21541: inodes are marked as "in use" in directory list

When updating directory contents (using merge()) and when the client
is reading a directory using opendir(), the inodes are marked as "in
use" so they don't get immediately reclaimed in a memory pressure
situation.

Arvados-DCO-1.1-Signed-off-by: Peter Amstutz <peter.amstutz@curii.com>

diff --git a/services/fuse/arvados_fuse/__init__.py b/services/fuse/arvados_fuse/__init__.py
index 31afcda8d12267970631372014706793ef95c9f3..b075c9085ead01a358b57f3fc6fd24d8530b4f0a 100644 (file)
--- a/services/fuse/arvados_fuse/__init__.py
+++ b/services/fuse/arvados_fuse/__init__.py
@@ -133,6 +133,13 @@ class DirectoryHandle(Handle):
     def __init__(self, fh, dirobj, entries):
         super(DirectoryHandle, self).__init__(fh, dirobj)
         self.entries = entries
+        for ent in self.entries:
+            ent[1].inc_use()
+
+    def release(self):
+        for ent in self.entries:
+            ent[1].dec_use()
+        super(DirectoryHandle, self).release()
 
 
 class InodeCache(object):
@@ -176,11 +183,11 @@ class InodeCache(object):
             # has_ref() check first.
 
             if obj.has_ref(True):
-                _logger.debug("InodeCache cannot clear inode %i, still referenced", obj.inode)
+                #_logger.debug("InodeCache cannot clear inode %i, still referenced", obj.inode)
                 return
 
             if obj.in_use():
-                _logger.debug("InodeCache cannot clear inode %i, in use", obj.inode)
+                #_logger.debug("InodeCache cannot clear inode %i, in use", obj.inode)
                 return
 
             obj.kernel_invalidate()
@@ -564,14 +571,13 @@ class Operations(llfuse.Operations):
 
         if name == '.':
             inode = parent_inode
-        else:
-            if parent_inode in self.inodes:
-                p = self.inodes[parent_inode]
-                self.inodes.touch(p)
-                if name == '..':
-                    inode = p.parent_inode
-                elif isinstance(p, Directory) and name in p:
-                    inode = p[name].inode
+        elif parent_inode in self.inodes:
+            p = self.inodes[parent_inode]
+            self.inodes.touch(p)
+            if name == '..':
+                inode = p.parent_inode
+            elif isinstance(p, Directory) and name in p:
+                inode = p[name].inode
 
         if inode != None:
             _logger.debug("arv-mount lookup: parent_inode %i name '%s' inode %i",
@@ -703,8 +709,11 @@ class Operations(llfuse.Operations):
         if p.parent_inode in self.inodes:
             parent = self.inodes[p.parent_inode]
         else:
+            _logger.warning("arv-mount opendir: parent inode %i of %i is missing", p.parent_inode, inode)
             raise llfuse.FUSEError(errno.EIO)
 
+        _logger.debug("arv-mount opendir: inode %i fh %i ", inode, fh)
+
         # update atime
         self.inodes.touch(p)
         self._filehandles[fh] = DirectoryHandle(fh, p, [('.', p), ('..', parent)] + listitems(p))
@@ -722,8 +731,9 @@ class Operations(llfuse.Operations):
 
         e = off
         while e < len(handle.entries):
-            if handle.entries[e][1].inode in self.inodes:
-                yield (handle.entries[e][0].encode(self.inodes.encoding), self.getattr(handle.entries[e][1].inode), e+1)
+            ent = handle.entries[e]
+            if ent[1].inode in self.inodes:
+                yield (ent[0].encode(self.inodes.encoding), self.getattr(ent[1].inode), e+1)
             e += 1
 
     @statfs_time.time()

diff --git a/services/fuse/arvados_fuse/fusedir.py b/services/fuse/arvados_fuse/fusedir.py
index e3b8dd4c2cca29616626dab55f6d440c22b58f51..eeb96bceb357b8e2ad4bc120ce68989f76e4b1bc 100644 (file)
--- a/services/fuse/arvados_fuse/fusedir.py
+++ b/services/fuse/arvados_fuse/fusedir.py
@@ -176,30 +176,44 @@ class Directory(FreshBase):
         changed = False
         for i in items:
             name = self.sanitize_filename(fn(i))
-            if name:
-                if name in oldentries and same(oldentries[name], i):
+            if not name:
+                continue
+            if name in oldentries:
+                ent = oldentries[name]
+                ent.inc_use()
+                if same(ent, i):
                     # move existing directory entry over
-                    self._entries[name] = oldentries[name]
+                    self._entries[name] = ent
                     del oldentries[name]
-                else:
-                    _logger.debug("Adding entry '%s' to inode %i", name, self.inode)
-                    # create new directory entry
-                    ent = new_entry(i)
-                    if ent is not None:
-                        self._entries[name] = self.inodes.add_entry(ent)
-                        changed = True
+
+        for i in items:
+            name = self.sanitize_filename(fn(i))
+            if not name:
+                continue
+            if name not in self._entries:
+                _logger.debug("Adding entry '%s' to inode %i", name, self.inode)
+                # create new directory entry
+                ent = new_entry(i)
+                if ent is not None:
+                    ent.inc_use()
+                    self._entries[name] = self.inodes.add_entry(ent)
+                    changed = True
 
         # delete any other directory entries that were not in found in 'items'
         for i in oldentries:
             _logger.debug("Forgetting about entry '%s' on inode %i", i, self.inode)
             self.inodes.invalidate_entry(self, i)
             self.inodes.del_entry(oldentries[i])
+            ent.dec_use()
             changed = True
 
         if changed:
             self.inodes.invalidate_inode(self)
             self._mtime = time.time()
 
+        for ent in self._entries.values():
+           ent.dec_use()
+
         self.fresh()
 
     def in_use(self):
@@ -1060,10 +1074,14 @@ class ProjectDirectory(Directory):
 
         try:
             with llfuse.lock_released:
+                _logger.debug("Getting lock to update %s", self.project_uuid)
                 self._updating_lock.acquire()
                 if not self.stale():
+                    _logger.debug("%s was updated already", self.project_uuid)
                     return
 
+                _logger.debug("Requesting update of %s", self.project_uuid)
+
                 if group_uuid_pattern.match(self.project_uuid):
                     self.project_object = self.api.groups().get(
                         uuid=self.project_uuid).execute(num_retries=self.num_retries)
@@ -1092,7 +1110,6 @@ class ProjectDirectory(Directory):
                         *self._filters_for('collections', qualified=True),
                     ],
                 ) if obj['current_version_uuid'] == obj['uuid'])
-
             # end with llfuse.lock_released, re-acquire lock
 
             self.merge(contents,