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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html