/*
* Copyright (C) STRATO AG 2012. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#if !defined(__BTRFS_DEV_REPLACE__)
#define __BTRFS_DEV_REPLACE__
struct btrfs_ioctl_dev_replace_args;
int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info);
int btrfs_run_dev_replace(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info);
void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info);
int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dev_replace_args *args);
int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, char *tgtdev_name,
u64 srcdevid, char *srcdev_name, int read_src);
void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dev_replace_args *args);
int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_dev_replace_args *args);
void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);
void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw);
void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw);
void btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace *dev_replace);
void btrfs_dev_replace_clear_lock_blocking(
struct btrfs_dev_replace *dev_replace);
static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value)
{
atomic64_inc(stat_value);
}
#endif
ass='form'>
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz < pending_sz"
when making the signal decision.
As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.
This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).
Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>