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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /fs/btrfs/block-rsv.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/btrfs/block-rsv.c')
-rw-r--r-- | fs/btrfs/block-rsv.c | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c new file mode 100644 index 0000000000..77684c5e0c --- /dev/null +++ b/fs/btrfs/block-rsv.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "misc.h" +#include "ctree.h" +#include "block-rsv.h" +#include "space-info.h" +#include "transaction.h" +#include "block-group.h" +#include "disk-io.h" +#include "fs.h" +#include "accessors.h" + +/* + * HOW DO BLOCK RESERVES WORK + * + * Think of block_rsv's as buckets for logically grouped metadata + * reservations. Each block_rsv has a ->size and a ->reserved. ->size is + * how large we want our block rsv to be, ->reserved is how much space is + * currently reserved for this block reserve. + * + * ->failfast exists for the truncate case, and is described below. + * + * NORMAL OPERATION + * + * -> Reserve + * Entrance: btrfs_block_rsv_add, btrfs_block_rsv_refill + * + * We call into btrfs_reserve_metadata_bytes() with our bytes, which is + * accounted for in space_info->bytes_may_use, and then add the bytes to + * ->reserved, and ->size in the case of btrfs_block_rsv_add. + * + * ->size is an over-estimation of how much we may use for a particular + * operation. + * + * -> Use + * Entrance: btrfs_use_block_rsv + * + * When we do a btrfs_alloc_tree_block() we call into btrfs_use_block_rsv() + * to determine the appropriate block_rsv to use, and then verify that + * ->reserved has enough space for our tree block allocation. Once + * successful we subtract fs_info->nodesize from ->reserved. + * + * -> Finish + * Entrance: btrfs_block_rsv_release + * + * We are finished with our operation, subtract our individual reservation + * from ->size, and then subtract ->size from ->reserved and free up the + * excess if there is any. + * + * There is some logic here to refill the delayed refs rsv or the global rsv + * as needed, otherwise the excess is subtracted from + * space_info->bytes_may_use. + * + * TYPES OF BLOCK RESERVES + * + * BLOCK_RSV_TRANS, BLOCK_RSV_DELOPS, BLOCK_RSV_CHUNK + * These behave normally, as described above, just within the confines of the + * lifetime of their particular operation (transaction for the whole trans + * handle lifetime, for example). + * + * BLOCK_RSV_GLOBAL + * It is impossible to properly account for all the space that may be required + * to make our extent tree updates. This block reserve acts as an overflow + * buffer in case our delayed refs reserve does not reserve enough space to + * update the extent tree. + * + * We can steal from this in some cases as well, notably on evict() or + * truncate() in order to help users recover from ENOSPC conditions. + * + * BLOCK_RSV_DELALLOC + * The individual item sizes are determined by the per-inode size + * calculations, which are described with the delalloc code. This is pretty + * straightforward, it's just the calculation of ->size encodes a lot of + * different items, and thus it gets used when updating inodes, inserting file + * extents, and inserting checksums. + * + * BLOCK_RSV_DELREFS + * We keep a running tally of how many delayed refs we have on the system. + * We assume each one of these delayed refs are going to use a full + * reservation. We use the transaction items and pre-reserve space for every + * operation, and use this reservation to refill any gap between ->size and + * ->reserved that may exist. + * + * From there it's straightforward, removing a delayed ref means we remove its + * count from ->size and free up reservations as necessary. Since this is + * the most dynamic block reserve in the system, we will try to refill this + * block reserve first with any excess returned by any other block reserve. + * + * BLOCK_RSV_EMPTY + * This is the fallback block reserve to make us try to reserve space if we + * don't have a specific bucket for this allocation. It is mostly used for + * updating the device tree and such, since that is a separate pool we're + * content to just reserve space from the space_info on demand. + * + * BLOCK_RSV_TEMP + * This is used by things like truncate and iput. We will temporarily + * allocate a block reserve, set it to some size, and then truncate bytes + * until we have no space left. With ->failfast set we'll simply return + * ENOSPC from btrfs_use_block_rsv() to signal that we need to unwind and try + * to make a new reservation. This is because these operations are + * unbounded, so we want to do as much work as we can, and then back off and + * re-reserve. + */ + +static u64 block_rsv_release_bytes(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, + struct btrfs_block_rsv *dest, u64 num_bytes, + u64 *qgroup_to_release_ret) +{ + struct btrfs_space_info *space_info = block_rsv->space_info; + u64 qgroup_to_release = 0; + u64 ret; + + spin_lock(&block_rsv->lock); + if (num_bytes == (u64)-1) { + num_bytes = block_rsv->size; + qgroup_to_release = block_rsv->qgroup_rsv_size; + } + block_rsv->size -= num_bytes; + if (block_rsv->reserved >= block_rsv->size) { + num_bytes = block_rsv->reserved - block_rsv->size; + block_rsv->reserved = block_rsv->size; + block_rsv->full = true; + } else { + num_bytes = 0; + } + if (qgroup_to_release_ret && + block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) { + qgroup_to_release = block_rsv->qgroup_rsv_reserved - + block_rsv->qgroup_rsv_size; + block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size; + } else { + qgroup_to_release = 0; + } + spin_unlock(&block_rsv->lock); + + ret = num_bytes; + if (num_bytes > 0) { + if (dest) { + spin_lock(&dest->lock); + if (!dest->full) { + u64 bytes_to_add; + + bytes_to_add = dest->size - dest->reserved; + bytes_to_add = min(num_bytes, bytes_to_add); + dest->reserved += bytes_to_add; + if (dest->reserved >= dest->size) + dest->full = true; + num_bytes -= bytes_to_add; + } + spin_unlock(&dest->lock); + } + if (num_bytes) + btrfs_space_info_free_bytes_may_use(fs_info, + space_info, + num_bytes); + } + if (qgroup_to_release_ret) + *qgroup_to_release_ret = qgroup_to_release; + return ret; +} + +int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src, + struct btrfs_block_rsv *dst, u64 num_bytes, + bool update_size) +{ + int ret; + + ret = btrfs_block_rsv_use_bytes(src, num_bytes); + if (ret) + return ret; + + btrfs_block_rsv_add_bytes(dst, num_bytes, update_size); + return 0; +} + +void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type) +{ + memset(rsv, 0, sizeof(*rsv)); + spin_lock_init(&rsv->lock); + rsv->type = type; +} + +void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *rsv, + enum btrfs_rsv_type type) +{ + btrfs_init_block_rsv(rsv, type); + rsv->space_info = btrfs_find_space_info(fs_info, + BTRFS_BLOCK_GROUP_METADATA); +} + +struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info, + enum btrfs_rsv_type type) +{ + struct btrfs_block_rsv *block_rsv; + + block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS); + if (!block_rsv) + return NULL; + + btrfs_init_metadata_block_rsv(fs_info, block_rsv, type); + return block_rsv; +} + +void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *rsv) +{ + if (!rsv) + return; + btrfs_block_rsv_release(fs_info, rsv, (u64)-1, NULL); + kfree(rsv); +} + +int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, u64 num_bytes, + enum btrfs_reserve_flush_enum flush) +{ + int ret; + + if (num_bytes == 0) + return 0; + + ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, num_bytes, flush); + if (!ret) + btrfs_block_rsv_add_bytes(block_rsv, num_bytes, true); + + return ret; +} + +int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent) +{ + u64 num_bytes = 0; + int ret = -ENOSPC; + + spin_lock(&block_rsv->lock); + num_bytes = mult_perc(block_rsv->size, min_percent); + if (block_rsv->reserved >= num_bytes) + ret = 0; + spin_unlock(&block_rsv->lock); + + return ret; +} + +int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, u64 num_bytes, + enum btrfs_reserve_flush_enum flush) +{ + int ret = -ENOSPC; + + if (!block_rsv) + return 0; + + spin_lock(&block_rsv->lock); + if (block_rsv->reserved >= num_bytes) + ret = 0; + else + num_bytes -= block_rsv->reserved; + spin_unlock(&block_rsv->lock); + + if (!ret) + return 0; + + ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, num_bytes, flush); + if (!ret) { + btrfs_block_rsv_add_bytes(block_rsv, num_bytes, false); + return 0; + } + + return ret; +} + +u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, u64 num_bytes, + u64 *qgroup_to_release) +{ + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; + struct btrfs_block_rsv *target = NULL; + + /* + * If we are the delayed_rsv then push to the global rsv, otherwise dump + * into the delayed rsv if it is not full. + */ + if (block_rsv == delayed_rsv) + target = global_rsv; + else if (block_rsv != global_rsv && !btrfs_block_rsv_full(delayed_rsv)) + target = delayed_rsv; + + if (target && block_rsv->space_info != target->space_info) + target = NULL; + + return block_rsv_release_bytes(fs_info, block_rsv, target, num_bytes, + qgroup_to_release); +} + +int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes) +{ + int ret = -ENOSPC; + + spin_lock(&block_rsv->lock); + if (block_rsv->reserved >= num_bytes) { + block_rsv->reserved -= num_bytes; + if (block_rsv->reserved < block_rsv->size) + block_rsv->full = false; + ret = 0; + } + spin_unlock(&block_rsv->lock); + return ret; +} + +void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv, + u64 num_bytes, bool update_size) +{ + spin_lock(&block_rsv->lock); + block_rsv->reserved += num_bytes; + if (update_size) + block_rsv->size += num_bytes; + else if (block_rsv->reserved >= block_rsv->size) + block_rsv->full = true; + spin_unlock(&block_rsv->lock); +} + +void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; + struct btrfs_space_info *sinfo = block_rsv->space_info; + struct btrfs_root *root, *tmp; + u64 num_bytes = btrfs_root_used(&fs_info->tree_root->root_item); + unsigned int min_items = 1; + + /* + * The global block rsv is based on the size of the extent tree, the + * checksum tree and the root tree. If the fs is empty we want to set + * it to a minimal amount for safety. + * + * We also are going to need to modify the minimum of the tree root and + * any global roots we could touch. + */ + read_lock(&fs_info->global_root_lock); + rbtree_postorder_for_each_entry_safe(root, tmp, &fs_info->global_root_tree, + rb_node) { + if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID || + root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID || + root->root_key.objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) { + num_bytes += btrfs_root_used(&root->root_item); + min_items++; + } + } + read_unlock(&fs_info->global_root_lock); + + if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE)) { + num_bytes += btrfs_root_used(&fs_info->block_group_root->root_item); + min_items++; + } + + /* + * But we also want to reserve enough space so we can do the fallback + * global reserve for an unlink, which is an additional + * BTRFS_UNLINK_METADATA_UNITS items. + * + * But we also need space for the delayed ref updates from the unlink, + * so add BTRFS_UNLINK_METADATA_UNITS units for delayed refs, one for + * each unlink metadata item. + */ + min_items += BTRFS_UNLINK_METADATA_UNITS; + + num_bytes = max_t(u64, num_bytes, + btrfs_calc_insert_metadata_size(fs_info, min_items) + + btrfs_calc_delayed_ref_bytes(fs_info, + BTRFS_UNLINK_METADATA_UNITS)); + + spin_lock(&sinfo->lock); + spin_lock(&block_rsv->lock); + + block_rsv->size = min_t(u64, num_bytes, SZ_512M); + + if (block_rsv->reserved < block_rsv->size) { + num_bytes = block_rsv->size - block_rsv->reserved; + btrfs_space_info_update_bytes_may_use(fs_info, sinfo, + num_bytes); + block_rsv->reserved = block_rsv->size; + } else if (block_rsv->reserved > block_rsv->size) { + num_bytes = block_rsv->reserved - block_rsv->size; + btrfs_space_info_update_bytes_may_use(fs_info, sinfo, + -num_bytes); + block_rsv->reserved = block_rsv->size; + btrfs_try_granting_tickets(fs_info, sinfo); + } + + block_rsv->full = (block_rsv->reserved == block_rsv->size); + + if (block_rsv->size >= sinfo->total_bytes) + sinfo->force_alloc = CHUNK_ALLOC_FORCE; + spin_unlock(&block_rsv->lock); + spin_unlock(&sinfo->lock); +} + +void btrfs_init_root_block_rsv(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + + switch (root->root_key.objectid) { + case BTRFS_CSUM_TREE_OBJECTID: + case BTRFS_EXTENT_TREE_OBJECTID: + case BTRFS_FREE_SPACE_TREE_OBJECTID: + case BTRFS_BLOCK_GROUP_TREE_OBJECTID: + root->block_rsv = &fs_info->delayed_refs_rsv; + break; + case BTRFS_ROOT_TREE_OBJECTID: + case BTRFS_DEV_TREE_OBJECTID: + case BTRFS_QUOTA_TREE_OBJECTID: + root->block_rsv = &fs_info->global_block_rsv; + break; + case BTRFS_CHUNK_TREE_OBJECTID: + root->block_rsv = &fs_info->chunk_block_rsv; + break; + default: + root->block_rsv = NULL; + break; + } +} + +void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + struct btrfs_space_info *space_info; + + space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); + fs_info->chunk_block_rsv.space_info = space_info; + + space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + fs_info->global_block_rsv.space_info = space_info; + fs_info->trans_block_rsv.space_info = space_info; + fs_info->empty_block_rsv.space_info = space_info; + fs_info->delayed_block_rsv.space_info = space_info; + fs_info->delayed_refs_rsv.space_info = space_info; + + btrfs_update_global_block_rsv(fs_info); +} + +void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + btrfs_block_rsv_release(fs_info, &fs_info->global_block_rsv, (u64)-1, + NULL); + WARN_ON(fs_info->trans_block_rsv.size > 0); + WARN_ON(fs_info->trans_block_rsv.reserved > 0); + WARN_ON(fs_info->chunk_block_rsv.size > 0); + WARN_ON(fs_info->chunk_block_rsv.reserved > 0); + WARN_ON(fs_info->delayed_block_rsv.size > 0); + WARN_ON(fs_info->delayed_block_rsv.reserved > 0); + WARN_ON(fs_info->delayed_refs_rsv.reserved > 0); + WARN_ON(fs_info->delayed_refs_rsv.size > 0); +} + +static struct btrfs_block_rsv *get_block_rsv( + const struct btrfs_trans_handle *trans, + const struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_rsv *block_rsv = NULL; + + if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) || + (root == fs_info->uuid_root) || + (trans->adding_csums && + root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID)) + block_rsv = trans->block_rsv; + + if (!block_rsv) + block_rsv = root->block_rsv; + + if (!block_rsv) + block_rsv = &fs_info->empty_block_rsv; + + return block_rsv; +} + +struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u32 blocksize) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_rsv *block_rsv; + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + int ret; + bool global_updated = false; + + block_rsv = get_block_rsv(trans, root); + + if (unlikely(block_rsv->size == 0)) + goto try_reserve; +again: + ret = btrfs_block_rsv_use_bytes(block_rsv, blocksize); + if (!ret) + return block_rsv; + + if (block_rsv->failfast) + return ERR_PTR(ret); + + if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) { + global_updated = true; + btrfs_update_global_block_rsv(fs_info); + goto again; + } + + /* + * The global reserve still exists to save us from ourselves, so don't + * warn_on if we are short on our delayed refs reserve. + */ + if (block_rsv->type != BTRFS_BLOCK_RSV_DELREFS && + btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { + static DEFINE_RATELIMIT_STATE(_rs, + DEFAULT_RATELIMIT_INTERVAL * 10, + /*DEFAULT_RATELIMIT_BURST*/ 1); + if (__ratelimit(&_rs)) + WARN(1, KERN_DEBUG + "BTRFS: block rsv %d returned %d\n", + block_rsv->type, ret); + } +try_reserve: + ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, blocksize, + BTRFS_RESERVE_NO_FLUSH); + if (!ret) + return block_rsv; + /* + * If we couldn't reserve metadata bytes try and use some from + * the global reserve if its space type is the same as the global + * reservation. + */ + if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL && + block_rsv->space_info == global_rsv->space_info) { + ret = btrfs_block_rsv_use_bytes(global_rsv, blocksize); + if (!ret) + return global_rsv; + } + + /* + * All hope is lost, but of course our reservations are overly + * pessimistic, so instead of possibly having an ENOSPC abort here, try + * one last time to force a reservation if there's enough actual space + * on disk to make the reservation. + */ + ret = btrfs_reserve_metadata_bytes(fs_info, block_rsv, blocksize, + BTRFS_RESERVE_FLUSH_EMERGENCY); + if (!ret) + return block_rsv; + + return ERR_PTR(ret); +} + +int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *rsv) +{ + u64 needed_bytes; + int ret; + + /* 1 for slack space, 1 for updating the inode */ + needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) + + btrfs_calc_metadata_size(fs_info, 1); + + spin_lock(&rsv->lock); + if (rsv->reserved < needed_bytes) + ret = -ENOSPC; + else + ret = 0; + spin_unlock(&rsv->lock); + return ret; +} |