[PATCH] [DLM] dlm_device interface changes [3/6]

From: swhiteho
Date: Mon Jul 09 2007 - 12:27:47 EST

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From: David Teigland <teigland@xxxxxxxxxx>

Change the user/kernel device interface used by libdlm:
- Add ability for userspace to check the version of the interface. libdlm
can now adapt to different versions of the kernel interface.
- Increase the size of the flags passed in a lock request so all possible
flags can be used from userspace.
- Add an opaque "xid" value for each lock. This "transaction id" will be
used later to associate locks with each other during deadlock detection.
- Add a "timeout" value for each lock. This is used along with the
DLM_LKF_TIMEOUT flag.

Also, remove a fragment of unused code in device_read().

This patch requires updating libdlm which is backward compatible with
older kernels.

Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 65a5fc0..a8d6e99 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -151,6 +151,7 @@ struct dlm_args {
void *bastaddr;
int mode;
struct dlm_lksb *lksb;
+ unsigned long timeout;
};

@@ -528,6 +529,7 @@ struct dlm_user_args {
void __user *castaddr;
void __user *bastparam;
void __user *bastaddr;
+ uint64_t xid;
};

#define DLM_PROC_FLAGS_CLOSING 1
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index ab986df..ad3797a 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -1098,6 +1098,8 @@ void dlm_scan_timeout(struct dlm_ls *ls)
}

if (do_cancel) {
+ log_debug("timeout cancel %x node %d %s", lkb->lkb_id,
+ lkb->lkb_nodeid, r->res_name);
lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
del_timeout(lkb);
@@ -1864,7 +1866,7 @@ static void confirm_master(struct dlm_rsb *r, int error)
}

static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
- int namelen, uint32_t parent_lkid, void *ast,
+ int namelen, unsigned long timeout_cs, void *ast,
void *astarg, void *bast, struct dlm_args *args)
{
int rv = -EINVAL;
@@ -1907,10 +1909,6 @@ static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
goto out;

- /* parent/child locks not yet supported */
- if (parent_lkid)
- goto out;
-
if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
goto out;

@@ -1922,6 +1920,7 @@ static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
args->astaddr = ast;
args->astparam = (long) astarg;
args->bastaddr = bast;
+ args->timeout = timeout_cs;
args->mode = mode;
args->lksb = lksb;
rv = 0;
@@ -1976,6 +1975,7 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
lkb->lkb_lksb = args->lksb;
lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
lkb->lkb_ownpid = (int) current->pid;
+ lkb->lkb_timeout_cs = args->timeout;
rv = 0;
out:
return rv;
@@ -2423,7 +2423,7 @@ int dlm_lock(dlm_lockspace_t *lockspace,
if (error)
goto out;

- error = set_lock_args(mode, lksb, flags, namelen, parent_lkid, ast,
+ error = set_lock_args(mode, lksb, flags, namelen, 0, ast,
astarg, bast, &args);
if (error)
goto out_put;
@@ -4175,7 +4175,7 @@ int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)

int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
int mode, uint32_t flags, void *name, unsigned int namelen,
- uint32_t parent_lkid)
+ unsigned long timeout_cs)
{
struct dlm_lkb *lkb;
struct dlm_args args;
@@ -4203,7 +4203,7 @@ int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
When DLM_IFL_USER is set, the dlm knows that this is a userspace
lock and that lkb_astparam is the dlm_user_args structure. */

- error = set_lock_args(mode, &ua->lksb, flags, namelen, parent_lkid,
+ error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
DLM_FAKE_USER_AST, ua, DLM_FAKE_USER_AST, &args);
lkb->lkb_flags |= DLM_IFL_USER;
ua->old_mode = DLM_LOCK_IV;
@@ -4240,7 +4240,8 @@ int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
}

int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
- int mode, uint32_t flags, uint32_t lkid, char *lvb_in)
+ int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
+ unsigned long timeout_cs)
{
struct dlm_lkb *lkb;
struct dlm_args args;
@@ -4268,6 +4269,7 @@ int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
if (lvb_in && ua->lksb.sb_lvbptr)
memcpy(ua->lksb.sb_lvbptr, lvb_in, DLM_USER_LVB_LEN);

+ ua->xid = ua_tmp->xid;
ua->castparam = ua_tmp->castparam;
ua->castaddr = ua_tmp->castaddr;
ua->bastparam = ua_tmp->bastparam;
@@ -4275,8 +4277,8 @@ int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
ua->user_lksb = ua_tmp->user_lksb;
ua->old_mode = lkb->lkb_grmode;

- error = set_lock_args(mode, &ua->lksb, flags, 0, 0, DLM_FAKE_USER_AST,
- ua, DLM_FAKE_USER_AST, &args);
+ error = set_lock_args(mode, &ua->lksb, flags, 0, timeout_cs,
+ DLM_FAKE_USER_AST, ua, DLM_FAKE_USER_AST, &args);
if (error)
goto out_put;

diff --git a/fs/dlm/lock.h b/fs/dlm/lock.h
index 6b5b71f..99ab463 100644
--- a/fs/dlm/lock.h
+++ b/fs/dlm/lock.h
@@ -38,9 +38,11 @@ int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc);

int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, int mode,
- uint32_t flags, void *name, unsigned int namelen, uint32_t parent_lkid);
+ uint32_t flags, void *name, unsigned int namelen,
+ unsigned long timeout_cs);
int dlm_user_convert(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
- int mode, uint32_t flags, uint32_t lkid, char *lvb_in);
+ int mode, uint32_t flags, uint32_t lkid, char *lvb_in,
+ unsigned long timeout_cs);
int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
uint32_t flags, uint32_t lkid, char *lvb_in);
int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index c7612da..37aad3f 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -33,16 +33,17 @@ static const struct file_operations device_fops;
struct dlm_lock_params32 {
__u8 mode;
__u8 namelen;
- __u16 flags;
+ __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];
};
@@ -68,6 +69,7 @@ struct dlm_lksb32 {
};

struct dlm_lock_result32 {
+ __u32 version[3];
__u32 length;
__u32 user_astaddr;
__u32 user_astparam;
@@ -102,6 +104,8 @@ static void compat_input(struct dlm_write_request *kb,
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;
@@ -115,6 +119,10 @@ static void compat_input(struct dlm_write_request *kb,
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;
@@ -252,16 +260,18 @@ static int device_user_lock(struct dlm_user_proc *proc,
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);
+ params->lkid, params->lvb,
+ (unsigned long) params->timeout);
else {
error = dlm_user_request(ls, ua,
params->mode, params->flags,
params->name, params->namelen,
- params->parent);
+ (unsigned long) params->timeout);
if (!error)
error = ua->lksb.sb_lkid;
}
@@ -641,6 +651,9 @@ static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type,
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;

@@ -699,6 +712,20 @@ static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type,
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,
@@ -710,6 +737,16 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
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
@@ -747,11 +784,6 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
}
}

- 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 */

@@ -823,6 +855,7 @@ static const struct file_operations device_fops = {
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,
};
diff --git a/include/linux/dlm_device.h b/include/linux/dlm_device.h
index c2735ca..f7b9b57 100644
--- a/include/linux/dlm_device.h
+++ b/include/linux/dlm_device.h
@@ -2,7 +2,7 @@
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2007 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
@@ -18,21 +18,24 @@
#define DLM_USER_LVB_LEN 32

/* Version of the device interface */
-#define DLM_DEVICE_VERSION_MAJOR 5
-#define DLM_DEVICE_VERSION_MINOR 1
+#define DLM_DEVICE_VERSION_MAJOR 6
+#define DLM_DEVICE_VERSION_MINOR 0
#define DLM_DEVICE_VERSION_PATCH 0

/* struct passed to the lock write */
struct dlm_lock_params {
__u8 mode;
__u8 namelen;
- __u16 flags;
+ __u16 unused;
+ __u32 flags;
__u32 lkid;
__u32 parent;
- void __user *castparam;
+ __u64 xid;
+ __u64 timeout;
+ void __user *castparam;
void __user *castaddr;
void __user *bastparam;
- void __user *bastaddr;
+ void __user *bastaddr;
struct dlm_lksb __user *lksb;
char lvb[DLM_USER_LVB_LEN];
char name[0];
@@ -62,9 +65,15 @@ struct dlm_write_request {
} i;
};

+struct dlm_device_version {
+ __u32 version[3];
+};
+
/* struct read from the "device" fd,
consists mainly of userspace pointers for the library to use */
+
struct dlm_lock_result {
+ __u32 version[3];
__u32 length;
void __user * user_astaddr;
void __user * user_astparam;
--
1.5.1.2

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Next message: swhiteho: "[PATCH] [DLM] cancel in conversion deadlock [4/6]"
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