[PATCH 4.2.y-ckt 182/305] sched/wait: Fix the signal handling fix
From: Kamal Mostafa <hidden>
Date: 2016-01-16 00:33:45
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, scheduler, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: Peter Zijlstra <peterz@infradead.org>
commit dfd01f026058a59a513f8a365b439a0681b803af upstream.
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 <redacted>
Tested-by: Jan Stancek <jstancek@redhat.com>
Tested-by: Vladimir Murzin <redacted>
Tested-by: Chris Mason <redacted>
Reviewed-by: Paul Turner <redacted>
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>
Signed-off-by: Kamal Mostafa <redacted>
---
fs/cifs/inode.c | 6 +++---
fs/nfs/inode.c | 6 +++---
fs/nfs/internal.h | 2 +-
fs/nfs/pagelist.c | 2 +-
fs/nfs/pnfs.c | 4 ++--
include/linux/wait.h | 10 +++++-----
kernel/sched/wait.c | 20 ++++++++++----------
net/sunrpc/sched.c | 6 +++---
8 files changed, 28 insertions(+), 28 deletions(-)
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 @@ cifs_invalidate_mapping(struct inode *inode) * @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 f27cc76..1c65e3f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c@@ -75,11 +75,11 @@ nfs_fattr_to_ino_t(struct nfs_fattr *fattr) * 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 1dad181..d7345c4 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h@@ -384,7 +384,7 @@ extern int nfs_drop_inode(struct inode *); 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 @@ __nfs_iocounter_wait(struct nfs_io_counter *c) 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 1cbebec..75abed0 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c@@ -1443,11 +1443,11 @@ static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx, } /* 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 @@ __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) 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 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); } 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 @@ __wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q, 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 @@ __wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q, 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 @@ void wake_up_atomic_t(atomic_t *p) } 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 337ca85..6c21ca1 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c@@ -250,11 +250,11 @@ void rpc_destroy_wait_queue(struct rpc_wait_queue *queue) } 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; }
--
1.9.1