The patch titled
make lockdep happy with r/o bind mounts
has been removed from the -mm tree. Its filename was
r-o-bind-mounts-track-number-of-mount-writers-make-lockdep-happy-with-r-o-bind-mounts.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: make lockdep happy with r/o bind mounts
From: Dave Hansen <haveblue@xxxxxxxxxx>
With the r/o bind mount patches, we can have as many
spinlocks nested as there are CPUs on the system.
Lockdep freaks out after 8.
So, create a new lockdep class of locks for the
mnt_writer spinlocks, and initialize each of the
cpu locks to be in a different class.
It should shut up warnings like this, while still
allowing some of the lockdep goodness to remain:
=============================================
[ INFO: possible recursive locking detected ]
2.6.23-rc6 #6
---------------------------------------------
swapper/1 is trying to acquire lock:
(&writer->lock){--..}, at: [<c016c094>] lock_and_coalesce_cpu_mnt_writer_counts+0x29/0x5c
but task is already holding lock:
(&writer->lock){--..}, at: [<c016c094>] lock_and_coalesce_cpu_mnt_writer_counts+0x29/0x5c
other info that might help us debug this:
1 lock held by swapper/1:
#0: (&writer->lock){--..}, at: [<c016c094>] lock_and_coalesce_cpu_mnt_writer_counts+0x29/0x5c
stack backtrace:
[<c01034ab>] show_trace_log_lvl+0x19/0x2e
[<c01034d2>] show_trace+0x12/0x14
[<c01035be>] dump_stack+0x14/0x16
[<c0130ab2>] print_deadlock_bug+0xb7/0xc1
[<c0130afc>] check_deadlock+0x40/0x54
[<c013100a>] validate_chain+0x26e/0x319
[<c0132cca>] __lock_acquire+0x6c4/0x731
[<c01332da>] lock_acquire+0x7a/0x94
[<c031bb01>] _spin_lock+0x38/0x62
[<c016c094>] lock_and_coalesce_cpu_mnt_writer_counts+0x29/0x5c
[<c016c5f8>] mntput_no_expire+0x38/0xad
[<c015fbed>] path_release_on_umount+0x15/0x18
[<c016cc76>] sys_umount+0x67/0x6f
[<c010058a>] name_to_dev_t+0x22a/0x24c
[<c0427207>] prepare_namespace+0x89/0x187
[<c0426cdd>] kernel_init+0x9a/0xa3
[<c010336f>] kernel_thread_helper+0x7/0x10
=======================
Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/namespace.c | 2 ++
1 files changed, 2 insertions(+)
diff -puN fs/namespace.c~r-o-bind-mounts-track-number-of-mount-writers-make-lockdep-happy-with-r-o-bind-mounts fs/namespace.c
--- a/fs/namespace.c~r-o-bind-mounts-track-number-of-mount-writers-make-lockdep-happy-with-r-o-bind-mounts
+++ a/fs/namespace.c
@@ -115,6 +115,7 @@ struct mnt_writer {
* must be ordered by cpu number.
*/
spinlock_t lock;
+ struct lock_class_key lock_class; /* compiles out with !lockdep */
unsigned long count;
struct vfsmount *mnt;
} ____cacheline_aligned_in_smp;
@@ -126,6 +127,7 @@ static int __init init_mnt_writers(void)
for_each_possible_cpu(cpu) {
struct mnt_writer *writer = &per_cpu(mnt_writers, cpu);
spin_lock_init(&writer->lock);
+ lockdep_set_class(&writer->lock, &writer->lock_class);
writer->count = 0;
}
return 0;
_
Patches currently in -mm which might be from haveblue@xxxxxxxxxx are
markers-fix-warnings.patch
maps4-add-proportional-set-size-accounting-in-smaps.patch
maps4-rework-task_size-macros.patch
maps4-move-is_swap_pte.patch
maps4-introduce-a-generic-page-walker.patch
maps4-use-pagewalker-in-clear_refs-and-smaps.patch
maps4-simplify-interdependence-of-maps-and-smaps.patch
maps4-move-clear_refs-code-to-task_mmuc.patch
maps4-regroup-task_mmu-by-interface.patch
maps4-add-proc-pid-pagemap-interface.patch
maps4-add-proc-kpagecount-interface.patch
maps4-add-proc-kpageflags-interface.patch
maps4-make-page-monitoring-proc-file-optional.patch
maps4-make-page-monitoring-proc-file-optional-fix.patch
hugetlb-split-alloc_huge_page-into-private-and-shared-components.patch
hugetlb-split-alloc_huge_page-into-private-and-shared-components-checkpatch-fixes.patch
hugetlb-fix-quota-management-for-private-mappings.patch
hugetlb-debit-quota-in-alloc_huge_page.patch
hugetlb-allow-bulk-updating-in-hugetlb__quota.patch
hugetlb-enforce-quotas-during-reservation-for-shared-mappings.patch
add-remove_memory-for-ppc64-2.patch
enable-hotplug-memory-remove-for-ppc64.patch
add-arch-specific-walk_memory_remove-for-ppc64.patch
r-o-bind-mounts-track-number-of-mount-writers-make-lockdep-happy-with-r-o-bind-mounts.patch
r-o-bind-mounts-track-number-of-mount-writers-fix.patch
r-o-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
reiser4.patch
page-owner-tracking-leak-detector.patch
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