On Wed, Mar 15, 2017 at 11:28:16AM -0700, Song Liu wrote:
> When journal device of an array fails, the array is forced into read-only
> mode. To make the array normal without adding another journal device, we
> need to remove journal _feature_ from the array.
>
> This patch allows remove journal _feature_ from an array, For journal
> remove to work, existing journal should be either missing or faulty.
>
> Two flags are added to GET_ARRAY_INFO for mdadm.
> 1. MD_SB_HAS_JOURNAL: meaning the array have journal feature;
> 2. MD_SB_JOURNAL_REMOVABLE: meaning the journal is faulty or missing
>
> When both flags are set, mdadm can clear MD_SB_HAS_JOURNAL to remove
> journal _feature_.
please use the new 'consistency_policy' interface to remove journal support
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> ---
> drivers/md/md.c | 42 ++++++++++++++++++++++++++++++++++++++++--
> include/uapi/linux/raid/md_p.h | 11 ++++++++---
> 2 files changed, 48 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index ac3bd15..32ee994 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -5981,6 +5981,25 @@ static void autorun_devices(int part)
> }
> #endif /* !MODULE */
>
> +/*
> + * the journal _feature_ is removable when:
> + * the array has journal support &&
> + * (journal is missing || journal is faulty)
> + */
> +static bool journal_removable(struct mddev *mddev)
> +{
> + struct md_rdev *rdev;
> +
> + if (!test_bit(MD_HAS_JOURNAL, &mddev->flags))
> + return false;
> +
> + rdev_for_each_rcu(rdev, mddev)
> + if (test_bit(Journal, &rdev->flags) &&
> + !test_bit(Faulty, &rdev->flags))
> + return false;
> + return true;
> +}
> +
> static int get_version(void __user *arg)
> {
> mdu_version_t ver;
> @@ -6041,6 +6060,10 @@ static int get_array_info(struct mddev *mddev, void __user *arg)
> info.state |= (1<<MD_SB_BITMAP_PRESENT);
> if (mddev_is_clustered(mddev))
> info.state |= (1<<MD_SB_CLUSTERED);
> + if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
> + info.state |= (1<<MD_SB_HAS_JOURNAL);
> + if (journal_removable(mddev))
> + info.state |= (1<<MD_SB_JOURNAL_REMOVABLE);
> info.active_disks = insync;
> info.working_disks = working;
> info.failed_disks = failed;
> @@ -6721,6 +6744,8 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
> /* calculate expected state,ignoring low bits */
> if (mddev->bitmap && mddev->bitmap_info.offset)
> state |= (1 << MD_SB_BITMAP_PRESENT);
> + if (journal_removable(mddev))
> + state |= (1 << MD_SB_JOURNAL_REMOVABLE);
>
> if (mddev->major_version != info->major_version ||
> mddev->minor_version != info->minor_version ||
> @@ -6730,8 +6755,11 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
> /* mddev->layout != info->layout || */
> mddev->persistent != !info->not_persistent ||
> mddev->chunk_sectors != info->chunk_size >> 9 ||
> - /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> - ((state^info->state) & 0xfffffe00)
> + /*
> + * ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> + * and SB_HAS_JOURNAL to change
> + */
> + ((state^info->state) & 0xfffffc00)
> )
> return -EINVAL;
> /* Check there is only one change */
> @@ -6743,6 +6771,8 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
> cnt++;
> if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
> cnt++;
> + if ((state ^ info->state) & (1<<MD_SB_HAS_JOURNAL))
> + cnt++;
> if (cnt == 0)
> return 0;
> if (cnt > 1)
> @@ -6831,6 +6861,14 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
> mddev->bitmap_info.offset = 0;
> }
> }
> + if ((state ^ info->state) & (1<<MD_SB_HAS_JOURNAL)) {
> + if (!journal_removable(mddev)) {
> + rv = -EINVAL;
> + goto err;
> + }
> + clear_bit(MD_HAS_JOURNAL, &mddev->flags);
> + }
> +
> md_update_sb(mddev, 1);
> return rv;
> err:
> diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
> index d9a1ead..b1f2b63 100644
> --- a/include/uapi/linux/raid/md_p.h
> +++ b/include/uapi/linux/raid/md_p.h
> @@ -1,15 +1,15 @@
> /*
> md_p.h : physical layout of Linux RAID devices
> Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
> -
> +
> 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.
> + Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> */
>
> #ifndef _MD_P_H
> @@ -119,6 +119,11 @@ typedef struct mdp_device_descriptor_s {
>
> #define MD_SB_CLUSTERED 5 /* MD is clustered */
> #define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */
> +#define MD_SB_HAS_JOURNAL 9
> +#define MD_SB_JOURNAL_REMOVABLE 10 /* journal _feature_ can be removed,
> + * which means the journal is either
> + * missing or Faulty
> + */
>
> /*
> * Notes:
> --
> 2.9.3
>
> --
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