2020-06-10 10:36:36

by Jeff Layton

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

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

Signed-off-by: Jeff Layton <[email protected]>
---
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


2020-06-10 19:51:33

by Eric Biggers

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

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 <[email protected]>
> ---
> 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

2020-06-10 21:21:39

by Jeff Layton

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

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 <[email protected]>
> > ---
> > 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 <[email protected]>

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

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 <[email protected]>
>>> ---
>>> 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/

2020-06-26 00:07:11

by Jeff Layton

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

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 <[email protected]>
> > > > ---
> > > > 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 <[email protected]>