diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2022-07-08 14:25:04 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2022-07-29 20:10:07 -0400 |
| commit | 668ed92e651d3c25f9b6e8cb7ceca54d00daa96d (patch) | |
| tree | dcca90f48461852185ce6b0e50b8de40bf88a439 /fs/nfsd/filecache.c | |
| parent | 2e6c6e4c4375bfd3defa5b1ff3604d9f33d1c936 (diff) | |
NFSD: WARN when freeing an item still linked via nf_lru
Add a guardrail to prevent freeing memory that is still on a list.
This includes either a dispose list or the LRU list.
This is the sign of a bug, but this class of bugs can be detected
so that they don't endanger system stability, especially while
debugging.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd/filecache.c')
| -rw-r--r-- | fs/nfsd/filecache.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 777698a2e5a6..f58685f1b120 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -214,6 +214,14 @@ nfsd_file_free(struct nfsd_file *nf) fput(nf->nf_file); flush = true; } + + /* + * If this item is still linked via nf_lru, that's a bug. + * WARN and leak it to preserve system stability. + */ + if (WARN_ON_ONCE(!list_empty(&nf->nf_lru))) + return flush; + call_rcu(&nf->nf_rcu, nfsd_file_slab_free); return flush; } @@ -343,7 +351,7 @@ nfsd_file_dispose_list(struct list_head *dispose) while(!list_empty(dispose)) { nf = list_first_entry(dispose, struct nfsd_file, nf_lru); - list_del(&nf->nf_lru); + list_del_init(&nf->nf_lru); nfsd_file_flush(nf); nfsd_file_put_noref(nf); } @@ -357,7 +365,7 @@ nfsd_file_dispose_list_sync(struct list_head *dispose) while(!list_empty(dispose)) { nf = list_first_entry(dispose, struct nfsd_file, nf_lru); - list_del(&nf->nf_lru); + list_del_init(&nf->nf_lru); nfsd_file_flush(nf); if (!refcount_dec_and_test(&nf->nf_ref)) continue; |