Fix kernel-doc warnings in PCI, sysfs, and kobject files.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".

Compile tested with gcc & sparse.
Signed-off-by: NJosef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*. 

What I want is a separate /sys/class/net directory in sysfs for each
network namespace, and I want to name each of them /sys/class/net.

I looked and the VFS actually allows that.  All that is needed is
for /sys/class/net to implement a follow link method to redirect
lookups to the real directory you want. 

Implementing a follow link method that is sensitive to the current
network namespace turns out to be 3 lines of code so it looks like a
clean approach.  Modifying sysfs so it doesn't get in my was is a bit
trickier. 

I am calling the concept of multiple directories all at the same path
in the filesystem shadow directories.  With the directory entry really
at that location the shadow master. 

The following patch modifies sysfs so it can handle a directory
structure slightly different from the kobject tree so I can implement
the shadow directories for handling /sys/class/net/.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

if a driver returns an error in fill_read_buffer(), the buffer will be
marked as filled. Subsequent reads will return eof. But there is
no data because of an error, not because it has been read.
Not marking the buffer filled is the obvious fix.
Signed-off-by: NOliver Neukum <oliver@neukum.name>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch removes redundant argument checks for kobject_put().
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Lockdep issues the following warning:
[    9.064000] =============================================
[    9.064000] [ INFO: possible recursive locking detected ]
[    9.064000] 2.6.20-rc3-mm1 #3
[    9.064000] ---------------------------------------------
[    9.064000] init/1 is trying to acquire lock:
[    9.064000]  (&sysfs_inode_imutex_key){--..}, at: [<c03e6afc>] mutex_lock+0x1c/0x1f
[    9.064000]
[    9.064000] but task is already holding lock:
[    9.064000]  (&sysfs_inode_imutex_key){--..}, at: [<c03e6afc>] mutex_lock+0x1c/0x1f
[    9.065000]
[    9.065000] other info that might help us debug this:
[    9.065000] 2 locks held by init/1:
[    9.065000]  #0:  (tty_mutex){--..}, at: [<c03e6afc>] mutex_lock+0x1c/0x1f
[    9.065000]  #1:  (&sysfs_inode_imutex_key){--..}, at: [<c03e6afc>] mutex_lock+0x1c/0x1f
[    9.065000]
[    9.065000] stack backtrace:
[    9.065000]  [<c010390d>] show_trace_log_lvl+0x1a/0x30
[    9.066000]  [<c0103935>] show_trace+0x12/0x14
[    9.066000]  [<c0103a2f>] dump_stack+0x16/0x18
[    9.066000]  [<c0138cb8>] print_deadlock_bug+0xb9/0xc3
[    9.066000]  [<c0138d17>] check_deadlock+0x55/0x5a
[    9.066000]  [<c013a953>] __lock_acquire+0x371/0xbf0
[    9.066000]  [<c013b7a9>] lock_acquire+0x69/0x83
[    9.066000]  [<c03e6b7e>] __mutex_lock_slowpath+0x75/0x2d1
[    9.066000]  [<c03e6afc>] mutex_lock+0x1c/0x1f
[    9.066000]  [<c01b249c>] sysfs_drop_dentry+0xb1/0x133
[    9.066000]  [<c01b25d1>] sysfs_hash_and_remove+0xb3/0x142
[    9.066000]  [<c01b30ed>] sysfs_remove_file+0xd/0x10
[    9.067000]  [<c02849e0>] device_remove_file+0x23/0x2e
[    9.067000]  [<c02850b2>] device_del+0x188/0x1e6
[    9.067000]  [<c028511b>] device_unregister+0xb/0x15
[    9.067000]  [<c0285318>] device_destroy+0x9c/0xa9
[    9.067000]  [<c0261431>] vcs_remove_sysfs+0x1c/0x3b
[    9.067000]  [<c0267a08>] con_close+0x5e/0x6b
[    9.067000]  [<c02598f2>] release_dev+0x4c4/0x6e5
[    9.067000]  [<c0259faa>] tty_release+0x12/0x1c
[    9.067000]  [<c0174872>] __fput+0x177/0x1a0
[    9.067000]  [<c01746f5>] fput+0x3b/0x41
[    9.068000]  [<c0172ee1>] filp_close+0x36/0x65
[    9.068000]  [<c0172f73>] sys_close+0x63/0xa4
[    9.068000]  [<c0102a96>] sysenter_past_esp+0x5f/0x99
[    9.068000]  =======================

This is due to sysfs_hash_and_remove() holding dir->d_inode->i_mutex
before calling sysfs_drop_dentry() which calls orphan_all_buffers()
which in turn takes node->i_mutex.
Signed-off-by: NFrederik Deweerdt <frederik.deweerdt@gmail.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch prevents a race between IO and removing a file from sysfs.
It introduces a list of sysfs_buffers associated with a file at the inode.
Upon removal of a file the list is walked and the buffers marked orphaned.
IO to orphaned buffers fails with -ENODEV. The driver can safely free
associated data structures or be unloaded.
Signed-off-by: NOliver Neukum <oliver@neukum.name>
Acked-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

If we allow NULL as the new parent in device_move(), we need to make sure
that the device is placed into the same place as it would if it was
newly registered:

- Consider the device virtual tree. In order to be able to reuse code,
  setup_parent() has been tweaked a bit.
- kobject_move() can fall back to the kset's kobject.
- sysfs_move_dir() uses the sysfs root dir as fallback.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the sysfs
filesystem code.
Signed-off-by: NJosef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Provide a function device_move() to move a device to a new parent device. Add
auxilliary functions kobject_move() and sysfs_move_dir().
kobject_move() generates a new uevent of type KOBJ_MOVE, containing the
previous path (DEVPATH_OLD) in addition to the usual values. For this, a new
interface kobject_uevent_env() is created that allows to add further
environmental data to the uevent at the kobject layer.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

since most of the files in sysfs are text files,
it would be nice, if the "store" function called
during sysfs_write_file() gets a zero terminated
string / data.
The current implementation seems not to ensure this.
(But only if it is the first time the zeroed buffer
page is allocated.)

So the buffer can be scanned by sscanf() easily,
for example.

This patch simply sets a \0 char behind the
data in buffer->page.
Signed-off-by: NThomas Maier <balagi@justmail.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

And the obsolete comment should be updated (or totally removed).
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Following function can drops d_count twice against one reference
by lookup_one_len.

<SOURCE>
/**
 * sysfs_update_file - update the modified timestamp on an object attribute.
 * @kobj: object we're acting for.
 * @attr: attribute descriptor.
 */
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
        struct dentry * dir = kobj->dentry;
        struct dentry * victim;
        int res = -ENOENT;

        mutex_lock(&dir->d_inode->i_mutex);
        victim = lookup_one_len(attr->name, dir, strlen(attr->name));
        if (!IS_ERR(victim)) {
                /* make sure dentry is really there */
                if (victim->d_inode &&
                    (victim->d_parent->d_inode == dir->d_inode)) {
                        victim->d_inode->i_mtime = CURRENT_TIME;
                        fsnotify_modify(victim);

                        /**
                         * Drop reference from initial sysfs_get_dentry().
                         */
                        dput(victim);
                        res = 0;
                } else
                        d_drop(victim);

                /**
                 * Drop the reference acquired from sysfs_get_dentry() above.
                 */
                dput(victim);
        }
        mutex_unlock(&dir->d_inode->i_mutex);

        return res;
}
</SOURCE>

PCI-hotplug (drivers/pci/hotplug/pci_hotplug_core.c) is only user of
this function. I confirmed that dentry of /sys/bus/pci/slots/XXX/*
have negative d_count value.

This patch removes unnecessary dput().
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

sysfs: use size_t length modifier in pr_debug format arguments
Signed-off-by: NZach Brown <zach.brown@oracle.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is mostly included for parity with dec_nlink(), where we will have some
more hooks.  This one should stay pretty darn straightforward for now.
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This eliminates the i_blksize field from struct inode.  Filesystems that want
to provide a per-inode st_blksize can do so by providing their own getattr
routine instead of using the generic_fillattr() function.

Note that some filesystems were providing pretty much random (and incorrect)
values for i_blksize.

[bunk@stusta.de: cleanup]
[akpm@osdl.org: generic_fillattr() fix]
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make sysfs_remove_bin_file() void.  If it detects an error,
printk the file name and call dump_stack().

sysfs_hash_and_remove() now returns an error code indicating
its success or failure so that sysfs_remove_bin_file() can
know success/failure.

Convert the only driver that checked the return value of
sysfs_remove_bin_file().
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is needed to make the compatible link for /sys/block in the future.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When no events have been reported by sysfs_notify(), sd->s_events
was previously set to zero.  The initial value for new readers is
also zero, so poll was blocking, regardless of whether the attribute
was read by the process or not.

Make poll behave consistently by setting the initial value of
sd->s_events to non-zero.
Signed-off-by: NJuha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

sysfs has a different i_mutex lock order behavior for i_mutex than the
other filesystems; sysfs i_mutex is called in many places with subsystem
locks held.  At the same time, many of the VFS locking rules do not apply
to sysfs at all (cross directory rename for example).  To untangle this
mess (which gives false positives in lockdep), we're giving sysfs inodes
their own class for i_mutex.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch converts the combination of list_del(A) and list_add(A, B) to
list_move(A, B).

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: NAkinobu Mita <mita@miraclelinux.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It works like this:
  Open the file
  Read all the contents.
  Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
  When poll returns,
     close the file and go to top of loop.
   or lseek to start of file and go back to the 'read'.

Events are signaled by an object manager calling
   sysfs_notify(kobj, dir, attr);

If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).

This has a cost of one int  per attribute, one wait_queuehead per kobject,
one int per open file.

The name "sysfs_notify" may be confused with the inotify
functionality.  Maybe it would be nice to support inotify for sysfs
attributes as well?

This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

No one should be writing a PAGE_SIZE worth of data to a normal sysfs
file, so properly terminate the buffer.

Thanks to Al Viro for pointing out my supidity here.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch updates the comments to match the actual code.
Signed-off-by: NMartin Waitz <tali@admingilde.org>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

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: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As pointed out by Oliver Neukum.

Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

These functions should only be used by the kobject core, and if any
driver tries to use them, bad things happen.  Unexport them to try to
prevent this from happening.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The following patch checks for existing sysfs_dirent before
preparing new one while creating sysfs directories and files.
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

this converts fs/sysfs to kzalloc() usage.
compile tested with make allyesconfig
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When calling sysfs_remove_dir() don't allow any further sysfs functions
to work for this kobject anymore.  This fixes a nasty USB cdc-acm oops
on disconnect.

Many thanks to Bob Copeland and Paul Fulghum for taking the time to
track this down.

Cc: Bob Copeland <email@bobcopeland.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

fs: Use <linux/capability.h> where capable() is used.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NIngo Molnar <mingo@elte.hu>

(finished the conversion)
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

I noticed that if sysfs_make_dirent fails to allocate the sd, then a
null will be passed to sysfs_put.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The problem arises if an entity in sysfs is created and removed without
ever having been made completely visible.  In SCSI this is triggered by
removing a device while it's initialising.

The problem appears to be that because it was never made visible in sysfs,
the sysfs dentry has a null d_inode which oopses when a reference is made
to it.  The solution is simply to check d_inode and assume the object was
never made visible (and thus doesn't need deleting) if it's NULL.

(akpm: possibly a stopgap for 2.6.13 scsi problems.  May not be the
long-term fix)
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>