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SUNRPC: replace inode lock with pipe lock for RPC PipeFS operations
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Currenly, inode i_lock is used to provide concurrent access to SUNPRC PipeFS
pipes. It looks redundant, since now other use of inode is present in most of
these places and thus can be easely replaced, which will allow to remove most
of inode references from PipeFS code. This is a first step towards to removing
PipeFS inode references from kernel code other than PipeFS itself.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Stanislav Kinsbursky authored and Trond Myklebust committed Jan 31, 2012
1 parent efc46bf commit 766347b
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Showing 3 changed files with 48 additions and 48 deletions.
1 change: 1 addition & 0 deletions include/linux/sunrpc/rpc_pipe_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ struct rpc_inode {
int flags;
struct delayed_work queue_timeout;
const struct rpc_pipe_ops *ops;
spinlock_t lock;
};

static inline struct rpc_inode *
Expand Down
57 changes: 28 additions & 29 deletions net/sunrpc/auth_gss/auth_gss.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -112,7 +112,7 @@ gss_put_ctx(struct gss_cl_ctx *ctx)
/* gss_cred_set_ctx:
* called by gss_upcall_callback and gss_create_upcall in order
* to set the gss context. The actual exchange of an old context
* and a new one is protected by the inode->i_lock.
* and a new one is protected by the rpci->lock.
*/
static void
gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
Expand Down Expand Up @@ -316,17 +316,16 @@ static inline struct gss_upcall_msg *
gss_add_msg(struct gss_upcall_msg *gss_msg)
{
struct rpc_inode *rpci = gss_msg->inode;
struct inode *inode = &rpci->vfs_inode;
struct gss_upcall_msg *old;

spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
old = __gss_find_upcall(rpci, gss_msg->uid);
if (old == NULL) {
atomic_inc(&gss_msg->count);
list_add(&gss_msg->list, &rpci->in_downcall);
} else
gss_msg = old;
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
return gss_msg;
}

Expand All @@ -342,14 +341,14 @@ __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
static void
gss_unhash_msg(struct gss_upcall_msg *gss_msg)
{
struct inode *inode = &gss_msg->inode->vfs_inode;
struct rpc_inode *rpci = gss_msg->inode;

if (list_empty(&gss_msg->list))
return;
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (!list_empty(&gss_msg->list))
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
}

static void
Expand All @@ -376,11 +375,11 @@ gss_upcall_callback(struct rpc_task *task)
struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
struct gss_cred, gc_base);
struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
struct inode *inode = &gss_msg->inode->vfs_inode;
struct rpc_inode *rpci = gss_msg->inode;

spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
gss_handle_downcall_result(gss_cred, gss_msg);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
task->tk_status = gss_msg->msg.errno;
gss_release_msg(gss_msg);
}
Expand Down Expand Up @@ -506,7 +505,7 @@ gss_refresh_upcall(struct rpc_task *task)
struct gss_cred *gss_cred = container_of(cred,
struct gss_cred, gc_base);
struct gss_upcall_msg *gss_msg;
struct inode *inode;
struct rpc_inode *rpci;
int err = 0;

dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
Expand All @@ -524,8 +523,8 @@ gss_refresh_upcall(struct rpc_task *task)
err = PTR_ERR(gss_msg);
goto out;
}
inode = &gss_msg->inode->vfs_inode;
spin_lock(&inode->i_lock);
rpci = gss_msg->inode;
spin_lock(&rpci->lock);
if (gss_cred->gc_upcall != NULL)
rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
Expand All @@ -538,7 +537,7 @@ gss_refresh_upcall(struct rpc_task *task)
gss_handle_downcall_result(gss_cred, gss_msg);
err = gss_msg->msg.errno;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
gss_release_msg(gss_msg);
out:
dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
Expand All @@ -549,7 +548,7 @@ gss_refresh_upcall(struct rpc_task *task)
static inline int
gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
{
struct inode *inode;
struct rpc_inode *rpci;
struct rpc_cred *cred = &gss_cred->gc_base;
struct gss_upcall_msg *gss_msg;
DEFINE_WAIT(wait);
Expand All @@ -573,14 +572,14 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
err = PTR_ERR(gss_msg);
goto out;
}
inode = &gss_msg->inode->vfs_inode;
rpci = gss_msg->inode;
for (;;) {
prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
break;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
if (fatal_signal_pending(current)) {
err = -ERESTARTSYS;
goto out_intr;
Expand All @@ -591,7 +590,7 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
gss_cred_set_ctx(cred, gss_msg->ctx);
else
err = gss_msg->msg.errno;
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
out_intr:
finish_wait(&gss_msg->waitqueue, &wait);
gss_release_msg(gss_msg);
Expand All @@ -609,7 +608,7 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
const void *p, *end;
void *buf;
struct gss_upcall_msg *gss_msg;
struct inode *inode = filp->f_path.dentry->d_inode;
struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
struct gss_cl_ctx *ctx;
uid_t uid;
ssize_t err = -EFBIG;
Expand Down Expand Up @@ -639,14 +638,14 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)

err = -ENOENT;
/* Find a matching upcall */
spin_lock(&inode->i_lock);
gss_msg = __gss_find_upcall(RPC_I(inode), uid);
spin_lock(&rpci->lock);
gss_msg = __gss_find_upcall(rpci, uid);
if (gss_msg == NULL) {
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
goto err_put_ctx;
}
list_del_init(&gss_msg->list);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);

p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
if (IS_ERR(p)) {
Expand Down Expand Up @@ -674,9 +673,9 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
err = mlen;

err_release_msg:
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
gss_release_msg(gss_msg);
err_put_ctx:
gss_put_ctx(ctx);
Expand Down Expand Up @@ -726,19 +725,19 @@ gss_pipe_release(struct inode *inode)
struct gss_upcall_msg *gss_msg;

restart:
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
list_for_each_entry(gss_msg, &rpci->in_downcall, list) {

if (!list_empty(&gss_msg->msg.list))
continue;
gss_msg->msg.errno = -EPIPE;
atomic_inc(&gss_msg->count);
__gss_unhash_msg(gss_msg);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
gss_release_msg(gss_msg);
goto restart;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);

put_pipe_version();
}
Expand Down
38 changes: 19 additions & 19 deletions net/sunrpc/rpc_pipe.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -83,20 +83,19 @@ rpc_timeout_upcall_queue(struct work_struct *work)
LIST_HEAD(free_list);
struct rpc_inode *rpci =
container_of(work, struct rpc_inode, queue_timeout.work);
struct inode *inode = &rpci->vfs_inode;
void (*destroy_msg)(struct rpc_pipe_msg *);

spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (rpci->ops == NULL) {
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
return;
}
destroy_msg = rpci->ops->destroy_msg;
if (rpci->nreaders == 0) {
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
}

Expand Down Expand Up @@ -136,7 +135,7 @@ rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
struct rpc_inode *rpci = RPC_I(inode);
int res = -EPIPE;

spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (rpci->ops == NULL)
goto out;
if (rpci->nreaders) {
Expand All @@ -153,7 +152,7 @@ rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
res = 0;
}
out:
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
wake_up(&rpci->waitq);
return res;
}
Expand All @@ -176,14 +175,14 @@ rpc_close_pipes(struct inode *inode)
ops = rpci->ops;
if (ops != NULL) {
LIST_HEAD(free_list);
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
rpci->nreaders = 0;
list_splice_init(&rpci->in_upcall, &free_list);
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
rpci->ops = NULL;
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
rpci->nwriters = 0;
if (need_release && ops->release_pipe)
Expand Down Expand Up @@ -255,10 +254,10 @@ rpc_pipe_release(struct inode *inode, struct file *filp)
goto out;
msg = filp->private_data;
if (msg != NULL) {
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
msg->errno = -EAGAIN;
list_del_init(&msg->list);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
rpci->ops->destroy_msg(msg);
}
if (filp->f_mode & FMODE_WRITE)
Expand All @@ -267,10 +266,10 @@ rpc_pipe_release(struct inode *inode, struct file *filp)
rpci->nreaders --;
if (rpci->nreaders == 0) {
LIST_HEAD(free_list);
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
list_splice_init(&rpci->pipe, &free_list);
rpci->pipelen = 0;
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
rpc_purge_list(rpci, &free_list,
rpci->ops->destroy_msg, -EAGAIN);
}
Expand Down Expand Up @@ -298,7 +297,7 @@ rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
}
msg = filp->private_data;
if (msg == NULL) {
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (!list_empty(&rpci->pipe)) {
msg = list_entry(rpci->pipe.next,
struct rpc_pipe_msg,
Expand All @@ -308,17 +307,17 @@ rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
filp->private_data = msg;
msg->copied = 0;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
if (msg == NULL)
goto out_unlock;
}
/* NOTE: it is up to the callback to update msg->copied */
res = rpci->ops->upcall(filp, msg, buf, len);
if (res < 0 || msg->len == msg->copied) {
filp->private_data = NULL;
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
list_del_init(&msg->list);
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
rpci->ops->destroy_msg(msg);
}
out_unlock:
Expand Down Expand Up @@ -367,9 +366,9 @@ rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

switch (cmd) {
case FIONREAD:
spin_lock(&inode->i_lock);
spin_lock(&rpci->lock);
if (rpci->ops == NULL) {
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
return -EPIPE;
}
len = rpci->pipelen;
Expand All @@ -378,7 +377,7 @@ rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
msg = filp->private_data;
len += msg->len - msg->copied;
}
spin_unlock(&inode->i_lock);
spin_unlock(&rpci->lock);
return put_user(len, (int __user *)arg);
default:
return -EINVAL;
Expand Down Expand Up @@ -1153,6 +1152,7 @@ init_once(void *foo)
INIT_DELAYED_WORK(&rpci->queue_timeout,
rpc_timeout_upcall_queue);
rpci->ops = NULL;
spin_lock_init(&rpci->lock);
}

int register_rpc_pipefs(void)
Expand Down

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