Implement negative lookup cache

Before creating any file negative lookups(1 in Fuse, 4 in SMB etc.)
are sent to verify if the file already exists. By serving these
lookups from the cache when possible, increases the create
performance by multiple folds in SMB access and some percentage
in Fuse/NFS access.

Feature page: https://review.gluster.org/#/c/16436

Updates #82
Change-Id: Ib1c0e7ac7a386f943d84f6398c27f9a03665b2a4
BUG: 1442569
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: https://review.gluster.org/16952
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

1 files changed, 173 insertions, 0 deletions

diff --git a/xlators/performance/nl-cache/src/nl-cache.h b/xlators/performance/nl-cache/src/nl-cache.h
new file mode 100644
index 00000000000..e94641c40d0
--- /dev/null
+++ b/xlators/performance/nl-cache/src/nl-cache.h
@@ -0,0 +1,173 @@
+/*
+ *   Copyright (c) 2016 Red Hat, Inc. <http://www.redhat.com>
+ *   This file is part of GlusterFS.
+ *
+ *   This file is licensed to you under your choice of the GNU Lesser
+ *   General Public License, version 3 or any later version (LGPLv3 or
+ *   later), or the GNU General Public License, version 2 (GPLv2), in all
+ *   cases as published by the Free Software Foundation.
+ */
+
+#ifndef __NL_CACHE_H__
+#define __NL_CACHE_H__
+
+#include "nl-cache-mem-types.h"
+#include "nl-cache-messages.h"
+#include "glusterfs.h"
+#include "xlator.h"
+#include "defaults.h"
+#include "atomic.h"
+
+#define NLC_INVALID 0x0000
+#define NLC_PE_FULL 0x0001
+#define NLC_PE_PARTIAL 0x0002
+#define NLC_NE_VALID 0x0004
+
+#define IS_PE_VALID(state) ((state != NLC_INVALID) && \
+                            (state & (NLC_PE_FULL | NLC_PE_PARTIAL)))
+#define IS_NE_VALID(state) ((state != NLC_INVALID) && (state & NLC_NE_VALID))
+
+#define IS_PEC_ENABLED(conf) (conf->positive_entry_cache)
+#define IS_CACHE_ENABLED(conf) ((!conf->cache_disabled))
+
+#define NLC_STACK_UNWIND(fop, frame, params ...) do {       \
+        nlc_local_t *__local = NULL;                        \
+        xlator_t *__xl      = NULL;                         \
+        if (frame) {                                        \
+                __xl = frame->this;                         \
+                __local = frame->local;                     \
+                frame->local = NULL;                        \
+        }                                                   \
+        STACK_UNWIND_STRICT (fop, frame, params);           \
+        nlc_local_wipe (__xl, __local);                     \
+} while (0)
+
+enum nlc_cache_clear_reason {
+        NLC_NONE = 0,
+        NLC_TIMER_EXPIRED,
+        NLC_LRU_PRUNE,
+};
+
+struct nlc_ne {
+        struct list_head  list;
+        char             *name;
+};
+typedef struct nlc_ne nlc_ne_t;
+
+struct nlc_pe {
+        struct list_head  list;
+        inode_t          *inode;
+        char             *name;
+};
+typedef struct nlc_pe nlc_pe_t;
+
+struct nlc_timer_data {
+        inode_t          *inode;
+        xlator_t         *this;
+};
+typedef struct nlc_timer_data nlc_timer_data_t;
+
+struct nlc_lru_node {
+        inode_t          *inode;
+        struct list_head  list;
+};
+typedef struct nlc_lru_node nlc_lru_node_t;
+
+struct nlc_ctx {
+        struct list_head         pe;   /* list of positive entries */
+        struct list_head         ne;   /* list of negative entries */
+        uint64_t                 state;
+        time_t                   cache_time;
+        struct gf_tw_timer_list *timer;
+        nlc_timer_data_t         *timer_data;
+        size_t                   cache_size;
+        uint64_t                 refd_inodes;
+        gf_lock_t                lock;
+};
+typedef struct nlc_ctx nlc_ctx_t;
+
+struct nlc_local {
+        loc_t    loc;
+        loc_t    loc2;
+        inode_t *inode;
+        inode_t *parent;
+        fd_t    *fd;
+        char    *linkname;
+        glusterfs_fop_t fop;
+};
+typedef struct nlc_local nlc_local_t;
+
+struct nlc_statistics {
+        gf_atomic_t nlc_hit; /* No. of times lookup/stat was served from this xl */
+        gf_atomic_t nlc_miss; /* No. of times negative lookups were sent to disk */
+        /* More granular counters */
+        gf_atomic_t nameless_lookup;
+        gf_atomic_t getrealfilename_hit;
+        gf_atomic_t getrealfilename_miss;
+        gf_atomic_t pe_inode_cnt;
+        gf_atomic_t ne_inode_cnt;
+        gf_atomic_t nlc_invals; /* No. of invalidates recieved from upcall*/
+};
+
+struct nlc_conf {
+        int32_t              cache_timeout;
+        gf_boolean_t         positive_entry_cache;
+        gf_boolean_t         negative_entry_cache;
+        gf_boolean_t         disable_cache;
+        uint64_t             cache_size;
+        gf_atomic_t          current_cache_size;
+        uint64_t             inode_limit;
+        gf_atomic_t          refd_inodes;
+        struct tvec_base    *timer_wheel;
+        time_t               last_child_down;
+        struct list_head     lru;
+        gf_lock_t            lock;
+        struct nlc_statistics nlc_counter;
+};
+typedef struct nlc_conf nlc_conf_t;
+
+gf_boolean_t
+nlc_get_real_file_name (xlator_t *this, loc_t *loc, const char *fname,
+                        int32_t *op_ret, int32_t *op_errno, dict_t *dict);
+
+gf_boolean_t
+nlc_is_negative_lookup (xlator_t *this, loc_t *loc);
+
+void
+nlc_set_dir_state (xlator_t *this, inode_t *inode, uint64_t state);
+
+void
+nlc_dir_add_pe (xlator_t *this, inode_t *inode, inode_t *entry_ino,
+                const char *name);
+
+void
+nlc_dir_remove_pe (xlator_t *this, inode_t *inode, inode_t *entry_ino,
+                   const char *name, gf_boolean_t multilink);
+
+void
+nlc_dir_add_ne (xlator_t *this, inode_t *inode, const char *name);
+
+void
+nlc_local_wipe (xlator_t *this, nlc_local_t *local);
+
+nlc_local_t *
+nlc_local_init (call_frame_t *frame, xlator_t *this, glusterfs_fop_t fop,
+                loc_t *loc, loc_t *loc2);
+
+void
+nlc_update_child_down_time (xlator_t *this, time_t *now);
+
+void
+nlc_inode_clear_cache (xlator_t *this, inode_t *inode,
+                      int reason);
+
+void
+nlc_dump_inodectx (xlator_t *this, inode_t *inode);
+
+void
+nlc_clear_all_cache (xlator_t *this);
+
+void
+nlc_disable_cache (xlator_t *this);
+
+#endif /* __NL_CACHE_H__ */