X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosc%2Fosc_cache.c;h=93cd2d6fdbab24b1f60d893cba5f55d4a150075d;hp=d3e23782555435f73ff141c11b1174c8165a5ca1;hb=1eee11c75ca13745d083410e1ced3a1a8b088ee9;hpb=39287411e32aeeed342c7da8417975e97310cd4a

diff --git a/lustre/osc/osc_cache.c b/lustre/osc/osc_cache.c
index d3e2378..93cd2d6 100644
--- a/lustre/osc/osc_cache.c
+++ b/lustre/osc/osc_cache.c
@@ -38,6 +38,7 @@
 #define DEBUG_SUBSYSTEM S_OSC
 
 #include <lustre_osc.h>
+#include <lustre_dlm.h>
 
 #include "osc_internal.h"
 
@@ -74,7 +75,7 @@ static inline char *ext_flags(struct osc_extent *ext, char *flags)
 {
 	char *buf = flags;
 	*buf++ = ext->oe_rw ? 'r' : 'w';
-	if (ext->oe_intree)
+	if (!RB_EMPTY_NODE(&ext->oe_node))
 		*buf++ = 'i';
 	if (ext->oe_sync)
 		*buf++ = 'S';
@@ -110,7 +111,7 @@ static const char *oes_strings[] = {
 		/* ----- extent part 0 ----- */				      \
 		__ext, EXTPARA(__ext),					      \
 		/* ----- part 1 ----- */				      \
-		atomic_read(&__ext->oe_refc),				      \
+		kref_read(&__ext->oe_refc),				      \
 		atomic_read(&__ext->oe_users),				      \
 		list_empty_marker(&__ext->oe_link),			      \
 		oes_strings[__ext->oe_state], ext_flags(__ext, __buf),	      \
@@ -154,7 +155,7 @@ static inline struct osc_extent *next_extent(struct osc_extent *ext)
 	if (ext == NULL)
 		return NULL;
 
-	LASSERT(ext->oe_intree);
+	LASSERT(!RB_EMPTY_NODE(&ext->oe_node));
 	return rb_extent(rb_next(&ext->oe_node));
 }
 
@@ -163,7 +164,7 @@ static inline struct osc_extent *prev_extent(struct osc_extent *ext)
 	if (ext == NULL)
 		return NULL;
 
-	LASSERT(ext->oe_intree);
+	LASSERT(!RB_EMPTY_NODE(&ext->oe_node));
 	return rb_extent(rb_prev(&ext->oe_node));
 }
 
@@ -186,10 +187,10 @@ static int osc_extent_sanity_check0(struct osc_extent *ext,
 	if (ext->oe_state >= OES_STATE_MAX)
 		GOTO(out, rc = 10);
 
-	if (atomic_read(&ext->oe_refc) <= 0)
+	if (kref_read(&ext->oe_refc) <= 0)
 		GOTO(out, rc = 20);
 
-	if (atomic_read(&ext->oe_refc) < atomic_read(&ext->oe_users))
+	if (kref_read(&ext->oe_refc) < atomic_read(&ext->oe_users))
 		GOTO(out, rc = 30);
 
 	switch (ext->oe_state) {
@@ -314,8 +315,8 @@ static void osc_extent_state_set(struct osc_extent *ext, int state)
 	/* LASSERT(sanity_check_nolock(ext) == 0); */
 
 	/* TODO: validate the state machine */
-	ext->oe_state = state;
-	wake_up_all(&ext->oe_waitq);
+	smp_store_release(&ext->oe_state, state);
+	wake_up(&ext->oe_waitq);
 }
 
 static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
@@ -329,7 +330,7 @@ static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
 	RB_CLEAR_NODE(&ext->oe_node);
 	ext->oe_obj = obj;
 	cl_object_get(osc2cl(obj));
-	atomic_set(&ext->oe_refc, 1);
+	kref_init(&ext->oe_refc);
 	atomic_set(&ext->oe_users, 0);
 	INIT_LIST_HEAD(&ext->oe_link);
 	ext->oe_state = OES_INV;
@@ -340,35 +341,50 @@ static struct osc_extent *osc_extent_alloc(struct osc_object *obj)
 	return ext;
 }
 
-static void osc_extent_free(struct osc_extent *ext)
+static void osc_extent_free(struct kref *kref)
 {
+	struct osc_extent *ext = container_of(kref, struct osc_extent,
+					      oe_refc);
+
+	LASSERT(list_empty(&ext->oe_link));
+	LASSERT(atomic_read(&ext->oe_users) == 0);
+	LASSERT(ext->oe_state == OES_INV);
+	LASSERT(RB_EMPTY_NODE(&ext->oe_node));
+
+	if (ext->oe_dlmlock) {
+		lu_ref_del(&ext->oe_dlmlock->l_reference,
+			   "osc_extent", ext);
+		LDLM_LOCK_PUT(ext->oe_dlmlock);
+		ext->oe_dlmlock = NULL;
+	}
+#if 0
+	/* If/When cl_object_put drops the need for 'env',
+	 * this code can be enabled, and matching code in
+	 * osc_extent_put removed.
+	 */
+	cl_object_put(osc2cl(ext->oe_obj));
+
 	OBD_SLAB_FREE_PTR(ext, osc_extent_kmem);
+#endif
 }
 
 static struct osc_extent *osc_extent_get(struct osc_extent *ext)
 {
-	LASSERT(atomic_read(&ext->oe_refc) >= 0);
-	atomic_inc(&ext->oe_refc);
+	LASSERT(kref_read(&ext->oe_refc) >= 0);
+	kref_get(&ext->oe_refc);
 	return ext;
 }
 
 static void osc_extent_put(const struct lu_env *env, struct osc_extent *ext)
 {
-	LASSERT(atomic_read(&ext->oe_refc) > 0);
-	if (atomic_dec_and_test(&ext->oe_refc)) {
-		LASSERT(list_empty(&ext->oe_link));
-		LASSERT(atomic_read(&ext->oe_users) == 0);
-		LASSERT(ext->oe_state == OES_INV);
-		LASSERT(!ext->oe_intree);
-
-		if (ext->oe_dlmlock != NULL) {
-			lu_ref_add(&ext->oe_dlmlock->l_reference,
-				   "osc_extent", ext);
-			LDLM_LOCK_PUT(ext->oe_dlmlock);
-			ext->oe_dlmlock = NULL;
-		}
+	LASSERT(kref_read(&ext->oe_refc) > 0);
+	if (kref_put(&ext->oe_refc, osc_extent_free)) {
+		/* This should be in osc_extent_free(), but
+		 * while we need to pass 'env' it cannot be.
+		 */
 		cl_object_put(env, osc2cl(ext->oe_obj));
-		osc_extent_free(ext);
+
+		OBD_SLAB_FREE_PTR(ext, osc_extent_kmem);
 	}
 }
 
@@ -379,9 +395,9 @@ static void osc_extent_put(const struct lu_env *env, struct osc_extent *ext)
  */
 static void osc_extent_put_trust(struct osc_extent *ext)
 {
-	LASSERT(atomic_read(&ext->oe_refc) > 1);
+	LASSERT(kref_read(&ext->oe_refc) > 1);
 	assert_osc_object_is_locked(ext->oe_obj);
-	atomic_dec(&ext->oe_refc);
+	osc_extent_put(NULL, ext);
 }
 
 /**
@@ -431,7 +447,7 @@ static void osc_extent_insert(struct osc_object *obj, struct osc_extent *ext)
 	struct rb_node    *parent = NULL;
 	struct osc_extent *tmp;
 
-	LASSERT(ext->oe_intree == 0);
+	LASSERT(RB_EMPTY_NODE(&ext->oe_node));
 	LASSERT(ext->oe_obj == obj);
 	assert_osc_object_is_locked(obj);
 	while (*n != NULL) {
@@ -448,7 +464,6 @@ static void osc_extent_insert(struct osc_object *obj, struct osc_extent *ext)
 	rb_link_node(&ext->oe_node, parent, n);
 	rb_insert_color(&ext->oe_node, &obj->oo_root);
 	osc_extent_get(ext);
-	ext->oe_intree = 1;
 }
 
 /* caller must have held object lock. */
@@ -456,9 +471,9 @@ static void osc_extent_erase(struct osc_extent *ext)
 {
 	struct osc_object *obj = ext->oe_obj;
 	assert_osc_object_is_locked(obj);
-	if (ext->oe_intree) {
+	if (!RB_EMPTY_NODE(&ext->oe_node)) {
 		rb_erase(&ext->oe_node, &obj->oo_root);
-		ext->oe_intree = 0;
+		RB_CLEAR_NODE(&ext->oe_node);
 		/* rbtree held a refcount */
 		osc_extent_put_trust(ext);
 	}
@@ -594,7 +609,10 @@ int osc_extent_release(const struct lu_env *env, struct osc_extent *ext)
 			if (osc_extent_merge(env, ext, next_extent(ext)) == 0)
 				grant += cli->cl_grant_extent_tax;
 
-			if (ext->oe_urgent)
+			if (ext->oe_hp)
+				list_move_tail(&ext->oe_link,
+					       &obj->oo_hp_exts);
+			else if (ext->oe_urgent)
 				list_move_tail(&ext->oe_link,
 					       &obj->oo_urgent_exts);
 			else if (ext->oe_nr_pages == ext->oe_mppr) {
@@ -893,17 +911,6 @@ int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext,
 	RETURN(0);
 }
 
-static int extent_wait_cb(struct osc_extent *ext, enum osc_extent_state state)
-{
-	int ret;
-
-	osc_object_lock(ext->oe_obj);
-	ret = ext->oe_state == state;
-	osc_object_unlock(ext->oe_obj);
-
-	return ret;
-}
-
 /**
  * Wait for the extent's state to become @state.
  */
@@ -932,14 +939,16 @@ static int osc_extent_wait(const struct lu_env *env, struct osc_extent *ext,
 		osc_extent_release(env, ext);
 
 	/* wait for the extent until its state becomes @state */
-	rc = wait_event_idle_timeout(ext->oe_waitq, extent_wait_cb(ext, state),
+	rc = wait_event_idle_timeout(ext->oe_waitq,
+				     smp_load_acquire(&ext->oe_state) == state,
 				     cfs_time_seconds(600));
 	if (rc == 0) {
 		OSC_EXTENT_DUMP(D_ERROR, ext,
 			"%s: wait ext to %u timedout, recovery in progress?\n",
 			cli_name(osc_cli(obj)), state);
 
-		wait_event_idle(ext->oe_waitq, extent_wait_cb(ext, state));
+		wait_event_idle(ext->oe_waitq,
+				smp_load_acquire(&ext->oe_state) == state);
 	}
 	if (ext->oe_rc < 0)
 		rc = ext->oe_rc;
@@ -1543,15 +1552,26 @@ out:
 	return rc;
 }
 
-static int ocw_granted(struct client_obd *cli, struct osc_cache_waiter *ocw)
+/* Following two inlines exist to pass code fragments
+ * to wait_event_idle_exclusive_timeout_cmd().  Passing
+ * code fragments as macro args can look confusing, so
+ * we provide inlines to encapsulate them.
+ */
+static inline void cli_unlock_and_unplug(const struct lu_env *env,
+					 struct client_obd *cli,
+					 struct osc_async_page *oap)
 {
-	int rc;
-	spin_lock(&cli->cl_loi_list_lock);
-	rc = list_empty(&ocw->ocw_entry);
 	spin_unlock(&cli->cl_loi_list_lock);
-	return rc;
+	osc_io_unplug_async(env, cli, NULL);
+	CDEBUG(D_CACHE,
+	       "%s: sleeping for cache space for %p\n",
+	       cli_name(cli), oap);
 }
 
+static inline void cli_lock_after_unplug(struct client_obd *cli)
+{
+	spin_lock(&cli->cl_loi_list_lock);
+}
 /**
  * The main entry to reserve dirty page accounting. Usually the grant reserved
  * in this function will be freed in bulk in osc_free_grant() unless it fails
@@ -1562,10 +1582,22 @@ static int ocw_granted(struct client_obd *cli, struct osc_cache_waiter *ocw)
 static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
 			   struct osc_async_page *oap, int bytes)
 {
-	struct osc_object	*osc = oap->oap_obj;
-	struct lov_oinfo	*loi = osc->oo_oinfo;
-	struct osc_cache_waiter	 ocw;
-	int			 rc = -EDQUOT;
+	struct osc_object *osc = oap->oap_obj;
+	struct lov_oinfo *loi = osc->oo_oinfo;
+	int rc = -EDQUOT;
+	int remain;
+	bool entered = false;
+	/* We cannot wait for a long time here since we are holding ldlm lock
+	 * across the actual IO. If no requests complete fast (e.g. due to
+	 * overloaded OST that takes a long time to process everything, we'd
+	 * get evicted if we wait for a normal obd_timeout or some such.
+	 * So we try to wait half the time it would take the client to be
+	 * evicted by server which is half obd_timeout when AT is off
+	 * or at least ldlm_enqueue_min with AT on.
+	 * See LU-13131 */
+	unsigned long timeout = cfs_time_seconds(AT_OFF ? obd_timeout / 2 :
+							  ldlm_enqueue_min / 2);
+
 	ENTRY;
 
 	OSC_DUMP_GRANT(D_CACHE, cli, "need:%d\n", bytes);
@@ -1581,83 +1613,40 @@ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli,
 		GOTO(out, rc = -EDQUOT);
 	}
 
-	/* Hopefully normal case - cache space and write credits available */
-	if (list_empty(&cli->cl_cache_waiters) &&
-	    osc_enter_cache_try(cli, oap, bytes)) {
-		OSC_DUMP_GRANT(D_CACHE, cli, "granted from cache\n");
-		GOTO(out, rc = 0);
-	}
-
-	/* We can get here for two reasons: too many dirty pages in cache, or
+	/*
+	 * We can wait here for two reasons: too many dirty pages in cache, or
 	 * run out of grants. In both cases we should write dirty pages out.
 	 * Adding a cache waiter will trigger urgent write-out no matter what
 	 * RPC size will be.
-	 * The exiting condition is no avail grants and no dirty pages caching,
-	 * that really means there is no space on the OST. */
-	init_waitqueue_head(&ocw.ocw_waitq);
-	ocw.ocw_oap   = oap;
-	ocw.ocw_grant = bytes;
-	while (cli->cl_dirty_pages > 0 || cli->cl_w_in_flight > 0) {
-		list_add_tail(&ocw.ocw_entry, &cli->cl_cache_waiters);
-		ocw.ocw_rc = 0;
-		spin_unlock(&cli->cl_loi_list_lock);
-
-		osc_io_unplug_async(env, cli, NULL);
-
-		CDEBUG(D_CACHE, "%s: sleeping for cache space @ %p for %p\n",
-		       cli_name(cli), &ocw, oap);
-
-		rc = wait_event_idle_timeout(ocw.ocw_waitq,
-					     ocw_granted(cli, &ocw),
-					     cfs_time_seconds(AT_OFF ?
-							      obd_timeout :
-							      at_max));
-
-		spin_lock(&cli->cl_loi_list_lock);
-
-		if (rc <= 0) {
-			/* wait_event_idle_timeout timed out */
-			list_del_init(&ocw.ocw_entry);
-			if (rc == 0)
-				rc = -ETIMEDOUT;
-			break;
-		}
-		LASSERT(list_empty(&ocw.ocw_entry));
-		rc = ocw.ocw_rc;
-
-		if (rc != -EDQUOT)
-			break;
-		if (osc_enter_cache_try(cli, oap, bytes)) {
-			rc = 0;
-			break;
-		}
-	}
-
-	switch (rc) {
-	case 0:
-		OSC_DUMP_GRANT(D_CACHE, cli, "finally got grant space\n");
-		break;
-	case -ETIMEDOUT:
+	 * The exiting condition (other than success) is no avail grants
+	 * and no dirty pages caching, that really means there is no space
+	 * on the OST.
+	 */
+	remain = wait_event_idle_exclusive_timeout_cmd(
+		cli->cl_cache_waiters,
+		(entered = osc_enter_cache_try(cli, oap, bytes)) ||
+		(cli->cl_dirty_pages == 0 && cli->cl_w_in_flight == 0),
+		timeout,
+		cli_unlock_and_unplug(env, cli, oap),
+		cli_lock_after_unplug(cli));
+
+	if (entered) {
+		if (remain == timeout)
+			OSC_DUMP_GRANT(D_CACHE, cli, "granted from cache\n");
+		else
+			OSC_DUMP_GRANT(D_CACHE, cli,
+				       "finally got grant space\n");
+		wake_up(&cli->cl_cache_waiters);
+		rc = 0;
+	} else if (remain == 0) {
 		OSC_DUMP_GRANT(D_CACHE, cli,
 			       "timeout, fall back to sync i/o\n");
 		osc_extent_tree_dump(D_CACHE, osc);
 		/* fall back to synchronous I/O */
-		rc = -EDQUOT;
-		break;
-	case -EINTR:
-		/* Ensures restartability - LU-3581 */
-		OSC_DUMP_GRANT(D_CACHE, cli, "interrupted\n");
-		rc = -ERESTARTSYS;
-		break;
-	case -EDQUOT:
+	} else {
 		OSC_DUMP_GRANT(D_CACHE, cli,
 			       "no grant space, fall back to sync i/o\n");
-		break;
-	default:
-		CDEBUG(D_CACHE, "%s: event for cache space @ %p never arrived "
-		       "due to %d, fall back to sync i/o\n",
-		       cli_name(cli), &ocw, rc);
-		break;
+		wake_up_all(&cli->cl_cache_waiters);
 	}
 	EXIT;
 out:
@@ -1665,36 +1654,6 @@ out:
 	RETURN(rc);
 }
 
-/* caller must hold loi_list_lock */
-void osc_wake_cache_waiters(struct client_obd *cli)
-{
-	struct list_head *l, *tmp;
-	struct osc_cache_waiter *ocw;
-
-	ENTRY;
-	list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
-		ocw = list_entry(l, struct osc_cache_waiter, ocw_entry);
-
-		ocw->ocw_rc = -EDQUOT;
-
-		if (osc_enter_cache_try(cli, ocw->ocw_oap, ocw->ocw_grant))
-			ocw->ocw_rc = 0;
-
-		if (ocw->ocw_rc == 0 ||
-		    !(cli->cl_dirty_pages > 0 || cli->cl_w_in_flight > 0)) {
-			list_del_init(&ocw->ocw_entry);
-			CDEBUG(D_CACHE, "wake up %p for oap %p, avail grant "
-			       "%ld, %d\n", ocw, ocw->ocw_oap,
-			       cli->cl_avail_grant, ocw->ocw_rc);
-
-			wake_up(&ocw->ocw_waitq);
-		}
-	}
-
-	EXIT;
-}
-EXPORT_SYMBOL(osc_wake_cache_waiters);
-
 static int osc_max_rpc_in_flight(struct client_obd *cli, struct osc_object *osc)
 {
 	int hprpc = !!list_empty(&osc->oo_hp_exts);
@@ -1734,8 +1693,9 @@ static int osc_makes_rpc(struct client_obd *cli, struct osc_object *osc,
 		}
 		/* trigger a write rpc stream as long as there are dirtiers
 		 * waiting for space.  as they're waiting, they're not going to
-		 * create more pages to coalesce with what's waiting.. */
-		if (!list_empty(&cli->cl_cache_waiters)) {
+		 * create more pages to coalesce with what's waiting..
+		 */
+		if (waitqueue_active(&cli->cl_cache_waiters)) {
 			CDEBUG(D_CACHE, "cache waiters forcing RPC\n");
 			RETURN(1);
 		}
@@ -2035,19 +1995,16 @@ static unsigned int get_write_extents(struct osc_object *obj,
 	if (data.erd_page_count == data.erd_max_pages)
 		return data.erd_page_count;
 
-	ext = first_extent(obj);
-	while (ext != NULL) {
+	for (ext = first_extent(obj);
+	     ext;
+	     ext = next_extent(ext)) {
 		if ((ext->oe_state != OES_CACHE) ||
 		    /* this extent may be already in current rpclist */
-		    (!list_empty(&ext->oe_link) && ext->oe_owner != NULL)) {
-			ext = next_extent(ext);
+		    (!list_empty(&ext->oe_link) && ext->oe_owner))
 			continue;
-		}
 
 		if (!try_to_add_extent_for_io(cli, ext, &data))
 			return data.erd_page_count;
-
-		ext = next_extent(ext);
 	}
 	return data.erd_page_count;
 }
@@ -2190,8 +2147,9 @@ static struct osc_object *osc_next_obj(struct client_obd *cli)
 	/* then if we have cache waiters, return all objects with queued
 	 * writes.  This is especially important when many small files
 	 * have filled up the cache and not been fired into rpcs because
-	 * they don't pass the nr_pending/object threshhold */
-	if (!list_empty(&cli->cl_cache_waiters) &&
+	 * they don't pass the nr_pending/object threshhold
+	 */
+	if (waitqueue_active(&cli->cl_cache_waiters) &&
 	    !list_empty(&cli->cl_loi_write_list))
 		RETURN(list_to_obj(&cli->cl_loi_write_list, write_item));
 
@@ -2222,7 +2180,12 @@ __must_hold(&cli->cl_loi_list_lock)
 
 		OSC_IO_DEBUG(osc, "%lu in flight\n", rpcs_in_flight(cli));
 
-		if (osc_max_rpc_in_flight(cli, osc)) {
+		/* even if we have reached our max in flight RPCs, we still
+		 * allow all high-priority RPCs through to prevent their
+		 * starvation and leading to server evicting us for not
+		 * writing out pages in a timely manner LU-13131 */
+		if (osc_max_rpc_in_flight(cli, osc) &&
+		    list_empty(&osc->oo_hp_exts)) {
 			__osc_list_maint(cli, osc);
 			break;
 		}
@@ -2599,7 +2562,7 @@ int osc_flush_async_page(const struct lu_env *env, struct cl_io *io,
 	oap->oap_async_flags |= ASYNC_READY|ASYNC_URGENT;
 	spin_unlock(&oap->oap_lock);
 
-	if (memory_pressure_get())
+	if (current->flags & PF_MEMALLOC)
 		ext->oe_memalloc = 1;
 
 	ext->oe_urgent = 1;
@@ -2945,7 +2908,7 @@ int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
 					EASSERT(!ext->oe_hp, ext);
 					ext->oe_hp = 1;
 					list = &obj->oo_hp_exts;
-				} else if (!ext->oe_urgent) {
+				} else if (!ext->oe_urgent && !ext->oe_hp) {
 					ext->oe_urgent = 1;
 					list = &obj->oo_urgent_exts;
 				}