diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-03-02 15:25:36 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-03-07 14:26:49 +1100 |
| commit | c391a36c9b415f3276d1059594a635e66d3f5d7a (patch) | |
| tree | b3971242e2d40ec624c88b7ae7ca54a9fd908ab0 /fs | |
| parent | 62159550cf357e60632a7ac147b4c66b1e2b0630 (diff) | |
coredump: make wait_for_dump_helpers() freezable
wait_for_dump_helpers() calls wake_up/kill_fasync from inside the
wait_event-like loop. This is not needed and in fact this is not strictly
correct, we can/should do this only once after we change pipe->writers.
We could even check if it becomes zero.
With this change it is trivial to convert this code to use
wait_event_freezable() and make this function freezable/killable, only
SIGKILL can set TIF_SIGPENDING.
With this patch we check pipe->readers without pipe_lock(), this is fine.
Once we see pipe->readers == 1 we know that the handler decremented the
counter, this is all we need.
Note: wait_event_freezable() is "strange", perhaps it should be changed or
simply removed. In the latter case we can change this code again to use
freezer_do_not_count + wait_event_interruptible.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>a
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/coredump.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index b0168c798923..7638895df974 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -32,6 +32,7 @@ #include <linux/pipe_fs_i.h> #include <linux/oom.h> #include <linux/compat.h> +#include <linux/freezer.h> #include <asm/uaccess.h> #include <asm/mmu_context.h> @@ -428,17 +429,16 @@ static void wait_for_dump_helpers(struct file *file) pipe_lock(pipe); pipe->readers++; pipe->writers--; + wake_up_interruptible_sync(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); + pipe_unlock(pipe); - while ((pipe->readers > 1) && (!signal_pending(current))) { - wake_up_interruptible_sync(&pipe->wait); - kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); - pipe_wait(pipe); - } + wait_event_freezable(pipe->wait, pipe->readers == 1); + pipe_lock(pipe); pipe->readers--; pipe->writers++; pipe_unlock(pipe); - } /* |