a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Let's show locks which are associated with a file descriptor in
its fdinfo file.

Currently we don't have a reliable way to determine who holds a lock.  We
can find some information in /proc/locks, but PID which is reported there
can be wrong.  For example, a process takes a lock, then forks a child and
dies.  In this case /proc/locks contains the parent pid, which can be
reused by another process.

$ cat /proc/locks
...
6: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF
...

$ ps -C rpcbind
  PID TTY          TIME CMD
  332 ?        00:00:00 rpcbind

$ cat /proc/332/fdinfo/4
pos:	0
flags:	0100000
mnt_id:	22
lock:	1: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF

$ ls -l /proc/332/fd/4
lr-x------ 1 root root 64 Mar  5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock

$ ls -l /proc/324/fd/
total 0
lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0

You can see that the process with the 324 pid doesn't hold the lock.

This information is required for proper dumping and restoring file
locks.
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Layton <jlayton@poochiereds.net>
Acked-by: N"J. Bruce Fields" <bfields@fieldses.org>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

docs: add missing and new /proc/PID/status file entries, fix typos
Signed-off-by: NNathan Scott <nathans@redhat.com>
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>
Cc: Serge Hallyn <serge.hallyn@canonical.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>

This will allow FS that uses VM_PFNMAP | VM_MIXEDMAP (no page structs) to
get notified when access is a write to a read-only PFN.

This can happen if we mmap() a file then first mmap-read from it to
page-in a read-only PFN, than we mmap-write to the same page.

We need this functionality to fix a DAX bug, where in the scenario above
we fail to set ctime/mtime though we modified the file.  An xfstest is
attached to this patchset that shows the failure and the fix.  (A DAX
patch will follow)

This functionality is extra important for us, because upon dirtying of a
pmem page we also want to RDMA the page to a remote cluster node.

We define a new pfn_mkwrite and do not reuse page_mkwrite because
  1 - The name ;-)
  2 - But mainly because it would take a very long and tedious
      audit of all page_mkwrite functions of VM_MIXEDMAP/VM_PFNMAP
      users. To make sure they do not now CRASH. For example current
      DAX code (which this is for) would crash.
      If we would want to reuse page_mkwrite, We will need to first
      patch all users, so to not-crash-on-no-page. Then enable this
      patch. But even if I did that I would not sleep so well at night.
      Adding a new vector is the safest thing to do, and is not that
      expensive. an extra pointer at a static function vector per driver.
      Also the new vector is better for performance, because else we
      Will call all current Kernel vectors, so to:
        check-ha-no-page-do-nothing and return.

No need to call it from do_shared_fault because do_wp_page is called to
change pte permissions anyway.
Signed-off-by: NYigal Korman <yigal@plexistor.com>
Signed-off-by: NBoaz Harrosh <boaz@plexistor.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ifconfig command has been deprecated for many years.
To encourage new users not to continue using it and learning
iproute2; the ifconfig should not be used in examples.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Now that no one is using rw, remove it completely.
Signed-off-by: NOmar Sandoval <osandov@osandov.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no remaining users
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Enable inline_data feature by default since it brings us better
performance and space utilization and now has already stable.
Add another option noinline_data to disable it during mount.
Suggested-by: NJaegeuk Kim <jaegeuk@kernel.org>
Suggested-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Commit ce0e7b28 ("sched, cpuacct: Fix niced guest time
accounting") added the guest_nice column to /proc/stat, but the example
output of `cat /proc/stat' in Documentation/filesystems/proc.txt wasn't
updated accordingly. Do so now.

Cc: Ryota Ozaki <ozaki.ryota@gmail.com>
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This patch adds a mount option 'extent_cache' in f2fs.

It is try to use a rb-tree based extent cache to cache more mapping information
with less memory if this option is set, otherwise we will use the original one
extent info cache.
Suggested-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We (the Ocfs2 project) recently moved the location of our ocfs2-tools
git tree and project web page.  The pertinent discussion can be seen
here:

  https://oss.oracle.com/pipermail/ocfs2-devel/2015-February/010579.html

The following patch updates the Ocfs2 documentation in MAINTAINERS,
ocfs2.txt, and dlmfs.txt.  I added our new official web page, changed
the location of our tools git tree and removed the link to Joel's
ancient kernel git tree - Andrew has handled our patches for a while
now.
Signed-off-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We recently removed deprecated sysctls; may as well
remove deprecated mount options as well, we've stated
that they'd be gone by now in the docs.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

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

The DAX code accesses the underlying storage through the kernel's linear
mapping, which may not be cache-coherent with user mappings on ARM, MIPS
or SPARC.  Temporarily disable the DAX code until this problem is
resolved.

The original XIP code also had this problem, but it was never noticed.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a port of the DAX functionality found in the current version of
ext2.

[matthew.r.wilcox@intel.com: heavily tweaked]
[akpm@linux-foundation.org: remap_pages went away]
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NAndreas Dilger <andreas.dilger@intel.com>
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This new function allows us to support hole-punch for DAX files by zeroing
a partial page, as opposed to the dax_truncate_page() function which can
only truncate to the end of the page.  Reimplement dax_truncate_page() to
call dax_zero_page_range().

[ross.zwisler@linux.intel.com: ported to 3.13-rc2]
[akpm@linux-foundation.org: fix typos in comments]
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To help people transition, accept the 'xip' mount option (and report it in
/proc/mounts), but print a message encouraging people to switch over to
the 'dax' option.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All callers of get_xip_mem() are now gone.  Remove checks for it,
initialisers of it, documentation of it and the only implementation of it.
 Also remove mm/filemap_xip.c as it is now empty.  Also remove
documentation of the long-gone get_xip_page().
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Based on the original XIP documentation, this documents the current state
of affairs, and includes instructions on how users can enable DAX if their
devices and kernel support it.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The output of /proc/$pid/numa_maps is in terms of number of pages like
anon=22 or dirty=54.  Here's some output:

  7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50
  7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50
  7fff8d425000 default stack anon=50 dirty=50 N0=50

Looks like we have a stack and a couple of anonymous hugetlbfs
areas page which both use the same amount of memory.  They don't.

The 'bigfile' uses 1GB pages and takes up ~50GB of space.  The
anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack
uses normal 4k pages.  You can go over to smaps to figure out what the
page size _really_ is with KernelPageSize or MMUPageSize.  But, I think
this is a pretty nasty and counterintuitive interface as it stands.

This patch introduces 'kernelpagesize_kB' line element to
/proc/<pid>/numa_maps report file in order to help identifying the size of
pages that are backing memory areas mapped by a given task.  This is
specially useful to help differentiating between HUGE and GIGANTIC page
backed VMAs.

This patch is based on Dave Hansen's proposal and reviewer's follow-ups
taken from the following dicussion threads:
 * https://lkml.org/lkml/2011/9/21/454
 * https://lkml.org/lkml/2014/12/20/66Signed-off-by: NRafael Aquini <aquini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a small section to proc.txt doc in order to document its
/proc/pid/numa_maps interface.  It does not introduce any functional
changes, just documentation.
Signed-off-by: NRafael Aquini <aquini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Peak resident size of a process can be reset back to the process's
current rss value by writing "5" to /proc/pid/clear_refs.  The driving
use-case for this would be getting the peak RSS value, which can be
retrieved from the VmHWM field in /proc/pid/status, per benchmark
iteration or test scenario.

[akpm@linux-foundation.org: clarify behaviour in documentation]
Signed-off-by: NPetr Cermak <petrcermak@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Primiano Tucci <primiano@chromium.org>
Cc: Petr Cermak <petrcermak@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

[akpm@linux-foundation.org: tweaks]
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch introduces a batched trimming feature, which submits split discard
commands.

This is to avoid long latency due to huge trim commands.
If fstrim was triggered ranging from 0 to the end of device, we should lock
all the checkpoint-related mutexes, resulting in very long latency.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a mount option, norecovery, which is mostly same as
disable_roll_forward. The only difference is that norecovery should be activated
with read-only mount option.

This can be used when user wants to check whether f2fs is mountable or not
without any recovery process. (e.g., xfstests/200)
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

__generic_block_fiemap may spin very long time for large sparse files.

Without this patch an unprivileged user may abuse system resources simply
by spawning a vast number of unkilable busyloops (works on ext2/ext3):

  truncate --size 1T test
  for ((i=0;i<1024;i++))
  do
         filefrag test > /dev/null &
  done
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a mount option to support JBD2 feature:

JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT.  When this feature is opened, journal
commit block can be written to disk without waiting for descriptor blocks,
which can improve journal commit performance.  This option will enable
'journal_checksum' internally.

Using the fs_mark benchmark, using journal_async_commit shows a 50%
improvement, the files per second go up from 215.2 to 317.5.

test script:
fs_mark  -d  /mnt/ocfs2/  -s  10240  -n  1000

default:
FSUse%        Count         Size    Files/sec     App Overhead
     0         1000        10240        215.2            17878

with journal_async_commit option:
FSUse%        Count         Size    Files/sec     App Overhead
     0         1000        10240        317.5            17881
Signed-off-by: NAlex Chen <alex.chen@huawei.com>
Signed-off-by: NWeiwei Wang <wangww631@huawei.comm>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The inotify interface has changed a lot.  The user interface was too
old, and the kernel interface was removed by Eric Paris in commit:
2dfc1cae inotify: remove inotify in kernel interface.
Signed-off-by: NZhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Wang Kai <morgan.wang@huawei.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Robert Love <robert.w.love@intel.com>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.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>

This bit of the docs didn't quite reflect reality.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Add a small shim between core nfsd and filesystems to translate the
somewhat cumbersome pNFS data structures and semantics to something
more palatable for Linux filesystems.

Thanks to Rick McNeal for the old prototype pNFS blocklayout server
code, which gave a lot of inspiration to this version even if no
code is left from it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NTom Haynes <loghyr@primarydata.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NJonathan Corbet <corbet@lwn.net>

In order to support accesses to larger chunks of memory, pass in a
'size' parameter (counted in bytes), and return the amount available at
that address.

Add a new helper function, bdev_direct_access(), to handle common
functionality including partition handling, checking the length requested
is positive, checking for the sector being page-aligned, and checking
the length of the request does not pass the end of the partition.
Signed-off-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NBoaz Harrosh <boaz@plexistor.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

xfsbufd_centisecs and age_buffer_centisecs were due for removal in
3.14. We forgot to do that - it's now well past time to remove these
deprecated, unused sysctls.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Reported-by: Fabian Sturm <fabian.sturm@aduu.de> 
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

Update descriptions of seq_path() and seq_path_root():
starting with commit v3.2-rc4-1-g02125a82, seq_path_root() no longer
changes the value of root;
starting with commit v3.2-rc7-104-g8c9379e9, some arguments of seq_path()
and seq_path_root() are const.
Signed-off-by: NDmitry V. Levin <ldv@altlinux.org>
Acked-by: NRob Landley <rob@landley.net>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Reported-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

Allow "lowerdir=" option to contain multiple lower directories separated by
a colon (e.g. "lowerdir=/bin:/usr/bin").  Colon characters in filenames can
be escaped with a backslash.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>