3.2.68-rt99-rc2 stable review patch. If anyone has any objections, please let me know.
------------------ From: Mike Galbraith <[email protected]> Sat Jul 14 12:30:41 CEST 2012 Trivially repeatable deadlock is cured by enabling lockdep code in btrfs_clear_path_blocking() as suggested by Chris Mason. He also suggested restricting blocking reader count to one, and not allowing a spinning reader while blocking reader exists. This has proven to be unnecessary, the strict lock order enforcement is enough.. or rather that's my box's opinion after long hours of hard pounding. Note: extent-tree.c bit is additional recommendation from Chris Mason, split into a separate patch after discussion. Link: http://lkml.kernel.org/r/[email protected] Cc: linux-rt-users <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Carsten Emde <[email protected]> Cc: John Kacur <[email protected]> Cc: Sebastian Andrzej Siewior <[email protected]> Cc: Clark Williams <[email protected]> Cc: Chris Mason <[email protected]> Signed-off-by: Mike Galbraith <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Conflicts: fs/btrfs/extent-tree.c --- fs/btrfs/ctree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index dede441bdeee..980adc0ecc3a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -77,7 +77,7 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, { int i; -#ifdef CONFIG_DEBUG_LOCK_ALLOC +#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE)) /* lockdep really cares that we take all of these spinlocks * in the right order. If any of the locks in the path are not * currently blocking, it is going to complain. So, make really @@ -104,7 +104,7 @@ noinline void btrfs_clear_path_blocking(struct btrfs_path *p, } } -#ifdef CONFIG_DEBUG_LOCK_ALLOC +#if (defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_PREEMPT_RT_BASE)) if (held) btrfs_clear_lock_blocking_rw(held, held_rw); #endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
