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| author | Joseph Qi <joseph.qi@huawei.com> | 2016-09-19 23:43:55 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-20 00:36:16 +0200 |
| commit | e6f0c6e6170fec175fe676495f29029aecdf486c (patch) | |
| tree | 9f0ccd2923830ee0088a81d3abb5526d829c2832 /fs | |
| parent | mem-hotplug: don't clear the only node in new_node_page() (diff) | |
| download | linux-e6f0c6e6170fec175fe676495f29029aecdf486c.tar.xz linux-e6f0c6e6170fec175fe676495f29029aecdf486c.zip | |
ocfs2/dlm: fix race between convert and migration
Commit ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery")
checks if lockres master has changed to identify whether new master has
finished recovery or not. This will introduce a race that right after
old master does umount ( means master will change), a new convert
request comes.
In this case, it will reset lockres state to DLM_RECOVERING and then
retry convert, and then fail with lockres->l_action being set to
OCFS2_AST_INVALID, which will cause inconsistent lock level between
ocfs2 and dlm, and then finally BUG.
Since dlm recovery will clear lock->convert_pending in
dlm_move_lockres_to_recovery_list, we can use it to correctly identify
the race case between convert and recovery. So fix it.
Fixes: ac7cf246dfdb ("ocfs2/dlm: fix race between convert and recovery")
Link: http://lkml.kernel.org/r/57CE1569.8010704@huawei.com
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/dlm/dlmconvert.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/ocfs2/dlm/dlmconvert.c b/fs/ocfs2/dlm/dlmconvert.c index cdeafb4e7ed6..0bb128659d4b 100644 --- a/fs/ocfs2/dlm/dlmconvert.c +++ b/fs/ocfs2/dlm/dlmconvert.c @@ -268,7 +268,6 @@ enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm, struct dlm_lock *lock, int flags, int type) { enum dlm_status status; - u8 old_owner = res->owner; mlog(0, "type=%d, convert_type=%d, busy=%d\n", lock->ml.type, lock->ml.convert_type, res->state & DLM_LOCK_RES_IN_PROGRESS); @@ -335,7 +334,6 @@ enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm, spin_lock(&res->spinlock); res->state &= ~DLM_LOCK_RES_IN_PROGRESS; - lock->convert_pending = 0; /* if it failed, move it back to granted queue. * if master returns DLM_NORMAL and then down before sending ast, * it may have already been moved to granted queue, reset to @@ -344,12 +342,14 @@ enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm, if (status != DLM_NOTQUEUED) dlm_error(status); dlm_revert_pending_convert(res, lock); - } else if ((res->state & DLM_LOCK_RES_RECOVERING) || - (old_owner != res->owner)) { - mlog(0, "res %.*s is in recovering or has been recovered.\n", - res->lockname.len, res->lockname.name); + } else if (!lock->convert_pending) { + mlog(0, "%s: res %.*s, owner died and lock has been moved back " + "to granted list, retry convert.\n", + dlm->name, res->lockname.len, res->lockname.name); status = DLM_RECOVERING; } + + lock->convert_pending = 0; bail: spin_unlock(&res->spinlock); |