Commit Graph

30 Commits

Author SHA1 Message Date
Al Viro
b0841eefd9 configfs: provide exclusion between IO and removals
Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04 22:33:51 +02:00
Al Viro
47320fbe11 configfs: new object reprsenting tree fragments
Refcounted, hangs of configfs_dirent, created by operations that add
fragments to configfs tree (mkdir and configfs_register_{subsystem,group}).
Will be used in the next commit to provide exclusion between fragment
removal and ->show/->store calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-02 22:10:44 +02:00
Al Viro
ff4dd08197 configfs: stash the data we need into configfs_buffer at open time
simplifies the ->read()/->write()/->release() instances nicely

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-02 22:10:43 +02:00
Thomas Gleixner
328970de0e treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 021110 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 84 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:18 -07:00
Thomas Meyer
3f6928c347 configfs: Fix bool initialization/comparison
Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19 16:15:14 +02:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Phil Turnbull
42857cf512 configfs: Return -EFBIG from configfs_write_bin_file.
The check for writing more than cb_max_size bytes does not 'goto out' so
it is a no-op which allows users to vmalloc an arbitrary amount.

Fixes: 03607ace80 ("configfs: implement binary attributes")
Cc: stable@kernel.org
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-09-16 12:58:28 +02:00
Tal Shorer
3dc3afadeb configfs: don't set buffer_needs_fill to zero if show() returns error
A confgifs attribute's show() callback is called once the first time
the user attempts to read from it. If it returns an error, that
error is returned to the user. However, the open file's
buffer_needs_fill is still set to zero and consecutive read() calls
will find an empty buffer that doesn't need filling and return 0 to
the user. This could give the user the wrong impression that the
attribute was read successfully.

Fix this by not setting buffer_needs_fill if show() returns an error,
making consecutive read() calls call show() again and either get an
error again or get data.

Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-07-10 21:02:18 +09:00
Marek Vasut
f8608985f8 configfs: Remove ppos increment in configfs_write_bin_file
The simple_write_to_buffer() already increments the @ppos on success,
see fs/libfs.c simple_write_to_buffer() comment:

"
On success, the number of bytes written is returned and the offset @ppos
advanced by this number, or negative value is returned on error.
"

If the configfs_write_bin_file() is invoked with @count smaller than the
total length of the written binary file, it will be invoked multiple times.
Since configfs_write_bin_file() increments @ppos on success, after calling
simple_write_to_buffer(), the @ppos is incremented twice.

Subsequent invocation of configfs_write_bin_file() will result in the next
piece of data being written to the offset twice as long as the length of
the previous write, thus creating buffer with "holes" in it.

The simple testcase using DTO follows:
  $ mkdir /sys/kernel/config/device-tree/overlays/1
  $ dd bs=1 if=foo.dtbo of=/sys/kernel/config/device-tree/overlays/1/dtbo
Without this patch, the testcase will result in twice as big buffer in the
kernel, which is then passed to the cfs_overlay_item_dtbo_write() .

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
2016-06-30 11:28:55 +02:00
Al Viro
5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Pantelis Antoniou
03607ace80 configfs: implement binary attributes
ConfigFS lacked binary attributes up until now. This patch
introduces support for binary attributes in a somewhat similar
manner of sysfs binary attributes albeit with changes that
fit the configfs usage model.

Problems that configfs binary attributes fix are everything that
requires a binary blob as part of the configuration of a resource,
such as bitstream loading for FPGAs, DTBs for dynamically created
devices etc.

Look at Documentation/filesystems/configfs/configfs.txt for internals
and howto use them.

This patch is against linux-next as of today that contains
Christoph's configfs rework.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[hch: folded a fix from Geert Uytterhoeven <geert+renesas@glider.be>]
[hch: a few tiny updates based on review feedback]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-01-04 12:31:46 +01:00
Christoph Hellwig
517982229f configfs: remove old API
Remove the old show_attribute and store_attribute methods and update
the documentation.  Also replace the two C samples with a single new
one in the proper samples directory where people expect to find it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-10-13 22:17:57 -07:00
Christoph Hellwig
870823e629 configfs: add show and store methods to struct configfs_attribute
Add methods to struct configfs_attribute to directly show and store
attributes without adding boilerplate code to every user.  In addition
to the methods this also adds 3 helper macros to define read/write,
read-only and write-only attributes with a single line of code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-10-13 22:08:43 -07:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Al Viro
28444a2bde configfs_add_file: fold into its sole caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17 22:16:46 -05:00
Dan Carpenter
7121064b21 configfs: use capped length for ->store_attribute()
The difference between "count" and "len" is that "len" is capped at
4095.  Changing it like this makes it match how sysfs_write_file() is
implemented.

This is a static analysis patch.  I haven't found any store_attribute()
functions where this change makes a difference.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:23 -07:00
Harvey Harrison
8e24eea728 fs: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:54 -07:00
Joonwoo Park
116ba5d5ea configfs: file.c fix possible recursive locking
configfs_register_subsystem() with default_groups triggers recursive locking.
it seems that mutex_lock_nested is needed.

=============================================
[ INFO: possible recursive locking detected ]
2.6.24-rc6 #145
---------------------------------------------
swapper/1 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40c9a9e>] configfs_add_file+0x2e/0x70

but task is already holding lock:
 (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130

other info that might help us debug this:
1 lock held by swapper/1:
 #0:  (&sb->s_type->i_mutex_key#3){--..}, at: [<c40ca985>] configfs_register_subsystem+0x55/0x130

stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24-rc6 #145
 [<c40053ba>] show_trace_log_lvl+0x1a/0x30
 [<c4005e82>] show_trace+0x12/0x20
 [<c400687e>] dump_stack+0x6e/0x80
 [<c404ec72>] __lock_acquire+0xe62/0x1120
 [<c404efb2>] lock_acquire+0x82/0xa0
 [<c43fda88>] mutex_lock_nested+0x98/0x2e0
 [<c40c9a9e>] configfs_add_file+0x2e/0x70
 [<c40c9b0c>] configfs_create_file+0x2c/0x40
 [<c40ca639>] configfs_attach_item+0x139/0x220
 [<c40ca734>] configfs_attach_group+0x14/0x140
 [<c40ca7e9>] configfs_attach_group+0xc9/0x140
 [<c40ca9f6>] configfs_register_subsystem+0xc6/0x130
 [<c45c8186>] init_netconsole+0x2b6/0x300
 [<c45a75f2>] kernel_init+0x142/0x320
 [<c4004fb3>] kernel_thread_helper+0x7/0x14
 =======================

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 15:05:47 -08:00
Johannes Berg
6d748924b7 [PATCH] configsfs buffer: use mutex
Seems copied from sysfs, but I don't see a reason here nor there to use
a semaphore instead of a mutex. Convert.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 17:10:58 -07:00
Joel Becker
b23cdde4c6 configfs: consistent attribute size
The attribute store/show code currently limits attributes at PAGE_SIZE.
This code comes from sysfs, where it still works that way.

However, PAGE_SIZE is not constant.  A 16k attribute string works on
ia64 but not on x86.  Really a subsystem shouldn't allow different
attribute sizes based on platform.

As such, limit all simple attributes to 4k.  This works on all
platforms, and is consistent with all current code.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 16:52:22 -07:00
Akinobu Mita
92f4c701aa use simple_read_from_buffer() in fs/
Cleanup using simple_read_from_buffer() in binfmt_misc, configfs, and sysfs.

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:49 -07:00
Joel Becker
ff05d1c464 configfs: Zero terminate data in configfs attribute writes.
Attributes in configfs are text files.  As such, most handlers expect to be
able to call functions like simple_strtoul() without checking the bounds
of the buffer.  Change the call to zero terminate the buffer before calling
the client's ->store() method.  This does reduce the attribute size from
PAGE_SIZE to PAGE_SIZE-1.

Also, change get_zeroed_page() to alloc_page(), as we are handling the
termination.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-02-07 12:17:08 -08:00
Josef "Jeff" Sipek
867fa491a2 [PATCH] configfs: change uses of f_{dentry, vfsmnt} to use f_path
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the
configfs filesystem.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:43 -08:00
Chandra Seetharaman
559c9ac391 configfs: handle kzalloc() failure in check_perm()
check_perm() does not drop the reference to the module when kzalloc()
failure occurs.

Signed-Off-By: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-10-20 15:29:00 -07:00
Zach Brown
4779efca14 [PATCH] pr_debug: configfs: use size_t length modifier in pr_debug format argument
configfs: use size_t length modifier in pr_debug format argument

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:04:19 -07:00
Panagiotis Issaris
f8314dc60c [PATCH] fs: Conversions from kmalloc+memset to k(z|c)alloc
Conversions from kmalloc+memset to kzalloc.

Signed-off-by: Panagiotis Issaris <takis@issaris.org>
Jffs2-bit-acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:10 -07:00
Arjan van de Ven
4b6f5d20b0 [PATCH] Make most file operations structs in fs/ const
This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:06 -08:00
Joel Becker
3d0f89bb16 configfs: Add permission and ownership to configfs objects.
configfs always made item and attribute ownership root.root and
permissions based on a umask of 022.  Add ->setattr() to allow
chown(2)/chmod(2), and persist the changes for the lifetime of the
items and attributes.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-02-03 14:01:05 -08:00
Jes Sorensen
1b1dcc1b57 [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.

Modified-by: Ingo Molnar <mingo@elte.hu>

(finished the conversion)

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-01-09 15:59:24 -08:00
Joel Becker
7063fbf226 [PATCH] configfs: User-driven configuration filesystem
Configfs, a file system for userspace-driven kernel object configuration.
The OCFS2 stack makes extensive use of this for propagation of cluster
configuration information into kernel.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2006-01-03 11:45:28 -08:00