diff options
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 298 |
1 files changed, 262 insertions, 36 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 07204bf601ed..5411f0ab5683 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1316,8 +1316,7 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, return ret; } -static noinline u32 extent_data_ref_count(struct btrfs_root *root, - struct btrfs_path *path, +static noinline u32 extent_data_ref_count(struct btrfs_path *path, struct btrfs_extent_inline_ref *iref) { struct btrfs_key key; @@ -1883,10 +1882,77 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans, return ret; } -static int btrfs_issue_discard(struct block_device *bdev, - u64 start, u64 len) +#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) +static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, + u64 *discarded_bytes) { - return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0); + int j, ret = 0; + u64 bytes_left, end; + u64 aligned_start = ALIGN(start, 1 << 9); + + if (WARN_ON(start != aligned_start)) { + len -= aligned_start - start; + len = round_down(len, 1 << 9); + start = aligned_start; + } + + *discarded_bytes = 0; + + if (!len) + return 0; + + end = start + len; + bytes_left = len; + + /* Skip any superblocks on this device. */ + for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) { + u64 sb_start = btrfs_sb_offset(j); + u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE; + u64 size = sb_start - start; + + if (!in_range(sb_start, start, bytes_left) && + !in_range(sb_end, start, bytes_left) && + !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE)) + continue; + + /* + * Superblock spans beginning of range. Adjust start and + * try again. + */ + if (sb_start <= start) { + start += sb_end - start; + if (start > end) { + bytes_left = 0; + break; + } + bytes_left = end - start; + continue; + } + + if (size) { + ret = blkdev_issue_discard(bdev, start >> 9, size >> 9, + GFP_NOFS, 0); + if (!ret) + *discarded_bytes += size; + else if (ret != -EOPNOTSUPP) + return ret; + } + + start = sb_end; + if (start > end) { + bytes_left = 0; + break; + } + bytes_left = end - start; + } + + if (bytes_left) { + ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9, + GFP_NOFS, 0); + if (!ret) + *discarded_bytes += bytes_left; + } + return ret; } int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, @@ -1907,14 +1973,16 @@ int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, for (i = 0; i < bbio->num_stripes; i++, stripe++) { + u64 bytes; if (!stripe->dev->can_discard) continue; ret = btrfs_issue_discard(stripe->dev->bdev, stripe->physical, - stripe->length); + stripe->length, + &bytes); if (!ret) - discarded_bytes += stripe->length; + discarded_bytes += bytes; else if (ret != -EOPNOTSUPP) break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */ @@ -6062,20 +6130,19 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_group_cache *block_group, *tmp; + struct list_head *deleted_bgs; struct extent_io_tree *unpin; u64 start; u64 end; int ret; - if (trans->aborted) - return 0; - if (fs_info->pinned_extents == &fs_info->freed_extents[0]) unpin = &fs_info->freed_extents[1]; else unpin = &fs_info->freed_extents[0]; - while (1) { + while (!trans->aborted) { mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY, NULL); @@ -6094,6 +6161,34 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, cond_resched(); } + /* + * Transaction is finished. We don't need the lock anymore. We + * do need to clean up the block groups in case of a transaction + * abort. + */ + deleted_bgs = &trans->transaction->deleted_bgs; + list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) { + u64 trimmed = 0; + + ret = -EROFS; + if (!trans->aborted) + ret = btrfs_discard_extent(root, + block_group->key.objectid, + block_group->key.offset, + &trimmed); + + list_del_init(&block_group->bg_list); + btrfs_put_block_group_trimming(block_group); + btrfs_put_block_group(block_group); + + if (ret) { + const char *errstr = btrfs_decode_error(ret); + btrfs_warn(fs_info, + "Discard failed while removing blockgroup: errno=%d %s\n", + ret, errstr); + } + } + return 0; } @@ -6349,7 +6444,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, } else { if (found_extent) { BUG_ON(is_data && refs_to_drop != - extent_data_ref_count(root, path, iref)); + extent_data_ref_count(path, iref)); if (iref) { BUG_ON(path->slots[0] != extent_slot); } else { @@ -7567,9 +7662,6 @@ static void unuse_block_rsv(struct btrfs_fs_info *fs_info, /* * finds a free extent and does all the dirty work required for allocation - * returns the key for the extent through ins, and a tree buffer for - * the first block of the extent through buf. - * * returns the tree buffer or an ERR_PTR on error. */ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, @@ -8723,14 +8815,13 @@ static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) return flags; } -static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) +static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force) { struct btrfs_space_info *sinfo = cache->space_info; u64 num_bytes; u64 min_allocable_bytes; int ret = -ENOSPC; - /* * We need some metadata space and system metadata space for * allocating chunks in some corner cases until we force to set @@ -8747,6 +8838,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) spin_lock(&cache->lock); if (cache->ro) { + cache->ro++; ret = 0; goto out; } @@ -8758,7 +8850,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes + min_allocable_bytes <= sinfo->total_bytes) { sinfo->bytes_readonly += num_bytes; - cache->ro = 1; + cache->ro++; list_add_tail(&cache->ro_list, &sinfo->ro_bgs); ret = 0; } @@ -8768,7 +8860,7 @@ out: return ret; } -int btrfs_set_block_group_ro(struct btrfs_root *root, +int btrfs_inc_block_group_ro(struct btrfs_root *root, struct btrfs_block_group_cache *cache) { @@ -8776,8 +8868,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root, u64 alloc_flags; int ret; - BUG_ON(cache->ro); - again: trans = btrfs_join_transaction(root); if (IS_ERR(trans)) @@ -8820,7 +8910,7 @@ again: goto out; } - ret = set_block_group_ro(cache, 0); + ret = inc_block_group_ro(cache, 0); if (!ret) goto out; alloc_flags = get_alloc_profile(root, cache->space_info->flags); @@ -8828,7 +8918,7 @@ again: CHUNK_ALLOC_FORCE); if (ret < 0) goto out; - ret = set_block_group_ro(cache, 0); + ret = inc_block_group_ro(cache, 0); out: if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { alloc_flags = update_block_group_flags(root, cache->flags); @@ -8891,7 +8981,7 @@ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo) return free_bytes; } -void btrfs_set_block_group_rw(struct btrfs_root *root, +void btrfs_dec_block_group_ro(struct btrfs_root *root, struct btrfs_block_group_cache *cache) { struct btrfs_space_info *sinfo = cache->space_info; @@ -8901,11 +8991,13 @@ void btrfs_set_block_group_rw(struct btrfs_root *root, spin_lock(&sinfo->lock); spin_lock(&cache->lock); - num_bytes = cache->key.offset - cache->reserved - cache->pinned - - cache->bytes_super - btrfs_block_group_used(&cache->item); - sinfo->bytes_readonly -= num_bytes; - cache->ro = 0; - list_del_init(&cache->ro_list); + if (!--cache->ro) { + num_bytes = cache->key.offset - cache->reserved - + cache->pinned - cache->bytes_super - + btrfs_block_group_used(&cache->item); + sinfo->bytes_readonly -= num_bytes; + list_del_init(&cache->ro_list); + } spin_unlock(&cache->lock); spin_unlock(&sinfo->lock); } @@ -9421,7 +9513,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) set_avail_alloc_bits(root->fs_info, cache->flags); if (btrfs_chunk_readonly(root, cache->key.objectid)) { - set_block_group_ro(cache, 1); + inc_block_group_ro(cache, 1); } else if (btrfs_block_group_used(&cache->item) == 0) { spin_lock(&info->unused_bgs_lock); /* Should always be true but just in case. */ @@ -9449,11 +9541,11 @@ int btrfs_read_block_groups(struct btrfs_root *root) list_for_each_entry(cache, &space_info->block_groups[BTRFS_RAID_RAID0], list) - set_block_group_ro(cache, 1); + inc_block_group_ro(cache, 1); list_for_each_entry(cache, &space_info->block_groups[BTRFS_RAID_SINGLE], list) - set_block_group_ro(cache, 1); + inc_block_group_ro(cache, 1); } init_global_block_rsv(info); @@ -9834,6 +9926,11 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans, * currently running transaction might finish and a new one start, * allowing for new block groups to be created that can reuse the same * physical device locations unless we take this special care. + * + * There may also be an implicit trim operation if the file system + * is mounted with -odiscard. The same protections must remain + * in place until the extents have been discarded completely when + * the transaction commit has completed. */ remove_em = (atomic_read(&block_group->trimming) == 0); /* @@ -9908,6 +10005,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) spin_lock(&fs_info->unused_bgs_lock); while (!list_empty(&fs_info->unused_bgs)) { u64 start, end; + int trimming; block_group = list_first_entry(&fs_info->unused_bgs, struct btrfs_block_group_cache, @@ -9941,7 +10039,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) spin_unlock(&block_group->lock); /* We don't want to force the issue, only flip if it's ok. */ - ret = set_block_group_ro(block_group, 0); + ret = inc_block_group_ro(block_group, 0); up_write(&space_info->groups_sem); if (ret < 0) { ret = 0; @@ -9955,7 +10053,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) /* 1 for btrfs_orphan_reserve_metadata() */ trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { - btrfs_set_block_group_rw(root, block_group); + btrfs_dec_block_group_ro(root, block_group); ret = PTR_ERR(trans); goto next; } @@ -9982,14 +10080,14 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) EXTENT_DIRTY, GFP_NOFS); if (ret) { mutex_unlock(&fs_info->unused_bg_unpin_mutex); - btrfs_set_block_group_rw(root, block_group); + btrfs_dec_block_group_ro(root, block_group); goto end_trans; } ret = clear_extent_bits(&fs_info->freed_extents[1], start, end, EXTENT_DIRTY, GFP_NOFS); if (ret) { mutex_unlock(&fs_info->unused_bg_unpin_mutex); - btrfs_set_block_group_rw(root, block_group); + btrfs_dec_block_group_ro(root, block_group); goto end_trans; } mutex_unlock(&fs_info->unused_bg_unpin_mutex); @@ -10007,12 +10105,39 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) spin_unlock(&block_group->lock); spin_unlock(&space_info->lock); + /* DISCARD can flip during remount */ + trimming = btrfs_test_opt(root, DISCARD); + + /* Implicit trim during transaction commit. */ + if (trimming) + btrfs_get_block_group_trimming(block_group); + /* * Btrfs_remove_chunk will abort the transaction if things go * horribly wrong. */ ret = btrfs_remove_chunk(trans, root, block_group->key.objectid); + + if (ret) { + if (trimming) + btrfs_put_block_group_trimming(block_group); + goto end_trans; + } + + /* + * If we're not mounted with -odiscard, we can just forget + * about this block group. Otherwise we'll need to wait + * until transaction commit to do the actual discard. + */ + if (trimming) { + WARN_ON(!list_empty(&block_group->bg_list)); + spin_lock(&trans->transaction->deleted_bgs_lock); + list_move(&block_group->bg_list, + &trans->transaction->deleted_bgs); + spin_unlock(&trans->transaction->deleted_bgs_lock); + btrfs_get_block_group(block_group); + } end_trans: btrfs_end_transaction(trans, root); next: @@ -10066,10 +10191,99 @@ int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end) return unpin_extent_range(root, start, end, false); } +/* + * It used to be that old block groups would be left around forever. + * Iterating over them would be enough to trim unused space. Since we + * now automatically remove them, we also need to iterate over unallocated + * space. + * + * We don't want a transaction for this since the discard may take a + * substantial amount of time. We don't require that a transaction be + * running, but we do need to take a running transaction into account + * to ensure that we're not discarding chunks that were released in + * the current transaction. + * + * Holding the chunks lock will prevent other threads from allocating + * or releasing chunks, but it won't prevent a running transaction + * from committing and releasing the memory that the pending chunks + * list head uses. For that, we need to take a reference to the + * transaction. + */ +static int btrfs_trim_free_extents(struct btrfs_device *device, + u64 minlen, u64 *trimmed) +{ + u64 start = 0, len = 0; + int ret; + + *trimmed = 0; + + /* Not writeable = nothing to do. */ + if (!device->writeable) + return 0; + + /* No free space = nothing to do. */ + if (device->total_bytes <= device->bytes_used) + return 0; + + ret = 0; + + while (1) { + struct btrfs_fs_info *fs_info = device->dev_root->fs_info; + struct btrfs_transaction *trans; + u64 bytes; + + ret = mutex_lock_interruptible(&fs_info->chunk_mutex); + if (ret) + return ret; + + down_read(&fs_info->commit_root_sem); + + spin_lock(&fs_info->trans_lock); + trans = fs_info->running_transaction; + if (trans) + atomic_inc(&trans->use_count); + spin_unlock(&fs_info->trans_lock); + + ret = find_free_dev_extent_start(trans, device, minlen, start, + &start, &len); + if (trans) + btrfs_put_transaction(trans); + + if (ret) { + up_read(&fs_info->commit_root_sem); + mutex_unlock(&fs_info->chunk_mutex); + if (ret == -ENOSPC) + ret = 0; + break; + } + + ret = btrfs_issue_discard(device->bdev, start, len, &bytes); + up_read(&fs_info->commit_root_sem); + mutex_unlock(&fs_info->chunk_mutex); + + if (ret) + break; + + start += len; + *trimmed += bytes; + + if (fatal_signal_pending(current)) { + ret = -ERESTARTSYS; + break; + } + + cond_resched(); + } + + return ret; +} + int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_block_group_cache *cache = NULL; + struct btrfs_device *device; + struct list_head *devices; u64 group_trimmed; u64 start; u64 end; @@ -10124,6 +10338,18 @@ int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) cache = next_block_group(fs_info->tree_root, cache); } + mutex_lock(&root->fs_info->fs_devices->device_list_mutex); + devices = &root->fs_info->fs_devices->alloc_list; + list_for_each_entry(device, devices, dev_alloc_list) { + ret = btrfs_trim_free_extents(device, range->minlen, + &group_trimmed); + if (ret) + break; + + trimmed += group_trimmed; + } + mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); + range->len = trimmed; return ret; } |