Firstly by applying the following with coccinelle's spatch:

	@@ expression SB; @@
	-SB->s_flags & MS_RDONLY
	+sb_rdonly(SB)

to effect the conversion to sb_rdonly(sb), then by applying:

	@@ expression A, SB; @@
	(
	-(!sb_rdonly(SB)) && A
	+!sb_rdonly(SB) && A
	|
	-A != (sb_rdonly(SB))
	+A != sb_rdonly(SB)
	|
	-A == (sb_rdonly(SB))
	+A == sb_rdonly(SB)
	|
	-!(sb_rdonly(SB))
	+!sb_rdonly(SB)
	|
	-A && (sb_rdonly(SB))
	+A && sb_rdonly(SB)
	|
	-A || (sb_rdonly(SB))
	+A || sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) != A
	+sb_rdonly(SB) != A
	|
	-(sb_rdonly(SB)) == A
	+sb_rdonly(SB) == A
	|
	-(sb_rdonly(SB)) && A
	+sb_rdonly(SB) && A
	|
	-(sb_rdonly(SB)) || A
	+sb_rdonly(SB) || A
	)

	@@ expression A, B, SB; @@
	(
	-(sb_rdonly(SB)) ? 1 : 0
	+sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) ? A : B
	+sb_rdonly(SB) ? A : B
	)

to remove left over excess bracketage and finally by applying:

	@@ expression A, SB; @@
	(
	-(A & MS_RDONLY) != sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
	|
	-(A & MS_RDONLY) == sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
	)

to make comparisons against the result of sb_rdonly() (which is a bool)
work correctly.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

When remounting with the no_bulk_read option,
there is a problem accessing the "bulk_read buffer(bu.buf)"
which has already been freed.

If the bulk_read option is enabled,
ubifs_tnc_bulk_read uses the pre-allocated bu.buf.

While bu.buf is being used by ubifs_tnc_bulk_read,
remounting with no_bulk_read frees bu.buf.

So I added code to check the use of "bu.buf" to avoid this situation.

------
I tested as follows(kernel v3.18) :

Use the script to repeat "no_bulk_read <-> bulk_read"
	remount.sh
	#!/bin/sh
	while true do;
		mount -o remount,no_bulk_read ${MOUNT_POINT};
		sleep 1;
		mount -o remount,bulk_read ${MOUNT_POINT};
		sleep 1;
	done

Perform read operation
	cat ${MOUNT_POINT}/* > /dev/null

The problem is reproduced immediately.

[  234.256845][kernel.0]Internal error: Oops: 17 [#1] PREEMPT ARM
[  234.258557][kernel.0]CPU: 0 PID: 2752 Comm: cat Tainted: G        W  O   3.18.31+ #51
[  234.259531][kernel.0]task: cbff8580 ti: cbd66000 task.ti: cbd66000
[  234.260306][kernel.0]PC is at validate_data_node+0x10/0x264
[  234.260994][kernel.0]LR is at ubifs_tnc_bulk_read+0x388/0x3ec
[  234.261712][kernel.0]pc : [<c01d98fc>]    lr : [<c01dc300>]    psr: 80000013
[  234.261712][kernel.0]sp : cbd67ba0  ip : 00000001  fp : 00000000
[  234.263337][kernel.0]r10: cd3e0260  r9 : c0df2008  r8 : 00000000
[  234.264087][kernel.0]r7 : cd3e0000  r6 : 00000000  r5 : cd3e0278  r4 : cd3e0000
[  234.264999][kernel.0]r3 : 00000003  r2 : cd3e0280  r1 : 00000000  r0 : cd3e0000
[  234.265910][kernel.0]Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  234.266896][kernel.0]Control: 10c53c7d  Table: 8c40c059  DAC: 00000015
[  234.267711][kernel.0]Process cat (pid: 2752, stack limit = 0xcbd66400)
[  234.268525][kernel.0]Stack: (0xcbd67ba0 to 0xcbd68000)
[  234.269169][kernel.0]7ba0: cd7c3940 c03d8650 0001bfe0 00002ab2 00000000 cbd67c5c cbd67c58 0001bfe0
[  234.270287][kernel.0]7bc0: cd3e0000 00002ab2 0001bfe0 00000014 cbd66000 cd3e0260 00000000 c01d6660
[  234.271403][kernel.0]7be0: 00002ab2 00000000 c82a5800 ffffffff cd3e0298 cd3e0278 00000000 cd3e0000
[  234.272520][kernel.0]7c00: 00000000 00000000 cd3e0260 c01dc300 00002ab2 00000000 60000013 d663affa
[  234.273639][kernel.0]7c20: cd3e01f0 cd3e01f0 60000013 c09397ec 00000000 cd3e0278 00002ab2 00000000
[  234.274755][kernel.0]7c40: cd3e0000 c01dbf48 00000014 00000003 00000160 00000015 00000004 d663affa
[  234.275874][kernel.0]7c60: ccdaa978 cd3e0278 cd3e0000 cf32a5f4 ccdaa820 00000044 cbd66000 cd3e0260
[  234.276992][kernel.0]7c80: 00000003 c01cec84 ccdaa8dc cbd67cc4 cbd67ec0 00000010 ccdaa978 00000000
[  234.278108][kernel.0]7ca0: 0000015e ccdaa8dc 00000000 00000000 cf32a5d0 00000000 0000015f ccdaa8dc
[  234.279228][kernel.0]7cc0: 00000000 c8488300 0009e5a4 0000000e cbd66000 0000015e cf32a5f4 c0113c04
[  234.280346][kernel.0]7ce0: 0000009f 0000003c c00098c4 ffffffff 00001000 00000000 000000ad 00000010
[  234.281463][kernel.0]7d00: 00000038 cd68f580 00000150 c8488360 00000000 cbd67d30 cbd67d70 0000000e
[  234.282579][kernel.0]7d20: 00000010 00000000 c0951874 c0112a9c cf379b60 cf379b84 cf379890 cf3798b4
[  234.283699][kernel.0]7d40: cf379578 cf37959c cf379380 cf3793a4 cf3790b0 cf3790d4 cf378fd8 cf378ffc
[  234.284814][kernel.0]7d60: cf378f48 cf378f6c cf32a5f4 cf32a5d0 00000000 00001000 00000018 00000000
[  234.285932][kernel.0]7d80: 00001000 c0050da4 00000000 00001000 cec04c00 00000000 00001000 c0e11328
[  234.287049][kernel.0]7da0: 00000000 00001000 cbd66000 00000000 00001000 c0012a60 00000000 00001000
[  234.288166][kernel.0]7dc0: cbd67dd4 00000000 00001000 80000013 00000000 00001000 cd68f580 00000000
[  234.289285][kernel.0]7de0: 00001000 c915d600 00000000 00001000 cbd67e48 00000000 00001000 00000018
[  234.290402][kernel.0]7e00: 00000000 00001000 00000000 00000000 00001000 c915d768 c915d768 c0113550
[  234.291522][kernel.0]7e20: cd68f580 cbd67e48 cd68f580 cb6713c0 00010000 000ac5a4 00000000 001fc5a4
[  234.292637][kernel.0]7e40: 00000000 c8488300 cbd67ec0 00eb0000 cd68f580 c0113ee4 00000000 cbd67ec0
[  234.293754][kernel.0]7e60: cd68f580 c8488300 cbd67ec0 00eb0000 cd68f580 00150000 c8488300 00eb0000
[  234.294874][kernel.0]7e80: 00010000 c0112fd0 00000000 cbd67ec0 cd68f580 00150000 00000000 cd68f580
[  234.295991][kernel.0]7ea0: cbd67ef0 c011308c 00000000 00000002 cd768850 00010000 00000000 c01133fc
[  234.297110][kernel.0]7ec0: 00150000 00000000 cbd67f50 00000000 00000000 cb6713c0 01000000 cbd67f48
[  234.298226][kernel.0]7ee0: cbd67f50 c8488300 00000000 c0113204 00010000 01000000 00000000 cb6713c0
[  234.299342][kernel.0]7f00: 00150000 00000000 cbd67f50 00000000 00000000 00000000 00000000 00000000
[  234.300462][kernel.0]7f20: cbd67f50 01000000 01000000 cb6713c0 c8488300 c00ebba8 01000000 00000000
[  234.301577][kernel.0]7f40: c8488300 cb6713c0 00000000 00000000 00000000 00000000 ccdaa820 00000000
[  234.302697][kernel.0]7f60: 00000000 01000000 00000003 00000001 cbd66000 00000000 00000001 c00ec678
[  234.303813][kernel.0]7f80: 00000000 00000200 00000000 01000000 01000000 00000000 00000000 000000ef
[  234.304933][kernel.0]7fa0: c000e904 c000e780 01000000 00000000 00000001 00000003 00000000 01000000
[  234.306049][kernel.0]7fc0: 01000000 00000000 00000000 000000ef 00000001 00000003 01000000 00000001
[  234.307165][kernel.0]7fe0: 00000000 beafb78c 0000ad08 00128d1c 60000010 00000001 00000000 00000000
[  234.308292][kernel.0][<c01d98fc>] (validate_data_node) from [<c01dc300>] (ubifs_tnc_bulk_read+0x388/0x3ec)
[  234.309493][kernel.0][<c01dc300>] (ubifs_tnc_bulk_read) from [<c01cec84>] (ubifs_readpage+0x1dc/0x46c)
[  234.310656][kernel.0][<c01cec84>] (ubifs_readpage) from [<c0113c04>] (__generic_file_splice_read+0x29c/0x4cc)
[  234.311890][kernel.0][<c0113c04>] (__generic_file_splice_read) from [<c0113ee4>] (generic_file_splice_read+0xb0/0xf4)
[  234.313214][kernel.0][<c0113ee4>] (generic_file_splice_read) from [<c0112fd0>] (do_splice_to+0x68/0x7c)
[  234.314386][kernel.0][<c0112fd0>] (do_splice_to) from [<c011308c>] (splice_direct_to_actor+0xa8/0x190)
[  234.315544][kernel.0][<c011308c>] (splice_direct_to_actor) from [<c0113204>] (do_splice_direct+0x90/0xb8)
[  234.316741][kernel.0][<c0113204>] (do_splice_direct) from [<c00ebba8>] (do_sendfile+0x17c/0x2b8)
[  234.317838][kernel.0][<c00ebba8>] (do_sendfile) from [<c00ec678>] (SyS_sendfile64+0xc4/0xcc)
[  234.318890][kernel.0][<c00ec678>] (SyS_sendfile64) from [<c000e780>] (ret_fast_syscall+0x0/0x38)
[  234.319983][kernel.0]Code: e92d47f0 e24dd050 e59f9228 e1a04000 (e5d18014)
Signed-off-by: Nkaram.lee <karam.lee@lge.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

There currently appears to be no way for userspace to find out the
underlying volume number for a mounted ubifs file system, since ubifs
uses anonymous block devices.  The volume name is present in
/proc/mounts but UBI volumes can be renamed after the volume has been
mounted.

To remedy this, show the UBI number and UBI volume number as part of the
options visible under /proc/mounts.

Also, accept and ignore the ubi= vol= options if they are used mounting
(patch from Richard Weinberger).

 # mount -t ubifs ubi:baz x
 # mount
 ubi:baz on /root/x type ubifs (rw,relatime,ubi=0,vol=2)
 # ubirename /dev/ubi0 baz bazz
 # mount
 ubi:baz on /root/x type ubifs (rw,relatime,ubi=0,vol=2)
 # ubinfo -d 0 -n 2
 Volume ID:   2 (on ubi0)
 Type:        dynamic
 Alignment:   1
 Size:        67 LEBs (1063424 bytes, 1.0 MiB)
 State:       OK
 Name:        bazz
 Character device major/minor: 254:3
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This SLAB is only being used in super.c, there is no need to expose
it into the global namespace.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Allocate struct backing_dev_info separately instead of embedding it
inside the superblock. This unifies handling of bdi among users.

CC: Richard Weinberger <richard@nod.at>
CC: Artem Bityutskiy <dedekind1@gmail.com>
CC: Adrian Hunter <adrian.hunter@intel.com>
CC: linux-mtd@lists.infradead.org
Acked-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDavid Gstir <david@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

...and provide a non const variant for fscrypto
Signed-off-by: NRichard Weinberger <richard@nod.at>

This is the first building block to provide file level
encryption on UBIFS.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Probe-mounting a volume too small for UBIFS results in kernel log
polution which might irritate users.
Address this by silencing errors which may happen during boot if the
rootfs is e.g. squashfs (and thus rather small) stored on a UBI volume.
Signed-off-by: NDaniel Golle <daniel@makrotopia.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

This change completes commit
90bea5a3 ("UBIFS: respect MS_SILENT mount flag")
which already implements support for MS_SILENT except for that one
error message which is still being displayed despite MS_SILENT being
set. Suppress that error message as well in case MS_SILENT is set.
Signed-off-by: NDaniel Golle <daniel@makrotopia.org>
[rw: massaged commit message]
Signed-off-by: NRichard Weinberger <richard@nod.at>

Ubifs internally uses special inodes for storing xattrs. Those inodes
had NULL {get,set,remove}xattr inode operations before this change, so
xattr operations on them would fail. The super block's s_xattr field
would also apply to those special inodes. However, the inodes are not
visible outside of ubifs, and so no xattr operations will ever be
carried out on them anyway.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Mostly direct substitution with occasional adjustment or removing
outdated comments.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Ubifs installs a security xattr handler in sb->s_xattr but doesn't use the
generic_{get,set,list,remove}xattr inode operations needed for processing
this list of attribute handlers; the handler is never called.  Instead,
ubifs uses its own xattr handlers which also process security xattrs.

Remove the dead code.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mtd@lists.infradead.org
Cc: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

To make ubifs support atime flexily, this commit introduces
a Kconfig option named as UBIFS_ATIME_SUPPORT.

With UBIFS_ATIME_SUPPORT=n:
	ubifs keeps the full compatibility to no_atime from
the start of ubifs.

=================UBIFS_ATIME_SUPPORT=n=======================
-o - no atime
-o atime - no atime
-o noatime - no atime
-o relatime - no atime
-o strictatime - no atime
-o lazyatime - no atime

With UBIFS_ATIME_SUPPORT=y:
	ubifs supports the atime same with other main stream
file systems.
=================UBIFS_ATIME_SUPPORT=y=======================
-o - default behavior (relatime currently)
-o atime - atime support
-o noatime - no atime support
-o relatime - relative atime support
-o strictatime - strict atime support
-o lazyatime - lazy atime support
Signed-off-by: NDongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

register_shrinker() in ubifs_init() can fail due to fail to call kzalloc.
This patch fixes to check the return value of register_shrinker, otherwise
our shrinker may be unregistered after ubifs initialized successfully.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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

In the case where we have more than one volumes on different UBI
devices, it may be not that easy to tell which volume prints the
messages.  Add ubi number and volume id in ubifs_msg/warn/error
to help debug. These two values are passed by struct ubifs_info.

For those where ubifs_info is not initialized yet, ubifs_* is
replaced by pr_*. For those where ubifs_info is not avaliable,
ubifs_info is passed to the calling function as a const parameter.

The output looks like,

[   95.444879] UBIFS (ubi0:1): background thread "ubifs_bgt0_1" started, PID 696
[   95.484688] UBIFS (ubi0:1): UBIFS: mounted UBI device 0, volume 1, name "test1"
[   95.484694] UBIFS (ubi0:1): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[   95.484699] UBIFS (ubi0:1): FS size: 30220288 bytes (28 MiB, 238 LEBs), journal size 1523712 bytes (1 MiB, 12 LEBs)
[   95.484703] UBIFS (ubi0:1): reserved for root: 1427378 bytes (1393 KiB)
[   95.484709] UBIFS (ubi0:1): media format: w4/r0 (latest is w4/r0), UUID 40DFFC0E-70BE-4193-8905-F7D6DFE60B17, small LPT model
[   95.489875] UBIFS (ubi1:0): background thread "ubifs_bgt1_0" started, PID 699
[   95.529713] UBIFS (ubi1:0): UBIFS: mounted UBI device 1, volume 0, name "test2"
[   95.529718] UBIFS (ubi1:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[   95.529724] UBIFS (ubi1:0): FS size: 19808256 bytes (18 MiB, 156 LEBs), journal size 1015809 bytes (0 MiB, 8 LEBs)
[   95.529727] UBIFS (ubi1:0): reserved for root: 935592 bytes (913 KiB)
[   95.529733] UBIFS (ubi1:0): media format: w4/r0 (latest is w4/r0), UUID EEB7779D-F419-4CA9-811B-831CAC7233D4, small LPT model

[  954.264767] UBIFS error (ubi1:0 pid 756): ubifs_read_node: bad node type (255 but expected 6)
[  954.367030] UBIFS error (ubi1:0 pid 756): ubifs_read_node: bad node at LEB 0:0, LEB mapping status 1
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The commits 781c5717 ("UBIFS: intialize LPT earlier") and 09801194 ("UBIFS:
fix-up free space earlier") move some initialization before marking the
master node dirty. But the modification changes the conditions of writing
master.

If unclean umount happens, ubifs may fail when mounting. But trying to
mount it will write new master nodes on the flash. This is useless but
increasing sqnum. So check need_recovery before writing master node, and
don't create new master node if filesystem needs recovery.

The behavour of the bug shows at:
http://lists.infradead.org/pipermail/linux-mtd/2015-February/057712.htmlSigned-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NBen Gardiner <ben.l.gardiner@gmail.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Artem: rename static functions so that they do not use the "ubifs_" prefix - we
       only use this prefix for non-static functions.
Artem: remove few junk white-space changes in file.c
Signed-off-by: NSubodh Nijsure <snijsure@grid-net.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NBen Shelton <ben.shelton@ni.com>
Acked-by: NBrad Mouring <brad.mouring@ni.com>
Acked-by: NTerry Wilcox <terry.wilcox@ni.com>
Acked-by: NGratian Crisan <gratian.crisan@ni.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTejun Heo <tj@kernel.org>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The 'mst_mutex' is not needed since because 'ubifs_write_master()' is only
called on the mount path and commit path. The mount path is sequential and
there is no parallelism, and the commit path is also serialized - there is only
one commit going on at a time.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Fix checkpatch warnings:
"WARNING: Prefer seq_puts to seq_printf"

Andrew Morton wrote:

"
- puts is presumably faster

- puts doesn't go rogue if you accidentally pass it a "%".

- this patch actually made fs/ubifs/super.o 12 bytes smaller.
  Perhaps because seq_printf() is a varargs function, forcing the
  caller to pass args on the stack instead of in registers.
"
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

kcalloc manages count*sizeof overflow.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

This patch removes useless and duplicate statements.
Signed-off-by: Nhujianyang <hujianyang@huawei.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

When attempting to mount a non-ubifs formatted volume, lots of error
messages (including a stack dump) are thrown to the kernel log even if
the MS_SILENT mount flag is set.
Fix this by introducing adding an additional state-variable in
struct ubifs_info and suppress error messages in ubifs_read_node if
MS_SILENT is set.
Signed-off-by: NDaniel Golle <daniel@makrotopia.org>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Dan's "smatch" checker found out that there was a bug in the error path of the
'ubifs_remount_rw()' function. Instead of jumping to the "out" label which
cleans-things up, we just returned.

This patch fixes the problem.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NMinchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree
Signed-off-by: NCody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix to return -ENOMEM in the kmalloc() and d_make_root() error handling
case instead of 0, as done elsewhere in those functions.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

Convert the filesystem shrinkers to use the new API, and standardise some
of the behaviours of the shrinkers at the same time.  For example,
nr_to_scan means the number of objects to scan, not the number of objects
to free.

I refactored the CIFS idmap shrinker a little - it really needs to be
broken up into a shrinker per tree and keep an item count with the tree
root so that we don't need to walk the tree every time the shrinker needs
to count the number of objects in the tree (i.e.  all the time under
memory pressure).

[glommer@openvz.org: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are needed mainly due to new code merged in the tree]
[assorted fixes folded in]
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NGlauber Costa <glommer@openvz.org>
Acked-by: NMel Gorman <mgorman@suse.de>
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When mounting an UBIFS R/W volume, we have the message:
UBIFS: mounted UBI device 0, volume 1, name "rootfs"(null)
With this patch, we'll have:
UBIFS: mounted UBI device 0, volume 1, name "rootfs"
Which is, I think, what was intended.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Cc: stable@vger.kernel.org [v3.7+]
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

The UBIFS space fixup is a useful feature which allows to fixup the "broken"
flash space at the time of the first mount. The "broken" space is usually the
result of using a "dumb" industrial flasher which is not able to skip empty
NAND pages and just writes all 0xFFs to the empty space, which has grave
side-effects for UBIFS when UBIFS trise to write useful data to those empty
pages.

The fix-up feature works roughly like this:
1. mkfs.ubifs sets the fixup flag in UBIFS superblock when creating the image
   (see -F option)
2. when the file-system is mounted for the first time, UBIFS notices the fixup
   flag and re-writes the entire media atomically, which may take really a lot
   of time.
3. UBIFS clears the fixup flag in the superblock.

This works fine when the file system is mounted R/W for the very first time.
But it did not really work in the case when we first mount the file-system R/O,
and then re-mount R/W. The reason was that we started the fixup procedure too
late, which we cannot really do because we have to fixup the space before it
starts being used.
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reported-by: NMark Jackson <mpfj-list@mimc.co.uk>
Cc: stable@vger.kernel.org # 3.0+

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: NKees Cook <keescook@chromium.org>
Reported-by: NKees Cook <keescook@google.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>