Bug#532561: status request

[Ben Hutchings]

On Tue, 2010-05-11 at 02:33 +0100, Ben Hutchings wrote:
> On Mon, 2010-05-10 at 10:01 +0300, roma1390 wrote:
> > Hello,
> > 
> > What issue blocks to fix this bug? May be some how I can help?
> 
> The major reason I see that this bug has not been fixed is that it has a
> severity of 'normal', while we have many other 'important' bugs to be
> dealt with.
> 
> If you are able to reproduce the bug, please test whether the attached
> patch fixes it for you.  Follow the instructions at
> 
> to build a new kernel package with this patch.

Actually, I think there may be two separate bugs here
(#516376/#519348/#538000 vs #517936/#532561) and this patch looks like
it may fix the first but not the second.  However, you are welcome to
try it anyway.

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.


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Bug#532561: status request

[Ben Hutchings]

On Mon, 2010-05-10 at 10:01 +0300, roma1390 wrote:
> Hello,
> 
> What issue blocks to fix this bug? May be some how I can help?

The major reason I see that this bug has not been fixed is that it has a
severity of 'normal', while we have many other 'important' bugs to be
dealt with.

If you are able to reproduce the bug, please test whether the attached
patch fixes it for you.  Follow the instructions at

 to build a new kernel package with this patch.

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.
From bedbdd8bada194a690d2901801bf8451965086b3 Mon Sep 17 00:00:00 2001
From: Neil Brown 
Date: Tue, 10 Jun 2008 08:40:35 -0400
Subject: [PATCH] knfsd: Replace lock_kernel with a mutex for nfsd thread startup/shutdown locking.

This removes the BKL from the RPC service creation codepath. The BKL
really isn't adequate for this job since some of this info needs
protection across sleeps.

Also, add some comments to try and clarify how the locking should work
and to make it clear that the BKL isn't necessary as long as there is
adequate locking between tasks when touching the svc_serv fields.

Signed-off-by: Neil Brown 
Signed-off-by: Jeff Layton 
Signed-off-by: J. Bruce Fields 
---
 fs/nfsd/nfsctl.c  |   37 +++--
 fs/nfsd/nfssvc.c  |   45 -
 include/linux/nfsd/nfsd.h |1 +
 net/sunrpc/svc.c  |   15 +--
 4 files changed, 65 insertions(+), 33 deletions(-)

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 5ac00c4..049d2a9 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -450,22 +450,26 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
 	int i;
 	int rv;
 	int len;
-	int npools = nfsd_nrpools();
+	int npools;
 	int *nthreads;
 
+	mutex_lock(&nfsd_mutex);
+	npools = nfsd_nrpools();
 	if (npools == 0) {
 		/*
 		 * NFS is shut down.  The admin can start it by
 		 * writing to the threads file but NOT the pool_threads
 		 * file, sorry.  Report zero threads.
 		 */
+		mutex_unlock(&nfsd_mutex);
 		strcpy(buf, "0\n");
 		return strlen(buf);
 	}
 
 	nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
+	rv = -ENOMEM;
 	if (nthreads == NULL)
-		return -ENOMEM;
+		goto out_free;
 
 	if (size > 0) {
 		for (i = 0; i < npools; i++) {
@@ -496,10 +500,12 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
 		mesg += len;
 	}
 
+	mutex_unlock(&nfsd_mutex);
 	return (mesg-buf);
 
 out_free:
 	kfree(nthreads);
+	mutex_unlock(&nfsd_mutex);
 	return rv;
 }
 
@@ -566,14 +572,13 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size)
 	return len;
 }
 
-static ssize_t write_ports(struct file *file, char *buf, size_t size)
+static ssize_t __write_ports(struct file *file, char *buf, size_t size)
 {
 	if (size == 0) {
 		int len = 0;
-		lock_kernel();
+
 		if (nfsd_serv)
 			len = svc_xprt_names(nfsd_serv, buf, 0);
-		unlock_kernel();
 		return len;
 	}
 	/* Either a single 'fd' number is written, in which
@@ -603,9 +608,7 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 			/* Decrease the count, but don't shutdown the
 			 * the service
 			 */
-			lock_kernel();
 			nfsd_serv->sv_nrthreads--;
-			unlock_kernel();
 		}
 		return err < 0 ? err : 0;
 	}
@@ -614,10 +617,8 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 		int len = 0;
 		if (!toclose)
 			return -ENOMEM;
-		lock_kernel();
 		if (nfsd_serv)
 			len = svc_sock_names(buf, nfsd_serv, toclose);
-		unlock_kernel();
 		if (len >= 0)
 			lockd_down();
 		kfree(toclose);
@@ -655,7 +656,6 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 		if (sscanf(&buf[1], "%15s %4d", transport, &port) == 2) {
 			if (port == 0)
 return -EINVAL;
-			lock_kernel();
 			if (nfsd_serv) {
 xprt = svc_find_xprt(nfsd_serv, transport,
 		 AF_UNSPEC, port);
@@ -666,13 +666,22 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 } else
 	err = -ENOTCONN;
 			}
-			unlock_kernel();
 			return err < 0 ? err : 0;
 		}
 	}
 	return -EINVAL;
 }
 
+static ssize_t write_ports(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+	mutex_lock(&nfsd_mutex);
+	rv = __write_ports(file, buf, size);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+
 int nfsd_max_blksize;
 
 static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
@@ -691,13 +700,13 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
 		if (bsize > NFSSVC_MAXBLKSIZE)
 			bsize = NFSSVC_MAXBLKSIZE;
 		bsize &= ~(1024-1);
-		lock_kernel();
+		mutex_lock(&nfsd_mutex);
 		if (nfsd_serv && nfsd_serv->sv_nrthreads) {
-			unlock_kernel();
+			mutex_unlock(&nfsd_mutex);
 			return -EBUSY;
 		}
 		nfsd_max_blksize = bsize;
-		unlock_kernel();
+		mutex_unlock(&nfsd_mut

Bug#532561: status request

[roma1390]

Hello,

What issue blocks to fix this bug? May be some how I can help?



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