core: tcmu-runner process continuous growing logs lru_size showing -1 (#1776)

* core: tcmu-runner process continuous growing logs lru_size showing -1

At the time of calling inode_table_prune it checks if current lru_size
is greater than lru_limit but lru_list is empty it throws a log message
"Empty inode lru list found but with (%d) lru_size".As per code reading
it seems lru_size is out of sync with the actual number of inodes in
lru_list. Due to throwing continuous error messages entire disk is
getting full and the user has to restart the tcmu-runner process to use
the volumes.The log message was introduce by a patch
https://review.gluster.org/#/c/glusterfs/+/15087/.

Solution: Introduce a flag in_lru_list to take decision about inode is
          being part of lru_list or not.
Fixes: #1775
Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>

Change-Id: I4b836bebf4b5db65fbf88ff41c6c88f4a7ac55c1

* core: tcmu-runner process continuous growing logs lru_size showing -1
Update in_lru_list flag only while modify lru_size

Fixes: #1775
Change-Id: I3bea1c6e748b4f50437999bae59edeb3d7677f47
Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>

* core: tcmu-runner process continuous growing logs lru_size showing -1

Resolve comments in inode_table_destroy and inode_table_prune

Fixes: #1775
Change-Id: I5aa4d8c254f0fe374daa5ec604f643dea8dd56ff
Signed-off-by: Mohit Agrawal moagrawa@redhat.com

* core: tcmu-runner process continuous growing logs lru_size showing -1

Update in_lru_list only while update lru_size

Fixes: #1775
Change-Id: I950eb1f0010c3d4bcc44a33225a502d2291d1a83
Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>

2 files changed, 15 insertions, 0 deletions

diff --git a/libglusterfs/src/glusterfs/inode.h b/libglusterfs/src/glusterfs/inode.h
index c126822698..d7dfb1bddd 100644
--- a/libglusterfs/src/glusterfs/inode.h
+++ b/libglusterfs/src/glusterfs/inode.h
@@ -114,6 +114,7 @@ struct _inode {
     struct _inode_ctx *_ctx; /* replacement for dict_t *(inode->ctx) */
     bool in_invalidate_list; /* Set if inode is in table invalidate list */
     bool invalidate_sent;    /* Set it if invalidator_fn is called for inode */
+    bool in_lru_list;        /* Set if inode is in table lru list */
 };
 
 #define UUID0_STR "00000000-0000-0000-0000-000000000000"
diff --git a/libglusterfs/src/inode.c b/libglusterfs/src/inode.c
index 5a15932f60..8b7cb7f41d 100644
--- a/libglusterfs/src/inode.c
+++ b/libglusterfs/src/inode.c
@@ -413,8 +413,10 @@ __inode_passivate(inode_t *inode)
     dentry_t *dentry = NULL;
     dentry_t *t = NULL;
 
+    GF_ASSERT(!inode->in_lru_list);
     list_move_tail(&inode->list, &inode->table->lru);
     inode->table->lru_size++;
+    inode->in_lru_list = _gf_true;
 
     list_for_each_entry_safe(dentry, t, &inode->dentry_list, inode_list)
     {
@@ -562,7 +564,10 @@ __inode_ref(inode_t *inode, bool is_invalidate)
             inode->in_invalidate_list = false;
             inode->table->invalidate_size--;
         } else {
+            GF_ASSERT(inode->table->lru_size > 0);
+            GF_ASSERT(inode->in_lru_list);
             inode->table->lru_size--;
+            inode->in_lru_list = _gf_false;
         }
         if (is_invalidate) {
             inode->in_invalidate_list = true;
@@ -701,6 +706,8 @@ inode_new(inode_table_t *table)
         {
             list_add(&inode->list, &table->lru);
             table->lru_size++;
+            GF_ASSERT(!inode->in_lru_list);
+            inode->in_lru_list = _gf_true;
             __inode_ref(inode, false);
         }
         pthread_mutex_unlock(&table->lock);
@@ -1564,6 +1571,7 @@ inode_table_prune(inode_table_t *table)
         lru_size = table->lru_size;
         while (lru_size > (table->lru_limit)) {
             if (list_empty(&table->lru)) {
+                GF_ASSERT(0);
                 gf_msg_callingfn(THIS->name, GF_LOG_WARNING, 0,
                                  LG_MSG_INVALID_INODE_LIST,
                                  "Empty inode lru list found"
@@ -1574,6 +1582,7 @@ inode_table_prune(inode_table_t *table)
 
             lru_size--;
             entry = list_entry(table->lru.next, inode_t, list);
+            GF_ASSERT(entry->in_lru_list);
             /* The logic of invalidation is required only if invalidator_fn
                is present */
             if (table->invalidator_fn) {
@@ -1591,6 +1600,7 @@ inode_table_prune(inode_table_t *table)
             }
 
             table->lru_size--;
+            entry->in_lru_list = _gf_false;
             __inode_retire(entry);
             ret++;
         }
@@ -1646,6 +1656,7 @@ __inode_table_init_root(inode_table_t *table)
 
     list_add(&root->list, &table->lru);
     table->lru_size++;
+    root->in_lru_list = _gf_true;
 
     iatt.ia_gfid[15] = 1;
     iatt.ia_ino = 1;
@@ -1907,8 +1918,11 @@ inode_table_destroy(inode_table_t *inode_table)
         while (!list_empty(&inode_table->lru)) {
             trav = list_first_entry(&inode_table->lru, inode_t, list);
             inode_forget_atomic(trav, 0);
+            GF_ASSERT(inode_table->lru_size > 0);
+            GF_ASSERT(trav->in_lru_list);
             __inode_retire(trav);
             inode_table->lru_size--;
+            trav->in_lru_list = _gf_false;
         }
 
         /* Same logic for invalidate list */