It seems that the recent Windows changed specification, and it's
undocumented.  Windows doesn't update ->free_clusters correctly.

This patch doesn't use ->free_clusters by default.  (instead, add "usefree"
for forcing to use it)
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Juergen Beisert <juergen127@kreuzholzen.de>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

use __set_current_state(TASK_*) instead of current->state = TASK_*, in
fs/reiserfs
Signed-off-by: NMilind Arun Choudhary <milindchoudhary@gmail.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the thread failed to create the subsequent wait_event will hang forever.

This is likely to happen if kernel hits max_threads limit.

Will be critical for virtualization systems that limit the number of tasks
and kernel memory usage within the container.

(akpm: JBD should be converted fully to the kthread API: kthread_should_stop()
and kthread_stop()).

Cc: <linux-ext4@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's a missing check for CAP_SYS_ADMIN in do_change_type().
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A patch that stores inode flags such as S_IMMUTABLE, S_APPEND, etc.  from
i_flags to EXT3_I(inode)->i_flags when inode is written to disk.  The same
thing is done on GETFLAGS ioctl.

Quota code changes these flags on quota files (to make it harder for
sysadmin to screw himself) and these changes were not correctly propagated
into the filesystem (especially, lsattr did not show them and users were
wondering...).

Propagate flags such as S_APPEND, S_IMMUTABLE, etc.  from i_flags into
ext3-specific i_flags.  Hence, when someone sets these flags via a
different interface than ioctl, they are stored correctly.
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are many places in the kernel where the construction like

   foo = list_entry(head->next, struct foo_struct, list);

are used.
The code might look more descriptive and neat if using the macro

   list_first_entry(head, type, member) \
             list_entry((head)->next, type, member)

Here is the macro itself and the examples of its usage in the generic code.
 If it will turn out to be useful, I can prepare the set of patches to
inject in into arch-specific code, drivers, networking, etc.
Signed-off-by: NPavel Emelianov <xemul@openvz.org>
Signed-off-by: NKirill Korotaev <dev@openvz.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A while back, Christoph mentioned that he thought that iunique ought to be
cleaned up to use a more conventional loop construct. This patch does that,
turning the strange goto loop into a do/while.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

notify_change() already calls security_inode_setattr() before
calling iop->setattr.

Alan sayeth

  This is a behaviour change on all of these and limits some behaviour of
  existing established security modules

  When inode_change_ok is called it has side effects.  This includes
  clearing the SGID bit on attribute changes caused by chmod.  If you make
  this change the results of some rulesets may be different before or after
  the change is made.

  I'm not saying the change is wrong but it does change behaviour so that
  needs looking at closely (ditto all other attribute twiddles)
Signed-off-by: NSteve Beattie <sbeattie@suse.de>
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NJohn Johansen <jjohansen@suse.de>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

notify_change() already calls security_inode_setattr() before
calling iop->setattr.
Signed-off-by: NTony Jones <tonyj@suse.de>
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NJohn Johansen <jjohansen@suse.de>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can save some lines of code by using seq_release_private().
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge all compat ioctl handling into compat_ioctl.c instead of splitting it
over compat.c and compat_ioctl.c.  This also allows to get rid of ioctl32.h
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Looks-good-to: Andi Kleen <ak@suse.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the Motorola sysv68 disk partition (slices in motorola
doc).
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that there is no arch-specific compat ioctl handling left there is not
point in having a separate copat_ioctl.h, so merge it into compat_ioctl.c
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ROUND_UP macro cleanup use ALIGN
Signed-off-by: NMilind Arun Choudhary <milindchoudhary@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ROUND_UP macro cleanup use,ALIGN or DIV_ROUND_UP where ever appropriate.
Signed-off-by: NMilind Arun Choudhary <milindchoudhary@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  linux/module.h
  -> linux/elf.h
     -> asm-i386/elf.h
        -> linux/utsname.h
           -> linux/sched.h

Noticeably cut the number of files which are rebuild upon touching sched.h
and cut down pulled junk from every module.h inclusion.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kallsyms_lookup() can go iterating over modules list unprotected which is OK
for emergency situations (oops), but not OK for regular stuff like
/proc/*/wchan.

Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol
name into caller-supplied buffer or return -ERANGE.  All copying is done with
module_mutex held, so...
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name.  Make kallsyms_lookup() accept NULLs where possible.

Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a binary format is unregistered and re-registered, register_binfmt
fails with -EBUSY.  The reason is that unregister_binfmt does not set
fmt->next to NULL, and seeing (fmt->next != NULL), register_binfmt fails
with -EBUSY.

One can find his way around by explicitly setting fmt->next to NULL after
unregistering, but that is kind of unclean (one should better be using only
the interfaces, and not the interal members, isn't it?)

Attached one-liner can fix it.
Signed-off-by: NKalash Nainwal <kalash.nainwal@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

remove_inode_dquot_ref() can now become static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Additions and removal from tty_drivers list were just done as well as
iterating on it for /proc/tty/drivers generation.

testing: modprobe/rmmod loop of simple module which does nothing but
tty_register_driver() vs cat /proc/tty/drivers loop

BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
 printing eip:
c01cefa7
*pde = 00000000
Oops: 0000 [#1]
PREEMPT
last sysfs file: devices/pci0000:00/0000:00:1d.7/usb5/5-0:1.0/bInterfaceProtocol
Modules linked in: ohci_hcd af_packet e1000 ehci_hcd uhci_hcd usbcore xfs
CPU:    0
EIP:    0060:[<c01cefa7>]    Not tainted VLI
EFLAGS: 00010297   (2.6.21-rc4-mm1 #4)
EIP is at vsnprintf+0x3a4/0x5fc
eax: 6b6b6b6b   ebx: f6cb50f2   ecx: 6b6b6b6b   edx: fffffffe
esi: c0354700   edi: f6cb6000   ebp: 6b6b6b6b   esp: f31f5e68
ds: 007b   es: 007b   fs: 00d8  gs: 0033  ss: 0068
Process cat (pid: 31864, ti=f31f4000 task=c1998030 task.ti=f31f4000)
Stack: 00000000 c0103f20 c013003a c0103f20 00000000 f6cb50da 0000000a 00000f0e
       f6cb50f2 00000010 00000014 ffffffff ffffffff 00000007 c0354753 f6cb50f2
       f73e39dc f73e39dc 00000001 c0175416 f31f5ed8 f31f5ed4 0ee00000 f32090bc
Call Trace:
 [<c0103f20>] restore_nocheck+0x12/0x15
 [<c013003a>] mark_held_locks+0x6d/0x86
 [<c0103f20>] restore_nocheck+0x12/0x15
 [<c0175416>] seq_printf+0x2e/0x52
 [<c0192895>] show_tty_range+0x35/0x1f3
 [<c0175416>] seq_printf+0x2e/0x52
 [<c0192add>] show_tty_driver+0x8a/0x1d9
 [<c01758f6>] seq_read+0x70/0x2ba
 [<c0175886>] seq_read+0x0/0x2ba
 [<c018d8e6>] proc_reg_read+0x63/0x9f
 [<c015e764>] vfs_read+0x7d/0xb5
 [<c018d883>] proc_reg_read+0x0/0x9f
 [<c015eab1>] sys_read+0x41/0x6a
 [<c0103e4e>] sysenter_past_esp+0x5f/0x99
 =======================
Code: 00 8b 4d 04 e9 44 ff ff ff 8d 4d 04 89 4c 24 50 8b 6d 00 81 fd ff 0f 00 00 b8 a4 c1 35 c0 0f 46 e8 8b 54 24 2c 89 e9 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 89 c6 8b 44 24 28 89
EIP: [<c01cefa7>] vsnprintf+0x3a4/0x5fc SS:ESP 0068:f31f5e68
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove do_sync_file_range() and convert callers to just use
do_sync_mapping_range().
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

REISER_FS /proc option needs to depend on PROC_FS.

fs/reiserfs/procfs.c: In function 'show_super':
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'max_hash_collisions'
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'breads'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'bread_miss'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_fs_changed'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'insert_item_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'paste_into_item_restarted'
fs/reiserfs/procfs.c:138: error: 'reiserfs_proc_info_data_t' has no member named 'cut_from_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_solid_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_item_restarted'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaked_oid'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaves_removable'
fs/reiserfs/procfs.c: In function 'show_per_level':
fs/reiserfs/procfs.c:184: error: 'reiserfs_proc_info_data_t' has no member named 'balance_at'
fs/reiserfs/procfs.c:185: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_read_at'
fs/reiserfs/procfs.c:186: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_fs_changed'
fs/reiserfs/procfs.c:187: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_restarted'
fs/reiserfs/procfs.c:188: error: 'reiserfs_proc_info_data_t' has no member named 'free_at'
fs/reiserfs/procfs.c:189: error: 'reiserfs_proc_info_data_t' has no member named 'items_at'
fs/reiserfs/procfs.c:190: error: 'reiserfs_proc_info_data_t' has no member named 'can_node_be_removed'
fs/reiserfs/procfs.c:191: error: 'reiserfs_proc_info_data_t' has no member named 'lnum'
fs/reiserfs/procfs.c:192: error: 'reiserfs_proc_info_data_t' has no member named 'rnum'
fs/reiserfs/procfs.c:193: error: 'reiserfs_proc_info_data_t' has no member named 'lbytes'
fs/reiserfs/procfs.c:194: error: 'reiserfs_proc_info_data_t' has no member named 'rbytes'
fs/reiserfs/procfs.c:195: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors'
fs/reiserfs/procfs.c:196: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors_restart'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_l_neighbor'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_r_neighbor'
fs/reiserfs/procfs.c: In function 'show_bitmap':
fs/reiserfs/procfs.c:224: error: 'reiserfs_proc_info_data_t' has no member named 'free_block'
fs/reiserfs/procfs.c:225: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:226: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:227: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:228: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:229: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c: In function 'show_journal':
fs/reiserfs/procfs.c:384: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:385: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:386: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:387: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:388: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:389: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:390: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:391: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:392: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:393: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:394: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_init':
fs/reiserfs/procfs.c:504: warning: implicit declaration of function '__PINFO'
fs/reiserfs/procfs.c:504: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_done':
fs/reiserfs/procfs.c:544: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c:545: error: request for member 'exiting' in something not a structure or union
fs/reiserfs/procfs.c:546: error: request for member 'lock' in something not a structure or union
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Eternal quest to make

	while true; do cat /proc/fs/xfs/stat >/dev/null 2>/dev/null; done
	while true; do find /proc -type f 2>/dev/null | xargs cat >/dev/null 2>/dev/null; done
	while true; do modprobe xfs; rmmod xfs; done

work reliably continues and now kernel oopses in the following way:

BUG: unable to handle ... at virtual address 6b6b6b6b
EIP is at badness
process: cat
	proc_oom_score
	proc_info_read
	sys_fstat64
	vfs_read
	proc_info_read
	sys_read

Failing code is prefetch hidden in list_for_each_entry() in badness().
badness() is reachable from two points. One is proc_oom_score, another
is out_of_memory() => select_bad_process() => badness().

Second path grabs tasklist_lock, while first doesn't.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1) Introduces a new method in 'struct dentry_operations'.  This method
   called d_dname() might be called from d_path() to build a pathname for
   special filesystems.  It is called without locks.

   Future patches (if we succeed in having one common dentry for all
   pipes/sockets) may need to change prototype of this method, but we now
   use : char *d_dname(struct dentry *dentry, char *buffer, int buflen);

2) Adds a dynamic_dname() helper function that eases d_dname() implementations

3) Defines d_dname method for sockets : No more sprintf() at socket
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

4) Defines d_dname method for pipes : No more sprintf() at pipe
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a
*nice* speedup on my Pentium(M) 1.6 Ghz :

3.090 s instead of 3.450 s
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for finding out the current file position, open flags and
possibly other info in the future.

These new entries are added:

  /proc/PID/fdinfo/FD
  /proc/PID/task/TID/fdinfo/FD

For each fd the information is provided in the following format:

pos:	1234
flags:	0100002

[bunk@stusta.de: make struct proc_fdinfo_file_operations static]
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change the order of fields of struct pid_entry (file fs/proc/base.c) in order
to avoid a hole on 64bit archs.  (8 bytes saved per object)

Also change all pid_entry arrays to be const qualified, to make clear they
must not be modified.

Before (on x86_64) :

# size fs/proc/base.o
   text    data     bss     dec     hex filename
  15549    2192       0   17741    454d fs/proc/base.o

After :

# size fs/proc/base.o
   text    data     bss     dec     hex filename
  17229     176       0   17405    43fd fs/proc/base.o

Thats 336 bytes saved on kernel size on x86_64
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive
information about the memory location and usage of processes.  Issues:

- maps should not be world-readable, especially if programs expect any
  kind of ASLR protection from local attackers.
- maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc
  check the maps when %n is in a *printf call, and a setuid(getuid())
  process wouldn't be able to read its own maps file.  (For reference
  see http://lkml.org/lkml/2006/1/22/150)
- a system-wide toggle is needed to allow prior behavior in the case of
  non-root applications that depend on access to the maps contents.

This change implements a check using "ptrace_may_attach" before allowing
access to read the maps contents.  To control this protection, the new knob
/proc/sys/kernel/maps_protect has been added, with corresponding updates to
the procfs documentation.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: New sysctl numbers are old hat]
Signed-off-by: NKees Cook <kees@outflux.net>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't have a routine called namei() anymore since at least 2.3.x, and
the comment is just totally out of sync with the current lookup logic.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

inode->i_sb is always set, not need to check for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

WARN_ON(de && de->deleted); is sooo unreliable. Why?

proc_lookup				remove_proc_entry
===========				=================
lock_kernel();
spin_lock(&proc_subdir_lock);
[find proc entry]
spin_unlock(&proc_subdir_lock);
					spin_lock(&proc_subdir_lock);
					[find proc entry]

proc_get_inode
==============
WARN_ON(de && de->deleted);			...

					if (!atomic_read(&de->count))
						free_proc_entry(de);
					else
						de->deleted = 1;

So, if you have some strange oops [1], and doesn't see this WARN_ON it means
nothing.

[1] try_module_get() of module which doesn't exist, two lines below
    should suffice, or not?
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following race:

proc_readdir				remove_proc_entry
============				=================

spin_lock(&proc_subdir_lock);
[choose PDE to start filldir from]
spin_unlock(&proc_subdir_lock);
					spin_lock(&proc_subdir_lock);
					[find PDE]
					[free PDE, refcount is 0]
					spin_unlock(&proc_subdir_lock);
		    /* boom */
if (filldir(dirent, de->name, ...

[de_put on error path --adobriyan]
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

proc_lookup				remove_proc_entry
===========				=================

lock_kernel();
spin_lock(&proc_subdir_lock);
[find PDE with refcount 0]
spin_unlock(&proc_subdir_lock);
					spin_lock(&proc_subdir_lock);
					[find PDE with refcount 0]
					[check refcount and free PDE]
					spin_unlock(&proc_subdir_lock);
proc_get_inode:
	de_get(de); /* boom */
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's a slight problem with filesystem type representation in fuse
based filesystems.

From the kernel's view, there are just two filesystem types: fuse and
fuseblk.  From the user's view there are lots of different filesystem
types.  The user is not even much concerned if the filesystem is fuse based
or not.  So there's a conflict of interest in how this should be
represented in fstab, mtab and /proc/mounts.

The current scheme is to encode the real filesystem type in the mount
source.  So an sshfs mount looks like this:

  sshfs#user@server:/   /mnt/server    fuse   rw,nosuid,nodev,...

This url-ish syntax works OK for sshfs and similar filesystems.  However
for block device based filesystems (ntfs-3g, zfs) it doesn't work, since
the kernel expects the mount source to be a real device name.

A possibly better scheme would be to encode the real type in the type
field as "type.subtype".  So fuse mounts would look like this:

  /dev/hda1       /mnt/windows   fuseblk.ntfs-3g   rw,...
  user@server:/   /mnt/server    fuse.sshfs        rw,nosuid,nodev,...

This patch adds the necessary code to the kernel so that this can be
correctly displayed in /proc/mounts.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Epoll is doing multiple passes over the ready set at the moment, because of
the constraints over the f_op->poll() call.  Looking at the code again, I
noticed that we already hold the epoll semaphore in read, and this
(together with other locking conditions that hold while doing an
epoll_wait()) can lead to a smarter way [1] to "ship" events to userspace
(in a single pass).

This is a stress application that can be used to test the new code.  It
spwans multiple thread and call epoll_wait() and epoll_ctl() from many
threads.  Stress tested on my dual Opteron 254 w/out any problems.

http://www.xmailserver.org/totalmess.c

This is not a benchmark, just something that tries to stress and exploit
possible problems with the new code.
Also, I made a stupid micro-benchmark:

http://www.xmailserver.org/epwbench.c

[1] Considering that epoll must be thread-safe, there are five ways we can
    be hit during an epoll_wait() transfer loop (ep_send_events()):

    1) The epoll fd going away and calling ep_free
       This just can't happen, since we did an fget() in sys_epoll_wait

    2) An epoll_ctl(EPOLL_CTL_DEL)
       This can't happen because epoll_ctl() gets ep->sem in write, and
       we're holding it in read during ep_send_events()

    3) An fd stored inside the epoll fd going away
       This can't happen because in eventpoll_release_file() we get
       ep->sem in write, and we're holding it in read during
       ep_send_events()

    4) Another epoll_wait() happening on another thread
       They both can be inside ep_send_events() at the same time, we get
       (splice) the ready-list under the spinlock, so each one will get
       its own ready list. Note that an fd cannot be at the same time
       inside more than one ready list, because ep_poll_callback() will
       not re-queue it if it sees it already linked:

       if (ep_is_linked(&epi->rdllink))
                goto is_linked;

       Another case that can happen, is two concurrent epoll_wait(),
       coming in with a userspace event buffer of size, say, ten.
       Suppose there are 50 event ready in the list. The first
       epoll_wait() will "steal" the whole list, while the second, seeing
       no events, will go to sleep. But at the end of ep_send_events() in
       the first epoll_wait(), we will re-inject surplus ready fds, and we
       will trigger the proper wake_up to the second epoll_wait().

    5) ep_poll_callback() hitting us asyncronously
       This is the tricky part. As I said above, the ep_is_linked() test
       done inside ep_poll_callback(), will guarantee us that until the
       item will result linked to a list, ep_poll_callback() will not try
       to re-queue it again (read, write data on any of its members). When
       we do a list_del() in ep_send_events(), the item will still satisfy
       the ep_is_linked() test (whatever data is written in prev/next,
       it'll never be its own pointer), so ep_poll_callback() will still
       leave us alone. It's only after the eventual smp_mb()+INIT_LIST_HEAD(&epi->rdllink)
       that it'll become visible to ep_poll_callback(), but at the point
       we're already past it.

[akpm@osdl.org: 80 cols]
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- ext3_dx_find_entry() exit with out setting proper error pointer

- do_split() exit with out setting proper error pointer
  it is realy painful because many callers contain folowing code:

          de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
          if (!(de))
                       return retval;
          <<< WOW retval wasn't changed by do_split(), so caller failed
          <<< but return SUCCESS :)

- Rearrange do_split() error path. Current error path is realy ugly, all
  this up and down jump stuff doesn't make code easy to understand.

[dmonakhov@sw.ru: fix annoying fake error messages]
Signed-off-by: NMonakhov Dmitriy <dmonakhov@openvz.org>
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NMonakhov Dmitriy <dmonakhov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sys_clone() and sys_unshare() both makes copies of nsproxy and its associated
namespaces.  But they have different code paths.

This patch merges all the nsproxy and its associated namespace copy/clone
handling (as much as possible).  Posted on container list earlier for
feedback.

- Create a new nsproxy and its associated namespaces and pass it back to
  caller to attach it to right process.

- Changed all copy_*_ns() routines to return a new copy of namespace
  instead of attaching it to task->nsproxy.

- Moved the CAP_SYS_ADMIN checks out of copy_*_ns() routines.

- Removed unnessary !ns checks from copy_*_ns() and added BUG_ON()
  just incase.

- Get rid of all individual unshare_*_ns() routines and make use of
  copy_*_ns() instead.

[akpm@osdl.org: cleanups, warning fix]
[clg@fr.ibm.com: remove dup_namespaces() declaration]
[serue@us.ibm.com: fix CONFIG_IPC_NS=n, clone(CLONE_NEWIPC) retval]
[akpm@linux-foundation.org: fix build with CONFIG_SYSVIPC=n]
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <containers@lists.osdl.org>
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Petr Tesarik discovered a problem in remove_arg_zero(). He writes:

 When a script is loaded, load_script() replaces argv[0] with the
 name of the interpreter and the filename passed to the exec syscall.
 However, there is no guarantee that the length of the interpreter
 name plus the length of the filename is greater than the length of
 the original argv[0]. If the difference happens to cross a page boundary,
 setup_arg_pages() will call put_dirty_page() [aka install_arg_page()]
 with an address outside the VMA.

 Therefore, remove_arg_zero() must free all pages which would be unused
 after the argument is removed.

So, rewrite the remove_arg_zero function without gotos, with a few comments,
and with the commonly used explicit index/offset. This fixes the problem
and makes it easier to understand as well.

[a.p.zijlstra@chello.nl: add comment]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>