1
0
Fork 0
Commit Graph

618 Commits (22ea97f05cc1096ff8e31f90f6e313862f1e7443)

Author SHA1 Message Date
Al Viro 5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Vladimir Davydov 5d097056c9 kmemcg: account certain kmem allocations to memcg
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: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Linus Torvalds 60b7eca1dc This pull request contains three changes, two cleanups and one UBI
wear leveling improvement by Sebastian Siewior.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABAgAGBQJWlWXmAAoJEEtJtSqsAOnW93QQAK8Dn68PxIn6qQFeah0Lg2bI
 a9sycpSHPvQniv7npgcFEh+9iDUPcvMMHVshc9qBPjENzW1VozL/5cZd8Utt5Ua/
 xU7kYRS1uXQLeL8HnASCrsVS4GrcHFJBx4+72XBom15/DsKNBuSa/Z5BkXL1fkOK
 VqBcHQK5FhJLe4I+Crwu7CbM5kc6CbnuyDNDkKrTLLKZZhNI/GormCi3+TmO2hK8
 gOt2z1DyvxyyFM7109WkSERW/9oEG4JDCy34/aAS6HY8YmBMFh9+cb8VU7IRmZD1
 YLS+u0ltwheoNuLs6/9zOEKqwUjY2wgsJk3dUkT05OQ4MNN/5AFSSKkU/kp7XAgp
 5yzrAuA+FGmPiEcfX8HrHYDN9aLctRIOibirYsy6eexwCiSfcWGfJf9FoZj522cG
 WgL7y2eS8ODOE2PzLSD2d756G0ka+tuFeQ9BhC3cfbxygy/cTcXaFPNRp8sJ8Biv
 hXQQss62L5Pn/vtlOxGLQAhWDHB4TG34NQ+1/Ni+4LB6pTHOfoD4yomPCxJqFXGE
 Pcz2rHb+mErWNesdI8J7MlXUbR5gRIE+lpZZvhzvRSlKw+CRT7OYDat1p7WXE4Qm
 FtuX+pSV86N3Mx3vTF6QyucrRANKMNr8M9VhPH8nZACZlfooIk3ax9eSjNEzJ1Be
 cN3vsR2y6d9U9q2wk+OX
 =Zouw
 -----END PGP SIGNATURE-----

Merge tag 'upstream-4.5-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "This contains three changes - two cleanups and one UBI wear leveling
  improvement by Sebastian Siewior"

* tag 'upstream-4.5-rc1' of git://git.infradead.org/linux-ubifs:
  ubifs: Use XATTR_*_PREFIX_LEN
  UBIFS: add a comment in key.h for unused parameter
  mtd: ubi: wl: avoid erasing a PEB which is empty
2016-01-12 18:20:20 -08:00
Richard Weinberger 4fdd1d51ad ubifs: Use XATTR_*_PREFIX_LEN
...instead of open coding it.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-01-10 12:33:47 +01:00
Dongsheng Yang 170eb55f7d UBIFS: add a comment in key.h for unused parameter
Add a comment in key.h to explain why we keep an unused
parameter in key helpers.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-01-10 12:33:30 +01:00
Al Viro 6b2553918d replace ->follow_link() with new method that could stay in RCU mode
new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:54 -05:00
Linus Torvalds 5d2eb548b3 Merge branch 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs xattr cleanups from Al Viro.

* 'for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  f2fs: xattr simplifications
  squashfs: xattr simplifications
  9p: xattr simplifications
  xattr handlers: Pass handler to operations instead of flags
  jffs2: Add missing capability check for listing trusted xattrs
  hfsplus: Remove unused xattr handler list operations
  ubifs: Remove unused security xattr handler
  vfs: Fix the posix_acl_xattr_list return value
  vfs: Check attribute names in posix acl xattr handers
2015-11-13 18:02:30 -08:00
Andreas Gruenbacher 13d3408f10 ubifs: Remove unused security xattr handler
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: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Richard 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: Al Viro <viro@zeniv.linux.org.uk>
2015-11-13 20:34:29 -05:00
Linus Torvalds 01504f5e9e This pull request includes the following UBI/UBIFS changes:
* access time support for UBIFS by Dongsheng Yang
 * random cleanups and bug fixes all over the place
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABAgAGBQJWQmnVAAoJEEtJtSqsAOnWpnkP/0pUN+Cx58QJoJXxaSgClH/l
 QwYGznz4Fv3QuSafXJZy8CPzsTasaOOtoVKJPfPTvP8Drrl3FFbtdhqlqdx1YKqw
 DuKeViwmE/HF49a5pxgtR8032l35s3zZUWwd2yKA3B6SVEIsjAoWlIutyzKA/DiR
 R4mGVsfRevfzq1+l2YXGGZ8PJXMtRKnFTjzmIUJY0OeT3xCvl/uUFCid2x693aut
 GpJ6AMKGYcU+BuQJmb89wvdRYCHPdYEJr7TWq+GBxU3gDPlLY9302IhPq9ftv8Lp
 ClA0X3GZqVPR921XR+aA4ysRbfENT+UBewiBt2OEwQLnI6jxEn9EqsgErATxpOYy
 PEduYuU56mqc67EE4r7+YHfkidMSa8KrR9s+GpzR6JStW9HNGFDfGfCAK7BcdvWT
 +TuHfNk787Gbl4TO41iFI87s6zNQszYOpxBTEFYHx0FQWLNxD5c79UkisL+biqvJ
 bX8+7pClJQXcY0CXqe56GVQLC5v4HbvMmnstiNk52ihxEB0NT6htzWe/GPb/+UZ1
 K+kOAT54DPeag3FK4J1WZ57cYyJHdbyASB5vKvb+A1IwzrYFo8P35GekoWNK7eAJ
 Od5mb++7pTEFSH7oSwsprPOmrHLRmXgRG8yhLRfqX1ZwFeyFdqGQxjce9O/QB1jo
 jr4dxAY6Gnjdo1q07QSI
 =9n2S
 -----END PGP SIGNATURE-----

Merge tag 'upstream-4.4-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:

 - access time support for UBIFS by Dongsheng Yang

 - random cleanups and bug fixes all over the place

* tag 'upstream-4.4-rc1' of git://git.infradead.org/linux-ubifs:
  ubifs: introduce UBIFS_ATIME_SUPPORT to ubifs
  ubifs: make ubifs_[get|set]xattr atomic
  UBIFS: Delete unnecessary checks before the function call "iput"
  UBI: Remove in vain semicolon
  UBI: Fastmap: Fix PEB array type
  UBIFS: Fix possible memory leak in ubifs_readdir()
  fs/ubifs: remove unnecessary new_valid_dev check
  ubi: fastmap: Implement produce_free_peb()
  UBIFS: print verbose message when rescanning a corrupted node
  UBIFS: call dbg_is_power_cut() instead of reading c->dbg->pc_happened
  UBI: drop null test before destroy functions
  UBI: Update comments to reflect UBI_METAONLY flag
  UBI: Fix debug message
  UBI: Fix typo in comment
  UBI: Fastmap: Simplify expression
  UBIFS: fix a typo in comment of ubifs_budget_req
  UBIFS: use kmemdup rather than duplicating its implementation
2015-11-10 16:35:06 -08:00
Dongsheng Yang 8c1c5f2638 ubifs: introduce UBIFS_ATIME_SUPPORT to ubifs
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: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07 11:35:08 +01:00
Dongsheng Yang ab92a20bce ubifs: make ubifs_[get|set]xattr atomic
This commit make the ubifs_[get|set]xattr protected by ui_mutex.

Originally, there is a possibility that ubifs_getxattr to get
a wrong value.

  P1                                  P2
----------                  	----------
ubifs_getxattr                      ubifs_setxattr
					- kfree()
- memcpy()
					- kmemdup()

Then ubifs_getxattr() would get a non-sense data. To solve this
problem, this commit make the xattr of ubifs_inode updated in
atomic.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-07 11:33:17 +01:00
Markus Elfring 54bcfdf19e UBIFS: Delete unnecessary checks before the function call "iput"
The iput() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 23:26:52 +01:00
Richard Weinberger aeeb14f763 UBIFS: Fix possible memory leak in ubifs_readdir()
If ubifs_tnc_next_ent() returns something else than -ENOENT
we leak file->private_data.

Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: David Gstir <david@sigma-star.at>
2015-11-06 23:26:49 +01:00
Yaowei Bai 86ba9ed928 fs/ubifs: remove unnecessary new_valid_dev check
As currently new_valid_dev always returns 1, so new_valid_dev check is not
needed, remove it.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-11-06 23:26:48 +01:00
shengyong be186cc4de UBIFS: print verbose message when rescanning a corrupted node
This is a trivial fix of showing verbose message when leb-recovery detects
a corrupted node, which is not the last one in the LEB. Rescan expects to
show more detail of the corrupted node.

Reviewed-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-03 20:42:01 +02:00
shengyong 8f6983abe3 UBIFS: call dbg_is_power_cut() instead of reading c->dbg->pc_happened
Call dbg_is_power_cut() to emulate power cut instead of reading
c->dbg->pc_happened. Otherwise, the function becomes dead code.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-10-03 20:40:21 +02:00
Dongsheng Yang 7d25b361a2 UBIFS: fix a typo in comment of ubifs_budget_req
s/now/how

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-10-03 20:03:25 +02:00
Andrzej Hajda bbc8a0044f UBIFS: use kmemdup rather than duplicating its implementation
The patch was generated using fixed coccinelle semantic patch
scripts/coccinelle/api/memdup.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2014320

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-10-03 20:03:14 +02:00
Richard Weinberger cf6f54e3f1 UBIFS: Kill unneeded locking in ubifs_init_security
Fixes the following lockdep splat:
[    1.244527] =============================================
[    1.245193] [ INFO: possible recursive locking detected ]
[    1.245193] 4.2.0-rc1+ #37 Not tainted
[    1.245193] ---------------------------------------------
[    1.245193] cp/742 is trying to acquire lock:
[    1.245193]  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0
[    1.245193]
[    1.245193] but task is already holding lock:
[    1.245193]  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280
[    1.245193]
[    1.245193] other info that might help us debug this:
[    1.245193]  Possible unsafe locking scenario:
[    1.245193]
[    1.245193]        CPU0
[    1.245193]        ----
[    1.245193]   lock(&sb->s_type->i_mutex_key#9);
[    1.245193]   lock(&sb->s_type->i_mutex_key#9);
[    1.245193]
[    1.245193]  *** DEADLOCK ***
[    1.245193]
[    1.245193]  May be due to missing lock nesting notation
[    1.245193]
[    1.245193] 2 locks held by cp/742:
[    1.245193]  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff811ad37f>] mnt_want_write+0x1f/0x50
[    1.245193]  #1:  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280
[    1.245193]
[    1.245193] stack backtrace:
[    1.245193] CPU: 2 PID: 742 Comm: cp Not tainted 4.2.0-rc1+ #37
[    1.245193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140816_022509-build35 04/01/2014
[    1.245193]  ffffffff8252d530 ffff88007b023a38 ffffffff814f6f49 ffffffff810b56c5
[    1.245193]  ffff88007c30cc80 ffff88007b023af8 ffffffff810a150d ffff88007b023a68
[    1.245193]  000000008101302a ffff880000000000 00000008f447e23f ffffffff8252d500
[    1.245193] Call Trace:
[    1.245193]  [<ffffffff814f6f49>] dump_stack+0x4c/0x65
[    1.245193]  [<ffffffff810b56c5>] ? console_unlock+0x1c5/0x510
[    1.245193]  [<ffffffff810a150d>] __lock_acquire+0x1a6d/0x1ea0
[    1.245193]  [<ffffffff8109fa78>] ? __lock_is_held+0x58/0x80
[    1.245193]  [<ffffffff810a1a93>] lock_acquire+0xd3/0x270
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff814fc83b>] mutex_lock_nested+0x6b/0x3a0
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff8128e286>] ubifs_create+0xa6/0x1f0
[    1.245193]  [<ffffffff81198e7f>] ? path_openat+0x3af/0x1280
[    1.245193]  [<ffffffff81195d15>] vfs_create+0x95/0xc0
[    1.245193]  [<ffffffff8119929c>] path_openat+0x7cc/0x1280
[    1.245193]  [<ffffffff8109ffe3>] ? __lock_acquire+0x543/0x1ea0
[    1.245193]  [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0
[    1.245193]  [<ffffffff81088c00>] ? calc_global_load_tick+0x60/0x90
[    1.245193]  [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0
[    1.245193]  [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180
[    1.245193]  [<ffffffff8119ac55>] do_filp_open+0x75/0xd0
[    1.245193]  [<ffffffff814ffd86>] ? _raw_spin_unlock+0x26/0x40
[    1.245193]  [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180
[    1.245193]  [<ffffffff81189bd9>] do_sys_open+0x129/0x200
[    1.245193]  [<ffffffff81189cc9>] SyS_open+0x19/0x20
[    1.245193]  [<ffffffff81500717>] entry_SYSCALL_64_fastpath+0x12/0x6f

While the lockdep splat is a false positive, becuase path_openat holds i_mutex
of the parent directory and ubifs_init_security() tries to acquire i_mutex
of a new inode, it reveals that taking i_mutex in ubifs_init_security() is
in vain because it is only being called in the inode allocation path
and therefore nobody else can see the inode yet.

Cc: stable@vger.kernel.org # 3.20-
Reported-and-tested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-and-tested-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: dedekind1@gmail.com
2015-09-29 12:45:42 +02:00
Linus Torvalds cc8a0a9439 This pull request includes the following UBI/UBIFS changes:
* Minor fixes for UBI and UBIFS
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABAgAGBQJVi9DTAAoJEPmeIjfg4UaaOlAP/AtZqcxpCHlKpbZUz7z1MmCb
 MP9AbowP0CSXrMYSA7GrBROw+bfTM7aZrhWqhhoJxAyBbb9LGldjW9xZmUqUvS5e
 LZjAO8sWqxEbfVBqnpTgA2AiSN37I3+epYqgDFNlNCtxPYxkEXpXVoLUSdrAUKw8
 24EjPe0tq1JKLmjh3XJQZJnmCW+7xPKRUj7KiwPZzombIoNXFA9z4PCOLLlnDx1X
 TRasArrncarslQaHQerRoZUKC/hoIGZMipv94pNovgO8HAcZ/N19ef1Fc4iG5zvS
 XUMerUyKMTVfR6LFjueMjRpEMOmDb4AifWeDKY00xqY4RCnkIcAAqVRBGWQep6Y4
 PxCwttNktykWj/LygPCsQk6gd0IxdVGsFra4DpxhCCWXaUw2RJCRg0a4mQFOqojO
 tmCVQVYgd4Ob2DDnxmS7Z8IvjIWzsSkgatF+Dde2feeHUwEuM9NoudHg704+A30x
 3fNwIFhuREhOymxGpBaprfaKh7khF88CcrGjiEOvw/DK0QfwlVoUVLqjkNVaLZXC
 nrwNATdheq2gMV2Mdydy/uo5NpUxeblSrlnuknKQSTmH5m2/U9F9lJ/v3Sv7ShjB
 gWqyNIoxJBKTSbsGkFP5bzWmxwsQ4HlPTcAmJhoUDK7SLeXThhgRwB4o2zlriYfS
 D7ZVxRMY5JCNxomIzD0X
 =xU0H
 -----END PGP SIGNATURE-----

Merge tag 'upstream-4.2-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "Minor fixes for UBI and UBIFS"

* tag 'upstream-4.2-rc1' of git://git.infradead.org/linux-ubifs:
  UBI: Remove unnecessary `\'
  UBI: Use static class and attribute groups
  UBI: add a helper function for updatting on-flash layout volumes
  UBI: Fastmap: Do not add vol if it already exists
  UBI: Init vol->reserved_pebs by assignment
  UBI: Fastmap: Rename variables to make them meaningful
  UBI: Fastmap: Remove unnecessary `\'
  UBI: Fastmap: Use max() to get the larger value
  ubifs: fix to check error code of register_shrinker
  UBI: block: Dynamically allocate minor numbers
2015-06-25 14:11:34 -07:00
Chao Yu a1fe33af5f ubifs: fix to check error code of register_shrinker
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: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-06-02 11:41:38 +02:00
Al Viro 0f301bd305 ubifs: switch to simple_follow_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:18:25 -04:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Linus Torvalds d613896926 This pull request includes the following UBI/UBIFS changes:
* Powercut emulation for UBI
 * A huge update to UBI Fastmap
 * Cleanups and bugfixes all over UBI and UBIFS
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABAgAGBQJVLsBfAAoJEEtJtSqsAOnWyaYP/30jnSEu4y2agDPwdev0wnqF
 QRAAVWxLCzinBkElXJ0POvhdQwnxP37ACqa/mNVuTa5++N1eI8PPpcRu+EUrVmoP
 mSRmEBdarvNYRLmOaoBBwY4qFvmcZx9Odt2BIdXz9xV+Mk220VdRW2PBn8JfGDn4
 JJziWKmq9HUKXMQY9SVkOfT5tW+xHdjRUuNwp2S5nuV4hz2rUv0ChlYqCBqvca8/
 tfjtlCLBGGuFSXfa9wtdCTWlU2Hyh4sG9u72c23iGqHmwOc9ZIpBlgiz+nYZFXoo
 GriBDBXG5ib1p+Px+oecWPBLv/Ipgc887IJHFAz3exPmSkQQTnuCSYFsraS1zqwZ
 91kOGjcF5wY9EwBbT0a1VDdOwYT9MC5gD7G71MarDt0BWEYDvPufd6XPc5qPfP/9
 xtscNQZ2FNd4gWGRT5irBOqIERdsWt2cjgD0aK2gbV1p9meUBU6hlvMIOU1YmBKg
 TwK8o+RwhE13JWwSExqcW+FRz9Aup/W/EDRNuuUGOXFFSnSvqSwE/y3JeP7jydIf
 7J3rvrKdRWObTO/uZvtx+mwU3FgNPoITCgQQtAz7jexjksLWMxVi1gF1VYULScW/
 p5ewCFsuRQSeCL/M1cKO1trYARbe9YITewbrQKuL8wknQKGcXY0XiV0OpPlH0xXD
 LqnvNoeixq4AH7rkMQIk
 =nzVw
 -----END PGP SIGNATURE-----

Merge tag 'upstream-4.1-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "This pull request includes the following UBI/UBIFS changes:

   - powercut emulation for UBI
   - a huge update to UBI Fastmap
   - cleanups and bugfixes all over UBI and UBIFS"

* tag 'upstream-4.1-rc1' of git://git.infradead.org/linux-ubifs: (50 commits)
  UBI: power cut emulation for testing
  UBIFS: fix output format of INUM_WATERMARK
  UBI: Fastmap: Fall back to scanning mode after ECC error
  UBI: Fastmap: Remove is_fm_block()
  UBI: Fastmap: Add blank line after declarations
  UBI: Fastmap: Remove else after return.
  UBI: Fastmap: Introduce may_reserve_for_fm()
  UBI: Fastmap: Introduce ubi_fastmap_init()
  UBI: Fastmap: Wire up WL accessor functions
  UBI: Add accessor functions for WL data structures
  UBI: Move fastmap specific functions out of wl.c
  UBI: Fastmap: Add new module parameter fm_debug
  UBI: Fastmap: Make self_check_eba() depend on fastmap self checking
  UBI: Fastmap: Add self check to detect absent PEBs
  UBI: Fix stale pointers in ubi->lookuptbl
  UBI: Fastmap: Enhance fastmap checking
  UBI: Add initial support for fastmap self checks
  UBI: Fastmap: Rework fastmap error paths
  UBI: Fastmap: Prepare for variable sized fastmaps
  UBI: Fastmap: Locking updates
  ...
2015-04-15 13:43:40 -07:00
David Howells 2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Sheng Yong 1a7e985dd1 UBIFS: fix output format of INUM_WATERMARK
The INUM_WATERMARK is a unsigned 32bit value, `%d' prints it as negatave:
[  103.682255] UBIFS warning (ubi0:0 pid 691): ubifs_new_inode: running out of inode numbers (current 122763, max -256)

Fix it as:
[  154.422940] UBIFS warning (ubi0:0 pid 688): ubifs_new_inode: running out of inode numbers (current 122765, max 4294967040)

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-04-13 13:37:31 +03:00
Al Viro 5d5d568975 make new_sync_{read,write}() static
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: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:40 -04:00
Christoph Hellwig e2e40f2c1e fs: move struct kiocb to fs.h
struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25 20:28:11 -04:00
Sheng Yong 235c362bd0 UBIFS: extend debug/message capabilities
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: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-03-25 11:08:41 +02:00
Fabian Frederick 8a87dc55f7 UBIFS: simplify returns
Directly return recover_head() and ubifs_leb_unmap()
instead of storing value in err and testing it.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-03-25 11:08:41 +02:00
Yannick Guerrini d3f9db00d0 UBIFS: Fix trivial typos in comments
Change 'comress' to 'compress'
Change 'inteval' to 'interval'
Change 'disabe' to 'disable'
Change 'nenver' to 'never'

Signed-off-by: Yannick Guerrini <yguerrini@tomshardware.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-03-25 11:08:41 +02:00
Sheng Yong 2c84599ca4 UBIFS: do not write master node if need recovery
The commits 781c571 ("UBIFS: intialize LPT earlier") and 0980119 ("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.html

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Ben Gardiner <ben.l.gardiner@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-03-25 11:08:40 +02:00
Taesoo Kim 9401a795c6 UBIFS: fix incorrect unlocking handling
When ubifs_init_security() fails, 'ui_mutex' is incorrectly
unlocked and incorrectly restores 'i_size'. Fix this.

Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
Fixes: d7f0b70d30 ("UBIFS: Add security.* XATTR support for the UBIFS")
Reviewed-by: Ben Shelton <ben.shelton@ni.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-03-25 11:08:40 +02:00
Linus Torvalds 8c988ae787 Merge branch 'for-linus-v3.20' of git://git.infradead.org/linux-ubifs
Pull UBI and UBIFS updates from Richard Weinberger:
 - cleanups and bug fixes all over UBI and UBIFS
 - block-mq support for UBI Block
 - UBI volumes can now be renamed while they are in use
 - security.* XATTR support for UBIFS
 - a maintainer update

* 'for-linus-v3.20' of git://git.infradead.org/linux-ubifs:
  UBI: block: Fix checking for NULL instead of IS_ERR()
  UBI: block: Continue creating ubiblocks after an initialization error
  UBIFS: return -EINVAL if log head is empty
  UBI: Block: Explain usage of blk_rq_map_sg()
  UBI: fix soft lockup in ubi_check_volume()
  UBI: Fastmap: Care about the protection queue
  UBIFS: add a couple of extra asserts
  UBI: do propagate positive error codes up
  UBI: clean-up printing helpers
  UBI: extend UBI layer debug/messaging capabilities - cosmetics
  UBIFS: add ubifs_err() to print error reason
  UBIFS: Add security.* XATTR support for the UBIFS
  UBIFS: Add xattr support for symlinks
  UBI: Block: Add blk-mq support
  UBI: Add initial support for scatter gather
  UBI: rename_volumes: Use UBI_METAONLY
  UBI: Implement UBI_METAONLY
  Add myself as UBI co-maintainer
2015-02-15 10:11:39 -08:00
Linus Torvalds 6bec003528 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block
Pull backing device changes from Jens Axboe:
 "This contains a cleanup of how the backing device is handled, in
  preparation for a rework of the life time rules.  In this part, the
  most important change is to split the unrelated nommu mmap flags from
  it, but also removing a backing_dev_info pointer from the
  address_space (and inode), and a cleanup of other various minor bits.

  Christoph did all the work here, I just fixed an oops with pages that
  have a swap backing.  Arnd fixed a missing export, and Oleg killed the
  lustre backing_dev_info from staging.  Last patch was from Al,
  unexporting parts that are now no longer needed outside"

* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
  Make super_blocks and sb_lock static
  mtd: export new mtd_mmap_capabilities
  fs: make inode_to_bdi() handle NULL inode
  staging/lustre/llite: get rid of backing_dev_info
  fs: remove default_backing_dev_info
  fs: don't reassign dirty inodes to default_backing_dev_info
  nfs: don't call bdi_unregister
  ceph: remove call to bdi_unregister
  fs: remove mapping->backing_dev_info
  fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
  nilfs2: set up s_bdi like the generic mount_bdev code
  block_dev: get bdev inode bdi directly from the block device
  block_dev: only write bdev inode on close
  fs: introduce f_op->mmap_capabilities for nommu mmap support
  fs: kill BDI_CAP_SWAP_BACKED
  fs: deduplicate noop_backing_dev_info
2015-02-12 13:50:21 -08:00
Kirill A. Shutemov d83a08db5b mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub
Nobody uses it anymore.

[akpm@linux-foundation.org: fix filemap_xip.c]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:30 -08:00
hujianyang 88cff0f0fb UBIFS: return -EINVAL if log head is empty
CS node is recognized as a sign in UBIFS log replay mechanism.
Log relaying during mount should find the CS node in log head
at beginning and then replay the following uncommitted buds.

Here is a bug in log replay path: If the log head, which is
indicated by @log_lnum in mst_node, is empty, current UBIFS
replay nothing and directly mount the partition without any
warning. This action will put filesystem in an abnormal state,
e.g. space management in LPT area is incorrect to the real
space usage in main area.

We reproduced this bug by fault injection: turn log head leb
into all 0xFF. UBIFS driver mount the polluted partition
normally. But errors occur while running fs_stress on this
mount:

[89068.055183] UBI error: ubi_io_read: error -74 (ECC error) while reading 59 bytes from PEB 711:33088, read 59 bytes
[89068.179877] UBIFS error (pid 10517): ubifs_check_node: bad magic 0x101031, expected 0x6101831
[89068.179882] UBIFS error (pid 10517): ubifs_check_node: bad node at LEB 591:28992
[89068.179891] Not a node, first 24 bytes:
[89068.179892] 00000000: 31 10 10 00 37 84 64 04 10 04 00 00 00 00 00 00 20 00 00 00 02 01 00 00                          1...7.d......... .......
[89068.180282] UBIFS error (pid 10517): ubifs_read_node: expected node type 2

This patch fix the problem by checking *lnum* to guarantee
the empty leb is not log head leb and return an error if the
log head leb is incorrectly empty. After this, we could catch
*log head empty* error in place.

Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-02-10 10:06:24 +02:00
Artem Bityutskiy fb4325a3d9 UBIFS: add a couple of extra asserts
... to catch possible memory corruptions.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-01-28 16:09:32 +01:00
Subodh Nijsure fee1756d80 UBIFS: add ubifs_err() to print error reason
This patch adds ubifs_err() output to some error paths to tell the user
what's going on.

Artem: improve the messages, rename too long variable

Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Shelton <ben.shelton@ni.com>
Acked-by: Brad Mouring <brad.mouring@ni.com>
Acked-by: Terry Wilcox <terry.wilcox@ni.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-01-28 16:09:01 +01:00
Subodh Nijsure d7f0b70d30 UBIFS: Add security.* XATTR support for the UBIFS
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: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Shelton <ben.shelton@ni.com>
Acked-by: Brad Mouring <brad.mouring@ni.com>
Acked-by: Terry Wilcox <terry.wilcox@ni.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-01-28 16:08:54 +01:00
Subodh Nijsure 895d9db253 UBIFS: Add xattr support for symlinks
Artem: rename the __ubifs_setxattr() functions to just 'setxattr()'.

Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Shelton <ben.shelton@ni.com>
Acked-by: Terry Wilcox <terry.wilcox@ni.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-01-28 16:08:46 +01:00
Christoph Hellwig b83ae6d421 fs: remove mapping->backing_dev_info
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: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:05 -07:00
Christoph Hellwig b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Subodh Nijsure a76284e6f8 UBIFS: fix a couple bugs in UBIFS xattr length calculation
The journal update function did not work for extended attributes properly,
because extended attribute inodes carry the xattr data, and the size of this
data was not taken into account.

Artem: improved commit message, amended the patch a bit.

Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Shelton <ben.shelton@ni.com>
Acked-by: Brad Mouring <brad.mouring@ni.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-11-07 12:32:22 +02:00
Artem Bityutskiy 789c89935c UBIFS: fix budget leak in error path
We forgot to free the budget in 'write_begin_slow()' when 'do_readpage()'
fails. This patch fixes the issue.

Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-11-07 12:08:50 +02:00
Richard Weinberger 443b39cdd5 UBIFS: Fix trivial typo in power_cut_emulated()
s/withing/within/

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-09-30 09:29:44 +03:00
hujianyang 4b1a43eab1 UBIFS: Align the dump messages of SB_NODE
I found the dump messages of UBIFS_SB_NODE is not aligned. This
patch remove the extra space from the line which is retracted.

Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-09-26 13:33:41 +03:00
Richard Weinberger d577bc104f UBIFS: Remove bogus assert
This assertion was only correct before UBIFS had xattr support.
Now with xattr support also a directory node can carry data
and can act as host node.

Suggested-by: Artem Bityutskiy <dedekind1@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-09-19 18:11:50 +03:00
Artem Bityutskiy ba29e721eb UBIFS: fix free log space calculation
Hu (hujianyang <hujianyang@huawei.com>) discovered an issue in the
'empty_log_bytes()' function, which calculates how many bytes are left in the
log:

"
If 'c->lhead_lnum + 1 == c->ltail_lnum' and 'c->lhead_offs == c->leb_size', 'h'
would equalent to 't' and 'empty_log_bytes()' would return 'c->log_bytes'
instead of 0.
"

At this point it is not clear what would be the consequences of this, and
whether this may lead to any problems, but this patch addresses the issue just
in case.

Cc: stable@vger.kernel.org
Tested-by: hujianyang <hujianyang@huawei.com>
Reported-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-09-08 15:55:28 +03:00
Artem Bityutskiy 052c28073f UBIFS: fix a race condition
Hu (hujianyang@huawei.com) discovered a race condition which may lead to a
situation when UBIFS is unable to mount the file-system after an unclean
reboot. The problem is theoretical, though.

In UBIFS, we have the log, which basically a set of LEBs in a certain area. The
log has the tail and the head.

Every time user writes data to the file-system, the UBIFS journal grows, and
the log grows as well, because we append new reference nodes to the head of the
log. So the head moves forward all the time, while the log tail stays at the
same position.

At any time, the UBIFS master node points to the tail of the log. When we mount
the file-system, we scan the log, and we always start from its tail, because
this is where the master node points to. The only occasion when the tail of the
log changes is the commit operation.

The commit operation has 2 phases - "commit start" and "commit end". The former
is relatively short, and does not involve much I/O. During this phase we mostly
just build various in-memory lists of the things which have to be written to
the flash media during "commit end" phase.

During the commit start phase, what we do is we "clean" the log. Indeed, the
commit operation will index all the data in the journal, so the entire journal
"disappears", and therefore the data in the log become unneeded. So we just
move the head of the log to the next LEB, and write the CS node there. This LEB
will be the tail of the new log when the commit operation finishes.

When the "commit start" phase finishes, users may write more data to the
file-system, in parallel with the ongoing "commit end" operation. At this point
the log tail was not changed yet, it is the same as it had been before we
started the commit. The log head keeps moving forward, though.

The commit operation now needs to write the new master node, and the new master
node should point to the new log tail. After this the LEBs between the old log
tail and the new log tail can be unmapped and re-used again.

And here is the possible problem. We do 2 operations: (a) We first update the
log tail position in memory (see 'ubifs_log_end_commit()'). (b) And then we
write the master node (see the big lock of code in 'do_commit()').

But nothing prevents the log head from moving forward between (a) and (b), and
the log head may "wrap" now to the old log tail. And when the "wrap" happens,
the contends of the log tail gets erased. Now a power cut happens and we are in
trouble. We end up with the old master node pointing to the old tail, which was
erased. And replay fails because it expects the master node to point to the
correct log tail at all times.

This patch merges the abovementioned (a) and (b) operations by moving the master
node change code to the 'ubifs_log_end_commit()' function, so that it runs with
the log mutex locked, which will prevent the log from being changed benween
operations (a) and (b).

Cc: stable@vger.kernel.org # 07e19df UBIFS: remove mst_mutex
Cc: stable@vger.kernel.org
Reported-by: hujianyang <hujianyang@huawei.com>
Tested-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-09-08 15:55:02 +03:00