| /* |
| * Copyright (C) 2006-2007 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" |
| #include "user.h" |
| |
| static const char *name_prefix="dlm"; |
| static struct miscdevice ctl_device; |
| static const struct file_operations device_fops; |
| |
| #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) |
| { |
| 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 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, kb->i.lock.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 |
| |
| /* 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, int type) |
| { |
| struct dlm_ls *ls; |
| struct dlm_user_args *ua; |
| struct dlm_user_proc *proc; |
| int eol = 0, ast_type; |
| |
| 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_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); |
| |
| ast_type = lkb->lkb_ast_type; |
| lkb->lkb_ast_type |= type; |
| |
| if (!ast_type) { |
| kref_get(&lkb->lkb_ref); |
| list_add_tail(&lkb->lkb_astqueue, &proc->asts); |
| wake_up_interruptible(&proc->wait); |
| } |
| if (type == AST_COMP && (ast_type & AST_COMP)) |
| log_debug(ls, "ast overlap %x status %x %x", |
| lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags); |
| |
| /* 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 |
| 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. */ |
| |
| if (type == AST_COMP && |
| lkb->lkb_grmode == DLM_LOCK_IV && |
| ua->lksb.sb_status == -EAGAIN) |
| eol = 1; |
| else if (ua->lksb.sb_status == -DLM_EUNLOCK || |
| (ua->lksb.sb_status == -DLM_ECANCEL && |
| lkb->lkb_grmode == DLM_LOCK_IV)) |
| eol = 1; |
| if (eol) { |
| lkb->lkb_ast_type &= ~AST_BAST; |
| lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; |
| } |
| |
| /* 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); |
| |
| if (eol) { |
| spin_lock(&ua->proc->locks_spin); |
| if (!list_empty(&lkb->lkb_ownqueue)) { |
| list_del_init(&lkb->lkb_ownqueue); |
| dlm_put_lkb(lkb); |
| } |
| spin_unlock(&ua->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; |
| 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; |
| 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 { |
| 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_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 create_misc_device(struct dlm_ls *ls, char *name) |
| { |
| int error, len; |
| |
| error = -ENOMEM; |
| len = strlen(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, |
| 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; |
| } |
| |
| 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, strlen(params->name), |
| &lockspace, params->flags, DLM_USER_LVB_LEN); |
| if (error) |
| return error; |
| |
| ls = dlm_find_lockspace_local(lockspace); |
| if (!ls) |
| return -ENOENT; |
| |
| error = create_misc_device(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; |
| |
| /* Deregister the misc device first, so we don't have |
| * a device that's not attached to a lockspace. If |
| * dlm_release_lockspace fails then we can recreate it |
| */ |
| error = misc_deregister(&ls->ls_device); |
| if (error) { |
| dlm_put_lockspace(ls); |
| goto out; |
| } |
| kfree(ls->ls_device.name); |
| |
| if (params->flags & DLM_USER_LSFLG_FORCEFREE) |
| force = 2; |
| |
| 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, force); |
| if (error) |
| create_misc_device(ls, ls->ls_name); |
| 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; |
| |
| case DLM_USER_PURGE: |
| if (!proc) { |
| log_print("no locking on control device"); |
| goto out_sig; |
| } |
| error = device_user_purge(proc, &kbuf->i.purge); |
| 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); |
| 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; |
| 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)); |
| 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 (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; |
| } |
| |
| 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; |
| struct dlm_user_args *ua; |
| DECLARE_WAITQUEUE(wait, current); |
| int error, type=0, bmode=0, removed = 0; |
| |
| if (count == sizeof(struct dlm_device_version)) { |
| error = copy_version_to_user(buf, count); |
| return error; |
| } |
| |
| 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; |
| |
| /* 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; |
| } |
| } |
| |
| /* 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 const struct file_operations device_fops = { |
| .open = device_open, |
| .release = device_close, |
| .read = device_read, |
| .write = device_write, |
| .poll = device_poll, |
| .owner = THIS_MODULE, |
| }; |
| |
| 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, |
| }; |
| |
| 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); |
| } |
| |