[PATCH] fs: Don't return 0 from get_anon

stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed

* [PATCH] fs: Don't return 0 from get_anon_bdev
       [not found] <20140403191617.GB2472@mtj.dyndns.org>
@ 2014-04-03 19:49 ` Thomas Bächler
  2014-04-03 19:51   ` Tejun Heo
                     ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Thomas Bächler @ 2014-04-03 19:49 UTC (permalink / raw)
  To: tj
  Cc: d, linux-kernel, gregkh, P, alexandre.f.demers,
	Thomas Bächler, 3.14

Commit 9e30cc9595303b27b48 removed an internal mount. This
has the side-effect that rootfs now has FSID 0. Many
userspace utilities assume that st_dev in struct stat
is never 0, so this change breaks a number of tools in
early userspace.

Since we don't know how many userspace programs are affected,
make sure that FSID is at least 1.

References: http://article.gmane.org/gmane.linux.kernel/1666905
References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
Cc: 3.14 <stable@vger.kernel.org>
Signed-off-by: Thomas Bächler <thomas@archlinux.org>
---
 fs/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/super.c b/fs/super.c
index 80d5cf2..d9fddde 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -802,7 +802,7 @@ void emergency_remount(void)
 
 static DEFINE_IDA(unnamed_dev_ida);
 static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
-static int unnamed_dev_start = 0; /* don't bother trying below it */
+static int unnamed_dev_start = 1; /* don't bother trying below it */
 
 int get_anon_bdev(dev_t *p)
 {
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] fs: Don't return 0 from get_anon_bdev
  2014-04-03 19:49 ` [PATCH] fs: Don't return 0 from get_anon_bdev Thomas Bächler
@ 2014-04-03 19:51   ` Tejun Heo
  2014-04-03 19:55     ` [PATCHv2] " Thomas Bächler
  2014-04-03 20:21   ` [PATCH] " H. Peter Anvin
  2014-04-03 23:41   ` Alexandre Demers
  2 siblings, 1 reply; 6+ messages in thread
From: Tejun Heo @ 2014-04-03 19:51 UTC (permalink / raw)
  To: Thomas Bächler; +Cc: d, linux-kernel, gregkh, P, alexandre.f.demers, 3.14

On Thu, Apr 03, 2014 at 09:49:55PM +0200, Thomas Bï¿½chler wrote:
> Commit 9e30cc9595303b27b48 removed an internal mount. This
> has the side-effect that rootfs now has FSID 0. Many
> userspace utilities assume that st_dev in struct stat
> is never 0, so this change breaks a number of tools in
> early userspace.
> 
> Since we don't know how many userspace programs are affected,
> make sure that FSID is at least 1.
> 
> References: http://article.gmane.org/gmane.linux.kernel/1666905
> References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
> Cc: 3.14 <stable@vger.kernel.org>
> Signed-off-by: Thomas Bï¿½chler <thomas@archlinux.org>

Provided Alexandre confirms the fix.

 Acked-by: Tejun Heo <tj@kernel.org>

> ---
>  fs/super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/super.c b/fs/super.c
> index 80d5cf2..d9fddde 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -802,7 +802,7 @@ void emergency_remount(void)
>  
>  static DEFINE_IDA(unnamed_dev_ida);
>  static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
> -static int unnamed_dev_start = 0; /* don't bother trying below it */
> +static int unnamed_dev_start = 1; /* don't bother trying below it */

Maybe a comment saying that userland considers fsid 0 to be invalid
would be nice?

Thanks.

-- 
tejun

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCHv2] fs: Don't return 0 from get_anon_bdev
  2014-04-03 19:51   ` Tejun Heo
@ 2014-04-03 19:55     ` Thomas Bächler
  2014-04-03 20:32       ` Greg KH
  0 siblings, 1 reply; 6+ messages in thread
From: Thomas Bächler @ 2014-04-03 19:55 UTC (permalink / raw)
  To: tj
  Cc: d, linux-kernel, gregkh, P, alexandre.f.demers,
	Thomas Bächler, 3.14

Commit 9e30cc9595303b27b48 removed an internal mount. This
has the side-effect that rootfs now has FSID 0. Many
userspace utilities assume that st_dev in struct stat
is never 0, so this change breaks a number of tools in
early userspace.

Since we don't know how many userspace programs are affected,
make sure that FSID is at least 1.

References: http://article.gmane.org/gmane.linux.kernel/1666905
References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
Cc: 3.14 <stable@vger.kernel.org>
Signed-off-by: Thomas Bächler <thomas@archlinux.org>
---
 fs/super.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/super.c b/fs/super.c
index 80d5cf2..7624267 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -802,7 +802,10 @@ void emergency_remount(void)
 
 static DEFINE_IDA(unnamed_dev_ida);
 static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
-static int unnamed_dev_start = 0; /* don't bother trying below it */
+/* Many userspace utilities consider an FSID of 0 invalid.
+ * Always return at least 1 from get_anon_bdev.
+ */
+static int unnamed_dev_start = 1;
 
 int get_anon_bdev(dev_t *p)
 {
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCHv2] fs: Don't return 0 from get_anon_bdev
  2014-04-03 19:55     ` [PATCHv2] " Thomas Bächler
@ 2014-04-03 20:32       ` Greg KH
  0 siblings, 0 replies; 6+ messages in thread
From: Greg KH @ 2014-04-03 20:32 UTC (permalink / raw)
  To: Thomas Bächler; +Cc: tj, d, linux-kernel, P, alexandre.f.demers, 3.14

On Thu, Apr 03, 2014 at 09:55:37PM +0200, Thomas Bï¿½chler wrote:
> Commit 9e30cc9595303b27b48 removed an internal mount. This
> has the side-effect that rootfs now has FSID 0. Many
> userspace utilities assume that st_dev in struct stat
> is never 0, so this change breaks a number of tools in
> early userspace.
> 
> Since we don't know how many userspace programs are affected,
> make sure that FSID is at least 1.
> 
> References: http://article.gmane.org/gmane.linux.kernel/1666905
> References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
> Cc: 3.14 <stable@vger.kernel.org>
> Signed-off-by: Thomas Bï¿½chler <thomas@archlinux.org>
> ---
>  fs/super.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/super.c b/fs/super.c
> index 80d5cf2..7624267 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -802,7 +802,10 @@ void emergency_remount(void)
>  
>  static DEFINE_IDA(unnamed_dev_ida);
>  static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
> -static int unnamed_dev_start = 0; /* don't bother trying below it */
> +/* Many userspace utilities consider an FSID of 0 invalid.
> + * Always return at least 1 from get_anon_bdev.
> + */
> +static int unnamed_dev_start = 1;
>  
>  int get_anon_bdev(dev_t *p)
>  {

Very nice, I'll go queue this one up instead of the other patch from
Tejun.

greg k-h

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] fs: Don't return 0 from get_anon_bdev
  2014-04-03 19:49 ` [PATCH] fs: Don't return 0 from get_anon_bdev Thomas Bächler
  2014-04-03 19:51   ` Tejun Heo
@ 2014-04-03 20:21   ` H. Peter Anvin
  2014-04-03 23:41   ` Alexandre Demers
  2 siblings, 0 replies; 6+ messages in thread
From: H. Peter Anvin @ 2014-04-03 20:21 UTC (permalink / raw)
  To: Thomas Bächler, tj
  Cc: d, linux-kernel, gregkh, P, alexandre.f.demers, 3.14

On 04/03/2014 12:49 PM, Thomas Bächler wrote:
> Commit 9e30cc9595303b27b48 removed an internal mount. This
> has the side-effect that rootfs now has FSID 0. Many
> userspace utilities assume that st_dev in struct stat
> is never 0, so this change breaks a number of tools in
> early userspace.
> 
> Since we don't know how many userspace programs are affected,
> make sure that FSID is at least 1.
> 
> References: http://article.gmane.org/gmane.linux.kernel/1666905
> References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
> Cc: 3.14 <stable@vger.kernel.org>
> Signed-off-by: Thomas Bächler <thomas@archlinux.org>
> ---
>  fs/super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Acked-by: H. Peter Anvin <hpa@zytor.com>

It is worth noting that zero has been documented as a null device number
since at least 1995, probably more like 1993.

	-hpa



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] fs: Don't return 0 from get_anon_bdev
  2014-04-03 19:49 ` [PATCH] fs: Don't return 0 from get_anon_bdev Thomas Bächler
  2014-04-03 19:51   ` Tejun Heo
  2014-04-03 20:21   ` [PATCH] " H. Peter Anvin
@ 2014-04-03 23:41   ` Alexandre Demers
  2 siblings, 0 replies; 6+ messages in thread
From: Alexandre Demers @ 2014-04-03 23:41 UTC (permalink / raw)
  To: Thomas Bächler, tj; +Cc: d, linux-kernel, gregkh, P, 3.14

It works over here, tested on 3.14-rc8 which was previously failing. You 
have my

Tested-by: Alexandre Demers

Alexandre Demers

On 04/03/2014 03:49 PM, Thomas Bächler wrote:
> Commit 9e30cc9595303b27b48 removed an internal mount. This
> has the side-effect that rootfs now has FSID 0. Many
> userspace utilities assume that st_dev in struct stat
> is never 0, so this change breaks a number of tools in
> early userspace.
>
> Since we don't know how many userspace programs are affected,
> make sure that FSID is at least 1.
>
> References: http://article.gmane.org/gmane.linux.kernel/1666905
> References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557
> Cc: 3.14 <stable@vger.kernel.org>
> Signed-off-by: Thomas Bächler <thomas@archlinux.org>
> ---
>   fs/super.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index 80d5cf2..d9fddde 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -802,7 +802,7 @@ void emergency_remount(void)
>   
>   static DEFINE_IDA(unnamed_dev_ida);
>   static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
> -static int unnamed_dev_start = 0; /* don't bother trying below it */
> +static int unnamed_dev_start = 1; /* don't bother trying below it */
>   
>   int get_anon_bdev(dev_t *p)
>   {


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-04-03 23:41 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <20140403191617.GB2472@mtj.dyndns.org>
2014-04-03 19:49 ` [PATCH] fs: Don't return 0 from get_anon_bdev Thomas Bächler
2014-04-03 19:51   ` Tejun Heo
2014-04-03 19:55     ` [PATCHv2] " Thomas Bächler
2014-04-03 20:32       ` Greg KH
2014-04-03 20:21   ` [PATCH] " H. Peter Anvin
2014-04-03 23:41   ` Alexandre Demers

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).