Re: [PATCH 5/5] Add manpage for fsconfig(2)
Hello David,
Ping!
Thanks,
Michael
On Mon, 24 Aug 2020 at 14:25, David Howells wrote:
>
> Add a manual page to document the fsconfig() system call.
>
> Signed-off-by: David Howells
> ---
>
> man2/fsconfig.2 | 277
> +++
> 1 file changed, 277 insertions(+)
> create mode 100644 man2/fsconfig.2
>
> diff --git a/man2/fsconfig.2 b/man2/fsconfig.2
> new file mode 100644
> index 0..da53d2fcb
> --- /dev/null
> +++ b/man2/fsconfig.2
> @@ -0,0 +1,277 @@
> +'\" t
> +.\" Copyright (c) 2020 David Howells
> +.\"
> +.\" %%%LICENSE_START(VERBATIM)
> +.\" Permission is granted to make and distribute verbatim copies of this
> +.\" manual provided the copyright notice and this permission notice are
> +.\" preserved on all copies.
> +.\"
> +.\" Permission is granted to copy and distribute modified versions of this
> +.\" manual under the conditions for verbatim copying, provided that the
> +.\" entire resulting derived work is distributed under the terms of a
> +.\" permission notice identical to this one.
> +.\"
> +.\" Since the Linux kernel and libraries are constantly changing, this
> +.\" manual page may be incorrect or out-of-date. The author(s) assume no
> +.\" responsibility for errors or omissions, or for damages resulting from
> +.\" the use of the information contained herein. The author(s) may not
> +.\" have taken the same level of care in the production of this manual,
> +.\" which is licensed free of charge, as they might when working
> +.\" professionally.
> +.\"
> +.\" Formatted or processed versions of this manual, if unaccompanied by
> +.\" the source, must acknowledge the copyright and authors of this work.
> +.\" %%%LICENSE_END
> +.\"
> +.TH FSCONFIG 2 2020-08-24 "Linux" "Linux Programmer's Manual"
> +.SH NAME
> +fsconfig \- Filesystem parameterisation
> +.SH SYNOPSIS
> +.nf
> +.B #include
> +.B #include
> +.B #include
> +.B #include
> +.PP
> +.BI "int fsconfig(int *" fd ", unsigned int " cmd ", const char *" key ,
> +.br
> +.BI " const void __user *" value ", int " aux ");"
> +.br
> +.BI
> +.fi
> +.PP
> +.IR Note :
> +There is no glibc wrapper for this system call.
> +.SH DESCRIPTION
> +.PP
> +.BR fsconfig ()
> +is used to supply parameters to and issue commands against a filesystem
> +configuration context as set up by
> +.BR fsopen (2)
> +or
> +.BR fspick (2).
> +The context is supplied attached to the file descriptor specified by
> +.I fd
> +argument.
> +.PP
> +The
> +.I cmd
> +argument indicates the command to be issued, where some of the commands
> simply
> +supply parameters to the context. The meaning of
> +.IR key ", " value " and " aux
> +are command-dependent; unless required for the command, these should be set
> to
> +NULL or 0.
> +.PP
> +The available commands are:
> +.TP
> +.B FSCONFIG_SET_FLAG
> +Set the parameter named by
> +.IR key
> +to true. This may fail with error
> +.B EINVAL
> +if the parameter requires an argument.
> +.TP
> +.B FSCONFIG_SET_STRING
> +Set the parameter named by
> +.I key
> +to a string. This may fail with error
> +.B EINVAL
> +if the parser doesn't want a parameter here, wants a non-string or the string
> +cannot be interpreted appropriately.
> +.I value
> +points to a NUL-terminated string.
> +.TP
> +.B FSCONFIG_SET_BINARY
> +Set the parameter named by
> +.I key
> +to be a binary blob argument. This may cause
> +.B EINVAL
> +to be returned if the filesystem parser isn't expecting a binary blob and it
> +can't be converted to something usable.
> +.I value
> +points to the data and
> +.I aux
> +indicates the size of the data.
> +.TP
> +.B FSCONFIG_SET_PATH
> +Set the parameter named by
> +.I key
> +to the object at the provided path.
> +.I value
> +should point to a NUL-terminated pathname string and aux may indicate
> +.B AT_FDCWD
> +or a file descriptor indicating a directory from which to begin a relative
> +path resolution. This may fail with error
> +.B EINVAL
> +if the parameter isn't expecting a path; it may also fail if the path cannot
> +be resolved with the typcal errors for that
> +.RB "(" ENOENT ", " ENOTDIR ", " EPERM ", " EACCES ", etc.)."
> +.IP
> +Note that FSCONFIG_SET_STRING can be used instead, implying AT_FDCWD.
> +.TP
> +.B FSCONFIG_SET_PATH_EMPTY
> +As FSCONFIG_SET_PATH, but with
> +.B AT_EMPTY_PATH
> +applied to the pathwalk.
> +.TP
> +.B FSCONFIG_SET_FD
> +Set the parameter named by
> +.I key
> +to the file descriptor specified by
> +.IR aux .
> +This will fail with
> +.B EINVAL
> +if the parameter doesn't expect a file descriptor or
> +.B EBADF
> +if the file descriptor is invalid.
> +.IP
> +Note that FSCONFIG_SET_STRING can be used instead with the file descriptor
> +passed as a decimal string.
> +.TP
> +.B FSCONFIG_CMD_CREATE
> +This command triggers the filesystem to take the parameters set in the
> context
> +and to try to create filesystem representation in the kernel. If an existing
> +representation can be shared, the filesystem may do
Re: [PATCH 5/5] Add manpage for fsconfig(2)
Hello David,
On 8/24/20 2:25 PM, David Howells wrote:
> Add a manual page to document the fsconfig() system call.
>
> Signed-off-by: David Howells
> ---
>
> man2/fsconfig.2 | 277
> +++
> 1 file changed, 277 insertions(+)
> create mode 100644 man2/fsconfig.2
>
> diff --git a/man2/fsconfig.2 b/man2/fsconfig.2
> new file mode 100644
> index 0..da53d2fcb
> --- /dev/null
> +++ b/man2/fsconfig.2
> @@ -0,0 +1,277 @@
> +'\" t
> +.\" Copyright (c) 2020 David Howells
> +.\"
> +.\" %%%LICENSE_START(VERBATIM)
> +.\" Permission is granted to make and distribute verbatim copies of this
> +.\" manual provided the copyright notice and this permission notice are
> +.\" preserved on all copies.
> +.\"
> +.\" Permission is granted to copy and distribute modified versions of this
> +.\" manual under the conditions for verbatim copying, provided that the
> +.\" entire resulting derived work is distributed under the terms of a
> +.\" permission notice identical to this one.
> +.\"
> +.\" Since the Linux kernel and libraries are constantly changing, this
> +.\" manual page may be incorrect or out-of-date. The author(s) assume no
> +.\" responsibility for errors or omissions, or for damages resulting from
> +.\" the use of the information contained herein. The author(s) may not
> +.\" have taken the same level of care in the production of this manual,
> +.\" which is licensed free of charge, as they might when working
> +.\" professionally.
> +.\"
> +.\" Formatted or processed versions of this manual, if unaccompanied by
> +.\" the source, must acknowledge the copyright and authors of this work.
> +.\" %%%LICENSE_END
> +.\"
> +.TH FSCONFIG 2 2020-08-24 "Linux" "Linux Programmer's Manual"
> +.SH NAME
> +fsconfig \- Filesystem parameterisation
> +.SH SYNOPSIS
> +.nf
> +.B #include
> +.B #include
> +.B #include
> +.B #include
> +.PP
> +.BI "int fsconfig(int *" fd ", unsigned int " cmd ", const char *" key ,
> +.br
> +.BI " const void __user *" value ", int " aux ");"
> +.br
Please remove two instances of .br above
> +.BI
> +.fi
> +.PP
> +.IR Note :
> +There is no glibc wrapper for this system call.
> +.SH DESCRIPTION
> +.PP
> +.BR fsconfig ()
> +is used to supply parameters to and issue commands against a filesystem
> +configuration context as set up by
> +.BR fsopen (2)
> +or
> +.BR fspick (2).
> +The context is supplied attached to the file descriptor specified by
s/by/by the/
> +.I fd
> +argument.
> +.PP
> +The
> +.I cmd
> +argument indicates the command to be issued, where some of the commands
> simply
> +supply parameters to the context. The meaning of
> +.IR key ", " value " and " aux
> +are command-dependent; unless required for the command, these should be set
> to
"should" or "must"? If not "must", why not? (It feels like an API design
error not to require these to be NULL/0 in cases where they are not used.)
> +NULL or 0.
> +.PP
> +The available commands are:
> +.TP
> +.B FSCONFIG_SET_FLAG
> +Set the parameter named by
> +.IR key
> +to true. This may fail with error
s/with error/with the error/
(and multiple times below)
> +.B EINVAL
> +if the parameter requires an argument.
> +.TP
> +.B FSCONFIG_SET_STRING
> +Set the parameter named by
> +.I key
> +to a string. This may fail with error
> +.B EINVAL
> +if the parser doesn't want a parameter here, wants a non-string or the string
> +cannot be interpreted appropriately.
> +.I value
> +points to a NUL-terminated string.
> +.TP
> +.B FSCONFIG_SET_BINARY
> +Set the parameter named by
> +.I key
> +to be a binary blob argument. This may cause
> +.B EINVAL
> +to be returned if the filesystem parser isn't expecting a binary blob and it
> +can't be converted to something usable.
> +.I value
> +points to the data and
> +.I aux
> +indicates the size of the data.
> +.TP
> +.B FSCONFIG_SET_PATH
> +Set the parameter named by
> +.I key
> +to the object at the provided path.
> +.I value
> +should point to a NUL-terminated pathname string and aux may indicate
> +.B AT_FDCWD
> +or a file descriptor indicating a directory from which to begin a relative
> +path resolution. This may fail with error
> +.B EINVAL
> +if the parameter isn't expecting a path; it may also fail if the path cannot
> +be resolved with the typcal errors for that
s/typcal/typical/
> +.RB "(" ENOENT ", " ENOTDIR ", " EPERM ", " EACCES ", etc.)."
> +.IP
> +Note that FSCONFIG_SET_STRING can be used instead, implying AT_FDCWD.
I don't understand the preceding sentence. Can you rewrite to supply more
detail? (E.g., "instead *of what*")
> +.TP
> +.B FSCONFIG_SET_PATH_EMPTY
> +As FSCONFIG_SET_PATH, but with
> +.B AT_EMPTY_PATH
> +applied to the pathwalk.
Can you please supply a bit more detail here, rather than just referring to
FSCONFIG_SET_PATH.
> +.TP
> +.B FSCONFIG_SET_FD
> +Set the parameter named by
> +.I key
> +to the file descriptor specified by
> +.IR aux .
> +This will fail with
> +.B EINVAL
> +if the
[PATCH 5/5] Add manpage for fsconfig(2)
Add a manual page to document the fsconfig() system call.
Signed-off-by: David Howells
---
man2/fsconfig.2 | 277 +++
1 file changed, 277 insertions(+)
create mode 100644 man2/fsconfig.2
diff --git a/man2/fsconfig.2 b/man2/fsconfig.2
new file mode 100644
index 0..da53d2fcb
--- /dev/null
+++ b/man2/fsconfig.2
@@ -0,0 +1,277 @@
+'\" t
+.\" Copyright (c) 2020 David Howells
+.\"
+.\" %%%LICENSE_START(VERBATIM)
+.\" Permission is granted to make and distribute verbatim copies of this
+.\" manual provided the copyright notice and this permission notice are
+.\" preserved on all copies.
+.\"
+.\" Permission is granted to copy and distribute modified versions of this
+.\" manual under the conditions for verbatim copying, provided that the
+.\" entire resulting derived work is distributed under the terms of a
+.\" permission notice identical to this one.
+.\"
+.\" Since the Linux kernel and libraries are constantly changing, this
+.\" manual page may be incorrect or out-of-date. The author(s) assume no
+.\" responsibility for errors or omissions, or for damages resulting from
+.\" the use of the information contained herein. The author(s) may not
+.\" have taken the same level of care in the production of this manual,
+.\" which is licensed free of charge, as they might when working
+.\" professionally.
+.\"
+.\" Formatted or processed versions of this manual, if unaccompanied by
+.\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
+.\"
+.TH FSCONFIG 2 2020-08-24 "Linux" "Linux Programmer's Manual"
+.SH NAME
+fsconfig \- Filesystem parameterisation
+.SH SYNOPSIS
+.nf
+.B #include
+.B #include
+.B #include
+.B #include
+.PP
+.BI "int fsconfig(int *" fd ", unsigned int " cmd ", const char *" key ,
+.br
+.BI " const void __user *" value ", int " aux ");"
+.br
+.BI
+.fi
+.PP
+.IR Note :
+There is no glibc wrapper for this system call.
+.SH DESCRIPTION
+.PP
+.BR fsconfig ()
+is used to supply parameters to and issue commands against a filesystem
+configuration context as set up by
+.BR fsopen (2)
+or
+.BR fspick (2).
+The context is supplied attached to the file descriptor specified by
+.I fd
+argument.
+.PP
+The
+.I cmd
+argument indicates the command to be issued, where some of the commands simply
+supply parameters to the context. The meaning of
+.IR key ", " value " and " aux
+are command-dependent; unless required for the command, these should be set to
+NULL or 0.
+.PP
+The available commands are:
+.TP
+.B FSCONFIG_SET_FLAG
+Set the parameter named by
+.IR key
+to true. This may fail with error
+.B EINVAL
+if the parameter requires an argument.
+.TP
+.B FSCONFIG_SET_STRING
+Set the parameter named by
+.I key
+to a string. This may fail with error
+.B EINVAL
+if the parser doesn't want a parameter here, wants a non-string or the string
+cannot be interpreted appropriately.
+.I value
+points to a NUL-terminated string.
+.TP
+.B FSCONFIG_SET_BINARY
+Set the parameter named by
+.I key
+to be a binary blob argument. This may cause
+.B EINVAL
+to be returned if the filesystem parser isn't expecting a binary blob and it
+can't be converted to something usable.
+.I value
+points to the data and
+.I aux
+indicates the size of the data.
+.TP
+.B FSCONFIG_SET_PATH
+Set the parameter named by
+.I key
+to the object at the provided path.
+.I value
+should point to a NUL-terminated pathname string and aux may indicate
+.B AT_FDCWD
+or a file descriptor indicating a directory from which to begin a relative
+path resolution. This may fail with error
+.B EINVAL
+if the parameter isn't expecting a path; it may also fail if the path cannot
+be resolved with the typcal errors for that
+.RB "(" ENOENT ", " ENOTDIR ", " EPERM ", " EACCES ", etc.)."
+.IP
+Note that FSCONFIG_SET_STRING can be used instead, implying AT_FDCWD.
+.TP
+.B FSCONFIG_SET_PATH_EMPTY
+As FSCONFIG_SET_PATH, but with
+.B AT_EMPTY_PATH
+applied to the pathwalk.
+.TP
+.B FSCONFIG_SET_FD
+Set the parameter named by
+.I key
+to the file descriptor specified by
+.IR aux .
+This will fail with
+.B EINVAL
+if the parameter doesn't expect a file descriptor or
+.B EBADF
+if the file descriptor is invalid.
+.IP
+Note that FSCONFIG_SET_STRING can be used instead with the file descriptor
+passed as a decimal string.
+.TP
+.B FSCONFIG_CMD_CREATE
+This command triggers the filesystem to take the parameters set in the context
+and to try to create filesystem representation in the kernel. If an existing
+representation can be shared, the filesystem may do that instead if the
+parameters permit. This is intended for use with
+.BR fsopen (2).
+.TP
+.B FSCONFIG_CMD_RECONFIGURE
+This command causes the driver to alter the parameters of an already live
+filesystem instance according to the parameters stored in the context. This
+is intended for use with
+.BR fspick (2),
+but may also by used against the context created by
+.BR fsopen()
+after
+.BR
Re: [PATCH 5/5] Add manpage for fsconfig(2)
Hello David, On Fri, 7 Aug 2020 at 16:03, David Howells wrote: > > Add a manual page to document the fsconfig() system call. > > Signed-off-by: David Howells > --- > > man2/fsconfig.2 | 282 > +++ > 1 file changed, 282 insertions(+) > create mode 100644 man2/fsconfig.2 > > diff --git a/man2/fsconfig.2 b/man2/fsconfig.2 > new file mode 100644 > index 0..32f0bce13 > --- /dev/null > +++ b/man2/fsconfig.2 > @@ -0,0 +1,282 @@ > +'\" t > +.\" Copyright (c) 2020 David Howells > +.\" > +.\" %%%LICENSE_START(VERBATIM) > +.\" Permission is granted to make and distribute verbatim copies of this > +.\" manual provided the copyright notice and this permission notice are > +.\" preserved on all copies. > +.\" > +.\" Permission is granted to copy and distribute modified versions of this > +.\" manual under the conditions for verbatim copying, provided that the > +.\" entire resulting derived work is distributed under the terms of a > +.\" permission notice identical to this one. > +.\" > +.\" Since the Linux kernel and libraries are constantly changing, this > +.\" manual page may be incorrect or out-of-date. The author(s) assume no > +.\" responsibility for errors or omissions, or for damages resulting from > +.\" the use of the information contained herein. The author(s) may not > +.\" have taken the same level of care in the production of this manual, > +.\" which is licensed free of charge, as they might when working > +.\" professionally. > +.\" > +.\" Formatted or processed versions of this manual, if unaccompanied by > +.\" the source, must acknowledge the copyright and authors of this work. > +.\" %%%LICENSE_END > +.\" > +.TH FSCONFIG 2 2020-08-07 "Linux" "Linux Programmer's Manual" > +.SH NAME > +fsconfig \- Filesystem parameterisation > +.SH SYNOPSIS > +.nf > +.B #include > +.br Remove all instances of ".br" here in the SYNOPSIS. They aren't needed. > +.B #include > +.br > +.B #include > +.br > +.B #include > +.PP > +.BI "int fsconfig(int *" fd ", unsigned int " cmd ", const char *" key , > +.br > +.BI " const void __user *" value ", int " aux ");" > +.br > +.BI > +.fi > +.PP > +.IR Note : > +There is no glibc wrapper for this system call. > +.SH DESCRIPTION > +.PP > +.BR fsconfig () > +is used to supply parameters to and issue commands against a filesystem > +configuration context as set up by > +.BR fsopen (2) > +or > +.BR fspick (2). > +The context is supplied attached to the file descriptor specified by > +.I fd > +argument. > +.PP > +The > +.I cmd > +argument indicates the command to be issued, where some of the commands > simply > +supply parameters to the context. The meaning of > +.IR key ", " value " and " aux > +are command-dependent; unless required for the command, these should be set > to > +NULL or 0. > +.PP > +The available commands are: > +.TP > +.B FSCONFIG_SET_FLAG > +Set the parameter named by > +.IR key > +to true. This may incur error s/incur error/fail with the error/ (and below as well please) > +.B EINVAL > +if the parameter requires an argument. > +.TP > +.B FSCONFIG_SET_STRING > +Set the parameter named by > +.I key > +to a string. This may incur error > +.B EINVAL > +if the parser doesn't want a parameter here, wants a non-string or the string > +cannot be interpreted appropriately. > +.I value > +points to a NUL-terminated string. > +.TP > +.B FSCONFIG_SET_BINARY > +Set the parameter named by > +.I key > +to be a binary blob argument. This may cause > +.B EINVAL > +to be returned if the filesystem parser isn't expecting a binary blob and it > +can't be converted to something usable. > +.I value > +points to the data and > +.I aux > +indicates the size of the data. > +.TP > +.B FSCONFIG_SET_PATH > +Set the parameter named by > +.I key > +to the object at the provided path. > +.I value > +should point to a NULL-terminated pathname string and aux may indicate > +.B AT_FDCWD > +or a file descriptor indicating a directory from which to begin a relative > +pathwalk. This may return any errors incurred by the pathwalk and may return "pathwalk" is not a standard term (at least not for user-space programmers). What do you mean with this term, and can you replace all instances please. > +.B EINVAL > +if the parameter isn't expecting a path. > +.IP > +Note that FSCONFIG_SET_STRING can be used instead, implying AT_FDCWD. > +.TP > +.B FSCONFIG_SET_PATH_EMPTY > +As FSCONFIG_SET_PATH, but with > +.B AT_EMPTY_PATH > +applied to the pathwalk. > +.TP > +.B FSCONFIG_SET_FD > +Set the parameter named by > +.I key > +to the file descriptor specified by > +.IR aux . > +This will incur > +.B EINVAL > +if the parameter doesn't expect a file descriptor or > +.B EBADF > +if the file descriptor is invalid. > +.IP > +Note that FSCONFIG_SET_STRING can be used instead with the file descriptor > +passed as a decimal string. > +.TP > +.B FSCONFIG_CMD_CREATE > +This command causes the filesystem to take the parameters
AW: AW: [PATCH 5/5] Add manpage for fsconfig(2)
found it, next i will look for version not varsion Von: David Howells [dhowe...@redhat.com] Gesendet: Freitag, 7. August 2020 18:27 An: Walter Harms Cc: dhowe...@redhat.com; mtk.manpa...@gmail.com; linux-fsde...@vger.kernel.org; christian.brau...@ubuntu.com; linux-...@vger.kernel.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org Betreff: Re: AW: [PATCH 5/5] Add manpage for fsconfig(2) Walter Harms wrote: > maybe it is obvious but i did not see it .. > starting with what kernel version are these features available ? See: +.SH VERSIONS +.BR fsconfig () +was added to Linux in kernel 5.1. David
Re: AW: [PATCH 5/5] Add manpage for fsconfig(2)
Walter Harms wrote: > maybe it is obvious but i did not see it .. > starting with what kernel version are these features available ? See: +.SH VERSIONS +.BR fsconfig () +was added to Linux in kernel 5.1. David
AW: [PATCH 5/5] Add manpage for fsconfig(2)
hi, thx for you efford, maybe it is obvious but i did not see it .. starting with what kernel version are these features available ? re, wh Von: linux-man-ow...@vger.kernel.org [linux-man-ow...@vger.kernel.org] im Auftrag von David Howells [dhowe...@redhat.com] Gesendet: Freitag, 7. August 2020 16:02 An: mtk.manpa...@gmail.com; v...@zeniv.linux.org.uk Cc: dhowe...@redhat.com; linux-fsde...@vger.kernel.org; christian.brau...@ubuntu.com; linux-...@vger.kernel.org; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org Betreff: [PATCH 5/5] Add manpage for fsconfig(2) Add a manual page to document the fsconfig() system call. Signed-off-by: David Howells ---
[PATCH 5/5] Add manpage for fsconfig(2)
Add a manual page to document the fsconfig() system call. Signed-off-by: David Howells --- man2/fsconfig.2 | 282 +++ 1 file changed, 282 insertions(+) create mode 100644 man2/fsconfig.2 diff --git a/man2/fsconfig.2 b/man2/fsconfig.2 new file mode 100644 index 0..32f0bce13 --- /dev/null +++ b/man2/fsconfig.2 @@ -0,0 +1,282 @@ +'\" t +.\" Copyright (c) 2020 David Howells +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" %%%LICENSE_END +.\" +.TH FSCONFIG 2 2020-08-07 "Linux" "Linux Programmer's Manual" +.SH NAME +fsconfig \- Filesystem parameterisation +.SH SYNOPSIS +.nf +.B #include +.br +.B #include +.br +.B #include +.br +.B #include +.PP +.BI "int fsconfig(int *" fd ", unsigned int " cmd ", const char *" key , +.br +.BI " const void __user *" value ", int " aux ");" +.br +.BI +.fi +.PP +.IR Note : +There is no glibc wrapper for this system call. +.SH DESCRIPTION +.PP +.BR fsconfig () +is used to supply parameters to and issue commands against a filesystem +configuration context as set up by +.BR fsopen (2) +or +.BR fspick (2). +The context is supplied attached to the file descriptor specified by +.I fd +argument. +.PP +The +.I cmd +argument indicates the command to be issued, where some of the commands simply +supply parameters to the context. The meaning of +.IR key ", " value " and " aux +are command-dependent; unless required for the command, these should be set to +NULL or 0. +.PP +The available commands are: +.TP +.B FSCONFIG_SET_FLAG +Set the parameter named by +.IR key +to true. This may incur error +.B EINVAL +if the parameter requires an argument. +.TP +.B FSCONFIG_SET_STRING +Set the parameter named by +.I key +to a string. This may incur error +.B EINVAL +if the parser doesn't want a parameter here, wants a non-string or the string +cannot be interpreted appropriately. +.I value +points to a NUL-terminated string. +.TP +.B FSCONFIG_SET_BINARY +Set the parameter named by +.I key +to be a binary blob argument. This may cause +.B EINVAL +to be returned if the filesystem parser isn't expecting a binary blob and it +can't be converted to something usable. +.I value +points to the data and +.I aux +indicates the size of the data. +.TP +.B FSCONFIG_SET_PATH +Set the parameter named by +.I key +to the object at the provided path. +.I value +should point to a NULL-terminated pathname string and aux may indicate +.B AT_FDCWD +or a file descriptor indicating a directory from which to begin a relative +pathwalk. This may return any errors incurred by the pathwalk and may return +.B EINVAL +if the parameter isn't expecting a path. +.IP +Note that FSCONFIG_SET_STRING can be used instead, implying AT_FDCWD. +.TP +.B FSCONFIG_SET_PATH_EMPTY +As FSCONFIG_SET_PATH, but with +.B AT_EMPTY_PATH +applied to the pathwalk. +.TP +.B FSCONFIG_SET_FD +Set the parameter named by +.I key +to the file descriptor specified by +.IR aux . +This will incur +.B EINVAL +if the parameter doesn't expect a file descriptor or +.B EBADF +if the file descriptor is invalid. +.IP +Note that FSCONFIG_SET_STRING can be used instead with the file descriptor +passed as a decimal string. +.TP +.B FSCONFIG_CMD_CREATE +This command causes the filesystem to take the parameters set in the context +and to try to create filesystem representation in the kernel. If it can share +an existing one, it may do that instead if the filesystem type and parameters +permit that. This is intended for use with +.BR fsopen (2). +.TP +.B FSCONFIG_CMD_RECONFIGURE +This command causes the filesystem to apply the parameters set in the context +to an already existing filesystem representation in memory and to alter it. +This is intended for use with +.BR fspick (2), +but may also by used against the context created by +.BR fsopen() +after +.BR fsmount (2) +has been called on it. + +.\" +.SH
