Yan, Zheng [Wed, 4 May 2016 03:05:10 +0000 (11:05 +0800)]
ceph: keep leaf frag when updating fragtree
Nodes in i_fragtree are sorted according to ceph_compare_frag().
It means frag node in i_fragtree always follow its direct parent
node. To check if a leaf node is valid, we just need to check if
it's child of previous split node.
Yan, Zheng [Tue, 3 May 2016 12:55:50 +0000 (20:55 +0800)]
ceph: don't assume frag tree splits in mds reply are sorted
The algorithm that updates i_fragtree relies on that the frag tree
splits in mds reply are of the same order of i_fragtree. This is not
true because current MDS encodes frag tree splits in ascending order
of (unsigned)frag_t. But nodes in i_fragtree are sorted according to
ceph_frag_compare().
The fix is sort the frag tree splits first, then updates i_fragtree.
This offset is stable across directory fragmentation. This alos means
there is no need to reset readdir offset if directory get fragmented
in the middle of readdir.
ceph: don't forbid marking directory complete after forward seek
Forward seek within same frag does not update fi->last_name, it will
not affect contents of later readdir reply. So there is no need to
forbid marking directory complete
ceph: define 'end/complete' in readdir reply as bit flags
Set a flag in readdir request, which indicates that client interprets
'end/complete' as bit flags. So that mds can reply additional flags in
readdir reply.
ceph: use CEPH_MDS_OP_RMXATTR request to remove xattr
Setxattr with NULL value and XATTR_REPLACE flag should be equivalent
to removexattr. But current MDS does not support deleting vxattrs through
MDS_OP_SETXATTR request. The workaround is sending MDS_OP_RMXATTR request
if setxattr actually removs xattr.
ceph: don't call truncate_pagecache in ceph_writepages_start
truncate_pagecache() may decrease inode's reference. This can cause
deadlock if inode's last reference is dropped and iput_final() wants
to evict the inode. (evict() calls inode_wait_for_writeback(), which
waits for ceph_writepages_start() to return).
The fix is use work thead to truncate dirty pages. Also add 'forced
umount' check to ceph_update_writeable_page(), which prevents new
pages getting dirty.
ceph: renew caps for read/write if mds session got killed.
When mds session gets killed, read/write operation may hang.
Client waits for Frw caps, but mds does not know what caps client
wants. To recover this, client sends an open request to mds. The
request will tell mds what caps client wants.
This adds the "map check" infrastructure for sending osdmap version
checks on CALC_TARGET_POOL_DNE and completing in-flight requests with
-ENOENT if the target pool doesn't exist or has just been deleted.
For map check, we are going to need to send CEPH_MSG_MON_GET_VERSION
messages asynchronously and get a callback on completion. Refactor MON
client to allow firing off generic requests asynchronously and add an
async variant of ceph_monc_get_version(). ceph_monc_do_statfs() is
switched over and remains sync.
Implement ceph_osdc_watch_check() to be able to check on status of
watch. Note that the time it takes for a watch/notify event to get
delivered through the notify_wq is taken into account.
Implement ceph_osdc_notify() for sending notifies.
Due to the fact that the current messenger can't do read-in into
pagelists (it can only do write-out from them), I had to go with a page
vector for a NOTIFY_COMPLETE payload, for now.
This adds support and switches rbd to a new, more reliable version of
watch/notify protocol. As with the OSD client update, this is mostly
about getting the right structures linked into the right places so that
reconnects are properly sent when needed. watch/notify v2 also
requires sending regular pings to the OSDs - send_linger_ping().
A major change from the old watch/notify implementation is the
introduction of ceph_osd_linger_request - linger requests no longer
piggy back on ceph_osd_request. ceph_osd_event has been merged into
ceph_osd_linger_request.
All the details are now hidden within libceph, the interface consists
of a simple pair of watch/unwatch functions and ceph_osdc_notify_ack().
ceph_osdc_watch() does return ceph_osd_linger_request, but only to keep
the lifetime management simple.
ceph_osdc_notify_ack() accepts an optional data payload, which is
relayed back to the notifier.
Portions of this patch are loosely based on work by Douglas Fuller
<dfuller@redhat.com> and Mike Christie <michaelc@cs.wisc.edu>.
Introduce __rbd_dev_header_unwatch_sync(), which doesn't flush notify
callbacks. This is for the new rados_watcherrcb_t, which would be
called from a notify callback.
The unwatch timeout is currently implemented in rbd. With
watch/unwatch code moving into libceph, we are going to need
a ceph_osdc_wait_request() variant with a timeout.
This is a major sync up, up to ~Jewel. The highlights are:
- per-session request trees (vs a global per-client tree)
- per-session locking (vs a global per-client rwlock)
- homeless OSD session
- no ad-hoc global per-client lists
- support for pool quotas
- foundation for watch/notify v2 support
- foundation for map check (pool deletion detection) support
The switchover is incomplete: lingering requests can be setup and
teared down but aren't ever reestablished. This functionality is
restored with the introduction of the new lingering infrastructure
(ceph_osd_linger_request, linger_work, etc) in a later commit.
libceph: protect osdc->osd_lru list with a spinlock
OSD client is getting moved from the big per-client lock to a set of
per-session locks. The big rwlock would only be held for read most of
the time, so a global osdc->osd_lru needs additional protection.
create_osd() is called way too deep in the stack to be able to error
out in a sane way; a failing create_osd() just messes everything up.
The current req_notarget list solution is broken - the list is never
traversed as it's not entirely clear when to do it, I guess.
If we were to start traversing it at regular intervals and retrying
each request, we wouldn't be far off from what __GFP_NOFAIL is doing,
so allocate OSD sessions with __GFP_NOFAIL, at least until we come up
with a better fix.
Separate osdmap handling from decoding and iterating over a bag of maps
in a fresh MOSDMap message. This sets up the scene for the updated OSD
client.
Of particular importance here is the addition of pi->was_full, which
can be used to answer "did this pool go full -> not-full in this map?".
This is the key bit for supporting pool quotas.
We won't be able to downgrade map_sem for much longer, so drop
downgrade_write().
Both homeless OSD sessions and watch/notify v2, introduced in later
commits, require periodic ticks which don't depend on ->num_requests.
Schedule the initial tick from ceph_osdc_init() and reschedule from
handle_timeout() unconditionally.
libceph: move schedule_delayed_work() in ceph_osdc_init()
ceph_osdc_stop() isn't called if ceph_osdc_init() fails, so we end up
with handle_osds_timeout() running on invalid memory if any one of the
allocations fails. Call schedule_delayed_work() after everything is
setup, just before returning.
libceph: redo callbacks and factor out MOSDOpReply decoding
If you specify ACK | ONDISK and set ->r_unsafe_callback, both
->r_callback and ->r_unsafe_callback(true) are called on ack. This is
very confusing. Redo this so that only one of them is called:
->r_unsafe_callback(true), on ack
->r_unsafe_callback(false), on commit
or
->r_callback, on ack|commit
Decode everything in decode_MOSDOpReply() to reduce clutter.
libceph: drop msg argument from ceph_osdc_callback_t
finish_read(), its only user, uses it to get to hdr.data_len, which is
what ->r_result is set to on success. This gains us the ability to
safely call callbacks from contexts other than reply, e.g. map check.
Ilya Dryomov [Wed, 25 May 2016 22:29:52 +0000 (00:29 +0200)]
libceph: switch to calc_target(), part 2
The crux of this is getting rid of ceph_osdc_build_request(), so that
MOSDOp can be encoded not before but after calc_target() calculates the
actual target. Encoding now happens within ceph_osdc_start_request().
Also nuked is the accompanying bunch of pointers into the encoded
buffer that was used to update fields on each send - instead, the
entire front is re-encoded. If we want to support target->name_len !=
base->name_len in the future, there is no other way, because oid is
surrounded by other fields in the encoded buffer.
Encoding OSD ops and adding data items to the request message were
mixed together in osd_req_encode_op(). While we want to re-encode OSD
ops, we don't want to add duplicate data items to the message when
resending, so all call to ceph_osdc_msg_data_add() are factored out
into a new setup_request_data().
Replace __calc_request_pg() and most of __map_request() with
calc_target() and start using req->r_t.
ceph_osdc_build_request() however still encodes base_oid, because it's
called before calc_target() is and target_oid is empty at that point in
time; a printf in osdc_show() also shows base_oid. This is fixed in
"libceph: switch to calc_target(), part 2".
Introduce ceph_osd_request_target, containing all mapping-related
fields of ceph_osd_request and calc_target() for calculating mappings
and populating it.
Knowning just acting set isn't enough, we need to be able to record up
set as well to detect interval changes. This means returning (up[],
up_len, up_primary, acting[], acting_len, acting_primary) and passing
it around. Introduce and switch to ceph_osds to help with that.
Rename ceph_calc_pg_acting() to ceph_pg_to_up_acting_osds() and return
both up and acting sets from it.
Rename ceph_oloc_oid_to_pg() to ceph_object_locator_to_pg(). Emphasise
that returned is raw PG and return -ENOENT instead of -EIO if the pool
doesn't exist.
eversion_t is version+epoch in userspace and is encoded in that order.
ceph_eversion is defined as epoch+version in rados.h, yet we memcpy it
in __send_request(). Reoder ceph_eversion fields.
Currently ceph_object_id can hold object names of up to 100
(CEPH_MAX_OID_NAME_LEN) characters. This is enough for all use cases,
expect one - long rbd image names:
- a format 1 header is named "<imgname>.rbd"
- an object that points to a format 2 header is named "rbd_id.<imgname>"
We operate on these potentially long-named objects during rbd map, and,
for format 1 images, during header refresh. (A format 2 header name is
a small system-generated string.)
Lift this 100 character limit by making ceph_object_id be able to point
to an externally-allocated string. Apart from being able to work with
almost arbitrarily-long named objects, this allows us to reduce the
size of ceph_object_id from >100 bytes to 64 bytes.
libceph: change how osd_op_reply message size is calculated
For a message pool message, preallocate a page, just like we do for
osd_op. For a normal message, take ceph_object_id into account and
don't bother subtracting CEPH_OSD_SLAB_OPS ceph_osd_ops.
libceph: move message allocation out of ceph_osdc_alloc_request()
The size of ->r_request and ->r_reply messages depends on the size of
the object name (ceph_object_id), while the size of ceph_osd_request is
fixed. Move message allocation into a separate function that would
have to be called after ceph_object_id and ceph_object_locator (which
is also going to become variable in size with RADOS namespaces) have
been filled in:
req = ceph_osdc_alloc_request(...);
<fill in req->r_base_oid>
<fill in req->r_base_oloc>
ceph_osdc_alloc_messages(req);
Ilya Dryomov [Mon, 16 May 2016 11:18:57 +0000 (13:18 +0200)]
rbd: get/put img_request in rbd_img_request_submit()
By the time we get to checking for_each_obj_request_safe(img_request)
terminating condition, all obj_requests may be complete and img_request
ref, that rbd_img_request_submit() takes away from its caller, may be
put. Moving the next_obj_request cursor is then a use-after-free on
img_request.
It's totally benign, as the value that's read is never used, but
I think it's still worth fixing.
Cc: Alex Elder <elder@linaro.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: e54bcde3d69d ("arm64: eBPF JIT compiler") Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Sat, 14 May 2016 18:11:44 +0000 (11:11 -0700)]
nf_conntrack: avoid kernel pointer value leak in slab name
The slab name ends up being visible in the directory structure under
/sys, and even if you don't have access rights to the file you can see
the filenames.
Just use a 64-bit counter instead of the pointer to the 'net' structure
to generate a unique name.
This code will go away in 4.7 when the conntrack code moves to a single
kmemcache, but this is the backportable simple solution to avoiding
leaking kernel pointers to user space.
Fixes: 5b3501faa874 ("netfilter: nf_conntrack: per netns nf_conntrack_cachep") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Sat, 14 May 2016 18:59:43 +0000 (11:59 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
"Overlayfs fixes from Miklos, assorted fixes from me.
Stable fodder of varying severity, all sat in -next for a while"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ovl: ignore permissions on underlying lookup
vfs: add lookup_hash() helper
vfs: rename: check backing inode being equal
vfs: add vfs_select_inode() helper
get_rock_ridge_filename(): handle malformed NM entries
ecryptfs: fix handling of directory opening
atomic_open(): fix the handling of create_error
fix the copy vs. map logics in blk_rq_map_user_iov()
do_splice_to(): cap the size before passing to ->splice_read()
Linus Torvalds [Fri, 13 May 2016 23:26:46 +0000 (16:26 -0700)]
Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"During v4.6-rc1 cgroup namespace support was merged. There is an
issue where it's impossible to tell whether a given cgroup mount point
is bind mounted or namespaced. Serge has been working on the issue
but it took longer than expected to resolve, so the late pull request.
Given that it's a completely new feature and the patches don't touch
anything else, the risk seems acceptable. However, if this is too
late, an alternative is plugging new cgroup ns creation for v4.6 and
retrying for v4.7"
* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix compile warning
kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call
cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
kernfs_path_from_node_locked: don't overwrite nlen
Linus Torvalds [Fri, 13 May 2016 23:16:51 +0000 (16:16 -0700)]
Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
"CPU hotplug callbacks can invoke DOWN_FAILED w/o preceding
DOWN_PREPARE which can trigger a WARN_ON() in workqueue.
The bug has been there for a very long time. It only triggers if CPU
down fails at a specific point and I don't think it has adverse
effects other than the warning messages. The fix is very low impact"
* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix rebind bound workers warning
Linus Torvalds [Fri, 13 May 2016 19:21:17 +0000 (12:21 -0700)]
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
"This is a revert to fix an interactivity problem.
The proper fixes for the problems that the reverted commit exposed are
now in sched/core (consisting of 3 patches), but were too risky for
v4.6 and will arrive in the v4.7 merge window"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "sched/fair: Fix fairness issue on migration"
Linus Torvalds [Fri, 13 May 2016 18:54:02 +0000 (11:54 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"An uncharacteristically large number of bugs popped up in the last
week:
- various tooling fixes, two crashes and build problems
- two Intel PT fixes
- an KNL uncore driver fix
- an Intel PMU driver fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf stat: Fallback to user only counters when perf_event_paranoid > 1
perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()
perf evsel: Improve EPERM error handling in open_strerror()
tools lib traceevent: Do not reassign parg after collapse_tree()
perf probe: Check if dwarf_getlocations() is available
perf dwarf: Guard !x86_64 definitions under #ifdef else clause
perf tools: Use readdir() instead of deprecated readdir_r()
perf thread_map: Use readdir() instead of deprecated readdir_r()
perf script: Use readdir() instead of deprecated readdir_r()
perf tools: Use readdir() instead of deprecated readdir_r()
perf/core: Disable the event on a truncated AUX record
perf/x86/intel/pt: Generate PMI in the STOP region as well
perf/x86: Fix undefined shift on 32-bit kernels
perf/x86/msr: Fix SMI overflow
perf/x86/intel/uncore: Fix CHA registers configuration procedure for Knights Landing platform
perf diff: Fix duplicated output column
Linus Torvalds [Fri, 13 May 2016 16:52:00 +0000 (09:52 -0700)]
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Arnd Bergmann:
"Three more bug fixes for ARM SoCs this week:
- The Atmel sama5d2 was registering the wrong NFC device type
- On Atmel sam9x5, the power management controller had an incorrect
register area size
- On ARM64 Allwinner machine was not secting the generic irqchip
code, causing build errors in some configurations"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: dts: at91: sam9x5: Fix the memory range assigned to the PMC
arm64/sunxi: 4.6-rc1: Add dependency on generic irq chip
ARM: dts: at91: sama5d2: use "atmel,sama5d3-nfc" compatible for nfc
Linus Torvalds [Fri, 13 May 2016 16:46:00 +0000 (09:46 -0700)]
Merge tag 'regulator-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
"A small collection of driver specific fixes for the regulator
subsysetem:
- Fix handling of probe deferral for GPIO regulators
- Fix a typo in the module alias for DA9053
- Fix the definition of BUCK9 in the S2MPS11 driver. This change
looks larger than it is because an irregularity in the hardware
means that the macro used to define bucks 6-10 needs duplicating
and tweaking to have a separate macro for 9
- Fix a series of errors in the definitions of the LDOs the AXP20x
regulators, some of which had always been present and some of which
were introduced in the merge window"
* tag 'regulator-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: da9063: Correct module alias prefix to fix module autoloading
regulator: axp20x: Fix axp22x ldo_io registration error on cold boot
regulator: axp20x: Fix axp22x ldo_io voltage ranges
regulator: axp20x: Fix LDO4 linear voltage range
regulator: s2mps11: Fix invalid selector mask and voltages for buck9
regulator: gpio: check return value of of_get_named_gpio
Linus Torvalds [Fri, 13 May 2016 16:40:32 +0000 (09:40 -0700)]
Merge tag 'regmap-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap fixes from Mark Brown:
"This is rather too late so it'd be completely understandable if you
don't want to pull it at this point, I had thought I'd sent this
earlier but it seems I didn't. Everything has been in -next for some
time now.
The main set of fixes here are mopping up some more issues with MMIO,
fixing handling of endianness configuration in DT (which just wasn't
working at all) and cases where the register and value endianness are
different.
There is also a fix for bulk register reads on SPMI"
* tag 'regmap-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: spmi: Fix regmap_spmi_ext_read in multi-byte case
regmap: mmio: Explicitly say little endian is the defualt in the bus config
regmap: mmio: Parse endianness definitions from DT
regmap: Fix implicit inclusion of device.h
regmap: mmio: Fix value endianness selection
regmap: fix documentation to match code
Linus Torvalds [Fri, 13 May 2016 16:34:59 +0000 (09:34 -0700)]
Merge tag 'media/v4.6-6' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media fix from Mauro Carvalho Chehab:
"A revert fixing a breakage that caused an OOPS on all VB2-based DVB
drivers.
We already have a proper fix, but it sounds safer to keep it being
tested for a while and not hurry, to avoid the risk of another
regression, specially since this is meant to be c/c to stable. So,
for now, let's just revert the broken patch"
* tag 'media/v4.6-6' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
Revert "[media] videobuf2-v4l2: Verify planes array in buffer dequeueing"
Linus Torvalds [Fri, 13 May 2016 16:27:05 +0000 (09:27 -0700)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"A bunch of radeon displayport mode setting fixes, and some misc i915
fixes.
There is one revert, the MST audio code in i915 was causing some
oopses, so we've decided just to drop it until next kernel when we can
fix it properly"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/amdgpu: fix DP mode validation
drm/radeon: fix DP mode validation
drm/i915: Bail out of pipe config compute loop on LPT
drm/radeon: fix PLL sharing on DCE6.1 (v2)
drm/radeon: fix DP link training issue with second 4K monitor
Revert "drm/i915: start adding dp mst audio"
drm/i915/bdw: Add missing delay during L3 SQC credit programming
drm/i915/lvds: separate border enable readout from panel fitter
drm/i915: Update CDCLK_FREQ register on BDW after changing cdclk frequency
Paul Durrant [Thu, 12 May 2016 13:43:03 +0000 (14:43 +0100)]
xen-netback: fix extra_info handling in xenvif_tx_err()
Patch 562abd39 "xen-netback: support multiple extra info fragments
passed from frontend" contained a mistake which can result in an in-
correct number of responses being generated when handling errors
encountered when processing packets containing extra info fragments.
This patch fixes the problem.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Reported-by: Jan Beulich <JBeulich@suse.com> Cc: Wei Liu <wei.liu2@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Ingo Molnar [Fri, 13 May 2016 05:35:12 +0000 (07:35 +0200)]
Merge tag 'perf-urgent-for-mingo-20160512' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
- Fallback to usermode-only counters when perf_event_paranoid > 1, which
is the case now (Arnaldo Carvalho de Melo)
- Do not reassign parg after collapse_tree() in libtraceevent, which
may cause tool crashes (Steven Rostedt)
- Fix the build on Fedora Rawhide, where readdir_r() is deprecated and
also wrt -Werror=unused-const-variable= + x86_32_regoffset_table on
!x86_64 (Arnaldo Carvalho de Melo)
- Fix the build on Ubuntu 12.04.5, where dwarf_getlocations() isn't
available, i.e. libdw-dev < 0.157 (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Fri, 13 May 2016 01:44:24 +0000 (18:44 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
"4 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: thp: calculate the mapcount correctly for THP pages during WP faults
ksm: fix conflict between mmput and scan_get_next_rmap_item
ocfs2: fix posix_acl_create deadlock
ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
Andrea Arcangeli [Thu, 12 May 2016 22:42:25 +0000 (15:42 -0700)]
mm: thp: calculate the mapcount correctly for THP pages during WP faults
This will provide fully accuracy to the mapcount calculation in the
write protect faults, so page pinning will not get broken by false
positive copy-on-writes.
total_mapcount() isn't the right calculation needed in
reuse_swap_page(), so this introduces a page_trans_huge_mapcount()
that is effectively the full accurate return value for page_mapcount()
if dealing with Transparent Hugepages, however we only use the
page_trans_huge_mapcount() during COW faults where it strictly needed,
due to its higher runtime cost.
This also provide at practical zero cost the total_mapcount
information which is needed to know if we can still relocate the page
anon_vma to the local vma. If page_trans_huge_mapcount() returns 1 we
can reuse the page no matter if it's a pte or a pmd_trans_huge
triggering the fault, but we can only relocate the page anon_vma to
the local vma->anon_vma if we're sure it's only this "vma" mapping the
whole THP physical range.
Kirill A. Shutemov discovered the problem with moving the page
anon_vma to the local vma->anon_vma in a previous version of this
patch and another problem in the way page_move_anon_rmap() was called.
Andrew Morton discovered that CONFIG_SWAP=n wouldn't build in a
previous version, because reuse_swap_page must be a macro to call
page_trans_huge_mapcount from swap.h, so this uses a macro again
instead of an inline function. With this change at least it's a less
dangerous usage than it was before, because "page" is used only once
now, while with the previous code reuse_swap_page(page++) would have
called page_mapcount on page+1 and it would have increased page twice
instead of just once.
Dean Luick noticed an uninitialized variable that could result in a
rmap inefficiency for the non-THP case in a previous version.
Mike Marciniszyn said:
: Our RDMA tests are seeing an issue with memory locking that bisects to
: commit 61f5d698cc97 ("mm: re-enable THP")
:
: The test program registers two rather large MRs (512M) and RDMA
: writes data to a passive peer using the first and RDMA reads it back
: into the second MR and compares that data. The sizes are chosen randomly
: between 0 and 1024 bytes.
:
: The test will get through a few (<= 4 iterations) and then gets a
: compare error.
:
: Tracing indicates the kernel logical addresses associated with the individual
: pages at registration ARE correct , the data in the "RDMA read response only"
: packets ARE correct.
:
: The "corruption" occurs when the packet crosse two pages that are not physically
: contiguous. The second page reads back as zero in the program.
:
: It looks like the user VA at the point of the compare error no longer points to
: the same physical address as was registered.
:
: This patch totally resolves the issue!
Link: http://lkml.kernel.org/r/1462547040-1737-2-git-send-email-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name> Reviewed-by: Dean Luick <dean.luick@intel.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Tested-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Tested-by: Josh Collier <josh.d.collier@intel.com> Cc: Marc Haber <mh+linux-kernel@zugschlus.de> Cc: <stable@vger.kernel.org> [4.5] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Zhou Chengming [Thu, 12 May 2016 22:42:21 +0000 (15:42 -0700)]
ksm: fix conflict between mmput and scan_get_next_rmap_item
A concurrency issue about KSM in the function scan_get_next_rmap_item.
task A (ksmd): |task B (the mm's task):
|
mm = slot->mm; |
down_read(&mm->mmap_sem); |
|
... |
|
spin_lock(&ksm_mmlist_lock); |
|
ksm_scan.mm_slot go to the next slot; |
|
spin_unlock(&ksm_mmlist_lock); |
|mmput() ->
| ksm_exit():
|
|spin_lock(&ksm_mmlist_lock);
|if (mm_slot && ksm_scan.mm_slot != mm_slot) {
| if (!mm_slot->rmap_list) {
| easy_to_free = 1;
| ...
|
|if (easy_to_free) {
| mmdrop(mm);
| ...
|
|So this mm_struct may be freed in the mmput().
|
up_read(&mm->mmap_sem); |
As we can see above, the ksmd thread may access a mm_struct that already
been freed to the kmem_cache. Suppose a fork will get this mm_struct from
the kmem_cache, the ksmd thread then call up_read(&mm->mmap_sem), will
cause mmap_sem.count to become -1.
As suggested by Andrea Arcangeli, unmerge_and_remove_all_rmap_items has
the same SMP race condition, so fix it too. My prev fix in function
scan_get_next_rmap_item will introduce a different SMP race condition, so
just invert the up_read/spin_unlock order as Andrea Arcangeli said.
Link: http://lkml.kernel.org/r/1462708815-31301-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Suggested-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Geliang Tang <geliangtang@163.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Li Bin <huawei.libin@huawei.com> Cc: Zhen Lei <thunder.leizhen@huawei.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Junxiao Bi [Thu, 12 May 2016 22:42:18 +0000 (15:42 -0700)]
ocfs2: fix posix_acl_create deadlock
Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create. The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs. For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted. And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.
Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Junxiao Bi [Thu, 12 May 2016 22:42:15 +0000 (15:42 -0700)]
ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
introduced this issue. ocfs2_setattr called by chmod command holds
cluster wide inode lock when calling posix_acl_chmod. This latter
function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These
two are also called directly from vfs layer for getfacl/setfacl commands
and therefore acquire the cluster wide inode lock. If a remote
conversion request comes after the first inode lock in ocfs2_setattr,
OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to
inode lock from the ocfs2_iop_get_acl() to block indefinetly.
The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which
does not call back into the filesystem. Therefore, we restore
ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that
instead.
Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arnd Bergmann [Wed, 11 May 2016 20:13:23 +0000 (22:13 +0200)]
net: mvneta: bm: fix dependencies again
I tried to fix this before, but my previous fix was incomplete
and we can still get the same link error in randconfig builds
because of the way that Kconfig treats the
default y if MVNETA=y && MVNETA_BM_ENABLE
line that does not actually trigger when MVNETA_BM_ENABLE=m,
unlike I intended.
Changing the line to use MVNETA_BM_ENABLE!=n however has
the desired effect and hopefully makes all configurations
work as expected.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 019ded3aa7c9 ("net: mvneta: bm: clarify dependencies") Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Thu, 12 May 2016 19:55:42 +0000 (12:55 -0700)]
Merge tag 'sound-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This is a pretty boring pull request as you wish: including a few
small and trivial HD-audio and USB-audio quirks and a couple of small
regression fixes in HD-audio"
* tag 'sound-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Yet another Phoneix Audio device quirk
ALSA: hda - Fix regression on ATI HDMI audio
ALSA: hda - Fix subwoofer pin on ASUS N751 and N551
ALSA: hda - Fix broken reconfig
ALSA: hda - Fix white noise on Asus UX501VW headset
ALSA: usb-audio: Quirk for yet another Phoenix Audio devices (v2)
perf stat: Fallback to user only counters when perf_event_paranoid > 1
After 0161028b7c8a ("perf/core: Change the default paranoia level to 2")
'perf stat' fails for users without CAP_SYS_ADMIN, so just use
'perf_evsel__fallback()' to have the same behaviour as 'perf record',
i.e. set perf_event_attr.exclude_kernel to 1.
perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()
Now with the default for the kernel.perf_event_paranoid sysctl being 2 [1]
we need to fall back to :u, i.e. to set perf_event_attr.exclude_kernel
to 1.
Before:
[acme@jouet linux]$ perf record usleep 1
Error:
You may not have permission to collect stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_SYS_ADMIN).
The current value is 2:
-1: Allow use of (almost) all events by all users
>= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
>= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
[acme@jouet linux]$
And if the user turns on verbose mode, an explanation will appear:
[acme@jouet linux]$ perf record -v usleep 1
Warning:
kernel.perf_event_paranoid=2, trying to fall back to excluding kernel samples
mmap size 528384B
[ perf record: Woken up 1 times to write data ]
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.6.0-rc7+/build/vmlinux for symbols
[ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
[acme@jouet linux]$
[1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2")
Reported-by: Ingo Molnar <mingo@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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