kernel/git/stable/linux.git/drivers/md/md.c, branch linux-5.2.y

md: only call set_in_sync() when it is expected to succeed.

2019-10-05T11:14:15+00:00

commit 480523feae581ab714ba6610388a3b4619a2f695 upstream. Since commit 4ad23a976413 ("MD: use per-cpu counter for writes_pending"), set_in_sync() is substantially more expensive: it can wait for a full RCU grace period which can be 10s of milliseconds. So we should only call it when the cost is justified. md_check_recovery() currently calls set_in_sync() every time it finds anything to do (on non-external active arrays). For an array performing resync or recovery, this will be quite often. Each call will introduce a delay to the md thread, which can noticeable affect IO submission latency. In md_check_recovery() we only need to call set_in_sync() if 'safemode' was non-zero at entry, meaning that there has been not recent IO. So we save this "safemode was nonzero" state, and only call set_in_sync() if it was non-zero. This measurably reduces mean and maximum IO submission latency during resync/recovery. Reported-and-tested-by: Jack Wang Fixes: 4ad23a976413 ("MD: use per-cpu counter for writes_pending") Cc: stable@vger.kernel.org (v4.12+) Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

md: don't report active array_state until after revalidate_disk() completes.

2019-10-05T11:14:15+00:00

commit 9d4b45d6af442237560d0bb5502a012baa5234b7 upstream. Until revalidate_disk() has completed, the size of a new md array will appear to be zero. So we shouldn't report, through array_state, that the array is active until that time. udev rules check array_state to see if the array is ready. As soon as it appear to be zero, fsck can be run. If it find the size to be zero, it will fail. So add a new flag to provide an interlock between do_md_run() and array_state_show(). This flag is set while do_md_run() is active and it prevents array_state_show() from reporting that the array is active. Before do_md_run() is called, ->pers will be NULL so array is definitely not active. After do_md_run() is called, revalidate_disk() will have run and the array will be completely ready. We also move various sysfs_notify*() calls out of md_run() into do_md_run() after MD_NOT_READY is cleared. This ensure the information is ready before the notification is sent. Prior to v4.12, array_state_show() was called with the mddev->reconfig_mutex held, which provided exclusion with do_md_run(). Note that MD_NOT_READY cleared twice. This is deliberate to cover both success and error paths with minimal noise. Fixes: b7b17c9b67e5 ("md: remove mddev_lock() from md_attr_show()") Cc: stable@vger.kernel.org (v4.12++) Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

md: don't set In_sync if array is frozen

2019-10-05T11:13:35+00:00

[ Upstream commit 062f5b2ae12a153644c765e7ba3b0f825427be1d ] When a disk is added to array, the following path is called in mdadm. Manage_subdevs -> sysfs_freeze_array -> Manage_add -> sysfs_set_str(&info, NULL, "sync_action","idle") Then from kernel side, Manage_add invokes the path (add_new_disk -> validate_super = super_1_validate) to set In_sync flag. Since In_sync means "device is in_sync with rest of array", and the new added disk need to resync thread to help the synchronization of data. And md_reap_sync_thread would call spare_active to set In_sync for the new added disk finally. So don't set In_sync if array is in frozen. Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu Signed-off-by: Sasha Levin

md: don't call spare_active in md_reap_sync_thread if all member devices can't work

2019-10-05T11:13:35+00:00

[ Upstream commit 0d8ed0e9bf9643f27f4816dca61081784dedb38d ] When add one disk to array, the md_reap_sync_thread is responsible to activate the spare and set In_sync flag for the new member in spare_active(). But if raid1 has one member disk A, and disk B is added to the array. Then we offline A before all the datas are synchronized from A to B, obviously B doesn't have the latest data as A, but B is still marked with In_sync flag. So let's not call spare_active under the condition, otherwise B is still showed with 'U' state which is not correct. Signed-off-by: Guoqing Jiang Signed-off-by: Song Liu Signed-off-by: Sasha Levin

md: fix for divide error in status_resync

2019-06-18T15:02:25+00:00

Stopping external metadata arrays during resync/recovery causes retries, loop of interrupting and starting reconstruction, until it hit at good moment to stop completely. While these retries curr_mark_cnt can be small- especially on HDD drives, so subtraction result can be smaller than 0. However it is casted to uint without checking. As a result of it the status bar in /proc/mdstat while stopping is strange (it jumps between 0% and 99%). The real problem occurs here after commit 72deb455b5ec ("block: remove CONFIG_LBDAF"). Sector_div() macro has been changed, now the divisor is casted to uint32. For db = -8 the divisior(db/32-1) becomes 0. Check if db value can be really counted and replace these macro by div64_u64() inline. Signed-off-by: Mariusz Tkaczyk Signed-off-by: Song Liu

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47

2019-05-24T15:27:13+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version you should have received a copy of the gnu general public license for example usr src linux copying if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 20 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Kate Stewart Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170858.552543146@linutronix.de Signed-off-by: Greg Kroah-Hartman

md: return -ENODEV if rdev has no mddev assigned

2019-04-16T16:31:21+00:00

Mdadm expects that setting drive as faulty will fail with -EBUSY only if this operation will cause RAID to be failed. If this happens, it will try to stop the array. Currently -EBUSY might also be returned if rdev is in the middle of the removal process - for example there is a race with mdmon that already requested the drive to be failed/removed. If rdev does not contain mddev, return -ENODEV instead, so the caller can distinguish between those two cases and behave accordingly. Reviewed-by: NeilBrown Signed-off-by: Pawel Baldysiak Signed-off-by: Song Liu

md: mark md_cluster_mod static

2019-04-10T22:26:09+00:00

Sparse complains that it has no external declaration, and it turns out that it is never even used outside of md.c. So just mark it static and drop the export. Acked-by: Guoqing Jiang Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu

md: use correct type in super_1_sync

2019-04-10T22:26:09+00:00

If we want to convert from a little endian format we need to cast to a little endian type, otherwise sparse will be unhappy. Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu

md: use correct type in super_1_load

2019-04-10T22:26:08+00:00

If we want to convert from a little endian format we need to cast to a little endian type, otherwise sparse will be unhappy. Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu