Tejun Heo [Wed, 20 Feb 2013 02:16:29 +0000 (13:16 +1100)]
idr: fix top layer handling
Most functions in idr fail to deal with the high bits when the idr
tree grows to the maximum height.
* idr_get_empty_slot() stops growing idr tree once the depth reaches
MAX_IDR_LEVEL - 1, which is one depth shallower than necessary to
cover the whole range. The function doesn't even notice that it
didn't grow the tree enough and ends up allocating the wrong ID
given sufficiently high @starting_id.
For example, on 64 bit, if the starting id is 0x7fffff01,
idr_get_empty_slot() will grow the tree 5 layer deep, which only
covers the 30 bits and then proceed to allocate as if the bit 30
wasn't specified. It ends up allocating 0x3fffff01 without the bit
30 but still returns 0x7fffff01.
* __idr_remove_all() will not remove anything if the tree is fully
grown.
* idr_find() can't find anything if the tree is fully grown.
* idr_for_each() and idr_get_next() can't iterate anything if the tree
is fully grown.
Fix it by introducing idr_max() which returns the maximum possible ID
given the depth of tree and replacing the id limit checks in all
affected places.
As the idr_layer pointer array pa[] needs to be 1 larger than the
maximum depth, enlarge pa[] arrays by one.
While this plugs the discovered issues, the whole code base is
horrible and in desparate need of rewrite. It's fragile like hell,
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:28 +0000 (13:16 +1100)]
sctp: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
v2: Don't preload if @gfp doesn't contain __GFP_WAIT as the function
may be being called from non-process ocntext. Also, add a comment
explaining @idr_low never becomes zero.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:27 +0000 (13:16 +1100)]
ipc-convert-to-idr_alloc-fix
v2: The v1 conversion of ipcget_public() was incorrect. As
idr_pre_get() returns 0 for -ENOMEM failure, @err should have been
initialized to 1 not 0. As the function doesn't do preloading
itself anymore, there's no point in the error handling path.
Simply remove the -ENOMEM path.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:26 +0000 (13:16 +1100)]
ipc: convert to idr_alloc()
Convert to the much saner new idr interface.
The new interface doesn't directly translate to the way idr_pre_get()
was used around ipc_addid() as preloading disables preemption. From
my cursory reading, it seems like we should be able to do all
allocation from ipc_addid(), so I moved it there. Can you please
check whether this would be okay? If this is wrong and ipc_addid()
should be allowed to be called from non-sleepable context, I'd suggest
allocating id itself in the outer functions and later install the
pointer using idr_replace().
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:26 +0000 (13:16 +1100)]
inotify: convert to idr_alloc()
Convert to the much saner new idr interface.
Note that the adhoc cyclic id allocation is buggy. If wraparound
happens, the previous code with idr_get_new_above() may segfault and
the converted code will trigger WARN and return -EINVAL. Even if it's
fixed to wrap to zero, the code will be prone to unnecessary -ENOSPC
failures after the first wraparound. We probably need to implement
proper cyclic support in idr.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:25 +0000 (13:16 +1100)]
dlm: convert to idr_alloc()
Convert to the much saner new idr interface. Error return values from
recover_idr_add() mix -1 and -errno. The conversion doesn't change
that but it looks iffy.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:24 +0000 (13:16 +1100)]
target/iscsi: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:21 +0000 (13:16 +1100)]
macvtap: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:18 +0000 (13:16 +1100)]
IB/mlx4: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jack Morgenstein <jackm@dev.mellanox.co.il> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Roland Dreier <roland@purestorage.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:16 +0000 (13:16 +1100)]
IB/core: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
v2: Mike triggered WARN_ON() in idr_preload() because send_mad(),
which may be used from non-process context, was calling
idr_preload() unconditionally. Preload iff @gfp_mask has
__GFP_WAIT.
Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Sean Hefty <sean.hefty@intel.com> Reported-by: "Marciniszyn, Mike" <mike.marciniszyn@intel.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:16 +0000 (13:16 +1100)]
i2c: style cleanups after idr_alloc() conversion
Style cleanups suggested by Wolfram.
* s/res/id/ in i2c_add_numbered_adapter() so that it matches
i2c_add_adapter().
* Add a blank line before return in i2c_add_numbered_adapter().
This patch is purely cosmetic.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Wolfram Sang <wolfram@the-dreams.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:16 +0000 (13:16 +1100)]
i2c-convert-to-idr_alloc-fix
v2: The original conversion accidentally dropped a call to
i2c_register_adapter() in i2c_add_numbered_adapter() leaving @adap
uninitialized and unregistered. Reported by Mark Brown. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Jean Delvare <khali@linux-fr.org> Cc: Wolfram Sang <wolfram@the-dreams.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:15 +0000 (13:16 +1100)]
i2c: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Wolfram Sang <wolfram@the-dreams.de> Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Artem Savkov [Wed, 20 Feb 2013 02:16:13 +0000 (13:16 +1100)]
drm: missing idr_preload_end in drm_gem_flink_ioctl
Added missing idr_preload_end calls in drm_gem_flink_ioctl(). Without
those preemption stays disabled resulting in lots of "scheduling while
atomic" BUGs.
Signed-off-by: Artem Savkov <artem.savkov@gmail.com> Cc: David Airlie <airlied@linux.ie> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tim Gardner [Wed, 20 Feb 2013 02:16:12 +0000 (13:16 +1100)]
firewire: fw_device_init: 'minor' may be used uninitialized
'firewire: convert to idr_alloc()' accidentally orphaned 'minor'.
drivers/firewire/core-device.c: In function `fw_device_init':
drivers/firewire/core-device.c:1029:24: warning: `minor' may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:12 +0000 (13:16 +1100)]
firewire: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
v2: Stefan pointed out that add_client_resource() may be called from
non-process context. Preload iff @gfp_mask contains __GFP_WAIT.
Also updated to include minor upper limit check.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:11 +0000 (13:16 +1100)]
dca: convert to idr_alloc()
Convert to the much saner new idr interface.
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> Cc: Shannon Nelson <shannon.nelson@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:10 +0000 (13:16 +1100)]
atm/nicstar: convert to idr_alloc()
Convert to the much saner new idr interface. The existing code looks
buggy to me - ID 0 is treated as no-ID but allocation specifies 0 as
lower limit and there's no error handling after partial success. This
conversion keeps the bugs unchanged.
Only compile tested.
v2: id1 and id2 are now directly used for -errno return and thus
should be signed. Make them int instead of u32. This was spotted
by kbuild test robot.
v3: Further simplify as suggested by Chas Williams.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Chas Williams <chas@cmf.nrl.navy.mil> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:09 +0000 (13:16 +1100)]
block: fix synchronization and limit check in blk_alloc_devt()
idr allocation in blk_alloc_devt() wasn't synchronized against lookup
and removal, and its limit check was off by one - 1 << MINORBITS is
the number of minors allowed, not the maximum allowed minor.
Add locking and rename MAX_EXT_DEVT to NR_EXT_DEVT and fix limit
checking.
Tejun Heo [Wed, 20 Feb 2013 02:16:09 +0000 (13:16 +1100)]
idr: implement idr_preload[_end]() and idr_alloc()
The current idr interface is very cumbersome.
* For all allocations, two function calls - idr_pre_get() and
idr_get_new*() - should be made.
* idr_pre_get() doesn't guarantee that the following idr_get_new*()
will not fail from memory shortage. If idr_get_new*() returns
-EAGAIN, the caller is expected to retry pre_get and allocation.
* idr_get_new*() can't enforce upper limit. Upper limit can only be
enforced by allocating and then freeing if above limit.
* idr_layer buffer is unnecessarily per-idr. Each idr ends up keeping
around MAX_IDR_FREE idr_layers. The memory consumed per idr is
under two pages but it makes it difficult to make idr_layer larger.
This patch implements the following new set of allocation functions.
* idr_preload[_end]() - Similar to radix preload but doesn't fail.
The first idr_alloc() inside preload section can be treated as if it
were called with @gfp_mask used for idr_preload().
* idr_alloc() - Allocate an ID w/ lower and upper limits. Takes
@gfp_flags and can be used w/o preloading. When used inside
preloaded section, the allocation mask of preloading can be assumed.
If idr_alloc() can be called from a context which allows sufficiently
relaxed @gfp_mask, it can be used by itself. If, for example,
idr_alloc() is called inside spinlock protected region, preloading can
be used like the following.
idr_preload(GFP_KERNEL);
spin_lock(lock);
id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT);
spin_unlock(lock);
idr_preload_end();
if (id < 0)
error;
which is much simpler and less error-prone than idr_pre_get and
idr_get_new*() loop.
The new interface uses per-pcu idr_layer buffer and thus the number of
idr's in the system doesn't affect the amount of memory used for
preloading.
idr_layer_alloc() is introduced to handle idr_layer allocations for
both old and new ID allocation paths. This is a bit hairy now but the
new interface is expected to replace the old and the internal
implementation eventually will become simpler.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:09 +0000 (13:16 +1100)]
idr: refactor idr_get_new_above()
Move slot filling to idr_fill_slot() from idr_get_new_above_int() and
make idr_get_new_above() directly call it. idr_get_new_above_int() is
no longer needed and removed.
This will be used to implement a new ID allocation interface.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:08 +0000 (13:16 +1100)]
idr: remove _idr_rc_to_errno() hack
idr uses -1, IDR_NEED_TO_GROW and IDR_NOMORE_SPACE to communicate
exception conditions internally. The return value is later translated
to errno values using _idr_rc_to_errno().
This is confusing. Drop the custom ones and consistently use -EAGAIN
for "tree needs to grow", -ENOMEM for "need more memory" and -ENOSPC
for "ran out of ID space".
Due to the weird memory preloading mechanism, [ra]_get_new*() return
-EAGAIN on memory shortage, so we need to substitute -ENOMEM w/
-EAGAIN on those interface functions. They'll eventually be cleaned
up and the translations will go away.
This patch doesn't introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:07 +0000 (13:16 +1100)]
idr: deprecate idr_remove_all()
There was only one legitimate use of idr_remove_all() and a lot more
of incorrect uses (or lack of it). Now that idr_destroy() implies
idr_remove_all() and all the in-kernel users updated not to use it,
there's no reason to keep it around. Mark it deprecated so that we
can later unexport it.
idr_remove_all() is made an inline function calling __idr_remove_all()
to avoid triggering deprecated warning on EXPORT_SYMBOL().
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:06 +0000 (13:16 +1100)]
inotify: don't use idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop its usage.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:06 +0000 (13:16 +1100)]
nfs: idr_destroy() no longer needs idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop reference to idr_remove_all(). Note that the code
wasn't completely correct before because idr_remove() on all entries
doesn't necessarily release all idr_layers which could lead to memory
leak.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:06 +0000 (13:16 +1100)]
dlm: don't use idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.
The conversion isn't completely trivial for recover_idr_clear() as
it's the only place in kernel which makes legitimate use of
idr_remove_all() w/o idr_destroy(). Replace it with idr_remove() call
inside idr_for_each_entry() loop. It goes on top so that it matches
the operation order in recover_idr_del().
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christine Caulfield <ccaulfie@redhat.com> Cc: David Teigland <teigland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:05 +0000 (13:16 +1100)]
dlm: use idr_for_each_entry() in recover_idr_clear() error path
Convert recover_idr_clear() to use idr_for_each_entry() instead of
idr_for_each(). It's somewhat less efficient this way but it
shouldn't matter in an error path. This is to help with deprecation
of idr_remove_all().
Only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christine Caulfield <ccaulfie@redhat.com> Cc: David Teigland <teigland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:04 +0000 (13:16 +1100)]
drm: don't use idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop its usage.
* drm_ctxbitmap_cleanup() was calling idr_remove_all() but forgetting
idr_destroy() thus leaking all buffered free idr_layers. Replace it
with idr_destroy().
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: David Airlie <airlied@linux.ie> Cc: Inki Dae <inki.dae@samsung.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: Seung-Woo Kim <sw0312.kim@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:03 +0000 (13:16 +1100)]
atm/nicstar: don't use idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop its usage.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Chas Williams <chas@cmf.nrl.navy.mil> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:03 +0000 (13:16 +1100)]
idr: make idr_destroy() imply idr_remove_all()
idr is silly in quite a few ways, one of which is how it's supposed to
be destroyed - idr_destroy() doesn't release IDs and doesn't even
whine if the idr isn't empty. If the caller forgets idr_remove_all(),
it simply leaks memory.
Even ida gets this wrong and leaks memory on destruction. There is
absoltely no reason not to call idr_remove_all() from idr_destroy().
Nobody is abusing idr_destroy() for shrinking free layer buffer and
continues to use idr after idr_destroy(), so it's safe to do
remove_all from destroy.
In the whole kernel, there is only one place where idr_remove_all() is
legitimiately used without following idr_destroy() while there are
quite a few places where the caller forgets either idr_remove_all() or
idr_destroy() leaking memory.
This patch makes idr_destroy() call idr_destroy_all() and updates the
function description accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tejun Heo [Wed, 20 Feb 2013 02:16:03 +0000 (13:16 +1100)]
idr: fix a subtle bug in idr_get_next()
The iteration logic of idr_get_next() is borrowed mostly verbatim from
idr_for_each(). It walks down the tree looking for the slot matching
the current ID. If the matching slot is not found, the ID is
incremented by the distance of single slot at the given level and
repeats.
The implementation assumes that during the whole iteration id is
aligned to the layer boundaries of the level closest to the leaf,
which is true for all iterations starting from zero or an existing
element and thus is fine for idr_for_each().
However, idr_get_next() may be given any point and if the starting id
hits in the middle of a non-existent layer, increment to the next
layer will end up skipping the same offset into it. For example, an
IDR with IDs filled between [64, 127] would look like the following.
[ 0 64 ... ]
/----/ |
| |
NULL [ 64 ... 127 ]
If idr_get_next() is called with 63 as the starting point, it will try
to follow down the pointer from 0. As it is NULL, it will then try to
proceed to the next slot in the same level by adding the slot distance
at that level which is 64 - making the next try 127. It goes around
the loop and finds and returns 127 skipping [64, 126].
Note that this bug also triggers in idr_for_each_entry() loop which
deletes during iteration as deletions can make layers go away leaving
the iteration with unaligned ID into missing layers.
Fix it by ensuring proceeding to the next slot doesn't carry over the
unaligned offset - ie. use round_up(id + 1, slot_distance) instead of
id += slot_distance.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: David Teigland <teigland@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This most likely happens because dev_t is freed while the number is still
used and idr_get_new() is not protected on every use. The fix adds a
mutex where it wasn't before and moves the dev_t free function so it is
called after device del.
Signed-off-by: Tomas Henzl <thenzl@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mitsuhiro Tanino [Wed, 20 Feb 2013 02:16:02 +0000 (13:16 +1100)]
kexec: export PG_hwpoison flag into vmcoreinfo
This patch exports a PG_hwpoison into vmcoreinfo when
CONFIG_MEMORY_FAILURE is defined. "makedumpfile" needs to read
information of memory, such as 'mem_section', 'zone', 'pageflags' from
vmcore.
We introduce a function into "makedumpfile" to exclude hwpoison page from
vmcore dump. In order to introduce this function, PG_hwpoison flag have
to export into vmcoreinfo.
Atsushi Kumagai [Wed, 20 Feb 2013 02:16:01 +0000 (13:16 +1100)]
kexec: add the values related to buddy system for filtering free pages.
tAdd adds the values related to buddy system to vmcoreinfo data so that
makedumpfile (dump filtering command) can filter out all free pages with
the new logic.
It's faster than the current logic because it can distinguish free page by
analyzing page structure at the same time as filtering for other
unnecessary pages (e.g. anonymous page).
OTOH, the current logic has to trace free_list to distinguish free pages
while analyzing page structure to filter out other unnecessary pages.
The new logic uses the fact that buddy page is marked by _mapcount ==
PAGE_BUDDY_MAPCOUNT_VALUE. But, _mapcount shares its memory with other
fields for SLAB/SLUB when PG_slab is set, so we need to check if PG_slab
is set or not before looking up _mapcount value. And we can get the order
of buddy system from private field. To sum it up, the values below are
required for this logic.
Changelog from v1 to v2:
1. remove SIZE(pageflags)
The new logic was changed after I sent v1 patch.
Accordingly, SIZE(pageflags) has been unnecessary for makedumpfile.
What's makedumpfile:
makedumpfile creates a small dumpfile by excluding unnecessary pages
for the analysis. To distinguish unnecessary pages, makedumpfile gets
the vmcoreinfo data which has the minimum debugging information only
for dump filtering.
Signed-off-by: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alan Cox [Wed, 20 Feb 2013 02:16:01 +0000 (13:16 +1100)]
fork: unshare: remove dead code
If new_nsproxy is set we will always call switch_task_namespaces and then
set new_nsproxy back to NULL so the reassignment and fall through check
are redundant
Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ben Chan [Wed, 20 Feb 2013 02:15:59 +0000 (13:15 +1100)]
coredump: abort core dump piping only due to a fatal signal
Make wait_for_dump_helpers() not abort piping the core dump data when the
crashing process has received a non-fatal signal. The abort still occurs
in the case of SIGKILL.
The rationale is that a crashing process may still receive uninteresting
signals such as SIGCHLD when its core dump data is being redirected to a
helper application. While it's necessary to allow terminating the core
dump piping via SIGKILL, it's practically more useful for the purpose of
debugging and crash reporting if the core dump piping is not aborted due
to other non-fatal signals.
Signed-off-by: Ben Chan <benchan@chromium.org> Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We shouldn't try_to_freeze if locks are held. Verified that I get no
lockdep warnings after applying this patch and "vfork: don't
freezer_count() for in-kernel users of CLONE_VFORK".
Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Ben Chan <benchan@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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