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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-08 12:31:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-08 12:31:53 -0700
commit3af968e066d593bc4dacc021715f3e95ddf0996f (patch)
tree37851a67d855e228d503a569973469b067ef218a /kernel/async.c
parent46056be71c37378f518711da651e4bb76d650ee9 (diff)
downloadvexpress-lsk-3af968e066d593bc4dacc021715f3e95ddf0996f.tar.gz
async: Fix lack of boot-time console due to insufficient synchronization
Our async work synchronization was broken by "async: make sure independent async domains can't accidentally entangle" (commit d5a877e8dd409d8c702986d06485c374b705d340), because it would report the wrong lowest active async ID when there was both running and pending async work. This caused things like no being able to read the root filesystem, resulting in missing console devices and inability to run 'init', causing a boot-time panic. This fixes it by properly returning the lowest pending async ID: if there is any running async work, that will have a lower ID than any pending work, and we should _not_ look at the pending work list. There were alternative patches from Jaswinder and James, but this one also cleans up the code by removing the pointless 'ret' variable and the unnecesary testing for an empty list around 'for_each_entry()' (if the list is empty, the for_each_entry() thing just won't execute). Fixes-bug: http://bugzilla.kernel.org/show_bug.cgi?id=13474 Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com> Cc: Jaswinder Singh Rajput <jaswinder@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/async.c')
-rw-r--r--kernel/async.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/kernel/async.c b/kernel/async.c
index 50540301ed0..27235f5de19 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -92,23 +92,18 @@ extern int initcall_debug;
static async_cookie_t __lowest_in_progress(struct list_head *running)
{
struct async_entry *entry;
- async_cookie_t ret = next_cookie; /* begin with "infinity" value */
if (!list_empty(running)) {
entry = list_first_entry(running,
struct async_entry, list);
- ret = entry->cookie;
+ return entry->cookie;
}
- if (!list_empty(&async_pending)) {
- list_for_each_entry(entry, &async_pending, list)
- if (entry->running == running) {
- ret = entry->cookie;
- break;
- }
- }
+ list_for_each_entry(entry, &async_pending, list)
+ if (entry->running == running)
+ return entry->cookie;
- return ret;
+ return next_cookie; /* "infinity" value */
}
static async_cookie_t lowest_in_progress(struct list_head *running)