Nothing outside of fs/sysfs/file.c references this function, so mark it static.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The warning check for duplicate sysfs entries can cause a buffer overflow
when printing the warning, as strcat() doesn't check buffer sizes.
Use strlcat() instead.

Since strlcat() doesn't return a pointer to the passed buffer, unlike
strcat(), I had to convert the nested concatenation in sysfs_add_one() to
an admittedly more obscure comma operator construct, to avoid emitting code
for the concatenation if CONFIG_BUG is disabled.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

More pedantry.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

don't assume that KOBJ_NS_TYPE_NONE==0.  Also save a test-n-branch.

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NSerge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When we change the namespace tag of a sysfs entry, the associated dentry
is still kept around. readdir() will work correctly and not display the
old entries, but open() will still succeed, so will reads and writes.

This will no longer happen if sysfs is remounted, hinting that this is a
cache-related problem.

I am using the following sequence to demonstrate that:

shell1:
ip link add type veth
unshare -nm

shell2:
ip link set veth1 <pid_of_shell_1>
cat /sys/devices/virtual/net/veth1/ifindex

Before that patch, this will succeed (fail to fail). After it, it will
correctly return an error. Differently from a normal rename, which we
handle fine, changing the object namespace will keep it's path intact.
So this check seems necessary as well.

[ v2: get type from parent, as suggested by Eric Biederman ]
Signed-off-by: NGlauber Costa <glommer@parallels.com>
CC: Tejun Heo <tj@kernel.org>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

same as for nfs et.al.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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: NAl Viro <viro@zeniv.linux.org.uk>

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Just the lookup flags.  Die, bastard, die...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

This patch (as1554) fixes a lockdep false-positive report.  The
problem arises because lockdep is unable to deal with the
tree-structured locks created by the device core and sysfs.

This particular problem involves a sysfs attribute method that
unregisters itself, not from the device it was called for, but from a
descendant device.  Lockdep doesn't understand the distinction and
reports a possible deadlock, even though the operation is safe.

This is the sort of thing that would normally be handled by using a
nested lock annotation; unfortunately it's not feasible to do that
here.  There's no sensible way to tell sysfs when attribute removal
occurs in the context of a parent attribute method.

As a workaround, the patch adds a new flag to struct attribute
telling sysfs not to inform lockdep when it acquires a readlock on a
sysfs_dirent instance for the attribute.  The readlock is still
acquired, but lockdep doesn't know about it and hence does not
complain about impossible deadlock scenarios.

Also added are macros for static initialization of attribute
structures with the ignore_lockdep flag set.  The three offending
attributes in the USB subsystem are converted to use the new macros.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NTejun Heo <tj@kernel.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>

Since no one using "dup_name", removed it completely in sysfs_rename.
Signed-off-by: NSasikantha babu <sasikanth.v19@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In scsi at least two cases of the parent device being deleted before the
child is added have been observed.

1/ scsi is performing async scans and the device is removed prior to the
   async can thread running (can happen with an in-opportune / unlikely
   unplug during initial scan).

2/ libsas discovery event running after the parent port has been torn
   down (this is a bug in libsas).

Result in crash signatures like:
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
 IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6
 ...
 Process scsi_scan_8 (pid: 5417, threadinfo ffff88080bd16000, task ffff880801b8a0b0)
 Stack:
  00000000fffffffe ffff880813470628 ffff88080bd17cd0 ffff88080614b7e8
  ffff88080b45c108 00000000fffffffe ffff88080bd17d20 ffffffff8125e4a8
  ffff88080bd17cf0 ffffffff81075149 ffff88080bd17d30 ffff88080614b7e8
 Call Trace:
  [<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3
  [<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf
  [<ffffffff8125e641>] kobject_add_varg+0x41/0x50
  [<ffffffff8125e70b>] kobject_add+0x64/0x66
  [<ffffffff8131122b>] device_add+0x12d/0x63a

In this scenario the parent is still valid (because we have a
reference), but it has been device_del()'d which means its kobj->sd
pointer is NULL'd via:

 device_del()->kobject_del()->sysfs_remove_dir()

...and then sysfs_create_dir() (without this fix) goes ahead and
de-references parent_sd via sysfs_ns_type():

 return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;

This scenario is being fixed in scsi/libsas, but if other subsystems
present the same ordering the system need not immediately crash.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Do not let the kernel crash when a device is registered with
sysfs while group attributes are not set (aka NULL).

Warn about the offender with some information about the offending
device.

This would warn instead of trying NULL pointer deref like:
 BUG: unable to handle kernel NULL pointer dereference at (null)
 IP: [<ffffffff81152673>] internal_create_group+0x83/0x1a0
 PGD 0
 Oops: 0000 [#1] SMP
 CPU 0
 Modules linked in:

 Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc1-x86_64 #3 HP ProLiant DL360 G4
 RIP: 0010:[<ffffffff81152673>]  [<ffffffff81152673>] internal_create_group+0x83/0x1a0
 RSP: 0018:ffff88019485fd70  EFLAGS: 00010202
 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001
 RDX: ffff880192e99908 RSI: ffff880192e99630 RDI: ffffffff81a26c60
 RBP: ffff88019485fdc0 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff880192e99908 R11: 0000000000000000 R12: ffffffff81a16a00
 R13: ffff880192e99908 R14: ffffffff81a16900 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88019bc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 0000000001a0c000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process swapper/0 (pid: 1, threadinfo ffff88019485e000, task ffff880194878000)
 Stack:
  ffff88019485fdd0 ffff880192da9d60 0000000000000000 ffff880192e99908
  ffff880192e995d8 0000000000000001 ffffffff81a16a00 ffff880192da9d60
  0000000000000000 0000000000000000 ffff88019485fdd0 ffffffff811527be
 Call Trace:
  [<ffffffff811527be>] sysfs_create_group+0xe/0x10
  [<ffffffff81376ca6>] device_add_groups+0x46/0x80
  [<ffffffff81377d3d>] device_add+0x46d/0x6a0
  ...
Signed-off-by: NBruno Prémont <bonbons@linux-vserver.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is needed to allow renaming network devices that have been moved
to another network namespace.
Signed-off-by: NTom Goff <thomas.goff@boeing.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This reverts commit 524b6c5b.

It has shown to break userspace tools, which is not acceptable.
Reported-by: NJiri Slaby <jslaby@suse.cz>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixies follwing two memory leak patterns that reported by kmemleak.
sysfs_sd_setsecdata() is called during sys_lsetxattr() operation.
It checks sd->s_iattr is NULL or not. Then if it is NULL, it calls
sysfs_init_inode_attrs() to allocate memory.
That code is this.

iattrs = sd->s_iattr;
if (!iattrs)
                iattrs = sysfs_init_inode_attrs(sd);

The iattrs recieves sysfs_init_inode_attrs()'s result,  but sd->s_iattr
doesn't know the address. so it needs to set correct address to
sd->s_iattr to free memory in other function.

unreferenced object 0xffff880250b73e60 (size 32):
  comm "systemd", pid 1, jiffies 4294683888 (age 94.553s)
  hex dump (first 32 bytes):
    73 79 73 74 65 6d 5f 75 3a 6f 62 6a 65 63 74 5f  system_u:object_
    72 3a 73 79 73 66 73 5f 74 3a 73 30 00 00 00 00  r:sysfs_t:s0....
  backtrace:
    [<ffffffff814cb1d0>] kmemleak_alloc+0x73/0x98
    [<ffffffff811270ab>] __kmalloc+0x100/0x12c
    [<ffffffff8120775a>] context_struct_to_string+0x106/0x210
    [<ffffffff81207cc1>] security_sid_to_context_core+0x10b/0x129
    [<ffffffff812090ef>] security_sid_to_context+0x10/0x12
    [<ffffffff811fb0da>] selinux_inode_getsecurity+0x7d/0xa8
    [<ffffffff811fb127>] selinux_inode_getsecctx+0x22/0x2e
    [<ffffffff811f4d62>] security_inode_getsecctx+0x16/0x18
    [<ffffffff81191dad>] sysfs_setxattr+0x96/0x117
    [<ffffffff811542f0>] __vfs_setxattr_noperm+0x73/0xd9
    [<ffffffff811543d9>] vfs_setxattr+0x83/0xa1
    [<ffffffff811544c6>] setxattr+0xcf/0x101
    [<ffffffff81154745>] sys_lsetxattr+0x6a/0x8f
    [<ffffffff814efda9>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff88024163c5a0 (size 96):
  comm "systemd", pid 1, jiffies 4294683888 (age 94.553s)
  hex dump (first 32 bytes):
    00 00 00 00 ed 41 00 00 00 00 00 00 00 00 00 00  .....A..........
    00 00 00 00 00 00 00 00 0c 64 42 4f 00 00 00 00  .........dBO....
  backtrace:
    [<ffffffff814cb1d0>] kmemleak_alloc+0x73/0x98
    [<ffffffff81127402>] kmem_cache_alloc_trace+0xc4/0xee
    [<ffffffff81191cbe>] sysfs_init_inode_attrs+0x2a/0x83
    [<ffffffff81191dd6>] sysfs_setxattr+0xbf/0x117
    [<ffffffff811542f0>] __vfs_setxattr_noperm+0x73/0xd9
    [<ffffffff811543d9>] vfs_setxattr+0x83/0xa1
    [<ffffffff811544c6>] setxattr+0xcf/0x101
    [<ffffffff81154745>] sys_lsetxattr+0x6a/0x8f
    [<ffffffff814efda9>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff
`
Signed-off-by: NMasami Ichikawa <masami256@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This fixes a bug introduced with sysfs name hashes where renaming a
network device appears to succeed but silently makes the sysfs files for
that network device inaccessible.

In at least one configuration this bug has stopped networking from
coming up during boot.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Tested-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There is a misleading difference between /proc and /sys permissions, /proc is 0555 and /sys is 0755. But
as it is impossible to create or unlink something in /sys it would be nice to have same permissions.
Signed-off-by: NVitaly Kuznetsov <vitty@altlinux.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NGreg 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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On 32bit this reduces sizeof(struct sysfs_dirent) by 2 bytes.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NGreg 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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Recently an OOPS was observed from the usb serial io_ti driver when it tried to remove
sysfs directories.  Upon investigation it turns out this driver was always buggy
and that a recent sysfs change had stopped guarding itself against removing attributes
from sysfs directories that had already been removed. :(

Historically we have been silent about attempting to files from nonexistent sysfs
directories and have politely returned error codes.  That has resulted in people writing
broken code that ignores the error codes.

Issue a kernel WARNING and a stack backtrace to make it clear in no uncertain
terms that abusing sysfs is not ok, and the callers need to fix their code.

This change transforms the io_ti OOPS into a more comprehensible error message
and stack backtrace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Reported-by: NWolfgang Frisch <wfpub@roembden.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Tested-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

In sysfs_rename we need to remove the optimization of not calling
sysfs_unlink_sibling and sysfs_link_sibling if the renamed parent
directory is not changing.  This optimization is no longer valid now
that sysfs dirents are stored in an rbtree sorted by name.

Move the assignment of s_ns before the call of sysfs_link_sibling.  With
no sysfs_dirent fields changing after the call of sysfs_link_sibling
this allows sysfs_link_sibling to take any of the directory entries into
account when it builds the rbtrees, and s_ns looks like a prime canidate
to be used in the rbtree in the future.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Greg KH <gregkh@suse.de>
Cc: David Miller <davem@davemloft.net>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 8a9ea323 ("Merge git://.../davem/net-next") where my sysfs
changes from the net tree merged with the sysfs rbtree changes from
Mickulas Patocka the conflict resolution failed to preserve the
simplified property that was the point of my changes.

That is sysfs_find_dirent can now say something is a match if and only
s_name and s_ns match what we are looking for, and sysfs_readdir can
simply return all of the directory entries where s_ns matches the
directory that we should be returning.

Now that we are back to exact matches we can tweak sysfs_find_dirent and
the name rb_tree to order sysfs_dirents by s_ns s_name and remove the
second loop in sysfs_find_dirent.  However that change seems a bit much
for a conflict resolution so it can come later.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sysfs is a core piece of ifrastructure that many people use and
few people have all of the rules in their head on how to use
it correctly.  Add warnings for people using tagged directories
improperly to that any misuses can be caught and diagnosed quickly.

A single inexpensive test in sysfs_find_dirent is almost sufficient
to catch all possible misuses.  An additional warning is needed
in sysfs_add_dirent so that we actually fail when attempting to
add an untagged dirent in a tagged directory.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that /sys/class/net/bonding_masters is implemented as a tagged sysfs
file we can remove support for untagged files in tagged directories.

This change removes any ambiguity of what a NULL namespace value
means.  A NULL namespace parameter after this patch means
that we are talking about an untagged sysfs dirent.

This makes the sysfs code much less prone to mistakes when during
maintenance.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Looking up files in sysfs is hard to understand and analyize because we
currently allow placing untagged files in tagged directories.  In the
implementation of that we have two subtly different meanings of NULL.
NULL meaning there is no tag on a directory entry and NULL meaning
we don't care which namespace the lookup is performed for.  This
multiple uses of NULL have resulted in subtle bugs (since fixed)
in the code.

Currently it is only the bonding driver that needs to have an untagged
file in a tagged directory.

To untagle this mess I am adding support for tagged files to sysfs.
Modifying the bonding driver to implement bonding_masters as a tagged
file.  Registering bonding_masters once for each network namespace.
Then I am removing support for untagged entries in tagged sysfs
directories.

Resulting in code that is much easier to reason about.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"sysfs: use rb-tree for inode number lookup" added a new printk which
causes a new compile warning on s390 (and few other architectures):

fs/sysfs/dir.c: In function 'sysfs_link_sibling':
fs/sysfs/dir.c:63:4: warning: format '%lx' expects argument of type
  'long unsigned int', but argument 2 has type 'ino_t' [-Wform

Add an explicit unsigned long cast since ino_t is an unsigned long on
most architectures.

Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

sysfs: use rb-tree for inode number lookup

This patch makes sysfs use red-black tree for inode number lookup.
Together with a previous patch to use red-black tree for name lookup,
this patch makes all sysfs lookups to have O(log n) complexity.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

sysfs: remove s_sibling hacks

s_sibling was used for three different purposes:
1) as a linked list of entries in the directory
2) as a linked list of entries to be deleted
3) as a pointer to "struct completion"

This patch removes the hack and introduces new union u which
holds pointers for cases 2) and 3).

This change is needed for the following patch that removes s_sibling at all
and replaces it with a rb tree.
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>