+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * dlmfs.c
- *
- * Code which implements the kernel side of a minimal userspace
- * interface to our DLM. This file handles the virtual file system
- * used for communication with userspace. Credit should go to ramfs,
- * which was a template for the fs side of this module.
- *
- * Copyright (C) 2003, 2004 Oracle. 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.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-/* Simple VFS hooks based on: */
-/*
- * Resizable simple ram filesystem for Linux.
- *
- * Copyright (C) 2000 Linus Torvalds.
- * 2000 Transmeta Corp.
- */
-
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/pagemap.h>
-#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/highmem.h>
-#include <linux/init.h>
-#include <linux/string.h>
-#include <linux/backing-dev.h>
-#include <linux/poll.h>
-
-#include <asm/uaccess.h>
-
-
-#include "cluster/nodemanager.h"
-#include "cluster/heartbeat.h"
-#include "cluster/tcp.h"
-
-#include "dlmapi.h"
-
-#include "userdlm.h"
-
-#include "dlmfsver.h"
-
-#define MLOG_MASK_PREFIX ML_DLMFS
-#include "cluster/masklog.h"
-
-#include "ocfs2_lockingver.h"
-
-static const struct super_operations dlmfs_ops;
-static const struct file_operations dlmfs_file_operations;
-static const struct inode_operations dlmfs_dir_inode_operations;
-static const struct inode_operations dlmfs_root_inode_operations;
-static const struct inode_operations dlmfs_file_inode_operations;
-static struct kmem_cache *dlmfs_inode_cache;
-
-struct workqueue_struct *user_dlm_worker;
-
-/*
- * This is the userdlmfs locking protocol version.
- *
- * See fs/ocfs2/dlmglue.c for more details on locking versions.
- */
-static const struct dlm_protocol_version user_locking_protocol = {
- .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
- .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
-};
-
-
-/*
- * These are the ABI capabilities of dlmfs.
- *
- * Over time, dlmfs has added some features that were not part of the
- * initial ABI. Unfortunately, some of these features are not detectable
- * via standard usage. For example, Linux's default poll always returns
- * POLLIN, so there is no way for a caller of poll(2) to know when dlmfs
- * added poll support. Instead, we provide this list of new capabilities.
- *
- * Capabilities is a read-only attribute. We do it as a module parameter
- * so we can discover it whether dlmfs is built in, loaded, or even not
- * loaded.
- *
- * The ABI features are local to this machine's dlmfs mount. This is
- * distinct from the locking protocol, which is concerned with inter-node
- * interaction.
- *
- * Capabilities:
- * - bast : POLLIN against the file descriptor of a held lock
- * signifies a bast fired on the lock.
- */
-#define DLMFS_CAPABILITIES "bast"
-extern int param_set_dlmfs_capabilities(const char *val,
- struct kernel_param *kp)
-{
- printk(KERN_ERR "%s: readonly parameter\n", kp->name);
- return -EINVAL;
-}
-static int param_get_dlmfs_capabilities(char *buffer,
- struct kernel_param *kp)
-{
- return strlcpy(buffer, DLMFS_CAPABILITIES,
- strlen(DLMFS_CAPABILITIES) + 1);
-}
-module_param_call(capabilities, param_set_dlmfs_capabilities,
- param_get_dlmfs_capabilities, NULL, 0444);
-MODULE_PARM_DESC(capabilities, DLMFS_CAPABILITIES);
-
-
-/*
- * decodes a set of open flags into a valid lock level and a set of flags.
- * returns < 0 if we have invalid flags
- * flags which mean something to us:
- * O_RDONLY -> PRMODE level
- * O_WRONLY -> EXMODE level
- *
- * O_NONBLOCK -> LKM_NOQUEUE
- */
-static int dlmfs_decode_open_flags(int open_flags,
- int *level,
- int *flags)
-{
- if (open_flags & (O_WRONLY|O_RDWR))
- *level = LKM_EXMODE;
- else
- *level = LKM_PRMODE;
-
- *flags = 0;
- if (open_flags & O_NONBLOCK)
- *flags |= LKM_NOQUEUE;
-
- return 0;
-}
-
-static int dlmfs_file_open(struct inode *inode,
- struct file *file)
-{
- int status, level, flags;
- struct dlmfs_filp_private *fp = NULL;
- struct dlmfs_inode_private *ip;
-
- if (S_ISDIR(inode->i_mode))
- BUG();
-
- mlog(0, "open called on inode %lu, flags 0x%x\n", inode->i_ino,
- file->f_flags);
-
- status = dlmfs_decode_open_flags(file->f_flags, &level, &flags);
- if (status < 0)
- goto bail;
-
- /* We don't want to honor O_APPEND at read/write time as it
- * doesn't make sense for LVB writes. */
- file->f_flags &= ~O_APPEND;
-
- fp = kmalloc(sizeof(*fp), GFP_NOFS);
- if (!fp) {
- status = -ENOMEM;
- goto bail;
- }
- fp->fp_lock_level = level;
-
- ip = DLMFS_I(inode);
-
- status = user_dlm_cluster_lock(&ip->ip_lockres, level, flags);
- if (status < 0) {
- /* this is a strange error to return here but I want
- * to be able userspace to be able to distinguish a
- * valid lock request from one that simply couldn't be
- * granted. */
- if (flags & LKM_NOQUEUE && status == -EAGAIN)
- status = -ETXTBSY;
- kfree(fp);
- goto bail;
- }
-
- file->private_data = fp;
-bail:
- return status;
-}
-
-static int dlmfs_file_release(struct inode *inode,
- struct file *file)
-{
- int level, status;
- struct dlmfs_inode_private *ip = DLMFS_I(inode);
- struct dlmfs_filp_private *fp =
- (struct dlmfs_filp_private *) file->private_data;
-
- if (S_ISDIR(inode->i_mode))
- BUG();
-
- mlog(0, "close called on inode %lu\n", inode->i_ino);
-
- status = 0;
- if (fp) {
- level = fp->fp_lock_level;
- if (level != LKM_IVMODE)
- user_dlm_cluster_unlock(&ip->ip_lockres, level);
-
- kfree(fp);
- file->private_data = NULL;
- }
-
- return 0;
-}
-
-static unsigned int dlmfs_file_poll(struct file *file, poll_table *wait)
-{
- int event = 0;
- struct inode *inode = file->f_path.dentry->d_inode;
- struct dlmfs_inode_private *ip = DLMFS_I(inode);
-
- poll_wait(file, &ip->ip_lockres.l_event, wait);
-
- spin_lock(&ip->ip_lockres.l_lock);
- if (ip->ip_lockres.l_flags & USER_LOCK_BLOCKED)
- event = POLLIN | POLLRDNORM;
- spin_unlock(&ip->ip_lockres.l_lock);
-
- return event;
-}
-
-static ssize_t dlmfs_file_read(struct file *filp,
- char __user *buf,
- size_t count,
- loff_t *ppos)
-{
- int bytes_left;
- ssize_t readlen;
- char *lvb_buf;
- struct inode *inode = filp->f_path.dentry->d_inode;
-
- mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
- inode->i_ino, count, *ppos);
-
- if (*ppos >= i_size_read(inode))
- return 0;
-
- if (!count)
- return 0;
-
- if (!access_ok(VERIFY_WRITE, buf, count))
- return -EFAULT;
-
- /* don't read past the lvb */
- if ((count + *ppos) > i_size_read(inode))
- readlen = i_size_read(inode) - *ppos;
- else
- readlen = count - *ppos;
-
- lvb_buf = kmalloc(readlen, GFP_NOFS);
- if (!lvb_buf)
- return -ENOMEM;
-
- user_dlm_read_lvb(inode, lvb_buf, readlen);
- bytes_left = __copy_to_user(buf, lvb_buf, readlen);
- readlen -= bytes_left;
-
- kfree(lvb_buf);
-
- *ppos = *ppos + readlen;
-
- mlog(0, "read %zd bytes\n", readlen);
- return readlen;
-}
-
-static ssize_t dlmfs_file_write(struct file *filp,
- const char __user *buf,
- size_t count,
- loff_t *ppos)
-{
- int bytes_left;
- ssize_t writelen;
- char *lvb_buf;
- struct inode *inode = filp->f_path.dentry->d_inode;
-
- mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
- inode->i_ino, count, *ppos);
-
- if (*ppos >= i_size_read(inode))
- return -ENOSPC;
-
- if (!count)
- return 0;
-
- if (!access_ok(VERIFY_READ, buf, count))
- return -EFAULT;
-
- /* don't write past the lvb */
- if ((count + *ppos) > i_size_read(inode))
- writelen = i_size_read(inode) - *ppos;
- else
- writelen = count - *ppos;
-
- lvb_buf = kmalloc(writelen, GFP_NOFS);
- if (!lvb_buf)
- return -ENOMEM;
-
- bytes_left = copy_from_user(lvb_buf, buf, writelen);
- writelen -= bytes_left;
- if (writelen)
- user_dlm_write_lvb(inode, lvb_buf, writelen);
-
- kfree(lvb_buf);
-
- *ppos = *ppos + writelen;
- mlog(0, "wrote %zd bytes\n", writelen);
- return writelen;
-}
-
-static void dlmfs_init_once(void *foo)
-{
- struct dlmfs_inode_private *ip =
- (struct dlmfs_inode_private *) foo;
-
- ip->ip_dlm = NULL;
- ip->ip_parent = NULL;
-
- inode_init_once(&ip->ip_vfs_inode);
-}
-
-static struct inode *dlmfs_alloc_inode(struct super_block *sb)
-{
- struct dlmfs_inode_private *ip;
-
- ip = kmem_cache_alloc(dlmfs_inode_cache, GFP_NOFS);
- if (!ip)
- return NULL;
-
- return &ip->ip_vfs_inode;
-}
-
-static void dlmfs_destroy_inode(struct inode *inode)
-{
- kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
-}
-
-static void dlmfs_clear_inode(struct inode *inode)
-{
- int status;
- struct dlmfs_inode_private *ip;
-
- if (!inode)
- return;
-
- mlog(0, "inode %lu\n", inode->i_ino);
-
- ip = DLMFS_I(inode);
-
- if (S_ISREG(inode->i_mode)) {
- status = user_dlm_destroy_lock(&ip->ip_lockres);
- if (status < 0)
- mlog_errno(status);
- iput(ip->ip_parent);
- goto clear_fields;
- }
-
- mlog(0, "we're a directory, ip->ip_dlm = 0x%p\n", ip->ip_dlm);
- /* we must be a directory. If required, lets unregister the
- * dlm context now. */
- if (ip->ip_dlm)
- user_dlm_unregister_context(ip->ip_dlm);
-clear_fields:
- ip->ip_parent = NULL;
- ip->ip_dlm = NULL;
-}
-
-static struct backing_dev_info dlmfs_backing_dev_info = {
- .name = "ocfs2-dlmfs",
- .ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
-
-static struct inode *dlmfs_get_root_inode(struct super_block *sb)
-{
- struct inode *inode = new_inode(sb);
- int mode = S_IFDIR | 0755;
- struct dlmfs_inode_private *ip;
-
- if (inode) {
- ip = DLMFS_I(inode);
-
- inode->i_mode = mode;
- inode->i_uid = current_fsuid();
- inode->i_gid = current_fsgid();
- inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- inc_nlink(inode);
-
- inode->i_fop = &simple_dir_operations;
- inode->i_op = &dlmfs_root_inode_operations;
- }
-
- return inode;
-}
-
-static struct inode *dlmfs_get_inode(struct inode *parent,
- struct dentry *dentry,
- int mode)
-{
- struct super_block *sb = parent->i_sb;
- struct inode * inode = new_inode(sb);
- struct dlmfs_inode_private *ip;
-
- if (!inode)
- return NULL;
-
- inode->i_mode = mode;
- inode->i_uid = current_fsuid();
- inode->i_gid = current_fsgid();
- inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-
- ip = DLMFS_I(inode);
- ip->ip_dlm = DLMFS_I(parent)->ip_dlm;
-
- switch (mode & S_IFMT) {
- default:
- /* for now we don't support anything other than
- * directories and regular files. */
- BUG();
- break;
- case S_IFREG:
- inode->i_op = &dlmfs_file_inode_operations;
- inode->i_fop = &dlmfs_file_operations;
-
- i_size_write(inode, DLM_LVB_LEN);
-
- user_dlm_lock_res_init(&ip->ip_lockres, dentry);
-
- /* released at clear_inode time, this insures that we
- * get to drop the dlm reference on each lock *before*
- * we call the unregister code for releasing parent
- * directories. */
- ip->ip_parent = igrab(parent);
- BUG_ON(!ip->ip_parent);
- break;
- case S_IFDIR:
- inode->i_op = &dlmfs_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
-
- /* directory inodes start off with i_nlink ==
- * 2 (for "." entry) */
- inc_nlink(inode);
- break;
- }
-
- if (parent->i_mode & S_ISGID) {
- inode->i_gid = parent->i_gid;
- if (S_ISDIR(mode))
- inode->i_mode |= S_ISGID;
- }
-
- return inode;
-}
-
-/*
- * File creation. Allocate an inode, and we're done..
- */
-/* SMP-safe */
-static int dlmfs_mkdir(struct inode * dir,
- struct dentry * dentry,
- int mode)
-{
- int status;
- struct inode *inode = NULL;
- struct qstr *domain = &dentry->d_name;
- struct dlmfs_inode_private *ip;
- struct dlm_ctxt *dlm;
- struct dlm_protocol_version proto = user_locking_protocol;
-
- mlog(0, "mkdir %.*s\n", domain->len, domain->name);
-
- /* verify that we have a proper domain */
- if (domain->len >= O2NM_MAX_NAME_LEN) {
- status = -EINVAL;
- mlog(ML_ERROR, "invalid domain name for directory.\n");
- goto bail;
- }
-
- inode = dlmfs_get_inode(dir, dentry, mode | S_IFDIR);
- if (!inode) {
- status = -ENOMEM;
- mlog_errno(status);
- goto bail;
- }
-
- ip = DLMFS_I(inode);
-
- dlm = user_dlm_register_context(domain, &proto);
- if (IS_ERR(dlm)) {
- status = PTR_ERR(dlm);
- mlog(ML_ERROR, "Error %d could not register domain \"%.*s\"\n",
- status, domain->len, domain->name);
- goto bail;
- }
- ip->ip_dlm = dlm;
-
- inc_nlink(dir);
- d_instantiate(dentry, inode);
- dget(dentry); /* Extra count - pin the dentry in core */
-
- status = 0;
-bail:
- if (status < 0)
- iput(inode);
- return status;
-}
-
-static int dlmfs_create(struct inode *dir,
- struct dentry *dentry,
- int mode,
- struct nameidata *nd)
-{
- int status = 0;
- struct inode *inode;
- struct qstr *name = &dentry->d_name;
-
- mlog(0, "create %.*s\n", name->len, name->name);
-
- /* verify name is valid and doesn't contain any dlm reserved
- * characters */
- if (name->len >= USER_DLM_LOCK_ID_MAX_LEN ||
- name->name[0] == '$') {
- status = -EINVAL;
- mlog(ML_ERROR, "invalid lock name, %.*s\n", name->len,
- name->name);
- goto bail;
- }
-
- inode = dlmfs_get_inode(dir, dentry, mode | S_IFREG);
- if (!inode) {
- status = -ENOMEM;
- mlog_errno(status);
- goto bail;
- }
-
- d_instantiate(dentry, inode);
- dget(dentry); /* Extra count - pin the dentry in core */
-bail:
- return status;
-}
-
-static int dlmfs_unlink(struct inode *dir,
- struct dentry *dentry)
-{
- int status;
- struct inode *inode = dentry->d_inode;
-
- mlog(0, "unlink inode %lu\n", inode->i_ino);
-
- /* if there are no current holders, or none that are waiting
- * to acquire a lock, this basically destroys our lockres. */
- status = user_dlm_destroy_lock(&DLMFS_I(inode)->ip_lockres);
- if (status < 0) {
- mlog(ML_ERROR, "unlink %.*s, error %d from destroy\n",
- dentry->d_name.len, dentry->d_name.name, status);
- goto bail;
- }
- status = simple_unlink(dir, dentry);
-bail:
- return status;
-}
-
-static int dlmfs_fill_super(struct super_block * sb,
- void * data,
- int silent)
-{
- struct inode * inode;
- struct dentry * root;
-
- sb->s_maxbytes = MAX_LFS_FILESIZE;
- sb->s_blocksize = PAGE_CACHE_SIZE;
- sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
- sb->s_magic = DLMFS_MAGIC;
- sb->s_op = &dlmfs_ops;
- inode = dlmfs_get_root_inode(sb);
- if (!inode)
- return -ENOMEM;
-
- root = d_alloc_root(inode);
- if (!root) {
- iput(inode);
- return -ENOMEM;
- }
- sb->s_root = root;
- return 0;
-}
-
-static const struct file_operations dlmfs_file_operations = {
- .open = dlmfs_file_open,
- .release = dlmfs_file_release,
- .poll = dlmfs_file_poll,
- .read = dlmfs_file_read,
- .write = dlmfs_file_write,
-};
-
-static const struct inode_operations dlmfs_dir_inode_operations = {
- .create = dlmfs_create,
- .lookup = simple_lookup,
- .unlink = dlmfs_unlink,
-};
-
-/* this way we can restrict mkdir to only the toplevel of the fs. */
-static const struct inode_operations dlmfs_root_inode_operations = {
- .lookup = simple_lookup,
- .mkdir = dlmfs_mkdir,
- .rmdir = simple_rmdir,
-};
-
-static const struct super_operations dlmfs_ops = {
- .statfs = simple_statfs,
- .alloc_inode = dlmfs_alloc_inode,
- .destroy_inode = dlmfs_destroy_inode,
- .clear_inode = dlmfs_clear_inode,
- .drop_inode = generic_delete_inode,
-};
-
-static const struct inode_operations dlmfs_file_inode_operations = {
- .getattr = simple_getattr,
-};
-
-static int dlmfs_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, dlmfs_fill_super, mnt);
-}
-
-static struct file_system_type dlmfs_fs_type = {
- .owner = THIS_MODULE,
- .name = "ocfs2_dlmfs",
- .get_sb = dlmfs_get_sb,
- .kill_sb = kill_litter_super,
-};
-
-static int __init init_dlmfs_fs(void)
-{
- int status;
- int cleanup_inode = 0, cleanup_worker = 0;
-
- dlmfs_print_version();
-
- status = bdi_init(&dlmfs_backing_dev_info);
- if (status)
- return status;
-
- dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache",
- sizeof(struct dlmfs_inode_private),
- 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
- SLAB_MEM_SPREAD),
- dlmfs_init_once);
- if (!dlmfs_inode_cache) {
- status = -ENOMEM;
- goto bail;
- }
- cleanup_inode = 1;
-
- user_dlm_worker = create_singlethread_workqueue("user_dlm");
- if (!user_dlm_worker) {
- status = -ENOMEM;
- goto bail;
- }
- cleanup_worker = 1;
-
- status = register_filesystem(&dlmfs_fs_type);
-bail:
- if (status) {
- if (cleanup_inode)
- kmem_cache_destroy(dlmfs_inode_cache);
- if (cleanup_worker)
- destroy_workqueue(user_dlm_worker);
- bdi_destroy(&dlmfs_backing_dev_info);
- } else
- printk("OCFS2 User DLM kernel interface loaded\n");
- return status;
-}
-
-static void __exit exit_dlmfs_fs(void)
-{
- unregister_filesystem(&dlmfs_fs_type);
-
- flush_workqueue(user_dlm_worker);
- destroy_workqueue(user_dlm_worker);
-
- kmem_cache_destroy(dlmfs_inode_cache);
-
- bdi_destroy(&dlmfs_backing_dev_info);
-}
-
-MODULE_AUTHOR("Oracle");
-MODULE_LICENSE("GPL");
-
-module_init(init_dlmfs_fs)
-module_exit(exit_dlmfs_fs)
git.openpandora.org / pandora-kernel.git / blobdiff