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* [Linux-kernel-mentees] [RFC PATCH] docs: filesystems: convert autofs.txt to reST
@ 2019-11-13  7:38 Jaskaran Singh
  2019-11-14 16:38 ` Jonathan Corbet
  0 siblings, 1 reply; 2+ messages in thread
From: Jaskaran Singh @ 2019-11-13  7:38 UTC (permalink / raw)
  To: corbet
  Cc: mszeredi, linux-doc, jaskaransingh7654321, neilb, willy,
	linux-kernel, stefanha, mchehab+samsung, akpm,
	linux-kernel-mentees, christian, raven

This patch converts autofs.txt to reST.

 - Most of the changes pertain to reST formatting.
 - Some of the code snippets are updated to reflect current source.
 - A definition of the autofs packet header has been added in the chapter
	"Communicating with autofs: the event pipe".
 - An indentation of an 8 space tab has been added wherever suitable, so
   as to maintain consistency.
 - Removed indentation of the description of the ioctls which are similar
   to the AUTOFS_IOC ioctls, as it does not come out quite right in HTML.

Signed-off-by: Jaskaran Singh <jaskaransingh7654321@gmail.com>
---
 .../filesystems/{autofs.txt => autofs.rst}    | 258 ++++++++++--------
 Documentation/filesystems/index.rst           |   1 +
 2 files changed, 140 insertions(+), 119 deletions(-)
 rename Documentation/filesystems/{autofs.txt => autofs.rst} (77%)

diff --git a/Documentation/filesystems/autofs.txt b/Documentation/filesystems/autofs.rst
similarity index 77%
rename from Documentation/filesystems/autofs.txt
rename to Documentation/filesystems/autofs.rst
index 3af38c7fd26d..a130cba76f07 100644
--- a/Documentation/filesystems/autofs.txt
+++ b/Documentation/filesystems/autofs.rst
@@ -1,12 +1,9 @@
-<head>
-<style> p { max-width:50em} ol, ul {max-width: 40em}</style>
-</head>
-
+=====================
 autofs - how it works
 =====================
 
 Purpose
--------
+=======
 
 The goal of autofs is to provide on-demand mounting and race free
 automatic unmounting of various other filesystems.  This provides two
@@ -28,7 +25,7 @@ key advantages:
    first accessed a name.
 
 Context
--------
+=======
 
 The "autofs" filesystem module is only one part of an autofs system.
 There also needs to be a user-space program which looks up names
@@ -43,7 +40,7 @@ filesystem type.  Several "autofs" filesystems can be mounted and they
 can each be managed separately, or all managed by the same daemon.
 
 Content
--------
+=======
 
 An autofs filesystem can contain 3 sorts of objects: directories,
 symbolic links and mount traps.  Mount traps are directories with
@@ -52,7 +49,7 @@ extra properties as described in the next section.
 Objects can only be created by the automount daemon: symlinks are
 created with a regular `symlink` system call, while directories and
 mount traps are created with `mkdir`.  The determination of whether a
-directory should be a mount trap or not is quite _ad hoc_, largely for
+directory should be a mount trap or not is quite _ad hoc\_, largely for
 historical reasons, and is determined in part by the
 *direct*/*indirect*/*offset* mount options, and the *maxproto* mount option.
 
@@ -80,7 +77,7 @@ where in the tree they are (root, top level, or lower), the *maxproto*,
 and whether the mount was *indirect* or not.
 
 Mount Traps
----------------
+===============
 
 A core element of the implementation of autofs is the Mount Traps
 which are provided by the Linux VFS.  Any directory provided by a
@@ -201,7 +198,7 @@ initiated or is being considered, otherwise it returns 0.
 
 
 Mountpoint expiry
------------------
+=================
 
 The VFS has a mechanism for automatically expiring unused mounts,
 much as it can expire any unused dentry information from the dcache.
@@ -301,7 +298,7 @@ completed (together with removing any directories that might have been
 necessary), or has been aborted.
 
 Communicating with autofs: detecting the daemon
------------------------------------------------
+===============================================
 
 There are several forms of communication between the automount daemon
 and the filesystem.  As we have already seen, the daemon can create and
@@ -317,33 +314,39 @@ If the daemon ever has to be stopped and restarted a new pgid can be
 provided through an ioctl as will be described below.
 
 Communicating with autofs: the event pipe
------------------------------------------
+=========================================
 
 When an autofs filesystem is mounted, the 'write' end of a pipe must
 be passed using the 'fd=' mount option.  autofs will write
 notification messages to this pipe for the daemon to respond to.
-For version 5, the format of the message is:
-
-        struct autofs_v5_packet {
-                int proto_version;                /* Protocol version */
-                int type;                        /* Type of packet */
-                autofs_wqt_t wait_queue_token;
-                __u32 dev;
-                __u64 ino;
-                __u32 uid;
-                __u32 gid;
-                __u32 pid;
-                __u32 tgid;
-                __u32 len;
-                char name[NAME_MAX+1];
+For version 5, the format of the message is: ::
+
+	struct autofs_v5_packet {
+		struct autofs_packet_hdr hdr;
+		autofs_wqt_t wait_queue_token;
+		__u32 dev;
+		__u64 ino;
+		__u32 uid;
+		__u32 gid;
+		__u32 pid;
+		__u32 tgid;
+		__u32 len;
+		char name[NAME_MAX+1];
         };
 
-where the type is one of
+And the format of the header is: ::
+
+	struct autofs_packet_hdr {
+		int proto_version;		/* Protocol version */
+		int type;			/* Type of packet */
+	};
 
-        autofs_ptype_missing_indirect
-        autofs_ptype_expire_indirect
-        autofs_ptype_missing_direct
-        autofs_ptype_expire_direct
+where the type is one of ::
+
+	autofs_ptype_missing_indirect
+	autofs_ptype_expire_indirect
+	autofs_ptype_missing_direct
+	autofs_ptype_expire_direct
 
 so messages can indicate that a name is missing (something tried to
 access it but it isn't there) or that it has been selected for expiry.
@@ -360,7 +363,7 @@ acknowledged using one of the ioctls below with the relevant
 `wait_queue_token`.
 
 Communicating with autofs: root directory ioctls
-------------------------------------------------
+================================================
 
 The root directory of an autofs filesystem will respond to a number of
 ioctls.  The process issuing the ioctl must have the CAP_SYS_ADMIN
@@ -368,58 +371,66 @@ capability, or must be the automount daemon.
 
 The available ioctl commands are:
 
-- **AUTOFS_IOC_READY**: a notification has been handled.  The argument
-    to the ioctl command is the "wait_queue_token" number
-    corresponding to the notification being acknowledged.
-- **AUTOFS_IOC_FAIL**: similar to above, but indicates failure with
-    the error code `ENOENT`.
-- **AUTOFS_IOC_CATATONIC**: Causes the autofs to enter "catatonic"
-    mode meaning that it stops sending notifications to the daemon.
-    This mode is also entered if a write to the pipe fails.
-- **AUTOFS_IOC_PROTOVER**:  This returns the protocol version in use.
-- **AUTOFS_IOC_PROTOSUBVER**: Returns the protocol sub-version which
-    is really a version number for the implementation.
-- **AUTOFS_IOC_SETTIMEOUT**:  This passes a pointer to an unsigned
-    long.  The value is used to set the timeout for expiry, and
-    the current timeout value is stored back through the pointer.
-- **AUTOFS_IOC_ASKUMOUNT**:  Returns, in the pointed-to `int`, 1 if
-    the filesystem could be unmounted.  This is only a hint as
-    the situation could change at any instant.  This call can be
-    used to avoid a more expensive full unmount attempt.
-- **AUTOFS_IOC_EXPIRE**: as described above, this asks if there is
-    anything suitable to expire.  A pointer to a packet:
-
-        struct autofs_packet_expire_multi {
-                int proto_version;              /* Protocol version */
-                int type;                       /* Type of packet */
-                autofs_wqt_t wait_queue_token;
-                int len;
-                char name[NAME_MAX+1];
-        };
+- **AUTOFS_IOC_READY**:
+	a notification has been handled.  The argument
+	to the ioctl command is the "wait_queue_token" number
+	corresponding to the notification being acknowledged.
+- **AUTOFS_IOC_FAIL**:
+	similar to above, but indicates failure with
+	the error code `ENOENT`.
+- **AUTOFS_IOC_CATATONIC**:
+	Causes the autofs to enter "catatonic"
+	mode meaning that it stops sending notifications to the daemon.
+	This mode is also entered if a write to the pipe fails.
+- **AUTOFS_IOC_PROTOVER**:
+	This returns the protocol version in use.
+- **AUTOFS_IOC_PROTOSUBVER**:
+	Returns the protocol sub-version which
+	is really a version number for the implementation.
+- **AUTOFS_IOC_SETTIMEOUT**:
+	This passes a pointer to an unsigned
+	long.  The value is used to set the timeout for expiry, and
+	the current timeout value is stored back through the pointer.
+- **AUTOFS_IOC_ASKUMOUNT**:
+	Returns, in the pointed-to `int`, 1 if
+	the filesystem could be unmounted.  This is only a hint as
+	the situation could change at any instant.  This call can be
+	used to avoid a more expensive full unmount attempt.
+- **AUTOFS_IOC_EXPIRE**:
+	as described above, this asks if there is
+	anything suitable to expire.  A pointer to a packet: ::
+
+		struct autofs_packet_expire_multi {
+			struct autofs_packet_hdr hdr;
+			autofs_wqt_t wait_queue_token;
+			int len;
+			char name[NAME_MAX+1];
+		};
 
-     is required.  This is filled in with the name of something
-     that can be unmounted or removed.  If nothing can be expired,
-     `errno` is set to `EAGAIN`.  Even though a `wait_queue_token`
-     is present in the structure, no "wait queue" is established
-     and no acknowledgment is needed.
-- **AUTOFS_IOC_EXPIRE_MULTI**:  This is similar to
-     **AUTOFS_IOC_EXPIRE** except that it causes notification to be
-     sent to the daemon, and it blocks until the daemon acknowledges.
-     The argument is an integer which can contain two different flags.
+	is required.  This is filled in with the name of something
+	that can be unmounted or removed.  If nothing can be expired,
+	`errno` is set to `EAGAIN`.  Even though a `wait_queue_token`
+	is present in the structure, no "wait queue" is established
+	and no acknowledgment is needed.
+- **AUTOFS_IOC_EXPIRE_MULTI**:
+	This is similar to
+	**AUTOFS_IOC_EXPIRE** except that it causes notification to be
+	sent to the daemon, and it blocks until the daemon acknowledges.
+	The argument is an integer which can contain two different flags.
 
-     **AUTOFS_EXP_IMMEDIATE** causes `last_used` time to be ignored
-     and objects are expired if the are not in use.
+	**AUTOFS_EXP_IMMEDIATE** causes `last_used` time to be ignored
+	and objects are expired if the are not in use.
 
-     **AUTOFS_EXP_FORCED** causes the in use status to be ignored
-     and objects are expired ieven if they are in use. This assumes
-     that the daemon has requested this because it is capable of
-     performing the umount.
+	**AUTOFS_EXP_FORCED** causes the in use status to be ignored
+	and objects are expired ieven if they are in use. This assumes
+	that the daemon has requested this because it is capable of
+	performing the umount.
 
-     **AUTOFS_EXP_LEAVES** will select a leaf rather than a top-level
-     name to expire.  This is only safe when *maxproto* is 4.
+	**AUTOFS_EXP_LEAVES** will select a leaf rather than a top-level
+	name to expire.  This is only safe when *maxproto* is 4.
 
 Communicating with autofs: char-device ioctls
----------------------------------------------
+=============================================
 
 It is not always possible to open the root of an autofs filesystem,
 particularly a *direct* mounted filesystem.  If the automount daemon
@@ -429,9 +440,9 @@ need there is a "miscellaneous" character device (major 10, minor 235)
 which can be used to communicate directly with the autofs filesystem.
 It requires CAP_SYS_ADMIN for access.
 
-The `ioctl`s that can be used on this device are described in a separate
+The `ioctl`\s that can be used on this device are described in a separate
 document `autofs-mount-control.txt`, and are summarised briefly here.
-Each ioctl is passed a pointer to an `autofs_dev_ioctl` structure:
+Each ioctl is passed a pointer to an `autofs_dev_ioctl` structure: ::
 
         struct autofs_dev_ioctl {
                 __u32 ver_major;
@@ -469,41 +480,50 @@ that the kernel module can support.
 
 Commands are:
 
-- **AUTOFS_DEV_IOCTL_VERSION_CMD**: does nothing, except validate and
-    set version numbers.
-- **AUTOFS_DEV_IOCTL_OPENMOUNT_CMD**: return an open file descriptor
-    on the root of an autofs filesystem.  The filesystem is identified
-    by name and device number, which is stored in `openmount.devid`.
-    Device numbers for existing filesystems can be found in
-    `/proc/self/mountinfo`.
-- **AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD**: same as `close(ioctlfd)`.
-- **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**: if the filesystem is in
-    catatonic mode, this can provide the write end of a new pipe
-    in `setpipefd.pipefd` to re-establish communication with a daemon.
-    The process group of the calling process is used to identify the
-    daemon.
-- **AUTOFS_DEV_IOCTL_REQUESTER_CMD**: `path` should be a
-    name within the filesystem that has been auto-mounted on.
-    On successful return, `requester.uid` and `requester.gid` will be
-    the UID and GID of the process which triggered that mount.
-- **AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD**: Check if path is a
-    mountpoint of a particular type - see separate documentation for
-    details.
-- **AUTOFS_DEV_IOCTL_PROTOVER_CMD**:
-- **AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD**:
-- **AUTOFS_DEV_IOCTL_READY_CMD**:
-- **AUTOFS_DEV_IOCTL_FAIL_CMD**:
-- **AUTOFS_DEV_IOCTL_CATATONIC_CMD**:
-- **AUTOFS_DEV_IOCTL_TIMEOUT_CMD**:
-- **AUTOFS_DEV_IOCTL_EXPIRE_CMD**:
-- **AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD**:  These all have the same
-    function as the similarly named **AUTOFS_IOC** ioctls, except
-    that **FAIL** can be given an explicit error number in `fail.status`
-    instead of assuming `ENOENT`, and this **EXPIRE** command
-    corresponds to **AUTOFS_IOC_EXPIRE_MULTI**.
+- **AUTOFS_DEV_IOCTL_VERSION_CMD**:
+	does nothing, except validate and
+	set version numbers.
+- **AUTOFS_DEV_IOCTL_OPENMOUNT_CMD**:
+	return an open file descriptor
+	on the root of an autofs filesystem.  The filesystem is identified
+	by name and device number, which is stored in `openmount.devid`.
+	Device numbers for existing filesystems can be found in
+	`/proc/self/mountinfo`.
+- **AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD**:
+	same as `close(ioctlfd)`.
+- **AUTOFS_DEV_IOCTL_SETPIPEFD_CMD**:
+	if the filesystem is in
+	catatonic mode, this can provide the write end of a new pipe
+	in `setpipefd.pipefd` to re-establish communication with a daemon.
+	The process group of the calling process is used to identify the
+	daemon.
+- **AUTOFS_DEV_IOCTL_REQUESTER_CMD**:
+	`path` should be a
+	name within the filesystem that has been auto-mounted on.
+	On successful return, `requester.uid` and `requester.gid` will be
+	the UID and GID of the process which triggered that mount.
+- **AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD**:
+	Check if path is a
+	mountpoint of a particular type - see separate documentation for
+	details.
+
+- **AUTOFS_DEV_IOCTL_PROTOVER_CMD**
+- **AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD**
+- **AUTOFS_DEV_IOCTL_READY_CMD**
+- **AUTOFS_DEV_IOCTL_FAIL_CMD**
+- **AUTOFS_DEV_IOCTL_CATATONIC_CMD**
+- **AUTOFS_DEV_IOCTL_TIMEOUT_CMD**
+- **AUTOFS_DEV_IOCTL_EXPIRE_CMD**
+- **AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD**
+
+These all have the same
+function as the similarly named **AUTOFS_IOC** ioctls, except
+that **FAIL** can be given an explicit error number in `fail.status`
+instead of assuming `ENOENT`, and this **EXPIRE** command
+corresponds to **AUTOFS_IOC_EXPIRE_MULTI**.
 
 Catatonic mode
---------------
+==============
 
 As mentioned, an autofs mount can enter "catatonic" mode.  This
 happens if a write to the notification pipe fails, or if it is
@@ -527,7 +547,7 @@ Catatonic mode can only be left via the
 **AUTOFS_DEV_IOCTL_OPENMOUNT_CMD** ioctl on the `/dev/autofs`.
 
 The "ignore" mount option
--------------------------
+=========================
 
 The "ignore" mount option can be used to provide a generic indicator
 to applications that the mount entry should be ignored when displaying
@@ -542,18 +562,18 @@ This is intended to be used by user space programs to exclude autofs
 mounts from consideration when reading the mounts list.
 
 autofs, name spaces, and shared mounts
---------------------------------------
+======================================
 
 With bind mounts and name spaces it is possible for an autofs
 filesystem to appear at multiple places in one or more filesystem
 name spaces.  For this to work sensibly, the autofs filesystem should
-always be mounted "shared". e.g.
+always be mounted "shared". e.g. ::
 
-> `mount --make-shared /autofs/mount/point`
+	mount --make-shared /autofs/mount/point
 
 The automount daemon is only able to manage a single mount location for
 an autofs filesystem and if mounts on that are not 'shared', other
 locations will not behave as expected.  In particular access to those
-other locations will likely result in the `ELOOP` error
+other locations will likely result in the `ELOOP` error ::
 
-> Too many levels of symbolic links
+	Too many levels of symbolic links
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index 2c3a9f761205..ad6315a48d14 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -46,4 +46,5 @@ Documentation for filesystem implementations.
 .. toctree::
    :maxdepth: 2
 
+   autofs
    virtiofs
-- 
2.21.0

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [Linux-kernel-mentees] [RFC PATCH] docs: filesystems: convert autofs.txt to reST
  2019-11-13  7:38 [Linux-kernel-mentees] [RFC PATCH] docs: filesystems: convert autofs.txt to reST Jaskaran Singh
@ 2019-11-14 16:38 ` Jonathan Corbet
  0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Corbet @ 2019-11-14 16:38 UTC (permalink / raw)
  To: Jaskaran Singh
  Cc: mszeredi, linux-doc, neilb, willy, linux-kernel, stefanha,
	mchehab+samsung, akpm, linux-kernel-mentees, christian, raven

On Wed, 13 Nov 2019 13:08:22 +0530
Jaskaran Singh <jaskaransingh7654321@gmail.com> wrote:

Thanks for doing this.  Naturally I have some requests :)

> This patch converts autofs.txt to reST.

Some subsystem maintainers react strongly to changelogs that read "this
patch"; it's best to express things in the imperative form described in
Documentation/process/submitting-patches.rst.

>  - Most of the changes pertain to reST formatting.
>  - Some of the code snippets are updated to reflect current source.
>  - A definition of the autofs packet header has been added in the chapter
> 	"Communicating with autofs: the event pipe".
>  - An indentation of an 8 space tab has been added wherever suitable, so
>    as to maintain consistency.
>  - Removed indentation of the description of the ioctls which are similar
>    to the AUTOFS_IOC ioctls, as it does not come out quite right in HTML.

These seems like good changes, but they are too much for a single patch.
Please split this into multiple patches, separating the formatting and
white-space changes from those that change the text.  That makes it much
easier to review.

Some nits below.

> Signed-off-by: Jaskaran Singh <jaskaransingh7654321@gmail.com>
> ---
>  .../filesystems/{autofs.txt => autofs.rst}    | 258 ++++++++++--------
>  Documentation/filesystems/index.rst           |   1 +
>  2 files changed, 140 insertions(+), 119 deletions(-)
>  rename Documentation/filesystems/{autofs.txt => autofs.rst} (77%)
> 
> diff --git a/Documentation/filesystems/autofs.txt b/Documentation/filesystems/autofs.rst
> similarity index 77%
> rename from Documentation/filesystems/autofs.txt
> rename to Documentation/filesystems/autofs.rst
> index 3af38c7fd26d..a130cba76f07 100644
> --- a/Documentation/filesystems/autofs.txt
> +++ b/Documentation/filesystems/autofs.rst
> @@ -1,12 +1,9 @@
> -<head>
> -<style> p { max-width:50em} ol, ul {max-width: 40em}</style>
> -</head>

Heh, yeah, I'm not sure why that's there, it should definitely go.

> +=====================
>  autofs - how it works
>  =====================
>  
>  Purpose
> --------
> +=======
>  
>  The goal of autofs is to provide on-demand mounting and race free
>  automatic unmounting of various other filesystems.  This provides two
> @@ -28,7 +25,7 @@ key advantages:
>     first accessed a name.
>  
>  Context
> --------
> +=======
>  
>  The "autofs" filesystem module is only one part of an autofs system.
>  There also needs to be a user-space program which looks up names
> @@ -43,7 +40,7 @@ filesystem type.  Several "autofs" filesystems can be mounted and they
>  can each be managed separately, or all managed by the same daemon.
>  
>  Content
> --------
> +=======
>  
>  An autofs filesystem can contain 3 sorts of objects: directories,
>  symbolic links and mount traps.  Mount traps are directories with
> @@ -52,7 +49,7 @@ extra properties as described in the next section.
>  Objects can only be created by the automount daemon: symlinks are
>  created with a regular `symlink` system call, while directories and
>  mount traps are created with `mkdir`.  The determination of whether a
> -directory should be a mount trap or not is quite _ad hoc_, largely for
> +directory should be a mount trap or not is quite _ad hoc\_, largely for

Remember that we want to preserve the readability of the plain-text
document; sprinkling that sort of escape doesn't really help.  Recognize
that what's there now is a sort of informal markup; I'd either fix it up or
take it out.  So "*ad hoc*" or just "ad hoc".

(Or rephrase it, since this doesn't actually seem to be an appropriate use
of "ad hoc" but that's a separate issue :)

>  historical reasons, and is determined in part by the
>  *direct*/*indirect*/*offset* mount options, and the *maxproto* mount option.
>  
> @@ -80,7 +77,7 @@ where in the tree they are (root, top level, or lower), the *maxproto*,
>  and whether the mount was *indirect* or not.
>  
>  Mount Traps
> ----------------
> +===============

As long as you're changing the underbar make it match the length of the
text.

>  A core element of the implementation of autofs is the Mount Traps
>  which are provided by the Linux VFS.  Any directory provided by a
> @@ -201,7 +198,7 @@ initiated or is being considered, otherwise it returns 0.
>  
>  
>  Mountpoint expiry
> ------------------
> +=================
>  
>  The VFS has a mechanism for automatically expiring unused mounts,
>  much as it can expire any unused dentry information from the dcache.
> @@ -301,7 +298,7 @@ completed (together with removing any directories that might have been
>  necessary), or has been aborted.
>  
>  Communicating with autofs: detecting the daemon
> ------------------------------------------------
> +===============================================
>  
>  There are several forms of communication between the automount daemon
>  and the filesystem.  As we have already seen, the daemon can create and
> @@ -317,33 +314,39 @@ If the daemon ever has to be stopped and restarted a new pgid can be
>  provided through an ioctl as will be described below.
>  
>  Communicating with autofs: the event pipe
> ------------------------------------------
> +=========================================
>  
>  When an autofs filesystem is mounted, the 'write' end of a pipe must
>  be passed using the 'fd=' mount option.  autofs will write
>  notification messages to this pipe for the daemon to respond to.
> -For version 5, the format of the message is:
> -
> -        struct autofs_v5_packet {
> -                int proto_version;                /* Protocol version */
> -                int type;                        /* Type of packet */
> -                autofs_wqt_t wait_queue_token;
> -                __u32 dev;
> -                __u64 ino;
> -                __u32 uid;
> -                __u32 gid;
> -                __u32 pid;
> -                __u32 tgid;
> -                __u32 len;
> -                char name[NAME_MAX+1];
> +For version 5, the format of the message is: ::

Too may colons.  Just say "...the message is::"  There's a few of these.

> +	struct autofs_v5_packet {
> +		struct autofs_packet_hdr hdr;
> +		autofs_wqt_t wait_queue_token;
> +		__u32 dev;
> +		__u64 ino;
> +		__u32 uid;
> +		__u32 gid;
> +		__u32 pid;
> +		__u32 tgid;
> +		__u32 len;
> +		char name[NAME_MAX+1];
>          };
>  
> -where the type is one of
> +And the format of the header is: ::
> +
> +	struct autofs_packet_hdr {
> +		int proto_version;		/* Protocol version */
> +		int type;			/* Type of packet */
> +	};
>  
> -        autofs_ptype_missing_indirect
> -        autofs_ptype_expire_indirect
> -        autofs_ptype_missing_direct
> -        autofs_ptype_expire_direct
> +where the type is one of ::
> +
> +	autofs_ptype_missing_indirect
> +	autofs_ptype_expire_indirect
> +	autofs_ptype_missing_direct
> +	autofs_ptype_expire_direct
>  
>  so messages can indicate that a name is missing (something tried to
>  access it but it isn't there) or that it has been selected for expiry.
> @@ -360,7 +363,7 @@ acknowledged using one of the ioctls below with the relevant
>  `wait_queue_token`.
>  
>  Communicating with autofs: root directory ioctls
> -------------------------------------------------
> +================================================
>  
>  The root directory of an autofs filesystem will respond to a number of
>  ioctls.  The process issuing the ioctl must have the CAP_SYS_ADMIN
> @@ -368,58 +371,66 @@ capability, or must be the automount daemon.
>  
>  The available ioctl commands are:
>  
> -- **AUTOFS_IOC_READY**: a notification has been handled.  The argument
> -    to the ioctl command is the "wait_queue_token" number
> -    corresponding to the notification being acknowledged.
> -- **AUTOFS_IOC_FAIL**: similar to above, but indicates failure with
> -    the error code `ENOENT`.
> -- **AUTOFS_IOC_CATATONIC**: Causes the autofs to enter "catatonic"
> -    mode meaning that it stops sending notifications to the daemon.
> -    This mode is also entered if a write to the pipe fails.
> -- **AUTOFS_IOC_PROTOVER**:  This returns the protocol version in use.
> -- **AUTOFS_IOC_PROTOSUBVER**: Returns the protocol sub-version which
> -    is really a version number for the implementation.
> -- **AUTOFS_IOC_SETTIMEOUT**:  This passes a pointer to an unsigned
> -    long.  The value is used to set the timeout for expiry, and
> -    the current timeout value is stored back through the pointer.
> -- **AUTOFS_IOC_ASKUMOUNT**:  Returns, in the pointed-to `int`, 1 if
> -    the filesystem could be unmounted.  This is only a hint as
> -    the situation could change at any instant.  This call can be
> -    used to avoid a more expensive full unmount attempt.
> -- **AUTOFS_IOC_EXPIRE**: as described above, this asks if there is
> -    anything suitable to expire.  A pointer to a packet:
> -
> -        struct autofs_packet_expire_multi {
> -                int proto_version;              /* Protocol version */
> -                int type;                       /* Type of packet */
> -                autofs_wqt_t wait_queue_token;
> -                int len;
> -                char name[NAME_MAX+1];
> -        };
> +- **AUTOFS_IOC_READY**:
> +	a notification has been handled.  The argument
> +	to the ioctl command is the "wait_queue_token" number
> +	corresponding to the notification being acknowledged.
> +- **AUTOFS_IOC_FAIL**:
> +	similar to above, but indicates failure with
> +	the error code `ENOENT`.
> +- **AUTOFS_IOC_CATATONIC**:
> +	Causes the autofs to enter "catatonic"
> +	mode meaning that it stops sending notifications to the daemon.
> +	This mode is also entered if a write to the pipe fails.
> +- **AUTOFS_IOC_PROTOVER**:
> +	This returns the protocol version in use.
> +- **AUTOFS_IOC_PROTOSUBVER**:
> +	Returns the protocol sub-version which
> +	is really a version number for the implementation.
> +- **AUTOFS_IOC_SETTIMEOUT**:
> +	This passes a pointer to an unsigned
> +	long.  The value is used to set the timeout for expiry, and
> +	the current timeout value is stored back through the pointer.
> +- **AUTOFS_IOC_ASKUMOUNT**:
> +	Returns, in the pointed-to `int`, 1 if
> +	the filesystem could be unmounted.  This is only a hint as
> +	the situation could change at any instant.  This call can be
> +	used to avoid a more expensive full unmount attempt.
> +- **AUTOFS_IOC_EXPIRE**:
> +	as described above, this asks if there is
> +	anything suitable to expire.  A pointer to a packet: ::
> +
> +		struct autofs_packet_expire_multi {
> +			struct autofs_packet_hdr hdr;
> +			autofs_wqt_t wait_queue_token;
> +			int len;
> +			char name[NAME_MAX+1];
> +		};
>  
> -     is required.  This is filled in with the name of something
> -     that can be unmounted or removed.  If nothing can be expired,
> -     `errno` is set to `EAGAIN`.  Even though a `wait_queue_token`
> -     is present in the structure, no "wait queue" is established
> -     and no acknowledgment is needed.
> -- **AUTOFS_IOC_EXPIRE_MULTI**:  This is similar to
> -     **AUTOFS_IOC_EXPIRE** except that it causes notification to be
> -     sent to the daemon, and it blocks until the daemon acknowledges.
> -     The argument is an integer which can contain two different flags.
> +	is required.  This is filled in with the name of something
> +	that can be unmounted or removed.  If nothing can be expired,
> +	`errno` is set to `EAGAIN`.  Even though a `wait_queue_token`
> +	is present in the structure, no "wait queue" is established
> +	and no acknowledgment is needed.
> +- **AUTOFS_IOC_EXPIRE_MULTI**:
> +	This is similar to
> +	**AUTOFS_IOC_EXPIRE** except that it causes notification to be
> +	sent to the daemon, and it blocks until the daemon acknowledges.
> +	The argument is an integer which can contain two different flags.
>  
> -     **AUTOFS_EXP_IMMEDIATE** causes `last_used` time to be ignored
> -     and objects are expired if the are not in use.
> +	**AUTOFS_EXP_IMMEDIATE** causes `last_used` time to be ignored
> +	and objects are expired if the are not in use.
>  
> -     **AUTOFS_EXP_FORCED** causes the in use status to be ignored
> -     and objects are expired ieven if they are in use. This assumes
> -     that the daemon has requested this because it is capable of
> -     performing the umount.
> +	**AUTOFS_EXP_FORCED** causes the in use status to be ignored
> +	and objects are expired ieven if they are in use. This assumes
> +	that the daemon has requested this because it is capable of
> +	performing the umount.
>  
> -     **AUTOFS_EXP_LEAVES** will select a leaf rather than a top-level
> -     name to expire.  This is only safe when *maxproto* is 4.
> +	**AUTOFS_EXP_LEAVES** will select a leaf rather than a top-level
> +	name to expire.  This is only safe when *maxproto* is 4.
>  
>  Communicating with autofs: char-device ioctls
> ----------------------------------------------
> +=============================================
>  
>  It is not always possible to open the root of an autofs filesystem,
>  particularly a *direct* mounted filesystem.  If the automount daemon
> @@ -429,9 +440,9 @@ need there is a "miscellaneous" character device (major 10, minor 235)
>  which can be used to communicate directly with the autofs filesystem.
>  It requires CAP_SYS_ADMIN for access.
>  
> -The `ioctl`s that can be used on this device are described in a separate
> +The `ioctl`\s that can be used on this device are described in a separate

Better to just avoid the use of the backtick here.  I'd say "ioctl()s" but
that's me.  If nothing else, change it to a regular apostrophe.

Thanks,

jon
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2019-11-13  7:38 [Linux-kernel-mentees] [RFC PATCH] docs: filesystems: convert autofs.txt to reST Jaskaran Singh
2019-11-14 16:38 ` Jonathan Corbet

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