This reverts commit cb26a31157.
It mysteriously causes NetworkManager to not find the wireless device
for me. As far as I can tell, Tejun *meant* for this commit to not make
any semantic changes, but there clearly are some. So revert it, taking
into account some of the calling convention changes that happened in
this area in subsequent commits.
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sysfs_assoc_lock is an odd piece of locking. In general, whoever owns
a kobject is responsible for synchronizing sysfs operations and sysfs
proper assumes that, for example, removal won't race with any other
operation; however, this doesn't work for symlinking because an entity
performing symlink doesn't usually own the target kobject and thus has
no control over its removal.
sysfs_assoc_lock synchronizes symlink operations against kobj->sd
disassociation so that symlink code doesn't end up dereferencing
already freed sysfs_dirent by racing with removal of the target
kobject.
This is quite obscure and the generic name of the lock and lack of
comments make it difficult to understand its role. Let's rename it to
sysfs_symlink_target_lock and add comments explaining what's going on.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Separate out sysfs_warn_dup() out of sysfs_add_one(). This will help
separating out the core sysfs functionalities into kernfs so that it
can be used by non-sysfs users too.
This doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Most removal related logic is implemented in fs/sysfs/dir.c. Move
sysfs_hash_and_remove() to fs/sysfs/dir.c so that __sysfs_remove()
doesn't have to be public.
This is pure relocation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs_get_dentry() has been gone for years now. Remove the left-over
prototype.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ignore_lockdep is currently honored only for regular files. There's
no reason to ignore it for bin files. Update sysfs_ignore_lockdep()
so that bin_attr.attr.ignore_lockdep works too.
While this doesn't have any in-kernel user, this unifies the behaviors
between regular and bin files and will help later changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3124eb1679 ("sysfs: merge regular and bin file handling") folded bin
file handling into regular file handling. Among other things, bin
file now shares the same open path including sysfs_open_dirent
association using sysfs_dirent->s_attr.open. This is buggy because
->s_bin_attr lives in the same union and doesn't have the field. This
bug doesn't trigger because sysfs_elem_bin_attr doesn't have an active
field at the conflicting position. It does have a field "buffers" but
it isn't used anymore.
This patch collapses sysfs_elem_bin_attr into sysfs_elem_attr so that
the bin_attr is accessed through ->s_attr.bin_attr which lives with
->s_attr.attr in an anonymous union. The code paths already assume
bin_attr contains attr as the first element, so this doesn't add any
more assumptions while making it explicit that the two types are
handled together.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
375b611e60 ("sysfs: remove sysfs_buffer->ops") introduced
sysfs_file_ops() which determines the associated file operation of a
given sysfs_dirent. As file ops access should be protected by an
active reference, the new function includes a lockdep assertion on the
sysfs_dirent; unfortunately, I forgot to take attr->ignore_lockdep
flag into account and the lockdep assertion trips spuriously for files
which opt out from active reference lockdep checking.
# cat /sys/devices/pci0000:00/0000:00:01.2/usb1/authorized
------------[ cut here ]------------
WARNING: CPU: 1 PID: 540 at /work/os/work/fs/sysfs/file.c:79 sysfs_file_ops+0x4e/0x60()
Modules linked in:
CPU: 1 PID: 540 Comm: cat Not tainted 3.11.0-work+ #3
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
0000000000000009 ffff880016205c08 ffffffff81ca0131 0000000000000000
ffff880016205c40 ffffffff81096d0d ffff8800166cb898 ffff8800166f6f60
ffffffff8125a220 ffff880011ab1ec0 ffff88000aff0c78 ffff880016205c50
Call Trace:
[<ffffffff81ca0131>] dump_stack+0x4e/0x82
[<ffffffff81096d0d>] warn_slowpath_common+0x7d/0xa0
[<ffffffff81096dea>] warn_slowpath_null+0x1a/0x20
[<ffffffff8125994e>] sysfs_file_ops+0x4e/0x60
[<ffffffff8125a274>] sysfs_open_file+0x54/0x300
[<ffffffff811df612>] do_dentry_open.isra.17+0x182/0x280
[<ffffffff811df820>] finish_open+0x30/0x40
[<ffffffff811f0623>] do_last+0x503/0xd90
[<ffffffff811f0f6b>] path_openat+0xbb/0x6d0
[<ffffffff811f23ba>] do_filp_open+0x3a/0x90
[<ffffffff811e09a9>] do_sys_open+0x129/0x220
[<ffffffff811e0abe>] SyS_open+0x1e/0x20
[<ffffffff81caf3c2>] system_call_fastpath+0x16/0x1b
---[ end trace aa48096b111dafdb ]---
Rename fs/sysfs/dir.c::ignore_lockdep() to sysfs_ignore_lockdep() and
move it to fs/sysfs/sysfs.h and make sysfs_file_ops() skip lockdep
assertion if sysfs_ignore_lockdep() is true.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the previous changes, sysfs regular file code is ready to handle
bin files too. This patch makes bin files share the regular file
path.
* sysfs_create/remove_bin_file() are moved to fs/sysfs/file.c.
* sysfs_init_inode() is updated to use the new sysfs_bin_operations
instead of bin_fops for bin files.
* fs/sysfs/bin.c and the related pieces are removed.
This patch shouldn't introduce any behavior difference to bin file
accesses.
Overall, this unification reduces the amount of duplicate logic, makes
behaviors more consistent and paves the road for building simpler and
more versatile interface which will allow other subsystems to make use
of sysfs for their pseudo filesystems.
v2: Stale fs/sysfs/bin.c reference dropped from
Documentation/DocBook/filesystems.tmpl. Reported by kbuild test
robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch copies mmap support from bin so that fs/sysfs/file.c can
handle mmapping bin files.
The code is copied mostly verbatim with the following updates.
* ->mmapped and ->vm_ops are added to sysfs_open_file and bin_buffer
references are replaced with sysfs_open_file ones.
* Symbols are prefixed with sysfs_.
* sysfs_unmap_bin_file() grabs sysfs_open_dirent and traverses
->files. Invocation of this function is added to
sysfs_addrm_finish().
* sysfs_bin_mmap() is added to sysfs_bin_operations.
This is a preparation and the new mmap path isn't used yet.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch prepares the write path.
bin file write is almost identical to regular file write except that
the write length is capped by the inode size and @off is passed to the
write method. This patch adds bin file handling to sysfs_write_file()
so that it can handle both regular and bin files.
A new file_operations struct sysfs_bin_operations is added, which
currently only hosts sysfs_write_file() and generic_file_llseek().
This isn't used yet but will eventually replace fs/sysfs/bin.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Given a sysfs_dirent, there is no reason to have multiple versions of
removal functions. A function which removes the specified
sysfs_dirent and its descendants is enough.
This patch intorduces [__}sysfs_remove() which replaces all internal
variations of removal functions. This will be the only removal
function in the planned new sysfs_dirent based interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs_addrm_start/finish() enclose sysfs_dirent additions and
deletions and sysfs_addrm_cxt is used to record information necessary
to finish the operations. Currently, sysfs_addrm_start() takes
@parent_sd, records it in sysfs_addrm_cxt, and assumes that all
operations in the block are performed under that @parent_sd.
This assumption has been fine until now but we want to make some
operations behave recursively and, while having @parent_sd recorded in
sysfs_addrm_cxt doesn't necessarily prevents that, it becomes
confusing.
This patch removes sysfs_addrm_cxt->parent_sd and makes
sysfs_add_one() take an explicit @parent_sd parameter. Note that
sysfs_remove_one() doesn't need the extra argument as its parent is
always known from the target @sd.
While at it, add __acquires/releases() notations to
sysfs_addrm_start/finish() respectively.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some internal sysfs functions which take explicit namespace argument
are weird in that they place the optional @ns in front of @name which
is contrary to the established convention. This is confusing and
error-prone especially as @ns and @name may be interchanged without
causing compilation warning.
Swap the positions of @name and @ns in the following internal
functions.
sysfs_find_dirent()
sysfs_rename()
sysfs_hash_and_remove()
sysfs_name_hash()
sysfs_name_compare()
create_dir()
This patch doesn't introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pre-existing sysfs interfaces which take explicit namespace
argument are weird in that they place the optional @ns in front of
@name which is contrary to the established convention. For example,
we end up forcing vast majority of sysfs_get_dirent() users to do
sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
especially as @ns and @name may be interchanged without causing
compilation warning.
This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
around sysfs_get_dirent_ns(). This makes confusions a lot less
likely.
There are other interfaces which take @ns before @name. They'll be
updated by following patches.
This patch doesn't introduce any functional changes.
v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
error on module builds. Reported by build test robot. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The way namespace tags are implemented in sysfs is more complicated
than necessary. As each tag is a pointer value and required to be
non-NULL under a namespace enabled parent, there's no need to record
separately what type each tag is or where namespace is enabled.
If multiple namespace types are needed, which currently aren't, we can
simply compare the tag to a set of allowed tags in the superblock
assuming that the tags, being pointers, won't have the same value
across multiple types. Also, whether to filter by namespace tag or
not can be trivially determined by whether the node has any tagged
children or not.
This patch rips out kobj_ns_type handling from sysfs. sysfs no longer
cares whether specific type of namespace is enabled or not. If a
sysfs_dirent has a non-NULL tag, the parent is marked as needing
namespace filtering and the value is tested against the allowed set of
tags for the superblock (currently only one but increasing this number
isn't difficult) and the sysfs_dirent is ignored if it doesn't match.
This removes most kobject namespace knowledge from sysfs proper which
will enable proper separation and layering of sysfs. The namespace
sanity checks in fs/sysfs/dir.c are replaced by the new sanity check
in kobject_namespace(). As this is the only place ktype->namespace()
is called for sysfs, this doesn't weaken the sanity check
significantly. I omitted converting the sanity check in
sysfs_do_create_link_sd(). While the check can be shifted to upper
layer, mistakes there are well contained and should be easily visible
anyway.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs ns (namespace) implementation became more convoluted than
necessary while trying to hide ns information from visible interface.
The relatively recent attr ns support is a good example.
* attr ns tag is determined by sysfs_ops->namespace() callback while
dir tag is determined by kobj_type->namespace(). The placement is
arbitrary.
* Instead of performing operations with explicit ns tag, the namespace
callback is routed through sysfs_attr_ns(), sysfs_ops->namespace(),
class_attr_namespace(), class_attr->namespace(). It's not simpler
in any sense. The only thing this convolution does is traversing
the whole stack backwards.
The namespace callbacks are unncessary because the operations involved
are inherently synchronous. The information can be provided in in
straight-forward top-down direction and reversing that direction is
unnecessary and against basic design principles.
This backward interface is unnecessarily convoluted and hinders
properly separating out sysfs from driver model / kobject for proper
layering. This patch updates attr ns support such that
* sysfs_ops->namespace() and class_attr->namespace() are dropped.
* sysfs_{create|remove}_file_ns(), which take explicit @ns param, are
added and sysfs_{create|remove}_file() are now simple wrappers
around the ns aware functions.
* ns handling is dropped from sysfs_chmod_file(). Nobody uses it at
this point. sysfs_chmod_file_ns() can be added later if necessary.
* Explicit @ns is propagated through class_{create|remove}_file_ns()
and netdev_class_{create|remove}_file_ns().
* driver/net/bonding which is currently the only user of attr
namespace is updated to use netdev_class_{create|remove}_file_ns()
with @bh->net as the ns tag instead of using the namespace callback.
This patch should be an equivalent conversion without any functional
difference. It makes the code easier to follow, reduces lines of code
a bit and helps proper separation and layering.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The most convenient way to expose ACPI power resources lists of a
device is to put symbolic links to sysfs directories representing
those resources into special attribute groups in the device's sysfs
directory. For this purpose, it is necessary to be able to add
symbolic links to attribute groups.
For this reason, add sysfs helper functions for adding/removing
symbolic links to/from attribute groups, sysfs_add_link_to_group()
and sysfs_remove_link_from_group(), respectively.
This change set includes a build fix from David Rientjes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
a) ->d_iput() is wrong here - what we do to inode is completely usual, it's
dentry->d_fsdata that we want to drop. Just use ->d_release().
b) switch to ->s_d_op - no need to play with d_set_d_op()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tracking the number of subdirectories requires an extra field that increases
the size of sysfs_dirent. nlinks are not particularly interesting for sysfs
and the nlink counts are wrong when network namespaces are involved so stop
counting them, and always return nlink == 1. Userspace already knows that
directories with nlink == 1 have an nlink count they can't use to count
subdirectories.
This reduces the size of sysfs_dirent by 8 bytes on 64bit platforms.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Store the sysfs inode number in an unsided int because
ida inode allocator can return at most a 31 bit number,
reducing the size of struct sysfs_dirent by 8 bytes
on 64bit platforms.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On 32bit this reduces sizeof(struct sysfs_dirent) by 2 bytes.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Compute a 31 bit hash of directory entries (that can fit in a signed
32bit off_t) and index the sysfs directory entries by that hash,
replacing the per directory indexes by name and by inode. Because we
now only use a single rbtree this reduces the size of sysfs_dirent by 2
pointers. Because we have fewer cases to deal with the code is now
simpler.
For now I use the simple hash that the dcache uses as that is easy to
use and seems simple enough.
In addition to makeing the code simpler using a hash for the file
position in readdir brings sysfs in line with other filesystems that
have non-trivial directory structures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Linus Torvalds
Tejun Heo
Greg Kroah-Hartman
Rafael J. Wysocki
Al Viro
Eric W. Biederman