pvfs_open: add pvfs_can_update_file_size()

TODO: this is not complete, we need more tests to trigger this

metze
(This used to be commit 66ad1081f2be8a0caa16fb0d614b857a5bde751c)

diff --git a/source4/ntvfs/posix/pvfs_open.c b/source4/ntvfs/posix/pvfs_open.c
index 4110df292d26fe4e5eb0ce2fb08dde60cb443d1a..12b70c00fd9909591c4de2ec91c9e2ef09163fe9 100644 (file)
--- a/source4/ntvfs/posix/pvfs_open.c
+++ b/source4/ntvfs/posix/pvfs_open.c
@@ -1620,6 +1620,68 @@ NTSTATUS pvfs_can_rename(struct pvfs_state *pvfs,
        return status;
 }
 
+/*
+  determine if the file size of a file can be changed,
+  or if it is prevented by an already open file
+*/
+NTSTATUS pvfs_can_update_file_size(struct pvfs_state *pvfs,
+                                  struct ntvfs_request *req,
+                                  struct pvfs_filename *name,
+                                  struct odb_lock **lckp)
+{
+       NTSTATUS status;
+       DATA_BLOB key;
+       struct odb_lock *lck;
+       uint32_t share_access;
+       uint32_t access_mask;
+       bool break_to_none;
+       bool delete_on_close;
+
+       status = pvfs_locking_key(name, name, &key);
+       if (!NT_STATUS_IS_OK(status)) {
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       lck = odb_lock(req, pvfs->odb_context, &key);
+       if (lck == NULL) {
+               DEBUG(0,("Unable to lock opendb for can_stat\n"));
+               return NT_STATUS_INTERNAL_DB_CORRUPTION;
+       }
+
+       /* TODO: this may needs some more flags */
+       share_access    = NTCREATEX_SHARE_ACCESS_WRITE;
+       access_mask     = 0;
+       delete_on_close = false;
+       break_to_none   = true;
+
+       status = odb_can_open(lck, name->stream_id,
+                             share_access, access_mask, delete_on_close,
+                             0, break_to_none);
+
+       /*
+        * if it's a sharing violation or we got no oplock
+        * only keep the lock if the caller requested access
+        * to the lock
+        */
+       if (NT_STATUS_EQUAL(status, NT_STATUS_SHARING_VIOLATION) ||
+           NT_STATUS_EQUAL(status, NT_STATUS_OPLOCK_NOT_GRANTED)) {
+               if (lckp) {
+                       *lckp = lck;
+               } else {
+                       talloc_free(lck);
+               }
+       } else if (!NT_STATUS_IS_OK(status)) {
+               talloc_free(lck);
+               if (lckp) {
+                       *lckp = NULL;
+               }
+       } else if (lckp) {
+               *lckp = lck;
+       }
+
+       return status;
+}
+
 /*
   determine if file meta data can be accessed, or if it is prevented by an
   already open file