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![Gustavo A. R. Silva](/assets/img/avatar_default.png)
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293
("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David Teigland <teigland@redhat.com>
1012 lines
24 KiB
C
1012 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2006-2010 Red Hat, Inc. All rights reserved.
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*/
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#include <linux/miscdevice.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/poll.h>
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#include <linux/signal.h>
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#include <linux/spinlock.h>
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#include <linux/dlm.h>
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#include <linux/dlm_device.h>
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#include <linux/slab.h>
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#include <linux/sched/signal.h>
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#include "dlm_internal.h"
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#include "lockspace.h"
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#include "lock.h"
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#include "lvb_table.h"
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#include "user.h"
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#include "ast.h"
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#include "config.h"
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static const char name_prefix[] = "dlm";
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static const struct file_operations device_fops;
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static atomic_t dlm_monitor_opened;
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static int dlm_monitor_unused = 1;
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#ifdef CONFIG_COMPAT
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struct dlm_lock_params32 {
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__u8 mode;
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__u8 namelen;
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__u16 unused;
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__u32 flags;
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__u32 lkid;
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__u32 parent;
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__u64 xid;
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__u64 timeout;
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__u32 castparam;
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__u32 castaddr;
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__u32 bastparam;
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__u32 bastaddr;
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__u32 lksb;
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char lvb[DLM_USER_LVB_LEN];
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char name[];
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};
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struct dlm_write_request32 {
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__u32 version[3];
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__u8 cmd;
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__u8 is64bit;
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__u8 unused[2];
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union {
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struct dlm_lock_params32 lock;
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struct dlm_lspace_params lspace;
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struct dlm_purge_params purge;
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} i;
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};
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struct dlm_lksb32 {
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__u32 sb_status;
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__u32 sb_lkid;
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__u8 sb_flags;
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__u32 sb_lvbptr;
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};
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struct dlm_lock_result32 {
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__u32 version[3];
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__u32 length;
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__u32 user_astaddr;
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__u32 user_astparam;
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__u32 user_lksb;
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struct dlm_lksb32 lksb;
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__u8 bast_mode;
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__u8 unused[3];
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/* Offsets may be zero if no data is present */
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__u32 lvb_offset;
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};
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static void compat_input(struct dlm_write_request *kb,
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struct dlm_write_request32 *kb32,
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int namelen)
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{
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kb->version[0] = kb32->version[0];
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kb->version[1] = kb32->version[1];
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kb->version[2] = kb32->version[2];
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kb->cmd = kb32->cmd;
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kb->is64bit = kb32->is64bit;
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if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
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kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
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kb->i.lspace.flags = kb32->i.lspace.flags;
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kb->i.lspace.minor = kb32->i.lspace.minor;
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memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
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} else if (kb->cmd == DLM_USER_PURGE) {
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kb->i.purge.nodeid = kb32->i.purge.nodeid;
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kb->i.purge.pid = kb32->i.purge.pid;
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} else {
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kb->i.lock.mode = kb32->i.lock.mode;
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kb->i.lock.namelen = kb32->i.lock.namelen;
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kb->i.lock.flags = kb32->i.lock.flags;
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kb->i.lock.lkid = kb32->i.lock.lkid;
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kb->i.lock.parent = kb32->i.lock.parent;
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kb->i.lock.xid = kb32->i.lock.xid;
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kb->i.lock.timeout = kb32->i.lock.timeout;
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kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
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kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
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kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
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kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
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kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
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memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
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memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
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}
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}
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static void compat_output(struct dlm_lock_result *res,
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struct dlm_lock_result32 *res32)
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{
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memset(res32, 0, sizeof(*res32));
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res32->version[0] = res->version[0];
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res32->version[1] = res->version[1];
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res32->version[2] = res->version[2];
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res32->user_astaddr = (__u32)(long)res->user_astaddr;
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res32->user_astparam = (__u32)(long)res->user_astparam;
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res32->user_lksb = (__u32)(long)res->user_lksb;
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res32->bast_mode = res->bast_mode;
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res32->lvb_offset = res->lvb_offset;
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res32->length = res->length;
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res32->lksb.sb_status = res->lksb.sb_status;
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res32->lksb.sb_flags = res->lksb.sb_flags;
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res32->lksb.sb_lkid = res->lksb.sb_lkid;
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res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
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}
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#endif
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/* Figure out if this lock is at the end of its life and no longer
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available for the application to use. The lkb still exists until
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the final ast is read. A lock becomes EOL in three situations:
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1. a noqueue request fails with EAGAIN
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2. an unlock completes with EUNLOCK
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3. a cancel of a waiting request completes with ECANCEL/EDEADLK
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An EOL lock needs to be removed from the process's list of locks.
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And we can't allow any new operation on an EOL lock. This is
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not related to the lifetime of the lkb struct which is managed
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entirely by refcount. */
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static int lkb_is_endoflife(int mode, int status)
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{
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switch (status) {
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case -DLM_EUNLOCK:
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return 1;
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case -DLM_ECANCEL:
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case -ETIMEDOUT:
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case -EDEADLK:
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case -EAGAIN:
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if (mode == DLM_LOCK_IV)
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return 1;
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break;
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}
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return 0;
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}
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/* we could possibly check if the cancel of an orphan has resulted in the lkb
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being removed and then remove that lkb from the orphans list and free it */
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void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
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int status, uint32_t sbflags, uint64_t seq)
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{
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struct dlm_ls *ls;
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struct dlm_user_args *ua;
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struct dlm_user_proc *proc;
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int rv;
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if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
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return;
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ls = lkb->lkb_resource->res_ls;
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mutex_lock(&ls->ls_clear_proc_locks);
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/* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
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can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
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lkb->ua so we can't try to use it. This second check is necessary
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for cases where a completion ast is received for an operation that
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began before clear_proc_locks did its cancel/unlock. */
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if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
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goto out;
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DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
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ua = lkb->lkb_ua;
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proc = ua->proc;
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if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
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goto out;
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if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
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lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
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spin_lock(&proc->asts_spin);
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rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
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if (rv < 0) {
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spin_unlock(&proc->asts_spin);
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goto out;
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}
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if (list_empty(&lkb->lkb_cb_list)) {
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kref_get(&lkb->lkb_ref);
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list_add_tail(&lkb->lkb_cb_list, &proc->asts);
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wake_up_interruptible(&proc->wait);
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}
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spin_unlock(&proc->asts_spin);
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if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
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/* N.B. spin_lock locks_spin, not asts_spin */
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spin_lock(&proc->locks_spin);
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if (!list_empty(&lkb->lkb_ownqueue)) {
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list_del_init(&lkb->lkb_ownqueue);
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dlm_put_lkb(lkb);
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}
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spin_unlock(&proc->locks_spin);
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}
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out:
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mutex_unlock(&ls->ls_clear_proc_locks);
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}
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static int device_user_lock(struct dlm_user_proc *proc,
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struct dlm_lock_params *params)
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{
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struct dlm_ls *ls;
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struct dlm_user_args *ua;
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uint32_t lkid;
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int error = -ENOMEM;
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ls = dlm_find_lockspace_local(proc->lockspace);
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if (!ls)
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return -ENOENT;
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if (!params->castaddr || !params->lksb) {
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error = -EINVAL;
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goto out;
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}
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ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
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if (!ua)
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goto out;
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ua->proc = proc;
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ua->user_lksb = params->lksb;
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ua->castparam = params->castparam;
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ua->castaddr = params->castaddr;
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ua->bastparam = params->bastparam;
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ua->bastaddr = params->bastaddr;
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ua->xid = params->xid;
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if (params->flags & DLM_LKF_CONVERT) {
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error = dlm_user_convert(ls, ua,
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params->mode, params->flags,
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params->lkid, params->lvb,
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(unsigned long) params->timeout);
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} else if (params->flags & DLM_LKF_ORPHAN) {
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error = dlm_user_adopt_orphan(ls, ua,
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params->mode, params->flags,
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params->name, params->namelen,
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(unsigned long) params->timeout,
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&lkid);
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if (!error)
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error = lkid;
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} else {
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error = dlm_user_request(ls, ua,
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params->mode, params->flags,
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params->name, params->namelen,
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(unsigned long) params->timeout);
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if (!error)
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error = ua->lksb.sb_lkid;
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}
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out:
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dlm_put_lockspace(ls);
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return error;
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}
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static int device_user_unlock(struct dlm_user_proc *proc,
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struct dlm_lock_params *params)
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{
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struct dlm_ls *ls;
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struct dlm_user_args *ua;
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int error = -ENOMEM;
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ls = dlm_find_lockspace_local(proc->lockspace);
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if (!ls)
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return -ENOENT;
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ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
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if (!ua)
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goto out;
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ua->proc = proc;
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ua->user_lksb = params->lksb;
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ua->castparam = params->castparam;
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ua->castaddr = params->castaddr;
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if (params->flags & DLM_LKF_CANCEL)
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error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
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else
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error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
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params->lvb);
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out:
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dlm_put_lockspace(ls);
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return error;
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}
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static int device_user_deadlock(struct dlm_user_proc *proc,
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struct dlm_lock_params *params)
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{
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struct dlm_ls *ls;
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int error;
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ls = dlm_find_lockspace_local(proc->lockspace);
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if (!ls)
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return -ENOENT;
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error = dlm_user_deadlock(ls, params->flags, params->lkid);
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dlm_put_lockspace(ls);
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return error;
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}
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static int dlm_device_register(struct dlm_ls *ls, char *name)
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{
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int error, len;
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/* The device is already registered. This happens when the
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lockspace is created multiple times from userspace. */
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if (ls->ls_device.name)
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return 0;
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error = -ENOMEM;
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len = strlen(name) + strlen(name_prefix) + 2;
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ls->ls_device.name = kzalloc(len, GFP_NOFS);
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if (!ls->ls_device.name)
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goto fail;
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snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
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name);
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ls->ls_device.fops = &device_fops;
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ls->ls_device.minor = MISC_DYNAMIC_MINOR;
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error = misc_register(&ls->ls_device);
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if (error) {
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kfree(ls->ls_device.name);
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/* this has to be set to NULL
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* to avoid a double-free in dlm_device_deregister
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*/
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ls->ls_device.name = NULL;
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}
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fail:
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return error;
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}
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int dlm_device_deregister(struct dlm_ls *ls)
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{
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/* The device is not registered. This happens when the lockspace
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was never used from userspace, or when device_create_lockspace()
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calls dlm_release_lockspace() after the register fails. */
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if (!ls->ls_device.name)
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return 0;
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misc_deregister(&ls->ls_device);
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kfree(ls->ls_device.name);
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return 0;
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}
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static int device_user_purge(struct dlm_user_proc *proc,
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struct dlm_purge_params *params)
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{
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struct dlm_ls *ls;
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int error;
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ls = dlm_find_lockspace_local(proc->lockspace);
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if (!ls)
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return -ENOENT;
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error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
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dlm_put_lockspace(ls);
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return error;
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}
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|
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static int device_create_lockspace(struct dlm_lspace_params *params)
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{
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dlm_lockspace_t *lockspace;
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struct dlm_ls *ls;
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int error;
|
|
|
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
|
|
|
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error = dlm_new_lockspace(params->name, dlm_config.ci_cluster_name, params->flags,
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DLM_USER_LVB_LEN, NULL, NULL, NULL,
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&lockspace);
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if (error)
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return error;
|
|
|
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ls = dlm_find_lockspace_local(lockspace);
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if (!ls)
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return -ENOENT;
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|
|
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error = dlm_device_register(ls, params->name);
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dlm_put_lockspace(ls);
|
|
|
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if (error)
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dlm_release_lockspace(lockspace, 0);
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else
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error = ls->ls_device.minor;
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|
|
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return error;
|
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}
|
|
|
|
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))
|
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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 &&
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|
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,
|
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task_pid_nr(current),
|
|
req->version[0],
|
|
req->version[1],
|
|
req->version[2],
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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 = memdup_user_nul(buf, count);
|
|
if (IS_ERR(kbuf))
|
|
return PTR_ERR(kbuf);
|
|
|
|
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, offsetof(struct dlm_lksb, sb_lvbptr));
|
|
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;
|
|
int old_mode, new_mode;
|
|
|
|
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);
|
|
|
|
/* rem_lkb_callback sets a new lkb_last_cast */
|
|
old_mode = lkb->lkb_last_cast.mode;
|
|
|
|
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) {
|
|
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 __poll_t 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 EPOLLIN | EPOLLRDNORM;
|
|
}
|
|
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);
|
|
}
|
|
|