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>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hugh Dickins pointed out problems with the new hugetlbfs fallocate hole
punch code. These problems are in the routine remove_inode_hugepages and
mostly occur in the case where there are holes in the range of pages to be
removed. These holes could be the result of a previous hole punch or
simply sparse allocation. The current code could access pages outside the
specified range.
remove_inode_hugepages handles both hole punch and truncate operations.
Page index handling was fixed/cleaned up so that the loop index always
matches the page being processed. The code now only makes a single pass
through the range of pages as it was determined page faults could not race
with truncate. A cond_resched() was added after removing up to
PAGEVEC_SIZE pages.
Some totally unnecessary code in hugetlbfs_fallocate() that remained from
early development was also removed.
Tested with fallocate tests submitted here:
http://librelist.com/browser//libhugetlbfs/2015/6/25/patch-tests-add-tests-for-fallocate-system-call/
And, some ftruncate tests under development
Fixes: b5cec28d36 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Hillf Danton" <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org> [4.3]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is based on the shmem version, but it has diverged quite a bit. We
have no swap to worry about, nor the new file sealing. Add
synchronication via the fault mutex table to coordinate page faults,
fallocate allocation and fallocate hole punch.
What this allows us to do is move physical memory in and out of a
hugetlbfs file without having it mapped. This also gives us the ability
to support MADV_REMOVE since it is currently implemented using
fallocate(). MADV_REMOVE lets madvise() remove pages from the middle of
a hugetlbfs file, which wasn't possible before.
hugetlbfs fallocate only operates on whole huge pages.
Based on code by Dave Hansen.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify truncate_hugepages() to take a range of pages (start, end)
instead of simply start. If an end value of LLONG_MAX is passed, the
current "truncate" functionality is maintained. Existing callers are
modified to pass LLONG_MAX as end of range. By keying off end ==
LLONG_MAX, the routine behaves differently for truncate and hole punch.
Page removal is now synchronized with page allocation via faults by
using the fault mutex table. The hole punch case can experience the
rare region_del error and must handle accordingly.
Add the routine hugetlb_fix_reserve_counts to fix up reserve counts in
the case where region_del returns an error.
Since the routine handles more than just the truncate case, it is
renamed to remove_inode_hugepages(). To be consistent, the routine
truncate_huge_page() is renamed remove_huge_page().
Downstream of remove_inode_hugepages(), the routine
hugetlb_unreserve_pages() is also modified to take a range of pages.
hugetlb_unreserve_pages is modified to detect an error from region_del and
pass it back to the caller.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fallocate hole punch will want to unmap a specific range of pages.
Modify the existing hugetlb_vmtruncate_list() routine to take a
start/end range. If end is 0, this indicates all pages after start
should be unmapped. This is the same as the existing truncate
functionality. Modify existing callers to add 0 as end of range.
Since the routine will be used in hole punch as well as truncate
operations, it is more appropriately renamed to hugetlb_vmdelete_list().
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The shm implementation internally uses shmem or hugetlbfs inodes for shm
segments. As these inodes are never directly exposed to userspace and
only accessed through the shm operations which are already hooked by
security modules, mark the inodes with the S_PRIVATE flag so that inode
security initialization and permission checking is skipped.
This was motivated by the following lockdep warning:
======================================================
[ INFO: possible circular locking dependency detected ]
4.2.0-0.rc3.git0.1.fc24.x86_64+debug #1 Tainted: G W
-------------------------------------------------------
httpd/1597 is trying to acquire lock:
(&ids->rwsem){+++++.}, at: shm_close+0x34/0x130
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: SyS_shmdt+0x4b/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&mm->mmap_sem){++++++}:
lock_acquire+0xc7/0x270
__might_fault+0x7a/0xa0
filldir+0x9e/0x130
xfs_dir2_block_getdents.isra.12+0x198/0x1c0 [xfs]
xfs_readdir+0x1b4/0x330 [xfs]
xfs_file_readdir+0x2b/0x30 [xfs]
iterate_dir+0x97/0x130
SyS_getdents+0x91/0x120
entry_SYSCALL_64_fastpath+0x12/0x76
-> #2 (&xfs_dir_ilock_class){++++.+}:
lock_acquire+0xc7/0x270
down_read_nested+0x57/0xa0
xfs_ilock+0x167/0x350 [xfs]
xfs_ilock_attr_map_shared+0x38/0x50 [xfs]
xfs_attr_get+0xbd/0x190 [xfs]
xfs_xattr_get+0x3d/0x70 [xfs]
generic_getxattr+0x4f/0x70
inode_doinit_with_dentry+0x162/0x670
sb_finish_set_opts+0xd9/0x230
selinux_set_mnt_opts+0x35c/0x660
superblock_doinit+0x77/0xf0
delayed_superblock_init+0x10/0x20
iterate_supers+0xb3/0x110
selinux_complete_init+0x2f/0x40
security_load_policy+0x103/0x600
sel_write_load+0xc1/0x750
__vfs_write+0x37/0x100
vfs_write+0xa9/0x1a0
SyS_write+0x58/0xd0
entry_SYSCALL_64_fastpath+0x12/0x76
...
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reported-by: Morten Stevens <mstevens@fedoraproject.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we have many duplicates in definitions of
hugetlb_prefault_arch_hook. In all architectures this function is empty.
Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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
Merge second patchbomb from Andrew Morton:
- the rest of MM
- various misc bits
- add ability to run /sbin/reboot at reboot time
- printk/vsprintf changes
- fiddle with seq_printf() return value
* akpm: (114 commits)
parisc: remove use of seq_printf return value
lru_cache: remove use of seq_printf return value
tracing: remove use of seq_printf return value
cgroup: remove use of seq_printf return value
proc: remove use of seq_printf return value
s390: remove use of seq_printf return value
cris fasttimer: remove use of seq_printf return value
cris: remove use of seq_printf return value
openrisc: remove use of seq_printf return value
ARM: plat-pxa: remove use of seq_printf return value
nios2: cpuinfo: remove use of seq_printf return value
microblaze: mb: remove use of seq_printf return value
ipc: remove use of seq_printf return value
rtc: remove use of seq_printf return value
power: wakeup: remove use of seq_printf return value
x86: mtrr: if: remove use of seq_printf return value
linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
MAINTAINERS: CREDITS: remove Stefano Brivio from B43
.mailmap: add Ricardo Ribalda
CREDITS: add Ricardo Ribalda Delgado
...
Make 'min_size=<value>' be an option when mounting a hugetlbfs. This
option takes the same value as the 'size' option. min_size can be
specified without specifying size. If both are specified, min_size must
be less that or equal to size else the mount will fail. If min_size is
specified, then at mount time an attempt is made to reserve min_size
pages. If the reservation fails, the mount fails. At umount time, the
reserved pages are released.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull second vfs update from Al Viro:
"Now that net-next went in... Here's the next big chunk - killing
->aio_read() and ->aio_write().
There'll be one more pile today (direct_IO changes and
generic_write_checks() cleanups/fixes), but I'd prefer to keep that
one separate"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
->aio_read and ->aio_write removed
pcm: another weird API abuse
infinibad: weird APIs switched to ->write_iter()
kill do_sync_read/do_sync_write
fuse: use iov_iter_get_pages() for non-splice path
fuse: switch to ->read_iter/->write_iter
switch drivers/char/mem.c to ->read_iter/->write_iter
make new_sync_{read,write}() static
coredump: accept any write method
switch /dev/loop to vfs_iter_write()
serial2002: switch to __vfs_read/__vfs_write
ashmem: use __vfs_read()
export __vfs_read()
autofs: switch to __vfs_write()
new helper: __vfs_write()
switch hugetlbfs to ->read_iter()
coda: switch to ->read_iter/->write_iter
ncpfs: switch to ->read_iter/->write_iter
net/9p: remove (now-)unused helpers
p9_client_attach(): set fid->uid correctly
...
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>
This patch replaces cancel_dirty_page() with a helper function
account_page_cleaned() which only updates counters. It's called from
truncate_complete_page() and from try_to_free_buffers() (hack for ext3).
Page is locked in both cases, page-lock protects against concurrent
dirtiers: see commit 2d6d7f9828 ("mm: protect set_page_dirty() from
ongoing truncation").
Delete_from_page_cache() shouldn't be called for dirty pages, they must
be handled by caller (either written or truncated). This patch treats
final dirty accounting fixup at the end of __delete_from_page_cache() as
a debug check and adds WARN_ON_ONCE() around it. If something removes
dirty pages without proper handling that might be a bug and unwritten
data might be lost.
Hugetlbfs has no dirty pages accounting, ClearPageDirty() is enough
here.
cancel_dirty_page() in nfs_wb_page_cancel() is redundant. This is
helper for nfs_invalidate_page() and it's called only in case complete
invalidation.
The mess was started in v2.6.20 after commits 46d2277c79 ("Clean up
and make try_to_free_buffers() not race with dirty pages") and
3e67c0987d ("truncate: clear page dirtiness before running
try_to_free_buffers()") first was reverted right in v2.6.20 in commit
ecdfc9787f ("Resurrect 'try_to_free_buffers()' VM hackery"), second in
v2.6.25 commit a2b345642f ("Fix dirty page accounting leak with ext3
data=journal").
Custom fixes were introduced between these points. NFS in v2.6.23, commit
1b3b4a1a2d ("NFS: Fix a write request leak in nfs_invalidate_page()").
Kludge in __delete_from_page_cache() in v2.6.24, commit 3a6927906f ("Do
dirty page accounting when removing a page from the page cache"). Since
v2.6.25 all of them are redundant.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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>
hugetlbfs, kernfs and dlmfs can simply use noop_backing_dev_info instead
of creating a local duplicate.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
The i_mmap_mutex is a close cousin of the anon vma lock, both protecting
similar data, one for file backed pages and the other for anon memory. To
this end, this lock can also be a rwsem. In addition, there are some
important opportunities to share the lock when there are no tree
modifications.
This conversion is straightforward. For now, all users take the write
lock.
[sfr@canb.auug.org.au: update fremap.c]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix checkpatch warning:
WARNING: kfree(NULL) is safe this check is probably not required
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
...like other filesystems.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hugetlbfs_i_mmap_mutex_key is only used in inode.c
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, I am seeing the following when I `mount -t hugetlbfs /none
/dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`. I think it's
related to the fact that hugetlbfs is properly not correctly setting
itself up in this state?:
Unable to handle kernel paging request for data at address 0x00000031
Faulting instruction address: 0xc000000000245710
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048 NUMA pSeries
....
In KVM guests on Power, in a guest not backed by hugepages, we see the
following:
AnonHugePages: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 64 kB
HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
are not supported at boot-time, but this is only checked in
hugetlb_init(). Extract the check to a helper function, and use it in a
few relevant places.
This does make hugetlbfs not supported (not registered at all) in this
environment. I believe this is fine, as there are no valid hugepages
and that won't change at runtime.
[akpm@linux-foundation.org: use pr_info(), per Mel]
[akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, to track reserved and allocated regions, we use two different
ways, depending on the mapping. For MAP_SHARED, we use
address_mapping's private_list and, while for MAP_PRIVATE, we use a
resv_map.
Now, we are preparing to change a coarse grained lock which protect a
region structure to fine grained lock, and this difference hinder it.
So, before changing it, unify region structure handling, consistently
using a resv_map regardless of the kind of mapping.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Dave has reported the following lockdep splat:
=================================
[ INFO: inconsistent lock state ]
3.11.0-rc1+ #9 Not tainted
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/49 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&mapping->i_mmap_mutex){+.+.?.}, at: [<c114971b>] page_referenced+0x87/0x5e3
{RECLAIM_FS-ON-W} state was registered at:
mark_held_locks+0x81/0xe7
lockdep_trace_alloc+0x5e/0xbc
__alloc_pages_nodemask+0x8b/0x9b6
__get_free_pages+0x20/0x31
get_zeroed_page+0x12/0x14
__pmd_alloc+0x1c/0x6b
huge_pmd_share+0x265/0x283
huge_pte_alloc+0x5d/0x71
hugetlb_fault+0x7c/0x64a
handle_mm_fault+0x255/0x299
__do_page_fault+0x142/0x55c
do_page_fault+0xd/0x16
error_code+0x6c/0x74
irq event stamp: 3136917
hardirqs last enabled at (3136917): _raw_spin_unlock_irq+0x27/0x50
hardirqs last disabled at (3136916): _raw_spin_lock_irq+0x15/0x78
softirqs last enabled at (3136180): __do_softirq+0x137/0x30f
softirqs last disabled at (3136175): irq_exit+0xa8/0xaa
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&mapping->i_mmap_mutex);
<Interrupt>
lock(&mapping->i_mmap_mutex);
*** DEADLOCK ***
no locks held by kswapd0/49.
stack backtrace:
CPU: 1 PID: 49 Comm: kswapd0 Not tainted 3.11.0-rc1+ #9
Hardware name: Dell Inc. Precision WorkStation 490 /0DT031, BIOS A08 04/25/2008
Call Trace:
dump_stack+0x4b/0x79
print_usage_bug+0x1d9/0x1e3
mark_lock+0x1e0/0x261
__lock_acquire+0x623/0x17f2
lock_acquire+0x7d/0x195
mutex_lock_nested+0x6c/0x3a7
page_referenced+0x87/0x5e3
shrink_page_list+0x3d9/0x947
shrink_inactive_list+0x155/0x4cb
shrink_lruvec+0x300/0x5ce
shrink_zone+0x53/0x14e
kswapd+0x517/0xa75
kthread+0xa8/0xaa
ret_from_kernel_thread+0x1b/0x28
which is a false positive caused by hugetlb pmd sharing code which
allocates a new pmd from withing mapping->i_mmap_mutex. If this
allocation causes reclaim then the lockdep detector complains that we
might self-deadlock.
This is not correct though, because hugetlb pages are not reclaimable so
their mapping will be never touched from the reclaim path.
The patch tells lockup detector that hugetlb i_mmap_mutex is special by
assigning it a separate lockdep class so it won't report possible
deadlocks on unrelated mappings.
[peterz@infradead.org: comment for annotation]
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current kernel returns -EINVAL unless a given mmap length is
"almost" hugepage aligned. This is because in sys_mmap_pgoff() the
given length is passed to vm_mmap_pgoff() as it is without being aligned
with hugepage boundary.
This is a regression introduced in commit 40716e2924 ("hugetlbfs: fix
alignment of huge page requests"), where alignment code is pushed into
hugetlb_file_setup() and the variable len in caller side is not changed.
To fix this, this patch partially reverts that commit, and adds
alignment code in caller side. And it also introduces hstate_sizelog()
in order to get proper hstate to specified hugepage size.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=56881
[akpm@linux-foundation.org: fix warning when CONFIG_HUGETLB_PAGE=n]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: <iceman_dvd@yahoo.com>
Cc: Steven Truelove <steven.truelove@utoronto.ca>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we fail to include any data on hugepages into coredump,
because VM_DONTDUMP is set on hugetlbfs's vma. This behavior was
recently introduced by commit 314e51b985 ("mm: kill vma flag
VM_RESERVED and mm->reserved_vm counter").
This looks to me a serious regression, so let's fix it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [3.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Allocating a file structure in function get_empty_filp() might fail because
of several reasons:
- not enough memory for file structures
- operation is not allowed
- user is over its limit
Currently the function returns NULL in all cases and we loose the exact
reason of the error. All callers of get_empty_filp() assume that the function
can fail with ENFILE only.
Return error through pointer. Change all callers to preserve this error code.
[AV: cleaned up a bit, carved the get_empty_filp() part out into a separate commit
(things remaining here deal with alloc_file()), removed pipe(2) behaviour change]
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull trivial branch from Jiri Kosina:
"Usual stuff -- comment/printk typo fixes, documentation updates, dead
code elimination."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
HOWTO: fix double words typo
x86 mtrr: fix comment typo in mtrr_bp_init
propagate name change to comments in kernel source
doc: Update the name of profiling based on sysfs
treewide: Fix typos in various drivers
treewide: Fix typos in various Kconfig
wireless: mwifiex: Fix typo in wireless/mwifiex driver
messages: i2o: Fix typo in messages/i2o
scripts/kernel-doc: check that non-void fcts describe their return value
Kernel-doc: Convention: Use a "Return" section to describe return values
radeon: Fix typo and copy/paste error in comments
doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
various: Fix spelling of "asynchronous" in comments.
Fix misspellings of "whether" in comments.
eisa: Fix spelling of "asynchronous".
various: Fix spelling of "registered" in comments.
doc: fix quite a few typos within Documentation
target: iscsi: fix comment typos in target/iscsi drivers
treewide: fix typo of "suport" in various comments and Kconfig
treewide: fix typo of "suppport" in various comments
...
Memory fragmentation introduced by ballooning might reduce significantly
the number of 2MB contiguous memory blocks that can be used within a
guest, thus imposing performance penalties associated with the reduced
number of transparent huge pages that could be used by the guest workload.
This patch-set follows the main idea discussed at 2012 LSFMMS session:
"Ballooning for transparent huge pages" -- http://lwn.net/Articles/490114/
to introduce the required changes to the virtio_balloon driver, as well as
the changes to the core compaction & migration bits, in order to make
those subsystems aware of ballooned pages and allow memory balloon pages
become movable within a guest, thus avoiding the aforementioned
fragmentation issue
Following are numbers that prove this patch benefits on allowing
compaction to be more effective at memory ballooned guests.
Results for STRESS-HIGHALLOC benchmark, from Mel Gorman's mmtests suite,
running on a 4gB RAM KVM guest which was ballooning 512mB RAM in 64mB
chunks, at every minute (inflating/deflating), while test was running:
===BEGIN stress-highalloc
STRESS-HIGHALLOC
highalloc-3.7 highalloc-3.7
rc4-clean rc4-patch
Pass 1 55.00 ( 0.00%) 62.00 ( 7.00%)
Pass 2 54.00 ( 0.00%) 62.00 ( 8.00%)
while Rested 75.00 ( 0.00%) 80.00 ( 5.00%)
MMTests Statistics: duration
3.7 3.7
rc4-clean rc4-patch
User 1207.59 1207.46
System 1300.55 1299.61
Elapsed 2273.72 2157.06
MMTests Statistics: vmstat
3.7 3.7
rc4-clean rc4-patch
Page Ins 3581516 2374368
Page Outs 11148692 10410332
Swap Ins 80 47
Swap Outs 3641 476
Direct pages scanned 37978 33826
Kswapd pages scanned 1828245 1342869
Kswapd pages reclaimed 1710236 1304099
Direct pages reclaimed 32207 31005
Kswapd efficiency 93% 97%
Kswapd velocity 804.077 622.546
Direct efficiency 84% 91%
Direct velocity 16.703 15.682
Percentage direct scans 2% 2%
Page writes by reclaim 79252 9704
Page writes file 75611 9228
Page writes anon 3641 476
Page reclaim immediate 16764 11014
Page rescued immediate 0 0
Slabs scanned 2171904 2152448
Direct inode steals 385 2261
Kswapd inode steals 659137 609670
Kswapd skipped wait 1 69
THP fault alloc 546 631
THP collapse alloc 361 339
THP splits 259 263
THP fault fallback 98 50
THP collapse fail 20 17
Compaction stalls 747 499
Compaction success 244 145
Compaction failures 503 354
Compaction pages moved 370888 474837
Compaction move failure 77378 65259
===END stress-highalloc
This patch:
Introduce MIGRATEPAGE_SUCCESS as the default return code for
address_space_operations.migratepage() method and documents the expected
return code for the same method in failure cases.
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update the hugetlb_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.
Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There was some desire in large applications using MAP_HUGETLB or
SHM_HUGETLB to use 1GB huge pages on some mappings, and stay with 2MB on
others. This is useful together with NUMA policy: use 2MB interleaving
on some mappings, but 1GB on local mappings.
This patch extends the IPC/SHM syscall interfaces slightly to allow
specifying the page size.
It borrows some upper bits in the existing flag arguments and allows
encoding the log of the desired page size in addition to the *_HUGETLB
flag. When 0 is specified the default size is used, this makes the
change fully compatible.
Extending the internal hugetlb code to handle this is straight forward.
Instead of a single mount it just keeps an array of them and selects the
right mount based on the specified page size. When no page size is
specified it uses the mount of the default page size.
The change is not visible in /proc/mounts because internal mounts don't
appear there. It also has very little overhead: the additional mounts
just consume a super block, but not more memory when not used.
I also exported the new flags to the user headers (they were previously
under __KERNEL__). Right now only symbols for x86 and some other
architecture for 1GB and 2MB are defined. The interface should already
work for all other architectures though. Only architectures that define
multiple hugetlb sizes actually need it (that is currently x86, tile,
powerpc). However tile and powerpc have user configurable hugetlb
sizes, so it's not easy to add defines. A program on those
architectures would need to query sysfs and use the appropiate log2.
[akpm@linux-foundation.org: cleanups]
[rientjes@google.com: fix build]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I've legally changed my name with New York State, the US Social Security
Administration, et al. This patch propagates the name change and change
in initials and login to comments in the kernel source as well.
Signed-off-by: Nadia Yvette Chambers <nyc@holomorphy.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Implement an interval tree as a replacement for the VMA prio_tree. The
algorithms are similar to lib/interval_tree.c; however that code can't be
directly reused as the interval endpoints are not explicitly stored in the
VMA. So instead, the common algorithm is moved into a template and the
details (node type, how to get interval endpoints from the node, etc) are
filled in using the C preprocessor.
Once the interval tree functions are available, using them as a
replacement to the VMA prio tree is a relatively simple, mechanical job.
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:
| effect | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
This patch removes reserved_vm counter from mm_struct. Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.
Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.
remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.
[akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs update from Al Viro:
- big one - consolidation of descriptor-related logics; almost all of
that is moved to fs/file.c
(BTW, I'm seriously tempted to rename the result to fd.c. As it is,
we have a situation when file_table.c is about handling of struct
file and file.c is about handling of descriptor tables; the reasons
are historical - file_table.c used to be about a static array of
struct file we used to have way back).
A lot of stray ends got cleaned up and converted to saner primitives,
disgusting mess in android/binder.c is still disgusting, but at least
doesn't poke so much in descriptor table guts anymore. A bunch of
relatively minor races got fixed in process, plus an ext4 struct file
leak.
- related thing - fget_light() partially unuglified; see fdget() in
there (and yes, it generates the code as good as we used to have).
- also related - bits of Cyrill's procfs stuff that got entangled into
that work; _not_ all of it, just the initial move to fs/proc/fd.c and
switch of fdinfo to seq_file.
- Alex's fs/coredump.c spiltoff - the same story, had been easier to
take that commit than mess with conflicts. The rest is a separate
pile, this was just a mechanical code movement.
- a few misc patches all over the place. Not all for this cycle,
there'll be more (and quite a few currently sit in akpm's tree)."
Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
MAX_LFS_FILESIZE should be a loff_t
compat: fs: Generic compat_sys_sendfile implementation
fs: push rcu_barrier() from deactivate_locked_super() to filesystems
btrfs: reada_extent doesn't need kref for refcount
coredump: move core dump functionality into its own file
coredump: prevent double-free on an error path in core dumper
usb/gadget: fix misannotations
fcntl: fix misannotations
ceph: don't abuse d_delete() on failure exits
hypfs: ->d_parent is never NULL or negative
vfs: delete surplus inode NULL check
switch simple cases of fget_light to fdget
new helpers: fdget()/fdput()
switch o2hb_region_dev_write() to fget_light()
proc_map_files_readdir(): don't bother with grabbing files
make get_file() return its argument
vhost_set_vring(): turn pollstart/pollstop into bool
switch prctl_set_mm_exe_file() to fget_light()
switch xfs_find_handle() to fget_light()
switch xfs_swapext() to fget_light()
...
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: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Note sysctl_hugetlb_shm_group can only be written in the root user
in the initial user namespace, so we can assume sysctl_hugetlb_shm_group
is in the initial user namespace.
Cc: William Irwin <wli@holomorphy.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Use a mmu_gather instead of a temporary linked list for accumulating pages
when we unmap a hugepage range
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux
Pull writeback tree from Wu Fengguang:
"Mainly from Jan Kara to avoid iput() in the flusher threads."
* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
writeback: Avoid iput() from flusher thread
vfs: Rename end_writeback() to clear_inode()
vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
writeback: Refactor writeback_single_inode()
writeback: Remove wb->list_lock from writeback_single_inode()
writeback: Separate inode requeueing after writeback
writeback: Move I_DIRTY_PAGES handling
writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
writeback: Move clearing of I_SYNC into inode_sync_complete()
writeback: initialize global_dirty_limit
fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
mm: page-writeback.c: local functions should not be exposed globally
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
This fixes the below reported false lockdep warning. e096d0c7e2
("lockdep: Add helper function for dir vs file i_mutex annotation") added
a similar annotation for every other inode in hugetlbfs but missed the
root inode because it was allocated by a separate function.
For HugeTLB fs we allow taking i_mutex in mmap. HugeTLB fs doesn't
support file write and its file read callback is modified in a05b0855fd
("hugetlbfs: avoid taking i_mutex from hugetlbfs_read()") to not take
i_mutex. Hence for HugeTLB fs with regular files we really don't take
i_mutex with mmap_sem held.
======================================================
[ INFO: possible circular locking dependency detected ]
3.4.0-rc1+ #322 Not tainted
-------------------------------------------------------
bash/1572 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: [<ffffffff810f1618>] might_fault+0x40/0x90
but task is already holding lock:
(&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<ffffffff81125f88>] vfs_readdir+0x56/0xa8
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#12){+.+.+.}:
[<ffffffff810a09e5>] lock_acquire+0xd5/0xfa
[<ffffffff816a2f5e>] __mutex_lock_common+0x48/0x350
[<ffffffff816a3325>] mutex_lock_nested+0x2a/0x31
[<ffffffff811fb8e1>] hugetlbfs_file_mmap+0x7d/0x104
[<ffffffff810f859a>] mmap_region+0x272/0x47d
[<ffffffff810f8a39>] do_mmap_pgoff+0x294/0x2ee
[<ffffffff810f8b65>] sys_mmap_pgoff+0xd2/0x10e
[<ffffffff8103d19e>] sys_mmap+0x1d/0x1f
[<ffffffff816a5922>] system_call_fastpath+0x16/0x1b
-> #0 (&mm->mmap_sem){++++++}:
[<ffffffff810a0256>] __lock_acquire+0xa81/0xd75
[<ffffffff810a09e5>] lock_acquire+0xd5/0xfa
[<ffffffff810f1645>] might_fault+0x6d/0x90
[<ffffffff81125d62>] filldir+0x6a/0xc2
[<ffffffff81133a83>] dcache_readdir+0x5c/0x222
[<ffffffff81125fa8>] vfs_readdir+0x76/0xa8
[<ffffffff811260b6>] sys_getdents+0x79/0xc9
[<ffffffff816a5922>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#12);
lock(&mm->mmap_sem);
lock(&sb->s_type->i_mutex_key#12);
lock(&mm->mmap_sem);
*** DEADLOCK ***
1 lock held by bash/1572:
#0: (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<ffffffff81125f88>] vfs_readdir+0x56/0xa8
stack backtrace:
Pid: 1572, comm: bash Not tainted 3.4.0-rc1+ #322
Call Trace:
[<ffffffff81699a3c>] print_circular_bug+0x1f8/0x209
[<ffffffff810a0256>] __lock_acquire+0xa81/0xd75
[<ffffffff810f38aa>] ? handle_pte_fault+0x5ff/0x614
[<ffffffff8109e622>] ? mark_lock+0x2d/0x258
[<ffffffff810f1618>] ? might_fault+0x40/0x90
[<ffffffff810a09e5>] lock_acquire+0xd5/0xfa
[<ffffffff810f1618>] ? might_fault+0x40/0x90
[<ffffffff816a3249>] ? __mutex_lock_common+0x333/0x350
[<ffffffff810f1645>] might_fault+0x6d/0x90
[<ffffffff810f1618>] ? might_fault+0x40/0x90
[<ffffffff81125d62>] filldir+0x6a/0xc2
[<ffffffff81133a83>] dcache_readdir+0x5c/0x222
[<ffffffff81125cf8>] ? sys_ioctl+0x74/0x74
[<ffffffff81125cf8>] ? sys_ioctl+0x74/0x74
[<ffffffff81125cf8>] ? sys_ioctl+0x74/0x74
[<ffffffff81125fa8>] vfs_readdir+0x76/0xa8
[<ffffffff811260b6>] sys_getdents+0x79/0xc9
[<ffffffff816a5922>] system_call_fastpath+0x16/0x1b
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was introduced by d1d5e05ffd ("hugetlbfs: return error code when
initializing module") but as Al pointed out, is a bad idea.
Quoted comments from Al:
"Note that unregister_filesystem() in module init is *always* wrong;
it's not an issue here (it's done too early to care about and
realistically the box is not going anywhere - it'll panic when attempt
to exec /sbin/init fails, if not earlier), but it's a damn bad
example.
Consider a normal fs module. Somebody loads it and in parallel with
that we get a mount attempt on that fs type. It comes between
register and failure exits that causes unregister; at that point we
are screwed since grabbing a reference to module as done by mount is
enough to prevent exit, but not to prevent the failure of init. As
the result, module will get freed when init fails, mounted fs of that
type be damned."
So remove it.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
