NFS: Don't allow waiting for exiting tasks

[ 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>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 1aa67fca69b2fbd8afb1c51be78198220b1e13c7..119e447758b994b34e55e7b28fd4f34fa089e2e1 100644 (file)
--- 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 59bb4d0338f39a6227333654743230e7b27fcdc5..3cedb7979fcd0264991947048c82e14e76e6923f 100644 (file)
--- 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 0c3bc98cd999cc39a0a883102a83a8b35b57c30d..c1736dbb92b638edaaf7f24d1a4dcbe09dcb3c69 100644 (file)
--- 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 810cfd9b7e533b2fc245ba8218a4357efdcc72d5..cfdbd521fc7b667c1a57011b7e23004b736899cf 100644 (file)
--- 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)