The afs_read objects created by afs_req_issue_op() get leaked because
afs_alloc_read() returns a ref and then afs_fetch_data() gets its own ref
which is released when the operation completes, but the initial ref is
never released.
Fix this by discarding the initial ref at the end of afs_req_issue_op().
This leak also covered another bug whereby a ref isn't got on the key
attached to the read record by afs_req_issue_op(). This isn't a problem as
long as the afs_read req never goes away...
Fix this by calling key_get() in afs_req_issue_op().
This was found by the generic/074 test. It leaks a bunch of kmalloc-192
objects each time it is run, which can be observed by watching
/proc/slabinfo.
Fixes: f7605fa869cf ("afs: Fix leak of afs_read objects")
Reported-by: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/163010394740.3035676.8516846193899793357.stgit@xxxxxxxxxxxxxxxxxxxxxx/
---
fs/afs/file.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index db035ae2a134..6688fff14b0b 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -295,7 +295,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
fsreq->subreq = subreq;
fsreq->pos = subreq->start + subreq->transferred;
fsreq->len = subreq->len - subreq->transferred;
- fsreq->key = subreq->rreq->netfs_priv;
+ fsreq->key = key_get(subreq->rreq->netfs_priv);
fsreq->vnode = vnode;
fsreq->iter = &fsreq->def_iter;
@@ -304,6 +304,7 @@ static void afs_req_issue_op(struct netfs_read_subrequest *subreq)
fsreq->pos, fsreq->len);
afs_fetch_data(fsreq->vnode, fsreq);
+ afs_put_read(fsreq);
}
static int afs_symlink_readpage(struct page *page)
