Trond Myklebust [Mon, 28 Oct 2013 23:33:36 +0000 (19:33 -0400)]
Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next
Pull fs-cache fixes from David Howells:
Can you pull these commits to fix an issue with NFS whereby caching can be
enabled on a file that is open for writing by subsequently opening it for
reading. This can be made to crash by opening it for writing again if you're
quick enough.
The gist of the patchset is that the cookie should be acquired at inode
creation only and subsequently enabled and disabled as appropriate (which
dispenses with the backing objects when they're not needed).
The extra synchronisation that NFS does can then be dispensed with as it is
thenceforth managed by FS-Cache.
Could you send these on to Linus?
This likely will need fixing also in CIFS and 9P also once the FS-Cache
changes are upstream. AFS and Ceph are probably safe.
* 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()
FS-Cache: Provide the ability to enable/disable cookies
FS-Cache: Add use/unuse/wake cookie wrappers
J. Bruce Fields [Tue, 15 Oct 2013 21:03:16 +0000 (17:03 -0400)]
nfs: use IS_ROOT not DCACHE_DISCONNECTED
This check was added by Al Viro with d9e80b7de91db05c1c4d2e5ebbfd70b3b3ba0e0f "nfs d_revalidate() is too
trigger-happy with d_drop()", with the explanation that we don't want to
remove the root of a disconnected tree, which will still be included on
the s_anon list.
But DCACHE_DISCONNECTED does *not* actually identify dentries that are
disconnected from the dentry tree or hashed on s_anon. IS_ROOT() is the
way to do that.
Also add a comment from Al's commit to remind us why this check is
there.
Signed-off-by: J. Bruce Fields <bfields@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Trond Myklebust [Mon, 28 Oct 2013 22:18:00 +0000 (18:18 -0400)]
SUNRPC: Fix buffer overflow checking in gss_encode_v0_msg/gss_encode_v1_msg
In gss_encode_v1_msg, it is pointless to BUG() after the overflow has
happened. Replace the existing sprintf()-based code with scnprintf(),
and warn if an overflow is ever triggered.
In gss_encode_v0_msg, replace the runtime BUG_ON() with an appropriate
compile-time BUILD_BUG_ON.
Reported-by: Bruce Fields <bfields@fieldses.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch adds support for multiple security options which can be
specified using a colon-delimited list of security flavors (the same
syntax as nfsd's exports file).
This is useful, for instance, when NFSv4.x mounts cross SECINFO
boundaries. With this patch a user can use "sec=krb5i,krb5p"
to mount a remote filesystem using krb5i, but can still cross
into krb5p-only exports.
New mounts will try all security options before failing. NFSv4.x
SECINFO results will be compared against the sec= flavors to
find the first flavor in both lists or if no match is found will
return -EPERM.
Since the parsed sec= flavor is now stored in nfs_server->auth_info,
we no longer need an nfs_server flag to determine if a sec= option was
used.
This flag has not been completely removed because it is still needed for
the (old but still supported) non-text parsed mount options ABI
compatability.
Chuck Lever [Thu, 17 Oct 2013 18:14:10 +0000 (14:14 -0400)]
NFS: Fix possible endless state recovery wait
In nfs4_wait_clnt_recover(), hold a reference to the clp being
waited on. The state manager can reduce clp->cl_count to 1, in
which case the nfs_put_client() in nfs4_run_state_manager() can
free *clp before wait_on_bit() returns and allows
nfs4_wait_clnt_recover() to run again.
The behavior at that point is non-deterministic. If the waited-on
bit still happens to be zero, wait_on_bit() will wake the waiter as
expected. If the bit is set again (say, if the memory was poisoned
when freed) wait_on_bit() can leave the waiter asleep.
This is a narrow fix which ensures the safety of accessing *clp in
nfs4_wait_clnt_recover(), but does not address the continued use
of a possibly freed *clp after nfs4_wait_clnt_recover() returns
(see nfs_end_delegation_return(), for example).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:14:04 +0000 (14:14 -0400)]
NFS: Set EXCHGID4_FLAG_SUPP_MOVED_MIGR
Broadly speaking, v4.1 migration is untested. There are no servers
in the wild that support NFSv4.1 migration. However, as server
implementations become available, we do want to enable testing by
developers, while leaving it disabled for environments for which
broken migration support would be an unpleasant surprise.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:13:58 +0000 (14:13 -0400)]
NFS: Handle SEQ4_STATUS_LEASE_MOVED
With the advent of NFSv4 sessions in NFSv4.1 and following, a "lease
moved" condition is reported differently than it is in NFSv4.0.
NFSv4 minor version 0 servers return an error status code,
NFS4ERR_LEASE_MOVED, to signal that a lease has moved. This error
causes the whole compound operation to fail. Normal compounds
against this server continue to fail until the client performs
migration recovery on the migrated share.
Minor version 1 and later servers assert a bit flag in the reply to
a compound's SEQUENCE operation to signal LEASE_MOVED. This is not
a fatal condition: operations against this server continue normally.
The server asserts this flag until the client performs migration
recovery on the migrated share.
Note that servers MUST NOT return NFS4ERR_LEASE_MOVED to NFSv4
clients not using NFSv4.0.
After the server asserts any of the sr_status_flags in the SEQUENCE
operation in a typical compound, our client initiates standard lease
recovery. For NFSv4.1+, a stand-alone SEQUENCE operation is
performed to discover what recovery is needed.
If SEQ4_STATUS_LEASE_MOVED is asserted in this stand-alone SEQUENCE
operation, our client attempts to discover which FSIDs have been
migrated, and then performs migration recovery on each.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:13:53 +0000 (14:13 -0400)]
NFS: Handle NFS4ERR_LEASE_MOVED during async RENEW
With NFSv4 minor version 0, the asynchronous lease RENEW
heartbeat can return NFS4ERR_LEASE_MOVED. Error recovery logic for
async RENEW is a separate code path from the generic NFS proc paths,
so it must be updated to handle NFS4ERR_LEASE_MOVED as well.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:13:47 +0000 (14:13 -0400)]
NFS: Migration support for RELEASE_LOCKOWNER
Currently the Linux NFS client ignores the operation status code for
the RELEASE_LOCKOWNER operation. Like NFSv3's UMNT operation,
RELEASE_LOCKOWNER is a courtesy to help servers manage their
resources, and the outcome is not consequential for the client.
During a migration, a server may report NFS4ERR_LEASE_MOVED, in
which case the client really should retry, since typically
LEASE_MOVED has nothing to do with the current operation, but does
prevent it from going forward.
Also, it's important for a client to respond as soon as possible to
a moved lease condition, since the client's lease could expire on
the destination without further action by the client.
NFS4ERR_DELAY is not included in the list of valid status codes for
RELEASE_LOCKOWNER in RFC 3530bis. However, rfc3530-migration-update
does permit migration-capable servers to return DELAY to clients,
but only in the context of an ongoing migration. In this case the
server has frozen lock state in preparation for migration, and a
client retry would help the destination server purge unneeded state
once migration recovery is complete.
Interestly, NFS4ERR_MOVED is not valid for RELEASE_LOCKOWNER, even
though lock owners can be migrated with Transparent State Migration.
Note that RFC 3530bis section 9.5 includes RELEASE_LOCKOWNER in the
list of operations that renew a client's lease on the server if they
succeed. Now that our client pays attention to the operation's
status code, we can note that renewal appropriately.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:13:35 +0000 (14:13 -0400)]
NFS: Support NFS4ERR_LEASE_MOVED recovery in state manager
A migration on the FSID in play for the current NFS operation
is reported via the error status code NFS4ERR_MOVED.
"Lease moved" means that a migration has occurred on some other
FSID than the one for the current operation. It's a signal that
the client should take action immediately to handle a migration
that it may not have noticed otherwise. This is so that the
client's lease does not expire unnoticed on the destination server.
In NFSv4.0, a moved lease is reported with the NFS4ERR_LEASE_MOVED
error status code.
To recover from NFS4ERR_LEASE_MOVED, check each FSID for that server
to see if it is still present. Invoke nfs4_try_migration() if the
FSID is no longer present on the server.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:13:30 +0000 (14:13 -0400)]
NFS: Add method to detect whether an FSID is still on the server
Introduce a mechanism for probing a server to determine if an FSID
is present or absent.
The on-the-wire compound is different between minor version 0 and 1.
Minor version 0 appends a RENEW operation to identify which client
ID is probing. Minor version 1 has a SEQUENCE operation in the
compound which effectively carries the same information.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:12:50 +0000 (14:12 -0400)]
NFS: Add method to retrieve fs_locations during migration recovery
The nfs4_proc_fs_locations() function is invoked during referral
processing to perform a GETATTR(fs_locations) on an object's parent
directory in order to discover the target of the referral. It
performs a LOOKUP in the compound, so the client needs to know the
parent's file handle a priori.
Unfortunately this function is not adequate for handling migration
recovery. We need to probe fs_locations information on an FSID, but
there's no parent directory available for many operations that
can return NFS4ERR_MOVED.
Another subtlety: recovering from NFS4ERR_LEASE_MOVED is a process
of walking over a list of known FSIDs that reside on the server, and
probing whether they have migrated. Once the server has detected
that the client has probed all migrated file systems, it stops
returning NFS4ERR_LEASE_MOVED.
A minor version zero server needs to know what client ID is
requesting fs_locations information so it can clear the flag that
forces it to continue returning NFS4ERR_LEASE_MOVED. This flag is
set per client ID and per FSID. However, the client ID is not an
argument of either the PUTFH or GETATTR operations. Later minor
versions have client ID information embedded in the compound's
SEQUENCE operation.
Therefore, by convention, minor version zero clients send a RENEW
operation in the same compound as the GETATTR(fs_locations), since
RENEW's one argument is a clientid4. This allows a minor version
zero server to identify correctly the client that is probing for a
migration.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:12:34 +0000 (14:12 -0400)]
NFS: Add functions to swap transports during migration recovery
Introduce functions that can walk through an array of returned
fs_locations information and connect a transport to one of the
destination servers listed therein.
Note that NFS minor version 1 introduces "fs_locations_info" which
extends the locations array sorting criteria available to clients.
This is not supported yet.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:12:28 +0000 (14:12 -0400)]
NFS: Add nfs4_update_server
New function nfs4_update_server() moves an nfs_server to a different
nfs_client. This is done as part of migration recovery.
Though it may be appealing to think of them as the same thing,
migration recovery is not the same as following a referral.
For a referral, the client has not descended into the file system
yet: it has no nfs_server, no super block, no inodes or open state.
It is enough to simply instantiate the nfs_server and super block,
and perform a referral mount.
For a migration, however, we have all of those things already, and
they have to be moved to a different nfs_client. No local namespace
changes are needed here.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Chuck Lever [Thu, 17 Oct 2013 18:12:17 +0000 (14:12 -0400)]
SUNRPC: Modify synopsis of rpc_client_register()
The rpc_client_register() helper was added in commit e73f4cc0,
"SUNRPC: split client creation routine into setup and registration,"
Mon Jun 24 11:52:52 2013. In a subsequent patch, I'd like to invoke
rpc_client_register() from a context where a struct rpc_create_args
is not available.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cached opens have already been handled by _nfs4_opendata_reclaim_to_nfs4_state
and can safely skip being reprocessed, but must still call update_open_stateid
to make sure that all active fmodes are recovered.
Trond Myklebust [Mon, 28 Oct 2013 18:57:12 +0000 (14:57 -0400)]
NFSv4: Fix state reference counting in _nfs4_opendata_reclaim_to_nfs4_state
Currently, if the call to nfs_refresh_inode fails, then we end up leaking
a reference count, due to the call to nfs4_get_open_state.
While we're at it, replace nfs4_get_open_state with a simple call to
atomic_inc(); there is no need to do a full lookup of the struct nfs_state
since it is passed as an argument in the struct nfs4_opendata, and
is already assigned to the variable 'state'.
_nfs4_opendata_reclaim_to_nfs4_state doesn't expect to see a cached
open CLAIM_PREVIOUS, but this can happen. An example is when there are
RDWR openers and RDONLY openers on a delegation stateid. The recovery
path will first try an open CLAIM_PREVIOUS for the RDWR openers, this
marks the delegation as not needing RECLAIM anymore, so the open
CLAIM_PREVIOUS for the RDONLY openers will not actually send an rpc.
The NULL dereference is due to _nfs4_opendata_reclaim_to_nfs4_state
returning PTR_ERR(rpc_status) when !rpc_done. When the open is
cached, rpc_done == 0 and rpc_status == 0, thus
_nfs4_opendata_reclaim_to_nfs4_state returns NULL - this is unexpected
by callers of nfs4_opendata_to_nfs4_state().
This can be reproduced easily by opening the same file two times on an
NFSv4.0 mount with delegations enabled, once as RDWR and once as RDONLY then
sleeping for a long time. While the files are held open, kick off state
recovery and this NULL dereference will be hit every time.
Trond Myklebust [Mon, 28 Oct 2013 18:50:38 +0000 (14:50 -0400)]
NFSv4.1: Don't change the security label as part of open reclaim.
The current caching model calls for the security label to be set on
first lookup and/or on any subsequent label changes. There is no
need to do it as part of an open reclaim.
SUNRPC: call_connect_status should recheck bind and connect status on error
Currently, we go directly to call_transmit which sends us to call_status
on error. If we know that the connect attempt failed, we should rather
just jump straight back to call_bind and call_connect.
SUNRPC: Don't set the request connect_cookie until a successful transmit
We're using the request connect_cookie to track whether or not a
request was successfully transmitted on the current transport
connection or not. For that reason we should ensure that it is
only set after we've successfully transmitted the request.
SUNRPC: Enable the keepalive option for TCP sockets
For NFSv4 we want to avoid retransmitting RPC calls unless the TCP
connection breaks. However we still want to detect TCP connection
breakage as soon as possible. Do this by setting the keepalive option
with the idle timeout and count set to the 'timeo' and 'retrans' mount
options.
The problem is that we don't clear the request->fl_ops after the first
try and so when we retry, nfs4_set_lock_state() exits early without
setting the lock stateid.
Regression introduced by commit 70cc6487a4e08b8698c0e2ec935fb48d10490162
(locks: make ->lock release private data before returning in GETLK case)
Linus Torvalds [Tue, 1 Oct 2013 00:10:26 +0000 (17:10 -0700)]
Merge tag 'nfs-for-3.12-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
- Stable fix for Oopses in the pNFS files layout driver
- Fix a regression when doing a non-exclusive file create on NFSv4.x
- NFSv4.1 security negotiation fixes when looking up the root
filesystem
- Fix a memory ordering issue in the pNFS files layout driver
* tag 'nfs-for-3.12-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Give "flavor" an initial value to fix a compile warning
NFSv4.1: try SECINFO_NO_NAME flavs until one works
NFSv4.1: Ensure memory ordering between nfs4_ds_connect and nfs4_fl_prepare_ds
NFSv4.1: nfs4_fl_prepare_ds - fix bugs when the connect attempt fails
NFSv4: Honour the 'opened' parameter in the atomic_open() filesystem method
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
pidns: fix free_pid() to handle the first fork failure
ipc,msg: prevent race with rmid in msgsnd,msgrcv
ipc/sem.c: update sem_otime for all operations
mm/hwpoison: fix the lack of one reference count against poisoned page
mm/hwpoison: fix false report on 2nd attempt at page recovery
mm/hwpoison: fix test for a transparent huge page
mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood
block: change config option name for cmdline partition parsing
mm/mlock.c: prevent walking off the end of a pagetable in no-pmd configuration
mm: avoid reinserting isolated balloon pages into LRU lists
arch/parisc/mm/fault.c: fix uninitialized variable usage
include/asm-generic/vtime.h: avoid zero-length file
nilfs2: fix issue with race condition of competition between segments for dirty blocks
Documentation/kernel-parameters.txt: replace kernelcore with Movable
mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored
kernel/kmod.c: check for NULL in call_usermodehelper_exec()
ipc/sem.c: synchronize the proc interface
ipc/sem.c: optimize sem_lock()
ipc/sem.c: fix race in sem_lock()
mm/compaction.c: periodically schedule when freeing pages
...
This fixes a race in both msgrcv() and msgsnd() between finding the msg
and actually dealing with the queue, as another thread can delete shmid
underneath us if we are preempted before acquiring the
kern_ipc_perm.lock.
Manfred illustrates this nicely:
Assume a preemptible kernel that is preempted just after
msq = msq_obtain_object_check(ns, msqid)
in do_msgrcv(). The only lock that is held is rcu_read_lock().
Now the other thread processes IPC_RMID. When the first task is
resumed, then it will happily wait for messages on a deleted queue.
Fix this by checking for if the queue has been deleted after taking the
lock.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reported-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: <stable@vger.kernel.org> [3.11] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit 0a2b9d4c7967 ("ipc/sem.c: move wake_up_process out of the
spinlock section"), the update of semaphore's sem_otime(last semop time)
was moved to one central position (do_smart_update).
But since do_smart_update() is only called for operations that modify
the array, this means that wait-for-zero semops do not update sem_otime
anymore.
The fix is simple:
Non-alter operations must update sem_otime.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Jia He <jiakernel@gmail.com> Tested-by: Jia He <jiakernel@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wanpeng Li [Mon, 30 Sep 2013 20:45:24 +0000 (13:45 -0700)]
mm/hwpoison: fix the lack of one reference count against poisoned page
The lack of one reference count against poisoned page for hwpoison_inject
w/o hwpoison_filter enabled result in hwpoison detect -1 users still
referenced the page, however, the number should be 0 except the poison
handler held one after successfully unmap. This patch fix it by hold one
referenced count against poisoned page for hwpoison_inject w/ and w/o
hwpoison_filter enabled.
Before patch:
[ 71.902112] Injecting memory failure at pfn 224706
[ 71.902137] MCE 0x224706: dirty LRU page recovery: Failed
[ 71.902138] MCE 0x224706: dirty LRU page still referenced by -1 users
Wanpeng Li [Mon, 30 Sep 2013 20:45:23 +0000 (13:45 -0700)]
mm/hwpoison: fix false report on 2nd attempt at page recovery
If the page is poisoned by software injection w/ MF_COUNT_INCREASED
flag, there is a false report during the 2nd attempt at page recovery
which is not truthful.
This patch fixes it by reporting the first attempt to try free buddy
page recovery if MF_COUNT_INCREASED is set.
Wanpeng Li [Mon, 30 Sep 2013 20:45:21 +0000 (13:45 -0700)]
mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood
madvise_hwpoison won't check if the page is small page or huge page and
traverses in small page granularity against the range unconditionally,
which result in a printk flood "MCE xxx: already hardware poisoned" if
the page is a huge page.
This patch fixes it by using compound_order(compound_head(page)) for
huge page iterator.
Paul Gortmaker [Mon, 30 Sep 2013 20:45:19 +0000 (13:45 -0700)]
block: change config option name for cmdline partition parsing
Recently commit bab55417b10c ("block: support embedded device command
line partition") introduced CONFIG_CMDLINE_PARSER. However, that name
is too generic and sounds like it enables/disables generic kernel boot
arg processing, when it really is block specific.
Before this option becomes a part of a full/final release, add the BLK_
prefix to it so that it is clear in absence of any other context that it
is block specific.
In addition, fix up the following less critical items:
- help text was not really at all helpful.
- index file for Documentation was not updated
- add the new arg to Documentation/kernel-parameters.txt
- clarify wording in source comments
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Cai Zhiyong <caizhiyong@huawei.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mlock.c: prevent walking off the end of a pagetable in no-pmd configuration
The function __munlock_pagevec_fill() introduced in commit 7a8010cd3627
("mm: munlock: manual pte walk in fast path instead of
follow_page_mask()") uses pmd_addr_end() for restricting its operation
within current page table.
This is insufficient on architectures/configurations where pmd is folded
and pmd_addr_end() just returns the end of the full range to be walked.
In this case, it allows pte++ to walk off the end of a page table
resulting in unpredictable behaviour.
This patch fixes the function by using pgd_addr_end() and pud_addr_end()
before pmd_addr_end(), which will yield correct page table boundary on
all configurations. This is similar to what existing page walkers do
when walking each level of the page table.
Additionaly, the patch clarifies a comment for get_locked_pte() call in the
function.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Cc: Jörn Engel <joern@logfs.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rafael Aquini [Mon, 30 Sep 2013 20:45:16 +0000 (13:45 -0700)]
mm: avoid reinserting isolated balloon pages into LRU lists
Isolated balloon pages can wrongly end up in LRU lists when
migrate_pages() finishes its round without draining all the isolated
page list.
The same issue can happen when reclaim_clean_pages_from_list() tries to
reclaim pages from an isolated page list, before migration, in the CMA
path. Such balloon page leak opens a race window against LRU lists
shrinkers that leads us to the following kernel panic:
This patch fixes the issue, by assuring the proper tests are made at
putback_movable_pages() & reclaim_clean_pages_from_list() to avoid
isolated balloon pages being wrongly reinserted in LRU lists.
But such error messages are consequence of file system's issue that takes
place more earlier. Fortunately, Jerome Poulin <jeromepoulin@gmail.com>
and Anton Eliasson <devel@antoneliasson.se> were reported about another
issue not so recently. These reports describe the issue with segctor
thread's crash:
BUG: unable to handle kernel paging request at 0000000000004c83
IP: nilfs_end_page_io+0x12/0xd0 [nilfs2]
These two issues have one reason. This reason can raise third issue
too. Third issue results in hanging of segctor thread with eating of
100% CPU.
REPRODUCING PATH:
One of the possible way or the issue reproducing was described by
Jermoe me Poulin <jeromepoulin@gmail.com>:
1. init S to get to single user mode.
2. sysrq+E to make sure only my shell is running
3. start network-manager to get my wifi connection up
4. login as root and launch "screen"
5. cd /boot/log/nilfs which is a ext3 mount point and can log when NILFS dies.
6. lscp | xz -9e > lscp.txt.xz
7. mount my snapshot using mount -o cp=3360839,ro /dev/vgUbuntu/root /mnt/nilfs
8. start a screen to dump /proc/kmsg to text file since rsyslog is killed
9. start a screen and launch strace -f -o find-cat.log -t find
/mnt/nilfs -type f -exec cat {} > /dev/null \;
10. start a screen and launch strace -f -o apt-get.log -t apt-get update
11. launch the last command again as it did not crash the first time
12. apt-get crashes
13. ps aux > ps-aux-crashed.log
13. sysrq+W
14. sysrq+E wait for everything to terminate
15. sysrq+SUSB
Simplified way of the issue reproducing is starting kernel compilation
task and "apt-get update" in parallel.
REPRODUCIBILITY:
The issue is reproduced not stable [60% - 80%]. It is very important to
have proper environment for the issue reproducing. The critical
conditions for successful reproducing:
(1) It should have big modified file by mmap() way.
(2) This file should have the count of dirty blocks are greater that
several segments in size (for example, two or three) from time to time
during processing.
(3) It should be intensive background activity of files modification
in another thread.
INVESTIGATION:
First of all, it is possible to see that the reason of crash is not valid
page address:
Moreover, value of b_page (0x1a82) is 6786. This value looks like segment
number. And b_blocknr with b_size values look like block numbers. So,
buffer_head's pointer points on not proper address value.
Detailed investigation of the issue is discovered such picture:
Usually, for every segment we collect dirty files in list. Then, dirty
blocks are gathered for every dirty file, prepared for write and
submitted by means of nilfs_segbuf_submit_bh() call. Finally, it takes
place complete write phase after calling nilfs_end_bio_write() on the
block layer. Buffers/pages are marked as not dirty on final phase and
processed files removed from the list of dirty files.
It is possible to see that we had three prepare_write and submit_bio
phases before segbuf_wait and complete_write phase. Moreover, segments
compete between each other for dirty blocks because on every iteration
of segments processing dirty buffer_heads are added in several lists of
payload_buffers:
The next pointer is the same but prev pointer has changed. It means
that buffer_head has next pointer from one list but prev pointer from
another. Such modification can be made several times. And, finally, it
can be resulted in various issues: (1) segctor hanging, (2) segctor
crashing, (3) file system metadata corruption.
FIX:
This patch adds:
(1) setting of BH_Async_Write flag in nilfs_segctor_prepare_write()
for every proccessed dirty block;
(2) checking of BH_Async_Write flag in
nilfs_lookup_dirty_data_buffers() and
nilfs_lookup_dirty_node_buffers();
(3) clearing of BH_Async_Write flag in nilfs_segctor_complete_write(),
nilfs_abort_logs(), nilfs_forget_buffer(), nilfs_clear_dirty_page().
Reported-by: Jerome Poulin <jeromepoulin@gmail.com> Reported-by: Anton Eliasson <devel@antoneliasson.se> Cc: Paul Fertser <fercerpav@gmail.com> Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp> Cc: Piotr Szymaniak <szarpaj@grubelek.pl> Cc: Juan Barry Manuel Canham <Linux@riotingpacifist.net> Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com> Cc: Elmer Zhang <freeboy6716@gmail.com> Cc: Kenneth Langga <klangga@gmail.com> Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Darrick J. Wong [Mon, 30 Sep 2013 20:45:09 +0000 (13:45 -0700)]
mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored
The "force" parameter in __blk_queue_bounce was being ignored, which
means that stable page snapshots are not always happening (on ext3).
This of course leads to DIF disks reporting checksum errors, so fix this
regression.
The regression was introduced in commit 6bc454d15004 ("bounce: Refactor
__blk_queue_bounce to not use bi_io_vec")
Reported-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/kmod.c: check for NULL in call_usermodehelper_exec()
If /proc/sys/kernel/core_pattern contains only "|", a NULL pointer
dereference happens upon core dump because argv_split("") returns
argv[0] == NULL.
This bug was once fixed by commit 264b83c07a84 ("usermodehelper: check
subprocess_info->path != NULL") but was by error reintroduced by commit 7f57cfa4e2aa ("usermodehelper: kill the sub_info->path[0] check").
This bug seems to exist since 2.6.19 (the version which core dump to
pipe was added). Depending on kernel version and config, some side
effect might happen immediately after this oops (e.g. kernel panic with
2.6.32-358.18.1.el6).
The proc interface is not aware of sem_lock(), it instead calls
ipc_lock_object() directly. This means that simple semop() operations
can run in parallel with the proc interface. Right now, this is
uncritical, because the implementation doesn't do anything that requires
a proper synchronization.
But it is dangerous and therefore should be fixed.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Operations that need access to the whole array must guarantee that there
are no simple operations ongoing. Right now this is achieved by
spin_unlock_wait(sem->lock) on all semaphores.
If complex_count is nonzero, then this spin_unlock_wait() is not
necessary, because it was already performed in the past by the thread
that increased complex_count and even though sem_perm.lock was dropped
inbetween, no simple operation could have started, because simple
operations cannot start when complex_count is non-zero.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The exclusion of complex operations in sem_lock() is insufficient: after
acquiring the per-semaphore lock, a simple op must first check that
sem_perm.lock is not locked and only after that test check
complex_count. The current code does it the other way around - and that
creates a race. Details are below.
The patch is a complete rewrite of sem_lock(), based in part on the code
from Mike Galbraith. It removes all gotos and all loops and thus the
risk of livelocks.
I have tested the patch (together with the next one) on my i3 laptop and
it didn't cause any problems.
The bug is probably also present in 3.10 and 3.11, but for these kernels
it might be simpler just to move the test of sma->complex_count after
the spin_is_locked() test.
Details of the bug:
Assume:
- sma->complex_count = 0.
- Thread 1: semtimedop(complex op that must sleep)
- Thread 2: semtimedop(simple op).
Pseudo-Trace:
Thread 1: sem_lock(): acquire sem_perm.lock
Thread 1: sem_lock(): check for ongoing simple ops
Nothing ongoing, thread 2 is still before sem_lock().
Thread 1: try_atomic_semop()
<<< preempted.
Thread 2: sem_lock():
static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
int nsops)
{
int locknum;
again:
if (nsops == 1 && !sma->complex_count) {
struct sem *sem = sma->sem_base + sops->sem_num;
/* Lock just the semaphore we are interested in. */
spin_lock(&sem->lock);
/*
* If sma->complex_count was set while we were spinning,
* we may need to look at things we did not lock here.
*/
if (unlikely(sma->complex_count)) {
spin_unlock(&sem->lock);
goto lock_array;
}
<<<<<<<<<
<<< complex_count is still 0.
<<<
<<< Here it is preempted
<<<<<<<<<
Thread 1: try_atomic_semop() returns, notices that it must sleep.
Thread 1: increases sma->complex_count.
Thread 1: drops sem_perm.lock
Thread 2:
/*
* Another process is holding the global lock on the
* sem_array; we cannot enter our critical section,
* but have to wait for the global lock to be released.
*/
if (unlikely(spin_is_locked(&sma->sem_perm.lock))) {
spin_unlock(&sem->lock);
spin_unlock_wait(&sma->sem_perm.lock);
goto again;
}
<<< sem_perm.lock already dropped, thus no "goto again;"
locknum = sops->sem_num;
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Mike Galbraith <bitbucket@online.de> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Mon, 30 Sep 2013 20:45:03 +0000 (13:45 -0700)]
mm/compaction.c: periodically schedule when freeing pages
We've been getting warnings about an excessive amount of time spent
allocating pages for migration during memory compaction without
scheduling. isolate_freepages_block() already periodically checks for
contended locks or the need to schedule, but isolate_freepages() never
does.
When a zone is massively long and no suitable targets can be found, this
iteration can be quite expensive without ever doing cond_resched().
Check periodically for the need to reschedule while the compaction free
scanner iterates.
Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Aloni [Mon, 30 Sep 2013 20:45:02 +0000 (13:45 -0700)]
fs/binfmt_elf.c: prevent a coredump with a large vm_map_count from Oopsing
A high setting of max_map_count, and a process core-dumping with a large
enough vm_map_count could result in an NT_FILE note not being written,
and the kernel crashing immediately later because it has assumed
otherwise.
Reproduction of the oops-causing bug described here:
https://lkml.org/lkml/2013/8/30/50
Rge ussue originated in commit 2aa362c49c31 ("coredump: extend core dump
note section to contain file names of mapped file") from Oct 4, 2012.
This patch make that section optional in that case. fill_files_note()
should signify the error, and also let the info struct in
elf_core_dump() be zero-initialized so that we can check for the
optionally written note.
[akpm@linux-foundation.org: avoid abusing E2BIG, remove a couple of not-really-needed local variables]
[akpm@linux-foundation.org: fix sparse warning] Signed-off-by: Dan Aloni <alonid@stratoscale.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Denys Vlasenko <vda.linux@googlemail.com> Reported-by: Martin MOKREJS <mmokrejs@gmail.com> Tested-by: Martin MOKREJS <mmokrejs@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
revert "mm/memory-hotplug: fix lowmem count overflow when offline pages"
This reverts commit cea27eb2a202 ("mm/memory-hotplug: fix lowmem count
overflow when offline pages").
The fixed bug by commit cea27eb was fixed to another way by commit 3dcc0571cd64 ("mm: correctly update zone->managed_pages"). That commit
enhances memory_hotplug.c to adjust totalhigh_pages when hot-removing
memory, for details please refer to:
Merge tag 'regulator-v3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
"Quite a few fixes here, mostly small driver specific ones.
The stand out thing is a fix for errors generating the documentation
from Randy Dunlap, otherwise unless you're using the driver in
question there should be no impact"
* tag 'regulator-v3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: ti-abb: Fix bias voltage glitch in transition to bypass mode
regulator: wm831x-ldo: Fix max_uV for gp_ldo and aldo linear range settings
regulator: wm8350: correct the max_uV of LDO
regulator: fix fatal kernel-doc error
regulator: palmas: Remove wrong comment for the equation calculating num_voltages
regulator: da9063: Fix PTR_ERR/ERR_PTR mismatch
regulator: palmas: configure enable time for LDOs
regulator: palmas: fix the n_voltages for smps to 122
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull apparmor fixes from James Morris:
"Bugfixes for the Apparmor code for regressions introduced in the 3.12
pull request"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
apparmor: fix suspicious RCU usage warning in policy.c/policy.h
apparmor: Use shash crypto API interface for profile hashes
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull assorted vfs fixes from Al Viro:
"A couple of bug fixes + removal of dead code in afs ->d_revalidate()"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
afs: dget_parent() can't return a negative dentry
ocfs2: needs ->d_lock to poke in ->d_parent->d_inode from ->d_revalidate()
sysv: Add forgotten superblock lock init for v7 fs
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32
Pull AVR32 fixes from Hans-Christian Egtvedt.
Fix build warnings and use the Kbuild infrastructure for generic headers
rather than doing it by hand.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32:
avr32: cast syscall_return to silence compiler warning
avr32: fix clockevents kernel warning
avr32: use Kbuild infrastructure to handle the asm-generic headers
Merge tag 'for-linus-20130929' of git://github.com/sctscore/official-linux
Pull S+core fixes from Lennox Wu:
"These updates include updating information of maintainers, fix some
trivial errors, and add a necessary function for supporting ipv6"
* tag 'for-linus-20130929' of git://github.com/sctscore/official-linux:
Score: Update the information of Score maintaners
Score: Modify the Makefile of Score, remove -mlong-calls for compiling
Score: Implement the function csum_ipv6_magic
Score: The commit is for compiling successfully
Merge tag 'arc-fixes-for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC Fixes from Vineet Gupta:
- Handle unaligned access in zero delay loops
- spinlock livelock fix for SMP systemC model
- fix 32bit overflow in access_ok
- better setup of clockevents
* tag 'arc-fixes-for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: Use clockevents_config_and_register over clockevents_register_device
ARC: Workaround spinlock livelock in SMP SystemC simulation
ARC: Fix 32-bit wrap around in access_ok()
ARC: Handle zero-overhead-loop in unaligned access handler
avr32: cast syscall_return to silence compiler warning
The patch fixes the following compiler warning:
CC arch/avr32/kernel/process.o
arch/avr32/kernel/process.c: In function 'copy_thread':
arch/avr32/kernel/process.c:292: warning: assignment makes integer \
from pointer without a cast
WARNING: at 900322e4 [verbose debug info unavailable]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.12.0-rc2 #117
task: 901c3ecc ti: 901c0000 task.ti: 901c0000
PC is at cpu_idle_poll_ctrl+0x1c/0x38
LR is at comparator_mode+0x3e/0x40
pc : [<900322e4>] lr : [<90014882>] Not tainted
sp : 901c1f74 r12: 00000000 r11: 901c74a0
r10: 901d2510 r9 : 00000001 r8 : 901db4de
r7 : 901c74a0 r6 : 00000001 r5 : 00410020 r4 : 901db574
r3 : 00410024 r2 : 90206fe0 r1 : 00000000 r0 : 007f0000
Flags: qvnzc
Mode bits: hjmde....G
CPU Mode: Supervisor
Call trace:
[<90039ede>] clockevents_set_mode+0x16/0x2e
[<90039f00>] clockevents_shutdown+0xa/0x1e
[<9003a078>] clockevents_exchange_device+0x58/0x70
[<9003a78c>] tick_check_new_device+0x38/0x54
[<9003a1a2>] clockevents_register_device+0x32/0x90
[<900035c4>] time_init+0xa8/0x108
[<90000520>] start_kernel+0x128/0x23c
When the 'avr32_comparator' clockevent device is registered,
the clockevent core sets the mode of that clockevent device
to CLOCK_EVT_MODE_SHUTDOWN. Due to this, the 'comparator_mode'
function calls the 'cpu_idle_poll_ctrl' to disables idle poll.
This results in the aforementioned warning because the polling
is not enabled yet.
Change the code to only disable idle poll if it is enabled by
the same function to avoid the warning.
sysv: Add forgotten superblock lock init for v7 fs
Superblock lock was replaced with (un)lock_super() removal, but left
uninitialized for Seventh Edition UNIX filesystem in the following commit (3.7): c07cb01 sysv: drop lock/unlock super
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
apparmor: Use shash crypto API interface for profile hashes
Use the shash interface, rather than the hash interface, when hashing
AppArmor profiles. The shash interface does not use scatterlists and it
is a better fit for what AppArmor needs.
This fixes a kernel paging BUG when aa_calc_profile_hash() is passed a
buffer from vmalloc(). The hash interface requires callers to handle
vmalloc() buffers differently than what AppArmor was doing. Due to
vmalloc() memory not being physically contiguous, each individual page
behind the buffer must be assigned to a scatterlist with sg_set_page()
and then the scatterlist passed to crypto_hash_update().
The shash interface does not have that limitation and allows vmalloc()
and kmalloc() buffers to be handled in the same manner.
projects / ~andy / linux / log