--- /dev/null
+/*
+ * Copyright (C) 2006-2010 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.
+ */
+
+#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/dlm.h>
+#include <linux/dlm_device.h>
+#include <linux/slab.h>
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+#include "lock.h"
+#include "lvb_table.h"
+#include "user.h"
+#include "ast.h"
+
+static const char name_prefix[] = "dlm";
+static const struct file_operations device_fops;
+static atomic_t dlm_monitor_opened;
+static int dlm_monitor_unused = 1;
+
+#ifdef CONFIG_COMPAT
+
+struct dlm_lock_params32 {
+ __u8 mode;
+ __u8 namelen;
+ __u16 unused;
+ __u32 flags;
+ __u32 lkid;
+ __u32 parent;
+ __u64 xid;
+ __u64 timeout;
+ __u32 castparam;
+ __u32 castaddr;
+ __u32 bastparam;
+ __u32 bastaddr;
+ __u32 lksb;
+ char lvb[DLM_USER_LVB_LEN];
+ char name[0];
+};
+
+struct dlm_write_request32 {
+ __u32 version[3];
+ __u8 cmd;
+ __u8 is64bit;
+ __u8 unused[2];
+
+ union {
+ struct dlm_lock_params32 lock;
+ struct dlm_lspace_params lspace;
+ struct dlm_purge_params purge;
+ } i;
+};
+
+struct dlm_lksb32 {
+ __u32 sb_status;
+ __u32 sb_lkid;
+ __u8 sb_flags;
+ __u32 sb_lvbptr;
+};
+
+struct dlm_lock_result32 {
+ __u32 version[3];
+ __u32 length;
+ __u32 user_astaddr;
+ __u32 user_astparam;
+ __u32 user_lksb;
+ struct dlm_lksb32 lksb;
+ __u8 bast_mode;
+ __u8 unused[3];
+ /* Offsets may be zero if no data is present */
+ __u32 lvb_offset;
+};
+
+static void compat_input(struct dlm_write_request *kb,
+ struct dlm_write_request32 *kb32,
+ int namelen)
+{
+ kb->version[0] = kb32->version[0];
+ kb->version[1] = kb32->version[1];
+ kb->version[2] = kb32->version[2];
+
+ kb->cmd = kb32->cmd;
+ kb->is64bit = kb32->is64bit;
+ if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
+ kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
+ kb->i.lspace.flags = kb32->i.lspace.flags;
+ kb->i.lspace.minor = kb32->i.lspace.minor;
+ memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
+ } else if (kb->cmd == DLM_USER_PURGE) {
+ kb->i.purge.nodeid = kb32->i.purge.nodeid;
+ kb->i.purge.pid = kb32->i.purge.pid;
+ } else {
+ kb->i.lock.mode = kb32->i.lock.mode;
+ kb->i.lock.namelen = kb32->i.lock.namelen;
+ kb->i.lock.flags = kb32->i.lock.flags;
+ kb->i.lock.lkid = kb32->i.lock.lkid;
+ kb->i.lock.parent = kb32->i.lock.parent;
+ kb->i.lock.xid = kb32->i.lock.xid;
+ kb->i.lock.timeout = kb32->i.lock.timeout;
+ kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
+ kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
+ kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
+ kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
+ kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
+ memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
+ memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
+ }
+}
+
+static void compat_output(struct dlm_lock_result *res,
+ struct dlm_lock_result32 *res32)
+{
+ res32->version[0] = res->version[0];
+ res32->version[1] = res->version[1];
+ res32->version[2] = res->version[2];
+
+ res32->user_astaddr = (__u32)(long)res->user_astaddr;
+ res32->user_astparam = (__u32)(long)res->user_astparam;
+ res32->user_lksb = (__u32)(long)res->user_lksb;
+ res32->bast_mode = res->bast_mode;
+
+ res32->lvb_offset = res->lvb_offset;
+ res32->length = res->length;
+
+ res32->lksb.sb_status = res->lksb.sb_status;
+ res32->lksb.sb_flags = res->lksb.sb_flags;
+ res32->lksb.sb_lkid = res->lksb.sb_lkid;
+ res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
+}
+#endif
+
+/* Figure out if this lock is at the end of its life and no longer
+ available for the application to use. The lkb still exists until
+ the final ast is read. A lock becomes EOL in three situations:
+ 1. a noqueue request fails with EAGAIN
+ 2. an unlock completes with EUNLOCK
+ 3. a cancel of a waiting request completes with ECANCEL/EDEADLK
+ An EOL lock needs to be removed from the process's list of locks.
+ And we can't allow any new operation on an EOL lock. This is
+ not related to the lifetime of the lkb struct which is managed
+ entirely by refcount. */
+
+static int lkb_is_endoflife(int mode, int status)
+{
+ switch (status) {
+ case -DLM_EUNLOCK:
+ return 1;
+ case -DLM_ECANCEL:
+ case -ETIMEDOUT:
+ case -EDEADLK:
+ case -EAGAIN:
+ if (mode == DLM_LOCK_IV)
+ return 1;
+ break;
+ }
+ return 0;
+}
+
+/* we could possibly check if the cancel of an orphan has resulted in the lkb
+ being removed and then remove that lkb from the orphans list and free it */
+
+void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
+ int status, uint32_t sbflags, uint64_t seq)
+{
+ struct dlm_ls *ls;
+ struct dlm_user_args *ua;
+ struct dlm_user_proc *proc;
+ int rv;
+
+ if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
+ return;
+
+ ls = lkb->lkb_resource->res_ls;
+ mutex_lock(&ls->ls_clear_proc_locks);
+
+ /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
+ can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
+ lkb->ua so we can't try to use it. This second check is necessary
+ for cases where a completion ast is received for an operation that
+ began before clear_proc_locks did its cancel/unlock. */
+
+ if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
+ goto out;
+
+ DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
+ ua = lkb->lkb_ua;
+ proc = ua->proc;
+
+ if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
+ goto out;
+
+ if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
+ lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
+
+ spin_lock(&proc->asts_spin);
+
+ rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
+ if (rv < 0) {
+ spin_unlock(&proc->asts_spin);
+ goto out;
+ }
+
+ if (list_empty(&lkb->lkb_cb_list)) {
+ kref_get(&lkb->lkb_ref);
+ list_add_tail(&lkb->lkb_cb_list, &proc->asts);
+ wake_up_interruptible(&proc->wait);
+ }
+ spin_unlock(&proc->asts_spin);
+
+ if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
+ /* N.B. spin_lock locks_spin, not asts_spin */
+ spin_lock(&proc->locks_spin);
+ if (!list_empty(&lkb->lkb_ownqueue)) {
+ list_del_init(&lkb->lkb_ownqueue);
+ dlm_put_lkb(lkb);
+ }
+ spin_unlock(&proc->locks_spin);
+ }
+ out:
+ mutex_unlock(&ls->ls_clear_proc_locks);
+}
+
+static int device_user_lock(struct dlm_user_proc *proc,
+ struct dlm_lock_params *params)
+{
+ struct dlm_ls *ls;
+ struct dlm_user_args *ua;
+ uint32_t lkid;
+ int error = -ENOMEM;
+
+ ls = dlm_find_lockspace_local(proc->lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ if (!params->castaddr || !params->lksb) {
+ error = -EINVAL;
+ goto out;
+ }
+
+ ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
+ if (!ua)
+ goto out;
+ ua->proc = proc;
+ ua->user_lksb = params->lksb;
+ ua->castparam = params->castparam;
+ ua->castaddr = params->castaddr;
+ ua->bastparam = params->bastparam;
+ ua->bastaddr = params->bastaddr;
+ ua->xid = params->xid;
+
+ if (params->flags & DLM_LKF_CONVERT) {
+ error = dlm_user_convert(ls, ua,
+ params->mode, params->flags,
+ params->lkid, params->lvb,
+ (unsigned long) params->timeout);
+ } else if (params->flags & DLM_LKF_ORPHAN) {
+ error = dlm_user_adopt_orphan(ls, ua,
+ params->mode, params->flags,
+ params->name, params->namelen,
+ (unsigned long) params->timeout,
+ &lkid);
+ if (!error)
+ error = lkid;
+ } else {
+ error = dlm_user_request(ls, ua,
+ params->mode, params->flags,
+ params->name, params->namelen,
+ (unsigned long) params->timeout);
+ if (!error)
+ error = ua->lksb.sb_lkid;
+ }
+ out:
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+static int device_user_unlock(struct dlm_user_proc *proc,
+ struct dlm_lock_params *params)
+{
+ struct dlm_ls *ls;
+ struct dlm_user_args *ua;
+ int error = -ENOMEM;
+
+ ls = dlm_find_lockspace_local(proc->lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
+ if (!ua)
+ goto out;
+ ua->proc = proc;
+ ua->user_lksb = params->lksb;
+ ua->castparam = params->castparam;
+ ua->castaddr = params->castaddr;
+
+ if (params->flags & DLM_LKF_CANCEL)
+ error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
+ else
+ error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
+ params->lvb);
+ out:
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+static int device_user_deadlock(struct dlm_user_proc *proc,
+ struct dlm_lock_params *params)
+{
+ struct dlm_ls *ls;
+ int error;
+
+ ls = dlm_find_lockspace_local(proc->lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ error = dlm_user_deadlock(ls, params->flags, params->lkid);
+
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+static int dlm_device_register(struct dlm_ls *ls, char *name)
+{
+ int error, len;
+
+ /* The device is already registered. This happens when the
+ lockspace is created multiple times from userspace. */
+ if (ls->ls_device.name)
+ return 0;
+
+ error = -ENOMEM;
+ len = strlen(name) + strlen(name_prefix) + 2;
+ ls->ls_device.name = kzalloc(len, GFP_NOFS);
+ if (!ls->ls_device.name)
+ goto fail;
+
+ snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
+ name);
+ ls->ls_device.fops = &device_fops;
+ ls->ls_device.minor = MISC_DYNAMIC_MINOR;
+
+ error = misc_register(&ls->ls_device);
+ if (error) {
+ kfree(ls->ls_device.name);
+ }
+fail:
+ return error;
+}
+
+int dlm_device_deregister(struct dlm_ls *ls)
+{
+ int error;
+
+ /* The device is not registered. This happens when the lockspace
+ was never used from userspace, or when device_create_lockspace()
+ calls dlm_release_lockspace() after the register fails. */
+ if (!ls->ls_device.name)
+ return 0;
+
+ error = misc_deregister(&ls->ls_device);
+ if (!error)
+ kfree(ls->ls_device.name);
+ return error;
+}
+
+static int device_user_purge(struct dlm_user_proc *proc,
+ struct dlm_purge_params *params)
+{
+ struct dlm_ls *ls;
+ int error;
+
+ ls = dlm_find_lockspace_local(proc->lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
+
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+static int device_create_lockspace(struct dlm_lspace_params *params)
+{
+ dlm_lockspace_t *lockspace;
+ struct dlm_ls *ls;
+ int error;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ error = dlm_new_lockspace(params->name, NULL, params->flags,
+ DLM_USER_LVB_LEN, NULL, NULL, NULL,
+ &lockspace);
+ if (error)
+ return error;
+
+ ls = dlm_find_lockspace_local(lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ error = dlm_device_register(ls, params->name);
+ dlm_put_lockspace(ls);
+
+ if (error)
+ dlm_release_lockspace(lockspace, 0);
+ else
+ error = ls->ls_device.minor;
+
+ return error;
+}
+
+static int device_remove_lockspace(struct dlm_lspace_params *params)
+{
+ dlm_lockspace_t *lockspace;
+ struct dlm_ls *ls;
+ int error, force = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ls = dlm_find_lockspace_device(params->minor);
+ if (!ls)
+ return -ENOENT;
+
+ if (params->flags & DLM_USER_LSFLG_FORCEFREE)
+ force = 2;
+
+ lockspace = ls->ls_local_handle;
+ dlm_put_lockspace(ls);
+
+ /* The final dlm_release_lockspace waits for references to go to
+ zero, so all processes will need to close their device for the
+ ls before the release will proceed. release also calls the
+ device_deregister above. Converting a positive return value
+ from release to zero means that userspace won't know when its
+ release was the final one, but it shouldn't need to know. */
+
+ error = dlm_release_lockspace(lockspace, force);
+ if (error > 0)
+ error = 0;
+ return error;
+}
+
+/* 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,
+ task_pid_nr(current),
+ 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;
+}
+
+/*
+ * device_write
+ *
+ * device_user_lock
+ * dlm_user_request -> request_lock
+ * dlm_user_convert -> convert_lock
+ *
+ * device_user_unlock
+ * dlm_user_unlock -> unlock_lock
+ * dlm_user_cancel -> cancel_lock
+ *
+ * device_create_lockspace
+ * dlm_new_lockspace
+ *
+ * device_remove_lockspace
+ * dlm_release_lockspace
+ */
+
+/* a write to a lockspace device is a lock or unlock request, a write
+ to the control device is to create/remove a lockspace */
+
+static ssize_t device_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct dlm_user_proc *proc = file->private_data;
+ struct dlm_write_request *kbuf;
+ int error;
+
+#ifdef CONFIG_COMPAT
+ if (count < sizeof(struct dlm_write_request32))
+#else
+ if (count < sizeof(struct dlm_write_request))
+#endif
+ return -EINVAL;
+
+ /*
+ * can't compare against COMPAT/dlm_write_request32 because
+ * we don't yet know if is64bit is zero
+ */
+ if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
+ return -EINVAL;
+
+ kbuf = kzalloc(count + 1, GFP_NOFS);
+ if (!kbuf)
+ return -ENOMEM;
+
+ if (copy_from_user(kbuf, buf, count)) {
+ error = -EFAULT;
+ goto out_free;
+ }
+
+ if (check_version(kbuf)) {
+ error = -EBADE;
+ goto out_free;
+ }
+
+#ifdef CONFIG_COMPAT
+ if (!kbuf->is64bit) {
+ struct dlm_write_request32 *k32buf;
+ int namelen = 0;
+
+ if (count > sizeof(struct dlm_write_request32))
+ namelen = count - sizeof(struct dlm_write_request32);
+
+ k32buf = (struct dlm_write_request32 *)kbuf;
+
+ /* add 1 after namelen so that the name string is terminated */
+ kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
+ GFP_NOFS);
+ if (!kbuf) {
+ kfree(k32buf);
+ return -ENOMEM;
+ }
+
+ if (proc)
+ set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
+
+ compat_input(kbuf, k32buf, namelen);
+ kfree(k32buf);
+ }
+#endif
+
+ /* do we really need this? can a write happen after a close? */
+ if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
+ (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
+ error = -EINVAL;
+ goto out_free;
+ }
+
+ error = -EINVAL;
+
+ switch (kbuf->cmd)
+ {
+ case DLM_USER_LOCK:
+ if (!proc) {
+ log_print("no locking on control device");
+ goto out_free;
+ }
+ error = device_user_lock(proc, &kbuf->i.lock);
+ break;
+
+ case DLM_USER_UNLOCK:
+ if (!proc) {
+ log_print("no locking on control device");
+ goto out_free;
+ }
+ error = device_user_unlock(proc, &kbuf->i.lock);
+ break;
+
+ case DLM_USER_DEADLOCK:
+ if (!proc) {
+ log_print("no locking on control device");
+ goto out_free;
+ }
+ error = device_user_deadlock(proc, &kbuf->i.lock);
+ break;
+
+ case DLM_USER_CREATE_LOCKSPACE:
+ if (proc) {
+ log_print("create/remove only on control device");
+ goto out_free;
+ }
+ error = device_create_lockspace(&kbuf->i.lspace);
+ break;
+
+ case DLM_USER_REMOVE_LOCKSPACE:
+ if (proc) {
+ log_print("create/remove only on control device");
+ goto out_free;
+ }
+ error = device_remove_lockspace(&kbuf->i.lspace);
+ break;
+
+ case DLM_USER_PURGE:
+ if (!proc) {
+ log_print("no locking on control device");
+ goto out_free;
+ }
+ error = device_user_purge(proc, &kbuf->i.purge);
+ break;
+
+ default:
+ log_print("Unknown command passed to DLM device : %d\n",
+ kbuf->cmd);
+ }
+
+ out_free:
+ kfree(kbuf);
+ return error;
+}
+
+/* Every process that opens the lockspace device has its own "proc" structure
+ hanging off the open file that's used to keep track of locks owned by the
+ process and asts that need to be delivered to the process. */
+
+static int device_open(struct inode *inode, struct file *file)
+{
+ struct dlm_user_proc *proc;
+ struct dlm_ls *ls;
+
+ ls = dlm_find_lockspace_device(iminor(inode));
+ if (!ls)
+ return -ENOENT;
+
+ proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
+ if (!proc) {
+ dlm_put_lockspace(ls);
+ return -ENOMEM;
+ }
+
+ proc->lockspace = ls->ls_local_handle;
+ INIT_LIST_HEAD(&proc->asts);
+ INIT_LIST_HEAD(&proc->locks);
+ INIT_LIST_HEAD(&proc->unlocking);
+ spin_lock_init(&proc->asts_spin);
+ spin_lock_init(&proc->locks_spin);
+ init_waitqueue_head(&proc->wait);
+ file->private_data = proc;
+
+ return 0;
+}
+
+static int device_close(struct inode *inode, struct file *file)
+{
+ struct dlm_user_proc *proc = file->private_data;
+ struct dlm_ls *ls;
+
+ ls = dlm_find_lockspace_local(proc->lockspace);
+ if (!ls)
+ return -ENOENT;
+
+ set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
+
+ dlm_clear_proc_locks(ls, proc);
+
+ /* at this point no more lkb's should exist for this lockspace,
+ so there's no chance of dlm_user_add_ast() being called and
+ looking for lkb->ua->proc */
+
+ kfree(proc);
+ file->private_data = NULL;
+
+ dlm_put_lockspace(ls);
+ dlm_put_lockspace(ls); /* for the find in device_open() */
+
+ /* FIXME: AUTOFREE: if this ls is no longer used do
+ device_remove_lockspace() */
+
+ return 0;
+}
+
+static int copy_result_to_user(struct dlm_user_args *ua, int compat,
+ uint32_t flags, int mode, int copy_lvb,
+ char __user *buf, size_t count)
+{
+#ifdef CONFIG_COMPAT
+ struct dlm_lock_result32 result32;
+#endif
+ struct dlm_lock_result result;
+ void *resultptr;
+ int error=0;
+ int len;
+ int struct_len;
+
+ memset(&result, 0, sizeof(struct dlm_lock_result));
+ result.version[0] = DLM_DEVICE_VERSION_MAJOR;
+ result.version[1] = DLM_DEVICE_VERSION_MINOR;
+ result.version[2] = DLM_DEVICE_VERSION_PATCH;
+ memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb));
+ result.user_lksb = ua->user_lksb;
+
+ /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
+ in a conversion unless the conversion is successful. See code
+ in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though,
+ notes that a new blocking AST address and parameter are set even if
+ the conversion fails, so maybe we should just do that. */
+
+ if (flags & DLM_CB_BAST) {
+ result.user_astaddr = ua->bastaddr;
+ result.user_astparam = ua->bastparam;
+ result.bast_mode = mode;
+ } else {
+ result.user_astaddr = ua->castaddr;
+ result.user_astparam = ua->castparam;
+ }
+
+#ifdef CONFIG_COMPAT
+ if (compat)
+ len = sizeof(struct dlm_lock_result32);
+ else
+#endif
+ len = sizeof(struct dlm_lock_result);
+ struct_len = len;
+
+ /* copy lvb to userspace if there is one, it's been updated, and
+ the user buffer has space for it */
+
+ if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
+ if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
+ DLM_USER_LVB_LEN)) {
+ error = -EFAULT;
+ goto out;
+ }
+
+ result.lvb_offset = len;
+ len += DLM_USER_LVB_LEN;
+ }
+
+ result.length = len;
+ resultptr = &result;
+#ifdef CONFIG_COMPAT
+ if (compat) {
+ compat_output(&result, &result32);
+ resultptr = &result32;
+ }
+#endif
+
+ if (copy_to_user(buf, resultptr, struct_len))
+ error = -EFAULT;
+ else
+ error = len;
+ out:
+ return error;
+}
+
+static int copy_version_to_user(char __user *buf, size_t count)
+{
+ struct dlm_device_version ver;
+
+ memset(&ver, 0, sizeof(struct dlm_device_version));
+ ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
+ ver.version[1] = DLM_DEVICE_VERSION_MINOR;
+ ver.version[2] = DLM_DEVICE_VERSION_PATCH;
+
+ if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
+ return -EFAULT;
+ return sizeof(struct dlm_device_version);
+}
+
+/* a read returns a single ast described in a struct dlm_lock_result */
+
+static ssize_t device_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct dlm_user_proc *proc = file->private_data;
+ struct dlm_lkb *lkb;
+ DECLARE_WAITQUEUE(wait, current);
+ struct dlm_callback cb;
+ int rv, resid, copy_lvb = 0;
+
+ if (count == sizeof(struct dlm_device_version)) {
+ rv = copy_version_to_user(buf, count);
+ return rv;
+ }
+
+ if (!proc) {
+ log_print("non-version read from control device %zu", count);
+ return -EINVAL;
+ }
+
+#ifdef CONFIG_COMPAT
+ if (count < sizeof(struct dlm_lock_result32))
+#else
+ if (count < sizeof(struct dlm_lock_result))
+#endif
+ return -EINVAL;
+
+ try_another:
+
+ /* do we really need this? can a read happen after a close? */
+ if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
+ return -EINVAL;
+
+ spin_lock(&proc->asts_spin);
+ if (list_empty(&proc->asts)) {
+ if (file->f_flags & O_NONBLOCK) {
+ spin_unlock(&proc->asts_spin);
+ return -EAGAIN;
+ }
+
+ add_wait_queue(&proc->wait, &wait);
+
+ repeat:
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (list_empty(&proc->asts) && !signal_pending(current)) {
+ spin_unlock(&proc->asts_spin);
+ schedule();
+ spin_lock(&proc->asts_spin);
+ goto repeat;
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&proc->wait, &wait);
+
+ if (signal_pending(current)) {
+ spin_unlock(&proc->asts_spin);
+ return -ERESTARTSYS;
+ }
+ }
+
+ /* if we empty lkb_callbacks, we don't want to unlock the spinlock
+ without removing lkb_cb_list; so empty lkb_cb_list is always
+ consistent with empty lkb_callbacks */
+
+ lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_cb_list);
+
+ rv = dlm_rem_lkb_callback(lkb->lkb_resource->res_ls, lkb, &cb, &resid);
+ if (rv < 0) {
+ /* this shouldn't happen; lkb should have been removed from
+ list when resid was zero */
+ log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
+ list_del_init(&lkb->lkb_cb_list);
+ spin_unlock(&proc->asts_spin);
+ /* removes ref for proc->asts, may cause lkb to be freed */
+ dlm_put_lkb(lkb);
+ goto try_another;
+ }
+ if (!resid)
+ list_del_init(&lkb->lkb_cb_list);
+ spin_unlock(&proc->asts_spin);
+
+ if (cb.flags & DLM_CB_SKIP) {
+ /* removes ref for proc->asts, may cause lkb to be freed */
+ if (!resid)
+ dlm_put_lkb(lkb);
+ goto try_another;
+ }
+
+ if (cb.flags & DLM_CB_CAST) {
+ int old_mode, new_mode;
+
+ old_mode = lkb->lkb_last_cast.mode;
+ new_mode = cb.mode;
+
+ if (!cb.sb_status && lkb->lkb_lksb->sb_lvbptr &&
+ dlm_lvb_operations[old_mode + 1][new_mode + 1])
+ copy_lvb = 1;
+
+ lkb->lkb_lksb->sb_status = cb.sb_status;
+ lkb->lkb_lksb->sb_flags = cb.sb_flags;
+ }
+
+ rv = copy_result_to_user(lkb->lkb_ua,
+ test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
+ cb.flags, cb.mode, copy_lvb, buf, count);
+
+ /* removes ref for proc->asts, may cause lkb to be freed */
+ if (!resid)
+ dlm_put_lkb(lkb);
+
+ return rv;
+}
+
+static unsigned int device_poll(struct file *file, poll_table *wait)
+{
+ struct dlm_user_proc *proc = file->private_data;
+
+ poll_wait(file, &proc->wait, wait);
+
+ spin_lock(&proc->asts_spin);
+ if (!list_empty(&proc->asts)) {
+ spin_unlock(&proc->asts_spin);
+ return POLLIN | POLLRDNORM;
+ }
+ spin_unlock(&proc->asts_spin);
+ return 0;
+}
+
+int dlm_user_daemon_available(void)
+{
+ /* dlm_controld hasn't started (or, has started, but not
+ properly populated configfs) */
+
+ if (!dlm_our_nodeid())
+ return 0;
+
+ /* This is to deal with versions of dlm_controld that don't
+ know about the monitor device. We assume that if the
+ dlm_controld was started (above), but the monitor device
+ was never opened, that it's an old version. dlm_controld
+ should open the monitor device before populating configfs. */
+
+ if (dlm_monitor_unused)
+ return 1;
+
+ return atomic_read(&dlm_monitor_opened) ? 1 : 0;
+}
+
+static int ctl_device_open(struct inode *inode, struct file *file)
+{
+ file->private_data = NULL;
+ return 0;
+}
+
+static int ctl_device_close(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static int monitor_device_open(struct inode *inode, struct file *file)
+{
+ atomic_inc(&dlm_monitor_opened);
+ dlm_monitor_unused = 0;
+ return 0;
+}
+
+static int monitor_device_close(struct inode *inode, struct file *file)
+{
+ if (atomic_dec_and_test(&dlm_monitor_opened))
+ dlm_stop_lockspaces();
+ return 0;
+}
+
+static const struct file_operations device_fops = {
+ .open = device_open,
+ .release = device_close,
+ .read = device_read,
+ .write = device_write,
+ .poll = device_poll,
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+};
+
+static const struct file_operations ctl_device_fops = {
+ .open = ctl_device_open,
+ .release = ctl_device_close,
+ .read = device_read,
+ .write = device_write,
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+};
+
+static struct miscdevice ctl_device = {
+ .name = "dlm-control",
+ .fops = &ctl_device_fops,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+static const struct file_operations monitor_device_fops = {
+ .open = monitor_device_open,
+ .release = monitor_device_close,
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+};
+
+static struct miscdevice monitor_device = {
+ .name = "dlm-monitor",
+ .fops = &monitor_device_fops,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+int __init dlm_user_init(void)
+{
+ int error;
+
+ atomic_set(&dlm_monitor_opened, 0);
+
+ error = misc_register(&ctl_device);
+ if (error) {
+ log_print("misc_register failed for control device");
+ goto out;
+ }
+
+ error = misc_register(&monitor_device);
+ if (error) {
+ log_print("misc_register failed for monitor device");
+ misc_deregister(&ctl_device);
+ }
+ out:
+ return error;
+}
+
+void dlm_user_exit(void)
+{
+ misc_deregister(&ctl_device);
+ misc_deregister(&monitor_device);
+}
+
Code Review / kvmfornfv.git / blobdiff