LU-8918 obdclass: hoist locking in lu_context_exit()

[fs/lustre-release.git] / lustre / obdclass / lu_object.c

diff --git a/lustre/obdclass/lu_object.c b/lustre/obdclass/lu_object.c
index 5cce81b..b633d26 100644 (file)
--- a/lustre/obdclass/lu_object.c
+++ b/lustre/obdclass/lu_object.c
@@ -15,11 +15,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2015, Intel Corporation.
+ * Copyright (c) 2011, 2016, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -44,8 +40,9 @@
 
 #define DEBUG_SUBSYSTEM S_CLASS
 
-#include <libcfs/libcfs.h>
 #include <linux/module.h>
+#include <linux/list.h>
+#include <libcfs/libcfs.h>
 #include <libcfs/libcfs_hash.h> /* hash_long() */
 #include <obd_class.h>
 #include <obd_support.h>
@@ -53,14 +50,13 @@
 #include <lustre_fid.h>
 #include <lu_object.h>
 #include <lu_ref.h>
-#include <libcfs/list.h>
 
 enum {
        LU_CACHE_PERCENT_MAX     = 50,
        LU_CACHE_PERCENT_DEFAULT = 20
 };
 
-#define        LU_CACHE_NR_MAX_ADJUST          128
+#define        LU_CACHE_NR_MAX_ADJUST          512
 #define        LU_CACHE_NR_UNLIMITED           -1
 #define        LU_CACHE_NR_DEFAULT             LU_CACHE_NR_UNLIMITED
 #define        LU_CACHE_NR_LDISKFS_LIMIT       LU_CACHE_NR_UNLIMITED
@@ -348,8 +344,11 @@ static void lu_object_free(const struct lu_env *env, struct lu_object *o)
 
 /**
  * Free \a nr objects from the cold end of the site LRU list.
+ * if canblock is 0, then don't block awaiting for another
+ * instance of lu_site_purge() to complete
  */
-int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
+int lu_site_purge_objects(const struct lu_env *env, struct lu_site *s,
+                         int nr, int canblock)
 {
         struct lu_object_header *h;
         struct lu_object_header *temp;
@@ -379,7 +378,11 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
         * It doesn't make any sense to make purge threads parallel, that can
         * only bring troubles to us. See LU-5331.
         */
-       mutex_lock(&s->ls_purge_mutex);
+       if (canblock != 0)
+               mutex_lock(&s->ls_purge_mutex);
+       else if (mutex_trylock(&s->ls_purge_mutex) == 0)
+               goto out;
+
         did_sth = 0;
         cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
                 if (i < start)
@@ -435,9 +438,10 @@ int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
         /* race on s->ls_purge_start, but nobody cares */
         s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash);
 
+out:
         return nr;
 }
-EXPORT_SYMBOL(lu_site_purge);
+EXPORT_SYMBOL(lu_site_purge_objects);
 
 /*
  * Object printing.
@@ -665,11 +669,11 @@ static void lu_object_limit(const struct lu_env *env,
 
        size = cfs_hash_size_get(dev->ld_site->ls_obj_hash);
        nr = (__u64)lu_cache_nr;
-       if (size > nr)
-               lu_site_purge(env, dev->ld_site,
-                             MIN(size - nr, LU_CACHE_NR_MAX_ADJUST));
+       if (size <= nr)
+               return;
 
-       return;
+       lu_site_purge_objects(env, dev->ld_site,
+                             MIN(size - nr, LU_CACHE_NR_MAX_ADJUST), 0);
 }
 
 static struct lu_object *lu_object_new(const struct lu_env *env,
@@ -950,8 +954,8 @@ static unsigned long lu_htable_order(struct lu_device *top)
 
 #if BITS_PER_LONG == 32
         /* limit hashtable size for lowmem systems to low RAM */
-       if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT))
-               cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4;
+       if (cache_size > 1 << (30 - PAGE_SHIFT))
+               cache_size = 1 << (30 - PAGE_SHIFT) * 3 / 4;
 #endif
 
         /* clear off unreasonable cache setting. */
@@ -964,7 +968,7 @@ static unsigned long lu_htable_order(struct lu_device *top)
                 lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
         }
         cache_size = cache_size / 100 * lu_cache_percent *
-               (PAGE_CACHE_SIZE / 1024);
+               (PAGE_SIZE / 1024);
 
         for (bits = 1; (1 << bits) < cache_size; ++bits) {
                 ;
@@ -1791,10 +1795,11 @@ void lu_context_exit(struct lu_context *ctx)
         LINVRNT(ctx->lc_state == LCS_ENTERED);
         ctx->lc_state = LCS_LEFT;
         if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
+               /* could race with key quiescency */
+               if (ctx->lc_tags & LCT_REMEMBER)
+                       read_lock(&lu_keys_guard);
+
                 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
-                       /* could race with key quiescency */
-                       if (ctx->lc_tags & LCT_REMEMBER)
-                               read_lock(&lu_keys_guard);
                        if (ctx->lc_value[i] != NULL) {
                                struct lu_context_key *key;
 
@@ -1804,9 +1809,10 @@ void lu_context_exit(struct lu_context *ctx)
                                        key->lct_exit(ctx,
                                                      key, ctx->lc_value[i]);
                        }
-                       if (ctx->lc_tags & LCT_REMEMBER)
-                               read_unlock(&lu_keys_guard);
                 }
+
+               if (ctx->lc_tags & LCT_REMEMBER)
+                       read_unlock(&lu_keys_guard);
         }
 }
 EXPORT_SYMBOL(lu_context_exit);
@@ -2288,19 +2294,24 @@ void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
 {
        struct lu_site          *s = o->lo_dev->ld_site;
        struct lu_fid           *old = &o->lo_header->loh_fid;
-       struct lu_object        *shadow;
-       wait_queue_t             waiter;
        struct cfs_hash         *hs;
        struct cfs_hash_bd       bd;
-       __u64                    version = 0;
 
        LASSERT(fid_is_zero(old));
 
+       /* supposed to be unique */
        hs = s->ls_obj_hash;
        cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1);
-       shadow = htable_lookup(s, &bd, fid, &waiter, &version);
-       /* supposed to be unique */
-       LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
+#ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
+       {
+               __u64                    version = 0;
+               wait_queue_t             waiter;
+               struct lu_object        *shadow;
+               shadow = htable_lookup(s, &bd, fid, &waiter, &version);
+               /* supposed to be unique */
+               LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
+       }
+#endif
        *old = *fid;
        cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
        cfs_hash_bd_unlock(hs, &bd, 1);