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The pandoc conversion is not perfect. Do handwork in order to:
- add a title to this chapter;
- use the proper warning and note markups;
- use kernel-doc to include Kernel header and c files;
- remove legacy notes with regards to DocBook;
- some other minor adjustments to make it better to read in
text mode and in html.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
- use the proper warning and note markups;
- add references for parts of the document that will be
cross-referenced on other USB docs;
- some minor adjustments to make it better to read in
text mode and in html.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
As we're moving out of DocBook, let's convert the remaining
USB docbooks to ReST.
The transformation itself on this patch is a no-brainer
conversion using pandoc via this script:
Documentation/sphinx/tmplcvt
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The structs there at device table are used by other documentation
at the Kernel. So, add it to the driver API.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, the script just assumes to be called at
Documentation/sphinx/. Change it to work on any directory,
and make it abort if something gets wrong.
Also, be sure that both parameters are specified.
That should avoid troubles like this:
$ Documentation/sphinx/tmplcvt Documentation/DocBook/writing_usb_driver.tmpl
sed: couldn't open file convert_template.sed: No such file or directory
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
A patch documenting how to specify which kernels a particular fix should
be backported to (seemingly) inadvertently added a minus sign after the
kernel version. This particular stable-tag format had never been used
prior to this patch, and was neither present when the patch in question
was first submitted (it was added in v2 without any comment).
Drop the minus sign to avoid any confusion.
Fixes: fdc81b7910 ("stable_kernel_rules: Add clause about specification of kernel versions to patch.")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit adds Japanese translation of HOWTO document into rst based
documentation build system with updates.
Signed-off-by: Tsugikazu Shibata <tshibata@ab.jp.nec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This is a straightforward conversion, without any real textual changes.
Since this document has seen no substantive changes since its addition in
2006, some such changes are probably warranted.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This is meant to be the place for documentation relevant to application
developers. It's empty for the moment, but at least we have a place now!
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There are several stuff there that are actually driver-specific.
Move those to the driver_api book.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This file has only "internal" functions:
./lib/crc32.c:1: warning: no structured comments found
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Brainless conversion of genericirq.tmpl book to ReST, via
Documentation/sphinx/tmplcvt
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The document describes several functions that are documented
there via kernel doc macros. Add cross-references to them.
In order to be consistend with other documents, use monospaced
fonts for fields.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Brainless conversion of genericirq.tmpl book to ReST, via
Documentation/sphinx/tmplcvt
Copyright information inserted manually.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Using the development version of sphinx caused the parsing of the
version to fail.
Signed-off-by: Rémy Léone <remy.leone@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Documentation/sparse.txt has been moved to
Documentation/dev-tools/sparse.rst
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Include whitespace shooting; correction; typo fix; superfluous word
dropping.
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
As ftp.kernel.org is closed [0], this commit fixes dead URLs in
documents to use www.kernel.org instead.
[0] https://www.kernel.org/shutting-down-ftp-services.html
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix typos in md-cluster.txt file to make documentation clear.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix typos in mmc-dev-attrs.txt to make documentation clear.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix spelling mistakes in leds-lp55xx.txt file to make documentation
clear.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Correct spelling mistakes in vfio-mediates-device.txt to make
documentation clear.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix spelling mistakes in sync_file.txt to make documentation clear.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix typos in acpi directory to make documentation grammatically correct.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fix typos in admin-guide directory.
Make documentation clear and grammatically correct.
Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The UAPI header split failed to update the documentation here; fix things
accordingly.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The UAPI header split failed to update the documentation here; fix things
accordingly.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The UAPI header split failed to update the documentation in
input-programming.txt; fix things accordingly.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The UAPI header split failed to update the documentation here; fix things
accordingly.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Since commit f9b6b0ef60 ("selftests: move vDSO tests from Documentation/vDSO")
parse_vdso.c moved under selftests. Update the reference to match.
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The user/admin documentation of cpufreq is badly outdated. It
conains stale and/or inaccurate information along with things
that are not particularly useful. Also, some of the important
pieces are missing from it.
For this reason, add a new user/admin document for cpufreq
containing current information to admin-guide and drop the old
outdated .txt documents it is replacing.
Since there will be more PM documents in admin-guide going forward,
create a separate directory for them and put the cpufreq document
in there right away.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Now that we have an extension to handle images, use it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
We're still pretty far away from anything like a consensus, but
there's clearly a lot of people who prefer an as-light as possible
approach to converting existing .txt files to .rst. Make sure this is
properly taken into account and clear.
Motivated by discussions with Peter and Christoph and others.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The patch replaces 'to to' with 'to' in the documentation.
Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The patch replaces 'the the' with 'the' in the documentation.
Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The patch replaces 'the the' with 'the' in the documantation.
Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The kernel security team is regularly asked to provide CVE identifiers,
which we don't normally do. This updates the documentation to mention
this and adds some more details about coordination and patch handling
that come up regularly. Based on an earlier draft by Willy Tarreau.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Merge tag 'docs-4.11-fixes' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"A few fixes for the docs tree, including one for a 4.11 build
regression"
* tag 'docs-4.11-fixes' of git://git.lwn.net/linux:
Documentation/sphinx: fix primary_domain configuration
docs: Fix htmldocs build failure
doc/ko_KR/memory-barriers: Update control-dependencies section
pcieaer doc: update the link
Documentation: Update path to sysrq.txt
These updates have been kept in a separate branch mostly because
they rely on updates to the respective clk drivers to keep the
shared header files in sync.
This includes two branches for arm64 dt updates, both following up
on earlier changes for the same platforms that are already merged:
Samsung:
- add USB3 support in Exynos7
- minor PM related updates
Amlogic:
- new machines: WeTek Set-top-boxes
- various devices added to DT
There are also a couple of bugfixes that trickled in since the
start of the merge window:
- The moxart_defconfig was not building the intended platform
- CPU-hotplug was broken on ux500
- Coresight was broken on Juno (never worked)
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Merge tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC late DT updates from Arnd Bergmann:
"These updates have been kept in a separate branch mostly because they
rely on updates to the respective clk drivers to keep the shared
header files in sync.
This includes two branches for arm64 dt updates, both following up on
earlier changes for the same platforms that are already merged:
Samsung:
- add USB3 support in Exynos7
- minor PM related updates
Amlogic:
- new machines: WeTek Set-top-boxes
- various devices added to DT
There are also a couple of bugfixes that trickled in since the start
of the merge window:
- The moxart_defconfig was not building the intended platform
- CPU-hotplug was broken on ux500
- Coresight was broken on Juno (never worked)"
* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (26 commits)
ARM: deconfig: fix the moxart defconfig
ARM: ux500: resume the second core properly
arm64: dts: juno: update definition for programmable replicator
arm64: dts: exynos: Add regulators for Vbus and Vbus-Boost
arm64: dts: exynos: Add USB 3.0 controller node for Exynos7
arm64: dts: exynos: Use macros for pinctrl configuration on Exynos7
pinctrl: dt-bindings: samsung: Add Exynos7 specific pinctrl macro definitions
arm64: dts: exynos: Add initial configuration for DISP clocks for TM2/TM2e
ARM64: dts: meson-gxbb-p200: add ADC laddered keys
ARM64: dts: meson: meson-gx: add the SAR ADC
ARM64: dts: meson-gxl: add the pwm_ao_b pin
ARM64: dts: meson-gx: add the missing pwm_AO_ab node
clk: gxbb: fix CLKID_ETH defined twice
ARM64: dts: meson-gxl: rename Nexbox A95x for consistency
clk: gxbb: add the SAR ADC clocks and expose them
dt-bindings: amlogic: Add WeTek boards
ARM64: dts: meson-gxbb: Add support for WeTek Hub and Play
dt-bindings: vendor-prefix: Add wetek vendor prefix
ARM64: dts: meson-gxm: Rename q200 and q201 DT files for consistency
ARM64: dts: meson-gx: Add HDMI HPD/DDC pinctrl nodes
...
With Sphinx 1.5.3 I get the warning:
WARNING: primary_domain 'C' not found, ignored.
It seems that domain names in Sphinx are case-sensitive and for the C
domain the name must be lower case.
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Build of HTML docs failing due to conversion of deviceiobook.tmpl in
8a8a602f and regulator.tmpl in 028f2533 to RST without removing from
DOCBOOKS in Makefile, resulting (in the case of deviceiobook) the
following error:
make[1]: *** No rule to make target 'Documentation/DocBook/deviceiobook.xml', needed by 'Documentation/DocBook/deviceiobook.aux.xml'. Stop.
Makefile:1452: recipe for target 'htmldocs' failed
make: *** [htmldocs] Error 2
Update DOCBOOKS to reflect available books.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit applies upstream change, commit c8241f8553 ("doc: Update
control-dependencies section of memory-barriers.txt"), to Korean
translation.
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Commit 9d85025b04 ("docs-rst: create an user's manual book") moved the
sysrq.txt leaving old paths in the kernel docs.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull vfs 'statx()' update from Al Viro.
This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.
It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?
From David Howells.
Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:
https://www.spinics.net/lists/linux-fsdevel/msg33831.html
* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
