The patch titled
dlm: fix unlock race
has been removed from the -mm tree. Its filename is
dlm-device-interface-fix-unlock-race.patch
This patch was probably dropped from -mm because
it has now been merged into a subsystem tree or
into Linus's tree, or because it was folded into
its parent patch in the -mm tree.
From: David Teigland <teigland@xxxxxxxxxx>
Fix a race where an attempt to unlock a lock in the completion AST routine
could crash on SMP.
Signed-off-by: Patrick Caulfield <pcaulfie@xxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
Cc: Steven Whitehouse <swhiteho@xxxxxxxxxx>
---
drivers/dlm/device.c | 11 +++++++++++
1 files changed, 11 insertions(+)
diff -puN drivers/dlm/device.c~dlm-device-interface-fix-unlock-race drivers/dlm/device.c
--- 25/drivers/dlm/device.c~dlm-device-interface-fix-unlock-race Thu Jan 19 16:00:26 2006
+++ 25-akpm/drivers/dlm/device.c Thu Jan 19 16:00:26 2006
@@ -54,6 +54,7 @@ static rwlock_t lockinfo_lock;
#define LI_FLAG_COMPLETE 1
#define LI_FLAG_FIRSTLOCK 2
#define LI_FLAG_PERSISTENT 3
+#define LI_FLAG_ONLIST 4
/* flags in ls_flags*/
#define LS_FLAG_DELETED 1
@@ -383,6 +384,7 @@ static void ast_routine(void *param)
spin_lock(&li->li_file->fi_li_lock);
list_del(&li->li_ownerqueue);
+ clear_bit(LI_FLAG_ONLIST, &li->li_flags);
spin_unlock(&li->li_file->fi_li_lock);
release_lockinfo(li);
return;
@@ -890,6 +892,7 @@ static int do_user_lock(struct file_info
spin_lock(&fi->fi_li_lock);
list_add(&li->li_ownerqueue, &fi->fi_li_list);
+ set_bit(LI_FLAG_ONLIST, &li->li_flags);
spin_unlock(&fi->fi_li_lock);
if (add_lockinfo(li))
printk(KERN_WARNING "Add lockinfo failed\n");
@@ -921,6 +924,7 @@ static int do_user_unlock(struct file_in
return -ENOMEM;
spin_lock(&fi->fi_li_lock);
list_add(&li->li_ownerqueue, &fi->fi_li_list);
+ set_bit(LI_FLAG_ONLIST, &li->li_flags);
spin_unlock(&fi->fi_li_lock);
}
@@ -935,6 +939,12 @@ static int do_user_unlock(struct file_in
if (kparams->flags & DLM_LKF_CANCEL && li->li_grmode != -1)
convert_cancel = 1;
+ /* Wait until dlm_lock() has completed */
+ if (!test_bit(LI_FLAG_ONLIST, &li->li_flags)) {
+ down(&li->li_firstlock);
+ up(&li->li_firstlock);
+ }
+
/* dlm_unlock() passes a 0 for castaddr which means don't overwrite
the existing li_castaddr as that's the completion routine for
unlocks. dlm_unlock_wait() specifies a new AST routine to be
@@ -950,6 +960,7 @@ static int do_user_unlock(struct file_in
if (!status && !convert_cancel) {
spin_lock(&fi->fi_li_lock);
list_del(&li->li_ownerqueue);
+ clear_bit(LI_FLAG_ONLIST, &li->li_flags);
spin_unlock(&fi->fi_li_lock);
}
_
Patches currently in -mm which might be from teigland@xxxxxxxxxx are
git-gfs2.patch
-
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