From 3069aa8def32b0c2b83cd27d1c37ed30b47ce879 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Thu, 13 Aug 2015 14:31:56 -0700 Subject: [PATCH] md: override md superblock recovery_offset for journal device Journal device stores data in a log structure. We need record the log start. Here we override md superblock recovery_offset for this purpose. This field of a journal device is meaningless otherwise. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/md.c | 6 ++++++ drivers/md/md.h | 8 +++++++- include/uapi/linux/raid/md_p.h | 5 ++++- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 391341a772c7..3592beb6931e 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1646,6 +1646,7 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev) return -EINVAL; } set_bit(Journal, &rdev->flags); + rdev->journal_tail = le64_to_cpu(sb->journal_tail); break; default: rdev->saved_raid_disk = role; @@ -1721,6 +1722,9 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev) sb->feature_map |= cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP); } + /* Note: recovery_offset and journal_tail share space */ + if (test_bit(Journal, &rdev->flags)) + sb->journal_tail = cpu_to_le64(rdev->journal_tail); if (test_bit(Replacement, &rdev->flags)) sb->feature_map |= cpu_to_le32(MD_FEATURE_REPLACEMENT); @@ -8097,6 +8101,8 @@ static int remove_and_add_spares(struct mddev *mddev, continue; if (test_bit(Faulty, &rdev->flags)) continue; + if (test_bit(Journal, &rdev->flags)) + continue; if (mddev->ro && ! (rdev->saved_raid_disk >= 0 && !test_bit(Bitmap_sync, &rdev->flags))) diff --git a/drivers/md/md.h b/drivers/md/md.h index 88dc6312f5d5..2b0f62fb6146 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -87,10 +87,16 @@ struct md_rdev { * array and could again if we did a partial * resync from the bitmap */ - sector_t recovery_offset;/* If this device has been partially + union { + sector_t recovery_offset;/* If this device has been partially * recovered, this is where we were * up to. */ + sector_t journal_tail; /* If this device is a journal device, + * this is the journal tail (journal + * recovery start point) + */ + }; atomic_t nr_pending; /* number of pending requests. * only maintained for arrays that diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h index eaaab52077a3..a5f54ff26c20 100644 --- a/include/uapi/linux/raid/md_p.h +++ b/include/uapi/linux/raid/md_p.h @@ -258,7 +258,10 @@ struct mdp_superblock_1 { __le64 data_offset; /* sector start of data, often 0 */ __le64 data_size; /* sectors in this device that can be used for data */ __le64 super_offset; /* sector start of this superblock */ - __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */ + union { + __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */ + __le64 journal_tail;/* journal tail of journal device (from data_offset) */ + }; __le32 dev_number; /* permanent identifier of this device - not role in raid */ __le32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */ __u8 device_uuid[16]; /* user-space setable, ignored by kernel */