[PATCH AUTOSEL 6.14 013/642] NFS: Don't allow waiting for exiting tasks

Sasha Levin
2025-05-05T22:14:41Z

[ Upstream commit 8d3ca331026a7f9700d3747eed59a67b8f828cdc ]

Once a task calls exit_signals() it can no longer be signalled. So do
not allow it to do killable waits.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/inode.c | 2 ++
fs/nfs/internal.h | 5 +++++
fs/nfs/nfs3proc.c | 2 +-
fs/nfs/nfs4proc.c | 9 +++++++--
4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 1aa67fca69b2f..119e447758b99 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -74,6 +74,8 @@ nfs_fattr_to_ino_t(struct nfs_fattr *fattr)

int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
{
+ if (unlikely(nfs_current_task_exiting()))
+ return -EINTR;
schedule();
if (signal_pending_state(mode, current))
return -ERESTARTSYS;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 59bb4d0338f39..3cedb7979fcd0 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -905,6 +905,11 @@ static inline u32 nfs_stateid_hash(const nfs4_stateid *stateid)
NFS4_STATEID_OTHER_SIZE);
}

+static inline bool nfs_current_task_exiting(void)
+{
+ return (current->flags & PF_EXITING) != 0;
+}
+
static inline bool nfs_error_is_fatal(int err)
{
switch (err) {
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 0c3bc98cd999c..c1736dbb92b63 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -39,7 +39,7 @@ nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
__set_current_state(TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
schedule_timeout(NFS_JUKEBOX_RETRY_TIME);
res = -ERESTARTSYS;
- } while (!fatal_signal_pending(current));
+ } while (!fatal_signal_pending(current) && !nfs_current_task_exiting());
return res;
}

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6e95db6c17e92..17bc4df0f29ce 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -443,6 +443,8 @@ static int nfs4_delay_killable(long *timeout)
{
might_sleep();

+ if (unlikely(nfs_current_task_exiting()))
+ return -EINTR;
__set_current_state(TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
schedule_timeout(nfs4_update_delay(timeout));
if (!__fatal_signal_pending(current))
@@ -454,6 +456,8 @@ static int nfs4_delay_interruptible(long *timeout)
{
might_sleep();

+ if (unlikely(nfs_current_task_exiting()))
+ return -EINTR;
__set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE_UNSAFE);
schedule_timeout(nfs4_update_delay(timeout));
if (!signal_pending(current))
@@ -1774,7 +1778,8 @@ static void nfs_set_open_stateid_locked(struct nfs4_state *state,
rcu_read_unlock();
trace_nfs4_open_stateid_update_wait(state->inode, stateid, 0);

- if (!fatal_signal_pending(current)) {
+ if (!fatal_signal_pending(current) &&
+ !nfs_current_task_exiting()) {
if (schedule_timeout(5*HZ) == 0)
status = -EAGAIN;
else
@@ -3578,7 +3583,7 @@ static bool nfs4_refresh_open_old_stateid(nfs4_stateid *dst,
write_sequnlock(&state->seqlock);
trace_nfs4_close_stateid_update_wait(state->inode, dst, 0);

- if (fatal_signal_pending(current))
+ if (fatal_signal_pending(current) || nfs_current_task_exiting())
status = -EINTR;
else
if (schedule_timeout(5*HZ) != 0)
--
2.39.5