* Author: Peter Braam <braam@clusterfs.com>
* Author: Phil Schwan <phil@clusterfs.com>
*
- * This file is part of Lustre, http://www.lustre.org.
+ * This file is part of the Lustre file system, http://www.lustre.org
+ * Lustre is a trademark of Cluster File Systems, Inc.
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * You may have signed or agreed to another license before downloading
+ * this software. If so, you are bound by the terms and conditions
+ * of that agreement, and the following does not apply to you. See the
+ * LICENSE file included with this distribution for more information.
*
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * If you did not agree to a different license, then this copy of Lustre
+ * is open source software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * In either case, Lustre is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * license text for more details.
*/
#define DEBUG_SUBSYSTEM S_LDLM
# include <liblustre.h>
#endif
-#include <linux/lustre_dlm.h>
-#include <linux/obd_support.h>
-#include <linux/lustre_lib.h>
+#include <lustre_dlm.h>
+#include <obd_support.h>
+#include <lustre_lib.h>
#include "ldlm_internal.h"
+#define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
+
+/* fixup the ldlm_extent after expanding */
+static void ldlm_extent_internal_policy_fixup(struct ldlm_lock *req,
+ struct ldlm_extent *new_ex,
+ int conflicting)
+{
+ ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_start = req->l_req_extent.start;
+ __u64 req_end = req->l_req_extent.end;
+ __u64 req_align, mask;
+
+ if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) {
+ if (req_end < req_start + LDLM_MAX_GROWN_EXTENT)
+ new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT,
+ new_ex->end);
+ }
+
+ if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) {
+ EXIT;
+ return;
+ }
+
+ /* we need to ensure that the lock extent is properly aligned to what
+ * the client requested. We align it to the lowest-common denominator
+ * of the clients requested lock start and end alignment. */
+ mask = 0x1000ULL;
+ req_align = (req_end + 1) | req_start;
+ if (req_align != 0) {
+ while ((req_align & mask) == 0)
+ mask <<= 1;
+ }
+ mask -= 1;
+ /* We can only shrink the lock, not grow it.
+ * This should never cause lock to be smaller than requested,
+ * since requested lock was already aligned on these boundaries. */
+ new_ex->start = ((new_ex->start - 1) | mask) + 1;
+ new_ex->end = ((new_ex->end + 1) & ~mask) - 1;
+ LASSERTF(new_ex->start <= req_start,
+ "mask "LPX64" grant start "LPU64" req start "LPU64"\n",
+ mask, new_ex->start, req_start);
+ LASSERTF(new_ex->end >= req_end,
+ "mask "LPX64" grant end "LPU64" req end "LPU64"\n",
+ mask, new_ex->end, req_end);
+}
+
+/* The purpose of this function is to return:
+ * - the maximum extent
+ * - containing the requested extent
+ * - and not overlapping existing conflicting extents outside the requested one
+ *
+ * Use interval tree to expand the lock extent for granted lock.
+ */
+static void ldlm_extent_internal_policy_granted(struct ldlm_lock *req,
+ struct ldlm_extent *new_ex)
+{
+ struct ldlm_resource *res = req->l_resource;
+ ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_start = req->l_req_extent.start;
+ __u64 req_end = req->l_req_extent.end;
+ struct ldlm_interval_tree *tree;
+ struct interval_node_extent limiter = { new_ex->start, new_ex->end };
+ int conflicting = 0;
+ int idx;
+ ENTRY;
+
+ lockmode_verify(req_mode);
+
+ /* using interval tree to handle the ldlm extent granted locks */
+ for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+ struct interval_node_extent ext = { req_start, req_end };
+
+ tree = &res->lr_itree[idx];
+ if (lockmode_compat(tree->lit_mode, req_mode))
+ continue;
+
+ conflicting += tree->lit_size;
+ if (conflicting > 4)
+ limiter.start = req_start;
+
+ if (interval_is_overlapped(tree->lit_root, &ext))
+ printk("req_mode = %d, tree->lit_mode = %d, tree->lit_size = %d\n",
+ req_mode, tree->lit_mode, tree->lit_size);
+ interval_expand(tree->lit_root, &ext, &limiter);
+ limiter.start = max(limiter.start, ext.start);
+ limiter.end = min(limiter.end, ext.end);
+ if (limiter.start == req_start && limiter.end == req_end)
+ break;
+ }
+
+ new_ex->start = limiter.start;
+ new_ex->end = limiter.end;
+ LASSERT(new_ex->start <= req_start);
+ LASSERT(new_ex->end >= req_end);
+
+ ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
+ EXIT;
+}
+
/* The purpose of this function is to return:
* - the maximum extent
* - containing the requested extent
* - and not overlapping existing conflicting extents outside the requested one
*/
static void
-ldlm_extent_internal_policy(struct list_head *queue, struct ldlm_lock *req,
- struct ldlm_extent *new_ex)
+ldlm_extent_internal_policy_waiting(struct ldlm_lock *req,
+ struct ldlm_extent *new_ex)
{
struct list_head *tmp;
+ struct ldlm_resource *res = req->l_resource;
ldlm_mode_t req_mode = req->l_req_mode;
__u64 req_start = req->l_req_extent.start;
__u64 req_end = req->l_req_extent.end;
lockmode_verify(req_mode);
- list_for_each(tmp, queue) {
+ /* for waiting locks */
+ list_for_each(tmp, &res->lr_waiting) {
struct ldlm_lock *lock;
struct ldlm_extent *l_extent;
lock = list_entry(tmp, struct ldlm_lock, l_res_link);
l_extent = &lock->l_policy_data.l_extent;
+ /* We already hit the minimum requested size, search no more */
if (new_ex->start == req_start && new_ex->end == req_end) {
EXIT;
return;
new_ex->start = req_start;
/* If lock doesn't overlap new_ex, skip it. */
- if (l_extent->end < new_ex->start ||
- l_extent->start > new_ex->end)
+ if (!ldlm_extent_overlap(l_extent, new_ex))
continue;
/* Locks conflicting in requested extents and we can't satisfy
* both locks, so ignore it. Either we will ping-pong this
* extent (we would regardless of what extent we granted) or
* lock is unused and it shouldn't limit our extent growth. */
- if (lock->l_req_extent.end >= req_start &&
- lock->l_req_extent.start <= req_end)
+ if (ldlm_extent_overlap(&lock->l_req_extent,&req->l_req_extent))
continue;
/* We grow extents downwards only as far as they don't overlap
}
}
-#define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
- if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) {
- if (req_end < req_start + LDLM_MAX_GROWN_EXTENT)
- new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT,
- new_ex->end);
- }
+ ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
EXIT;
}
+
/* In order to determine the largest possible extent we can grant, we need
* to scan all of the queues. */
static void ldlm_extent_policy(struct ldlm_resource *res,
struct ldlm_lock *lock, int *flags)
{
- struct ldlm_extent new_ex = { .start = 0, .end = ~0};
+ struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF };
+
+ if (lock->l_export == NULL)
+ /*
+ * this is local lock taken by server (e.g., as a part of
+ * OST-side locking, or unlink handling). Expansion doesn't
+ * make a lot of sense for local locks, because they are
+ * dropped immediately on operation completion and would only
+ * conflict with other threads.
+ */
+ return;
- if (lock->l_req_mode == LCK_GROUP)
+ if (lock->l_policy_data.l_extent.start == 0 &&
+ lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
+ /* fast-path whole file locks */
return;
- ldlm_extent_internal_policy(&res->lr_granted, lock, &new_ex);
- ldlm_extent_internal_policy(&res->lr_waiting, lock, &new_ex);
+ ldlm_extent_internal_policy_granted(lock, &new_ex);
+ ldlm_extent_internal_policy_waiting(lock, &new_ex);
if (new_ex.start != lock->l_policy_data.l_extent.start ||
new_ex.end != lock->l_policy_data.l_extent.end) {
}
}
+struct ldlm_extent_compat_args {
+ struct list_head *work_list;
+ struct ldlm_lock *lock;
+ ldlm_mode_t mode;
+ int *compat;
+};
+
+static enum interval_iter ldlm_extent_compat_cb(struct interval_node *n,
+ void *data)
+{
+ struct ldlm_extent_compat_args *priv = data;
+ struct ldlm_interval *node = to_ldlm_interval(n);
+ struct list_head *work_list = priv->work_list;
+ struct ldlm_lock *lock, *enq = priv->lock;
+ ldlm_mode_t mode = priv->mode;
+ ENTRY;
+
+ LASSERT(!list_empty(&node->li_group));
+
+ list_for_each_entry(lock, &node->li_group, l_sl_policy) {
+ /* interval tree is for granted lock */
+ LASSERTF(mode == lock->l_granted_mode,
+ "mode = %s, lock->l_granted_mode = %s\n",
+ ldlm_lockname[mode],
+ ldlm_lockname[lock->l_granted_mode]);
+
+ if (lock->l_blocking_ast)
+ ldlm_add_ast_work_item(lock, enq, work_list);
+ }
+
+ if (priv->compat)
+ *priv->compat = 0;
+
+ RETURN(INTERVAL_ITER_CONT);
+}
+
/* Determine if the lock is compatible with all locks on the queue.
* We stop walking the queue if we hit ourselves so we don't take
* conflicting locks enqueued after us into accound, or we'd wait forever.
*/
static int
ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
- int *flags, struct list_head *work_list,
- struct list_head **insertp)
+ int *flags, ldlm_error_t *err,
+ struct list_head *work_list)
{
struct list_head *tmp;
- struct list_head *save = NULL;
- struct ldlm_lock *lock = NULL;
+ struct ldlm_lock *lock;
+ struct ldlm_resource *res = req->l_resource;
ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_start = req->l_req_extent.start;
+ __u64 req_end = req->l_req_extent.end;
int compat = 1;
- int found = 0;
+ int scan = 0;
ENTRY;
lockmode_verify(req_mode);
- /* Extent locks are only queued once. We can get back here with
- * insertp != NULL if the blocking ASTs returned -ERESTART. */
- if (!list_empty(&req->l_res_link))
- insertp = NULL;
-
- if (req->l_req_mode != LCK_GROUP) {
- __u64 req_start = req->l_req_extent.start;
- __u64 req_end = req->l_req_extent.end;
+ /* Using interval tree for granted lock */
+ if (queue == &res->lr_granted) {
+ struct ldlm_interval_tree *tree;
+ struct ldlm_extent_compat_args data = {.work_list = work_list,
+ .lock = req,
+ .compat = &compat };
+ struct interval_node_extent ex = { .start = req_start,
+ .end = req_end };
+ int idx, rc;
+
+ for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+ tree = &res->lr_itree[idx];
+ if (tree->lit_root == NULL) /* empty tree, skipped */
+ continue;
- list_for_each(tmp, queue) {
- lock = list_entry(tmp, struct ldlm_lock, l_res_link);
- if (req == lock)
- break;
+ data.mode = tree->lit_mode;
+ if (lockmode_compat(req_mode, tree->lit_mode)) {
+ struct ldlm_interval *node;
+ struct ldlm_extent *extent;
- if (lock->l_req_mode == LCK_GROUP) {
- if (*flags & LDLM_FL_BLOCK_NOWAIT)
- RETURN(-EWOULDBLOCK);
+ if (req_mode != LCK_GROUP)
+ continue;
- /* No blocking ASTs are sent for group locks. */
- compat = 0;
+ /* group lock, grant it immediately if
+ * compatible */
+ node = to_ldlm_interval(tree->lit_root);
+ extent = ldlm_interval_extent(node);
+ if (req->l_policy_data.l_extent.gid ==
+ extent->gid)
+ RETURN(2);
+ }
- /* there's a blocking group lock in front
- * of us on the queue. It can be held
- * indefinitely, so don't timeout. */
- if (insertp) {
- *flags |= LDLM_FL_NO_TIMEOUT;
- /* lock_bitlock(req) is held here. */
- req->l_flags |= LDLM_FL_NO_TIMEOUT;
+ if (tree->lit_mode == LCK_GROUP) {
+ if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ compat = -EWOULDBLOCK;
+ goto destroylock;
}
- if (work_list)
- continue;
- else
- break;
- }
+ *flags |= LDLM_FL_NO_TIMEOUT;
+ if (!work_list)
+ RETURN(0);
- /* locks are compatible, overlap doesn't matter */
- if (lockmode_compat(lock->l_req_mode, req_mode))
- continue;
-
- if (lock->l_policy_data.l_extent.end < req_start ||
- lock->l_policy_data.l_extent.start > req_end)
+ /* if work list is not NULL,add all
+ locks in the tree to work list */
+ compat = 0;
+ interval_iterate(tree->lit_root,
+ ldlm_extent_compat_cb, &data);
continue;
+ }
- compat = 0;
-
- if (!work_list)
- break;
-
- if (lock->l_blocking_ast)
- ldlm_add_ast_work_item(lock, req, work_list);
+ if (!work_list) {
+ rc = interval_is_overlapped(tree->lit_root,&ex);
+ if (rc)
+ RETURN(0);
+ } else {
+ interval_search(tree->lit_root, &ex,
+ ldlm_extent_compat_cb, &data);
+ if (!list_empty(work_list) && compat)
+ compat = 0;
+ }
}
-
- if (insertp)
- *insertp = queue;
-
RETURN(compat);
}
+ /* for waiting queue */
list_for_each(tmp, queue) {
lock = list_entry(tmp, struct ldlm_lock, l_res_link);
- if (req == lock)
- break;
- if (lock->l_req_mode != LCK_GROUP) {
- if (lock->l_req_mode != lock->l_granted_mode) {
- /* we must be traversing the waitq. */
-
- /* If a group lock was already found then
- * req can be queued before any extent locks
- * that come after the found group lock. */
- if (found)
- break;
+ if (req == lock)
+ RETURN(compat);
+
+ if (unlikely(scan)) {
+ /* We only get here if we are queuing GROUP lock
+ and met some incompatible one. The main idea of this
+ code is to insert GROUP lock past compatible GROUP
+ lock in the waiting queue or if there is not any,
+ then in front of first non-GROUP lock */
+ if (lock->l_req_mode != LCK_GROUP) {
+ /* Ok, we hit non-GROUP lock, there should
+ * be no more GROUP locks later on, queue in
+ * front of first non-GROUP lock */
+
+ ldlm_resource_insert_lock_after(lock, req);
+ list_del_init(&lock->l_res_link);
+ ldlm_resource_insert_lock_after(req, lock);
+ RETURN(0);
+ }
+ if (req->l_policy_data.l_extent.gid ==
+ lock->l_policy_data.l_extent.gid) {
+ /* found it */
+ ldlm_resource_insert_lock_after(lock, req);
+ RETURN(0);
+ }
+ continue;
+ }
- if (!insertp) {
- /* We've hit a conflicting extent lock
- * on the waitq before hitting the req
- * group lock. See comments below. */
- compat = 0;
- break;
+ /* locks are compatible, overlap doesn't matter */
+ if (lockmode_compat(lock->l_req_mode, req_mode)) {
+ if (req_mode == LCK_PR &&
+ ((lock->l_policy_data.l_extent.start <=
+ req->l_policy_data.l_extent.start) &&
+ (lock->l_policy_data.l_extent.end >=
+ req->l_policy_data.l_extent.end))) {
+ /* If we met a PR lock just like us or wider,
+ and nobody down the list conflicted with
+ it, that means we can skip processing of
+ the rest of the list and safely place
+ ourselves at the end of the list, or grant
+ (dependent if we met an conflicting locks
+ before in the list).
+ In case of 1st enqueue only we continue
+ traversing if there is something conflicting
+ down the list because we need to make sure
+ that something is marked as AST_SENT as well,
+ in cse of empy worklist we would exit on
+ first conflict met. */
+ /* There IS a case where such flag is
+ not set for a lock, yet it blocks
+ something. Luckily for us this is
+ only during destroy, so lock is
+ exclusive. So here we are safe */
+ if (!(lock->l_flags & LDLM_FL_AST_SENT)) {
+ RETURN(compat);
}
+ }
- /* Group locks are not normally blocked by
- * waiting PR|PW locks. */
+ /* non-group locks are compatible, overlap doesn't
+ matter */
+ if (likely(req_mode != LCK_GROUP))
+ continue;
- /* If NO_TIMEOUT was sent back to the client
- * we can queue the group lock in front of
- * this extent lock. */
- if (lock->l_flags & LDLM_FL_NO_TIMEOUT) {
- if (save == NULL)
- save = tmp;
- continue;
+ /* If we are trying to get a GROUP lock and there is
+ another one of this kind, we need to compare gid */
+ if (req->l_policy_data.l_extent.gid ==
+ lock->l_policy_data.l_extent.gid) {
+ /* If existing lock with matched gid is granted,
+ we grant new one too. */
+ if (lock->l_req_mode == lock->l_granted_mode)
+ RETURN(2);
+
+ /* Otherwise we are scanning queue of waiting
+ * locks and it means current request would
+ * block along with existing lock (that is
+ * already blocked.
+ * If we are in nonblocking mode - return
+ * immediately */
+ if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ compat = -EWOULDBLOCK;
+ goto destroylock;
}
-
- /* If we did NOT send NO_TIMEOUT back to the
- * client for this extent lock then the client
- * could possibly timeout if we queue this
- * group lock before it, so don't. This is the
- * only way to get a conflicting extent lock
- * in front of a group lock on the waitq. */
+ /* If this group lock is compatible with another
+ * group lock on the waiting list, they must be
+ * together in the list, so they can be granted
+ * at the same time. Otherwise the later lock
+ * can get stuck behind another, incompatible,
+ * lock. */
+ ldlm_resource_insert_lock_after(lock, req);
+ /* Because 'lock' is not granted, we can stop
+ * processing this queue and return immediately.
+ * There is no need to check the rest of the
+ * list. */
+ RETURN(0);
}
+ }
+ if (unlikely(req_mode == LCK_GROUP &&
+ (lock->l_req_mode != lock->l_granted_mode))) {
+ scan = 1;
compat = 0;
- if (!work_list) {
- LASSERT(save == NULL);
- break;
+ if (lock->l_req_mode != LCK_GROUP) {
+ /* Ok, we hit non-GROUP lock, there should be no
+ more GROUP locks later on, queue in front of
+ first non-GROUP lock */
+
+ ldlm_resource_insert_lock_after(lock, req);
+ list_del_init(&lock->l_res_link);
+ ldlm_resource_insert_lock_after(req, lock);
+ RETURN(0);
}
-
- /* If we previously skipped over some extent locks
- * because we thought we were going to queue the
- * group lock in front of them then we need to go back
- * and send blocking ASTs for the locks we skipped. */
- if (save != NULL) {
- struct ldlm_lock *lck2;
-
- for (; save != tmp; save = save->next) {
- lck2 = list_entry(save,
- struct ldlm_lock,
- l_res_link);
-
- /* If there was a group lock after save
- * then we would have exited this loop
- * above. */
- LASSERT(lck2->l_req_mode!=LCK_GROUP);
-
- if (lck2->l_blocking_ast) {
- ldlm_add_ast_work_item(lck2,req,
- work_list);
- }
- }
- save = NULL;
+ if (req->l_policy_data.l_extent.gid ==
+ lock->l_policy_data.l_extent.gid) {
+ /* found it */
+ ldlm_resource_insert_lock_after(lock, req);
+ RETURN(0);
}
-
- if (lock->l_blocking_ast)
- ldlm_add_ast_work_item(lock, req, work_list);
continue;
}
- /* If it was safe to insert a group lock at save,
- * i.e. save != NULL, then this group lock already
- * on the queue would have been inserted before save. */
- LASSERT(save == NULL);
-
- /* Note: no blocking ASTs are sent for group locks. */
-
- if (lock->l_policy_data.l_extent.gid ==
- req->l_policy_data.l_extent.gid) {
- /* group locks with this gid already on the waitq. */
- found = 2;
-
- if (lock->l_req_mode == lock->l_granted_mode) {
- /* if a group lock with this gid has already
- * been granted then grant this one. */
- compat = 2;
- break;
+ if (unlikely(lock->l_req_mode == LCK_GROUP)) {
+ /* If compared lock is GROUP, then requested is PR/PW/
+ * so this is not compatible; extent range does not
+ * matter */
+ if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ compat = -EWOULDBLOCK;
+ goto destroylock;
+ } else {
+ *flags |= LDLM_FL_NO_TIMEOUT;
}
- } else {
- if (found == 2)
- break;
-
- /* group locks already exist on the queue. */
- found = 1;
-
- if (*flags & LDLM_FL_BLOCK_NOWAIT)
- RETURN(-EWOULDBLOCK);
-
- compat = 0;
-
- /* there's a blocking group lock in front
- * of us on the queue. It can be held
- * indefinitely, so don't timeout. */
- *flags |= LDLM_FL_NO_TIMEOUT;
-
- /* the only reason to continue traversing the
- * list at this point is to find the proper
- * place to insert the lock in the waitq. */
- if (!insertp)
- break;
+ } else if (lock->l_policy_data.l_extent.end < req_start ||
+ lock->l_policy_data.l_extent.start > req_end) {
+ /* if a non group lock doesn't overlap skip it */
+ continue;
}
- }
- if (insertp != NULL) {
- if (save != NULL)
- *insertp = save;
- else
- *insertp = tmp;
+ if (!work_list)
+ RETURN(0);
+
+ compat = 0;
+ if (lock->l_blocking_ast)
+ ldlm_add_ast_work_item(lock, req, work_list);
}
RETURN(compat);
+destroylock:
+ list_del_init(&req->l_res_link);
+ ldlm_lock_destroy_nolock(req);
+ *err = compat;
+ RETURN(compat);
}
/* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
* - blocking ASTs have already been sent
- * - the caller has already initialized req->lr_tmp
* - must call this function with the ns lock held
*
* If first_enq is 1 (ie, called from ldlm_lock_enqueue):
* - blocking ASTs have not been sent
- * - the caller has NOT initialized req->lr_tmp, so we must
* - must call this function with the ns lock held once */
int ldlm_process_extent_lock(struct ldlm_lock *lock, int *flags, int first_enq,
ldlm_error_t *err, struct list_head *work_list)
{
struct ldlm_resource *res = lock->l_resource;
- struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
- struct list_head *insertp = NULL;
+ struct list_head rpc_list = CFS_LIST_HEAD_INIT(rpc_list);
int rc, rc2;
ENTRY;
LASSERT(list_empty(&res->lr_converting));
+ check_res_locked(res);
*err = ELDLM_OK;
if (!first_enq) {
- /* -EWOULDBLOCK can't occur here since (flags & BLOCK_NOWAIT)
- * lock requests would either be granted or fail on their
- * first_enq. flags should always be zero here, and if that
- * ever changes we want to find out. */
+ /* Careful observers will note that we don't handle -EWOULDBLOCK
+ * here, but it's ok for a non-obvious reason -- compat_queue
+ * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT).
+ * flags should always be zero here, and if that ever stops
+ * being true, we want to find out. */
LASSERT(*flags == 0);
- rc = ldlm_extent_compat_queue(&res->lr_granted, lock,
- flags, NULL, NULL);
+ rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags,
+ err, NULL);
if (rc == 1) {
rc = ldlm_extent_compat_queue(&res->lr_waiting, lock,
- flags, NULL, NULL);
+ flags, err, NULL);
}
if (rc == 0)
RETURN(LDLM_ITER_STOP);
ldlm_resource_unlink_lock(lock);
- ldlm_extent_policy(res, lock, flags);
- lock_bitlock(lock);
- lock->l_flags &= ~LDLM_FL_NO_TIMEOUT;
- unlock_bitlock(lock);
+
+ if (!OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_EVICT_RACE))
+ ldlm_extent_policy(res, lock, flags);
ldlm_grant_lock(lock, work_list);
RETURN(LDLM_ITER_CONTINUE);
}
restart:
- rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, &rpc_list,
- NULL);
+ rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, err, &rpc_list);
if (rc < 0)
- GOTO(destroylock, rc);
+ GOTO(out, rc); /* lock was destroyed */
if (rc == 2)
goto grant;
- /* Traverse the waiting list in case there are other conflicting
- * lock requests ahead of us in the queue and send blocking ASTs */
- rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock, flags, &rpc_list,
- &insertp);
+ rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock, flags, err, &rpc_list);
if (rc2 < 0)
- GOTO(destroylock, rc);
+ GOTO(out, rc = rc2); /* lock was destroyed */
+
if (rc + rc2 == 2) {
- grant:
+ grant:
ldlm_extent_policy(res, lock, flags);
ldlm_resource_unlink_lock(lock);
- lock->l_flags &= ~LDLM_FL_NO_TIMEOUT;
ldlm_grant_lock(lock, NULL);
} else {
/* If either of the compat_queue()s returned failure, then we
* terrible folly -- if we goto restart, we could get
* re-ordered! Causes deadlock, because ASTs aren't sent! */
if (list_empty(&lock->l_res_link))
- ldlm_resource_add_lock(res, insertp, lock);
+ ldlm_resource_add_lock(res, &res->lr_waiting, lock);
unlock_res(res);
- rc = ldlm_run_bl_ast_work(&rpc_list);
+ rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_BL_AST);
lock_res(res);
- if (rc == -ERESTART)
+
+ if (rc == -ERESTART) {
+ /* lock was granted while resource was unlocked. */
+ if (lock->l_granted_mode == lock->l_req_mode) {
+ /* bug 11300: if the lock has been granted,
+ * break earlier because otherwise, we will go
+ * to restart and ldlm_resource_unlink will be
+ * called and it causes the interval node to be
+ * freed. Then we will fail at
+ * ldlm_extent_add_lock() */
+ *flags &= ~(LDLM_FL_BLOCK_GRANTED | LDLM_FL_BLOCK_CONV |
+ LDLM_FL_BLOCK_WAIT);
+ GOTO(out, rc = 0);
+ }
+
GOTO(restart, -ERESTART);
- *flags |= LDLM_FL_BLOCK_GRANTED;
- }
+ }
- RETURN(0);
+ *flags |= LDLM_FL_BLOCK_GRANTED;
+ /* this way we force client to wait for the lock
+ * endlessly once the lock is enqueued -bzzz */
+ *flags |= LDLM_FL_NO_TIMEOUT;
- destroylock:
- list_del_init(&lock->l_res_link);
- unlock_res(res);
- ldlm_lock_destroy(lock);
- lock_res(res);
- *err = rc;
+ }
+ rc = 0;
+out:
RETURN(rc);
}
/* When a lock is cancelled by a client, the KMS may undergo change if this
* is the "highest lock". This function returns the new KMS value.
- * Caller must hold ns_lock already.
+ * Caller must hold ns_lock already.
*
* NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */
__u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms)
/* don't let another thread in ldlm_extent_shift_kms race in
* just after we finish and take our lock into account in its
* calculation of the kms */
-
lock->l_flags |= LDLM_FL_KMS_IGNORE;
list_for_each(tmp, &res->lr_granted) {
RETURN(kms);
}
+
+cfs_mem_cache_t *ldlm_interval_slab;
+struct ldlm_interval *ldlm_interval_alloc(struct ldlm_lock *lock)
+{
+ struct ldlm_interval *node;
+ ENTRY;
+
+ LASSERT(lock->l_resource->lr_type == LDLM_EXTENT);
+ OBD_SLAB_ALLOC(node, ldlm_interval_slab, CFS_ALLOC_IO, sizeof(*node));
+ if (node == NULL)
+ RETURN(NULL);
+
+ CFS_INIT_LIST_HEAD(&node->li_group);
+ ldlm_interval_attach(node, lock);
+ RETURN(node);
+}
+
+void ldlm_interval_free(struct ldlm_interval *node)
+{
+ if (node) {
+ LASSERT(list_empty(&node->li_group));
+ OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
+ }
+}
+
+/* interval tree, for LDLM_EXTENT. */
+void ldlm_interval_attach(struct ldlm_interval *n,
+ struct ldlm_lock *l)
+{
+ LASSERT(l->l_tree_node == NULL);
+ LASSERT(l->l_resource->lr_type == LDLM_EXTENT);
+
+ list_add_tail(&l->l_sl_policy, &n->li_group);
+ l->l_tree_node = n;
+}
+
+struct ldlm_interval *ldlm_interval_detach(struct ldlm_lock *l)
+{
+ struct ldlm_interval *n = l->l_tree_node;
+
+ if (n == NULL)
+ return NULL;
+
+ LASSERT(!list_empty(&n->li_group));
+ l->l_tree_node = NULL;
+ list_del_init(&l->l_sl_policy);
+
+ return (list_empty(&n->li_group) ? n : NULL);
+}
+
+static inline int lock_mode_to_index(ldlm_mode_t mode)
+{
+ int index;
+
+ LASSERT(mode != 0);
+ LASSERT(IS_PO2(mode));
+ for (index = -1; mode; index++, mode >>= 1) ;
+ LASSERT(index < LCK_MODE_NUM);
+ return index;
+}
+
+void ldlm_extent_add_lock(struct ldlm_resource *res,
+ struct ldlm_lock *lock)
+{
+ struct interval_node *found, **root;
+ struct ldlm_interval *node;
+ struct ldlm_extent *extent;
+ int idx;
+
+ LASSERT(lock->l_granted_mode == lock->l_req_mode);
+
+ node = lock->l_tree_node;
+ LASSERT(node != NULL);
+
+ idx = lock_mode_to_index(lock->l_granted_mode);
+ LASSERT(lock->l_granted_mode == 1 << idx);
+ LASSERT(lock->l_granted_mode == res->lr_itree[idx].lit_mode);
+
+ /* node extent initialize */
+ extent = &lock->l_policy_data.l_extent;
+ interval_set(&node->li_node, extent->start, extent->end);
+
+ root = &res->lr_itree[idx].lit_root;
+ found = interval_insert(&node->li_node, root);
+ if (found) { /* The policy group found. */
+ struct ldlm_interval *tmp = ldlm_interval_detach(lock);
+ LASSERT(tmp != NULL);
+ ldlm_interval_free(tmp);
+ ldlm_interval_attach(to_ldlm_interval(found), lock);
+ }
+ res->lr_itree[idx].lit_size++;
+
+ /* even though we use interval tree to manage the extent lock, we also
+ * add the locks into grant list, for debug purpose, .. */
+ ldlm_resource_add_lock(res, &res->lr_granted, lock);
+}
+
+void ldlm_extent_unlink_lock(struct ldlm_lock *lock)
+{
+ struct ldlm_resource *res = lock->l_resource;
+ struct ldlm_interval *node;
+ struct ldlm_interval_tree *tree;
+ int idx;
+
+ if (lock->l_granted_mode != lock->l_req_mode)
+ return;
+
+ LASSERT(lock->l_tree_node != NULL);
+ idx = lock_mode_to_index(lock->l_granted_mode);
+ LASSERT(lock->l_granted_mode == 1 << idx);
+ tree = &res->lr_itree[idx];
+
+ LASSERT(tree->lit_root != NULL); /* assure the tree is not null */
+
+ tree->lit_size--;
+ node = ldlm_interval_detach(lock);
+ if (node) {
+ interval_erase(&node->li_node, &tree->lit_root);
+ ldlm_interval_free(node);
+ }
+}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff