Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g.  new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files.  This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else.  This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink).  Imagine the use
of "sudo" is something more sneaky:

  $ BASE="ovl"
  $ MNT="$BASE/mnt"
  $ LOW="$BASE/lower"
  $ UP="$BASE/upper"
  $ WORK="$BASE/work/ 0 0
  none /proc fuse.pwn user_id=1000"
  $ mkdir -p "$LOW" "$UP" "$WORK"
  $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" no...

Replace seq_printf where possible
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Current implementation of HFS+ driver has small issue with remount
option.  Namely, for example, you are unable to remount from RO mode
into RW mode by means of command "mount -o remount,rw /dev/loop0
/mnt/hfsplus".  Trying to execute sequence of commands results in an
error message:

  mount /dev/loop0 /mnt/hfsplus
  mount -o remount,ro /dev/loop0 /mnt/hfsplus
  mount -o remount,rw /dev/loop0 /mnt/hfsplus

  mount: you must specify the filesystem type

  mount -t hfsplus -o remount,rw /dev/loop0 /mnt/hfsplus

  mount: /mnt/hfsplus not mounted or bad option

The reason of such issue is failure of mount syscall:

  mount("/dev/loop0", "/mnt/hfsplus", 0x2282a60, MS_MGC_VAL|MS_REMOUNT, NULL) = -1 EINVAL (Invalid argument)

Namely, hfsplus_parse_options_remount() method receives empty "input"
argument and return false in such case.  As a result, hfsplus_remount()
returns -EINVAL error code.

This patch fixes the issue by means of return true for the case of empty
"input" argument in hfsplus_parse_options_remount() method.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use a more current logging style.

Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
hfsplus now uses "hfsplus: " for all messages.
Coalesce formats.
Prefix debugging messages too.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

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

Match coding style line length limitation where checkpatch.pl
reported over-80-character-line warnings.
Signed-off-by: Anton Salikhmetov <alexo@tuxera.com>
Signed-off-by: Christoph Hellwig <hch@tuxera.com>

Flush the disk cache in fsync and sync to make sure data actually is
on disk on completion of these system calls.  There is a nobarrier
mount option to disable this behaviour.  It's slightly misnamed now
that barrier actually are gone, but it matches the name used by all
major filesystems.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>

hfsplus only actually uses the force option during remount, but it uses
the full option parser with a fake superblock to do so.  This means remount
will fail if any nls option is set (which happens frequently with older
mount tools), even if it is the same.

Fix this by adding a simpler version of the parser that only parses the force
option for remount.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>

The flags in the HFS+-specific superlock do get modified during runtime,
use atomic bitops to make the modifications SMP safe.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>

HFSPLUS_SB doesn't return a pointer to the hfsplus-specific superblock
information like all other FOO_SB macros, but dereference the pointer in a way
that made it look like a direct struct derefence.  This only works as long
as the HFSPLUS_SB macro is used directly and prevents us from keepig a local
hfsplus_sb_info pointer.  Fix the calling convention and introduce a local
sbi variable in all functions that use it constantly.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py



The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: James Morris <jmorris@namei.org>

This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hfsplus/options.c (hfsplus_parse_options): Handle match_strdup failure.
Signed-off-by: Jim Meyering <meyering@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add the log level and a "hfs: " prefix to all kernel prints.  (HFS and HFS+
will use the same prefix, as they share some code and could be merged at some
point.)
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Access to a journaled HFS+ volume is not officially supported under Linux, so
mount such a volume read-only, but users can override this behaviour using the
"force" mount option.

The minimum requirement to relax this check is to at least check that the
journal is empty and so nothing needs to be replayed to make sure the volume
is consistent.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This adds support for show_options.  It also fixes some namespace polution in
the hfsplus driver.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!