From 16715c01f7ea4410d3b0eb3fe8bd66ab9241f036 Mon Sep 17 00:00:00 2001 From: Doug Ledford Date: Mon, 19 Sep 2011 13:06:38 +1000 Subject: [PATCH] Fix readding of a readwrite drive into a writemostly array If you create a two drive raid1 array with one device writemostly, then fail the readwrite drive, when you add a new device, it will get the writemostly bit copied out of the remaining device's superblock into it's own. You can then remove the new drive and readd it as readwrite, which will work for the readd, but it leaves the stale WriteMostly1 bit in devflags resulting in the device going back to writemostly on the next assembly. The fix is to make sure that A) when we readd a device and we might have filled the st->sb info from a running device instead of the device being readded, then clear/set the WriteMostly1 bit in the super1 struct in addition to setting the disk state (ditto for super0, but slightly different mechanism) and B) when adding a clean device to an array (when we most certainly did copy the superblock info from an existing device), then clear any writemostly bits. Signed-off-by: Doug Ledford Signed-off-by: NeilBrown --- Manage.c | 17 +++++++++++++++-- mdadm.h | 2 ++ super0.c | 6 ++++++ super1.c | 5 +++++ 4 files changed, 28 insertions(+), 2 deletions(-) diff --git a/Manage.c b/Manage.c index 1b2b75a..2d8c916 100644 --- a/Manage.c +++ b/Manage.c @@ -762,11 +762,24 @@ int Manage_subdevs(char *devname, int fd, remove_partitions(tfd); close(tfd); tfd = -1; - if (update) { + if (update || dv->writemostly > 0) { int rv = -1; tfd = dev_open(dv->devname, O_RDWR); + if (tfd < 0) { + fprintf(stderr, Name ": failed to open %s for" + " superblock update during re-add\n", dv->devname); + return 1; + } - if (tfd >= 0) + if (dv->writemostly == 1) + rv = st->ss->update_super( + st, NULL, "writemostly", + devname, verbose, 0, NULL); + if (dv->writemostly == 2) + rv = st->ss->update_super( + st, NULL, "readwrite", + devname, verbose, 0, NULL); + if (update) rv = st->ss->update_super( st, NULL, update, devname, verbose, 0, NULL); diff --git a/mdadm.h b/mdadm.h index d616966..6a36f43 100644 --- a/mdadm.h +++ b/mdadm.h @@ -646,6 +646,8 @@ extern struct superswitch { * linear-grow-new - add a new device to a linear array, but don't * change the size: so superblock still matches * linear-grow-update - now change the size of the array. + * writemostly - set the WriteMostly1 bit in the superblock devflags + * readwrite - clear the WriteMostly1 bit in the superblock devflags */ int (*update_super)(struct supertype *st, struct mdinfo *info, char *update, diff --git a/super0.c b/super0.c index 62c4ff0..f791e9d 100644 --- a/super0.c +++ b/super0.c @@ -570,6 +570,10 @@ static int update_super0(struct supertype *st, struct mdinfo *info, sb->state &= ~(1<reshape_position = info->reshape_progress; + else if (strcmp(update, "writemostly")==0) + sb->state |= (1<state &= ~(1<minor = dinfo->minor; dk->raid_disk = dinfo->raid_disk; dk->state = dinfo->state; + /* In case our source disk was writemostly, don't copy that bit */ + dk->state &= ~(1<this_disk = sb->disks[dinfo->number]; sb->sb_csum = calc_sb0_csum(sb); diff --git a/super1.c b/super1.c index 35e92a3..0cd4124 100644 --- a/super1.c +++ b/super1.c @@ -803,6 +803,10 @@ static int update_super1(struct supertype *st, struct mdinfo *info, __le64_to_cpu(sb->data_size)); } else if (strcmp(update, "_reshape_progress")==0) sb->reshape_position = __cpu_to_le64(info->reshape_progress); + else if (strcmp(update, "writemostly")==0) + sb->devflags |= WriteMostly1; + else if (strcmp(update, "readwrite")==0) + sb->devflags &= ~WriteMostly1; else rv = -1; @@ -923,6 +927,7 @@ static int add_to_super1(struct supertype *st, mdu_disk_info_t *dk, sb->max_dev = __cpu_to_le32(dk->number+1); sb->dev_number = __cpu_to_le32(dk->number); + sb->devflags = 0; /* don't copy another disks flags */ sb->sb_csum = calc_sb_1_csum(sb); dip = (struct devinfo **)&st->info;