diff options
Diffstat (limited to 'fs/dlm/user.c')
| -rw-r--r-- | fs/dlm/user.c | 769 |
1 files changed, 769 insertions, 0 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c new file mode 100644 index 000000000000..1f05960a916f --- /dev/null +++ b/fs/dlm/user.c @@ -0,0 +1,769 @@ +/* + * Copyright (C) 2006 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 "dlm_internal.h" +#include "lockspace.h" +#include "lock.h" +#include "lvb_table.h" + +static const char *name_prefix="dlm"; +static struct miscdevice ctl_device; +static struct file_operations device_fops; + +#ifdef CONFIG_COMPAT + +struct dlm_lock_params32 { + __u8 mode; + __u8 namelen; + __u16 flags; + __u32 lkid; + __u32 parent; + + __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; + } i; +}; + +struct dlm_lksb32 { + __u32 sb_status; + __u32 sb_lkid; + __u8 sb_flags; + __u32 sb_lvbptr; +}; + +struct dlm_lock_result32 { + __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) +{ + 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; + strcpy(kb->i.lspace.name, kb32->i.lspace.name); + } 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.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, kb->i.lock.namelen); + } +} + +static void compat_output(struct dlm_lock_result *res, + struct dlm_lock_result32 *res32) +{ + res32->length = res->length - (sizeof(struct dlm_lock_result) - + sizeof(struct dlm_lock_result32)); + 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 + + +void dlm_user_add_ast(struct dlm_lkb *lkb, int type) +{ + struct dlm_ls *ls; + struct dlm_user_args *ua; + struct dlm_user_proc *proc; + + /* dlm_clear_proc_locks() sets ORPHAN/DEAD flag on each + lkb before dealing with it. We need to check this + flag before taking ls_clear_proc_locks mutex because if + it's set, dlm_clear_proc_locks() holds the mutex. */ + + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { + /* log_print("user_add_ast skip1 %x", lkb->lkb_flags); */ + 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. */ + + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { + /* log_print("user_add_ast skip2 %x", lkb->lkb_flags); */ + goto out; + } + + DLM_ASSERT(lkb->lkb_astparam, dlm_print_lkb(lkb);); + ua = (struct dlm_user_args *)lkb->lkb_astparam; + proc = ua->proc; + + if (type == AST_BAST && ua->bastaddr == NULL) + goto out; + + spin_lock(&proc->asts_spin); + if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) { + kref_get(&lkb->lkb_ref); + list_add_tail(&lkb->lkb_astqueue, &proc->asts); + lkb->lkb_ast_type |= type; + wake_up_interruptible(&proc->wait); + } + + /* We want to copy the lvb to userspace when the completion + ast is read if the status is 0, the lock has an lvb and + lvb_ops says we should. We could probably have set_lvb_lock() + set update_user_lvb instead and not need old_mode */ + + if ((lkb->lkb_ast_type & AST_COMP) && + (lkb->lkb_lksb->sb_status == 0) && + lkb->lkb_lksb->sb_lvbptr && + dlm_lvb_operations[ua->old_mode + 1][lkb->lkb_grmode + 1]) + ua->update_user_lvb = 1; + else + ua->update_user_lvb = 0; + + spin_unlock(&proc->asts_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; + 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_KERNEL); + 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; + + if (params->flags & DLM_LKF_CONVERT) + error = dlm_user_convert(ls, ua, + params->mode, params->flags, + params->lkid, params->lvb); + else { + error = dlm_user_request(ls, ua, + params->mode, params->flags, + params->name, params->namelen, + params->parent); + 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_KERNEL); + 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_create_lockspace(struct dlm_lspace_params *params) +{ + dlm_lockspace_t *lockspace; + struct dlm_ls *ls; + int error, len; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + error = dlm_new_lockspace(params->name, strlen(params->name), + &lockspace, 0, DLM_USER_LVB_LEN); + if (error) + return error; + + ls = dlm_find_lockspace_local(lockspace); + if (!ls) + return -ENOENT; + + error = -ENOMEM; + len = strlen(params->name) + strlen(name_prefix) + 2; + ls->ls_device.name = kzalloc(len, GFP_KERNEL); + if (!ls->ls_device.name) + goto fail; + snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix, + params->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); + goto fail; + } + + error = ls->ls_device.minor; + dlm_put_lockspace(ls); + return error; + + fail: + dlm_put_lockspace(ls); + dlm_release_lockspace(lockspace, 0); + return error; +} + +static int device_remove_lockspace(struct dlm_lspace_params *params) +{ + dlm_lockspace_t *lockspace; + struct dlm_ls *ls; + int error; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + ls = dlm_find_lockspace_device(params->minor); + if (!ls) + return -ENOENT; + + error = misc_deregister(&ls->ls_device); + if (error) { + dlm_put_lockspace(ls); + goto out; + } + kfree(ls->ls_device.name); + + lockspace = ls->ls_local_handle; + + /* 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 procede */ + + dlm_put_lockspace(ls); + error = dlm_release_lockspace(lockspace, 0); +out: + 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, + 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; +} + +/* + * 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; + sigset_t tmpsig, allsigs; + int error; + +#ifdef CONFIG_COMPAT + if (count < sizeof(struct dlm_write_request32)) +#else + if (count < sizeof(struct dlm_write_request)) +#endif + return -EINVAL; + + kbuf = kmalloc(count, GFP_KERNEL); + 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; + k32buf = (struct dlm_write_request32 *)kbuf; + kbuf = kmalloc(count + (sizeof(struct dlm_write_request) - + sizeof(struct dlm_write_request32)), GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + if (proc) + set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); + compat_input(kbuf, k32buf); + 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) && + test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) + return -EINVAL; + + sigfillset(&allsigs); + sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); + + error = -EINVAL; + + switch (kbuf->cmd) + { + case DLM_USER_LOCK: + if (!proc) { + log_print("no locking on control device"); + goto out_sig; + } + error = device_user_lock(proc, &kbuf->i.lock); + break; + + case DLM_USER_UNLOCK: + if (!proc) { + log_print("no locking on control device"); + goto out_sig; + } + error = device_user_unlock(proc, &kbuf->i.lock); + break; + + case DLM_USER_CREATE_LOCKSPACE: + if (proc) { + log_print("create/remove only on control device"); + goto out_sig; + } + 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_sig; + } + error = device_remove_lockspace(&kbuf->i.lspace); + break; + + default: + log_print("Unknown command passed to DLM device : %d\n", + kbuf->cmd); + } + + out_sig: + sigprocmask(SIG_SETMASK, &tmpsig, NULL); + recalc_sigpending(); + 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_KERNEL); + if (!proc) { + dlm_put_lockspace(ls); + return -ENOMEM; + } + + proc->lockspace = ls->ls_local_handle; + INIT_LIST_HEAD(&proc->asts); + INIT_LIST_HEAD(&proc->locks); + 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; + sigset_t tmpsig, allsigs; + + ls = dlm_find_lockspace_local(proc->lockspace); + if (!ls) + return -ENOENT; + + sigfillset(&allsigs); + sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); + + 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() */ + + sigprocmask(SIG_SETMASK, &tmpsig, NULL); + recalc_sigpending(); + + return 0; +} + +static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type, + int bmode, 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)); + 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 (type == AST_BAST) { + result.user_astaddr = ua->bastaddr; + result.user_astparam = ua->bastparam; + result.bast_mode = bmode; + } 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 (ua->update_user_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; +} + +/* 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; + struct dlm_user_args *ua; + DECLARE_WAITQUEUE(wait, current); + int error, type=0, bmode=0, removed = 0; + +#ifdef CONFIG_COMPAT + if (count < sizeof(struct dlm_lock_result32)) +#else + if (count < sizeof(struct dlm_lock_result)) +#endif + return -EINVAL; + + /* 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 (list_empty(&proc->asts)) { + spin_unlock(&proc->asts_spin); + return -EAGAIN; + } + + /* there may be both completion and blocking asts to return for + the lkb, don't remove lkb from asts list unless no asts remain */ + + lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue); + + if (lkb->lkb_ast_type & AST_COMP) { + lkb->lkb_ast_type &= ~AST_COMP; + type = AST_COMP; + } else if (lkb->lkb_ast_type & AST_BAST) { + lkb->lkb_ast_type &= ~AST_BAST; + type = AST_BAST; + bmode = lkb->lkb_bastmode; + } + + if (!lkb->lkb_ast_type) { + list_del(&lkb->lkb_astqueue); + removed = 1; + } + spin_unlock(&proc->asts_spin); + + ua = (struct dlm_user_args *)lkb->lkb_astparam; + error = copy_result_to_user(ua, + test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), + type, bmode, buf, count); + + /* removes reference for the proc->asts lists added by + dlm_user_add_ast() and may result in the lkb being freed */ + if (removed) + dlm_put_lkb(lkb); + + return error; +} + +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; +} + +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 struct file_operations device_fops = { + .open = device_open, + .release = device_close, + .read = device_read, + .write = device_write, + .poll = device_poll, + .owner = THIS_MODULE, +}; + +static struct file_operations ctl_device_fops = { + .open = ctl_device_open, + .release = ctl_device_close, + .write = device_write, + .owner = THIS_MODULE, +}; + +int dlm_user_init(void) +{ + int error; + + ctl_device.name = "dlm-control"; + ctl_device.fops = &ctl_device_fops; + ctl_device.minor = MISC_DYNAMIC_MINOR; + + error = misc_register(&ctl_device); + if (error) + log_print("misc_register failed for control device"); + + return error; +} + +void dlm_user_exit(void) +{ + misc_deregister(&ctl_device); +} + |