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linux-sg2042/fs/dlm/device.c

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/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
/*
* device.c
*
* This is the userland interface to the DLM.
*
* The locking is done via a misc char device (find the
* registered minor number in /proc/misc).
*
* User code should not use this interface directly but
* call the library routines in libdlm.a instead.
*
*/
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <linux/dlm.h>
#include <linux/dlm_device.h>
#include "lvb_table.h"
static struct file_operations _dlm_fops;
static const char *name_prefix="dlm";
static struct list_head user_ls_list;
static struct semaphore user_ls_lock;
/* Lock infos are stored in here indexed by lock ID */
static DEFINE_IDR(lockinfo_idr);
static rwlock_t lockinfo_lock;
/* Flags in li_flags */
#define LI_FLAG_COMPLETE 1
#define LI_FLAG_FIRSTLOCK 2
#define LI_FLAG_PERSISTENT 3
/* flags in ls_flags*/
#define LS_FLAG_DELETED 1
#define LS_FLAG_AUTOFREE 2
#define LOCKINFO_MAGIC 0x53595324
struct lock_info {
uint32_t li_magic;
uint8_t li_cmd;
int8_t li_grmode;
int8_t li_rqmode;
struct dlm_lksb li_lksb;
wait_queue_head_t li_waitq;
unsigned long li_flags;
void __user *li_castparam;
void __user *li_castaddr;
void __user *li_bastparam;
void __user *li_bastaddr;
void __user *li_pend_bastparam;
void __user *li_pend_bastaddr;
struct list_head li_ownerqueue;
struct file_info *li_file;
struct dlm_lksb __user *li_user_lksb;
struct semaphore li_firstlock;
};
/* A queued AST no less */
struct ast_info {
struct dlm_lock_result result;
struct list_head list;
uint32_t lvb_updated;
uint32_t progress; /* How much has been read */
};
/* One of these per userland lockspace */
struct user_ls {
void *ls_lockspace;
atomic_t ls_refcnt;
long ls_flags;
/* Passed into misc_register() */
struct miscdevice ls_miscinfo;
struct list_head ls_list;
};
/* misc_device info for the control device */
static struct miscdevice ctl_device;
/*
* Stuff we hang off the file struct.
* The first two are to cope with unlocking all the
* locks help by a process when it dies.
*/
struct file_info {
struct list_head fi_li_list; /* List of active lock_infos */
spinlock_t fi_li_lock;
struct list_head fi_ast_list; /* Queue of ASTs to be delivered */
spinlock_t fi_ast_lock;
wait_queue_head_t fi_wait;
struct user_ls *fi_ls;
atomic_t fi_refcnt; /* Number of users */
unsigned long fi_flags; /* Bit 1 means the device is open */
};
/* get and put ops for file_info.
Actually I don't really like "get" and "put", but everyone
else seems to use them and I can't think of anything
nicer at the moment */
static void get_file_info(struct file_info *f)
{
atomic_inc(&f->fi_refcnt);
}
static void put_file_info(struct file_info *f)
{
if (atomic_dec_and_test(&f->fi_refcnt))
kfree(f);
}
static void release_lockinfo(struct lock_info *li)
{
put_file_info(li->li_file);
write_lock(&lockinfo_lock);
idr_remove(&lockinfo_idr, li->li_lksb.sb_lkid);
write_unlock(&lockinfo_lock);
if (li->li_lksb.sb_lvbptr)
kfree(li->li_lksb.sb_lvbptr);
kfree(li);
module_put(THIS_MODULE);
}
static struct lock_info *get_lockinfo(uint32_t lockid)
{
struct lock_info *li;
read_lock(&lockinfo_lock);
li = idr_find(&lockinfo_idr, lockid);
read_unlock(&lockinfo_lock);
return li;
}
static int add_lockinfo(struct lock_info *li)
{
int n;
int r;
int ret = -EINVAL;
write_lock(&lockinfo_lock);
if (idr_find(&lockinfo_idr, li->li_lksb.sb_lkid))
goto out_up;
ret = -ENOMEM;
r = idr_pre_get(&lockinfo_idr, GFP_KERNEL);
if (!r)
goto out_up;
r = idr_get_new_above(&lockinfo_idr, li, li->li_lksb.sb_lkid, &n);
if (r)
goto out_up;
if (n != li->li_lksb.sb_lkid) {
idr_remove(&lockinfo_idr, n);
goto out_up;
}
ret = 0;
out_up:
write_unlock(&lockinfo_lock);
return ret;
}
static struct user_ls *__find_lockspace(int minor)
{
struct user_ls *lsinfo;
list_for_each_entry(lsinfo, &user_ls_list, ls_list) {
if (lsinfo->ls_miscinfo.minor == minor)
return lsinfo;
}
return NULL;
}
/* Find a lockspace struct given the device minor number */
static struct user_ls *find_lockspace(int minor)
{
struct user_ls *lsinfo;
down(&user_ls_lock);
lsinfo = __find_lockspace(minor);
up(&user_ls_lock);
return lsinfo;
}
static void add_lockspace_to_list(struct user_ls *lsinfo)
{
down(&user_ls_lock);
list_add(&lsinfo->ls_list, &user_ls_list);
up(&user_ls_lock);
}
/* Register a lockspace with the DLM and create a misc
device for userland to access it */
static int register_lockspace(char *name, struct user_ls **ls, int flags)
{
struct user_ls *newls;
int status;
int namelen;
namelen = strlen(name)+strlen(name_prefix)+2;
newls = kmalloc(sizeof(struct user_ls), GFP_KERNEL);
if (!newls)
return -ENOMEM;
memset(newls, 0, sizeof(struct user_ls));
newls->ls_miscinfo.name = kmalloc(namelen, GFP_KERNEL);
if (!newls->ls_miscinfo.name) {
kfree(newls);
return -ENOMEM;
}
status = dlm_new_lockspace(name, strlen(name), &newls->ls_lockspace, 0,
DLM_USER_LVB_LEN);
if (status != 0) {
kfree(newls->ls_miscinfo.name);
kfree(newls);
return status;
}
snprintf((char*)newls->ls_miscinfo.name, namelen, "%s_%s",
name_prefix, name);
newls->ls_miscinfo.fops = &_dlm_fops;
newls->ls_miscinfo.minor = MISC_DYNAMIC_MINOR;
status = misc_register(&newls->ls_miscinfo);
if (status) {
printk(KERN_ERR "dlm: misc register failed for %s\n", name);
dlm_release_lockspace(newls->ls_lockspace, 0);
kfree(newls->ls_miscinfo.name);
kfree(newls);
return status;
}
if (flags & DLM_USER_LSFLG_AUTOFREE)
set_bit(LS_FLAG_AUTOFREE, &newls->ls_flags);
add_lockspace_to_list(newls);
*ls = newls;
return 0;
}
/* Called with the user_ls_lock semaphore held */
static int unregister_lockspace(struct user_ls *lsinfo, int force)
{
int status;
status = dlm_release_lockspace(lsinfo->ls_lockspace, force);
if (status)
return status;
status = misc_deregister(&lsinfo->ls_miscinfo);
if (status)
return status;
list_del(&lsinfo->ls_list);
set_bit(LS_FLAG_DELETED, &lsinfo->ls_flags);
lsinfo->ls_lockspace = NULL;
if (atomic_read(&lsinfo->ls_refcnt) == 0) {
kfree(lsinfo->ls_miscinfo.name);
kfree(lsinfo);
}
return 0;
}
/* Add it to userland's AST queue */
static void add_to_astqueue(struct lock_info *li, void *astaddr, void *astparam,
int lvb_updated)
{
struct ast_info *ast = kmalloc(sizeof(struct ast_info), GFP_KERNEL);
if (!ast)
return;
memset(ast, 0, sizeof(*ast));
ast->result.user_astparam = astparam;
ast->result.user_astaddr = astaddr;
ast->result.user_lksb = li->li_user_lksb;
memcpy(&ast->result.lksb, &li->li_lksb, sizeof(struct dlm_lksb));
ast->lvb_updated = lvb_updated;
spin_lock(&li->li_file->fi_ast_lock);
list_add_tail(&ast->list, &li->li_file->fi_ast_list);
spin_unlock(&li->li_file->fi_ast_lock);
wake_up_interruptible(&li->li_file->fi_wait);
}
static void bast_routine(void *param, int mode)
{
struct lock_info *li = param;
if (li && li->li_bastaddr)
add_to_astqueue(li, li->li_bastaddr, li->li_bastparam, 0);
}
/*
* This is the kernel's AST routine.
* All lock, unlock & query operations complete here.
* The only syncronous ops are those done during device close.
*/
static void ast_routine(void *param)
{
struct lock_info *li = param;
/* Param may be NULL if a persistent lock is unlocked by someone else */
if (!li)
return;
/* If this is a succesful conversion then activate the blocking ast
* args from the conversion request */
if (!test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags) &&
li->li_lksb.sb_status == 0) {
li->li_bastparam = li->li_pend_bastparam;
li->li_bastaddr = li->li_pend_bastaddr;
li->li_pend_bastaddr = NULL;
}
/* If it's an async request then post data to the user's AST queue. */
if (li->li_castaddr) {
int lvb_updated = 0;
/* See if the lvb has been updated */
if (dlm_lvb_operations[li->li_grmode+1][li->li_rqmode+1] == 1)
lvb_updated = 1;
if (li->li_lksb.sb_status == 0)
li->li_grmode = li->li_rqmode;
/* Only queue AST if the device is still open */
if (test_bit(1, &li->li_file->fi_flags))
add_to_astqueue(li, li->li_castaddr, li->li_castparam,
lvb_updated);
/* If it's a new lock operation that failed, then
* remove it from the owner queue and free the
* lock_info.
*/
if (test_and_clear_bit(LI_FLAG_FIRSTLOCK, &li->li_flags) &&
li->li_lksb.sb_status != 0) {
/* Wait till dlm_lock() has finished */
down(&li->li_firstlock);
up(&li->li_firstlock);
spin_lock(&li->li_file->fi_li_lock);
list_del(&li->li_ownerqueue);
spin_unlock(&li->li_file->fi_li_lock);
release_lockinfo(li);
return;
}
/* Free unlocks & queries */
if (li->li_lksb.sb_status == -DLM_EUNLOCK ||
li->li_cmd == DLM_USER_QUERY) {
release_lockinfo(li);
}
} else {
/* Synchronous request, just wake up the caller */
set_bit(LI_FLAG_COMPLETE, &li->li_flags);
wake_up_interruptible(&li->li_waitq);
}
}
/*
* Wait for the lock op to complete and return the status.
*/
static int wait_for_ast(struct lock_info *li)
{
/* Wait for the AST routine to complete */
set_task_state(current, TASK_INTERRUPTIBLE);
while (!test_bit(LI_FLAG_COMPLETE, &li->li_flags))
schedule();
set_task_state(current, TASK_RUNNING);
return li->li_lksb.sb_status;
}
/* Open on control device */
static int dlm_ctl_open(struct inode *inode, struct file *file)
{
file->private_data = NULL;
return 0;
}
/* Close on control device */
static int dlm_ctl_close(struct inode *inode, struct file *file)
{
return 0;
}
/* Open on lockspace device */
static int dlm_open(struct inode *inode, struct file *file)
{
struct file_info *f;
struct user_ls *lsinfo;
lsinfo = find_lockspace(iminor(inode));
if (!lsinfo)
return -ENOENT;
f = kmalloc(sizeof(struct file_info), GFP_KERNEL);
if (!f)
return -ENOMEM;
atomic_inc(&lsinfo->ls_refcnt);
INIT_LIST_HEAD(&f->fi_li_list);
INIT_LIST_HEAD(&f->fi_ast_list);
spin_lock_init(&f->fi_li_lock);
spin_lock_init(&f->fi_ast_lock);
init_waitqueue_head(&f->fi_wait);
f->fi_ls = lsinfo;
f->fi_flags = 0;
get_file_info(f);
set_bit(1, &f->fi_flags);
file->private_data = f;
return 0;
}
/* Check the user's version matches ours */
static int check_version(struct dlm_write_request *req)
{
if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
(req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
"user (%d.%d.%d) kernel (%d.%d.%d)\n",
current->comm,
current->pid,
req->version[0],
req->version[1],
req->version[2],
DLM_DEVICE_VERSION_MAJOR,
DLM_DEVICE_VERSION_MINOR,
DLM_DEVICE_VERSION_PATCH);
return -EINVAL;
}
return 0;
}
/* Close on lockspace device */
static int dlm_close(struct inode *inode, struct file *file)
{
struct file_info *f = file->private_data;
struct lock_info li;
struct lock_info *old_li, *safe;
sigset_t tmpsig;
sigset_t allsigs;
struct user_ls *lsinfo;
DECLARE_WAITQUEUE(wq, current);
lsinfo = find_lockspace(iminor(inode));
if (!lsinfo)
return -ENOENT;
/* Mark this closed so that ASTs will not be delivered any more */
clear_bit(1, &f->fi_flags);
/* Block signals while we are doing this */
sigfillset(&allsigs);
sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
/* We use our own lock_info struct here, so that any
* outstanding "real" ASTs will be delivered with the
* corresponding "real" params, thus freeing the lock_info
* that belongs the lock. This catches the corner case where
* a lock is BUSY when we try to unlock it here
*/
memset(&li, 0, sizeof(li));
clear_bit(LI_FLAG_COMPLETE, &li.li_flags);
init_waitqueue_head(&li.li_waitq);
add_wait_queue(&li.li_waitq, &wq);
/*
* Free any outstanding locks, they are on the
* list in LIFO order so there should be no problems
* about unlocking parents before children.
*/
list_for_each_entry_safe(old_li, safe, &f->fi_li_list, li_ownerqueue) {
int status;
int flags = 0;
/* Don't unlock persistent locks, just mark them orphaned */
if (test_bit(LI_FLAG_PERSISTENT, &old_li->li_flags)) {
list_del(&old_li->li_ownerqueue);
/* Update master copy */
/* TODO: Check locking core updates the local and
remote ORPHAN flags */
li.li_lksb.sb_lkid = old_li->li_lksb.sb_lkid;
status = dlm_lock(f->fi_ls->ls_lockspace,
old_li->li_grmode, &li.li_lksb,
DLM_LKF_CONVERT|DLM_LKF_ORPHAN,
NULL, 0, 0, ast_routine, NULL,
NULL, NULL);
if (status != 0)
printk("dlm: Error orphaning lock %x: %d\n",
old_li->li_lksb.sb_lkid, status);
/* But tidy our references in it */
release_lockinfo(old_li);
continue;
}
clear_bit(LI_FLAG_COMPLETE, &li.li_flags);
flags = DLM_LKF_FORCEUNLOCK;
if (old_li->li_grmode >= DLM_LOCK_PW)
flags |= DLM_LKF_IVVALBLK;
status = dlm_unlock(f->fi_ls->ls_lockspace,
old_li->li_lksb.sb_lkid, flags,
&li.li_lksb, &li);
/* Must wait for it to complete as the next lock could be its
* parent */
if (status == 0)
wait_for_ast(&li);
/* Unlock suceeded, free the lock_info struct. */
if (status == 0)
release_lockinfo(old_li);
}
remove_wait_queue(&li.li_waitq, &wq);
/*
* If this is the last reference to the lockspace
* then free the struct. If it's an AUTOFREE lockspace
* then free the whole thing.
*/
down(&user_ls_lock);
if (atomic_dec_and_test(&lsinfo->ls_refcnt)) {
if (lsinfo->ls_lockspace) {
if (test_bit(LS_FLAG_AUTOFREE, &lsinfo->ls_flags)) {
unregister_lockspace(lsinfo, 1);
}
} else {
kfree(lsinfo->ls_miscinfo.name);
kfree(lsinfo);
}
}
up(&user_ls_lock);
put_file_info(f);
/* Restore signals */
sigprocmask(SIG_SETMASK, &tmpsig, NULL);
recalc_sigpending();
return 0;
}
static int do_user_create_lockspace(struct file_info *fi, uint8_t cmd,
struct dlm_lspace_params *kparams)
{
int status;
struct user_ls *lsinfo;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
status = register_lockspace(kparams->name, &lsinfo, kparams->flags);
/* If it succeeded then return the minor number */
if (status == 0)
status = lsinfo->ls_miscinfo.minor;
return status;
}
static int do_user_remove_lockspace(struct file_info *fi, uint8_t cmd,
struct dlm_lspace_params *kparams)
{
int status;
int force = 1;
struct user_ls *lsinfo;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
down(&user_ls_lock);
lsinfo = __find_lockspace(kparams->minor);
if (!lsinfo) {
up(&user_ls_lock);
return -EINVAL;
}
if (kparams->flags & DLM_USER_LSFLG_FORCEFREE)
force = 2;
status = unregister_lockspace(lsinfo, force);
up(&user_ls_lock);
return status;
}
/* Read call, might block if no ASTs are waiting.
* It will only ever return one message at a time, regardless
* of how many are pending.
*/
static ssize_t dlm_read(struct file *file, char __user *buffer, size_t count,
loff_t *ppos)
{
struct file_info *fi = file->private_data;
struct ast_info *ast;
int data_size;
int offset;
DECLARE_WAITQUEUE(wait, current);
if (count < sizeof(struct dlm_lock_result))
return -EINVAL;
spin_lock(&fi->fi_ast_lock);
if (list_empty(&fi->fi_ast_list)) {
/* No waiting ASTs.
* Return EOF if the lockspace been deleted.
*/
if (test_bit(LS_FLAG_DELETED, &fi->fi_ls->ls_flags))
return 0;
if (file->f_flags & O_NONBLOCK) {
spin_unlock(&fi->fi_ast_lock);
return -EAGAIN;
}
add_wait_queue(&fi->fi_wait, &wait);
repeat:
set_current_state(TASK_INTERRUPTIBLE);
if (list_empty(&fi->fi_ast_list) &&
!signal_pending(current)) {
spin_unlock(&fi->fi_ast_lock);
schedule();
spin_lock(&fi->fi_ast_lock);
goto repeat;
}
current->state = TASK_RUNNING;
remove_wait_queue(&fi->fi_wait, &wait);
if (signal_pending(current)) {
spin_unlock(&fi->fi_ast_lock);
return -ERESTARTSYS;
}
}
ast = list_entry(fi->fi_ast_list.next, struct ast_info, list);
list_del(&ast->list);
spin_unlock(&fi->fi_ast_lock);
/* Work out the size of the returned data */
data_size = sizeof(struct dlm_lock_result);
if (ast->lvb_updated && ast->result.lksb.sb_lvbptr)
data_size += DLM_USER_LVB_LEN;
offset = sizeof(struct dlm_lock_result);
/* Room for the extended data ? */
if (count >= data_size) {
if (ast->lvb_updated && ast->result.lksb.sb_lvbptr) {
if (copy_to_user(buffer+offset,
ast->result.lksb.sb_lvbptr,
DLM_USER_LVB_LEN))
return -EFAULT;
ast->result.lvb_offset = offset;
offset += DLM_USER_LVB_LEN;
}
}
ast->result.length = data_size;
/* Copy the header now it has all the offsets in it */
if (copy_to_user(buffer, &ast->result, sizeof(struct dlm_lock_result)))
offset = -EFAULT;
/* If we only returned a header and there's more to come then put it
back on the list */
if (count < data_size) {
spin_lock(&fi->fi_ast_lock);
list_add(&ast->list, &fi->fi_ast_list);
spin_unlock(&fi->fi_ast_lock);
} else
kfree(ast);
return offset;
}
static unsigned int dlm_poll(struct file *file, poll_table *wait)
{
struct file_info *fi = file->private_data;
poll_wait(file, &fi->fi_wait, wait);
spin_lock(&fi->fi_ast_lock);
if (!list_empty(&fi->fi_ast_list)) {
spin_unlock(&fi->fi_ast_lock);
return POLLIN | POLLRDNORM;
}
spin_unlock(&fi->fi_ast_lock);
return 0;
}
static struct lock_info *allocate_lockinfo(struct file_info *fi, uint8_t cmd,
struct dlm_lock_params *kparams)
{
struct lock_info *li;
if (!try_module_get(THIS_MODULE))
return NULL;
li = kmalloc(sizeof(struct lock_info), GFP_KERNEL);
if (li) {
li->li_magic = LOCKINFO_MAGIC;
li->li_file = fi;
li->li_cmd = cmd;
li->li_flags = 0;
li->li_grmode = -1;
li->li_rqmode = -1;
li->li_pend_bastparam = NULL;
li->li_pend_bastaddr = NULL;
li->li_castaddr = NULL;
li->li_castparam = NULL;
li->li_lksb.sb_lvbptr = NULL;
li->li_bastaddr = kparams->bastaddr;
li->li_bastparam = kparams->bastparam;
get_file_info(fi);
}
return li;
}
static int do_user_lock(struct file_info *fi, uint8_t cmd,
struct dlm_lock_params *kparams)
{
struct lock_info *li;
int status;
/*
* Validate things that we need to have correct.
*/
if (!kparams->castaddr)
return -EINVAL;
if (!kparams->lksb)
return -EINVAL;
/* Persistent child locks are not available yet */
if ((kparams->flags & DLM_LKF_PERSISTENT) && kparams->parent)
return -EINVAL;
/* For conversions, there should already be a lockinfo struct,
unless we are adopting an orphaned persistent lock */
if (kparams->flags & DLM_LKF_CONVERT) {
li = get_lockinfo(kparams->lkid);
/* If this is a persistent lock we will have to create a
lockinfo again */
if (!li && DLM_LKF_PERSISTENT) {
li = allocate_lockinfo(fi, cmd, kparams);
li->li_lksb.sb_lkid = kparams->lkid;
li->li_castaddr = kparams->castaddr;
li->li_castparam = kparams->castparam;
/* OK, this isn;t exactly a FIRSTLOCK but it is the
first time we've used this lockinfo, and if things
fail we want rid of it */
init_MUTEX_LOCKED(&li->li_firstlock);
set_bit(LI_FLAG_FIRSTLOCK, &li->li_flags);
add_lockinfo(li);
/* TODO: do a query to get the current state ?? */
}
if (!li)
return -EINVAL;
if (li->li_magic != LOCKINFO_MAGIC)
return -EINVAL;
/* For conversions don't overwrite the current blocking AST
info so that:
a) if a blocking AST fires before the conversion is queued
it runs the current handler
b) if the conversion is cancelled, the original blocking AST
declaration is active
The pend_ info is made active when the conversion
completes.
*/
li->li_pend_bastaddr = kparams->bastaddr;
li->li_pend_bastparam = kparams->bastparam;
} else {
li = allocate_lockinfo(fi, cmd, kparams);
if (!li)
return -ENOMEM;
/* semaphore to allow us to complete our work before
the AST routine runs. In fact we only need (and use) this
when the initial lock fails */
init_MUTEX_LOCKED(&li->li_firstlock);
set_bit(LI_FLAG_FIRSTLOCK, &li->li_flags);
}
li->li_user_lksb = kparams->lksb;
li->li_castaddr = kparams->castaddr;
li->li_castparam = kparams->castparam;
li->li_lksb.sb_lkid = kparams->lkid;
li->li_rqmode = kparams->mode;
if (kparams->flags & DLM_LKF_PERSISTENT)
set_bit(LI_FLAG_PERSISTENT, &li->li_flags);
/* Copy in the value block */
if (kparams->flags & DLM_LKF_VALBLK) {
if (!li->li_lksb.sb_lvbptr) {
li->li_lksb.sb_lvbptr = kmalloc(DLM_USER_LVB_LEN,
GFP_KERNEL);
if (!li->li_lksb.sb_lvbptr) {
status = -ENOMEM;
goto out_err;
}
}
memcpy(li->li_lksb.sb_lvbptr, kparams->lvb, DLM_USER_LVB_LEN);
}
/* Lock it ... */
status = dlm_lock(fi->fi_ls->ls_lockspace,
kparams->mode, &li->li_lksb,
kparams->flags,
kparams->name, kparams->namelen,
kparams->parent,
ast_routine,
li,
(li->li_pend_bastaddr || li->li_bastaddr) ?
bast_routine : NULL,
kparams->range.ra_end ? &kparams->range : NULL);
if (status)
goto out_err;
/* If it succeeded (this far) with a new lock then keep track of
it on the file's lockinfo list */
if (!status && test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags)) {
spin_lock(&fi->fi_li_lock);
list_add(&li->li_ownerqueue, &fi->fi_li_list);
spin_unlock(&fi->fi_li_lock);
if (add_lockinfo(li))
printk(KERN_WARNING "Add lockinfo failed\n");
up(&li->li_firstlock);
}
/* Return the lockid as the user needs it /now/ */
return li->li_lksb.sb_lkid;
out_err:
if (test_bit(LI_FLAG_FIRSTLOCK, &li->li_flags))
release_lockinfo(li);
return status;
}
static int do_user_unlock(struct file_info *fi, uint8_t cmd,
struct dlm_lock_params *kparams)
{
struct lock_info *li;
int status;
int convert_cancel = 0;
li = get_lockinfo(kparams->lkid);
if (!li) {
li = allocate_lockinfo(fi, cmd, kparams);
spin_lock(&fi->fi_li_lock);
list_add(&li->li_ownerqueue, &fi->fi_li_list);
spin_unlock(&fi->fi_li_lock);
}
if (!li)
return -ENOMEM;
if (li->li_magic != LOCKINFO_MAGIC)
return -EINVAL;
li->li_user_lksb = kparams->lksb;
li->li_castparam = kparams->castparam;
li->li_cmd = cmd;
/* Cancelling a conversion doesn't remove the lock...*/
if (kparams->flags & DLM_LKF_CANCEL && li->li_grmode != -1)
convert_cancel = 1;
/* dlm_unlock() passes a 0 for castaddr which means don't overwrite
the existing li_castaddr as that's the completion routine for
unlocks. dlm_unlock_wait() specifies a new AST routine to be
executed when the unlock completes. */
if (kparams->castaddr)
li->li_castaddr = kparams->castaddr;
/* Use existing lksb & astparams */
status = dlm_unlock(fi->fi_ls->ls_lockspace,
kparams->lkid,
kparams->flags, &li->li_lksb, li);
if (!status && !convert_cancel) {
spin_lock(&fi->fi_li_lock);
list_del(&li->li_ownerqueue);
spin_unlock(&fi->fi_li_lock);
}
return status;
}
/* Write call, submit a locking request */
static ssize_t dlm_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
struct file_info *fi = file->private_data;
struct dlm_write_request *kparams;
sigset_t tmpsig;
sigset_t allsigs;
int status;
/* -1 because lock name is optional */
if (count < sizeof(struct dlm_write_request)-1)
return -EINVAL;
/* Has the lockspace been deleted */
if (fi && test_bit(LS_FLAG_DELETED, &fi->fi_ls->ls_flags))
return -ENOENT;
kparams = kmalloc(count, GFP_KERNEL);
if (!kparams)
return -ENOMEM;
status = -EFAULT;
/* Get the command info */
if (copy_from_user(kparams, buffer, count))
goto out_free;
status = -EBADE;
if (check_version(kparams))
goto out_free;
/* Block signals while we are doing this */
sigfillset(&allsigs);
sigprocmask(SIG_BLOCK, &allsigs, &tmpsig);
status = -EINVAL;
switch (kparams->cmd)
{
case DLM_USER_LOCK:
if (!fi) goto out_sig;
status = do_user_lock(fi, kparams->cmd, &kparams->i.lock);
break;
case DLM_USER_UNLOCK:
if (!fi) goto out_sig;
status = do_user_unlock(fi, kparams->cmd, &kparams->i.lock);
break;
case DLM_USER_CREATE_LOCKSPACE:
if (fi) goto out_sig;
status = do_user_create_lockspace(fi, kparams->cmd,
&kparams->i.lspace);
break;
case DLM_USER_REMOVE_LOCKSPACE:
if (fi) goto out_sig;
status = do_user_remove_lockspace(fi, kparams->cmd,
&kparams->i.lspace);
break;
default:
printk("Unknown command passed to DLM device : %d\n",
kparams->cmd);
break;
}
out_sig:
/* Restore signals */
sigprocmask(SIG_SETMASK, &tmpsig, NULL);
recalc_sigpending();
out_free:
kfree(kparams);
if (status == 0)
return count;
else
return status;
}
static struct file_operations _dlm_fops = {
.open = dlm_open,
.release = dlm_close,
.read = dlm_read,
.write = dlm_write,
.poll = dlm_poll,
.owner = THIS_MODULE,
};
static struct file_operations _dlm_ctl_fops = {
.open = dlm_ctl_open,
.release = dlm_ctl_close,
.write = dlm_write,
.owner = THIS_MODULE,
};
/*
* Create control device
*/
static int __init dlm_device_init(void)
{
int r;
INIT_LIST_HEAD(&user_ls_list);
init_MUTEX(&user_ls_lock);
rwlock_init(&lockinfo_lock);
ctl_device.name = "dlm-control";
ctl_device.fops = &_dlm_ctl_fops;
ctl_device.minor = MISC_DYNAMIC_MINOR;
r = misc_register(&ctl_device);
if (r) {
printk(KERN_ERR "dlm: misc_register failed for control dev\n");
return r;
}
return 0;
}
static void __exit dlm_device_exit(void)
{
misc_deregister(&ctl_device);
}
MODULE_DESCRIPTION("Distributed Lock Manager device interface");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
module_init(dlm_device_init);
module_exit(dlm_device_exit);
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