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authorNeilBrown <neilb@suse.de>2014-07-07 09:16:04 +0400
committerIngo Molnar <mingo@kernel.org>2014-07-16 17:10:39 +0400
commit743162013d40ca612b4cb53d3a200dff2d9ab26e (patch)
treeb688e8afdbb96d18c7466b088b2dc21156a0bedd /security/keys
parentd26fad5b38e1c4667d4f2604936e59c837caa54d (diff)
downloadlinux-743162013d40ca612b4cb53d3a200dff2d9ab26e.tar.xz
sched: Remove proliferation of wait_on_bit() action functions
The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'security/keys')
-rw-r--r--security/keys/gc.c11
-rw-r--r--security/keys/request_key.c23
2 files changed, 3 insertions, 31 deletions
diff --git a/security/keys/gc.c b/security/keys/gc.c
index d3222b6d7d59..9609a7f0faea 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -92,15 +92,6 @@ static void key_gc_timer_func(unsigned long data)
}
/*
- * wait_on_bit() sleep function for uninterruptible waiting
- */
-static int key_gc_wait_bit(void *flags)
-{
- schedule();
- return 0;
-}
-
-/*
* Reap keys of dead type.
*
* We use three flags to make sure we see three complete cycles of the garbage
@@ -123,7 +114,7 @@ void key_gc_keytype(struct key_type *ktype)
schedule_work(&key_gc_work);
kdebug("sleep");
- wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit,
+ wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE,
TASK_UNINTERRUPTIBLE);
key_gc_dead_keytype = NULL;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 381411941cc1..26a94f18af94 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -21,24 +21,6 @@
#define key_negative_timeout 60 /* default timeout on a negative key's existence */
-/*
- * wait_on_bit() sleep function for uninterruptible waiting
- */
-static int key_wait_bit(void *flags)
-{
- schedule();
- return 0;
-}
-
-/*
- * wait_on_bit() sleep function for interruptible waiting
- */
-static int key_wait_bit_intr(void *flags)
-{
- schedule();
- return signal_pending(current) ? -ERESTARTSYS : 0;
-}
-
/**
* complete_request_key - Complete the construction of a key.
* @cons: The key construction record.
@@ -592,10 +574,9 @@ int wait_for_key_construction(struct key *key, bool intr)
int ret;
ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
- intr ? key_wait_bit_intr : key_wait_bit,
intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
- if (ret < 0)
- return ret;
+ if (ret)
+ return -ERESTARTSYS;
if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
smp_rmb();
return key->type_data.reject_error;