Commit dfd01f02 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
Browse files

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: 68985633 ("sched/wait: Fix signal handling in bit wait helpers")
Reported-by: default avatarJan Stancek <jstancek@redhat.com>
Reported-by: default avatarChris Mason <clm@fb.com>
Tested-by: default avatarJan Stancek <jstancek@redhat.com>
Tested-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: default avatarChris Mason <clm@fb.com>
Reviewed-by: default avatarPaul 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: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fc891828

fs/cifs/inode.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

}

fs/nfs/inode.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

fs/nfs/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -379,7 +379,7 @@ 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;

fs/nfs/pagelist.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

fs/nfs/pnfs.c

+2 −2
Original line number Diff line number Diff line
@@ -1466,11 +1466,11 @@ 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)

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