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authorPaul Dagnelie <[email protected]>2017-07-06 10:35:20 -0700
committerBrian Behlendorf <[email protected]>2018-05-04 10:50:24 -0700
commit64c1dcefe38a62d304177475a2ef77111cec612a (patch)
tree71f70307a257affa27e7e8798337f93a20e571c9 /module/zfs
parent5e097c67f14e32de67c62752e728e9fbabb920dc (diff)
OpenZFS 9421, 9422 - zdb show possibly leaked objects
9421 zdb should detect and print out the number of "leaked" objects 9422 zfs diff and zdb should explicitly mark objects that are on the deleted queue It is possible for zfs to "leak" objects in such a way that they are not freed, but are also not accessible via the POSIX interface. As the only way to know that this is happened is to see one of them directly in a zdb run, or by noting unaccounted space usage, zdb should be enhanced to count these objects and return failure if some are detected. We have access to the delete queue through the zfs_get_deleteq function; we should call it in dump_znode to determine if the object is on the delete queue. This is not the most efficient possible method, but it is the simplest to implement, and should suffice for the common case where there few objects on the delete queue. Also zfs diff and zdb currently traverse every single dnode in a dataset and tries to figure out the path of the object by following it's parent. When an object is placed on the delete queue, for all practical purposes it's already discarded, it's parent might not exist anymore, and another object might now have the object number that belonged to the parent. While all of the above makes sense, when trying to figure out the path of an object that is on the delete queue, we can run into issues where either it is impossible to determine the path because the parent is gone, or another dnode has taken it's place and thus we are returned a wrong path. We should therefore avoid trying to determine the path of an object on the delete queue and mark the object itself as being on the delete queue to avoid confusion. To achieve this, we currently have two ideas: 1. When putting an object on the delete queue, change it's parent object number to a known constant that means NULL. 2. When displaying objects, first check if it is present on the delete queue. Authored by: Paul Dagnelie <[email protected]> Reviewed by: Matt Ahrens <[email protected]> Reviewed by: Pavel Zakharov <[email protected]> Approved by: Matt Ahrens <[email protected]> Ported-by: Brian Behlendorf <[email protected]> OpenZFS-issue: https://illumos.org/issues/9421 OpenZFS-issue: https://illumos.org/issues/9422 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45ae0dd9ca Closes #7500
Diffstat (limited to 'module/zfs')
-rw-r--r--module/zfs/zfs_znode.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
index 5288c9c68..c8a613f14 100644
--- a/module/zfs/zfs_znode.c
+++ b/module/zfs/zfs_znode.c
@@ -2120,6 +2120,17 @@ zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
*path = '\0';
sa_hdl = hdl;
+ uint64_t deleteq_obj;
+ VERIFY0(zap_lookup(osp, MASTER_NODE_OBJ,
+ ZFS_UNLINKED_SET, sizeof (uint64_t), 1, &deleteq_obj));
+ error = zap_lookup_int(osp, deleteq_obj, obj);
+ if (error == 0) {
+ return (ESTALE);
+ } else if (error != ENOENT) {
+ return (error);
+ }
+ error = 0;
+
for (;;) {
uint64_t pobj = 0;
char component[MAXNAMELEN + 2];