cifs: enable mounting cifs drives visible to all apps (tomkasick)

Restrict slave mountspace so Dalvik apps can mount system-wide volumes

Android 4.2 implements multi-user storage using per-process mount
namespaces. Everything under "/" (the entire filesystem hierarchy) is
marked as a recursive-slave mountspace for all zygote instances. This is
done so that user-storage sandbox mounts under /storage/emulated are hidden
from other apps and users.

Unfortunately this means that any Dalvik app (actually, any program whose
clone/fork ancestry includes a Dalvik zygote, which is everything except
services spawned directly from init) cannot mount system-wide volumes.
Thus, apps like CifsManager are effectively broken in Android 4.2, since
its cifs mounts are only visible to the CifsManager app itself. All other
apps see empty mountpoints instead of the mounted volume. Furthermore,
Linux provides no provision for a process to "escape" a recursive-slave
mountspace in versions prior to Linux 3.8 (setns syscall).

Here, we restrict rootfs-slave calls to /storage (and, due to a possible
kernel bug, /mnt/shell/emulated) so that Dalvik apps can mount system-wide
volumes elsewhere (with appropriate permission, as in earlier versions of
Android), while retaining full multi-user storage compatibility. It is
made available as a kernel-based workaround for instances where libdvm can
not be modified.

This change requires that a tmpfs volume is mounted as /storage in init.rc.
If this volume is unavailable, then we falls back to the previous behavior
of marking the entire filesystem hierarchy as slave.

*** Do not commit to CyanogenMod Project kernels, as a similar workaround
for this problem is patched in Zygote/Dalvik/libdvm instead. ***
fs: import f2fs from git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git (branch dev)

Up-to-date with
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git @04a17fb17fafada39f96bfb41ceb2dc1c11b2af6
(f2fs: avoid to read inline data except first page)

Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
cfg80211: Fix memory leak

When a driver requests a specific regulatory domain after cfg80211 already
has one, a struct ieee80211_regdomain is leaked.

Change-Id: Id28fc9861b9c911a97bd242439eabca097d76258
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Git-commit: b7566fc363e23f0efd3fa1e1460f9421cdc0d77e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[mattw@codeaurora.org: trivially backport to the msm-3.4 kernel]
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
f2fs: support 3.4

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: support 3.0

Initial backporting done by nowcomputing,
(https://github.com/nowcomputing/f2fs-backports.git)

Additional patches required by upstream jaegeuk/f2fs.git/linux-3.4 done by arter97.

Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
f2fs: improve write performance under frequent fsync calls

When considering a bunch of data writes with very frequent fsync calls, we
are able to think the following performance regression.

N: Node IO, D: Data IO, IO scheduler: cfq

Issue    pending IOs
	 D1 D2 D3 D4
 D1         D2 D3 D4 N1
 D2            D3 D4 N1 N2
 N1            D3 D4 N2 D1
 --> N1 can be selected by cfq becase of the same priority of N and D.
     Then D3 and D4 would be delayed, resuling in performance degradation.

So, when processing the fsync call, it'd better give higher priority to data IOs
than node IOs by assigning WRITE and WRITE_SYNC respectively.
This patch improves the random wirte performance with frequent fsync calls by up
to 10%.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add a sysfs entry to control max_victim_search

Previously during SSR and GC, the maximum number of retrials to find a victim
segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default.

This number makes an effect on IO locality, when SSR mode is activated, which
results in performance fluctuation on some low-end devices.

If max_victim_search = 4, the victim will be searched like below.
("D" represents a dirty segment, and "*" indicates a selected victim segment.)

 D1 D2 D3 D4 D5 D6 D7 D8 D9
[   *       ]
      [   *    ]
            [         * ]
	                [ ....]

This patch adds a sysfs entry to control the number dynamically through:
  /sys/fs/f2fs/$dev/max_victim_search

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: update documents and a MAINTAINERS entry

This patch adds missing some description of sysfs entries in
 - Documentation/ABI/testing/sysfs-fs-f2fs
 - Documentation/filesystems/f2fs.txt.

And it adds a maintained document entry of F2FS in MAINTAINERS.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: remove the needless parameter of f2fs_wait_on_page_writeback

"boo sync" parameter is never referenced in f2fs_wait_on_page_writeback.
We should remove this parameter.

Signed-off-by: Yuan Zhong <yuan.mark.zhong@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: move grabing orphan pages out of protection region

Move grabing orphan block page out of protection region, and grab all
the orphan block pages ahead.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: remove unnecessary code pointed by Chao Yu]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: move alloc new orphan node out of lock protection region

Move alloc new orphan node out of lock protection region.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: use spinlock rather than mutex for better speed

With the 2 previous changes, all the long time operations are moved out
of the protection region, so here we can use spinlock rather than mutex
(orphan_inode_mutex) for lower overhead.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: add delimiter to seperate name and value in debug phrase

Support for f2fs-tools/tools/f2stat to monitor
/sys/kernel/debug/f2fs/status

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: avoid f2fs_balance_fs call during pageout

This patch should resolve the following bug.

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.13.0-rc5.f2fs+ #6 Not tainted
---------------------------------------------------------
kswapd0/41 just changed the state of lock:
 (&sbi->gc_mutex){+.+.-.}, at: [<ffffffffa030503e>] f2fs_balance_fs+0xae/0xd0 [f2fs]
but this lock took another, RECLAIM_FS-READ-unsafe lock in the past:
 (&sbi->cp_rwsem){++++.?}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Chain exists of:
  &sbi->gc_mutex --> &sbi->cp_mutex --> &sbi->cp_rwsem

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->cp_rwsem);
                               local_irq_disable();
                               lock(&sbi->gc_mutex);
                               lock(&sbi->cp_mutex);
  <Interrupt>
    lock(&sbi->gc_mutex);

 *** DEADLOCK ***

This bug is due to the f2fs_balance_fs call in f2fs_write_data_page.
If f2fs_write_data_page is triggered by wbc->for_reclaim via kswapd, it should
not call f2fs_balance_fs which tries to get a mutex grabbed by original syscall
flow.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: missing REQ_META and REQ_PRIO when sync_meta_pages(META_FLUSH)

Doing sync_meta_pages with META_FLUSH when checkpoint, we overide rw
using WRITE_FLUSH_FUA. At this time, we also should set
REQ_META|REQ_PRIO.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: clean checkpatch warnings

Fixed a variety of trivial checkpatch warnings.  The only delta should
be some minor formatting on log strings that were split / too long.

Signed-off-by: Chris Fries <cfries@motorola.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: Missing definition for down_write_nest_lock
Enable F2FS
f2fs: call mark_inode_dirty to flush dirty pages

If a dentry page is updated, we should call mark_inode_dirty to add the inode
into the dirty list, so that its dentry pages are flushed to the disk.
Otherwise, the inode can be evicted without flush.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: move a branch for code redability

This patch moves a function in f2fs_delete_entry for code readability.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>