+ if (!test_bit(NETFS_INODE_CREATED, &pi->state))
+ return 0;
+
+ if (test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state))
+ return 0;
+
+ if (!igrab(inode)) {
+ err = -ENOENT;
+ goto err_out_exit;
+ }
+
+ err = pohmelfs_meta_command(pi, NETFS_READDIR, NETFS_TRANS_SINGLE_DST,
+ pohmelfs_remote_sync_complete, pi, 0);
+ if (err)
+ goto err_out_exit;
+
+ pi->error = 0;
+ ret = wait_event_interruptible_timeout(psb->wait,
+ test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state) || pi->error, ret);
+ dprintk("%s: awake dir: %llu, ret: %ld, err: %d.\n", __func__, pi->ino, ret, pi->error);
+ if (ret <= 0) {
+ err = -ETIMEDOUT;
+ goto err_out_exit;
+ }
+
+ if (pi->error)
+ return pi->error;
+
+ return 0;
+
+err_out_exit:
+ clear_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state);
+
+ return err;
+}
+
+/*
+ * VFS readdir callback. Syncs directory content from server if needed,
+ * and provide info to userspace.
+ */
+static int pohmelfs_readdir(struct file *file, void *dirent, filldir_t filldir)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ struct pohmelfs_name *n;
+ int err = 0, mode;
+ u64 len;
+
+ dprintk("%s: parent: %llu.\n", __func__, pi->ino);
+
+ err = pohmelfs_sync_remote_dir(pi);
+ if (err)
+ return err;
+
+ while (1) {
+ mutex_lock(&pi->offset_lock);
+ n = pohmelfs_search_offset(pi, file->f_pos);
+ if (!n) {
+ mutex_unlock(&pi->offset_lock);
+ err = 0;
+ break;
+ }
+
+ mode = (n->mode >> 12) & 15;
+
+ dprintk("%s: offset: %llu, parent ino: %llu, name: '%s', len: %u, ino: %llu, mode: %o/%o.\n",
+ __func__, file->f_pos, pi->ino, n->data, n->len,
+ n->ino, n->mode, mode);
+
+ len = n->len;
+ err = filldir(dirent, n->data, n->len, file->f_pos, n->ino, mode);
+ mutex_unlock(&pi->offset_lock);
+
+ if (err < 0) {
+ dprintk("%s: err: %d.\n", __func__, err);
+ err = 0;
+ break;
+ }
+
+ file->f_pos += len;
+ }
+
+ return err;
+}
+
+const struct file_operations pohmelfs_dir_fops = {
+ .read = generic_read_dir,
+ .readdir = pohmelfs_readdir,
+};
+
+/*
+ * Lookup single object on server.
+ */
+static int pohmelfs_lookup_single(struct pohmelfs_inode *parent,
+ struct qstr *str, u64 ino)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(parent->vfs_inode.i_sb);
+ long ret = msecs_to_jiffies(5000);
+ int err;
+
+ set_bit(NETFS_COMMAND_PENDING, &parent->state);
+ err = pohmelfs_meta_command_data(parent, NETFS_LOOKUP,
+ (char *)str->name, NETFS_TRANS_SINGLE_DST, NULL, NULL, ino);
+ if (err)
+ goto err_out_exit;
+
+ err = 0;
+ ret = wait_event_interruptible_timeout(psb->wait,
+ !test_bit(NETFS_COMMAND_PENDING, &parent->state), ret);
+ if (ret == 0)
+ err = -ETIMEDOUT;
+ else if (signal_pending(current))
+ err = -EINTR;
+
+ if (err)
+ goto err_out_exit;
+
+ return 0;
+
+err_out_exit:
+ clear_bit(NETFS_COMMAND_PENDING, &parent->state);
+
+ printk("%s: failed: parent: %llu, ino: %llu, name: '%s', err: %d.\n",
+ __func__, parent->ino, ino, str->name, err);
+
+ return err;
+}
+
+/*
+ * VFS lookup callback.
+ * We first try to get inode number from local name cache, if we have one,
+ * then inode can be found in inode cache. If there is no inode or no object in
+ * local cache, try to lookup it on server. This only should be done for directories,
+ * which were not created locally, otherwise remote server does not know about dir at all,
+ * so no need to try to know that.
+ */
+struct dentry *pohmelfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+ struct pohmelfs_inode *parent = POHMELFS_I(dir);
+ struct pohmelfs_name *n;
+ struct inode *inode = NULL;
+ unsigned long ino = 0;
+ int err;
+ struct qstr str = dentry->d_name;
+
+ str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
+
+ mutex_lock(&parent->offset_lock);
+ n = pohmelfs_search_hash(parent, str.hash, str.len);
+ if (n)
+ ino = n->ino;
+ mutex_unlock(&parent->offset_lock);
+
+ dprintk("%s: 1 ino: %lu, inode: %p, name: '%s', hash: %x, parent_state: %lx.\n",
+ __func__, ino, inode, str.name, str.hash, parent->state);
+
+ if (ino) {
+ inode = ilookup(dir->i_sb, ino);
+ if (inode)
+ goto out;
+ }
+
+ dprintk("%s: dir: %p, dir_ino: %llu, name: '%s', len: %u, dir_state: %lx, ino: %lu.\n",
+ __func__, dir, parent->ino,
+ str.name, str.len, parent->state, ino);
+
+ if (!ino) {
+ if (!test_bit(NETFS_INODE_CREATED, &parent->state))
+ goto out;
+
+ if (test_bit(NETFS_INODE_REMOTE_SYNCED, &parent->state))
+ goto out;
+ }
+
+ err = pohmelfs_lookup_single(parent, &str, ino);
+ if (err)
+ goto out;
+
+ if (!ino) {
+ mutex_lock(&parent->offset_lock);
+ n = pohmelfs_search_hash(parent, str.hash, str.len);
+ if (n)
+ ino = n->ino;
+ mutex_unlock(&parent->offset_lock);
+ }
+
+ if (ino) {
+ inode = ilookup(dir->i_sb, ino);
+ printk("%s: second lookup ino: %lu, inode: %p, name: '%s', hash: %x.\n",
+ __func__, ino, inode, str.name, str.hash);
+ if (!inode) {
+ printk("%s: No inode for ino: %lu, name: '%s', hash: %x.\n",
+ __func__, ino, str.name, str.hash);
+ //return NULL;
+ return ERR_PTR(-EACCES);
+ }
+ } else {
+ printk("%s: No inode number : name: '%s', hash: %x.\n",
+ __func__, str.name, str.hash);
+ }
+out:
+ return d_splice_alias(inode, dentry);
+}
+
+/*
+ * Create new object in local cache. Object will be synced to server
+ * during writeback for given inode.
+ */
+struct pohmelfs_inode *pohmelfs_create_entry_local(struct pohmelfs_sb *psb,
+ struct pohmelfs_inode *parent, struct qstr *str, u64 start, int mode)
+{
+ struct pohmelfs_inode *npi;
+ int err = -ENOMEM;
+ struct netfs_inode_info info;
+
+ dprintk("%s: name: '%s', mode: %o, start: %llu.\n",
+ __func__, str->name, mode, start);
+
+ info.mode = mode;
+ info.ino = start;
+
+ if (!start)
+ info.ino = pohmelfs_new_ino(psb);
+
+ info.nlink = S_ISDIR(mode)?2:1;
+ info.uid = current->uid;
+ info.gid = current->gid;
+ info.size = 0;
+ info.blocksize = 512;
+ info.blocks = 0;
+ info.rdev = 0;
+ info.version = 0;
+
+ npi = pohmelfs_new_inode(psb, parent, str, &info, !!start);
+ if (IS_ERR(npi)) {
+ err = PTR_ERR(npi);
+ goto err_out_unlock;
+ }
+
+ set_bit(NETFS_INODE_REMOTE_SYNCED, &npi->state);
+
+ return npi;
+
+err_out_unlock:
+ dprintk("%s: err: %d.\n", __func__, err);
+ return ERR_PTR(err);
+}
+
+/*
+ * Create local object and bind it to dentry.
+ */
+static int pohmelfs_create_entry(struct inode *dir, struct dentry *dentry, u64 start, int mode)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb);
+ struct pohmelfs_inode *npi;
+ struct qstr str = dentry->d_name;
+
+ str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
+
+ npi = pohmelfs_create_entry_local(psb, POHMELFS_I(dir), &str, start, mode);
+ if (IS_ERR(npi))
+ return PTR_ERR(npi);
+
+ d_instantiate(dentry, &npi->vfs_inode);
+
+ dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n",
+ __func__, POHMELFS_I(dir)->ino, npi->ino, dentry->d_name.name,
+ (signed)dir->i_nlink, (signed)npi->vfs_inode.i_nlink);
+
+ return 0;
+}
+
+/*
+ * VFS create and mkdir callbacks.
+ */
+static int pohmelfs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ return pohmelfs_create_entry(dir, dentry, 0, mode);
+}
+
+static int pohmelfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ int err;
+
+ inode_inc_link_count(dir);
+ err = pohmelfs_create_entry(dir, dentry, 0, mode | S_IFDIR);
+ if (err)
+ inode_dec_link_count(dir);
+
+ return err;
+}
+
+/*
+ * Remove entry from local cache.
+ * Object will not be removed from server, instead it will be queued into parent
+ * to-be-removed queue, which will be processed during parent writeback (parent
+ * also marked as dirty). Writeback will send remove request to server.
+ * Such approach allows to remove vey huge directories (like 2.6.24 kernel tree)
+ * with only single network command.
+ */
+static int pohmelfs_remove_entry(struct inode *dir, struct dentry *dentry)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb);
+ struct inode *inode = dentry->d_inode;
+ struct pohmelfs_inode *parent = POHMELFS_I(dir), *pi = POHMELFS_I(inode);
+ struct pohmelfs_name *n;
+ int err = -ENOENT;
+ struct qstr str = dentry->d_name;
+
+ str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
+
+ dprintk("%s: dir_ino: %llu, inode: %llu, name: '%s', nlink: %d.\n",
+ __func__, parent->ino, pi->ino,
+ str.name, (signed)inode->i_nlink);
+
+ mutex_lock(&parent->offset_lock);
+ n = pohmelfs_search_hash(parent, str.hash, str.len);
+ if (n) {
+ pohmelfs_fix_offset(parent, n);
+ if (test_bit(NETFS_INODE_CREATED, &pi->state)) {
+ __pohmelfs_name_del(parent, n);
+ list_add_tail(&n->sync_del_entry, &parent->sync_del_list);
+ } else
+ pohmelfs_name_free(parent, n);
+ err = 0;
+ }
+ mutex_unlock(&parent->offset_lock);
+
+ if (!err) {
+ mutex_lock(&psb->path_lock);
+ pohmelfs_remove_path_entry_by_ino(psb, pi->ino);
+ mutex_unlock(&psb->path_lock);
+
+ pohmelfs_inode_del_inode(psb, pi);
+
+ mark_inode_dirty(dir);
+
+ inode->i_ctime = dir->i_ctime;
+ if (inode->i_nlink)
+ inode_dec_link_count(inode);
+ }
+ dprintk("%s: inode: %p, lock: %ld, unhashed: %d.\n",
+ __func__, pi, inode->i_state & I_LOCK, hlist_unhashed(&inode->i_hash));
+
+ return err;
+}
+
+/*
+ * Unlink and rmdir VFS callbacks.
+ */
+static int pohmelfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ return pohmelfs_remove_entry(dir, dentry);
+}
+
+static int pohmelfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ int err;
+ struct inode *inode = dentry->d_inode;
+
+ dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n",
+ __func__, POHMELFS_I(dir)->ino, POHMELFS_I(inode)->ino,
+ dentry->d_name.name, (signed)dir->i_nlink, (signed)inode->i_nlink);
+
+ err = pohmelfs_remove_entry(dir, dentry);
+ if (!err) {
+ inode_dec_link_count(dir);
+ inode_dec_link_count(inode);
+ }
+
+ return err;
+}
+
+/*
+ * Link creation is synchronous.
+ * I'm lazy.
+ * Earth is somewhat round.
+ */
+static int pohmelfs_create_link(struct pohmelfs_inode *parent, struct qstr *obj,
+ struct pohmelfs_inode *target, struct qstr *tstr)
+{
+ struct super_block *sb = parent->vfs_inode.i_sb;
+ struct pohmelfs_sb *psb = POHMELFS_SB(sb);
+ struct netfs_cmd *cmd;
+ struct netfs_trans *t;
+ void *data;
+ int err, parent_len, target_len = 0, cur_len, path_size = 0;
+
+ err = sb->s_op->write_inode(&parent->vfs_inode, 0);
+ if (err)
+ goto err_out_exit;
+
+ if (tstr)
+ target_len = tstr->len;
+
+ mutex_lock(&psb->path_lock);
+ parent_len = pohmelfs_path_length(parent);
+ if (target)
+ target_len += pohmelfs_path_length(target);
+ mutex_unlock(&psb->path_lock);
+
+ if (parent_len < 0) {
+ err = parent_len;
+ goto err_out_exit;
+ }
+
+ if (target_len < 0) {
+ err = target_len;
+ goto err_out_exit;
+ }
+
+ t = netfs_trans_alloc(parent_len + target_len + obj->len +
+ sizeof(struct netfs_cmd) + 2, 0, 0);
+ if (!t) {
+ err = -ENOMEM;
+ goto err_out_exit;
+ }
+ cur_len = netfs_trans_cur_len(t);
+
+ cmd = netfs_trans_add(t, cur_len);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_free;
+ }
+
+ data = (void *)(cmd + 1);
+ cur_len -= sizeof(struct netfs_cmd);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(parent, data, parent_len);
+ if (err > 0) {
+ path_size = err;
+ cur_len -= path_size;
+
+ err = snprintf(data + path_size, cur_len, "/%s|", obj->name);
+
+ path_size += err;
+ cur_len -= err;
+
+ cmd->ext = path_size - 1; /* No | symbol */
+
+ if (target) {
+ err = pohmelfs_construct_path_string(target, data + path_size, target_len);
+ if (err > 0) {
+ path_size += err + 1;
+ cur_len -= err + 1;
+ }
+ }
+ }
+ mutex_unlock(&psb->path_lock);
+
+ if (err < 0)
+ goto err_out_free;
+
+ cmd->start = 0;
+
+ if (!target && tstr) {
+ if (tstr->len > cur_len - 1) {
+ err = -ENAMETOOLONG;
+ goto err_out_free;
+ }
+
+ err = snprintf(data + path_size, cur_len, "%s", tstr->name) + 1 /* 0-byte */;
+ path_size += err;
+ cur_len -= err;
+ cmd->start = 1;
+ }
+
+ netfs_trans_fixup_last(t, -cur_len);
+
+ dprintk("%s: parent: %llu, obj: '%s', target_inode: %llu, target_str: '%s', full: '%s'.\n",
+ __func__, parent->ino, obj->name, (target)?target->ino:0, (tstr)?tstr->name:NULL,
+ (char *)data);
+
+ cmd->cmd = NETFS_LINK;
+ cmd->size = path_size;
+ cmd->id = parent->ino;
+ netfs_convert_cmd(cmd);
+
+ err = netfs_trans_finish(t, psb);
+ if (err)
+ goto err_out_exit;
+
+ return 0;
+
+err_out_free:
+ t->result = err;
+ netfs_trans_put(t);
+err_out_exit:
+ return err;
+}
+
+/*
+ * VFS hard and soft link callbacks.
+ */
+static int pohmelfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ int err;
+ struct qstr str = dentry->d_name;
+
+ str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
+
+ err = inode->i_sb->s_op->write_inode(inode, 0);
+ if (err)
+ return err;
+
+ err = pohmelfs_create_link(POHMELFS_I(dir), &str, pi, NULL);
+ if (err)
+ return err;
+
+ return pohmelfs_create_entry(dir, dentry, pi->ino, inode->i_mode);
+}
+
+static int pohmelfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ struct qstr sym_str;
+ struct qstr str = dentry->d_name;
+ struct inode *inode;
+ int err;
+
+ str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0);
+
+ sym_str.name = symname;
+ sym_str.len = strlen(symname);
+
+ err = pohmelfs_create_link(POHMELFS_I(dir), &str, NULL, &sym_str);
+ if (err)
+ goto err_out_exit;
+
+ err = pohmelfs_create_entry(dir, dentry, 0, S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO);
+ if (err)
+ goto err_out_exit;
+
+ inode = dentry->d_inode;
+
+ err = page_symlink(inode, symname, sym_str.len + 1);
+ if (err)
+ goto err_out_put;
+
+ return 0;
+
+err_out_put:
+ iput(inode);
+err_out_exit:
+ return err;
+}
+
+static int pohmelfs_send_rename(struct pohmelfs_inode *pi, struct pohmelfs_inode *parent,
+ struct qstr *str)
+{
+ int path_len, err, total_len = 0, inode_len, parent_len;
+ char *path;
+ struct netfs_trans *t;
+ struct netfs_cmd *cmd;
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+
+ mutex_lock(&psb->path_lock);
+ parent_len = pohmelfs_path_length(parent);
+ inode_len = pohmelfs_path_length(pi);
+ mutex_unlock(&psb->path_lock);
+
+ if (parent_len < 0 || inode_len < 0)
+ return -EINVAL;
+
+ path_len = parent_len + inode_len + str->len + 3;
+
+ t = netfs_trans_alloc(path_len + sizeof(struct netfs_cmd), 0, 0);
+ if (!t)
+ return -ENOMEM;
+
+ cmd = netfs_trans_add(t, path_len + sizeof(struct netfs_cmd));
+ path = (char *)(cmd + 1);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(pi, path, inode_len + 1);
+ if (err < 0)
+ goto err_out_unlock;
+
+ cmd->ext = err;
+
+ path += err;
+ total_len += err;
+ path_len -= err;
+
+ *path = '|';
+ path++;
+ total_len++;
+ path_len--;
+
+ err = pohmelfs_construct_path_string(parent, path, parent_len + 1);
+ if (err < 0)
+ goto err_out_unlock;
+ mutex_unlock(&psb->path_lock);
+
+ path += err;
+ total_len += err;
+ path_len -= err;
+
+ err = snprintf(path, path_len - 1, "/%s", str->name);
+
+ total_len += err + 1; /* 0 symbol */
+ path_len -= err + 1;
+
+ netfs_trans_fixup_last(t, -path_len);
+
+ cmd->cmd = NETFS_RENAME;
+ cmd->id = pi->ino;
+ cmd->start = parent->ino;
+ cmd->size = total_len;
+
+ netfs_convert_cmd(cmd);
+
+ return netfs_trans_finish(t, psb);
+
+err_out_unlock:
+ mutex_unlock(&psb->path_lock);
+ netfs_trans_free(t);
+ return err;
+}
+
+static int pohmelfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(old_dir->i_sb);
+ struct inode *old_inode = old_dentry->d_inode;
+ struct pohmelfs_inode *old_parent, *old, *new_parent;
+ struct qstr str = new_dentry->d_name;
+ struct pohmelfs_name *n;
+ unsigned int old_hash;
+ int err = -ENOENT;
+
+ if (new_dir) {
+ err = new_dir->i_sb->s_op->write_inode(new_dir, 0);
+ if (err)
+ return err;
+ }
+
+ err = old_inode->i_sb->s_op->write_inode(old_inode, 0);
+ if (err)
+ return err;
+
+ old_hash = jhash(old_dentry->d_name.name, old_dentry->d_name.len, 0);
+ str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0);
+
+ old = POHMELFS_I(old_inode);
+ old_parent = POHMELFS_I(old_dir);
+
+ str.len = new_dentry->d_name.len;
+ str.name = new_dentry->d_name.name;
+ str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0);
+
+ if (new_dir) {
+ new_parent = POHMELFS_I(new_dir);
+ err = -ENOTEMPTY;
+
+ if (S_ISDIR(old_inode->i_mode) &&
+ new_parent->total_len <= 3)
+ goto err_out_exit;
+ } else {
+ new_parent = old_parent;
+ }
+
+ dprintk("%s: ino: %llu, parent: %llu, name: '%s' -> parent: %llu, name: '%s'.\n",
+ __func__, old->ino, old_parent->ino, old_dentry->d_name.name,
+ new_parent->ino, new_dentry->d_name.name);
+
+ err = pohmelfs_send_rename(old, new_parent, &str);
+ if (err)
+ goto err_out_exit;
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_rename_path_entry(psb, old->ino, new_parent->ino, &str);
+ mutex_unlock(&psb->path_lock);
+ if (err)
+ goto err_out_exit;
+
+ n = pohmelfs_name_clone(str.len + 1);
+ if (!n)
+ goto err_out_exit;
+
+ mutex_lock(&new_parent->offset_lock);
+ n->ino = old->ino;
+ n->offset = new_parent->total_len;
+ n->mode = old_inode->i_mode;
+ n->len = str.len;
+ n->hash = str.hash;
+ sprintf(n->data, str.name);
+
+ err = pohmelfs_insert_name(new_parent, n);
+ mutex_unlock(&new_parent->offset_lock);
+
+ if (err)
+ goto err_out_exit;
+
+ mutex_lock(&old_parent->offset_lock);
+ n = pohmelfs_search_hash(old_parent, old_hash, old_dentry->d_name.len);
+ if (n)
+ pohmelfs_name_del(old_parent, n);
+ mutex_unlock(&old_parent->offset_lock);
+
+ mark_inode_dirty(old_inode);
+ mark_inode_dirty(&new_parent->vfs_inode);
+
+ return 0;
+
+err_out_exit:
+ return err;
+}
+
+/*
+ * POHMELFS directory inode operations.
+ */
+const struct inode_operations pohmelfs_dir_inode_ops = {
+ .link = pohmelfs_link,
+ .symlink = pohmelfs_symlink,
+ .unlink = pohmelfs_unlink,
+ .mkdir = pohmelfs_mkdir,
+ .rmdir = pohmelfs_rmdir,
+ .create = pohmelfs_create,
+ .lookup = pohmelfs_lookup,
+ .setattr = pohmelfs_setattr,
+ .rename = pohmelfs_rename,
+};
diff --git a/fs/pohmelfs/inode.c b/fs/pohmelfs/inode.c
new file mode 100644
index 0000000..2cfe84b
--- /dev/null
+++ b/fs/pohmelfs/inode.c
@@ -0,0 +1,1702 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/backing-dev.h>
+#include <linux/fs.h>
+#include <linux/jhash.h>
+#include <linux/hash.h>
+#include <linux/ktime.h>
+#include <linux/mm.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/parser.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/writeback.h>
+#include <linux/quotaops.h>
+
+#include "netfs.h"
+
+#define POHMELFS_MAGIC_NUM 0x504f482e
+
+static struct kmem_cache *pohmelfs_inode_cache;
+
+static atomic_t pohmelfs_readpage_counter = ATOMIC_INIT(0);
+static atomic_t pohmelfs_readpages_counter = ATOMIC_INIT(0);
+
+/*
+ * Removes inode from all trees, drops local name cache and removes all queued
+ * requests for object removal.
+ */
+void pohmelfs_inode_del_inode(struct pohmelfs_sb *psb, struct pohmelfs_inode *pi)
+{
+ struct pohmelfs_name *n, *tmp;
+
+ mutex_lock(&pi->offset_lock);
+ pohmelfs_free_names(pi);
+
+ list_for_each_entry_safe(n, tmp, &pi->sync_create_list, sync_create_entry) {
+ list_del_init(&n->sync_create_entry);
+ list_del_init(&n->sync_del_entry);
+ kfree(n);
+ }
+
+ list_for_each_entry_safe(n, tmp, &pi->sync_del_list, sync_del_entry) {
+ list_del_init(&n->sync_create_entry);
+ list_del_init(&n->sync_del_entry);
+ kfree(n);
+ }
+ mutex_unlock(&pi->offset_lock);
+
+ dprintk("%s: deleted stuff in ino: %llu.\n", __func__, pi->ino);
+}
+
+/*
+ * Sync inode to server.
+ * Returns zero in success and negative error value otherwise.
+ * It will gather path to root directory into structures containing
+ * creation mode, permissions and names, so that the whole path
+ * to given inode could be created using only single network command.
+ */
+static int pohmelfs_write_inode_create(struct inode *inode, struct netfs_trans *trans)
+{
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ int err = -ENOMEM, size;
+ struct netfs_cmd *cmd;
+ void *data;
+ int cur_len = netfs_trans_cur_len(trans);
+
+ if (unlikely(cur_len < 0))
+ return -ETOOSMALL;
+
+ cmd = netfs_trans_add(trans, cur_len);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_exit;
+ }
+
+ cur_len -= sizeof(struct netfs_cmd);
+
+ data = (void *)(cmd + 1);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path(pi, data, cur_len);
+ mutex_unlock(&psb->path_lock);
+
+ dprintk("%s: cmd: %p, data: %p, len: %u, err: %u.\n",
+ __func__, cmd, data, cur_len, err);
+
+ if (err < 0)
+ goto err_out_unroll;
+
+ size = err;
+
+ netfs_trans_fixup_last(trans, size - cur_len);
+
+ if (size) {
+ cmd->start = 0;
+ cmd->cmd = NETFS_CREATE;
+ cmd->size = size;
+ cmd->id = pi->ino;
+ cmd->ext = 0;
+
+ netfs_convert_cmd(cmd);
+ }
+
+ return 0;
+
+err_out_unroll:
+ netfs_trans_fixup_last(trans, cur_len);
+err_out_exit:
+ clear_bit(NETFS_INODE_CREATED, &pi->state);
+ printk("%s: completed ino: %llu, err: %d.\n", __func__, pi->ino, err);
+ return err;
+}
+
+static int pohmelfs_write_trans_complete(struct page **pages, unsigned int page_num,
+ void *private, int err)
+{
+ unsigned i;
+
+ dprintk("%s: page_num: %u, err: %d.\n",
+ __func__, page_num, err);
+
+ for (i = 0; i < page_num; i++) {
+ struct page *page = pages[i];
+
+ if (!page)
+ continue;
+
+ if (err)
+ SetPageError(page);
+ end_page_writeback(page);
+
+ BUG_ON(PageWriteback(page));
+
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ return err;
+}
+
+static int pohmelfs_inode_has_dirty_pages(struct address_space *mapping, pgoff_t index)
+{
+ int ret;
+ struct page *page;
+
+ read_lock_irq(&mapping->tree_lock);
+ ret = radix_tree_gang_lookup_tag(&mapping->page_tree,
+ (void **)&page, index, 1, PAGECACHE_TAG_DIRTY);
+ read_unlock_irq(&mapping->tree_lock);
+ return ret;
+}
+
+static int pohmelfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ struct inode *inode = mapping->host;
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
+ int err = 0;
+ int done = 0;
+ int nr_pages;
+ int created = 0;
+ pgoff_t index;
+ pgoff_t end; /* Inclusive */
+ int scanned = 0;
+ int range_whole = 0;
+
+ if (wbc->nonblocking && bdi_write_congested(bdi)) {
+ wbc->encountered_congestion = 1;
+ return 0;
+ }
+
+ if (wbc->range_cyclic) {
+ index = mapping->writeback_index; /* Start from prev offset */
+ end = -1;
+ } else {
+ index = wbc->range_start >> PAGE_CACHE_SHIFT;
+ end = wbc->range_end >> PAGE_CACHE_SHIFT;
+ if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+ range_whole = 1;
+ scanned = 1;
+ }
+retry:
+ while (!done && (index <= end)) {
+ unsigned int i = min(end - index, (pgoff_t)1024);
+ unsigned int path_len;
+ struct netfs_trans *trans;
+
+ err = pohmelfs_inode_has_dirty_pages(mapping, index);
+ if (!err)
+ break;
+
+ mutex_lock(&psb->path_lock);
+ if (!test_bit(NETFS_INODE_CREATED, &pi->state))
+ err = pohmelfs_path_length_create(pi);
+ else
+ err = pohmelfs_path_length(pi);
+ mutex_unlock(&psb->path_lock);
+
+ if (err < 0)
+ break;
+
+ path_len = err;
+
+ trans = netfs_trans_alloc(path_len + sizeof(struct netfs_cmd), 0, i);
+ if (!trans) {
+ err = -ENOMEM;
+ break;
+ }
+ trans->complete = &pohmelfs_write_trans_complete;
+
+ trans->page_num = nr_pages = find_get_pages_tag(mapping, &index,
+ PAGECACHE_TAG_DIRTY, trans->page_num,
+ trans->pages);
+
+ dprintk("%s: t: %p, nr_pages: %u, end: %lu, index: %lu, max: %u.\n",
+ __func__, trans, nr_pages, end, index, trans->page_num);
+
+ if (!nr_pages)
+ goto err_out_reset;
+
+ if (!test_bit(NETFS_INODE_CREATED, &pi->state)) {
+ err = pohmelfs_write_inode_create(inode, trans);
+ if (err)
+ goto err_out_reset;
+ created = 1;
+ } else {
+ void *data;
+ struct netfs_cmd *cmd;
+
+ cmd = netfs_trans_add(trans, path_len + sizeof(struct netfs_cmd));
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_reset;
+ }
+
+ data = (void *)(cmd + 1);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(pi, data, path_len);
+ mutex_unlock(&psb->path_lock);
+ if (err < 0)
+ goto err_out_reset;
+
+ netfs_trans_fixup_last(trans, err + 1 - path_len);
+
+ cmd->id = pi->ino;
+ cmd->start = 0;
+ cmd->size = err + 1;
+ cmd->cmd = NETFS_OPEN;
+ cmd->ext = O_RDWR | O_LARGEFILE;
+
+ netfs_convert_cmd(cmd);
+ }
+
+ err = 0;
+ scanned = 1;
+ for (i = 0; i < trans->page_num; i++) {
+ struct page *page = trans->pages[i];
+
+ dprintk("%s: %u/%u page: %p.\n", __func__, i, trans->page_num, page);
+
+ lock_page(page);
+
+ if (unlikely(page->mapping != mapping))
+ goto out_continue;
+
+ if (!wbc->range_cyclic && page->index > end) {
+ done = 1;
+ goto out_continue;
+ }
+
+ if (wbc->sync_mode != WB_SYNC_NONE)
+ wait_on_page_writeback(page);
+
+ if (PageWriteback(page) ||
+ !clear_page_dirty_for_io(page)) {
+ dprintk("%s: not clear for io page: %p, writeback: %d.\n",
+ __func__, page, PageWriteback(page));
+ goto out_continue;
+ }
+
+ set_page_writeback(page);
+
+ trans->attached_size += page_private(page);
+ trans->attached_pages++;
+
+ dprintk("%s: added trans: %p, gen: %u, page: %p, [High: %d], size: %lu.\n",
+ __func__, trans, trans->gen, page,
+ !!PageHighMem(page), page_private(page));
+ wbc->nr_to_write--;
+
+ if (wbc->nr_to_write <= 0)
+ done = 1;
+ if (wbc->nonblocking && bdi_write_congested(bdi)) {
+ wbc->encountered_congestion = 1;
+ done = 1;
+ }
+
+ continue;
+out_continue:
+ unlock_page(page);
+ trans->pages[i] = NULL;
+ }
+
+ if (trans->attached_size || created) {
+ err = netfs_trans_finish(trans, psb);
+ } else {
+ netfs_trans_reset(trans);
+ netfs_trans_put(trans);
+ }
+
+ if (err)
+ break;
+
+ continue;
+
+err_out_reset:
+ trans->result = err;
+ netfs_trans_reset(trans);
+ netfs_trans_put(trans);
+ break;
+ }
+
+ if (!scanned && !done) {
+ /*
+ * We hit the last page and there is more work to be done: wrap
+ * back to the start of the file
+ */
+ scanned = 1;
+ index = 0;
+ goto retry;
+ }
+
+ if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+ mapping->writeback_index = index;
+
+ return err;
+}
+
+/*
+ * Removes given child from given inode on server.
+ */
+static int pohmelfs_remove_child(struct pohmelfs_inode *parent, struct pohmelfs_name *n)
+{
+ dprintk("%s: parent: %llu, ino: %llu, name: '%s'.\n",
+ __func__, parent->ino, n->ino, n->data);
+
+ return pohmelfs_meta_command_data(parent, NETFS_REMOVE, n->data, 0, NULL, NULL, 0);
+}
+
+/*
+ * Removes all childs, marked for deletion, on server.
+ */
+static int pohmelfs_write_inode_remove_children(struct inode *inode)
+{
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ int err, error = 0;
+ struct pohmelfs_name *n, *tmp;
+
+ if (!list_empty(&pi->sync_del_list)) {
+ dprintk("%s: parent: %llu.\n", __func__, pi->ino);
+
+ mutex_lock(&pi->offset_lock);
+ list_for_each_entry_safe(n, tmp, &pi->sync_del_list, sync_del_entry) {
+ list_del_init(&n->sync_del_entry);
+ list_del_init(&n->sync_create_entry);
+
+ err = pohmelfs_remove_child(pi, n);
+ if (err)
+ error = err;
+
+ kfree(n);
+ }
+ mutex_unlock(&pi->offset_lock);
+ }
+
+ return error;
+}
+
+/*
+ * Inode writeback creation completion callback.
+ * Only invoked for just created inodes, which do not have pages attached,
+ * like dirs and empty files.
+ */
+static int pohmelfs_write_inode_complete(struct page **pages, unsigned int page_num,
+ void *private, int err)
+{
+ struct inode *inode = private;
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+
+ if (inode) {
+ if (err) {
+ mark_inode_dirty(inode);
+ clear_bit(NETFS_INODE_CREATED, &pi->state);
+ } else
+ set_bit(NETFS_INODE_CREATED, &pi->state);
+
+ pohmelfs_put_inode(pi);
+ }
+
+ return err;
+}
+
+/*
+ * Writeback for given inode.
+ */
+static int pohmelfs_write_inode(struct inode *inode, int sync)
+{
+ int err;
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ struct netfs_trans *t;
+
+ if (!test_bit(NETFS_INODE_CREATED, &pi->state)) {
+ dprintk("%s: started ino: %llu.\n", __func__, pi->ino);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_path_length_create(pi);
+ mutex_unlock(&psb->path_lock);
+ if (err < 0)
+ goto err_out_remove;
+
+ t = netfs_trans_alloc(err + 1 + sizeof(struct netfs_cmd), 0, 0);
+ if (!t) {
+ err = -ENOMEM;
+ goto err_out_put;
+ }
+ t->complete = pohmelfs_write_inode_complete;
+ t->private = igrab(inode);
+ if (!t->private) {
+ err = -ENOENT;
+ goto err_out_put;
+ }
+
+ err = pohmelfs_write_inode_create(inode, t);
+ if (err)
+ goto err_out_put;
+
+ err = netfs_trans_finish(t, POHMELFS_SB(inode->i_sb));
+ if (err)
+ goto err_out_remove;
+ }
+
+ pohmelfs_write_inode_remove_children(inode);
+
+ return 0;
+
+err_out_put:
+ t->result = err;
+ netfs_trans_put(t);
+err_out_remove:
+ pohmelfs_write_inode_remove_children(inode);
+
+ return err;
+}
+
+/*
+ * It is not exported, sorry...
+ */
+static inline wait_queue_head_t *page_waitqueue(struct page *page)
+{
+ const struct zone *zone = page_zone(page);
+
+ return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)];
+}
+
+static int pohmelfs_wait_on_page_locked(struct page *page)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(page->mapping->host->i_sb);
+ long ret = psb->wait_on_page_timeout;
+ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
+ int err = 0;
+
+ if (!PageLocked(page))
+ return 0;
+
+ for (;;) {
+ prepare_to_wait(page_waitqueue(page),
+ &wait.wait, TASK_INTERRUPTIBLE);
+
+ dprintk("%s: page: %p, locked: %d, uptodate: %d, error: %d, flags: %lx.\n",
+ __func__, page, PageLocked(page), PageUptodate(page),
+ PageError(page), page->flags);
+
+ if (!PageLocked(page))
+ break;
+
+ if (!signal_pending(current)) {
+ ret = schedule_timeout(ret);
+ if (!ret)
+ break;
+ continue;
+ }
+ ret = -ERESTARTSYS;
+ break;
+ }
+ finish_wait(page_waitqueue(page), &wait.wait);
+
+ if (!ret)
+ err = -ETIMEDOUT;
+
+ dprintk("%s: page: %p, uptodate: %d, locked: %d, err: %d.\n",
+ __func__, page, PageUptodate(page), PageLocked(page), err);
+
+ if (!PageUptodate(page))
+ err = -EIO;
+
+ return err;
+}
+
+static int pohmelfs_read_page_complete(struct page **pages, unsigned int page_num,
+ void *private, int err)
+{
+ struct page *page = private;
+
+ if (err)
+ SetPageError(page);
+ unlock_page(page);
+
+ return err;
+}
+
+/*
+ * Read a page from remote server.
+ * Function will wait until page is unlocked.
+ */
+static int pohmelfs_readpage(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ struct netfs_trans *t;
+ struct netfs_cmd *cmd;
+ int err, path_len;
+ void *data;
+
+ mutex_lock(&psb->path_lock);
+ path_len = pohmelfs_path_length(pi);
+ mutex_unlock(&psb->path_lock);
+
+ if (path_len < 0) {
+ err = path_len;
+ goto err_out_exit;
+ }
+
+ path_len += sizeof(struct netfs_cmd);
+
+ t = netfs_trans_alloc(path_len, NETFS_TRANS_SINGLE_DST, 0);
+ if (!t) {
+ err = -ENOMEM;
+ goto err_out_exit;
+ }
+
+ t->complete = pohmelfs_read_page_complete;
+ t->private = page;
+
+ cmd = netfs_trans_add(t, path_len);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_free;
+ }
+ data = (void *)(cmd + 1);
+ path_len -= sizeof(struct netfs_cmd);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(pi, data, path_len);
+ mutex_unlock(&psb->path_lock);
+ if (err < 0)
+ goto err_out_free;
+
+ netfs_trans_fixup_last(t, err + 1 - path_len);
+ path_len = err + 1;
+
+ cmd->id = pi->ino;
+ cmd->start = page->index;
+ cmd->start <<= PAGE_CACHE_SHIFT;
+ cmd->size = PAGE_CACHE_SIZE + path_len;
+ cmd->cmd = NETFS_READ_PAGE;
+ cmd->ext = path_len;
+
+ atomic_inc(&pohmelfs_readpage_counter);
+ dprintk("%s: path: '%s', page: %p, ino: %llu, start: %llu, size: %lu.\n",
+ __func__, (char *)data, page, pi->ino, cmd->start, PAGE_CACHE_SIZE);
+
+ netfs_convert_cmd(cmd);
+
+ err = netfs_trans_finish(t, psb);
+ if (err)
+ goto err_out_exit;
+
+ return pohmelfs_wait_on_page_locked(page);
+
+err_out_free:
+ t->result = err;
+ netfs_trans_put(t);
+err_out_exit:
+ SetPageError(page);
+ if (PageLocked(page))
+ unlock_page(page);
+
+ printk("%s: page: %p, start: %lu, size: %lu, err: %d.\n",
+ __func__, page, page->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE, err);
+
+ return err;
+}
+
+/*
+ * Write begin/end magic.
+ * Allocates a page and writes inode if it was not synced to server before.
+ */
+static int pohmelfs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct page *page;
+ pgoff_t index;
+ unsigned start, end;
+ int err;
+
+ *pagep = NULL;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ start = pos & (PAGE_CACHE_SIZE - 1);
+ end = start + len;
+
+ page = __grab_cache_page(mapping, index);
+
+ dprintk("%s: page: %p pos: %llu, len: %u, index: %lu, start: %u, end: %u, uptodate: %d.\n",
+ __func__, page, pos, len, index, start, end, PageUptodate(page));
+
+ if (!page) {
+ err = -ENOMEM;
+ goto err_out_exit;
+ }
+
+ while (!PageUptodate(page)) {
+ if (start && test_bit(NETFS_INODE_CREATED, &POHMELFS_I(inode)->state)) {
+ err = pohmelfs_readpage(file, page);
+ if (err)
+ goto err_out_exit;
+
+ lock_page(page);
+ continue;
+ }
+
+ if (len != PAGE_CACHE_SIZE) {
+ void *kaddr = kmap_atomic(page, KM_USER0);
+
+ memset(kaddr + start, 0, PAGE_CACHE_SIZE - start);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ SetPageUptodate(page);
+ }
+
+ set_page_private(page, end);
+
+ *pagep = page;
+
+ return 0;
+
+err_out_exit:
+ page_cache_release(page);
+ *pagep = NULL;
+
+ return err;
+}
+
+static int pohmelfs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+
+ if (copied != len) {
+ unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+ void *kaddr = kmap_atomic(page, KM_USER0);
+
+ memset(kaddr + from + copied, 0, len - copied);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+
+ SetPageUptodate(page);
+ set_page_dirty(page);
+
+ dprintk("%s: page: %p [U: %d, D: %d, L: %d], pos: %llu, len: %u, copied: %u.\n",
+ __func__, page,
+ PageUptodate(page), PageDirty(page), PageLocked(page),
+ pos, len, copied);
+
+ flush_dcache_page(page);
+
+ unlock_page(page);
+ page_cache_release(page);
+
+ if (pos + copied > inode->i_size) {
+ i_size_write(inode, pos + copied);
+#if 0
+ if (test_bit(NETFS_INODE_CREATED, &POHMELFS_I(inode)->state)) {
+ int err = pohmelfs_meta_command(POHMELFS_I(inode), NETFS_INODE_INFO,
+ 0, NULL, NULL, 0);
+ if (err)
+ return err;
+ }
+#endif
+ }
+
+ return copied;
+}
+
+static int pohmelfs_readpages_trans_complete(struct page **__pages, unsigned int page_num,
+ void *private, int err)
+{
+ struct pohmelfs_inode *pi = private;
+ unsigned int i, num;
+ struct page **pages, *page = (struct page *)__pages;
+ loff_t index = page->index;
+
+ pages = kzalloc(sizeof(void *) * page_num, GFP_NOIO);
+ if (!pages)
+ return -ENOMEM;
+
+ num = find_get_pages_contig(pi->vfs_inode.i_mapping, index, page_num, pages);
+ if (num <= 0) {
+ err = num;
+ goto err_out_free;
+ }
+
+ for (i=0; i<num; ++i) {
+ page = pages[i];
+ dprintk("%s: %u/%u: page: %p, index: %llu, uptodate: %d, locked: %d.\n",
+ __func__, i, num, page, index,
+ PageUptodate(page), PageLocked(page));
+
+ if (err)
+ SetPageError(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
+err_out_free:
+ kfree(pages);
+ return err;
+}
+
+static int pohmelfs_send_readpages(struct pohmelfs_inode *pi, struct page *first, unsigned int num)
+{
+ struct netfs_trans *t;
+ struct netfs_cmd *cmd;
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+ int err, path_len;
+ void *data;
+
+ mutex_lock(&psb->path_lock);
+ path_len = pohmelfs_path_length(pi);
+ mutex_unlock(&psb->path_lock);
+
+ if (path_len < 0) {
+ err = path_len;
+ goto err_out_exit;
+ }
+
+ path_len += sizeof(struct netfs_cmd);
+
+ t = netfs_trans_alloc(path_len, NETFS_TRANS_SINGLE_DST, 0);
+ if (!t) {
+ err = -ENOMEM;
+ goto err_out_exit;
+ }
+
+ cmd = netfs_trans_add(t, path_len);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_put;
+ }
+ data = (void *)(cmd + 1);
+
+ t->complete = pohmelfs_readpages_trans_complete;
+ t->private = pi;
+ t->page_num = num;
+ t->pages = (struct page **)first;
+
+ path_len -= sizeof(struct netfs_cmd);
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(pi, data, path_len);
+ mutex_unlock(&psb->path_lock);
+ if (err < 0)
+ goto err_out_put;
+
+ netfs_trans_fixup_last(t, err + 1 - path_len);
+ path_len = err + 1;
+
+ cmd->cmd = NETFS_READ_PAGES;
+ cmd->start = first->index;
+ cmd->start <<= PAGE_CACHE_SHIFT;
+ cmd->size = (num << 8 | PAGE_CACHE_SHIFT);
+ cmd->id = pi->ino;
+ cmd->ext = path_len;
+
+ atomic_inc(&pohmelfs_readpages_counter);
+ dprintk("%s: t: %p, gen: %u, path: '%s', path_len: %u, "
+ "start: %lu, num: %u.\n",
+ __func__, t, t->gen, (char *)data, path_len,
+ first->index, num);
+
+ netfs_convert_cmd(cmd);
+
+ return netfs_trans_finish(t, psb);
+
+err_out_put:
+ netfs_trans_free(t);
+err_out_exit:
+ pohmelfs_readpages_trans_complete((struct page **)first, num, pi, err);
+ return err;
+}
+
+#define list_to_page(head) (list_entry((head)->prev, struct page, lru))
+
+static int pohmelfs_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ unsigned int page_idx, num = 0;
+ struct page *page = NULL, *first = NULL;
+
+ for (page_idx = 0; page_idx < nr_pages; page_idx++) {
+ page = list_to_page(pages);
+
+ prefetchw(&page->flags);
+ list_del(&page->lru);
+
+ if (!add_to_page_cache_lru(page, mapping,
+ page->index, GFP_KERNEL)) {
+
+ if (!num) {
+ num = 1;
+ first = page;
+ page_cache_release(page);
+ continue;
+ }
+
+ dprintk("%s: added to lru page: %p, page_index: %lu, first_index: %lu.\n",
+ __func__, page, page->index, first->index);
+
+ if (unlikely(first->index + num != page->index) || (num > 500)) {
+ pohmelfs_send_readpages(POHMELFS_I(mapping->host),
+ first, num);
+ first = page;
+ num = 0;
+ }
+
+ num++;
+ }
+ page_cache_release(page);
+ }
+ pohmelfs_send_readpages(POHMELFS_I(mapping->host), first, num);
+
+ /*
+ * This will be sync read, so when last page is processed,
+ * all previous are alerady unlocked and ready to be used.
+ */
+ return 0;
+}
+
+/*
+ * Small addres space operations for POHMELFS.
+ */
+const struct address_space_operations pohmelfs_aops = {
+ .readpage = pohmelfs_readpage,
+ .readpages = pohmelfs_readpages,
+ .writepages = pohmelfs_writepages,
+ .write_begin = pohmelfs_write_begin,
+ .write_end = pohmelfs_write_end,
+ .set_page_dirty = __set_page_dirty_nobuffers,
+};
+
+static atomic_t inodes_allocated = ATOMIC_INIT(0);
+static atomic_t inodes_destroyed = ATOMIC_INIT(0);
+
+/*
+ * ->detroy_inode() callback. Deletes inode from the caches
+ * and frees private data.
+ */
+static void pohmelfs_destroy_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct pohmelfs_sb *psb = POHMELFS_SB(sb);
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+
+ pohmelfs_inode_del_inode(psb, pi);
+#ifdef POHMELFS_CC_GROUP
+ pohmelfs_meta_command(pi, NETFS_LEAVE_GROUP, 0, NULL, NULL, 0);
+#endif
+
+ dprintk("%s: pi: %p, inode: %p, ino: %llu.\n",
+ __func__, pi, &pi->vfs_inode, pi->ino);
+ kmem_cache_free(pohmelfs_inode_cache, pi);
+ atomic_inc(&inodes_destroyed);
+}
+
+/*
+ * ->alloc_inode() callback. Allocates inode and initilizes private data.
+ */
+static struct inode *pohmelfs_alloc_inode(struct super_block *sb)
+{
+ struct pohmelfs_inode *pi;
+
+ pi = kmem_cache_alloc(pohmelfs_inode_cache, GFP_NOIO);
+ if (!pi)
+ return NULL;
+
+ pi->offset_root = RB_ROOT;
+ pi->hash_root = RB_ROOT;
+ mutex_init(&pi->offset_lock);
+
+ INIT_LIST_HEAD(&pi->sync_del_list);
+ INIT_LIST_HEAD(&pi->sync_create_list);
+
+ INIT_LIST_HEAD(&pi->inode_entry);
+
+ pi->state = 0;
+ pi->total_len = 0;
+ pi->drop_count = 0;
+
+ dprintk("%s: pi: %p, inode: %p.\n", __func__, pi, &pi->vfs_inode);
+
+ atomic_inc(&inodes_allocated);
+
+ return &pi->vfs_inode;
+}
+
+/*
+ * We want fsync() to work on POHMELFS.
+ */
+static int pohmelfs_fsync(struct file *file, struct dentry *dentry, int datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 0, /* sys_fsync did this */
+ };
+
+ return sync_inode(inode, &wbc);
+}
+
+const static struct file_operations pohmelfs_file_ops = {
+ .open = generic_file_open,
+ .fsync = pohmelfs_fsync,
+
+ .llseek = generic_file_llseek,
+
+ .read = do_sync_read,
+ .aio_read = generic_file_aio_read,
+
+ .mmap = generic_file_mmap,
+
+ .splice_read = generic_file_splice_read,
+ .splice_write = generic_file_splice_write,
+
+ .write = do_sync_write,
+ .aio_write = generic_file_aio_write,
+};
+
+const struct inode_operations pohmelfs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+};
+
+int pohmelfs_setattr_raw(struct inode *inode, struct iattr *attr)
+{
+ int err;
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ goto err_out_exit;
+
+ if ((attr->ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
+ (attr->ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
+ err = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
+ if (err)
+ goto err_out_exit;
+ }
+
+ err = inode_setattr(inode, attr);
+ if (err)
+ goto err_out_exit;
+
+ if (attr->ia_valid & ATTR_MODE) {
+ mutex_lock(&psb->path_lock);
+ pohmelfs_change_path_entry(psb, pi->ino, inode->i_mode);
+ mutex_unlock(&psb->path_lock);
+ }
+
+ dprintk("%s: ino: %llu, mode: %o -> %o, uid: %u -> %u, gid: %u -> %u, size: %llu -> %llu.\n",
+ __func__, pi->ino, inode->i_mode, attr->ia_mode,
+ inode->i_uid, attr->ia_uid, inode->i_gid, attr->ia_gid, inode->i_size, attr->ia_size);
+
+ return 0;
+
+err_out_exit:
+ return err;
+}
+
+int pohmelfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+ int err;
+
+ err = security_inode_setattr(dentry, attr);
+ if (err)
+ goto err_out_exit;
+
+ err = pohmelfs_setattr_raw(inode, attr);
+ if (err)
+ goto err_out_exit;
+
+ if (!test_bit(NETFS_INODE_CREATED, &pi->state))
+ return 0;
+
+ err = pohmelfs_meta_command(pi, NETFS_INODE_INFO, 0, NULL, NULL, 0);
+ if (err)
+ return err;
+
+ return 0;
+
+err_out_exit:
+ return err;
+}
+
+const struct inode_operations pohmelfs_file_inode_operations = {
+ .setattr = pohmelfs_setattr,
+};
+
+/*
+ * Fill inode data: mode, size, operation callbacks and so on...
+ */
+void pohmelfs_fill_inode(struct inode *inode, struct netfs_inode_info *info)
+{
+ inode->i_mode = info->mode;
+ inode->i_nlink = info->nlink;
+ inode->i_uid = info->uid;
+ inode->i_gid = info->gid;
+ inode->i_blocks = info->blocks;
+ inode->i_rdev = info->rdev;
+ inode->i_size = info->size;
+ inode->i_version = info->version;
+ inode->i_blkbits = ffs(info->blocksize);
+
+ dprintk("%s: inode: %p, num: %lu/%llu inode is regular: %d, dir: %d, link: %d, mode: %o, size: %llu.\n",
+ __func__, inode, inode->i_ino, info->ino,
+ S_ISREG(inode->i_mode), S_ISDIR(inode->i_mode),
+ S_ISLNK(inode->i_mode), inode->i_mode, inode->i_size);
+
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+
+ /*
+ * i_mapping is a pointer to i_data during inode initialization.
+ */
+ inode->i_data.a_ops = &pohmelfs_aops;
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_fop = &pohmelfs_file_ops;
+ inode->i_op = &pohmelfs_file_inode_operations;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_fop = &pohmelfs_dir_fops;
+ inode->i_op = &pohmelfs_dir_inode_ops;
+ } else if (S_ISLNK(inode->i_mode)) {
+ inode->i_op = &pohmelfs_symlink_inode_operations;
+ inode->i_fop = &pohmelfs_file_ops;
+ } else {
+ inode->i_fop = &generic_ro_fops;
+ }
+}
+
+static void pohmelfs_drop_inode(struct inode *inode)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ struct pohmelfs_inode *pi = POHMELFS_I(inode);
+
+ spin_lock(&psb->ino_lock);
+ list_del_init(&pi->inode_entry);
+ spin_unlock(&psb->ino_lock);
+
+ generic_drop_inode(inode);
+}
+
+static struct pohmelfs_inode *pohmelfs_get_inode_from_list(struct pohmelfs_sb *psb,
+ struct list_head *head, unsigned int *count)
+{
+ struct pohmelfs_inode *pi = NULL;
+
+ spin_lock(&psb->ino_lock);
+ if (!list_empty(head)) {
+ pi = list_entry(head->next, struct pohmelfs_inode,
+ inode_entry);
+ list_del_init(&pi->inode_entry);
+ *count = pi->drop_count;
+ pi->drop_count = 0;
+ }
+ spin_unlock(&psb->ino_lock);
+
+ return pi;
+}
+
+/*
+ * ->put_super() callback. Invoked before superblock is destroyed,
+ * so it has to clean all private data.
+ */
+static void pohmelfs_put_super(struct super_block *sb)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(sb);
+ struct rb_node *rb_node;
+ struct pohmelfs_path_entry *e;
+ struct pohmelfs_inode *pi;
+ unsigned int count;
+ unsigned int in_drop_list = 0;
+ struct inode *inode, *tmp;
+
+ dprintk("\n%s.\n", __func__);
+
+ psb->trans_scan_timeout = psb->drop_scan_timeout = 0;
+ cancel_rearming_delayed_work(&psb->dwork);
+ cancel_rearming_delayed_work(&psb->drop_dwork);
+ flush_scheduled_work();
+
+ dprintk("\n%s: stopped workqueues.\n", __func__);
+
+ pohmelfs_state_exit(psb);
+
+ while ((pi = pohmelfs_get_inode_from_list(psb, &psb->drop_list, &count))) {
+ inode = &pi->vfs_inode;
+
+ dprintk("%s: ino: %llu, pi: %p, inode: %p, count: %u.\n",
+ __func__, pi->ino, pi, inode, count);
+
+ if (atomic_read(&inode->i_count) != count) {
+ printk("%s: ino: %llu, pi: %p, inode: %p, count: %u, i_count: %d.\n",
+ __func__, pi->ino, pi, inode, count,
+ atomic_read(&inode->i_count));
+ count = atomic_read(&inode->i_count);
+ in_drop_list++;
+ }
+
+ while (count--)
+ iput(&pi->vfs_inode);
+ }
+
+ list_for_each_entry_safe(inode, tmp, &sb->s_inodes, i_sb_list) {
+ pi = POHMELFS_I(inode);
+
+ dprintk("%s: ino: %llu, pi: %p, inode: %p, i_count: %u.\n",
+ __func__, pi->ino, pi, inode, atomic_read(&inode->i_count));
+
+ /*
+ * These are special inodes, they were created during
+ * directory reading or lookup, and were not bound to dentry,
+ * so they live here with reference counter being 1 and prevent
+ * umount from succeed since it believes that they are busy.
+ */
+ if (atomic_read(&inode->i_count)) {
+ list_del_init(&inode->i_sb_list);
+ iput(inode);
+ }
+ }
+
+ for (rb_node = rb_first(&psb->path_root); rb_node; ) {
+ e = rb_entry(rb_node, struct pohmelfs_path_entry, path_entry);
+ rb_node = rb_next(rb_node);
+
+ pohmelfs_remove_path_entry(psb, e);
+ }
+
+ printk("%s: inodes allocated: %d, destroyed: %d.\n", __func__,
+ atomic_read(&inodes_allocated), atomic_read(&inodes_destroyed));
+
+ kfree(psb);
+ sb->s_fs_info = NULL;
+}
+
+static int pohmelfs_remount(struct super_block *sb, int *flags, char *data)
+{
+ *flags |= MS_RDONLY;
+ return 0;
+}
+
+static int pohmelfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct super_block *sb = dentry->d_sb;
+ struct pohmelfs_sb *psb = POHMELFS_SB(sb);
+
+ /*
+ * There are no filesystem size limits yet.
+ */
+ memset(buf, 0, sizeof(struct kstatfs));
+
+ buf->f_type = POHMELFS_MAGIC_NUM; /* 'POH.' */
+ buf->f_bsize = sb->s_blocksize;
+ buf->f_files = psb->ino;
+ buf->f_namelen = 255;
+
+ return 0;
+}
+
+static int pohmelfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(vfs->mnt_sb);
+
+ seq_printf(seq, ",idx=%u", psb->idx);
+ seq_printf(seq, ",trans_scan_timeout=%u", jiffies_to_msecs(psb->trans_scan_timeout));
+ seq_printf(seq, ",drop_scan_timeout=%u", jiffies_to_msecs(psb->drop_scan_timeout));
+ seq_printf(seq, ",wait_on_page_timeout=%u", jiffies_to_msecs(psb->wait_on_page_timeout));
+ seq_printf(seq, ",trans_retries=%u", psb->trans_retries);
+
+ return 0;
+}
+
+static const struct super_operations pohmelfs_sb_ops = {
+ .alloc_inode = pohmelfs_alloc_inode,
+ .destroy_inode = pohmelfs_destroy_inode,
+ .drop_inode = pohmelfs_drop_inode,
+ .write_inode = pohmelfs_write_inode,
+ .put_super = pohmelfs_put_super,
+ .remount_fs = pohmelfs_remount,
+ .statfs = pohmelfs_statfs,
+ .show_options = pohmelfs_show_options,
+};
+
+enum {
+ pohmelfs_opt_idx,
+ pohmelfs_opt_trans_scan_timeout,
+ pohmelfs_opt_drop_scan_timeout,
+ pohmelfs_opt_wait_on_page_timeout,
+ pohmelfs_opt_trans_retries,
+};
+
+static struct match_token pohmelfs_tokens[] = {
+ {pohmelfs_opt_idx, "idx=%u"},
+ {pohmelfs_opt_trans_scan_timeout, "trans_scan_timeout=%u"},
+ {pohmelfs_opt_drop_scan_timeout, "drop_scan_timeout=%u"},
+ {pohmelfs_opt_wait_on_page_timeout, "wait_on_page_timeout=%u"},
+ {pohmelfs_opt_trans_retries, "trans_retries=%u"},
+};
+
+static int pohmelfs_parse_options(char *options, struct pohmelfs_sb *psb)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option, err;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, pohmelfs_tokens, args);
+ switch (token) {
+ case pohmelfs_opt_idx:
+ err = match_int(&args[0], &option);
+ if (err)
+ return err;
+ psb->idx = option;
+ break;
+ case pohmelfs_opt_trans_scan_timeout:
+ err = match_int(&args[0], &option);
+ if (err)
+ return err;
+ psb->trans_scan_timeout = msecs_to_jiffies(option);
+ break;
+ case pohmelfs_opt_drop_scan_timeout:
+ err = match_int(&args[0], &option);
+ if (err)
+ return err;
+ psb->drop_scan_timeout = msecs_to_jiffies(option);
+ break;
+ case pohmelfs_opt_wait_on_page_timeout:
+ err = match_int(&args[0], &option);
+ if (err)
+ return err;
+ psb->wait_on_page_timeout = msecs_to_jiffies(option);
+ break;
+ case pohmelfs_opt_trans_retries:
+ err = match_int(&args[0], &option);
+ if (err)
+ return err;
+ psb->trans_retries = option;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static void pohmelfs_drop_scan(struct work_struct *work)
+{
+ struct pohmelfs_sb *psb =
+ container_of(work, struct pohmelfs_sb, drop_dwork.work);
+ struct pohmelfs_inode *pi;
+ unsigned int count = 0;
+
+ while ((pi = pohmelfs_get_inode_from_list(psb, &psb->drop_list, &count))) {
+ dprintk("%s: ino: %llu, pi: %p, inode: %p, count: %u.\n",
+ __func__, pi->ino, pi, &pi->vfs_inode, count);
+ while (count--)
+ iput(&pi->vfs_inode);
+ }
+#if 0
+ dprintk("%s: page: %d, pages: %d.\n", __func__,
+ atomic_read(&pohmelfs_readpage_counter),
+ atomic_read(&pohmelfs_readpages_counter));
+#endif
+ pohmelfs_check_states(psb);
+
+ if (psb->drop_scan_timeout)
+ schedule_delayed_work(&psb->drop_dwork, psb->drop_scan_timeout);
+}
+
+/*
+ * Run through all transactions starting from the oldest,
+ * drop transaction from current state and try to send it
+ * to all remote nodes, which are currently installed.
+ */
+static void pohmelfs_trans_scan_state(struct netfs_state *st)
+{
+ struct rb_node *rb_node;
+ struct netfs_trans_dst *dst;
+ struct pohmelfs_sb *psb = st->psb;
+ unsigned int timeout = psb->trans_scan_timeout;
+ struct netfs_trans *t;
+ int err;
+
+ mutex_lock(&st->trans_lock);
+ for (rb_node = rb_first(&st->trans_root); rb_node; ) {
+ dst = rb_entry(rb_node, struct netfs_trans_dst, state_entry);
+ t = dst->trans;
+
+ if (timeout && time_after(dst->send_time + timeout, jiffies)
+ && dst->retries == 0)
+ break;
+
+ netfs_trans_get(t);
+
+ rb_node = rb_next(rb_node);
+
+ err = -ETIMEDOUT;
+ if (timeout && (++dst->retries < psb->trans_retries)) {
+ err = netfs_trans_resend(t, psb);
+ }
+
+ if (err || (t->flags & NETFS_TRANS_SINGLE_DST)) {
+ netfs_trans_remove_nolock(dst, st);
+ netfs_trans_drop_dst_nostate(dst);
+ }
+
+ t->result = err;
+ netfs_trans_put(t);
+ }
+ mutex_unlock(&st->trans_lock);
+}
+
+/*
+ * Walk through all installed network states and resend all
+ * transactions, which are old enough.
+ */
+static void pohmelfs_trans_scan(struct work_struct *work)
+{
+ struct pohmelfs_sb *psb =
+ container_of(work, struct pohmelfs_sb, dwork.work);
+ struct netfs_state *st;
+ struct pohmelfs_config *c;
+
+ mutex_lock(&psb->state_lock);
+ list_for_each_entry(c, &psb->state_list, config_entry) {
+ st = &c->state;
+
+ pohmelfs_trans_scan_state(st);
+ }
+ mutex_unlock(&psb->state_lock);
+
+ /*
+ * If no timeout specified then system is in the middle of umount process,
+ * so no need to reschedule scanning process again.
+ */
+ if (psb->trans_scan_timeout)
+ schedule_delayed_work(&psb->dwork, psb->trans_scan_timeout);
+}
+
+int pohmelfs_meta_command_data(struct pohmelfs_inode *pi, unsigned int cmd_op, char *addon,
+ unsigned int flags, netfs_trans_complete_t complete, void *priv, u64 start)
+{
+ struct inode *inode = &pi->vfs_inode;
+ struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
+ int err, sz, diff;
+ struct netfs_trans *t;
+ unsigned int path_len, addon_len = 0;
+ void *data;
+ struct netfs_inode_info *info;
+ struct netfs_cmd *cmd;
+
+ dprintk("%s: ino: %llu, cmd: %u, addon: %p.\n", __func__, pi->ino, cmd_op, addon);
+
+ mutex_lock(&psb->path_lock);
+ sz = path_len = pohmelfs_path_length(pi);
+ mutex_unlock(&psb->path_lock);
+
+ if (path_len < 0) {
+ err = path_len;
+ goto err_out_exit;
+ }
+
+ if (addon)
+ addon_len = strlen(addon) + 1; /* 0-byte */
+ sz += addon_len;
+
+ if (cmd_op == NETFS_INODE_INFO)
+ sz += sizeof(struct netfs_inode_info);
+
+ t = netfs_trans_alloc(sz + sizeof(struct netfs_cmd), flags, 0);
+ if (!t) {
+ err = -ENOMEM;
+ goto err_out_exit;
+ }
+ t->complete = complete;
+ t->private = priv;
+
+ cmd = netfs_trans_add(t, sizeof(struct netfs_cmd) + sz);
+ if (IS_ERR(cmd)) {
+ err = PTR_ERR(cmd);
+ goto err_out_free;
+ }
+
+ data = (void *)(cmd + 1);
+
+ if (cmd_op == NETFS_INODE_INFO) {
+ info = (struct netfs_inode_info *)(cmd + 1);
+ data = (void *)(info + 1);
+
+ /*
+ * We are under i_mutex, can read and change whatever we want...
+ */
+ info->mode = inode->i_mode;
+ info->nlink = inode->i_nlink;
+ info->uid = inode->i_uid;
+ info->gid = inode->i_gid;
+ info->blocks = inode->i_blocks;
+ info->rdev = inode->i_rdev;
+ info->size = inode->i_size;
+ info->version = inode->i_version;
+
+ netfs_convert_inode_info(info);
+ }
+
+ mutex_lock(&psb->path_lock);
+ err = pohmelfs_construct_path_string(pi, data, path_len);
+ mutex_unlock(&psb->path_lock);
+ if (err < 0)
+ goto err_out_free;
+
+ dprintk("%s: err: %d, path_len: %d.\n", __func__, err, path_len);
+
+ diff = err + 1 - path_len;
+ sz += diff;
+ path_len += diff;
+
+ netfs_trans_fixup_last(t, diff);
+
+ if (addon)
+ path_len += sprintf(data + err, "/%s", addon) + 1 /* 0 - byte */;
+
+ cmd->cmd = cmd_op;
+ cmd->ext = path_len;
+ cmd->size = sz;
+ cmd->id = pi->ino;
+ cmd->start = start;
+
+ netfs_convert_cmd(cmd);
+
+ /*
+ * Note, that it is possible to leak error here: transaction callback will not
+ * be invoked for allocation path failure.
+ */
+ return netfs_trans_finish(t, psb);
+
+err_out_free:
+ netfs_trans_free(t);
+err_out_exit:
+ if (complete)
+ complete(NULL, 0, priv, err);
+ return err;
+}
+
+int pohmelfs_meta_command(struct pohmelfs_inode *pi, unsigned int cmd_op, unsigned int flags,
+ netfs_trans_complete_t complete, void *priv, u64 start)
+{
+ return pohmelfs_meta_command_data(pi, cmd_op, NULL, flags, complete, priv, start);
+}
+
+/*
+ * Allocate private superblock and create root dir.
+ */
+static int pohmelfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct pohmelfs_sb *psb;
+ int err = -ENOMEM;
+ struct inode *root;
+ struct pohmelfs_inode *npi;
+ struct qstr str;
+
+ psb = kzalloc(sizeof(struct pohmelfs_sb), GFP_NOIO);
+ if (!psb)
+ goto err_out_exit;
+
+ sb->s_fs_info = psb;
+ sb->s_op = &pohmelfs_sb_ops;
+ sb->s_magic = POHMELFS_MAGIC_NUM;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+
+ psb->sb = sb;
+ psb->path_root = RB_ROOT;
+
+ psb->ino = 2;
+ psb->idx = 0;
+ psb->active_state = NULL;
+ psb->trans_retries = 5;
+ psb->trans_data_size = PAGE_SIZE;
+ psb->drop_scan_timeout = msecs_to_jiffies(1000);
+ psb->trans_scan_timeout = msecs_to_jiffies(5000);
+ psb->wait_on_page_timeout = msecs_to_jiffies(5000);
+ init_waitqueue_head(&psb->wait);
+
+ spin_lock_init(&psb->ino_lock);
+
+ mutex_init(&psb->path_lock);
+ INIT_LIST_HEAD(&psb->drop_list);
+
+ atomic_set(&psb->trans_gen, 1);
+
+ mutex_init(&psb->state_lock);
+ INIT_LIST_HEAD(&psb->state_list);
+
+ err = pohmelfs_parse_options((char *) data, psb);
+ if (err)
+ goto err_out_free_sb;
+
+ err = pohmelfs_state_init(psb);
+ if (err)
+ goto err_out_free_sb;
+
+ str.name = "/";
+ str.hash = jhash("/", 1, 0);
+ str.len = 1;
+
+ npi = pohmelfs_create_entry_local(psb, NULL, &str, 0, 0755|S_IFDIR);
+ if (IS_ERR(npi)) {
+ err = PTR_ERR(npi);
+ goto err_out_state_exit;
+ }
+ set_bit(NETFS_INODE_CREATED, &npi->state);
+ clear_bit(NETFS_INODE_REMOTE_SYNCED, &npi->state);
+
+ root = &npi->vfs_inode;
+
+ sb->s_root = d_alloc_root(root);
+ if (!sb->s_root)
+ goto err_out_put_root;
+
+ INIT_DELAYED_WORK(&psb->drop_dwork, pohmelfs_drop_scan);
+ schedule_delayed_work(&psb->drop_dwork, psb->drop_scan_timeout);
+
+ INIT_DELAYED_WORK(&psb->dwork, pohmelfs_trans_scan);
+ schedule_delayed_work(&psb->dwork, psb->trans_scan_timeout);
+
+ return 0;
+
+err_out_put_root:
+ iput(root);
+err_out_state_exit:
+ pohmelfs_state_exit(psb);
+err_out_free_sb:
+ kfree(psb);
+err_out_exit:
+ return err;
+}
+
+/*
+ * Some VFS magic here...
+ */
+static int pohmelfs_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+{
+ return get_sb_nodev(fs_type, flags, data, pohmelfs_fill_super,
+ mnt);
+}
+
+static struct file_system_type pohmel_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "pohmel",
+ .get_sb = pohmelfs_get_sb,
+ .kill_sb = kill_anon_super,
+};
+
+/*
+ * Cache and module initializations and freeing routings.
+ */
+static void pohmelfs_init_once(struct kmem_cache *cachep, void *data)
+{
+ struct pohmelfs_inode *inode = data;
+
+ inode_init_once(&inode->vfs_inode);
+}
+
+static int pohmelfs_init_inodecache(void)
+{
+ pohmelfs_inode_cache = kmem_cache_create("pohmelfs_inode_cache",
+ sizeof(struct pohmelfs_inode),
+ 0, (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
+ pohmelfs_init_once);
+ if (!pohmelfs_inode_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void pohmelfs_destroy_inodecache(void)
+{
+ kmem_cache_destroy(pohmelfs_inode_cache);
+}
+
+static int __init init_pohmel_fs(void)
+{
+ int err;
+
+ err = pohmelfs_config_init();
+ if (err)
+ goto err_out_exit;
+
+ err = pohmelfs_init_inodecache();
+ if (err)
+ goto err_out_config_exit;
+
+ err = netfs_trans_init();
+ if (err)
+ goto err_out_destroy;
+
+ err = register_filesystem(&pohmel_fs_type);
+ if (err)
+ goto err_out_trans;
+
+ return 0;
+
+err_out_trans:
+ netfs_trans_exit();
+err_out_destroy:
+ pohmelfs_destroy_inodecache();
+err_out_config_exit:
+ pohmelfs_config_exit();
+err_out_exit:
+ return err;
+}
+
+static void __exit exit_pohmel_fs(void)
+{
+ unregister_filesystem(&pohmel_fs_type);
+ pohmelfs_destroy_inodecache();
+ pohmelfs_config_exit();
+ netfs_trans_exit();
+}
+
+module_init(init_pohmel_fs);
+module_exit(exit_pohmel_fs);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Evgeniy Polyakov <johnpol@....mipt.ru>");
+MODULE_DESCRIPTION("Pohmel filesystem");
diff --git a/fs/pohmelfs/net.c b/fs/pohmelfs/net.c
new file mode 100644
index 0000000..46a0518
--- /dev/null
+++ b/fs/pohmelfs/net.c
@@ -0,0 +1,1006 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/fsnotify.h>
+#include <linux/jhash.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/kthread.h>
+#include <linux/pagemap.h>
+#include <linux/poll.h>
+#include <linux/swap.h>
+#include <linux/syscalls.h>
+
+#include "netfs.h"
+
+/*
+ * Async machinery lives here.
+ * All commands being sent to server do _not_ require sync reply,
+ * instead, if it is really needed, like readdir or readpage, caller
+ * sleeps waiting for data, which will be placed into provided buffer
+ * and caller will be awakened.
+ *
+ * Every command response can come without some listener. For example
+ * readdir response will add new objects into cache without appropriate
+ * request from userspace. This is used in cache coherency.
+ *
+ * If object is not found for given data, it is discarded.
+ *
+ * All requests are received by dedicated kernel thread.
+ */
+
+/*
+ * Basic network sending/receiving functions.
+ * Blocked mode is used.
+ */
+static int netfs_data_recv(struct netfs_state *st, void *buf, u64 size)
+{
+ struct msghdr msg;
+ struct kvec iov;
+ int err;
+
+ BUG_ON(!size);
+
+ iov.iov_base = buf;
+ iov.iov_len = size;
+
+ msg.msg_iov = (struct iovec *)&iov;
+ msg.msg_iovlen = 1;
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = MSG_DONTWAIT;
+
+ err = kernel_recvmsg(st->socket, &msg, &iov, 1, iov.iov_len,
+ msg.msg_flags);
+ if (err <= 0) {
+ printk("%s: failed to recv data: size: %llu, err: %d.\n", __func__, size, err);
+ if (err == 0)
+ err = -ECONNRESET;
+
+ netfs_state_exit(st);
+ }
+
+ return err;
+}
+
+int netfs_data_send(struct netfs_state *st, void *buf, u64 size, int more)
+{
+ struct msghdr msg;
+ struct kvec iov;
+ int err, error = 0;
+
+ BUG_ON(!size);
+
+ if (!st->socket) {
+ err = netfs_state_init(st);
+ if (err)
+ return err;
+ }
+
+ iov.iov_base = buf;
+ iov.iov_len = size;
+
+ msg.msg_iov = (struct iovec *)&iov;
+ 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 (more)
+ msg.msg_flags |= MSG_MORE;
+
+ err = kernel_sendmsg(st->socket, &msg, &iov, 1, iov.iov_len);
+ if (err != size) {
+ error = err;
+ printk("%s: failed to send data: size: %llu, err: %d.\n", __func__, size, err);
+ if (err == 0)
+ error = -ECONNRESET;
+ if (err > 0)
+ error = -ETIMEDOUT;
+
+ netfs_state_exit(st);
+ }
+
+ return error;
+}
+
+static int pohmelfs_data_recv(struct netfs_state *st, void *data, unsigned int size)
+{
+ unsigned int revents = 0;
+ unsigned int err_mask = POLLERR | POLLHUP | POLLRDHUP;
+ unsigned int mask = err_mask | POLLIN;
+ int err = 0;
+
+ while (size && !err) {
+ revents = netfs_state_poll(st);
+
+ if (!(revents & mask)) {
+ DEFINE_WAIT(wait);
+
+ for (;;) {
+ prepare_to_wait(&st->thread_wait, &wait, TASK_INTERRUPTIBLE);
+ if (kthread_should_stop())
+ break;
+
+ revents = netfs_state_poll(st);
+
+ if (revents & mask)
+ break;
+
+ if (signal_pending(current))
+ break;
+
+ schedule();
+ continue;
+ }
+ finish_wait(&st->thread_wait, &wait);
+ }
+
+ err = -ECONNRESET;
+ netfs_state_lock(st);
+
+ if (st->socket && (st->read_socket == st->socket) && (revents & POLLIN)) {
+ err = netfs_data_recv(st, data, size);
+ if (err > 0) {
+ data += err;
+ size -= err;
+ err = 0;
+ }
+ }
+
+ if (revents & err_mask) {
+ printk("%s: revents: %x, socket: %p, size: %u, err: %d.\n",
+ __func__, revents, st->socket, size, err);
+ netfs_state_exit(st);
+ err = -ECONNRESET;
+ }
+
+ if (!st->socket) {
+ err = netfs_state_init(st);
+ if (!err)
+ err = -EAGAIN;
+ }
+
+ netfs_state_unlock(st);
+
+ if (kthread_should_stop())
+ err = -ENODEV;
+
+ if (err)
+ printk("%s: socket: %p, read_socket: %p, revents: %x, rev_error: %d, "
+ "should_stop: %d, size: %u, err: %d.\n",
+ __func__, st->socket, st->read_socket,
+ revents, revents & err_mask, kthread_should_stop(), size, err);
+ }
+
+ return err;
+}
+
+/*
+ * Polling machinery.
+ */
+
+struct netfs_poll_helper
+{
+ poll_table pt;
+ struct netfs_state *st;
+};
+
+static int netfs_queue_wake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct netfs_state *st = container_of(wait, struct netfs_state, wait);
+
+ wake_up(&st->thread_wait);
+ return 1;
+}
+
+static void netfs_queue_func(struct file *file, wait_queue_head_t *whead,
+ poll_table *pt)
+{
+ struct netfs_state *st = container_of(pt, struct netfs_poll_helper, pt)->st;
+
+ st->whead = whead;
+ init_waitqueue_func_entry(&st->wait, netfs_queue_wake);
+ add_wait_queue(whead, &st->wait);
+}
+
+static void netfs_poll_exit(struct netfs_state *st)
+{
+ if (st->whead) {
+ remove_wait_queue(st->whead, &st->wait);
+ st->whead = NULL;
+ }
+}
+
+static int netfs_poll_init(struct netfs_state *st)
+{
+ struct netfs_poll_helper ph;
+
+ ph.st = st;
+ init_poll_funcptr(&ph.pt, &netfs_queue_func);
+
+ st->socket->ops->poll(NULL, st->socket, &ph.pt);
+ return 0;
+}
+
+/*
+ * Get response for readpage command. We search inode and page in its mapping
+ * and copy data into. If it was async request, then we queue page into shared
+ * data and wakeup listener, who will copy it to userspace.
+ *
+ * There is a work in progress of allowing to call copy_to_user() directly from
+ * async receiving kernel thread.
+ */
+static int pohmelfs_read_page_response(struct netfs_state *st)
+{
+ struct inode *inode;
+ struct page *page;
+ void *addr;
+ struct netfs_cmd *cmd = &st->cmd;
+ int err = 0;
+
+ if (cmd->size > PAGE_CACHE_SIZE) {
+ err = -EINVAL;
+ goto err_out_exit;
+ }
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode) {
+ printk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
+ err = -ENOENT;
+ goto err_out_exit;
+ }
+
+ page = find_get_page(inode->i_mapping, cmd->start >> PAGE_CACHE_SHIFT);
+ if (!page) {
+ printk("%s: failed to find page: id: %llu, start: %llu, index: %llu.\n",
+ __func__, cmd->id, cmd->start, cmd->start >> PAGE_CACHE_SHIFT);
+ }
+
+ if (cmd->size) {
+ if (page && PageLocked(page)) {
+ addr = kmap(page);
+ err = pohmelfs_data_recv(st, addr, cmd->size);
+ kunmap(page);
+
+ if (err < 0)
+ SetPageError(page);
+ } else {
+ while (cmd->size) {
+ unsigned int sz = min(cmd->size, st->size);
+
+ err = pohmelfs_data_recv(st, st->data, sz);
+ if (err)
+ break;
+
+ cmd->size -= sz;
+ }
+ err = -ENODEV;
+ if (page) {
+ SetPageError(page);
+ page_cache_release(page);
+ }
+ goto err_out_put;
+ }
+ }
+
+ dprintk("%s: page: %p, start: %llu, size: %u, err: %d, locked: %d.\n",
+ __func__, page, cmd->start, cmd->size, err, PageLocked(page));
+
+ if (!err)
+ SetPageUptodate(page);
+
+ page_cache_release(page);
+
+ if (err)
+ goto err_out_put;
+
+ pohmelfs_put_inode(POHMELFS_I(inode));
+ wake_up(&st->psb->wait);
+
+ return 0;
+
+err_out_put:
+ pohmelfs_put_inode(POHMELFS_I(inode));
+err_out_exit:
+ wake_up(&st->psb->wait);
+ return err;
+}
+
+/*
+ * Readdir response from server. If special field is set, we wakeup
+ * listener (readdir() call), which will copy data to userspace.
+ */
+static int pohmelfs_readdir_response(struct netfs_state *st)
+{
+ struct inode *inode;
+ struct netfs_cmd *cmd = &st->cmd;
+ struct netfs_inode_info *info;
+ struct pohmelfs_inode *parent = NULL, *npi;
+ int err = 0, last = cmd->ext;
+ struct qstr str;
+
+ if (cmd->size > st->size)
+ return -EINVAL;
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode)
+ return -ENOENT;
+ parent = POHMELFS_I(inode);
+
+ if (!cmd->size && cmd->start) {
+ err = -cmd->start;
+ goto out;
+ }
+
+ if (cmd->size) {
+ err = pohmelfs_data_recv(st, st->data, cmd->size);
+ if (err)
+ goto err_out_put;
+
+ info = (struct netfs_inode_info *)(st->data);
+
+ str.name = (char *)(info + 1);
+ str.len = cmd->size - sizeof(struct netfs_inode_info) - 1;
+ str.hash = jhash(str.name, str.len, 0);
+
+ netfs_convert_inode_info(info);
+
+ info->ino = cmd->start;
+ if (!info->ino)
+ info->ino = pohmelfs_new_ino(st->psb);
+
+ dprintk("%s: parent: %llu, ino: %llu, name: '%s', hash: %x, len: %u, mode: %o.\n",
+ __func__, parent->ino, info->ino, str.name, str.hash, str.len,
+ info->mode);
+
+ npi = pohmelfs_new_inode(st->psb, parent, &str, info, 0);
+ if (IS_ERR(npi)) {
+ err = PTR_ERR(npi);
+
+ if (err != -EEXIST)
+ goto err_out_put;
+ } else {
+ set_bit(NETFS_INODE_CREATED, &npi->state);
+ }
+ }
+out:
+ if (last) {
+ set_bit(NETFS_INODE_REMOTE_SYNCED, &parent->state);
+ wake_up(&st->psb->wait);
+ }
+ pohmelfs_put_inode(parent);
+
+ return err;
+
+err_out_put:
+ clear_bit(NETFS_INODE_REMOTE_SYNCED, &parent->state);
+ printk("%s: parent: %llu, ino: %llu, cmd_id: %llu.\n", __func__, parent->ino, cmd->start, cmd->id);
+ pohmelfs_put_inode(parent);
+ wake_up(&st->psb->wait);
+ return err;
+}
+
+/*
+ * Lookup command response.
+ * It searches for inode to be looked at (if it exists) and substitutes
+ * its inode information (size, permission, mode and so on), if inode does
+ * not exist, new one will be created and inserted into caches.
+ */
+static int pohmelfs_lookup_response(struct netfs_state *st)
+{
+ struct inode *inode = NULL;
+ struct netfs_cmd *cmd = &st->cmd;
+ struct netfs_inode_info *info;
+ struct pohmelfs_inode *parent = NULL, *npi;
+ int err = -EINVAL;
+ char *name;
+
+ if (cmd->size > st->size)
+ goto err_out_exit;
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode) {
+ printk("%s: lookup response: id: %llu, start: %llu, size: %u.\n",
+ __func__, cmd->id, cmd->start, cmd->size);
+ err = -ENOENT;
+ goto err_out_exit;
+ }
+ parent = POHMELFS_I(inode);
+
+ if (!cmd->size) {
+ err = -cmd->start;
+ goto err_out_put;
+ }
+
+ if (cmd->size < sizeof(struct netfs_inode_info)) {
+ printk("%s: broken lookup response: id: %llu, start: %llu, size: %u.\n",
+ __func__, cmd->id, cmd->start, cmd->size);
+ err = -EINVAL;
+ goto err_out_put;
+ }
+
+ err = pohmelfs_data_recv(st, st->data, cmd->size);
+ if (err)
+ goto err_out_put;
+
+ info = (struct netfs_inode_info *)(st->data);
+ name = (char *)(info + 1);
+
+ netfs_convert_inode_info(info);
+
+ info->ino = cmd->start;
+ if (!info->ino)
+ info->ino = pohmelfs_new_ino(st->psb);
+
+ dprintk("%s: parent: %llu, ino: %llu, name: '%s', start: %llu.\n",
+ __func__, parent->ino, info->ino, name, cmd->start);
+
+ if (cmd->start)
+ npi = pohmelfs_new_inode(st->psb, parent, NULL, info, 0);
+ else {
+ struct qstr str;
+
+ str.name = name;
+ str.len = cmd->size - sizeof(struct netfs_inode_info) - 1;
+ str.hash = jhash(name, str.len, 0);
+
+ npi = pohmelfs_new_inode(st->psb, parent, &str, info, 0);
+ }
+ if (IS_ERR(npi)) {
+ err = PTR_ERR(npi);
+
+ if (err != -EEXIST)
+ goto err_out_put;
+ } else {
+ set_bit(NETFS_INODE_CREATED, &npi->state);
+ }
+
+ clear_bit(NETFS_COMMAND_PENDING, &parent->state);
+ pohmelfs_put_inode(parent);
+
+ wake_up(&st->psb->wait);
+
+ return 0;
+
+err_out_put:
+ pohmelfs_put_inode(parent);
+err_out_exit:
+ clear_bit(NETFS_COMMAND_PENDING, &parent->state);
+ wake_up(&st->psb->wait);
+ printk("%s: inode: %p, id: %llu, start: %llu, size: %u, err: %d.\n",
+ __func__, inode, cmd->id, cmd->start, cmd->size, err);
+ return err;
+}
+
+/*
+ * Create response, just marks local inode as 'created', so that writeback
+ * for any of its children (or own) would not try to sync it again.
+ */
+static int pohmelfs_create_response(struct netfs_state *st)
+{
+ struct inode *inode;
+ struct netfs_cmd *cmd = &st->cmd;
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode) {
+ printk("%s: failed to find inode: id: %llu, start: %llu.\n",
+ __func__, cmd->id, cmd->start);
+ goto err_out_exit;
+ }
+
+ /*
+ * To lock or not to lock?
+ * We actually do not care if it races...
+ */
+ if (cmd->start)
+ make_bad_inode(inode);
+
+ set_bit(NETFS_INODE_CREATED, &POHMELFS_I(inode)->state);
+
+ pohmelfs_put_inode(POHMELFS_I(inode));
+
+ wake_up(&st->psb->wait);
+ return 0;
+
+err_out_exit:
+ wake_up(&st->psb->wait);
+ return -ENOENT;
+}
+
+/*
+ * Object remove response. Just says that remove request has been received.
+ * Used in cache coherency protocol.
+ */
+static int pohmelfs_remove_response(struct netfs_state *st)
+{
+ struct netfs_cmd *cmd = &st->cmd;
+ int err;
+
+ if (cmd->size > st->size) {
+ printk("%s: wrong data size: %u.\n", __func__, cmd->size);
+ return -EINVAL;
+ }
+
+ err = pohmelfs_data_recv(st, st->data, cmd->size);
+ if (err)
+ return err;
+
+ dprintk("%s: parent: %llu, path: '%s'.\n", __func__, cmd->id, (char *)st->data);
+
+ return 0;
+}
+
+/*
+ * Transaction reply processing.
+ *
+ * Find transaction based on its generation number, bump its reference counter,
+ * so that none could free it under us, drop from the trees and lists and
+ * drop reference counter. When it hits zero (when all destinations replied
+ * and all timeout handled by async scanning code), completion will be called
+ * and transaction will be freed.
+ */
+static int pohmelfs_transaction_response(struct netfs_state *st)
+{
+ struct netfs_trans_dst *dst;
+ struct netfs_trans *t = NULL;
+ struct netfs_cmd *cmd = &st->cmd;
+ int err = -cmd->ext;
+
+ mutex_lock(&st->trans_lock);
+ dst = netfs_trans_search(st, cmd->start);
+ if (dst) {
+ netfs_trans_remove_nolock(dst, st);
+ t = dst->trans;
+ }
+ mutex_unlock(&st->trans_lock);
+
+ if (!t) {
+ printk("%s: failed to find transaction: start: %llu: id: %llu, size: %u, ext: %u.\n",
+ __func__, cmd->start, cmd->id, cmd->size, cmd->ext);
+ err = -EINVAL;
+ goto out;
+ }
+
+ dprintk("%s: sync transaction reply: t: %p, refcnt: %d, gen: %u, flags: %x, err: %d.\n",
+ __func__, t, atomic_read(&t->refcnt), t->gen, t->flags, err);
+ t->result = err;
+ netfs_trans_drop_dst_nostate(dst);
+
+out:
+ wake_up(&st->psb->wait);
+ return err;
+}
+
+/*
+ * Inode metadata cache coherency message.
+ */
+static int pohmelfs_inode_info_response(struct netfs_state *st)
+{
+ struct netfs_cmd *cmd = &st->cmd;
+ struct netfs_inode_info *info;
+ struct inode *inode;
+ struct iattr iattr;
+ struct dentry *dentry;
+ int err = -EINVAL;
+
+ if (cmd->size != sizeof(struct netfs_inode_info))
+ goto err_out_exit;
+
+ err = pohmelfs_data_recv(st, st->data, cmd->size);
+ if (err)
+ return err;
+
+ info = st->data;
+
+ netfs_convert_inode_info(info);
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode) {
+ dprintk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
+ err = -ENOENT;
+ goto err_out_exit;
+ }
+
+ iattr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_SIZE | ATTR_ATIME;
+ iattr.ia_mode = info->mode;
+ iattr.ia_uid = info->uid;
+ iattr.ia_gid = info->gid;
+ iattr.ia_size = info->size;
+ iattr.ia_atime = CURRENT_TIME;
+
+ mutex_lock(&inode->i_mutex);
+
+ dprintk("%s: ino: %llu, mode: %o -> %o, uid: %u -> %u, gid: %u -> %u, size: %llu -> %llu.\n",
+ __func__, POHMELFS_I(inode)->ino, inode->i_mode, info->mode,
+ inode->i_uid, info->uid, inode->i_gid, info->gid, inode->i_size, info->size);
+
+ err = pohmelfs_setattr_raw(inode, &iattr);
+ if (err)
+ goto err_out_unlock;
+
+ dentry = d_find_alias(inode);
+ if (dentry) {
+ fsnotify_change(dentry, iattr.ia_valid);
+ dput(dentry);
+ }
+ mutex_unlock(&inode->i_mutex);
+
+ pohmelfs_put_inode(POHMELFS_I(inode));
+
+ return 0;
+
+err_out_unlock:
+ mutex_unlock(&inode->i_mutex);
+ pohmelfs_put_inode(POHMELFS_I(inode));
+err_out_exit:
+ return err;
+}
+
+/*
+ * Inode metadata cache coherency message.
+ */
+static int pohmelfs_page_cache_response(struct netfs_state *st)
+{
+ struct netfs_cmd *cmd = &st->cmd;
+ struct inode *inode;
+ int err = 0;
+ u64 isize = cmd->start;
+
+ inode = ilookup(st->psb->sb, cmd->id);
+ if (!inode) {
+ dprintk("%s: failed to find inode: id: %llu.\n", __func__, cmd->id);
+ err = -ENOENT;
+ goto err_out_exit;
+ }
+
+ if (i_size_read(inode) != cmd->start) {
+ mutex_lock(&inode->i_mutex);
+ if (inode->i_size != cmd->start) {
+ isize = inode->i_size;
+ err = vmtruncate(inode, cmd->start);
+ }
+ mutex_unlock(&inode->i_mutex);
+ }
+
+ dprintk("%s: ino: %llu, isize: %llu, new_size: %llu.\n",
+ __func__, POHMELFS_I(inode)->ino, isize, cmd->start);
+
+ if ((cmd->start >> PAGE_CACHE_SHIFT) <= (isize >> PAGE_CACHE_SHIFT)) {
+ struct page *page;
+
+ page = find_lock_page(inode->i_mapping, cmd->start >> PAGE_CACHE_SHIFT);
+ if (!page) {
+ dprintk("%s: failed to find page: id: %llu, start: %llu, index: %llu.\n",
+ __func__, cmd->id, cmd->start, cmd->start >> PAGE_CACHE_SHIFT);
+ err = -ENOENT;
+ goto err_out_put;
+ }
+
+ ClearPageUptodate(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
+ pohmelfs_put_inode(POHMELFS_I(inode));
+
+ return err;
+
+err_out_put:
+ pohmelfs_put_inode(POHMELFS_I(inode));
+err_out_exit:
+ return err;
+}
+
+/*
+ * Main receiving function, called from dedicated kernel thread.
+ */
+static int pohmelfs_recv(void *data)
+{
+ int err = -EINTR;
+ struct netfs_state *st = data;
+ struct netfs_cmd *cmd = &st->cmd;
+
+ while (!kthread_should_stop()) {
+ /*
+ * If socket will be reset after this statement, then
+ * pohmelfs_data_recv() will just fail and loop will
+ * start again, so it can be done without any locks.
+ *
+ * st->read_socket is needed to prevents state machine
+ * breaking between this data reading and subsequent one
+ * in protocol specific functions during connection reset.
+ * In case of reset we have to read next command and do
+ * not expect data for old command to magically appear in
+ * new connection.
+ */
+ st->read_socket = st->socket;
+ err = pohmelfs_data_recv(st, cmd, sizeof(struct netfs_cmd));
+ if (err) {
+ msleep(1000);
+ continue;
+ }
+
+ netfs_convert_cmd(cmd);
+
+ dprintk("%s: cmd: %u, id: %llu, start: %llu, size: %u, ext: %u.\n",
+ __func__, cmd->cmd, cmd->id, cmd->start, cmd->size, cmd->ext);
+
+ if (cmd->size > PAGE_SIZE) {
+ netfs_state_lock(st);
+ netfs_state_exit(st);
+ netfs_state_init(st);
+ netfs_state_unlock(st);
+ continue;
+ }
+
+ switch (cmd->cmd) {
+ case NETFS_READ_PAGE:
+ err = pohmelfs_read_page_response(st);
+ break;
+ case NETFS_READDIR:
+ err = pohmelfs_readdir_response(st);
+ break;
+ case NETFS_LOOKUP:
+ err = pohmelfs_lookup_response(st);
+ break;
+ case NETFS_CREATE:
+ err = pohmelfs_create_response(st);
+ break;
+ case NETFS_REMOVE:
+ err = pohmelfs_remove_response(st);
+ break;
+ case NETFS_TRANS:
+ err = pohmelfs_transaction_response(st);
+ break;
+ case NETFS_INODE_INFO:
+ err = pohmelfs_inode_info_response(st);
+ break;
+ case NETFS_PAGE_CACHE:
+ err = pohmelfs_page_cache_response(st);
+ break;
+ default:
+ printk("%s: wrong cmd: %u, id: %llu, start: %llu, size: %u, ext: %u.\n",
+ __func__, cmd->cmd, cmd->id, cmd->start, cmd->size, cmd->ext);
+ netfs_state_lock(st);
+ netfs_state_exit(st);
+ netfs_state_init(st);
+ netfs_state_unlock(st);
+ break;
+ }
+ }
+
+ while (!kthread_should_stop())
+ schedule_timeout_uninterruptible(msecs_to_jiffies(10));
+
+ return err;
+}
+
+int netfs_state_init(struct netfs_state *st)
+{
+ int err;
+ struct pohmelfs_ctl *ctl = &st->ctl;
+
+ err = sock_create(ctl->addr.sa_family, ctl->type, ctl->proto, &st->socket);
+ if (err)
+ goto err_out_exit;
+
+ st->socket->sk->sk_allocation = GFP_NOIO;
+ st->socket->sk->sk_sndtimeo = st->socket->sk->sk_rcvtimeo = msecs_to_jiffies(60000);
+
+ err = kernel_connect(st->socket, (struct sockaddr *)&ctl->addr, ctl->addrlen, 0);
+ if (err) {
+ printk("%s: failed to connect to server: idx: %u, err: %d.\n",
+ __func__, st->psb->idx, err);
+ goto err_out_release;
+ }
+ //st->socket->sk->sk_sndtimeo = st->socket->sk->sk_rcvtimeo = msecs_to_jiffies(5000);
+
+ err = netfs_poll_init(st);
+ if (err)
+ goto err_out_release;
+
+ if (st->socket->ops->family == AF_INET) {
+ struct sockaddr_in *sin = (struct sockaddr_in *)&ctl->addr;
+ printk(KERN_INFO "%s: (re)connected to peer %u.%u.%u.%u:%d.\n", __func__,
+ NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));
+ } else if (st->socket->ops->family == AF_INET6) {
+ struct sockaddr_in6 *sin = (struct sockaddr_in6 *)&ctl->addr;
+ printk(KERN_INFO "%s: (re)connected to peer "
+ "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%d",
+ __func__, NIP6(sin->sin6_addr), ntohs(sin->sin6_port));
+ }
+
+ dprintk("%s: st: %p, socket: %p, revents: %x.\n", __func__, st, st->socket, netfs_state_poll(st));
+
+ return 0;
+
+err_out_release:
+ sock_release(st->socket);
+err_out_exit:
+ st->socket = NULL;
+ return err;
+}
+
+void netfs_state_exit(struct netfs_state *st)
+{
+ if (st->socket) {
+ netfs_poll_exit(st);
+ st->socket->ops->shutdown(st->socket, 2);
+
+ if (st->socket->ops->family == AF_INET) {
+ struct sockaddr_in *sin = (struct sockaddr_in *)&st->ctl.addr;
+ printk(KERN_INFO "%s: disconnected from peer %u.%u.%u.%u:%d.\n", __func__,
+ NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));
+ } else if (st->socket->ops->family == AF_INET6) {
+ struct sockaddr_in6 *sin = (struct sockaddr_in6 *)&st->ctl.addr;
+ printk(KERN_INFO "%s: disconnected from peer "
+ "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%d",
+ __func__, NIP6(sin->sin6_addr), ntohs(sin->sin6_port));
+ }
+
+ sock_release(st->socket);
+ st->socket = NULL;
+ st->read_socket = NULL;
+ }
+}
+
+int pohmelfs_state_init_one(struct pohmelfs_sb *psb, struct pohmelfs_config *conf)
+{
+ struct netfs_state *st = &conf->state;
+ int err = -ENOMEM;
+
+ mutex_init(&st->__state_lock);
+ init_waitqueue_head(&st->thread_wait);
+
+ st->psb = psb;
+ st->trans_root = RB_ROOT;
+ mutex_init(&st->trans_lock);
+
+ st->size = psb->trans_data_size;
+ st->data = kmalloc(st->size, GFP_KERNEL);
+ if (!st->data)
+ goto err_out_exit;
+
+ err = netfs_state_init(st);
+ if (err)
+ goto err_out_free_data;
+
+ st->thread = kthread_run(pohmelfs_recv, st, "pohmelfs/%u", psb->idx);
+ if (IS_ERR(st->thread)) {
+ err = PTR_ERR(st->thread);
+ goto err_out_netfs_exit;
+ }
+
+ if (!psb->active_state)
+ psb->active_state = conf;
+
+ dprintk("%s: conf: %p, st: %p, socket: %p.\n",
+ __func__, conf, st, st->socket);
+ return 0;
+
+err_out_netfs_exit:
+ netfs_state_exit(st);
+err_out_free_data:
+ kfree(st->data);
+err_out_exit:
+ return err;
+
+}
+
+static void pohmelfs_state_exit_one(struct pohmelfs_config *c)
+{
+ struct netfs_state *st = &c->state;
+ struct rb_node *rb_node;
+ struct netfs_trans_dst *dst;
+
+ dprintk("%s: exiting, st: %p.\n", __func__, st);
+ if (st->thread) {
+ kthread_stop(st->thread);
+ st->thread = NULL;
+ }
+
+ netfs_state_lock(st);
+ netfs_state_exit(st);
+ netfs_state_unlock(st);
+
+ for (rb_node = rb_first(&st->trans_root); rb_node; ) {
+ dst = rb_entry(rb_node, struct netfs_trans_dst, state_entry);
+ rb_node = rb_next(rb_node);
+
+ dst->trans->result = -EINVAL;
+ netfs_trans_remove_nolock(dst, st);
+ netfs_trans_finish_send(dst->trans, st->psb);
+
+ netfs_trans_drop_dst_nostate(dst);
+ }
+
+ kfree(st->data);
+
+ kfree(c);
+}
+
+/*
+ * Initialize network stack. It searches for given ID in global
+ * configuration table, this contains information of the remote server
+ * (address (any supported by socket interface) and port, protocol and so on).
+ */
+int pohmelfs_state_init(struct pohmelfs_sb *psb)
+{
+ int err = -ENOMEM;
+
+ mutex_lock(&psb->state_lock);
+ err = pohmelfs_copy_config(psb);
+ mutex_unlock(&psb->state_lock);
+
+ return err;
+}
+
+void pohmelfs_state_exit(struct pohmelfs_sb *psb)
+{
+ struct pohmelfs_config *c, *tmp;
+
+ list_for_each_entry_safe(c, tmp, &psb->state_list, config_entry) {
+ list_del(&c->config_entry);
+ pohmelfs_state_exit_one(c);
+ }
+}
+
+void pohmelfs_switch_active(struct pohmelfs_sb *psb)
+{
+ struct pohmelfs_config *c = psb->active_state;
+
+ if (!list_empty(&psb->state_list)) {
+ if (c->config_entry.next != &psb->state_list) {
+ psb->active_state = list_entry(c->config_entry.next,
+ struct pohmelfs_config, config_entry);
+ } else {
+ psb->active_state = list_entry(psb->state_list.next,
+ struct pohmelfs_config, config_entry);
+ }
+ } else
+ psb->active_state = NULL;
+
+ dprintk("%s: empty: %d, active %p -> %p.\n",
+ __func__, list_empty(&psb->state_list), c,
+ psb->active_state);
+}
+
+void pohmelfs_check_states(struct pohmelfs_sb *psb)
+{
+ struct pohmelfs_config *c, *tmp;
+ LIST_HEAD(delete_list);
+
+ mutex_lock(&psb->state_lock);
+ list_for_each_entry_safe(c, tmp, &psb->state_list, config_entry) {
+ if (pohmelfs_config_check(c, psb->idx)) {
+
+ if (psb->active_state == c)
+ pohmelfs_switch_active(psb);
+ list_move(&c->config_entry, &delete_list);
+ }
+ }
+ pohmelfs_copy_config(psb);
+ mutex_unlock(&psb->state_lock);
+
+ list_for_each_entry_safe(c, tmp, &delete_list, config_entry) {
+ list_del(&c->config_entry);
+ pohmelfs_state_exit_one(c);
+ }
+}
diff --git a/fs/pohmelfs/netfs.h b/fs/pohmelfs/netfs.h
new file mode 100644
index 0000000..015c403
--- /dev/null
+++ b/fs/pohmelfs/netfs.h
@@ -0,0 +1,592 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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.
+ */
+
+#ifndef __NETFS_H
+#define __NETFS_H
+
+#include <linux/types.h>
+#include <linux/connector.h>
+
+#define POHMELFS_CN_IDX 5
+#define POHMELFS_CN_VAL 0
+
+/*
+ * Network command structure.
+ * Will be extended.
+ */
+struct netfs_cmd
+{
+ __u16 cmd; /* Command number */
+ __u16 ext; /* External flags */
+ __u32 size; /* Size of the attached data */
+ __u64 id; /* Object ID to operate on. Used for feedback.*/
+ __u64 start; /* Start of the object. */
+ __u8 data[];
+};
+
+static inline void netfs_convert_cmd(struct netfs_cmd *cmd)
+{
+ cmd->id = __be64_to_cpu(cmd->id);
+ cmd->start = __be64_to_cpu(cmd->start);
+ cmd->cmd = __be16_to_cpu(cmd->cmd);
+ cmd->ext = __be16_to_cpu(cmd->ext);
+ cmd->size = __be32_to_cpu(cmd->size);
+}
+
+#define NETFS_TRANS_SINGLE_DST (1<<0)
+
+enum {
+ NETFS_READDIR = 1, /* Read directory for given inode number */
+ NETFS_READ_PAGE, /* Read data page from the server */
+ NETFS_WRITE_PAGE, /* Write data page to the server */
+ NETFS_CREATE, /* Create directory entry */
+ NETFS_REMOVE, /* Remove directory entry */
+ NETFS_LOOKUP, /* Lookup single object */
+ NETFS_LINK, /* Create a link */
+ NETFS_TRANS, /* Transaction */
+ NETFS_OPEN, /* Open intent */
+ NETFS_INODE_INFO, /* Metadata cache coherency synchronization message */
+ NETFS_JOIN_GROUP, /* Joing metadata update group */
+ NETFS_LEAVE_GROUP, /* Leave metadata update group */
+ NETFS_PAGE_CACHE, /* Page cache invalidation message */
+ NETFS_READ_PAGES, /* Read multiple contiguous pages in one go */
+ NETFS_RENAME, /* Rename object */
+ NETFS_CMD_MAX
+};
+
+/*
+ * Always wanted to copy it from socket headers into public one,
+ * since they are __KERNEL__ protected there.
+ */
+#define _K_SS_MAXSIZE 128
+
+struct saddr
+{
+ unsigned short sa_family;
+ char addr[_K_SS_MAXSIZE];
+};
+
+/*
+ * Configuration command used to create table of different remote servers.
+ */
+struct pohmelfs_ctl
+{
+ unsigned int idx; /* Config index */
+ unsigned int type; /* Socket type */
+ unsigned int proto; /* Socket protocol */
+ unsigned int addrlen; /* Size of the address*/
+ struct saddr addr; /* Remote server address */
+};
+
+/*
+ * Ack for userspace about requested command.
+ */
+struct pohmelfs_cn_ack
+{
+ struct cn_msg msg;
+ int error;
+ int unused[3];
+};
+
+/*
+ * Inode info structure used to sync with server.
+ * Check what stat() returns.
+ */
+struct netfs_inode_info
+{
+ unsigned int mode;
+ unsigned int nlink;
+ unsigned int uid;
+ unsigned int gid;
+ unsigned int blocksize;
+ unsigned int padding;
+ __u64 ino;
+ __u64 blocks;
+ __u64 rdev;
+ __u64 size;
+ __u64 version;
+};
+
+static inline void netfs_convert_inode_info(struct netfs_inode_info *info)
+{
+ info->mode = __cpu_to_be32(info->mode);
+ info->nlink = __cpu_to_be32(info->nlink);
+ info->uid = __cpu_to_be32(info->uid);
+ info->gid = __cpu_to_be32(info->gid);
+ info->blocksize = __cpu_to_be32(info->blocksize);
+ info->blocks = __cpu_to_be64(info->blocks);
+ info->rdev = __cpu_to_be64(info->rdev);
+ info->size = __cpu_to_be64(info->size);
+ info->version = __cpu_to_be64(info->version);
+ info->ino = __cpu_to_be64(info->ino);
+}
+
+/*
+ * Cache state machine.
+ */
+enum {
+ NETFS_COMMAND_PENDING = 0, /* Command is being executed */
+ NETFS_INODE_CREATED, /* Inode was created locally */
+ NETFS_INODE_REMOTE_SYNCED, /* Inode was synced to server */
+};
+
+/*
+ * Path entry, used to create full path to object by single command.
+ */
+struct netfs_path_entry
+{
+ __u8 len; /* Data length, if less than 5 */
+ __u8 unused[5]; /* then data is embedded here */
+
+ __u16 mode; /* mode of the object (dir, file and so on) */
+
+ char data[];
+};
+
+static inline void netfs_convert_path_entry(struct netfs_path_entry *e)
+{
+ e->mode = __cpu_to_be16(e->mode);
+};
+
+#ifdef __KERNEL__
+
+#include <linux/kernel.h>
+#include <linux/rbtree.h>
+#include <linux/net.h>
+#include <linux/poll.h>
+
+/*
+ * Private POHMELFS cache of objects in directory.
+ */
+struct pohmelfs_name
+{
+ struct rb_node offset_node;
+ struct rb_node hash_node;
+
+ struct list_head sync_del_entry, sync_create_entry;
+
+ u64 ino;
+
+ u64 offset;
+
+ u32 hash;
+ u32 mode;
+ u32 len;
+
+ char *data;
+};
+
+/*
+ * POHMELFS inode. Main object.
+ */
+struct pohmelfs_inode
+{
+ struct list_head inode_entry; /* Entry in superblock list.
+ * Objects which are not bound to dentry require to be dropped
+ * in ->put_super()
+ */
+ struct rb_root offset_root; /* Local cache for names in dir */
+ struct rb_root hash_root; /* The same, but indexed by name hash and len */
+ struct mutex offset_lock; /* Protect both above trees */
+
+ struct list_head sync_del_list, sync_create_list; /* Sync list (create is not used).
+ * It contains children scheduled to be removed
+ */
+
+ unsigned int drop_count;
+
+ int error; /* Transaction error for given inode */
+
+ long state; /* State machine above */
+
+ u64 ino; /* Inode number */
+ u64 total_len; /* Total length of all children names, used to create offsets */
+
+ struct inode vfs_inode;
+};
+
+struct netfs_trans;
+typedef int (* netfs_trans_complete_t)(struct page **pages, unsigned int page_num,
+ void *private, int err);
+
+struct netfs_state;
+struct pohmelfs_sb;
+
+struct netfs_trans
+{
+ /*
+ * Transaction header and attached contiguous data live here.
+ */
+ struct iovec iovec;
+
+ /*
+ * Pages attached to transaction.
+ */
+ struct page **pages;
+
+ /*
+ * List and protecting lock for transaction destination
+ * network states.
+ */
+ struct mutex dst_lock;
+ struct list_head dst_list;
+
+ /*
+ * Number of users for given transaction.
+ * For example each network state attached to transaction
+ * via dst_list increases it.
+ */
+ atomic_t refcnt;
+
+ /*
+ * Number of pages attached to given transaction.
+ * Some slots in above page array can be NULL, since
+ * for example page can be under writeback already,
+ * so we skip it in this transaction.
+ */
+ unsigned int page_num;
+
+ /*
+ * Transaction flags: single dst or broadcast and so on.
+ */
+ unsigned int flags;
+
+ /*
+ * Size of the data, which can be placed into
+ * iovec.iov_base area.
+ */
+ unsigned int total_size;
+
+ /*
+ * Number of pages to be sent to remote server.
+ * Usually equal to above page_num, but in case of partial
+ * writeback it can accumulate only pages already completed
+ * previous writeback.
+ */
+ unsigned int attached_pages;
+
+ /*
+ * Attached number of bytes in all above pages.
+ */
+ unsigned int attached_size;
+
+ /*
+ * Unique transacton generation number.
+ * Used as identity in the network state tree of transactions.
+ */
+ unsigned int gen;
+
+ /*
+ * Transaction completion status.
+ */
+ int result;
+
+ /* Private data */
+ void *private;
+
+ /* Completion callback, invoked just before transaction is destroyed */
+ netfs_trans_complete_t complete;
+};
+
+static inline int netfs_trans_cur_len(struct netfs_trans *t)
+{
+ return (signed)(t->total_size - t->iovec.iov_len);
+}
+
+struct netfs_trans *netfs_trans_alloc(unsigned int size, unsigned int flags,
+ unsigned int nr);
+void netfs_trans_free(struct netfs_trans *t);
+
+static inline void netfs_trans_get(struct netfs_trans *t)
+{
+#if 0
+ printk("%s: t: %p, gen: %u, refcnt: %d.\n",
+ __func__, t, t->gen, atomic_read(&t->refcnt));
+#endif
+ atomic_inc(&t->refcnt);
+}
+
+static inline void netfs_trans_put(struct netfs_trans *t)
+{
+#if 0
+ printk("%s: t: %p, gen: %u, refcnt: %d.\n",
+ __func__, t, t->gen, atomic_read(&t->refcnt));
+#endif
+ if (atomic_dec_and_test(&t->refcnt)) {
+ if (t->complete)
+ t->complete(t->pages, t->page_num,
+ t->private, t->result);
+ netfs_trans_free(t);
+ }
+}
+
+int netfs_trans_finish(struct netfs_trans *t, struct pohmelfs_sb *psb);
+int netfs_trans_finish_send(struct netfs_trans *t, struct pohmelfs_sb *psb);
+
+void *netfs_trans_add(struct netfs_trans *t, unsigned int size);
+int netfs_trans_fixup_last(struct netfs_trans *t, int diff);
+
+static inline void netfs_trans_reset(struct netfs_trans *t)
+{
+ t->complete = NULL;
+}
+
+struct netfs_trans_dst
+{
+ struct list_head trans_entry;
+ struct rb_node state_entry;
+
+ unsigned long send_time;
+
+ /*
+ * Times this transaction was resent to its old or new,
+ * depending on flags, destinations. When it reaches maximum
+ * allowed number, specified in superblock->trans_retries,
+ * transaction will be freed with ETIMEDOUT error.
+ */
+ unsigned int retries;
+
+ struct netfs_trans *trans;
+ struct netfs_state *state;
+};
+
+struct netfs_trans_dst *netfs_trans_search(struct netfs_state *st, unsigned int gen);
+void netfs_trans_drop_dst(struct netfs_trans_dst *dst);
+void netfs_trans_drop_dst_nostate(struct netfs_trans_dst *dst);
+void netfs_trans_drop_trans(struct netfs_trans *t, struct netfs_state *st);
+void netfs_trans_drop_last(struct netfs_trans *t, struct netfs_state *st);
+int netfs_trans_resend(struct netfs_trans *t, struct pohmelfs_sb *psb);
+int netfs_trans_remove_nolock(struct netfs_trans_dst *dst, struct netfs_state *st);
+
+int netfs_trans_init(void);
+void netfs_trans_exit(void);
+
+/*
+ * Network state, attached to one server.
+ */
+struct netfs_state
+{
+ struct mutex __state_lock; /* Can not allow to use the same socket simultaneously */
+ struct netfs_cmd cmd; /* Cached command */
+ struct netfs_inode_info info; /* Cached inode info */
+
+ void *data; /* Cached some data */
+ unsigned int size; /* Size of that data */
+
+ struct pohmelfs_sb *psb; /* Superblock */
+
+ struct task_struct *thread; /* Async receiving thread */
+
+ /* Waiting/polling machinery */
+ wait_queue_t wait;
+ wait_queue_head_t *whead;
+ wait_queue_head_t thread_wait;
+
+ struct mutex trans_lock;
+ struct rb_root trans_root;
+
+ struct pohmelfs_ctl ctl; /* Remote peer */
+
+ struct socket *socket; /* Socket object */
+ struct socket *read_socket; /* Cached pointer to socket object.
+ * Used to determine if between lock drops socket was changed.
+ * Never used to read data or any kind of access.
+ */
+};
+
+int netfs_state_init(struct netfs_state *st);
+void netfs_state_exit(struct netfs_state *st);
+
+static inline void netfs_state_lock(struct netfs_state *st)
+{
+ mutex_lock(&st->__state_lock);
+}
+
+static inline void netfs_state_unlock(struct netfs_state *st)
+{
+ BUG_ON(!mutex_is_locked(&st->__state_lock));
+
+ mutex_unlock(&st->__state_lock);
+}
+
+static inline unsigned int netfs_state_poll(struct netfs_state *st)
+{
+ unsigned int revents = POLLHUP | POLLERR;
+
+ netfs_state_lock(st);
+ if (st->socket)
+ revents = st->socket->ops->poll(NULL, st->socket, NULL);
+ netfs_state_unlock(st);
+
+ return revents;
+}
+
+struct pohmelfs_config;
+
+struct pohmelfs_sb
+{
+ struct rb_root path_root;
+ struct mutex path_lock;
+
+ unsigned int idx;
+
+ unsigned int trans_retries;
+
+ atomic_t trans_gen;
+
+ unsigned long trans_data_size;
+ unsigned long trans_timeout;
+
+ unsigned long drop_scan_timeout;
+ unsigned long trans_scan_timeout;
+
+ unsigned long wait_on_page_timeout;
+
+ struct list_head drop_list;
+ spinlock_t ino_lock;
+ u64 ino;
+
+ struct list_head state_list;
+ struct mutex state_lock;
+
+ wait_queue_head_t wait;
+
+ struct delayed_work dwork;
+
+ struct delayed_work drop_dwork;
+
+ struct pohmelfs_config *active_state;
+
+ struct super_block *sb;
+};
+
+static inline struct pohmelfs_sb *POHMELFS_SB(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+static inline struct pohmelfs_inode *POHMELFS_I(struct inode *inode)
+{
+ return container_of(inode, struct pohmelfs_inode, vfs_inode);
+}
+
+static inline u64 pohmelfs_new_ino(struct pohmelfs_sb *psb)
+{
+ u64 ino;
+
+ spin_lock(&psb->ino_lock);
+ ino = psb->ino++;
+ spin_unlock(&psb->ino_lock);
+
+ return ino;
+}
+
+static inline void pohmelfs_put_inode(struct pohmelfs_inode *pi)
+{
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+
+ spin_lock(&psb->ino_lock);
+ list_move_tail(&pi->inode_entry, &psb->drop_list);
+ pi->drop_count++;
+ spin_unlock(&psb->ino_lock);
+}
+
+struct pohmelfs_config
+{
+ struct list_head config_entry;
+
+ struct netfs_state state;
+};
+
+int __init pohmelfs_config_init(void);
+void __exit pohmelfs_config_exit(void);
+int pohmelfs_copy_config(struct pohmelfs_sb *psb);
+int pohmelfs_config_check(struct pohmelfs_config *config, int idx);
+int pohmelfs_state_init_one(struct pohmelfs_sb *psb, struct pohmelfs_config *conf);
+
+extern const struct file_operations pohmelfs_dir_fops;
+extern const struct inode_operations pohmelfs_dir_inode_ops;
+
+int netfs_data_send(struct netfs_state *st, void *buf, u64 size, int more);
+
+int pohmelfs_state_init(struct pohmelfs_sb *psb);
+void pohmelfs_state_exit(struct pohmelfs_sb *psb);
+
+void pohmelfs_fill_inode(struct inode *inode, struct netfs_inode_info *info);
+
+void pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *n);
+void pohmelfs_free_names(struct pohmelfs_inode *parent);
+
+void pohmelfs_inode_del_inode(struct pohmelfs_sb *psb, struct pohmelfs_inode *pi);
+
+struct pohmelfs_inode *pohmelfs_create_entry_local(struct pohmelfs_sb *psb,
+ struct pohmelfs_inode *parent, struct qstr *str, u64 start, int mode);
+
+struct pohmelfs_inode *pohmelfs_new_inode(struct pohmelfs_sb *psb,
+ struct pohmelfs_inode *parent, struct qstr *str,
+ struct netfs_inode_info *info, int link);
+
+int pohmelfs_setattr(struct dentry *dentry, struct iattr *attr);
+int pohmelfs_setattr_raw(struct inode *inode, struct iattr *attr);
+
+int pohmelfs_meta_command(struct pohmelfs_inode *pi, unsigned int cmd_op, unsigned int flags,
+ netfs_trans_complete_t complete, void *priv, u64 start);
+int pohmelfs_meta_command_data(struct pohmelfs_inode *pi, unsigned int cmd_op, char *addon,
+ unsigned int flags, netfs_trans_complete_t complete, void *priv, u64 start);
+
+void pohmelfs_check_states(struct pohmelfs_sb *psb);
+void pohmelfs_switch_active(struct pohmelfs_sb *psb);
+
+struct pohmelfs_path_entry
+{
+ struct rb_node path_entry;
+ struct list_head entry;
+ u8 len, link;
+ u8 unused[2];
+ atomic_t refcnt;
+ u32 mode;
+ u32 hash;
+ u64 ino;
+ struct pohmelfs_path_entry *parent;
+ char *name;
+};
+
+void pohmelfs_remove_path_entry(struct pohmelfs_sb *psb, struct pohmelfs_path_entry *e);
+void pohmelfs_remove_path_entry_by_ino(struct pohmelfs_sb *psb, u64 ino);
+struct pohmelfs_path_entry * pohmelfs_add_path_entry(struct pohmelfs_sb *psb,
+ u64 parent_ino, u64 ino, struct qstr *str, int link, unsigned int mode);
+int pohmelfs_rename_path_entry(struct pohmelfs_sb *psb, u64 ino, u64 parent_ino, struct qstr *str);
+int pohmelfs_change_path_entry(struct pohmelfs_sb *psb, u64 ino, unsigned int mode);
+int pohmelfs_construct_path(struct pohmelfs_inode *pi, void *data, int len);
+int pohmelfs_construct_path_string(struct pohmelfs_inode *pi, void *data, int len);
+
+int pohmelfs_path_length(struct pohmelfs_inode *pi);
+int pohmelfs_path_length_create(struct pohmelfs_inode *pi);
+
+#ifdef CONFIG_POHMELFS_CC_GROUP
+#define POHMELFS_CC_GROUP
+#endif
+
+#define CONFIG_POHMELFS_DEBUG
+
+#ifdef CONFIG_POHMELFS_DEBUG
+#define dprintk(f, a...) printk(f, ##a)
+#else
+#define dprintk(f, a...) do {} while (0)
+#endif
+
+#endif /* __KERNEL__*/
+
+#endif /* __NETFS_H */
diff --git a/fs/pohmelfs/path_entry.c b/fs/pohmelfs/path_entry.c
new file mode 100644
index 0000000..884e7c3
--- /dev/null
+++ b/fs/pohmelfs/path_entry.c
@@ -0,0 +1,356 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/slab.h>
+#include <linux/fs.h>
+#include <linux/ktime.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/mm.h>
+
+#include "netfs.h"
+
+/*
+ * Path cache.
+ *
+ * Used to create pathes to root, strings (or structures,
+ * containing name, mode, permissions and so on) used by userspace
+ * server to process data.
+ *
+ * Cache is local for client, and its inode numbers are never synced
+ * with anyone else, server operates on names and pathes, not some obscure ids.
+ */
+
+static void pohmelfs_free_path_entry(struct pohmelfs_path_entry *e)
+{
+ kfree(e);
+}
+
+static struct pohmelfs_path_entry *pohmelfs_alloc_path_entry(unsigned int len)
+{
+ struct pohmelfs_path_entry *e;
+
+ e = kzalloc(len + 1 + sizeof(struct pohmelfs_path_entry), GFP_KERNEL);
+ if (!e)
+ return NULL;
+
+ e->name = (char *)((struct pohmelfs_path_entry *)(e + 1));
+ e->len = len;
+ atomic_set(&e->refcnt, 1);
+
+ return e;
+}
+
+static inline int pohmelfs_cmp_path_entry(u64 path_ino, u64 new_ino)
+{
+ if (path_ino > new_ino)
+ return -1;
+ if (path_ino < new_ino)
+ return 1;
+ return 0;
+}
+
+static struct pohmelfs_path_entry *pohmelfs_search_path_entry(struct rb_root *root, u64 ino)
+{
+ struct rb_node *n = root->rb_node;
+ struct pohmelfs_path_entry *tmp;
+ int cmp;
+
+ while (n) {
+ tmp = rb_entry(n, struct pohmelfs_path_entry, path_entry);
+
+ cmp = pohmelfs_cmp_path_entry(tmp->ino, ino);
+ if (cmp < 0)
+ n = n->rb_left;
+ else if (cmp > 0)
+ n = n->rb_right;
+ else
+ return tmp;
+ }
+
+ dprintk("%s: Failed to find path entry for ino: %llu.\n", __func__, ino);
+ return NULL;
+}
+
+static struct pohmelfs_path_entry *pohmelfs_insert_path_entry(struct rb_root *root,
+ struct pohmelfs_path_entry *new)
+{
+ struct rb_node **n = &root->rb_node, *parent = NULL;
+ struct pohmelfs_path_entry *ret = NULL, *tmp;
+ int cmp;
+
+ while (*n) {
+ parent = *n;
+
+ tmp = rb_entry(parent, struct pohmelfs_path_entry, path_entry);
+
+ cmp = pohmelfs_cmp_path_entry(tmp->ino, new->ino);
+ if (cmp < 0)
+ n = &parent->rb_left;
+ else if (cmp > 0)
+ n = &parent->rb_right;
+ else {
+ ret = tmp;
+ break;
+ }
+ }
+
+ if (ret) {
+ printk("%s: exist: ino: %llu, data: '%s', new: ino: %llu, data: '%s'.\n",
+ __func__, ret->ino, ret->name, new->ino, new->name);
+ return ret;
+ }
+
+ rb_link_node(&new->path_entry, parent, n);
+ rb_insert_color(&new->path_entry, root);
+
+ dprintk("%s: inserted: ino: %llu, data: '%s', parent: ino: %llu, data: '%s'.\n",
+ __func__, new->ino, new->name, new->parent->ino, new->parent->name);
+
+ return new;
+}
+
+void pohmelfs_remove_path_entry(struct pohmelfs_sb *psb, struct pohmelfs_path_entry *e)
+{
+ if (atomic_dec_and_test(&e->refcnt)) {
+ rb_erase(&e->path_entry, &psb->path_root);
+
+ if (e->parent != e)
+ pohmelfs_remove_path_entry(psb, e->parent);
+ pohmelfs_free_path_entry(e);
+ }
+}
+
+void pohmelfs_remove_path_entry_by_ino(struct pohmelfs_sb *psb, u64 ino)
+{
+ struct pohmelfs_path_entry *e;
+
+ e = pohmelfs_search_path_entry(&psb->path_root, ino);
+ if (e)
+ pohmelfs_remove_path_entry(psb, e);
+}
+
+int pohmelfs_change_path_entry(struct pohmelfs_sb *psb, u64 ino, unsigned int mode)
+{
+ struct pohmelfs_path_entry *e;
+
+ e = pohmelfs_search_path_entry(&psb->path_root, ino);
+ if (!e)
+ return -ENOENT;
+
+ e->mode = mode;
+ return 0;
+}
+
+int pohmelfs_rename_path_entry(struct pohmelfs_sb *psb, u64 ino, u64 parent_ino, struct qstr *str)
+{
+ struct pohmelfs_path_entry *e;
+ unsigned int mode, link;
+
+ e = pohmelfs_search_path_entry(&psb->path_root, ino);
+ if (!e)
+ return -ENOENT;
+
+ if ((e->len >= str->len) && (parent_ino == e->parent->ino)) {
+ sprintf(e->name, "%s", str->name);
+ e->len = str->len;
+ e->hash = str->hash;
+
+ return 0;
+ }
+
+ mode = e->mode;
+ link = e->link;
+
+ pohmelfs_remove_path_entry(psb, e);
+
+ e = pohmelfs_add_path_entry(psb, parent_ino, ino, str, link, mode);
+ if (IS_ERR(e))
+ return PTR_ERR(e);
+
+ return 0;
+}
+
+struct pohmelfs_path_entry * pohmelfs_add_path_entry(struct pohmelfs_sb *psb,
+ u64 parent_ino, u64 ino, struct qstr *str, int link, unsigned int mode)
+{
+ struct pohmelfs_path_entry *e, *ret, *parent;
+
+ parent = pohmelfs_search_path_entry(&psb->path_root, parent_ino);
+
+ e = pohmelfs_alloc_path_entry(str->len);
+ if (!e)
+ return ERR_PTR(-ENOMEM);
+
+ e->parent = e;
+ if (parent) {
+ e->parent = parent;
+ atomic_inc(&parent->refcnt);
+ }
+
+ e->ino = ino;
+ e->hash = str->hash;
+ e->link = link;
+ e->mode = mode;
+
+ sprintf(e->name, "%s", str->name);
+
+ ret = pohmelfs_insert_path_entry(&psb->path_root, e);
+ if (ret != e) {
+ pohmelfs_free_path_entry(e);
+ e = ret;
+ }
+
+ dprintk("%s: parent: %llu, ino: %llu, name: '%s', len: %u.\n",
+ __func__, parent_ino, ino, e->name, e->len);
+
+ return e;
+}
+
+static int pohmelfs_prepare_path(struct pohmelfs_inode *pi, struct list_head *list, int len, int create)
+{
+ struct pohmelfs_path_entry *e;
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+
+ e = pohmelfs_search_path_entry(&psb->path_root, pi->ino);
+ if (!e)
+ return -ENOENT;
+
+ while (e && e->parent != e) {
+ if (len < e->len + create)
+ return -ETOOSMALL;
+
+ len -= e->len + create;
+
+ list_add(&e->entry, list);
+ e = e->parent;
+ }
+
+ return 0;
+}
+
+/*
+ * Create path from root for given inode.
+ * Path is formed as set of stuctures, containing name of the object
+ * and its inode data (mode, permissions and so on).
+ */
+int pohmelfs_construct_path(struct pohmelfs_inode *pi, void *data, int len)
+{
+ struct pohmelfs_path_entry *e;
+ struct netfs_path_entry *ne = data;
+ int used = 0, err;
+ LIST_HEAD(list);
+
+ err = pohmelfs_prepare_path(pi, &list, len, sizeof(struct netfs_path_entry));
+ if (err)
+ return err;
+
+ list_for_each_entry(e, &list, entry) {
+ ne = data;
+ ne->mode = e->mode;
+ ne->len = e->len;
+
+ used += sizeof(struct netfs_path_entry);
+ data += sizeof(struct netfs_path_entry);
+
+ if (ne->len <= sizeof(ne->unused)) {
+ memcpy(ne->unused, e->name, ne->len);
+ } else {
+ memcpy(data, e->name, ne->len);
+ data += ne->len;
+ used += ne->len;
+ }
+
+ dprintk("%s: ino: %llu, mode: %o, is_link: %d, name: '%s', used: %d, ne_len: %u.\n",
+ __func__, e->ino, ne->mode, e->link, e->name, used, ne->len);
+
+ netfs_convert_path_entry(ne);
+ }
+
+ return used;
+}
+
+/*
+ * Create path from root for given inode.
+ */
+int pohmelfs_construct_path_string(struct pohmelfs_inode *pi, void *data, int len)
+{
+ struct pohmelfs_path_entry *e;
+ int used = 0, err;
+ char *ptr = data;
+ LIST_HEAD(list);
+
+ err = pohmelfs_prepare_path(pi, &list, len, 0);
+ if (err)
+ return err;
+
+ if (list_empty(&list)) {
+ err = sprintf(ptr, "/");
+ ptr += err;
+ used += err;
+ } else {
+ list_for_each_entry(e, &list, entry) {
+ err = sprintf(ptr, "/%s", e->name);
+
+ BUG_ON(!e->name);
+
+ ptr += err;
+ used += err;
+ }
+ }
+
+ dprintk("%s: inode: %llu, full path: '%s', used: %d.\n",
+ __func__, pi->ino, (char *)data, used);
+
+ return used;
+}
+
+static int pohmelfs_get_path_length(struct pohmelfs_inode *pi, int create)
+{
+ struct pohmelfs_path_entry *e;
+ struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb);
+ int len = 1 + create;
+
+ e = pohmelfs_search_path_entry(&psb->path_root, pi->ino);
+
+ /*
+ * This should never happen actually.
+ */
+ if (!e)
+ return -ENOENT;
+
+ while (e && e->parent != e) {
+ len += e->len + create + 1;
+ e = e->parent;
+ }
+
+ return len;
+}
+
+int pohmelfs_path_length(struct pohmelfs_inode *pi)
+{
+ int len = pohmelfs_get_path_length(pi, 0);
+
+ if (len < 0)
+ return len;
+ return len + 1;
+}
+
+int pohmelfs_path_length_create(struct pohmelfs_inode *pi)
+{
+ return pohmelfs_get_path_length(pi, sizeof(struct netfs_path_entry));
+}
diff --git a/fs/pohmelfs/trans.c b/fs/pohmelfs/trans.c
new file mode 100644
index 0000000..9483a0e
--- /dev/null
+++ b/fs/pohmelfs/trans.c
@@ -0,0 +1,685 @@
+/*
+ * 2007+ Copyright (c) Evgeniy Polyakov <johnpol@....mipt.ru>
+ * 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/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);
+
+ mutex_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;
+ struct msghdr msg;
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = MSG_WAITALL | MSG_MORE;
+
+ for (i=0; i<t->page_num; ++i) {
+ struct page *page = t->pages[i];
+ struct netfs_cmd cmd;
+ struct iovec io;
+
+ if (!page)
+ continue;
+
+ io.iov_base = &cmd;
+ io.iov_len = sizeof(struct netfs_cmd);
+
+ cmd.cmd = NETFS_WRITE_PAGE;
+ cmd.ext = 0;
+ cmd.id = 0;
+ cmd.size = page_private(page);
+ cmd.start = page->index;
+ cmd.start <<= PAGE_CACHE_SHIFT;
+
+ 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, page_private(page), msg.msg_flags);
+ if (err <= 0) {
+ printk("%s: %d/%d failed to send transaction page: t: %p, gen: %u, size: %lu, err: %d.\n",
+ __func__, i, t->page_num, t, t->gen, page_private(page), err);
+ if (err == 0)
+ err = -ECONNRESET;
+ goto err_out;
+ }
+
+ attached_pages--;
+
+ dprintk("%s: %d/%d sent t: %p, gen: %u, page: %p, size: %lu.\n",
+ __func__, i, t->page_num, t, t->gen, page, page_private(page));
+
+ err = 0;
+ 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;
+
+ netfs_state_lock(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:
+ netfs_state_unlock(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;
+
+ dprintk("%s: inserted: gen: %u, flags: %x, send_time: %lu.\n",
+ __func__, new->gen, new->flags, ndst->send_time);
+
+ 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;
+
+ mutex_lock(&t->dst_lock);
+ list_add_tail(&dst->trans_entry, &t->dst_list);
+ mutex_unlock(&t->dst_lock);
+
+ dprintk("%s: t: %p, gen: %u, state: %p, dst: %p.\n",
+ __func__, t, t->gen, st, dst);
+
+ 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)
+{
+ dprintk("%s: t: %p, gen: %u, state: %p, dst: %p.\n",
+ __func__, dst->trans, dst->trans->gen, dst->state, dst);
+
+ netfs_trans_put(dst->trans);
+ mempool_free(dst, netfs_trans_dst_pool);
+}
+
+static void netfs_trans_remove_dst(struct netfs_trans_dst *dst)
+{
+ 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;
+
+ mutex_lock(&t->dst_lock);
+ list_del_init(&dst->trans_entry);
+ mutex_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;
+
+ dprintk("%s: t: %p, gen: %u, state: %p, dst: %p.\n",
+ __func__, t, t->gen, dst->state, dst);
+
+ mutex_lock(&t->dst_lock);
+ list_del_init(&dst->trans_entry);
+ mutex_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;
+
+ mutex_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;
+ }
+ }
+ mutex_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;
+
+ mutex_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);
+ }
+ mutex_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;
+
+ 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);
+
+ 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);
+
+ 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);
+
+ 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);
+
+ 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->ext = t->flags;
+ cmd->id = 0;
+
+ netfs_convert_cmd(cmd);
+
+ err = netfs_trans_finish_send(t, psb);
+
+ dprintk("%s: putting transaction %p, gen: %u, err: %d.\n", __func__, t, t->gen, 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;
+ mutex_lock(&t->dst_lock);
+ list_for_each_entry(dst, &t->dst_list, trans_entry) {
+ if (st == dst->state) {
+ exist = 1;
+ break;
+ }
+ }
+ mutex_unlock(&t->dst_lock);
+
+ if (exist) {
+ if (!(t->flags & NETFS_TRANS_SINGLE_DST)) {
+ err = netfs_trans_send(t, st);
+ if (!err)
+ error = 0;
+ }
+ continue;
+ }
+
+ 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;
+}
+
+int netfs_trans_fixup_last(struct netfs_trans *t, int diff)
+{
+ struct iovec *io = &t->iovec;
+ int len = io->iov_len + diff;
+
+ if (unlikely(len > t->total_size || len < 0)) {
+ dprintk("%s: wrong fixup t: %p, total_size: %u, "
+ "len: %d, cur_io_len: %u, diff: %d.\n",
+ __func__, t, t->total_size, len, io->iov_len, diff);
+
+ return -EINVAL;
+ }
+
+ io->iov_len += diff;
+ return 0;
+}
+
+void netfs_trans_free(struct netfs_trans *t)
+{
+ kfree(t);
+}
+
+struct netfs_trans *netfs_trans_alloc(unsigned int size, unsigned int flags, unsigned int nr)
+{
+ struct netfs_trans *t;
+ unsigned int num, cont;
+
+ /*
+ * |sizeof(struct netfs_trans)|
+ * |sizeof(struct netfs_cmd)| - transaction header
+ * |size| - buffer with requested size
+ * |nr * sizeof(struct page *)| - array of page pointers
+ *
+ * Overall size should be less than PAGE_SIZE for guaranteed allocation.
+ */
+
+ cont = size + sizeof(struct netfs_trans) + sizeof(struct netfs_cmd);
+
+ num = (PAGE_SIZE - cont)/sizeof(struct page *);
+
+ if (nr > num)
+ nr = num;
+
+ t = kmalloc(cont + nr*sizeof(struct page *), GFP_NOIO);
+ if (!t)
+ goto err_out_exit;
+
+ memset(t, 0, sizeof(struct netfs_trans));
+
+ t->iovec.iov_base = (void *)(t + 1);
+ t->pages = (struct page **)(t->iovec.iov_base + size + sizeof(struct netfs_cmd));
+
+ /*
+ * Reserving space for transaction header.
+ */
+ t->iovec.iov_len = sizeof(struct netfs_cmd);
+
+ t->page_num = nr;
+ netfs_trans_init_static(t, nr, size + sizeof(struct netfs_cmd));
+
+ t->flags = flags;
+
+ dprintk("%s: t: %p, gen: %u, size: %u, flags: %x, page_num: %u, base: %p, pages: %p.\n",
+ __func__, t, t->gen, 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);
+}
--
Evgeniy Polyakov
--
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