From 0b3d4cd371edb6c4ef47f3fb0cb55bdd9aa471c1 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Tue, 14 Mar 2017 13:33:56 -0700 Subject: [PATCH] Btrfs: separate DISCARD from __btrfs_map_block Since DISCARD is not as important as an operation like write, we don't copy it to target device during replace, and it makes __btrfs_map_block less complex. Signed-off-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 289 ++++++++++++++++++++++++++++++++--------------------- 1 file changed, 175 insertions(+), 114 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 122201897bee..d777d626aa87 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5298,6 +5298,158 @@ void btrfs_put_bbio(struct btrfs_bio *bbio) kfree(bbio); } +/* can REQ_OP_DISCARD be sent with other REQ like REQ_OP_WRITE? */ +/* + * Please note that, discard won't be sent to target device of device + * replace. + */ +static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info, + u64 logical, u64 length, + struct btrfs_bio **bbio_ret) +{ + struct extent_map *em; + struct map_lookup *map; + struct btrfs_bio *bbio; + u64 offset; + u64 stripe_nr; + u64 stripe_nr_end; + u64 stripe_end_offset; + u64 stripe_cnt; + u64 stripe_len; + u64 stripe_offset; + u64 num_stripes; + u32 stripe_index; + u32 factor = 0; + u32 sub_stripes = 0; + u64 stripes_per_dev = 0; + u32 remaining_stripes = 0; + u32 last_stripe = 0; + int ret = 0; + int i; + + /* discard always return a bbio */ + ASSERT(bbio_ret); + + em = get_chunk_map(fs_info, logical, length); + if (IS_ERR(em)) + return PTR_ERR(em); + + map = em->map_lookup; + /* we don't discard raid56 yet */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + ret = -EOPNOTSUPP; + goto out; + } + + offset = logical - em->start; + length = min_t(u64, em->len - offset, length); + + stripe_len = map->stripe_len; + /* + * stripe_nr counts the total number of stripes we have to stride + * to get to this block + */ + stripe_nr = div64_u64(offset, stripe_len); + + /* stripe_offset is the offset of this block in its stripe */ + stripe_offset = offset - stripe_nr * stripe_len; + + stripe_nr_end = round_up(offset + length, map->stripe_len); + stripe_nr_end = div_u64(stripe_nr_end, map->stripe_len); + stripe_cnt = stripe_nr_end - stripe_nr; + stripe_end_offset = stripe_nr_end * map->stripe_len - + (offset + length); + /* + * after this, stripe_nr is the number of stripes on this + * device we have to walk to find the data, and stripe_index is + * the number of our device in the stripe array + */ + num_stripes = 1; + stripe_index = 0; + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + if (map->type & BTRFS_BLOCK_GROUP_RAID0) + sub_stripes = 1; + else + sub_stripes = map->sub_stripes; + + factor = map->num_stripes / sub_stripes; + num_stripes = min_t(u64, map->num_stripes, + sub_stripes * stripe_cnt); + stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index); + stripe_index *= sub_stripes; + stripes_per_dev = div_u64_rem(stripe_cnt, factor, + &remaining_stripes); + div_u64_rem(stripe_nr_end - 1, factor, &last_stripe); + last_stripe *= sub_stripes; + } else if (map->type & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_DUP)) { + num_stripes = map->num_stripes; + } else { + stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, + &stripe_index); + } + + bbio = alloc_btrfs_bio(num_stripes, 0); + if (!bbio) { + ret = -ENOMEM; + goto out; + } + + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = map->stripes[stripe_index].dev; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + bbio->stripes[i].length = stripes_per_dev * + map->stripe_len; + + if (i / sub_stripes < remaining_stripes) + bbio->stripes[i].length += + map->stripe_len; + + /* + * Special for the first stripe and + * the last stripe: + * + * |-------|...|-------| + * |----------| + * off end_off + */ + if (i < sub_stripes) + bbio->stripes[i].length -= + stripe_offset; + + if (stripe_index >= last_stripe && + stripe_index <= (last_stripe + + sub_stripes - 1)) + bbio->stripes[i].length -= + stripe_end_offset; + + if (i == sub_stripes - 1) + stripe_offset = 0; + } else { + bbio->stripes[i].length = length; + } + + stripe_index++; + if (stripe_index == map->num_stripes) { + stripe_index = 0; + stripe_nr++; + } + } + + *bbio_ret = bbio; + bbio->map_type = map->type; + bbio->num_stripes = num_stripes; +out: + free_extent_map(em); + return ret; +} + static int __btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, u64 logical, u64 *length, @@ -5308,10 +5460,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, struct map_lookup *map; u64 offset; u64 stripe_offset; - u64 stripe_end_offset; u64 stripe_nr; - u64 stripe_nr_orig; - u64 stripe_nr_end; u64 stripe_len; u32 stripe_index; int i; @@ -5327,6 +5476,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, u64 physical_to_patch_in_first_stripe = 0; u64 raid56_full_stripe_start = (u64)-1; + if (op == BTRFS_MAP_DISCARD) + return __btrfs_map_block_for_discard(fs_info, logical, + *length, bbio_ret); + em = get_chunk_map(fs_info, logical, *length); if (IS_ERR(em)) return PTR_ERR(em); @@ -5368,14 +5521,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, raid56_full_stripe_start *= full_stripe_len; } - if (op == BTRFS_MAP_DISCARD) { - /* we don't discard raid56 yet */ - if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { - ret = -EOPNOTSUPP; - goto out; - } - *length = min_t(u64, em->len - offset, *length); - } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { u64 max_len; /* For writes to RAID[56], allow a full stripeset across all disks. For other RAID types and for RAID[56] reads, just allow a single @@ -5406,8 +5552,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, btrfs_dev_replace_set_lock_blocking(dev_replace); if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 && - op != BTRFS_MAP_WRITE && op != BTRFS_MAP_DISCARD && - op != BTRFS_MAP_GET_READ_MIRRORS && dev_replace->tgtdev != NULL) { + op != BTRFS_MAP_WRITE && op != BTRFS_MAP_GET_READ_MIRRORS && + dev_replace->tgtdev != NULL) { /* * in dev-replace case, for repair case (that's the only * case where the mirror is selected explicitly when @@ -5487,24 +5633,13 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, num_stripes = 1; stripe_index = 0; - stripe_nr_orig = stripe_nr; - stripe_nr_end = ALIGN(offset + *length, map->stripe_len); - stripe_nr_end = div_u64(stripe_nr_end, map->stripe_len); - stripe_end_offset = stripe_nr_end * map->stripe_len - - (offset + *length); - if (map->type & BTRFS_BLOCK_GROUP_RAID0) { - if (op == BTRFS_MAP_DISCARD) - num_stripes = min_t(u64, map->num_stripes, - stripe_nr_end - stripe_nr_orig); stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &stripe_index); - if (op != BTRFS_MAP_WRITE && op != BTRFS_MAP_DISCARD && - op != BTRFS_MAP_GET_READ_MIRRORS) + if (op != BTRFS_MAP_WRITE && op != BTRFS_MAP_GET_READ_MIRRORS) mirror_num = 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) { - if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_DISCARD || - op == BTRFS_MAP_GET_READ_MIRRORS) + if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS) num_stripes = map->num_stripes; else if (mirror_num) stripe_index = mirror_num - 1; @@ -5517,8 +5652,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, } } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { - if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_DISCARD || - op == BTRFS_MAP_GET_READ_MIRRORS) { + if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS) { num_stripes = map->num_stripes; } else if (mirror_num) { stripe_index = mirror_num - 1; @@ -5534,10 +5668,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS) num_stripes = map->sub_stripes; - else if (op == BTRFS_MAP_DISCARD) - num_stripes = min_t(u64, map->sub_stripes * - (stripe_nr_end - stripe_nr_orig), - map->num_stripes); else if (mirror_num) stripe_index += mirror_num - 1; else { @@ -5580,8 +5710,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, /* We distribute the parity blocks across stripes */ div_u64_rem(stripe_nr + stripe_index, map->num_stripes, &stripe_index); - if ((op != BTRFS_MAP_WRITE && op != BTRFS_MAP_DISCARD && - op != BTRFS_MAP_GET_READ_MIRRORS) && mirror_num <= 1) + if ((op != BTRFS_MAP_WRITE && + op != BTRFS_MAP_GET_READ_MIRRORS) && + mirror_num <= 1) mirror_num = 1; } } else { @@ -5604,7 +5735,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, num_alloc_stripes = num_stripes; if (dev_replace_is_ongoing) { - if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_DISCARD) + if (op == BTRFS_MAP_WRITE) num_alloc_stripes <<= 1; if (op == BTRFS_MAP_GET_READ_MIRRORS) num_alloc_stripes++; @@ -5647,84 +5778,15 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, RAID6_Q_STRIPE; } - if (op == BTRFS_MAP_DISCARD) { - u32 factor = 0; - u32 sub_stripes = 0; - u64 stripes_per_dev = 0; - u32 remaining_stripes = 0; - u32 last_stripe = 0; - - if (map->type & - (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { - if (map->type & BTRFS_BLOCK_GROUP_RAID0) - sub_stripes = 1; - else - sub_stripes = map->sub_stripes; - - factor = map->num_stripes / sub_stripes; - stripes_per_dev = div_u64_rem(stripe_nr_end - - stripe_nr_orig, - factor, - &remaining_stripes); - div_u64_rem(stripe_nr_end - 1, factor, &last_stripe); - last_stripe *= sub_stripes; - } - for (i = 0; i < num_stripes; i++) { - bbio->stripes[i].physical = - map->stripes[stripe_index].physical + - stripe_offset + stripe_nr * map->stripe_len; - bbio->stripes[i].dev = map->stripes[stripe_index].dev; - - if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | - BTRFS_BLOCK_GROUP_RAID10)) { - bbio->stripes[i].length = stripes_per_dev * - map->stripe_len; - - if (i / sub_stripes < remaining_stripes) - bbio->stripes[i].length += - map->stripe_len; - - /* - * Special for the first stripe and - * the last stripe: - * - * |-------|...|-------| - * |----------| - * off end_off - */ - if (i < sub_stripes) - bbio->stripes[i].length -= - stripe_offset; - - if (stripe_index >= last_stripe && - stripe_index <= (last_stripe + - sub_stripes - 1)) - bbio->stripes[i].length -= - stripe_end_offset; - - if (i == sub_stripes - 1) - stripe_offset = 0; - } else - bbio->stripes[i].length = *length; - - stripe_index++; - if (stripe_index == map->num_stripes) { - /* This could only happen for RAID0/10 */ - stripe_index = 0; - stripe_nr++; - } - } - } else { - for (i = 0; i < num_stripes; i++) { - bbio->stripes[i].physical = - map->stripes[stripe_index].physical + - stripe_offset + - stripe_nr * map->stripe_len; - bbio->stripes[i].dev = - map->stripes[stripe_index].dev; - stripe_index++; - } + for (i = 0; i < num_stripes; i++) { + bbio->stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + + stripe_nr * map->stripe_len; + bbio->stripes[i].dev = + map->stripes[stripe_index].dev; + stripe_index++; } if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS) @@ -5734,8 +5796,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, sort_parity_stripes(bbio, num_stripes); tgtdev_indexes = 0; - if (dev_replace_is_ongoing && - (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_DISCARD) && + if (dev_replace_is_ongoing && op == BTRFS_MAP_WRITE && dev_replace->tgtdev != NULL) { int index_where_to_add; u64 srcdev_devid = dev_replace->srcdev->devid; -- 2.11.0