task_will_free_mem() is wrong in many ways, and in particular the
SIGNAL_GROUP_COREDUMP check is not reliable: a task can participate in the
coredumping without SIGNAL_GROUP_COREDUMP bit set.
change zap_threads() paths to always set SIGNAL_GROUP_COREDUMP even if
other CLONE_VM processes can't react to SIGKILL. Fortunately, at least
oom-kill case if fine; it kills all tasks sharing the same mm, so it
should also kill the process which actually dumps the core.
The change in prepare_signal() is not strictly necessary, it just ensures
that the patch does not bring another subtle behavioural change. But it
reminds us that this SIGNAL_GROUP_EXIT/COREDUMP case needs more changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kyle Walker <kwalker@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Stanislav Kozina <skozina@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. Rename dequeue_signal_lock() to kernel_dequeue_signal(). This
matches another "for kthreads only" kernel_sigaction() helper.
2. Remove the "tsk" and "mask" arguments, they are always current
and current->blocked. And it is simply wrong if tsk != current.
3. We could also remove the 3rd "siginfo_t *info" arg but it looks
potentially useful. However we can simplify the callers if we
change kernel_dequeue_signal() to accept info => NULL.
4. Remove _irqsave, it is never called from atomic context.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is hardly possible to enumerate all problems with block_all_signals()
and unblock_all_signals(). Just for example,
1. block_all_signals(SIGSTOP/etc) simply can't help if the caller is
multithreaded. Another thread can dequeue the signal and force the
group stop.
2. Even is the caller is single-threaded, it will "stop" anyway. It
will not sleep, but it will spin in kernel space until SIGCONT or
SIGKILL.
And a lot more. In short, this interface doesn't work at all, at least
the last 10+ years.
Daniel said:
Yeah the only times I played around with the DRM_LOCK stuff was when
old drivers accidentally deadlocked - my impression is that the entire
DRM_LOCK thing was never really tested properly ;-) Hence I'm all for
purging where this leaks out of the drm subsystem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some false positive warnings are reported for powerpc build.
The following warnings are reported in
http://kisskb.ellerman.id.au/kisskb/buildresult/12519703/
CC fs/nilfs2/super.o
fs/nilfs2/super.c: In function 'nilfs_resize_fs':
fs/nilfs2/super.c:376:2: warning: 'blocknr' may be used uninitialized in this function [-Wuninitialized]
fs/nilfs2/super.c:362:11: note: 'blocknr' was declared here
CC fs/nilfs2/recovery.o
fs/nilfs2/recovery.c: In function 'nilfs_salvage_orphan_logs':
fs/nilfs2/recovery.c:631:21: warning: 'sum' may be used uninitialized in this function [-Wuninitialized]
fs/nilfs2/recovery.c:585:32: note: 'sum' was declared here
fs/nilfs2/recovery.c: In function 'nilfs_search_super_root':
fs/nilfs2/recovery.c:873:11: warning: 'sum' may be used uninitialized in this function [-Wuninitialized]
Another similar warning is reported in
http://kisskb.ellerman.id.au/kisskb/buildresult/12520079/
CC fs/nilfs2/btree.o
fs/nilfs2/btree.c: In function 'nilfs_btree_convert_and_insert':
include/asm-generic/bitops/non-atomic.h:105:20: warning: 'bh' may be used uninitialized in this function [-Wuninitialized]
fs/nilfs2/btree.c:1859:22: note: 'bh' was declared here
This cleans out these warnings by forcing the variables to be initialized.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following build warnings:
$ make W=1
[...]
CC [M] fs/nilfs2/btree.o
fs/nilfs2/btree.c: In function 'nilfs_btree_split':
fs/nilfs2/btree.c:923:8: warning: variable 'newptr' set but not used [-Wunused-but-set-variable]
__u64 newptr;
^
fs/nilfs2/btree.c:922:8: warning: variable 'newkey' set but not used [-Wunused-but-set-variable]
__u64 newkey;
^
CC [M] fs/nilfs2/dat.o
fs/nilfs2/dat.c: In function 'nilfs_dat_prepare_end':
fs/nilfs2/dat.c:158:8: warning: variable 'start' set but not used [-Wunused-but-set-variable]
__u64 start;
^
CC [M] fs/nilfs2/segment.o
fs/nilfs2/segment.c: In function 'nilfs_segctor_do_immediate_flush':
fs/nilfs2/segment.c:2433:6: warning: variable 'err' set but not used [-Wunused-but-set-variable]
int err;
^
CC [M] fs/nilfs2/sufile.o
fs/nilfs2/sufile.c: In function 'nilfs_sufile_alloc':
fs/nilfs2/sufile.c:320:27: warning: variable 'ncleansegs' set but not used [-Wunused-but-set-variable]
unsigned long nsegments, ncleansegs, nsus, cnt;
^
CC [M] fs/nilfs2/alloc.o
fs/nilfs2/alloc.c: In function 'nilfs_palloc_prepare_alloc_entry':
fs/nilfs2/alloc.c:478:38: warning: variable 'groups_per_desc_block' set but not used [-Wunused-but-set-variable]
unsigned long n, entries_per_group, groups_per_desc_block;
^
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds tracepoints which would be useful for analyzing segment
usage from a perspective of high level sufile manipulation (check, alloc,
free). sufile is an important in-place updated metadata file, so
analyzing the behavior would be useful for performance turning.
example of usage (a case of allocation):
$ sudo bin/tpoint nilfs2:nilfs2_segment_usage_allocated
Tracing nilfs2:nilfs2_segment_usage_allocated. Ctrl-C to end.
segctord-17800 [002] ...1 10671.867294: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 2
segctord-17800 [002] ...1 10675.073477: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 3
Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benixon Dhas <benixon.dhas@wdc.com>
Cc: TK Kato <TK.Kato@wdc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds a tracepoint for transaction events of nilfs. With the
tracepoint, these events can be tracked: begin, abort, commit, trylock,
lock, and unlock. Basically, these events have corresponding functions
e.g. begin event corresponds nilfs_transaction_begin(). The unlock event
is an exception. It corresponds to the iteration in
nilfs_transaction_lock().
Only one tracepoint is introcued: nilfs2_transaction_transition. The
above events are distinguished with newly introduced enum. With this
tracepoint, we can analyse a critical section of segment constructoin.
Sample output by tpoint of perf-tools:
cp-4457 [000] ...1 63.266220: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 1 flags = 9 state = BEGIN
cp-4457 [000] ...1 63.266221: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 0 flags = 9 state = COMMIT
cp-4457 [000] ...1 63.266221: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800bf5ccc58 count = 0 flags = 9 state = COMMIT
segctord-4371 [001] ...1 68.261196: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = TRYLOCK
segctord-4371 [001] ...1 68.261280: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = LOCK
segctord-4371 [001] ...1 68.261877: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 1 flags = 10 state = BEGIN
segctord-4371 [001] ...1 68.262116: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 18 state = COMMIT
segctord-4371 [001] ...1 68.265032: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 18 state = UNLOCK
segctord-4371 [001] ...1 132.376847: nilfs2_transaction_transition: sb = ffff8802112b8800 ti = ffff8800b889bdf8 count = 0 flags = 10 state = TRYLOCK
This patch also does trivial cleaning of comma usage in collection stage
transition event for consistent coding style.
Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds a tracepoint for tracking stage transition of block
collection in segment construction. With the tracepoint, we can analysis
the behavior of segment construction in depth. It would be useful for
bottleneck detection and debugging, etc.
The tracepoint is created with the standard trace API of linux (like ext3,
ext4, f2fs and btrfs). So we can analysis with existing tools easily. Of
course, more detailed analysis will be possible if we can create nilfs
specific analysis tools.
Below is an example of event dump with Brendan Gregg's perf-tools
(https://github.com/brendangregg/perf-tools). Time consumption between
each stage can be obtained.
$ sudo bin/tpoint nilfs2:nilfs2_collection_stage_transition
Tracing nilfs2:nilfs2_collection_stage_transition. Ctrl-C to end.
segctord-14875 [003] ...1 28311.067794: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_INIT
segctord-14875 [003] ...1 28311.068139: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_GC
segctord-14875 [003] ...1 28311.068139: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_FILE
segctord-14875 [003] ...1 28311.068486: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_IFILE
segctord-14875 [003] ...1 28311.068540: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_CPFILE
segctord-14875 [003] ...1 28311.068561: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_SUFILE
segctord-14875 [003] ...1 28311.068565: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_DAT
segctord-14875 [003] ...1 28311.068573: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_SR
segctord-14875 [003] ...1 28311.068574: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_DONE
For capturing transition correctly, this patch adds wrappers for the
member scnt of nilfs_cstage. With this change, every transition of the
stage can produce trace event in a correct manner.
Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As a nilfs2 volume ages, the amount of available disk space decreases
little by little due to bloat of DAT (disk address translation) metadata
file. Even if we delete all files in a file system and free their block
addresses from the DAT file through a garbage collection, empty DAT blocks
are not freed.
This fixes the issue by extending the deallocator of block addresses so
that empty data blocks and empty bitmap blocks of DAT are deleted.
The following comparison shows the effect of this patch. Each shows disk
amount information of a nilfs2 volume that we cleaned out by deleting all
files and running gc after having filled 90% of its capacity.
Before:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 500105212 3022844 472072192 1% /test
After:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 500105212 16380 475078656 1% /test
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds delete functions for data blocks of metadata files using bitmap
based allocator. nilfs_palloc_delete_entry_block() deletes an entry block
(e.g. block storing dat entries), and nilfs_palloc_delete_bitmap_block()
deletes a bitmap block, respectively.
These helpers are intended to be used in the successive change on
deallocator of block addresses ("nilfs2: free unused dat file blocks
during garbage collection").
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This unfolds nilfs_palloc_group_is_in() helper function into
nilfs_palloc_freev() function to simplify a range check and an index
calculation repeatedy performed in a loop of the function.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current implementation of nilfs_palloc_find_available_slot() function
is overkill. The underlying bit search routine is well optimized, so this
uses it more simply in nilfs_palloc_find_available_slot().
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the bitmap based allocator implementation, nilfs_mdt_bgl_lock() helper
is frequently used to get a spinlock protecting a target block group.
This reduces its usage and simplifies arguments of some related functions
by directly passing a pointer to the spinlock.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This uses nilfs_warning() to replace "printk(KERN_WARNING ...);" in the
bitmap based allocator implementation of nilfs2. The warning messages are
modified to include the device name and the inode number in each message.
This makes it clear which metadata file of which device has output
warnings such as "entry number xxxx already freed".
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Global and static variables don't need to be initialized to 0.
There is already a test for this but the output message doesn't
mention booleans initialized to false.
Improve the output message and the test by adding various forms
with possible specific integer types and possible multiple zeros.
Miscellanea:
o Use a variable to hold the possible 0 test
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Shailendra Verma <shailendra.v@samsung.com>
Tested-by: Shailendra Verma <shailendra.v@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Including BUG and stack dumps in commit logs makes checkpatch produce some
false positive warning messages.
checkpatch has multiple types of false positives:
o Commit message lines > 75 chars
o Stack dump address are mistaken for git commit IDs
o Link: and Fixes: lines are allowed to be > 75 chars.
o Fixes: style doesn't require ("<commit_description>")
parentheses and double quotes like other uses of
git commit ID and description.
Fix these.
Miscellanea:
o Move the test for checking $commit_log_possible_stack_dump
above the test for a long line commit message
o Add test for hex address surrounded by square or angle brackets
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a classical off-by-one error in case when we try to place, for
example, 1+1 bytes as hex in the buffer of size 6. The expected result is
to get an output truncated, but in the reality we get 6 bytes filed
followed by terminating NUL.
Change the logic how we fill the output in case of byte dumping into
limited space. This will follow the snprintf() behaviour by truncating
output even on half bytes.
Fixes: 114fc1afb2 (hexdump: make it return number of bytes placed in buffer)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that commit a20135ffbc ("writeback: don't drain
bdi_writeback_congested on bdi destruction") added a usage of
rbtree_postorder_for_each_entry_safe() in mm/backing-dev.c which appears
to try to rb_erase() elements from an rbtree while iterating over it using
rbtree_postorder_for_each_entry_safe().
Doing this will cause random nodes to be missed by the iteration because
rb_erase() may rebalance the tree, changing the ordering that we're trying
to iterate over.
The previous documentation for rbtree_postorder_for_each_entry_safe()
wasn't clear that this wasn't allowed, it was taken from the docs for
list_for_each_entry_safe(), where erasing isn't a problem due to
list_del() not reordering.
Explicitly warn developers about this potential pit-fall.
Note that I haven't fixed the actual issue that (it appears) the commit
referenced above introduced (not familiar enough with that code).
In general (and in this case), the patterns to follow are:
- switch to rb_first() + rb_erase(), don't use
rbtree_postorder_for_each_entry_safe().
- keep the postorder iteration and don't rb_erase() at all. Instead
just clear the fields of rb_node & cgwb_congested_tree as required by
other users of those structures.
[akpm@linux-foundation.org: tweak comments]
Signed-off-by: Cody P Schafer <dev@codyps.com>
Cc: John de la Garza <john@jjdev.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
