diff options
| -rw-r--r-- | fs/dlm/dlm_internal.h | 10 | ||||
| -rw-r--r-- | fs/dlm/lock.c | 710 | ||||
| -rw-r--r-- | fs/dlm/lockspace.c | 4 | ||||
| -rw-r--r-- | fs/dlm/user.c | 77 |
4 files changed, 577 insertions, 224 deletions
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index 61d93201e1b2..178931cca67c 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -2,7 +2,7 @@ ******************************************************************************* ** ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. -** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. +** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions @@ -210,6 +210,9 @@ struct dlm_args { #define DLM_IFL_MSTCPY 0x00010000 #define DLM_IFL_RESEND 0x00020000 #define DLM_IFL_DEAD 0x00040000 +#define DLM_IFL_OVERLAP_UNLOCK 0x00080000 +#define DLM_IFL_OVERLAP_CANCEL 0x00100000 +#define DLM_IFL_ENDOFLIFE 0x00200000 #define DLM_IFL_USER 0x00000001 #define DLM_IFL_ORPHAN 0x00000002 @@ -230,8 +233,8 @@ struct dlm_lkb { int8_t lkb_grmode; /* granted lock mode */ int8_t lkb_bastmode; /* requested mode */ int8_t lkb_highbast; /* highest mode bast sent for */ - int8_t lkb_wait_type; /* type of reply waiting for */ + int8_t lkb_wait_count; int8_t lkb_ast_type; /* type of ast queued for */ struct list_head lkb_idtbl_list; /* lockspace lkbtbl */ @@ -440,6 +443,9 @@ struct dlm_ls { struct mutex ls_waiters_mutex; struct list_head ls_waiters; /* lkbs needing a reply */ + struct mutex ls_orphans_mutex; + struct list_head ls_orphans; + struct list_head ls_nodes; /* current nodes in ls */ struct list_head ls_nodes_gone; /* dead node list, recovery */ int ls_num_nodes; /* number of nodes in ls */ diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index e725005fafd0..b865a46059dd 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -1,7 +1,7 @@ /****************************************************************************** ******************************************************************************* ** -** Copyright (C) 2005 Red Hat, Inc. All rights reserved. +** Copyright (C) 2005-2007 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions @@ -254,6 +254,22 @@ static inline int down_conversion(struct dlm_lkb *lkb) return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode); } +static inline int is_overlap_unlock(struct dlm_lkb *lkb) +{ + return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK; +} + +static inline int is_overlap_cancel(struct dlm_lkb *lkb) +{ + return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL; +} + +static inline int is_overlap(struct dlm_lkb *lkb) +{ + return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK | + DLM_IFL_OVERLAP_CANCEL)); +} + static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) { if (is_master_copy(lkb)) @@ -267,6 +283,12 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) dlm_add_ast(lkb, AST_COMP); } +static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb) +{ + queue_cast(r, lkb, + is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL); +} + static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode) { if (is_master_copy(lkb)) @@ -547,6 +569,7 @@ static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret) lkb->lkb_grmode = DLM_LOCK_IV; kref_init(&lkb->lkb_ref); INIT_LIST_HEAD(&lkb->lkb_ownqueue); + INIT_LIST_HEAD(&lkb->lkb_rsb_lookup); get_random_bytes(&bucket, sizeof(bucket)); bucket &= (ls->ls_lkbtbl_size - 1); @@ -735,23 +758,75 @@ static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts) unhold_lkb(lkb); } +static int msg_reply_type(int mstype) +{ + switch (mstype) { + case DLM_MSG_REQUEST: + return DLM_MSG_REQUEST_REPLY; + case DLM_MSG_CONVERT: + return DLM_MSG_CONVERT_REPLY; + case DLM_MSG_UNLOCK: + return DLM_MSG_UNLOCK_REPLY; + case DLM_MSG_CANCEL: + return DLM_MSG_CANCEL_REPLY; + case DLM_MSG_LOOKUP: + return DLM_MSG_LOOKUP_REPLY; + } + return -1; +} + /* add/remove lkb from global waiters list of lkb's waiting for a reply from a remote node */ -static void add_to_waiters(struct dlm_lkb *lkb, int mstype) +static int add_to_waiters(struct dlm_lkb *lkb, int mstype) { struct dlm_ls *ls = lkb->lkb_resource->res_ls; + int error = 0; mutex_lock(&ls->ls_waiters_mutex); - if (lkb->lkb_wait_type) { - log_print("add_to_waiters error %d", lkb->lkb_wait_type); + + if (is_overlap_unlock(lkb) || + (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) { + error = -EINVAL; + goto out; + } + + if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) { + switch (mstype) { + case DLM_MSG_UNLOCK: + lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; + break; + case DLM_MSG_CANCEL: + lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; + break; + default: + error = -EBUSY; + goto out; + } + lkb->lkb_wait_count++; + hold_lkb(lkb); + + log_debug(ls, "add overlap %x cur %d new %d count %d flags %x", + lkb->lkb_id, lkb->lkb_wait_type, mstype, + lkb->lkb_wait_count, lkb->lkb_flags); goto out; } + + DLM_ASSERT(!lkb->lkb_wait_count, + dlm_print_lkb(lkb); + printk("wait_count %d\n", lkb->lkb_wait_count);); + + lkb->lkb_wait_count++; lkb->lkb_wait_type = mstype; - kref_get(&lkb->lkb_ref); + hold_lkb(lkb); list_add(&lkb->lkb_wait_reply, &ls->ls_waiters); out: + if (error) + log_error(ls, "add_to_waiters %x error %d flags %x %d %d %s", + lkb->lkb_id, error, lkb->lkb_flags, mstype, + lkb->lkb_wait_type, lkb->lkb_resource->res_name); mutex_unlock(&ls->ls_waiters_mutex); + return error; } /* We clear the RESEND flag because we might be taking an lkb off the waiters @@ -759,34 +834,85 @@ static void add_to_waiters(struct dlm_lkb *lkb, int mstype) request reply on the requestqueue) between dlm_recover_waiters_pre() which set RESEND and dlm_recover_waiters_post() */ -static int _remove_from_waiters(struct dlm_lkb *lkb) +static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) { - int error = 0; + struct dlm_ls *ls = lkb->lkb_resource->res_ls; + int overlap_done = 0; - if (!lkb->lkb_wait_type) { - log_print("remove_from_waiters error"); - error = -EINVAL; - goto out; + if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) { + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; + overlap_done = 1; + goto out_del; } - lkb->lkb_wait_type = 0; + + if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) { + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + overlap_done = 1; + goto out_del; + } + + /* N.B. type of reply may not always correspond to type of original + msg due to lookup->request optimization, verify others? */ + + if (lkb->lkb_wait_type) { + lkb->lkb_wait_type = 0; + goto out_del; + } + + log_error(ls, "remove_from_waiters lkid %x flags %x types %d %d", + lkb->lkb_id, lkb->lkb_flags, mstype, lkb->lkb_wait_type); + return -1; + + out_del: + /* the force-unlock/cancel has completed and we haven't recvd a reply + to the op that was in progress prior to the unlock/cancel; we + give up on any reply to the earlier op. FIXME: not sure when/how + this would happen */ + + if (overlap_done && lkb->lkb_wait_type) { + log_error(ls, "remove_from_waiters %x reply %d give up on %d", + lkb->lkb_id, mstype, lkb->lkb_wait_type); + lkb->lkb_wait_count--; + lkb->lkb_wait_type = 0; + } + + DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb);); + lkb->lkb_flags &= ~DLM_IFL_RESEND; - list_del(&lkb->lkb_wait_reply); + lkb->lkb_wait_count--; + if (!lkb->lkb_wait_count) + list_del_init(&lkb->lkb_wait_reply); unhold_lkb(lkb); - out: - return error; + return 0; } -static int remove_from_waiters(struct dlm_lkb *lkb) +static int remove_from_waiters(struct dlm_lkb *lkb, int mstype) { struct dlm_ls *ls = lkb->lkb_resource->res_ls; int error; mutex_lock(&ls->ls_waiters_mutex); - error = _remove_from_waiters(lkb); + error = _remove_from_waiters(lkb, mstype); mutex_unlock(&ls->ls_waiters_mutex); return error; } +/* Handles situations where we might be processing a "fake" or "stub" reply in + which we can't try to take waiters_mutex again. */ + +static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms) +{ + struct dlm_ls *ls = lkb->lkb_resource->res_ls; + int error; + + if (ms != &ls->ls_stub_ms) + mutex_lock(&ls->ls_waiters_mutex); + error = _remove_from_waiters(lkb, ms->m_type); + if (ms != &ls->ls_stub_ms) + mutex_unlock(&ls->ls_waiters_mutex); + return error; +} + static void dir_remove(struct dlm_rsb *r) { int to_nodeid; @@ -988,8 +1114,14 @@ static void remove_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) _remove_lock(r, lkb); } -static void revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) +/* returns: 0 did nothing + 1 moved lock to granted + -1 removed lock */ + +static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) { + int rv = 0; + lkb->lkb_rqmode = DLM_LOCK_IV; switch (lkb->lkb_status) { @@ -997,6 +1129,7 @@ static void revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) break; case DLM_LKSTS_CONVERT: move_lkb(r, lkb, DLM_LKSTS_GRANTED); + rv = 1; break; case DLM_LKSTS_WAITING: del_lkb(r, lkb); @@ -1004,15 +1137,17 @@ static void revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) /* this unhold undoes the original ref from create_lkb() so this leads to the lkb being freed */ unhold_lkb(lkb); + rv = -1; break; default: log_print("invalid status for revert %d", lkb->lkb_status); } + return rv; } -static void revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) +static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb) { - revert_lock(r, lkb); + return revert_lock(r, lkb); } static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb) @@ -1499,7 +1634,7 @@ static void process_lookup_list(struct dlm_rsb *r) struct dlm_lkb *lkb, *safe; list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) { - list_del(&lkb->lkb_rsb_lookup); + list_del_init(&lkb->lkb_rsb_lookup); _request_lock(r, lkb); schedule(); } @@ -1530,7 +1665,7 @@ static void confirm_master(struct dlm_rsb *r, int error) if (!list_empty(&r->res_lookup)) { lkb = list_entry(r->res_lookup.next, struct dlm_lkb, lkb_rsb_lookup); - list_del(&lkb->lkb_rsb_lookup); + list_del_init(&lkb->lkb_rsb_lookup); r->res_first_lkid = lkb->lkb_id; _request_lock(r, lkb); } else @@ -1614,6 +1749,9 @@ static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args) DLM_LKF_FORCEUNLOCK)) return -EINVAL; + if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK) + return -EINVAL; + args->flags = flags; args->astparam = (long) astarg; return 0; @@ -1638,6 +1776,9 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, if (lkb->lkb_wait_type) goto out; + + if (is_overlap(lkb)) + goto out; } lkb->lkb_exflags = args->flags; @@ -1654,35 +1795,126 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, return rv; } +/* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0 + for success */ + +/* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here + because there may be a lookup in progress and it's valid to do + cancel/unlockf on it */ + static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args) { + struct dlm_ls *ls = lkb->lkb_resource->res_ls; int rv = -EINVAL; - if (lkb->lkb_flags & DLM_IFL_MSTCPY) + if (lkb->lkb_flags & DLM_IFL_MSTCPY) { + log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id); + dlm_print_lkb(lkb); goto out; + } - if (args->flags & DLM_LKF_FORCEUNLOCK) - goto out_ok; + /* an lkb may still exist even though the lock is EOL'ed due to a + cancel, unlock or failed noqueue request; an app can't use these + locks; return same error as if the lkid had not been found at all */ - if (args->flags & DLM_LKF_CANCEL && - lkb->lkb_status == DLM_LKSTS_GRANTED) + if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) { + log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id); + rv = -ENOENT; goto out; + } - if (!(args->flags & DLM_LKF_CANCEL) && - lkb->lkb_status != DLM_LKSTS_GRANTED) - goto out; + /* an lkb may be waiting for an rsb lookup to complete where the + lookup was initiated by another lock */ + + if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) { + if (!list_empty(&lkb->lkb_rsb_lookup)) { + log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id); + list_del_init(&lkb->lkb_rsb_lookup); + queue_cast(lkb->lkb_resource, lkb, + args->flags & DLM_LKF_CANCEL ? + -DLM_ECANCEL : -DLM_EUNLOCK); + unhold_lkb(lkb); /* undoes create_lkb() */ + rv = -EBUSY; + goto out; + } + } + + /* cancel not allowed with another cancel/unlock in progress */ + + if (args->flags & DLM_LKF_CANCEL) { + if (lkb->lkb_exflags & DLM_LKF_CANCEL) + goto out; + + if (is_overlap(lkb)) + goto out; + + if (lkb->lkb_flags & DLM_IFL_RESEND) { + lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; + rv = -EBUSY; + goto out; + } + + switch (lkb->lkb_wait_type) { + case DLM_MSG_LOOKUP: + case DLM_MSG_REQUEST: + lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL; + rv = -EBUSY; + goto out; + case DLM_MSG_UNLOCK: + case DLM_MSG_CANCEL: + goto out; + } + /* add_to_waiters() will set OVERLAP_CANCEL */ + goto out_ok; + } + + /* do we need to allow a force-unlock if there's a normal unlock + already in progress? in what conditions could the normal unlock + fail such that we'd want to send a force-unlock to be sure? */ + + if (args->flags & DLM_LKF_FORCEUNLOCK) { + if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK) + goto out; + + if (is_overlap_unlock(lkb)) + goto out; + if (lkb->lkb_flags & DLM_IFL_RESEND) { + lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; + rv = -EBUSY; + goto out; + } + + switch (lkb->lkb_wait_type) { + case DLM_MSG_LOOKUP: + case DLM_MSG_REQUEST: + lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK; + rv = -EBUSY; + goto out; + case DLM_MSG_UNLOCK: + goto out; + } + /* add_to_waiters() will set OVERLAP_UNLOCK */ + goto out_ok; + } + + /* normal unlock not allowed if there's any op in progress */ rv = -EBUSY; - if (lkb->lkb_wait_type) + if (lkb->lkb_wait_type || lkb->lkb_wait_count) goto out; out_ok: - lkb->lkb_exflags = args->flags; + /* an overlapping op shouldn't blow away exflags from other op */ + lkb->lkb_exflags |= args->flags; lkb->lkb_sbflags = 0; lkb->lkb_astparam = args->astparam; - rv = 0; out: + if (rv) + log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv, + lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags, + args->flags, lkb->lkb_wait_type, + lkb->lkb_resource->res_name); return rv; } @@ -1759,17 +1991,19 @@ static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb) return -DLM_EUNLOCK; } -/* FIXME: if revert_lock() finds that the lkb is granted, we should - skip the queue_cast(ECANCEL). It indicates that the request/convert - completed (and queued a normal ast) just before the cancel; we don't - want to clobber the sb_result for the normal ast with ECANCEL. */ +/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */ static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) { - revert_lock(r, lkb); - queue_cast(r, lkb, -DLM_ECANCEL); - grant_pending_locks(r); - return -DLM_ECANCEL; + int error; + + error = revert_lock(r, lkb); + if (error) { + queue_cast(r, lkb, -DLM_ECANCEL); + grant_pending_locks(r); + return -DLM_ECANCEL; + } + return 0; } /* @@ -2035,6 +2269,8 @@ int dlm_unlock(dlm_lockspace_t *lockspace, if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL) error = 0; + if (error == -EBUSY && (flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK))) + error = 0; out_put: dlm_put_lkb(lkb); out: @@ -2176,7 +2412,9 @@ static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype) struct dlm_mhandle *mh; int to_nodeid, error; - add_to_waiters(lkb, mstype); + error = add_to_waiters(lkb, mstype); + if (error) + return error; to_nodeid = r->res_nodeid; @@ -2192,7 +2430,7 @@ static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype) return 0; fail: - remove_from_waiters(lkb); + remove_from_waiters(lkb, msg_reply_type(mstype)); return error; } @@ -2209,7 +2447,8 @@ static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) /* down conversions go without a reply from the master */ if (!error && down_conversion(lkb)) { - remove_from_waiters(lkb); + remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY); + r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY; r->res_ls->ls_stub_ms.m_result = 0; r->res_ls->ls_stub_ms.m_flags = lkb->lkb_flags; __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms); @@ -2280,7 +2519,9 @@ static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb) struct dlm_mhandle *mh; int to_nodeid, error; - add_to_waiters(lkb, DLM_MSG_LOOKUP); + error = add_to_waiters(lkb, DLM_MSG_LOOKUP); + if (error) + return error; to_nodeid = dlm_dir_nodeid(r); @@ -2296,7 +2537,7 @@ static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb) return 0; fail: - remove_from_waiters(lkb); + remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); return error; } @@ -2740,7 +2981,7 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) { struct dlm_lkb *lkb; struct dlm_rsb *r; - int error, mstype; + int error, mstype, result; error = find_lkb(ls, ms->m_remid, &lkb); if (error) { @@ -2749,20 +2990,15 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) } DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb);); - mstype = lkb->lkb_wait_type; - error = remove_from_waiters(lkb); - if (error) { - log_error(ls, "receive_request_reply not on waiters"); - goto out; - } - - /* this is the value returned from do_request() on the master */ - error = ms->m_result; - r = lkb->lkb_resource; hold_rsb(r); lock_rsb(r); + mstype = lkb->lkb_wait_type; + error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY); + if (error) + goto out; + /* Optimization: the dir node was also the master, so it took our lookup as a request and sent request reply instead of lookup reply */ if (mstype == DLM_MSG_LOOKUP) { @@ -2770,14 +3006,15 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) lkb->lkb_nodeid = r->res_nodeid; } - switch (error) { + /* this is the value returned from do_request() on the master */ + result = ms->m_result; + + switch (result) { case -EAGAIN: - /* request would block (be queued) on remote master; - the unhold undoes the original ref from create_lkb() - so it leads to the lkb being freed */ + /* request would block (be queued) on remote master */ queue_cast(r, lkb, -EAGAIN); confirm_master(r, -EAGAIN); - unhold_lkb(lkb); + unhold_lkb(lkb); /* undoes create_lkb() */ break; case -EINPROGRESS: @@ -2785,41 +3022,62 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) /* request was queued or granted on remote master */ receive_flags_reply(lkb, ms); lkb->lkb_remid = ms->m_lkid; - if (error) + if (result) add_lkb(r, lkb, DLM_LKSTS_WAITING); else { grant_lock_pc(r, lkb, ms); queue_cast(r, lkb, 0); } - confirm_master(r, error); + confirm_master(r, result); break; case -EBADR: case -ENOTBLK: /* find_rsb failed to find rsb or rsb wasn't master */ + log_debug(ls, "receive_request_reply %x %x master diff %d %d", + lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result); r->res_nodeid = -1; lkb->lkb_nodeid = -1; - _request_lock(r, lkb); + + if (is_overlap(lkb)) { + /* we'll ignore error in cancel/unlock reply */ + queue_cast_overlap(r, lkb); + unhold_lkb(lkb); /* undoes create_lkb() */ + } else + _request_lock(r, lkb); break; default: - log_error(ls, "receive_request_reply error %d", error); + log_error(ls, "receive_request_reply %x error %d", + lkb->lkb_id, result); } + if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS)) { + log_debug(ls, "receive_request_reply %x result %d unlock", + lkb->lkb_id, result); + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + send_unlock(r, lkb); + } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) { + log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id); + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + send_cancel(r, lkb); + } else { + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; + } + out: unlock_rsb(r); put_rsb(r); - out: dlm_put_lkb(lkb); } static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, struct dlm_message *ms) { - int error = ms->m_result; - /* this is the value returned from do_convert() on the master */ - - switch (error) { + switch (ms->m_result) { case -EAGAIN: /* convert would block (be queued) on remote master */ queue_cast(r, lkb, -EAGAIN); @@ -2839,19 +3097,26 @@ static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, break; default: - log_error(r->res_ls, "receive_convert_reply error %d", error); + log_error(r->res_ls, "receive_convert_reply %x error %d", + lkb->lkb_id, ms->m_result); } } static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms) { struct dlm_rsb *r = lkb->lkb_resource; + int error; hold_rsb(r); lock_rsb(r); - __receive_convert_reply(r, lkb, ms); + /* stub reply can happen with waiters_mutex held */ + error = remove_from_waiters_ms(lkb, ms); + if (error) + goto out; + __receive_convert_reply(r, lkb, ms); + out: unlock_rsb(r); put_rsb(r); } @@ -2868,37 +3133,38 @@ static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms) } DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb);); - error = remove_from_waiters(lkb); - if (error) { - log_error(ls, "receive_convert_reply not on waiters"); - goto out; - } - _receive_convert_reply(lkb, ms); - out: dlm_put_lkb(lkb); } static void _receive_unlock_reply(struct dlm_lkb *lkb, struct dlm_message *ms) { struct dlm_rsb *r = lkb->lkb_resource; - int error = ms->m_result; + int error; hold_rsb(r); lock_rsb(r); + /* stub reply can happen with waiters_mutex held */ + error = remove_from_waiters_ms(lkb, ms); + if (error) + goto out; + /* this is the value returned from do_unlock() on the master */ - switch (error) { + switch (ms->m_result) { case -DLM_EUNLOCK: receive_flags_reply(lkb, ms); remove_lock_pc(r, lkb); queue_cast(r, lkb, -DLM_EUNLOCK); break; + case -ENOENT: + break; default: - log_error(r->res_ls, "receive_unlock_reply error %d", error); + log_error(r->res_ls, "receive_unlock_reply %x error %d", + lkb->lkb_id, ms->m_result); } - + out: unlock_rsb(r); put_rsb(r); } @@ -2915,37 +3181,39 @@ static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms) } DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb);); - error = remove_from_waiters(lkb); - if (error) { - log_error(ls, "receive_unlock_reply not on waiters"); - goto out; - } - _receive_unlock_reply(lkb, ms); - out: dlm_put_lkb(lkb); } static void _receive_cancel_reply(struct dlm_lkb *lkb, struct dlm_message *ms) { struct dlm_rsb *r = lkb->lkb_resource; - int error = ms->m_result; + int error; hold_rsb(r); lock_rsb(r); + /* stub reply can happen with waiters_mutex held */ + error = remove_from_waiters_ms(lkb, ms); + if (error) + goto out; + /* this is the value returned from do_cancel() on the master */ - switch (error) { + switch (ms->m_result) { case -DLM_ECANCEL: receive_flags_reply(lkb, ms); revert_lock_pc(r, lkb); - queue_cast(r, lkb, -DLM_ECANCEL); + if (ms->m_result) + queue_cast(r, lkb, -DLM_ECANCEL); + break; + case 0: break; default: - log_error(r->res_ls, "receive_cancel_reply error %d", error); + log_error(r->res_ls, "receive_cancel_reply %x error %d", + lkb->lkb_id, ms->m_result); } - + out: unlock_rsb(r); put_rsb(r); } @@ -2962,14 +3230,7 @@ static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms) } DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb);); - error = remove_from_waiters(lkb); - if (error) { - log_error(ls, "receive_cancel_reply not on waiters"); - goto out; - } - _receive_cancel_reply(lkb, ms); - out: dlm_put_lkb(lkb); } @@ -2985,20 +3246,17 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) return; } - error = remove_from_waiters(lkb); - if (error) { - log_error(ls, "receive_lookup_reply not on waiters"); - goto out; - } - - /* this is the value returned by dlm_dir_lookup on dir node + /* ms->m_result is the value returned by dlm_dir_lookup on dir node FIXME: will a non-zero error ever be returned? */ - error = ms->m_result; r = lkb->lkb_resource; hold_rsb(r); lock_rsb(r); + error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY); + if (error) + goto out; + ret_nodeid = ms->m_nodeid; if (ret_nodeid == dlm_our_nodeid()) { r->res_nodeid = 0; @@ -3009,14 +3267,22 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) r->res_nodeid = ret_nodeid; } + if (is_overlap(lkb)) { + log_debug(ls, "receive_lookup_reply %x unlock %x", + lkb->lkb_id, lkb->lkb_flags); + queue_cast_overlap(r, lkb); + unhold_lkb(lkb); /* undoes create_lkb() */ + goto out_list; + } + _request_lock(r, lkb); + out_list: if (!ret_nodeid) process_lookup_list(r); - + out: unlock_rsb(r); put_rsb(r); - out: dlm_put_lkb(lkb); } @@ -3153,9 +3419,9 @@ static void recover_convert_waiter(struct dlm_ls *ls, struct dlm_lkb *lkb) { if (middle_conversion(lkb)) { hold_lkb(lkb); + ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY; ls->ls_stub_ms.m_result = -EINPROGRESS; ls->ls_stub_ms.m_flags = lkb->lkb_flags; - _remove_from_waiters(lkb); _receive_convert_reply(lkb, &ls->ls_stub_ms); /* Same special case as in receive_rcom_lock_args() */ @@ -3227,18 +3493,18 @@ void dlm_recover_waiters_pre(struct dlm_ls *ls) case DLM_MSG_UNLOCK: hold_lkb(lkb); + ls->ls_stub_ms.m_type = DLM_MSG_UNLOCK_REPLY; ls->ls_stub_ms.m_result = -DLM_EUNLOCK; ls->ls_stub_ms.m_flags = lkb->lkb_flags; - _remove_from_waiters(lkb); _receive_unlock_reply(lkb, &ls->ls_stub_ms); dlm_put_lkb(lkb); break; case DLM_MSG_CANCEL: hold_lkb(lkb); + ls->ls_stub_ms.m_type = DLM_MSG_CANCEL_REPLY; ls->ls_stub_ms.m_result = -DLM_ECANCEL; ls->ls_stub_ms.m_flags = lkb->lkb_flags; - _remove_from_waiters(lkb); _receive_cancel_reply(lkb, &ls->ls_stub_ms); dlm_put_lkb(lkb); break; @@ -3252,37 +3518,47 @@ void dlm_recover_waiters_pre(struct dlm_ls *ls) mutex_unlock(&ls->ls_waiters_mutex); } -static int remove_resend_waiter(struct dlm_ls *ls, struct dlm_lkb **lkb_ret) +static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls) { struct dlm_lkb *lkb; - int rv = 0; + int found = 0; mutex_lock(&ls->ls_waiters_mutex); list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) { if (lkb->lkb_flags & DLM_IFL_RESEND) { - rv = lkb->lkb_wait_type; - _remove_from_waiters(lkb); - lkb->lkb_flags &= ~DLM_IFL_RESEND; + hold_lkb(lkb); + found = 1; break; } } mutex_unlock(&ls->ls_waiters_mutex); - if (!rv) + if (!found) lkb = NULL; - *lkb_ret = lkb; - return rv; + return lkb; } /* Deal with lookups and lkb's marked RESEND from _pre. We may now be the master or dir-node for r. Processing the lkb may result in it being placed back on waiters. */ +/* We do this after normal locking has been enabled and any saved messages + (in requestqueue) have been processed. We should be confident that at + this point we won't get or process a reply to any of these waiting + operations. But, new ops may be coming in on the rsbs/locks here from + userspace or remotely. */ + +/* there may have been an overlap unlock/cancel prior to recovery or after + recovery. if before, the lkb may still have a pos wait_count; if after, the + overlap flag would just have been set and nothing new sent. we can be + confident here than any replies to either the initial op or overlap ops + prior to recovery have been received. */ + int dlm_recover_waiters_post(struct dlm_ls *ls) { struct dlm_lkb *lkb; struct dlm_rsb *r; - int error = 0, mstype; + int error = 0, mstype, err, oc, ou; while (1) { if (dlm_locking_stopped(ls)) { @@ -3291,48 +3567,78 @@ int dlm_recover_waiters_post(struct dlm_ls *ls) break; } - mstype = remove_resend_waiter(ls, &lkb); - if (!mstype) + lkb = find_resend_waiter(ls); + if (!lkb) break; r = lkb->lkb_resource; + hold_rsb(r); + lock_rsb(r); + + mstype = lkb->lkb_wait_type; + oc = is_overlap_cancel(lkb); + ou = is_overlap_unlock(lkb); + err = 0; log_debug(ls, "recover_waiters_post %x type %d flags %x %s", lkb->lkb_id, mstype, lkb->lkb_flags, r->res_name); - switch (mstype) { - - case DLM_MSG_LOOKUP: - hold_rsb(r); - lock_rsb(r); - _request_lock(r, lkb); - if (is_master(r)) - confirm_master(r, 0); - unlock_rsb(r); - put_rsb(r); - break; - - case DLM_MSG_REQUEST: - hold_rsb(r); - lock_rsb(r); - _request_lock(r, lkb); - if (is_master(r)) - confirm_master(r, 0); - unlock_rsb(r); - put_rsb(r); - break; - - case DLM_MSG_CONVERT: - hold_rsb(r); - lock_rsb(r); - _convert_lock(r, lkb); - unlock_rsb(r); - put_rsb(r); - break; - - default: - log_error(ls, "recover_waiters_post type %d", mstype); + /* At this point we assume that we won't get a reply to any + previous op or overlap op on this lock. First, do a big + remove_from_waiters() for all previous ops. */ + + lkb->lkb_flags &= ~DLM_IFL_RESEND; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + lkb->lkb_wait_type = 0; + lkb->lkb_wait_count = 0; + mutex_lock(&ls->ls_waiters_mutex); + list_del_init(&lkb->lkb_wait_reply); + mutex_unlock(&ls->ls_waiters_mutex); + unhold_lkb(lkb); /* for waiters list */ + + if (oc || ou) { + /* do an unlock or cancel instead of resending */ + switch (mstype) { + case DLM_MSG_LOOKUP: + case DLM_MSG_REQUEST: + queue_cast(r, lkb, ou ? -DLM_EUNLOCK : + -DLM_ECANCEL); + unhold_lkb(lkb); /* undoes create_lkb() */ + break; + case DLM_MSG_CONVERT: + if (oc) { + queue_cast(r, lkb, -DLM_ECANCEL); + } else { + lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK; + _unlock_lock(r, lkb); + } + break; + default: + err = 1; + } + } else { + switch (mstype) { + case DLM_MSG_LOOKUP: + case DLM_MSG_REQUEST: + _request_lock(r, lkb); + if (is_master(r)) + confirm_master(r, 0); + break; + case DLM_MSG_CONVERT: + _convert_lock(r, lkb); + break; + default: + err = 1; + } } + + if (err) + log_error(ls, "recover_waiters_post %x %d %x %d %d", + lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou); + unlock_rsb(r); + put_rsb(r); + dlm_put_lkb(lkb); } return error; @@ -3684,7 +3990,7 @@ int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua, /* add this new lkb to the per-process list of locks */ spin_lock(&ua->proc->locks_spin); - kref_get(&lkb->lkb_ref); + hold_lkb(lkb); list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks); spin_unlock(&ua->proc->locks_spin); out: @@ -3774,6 +4080,9 @@ int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, if (error == -DLM_EUNLOCK) error = 0; + /* from validate_unlock_args() */ + if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK)) + error = 0; if (error) goto out_put; @@ -3786,6 +4095,7 @@ int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, dlm_put_lkb(lkb); out: unlock_recovery(ls); + kfree(ua_tmp); return error; } @@ -3815,33 +4125,37 @@ int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, if (error == -DLM_ECANCEL) error = 0; - if (error) - goto out_put; - - /* this lkb was removed from the WAITING queue */ - if (lkb->lkb_grmode == DLM_LOCK_IV) { - spin_lock(&ua->proc->locks_spin); - list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking); - spin_unlock(&ua->proc->locks_spin); - } + /* from validate_unlock_args() */ + if (error == -EBUSY) + error = 0; out_put: dlm_put_lkb(lkb); out: unlock_recovery(ls); + kfree(ua_tmp); return error; } +/* lkb's that are removed from the waiters list by revert are just left on the + orphans list with the granted orphan locks, to be freed by purge */ + static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) { struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam; + struct dlm_args args; + int error; - if (ua->lksb.sb_lvbptr) - kfree(ua->lksb.sb_lvbptr); - kfree(ua); - lkb->lkb_astparam = (long)NULL; + hold_lkb(lkb); + mutex_lock(&ls->ls_orphans_mutex); + list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans); + mutex_unlock(&ls->ls_orphans_mutex); - /* TODO: propogate to master if needed */ - return 0; + set_unlock_args(0, ua, &args); + + error = cancel_lock(ls, lkb, &args); + if (error == -DLM_ECANCEL) + error = 0; + return error; } /* The force flag allows the unlock to go ahead even if the lkb isn't granted. @@ -3853,10 +4167,6 @@ static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) struct dlm_args args; int error; - /* FIXME: we need to handle the case where the lkb is in limbo - while the rsb is being looked up, currently we assert in - _unlock_lock/is_remote because rsb nodeid is -1. */ - set_unlock_args(DLM_LKF_FORCEUNLOCK, ua, &args); error = unlock_lock(ls, lkb, &args); @@ -3865,6 +4175,31 @@ static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb) return error; } +/* We have to release clear_proc_locks mutex before calling unlock_proc_lock() + (which does lock_rsb) due to deadlock with receiving a message that does + lock_rsb followed by dlm_user_add_ast() */ + +static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls, + struct dlm_user_proc *proc) +{ + struct dlm_lkb *lkb = NULL; + + mutex_lock(&ls->ls_clear_proc_locks); + if (list_empty(&proc->locks)) + goto out; + + lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue); + list_del_init(&lkb->lkb_ownqueue); + + if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) + lkb->lkb_flags |= DLM_IFL_ORPHAN; + else + lkb->lkb_flags |= DLM_IFL_DEAD; + out: + mutex_unlock(&ls->ls_clear_proc_locks); + return lkb; +} + /* The ls_clear_proc_locks mutex protects against dlm_user_add_asts() which 1) references lkb->ua which we free here and 2) adds lkbs to proc->asts, which we clear here. */ @@ -3880,18 +4215,15 @@ void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) struct dlm_lkb *lkb, *safe; lock_recovery(ls); - mutex_lock(&ls->ls_clear_proc_locks); - list_for_each_entry_safe(lkb, safe, &proc->locks, lkb_ownqueue) { - list_del_init(&lkb->lkb_ownqueue); - - if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) { - lkb->lkb_flags |= DLM_IFL_ORPHAN; + while (1) { + lkb = del_proc_lock(ls, proc); + if (!lkb) + break; + if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) orphan_proc_lock(ls, lkb); - } else { - lkb->lkb_flags |= DLM_IFL_DEAD; + else unlock_proc_lock(ls, lkb); - } /* this removes the reference for the proc->locks list added by dlm_user_request, it may result in the lkb @@ -3900,6 +4232,8 @@ void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc) dlm_put_lkb(lkb); } + mutex_lock(&ls->ls_clear_proc_locks); + /* in-progress unlocks */ list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) { list_del_init(&lkb->lkb_ownqueue); diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index f40817b53c6f..f607ca2f0792 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -2,7 +2,7 @@ ******************************************************************************* ** ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. -** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. +** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions @@ -459,6 +459,8 @@ static int new_lockspace(char *name, int namelen, void **lockspace, INIT_LIST_HEAD(&ls->ls_waiters); mutex_init(&ls->ls_waiters_mutex); + INIT_LIST_HEAD(&ls->ls_orphans); + mutex_init(&ls->ls_orphans_mutex); INIT_LIST_HEAD(&ls->ls_nodes); INIT_LIST_HEAD(&ls->ls_nodes_gone); diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 27a75ce571cf..c978c67b1eff 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2006 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions @@ -128,35 +128,30 @@ static void compat_output(struct dlm_lock_result *res, } #endif +/* we could possibly check if the cancel of an orphan has resulted in the lkb + being removed and then remove that lkb from the orphans list and free it */ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) { struct dlm_ls *ls; struct dlm_user_args *ua; struct dlm_user_proc *proc; - int remove_ownqueue = 0; + int eol = 0, ast_type; - /* dlm_clear_proc_locks() sets ORPHAN/DEAD flag on each - lkb before dealing with it. We need to check this - flag before taking ls_clear_proc_locks mutex because if - it's set, dlm_clear_proc_locks() holds the mutex. */ - - if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { - /* log_print("user_add_ast skip1 %x", lkb->lkb_flags); */ + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) return; - } ls = lkb->lkb_resource->res_ls; mutex_lock(&ls->ls_clear_proc_locks); /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed - lkb->ua so we can't try to use it. */ + lkb->ua so we can't try to use it. This second check is necessary + for cases where a completion ast is received for an operation that + began before clear_proc_locks did its cancel/unlock. */ - if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { - /* log_print("user_add_ast skip2 %x", lkb->lkb_flags); */ + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) goto out; - } DLM_ASSERT(lkb->lkb_astparam, dlm_print_lkb(lkb);); ua = (struct dlm_user_args *)lkb->lkb_astparam; @@ -166,28 +161,42 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) goto out; spin_lock(&proc->asts_spin); - if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) { + + ast_type = lkb->lkb_ast_type; + lkb->lkb_ast_type |= type; + + if (!ast_type) { kref_get(&lkb->lkb_ref); list_add_tail(&lkb->lkb_astqueue, &proc->asts); - lkb->lkb_ast_type |= type; wake_up_interruptible(&proc->wait); } - - /* noqueue requests that fail may need to be removed from the - proc's locks list, there should be a better way of detecting - this situation than checking all these things... */ - - if (type == AST_COMP && lkb->lkb_grmode == DLM_LOCK_IV && - ua->lksb.sb_status == -EAGAIN && !list_empty(&lkb->lkb_ownqueue)) - remove_ownqueue = 1; - - /* unlocks or cancels of waiting requests need to be removed from the - proc's unlocking list, again there must be a better way... */ - - if (ua->lksb.sb_status == -DLM_EUNLOCK || + if (type == AST_COMP && (ast_type & AST_COMP)) + log_debug(ls, "ast overlap %x status %x %x", + lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags); + + /* Figure out if this lock is at the end of its life and no longer + available for the application to use. The lkb still exists until + the final ast is read. A lock becomes EOL in three situations: + 1. a noqueue request fails with EAGAIN + 2. an unlock completes with EUNLOCK + 3. a cancel of a waiting request completes with ECANCEL + An EOL lock needs to be removed from the process's list of locks. + And we can't allow any new operation on an EOL lock. This is + not related to the lifetime of the lkb struct which is managed + entirely by refcount. */ + + if (type == AST_COMP && + lkb->lkb_grmode == DLM_LOCK_IV && + ua->lksb.sb_status == -EAGAIN) + eol = 1; + else if (ua->lksb.sb_status == -DLM_EUNLOCK || (ua->lksb.sb_status == -DLM_ECANCEL && lkb->lkb_grmode == DLM_LOCK_IV)) - remove_ownqueue = 1; + eol = 1; + if (eol) { + lkb->lkb_ast_type &= ~AST_BAST; + lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; + } /* We want to copy the lvb to userspace when the completion ast is read if the status is 0, the lock has an lvb and @@ -204,11 +213,13 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) spin_unlock(&proc->asts_spin); - if (remove_ownqueue) { + if (eol) { spin_lock(&ua->proc->locks_spin); - list_del_init(&lkb->lkb_ownqueue); + if (!list_empty(&lkb->lkb_ownqueue)) { + list_del_init(&lkb->lkb_ownqueue); + dlm_put_lkb(lkb); + } spin_unlock(&ua->proc->locks_spin); - dlm_put_lkb(lkb); } out: mutex_unlock(&ls->ls_clear_proc_locks); |