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| author | Steven Whitehouse <swhiteho@redhat.com> | 2009-09-22 11:56:16 +0200 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2009-12-03 12:42:25 +0100 |
| commit | 7e71c55ee73988d0cb61045660b899eaac23bf8f (patch) | |
| tree | ef96dc44cd067cc758a8df0408ba36818c9ebc35 | |
| parent | Linux 2.6.32 (diff) | |
| download | linux-7e71c55ee73988d0cb61045660b899eaac23bf8f.tar.xz linux-7e71c55ee73988d0cb61045660b899eaac23bf8f.zip | |
GFS2: Fix potential race in glock code
We need to be careful of the ordering between clearing the
GLF_LOCK bit and scheduling the workqueue.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| -rw-r--r-- | fs/gfs2/glock.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 8b674b1f3a55..a3f90ad2af80 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -672,12 +672,17 @@ out: return; out_sched: + clear_bit(GLF_LOCK, &gl->gl_flags); + smp_mb__after_clear_bit(); gfs2_glock_hold(gl); if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) gfs2_glock_put_nolock(gl); + return; + out_unlock: clear_bit(GLF_LOCK, &gl->gl_flags); - goto out; + smp_mb__after_clear_bit(); + return; } static void delete_work_func(struct work_struct *work) @@ -1375,10 +1380,11 @@ static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask) handle_callback(gl, LM_ST_UNLOCKED, 0); nr--; } + clear_bit(GLF_LOCK, &gl->gl_flags); + smp_mb__after_clear_bit(); if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) gfs2_glock_put_nolock(gl); spin_unlock(&gl->gl_spin); - clear_bit(GLF_LOCK, &gl->gl_flags); spin_lock(&lru_lock); continue; } |