sched/wait: Fix the signal handling fix
Jan Stancek reported that I wrecked things for him by fixing things for
Vladimir :/
His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which
should not be possible, however my previous patch made this possible by
unconditionally checking signal_pending().
We cannot use current->state as was done previously, because the
instruction after the store to that variable it can be changed. We must
instead pass the initial state along and use that.
Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers")
Reported-by: Jan Stancek <jstancek@redhat.com>
Reported-by: Chris Mason <clm@fb.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Chris Mason <clm@fb.com>
Reviewed-by: Paul Turner <pjt@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: tglx@linutronix.de
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: hpa@zytor.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 6b66dd5..a329f5b 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1831,11 +1831,11 @@
* @word: long word containing the bit lock
*/
static int
-cifs_wait_bit_killable(struct wait_bit_key *key)
+cifs_wait_bit_killable(struct wait_bit_key *key, int mode)
{
- if (fatal_signal_pending(current))
- return -ERESTARTSYS;
freezable_schedule_unsafe();
+ if (signal_pending_state(mode, current))
+ return -ERESTARTSYS;
return 0;
}
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 31b0a52..c7e8b87 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -75,11 +75,11 @@
* nfs_wait_bit_killable - helper for functions that are sleeping on bit locks
* @word: long word containing the bit lock
*/
-int nfs_wait_bit_killable(struct wait_bit_key *key)
+int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
{
- if (fatal_signal_pending(current))
- return -ERESTARTSYS;
freezable_schedule_unsafe();
+ if (signal_pending_state(mode, current))
+ return -ERESTARTSYS;
return 0;
}
EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 56cfde2..9dea85f 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -379,7 +379,7 @@
extern void nfs_clear_inode(struct inode *);
extern void nfs_evict_inode(struct inode *);
void nfs_zap_acl_cache(struct inode *inode);
-extern int nfs_wait_bit_killable(struct wait_bit_key *key);
+extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);
/* super.c */
extern const struct super_operations nfs_sops;
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index fe3ddd2..452a011 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -129,7 +129,7 @@
set_bit(NFS_IO_INPROGRESS, &c->flags);
if (atomic_read(&c->io_count) == 0)
break;
- ret = nfs_wait_bit_killable(&q.key);
+ ret = nfs_wait_bit_killable(&q.key, TASK_KILLABLE);
} while (atomic_read(&c->io_count) != 0 && !ret);
finish_wait(wq, &q.wait);
return ret;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 5a8ae21..bec0384 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1466,11 +1466,11 @@
}
/* stop waiting if someone clears NFS_LAYOUT_RETRY_LAYOUTGET bit. */
-static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key)
+static int pnfs_layoutget_retry_bit_wait(struct wait_bit_key *key, int mode)
{
if (!test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, key->flags))
return 1;
- return nfs_wait_bit_killable(key);
+ return nfs_wait_bit_killable(key, mode);
}
static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 1e1bf9f..513b36f 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -145,7 +145,7 @@
list_del(&old->task_list);
}
-typedef int wait_bit_action_f(struct wait_bit_key *);
+typedef int wait_bit_action_f(struct wait_bit_key *, int mode);
void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
@@ -960,10 +960,10 @@
} while (0)
-extern int bit_wait(struct wait_bit_key *);
-extern int bit_wait_io(struct wait_bit_key *);
-extern int bit_wait_timeout(struct wait_bit_key *);
-extern int bit_wait_io_timeout(struct wait_bit_key *);
+extern int bit_wait(struct wait_bit_key *, int);
+extern int bit_wait_io(struct wait_bit_key *, int);
+extern int bit_wait_timeout(struct wait_bit_key *, int);
+extern int bit_wait_io_timeout(struct wait_bit_key *, int);
/**
* wait_on_bit - wait for a bit to be cleared
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index f10bd87..f15d6b6 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -392,7 +392,7 @@
do {
prepare_to_wait(wq, &q->wait, mode);
if (test_bit(q->key.bit_nr, q->key.flags))
- ret = (*action)(&q->key);
+ ret = (*action)(&q->key, mode);
} while (test_bit(q->key.bit_nr, q->key.flags) && !ret);
finish_wait(wq, &q->wait);
return ret;
@@ -431,7 +431,7 @@
prepare_to_wait_exclusive(wq, &q->wait, mode);
if (!test_bit(q->key.bit_nr, q->key.flags))
continue;
- ret = action(&q->key);
+ ret = action(&q->key, mode);
if (!ret)
continue;
abort_exclusive_wait(wq, &q->wait, mode, &q->key);
@@ -581,43 +581,43 @@
}
EXPORT_SYMBOL(wake_up_atomic_t);
-__sched int bit_wait(struct wait_bit_key *word)
+__sched int bit_wait(struct wait_bit_key *word, int mode)
{
schedule();
- if (signal_pending(current))
+ if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(bit_wait);
-__sched int bit_wait_io(struct wait_bit_key *word)
+__sched int bit_wait_io(struct wait_bit_key *word, int mode)
{
io_schedule();
- if (signal_pending(current))
+ if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL(bit_wait_io);
-__sched int bit_wait_timeout(struct wait_bit_key *word)
+__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
if (time_after_eq(now, word->timeout))
return -EAGAIN;
schedule_timeout(word->timeout - now);
- if (signal_pending(current))
+ if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
EXPORT_SYMBOL_GPL(bit_wait_timeout);
-__sched int bit_wait_io_timeout(struct wait_bit_key *word)
+__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
{
unsigned long now = READ_ONCE(jiffies);
if (time_after_eq(now, word->timeout))
return -EAGAIN;
io_schedule_timeout(word->timeout - now);
- if (signal_pending(current))
+ if (signal_pending_state(mode, current))
return -EINTR;
return 0;
}
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index f14f24e..73ad57a 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -250,11 +250,11 @@
}
EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue);
-static int rpc_wait_bit_killable(struct wait_bit_key *key)
+static int rpc_wait_bit_killable(struct wait_bit_key *key, int mode)
{
- if (fatal_signal_pending(current))
- return -ERESTARTSYS;
freezable_schedule_unsafe();
+ if (signal_pending_state(mode, current))
+ return -ERESTARTSYS;
return 0;
}
