- regressions introduced by the new stable kernel

[packages/kernel.git] / kernel-regressions.patch

From jlayton@redhat.com  Thu Dec 11 08:49:55 2008
From: Jeff Layton <jlayton@redhat.com>
Date: Wed, 10 Dec 2008 06:44:29 -0500
Subject: cifs: fix a regression in cifs umount codepath
To: greg@kroah.com, stable@kernel.org
Cc: smfrench@gmail.com, shirishp@us.ibm.com, sjayaraman@suse.de
Message-ID: <1228909469-438-1-git-send-email-jlayton@redhat.com>

From: Jeff Layton <jlayton@redhat.com>

backport of 469ee614aaa367d9cde01cbdd2027212f56c6cc6 upstream.

Several cifs patches were added to 2.6.27.8 to fix some races in the
mount/umount codepath. When this was done, a couple of prerequisite
patches were missed causing a minor regression.

When the last cifs mount to a server goes away, the kthread that manages
the socket is supposed to come down. The patches that went into 2.6.27.8
removed the kthread_stop calls that used to take down these threads, but
left the thread function expecting them. This made the thread stay up
even after the last mount was gone.

This patch should fix up this regression and also prevent a possible
race where a dead task could be signalled.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/cifs/connect.c |   36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -128,7 +128,7 @@ cifs_reconnect(struct TCP_Server_Info *s
 	struct mid_q_entry *mid_entry;
 
 	spin_lock(&GlobalMid_Lock);
-	if (kthread_should_stop()) {
+	if (server->tcpStatus == CifsExiting) {
 		/* the demux thread will exit normally
 		next time through the loop */
 		spin_unlock(&GlobalMid_Lock);
@@ -182,7 +182,8 @@ cifs_reconnect(struct TCP_Server_Info *s
 	spin_unlock(&GlobalMid_Lock);
 	up(&server->tcpSem);
 
-	while ((!kthread_should_stop()) && (server->tcpStatus != CifsGood)) {
+	while ((server->tcpStatus != CifsExiting) &&
+	       (server->tcpStatus != CifsGood)) {
 		try_to_freeze();
 		if (server->addr.sockAddr6.sin6_family == AF_INET6) {
 			rc = ipv6_connect(&server->addr.sockAddr6,
@@ -200,7 +201,7 @@ cifs_reconnect(struct TCP_Server_Info *s
 		} else {
 			atomic_inc(&tcpSesReconnectCount);
 			spin_lock(&GlobalMid_Lock);
-			if (!kthread_should_stop())
+			if (server->tcpStatus != CifsExiting)
 				server->tcpStatus = CifsGood;
 			server->sequence_number = 0;
 			spin_unlock(&GlobalMid_Lock);
@@ -355,7 +356,7 @@ cifs_demultiplex_thread(struct TCP_Serve
 				GFP_KERNEL);
 
 	set_freezable();
-	while (!kthread_should_stop()) {
+	while (server->tcpStatus != CifsExiting) {
 		if (try_to_freeze())
 			continue;
 		if (bigbuf == NULL) {
@@ -396,7 +397,7 @@ incomplete_rcv:
 		    kernel_recvmsg(csocket, &smb_msg,
 				&iov, 1, pdu_length, 0 /* BB other flags? */);
 
-		if (kthread_should_stop()) {
+		if (server->tcpStatus == CifsExiting) {
 			break;
 		} else if (server->tcpStatus == CifsNeedReconnect) {
 			cFYI(1, ("Reconnect after server stopped responding"));
@@ -527,7 +528,7 @@ incomplete_rcv:
 		     total_read += length) {
 			length = kernel_recvmsg(csocket, &smb_msg, &iov, 1,
 						pdu_length - total_read, 0);
-			if (kthread_should_stop() ||
+			if ((server->tcpStatus == CifsExiting) ||
 			    (length == -EINTR)) {
 				/* then will exit */
 				reconnect = 2;
@@ -661,14 +662,6 @@ multi_t2_fnd:
 	spin_unlock(&GlobalMid_Lock);
 	wake_up_all(&server->response_q);
 
-	/* don't exit until kthread_stop is called */
-	set_current_state(TASK_UNINTERRUPTIBLE);
-	while (!kthread_should_stop()) {
-		schedule();
-		set_current_state(TASK_UNINTERRUPTIBLE);
-	}
-	set_current_state(TASK_RUNNING);
-
 	/* check if we have blocked requests that need to free */
 	/* Note that cifs_max_pending is normally 50, but
 	can be set at module install time to as little as two */
@@ -764,6 +757,7 @@ multi_t2_fnd:
 	read_unlock(&cifs_tcp_ses_lock);
 
 	kfree(server->hostname);
+	task_to_wake = xchg(&server->tsk, NULL);
 	kfree(server);
 
 	length = atomic_dec_return(&tcpSesAllocCount);
@@ -771,6 +765,16 @@ multi_t2_fnd:
 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
 				GFP_KERNEL);
 
+	/* if server->tsk was NULL then wait for a signal before exiting */
+	if (!task_to_wake) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		while (!signal_pending(current)) {
+			schedule();
+			set_current_state(TASK_INTERRUPTIBLE);
+		}
+		set_current_state(TASK_RUNNING);
+	}
+
 	return 0;
 }
 
@@ -2310,7 +2314,7 @@ cifs_mount(struct super_block *sb, struc
 	/* on error free sesinfo and tcon struct if needed */
 mount_fail_check:
 	if (rc) {
-		 /* If find_unc succeeded then rc == 0 so we can not end */
+		/* If find_unc succeeded then rc == 0 so we can not end */
 		/* up accidently freeing someone elses tcon struct */
 		if (tcon)
 			cifs_put_tcon(tcon);
@@ -3715,8 +3719,10 @@ int cifs_setup_session(unsigned int xid,
 		cERROR(1, ("Send error in SessSetup = %d", rc));
 	} else {
 		cFYI(1, ("CIFS Session Established successfully"));
+			spin_lock(&GlobalMid_Lock);
 			pSesInfo->status = CifsGood;
 			pSesInfo->need_reconnect = false;
+			spin_unlock(&GlobalMid_Lock);
 	}
 
 ss_err_exit:
From 218d11a8b071b23b76c484fd5f72a4fe3306801e Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Fri, 5 Dec 2008 16:12:48 -0700
Subject: Fix a race condition in FASYNC handling

From: Jonathan Corbet <corbet@lwn.net>

commit 218d11a8b071b23b76c484fd5f72a4fe3306801e upstream.

Changeset a238b790d5f99c7832f9b73ac8847025815b85f7 (Call fasync()
functions without the BKL) introduced a race which could leave
file->f_flags in a state inconsistent with what the underlying
driver/filesystem believes.  Revert that change, and also fix the same
races in ioctl_fioasync() and ioctl_fionbio().

This is a minimal, short-term fix; the real fix will not involve the
BKL.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/fcntl.c |    7 +++++++
 fs/ioctl.c |   12 ++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -19,6 +19,7 @@
 #include <linux/signal.h>
 #include <linux/rcupdate.h>
 #include <linux/pid_namespace.h>
+#include <linux/smp_lock.h>
 
 #include <asm/poll.h>
 #include <asm/siginfo.h>
@@ -175,6 +176,11 @@ static int setfl(int fd, struct file * f
 	if (error)
 		return error;
 
+	/*
+	 * We still need a lock here for now to keep multiple FASYNC calls
+	 * from racing with each other.
+	 */
+	lock_kernel();
 	if ((arg ^ filp->f_flags) & FASYNC) {
 		if (filp->f_op && filp->f_op->fasync) {
 			error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
@@ -185,6 +191,7 @@ static int setfl(int fd, struct file * f
 
 	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
  out:
+	unlock_kernel();
 	return error;
 }
 
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -123,11 +123,9 @@ static int ioctl_fioasync(unsigned int f
 
 	/* Did FASYNC state change ? */
 	if ((flag ^ filp->f_flags) & FASYNC) {
-		if (filp->f_op && filp->f_op->fasync) {
-			lock_kernel();
+		if (filp->f_op && filp->f_op->fasync)
 			error = filp->f_op->fasync(fd, filp, on);
-			unlock_kernel();
-		} else
+		else
 			error = -ENOTTY;
 	}
 	if (error)
@@ -163,11 +161,17 @@ int do_vfs_ioctl(struct file *filp, unsi
 		break;
 
 	case FIONBIO:
+		/* BKL needed to avoid races tweaking f_flags */
+		lock_kernel();
 		error = ioctl_fionbio(filp, argp);
+		unlock_kernel();
 		break;
 
 	case FIOASYNC:
+		/* BKL needed to avoid races tweaking f_flags */
+		lock_kernel();
 		error = ioctl_fioasync(fd, filp, argp);
+		unlock_kernel();
 		break;
 
 	case FIOQSIZE:
From 49c50342c728344b79c8f9e8293637fe80ef5ad5 Mon Sep 17 00:00:00 2001
From: Matt Mackall <mpm@selenic.com>
Date: Tue, 9 Dec 2008 13:14:21 -0800
Subject: pagemap: fix 32-bit pagemap regression

From: Matt Mackall <mpm@selenic.com>

commit 49c50342c728344b79c8f9e8293637fe80ef5ad5 upstream.

The large pages fix from bcf8039ed45 broke 32-bit pagemap by pulling the
pagemap entry code out into a function with the wrong return type.
Pagemap entries are 64 bits on all systems and unsigned long is only 32
bits on 32-bit systems.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Reported-by: Doug Graham <dgraham@nortel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/proc/task_mmu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -563,9 +563,9 @@ static u64 swap_pte_to_pagemap_entry(pte
 	return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
 }
 
-static unsigned long pte_to_pagemap_entry(pte_t pte)
+static u64 pte_to_pagemap_entry(pte_t pte)
 {
-	unsigned long pme = 0;
+	u64 pme = 0;
 	if (is_swap_pte(pte))
 		pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
 			| PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
rom ae060e0b7bc071bd73dd5319b93c3344d9e10212 Mon Sep 17 00:00:00 2001
From: Manfred Spraul <manfred@colorfullife.com>
To: torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: cebbert@redhat.com
Cc: airlied@gmail.com
Cc: akpm@linux-foundation.org
Bcc: manfred@colorfullife.com
Date: Wed, 10 Dec 2008 18:17:06 +0100
Subject: [PATCH] lib/idr.c: Fix bug introduced by RCU fix

The last patch to lib/idr.c caused a bug if idr_get_new_above() was
called on an empty idr:
Usually, nodes stay on the same layer. New layers are added to the top
of the tree.
The exception is idr_get_new_above() on an empty tree: In this case,
the new root node is first added on layer 0, then moved upwards.
p->layer was not updated.

As usual: You shall never rely on the source code comments, they
will only mislead you.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 lib/idr.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/lib/idr.c b/lib/idr.c
index 7a785a0..1c4f928 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -220,8 +220,14 @@ build_up:
 	 */
 	while ((layers < (MAX_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) {
 		layers++;
-		if (!p->count)
+		if (!p->count) {
+			/* special case: if the tree is currently empty,
+			 * then we grow the tree by moving the top node
+			 * upwards.
+			 */
+			p->layer++;
 			continue;
+		}
 		if (!(new = get_from_free_list(idp))) {
 			/*
 			 * The allocation failed.  If we built part of
-- 
1.5.6.5