[PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[Jeff Layton]

A patch has been merged for v5.8 that changes how syncfs() reports
errors. Change the sync() manpage accordingly.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 man2/sync.2 | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/man2/sync.2 b/man2/sync.2
index 7198f3311b05..27e04cff5845 100644
--- a/man2/sync.2
+++ b/man2/sync.2
@@ -86,11 +86,26 @@ to indicate the error.
 is always successful.
 .PP
 .BR syncfs ()
-can fail for at least the following reason:
+can fail for at least the following reasons:
 .TP
 .B EBADF
 .I fd
 is not a valid file descriptor.
+.TP
+.B EIO
+An error occurred during synchronization.
+This error may relate to data written to any file on the filesystem, or on
+metadata related to the filesytem itself.
+.TP
+.B ENOSPC
+Disk space was exhausted while synchronizing.
+.TP
+.BR ENOSPC ", " EDQUOT
+Data was written to a files on NFS or another filesystem which does not
+allocate space at the time of a
+.BR write (2)
+system call, and some previous write failed due to insufficient
+storage space.
 .SH VERSIONS
 .BR syncfs ()
 first appeared in Linux 2.6.39;
@@ -121,6 +136,13 @@ or
 .BR syncfs ()
 provide the same guarantees as fsync called on every file in
 the system or filesystem respectively.
+.PP
+In mainline kernel versions prior to 5.8,
+.\" commit 735e4ae5ba28c886d249ad04d3c8cc097dad6336
+.BR syncfs ()
+will only fail with EBADF when passed a bad file descriptor. In 5.8
+and later kernels, it will also report an error if one or more inodes failed
+to be written back since the last syncfs call.
 .SH BUGS
 Before version 1.3.20 Linux did not wait for I/O to complete
 before returning.
-- 
2.26.2

Re: [PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[Eric Biggers]

On Wed, Jun 10, 2020 at 06:33:47AM -0400, Jeff Layton wrote:
> A patch has been merged for v5.8 that changes how syncfs() reports
> errors. Change the sync() manpage accordingly.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  man2/sync.2 | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/man2/sync.2 b/man2/sync.2
> index 7198f3311b05..27e04cff5845 100644
> --- a/man2/sync.2
> +++ b/man2/sync.2
> @@ -86,11 +86,26 @@ to indicate the error.
>  is always successful.
>  .PP
>  .BR syncfs ()
> -can fail for at least the following reason:
> +can fail for at least the following reasons:
>  .TP
>  .B EBADF
>  .I fd
>  is not a valid file descriptor.
> +.TP
> +.B EIO
> +An error occurred during synchronization.
> +This error may relate to data written to any file on the filesystem, or on
> +metadata related to the filesytem itself.
> +.TP
> +.B ENOSPC
> +Disk space was exhausted while synchronizing.
> +.TP
> +.BR ENOSPC ", " EDQUOT
> +Data was written to a files on NFS or another filesystem which does not
> +allocate space at the time of a
> +.BR write (2)
> +system call, and some previous write failed due to insufficient
> +storage space.
>  .SH VERSIONS
>  .BR syncfs ()
>  first appeared in Linux 2.6.39;
> @@ -121,6 +136,13 @@ or
>  .BR syncfs ()
>  provide the same guarantees as fsync called on every file in
>  the system or filesystem respectively.
> +.PP
> +In mainline kernel versions prior to 5.8,
> +.\" commit 735e4ae5ba28c886d249ad04d3c8cc097dad6336
> +.BR syncfs ()
> +will only fail with EBADF when passed a bad file descriptor. In 5.8
> +and later kernels, it will also report an error if one or more inodes failed
> +to be written back since the last syncfs call.

The sentence "In mainline kernel versions prior to 5.8, syncfs() will only fail
with EBADF when passed a bad file descriptor" is ambiguous.  It could mean that
EBADF can now mean other things too.

Maybe write: "In mainline kernel versions prior to 5.8, syncfs() will only fail
when passed a bad file descriptor (EBADF)."

- Eric

Re: [PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[Jeff Layton]

On Wed, 2020-06-10 at 08:50 -0700, Eric Biggers wrote:
> On Wed, Jun 10, 2020 at 06:33:47AM -0400, Jeff Layton wrote:
> > A patch has been merged for v5.8 that changes how syncfs() reports
> > errors. Change the sync() manpage accordingly.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> >  man2/sync.2 | 24 +++++++++++++++++++++++-
> >  1 file changed, 23 insertions(+), 1 deletion(-)
> > 
> > diff --git a/man2/sync.2 b/man2/sync.2
> > index 7198f3311b05..27e04cff5845 100644
> > --- a/man2/sync.2
> > +++ b/man2/sync.2
> > @@ -86,11 +86,26 @@ to indicate the error.
> >  is always successful.
> >  .PP
> >  .BR syncfs ()
> > -can fail for at least the following reason:
> > +can fail for at least the following reasons:
> >  .TP
> >  .B EBADF
> >  .I fd
> >  is not a valid file descriptor.
> > +.TP
> > +.B EIO
> > +An error occurred during synchronization.
> > +This error may relate to data written to any file on the filesystem, or on
> > +metadata related to the filesytem itself.
> > +.TP
> > +.B ENOSPC
> > +Disk space was exhausted while synchronizing.
> > +.TP
> > +.BR ENOSPC ", " EDQUOT
> > +Data was written to a files on NFS or another filesystem which does not
> > +allocate space at the time of a
> > +.BR write (2)
> > +system call, and some previous write failed due to insufficient
> > +storage space.
> >  .SH VERSIONS
> >  .BR syncfs ()
> >  first appeared in Linux 2.6.39;
> > @@ -121,6 +136,13 @@ or
> >  .BR syncfs ()
> >  provide the same guarantees as fsync called on every file in
> >  the system or filesystem respectively.
> > +.PP
> > +In mainline kernel versions prior to 5.8,
> > +.\" commit 735e4ae5ba28c886d249ad04d3c8cc097dad6336
> > +.BR syncfs ()
> > +will only fail with EBADF when passed a bad file descriptor. In 5.8
> > +and later kernels, it will also report an error if one or more inodes failed
> > +to be written back since the last syncfs call.
> 
> The sentence "In mainline kernel versions prior to 5.8, syncfs() will only fail
> with EBADF when passed a bad file descriptor" is ambiguous.  It could mean that
> EBADF can now mean other things too.
> 
> Maybe write: "In mainline kernel versions prior to 5.8, syncfs() will only fail
> when passed a bad file descriptor (EBADF)."
> 
> - Eric

Good point. Fixed in my tree using your verbiage. I'll send out a v2
patch once I give others a chance to comment.

Thanks!
-- 
Jeff Layton <jlayton@kernel.org>

Re: [PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[Michael Kerrisk (man-pages)]

Hi Jeff,

Any progress with v2 of this patch?

Thanks,

Michael


On 6/10/20 11:19 PM, Jeff Layton wrote:
> On Wed, 2020-06-10 at 08:50 -0700, Eric Biggers wrote:
>> On Wed, Jun 10, 2020 at 06:33:47AM -0400, Jeff Layton wrote:
>>> A patch has been merged for v5.8 that changes how syncfs() reports
>>> errors. Change the sync() manpage accordingly.
>>>
>>> Signed-off-by: Jeff Layton <jlayton@kernel.org>
>>> ---
>>>  man2/sync.2 | 24 +++++++++++++++++++++++-
>>>  1 file changed, 23 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/man2/sync.2 b/man2/sync.2
>>> index 7198f3311b05..27e04cff5845 100644
>>> --- a/man2/sync.2
>>> +++ b/man2/sync.2
>>> @@ -86,11 +86,26 @@ to indicate the error.
>>>  is always successful.
>>>  .PP
>>>  .BR syncfs ()
>>> -can fail for at least the following reason:
>>> +can fail for at least the following reasons:
>>>  .TP
>>>  .B EBADF
>>>  .I fd
>>>  is not a valid file descriptor.
>>> +.TP
>>> +.B EIO
>>> +An error occurred during synchronization.
>>> +This error may relate to data written to any file on the filesystem, or on
>>> +metadata related to the filesytem itself.
>>> +.TP
>>> +.B ENOSPC
>>> +Disk space was exhausted while synchronizing.
>>> +.TP
>>> +.BR ENOSPC ", " EDQUOT
>>> +Data was written to a files on NFS or another filesystem which does not
>>> +allocate space at the time of a
>>> +.BR write (2)
>>> +system call, and some previous write failed due to insufficient
>>> +storage space.
>>>  .SH VERSIONS
>>>  .BR syncfs ()
>>>  first appeared in Linux 2.6.39;
>>> @@ -121,6 +136,13 @@ or
>>>  .BR syncfs ()
>>>  provide the same guarantees as fsync called on every file in
>>>  the system or filesystem respectively.
>>> +.PP
>>> +In mainline kernel versions prior to 5.8,
>>> +.\" commit 735e4ae5ba28c886d249ad04d3c8cc097dad6336
>>> +.BR syncfs ()
>>> +will only fail with EBADF when passed a bad file descriptor. In 5.8
>>> +and later kernels, it will also report an error if one or more inodes failed
>>> +to be written back since the last syncfs call.
>>
>> The sentence "In mainline kernel versions prior to 5.8, syncfs() will only fail
>> with EBADF when passed a bad file descriptor" is ambiguous.  It could mean that
>> EBADF can now mean other things too.
>>
>> Maybe write: "In mainline kernel versions prior to 5.8, syncfs() will only fail
>> when passed a bad file descriptor (EBADF)."
>>
>> - Eric
> 
> Good point. Fixed in my tree using your verbiage. I'll send out a v2
> patch once I give others a chance to comment.
> 
> Thanks!
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/

Re: [PATCH][man-pages] sync.2: syncfs() now returns errors if writeback fails

[Jeff Layton]

On Thu, 2020-06-25 at 11:45 +0200, Michael Kerrisk (man-pages) wrote:
> Hi Jeff,
> 
> Any progress with v2 of this patch?
> 
> Thanks,
> 
> Michael
> 

Just sent it. Thanks for the reminder!

> 
> On 6/10/20 11:19 PM, Jeff Layton wrote:
> > On Wed, 2020-06-10 at 08:50 -0700, Eric Biggers wrote:
> > > On Wed, Jun 10, 2020 at 06:33:47AM -0400, Jeff Layton wrote:
> > > > A patch has been merged for v5.8 that changes how syncfs() reports
> > > > errors. Change the sync() manpage accordingly.
> > > > 
> > > > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > > > ---
> > > >  man2/sync.2 | 24 +++++++++++++++++++++++-
> > > >  1 file changed, 23 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/man2/sync.2 b/man2/sync.2
> > > > index 7198f3311b05..27e04cff5845 100644
> > > > --- a/man2/sync.2
> > > > +++ b/man2/sync.2
> > > > @@ -86,11 +86,26 @@ to indicate the error.
> > > >  is always successful.
> > > >  .PP
> > > >  .BR syncfs ()
> > > > -can fail for at least the following reason:
> > > > +can fail for at least the following reasons:
> > > >  .TP
> > > >  .B EBADF
> > > >  .I fd
> > > >  is not a valid file descriptor.
> > > > +.TP
> > > > +.B EIO
> > > > +An error occurred during synchronization.
> > > > +This error may relate to data written to any file on the filesystem, or on
> > > > +metadata related to the filesytem itself.
> > > > +.TP
> > > > +.B ENOSPC
> > > > +Disk space was exhausted while synchronizing.
> > > > +.TP
> > > > +.BR ENOSPC ", " EDQUOT
> > > > +Data was written to a files on NFS or another filesystem which does not
> > > > +allocate space at the time of a
> > > > +.BR write (2)
> > > > +system call, and some previous write failed due to insufficient
> > > > +storage space.
> > > >  .SH VERSIONS
> > > >  .BR syncfs ()
> > > >  first appeared in Linux 2.6.39;
> > > > @@ -121,6 +136,13 @@ or
> > > >  .BR syncfs ()
> > > >  provide the same guarantees as fsync called on every file in
> > > >  the system or filesystem respectively.
> > > > +.PP
> > > > +In mainline kernel versions prior to 5.8,
> > > > +.\" commit 735e4ae5ba28c886d249ad04d3c8cc097dad6336
> > > > +.BR syncfs ()
> > > > +will only fail with EBADF when passed a bad file descriptor. In 5.8
> > > > +and later kernels, it will also report an error if one or more inodes failed
> > > > +to be written back since the last syncfs call.
> > > 
> > > The sentence "In mainline kernel versions prior to 5.8, syncfs() will only fail
> > > with EBADF when passed a bad file descriptor" is ambiguous.  It could mean that
> > > EBADF can now mean other things too.
> > > 
> > > Maybe write: "In mainline kernel versions prior to 5.8, syncfs() will only fail
> > > when passed a bad file descriptor (EBADF)."
> > > 
> > > - Eric
> > 
> > Good point. Fixed in my tree using your verbiage. I'll send out a v2
> > patch once I give others a chance to comment.
> > 
> > Thanks!
> > 
> 
> 

-- 
Jeff Layton <jlayton@kernel.org>