netfs: Fix double put of request

If a netfs request finishes during the pause loop, it will have the ref
that belongs to the IN_PROGRESS flag removed at that point - however, if it
then goes to the final wait loop, that will *also* put the ref because it
sees that the IN_PROGRESS flag is clear and incorrectly assumes that this
happened when it called the collector.

In fact, since IN_PROGRESS is clear, we shouldn't call the collector again
since it's done all the cleanup, such as calling ->ki_complete().

Fix this by making netfs_collect_in_app() just return, indicating that
we're done if IN_PROGRESS is removed.

Fixes: 2b1424cd131c ("netfs: Fix wait/wake to be consistent about the waitqueue used")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250701163852.2171681-3-dhowells@redhat.com
Tested-by: Steve French <sfrench@samba.org>
Reviewed-by: Paulo Alcantara <pc@manguebit.org>
cc: Steve French <sfrench@samba.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index 0a54b12034868922e6b0a99ba4ee6abb5bccc2e0..8cf73b237269a9a492d2909ae3cd66730aeb9a85 100644 (file)
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -383,6 +383,11 @@ static int netfs_collect_in_app(struct netfs_io_request *rreq,
 {
        bool need_collect = false, inactive = true, done = true;
 
+       if (!netfs_check_rreq_in_progress(rreq)) {
+               trace_netfs_rreq(rreq, netfs_rreq_trace_recollect);
+               return 1; /* Done */
+       }
+
        for (int i = 0; i < NR_IO_STREAMS; i++) {
                struct netfs_io_subrequest *subreq;
                struct netfs_io_stream *stream = &rreq->io_streams[i];

diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 333d2e38dd2cbc16b80a16fad06c782f13e6a001..ba35dc66e98619d32f3437cc90302e4ccc915c4f 100644 (file)
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -56,6 +56,7 @@
        EM(netfs_rreq_trace_dirty,              "DIRTY  ")      \
        EM(netfs_rreq_trace_done,               "DONE   ")      \
        EM(netfs_rreq_trace_free,               "FREE   ")      \
+       EM(netfs_rreq_trace_recollect,          "RECLLCT")      \
        EM(netfs_rreq_trace_redirty,            "REDIRTY")      \
        EM(netfs_rreq_trace_resubmit,           "RESUBMT")      \
        EM(netfs_rreq_trace_set_abandon,        "S-ABNDN")      \