2005-05-16 07:43:18

by David Teigland

Subject: [PATCH 1/8] dlm: core locking

The core dlm functions. Processes dlm_lock() and dlm_unlock() requests.
Manages locks on resources' grant/convert/wait queues. Sends and receives
high level locking operations between nodes.

Signed-off-by: Dave Teigland <[email protected]>
Signed-off-by: Patrick Caulfield <[email protected]>

---

drivers/dlm/lock.c | 3569 +++++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/dlm/lock.h | 51
2 files changed, 3620 insertions(+)

--- a/drivers/dlm/lock.c 1970-01-01 07:30:00.000000000 +0730
+++ b/drivers/dlm/lock.c 2005-05-12 23:13:15.829485512 +0800
@@ -0,0 +1,3569 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) 2005 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
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+/* Central locking logic has four stages:
+
+ dlm_lock()
+ dlm_unlock()
+
+ request_lock(ls, lkb)
+ convert_lock(ls, lkb)
+ unlock_lock(ls, lkb)
+ cancel_lock(ls, lkb)
+
+ _request_lock(r, lkb)
+ _convert_lock(r, lkb)
+ _unlock_lock(r, lkb)
+ _cancel_lock(r, lkb)
+
+ do_request(r, lkb)
+ do_convert(r, lkb)
+ do_unlock(r, lkb)
+ do_cancel(r, lkb)
+
+ Stage 1 (lock, unlock) is mainly about checking input args and
+ splitting into one of the four main operations:
+
+ dlm_lock = request_lock
+ dlm_lock+CONVERT = convert_lock
+ dlm_unlock = unlock_lock
+ dlm_unlock+CANCEL = cancel_lock
+
+ Stage 2, xxxx_lock(), just finds and locks the relevant rsb which is
+ provided to the next stage.
+
+ Stage 3, _xxxx_lock(), determines if the operation is local or remote.
+ When remote, it calls send_xxxx(), when local it calls do_xxxx().
+
+ Stage 4, do_xxxx(), is the guts of the operation. It manipulates the
+ given rsb and lkb and queues callbacks.
+
+ For remote operations, send_xxxx() results in the corresponding do_xxxx()
+ function being executed on the remote node. The connecting send/receive
+ calls on local (L) and remote (R) nodes:
+
+ L: send_xxxx() -> R: receive_xxxx()
+ R: do_xxxx()
+ L: receive_xxxx_reply() <- R: send_xxxx_reply()
+*/
+
+#include "dlm_internal.h"
+#include "memory.h"
+#include "lowcomms.h"
+#include "requestqueue.h"
+#include "util.h"
+#include "dir.h"
+#include "member.h"
+#include "lockspace.h"
+#include "ast.h"
+#include "lock.h"
+#include "rcom.h"
+#include "recover.h"
+#include "lvb_table.h"
+#include "config.h"
+
+static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
+static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int send_remove(struct dlm_rsb *r);
+static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ struct dlm_message *ms);
+static int receive_extralen(struct dlm_message *ms);
+
+/*
+ * Lock compatibilty matrix - thanks Steve
+ * UN = Unlocked state. Not really a state, used as a flag
+ * PD = Padding. Used to make the matrix a nice power of two in size
+ * Other states are the same as the VMS DLM.
+ * Usage: matrix[grmode+1][rqmode+1] (although m[rq+1][gr+1] is the same)
+ */
+
+const int __dlm_compat_matrix[8][8] = {
+ /* UN NL CR CW PR PW EX PD */
+ {1, 1, 1, 1, 1, 1, 1, 0}, /* UN */
+ {1, 1, 1, 1, 1, 1, 1, 0}, /* NL */
+ {1, 1, 1, 1, 1, 1, 0, 0}, /* CR */
+ {1, 1, 1, 1, 0, 0, 0, 0}, /* CW */
+ {1, 1, 1, 0, 1, 0, 0, 0}, /* PR */
+ {1, 1, 1, 0, 0, 0, 0, 0}, /* PW */
+ {1, 1, 0, 0, 0, 0, 0, 0}, /* EX */
+ {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
+};
+
+#define modes_compat(gr, rq) \
+ __dlm_compat_matrix[(gr)->lkb_grmode + 1][(rq)->lkb_rqmode + 1]
+
+int dlm_modes_compat(int mode1, int mode2)
+{
+ return __dlm_compat_matrix[mode1 + 1][mode2 + 1];
+}
+
+/*
+ * Compatibility matrix for conversions with QUECVT set.
+ * Granted mode is the row; requested mode is the column.
+ * Usage: matrix[grmode+1][rqmode+1]
+ */
+
+const int __quecvt_compat_matrix[8][8] = {
+ /* UN NL CR CW PR PW EX PD */
+ {0, 0, 0, 0, 0, 0, 0, 0}, /* UN */
+ {0, 0, 1, 1, 1, 1, 1, 0}, /* NL */
+ {0, 0, 0, 1, 1, 1, 1, 0}, /* CR */
+ {0, 0, 0, 0, 1, 1, 1, 0}, /* CW */
+ {0, 0, 0, 1, 0, 1, 1, 0}, /* PR */
+ {0, 0, 0, 0, 0, 0, 1, 0}, /* PW */
+ {0, 0, 0, 0, 0, 0, 0, 0}, /* EX */
+ {0, 0, 0, 0, 0, 0, 0, 0} /* PD */
+};
+
+void dlm_print_lkb(struct dlm_lkb *lkb)
+{
+ printk(KERN_ERR "lkb: nodeid %d id %x remid %x exflags %x flags %x\n"
+ " status %d rqmode %d grmode %d wait_type %d ast_type %d\n",
+ lkb->lkb_nodeid, lkb->lkb_id, lkb->lkb_remid, lkb->lkb_exflags,
+ lkb->lkb_flags, lkb->lkb_status, lkb->lkb_rqmode,
+ lkb->lkb_grmode, lkb->lkb_wait_type, lkb->lkb_ast_type);
+}
+
+void dlm_print_rsb(struct dlm_rsb *r)
+{
+ printk(KERN_ERR "rsb: nodeid %d flags %lx trial %x rlc %d name %s\n",
+ r->res_nodeid, r->res_flags, r->res_trial_lkid,
+ r->res_recover_locks_count, r->res_name);
+}
+
+/* Threads cannot use the lockspace while it's being recovered */
+
+static inline void lock_recovery(struct dlm_ls *ls)
+{
+ down_read(&ls->ls_in_recovery);
+}
+
+static inline void unlock_recovery(struct dlm_ls *ls)
+{
+ up_read(&ls->ls_in_recovery);
+}
+
+static inline int lock_recovery_try(struct dlm_ls *ls)
+{
+ return down_read_trylock(&ls->ls_in_recovery);
+}
+
+static inline int can_be_queued(struct dlm_lkb *lkb)
+{
+ return !(lkb->lkb_exflags & DLM_LKF_NOQUEUE);
+}
+
+static inline int force_blocking_asts(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_exflags & DLM_LKF_NOQUEUEBAST);
+}
+
+static inline int is_demoted(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
+}
+
+static inline int is_remote(struct dlm_rsb *r)
+{
+ DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
+ return !!r->res_nodeid;
+}
+
+static inline int is_process_copy(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_nodeid && !(lkb->lkb_flags & DLM_IFL_MSTCPY));
+}
+
+static inline int is_master_copy(struct dlm_lkb *lkb)
+{
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY)
+ DLM_ASSERT(lkb->lkb_nodeid, dlm_print_lkb(lkb););
+ return (lkb->lkb_flags & DLM_IFL_MSTCPY) ? TRUE : FALSE;
+}
+
+static inline int middle_conversion(struct dlm_lkb *lkb)
+{
+ if ((lkb->lkb_grmode==DLM_LOCK_PR && lkb->lkb_rqmode==DLM_LOCK_CW) ||
+ (lkb->lkb_rqmode==DLM_LOCK_PR && lkb->lkb_grmode==DLM_LOCK_CW))
+ return TRUE;
+ return FALSE;
+}
+
+static inline int down_conversion(struct dlm_lkb *lkb)
+{
+ return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
+}
+
+static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
+{
+ if (is_master_copy(lkb))
+ return;
+
+ DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
+
+ lkb->lkb_lksb->sb_status = rv;
+ lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
+
+ dlm_add_ast(lkb, AST_COMP);
+}
+
+static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
+{
+ if (is_master_copy(lkb))
+ send_bast(r, lkb, rqmode);
+ else {
+ lkb->lkb_bastmode = rqmode;
+ dlm_add_ast(lkb, AST_BAST);
+ }
+}
+
+/*
+ * Basic operations on rsb's and lkb's
+ */
+
+static struct dlm_rsb *create_rsb(struct dlm_ls *ls, char *name, int len)
+{
+ struct dlm_rsb *r;
+
+ r = allocate_rsb(ls, len);
+ if (!r)
+ return NULL;
+
+ r->res_ls = ls;
+ r->res_length = len;
+ memcpy(r->res_name, name, len);
+ init_MUTEX(&r->res_sem);
+
+ INIT_LIST_HEAD(&r->res_lookup);
+ INIT_LIST_HEAD(&r->res_grantqueue);
+ INIT_LIST_HEAD(&r->res_convertqueue);
+ INIT_LIST_HEAD(&r->res_waitqueue);
+ INIT_LIST_HEAD(&r->res_root_list);
+ INIT_LIST_HEAD(&r->res_recover_list);
+
+ return r;
+}
+
+static int search_rsb_list(struct list_head *head, char *name, int len,
+ unsigned int flags, struct dlm_rsb **r_ret)
+{
+ struct dlm_rsb *r;
+ int error = 0;
+
+ list_for_each_entry(r, head, res_hashchain) {
+ if (len == r->res_length && !memcmp(name, r->res_name, len))
+ goto found;
+ }
+ return -ENOENT;
+
+ found:
+ if (r->res_nodeid && (flags & R_MASTER))
+ error = -ENOTBLK;
+ *r_ret = r;
+ return error;
+}
+
+static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
+ unsigned int flags, struct dlm_rsb **r_ret)
+{
+ struct dlm_rsb *r;
+ int error;
+
+ error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
+ if (!error) {
+ kref_get(&r->res_ref);
+ goto out;
+ }
+ error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
+ if (error)
+ goto out;
+
+ list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
+
+ if (r->res_nodeid == -1) {
+ clear_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ clear_bit(RESFL_MASTER_UNCERTAIN, &r->res_flags);
+ r->res_trial_lkid = 0;
+ } else if (r->res_nodeid > 0) {
+ clear_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ set_bit(RESFL_MASTER_UNCERTAIN, &r->res_flags);
+ r->res_trial_lkid = 0;
+ } else {
+ DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
+ DLM_ASSERT(!test_bit(RESFL_MASTER_WAIT, &r->res_flags),
+ dlm_print_rsb(r););
+ DLM_ASSERT(!test_bit(RESFL_MASTER_UNCERTAIN, &r->res_flags),);
+ }
+ out:
+ *r_ret = r;
+ return error;
+}
+
+static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
+ unsigned int flags, struct dlm_rsb **r_ret)
+{
+ int error;
+ write_lock(&ls->ls_rsbtbl[b].lock);
+ error = _search_rsb(ls, name, len, b, flags, r_ret);
+ write_unlock(&ls->ls_rsbtbl[b].lock);
+ return error;
+}
+
+/*
+ * Find rsb in rsbtbl and potentially create/add one
+ *
+ * Delaying the release of rsb's has a similar benefit to applications keeping
+ * NL locks on an rsb, but without the guarantee that the cached master value
+ * will still be valid when the rsb is reused. Apps aren't always smart enough
+ * to keep NL locks on an rsb that they may lock again shortly; this can lead
+ * to excessive master lookups and removals if we don't delay the release.
+ *
+ * Searching for an rsb means looking through both the normal list and toss
+ * list. When found on the toss list the rsb is moved to the normal list with
+ * ref count of 1; when found on normal list the ref count is incremented.
+ */
+
+static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
+ unsigned int flags, struct dlm_rsb **r_ret)
+{
+ struct dlm_rsb *r, *tmp;
+ uint32_t bucket;
+ int error = 0;
+
+ bucket = dlm_hash(name, namelen);
+ bucket &= (ls->ls_rsbtbl_size - 1);
+
+ error = search_rsb(ls, name, namelen, bucket, flags, &r);
+ if (!error)
+ goto out;
+
+ if (error == -ENOENT && !(flags & R_CREATE))
+ goto out;
+
+ /* the rsb was found but wasn't a master copy */
+ if (error == -ENOTBLK)
+ goto out;
+
+ error = -ENOMEM;
+ r = create_rsb(ls, name, namelen);
+ if (!r)
+ goto out;
+
+ r->res_bucket = bucket;
+ r->res_nodeid = -1;
+ kref_init(&r->res_ref);
+
+ write_lock(&ls->ls_rsbtbl[bucket].lock);
+ error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
+ if (!error) {
+ write_unlock(&ls->ls_rsbtbl[bucket].lock);
+ free_rsb(r);
+ r = tmp;
+ goto out;
+ }
+ list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
+ write_unlock(&ls->ls_rsbtbl[bucket].lock);
+ error = 0;
+ out:
+ *r_ret = r;
+ return error;
+}
+
+int dlm_find_rsb(struct dlm_ls *ls, char *name, int namelen,
+ unsigned int flags, struct dlm_rsb **r_ret)
+{
+ return find_rsb(ls, name, namelen, flags, r_ret);
+}
+
+/* This is only called to add a reference when the code already holds
+ a valid reference to the rsb, so there's no need for locking. */
+
+static inline void hold_rsb(struct dlm_rsb *r)
+{
+ kref_get(&r->res_ref);
+}
+
+void dlm_hold_rsb(struct dlm_rsb *r)
+{
+ hold_rsb(r);
+}
+
+static void toss_rsb(struct kref *kref)
+{
+ struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
+ struct dlm_ls *ls = r->res_ls;
+
+ DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
+ kref_init(&r->res_ref);
+ list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
+ r->res_toss_time = jiffies;
+ if (r->res_lvbptr) {
+ free_lvb(r->res_lvbptr);
+ r->res_lvbptr = NULL;
+ }
+}
+
+/* When all references to the rsb are gone it's transfered to
+ the tossed list for later disposal. */
+
+static void put_rsb(struct dlm_rsb *r)
+{
+ struct dlm_ls *ls = r->res_ls;
+ uint32_t bucket = r->res_bucket;
+
+ write_lock(&ls->ls_rsbtbl[bucket].lock);
+ kref_put(&r->res_ref, toss_rsb);
+ write_unlock(&ls->ls_rsbtbl[bucket].lock);
+}
+
+void dlm_put_rsb(struct dlm_rsb *r)
+{
+ put_rsb(r);
+}
+
+/* See comment for unhold_lkb */
+
+static void unhold_rsb(struct dlm_rsb *r)
+{
+ int rv;
+ rv = kref_put(&r->res_ref, toss_rsb);
+ DLM_ASSERT(!rv, dlm_print_rsb(r););
+}
+
+static void kill_rsb(struct kref *kref)
+{
+ struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);
+
+ /* All work is done after the return from kref_put() so we
+ can release the write_lock before the remove and free. */
+
+ DLM_ASSERT(list_empty(&r->res_lookup),);
+ DLM_ASSERT(list_empty(&r->res_grantqueue),);
+ DLM_ASSERT(list_empty(&r->res_convertqueue),);
+ DLM_ASSERT(list_empty(&r->res_waitqueue),);
+ DLM_ASSERT(list_empty(&r->res_root_list),);
+ DLM_ASSERT(list_empty(&r->res_recover_list),);
+}
+
+/* Attaching/detaching lkb's from rsb's is for rsb reference counting.
+ The rsb must exist as long as any lkb's for it do. */
+
+static void attach_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ hold_rsb(r);
+ lkb->lkb_resource = r;
+}
+
+static void detach_lkb(struct dlm_lkb *lkb)
+{
+ if (lkb->lkb_resource) {
+ put_rsb(lkb->lkb_resource);
+ lkb->lkb_resource = NULL;
+ }
+}
+
+static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
+{
+ struct dlm_lkb *lkb, *tmp;
+ uint32_t lkid = 0;
+ uint16_t bucket;
+
+ lkb = allocate_lkb(ls);
+ if (!lkb)
+ return -ENOMEM;
+
+ lkb->lkb_nodeid = -1;
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ kref_init(&lkb->lkb_ref);
+
+ get_random_bytes(&bucket, sizeof(bucket));
+ bucket &= (ls->ls_lkbtbl_size - 1);
+
+ write_lock(&ls->ls_lkbtbl[bucket].lock);
+
+ /* counter can roll over so we must verify lkid is not in use */
+
+ while (lkid == 0) {
+ lkid = bucket | (ls->ls_lkbtbl[bucket].counter++ << 16);
+
+ list_for_each_entry(tmp, &ls->ls_lkbtbl[bucket].list,
+ lkb_idtbl_list) {
+ if (tmp->lkb_id != lkid)
+ continue;
+ lkid = 0;
+ break;
+ }
+ }
+
+ lkb->lkb_id = lkid;
+ list_add(&lkb->lkb_idtbl_list, &ls->ls_lkbtbl[bucket].list);
+ write_unlock(&ls->ls_lkbtbl[bucket].lock);
+
+ *lkb_ret = lkb;
+ return 0;
+}
+
+static struct dlm_lkb *__find_lkb(struct dlm_ls *ls, uint32_t lkid)
+{
+ uint16_t bucket = lkid & 0xFFFF;
+ struct dlm_lkb *lkb;
+
+ list_for_each_entry(lkb, &ls->ls_lkbtbl[bucket].list, lkb_idtbl_list) {
+ if (lkb->lkb_id == lkid)
+ return lkb;
+ }
+ return NULL;
+}
+
+static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret)
+{
+ struct dlm_lkb *lkb;
+ uint16_t bucket = lkid & 0xFFFF;
+
+ if (bucket >= ls->ls_lkbtbl_size)
+ return -EBADSLT;
+
+ read_lock(&ls->ls_lkbtbl[bucket].lock);
+ lkb = __find_lkb(ls, lkid);
+ if (lkb)
+ kref_get(&lkb->lkb_ref);
+ read_unlock(&ls->ls_lkbtbl[bucket].lock);
+
+ *lkb_ret = lkb;
+ return lkb ? 0 : -ENOENT;
+}
+
+static void kill_lkb(struct kref *kref)
+{
+ struct dlm_lkb *lkb = container_of(kref, struct dlm_lkb, lkb_ref);
+
+ /* All work is done after the return from kref_put() so we
+ can release the write_lock before the detach_lkb */
+
+ DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
+}
+
+static int put_lkb(struct dlm_lkb *lkb)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ uint16_t bucket = lkb->lkb_id & 0xFFFF;
+
+ write_lock(&ls->ls_lkbtbl[bucket].lock);
+ if (kref_put(&lkb->lkb_ref, kill_lkb)) {
+ list_del(&lkb->lkb_idtbl_list);
+ write_unlock(&ls->ls_lkbtbl[bucket].lock);
+
+ detach_lkb(lkb);
+
+ /* for local/process lkbs, lvbptr points to caller's lksb */
+ if (lkb->lkb_lvbptr && is_master_copy(lkb))
+ free_lvb(lkb->lkb_lvbptr);
+ if (lkb->lkb_range)
+ free_range(lkb->lkb_range);
+ free_lkb(lkb);
+ return 1;
+ } else {
+ write_unlock(&ls->ls_lkbtbl[bucket].lock);
+ return 0;
+ }
+}
+
+int dlm_put_lkb(struct dlm_lkb *lkb)
+{
+ return put_lkb(lkb);
+}
+
+/* This is only called to add a reference when the code already holds
+ a valid reference to the lkb, so there's no need for locking. */
+
+static inline void hold_lkb(struct dlm_lkb *lkb)
+{
+ kref_get(&lkb->lkb_ref);
+}
+
+/* This is called when we need to remove a reference and are certain
+ it's not the last ref. e.g. del_lkb is always called between a
+ find_lkb/put_lkb and is always the inverse of a previous add_lkb.
+ put_lkb would work fine, but would involve unnecessary locking */
+
+static inline void unhold_lkb(struct dlm_lkb *lkb)
+{
+ int rv;
+ rv = kref_put(&lkb->lkb_ref, kill_lkb);
+ DLM_ASSERT(!rv, dlm_print_lkb(lkb););
+}
+
+static void lkb_add_ordered(struct list_head *new, struct list_head *head,
+ int mode)
+{
+ struct dlm_lkb *lkb = NULL;
+
+ list_for_each_entry(lkb, head, lkb_statequeue)
+ if (lkb->lkb_rqmode < mode)
+ break;
+
+ if (!lkb)
+ list_add_tail(new, head);
+ else
+ __list_add(new, lkb->lkb_statequeue.prev, &lkb->lkb_statequeue);
+}
+
+/* add/remove lkb to rsb's grant/convert/wait queue */
+
+static void add_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int status)
+{
+ kref_get(&lkb->lkb_ref);
+
+ DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););
+
+ lkb->lkb_status = status;
+
+ switch (status) {
+ case DLM_LKSTS_WAITING:
+ if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
+ list_add(&lkb->lkb_statequeue, &r->res_waitqueue);
+ else
+ list_add_tail(&lkb->lkb_statequeue, &r->res_waitqueue);
+ break;
+ case DLM_LKSTS_GRANTED:
+ /* convention says granted locks kept in order of grmode */
+ lkb_add_ordered(&lkb->lkb_statequeue, &r->res_grantqueue,
+ lkb->lkb_grmode);
+ break;
+ case DLM_LKSTS_CONVERT:
+ if (lkb->lkb_exflags & DLM_LKF_HEADQUE)
+ list_add(&lkb->lkb_statequeue, &r->res_convertqueue);
+ else
+ list_add_tail(&lkb->lkb_statequeue,
+ &r->res_convertqueue);
+ break;
+ default:
+ DLM_ASSERT(0, dlm_print_lkb(lkb); printk("sts=%d\n", status););
+ }
+}
+
+static void del_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ lkb->lkb_status = 0;
+ list_del(&lkb->lkb_statequeue);
+ unhold_lkb(lkb);
+}
+
+static void move_lkb(struct dlm_rsb *r, struct dlm_lkb *lkb, int sts)
+{
+ hold_lkb(lkb);
+ del_lkb(r, lkb);
+ add_lkb(r, lkb, sts);
+ unhold_lkb(lkb);
+}
+
+/* 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)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+
+ down(&ls->ls_waiters_sem);
+ if (lkb->lkb_wait_type) {
+ log_print("add_to_waiters error %d", lkb->lkb_wait_type);
+ goto out;
+ }
+ lkb->lkb_wait_type = mstype;
+ kref_get(&lkb->lkb_ref);
+ list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
+ out:
+ up(&ls->ls_waiters_sem);
+}
+
+static int _remove_from_waiters(struct dlm_lkb *lkb)
+{
+ int error = 0;
+
+ if (!lkb->lkb_wait_type) {
+ log_print("remove_from_waiters error");
+ error = -EINVAL;
+ goto out;
+ }
+ lkb->lkb_wait_type = 0;
+ list_del(&lkb->lkb_wait_reply);
+ unhold_lkb(lkb);
+ out:
+ return error;
+}
+
+static int remove_from_waiters(struct dlm_lkb *lkb)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ int error;
+
+ down(&ls->ls_waiters_sem);
+ error = _remove_from_waiters(lkb);
+ up(&ls->ls_waiters_sem);
+ return error;
+}
+
+int dlm_remove_from_waiters(struct dlm_lkb *lkb)
+{
+ return remove_from_waiters(lkb);
+}
+
+static void dir_remove(struct dlm_rsb *r)
+{
+ int to_nodeid = dlm_dir_nodeid(r);
+
+ if (to_nodeid != dlm_our_nodeid())
+ send_remove(r);
+ else
+ dlm_dir_remove_entry(r->res_ls, to_nodeid,
+ r->res_name, r->res_length);
+}
+
+/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
+ found since they are in order of newest to oldest? */
+
+static int shrink_bucket(struct dlm_ls *ls, int b)
+{
+ struct dlm_rsb *r;
+ int count = 0, found;
+
+ for (;;) {
+ found = FALSE;
+ write_lock(&ls->ls_rsbtbl[b].lock);
+ list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
+ res_hashchain) {
+ if (!time_after_eq(jiffies, r->res_toss_time +
+ dlm_config.toss_secs * HZ))
+ continue;
+ found = TRUE;
+ break;
+ }
+
+ if (!found) {
+ write_unlock(&ls->ls_rsbtbl[b].lock);
+ break;
+ }
+
+ if (kref_put(&r->res_ref, kill_rsb)) {
+ list_del(&r->res_hashchain);
+ write_unlock(&ls->ls_rsbtbl[b].lock);
+
+ if (is_master(r))
+ dir_remove(r);
+ free_rsb(r);
+ count++;
+ } else {
+ write_unlock(&ls->ls_rsbtbl[b].lock);
+ log_error(ls, "tossed rsb in use %s", r->res_name);
+ }
+ }
+
+ return count;
+}
+
+void dlm_scan_rsbs(struct dlm_ls *ls)
+{
+ int i;
+
+ if (!test_bit(LSFL_LS_RUN, &ls->ls_flags))
+ return;
+
+ for (i = 0; i < ls->ls_rsbtbl_size; i++) {
+ shrink_bucket(ls, i);
+ cond_resched();
+ }
+}
+
+/* lkb is master or local copy */
+
+static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int b, len = r->res_ls->ls_lvblen;
+
+ /* b=1 lvb returned to caller
+ b=0 lvb written to rsb or invalidated
+ b=-1 do nothing */
+
+ b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
+
+ if (b == 1) {
+ if (!lkb->lkb_lvbptr)
+ return;
+
+ if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
+ return;
+
+ if (!r->res_lvbptr)
+ return;
+
+ memcpy(lkb->lkb_lvbptr, r->res_lvbptr, len);
+ lkb->lkb_lvbseq = r->res_lvbseq;
+
+ } else if (b == 0) {
+ if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
+ set_bit(RESFL_VALNOTVALID, &r->res_flags);
+ return;
+ }
+
+ if (!lkb->lkb_lvbptr)
+ return;
+
+ if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
+ return;
+
+ if (!r->res_lvbptr)
+ r->res_lvbptr = allocate_lvb(r->res_ls);
+
+ if (!r->res_lvbptr)
+ return;
+
+ memcpy(r->res_lvbptr, lkb->lkb_lvbptr, len);
+ r->res_lvbseq++;
+ lkb->lkb_lvbseq = r->res_lvbseq;
+ clear_bit(RESFL_VALNOTVALID, &r->res_flags);
+ }
+
+ if (test_bit(RESFL_VALNOTVALID, &r->res_flags))
+ lkb->lkb_sbflags |= DLM_SBF_VALNOTVALID;
+}
+
+static void set_lvb_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ if (lkb->lkb_grmode < DLM_LOCK_PW)
+ return;
+
+ if (lkb->lkb_exflags & DLM_LKF_IVVALBLK) {
+ set_bit(RESFL_VALNOTVALID, &r->res_flags);
+ return;
+ }
+
+ if (!lkb->lkb_lvbptr)
+ return;
+
+ if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
+ return;
+
+ if (!r->res_lvbptr)
+ r->res_lvbptr = allocate_lvb(r->res_ls);
+
+ if (!r->res_lvbptr)
+ return;
+
+ memcpy(r->res_lvbptr, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
+ r->res_lvbseq++;
+ clear_bit(RESFL_VALNOTVALID, &r->res_flags);
+}
+
+/* lkb is process copy (pc) */
+
+static void set_lvb_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ int b;
+
+ if (!lkb->lkb_lvbptr)
+ return;
+
+ if (!(lkb->lkb_exflags & DLM_LKF_VALBLK))
+ return;
+
+ b = dlm_lvb_operations[lkb->lkb_grmode + 1][lkb->lkb_rqmode + 1];
+ if (b == 1) {
+ int len = receive_extralen(ms);
+ memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
+ lkb->lkb_lvbseq = ms->m_lvbseq;
+ }
+}
+
+/* Manipulate lkb's on rsb's convert/granted/waiting queues
+ remove_lock -- used for unlock, removes lkb from granted
+ revert_lock -- used for cancel, moves lkb from convert to granted
+ grant_lock -- used for request and convert, adds lkb to granted or
+ moves lkb from convert or waiting to granted
+
+ Each of these is used for master or local copy lkb's. There is
+ also a _pc() variation used to make the corresponding change on
+ a process copy (pc) lkb. */
+
+static void _remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ del_lkb(r, lkb);
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ /* this unhold undoes the original ref from create_lkb()
+ so this leads to the lkb being freed */
+ unhold_lkb(lkb);
+}
+
+static void remove_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ set_lvb_unlock(r, lkb);
+ _remove_lock(r, lkb);
+}
+
+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)
+{
+ lkb->lkb_rqmode = DLM_LOCK_IV;
+
+ switch (lkb->lkb_status) {
+ case DLM_LKSTS_CONVERT:
+ move_lkb(r, lkb, DLM_LKSTS_GRANTED);
+ break;
+ case DLM_LKSTS_WAITING:
+ del_lkb(r, lkb);
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ /* this unhold undoes the original ref from create_lkb()
+ so this leads to the lkb being freed */
+ unhold_lkb(lkb);
+ break;
+ default:
+ log_print("invalid status for revert %d", lkb->lkb_status);
+ }
+}
+
+static void revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ revert_lock(r, lkb);
+}
+
+static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ if (lkb->lkb_grmode != lkb->lkb_rqmode) {
+ lkb->lkb_grmode = lkb->lkb_rqmode;
+ if (lkb->lkb_status)
+ move_lkb(r, lkb, DLM_LKSTS_GRANTED);
+ else
+ add_lkb(r, lkb, DLM_LKSTS_GRANTED);
+ }
+
+ lkb->lkb_rqmode = DLM_LOCK_IV;
+
+ if (lkb->lkb_range) {
+ lkb->lkb_range[GR_RANGE_START] = lkb->lkb_range[RQ_RANGE_START];
+ lkb->lkb_range[GR_RANGE_END] = lkb->lkb_range[RQ_RANGE_END];
+ }
+}
+
+static void grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ set_lvb_lock(r, lkb);
+ _grant_lock(r, lkb);
+ lkb->lkb_highbast = 0;
+}
+
+static void grant_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ set_lvb_lock_pc(r, lkb, ms);
+ _grant_lock(r, lkb);
+}
+
+/* called by grant_pending_locks() which means an async grant message must
+ be sent to the requesting node in addition to granting the lock if the
+ lkb belongs to a remote node. */
+
+static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ grant_lock(r, lkb);
+ if (is_master_copy(lkb))
+ send_grant(r, lkb);
+ else
+ queue_cast(r, lkb, 0);
+}
+
+static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
+{
+ struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
+ lkb_statequeue);
+ if (lkb->lkb_id == first->lkb_id)
+ return TRUE;
+
+ return FALSE;
+}
+
+/* Return 1 if the locks' ranges overlap. If the lkb has no range then it is
+ assumed to cover 0-ffffffff.ffffffff */
+
+static inline int ranges_overlap(struct dlm_lkb *lkb1, struct dlm_lkb *lkb2)
+{
+ if (!lkb1->lkb_range || !lkb2->lkb_range)
+ return TRUE;
+
+ if (lkb1->lkb_range[RQ_RANGE_END] < lkb2->lkb_range[GR_RANGE_START] ||
+ lkb1->lkb_range[RQ_RANGE_START] > lkb2->lkb_range[GR_RANGE_END])
+ return FALSE;
+
+ return TRUE;
+}
+
+/* Check if the given lkb conflicts with another lkb on the queue. */
+
+static int queue_conflict(struct list_head *head, struct dlm_lkb *lkb)
+{
+ struct dlm_lkb *this;
+
+ list_for_each_entry(this, head, lkb_statequeue) {
+ if (this == lkb)
+ continue;
+ if (ranges_overlap(lkb, this) && !modes_compat(this, lkb))
+ return TRUE;
+ }
+ return FALSE;
+}
+
+/*
+ * "A conversion deadlock arises with a pair of lock requests in the converting
+ * queue for one resource. The granted mode of each lock blocks the requested
+ * mode of the other lock."
+ *
+ * Part 2: if the granted mode of lkb is preventing the first lkb in the
+ * convert queue from being granted, then demote lkb (set grmode to NL).
+ * This second form requires that we check for conv-deadlk even when
+ * now == 0 in _can_be_granted().
+ *
+ * Example:
+ * Granted Queue: empty
+ * Convert Queue: NL->EX (first lock)
+ * PR->EX (second lock)
+ *
+ * The first lock can't be granted because of the granted mode of the second
+ * lock and the second lock can't be granted because it's not first in the
+ * list. We demote the granted mode of the second lock (the lkb passed to this
+ * function).
+ *
+ * After the resolution, the "grant pending" function needs to go back and try
+ * to grant locks on the convert queue again since the first lock can now be
+ * granted.
+ */
+
+static int conversion_deadlock_detect(struct dlm_rsb *rsb, struct dlm_lkb *lkb)
+{
+ struct dlm_lkb *this, *first = NULL, *self = NULL;
+
+ list_for_each_entry(this, &rsb->res_convertqueue, lkb_statequeue) {
+ if (!first)
+ first = this;
+ if (this == lkb) {
+ self = lkb;
+ continue;
+ }
+
+ if (!ranges_overlap(lkb, this))
+ continue;
+
+ if (!modes_compat(this, lkb) && !modes_compat(lkb, this))
+ return TRUE;
+ }
+
+ /* if lkb is on the convert queue and is preventing the first
+ from being granted, then there's deadlock and we demote lkb.
+ multiple converting locks may need to do this before the first
+ converting lock can be granted. */
+
+ if (self && self != first) {
+ if (!modes_compat(lkb, first) &&
+ !queue_conflict(&rsb->res_grantqueue, first))
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+/*
+ * Return 1 if the lock can be granted, 0 otherwise.
+ * Also detect and resolve conversion deadlocks.
+ *
+ * lkb is the lock to be granted
+ *
+ * now is 1 if the function is being called in the context of the
+ * immediate request, it is 0 if called later, after the lock has been
+ * queued.
+ *
+ * References are from chapter 6 of "VAXcluster Principles" by Roy Davis
+ */
+
+static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
+{
+ int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV);
+
+ /*
+ * 6-10: Version 5.4 introduced an option to address the phenomenon of
+ * a new request for a NL mode lock being blocked.
+ *
+ * 6-11: If the optional EXPEDITE flag is used with the new NL mode
+ * request, then it would be granted. In essence, the use of this flag
+ * tells the Lock Manager to expedite theis request by not considering
+ * what may be in the CONVERTING or WAITING queues... As of this
+ * writing, the EXPEDITE flag can be used only with new requests for NL
+ * mode locks. This flag is not valid for conversion requests.
+ *
+ * A shortcut. Earlier checks return an error if EXPEDITE is used in a
+ * conversion or used with a non-NL requested mode. We also know an
+ * EXPEDITE request is always granted immediately, so now must always
+ * be 1. The full condition to grant an expedite request: (now &&
+ * !conv && lkb->rqmode == DLM_LOCK_NL && (flags & EXPEDITE)) can
+ * therefore be shortened to just checking the flag.
+ */
+
+ if (lkb->lkb_exflags & DLM_LKF_EXPEDITE)
+ return TRUE;
+
+ /*
+ * A shortcut. Without this, !queue_conflict(grantqueue, lkb) would be
+ * added to the remaining conditions.
+ */
+
+ if (queue_conflict(&r->res_grantqueue, lkb))
+ goto out;
+
+ /*
+ * 6-3: By default, a conversion request is immediately granted if the
+ * requested mode is compatible with the modes of all other granted
+ * locks
+ */
+
+ if (queue_conflict(&r->res_convertqueue, lkb))
+ goto out;
+
+ /*
+ * 6-5: But the default algorithm for deciding whether to grant or
+ * queue conversion requests does not by itself guarantee that such
+ * requests are serviced on a "first come first serve" basis. This, in
+ * turn, can lead to a phenomenon known as "indefinate postponement".
+ *
+ * 6-7: This issue is dealt with by using the optional QUECVT flag with
+ * the system service employed to request a lock conversion. This flag
+ * forces certain conversion requests to be queued, even if they are
+ * compatible with the granted modes of other locks on the same
+ * resource. Thus, the use of this flag results in conversion requests
+ * being ordered on a "first come first servce" basis.
+ *
+ * DCT: This condition is all about new conversions being able to occur
+ * "in place" while the lock remains on the granted queue (assuming
+ * nothing else conflicts.) IOW if QUECVT isn't set, a conversion
+ * doesn't _have_ to go onto the convert queue where it's processed in
+ * order. The "now" variable is necessary to distinguish converts
+ * being received and processed for the first time now, because once a
+ * convert is moved to the conversion queue the condition below applies
+ * requiring fifo granting.
+ */
+
+ if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
+ return TRUE;
+
+ /*
+ * When using range locks the NOORDER flag is set to avoid the standard
+ * vms rules on grant order.
+ */
+
+ if (lkb->lkb_exflags & DLM_LKF_NOORDER)
+ return TRUE;
+
+ /*
+ * 6-3: Once in that queue [CONVERTING], a conversion request cannot be
+ * granted until all other conversion requests ahead of it are granted
+ * and/or canceled.
+ */
+
+ if (!now && conv && first_in_list(lkb, &r->res_convertqueue))
+ return TRUE;
+
+ /*
+ * 6-4: By default, a new request is immediately granted only if all
+ * three of the following conditions are satisfied when the request is
+ * issued:
+ * - The queue of ungranted conversion requests for the resource is
+ * empty.
+ * - The queue of ungranted new requests for the resource is empty.
+ * - The mode of the new request is compatible with the most
+ * restrictive mode of all granted locks on the resource.
+ */
+
+ if (now && !conv && list_empty(&r->res_convertqueue) &&
+ list_empty(&r->res_waitqueue))
+ return TRUE;
+
+ /*
+ * 6-4: Once a lock request is in the queue of ungranted new requests,
+ * it cannot be granted until the queue of ungranted conversion
+ * requests is empty, all ungranted new requests ahead of it are
+ * granted and/or canceled, and it is compatible with the granted mode
+ * of the most restrictive lock granted on the resource.
+ */
+
+ if (!now && !conv && list_empty(&r->res_convertqueue) &&
+ first_in_list(lkb, &r->res_waitqueue))
+ return TRUE;
+
+ out:
+ /*
+ * The following, enabled by CONVDEADLK, departs from VMS.
+ */
+
+ if (conv && (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) &&
+ conversion_deadlock_detect(r, lkb)) {
+ lkb->lkb_grmode = DLM_LOCK_NL;
+ lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
+ }
+
+ return FALSE;
+}
+
+/*
+ * The ALTPR and ALTCW flags aren't traditional lock manager flags, but are a
+ * simple way to provide a big optimization to applications that can use them.
+ */
+
+static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
+{
+ uint32_t flags = lkb->lkb_exflags;
+ int rv;
+ int8_t alt = 0, rqmode = lkb->lkb_rqmode;
+
+ rv = _can_be_granted(r, lkb, now);
+ if (rv)
+ goto out;
+
+ if (lkb->lkb_sbflags & DLM_SBF_DEMOTED)
+ goto out;
+
+ if (rqmode != DLM_LOCK_PR && flags & DLM_LKF_ALTPR)
+ alt = DLM_LOCK_PR;
+ else if (rqmode != DLM_LOCK_CW && flags & DLM_LKF_ALTCW)
+ alt = DLM_LOCK_CW;
+
+ if (alt) {
+ lkb->lkb_rqmode = alt;
+ rv = _can_be_granted(r, lkb, now);
+ if (rv)
+ lkb->lkb_sbflags |= DLM_SBF_ALTMODE;
+ else
+ lkb->lkb_rqmode = rqmode;
+ }
+ out:
+ return rv;
+}
+
+static int grant_pending_convert(struct dlm_rsb *r, int high)
+{
+ struct dlm_lkb *lkb, *s;
+ int hi, demoted, quit, grant_restart, demote_restart;
+
+ quit = 0;
+ restart:
+ grant_restart = 0;
+ demote_restart = 0;
+ hi = DLM_LOCK_IV;
+
+ list_for_each_entry_safe(lkb, s, &r->res_convertqueue, lkb_statequeue) {
+ demoted = is_demoted(lkb);
+ if (can_be_granted(r, lkb, FALSE)) {
+ grant_lock_pending(r, lkb);
+ grant_restart = 1;
+ } else {
+ hi = max_t(int, lkb->lkb_rqmode, hi);
+ if (!demoted && is_demoted(lkb))
+ demote_restart = 1;
+ }
+ }
+
+ if (grant_restart)
+ goto restart;
+ if (demote_restart && !quit) {
+ quit = 1;
+ goto restart;
+ }
+
+ return max_t(int, high, hi);
+}
+
+static int grant_pending_wait(struct dlm_rsb *r, int high)
+{
+ struct dlm_lkb *lkb, *s;
+
+ list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) {
+ if (can_be_granted(r, lkb, FALSE))
+ grant_lock_pending(r, lkb);
+ else
+ high = max_t(int, lkb->lkb_rqmode, high);
+ }
+
+ return high;
+}
+
+static void grant_pending_locks(struct dlm_rsb *r)
+{
+ struct dlm_lkb *lkb, *s;
+ int high = DLM_LOCK_IV;
+
+ DLM_ASSERT(is_master(r), dlm_print_rsb(r););
+
+ high = grant_pending_convert(r, high);
+ high = grant_pending_wait(r, high);
+
+ if (high == DLM_LOCK_IV)
+ return;
+
+ /*
+ * If there are locks left on the wait/convert queue then send blocking
+ * ASTs to granted locks based on the largest requested mode (high)
+ * found above. This can generate spurious blocking ASTs for range
+ * locks. FIXME: highbast < high comparison not valid for PR/CW.
+ */
+
+ list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) {
+ if (lkb->lkb_bastaddr && (lkb->lkb_highbast < high) &&
+ !__dlm_compat_matrix[lkb->lkb_grmode+1][high+1]) {
+ queue_bast(r, lkb, high);
+ lkb->lkb_highbast = high;
+ }
+ }
+}
+
+static void send_bast_queue(struct dlm_rsb *r, struct list_head *head,
+ struct dlm_lkb *lkb)
+{
+ struct dlm_lkb *gr;
+
+ list_for_each_entry(gr, head, lkb_statequeue) {
+ if (gr->lkb_bastaddr &&
+ gr->lkb_highbast < lkb->lkb_rqmode &&
+ ranges_overlap(lkb, gr) && !modes_compat(gr, lkb)) {
+ queue_bast(r, gr, lkb->lkb_rqmode);
+ gr->lkb_highbast = lkb->lkb_rqmode;
+ }
+ }
+}
+
+static void send_blocking_asts(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ send_bast_queue(r, &r->res_grantqueue, lkb);
+}
+
+static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ send_bast_queue(r, &r->res_grantqueue, lkb);
+ send_bast_queue(r, &r->res_convertqueue, lkb);
+}
+
+/* set_master(r, lkb) -- set the master nodeid of a resource
+
+ The purpose of this function is to set the nodeid field in the given
+ lkb using the nodeid field in the given rsb. If the rsb's nodeid is
+ known, it can just be copied to the lkb and the function will return
+ 0. If the rsb's nodeid is _not_ known, it needs to be looked up
+ before it can be copied to the lkb.
+
+ When the rsb nodeid is being looked up remotely, the initial lkb
+ causing the lookup is kept on the ls_waiters list waiting for the
+ lookup reply. Other lkb's waiting for the same rsb lookup are kept
+ on the rsb's res_lookup list until the master is verified.
+
+ After a remote lookup or when a tossed rsb is retrived that specifies
+ a remote master, that master value is uncertain -- it may have changed
+ by the time we send it a request. While it's uncertain, only one lkb
+ is allowed to go ahead and use the master value; that lkb is specified
+ by res_trial_lkid. Once the trial lkb is queued on the master node
+ we know the rsb master is correct and any other lkbs on res_lookup
+ can get the rsb nodeid and go ahead with their request.
+
+ Return values:
+ 0: nodeid is set in rsb/lkb and the caller should go ahead and use it
+ 1: the rsb master is not available and the lkb has been placed on
+ a wait queue
+ -EXXX: there was some error in processing
+*/
+
+static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ struct dlm_ls *ls = r->res_ls;
+ int error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
+
+ if (test_and_clear_bit(RESFL_MASTER_UNCERTAIN, &r->res_flags)) {
+ set_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ r->res_trial_lkid = lkb->lkb_id;
+ lkb->lkb_nodeid = r->res_nodeid;
+ return 0;
+ }
+
+ if (r->res_nodeid == 0) {
+ lkb->lkb_nodeid = 0;
+ return 0;
+ }
+
+ if (r->res_trial_lkid == lkb->lkb_id) {
+ DLM_ASSERT(lkb->lkb_id, dlm_print_lkb(lkb););
+ lkb->lkb_nodeid = r->res_nodeid;
+ return 0;
+ }
+
+ if (test_bit(RESFL_MASTER_WAIT, &r->res_flags)) {
+ list_add_tail(&lkb->lkb_rsb_lookup, &r->res_lookup);
+ return 1;
+ }
+
+ if (r->res_nodeid > 0) {
+ lkb->lkb_nodeid = r->res_nodeid;
+ return 0;
+ }
+
+ /* This is the first lkb requested on this rsb since the rsb
+ was created. We need to figure out who the rsb master is. */
+
+ DLM_ASSERT(r->res_nodeid == -1, );
+
+ dir_nodeid = dlm_dir_nodeid(r);
+
+ if (dir_nodeid != our_nodeid) {
+ set_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ send_lookup(r, lkb);
+ return 1;
+ }
+
+ for (;;) {
+ /* It's possible for dlm_scand to remove an old rsb for
+ this same resource from the toss list, us to create
+ a new one, look up the master locally, and find it
+ already exists just before dlm_scand does the
+ dir_remove() on the previous rsb. */
+
+ error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
+ r->res_length, &ret_nodeid);
+ if (!error)
+ break;
+ log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
+ schedule();
+ }
+
+ if (ret_nodeid == our_nodeid) {
+ r->res_nodeid = 0;
+ lkb->lkb_nodeid = 0;
+ return 0;
+ }
+
+ set_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ r->res_trial_lkid = lkb->lkb_id;
+ r->res_nodeid = ret_nodeid;
+ lkb->lkb_nodeid = ret_nodeid;
+ return 0;
+}
+
+/* confirm_master -- confirm (or deny) an rsb's master nodeid
+
+ This is called when we get a request reply from a remote node
+ who we believe is the master. The return value (error) we got
+ back indicates whether it's really the master or not. If it
+ wasn't, we need to start over and do another master lookup. If
+ it was and our lock was queued, then we know the master won't
+ change. If it was and our lock wasn't queued, we need to do
+ another trial with the next lkb.
+*/
+
+static void confirm_master(struct dlm_rsb *r, int error)
+{
+ struct dlm_lkb *lkb, *safe;
+
+ if (!test_bit(RESFL_MASTER_WAIT, &r->res_flags))
+ return;
+
+ switch (error) {
+ case 0:
+ case -EINPROGRESS:
+ /* the remote master queued our request, or
+ the remote dir node told us we're the master */
+
+ clear_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ r->res_trial_lkid = 0;
+
+ list_for_each_entry_safe(lkb, safe, &r->res_lookup,
+ lkb_rsb_lookup) {
+ list_del(&lkb->lkb_rsb_lookup);
+ _request_lock(r, lkb);
+ schedule();
+ }
+ break;
+
+ case -EAGAIN:
+ /* the remote master didn't queue our NOQUEUE request;
+ do another trial with the next waiting lkb */
+
+ 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);
+ r->res_trial_lkid = lkb->lkb_id;
+ _request_lock(r, lkb);
+ break;
+ }
+ /* fall through so the rsb looks new */
+
+ case -ENOENT:
+ case -ENOTBLK:
+ /* the remote master wasn't really the master, i.e. our
+ trial failed; so we start over with another lookup */
+
+ r->res_nodeid = -1;
+ r->res_trial_lkid = 0;
+ clear_bit(RESFL_MASTER_WAIT, &r->res_flags);
+ break;
+
+ default:
+ log_error(r->res_ls, "confirm_master unknown error %d", error);
+ }
+}
+
+static int set_lock_args(int mode, struct dlm_lksb *lksb, uint32_t flags,
+ int namelen, uint32_t parent_lkid, void *ast,
+ void *astarg, void *bast, struct dlm_range *range,
+ struct dlm_args *args)
+{
+ int rv = -EINVAL;
+
+ /* check for invalid arg usage */
+
+ if (mode < 0 || mode > DLM_LOCK_EX)
+ goto out;
+
+ if (!(flags & DLM_LKF_CONVERT) && (namelen > DLM_RESNAME_MAXLEN))
+ goto out;
+
+ if (flags & DLM_LKF_CANCEL)
+ goto out;
+
+ if (flags & DLM_LKF_QUECVT && !(flags & DLM_LKF_CONVERT))
+ goto out;
+
+ if (flags & DLM_LKF_CONVDEADLK && !(flags & DLM_LKF_CONVERT))
+ goto out;
+
+ if (flags & DLM_LKF_CONVDEADLK && flags & DLM_LKF_NOQUEUE)
+ goto out;
+
+ if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_CONVERT)
+ goto out;
+
+ if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_QUECVT)
+ goto out;
+
+ if (flags & DLM_LKF_EXPEDITE && flags & DLM_LKF_NOQUEUE)
+ goto out;
+
+ if (flags & DLM_LKF_EXPEDITE && mode != DLM_LOCK_NL)
+ goto out;
+
+ if (!ast || !lksb)
+ goto out;
+
+ if (flags & DLM_LKF_VALBLK && !lksb->sb_lvbptr)
+ goto out;
+
+ /* parent/child locks not yet supported */
+ if (parent_lkid)
+ goto out;
+
+ if (flags & DLM_LKF_CONVERT && !lksb->sb_lkid)
+ goto out;
+
+ /* these args will be copied to the lkb in validate_lock_args,
+ it cannot be done now because when converting locks, fields in
+ an active lkb cannot be modified before locking the rsb */
+
+ args->flags = flags;
+ args->astaddr = ast;
+ args->astparam = (long) astarg;
+ args->bastaddr = bast;
+ args->mode = mode;
+ args->lksb = lksb;
+ args->range = range;
+ rv = 0;
+ out:
+ return rv;
+}
+
+static int set_unlock_args(uint32_t flags, void *astarg, struct dlm_args *args)
+{
+ if (flags & ~(DLM_LKF_CANCEL | DLM_LKF_VALBLK | DLM_LKF_IVVALBLK))
+ return -EINVAL;
+
+ args->flags = flags;
+ args->astparam = (long) astarg;
+ return 0;
+}
+
+int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_args *args)
+{
+ int rv = -EINVAL;
+
+ if (args->flags & DLM_LKF_CONVERT) {
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY)
+ goto out;
+
+ if (args->flags & DLM_LKF_QUECVT &&
+ !__quecvt_compat_matrix[lkb->lkb_grmode+1][args->mode+1])
+ goto out;
+
+ rv = -EBUSY;
+ if (lkb->lkb_status != DLM_LKSTS_GRANTED)
+ goto out;
+
+ if (lkb->lkb_wait_type)
+ goto out;
+ }
+
+ lkb->lkb_exflags = args->flags;
+ lkb->lkb_sbflags = 0;
+ lkb->lkb_astaddr = args->astaddr;
+ lkb->lkb_astparam = args->astparam;
+ lkb->lkb_bastaddr = args->bastaddr;
+ lkb->lkb_rqmode = args->mode;
+ lkb->lkb_lksb = args->lksb;
+ lkb->lkb_lvbptr = args->lksb->sb_lvbptr;
+ lkb->lkb_ownpid = (int) current->pid;
+
+ rv = 0;
+ if (!args->range)
+ goto out;
+
+ if (!lkb->lkb_range) {
+ rv = -ENOMEM;
+ lkb->lkb_range = allocate_range(ls);
+ if (!lkb->lkb_range)
+ goto out;
+ /* This is needed for conversions that contain ranges
+ where the original lock didn't but it's harmless for
+ new locks too. */
+ lkb->lkb_range[GR_RANGE_START] = 0LL;
+ lkb->lkb_range[GR_RANGE_END] = 0xffffffffffffffffULL;
+ }
+
+ lkb->lkb_range[RQ_RANGE_START] = args->range->ra_start;
+ lkb->lkb_range[RQ_RANGE_END] = args->range->ra_end;
+ lkb->lkb_flags |= DLM_IFL_RANGE;
+ rv = 0;
+ out:
+ return rv;
+}
+
+int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
+{
+ int rv = -EINVAL;
+
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY)
+ goto out;
+
+ if (args->flags & DLM_LKF_CANCEL &&
+ lkb->lkb_status == DLM_LKSTS_GRANTED)
+ goto out;
+
+ if (!(args->flags & DLM_LKF_CANCEL) &&
+ lkb->lkb_status != DLM_LKSTS_GRANTED)
+ goto out;
+
+ rv = -EBUSY;
+ if (lkb->lkb_wait_type)
+ goto out;
+
+ lkb->lkb_exflags = args->flags;
+ lkb->lkb_sbflags = 0;
+ lkb->lkb_astparam = args->astparam;
+ rv = 0;
+ out:
+ return rv;
+}
+
+/*
+ * Four stage 4 varieties:
+ * do_request(), do_convert(), do_unlock(), do_cancel()
+ * These are called on the master node for the given lock and
+ * from the central locking logic.
+ */
+
+static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error = 0;
+
+ if (can_be_granted(r, lkb, TRUE)) {
+ grant_lock(r, lkb);
+ queue_cast(r, lkb, 0);
+ goto out;
+ }
+
+ if (can_be_queued(lkb)) {
+ error = -EINPROGRESS;
+ add_lkb(r, lkb, DLM_LKSTS_WAITING);
+ send_blocking_asts(r, lkb);
+ goto out;
+ }
+
+ error = -EAGAIN;
+ if (force_blocking_asts(lkb))
+ send_blocking_asts_all(r, lkb);
+ queue_cast(r, lkb, -EAGAIN);
+
+ out:
+ return error;
+}
+
+static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error = 0;
+
+ /* changing an existing lock may allow others to be granted */
+
+ if (can_be_granted(r, lkb, TRUE)) {
+ grant_lock(r, lkb);
+ queue_cast(r, lkb, 0);
+ grant_pending_locks(r);
+ goto out;
+ }
+
+ if (can_be_queued(lkb)) {
+ if (is_demoted(lkb))
+ grant_pending_locks(r);
+ error = -EINPROGRESS;
+ del_lkb(r, lkb);
+ add_lkb(r, lkb, DLM_LKSTS_CONVERT);
+ send_blocking_asts(r, lkb);
+ goto out;
+ }
+
+ error = -EAGAIN;
+ if (force_blocking_asts(lkb))
+ send_blocking_asts_all(r, lkb);
+ queue_cast(r, lkb, -EAGAIN);
+
+ out:
+ return error;
+}
+
+static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ remove_lock(r, lkb);
+ queue_cast(r, lkb, -DLM_EUNLOCK);
+ grant_pending_locks(r);
+ return -DLM_EUNLOCK;
+}
+
+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;
+}
+
+/*
+ * Four stage 3 varieties:
+ * _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
+ */
+
+/* add a new lkb to a possibly new rsb, called by requesting process */
+
+static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error;
+
+ /* set_master: sets lkb nodeid from r */
+
+ error = set_master(r, lkb);
+ if (error < 0)
+ goto out;
+ if (error) {
+ error = 0;
+ goto out;
+ }
+
+ if (is_remote(r))
+ /* receive_request() calls do_request() on remote node */
+ error = send_request(r, lkb);
+ else
+ error = do_request(r, lkb);
+ out:
+ return error;
+}
+
+/* change some property of an existing lkb, e.g. mode, range */
+
+static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error;
+
+ if (is_remote(r))
+ /* receive_convert() calls do_convert() on remote node */
+ error = send_convert(r, lkb);
+ else
+ error = do_convert(r, lkb);
+
+ return error;
+}
+
+/* remove an existing lkb from the granted queue */
+
+static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error;
+
+ if (is_remote(r))
+ /* receive_unlock() calls do_unlock() on remote node */
+ error = send_unlock(r, lkb);
+ else
+ error = do_unlock(r, lkb);
+
+ return error;
+}
+
+/* remove an existing lkb from the convert or wait queue */
+
+static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error;
+
+ if (is_remote(r))
+ /* receive_cancel() calls do_cancel() on remote node */
+ error = send_cancel(r, lkb);
+ else
+ error = do_cancel(r, lkb);
+
+ return error;
+}
+
+/*
+ * Four stage 2 varieties:
+ * request_lock(), convert_lock(), unlock_lock(), cancel_lock()
+ */
+
+static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name,
+ int len, struct dlm_args *args)
+{
+ struct dlm_rsb *r;
+ int error;
+
+ error = validate_lock_args(ls, lkb, args);
+ if (error)
+ goto out;
+
+ error = find_rsb(ls, name, len, R_CREATE, &r);
+ if (error)
+ goto out;
+
+ lock_rsb(r);
+
+ attach_lkb(r, lkb);
+ lkb->lkb_lksb->sb_lkid = lkb->lkb_id;
+
+ error = _request_lock(r, lkb);
+
+ unlock_rsb(r);
+ put_rsb(r);
+
+ out:
+ return error;
+}
+
+static int convert_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_args *args)
+{
+ struct dlm_rsb *r;
+ int error;
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ error = validate_lock_args(ls, lkb, args);
+ if (error)
+ goto out;
+
+ error = _convert_lock(r, lkb);
+ out:
+ unlock_rsb(r);
+ put_rsb(r);
+ return error;
+}
+
+static int unlock_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_args *args)
+{
+ struct dlm_rsb *r;
+ int error;
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ error = validate_unlock_args(lkb, args);
+ if (error)
+ goto out;
+
+ error = _unlock_lock(r, lkb);
+ out:
+ unlock_rsb(r);
+ put_rsb(r);
+ return error;
+}
+
+static int cancel_lock(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_args *args)
+{
+ struct dlm_rsb *r;
+ int error;
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ error = validate_unlock_args(lkb, args);
+ if (error)
+ goto out;
+
+ error = _cancel_lock(r, lkb);
+ out:
+ unlock_rsb(r);
+ put_rsb(r);
+ return error;
+}
+
+/*
+ * Two stage 1 varieties: dlm_lock() and dlm_unlock()
+ */
+
+int dlm_lock(dlm_lockspace_t *lockspace,
+ int mode,
+ struct dlm_lksb *lksb,
+ uint32_t flags,
+ void *name,
+ unsigned int namelen,
+ uint32_t parent_lkid,
+ void (*ast) (void *astarg),
+ void *astarg,
+ void (*bast) (void *astarg, int mode),
+ struct dlm_range *range)
+{
+ struct dlm_ls *ls;
+ struct dlm_lkb *lkb;
+ struct dlm_args args;
+ int error, convert = flags & DLM_LKF_CONVERT;
+
+ ls = dlm_find_lockspace_local(lockspace);
+ if (!ls)
+ return -EINVAL;
+
+ lock_recovery(ls);
+
+ if (convert)
+ error = find_lkb(ls, lksb->sb_lkid, &lkb);
+ else
+ error = create_lkb(ls, &lkb);
+
+ if (error)
+ goto out;
+
+ error = set_lock_args(mode, lksb, flags, namelen, parent_lkid, ast,
+ astarg, bast, range, &args);
+ if (error)
+ goto out_put;
+
+ if (convert)
+ error = convert_lock(ls, lkb, &args);
+ else
+ error = request_lock(ls, lkb, name, namelen, &args);
+
+ if (error == -EINPROGRESS)
+ error = 0;
+ out_put:
+ if (convert || error)
+ put_lkb(lkb);
+ if (error == -EAGAIN)
+ error = 0;
+ out:
+ unlock_recovery(ls);
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+int dlm_unlock(dlm_lockspace_t *lockspace,
+ uint32_t lkid,
+ uint32_t flags,
+ struct dlm_lksb *lksb,
+ void *astarg)
+{
+ struct dlm_ls *ls;
+ struct dlm_lkb *lkb;
+ struct dlm_args args;
+ int error;
+
+ ls = dlm_find_lockspace_local(lockspace);
+ if (!ls)
+ return -EINVAL;
+
+ lock_recovery(ls);
+
+ error = find_lkb(ls, lkid, &lkb);
+ if (error)
+ goto out;
+
+ error = set_unlock_args(flags, astarg, &args);
+ if (error)
+ goto out_put;
+
+ if (flags & DLM_LKF_CANCEL)
+ error = cancel_lock(ls, lkb, &args);
+ else
+ error = unlock_lock(ls, lkb, &args);
+
+ if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
+ error = 0;
+ out_put:
+ put_lkb(lkb);
+ out:
+ unlock_recovery(ls);
+ dlm_put_lockspace(ls);
+ return error;
+}
+
+/*
+ * send/receive routines for remote operations and replies
+ *
+ * send_args
+ * send_common
+ * send_request receive_request
+ * send_convert receive_convert
+ * send_unlock receive_unlock
+ * send_cancel receive_cancel
+ * send_grant receive_grant
+ * send_bast receive_bast
+ * send_lookup receive_lookup
+ * send_remove receive_remove
+ *
+ * send_common_reply
+ * receive_request_reply send_request_reply
+ * receive_convert_reply send_convert_reply
+ * receive_unlock_reply send_unlock_reply
+ * receive_cancel_reply send_cancel_reply
+ * receive_lookup_reply send_lookup_reply
+ */
+
+static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ int to_nodeid, int mstype,
+ struct dlm_message **ms_ret,
+ struct dlm_mhandle **mh_ret)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ char *mb;
+ int mb_len = sizeof(struct dlm_message);
+
+ switch (mstype) {
+ case DLM_MSG_REQUEST:
+ case DLM_MSG_LOOKUP:
+ case DLM_MSG_REMOVE:
+ mb_len += r->res_length;
+ break;
+ case DLM_MSG_CONVERT:
+ case DLM_MSG_UNLOCK:
+ case DLM_MSG_REQUEST_REPLY:
+ case DLM_MSG_CONVERT_REPLY:
+ case DLM_MSG_GRANT:
+ if (lkb && lkb->lkb_lvbptr)
+ mb_len += r->res_ls->ls_lvblen;
+ break;
+ }
+
+ /* get_buffer gives us a message handle (mh) that we need to
+ pass into lowcomms_commit and a message buffer (mb) that we
+ write our data into */
+
+ mh = dlm_lowcomms_get_buffer(to_nodeid, mb_len, GFP_KERNEL, &mb);
+ if (!mh)
+ return -ENOBUFS;
+
+ memset(mb, 0, mb_len);
+
+ ms = (struct dlm_message *) mb;
+
+ ms->m_header.h_version = (DLM_HEADER_MAJOR | DLM_HEADER_MINOR);
+ ms->m_header.h_lockspace = r->res_ls->ls_global_id;
+ ms->m_header.h_nodeid = dlm_our_nodeid();
+ ms->m_header.h_length = mb_len;
+ ms->m_header.h_cmd = DLM_MSG;
+
+ ms->m_type = mstype;
+
+ *mh_ret = mh;
+ *ms_ret = ms;
+ return 0;
+}
+
+/* further lowcomms enhancements or alternate implementations may make
+ the return value from this function useful at some point */
+
+static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
+{
+ dlm_message_out(ms);
+ dlm_lowcomms_commit_buffer(mh);
+ return 0;
+}
+
+static void send_args(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ ms->m_nodeid = lkb->lkb_nodeid;
+ ms->m_pid = lkb->lkb_ownpid;
+ ms->m_lkid = lkb->lkb_id;
+ ms->m_remid = lkb->lkb_remid;
+ ms->m_exflags = lkb->lkb_exflags;
+ ms->m_sbflags = lkb->lkb_sbflags;
+ ms->m_flags = lkb->lkb_flags;
+ ms->m_lvbseq = lkb->lkb_lvbseq;
+ ms->m_status = lkb->lkb_status;
+ ms->m_grmode = lkb->lkb_grmode;
+ ms->m_rqmode = lkb->lkb_rqmode;
+
+ /* m_result and m_bastmode are set from function args,
+ not from lkb fields */
+
+ if (lkb->lkb_bastaddr)
+ ms->m_asts |= AST_BAST;
+ if (lkb->lkb_astaddr)
+ ms->m_asts |= AST_COMP;
+
+ if (lkb->lkb_range) {
+ ms->m_range[0] = lkb->lkb_range[RQ_RANGE_START];
+ ms->m_range[1] = lkb->lkb_range[RQ_RANGE_END];
+ }
+
+ if (ms->m_type == DLM_MSG_REQUEST || ms->m_type == DLM_MSG_LOOKUP)
+ memcpy(ms->m_extra, r->res_name, r->res_length);
+
+ else if (lkb->lkb_lvbptr)
+ memcpy(ms->m_extra, lkb->lkb_lvbptr, r->res_ls->ls_lvblen);
+
+}
+
+static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ add_to_waiters(lkb, mstype);
+
+ to_nodeid = r->res_nodeid;
+
+ error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
+ if (error)
+ goto fail;
+
+ send_args(r, lkb, ms);
+
+ error = send_message(mh, ms);
+ if (error)
+ goto fail;
+ return 0;
+
+ fail:
+ remove_from_waiters(lkb);
+ return error;
+}
+
+static int send_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ return send_common(r, lkb, DLM_MSG_REQUEST);
+}
+
+static int send_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ int error;
+
+ error = send_common(r, lkb, DLM_MSG_CONVERT);
+
+ /* down conversions go without a reply from the master */
+ if (!error && down_conversion(lkb)) {
+ remove_from_waiters(lkb);
+ r->res_ls->ls_stub_ms.m_result = 0;
+ __receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
+ }
+
+ return error;
+}
+
+/* FIXME: if this lkb is the only lock we hold on the rsb, then set
+ MASTER_UNCERTAIN to force the next request on the rsb to confirm
+ that the master is still correct. */
+
+static int send_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ return send_common(r, lkb, DLM_MSG_UNLOCK);
+}
+
+static int send_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ return send_common(r, lkb, DLM_MSG_CANCEL);
+}
+
+static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ to_nodeid = lkb->lkb_nodeid;
+
+ error = create_message(r, lkb, to_nodeid, DLM_MSG_GRANT, &ms, &mh);
+ if (error)
+ goto out;
+
+ send_args(r, lkb, ms);
+
+ ms->m_result = 0;
+
+ error = send_message(mh, ms);
+ out:
+ return error;
+}
+
+static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ to_nodeid = lkb->lkb_nodeid;
+
+ error = create_message(r, NULL, to_nodeid, DLM_MSG_BAST, &ms, &mh);
+ if (error)
+ goto out;
+
+ send_args(r, lkb, ms);
+
+ ms->m_bastmode = mode;
+
+ error = send_message(mh, ms);
+ out:
+ return error;
+}
+
+static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ add_to_waiters(lkb, DLM_MSG_LOOKUP);
+
+ to_nodeid = dlm_dir_nodeid(r);
+
+ error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
+ if (error)
+ goto fail;
+
+ send_args(r, lkb, ms);
+
+ error = send_message(mh, ms);
+ if (error)
+ goto fail;
+ return 0;
+
+ fail:
+ remove_from_waiters(lkb);
+ return error;
+}
+
+static int send_remove(struct dlm_rsb *r)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ to_nodeid = dlm_dir_nodeid(r);
+
+ error = create_message(r, NULL, to_nodeid, DLM_MSG_REMOVE, &ms, &mh);
+ if (error)
+ goto out;
+
+ memcpy(ms->m_extra, r->res_name, r->res_length);
+
+ error = send_message(mh, ms);
+ out:
+ return error;
+}
+
+static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
+ int mstype, int rv)
+{
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int to_nodeid, error;
+
+ to_nodeid = lkb->lkb_nodeid;
+
+ error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
+ if (error)
+ goto out;
+
+ send_args(r, lkb, ms);
+
+ ms->m_result = rv;
+
+ error = send_message(mh, ms);
+ out:
+ return error;
+}
+
+static int send_request_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
+{
+ return send_common_reply(r, lkb, DLM_MSG_REQUEST_REPLY, rv);
+}
+
+static int send_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
+{
+ return send_common_reply(r, lkb, DLM_MSG_CONVERT_REPLY, rv);
+}
+
+static int send_unlock_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
+{
+ return send_common_reply(r, lkb, DLM_MSG_UNLOCK_REPLY, rv);
+}
+
+static int send_cancel_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
+{
+ return send_common_reply(r, lkb, DLM_MSG_CANCEL_REPLY, rv);
+}
+
+static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
+ int ret_nodeid, int rv)
+{
+ struct dlm_rsb *r = &ls->ls_stub_rsb;
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ int error, nodeid = ms_in->m_header.h_nodeid;
+
+ error = create_message(r, NULL, nodeid, DLM_MSG_LOOKUP_REPLY, &ms, &mh);
+ if (error)
+ goto out;
+
+ ms->m_lkid = ms_in->m_lkid;
+ ms->m_result = rv;
+ ms->m_nodeid = ret_nodeid;
+
+ error = send_message(mh, ms);
+ out:
+ return error;
+}
+
+/* which args we save from a received message depends heavily on the type
+ of message, unlike the send side where we can safely send everything about
+ the lkb for any type of message */
+
+static void receive_flags(struct dlm_lkb *lkb, struct dlm_message *ms)
+{
+ lkb->lkb_exflags = ms->m_exflags;
+ lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
+ (ms->m_flags & 0x0000FFFF);
+}
+
+static void receive_flags_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
+{
+ lkb->lkb_sbflags = ms->m_sbflags;
+ lkb->lkb_flags = (lkb->lkb_flags & 0xFFFF0000) |
+ (ms->m_flags & 0x0000FFFF);
+}
+
+static int receive_extralen(struct dlm_message *ms)
+{
+ return (ms->m_header.h_length - sizeof(struct dlm_message));
+}
+
+static int receive_range(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ if (lkb->lkb_flags & DLM_IFL_RANGE) {
+ if (!lkb->lkb_range)
+ lkb->lkb_range = allocate_range(ls);
+ if (!lkb->lkb_range)
+ return -ENOMEM;
+ lkb->lkb_range[RQ_RANGE_START] = ms->m_range[0];
+ lkb->lkb_range[RQ_RANGE_END] = ms->m_range[1];
+ }
+ return 0;
+}
+
+static int receive_lvb(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ int len;
+
+ if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
+ if (!lkb->lkb_lvbptr)
+ lkb->lkb_lvbptr = allocate_lvb(ls);
+ if (!lkb->lkb_lvbptr)
+ return -ENOMEM;
+ len = receive_extralen(ms);
+ memcpy(lkb->lkb_lvbptr, ms->m_extra, len);
+ }
+ return 0;
+}
+
+static int receive_request_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ lkb->lkb_nodeid = ms->m_header.h_nodeid;
+ lkb->lkb_ownpid = ms->m_pid;
+ lkb->lkb_remid = ms->m_lkid;
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ lkb->lkb_rqmode = ms->m_rqmode;
+ lkb->lkb_bastaddr = (void *) (long) (ms->m_asts & AST_BAST);
+ lkb->lkb_astaddr = (void *) (long) (ms->m_asts & AST_COMP);
+
+ DLM_ASSERT(is_master_copy(lkb), dlm_print_lkb(lkb););
+
+ if (receive_range(ls, lkb, ms))
+ return -ENOMEM;
+
+ if (receive_lvb(ls, lkb, ms))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int receive_convert_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ if (lkb->lkb_nodeid != ms->m_header.h_nodeid) {
+ log_error(ls, "convert_args nodeid %d %d lkid %x %x",
+ lkb->lkb_nodeid, ms->m_header.h_nodeid,
+ lkb->lkb_id, lkb->lkb_remid);
+ return -EINVAL;
+ }
+
+ if (!is_master_copy(lkb))
+ return -EINVAL;
+
+ if (lkb->lkb_status != DLM_LKSTS_GRANTED)
+ return -EBUSY;
+
+ if (receive_range(ls, lkb, ms))
+ return -ENOMEM;
+ if (lkb->lkb_range) {
+ lkb->lkb_range[GR_RANGE_START] = 0LL;
+ lkb->lkb_range[GR_RANGE_END] = 0xffffffffffffffffULL;
+ }
+
+ if (receive_lvb(ls, lkb, ms))
+ return -ENOMEM;
+
+ lkb->lkb_rqmode = ms->m_rqmode;
+ lkb->lkb_lvbseq = ms->m_lvbseq;
+
+ return 0;
+}
+
+static int receive_unlock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_message *ms)
+{
+ if (!is_master_copy(lkb))
+ return -EINVAL;
+ if (receive_lvb(ls, lkb, ms))
+ return -ENOMEM;
+ return 0;
+}
+
+/* We fill in the stub-lkb fields with the info that send_xxxx_reply()
+ uses to send a reply and that the remote end uses to process the reply. */
+
+static void setup_stub_lkb(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb = &ls->ls_stub_lkb;
+ lkb->lkb_nodeid = ms->m_header.h_nodeid;
+ lkb->lkb_remid = ms->m_lkid;
+}
+
+static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error, namelen;
+
+ error = create_lkb(ls, &lkb);
+ if (error)
+ goto fail;
+
+ receive_flags(lkb, ms);
+ lkb->lkb_flags |= DLM_IFL_MSTCPY;
+ error = receive_request_args(ls, lkb, ms);
+ if (error) {
+ put_lkb(lkb);
+ goto fail;
+ }
+
+ namelen = receive_extralen(ms);
+
+ error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
+ if (error) {
+ put_lkb(lkb);
+ goto fail;
+ }
+
+ lock_rsb(r);
+
+ attach_lkb(r, lkb);
+ error = do_request(r, lkb);
+ send_request_reply(r, lkb, error);
+
+ unlock_rsb(r);
+ put_rsb(r);
+
+ if (error == -EINPROGRESS)
+ error = 0;
+ if (error)
+ put_lkb(lkb);
+ return;
+
+ fail:
+ setup_stub_lkb(ls, ms);
+ send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
+}
+
+static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error, reply = TRUE;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error)
+ goto fail;
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ receive_flags(lkb, ms);
+ error = receive_convert_args(ls, lkb, ms);
+ if (error)
+ goto out;
+ reply = !down_conversion(lkb);
+
+ error = do_convert(r, lkb);
+ out:
+ if (reply)
+ send_convert_reply(r, lkb, error);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+ return;
+
+ fail:
+ setup_stub_lkb(ls, ms);
+ send_convert_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
+}
+
+static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error)
+ goto fail;
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ receive_flags(lkb, ms);
+ error = receive_unlock_args(ls, lkb, ms);
+ if (error)
+ goto out;
+
+ error = do_unlock(r, lkb);
+ out:
+ send_unlock_reply(r, lkb, error);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+ return;
+
+ fail:
+ setup_stub_lkb(ls, ms);
+ send_unlock_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
+}
+
+static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error)
+ goto fail;
+
+ receive_flags(lkb, ms);
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ error = do_cancel(r, lkb);
+ send_cancel_reply(r, lkb, error);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+ return;
+
+ fail:
+ setup_stub_lkb(ls, ms);
+ send_cancel_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
+}
+
+static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_grant no lkb");
+ return;
+ }
+ DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ receive_flags_reply(lkb, ms);
+ grant_lock_pc(r, lkb, ms);
+ queue_cast(r, lkb, 0);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+}
+
+static void receive_bast(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_bast no lkb");
+ return;
+ }
+ DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
+
+ r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ queue_bast(r, lkb, ms->m_bastmode);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+}
+
+static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
+
+ from_nodeid = ms->m_header.h_nodeid;
+ our_nodeid = dlm_our_nodeid();
+
+ len = receive_extralen(ms);
+
+ dir_nodeid = dlm_dir_name2nodeid(ls, ms->m_extra, len);
+ if (dir_nodeid != our_nodeid) {
+ log_error(ls, "lookup dir_nodeid %d from %d",
+ dir_nodeid, from_nodeid);
+ error = -EINVAL;
+ ret_nodeid = -1;
+ goto out;
+ }
+
+ error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
+
+ /* Optimization: we're master so treat lookup as a request */
+ if (!error && ret_nodeid == our_nodeid) {
+ receive_request(ls, ms);
+ return;
+ }
+ out:
+ send_lookup_reply(ls, ms, ret_nodeid, error);
+}
+
+static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ int len, dir_nodeid, from_nodeid;
+
+ from_nodeid = ms->m_header.h_nodeid;
+
+ len = receive_extralen(ms);
+
+ dir_nodeid = dlm_dir_name2nodeid(ls, ms->m_extra, len);
+ if (dir_nodeid != dlm_our_nodeid()) {
+ log_error(ls, "remove dir entry dir_nodeid %d from %d",
+ dir_nodeid, from_nodeid);
+ return;
+ }
+
+ dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
+}
+
+static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error, mstype;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_request_reply no lkb");
+ return;
+ }
+ 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);
+
+ /* 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) {
+ r->res_nodeid = ms->m_header.h_nodeid;
+ lkb->lkb_nodeid = r->res_nodeid;
+ r->res_trial_lkid = lkb->lkb_id;
+ }
+
+ switch (error) {
+ 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 */
+ queue_cast(r, lkb, -EAGAIN);
+ confirm_master(r, -EAGAIN);
+ unhold_lkb(lkb);
+ break;
+
+ case -EINPROGRESS:
+ case 0:
+ /* request was queued or granted on remote master */
+ receive_flags_reply(lkb, ms);
+ lkb->lkb_remid = ms->m_lkid;
+ if (error)
+ add_lkb(r, lkb, DLM_LKSTS_WAITING);
+ else {
+ grant_lock_pc(r, lkb, ms);
+ queue_cast(r, lkb, 0);
+ }
+ confirm_master(r, error);
+ break;
+
+ case -ENOENT:
+ case -ENOTBLK:
+ /* find_rsb failed to find rsb or rsb wasn't master */
+
+ DLM_ASSERT(test_bit(RESFL_MASTER_WAIT, &r->res_flags),
+ log_print("receive_request_reply error %d", error);
+ dlm_print_lkb(lkb);
+ dlm_print_rsb(r););
+
+ confirm_master(r, error);
+ lkb->lkb_nodeid = -1;
+ _request_lock(r, lkb);
+ break;
+
+ default:
+ log_error(ls, "receive_request_reply error %d", error);
+ }
+
+ unlock_rsb(r);
+ put_rsb(r);
+ out:
+ 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) {
+ case -EAGAIN:
+ /* convert would block (be queued) on remote master */
+ queue_cast(r, lkb, -EAGAIN);
+ break;
+
+ case -EINPROGRESS:
+ /* convert was queued on remote master */
+ del_lkb(r, lkb);
+ add_lkb(r, lkb, DLM_LKSTS_CONVERT);
+ break;
+
+ case 0:
+ /* convert was granted on remote master */
+ receive_flags_reply(lkb, ms);
+ grant_lock_pc(r, lkb, ms);
+ queue_cast(r, lkb, 0);
+ break;
+
+ default:
+ log_error(r->res_ls, "receive_convert_reply error %d", error);
+ }
+}
+
+static void _receive_convert_reply(struct dlm_lkb *lkb, struct dlm_message *ms)
+{
+ struct dlm_rsb *r = lkb->lkb_resource;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ __receive_convert_reply(r, lkb, ms);
+
+ unlock_rsb(r);
+ put_rsb(r);
+}
+
+static void receive_convert_reply(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_convert_reply no lkb");
+ return;
+ }
+ 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:
+ 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;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ /* this is the value returned from do_unlock() on the master */
+
+ switch (error) {
+ case -DLM_EUNLOCK:
+ receive_flags_reply(lkb, ms);
+ remove_lock_pc(r, lkb);
+ queue_cast(r, lkb, -DLM_EUNLOCK);
+ break;
+ default:
+ log_error(r->res_ls, "receive_unlock_reply error %d", error);
+ }
+
+ unlock_rsb(r);
+ put_rsb(r);
+}
+
+static void receive_unlock_reply(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_unlock_reply no lkb");
+ return;
+ }
+ 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:
+ 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;
+
+ hold_rsb(r);
+ lock_rsb(r);
+
+ /* this is the value returned from do_cancel() on the master */
+
+ switch (error) {
+ case -DLM_ECANCEL:
+ receive_flags_reply(lkb, ms);
+ revert_lock_pc(r, lkb);
+ queue_cast(r, lkb, -DLM_ECANCEL);
+ break;
+ default:
+ log_error(r->res_ls, "receive_cancel_reply error %d", error);
+ }
+
+ unlock_rsb(r);
+ put_rsb(r);
+}
+
+static void receive_cancel_reply(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ int error;
+
+ error = find_lkb(ls, ms->m_remid, &lkb);
+ if (error) {
+ log_error(ls, "receive_cancel_reply no lkb");
+ return;
+ }
+ 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:
+ put_lkb(lkb);
+}
+
+static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error, ret_nodeid;
+
+ error = find_lkb(ls, ms->m_lkid, &lkb);
+ if (error) {
+ log_error(ls, "receive_lookup_reply no lkb");
+ 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
+ FIXME: will a non-zero error ever be returned? */
+ error = ms->m_result;
+
+ r = lkb->lkb_resource;
+ hold_rsb(r);
+ lock_rsb(r);
+
+ ret_nodeid = ms->m_nodeid;
+ if (ret_nodeid == dlm_our_nodeid())
+ r->res_nodeid = ret_nodeid = 0;
+ else {
+ r->res_nodeid = ret_nodeid;
+ r->res_trial_lkid = lkb->lkb_id;
+ }
+
+ _request_lock(r, lkb);
+
+ if (!ret_nodeid)
+ confirm_master(r, 0);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ out:
+ put_lkb(lkb);
+}
+
+int dlm_receive_message(struct dlm_header *hd, int nodeid, int recovery)
+{
+ struct dlm_message *ms = (struct dlm_message *) hd;
+ struct dlm_ls *ls;
+ int error;
+
+ if (!recovery)
+ dlm_message_in(ms);
+
+ ls = dlm_find_lockspace_global(hd->h_lockspace);
+ if (!ls) {
+ log_print("drop message %d from %d for unknown lockspace %d",
+ ms->m_type, nodeid, hd->h_lockspace);
+ return -EINVAL;
+ }
+
+ /* recovery may have just ended leaving a bunch of backed-up requests
+ in the requestqueue; wait while dlm_recoverd clears them */
+
+ if (!recovery)
+ dlm_wait_requestqueue(ls);
+
+ /* recovery may have just started while there were a bunch of
+ in-flight requests -- save them in requestqueue to be processed
+ after recovery. we can't let dlm_recvd block on the recovery
+ lock. if dlm_recoverd is calling this function to clear the
+ requestqueue, it needs to be interrupted (-EINTR) if another
+ recovery operation is starting. */
+
+ while (1) {
+ if (!test_bit(LSFL_LS_RUN, &ls->ls_flags)) {
+ if (!recovery)
+ dlm_add_requestqueue(ls, nodeid, hd);
+ error = -EINTR;
+ goto out;
+ }
+
+ if (lock_recovery_try(ls))
+ break;
+ schedule();
+ }
+
+ switch (ms->m_type) {
+
+ /* messages sent to a master node */
+
+ case DLM_MSG_REQUEST:
+ receive_request(ls, ms);
+ break;
+
+ case DLM_MSG_CONVERT:
+ receive_convert(ls, ms);
+ break;
+
+ case DLM_MSG_UNLOCK:
+ receive_unlock(ls, ms);
+ break;
+
+ case DLM_MSG_CANCEL:
+ receive_cancel(ls, ms);
+ break;
+
+ /* messages sent from a master node (replies to above) */
+
+ case DLM_MSG_REQUEST_REPLY:
+ receive_request_reply(ls, ms);
+ break;
+
+ case DLM_MSG_CONVERT_REPLY:
+ receive_convert_reply(ls, ms);
+ break;
+
+ case DLM_MSG_UNLOCK_REPLY:
+ receive_unlock_reply(ls, ms);
+ break;
+
+ case DLM_MSG_CANCEL_REPLY:
+ receive_cancel_reply(ls, ms);
+ break;
+
+ /* messages sent from a master node (only two types of async msg) */
+
+ case DLM_MSG_GRANT:
+ receive_grant(ls, ms);
+ break;
+
+ case DLM_MSG_BAST:
+ receive_bast(ls, ms);
+ break;
+
+ /* messages sent to a dir node */
+
+ case DLM_MSG_LOOKUP:
+ receive_lookup(ls, ms);
+ break;
+
+ case DLM_MSG_REMOVE:
+ receive_remove(ls, ms);
+ break;
+
+ /* messages sent from a dir node (remove has no reply) */
+
+ case DLM_MSG_LOOKUP_REPLY:
+ receive_lookup_reply(ls, ms);
+ break;
+
+ default:
+ log_error(ls, "unknown message type %d", ms->m_type);
+ }
+
+ unlock_recovery(ls);
+ out:
+ dlm_put_lockspace(ls);
+ dlm_astd_wake();
+ return 0;
+}
+
+
+/*
+ * Recovery related
+ */
+
+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_result = -EINPROGRESS;
+ _remove_from_waiters(lkb);
+ _receive_convert_reply(lkb, &ls->ls_stub_ms);
+
+ /* Same special case as in receive_rcom_lock_args() */
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ set_bit(RESFL_RECOVER_CONVERT, &lkb->lkb_resource->res_flags);
+ unhold_lkb(lkb);
+
+ } else if (lkb->lkb_rqmode >= lkb->lkb_grmode) {
+ lkb->lkb_flags |= DLM_IFL_RESEND;
+ }
+
+ /* lkb->lkb_rqmode < lkb->lkb_grmode shouldn't happen since down
+ conversions are async; there's no reply from the remote master */
+}
+
+/* Recovery for locks that are waiting for replies from nodes that are now
+ gone. We can just complete unlocks and cancels by faking a reply from the
+ dead node. Requests and up-conversions we flag to be resent after
+ recovery. Down-conversions can just be completed with a fake reply like
+ unlocks. Conversions between PR and CW need special attention. */
+
+void dlm_recover_waiters_pre(struct dlm_ls *ls)
+{
+ struct dlm_lkb *lkb, *safe;
+
+ down(&ls->ls_waiters_sem);
+
+ list_for_each_entry_safe(lkb, safe, &ls->ls_waiters, lkb_wait_reply) {
+ if (!dlm_is_removed(ls, lkb->lkb_nodeid))
+ continue;
+
+ log_debug(ls, "pre recover waiter lkid %x type %d flags %x",
+ lkb->lkb_id, lkb->lkb_wait_type, lkb->lkb_flags);
+
+ switch (lkb->lkb_wait_type) {
+
+ case DLM_MSG_REQUEST:
+ lkb->lkb_flags |= DLM_IFL_RESEND;
+ break;
+
+ case DLM_MSG_CONVERT:
+ recover_convert_waiter(ls, lkb);
+ break;
+
+ case DLM_MSG_UNLOCK:
+ hold_lkb(lkb);
+ ls->ls_stub_ms.m_result = -DLM_EUNLOCK;
+ _remove_from_waiters(lkb);
+ _receive_unlock_reply(lkb, &ls->ls_stub_ms);
+ put_lkb(lkb);
+ break;
+
+ case DLM_MSG_CANCEL:
+ hold_lkb(lkb);
+ ls->ls_stub_ms.m_result = -DLM_ECANCEL;
+ _remove_from_waiters(lkb);
+ _receive_cancel_reply(lkb, &ls->ls_stub_ms);
+ put_lkb(lkb);
+ break;
+
+ case DLM_MSG_LOOKUP:
+ /* all outstanding lookups, regardless of dest.
+ will be resent after recovery is done */
+ break;
+
+ default:
+ log_error(ls, "invalid lkb wait_type %d",
+ lkb->lkb_wait_type);
+ }
+ }
+ up(&ls->ls_waiters_sem);
+}
+
+static int remove_resend_waiter(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
+{
+ struct dlm_lkb *lkb;
+ int rv = 0;
+
+ down(&ls->ls_waiters_sem);
+ 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;
+ break;
+ }
+ }
+ up(&ls->ls_waiters_sem);
+
+ if (!rv)
+ lkb = NULL;
+ *lkb_ret = lkb;
+ return rv;
+}
+
+/* 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. */
+
+int dlm_recover_waiters_post(struct dlm_ls *ls)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_rsb *r;
+ int error = 0, mstype;
+
+ while (1) {
+ if (!test_bit(LSFL_LS_RUN, &ls->ls_flags)) {
+ log_debug(ls, "recover_waiters_post aborted");
+ error = -EINTR;
+ break;
+ }
+
+ mstype = remove_resend_waiter(ls, &lkb);
+ if (!mstype)
+ break;
+
+ r = lkb->lkb_resource;
+
+ 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:
+ case DLM_MSG_REQUEST:
+ hold_rsb(r);
+ lock_rsb(r);
+ _request_lock(r, lkb);
+ 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);
+ }
+ }
+
+ return error;
+}
+
+static void purge_queue(struct dlm_rsb *r, struct list_head *queue,
+ int (*test)(struct dlm_ls *ls, struct dlm_lkb *lkb))
+{
+ struct dlm_ls *ls = r->res_ls;
+ struct dlm_lkb *lkb, *safe;
+
+ list_for_each_entry_safe(lkb, safe, queue, lkb_statequeue) {
+ if (test(ls, lkb)) {
+ del_lkb(r, lkb);
+ /* this put should free the lkb */
+ if (!put_lkb(lkb))
+ log_error(ls, "purged lkb not released");
+ }
+ }
+}
+
+static int purge_dead_test(struct dlm_ls *ls, struct dlm_lkb *lkb)
+{
+ return (is_master_copy(lkb) && dlm_is_removed(ls, lkb->lkb_nodeid));
+}
+
+static void purge_dead_locks(struct dlm_rsb *r)
+{
+ purge_queue(r, &r->res_grantqueue, &purge_dead_test);
+ purge_queue(r, &r->res_convertqueue, &purge_dead_test);
+ purge_queue(r, &r->res_waitqueue, &purge_dead_test);
+}
+
+/* Get rid of locks held by nodes that are gone. */
+
+int dlm_purge_locks(struct dlm_ls *ls)
+{
+ struct dlm_rsb *r;
+
+ log_debug(ls, "dlm_purge_locks");
+
+ down_write(&ls->ls_root_sem);
+ list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
+ hold_rsb(r);
+ lock_rsb(r);
+ if (is_master(r))
+ purge_dead_locks(r);
+ unlock_rsb(r);
+ unhold_rsb(r);
+
+ schedule();
+ }
+ up_write(&ls->ls_root_sem);
+
+ return 0;
+}
+
+int 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);
+ }
+ read_unlock(&ls->ls_rsbtbl[i].lock);
+ }
+
+ return 0;
+}
+
+static struct dlm_lkb *search_remid_list(struct list_head *head, int nodeid,
+ uint32_t remid)
+{
+ struct dlm_lkb *lkb;
+
+ list_for_each_entry(lkb, head, lkb_statequeue) {
+ if (lkb->lkb_nodeid == nodeid && lkb->lkb_remid == remid)
+ return lkb;
+ }
+ return NULL;
+}
+
+static struct dlm_lkb *search_remid(struct dlm_rsb *r, int nodeid,
+ uint32_t remid)
+{
+ struct dlm_lkb *lkb;
+
+ lkb = search_remid_list(&r->res_grantqueue, nodeid, remid);
+ if (lkb)
+ return lkb;
+ lkb = search_remid_list(&r->res_convertqueue, nodeid, remid);
+ if (lkb)
+ return lkb;
+ lkb = search_remid_list(&r->res_waitqueue, nodeid, remid);
+ if (lkb)
+ return lkb;
+ return NULL;
+}
+
+static int receive_rcom_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb,
+ struct dlm_rsb *r, struct dlm_rcom *rc)
+{
+ struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
+ int lvblen;
+
+ lkb->lkb_nodeid = rc->rc_header.h_nodeid;
+ lkb->lkb_ownpid = rl->rl_ownpid;
+ lkb->lkb_remid = rl->rl_lkid;
+ lkb->lkb_exflags = rl->rl_exflags;
+ lkb->lkb_flags = rl->rl_flags & 0x0000FFFF;
+ lkb->lkb_flags |= DLM_IFL_MSTCPY;
+ lkb->lkb_lvbseq = rl->rl_lvbseq;
+ lkb->lkb_rqmode = rl->rl_rqmode;
+ lkb->lkb_grmode = rl->rl_grmode;
+ /* don't set lkb_status because add_lkb wants to itself */
+
+ lkb->lkb_bastaddr = (void *) (long) (rl->rl_asts & AST_BAST);
+ lkb->lkb_astaddr = (void *) (long) (rl->rl_asts & AST_COMP);
+
+ if (lkb->lkb_flags & DLM_IFL_RANGE) {
+ lkb->lkb_range = allocate_range(ls);
+ if (!lkb->lkb_range)
+ return -ENOMEM;
+ memcpy(lkb->lkb_range, rl->rl_range, 4*sizeof(uint64_t));
+ }
+
+ if (lkb->lkb_exflags & DLM_LKF_VALBLK) {
+ lkb->lkb_lvbptr = allocate_lvb(ls);
+ if (!lkb->lkb_lvbptr)
+ return -ENOMEM;
+ lvblen = rc->rc_header.h_length - sizeof(struct dlm_rcom) -
+ sizeof(struct rcom_lock);
+ memcpy(lkb->lkb_lvbptr, rl->rl_lvb, lvblen);
+ }
+
+ /* Conversions between PR and CW (middle modes) need special handling.
+ The real granted mode of these converting locks cannot be determined
+ until all locks have been rebuilt on the rsb (recover_conversion) */
+
+ if (rl->rl_wait_type == DLM_MSG_CONVERT && middle_conversion(lkb)) {
+ rl->rl_status = DLM_LKSTS_CONVERT;
+ lkb->lkb_grmode = DLM_LOCK_IV;
+ set_bit(RESFL_RECOVER_CONVERT, &r->res_flags);
+ }
+
+ return 0;
+}
+
+/* This lkb may have been recovered in a previous aborted recovery so we need
+ to check if the rsb already has an lkb with the given remote nodeid/lkid.
+ If so we just send back a standard reply. If not, we create a new lkb with
+ the given values and send back our lkid. We send back our lkid by sending
+ back the rcom_lock struct we got but with the remid field filled in. */
+
+int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
+{
+ struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
+ struct dlm_rsb *r;
+ struct dlm_lkb *lkb;
+ int error;
+
+ if (rl->rl_parent_lkid) {
+ error = -EOPNOTSUPP;
+ goto out;
+ }
+
+ error = find_rsb(ls, rl->rl_name, rl->rl_namelen, R_MASTER, &r);
+ if (error)
+ goto out;
+
+ lock_rsb(r);
+
+ lkb = search_remid(r, rc->rc_header.h_nodeid, rl->rl_lkid);
+ if (lkb) {
+ error = -EEXIST;
+ goto out_remid;
+ }
+
+ error = create_lkb(ls, &lkb);
+ if (error)
+ goto out_unlock;
+
+ error = receive_rcom_lock_args(ls, lkb, r, rc);
+ if (error) {
+ put_lkb(lkb);
+ goto out_unlock;
+ }
+
+ attach_lkb(r, lkb);
+ add_lkb(r, lkb, rl->rl_status);
+ error = 0;
+
+ out_remid:
+ /* this is the new value returned to the lock holder for
+ saving in its process-copy lkb */
+ rl->rl_remid = lkb->lkb_id;
+
+ out_unlock:
+ unlock_rsb(r);
+ put_rsb(r);
+ out:
+ if (error)
+ log_print("recover_master_copy %d %x", error, rl->rl_lkid);
+ rl->rl_result = error;
+ return error;
+}
+
+int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc)
+{
+ struct rcom_lock *rl = (struct rcom_lock *) rc->rc_buf;
+ struct dlm_rsb *r;
+ struct dlm_lkb *lkb;
+ int error;
+
+ error = find_lkb(ls, rl->rl_lkid, &lkb);
+ if (error) {
+ log_error(ls, "recover_process_copy no lkid %x", rl->rl_lkid);
+ return error;
+ }
+
+ DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););
+
+ error = rl->rl_result;
+
+ r = lkb->lkb_resource;
+ hold_rsb(r);
+ lock_rsb(r);
+
+ switch (error) {
+ case -EEXIST:
+ log_debug(ls, "master copy exists %x", lkb->lkb_id);
+ /* fall through */
+ case 0:
+ lkb->lkb_remid = rl->rl_remid;
+ break;
+ default:
+ log_error(ls, "dlm_recover_process_copy unknown error %d %x",
+ error, lkb->lkb_id);
+ }
+
+ /* an ack for dlm_recover_locks() which waits for replies from
+ all the locks it sends to new masters */
+ dlm_recovered_lock(r);
+
+ unlock_rsb(r);
+ put_rsb(r);
+ put_lkb(lkb);
+
+ return 0;
+}
+
--- a/drivers/dlm/lock.h 1970-01-01 07:30:00.000000000 +0730
+++ b/drivers/dlm/lock.h 2005-05-12 23:13:15.829485512 +0800
@@ -0,0 +1,51 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) 2005 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
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+#ifndef __LOCK_DOT_H__
+#define __LOCK_DOT_H__
+
+void dlm_print_lkb(struct dlm_lkb *lkb);
+void dlm_print_rsb(struct dlm_rsb *r);
+int dlm_receive_message(struct dlm_header *hd, int nodeid, int recovery);
+int dlm_modes_compat(int mode1, int mode2);
+int dlm_find_rsb(struct dlm_ls *ls, char *name, int namelen,
+ unsigned int flags, struct dlm_rsb **r_ret);
+void dlm_put_rsb(struct dlm_rsb *r);
+void dlm_hold_rsb(struct dlm_rsb *r);
+int dlm_put_lkb(struct dlm_lkb *lkb);
+int dlm_remove_from_waiters(struct dlm_lkb *lkb);
+void dlm_scan_rsbs(struct dlm_ls *ls);
+
+int dlm_purge_locks(struct dlm_ls *ls);
+int dlm_grant_after_purge(struct dlm_ls *ls);
+int dlm_recover_waiters_post(struct dlm_ls *ls);
+void dlm_recover_waiters_pre(struct dlm_ls *ls);
+int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
+int dlm_recover_process_copy(struct dlm_ls *ls, struct dlm_rcom *rc);
+
+static inline int is_master(struct dlm_rsb *r)
+{
+ return !r->res_nodeid;
+}
+
+static inline void lock_rsb(struct dlm_rsb *r)
+{
+ down(&r->res_sem);
+}
+
+static inline void unlock_rsb(struct dlm_rsb *r)
+{
+ up(&r->res_sem);
+}
+
+#endif
+