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author | 2006-05-02 13:34:03 -0400 | |
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committer | 2006-05-02 13:34:03 -0400 | |
commit | 97a35d1e5fab9ff8de27814082b78b2fc9ad94f0 (patch) | |
tree | 551025da17641ccc4df7378da2bb94cedfb2482e /fs/dlm/lock.c | |
parent | [GFS2] Fix bug in writepage() (diff) | |
download | linux-97a35d1e5fab9ff8de27814082b78b2fc9ad94f0.tar.gz linux-97a35d1e5fab9ff8de27814082b78b2fc9ad94f0.tar.bz2 linux-97a35d1e5fab9ff8de27814082b78b2fc9ad94f0.zip |
[DLM] fix grant_after_purge softlockup
In dlm_grant_after_purge() we were holding a hash table read_lock while
calling put_rsb() which potentially removes the rsb from the hash table,
taking the same lock in write. Fix this by flagging rsb's ahead of time
that have been purged. Then iteratively read_lock the hash table, find a
flagged rsb, unlock, process rsb.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/dlm/lock.c')
-rw-r--r-- | fs/dlm/lock.c | 42 |
1 files changed, 28 insertions, 14 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 85a0e73ba808..5f6963904107 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -3278,6 +3278,7 @@ static void purge_queue(struct dlm_rsb *r, struct list_head *queue, list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) { if (test(ls, lkb)) { + rsb_set_flag(r, RSB_LOCKS_PURGED); del_lkb(r, lkb); /* this put should free the lkb */ if (!dlm_put_lkb(lkb)) @@ -3334,27 +3335,40 @@ int dlm_purge_locks(struct dlm_ls *ls) return 0; } -int dlm_grant_after_purge(struct dlm_ls *ls) +static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket) +{ + struct dlm_rsb *r, *r_ret = NULL; + + read_lock(&ls->ls_rsbtbl[bucket].lock); + list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) { + if (!rsb_flag(r, RSB_LOCKS_PURGED)) + continue; + hold_rsb(r); + rsb_clear_flag(r, RSB_LOCKS_PURGED); + r_ret = r; + break; + } + read_unlock(&ls->ls_rsbtbl[bucket].lock); + return r_ret; +} + +void dlm_grant_after_purge(struct dlm_ls *ls) { struct dlm_rsb *r; int i; for (i = 0; i < ls->ls_rsbtbl_size; i++) { - read_lock(&ls->ls_rsbtbl[i].lock); - list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) { - hold_rsb(r); - lock_rsb(r); - if (is_master(r)) { - grant_pending_locks(r); - confirm_master(r, 0); - } - unlock_rsb(r); - put_rsb(r); + r = find_purged_rsb(ls, i); + if (!r) + continue; + lock_rsb(r); + if (is_master(r)) { + grant_pending_locks(r); + confirm_master(r, 0); } - read_unlock(&ls->ls_rsbtbl[i].lock); + unlock_rsb(r); + put_rsb(r); } - - return 0; } static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid, |