Got this while compiling for ARM/SA1100:
mm/sparse.c: In function '__section_nr':
mm/sparse.c:135: warning: 'root' is used uninitialized in this function
This patch follows Russell King's suggestion for a new calculation for
NR_SECTION_ROOTS. Thanks also to Sergei Shtylyov for pointing out the
existence of the macro DIV_ROUND_UP.
Atsushi Nemoto observed:
: This fix doesn't just silence the warning - it fixes a real problem.
:
: Without this fix, mem_section[] might have 0 size so mem_section[0]
: will share other variable area. For example, I got:
:
: c030c700 b __warned.16478
: c030c700 B mem_section
: c030c701 b __warned.16483
:
: This might cause very strange behavior. Your patch actually fixes it.
Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In f4112de6b6 ("mm: introduce
debug_kmap_atomic") I said that debug_kmap_atomic() needs
CONFIG_TRACE_IRQFLAGS_SUPPORT.
It was wrong. (I thought irqs_disabled() is only available when the
architecture has CONFIG_TRACE_IRQFLAGS_SUPPORT)
Remove the #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT check to enable
kmap_atomic() debugging for the architectures which do not have
CONFIG_TRACE_IRQFLAGS_SUPPORT.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add parenthesis in a define. This doesn't change functionality.
checkpatch errors:
1) white space fixes
2) add spaces after comas
Signed-off-by: matt mooney <mfm@muteddisk.com>
Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix minor spelling errors in a few comments; no code changes.
Signed-off-by: matt mooney <mfm@muteddisk.com>
Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable users to online CPUs even if the CPUs belongs to a numa node which
doesn't have onlined local memory.
The zonlists(pg_data_t.node_zonelists[]) of a numa node are created either
in system boot/init period, or at the time of local memory online. For a
numa node without onlined local memory, its zonelists are not initialized
at present. As a result, any memory allocation operations executed by
CPUs within this node will fail. In fact, an out-of-memory error is
triggered when attempt to online CPUs before memory comes to online.
This patch tries to create zonelists for such numa nodes, so that the
memory allocation for this node can be fallback'ed to other nodes.
[akpm@linux-foundation.org: remove unneeded export]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: minskey guo<chaohong.guo@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For now, we have global isolation vs. memory control group isolation, do
not allow the reclaim entry function to set an arbitrary page isolation
callback, we do not need that flexibility.
And since we already pass around the group descriptor for the memory
control group isolation case, just use it to decide which one of the two
isolator functions to use.
The decisions can be merged into nearby branches, so no extra cost there.
In fact, we save the indirect calls.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
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>
The fragmentation index may indicate that a failure is due to external
fragmentation but after a compaction run completes, it is still possible
for an allocation to fail. There are two obvious reasons as to why
o Page migration cannot move all pages so fragmentation remains
o A suitable page may exist but watermarks are not met
In the event of compaction followed by an allocation failure, this patch
defers further compaction in the zone (1 << compact_defer_shift) times.
If the next compaction attempt also fails, compact_defer_shift is
increased up to a maximum of 6. If compaction succeeds, the defer
counters are reset again.
The zone that is deferred is the first zone in the zonelist - i.e. the
preferred zone. To defer compaction in the other zones, the information
would need to be stored in the zonelist or implemented similar to the
zonelist_cache. This would impact the fast-paths and is not justified at
this time.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel applies some heuristics when deciding if memory should be
compacted or reclaimed to satisfy a high-order allocation. One of these
is based on the fragmentation. If the index is below 500, memory will not
be compacted. This choice is arbitrary and not based on data. To help
optimise the system and set a sensible default for this value, this patch
adds a sysctl extfrag_threshold. The kernel will only compact memory if
the fragmentation index is above the extfrag_threshold.
[randy.dunlap@oracle.com: Fix build errors when proc fs is not configured]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ordinarily when a high-order allocation fails, direct reclaim is entered
to free pages to satisfy the allocation. With this patch, it is
determined if an allocation failed due to external fragmentation instead
of low memory and if so, the calling process will compact until a suitable
page is freed. Compaction by moving pages in memory is considerably
cheaper than paging out to disk and works where there are locked pages or
no swap. If compaction fails to free a page of a suitable size, then
reclaim will still occur.
Direct compaction returns as soon as possible. As each block is
compacted, it is checked if a suitable page has been freed and if so, it
returns.
[akpm@linux-foundation.org: Fix build errors]
[aarcange@redhat.com: fix count_vm_event preempt in memory compaction direct reclaim]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a per-node sysfs file called compact. When the file is written to,
each zone in that node is compacted. The intention that this would be
used by something like a job scheduler in a batch system before a job
starts so that the job can allocate the maximum number of hugepages
without significant start-up cost.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a proc file /proc/sys/vm/compact_memory. When an arbitrary value is
written to the file, all zones are compacted. The expected user of such a
trigger is a job scheduler that prepares the system before the target
application runs.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is the core of a mechanism which compacts memory in a zone by
relocating movable pages towards the end of the zone.
A single compaction run involves a migration scanner and a free scanner.
Both scanners operate on pageblock-sized areas in the zone. The migration
scanner starts at the bottom of the zone and searches for all movable
pages within each area, isolating them onto a private list called
migratelist. The free scanner starts at the top of the zone and searches
for suitable areas and consumes the free pages within making them
available for the migration scanner. The pages isolated for migration are
then migrated to the newly isolated free pages.
[aarcange@redhat.com: Fix unsafe optimisation]
[mel@csn.ul.ie: do not schedule work on other CPUs for compaction]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Page migration requires rmap to be able to find all ptes mapping a page
at all times, otherwise the migration entry can be instantiated, but it
is possible to leave one behind if the second rmap_walk fails to find
the page. If this page is later faulted, migration_entry_to_page() will
call BUG because the page is locked indicating the page was migrated by
the migration PTE not cleaned up. For example
kernel BUG at include/linux/swapops.h:105!
invalid opcode: 0000 [#1] PREEMPT SMP
...
Call Trace:
[<ffffffff810e951a>] handle_mm_fault+0x3f8/0x76a
[<ffffffff8130c7a2>] do_page_fault+0x44a/0x46e
[<ffffffff813099b5>] page_fault+0x25/0x30
[<ffffffff8114de33>] load_elf_binary+0x152a/0x192b
[<ffffffff8111329b>] search_binary_handler+0x173/0x313
[<ffffffff81114896>] do_execve+0x219/0x30a
[<ffffffff8100a5c6>] sys_execve+0x43/0x5e
[<ffffffff8100320a>] stub_execve+0x6a/0xc0
RIP [<ffffffff811094ff>] migration_entry_wait+0xc1/0x129
There is a race between shift_arg_pages and migration that triggers this
bug. A temporary stack is setup during exec and later moved. If
migration moves a page in the temporary stack and the VMA is then removed
before migration completes, the migration PTE may not be found leading to
a BUG when the stack is faulted.
This patch causes pages within the temporary stack during exec to be
skipped by migration. It does this by marking the VMA covering the
temporary stack with an otherwise impossible combination of VMA flags.
These flags are cleared when the temporary stack is moved to its final
location.
[kamezawa.hiroyu@jp.fujitsu.com: idea for having migration skip temporary stacks]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For clarity of review, KSM and page migration have separate refcounts on
the anon_vma. While clear, this is a waste of memory. This patch gets
KSM and page migration to share their toys in a spirit of harmony.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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>
This patchset is a memory compaction mechanism that reduces external
fragmentation memory by moving GFP_MOVABLE pages to a fewer number of
pageblocks. The term "compaction" was chosen as there are is a number of
mechanisms that are not mutually exclusive that can be used to defragment
memory. For example, lumpy reclaim is a form of defragmentation as was
slub "defragmentation" (really a form of targeted reclaim). Hence, this
is called "compaction" to distinguish it from other forms of
defragmentation.
In this implementation, a full compaction run involves two scanners
operating within a zone - a migration and a free scanner. The migration
scanner starts at the beginning of a zone and finds all movable pages
within one pageblock_nr_pages-sized area and isolates them on a
migratepages list. The free scanner begins at the end of the zone and
searches on a per-area basis for enough free pages to migrate all the
pages on the migratepages list. As each area is respectively migrated or
exhausted of free pages, the scanners are advanced one area. A compaction
run completes within a zone when the two scanners meet.
This method is a bit primitive but is easy to understand and greater
sophistication would require maintenance of counters on a per-pageblock
basis. This would have a big impact on allocator fast-paths to improve
compaction which is a poor trade-off.
It also does not try relocate virtually contiguous pages to be physically
contiguous. However, assuming transparent hugepages were in use, a
hypothetical khugepaged might reuse compaction code to isolate free pages,
split them and relocate userspace pages for promotion.
Memory compaction can be triggered in one of three ways. It may be
triggered explicitly by writing any value to /proc/sys/vm/compact_memory
and compacting all of memory. It can be triggered on a per-node basis by
writing any value to /sys/devices/system/node/nodeN/compact where N is the
node ID to be compacted. When a process fails to allocate a high-order
page, it may compact memory in an attempt to satisfy the allocation
instead of entering direct reclaim. Explicit compaction does not finish
until the two scanners meet and direct compaction ends if a suitable page
becomes available that would meet watermarks.
The series is in 14 patches. The first three are not "core" to the series
but are important pre-requisites.
Patch 1 reference counts anon_vma for rmap_walk_anon(). Without this
patch, it's possible to use anon_vma after free if the caller is
not holding a VMA or mmap_sem for the pages in question. While
there should be no existing user that causes this problem,
it's a requirement for memory compaction to be stable. The patch
is at the start of the series for bisection reasons.
Patch 2 merges the KSM and migrate counts. It could be merged with patch 1
but would be slightly harder to review.
Patch 3 skips over unmapped anon pages during migration as there are no
guarantees about the anon_vma existing. There is a window between
when a page was isolated and migration started during which anon_vma
could disappear.
Patch 4 notes that PageSwapCache pages can still be migrated even if they
are unmapped.
Patch 5 allows CONFIG_MIGRATION to be set without CONFIG_NUMA
Patch 6 exports a "unusable free space index" via debugfs. It's
a measure of external fragmentation that takes the size of the
allocation request into account. It can also be calculated from
userspace so can be dropped if requested
Patch 7 exports a "fragmentation index" which only has meaning when an
allocation request fails. It determines if an allocation failure
would be due to a lack of memory or external fragmentation.
Patch 8 moves the definition for LRU isolation modes for use by compaction
Patch 9 is the compaction mechanism although it's unreachable at this point
Patch 10 adds a means of compacting all of memory with a proc trgger
Patch 11 adds a means of compacting a specific node with a sysfs trigger
Patch 12 adds "direct compaction" before "direct reclaim" if it is
determined there is a good chance of success.
Patch 13 adds a sysctl that allows tuning of the threshold at which the
kernel will compact or direct reclaim
Patch 14 temporarily disables compaction if an allocation failure occurs
after compaction.
Testing of compaction was in three stages. For the test, debugging,
preempt, the sleep watchdog and lockdep were all enabled but nothing nasty
popped out. min_free_kbytes was tuned as recommended by hugeadm to help
fragmentation avoidance and high-order allocations. It was tested on X86,
X86-64 and PPC64.
Ths first test represents one of the easiest cases that can be faced for
lumpy reclaim or memory compaction.
1. Machine freshly booted and configured for hugepage usage with
a) hugeadm --create-global-mounts
b) hugeadm --pool-pages-max DEFAULT:8G
c) hugeadm --set-recommended-min_free_kbytes
d) hugeadm --set-recommended-shmmax
The min_free_kbytes here is important. Anti-fragmentation works best
when pageblocks don't mix. hugeadm knows how to calculate a value that
will significantly reduce the worst of external-fragmentation-related
events as reported by the mm_page_alloc_extfrag tracepoint.
2. Load up memory
a) Start updatedb
b) Create in parallel a X files of pagesize*128 in size. Wait
until files are created. By parallel, I mean that 4096 instances
of dd were launched, one after the other using &. The crude
objective being to mix filesystem metadata allocations with
the buffer cache.
c) Delete every second file so that pageblocks are likely to
have holes
d) kill updatedb if it's still running
At this point, the system is quiet, memory is full but it's full with
clean filesystem metadata and clean buffer cache that is unmapped.
This is readily migrated or discarded so you'd expect lumpy reclaim
to have no significant advantage over compaction but this is at
the POC stage.
3. In increments, attempt to allocate 5% of memory as hugepages.
Measure how long it took, how successful it was, how many
direct reclaims took place and how how many compactions. Note
the compaction figures might not fully add up as compactions
can take place for orders other than the hugepage size
X86 vanilla compaction
Final page count 913 916 (attempted 1002)
pages reclaimed 68296 9791
X86-64 vanilla compaction
Final page count: 901 902 (attempted 1002)
Total pages reclaimed: 112599 53234
PPC64 vanilla compaction
Final page count: 93 94 (attempted 110)
Total pages reclaimed: 103216 61838
There was not a dramatic improvement in success rates but it wouldn't be
expected in this case either. What was important is that fewer pages were
reclaimed in all cases reducing the amount of IO required to satisfy a
huge page allocation.
The second tests were all performance related - kernbench, netperf, iozone
and sysbench. None showed anything too remarkable.
The last test was a high-order allocation stress test. Many kernel
compiles are started to fill memory with a pressured mix of unmovable and
movable allocations. During this, an attempt is made to allocate 90% of
memory as huge pages - one at a time with small delays between attempts to
avoid flooding the IO queue.
vanilla compaction
Percentage of request allocated X86 98 99
Percentage of request allocated X86-64 95 98
Percentage of request allocated PPC64 55 70
This patch:
rmap_walk_anon() does not use page_lock_anon_vma() for looking up and
locking an anon_vma and it does not appear to have sufficient locking to
ensure the anon_vma does not disappear from under it.
This patch copies an approach used by KSM to take a reference on the
anon_vma while pages are being migrated. This should prevent rmap_walk()
running into nasty surprises later because anon_vma has been freed.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later. But in the way, the allocator may find that
there is no node to alloc memory.
The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:
(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oom
This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits). So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.
[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin reported that the allocator may see an empty nodemask when
changing cpuset's mems[1]. It happens only on the kernel that do not do
atomic nodemask_t stores. (MAX_NUMNODES > BITS_PER_LONG)
But I found that there is also a problem on the kernel that can do atomic
nodemask_t stores. The problem is that the allocator can't find a node to
alloc page when changing cpuset's mems though there is a lot of free
memory. The reason is like this:
(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oom
I can use the attached program reproduce it by the following step:
# mkdir /dev/cpuset
# mount -t cpuset cpuset /dev/cpuset
# mkdir /dev/cpuset/1
# echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus
# echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems
# echo $$ > /dev/cpuset/1/tasks
# numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> &
<nr_tasks> = max(nr_cpus - 1, 1)
# killall -s SIGUSR1 cpuset_mem_hog
# ./change_mems.sh
several hours later, oom will happen though there is a lot of free memory.
This patchset fixes this problem by expanding the nodes range first(set
newly allowed bits) and shrink it lazily(clear newly disallowed bits). So
we use a variable to tell the write-side task that read-side task is
reading nodemask, and the write-side task clears newly disallowed nodes
after read-side task ends the current memory allocation.
This patch:
In order to fix no node to alloc memory, when we want to update mempolicy
and mems_allowed, we expand the set of nodes first (set all the newly
nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the
mempolicy's rebind functions may breaks the expanding.
So we restructure the mempolicy's rebind functions and split the rebind
work to two steps, just like the update of cpuset's mems: The 1st step:
expand the set of the mempolicy's nodes. The 2nd step: shrink the set of
the mempolicy's nodes. It is used when there is no real lock to protect
the mempolicy in the read-side. Otherwise we can do rebind work at once.
In order to implement it, we define
enum mpol_rebind_step {
MPOL_REBIND_ONCE,
MPOL_REBIND_STEP1,
MPOL_REBIND_STEP2,
MPOL_REBIND_NSTEP,
};
If the mempolicy needn't be updated by two steps, we can pass
MPOL_REBIND_ONCE to the rebind functions. Or we can pass
MPOL_REBIND_STEP1 to do the first step of the rebind work and pass
MPOL_REBIND_STEP2 to do the second step work.
Besides that, it maybe long time between these two step and we have to
release the lock that protects mempolicy and mems_allowed. If we hold the
lock once again, we must check whether the current mempolicy is under the
rebinding (the first step has been done) or not, because the task may
alloc a new mempolicy when we don't hold the lock. So we defined the
following flag to identify it:
#define MPOL_F_REBINDING (1 << 2)
The new functions will be used in the next patch.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
putback_lru_page() never can fail. So it doesn't matter count of "the
number of pages put back".
In addition, users of this functions don't use return value.
Let's remove unnecessary code.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first"). Wow, It is 2 years old patch!
Currently, tmpfs file cache is inserted active list at first. This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio. Therefore, vmscan will get totally
confused. It scans almost only file LRU even though the system has plenty
unused tmpfs pages.
Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.
But we've lost both motivation because (1) Now we have separate anon and
file LRU list. then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation. then to
insert inactive list with pte access bit mean higher priority than to
insert active list. Its priority inversion may lead to uninteded lru
chun. but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once). (Thanks Hannes, you are great!)
Thus, now we can use lru_cache_add_anon() instead.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A lot of condition comparision statements are used in original driver. These
statements are used to check the boundary of voltage numbers since voltage
number isn't linear.
Now use array of voltage numbers instead. Clean code with simpler way.
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
When one regulator supplies another allow the relationship to be specified
using names rather than struct regulators, in a similar manner to that
allowed for consumer supplies. This allows static configuration at compile
time, reducing the need for dynamic init code.
Also change the references to LINE supply to be system supply since line
is sometimes used for actual supplies and therefore potentially confusing.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
A number of files in drivers/spi fail checkincludes.pl due to the double
include of <linux/spi/spi_bitbang.h>.
The first include is needed to get the struct spi_bitbang definition and
the spi_bitbang_* function prototypes.
The second include happens after defining EXPAND_BITBANG_TXRX to get the
inlined bitbang_txrx_* utility functions.
The <linux/spi/spi_bitbang.h> header is also included by a number of other
spi drivers, as well as some arch/ code, in order to use struct spi_bitbang
and the associated functions.
To fix the double include, and remove any potential confusion about it, move
the inlined bitbang_txrx_* functions to a new private header in drivers/spi
and also remove the need to define EXPAND_BITBANG_TXRX.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This adds support for a further ST variant of the PL022 called
PL023. Some differences in the control registers due to being
stripped down to SPI mode only, and a new clock feedback sample
delay config setting is available.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The PL022 SPI driver did not cleanly separate between the
original unmodified ARM version and the ST Microelectronics
versions. Split this more cleanly and fix some whitespace
moaning from checkpatch at the same time.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
cmd640: fix kernel oops in test_irq() method
pdc202xx_old: ignore "FIFO empty" bit in test_irq() method
pdc202xx_old: wire test_irq() method for PDC2026x
IDE: pass IRQ flags to the IDE core
ide: fix comment typo in ide.h
* 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
uml: Pushdown the bkl from harddog_kern ioctl
sunrpc: Pushdown the bkl from sunrpc cache ioctl
sunrpc: Pushdown the bkl from ioctl
autofs4: Pushdown the bkl from ioctl
uml: Convert to unlocked_ioctls to remove implicit BKL
ncpfs: BKL ioctl pushdown
coda: Clean-up whitespace problems in pioctl.c
coda: BKL ioctl pushdown
drivers: Push down BKL into various drivers
isdn: Push down BKL into ioctl functions
scsi: Push down BKL into ioctl functions
dvb: Push down BKL into ioctl functions
smbfs: Push down BKL into ioctl function
coda/psdev: Remove BKL from ioctl function
um/mmapper: Remove BKL usage
sn_hwperf: Kill BKL usage
hfsplus: Push down BKL into ioctl function
* git://git.infradead.org/battery-2.6:
ds2760_battery: Document ABI change
ds2760_battery: Make charge_now and charge_full writeable
power_supply: Add support for writeable properties
power_supply: Use attribute groups
power_supply: Add test_power driver
tosa_battery: Fix build error due to direct driver_data usage
wm97xx_battery: Quieten sparse warning (bat_set_pdata not declared)
ds2782_battery: Get rid of magic numbers in driver_data
ds2782_battery: Add support for ds2786 battery gas gauge
pda_power: Add function callbacks for suspend and resume
wm831x_power: Use genirq
Driver for Zipit Z2 battery chip
ds2782_battery: Fix clientdata on removal
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (25 commits)
sh: fix up sh7785lcr_32bit_defconfig.
arch/sh/lib/strlen.S: Checkpatch cleanup
sh: fix up sh7786 dmaengine build.
sh: guard cookie consistency across termination in the DMA driver
sh: prevent the DMA driver from unloading, while in use
sh: fix Oops in the serial SCI driver
sh: allow platforms to specify SD-card supported voltages
mmc: let MFD's provide supported Vdd card voltages to tmio_mmc
sh: disable SD-card write-protection detection on kfr2r09
mfd: pass platform flags down to the tmio_mmc driver
tmio: add a platform flag to disable card write-protection detection
sh: Add SDHI DMA support to migor
sh: Add SDHI DMA support to kfr2r09
sh: Add SDHI DMA support to ms7724se
sh: Add SDHI DMA support to ecovec
mmc: add DMA support to tmio_mmc driver, when used on SuperH
sh: prepare the SDHI MFD driver to pass DMA configuration to tmio_mmc.c
mmc: prepare tmio_mmc for passing of DMA configuration from the MFD cell
sh: add DMA slave definitions to sh7724
sh: add DMA slaves for two SDHI controllers to sh7722
...
* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6:
of: change of_match_device to work with struct device
of: Remove duplicate fields from of_platform_driver
drivercore: Add of_match_table to the common device drivers
arch/microblaze: Move dma_mask from of_device into pdev_archdata
arch/powerpc: Move dma_mask from of_device into pdev_archdata
of: eliminate of_device->node and dev_archdata->{of,prom}_node
of: Always use 'struct device.of_node' to get device node pointer.
i2c/of: Allow device node to be passed via i2c_board_info
driver-core: Add device node pointer to struct device
of: protect contents of of_platform.h and of_device.h
of/flattree: Make unflatten_device_tree() safe to call from any arch
of/flattree: make of_fdt.h safe to unconditionally include.
The i.MX25 PDK uses RMII to communicate with its PHY. This patch adds
the ability to configure RMII, based on platform data.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Boards can have different supplied voltages on different SD card slots. This
information has to be passed down to the SD/MMC driver.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Ian Molton <ian@mnementh.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Write-protection status is not always available, e.g., micro-SD cards do not
have a write-protection switch at all. This patch adds a flag to let platforms
force tmio_mmc to consider the card writable.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Ian Molton <ian@mnementh.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Pass DMA slave IDs from platform down to the tmio_mmc driver, to be used
for dmaengine configuration.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
After this patch, if the "dma" pointer in struct tmio_mmc_data is not NULL, it
points to a struct, containing two tokens, that have to be passed to the
dmaengine driver for channel configuration.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Merging in current state of Linus' tree to deal with merge conflicts and
build failures in vio.c after merge.
Conflicts:
drivers/i2c/busses/i2c-cpm.c
drivers/i2c/busses/i2c-mpc.c
drivers/net/gianfar.c
Also fixed up one line in arch/powerpc/kernel/vio.c to use the
correct node pointer.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The of_node pointer is now stored directly in struct device, so
of_match_device() should work with any device, not just struct of_device.
This patch changes the interface to of_match_device() to accept a
struct device instead of struct of_device.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
.name, .match_table and .owner are duplicated in both of_platform_driver
and device_driver. This patch is a removes the extra copies from struct
of_platform_driver and converts all users to the device_driver members.
This patch is a pretty mechanical change. The usage model doesn't change
and if any drivers have been missed, or if anything has been fixed up
incorrectly, then it will fail with a compile time error, and the fixup
will be trivial. This patch looks big and scary because it touches so
many files, but it should be pretty safe.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
OF-style matching can be available to any device, on any type of bus.
This patch allows any driver to provide an OF match table when CONFIG_OF
is enabled so that drivers can be bound against devices described in
the device tree.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
The declarations for elf_core_extra_phdrs() et al got added on the
wrong side of #ifdef __KERNEL__ in linux/elfcore.h so they leak into
the user header copy and we get a warning at build time about it.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits)
fix handling of offsets in cris eeprom.c, get rid of fake on-stack files
get rid of home-grown mutex in cris eeprom.c
switch ecryptfs_write() to struct inode *, kill on-stack fake files
switch ecryptfs_get_locked_page() to struct inode *
simplify access to ecryptfs inodes in ->readpage() and friends
AFS: Don't put struct file on the stack
Ban ecryptfs over ecryptfs
logfs: replace inode uid,gid,mode initialization with helper function
ufs: replace inode uid,gid,mode initialization with helper function
udf: replace inode uid,gid,mode init with helper
ubifs: replace inode uid,gid,mode initialization with helper function
sysv: replace inode uid,gid,mode initialization with helper function
reiserfs: replace inode uid,gid,mode initialization with helper function
ramfs: replace inode uid,gid,mode initialization with helper function
omfs: replace inode uid,gid,mode initialization with helper function
bfs: replace inode uid,gid,mode initialization with helper function
ocfs2: replace inode uid,gid,mode initialization with helper function
nilfs2: replace inode uid,gid,mode initialization with helper function
minix: replace inode uid,gid,mode init with helper
ext4: replace inode uid,gid,mode init with helper
...
Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
* git://git.infradead.org/iommu-2.6:
intel-iommu: Set a more specific taint flag for invalid BIOS DMAR tables
intel-iommu: Combine the BIOS DMAR table warning messages
panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I')
panic: Allow warnings to set different taint flags
intel-iommu: intel_iommu_map_range failed at very end of address space
intel-iommu: errors with smaller iommu widths
intel-iommu: Fix boot inside 64bit virtualbox with io-apic disabled
intel-iommu: use physfn to search drhd for VF
intel-iommu: Print out iommu seq_id
intel-iommu: Don't complain that ACPI_DMAR_SCOPE_TYPE_IOAPIC is not supported
intel-iommu: Avoid global flushes with caching mode.
intel-iommu: Use correct domain ID when caching mode is enabled
intel-iommu mistakenly uses offset_pfn when caching mode is enabled
intel-iommu: use for_each_set_bit()
intel-iommu: Fix section mismatch dmar_ir_support() uses dmar_tbl.
* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (27 commits)
drivers/char: Eliminate use after free
virtio: console: Accept console size along with resize control message
virtio: console: Store each console's size in the console structure
virtio: console: Resize console port 0 on config intr only if multiport is off
virtio: console: Add support for nonblocking write()s
virtio: console: Rename wait_is_over() to will_read_block()
virtio: console: Don't always create a port 0 if using multiport
virtio: console: Use a control message to add ports
virtio: console: Move code around for future patches
virtio: console: Remove config work handler
virtio: console: Don't call hvc_remove() on unplugging console ports
virtio: console: Return -EPIPE to hvc_console if we lost the connection
virtio: console: Let host know of port or device add failures
virtio: console: Add a __send_control_msg() that can send messages without a valid port
virtio: Revert "virtio: disable multiport console support."
virtio: add_buf_gfp
trans_virtio: use virtqueue_xxx wrappers
virtio-rng: use virtqueue_xxx wrappers
virtio_ring: remove a level of indirection
virtio_net: use virtqueue_xxx wrappers
...
Fix up conflicts in drivers/net/virtio_net.c due to new virtqueue_xxx
wrappers changes conflicting with some other cleanups.
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
KVM: x86: Add missing locking to arch specific vcpu ioctls
KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
KVM: MMU: Segregate shadow pages with different cr0.wp
KVM: x86: Check LMA bit before set_efer
KVM: Don't allow lmsw to clear cr0.pe
KVM: Add cpuid.txt file
KVM: x86: Tell the guest we'll warn it about tsc stability
x86, paravirt: don't compute pvclock adjustments if we trust the tsc
x86: KVM guest: Try using new kvm clock msrs
KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
KVM: x86: add new KVMCLOCK cpuid feature
KVM: x86: change msr numbers for kvmclock
x86, paravirt: Add a global synchronization point for pvclock
x86, paravirt: Enable pvclock flags in vcpu_time_info structure
KVM: x86: Inject #GP with the right rip on efer writes
KVM: SVM: Don't allow nested guest to VMMCALL into host
KVM: x86: Fix exception reinjection forced to true
KVM: Fix wallclock version writing race
KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
...
* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
module: drop the lock while waiting for module to complete initialization.
MODULE_DEVICE_TABLE(isapnp, ...) does nothing
hisax_fcpcipnp: fix broken isapnp device table.
isapnp: move definitions to mod_devicetable.h so file2alias can reach them.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
DMAENGINE: extend the control command to include an arg
async_tx: trim dma_async_tx_descriptor in 'no channel switch' case
DMAENGINE: DMA40 fix for allocation of logical channel 0
DMAENGINE: DMA40 support paused channel status
dmaengine: mpc512x: Use resource_size
DMA ENGINE: Do not reset 'private' of channel
ioat: Remove duplicated devm_kzalloc() calls for ioatdma_device
ioat3: disable cacheline-unaligned transfers for raid operations
ioat2,3: convert to producer/consumer locking
ioat: convert to circ_buf
DMAENGINE: Support for ST-Ericssons DMA40 block v3
async_tx: use of kzalloc/kfree requires the include of slab.h
dmaengine: provide helper for setting txstate
DMAENGINE: generic channel status v2
DMAENGINE: generic slave control v2
dma: timb-dma: Update comment and fix compiler warning
dma: Add timb-dma
DMAENGINE: COH 901 318 fix bytesleft
DMAENGINE: COH 901 318 rename confusing vars
- seems what ramfs_get_inode is only locally, make it static.
[AV: the hell it is; it's used by shmem, so shmem needed conversion too
and no, that function can't be made static]
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.31-2-generic #14~rbd3
> ---------------------------------------------
> firefox-3.5/4162 is trying to acquire lock:
> (&s->s_vfs_rename_mutex){+.+.+.}, at: [<ffffffff81139d31>] lock_rename+0x41/0xf0
>
> but task is already holding lock:
> (&s->s_vfs_rename_mutex){+.+.+.}, at: [<ffffffff81139d31>] lock_rename+0x41/0xf0
>
> other info that might help us debug this:
> 3 locks held by firefox-3.5/4162:
> #0: (&s->s_vfs_rename_mutex){+.+.+.}, at: [<ffffffff81139d31>] lock_rename+0x41/0xf0
> #1: (&sb->s_type->i_mutex_key#11/1){+.+.+.}, at: [<ffffffff81139d5a>] lock_rename+0x6a/0xf0
> #2: (&sb->s_type->i_mutex_key#11/2){+.+.+.}, at: [<ffffffff81139d6f>] lock_rename+0x7f/0xf0
>
> stack backtrace:
> Pid: 4162, comm: firefox-3.5 Tainted: G C 2.6.31-2-generic #14~rbd3
> Call Trace:
> [<ffffffff8108ae74>] print_deadlock_bug+0xf4/0x100
> [<ffffffff8108ce26>] validate_chain+0x4c6/0x750
> [<ffffffff8108d2e7>] __lock_acquire+0x237/0x430
> [<ffffffff8108d585>] lock_acquire+0xa5/0x150
> [<ffffffff81139d31>] ? lock_rename+0x41/0xf0
> [<ffffffff815526ad>] __mutex_lock_common+0x4d/0x3d0
> [<ffffffff81139d31>] ? lock_rename+0x41/0xf0
> [<ffffffff81139d31>] ? lock_rename+0x41/0xf0
> [<ffffffff8120eaf9>] ? ecryptfs_rename+0x99/0x170
> [<ffffffff81552b36>] mutex_lock_nested+0x46/0x60
> [<ffffffff81139d31>] lock_rename+0x41/0xf0
> [<ffffffff8120eb2a>] ecryptfs_rename+0xca/0x170
> [<ffffffff81139a9e>] vfs_rename_dir+0x13e/0x160
> [<ffffffff8113ac7e>] vfs_rename+0xee/0x290
> [<ffffffff8113c212>] ? __lookup_hash+0x102/0x160
> [<ffffffff8113d512>] sys_renameat+0x252/0x280
> [<ffffffff81133eb4>] ? cp_new_stat+0xe4/0x100
> [<ffffffff8101316a>] ? sysret_check+0x2e/0x69
> [<ffffffff8108c34d>] ? trace_hardirqs_on_caller+0x14d/0x190
> [<ffffffff8113d55b>] sys_rename+0x1b/0x20
> [<ffffffff81013132>] system_call_fastpath+0x16/0x1b
The trace above is totally reproducible by doing a cross-directory
rename on an ecryptfs directory.
The issue seems to be that sys_renameat() does lock_rename() then calls
into the filesystem; if the filesystem is ecryptfs, then
ecryptfs_rename() again does lock_rename() on the lower filesystem, and
lockdep can't tell that the two s_vfs_rename_mutexes are different. It
seems an annotation like the following is sufficient to fix this (it
does get rid of the lockdep trace in my simple tests); however I would
like to make sure I'm not misunderstanding the locking, hence the CC
list...
Signed-off-by: Roland Dreier <rdreier@cisco.com>
Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.
The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The entries in xattr handler table should be immutable (ie const)
like other operation tables.
Later patches convert common filesystems. Uncoverted filesystems
will still work, but will generate a compiler warning.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently the way we do freezing is by passing sb>s_bdev to freeze_bdev and then
letting it do all the work. But freezing is more of an fs thing, and doesn't
really have much to do with the bdev at all, all the work gets done with the
super. In btrfs we do not populate s_bdev, since we can have multiple bdev's
for one fs and setting s_bdev makes removing devices from a pool kind of tricky.
This means that freezing a btrfs filesystem fails, which causes us to corrupt
with things like tux-on-ice which use the fsfreeze mechanism. So instead of
populating sb->s_bdev with a random bdev in our pool, I've broken the actual fs
freezing stuff into freeze_super and thaw_super. These just take the
super_block that we're freezing and does the appropriate work. It's basically
just copy and pasted from freeze_bdev. I've then converted freeze_bdev over to
use the new super helpers. I've tested this with ext4 and btrfs and verified
everything continues to work the same as before.
The only new gotcha is multiple calls to the fsfreeze ioctl will return EBUSY if
the fs is already frozen. I thought this was a better solution than adding a
freeze counter to the super_block, but if everybody hates this idea I'm open to
suggestions. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
At the same time we can kill s_need_restart and local mutex in there.
__put_super() made public for a while; will be gone later.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (577 commits)
Staging: ramzswap: Handler for swap slot free callback
swap: Add swap slot free callback to block_device_operations
swap: Add flag to identify block swap devices
Staging: vt6655: use ETH_FRAME_LEN macro instead of custom one
Staging: vt6655: use ETH_DATA_LEN macro instead of custom one
Staging: vt6655: use ETH_FCS_LEN macro instead of custom one
Staging: vt6656: use ETH_HLEN macro instead of custom one
Staging: comedi: quatech_daqp_cs.c Replace eos semaphore with a completion.
Staging: dt3155v4l: remove private memory allocator
Staging: crystalhd: Remove typedefs from driver
Staging: winbond: Fix for pointer name format issue in mds.c
Staging: vt6656: removed custom UCHAR/USHORT/UINT/ULONG/ULONGLONG typedefs
Staging: vt6656: removed custom CHAR/SHORT/INT/LONG typedefs
Staging: comedi: Altered the way printk is used in 8255.c
staging: iio: adis16350 and similar IMU driver
Staging: iio: max1363 Fix two bugs in single_channel_from_ring
Staging: iio: adis16220 extract bin_attribute structures from state
Staging: iio: adis16220 vibration sensor driver
Staging: comedi: Kconfig dependancy fixes
Staging: comedi: fix up build error from last Kconfig changes
...
* 'for-2.6.35' of git://git.kernel.dk/linux-2.6-block: (86 commits)
pipe: set lower and upper limit on max pages in the pipe page array
pipe: add support for shrinking and growing pipes
drbd: This is now equivalent to drbd release 8.3.8rc1
drbd: Do not free p_uuid early, this is done in the exit code of the receiver
drbd: Null pointer deref fix to the large "multi bio rewrite"
drbd: Fix: Do not detach, if a bio with a barrier fails
drbd: Ensure to not trigger late-new-UUID creation multiple times
drbd: Do not Oops when C_STANDALONE when uuid gets generated
writeback: fix mixed up arguments to bdi_start_writeback()
writeback: fix problem with !CONFIG_BLOCK compilation
block: improve automatic native capacity unlocking
block: use struct parsed_partitions *state universally in partition check code
block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()
block: restart partition scan after resizing a device
buffer: make invalidate_bdev() drain all percpu LRU add caches
block: remove all rcu head initializations
writeback: fixups for !dirty_writeback_centisecs
writeback: bdi_writeback_task() must set task state before calling schedule()
writeback: ensure that WB_SYNC_NONE writeback with sb pinned is sync
drivers/block/drbd: Use kzalloc
...
Conflicts:
drivers/staging/arlan/arlan-main.c
drivers/staging/comedi/drivers/cb_das16_cs.c
drivers/staging/cx25821/cx25821-alsa.c
drivers/staging/dt3155/dt3155_drv.c
drivers/staging/hv/hv.c
drivers/staging/netwave/netwave_cs.c
drivers/staging/wavelan/wavelan.c
drivers/staging/wavelan/wavelan_cs.c
drivers/staging/wlags49_h2/wl_cs.c
This required a bit of hand merging due to the conflicts
that happened in the later .34-rc releases, as well as
some staging driver changing coming in through other trees
(v4l and pcmcia).
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need at least two to guarantee proper POSIX behaviour, so
never allow a smaller limit than that.
Also expose a /proc/sys/fs/pipe-max-pages sysctl file that allows
root to define a sane upper limit. Make it default to 16 times the
default size, which is 16 pages.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for
growing and shrinking the size of a pipe and adjusts pipe.c and splice.c
(and relay and network splice) usage to work with these larger (or smaller)
pipes.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (92 commits)
powerpc: Remove unused 'protect4gb' boot parameter
powerpc: Build-in e1000e for pseries & ppc64_defconfig
powerpc/pseries: Make request_ras_irqs() available to other pseries code
powerpc/numa: Use ibm,architecture-vec-5 to detect form 1 affinity
powerpc/numa: Set a smaller value for RECLAIM_DISTANCE to enable zone reclaim
powerpc: Use smt_snooze_delay=-1 to always busy loop
powerpc: Remove check of ibm,smt-snooze-delay OF property
powerpc/kdump: Fix race in kdump shutdown
powerpc/kexec: Fix race in kexec shutdown
powerpc/kexec: Speedup kexec hash PTE tear down
powerpc/pseries: Add hcall to read 4 ptes at a time in real mode
powerpc: Use more accurate limit for first segment memory allocations
powerpc/kdump: Use chip->shutdown to disable IRQs
powerpc/kdump: CPUs assume the context of the oopsing CPU
powerpc/crashdump: Do not fail on NULL pointer dereferencing
powerpc/eeh: Fix oops when probing in early boot
powerpc/pci: Check devices status property when scanning OF tree
powerpc/vio: Switch VIO Bus PM to use generic helpers
powerpc: Avoid bad relocations in iSeries code
powerpc: Use common cpu_die (fixes SMP+SUSPEND build)
...
* 'drm-for-2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (207 commits)
drm/radeon/kms/pm/r600: select the mid clock mode for single head low profile
drm/radeon: fix power supply kconfig interaction.
drm/radeon/kms: record object that have been list reserved
drm/radeon: AGP memory is only I/O if the aperture can be mapped by the CPU.
drm/radeon/kms: don't default display priority to high on rs4xx
drm/edid: fix typo in 1600x1200@75 mode
drm/nouveau: fix i2c-related init table handlers
drm/nouveau: support init table i2c device identifier 0x81
drm/nouveau: ensure we've parsed i2c table entry for INIT_*I2C* handlers
drm/nouveau: display error message for any failed init table opcode
drm/nouveau: fix init table handlers to return proper error codes
drm/nv50: support fractional feedback divider on newer chips
drm/nv50: fix monitor detection on certain chipsets
drm/nv50: store full dcb i2c entry from vbios
drm/nv50: fix suspend/resume with DP outputs
drm/nv50: output calculated crtc pll when debugging on
drm/nouveau: dump pll limits entries when debugging is on
drm/nouveau: bios parser fixes for eDP boards
drm/nouveau: fix a nouveau_bo dereference after it's been destroyed
drm/nv40: remove some completed ctxprog TODOs
...
* 'dbg-early-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
echi-dbgp: Add kernel debugger support for the usb debug port
earlyprintk,vga,kdb: Fix \b and \r for earlyprintk=vga with kdb
kgdboc: Add ekgdboc for early use of the kernel debugger
x86,early dr regs,kgdb: Allow kernel debugger early dr register access
x86,kgdb: Implement early hardware breakpoint debugging
x86, kgdb, init: Add early and late debug states
x86, kgdb: early trap init for early debug
* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
kdb,debug_core: Allow the debug core to receive a panic notification
MAINTAINERS: update kgdb, kdb, and debug_core info
debug_core,kdb: Allow the debug core to process a recursive debug entry
printk,kdb: capture printk() when in kdb shell
kgdboc,kdb: Allow kdb to work on a non open console port
kgdb: Add the ability to schedule a breakpoint via a tasklet
mips,kgdb: kdb low level trap catch and stack trace
powerpc,kgdb: Introduce low level trap catching
x86,kgdb: Add low level debug hook
kgdb: remove post_primary_code references
kgdb,docs: Update the kgdb docs to include kdb
kgdboc,keyboard: Keyboard driver for kdb with kgdb
kgdb: gdb "monitor" -> kdb passthrough
sparc,sunzilog: Add console polling support for sunzilog serial driver
sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
kgdb,8250,pl011: Return immediately from console poll
kgdb: core changes to support kdb
kdb: core for kgdb back end (2 of 2)
kdb: core for kgdb back end (1 of 2)
kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
...
When CONFIG_BLOCK isn't enabled:
mm/page-writeback.c: In function 'laptop_mode_timer_fn':
mm/page-writeback.c:708: error: dereferencing pointer to incomplete type
mm/page-writeback.c:709: error: dereferencing pointer to incomplete type
Fix this by essentially eliminating the laptop sync handlers when
CONFIG_BLOCK isn't set, as most are only used from the block layer code.
The exception is laptop_sync_completion() which is used from sys_sync(),
make that an empty declaration in that case.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
bdops->set_capacity() is unnecessarily generic. All that's required
is a simple one way notification to lower level driver telling it to
try to unlock native capacity. There's no reason to pass in target
capacity or return the new capacity. The former is always the
inherent native capacity and the latter can be handled via the usual
device resize / revalidation path. In fact, the current API is always
used that way.
Replace ->set_capacity() with ->unlock_native_capacity() which take
only @disk and doesn't return anything. IDE which is the only current
user of the API is converted accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commit 69b62d01 fixed up most of the places where we would enter
busy schedule() spins when disabling the periodic background
writeback. This fixes up the sb timer so that it doesn't get
hammered on with the delay disabled, and ensures that it gets
rearmed if needed when /proc/sys/vm/dirty_writeback_centisecs
gets modified.
bdi_forker_task() also needs to check for !dirty_writeback_centisecs
and use schedule() appropriately, fix that up too.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (31 commits)
dquot: Detect partial write error to quota file in write_blk() and add printk_ratelimit for quota error messages
ocfs2: Fix lock inversion in quotas during umount
ocfs2: Use __dquot_transfer to avoid lock inversion
ocfs2: Fix NULL pointer deref when writing local dquot
ocfs2: Fix estimate of credits needed for quota allocation
ocfs2: Fix quota locking
ocfs2: Avoid unnecessary block mapping when refreshing quota info
ocfs2: Do not map blocks from local quota file on each write
quota: Refactor dquot_transfer code so that OCFS2 can pass in its references
quota: unify quota init condition in setattr
quota: remove sb_has_quota_active in get/set_info
quota: unify ->set_dqblk
quota: unify ->get_dqblk
ext3: make barrier options consistent with ext4
quota: Make quota stat accounting lockless.
suppress warning: "quotatypes" defined but not used
ext3: Fix waiting on transaction during fsync
jbd: Provide function to check whether transaction will issue data barrier
ufs: add ufs speciffic ->setattr call
BKL: Remove BKL from ext2 filesystem
...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (25 commits)
serial: Tidy REMOTE_DEBUG
serial: isicomm: handle running out of slots
serial: bfin_sport_uart: Use resource size to fix off-by-one error
tty: fix obsolete comment on tty_insert_flip_string_fixed_flag
serial: Add driver for the Altera UART
serial: Add driver for the Altera JTAG UART
serial: timbuart: make sure last byte is sent when port is closed
serial: two branches the same in timbuart_set_mctrl()
serial: uartlite: move from byte accesses to word accesses
tty: n_gsm: depends on NET
tty: n_gsm line discipline
serial: TTY: new ldiscs for staging
serial: bfin_sport_uart: drop redundant cpu depends
serial: bfin_sport_uart: drop the experimental markings
serial: bfin_sport_uart: pull in bfin_sport.h for SPORT defines
serial: bfin_sport_uart: only enable SPORT TX if data is to be sent
serial: bfin_sport_uart: drop useless status masks
serial: bfin_sport_uart: zero sport_uart_port if allocated dynamically
serial: bfin_sport_uart: protect changes to uart_port
serial: bfin_sport_uart: add support for CTS/RTS via GPIOs
...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (38 commits)
net: Expose all network devices in a namespaces in sysfs
hotplug: netns aware uevent_helper
kobj: Send hotplug events in the proper namespace.
netlink: Implment netlink_broadcast_filtered
net/sysfs: Fix the bitrot in network device kobject namespace support
netns: Teach network device kobjects which namespace they are in.
kobject: Send hotplug events in all network namespaces
driver-core: fix Typo in drivers/base/core.c for CONFIG_MODULE
pci: check caps from sysfs file open to read device dependent config space
sysfs: add struct file* to bin_attr callbacks
sysfs: Remove usage of S_BIAS to avoid merge conflict with the vfs tree
sysfs: Don't use enums in inline function declaration.
sysfs-namespaces: add a high-level Documentation file
sysfs: Comment sysfs directory tagging logic
driver core: Implement ns directory support for device classes.
sysfs: Implement sysfs_delete_link
sysfs: Add support for tagged directories with untagged members.
sysfs: Implement sysfs tagged directory support.
kobj: Add basic infrastructure for dealing with namespaces.
sysfs: Remove double free sysfs_get_sb
...
Currently, __dquot_transfer() acquires its own references of dquot structures
that will be put into inode. But for OCFS2, this creates a lock inversion
between dq_lock (waited on in dqget) and transaction start (started in
ocfs2_setattr). Currently, deadlock is impossible because dq_lock is acquired
only during dquot_acquire and dquot_release and we already hold a reference to
dquot structures in ocfs2_setattr so neither of these functions can be called
while we call dquot_transfer. But this is rather subtle and it is hard to teach
lockdep about it. So provide __dquot_transfer function that can be passed dquot
references directly. OCFS2 can then pass acquired dquot references directly to
__dquot_transfer with proper locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Quota must being initialized if size or uid/git changes requested.
But initialization performed in two different places:
in case of i_size file system is responsible for dquot init
, but in case of uid/gid init will be called internally in
dquot_transfer().
This ambiguity makes code harder to understand.
Let's move this logic to one common helper function.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Pass the larger struct fs_disk_quota to the ->set_dqblk operation so
that the Q_SETQUOTA and Q_XSETQUOTA operations can be implemented
with a single filesystem operation and we can retire the ->set_xquota
operation. The additional information (RT-subvolume accounting and
warn counts) are left zero for the VFS quota implementation.
Add new fieldmask values for setting the numer of blocks and inodes
values which is required for the VFS quota, but wasn't for XFS.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Pass the larger struct fs_disk_quota to the ->get_dqblk operation so
that the Q_GETQUOTA and Q_XGETQUOTA operations can be implemented
with a single filesystem operation and we can retire the ->get_xquota
operation. The additional information (RT-subvolume accounting and
warn counts) are left zero for the VFS quota implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Quota stats is mostly writable data structure. Let's alloc percpu
bucket for each value.
NOTE: dqstats_read() function is racy against dqstats_{inc,dec}
and may return inconsistent value. But this is ok since absolute
accuracy is not required.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Provide a function which returns whether a transaction with given tid
will send a barrier to the filesystem device. The function will be used
by ext3 to detect whether fsync needs to send a separate barrier or not.
Signed-off-by: Jan Kara <jack@suse.cz>
Add a spinlock that protects against concurrent modifications of
s_mount_state, s_blocks_last, s_overhead_last and the content of the
superblock's buffer pointed to by sbi->s_es. The spinlock is now used in
ext2_xattr_update_super_block() which was setting the
EXT2_FEATURE_COMPAT_EXT_ATTR flag on the superblock without protection
before. Likewise the spinlock is used in ext2_show_options() to have a
consistent view of the mount options.
This is a preparation patch for removing the BKL from ext2 in the next
patch.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jan Kara <jack@suse.cz>
When netlink sockets are used to convey data that is in a namespace
we need a way to select a subset of the listening sockets to deliver
the packet to. For the network namespace we have been doing this
by only transmitting packets in the correct network namespace.
For data belonging to other namespaces netlink_bradcast_filtered
provides a mechanism that allows us to examine the destination
socket and to decide if we should transmit the specified packet
to it.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The problem. Network devices show up in sysfs and with the network
namespace active multiple devices with the same name can show up in
the same directory, ouch!
To avoid that problem and allow existing applications in network namespaces
to see the same interface that is currently presented in sysfs, this
patch enables the tagging directory support in sysfs.
By using the network namespace pointers as tags to separate out the
the sysfs directory entries we ensure that we don't have conflicts
in the directories and applications only see a limited set of
the network devices.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It appears gcc can't cope with using an enum that is only declared in
an inline function declaration, that doesn't even use the variable
that is so declared.
Avoid the silliness and replace the enum with an int, and make gcc
happy.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add some in-line comments to explain the new infrastructure, which
was introduced to support sysfs directory tagging with namespaces.
I think an overall description someplace might be good too, but it
didn't really seem to fit into Documentation/filesystems/sysfs.txt,
which appears more geared toward users, rather than maintainers, of
sysfs.
(Tejun, please let me know if I can make anything clearer or failed
altogether to comment something that should be commented.)
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When removing a symlink sysfs_remove_link does not provide
enough information to figure out which tagged directory the symlink
falls in. So I need sysfs_delete_link which is passed the target
of the symlink to delete.
sysfs_rename_link is updated to call sysfs_delete_link instead
of sysfs_remove_link as we have all of the information necessary
and the callers are interesting.
Both of these functions now have enough information to find a symlink
in a tagged directory. The only restriction is that they must be called
before the target kobject is renamed or deleted. If they are called
later I loose track of which tag the target kobject was marked with
and can no longer find the old symlink to remove it.
This patch was split from an earlier patch.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The problem. When implementing a network namespace I need to be able
to have multiple network devices with the same name. Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.
What this patch does is to add an additional tag field to the
sysfs dirent structure. For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible. Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.
I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.
For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded. Which means I need
a simple race free way to setup those directories as tagged.
To achieve a reace free design all tagged directories are created
and managed by sysfs itself.
Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid
- Implement mount_ns() which returns the ns of the calling process
so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.
Everything else is left up to sysfs and the driver layer.
For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.
Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.
The work needed in sysfs is more extensive. At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent. Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.
Currently only directories which hold kobjects, and
symlinks are supported. There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move complete knowledge of namespaces into the kobject layer
so we can use that information when reporting kobjects to
userspace.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
