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| author | Sunil Mushran <sunil.mushran@oracle.com> | 2010-01-21 10:50:03 -0800 |
|---|---|---|
| committer | Joel Becker <joel.becker@oracle.com> | 2010-02-02 23:51:13 -0800 |
| commit | a19128260107f951d1b4c421cf98b92f8092b069 (patch) | |
| tree | 0e98386142589c986fe433e1dd390f4a21db7bc9 /fs/ocfs2/ocfs2.h | |
| parent | 0b94a909eb2e2f6990d05fd486a0cb4902ef1ae7 (diff) | |
| download | linux-a19128260107f951d1b4c421cf98b92f8092b069.tar.gz linux-a19128260107f951d1b4c421cf98b92f8092b069.tar.bz2 linux-a19128260107f951d1b4c421cf98b92f8092b069.zip | |
ocfs2: Prevent a livelock in dlmglue
There is possibility of a livelock in __ocfs2_cluster_lock(). If a node were
to get an ast for an upconvert request, followed immediately by a bast,
there is a small window where the fs may downconvert the lock before the
process requesting the upconvert is able to take the lock.
This patch adds a new flag to indicate that the upconvert is still in
progress and that the dc thread should not downconvert it right now.
Wengang Wang <wen.gang.wang@oracle.com> and Joel Becker
<joel.becker@oracle.com> contributed heavily to this patch.
Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2/ocfs2.h')
| -rw-r--r-- | fs/ocfs2/ocfs2.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 9362eea7424b..740f448041e2 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -136,6 +136,10 @@ enum ocfs2_unlock_action { #define OCFS2_LOCK_PENDING (0x00000400) /* This lockres is pending a call to dlm_lock. Only exists with BUSY set. */ +#define OCFS2_LOCK_UPCONVERT_FINISHING (0x00000800) /* blocks the dc thread + * from downconverting + * before the upconvert + * has completed */ struct ocfs2_lock_res_ops; |