From 3a4d4eb3cb03fbc66696fc8cd472701d56f3aee7 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 19 Mar 2013 18:16:44 +0100 Subject: [PATCH] drbd: prepare for new striped layout of activity log Introduce two new on-disk meta data fields: al_stripes and al_stripe_size_4k The intended use case is activity log on RAID 0 or similar. Logically consecutive transactions will advance their on-disk position by al_stripe_size_4k 4kB (transaction sized) blocks. Right now, these are still asserted to be the backward compatible values al_stripes = 1, al_stripe_size_4k = 8 (which amounts to 32kB). Also introduce a caching member for meta_dev_idx in the in-core structure: even though it is initially passed in in the rcu-protected disk_conf structure, it cannot change without a detach/attach cycle. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_actlog.c | 6 ++-- drivers/block/drbd/drbd_int.h | 46 +++++++++++------------- drivers/block/drbd/drbd_main.c | 77 +++++++++++++++++++++++++++++++++++----- drivers/block/drbd/drbd_nl.c | 5 ++- 4 files changed, 94 insertions(+), 40 deletions(-) diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index b230d91..7e7680e 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -353,11 +353,11 @@ static unsigned int rs_extent_to_bm_page(unsigned int rs_enr) static sector_t al_tr_number_to_on_disk_sector(struct drbd_conf *mdev) { - const unsigned int stripes = 1; - const unsigned int stripe_size_4kB = MD_32kB_SECT/MD_4kB_SECT; + const unsigned int stripes = mdev->ldev->md.al_stripes; + const unsigned int stripe_size_4kB = mdev->ldev->md.al_stripe_size_4k; /* transaction number, modulo on-disk ring buffer wrap around */ - unsigned int t = mdev->al_tr_number % (stripe_size_4kB * stripes); + unsigned int t = mdev->al_tr_number % (mdev->ldev->md.al_size_4k); /* ... to aligned 4k on disk block */ t = ((t % stripes) * stripe_size_4kB) + t/stripes; diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 60c89e5..ee19ba2 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -755,6 +755,14 @@ struct drbd_md { s32 al_offset; /* signed relative sector offset to activity log */ s32 bm_offset; /* signed relative sector offset to bitmap */ + + /* cached value of bdev->disk_conf->meta_dev_idx (see below) */ + s32 meta_dev_idx; + + /* see al_tr_number_to_on_disk_sector() */ + u32 al_stripes; + u32 al_stripe_size_4k; + u32 al_size_4k; /* cached product of the above */ }; struct drbd_backing_dev { @@ -1862,38 +1870,24 @@ static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) } /** - * drbd_md_ss__() - Return the sector number of our meta data super block - * @mdev: DRBD device. + * drbd_md_ss() - Return the sector number of our meta data super block * @bdev: Meta data block device. */ -static inline sector_t drbd_md_ss__(struct drbd_conf *mdev, - struct drbd_backing_dev *bdev) +static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev) { - int meta_dev_idx; + const int meta_dev_idx = bdev->md.meta_dev_idx; - rcu_read_lock(); - meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; - rcu_read_unlock(); + if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT) + return 0; - switch (meta_dev_idx) { - default: /* external, some index; this is the old fixed size layout */ - return MD_128MB_SECT * meta_dev_idx; - case DRBD_MD_INDEX_INTERNAL: - /* with drbd08, internal meta data is always "flexible" */ - case DRBD_MD_INDEX_FLEX_INT: - if (!bdev->backing_bdev) { - if (__ratelimit(&drbd_ratelimit_state)) { - dev_err(DEV, "bdev->backing_bdev==NULL\n"); - dump_stack(); - } - return 0; - } - /* sizeof(struct md_on_disk_07) == 4k - * position: last 4k aligned block of 4k size */ + /* Since drbd08, internal meta data is always "flexible". + * position: last 4k aligned block of 4k size */ + if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL || + meta_dev_idx == DRBD_MD_INDEX_FLEX_INT) return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8; - case DRBD_MD_INDEX_FLEX_EXT: - return 0; - } + + /* external, some index; this is the old fixed size layout */ + return MD_128MB_SECT * bdev->md.meta_dev_idx; } static inline void diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 76faeab..7a2e07b 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2850,7 +2850,11 @@ struct meta_data_on_disk { u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */ u32 la_peer_max_bio_size; /* last peer max_bio_size */ - u8 reserved_u8[4096 - (7*8 + 8*4)]; + /* see al_tr_number_to_on_disk_sector() */ + u32 al_stripes; + u32 al_stripe_size_4k; + + u8 reserved_u8[4096 - (7*8 + 10*4)]; } __packed; /** @@ -2898,7 +2902,10 @@ void drbd_md_sync(struct drbd_conf *mdev) buffer->bm_offset = cpu_to_be32(mdev->ldev->md.bm_offset); buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size); - D_ASSERT(drbd_md_ss__(mdev, mdev->ldev) == mdev->ldev->md.md_offset); + buffer->al_stripes = cpu_to_be32(mdev->ldev->md.al_stripes); + buffer->al_stripe_size_4k = cpu_to_be32(mdev->ldev->md.al_stripe_size_4k); + + D_ASSERT(drbd_md_ss(mdev->ldev) == mdev->ldev->md.md_offset); sector = mdev->ldev->md.md_offset; if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) { @@ -2916,13 +2923,60 @@ out: put_ldev(mdev); } +static int check_activity_log_stripe_size(struct drbd_conf *mdev, + struct meta_data_on_disk *on_disk, + struct drbd_md *in_core) +{ + u32 al_stripes = be32_to_cpu(on_disk->al_stripes); + u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k); + u64 al_size_4k; + + /* both not set: default to old fixed size activity log */ + if (al_stripes == 0 && al_stripe_size_4k == 0) { + al_stripes = 1; + al_stripe_size_4k = MD_32kB_SECT/8; + } + + /* some paranoia plausibility checks */ + + /* we need both values to be set */ + if (al_stripes == 0 || al_stripe_size_4k == 0) + goto err; + + al_size_4k = (u64)al_stripes * al_stripe_size_4k; + + /* Upper limit of activity log area, to avoid potential overflow + * problems in al_tr_number_to_on_disk_sector(). As right now, more + * than 72 * 4k blocks total only increases the amount of history, + * limiting this arbitrarily to 16 GB is not a real limitation ;-) */ + if (al_size_4k > (16 * 1024 * 1024/4)) + goto err; + + /* Lower limit: we need at least 8 transaction slots (32kB) + * to not break existing setups */ + if (al_size_4k < MD_32kB_SECT/8) + goto err; + + in_core->al_stripe_size_4k = al_stripe_size_4k; + in_core->al_stripes = al_stripes; + in_core->al_size_4k = al_size_4k; + + return 0; +err: + dev_err(DEV, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n", + al_stripes, al_stripe_size_4k); + return -EINVAL; +} + /** * drbd_md_read() - Reads in the meta data super block * @mdev: DRBD device. * @bdev: Device from which the meta data should be read in. * - * Return 0 (NO_ERROR) on success, and an enum drbd_ret_code in case + * Return NO_ERROR on success, and an enum drbd_ret_code in case * something goes wrong. + * + * Called exactly once during drbd_adm_attach() */ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) { @@ -2937,6 +2991,10 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) if (!buffer) goto out; + /* First, figure out where our meta data superblock is located. */ + bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx; + bdev->md.md_offset = drbd_md_ss(bdev); + if (drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) { /* NOTE: can't do normal error processing here as this is called BEFORE disk is attached */ @@ -2954,40 +3012,43 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev) rv = ERR_MD_UNCLEAN; goto err; } + + rv = ERR_MD_INVALID; if (magic != DRBD_MD_MAGIC_08) { if (magic == DRBD_MD_MAGIC_07) dev_err(DEV, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n"); else dev_err(DEV, "Meta data magic not found. Did you \"drbdadm create-md\"?\n"); - rv = ERR_MD_INVALID; goto err; } + + if (check_activity_log_stripe_size(mdev, buffer, &bdev->md)) + goto err; + if (be32_to_cpu(buffer->al_offset) != bdev->md.al_offset) { dev_err(DEV, "unexpected al_offset: %d (expected %d)\n", be32_to_cpu(buffer->al_offset), bdev->md.al_offset); - rv = ERR_MD_INVALID; goto err; } if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) { dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n", be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset); - rv = ERR_MD_INVALID; goto err; } if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) { dev_err(DEV, "unexpected md_size: %u (expected %u)\n", be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect); - rv = ERR_MD_INVALID; goto err; } if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) { dev_err(DEV, "unexpected bm_bytes_per_bit: %u (expected %u)\n", be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE); - rv = ERR_MD_INVALID; goto err; } + rv = NO_ERROR; + bdev->md.la_size_sect = be64_to_cpu(buffer->la_size); for (i = UI_CURRENT; i < UI_SIZE; i++) bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]); diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 581f680..104b7ce 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -727,24 +727,23 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev, rcu_read_lock(); meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; + bdev->md.md_offset = drbd_md_ss(bdev); + switch (meta_dev_idx) { default: /* v07 style fixed size indexed meta data */ bdev->md.md_size_sect = MD_128MB_SECT; - bdev->md.md_offset = drbd_md_ss__(mdev, bdev); bdev->md.al_offset = MD_4kB_SECT; bdev->md.bm_offset = MD_4kB_SECT + al_size_sect; break; case DRBD_MD_INDEX_FLEX_EXT: /* just occupy the full device; unit: sectors */ bdev->md.md_size_sect = drbd_get_capacity(bdev->md_bdev); - bdev->md.md_offset = 0; bdev->md.al_offset = MD_4kB_SECT; bdev->md.bm_offset = MD_4kB_SECT + al_size_sect; break; case DRBD_MD_INDEX_INTERNAL: case DRBD_MD_INDEX_FLEX_INT: - bdev->md.md_offset = drbd_md_ss__(mdev, bdev); /* al size is still fixed */ bdev->md.al_offset = -al_size_sect; /* we need (slightly less than) ~ this much bitmap sectors: */ -- 2.7.4