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343a63594b
The parameter is unused and we can get it from space info if needed. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2085 lines
66 KiB
C
2085 lines
66 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include "linux/spinlock.h"
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#include <linux/minmax.h>
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#include "misc.h"
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#include "ctree.h"
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#include "space-info.h"
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#include "sysfs.h"
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#include "volumes.h"
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#include "free-space-cache.h"
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#include "ordered-data.h"
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#include "transaction.h"
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#include "block-group.h"
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#include "fs.h"
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#include "accessors.h"
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#include "extent-tree.h"
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/*
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* HOW DOES SPACE RESERVATION WORK
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*
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* If you want to know about delalloc specifically, there is a separate comment
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* for that with the delalloc code. This comment is about how the whole system
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* works generally.
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*
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* BASIC CONCEPTS
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*
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* 1) space_info. This is the ultimate arbiter of how much space we can use.
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* There's a description of the bytes_ fields with the struct declaration,
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* refer to that for specifics on each field. Suffice it to say that for
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* reservations we care about total_bytes - SUM(space_info->bytes_) when
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* determining if there is space to make an allocation. There is a space_info
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* for METADATA, SYSTEM, and DATA areas.
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*
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* 2) block_rsv's. These are basically buckets for every different type of
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* metadata reservation we have. You can see the comment in the block_rsv
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* code on the rules for each type, but generally block_rsv->reserved is how
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* much space is accounted for in space_info->bytes_may_use.
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*
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* 3) btrfs_calc*_size. These are the worst case calculations we used based
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* on the number of items we will want to modify. We have one for changing
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* items, and one for inserting new items. Generally we use these helpers to
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* determine the size of the block reserves, and then use the actual bytes
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* values to adjust the space_info counters.
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*
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* MAKING RESERVATIONS, THE NORMAL CASE
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*
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* We call into either btrfs_reserve_data_bytes() or
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* btrfs_reserve_metadata_bytes(), depending on which we're looking for, with
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* num_bytes we want to reserve.
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*
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* ->reserve
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* space_info->bytes_may_reserve += num_bytes
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*
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* ->extent allocation
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* Call btrfs_add_reserved_bytes() which does
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* space_info->bytes_may_reserve -= num_bytes
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* space_info->bytes_reserved += extent_bytes
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*
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* ->insert reference
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* Call btrfs_update_block_group() which does
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* space_info->bytes_reserved -= extent_bytes
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* space_info->bytes_used += extent_bytes
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*
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* MAKING RESERVATIONS, FLUSHING NORMALLY (non-priority)
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*
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* Assume we are unable to simply make the reservation because we do not have
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* enough space
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*
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* -> __reserve_bytes
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* create a reserve_ticket with ->bytes set to our reservation, add it to
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* the tail of space_info->tickets, kick async flush thread
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*
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* ->handle_reserve_ticket
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* wait on ticket->wait for ->bytes to be reduced to 0, or ->error to be set
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* on the ticket.
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*
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* -> btrfs_async_reclaim_metadata_space/btrfs_async_reclaim_data_space
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* Flushes various things attempting to free up space.
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*
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* -> btrfs_try_granting_tickets()
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* This is called by anything that either subtracts space from
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* space_info->bytes_may_use, ->bytes_pinned, etc, or adds to the
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* space_info->total_bytes. This loops through the ->priority_tickets and
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* then the ->tickets list checking to see if the reservation can be
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* completed. If it can the space is added to space_info->bytes_may_use and
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* the ticket is woken up.
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*
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* -> ticket wakeup
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* Check if ->bytes == 0, if it does we got our reservation and we can carry
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* on, if not return the appropriate error (ENOSPC, but can be EINTR if we
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* were interrupted.)
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*
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* MAKING RESERVATIONS, FLUSHING HIGH PRIORITY
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*
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* Same as the above, except we add ourselves to the
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* space_info->priority_tickets, and we do not use ticket->wait, we simply
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* call flush_space() ourselves for the states that are safe for us to call
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* without deadlocking and hope for the best.
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*
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* THE FLUSHING STATES
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*
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* Generally speaking we will have two cases for each state, a "nice" state
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* and a "ALL THE THINGS" state. In btrfs we delay a lot of work in order to
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* reduce the locking over head on the various trees, and even to keep from
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* doing any work at all in the case of delayed refs. Each of these delayed
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* things however hold reservations, and so letting them run allows us to
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* reclaim space so we can make new reservations.
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*
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* FLUSH_DELAYED_ITEMS
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* Every inode has a delayed item to update the inode. Take a simple write
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* for example, we would update the inode item at write time to update the
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* mtime, and then again at finish_ordered_io() time in order to update the
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* isize or bytes. We keep these delayed items to coalesce these operations
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* into a single operation done on demand. These are an easy way to reclaim
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* metadata space.
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*
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* FLUSH_DELALLOC
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* Look at the delalloc comment to get an idea of how much space is reserved
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* for delayed allocation. We can reclaim some of this space simply by
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* running delalloc, but usually we need to wait for ordered extents to
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* reclaim the bulk of this space.
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*
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* FLUSH_DELAYED_REFS
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* We have a block reserve for the outstanding delayed refs space, and every
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* delayed ref operation holds a reservation. Running these is a quick way
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* to reclaim space, but we want to hold this until the end because COW can
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* churn a lot and we can avoid making some extent tree modifications if we
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* are able to delay for as long as possible.
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*
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* ALLOC_CHUNK
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* We will skip this the first time through space reservation, because of
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* overcommit and we don't want to have a lot of useless metadata space when
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* our worst case reservations will likely never come true.
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*
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* RUN_DELAYED_IPUTS
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* If we're freeing inodes we're likely freeing checksums, file extent
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* items, and extent tree items. Loads of space could be freed up by these
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* operations, however they won't be usable until the transaction commits.
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*
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* COMMIT_TRANS
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* This will commit the transaction. Historically we had a lot of logic
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* surrounding whether or not we'd commit the transaction, but this waits born
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* out of a pre-tickets era where we could end up committing the transaction
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* thousands of times in a row without making progress. Now thanks to our
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* ticketing system we know if we're not making progress and can error
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* everybody out after a few commits rather than burning the disk hoping for
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* a different answer.
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*
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* OVERCOMMIT
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*
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* Because we hold so many reservations for metadata we will allow you to
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* reserve more space than is currently free in the currently allocate
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* metadata space. This only happens with metadata, data does not allow
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* overcommitting.
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*
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* You can see the current logic for when we allow overcommit in
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* btrfs_can_overcommit(), but it only applies to unallocated space. If there
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* is no unallocated space to be had, all reservations are kept within the
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* free space in the allocated metadata chunks.
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*
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* Because of overcommitting, you generally want to use the
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* btrfs_can_overcommit() logic for metadata allocations, as it does the right
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* thing with or without extra unallocated space.
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*/
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u64 __pure btrfs_space_info_used(const struct btrfs_space_info *s_info,
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bool may_use_included)
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{
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ASSERT(s_info);
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return s_info->bytes_used + s_info->bytes_reserved +
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s_info->bytes_pinned + s_info->bytes_readonly +
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s_info->bytes_zone_unusable +
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(may_use_included ? s_info->bytes_may_use : 0);
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}
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/*
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* after adding space to the filesystem, we need to clear the full flags
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* on all the space infos.
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*/
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void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
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{
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struct list_head *head = &info->space_info;
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struct btrfs_space_info *found;
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list_for_each_entry(found, head, list)
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found->full = 0;
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}
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/*
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* Block groups with more than this value (percents) of unusable space will be
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* scheduled for background reclaim.
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*/
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#define BTRFS_DEFAULT_ZONED_RECLAIM_THRESH (75)
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#define BTRFS_UNALLOC_BLOCK_GROUP_TARGET (10ULL)
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/*
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* Calculate chunk size depending on volume type (regular or zoned).
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*/
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static u64 calc_chunk_size(const struct btrfs_fs_info *fs_info, u64 flags)
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{
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if (btrfs_is_zoned(fs_info))
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return fs_info->zone_size;
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ASSERT(flags & BTRFS_BLOCK_GROUP_TYPE_MASK);
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if (flags & BTRFS_BLOCK_GROUP_DATA)
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return BTRFS_MAX_DATA_CHUNK_SIZE;
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else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
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return SZ_32M;
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/* Handle BTRFS_BLOCK_GROUP_METADATA */
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if (fs_info->fs_devices->total_rw_bytes > 50ULL * SZ_1G)
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return SZ_1G;
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return SZ_256M;
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}
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/*
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* Update default chunk size.
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*/
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void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,
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u64 chunk_size)
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{
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WRITE_ONCE(space_info->chunk_size, chunk_size);
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}
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static int create_space_info(struct btrfs_fs_info *info, u64 flags)
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{
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struct btrfs_space_info *space_info;
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int i;
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int ret;
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space_info = kzalloc(sizeof(*space_info), GFP_NOFS);
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if (!space_info)
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return -ENOMEM;
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space_info->fs_info = info;
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for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
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INIT_LIST_HEAD(&space_info->block_groups[i]);
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init_rwsem(&space_info->groups_sem);
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spin_lock_init(&space_info->lock);
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space_info->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
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space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
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INIT_LIST_HEAD(&space_info->ro_bgs);
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INIT_LIST_HEAD(&space_info->tickets);
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INIT_LIST_HEAD(&space_info->priority_tickets);
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space_info->clamp = 1;
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btrfs_update_space_info_chunk_size(space_info, calc_chunk_size(info, flags));
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if (btrfs_is_zoned(info))
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space_info->bg_reclaim_threshold = BTRFS_DEFAULT_ZONED_RECLAIM_THRESH;
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ret = btrfs_sysfs_add_space_info_type(info, space_info);
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if (ret)
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return ret;
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list_add(&space_info->list, &info->space_info);
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if (flags & BTRFS_BLOCK_GROUP_DATA)
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info->data_sinfo = space_info;
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return ret;
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}
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int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
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{
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struct btrfs_super_block *disk_super;
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u64 features;
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u64 flags;
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int mixed = 0;
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int ret;
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disk_super = fs_info->super_copy;
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if (!btrfs_super_root(disk_super))
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return -EINVAL;
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features = btrfs_super_incompat_flags(disk_super);
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if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
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mixed = 1;
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flags = BTRFS_BLOCK_GROUP_SYSTEM;
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ret = create_space_info(fs_info, flags);
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if (ret)
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goto out;
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if (mixed) {
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flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
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ret = create_space_info(fs_info, flags);
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} else {
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flags = BTRFS_BLOCK_GROUP_METADATA;
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ret = create_space_info(fs_info, flags);
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if (ret)
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goto out;
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flags = BTRFS_BLOCK_GROUP_DATA;
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ret = create_space_info(fs_info, flags);
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}
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out:
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return ret;
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}
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void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
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struct btrfs_block_group *block_group)
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{
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struct btrfs_space_info *found;
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int factor, index;
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factor = btrfs_bg_type_to_factor(block_group->flags);
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found = btrfs_find_space_info(info, block_group->flags);
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ASSERT(found);
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spin_lock(&found->lock);
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found->total_bytes += block_group->length;
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found->disk_total += block_group->length * factor;
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found->bytes_used += block_group->used;
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found->disk_used += block_group->used * factor;
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found->bytes_readonly += block_group->bytes_super;
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btrfs_space_info_update_bytes_zone_unusable(info, found, block_group->zone_unusable);
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if (block_group->length > 0)
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found->full = 0;
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btrfs_try_granting_tickets(info, found);
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spin_unlock(&found->lock);
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block_group->space_info = found;
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index = btrfs_bg_flags_to_raid_index(block_group->flags);
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down_write(&found->groups_sem);
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list_add_tail(&block_group->list, &found->block_groups[index]);
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up_write(&found->groups_sem);
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}
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struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
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u64 flags)
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{
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struct list_head *head = &info->space_info;
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struct btrfs_space_info *found;
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flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
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list_for_each_entry(found, head, list) {
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if (found->flags & flags)
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return found;
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}
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return NULL;
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}
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static u64 calc_effective_data_chunk_size(struct btrfs_fs_info *fs_info)
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{
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struct btrfs_space_info *data_sinfo;
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u64 data_chunk_size;
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/*
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* Calculate the data_chunk_size, space_info->chunk_size is the
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* "optimal" chunk size based on the fs size. However when we actually
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* allocate the chunk we will strip this down further, making it no
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* more than 10% of the disk or 1G, whichever is smaller.
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*
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* On the zoned mode, we need to use zone_size (= data_sinfo->chunk_size)
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* as it is.
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*/
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data_sinfo = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
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if (btrfs_is_zoned(fs_info))
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return data_sinfo->chunk_size;
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data_chunk_size = min(data_sinfo->chunk_size,
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mult_perc(fs_info->fs_devices->total_rw_bytes, 10));
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return min_t(u64, data_chunk_size, SZ_1G);
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}
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static u64 calc_available_free_space(struct btrfs_fs_info *fs_info,
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const struct btrfs_space_info *space_info,
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enum btrfs_reserve_flush_enum flush)
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{
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u64 profile;
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u64 avail;
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u64 data_chunk_size;
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int factor;
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if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
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profile = btrfs_system_alloc_profile(fs_info);
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else
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profile = btrfs_metadata_alloc_profile(fs_info);
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avail = atomic64_read(&fs_info->free_chunk_space);
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/*
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* If we have dup, raid1 or raid10 then only half of the free
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* space is actually usable. For raid56, the space info used
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* doesn't include the parity drive, so we don't have to
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* change the math
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*/
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factor = btrfs_bg_type_to_factor(profile);
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avail = div_u64(avail, factor);
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if (avail == 0)
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return 0;
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data_chunk_size = calc_effective_data_chunk_size(fs_info);
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/*
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* Since data allocations immediately use block groups as part of the
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* reservation, because we assume that data reservations will == actual
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* usage, we could potentially overcommit and then immediately have that
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* available space used by a data allocation, which could put us in a
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* bind when we get close to filling the file system.
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*
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* To handle this simply remove the data_chunk_size from the available
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* space. If we are relatively empty this won't affect our ability to
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* overcommit much, and if we're very close to full it'll keep us from
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* getting into a position where we've given ourselves very little
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* metadata wiggle room.
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*/
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if (avail <= data_chunk_size)
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return 0;
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avail -= data_chunk_size;
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/*
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* If we aren't flushing all things, let us overcommit up to
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* 1/2th of the space. If we can flush, don't let us overcommit
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* too much, let it overcommit up to 1/8 of the space.
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*/
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if (flush == BTRFS_RESERVE_FLUSH_ALL)
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avail >>= 3;
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else
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avail >>= 1;
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/*
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* On the zoned mode, we always allocate one zone as one chunk.
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* Returning non-zone size alingned bytes here will result in
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* less pressure for the async metadata reclaim process, and it
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* will over-commit too much leading to ENOSPC. Align down to the
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* zone size to avoid that.
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*/
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if (btrfs_is_zoned(fs_info))
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avail = ALIGN_DOWN(avail, fs_info->zone_size);
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return avail;
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}
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int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
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const struct btrfs_space_info *space_info, u64 bytes,
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enum btrfs_reserve_flush_enum flush)
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{
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u64 avail;
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u64 used;
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/* Don't overcommit when in mixed mode */
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if (space_info->flags & BTRFS_BLOCK_GROUP_DATA)
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return 0;
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used = btrfs_space_info_used(space_info, true);
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avail = calc_available_free_space(fs_info, space_info, flush);
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if (used + bytes < space_info->total_bytes + avail)
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return 1;
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return 0;
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}
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static void remove_ticket(struct btrfs_space_info *space_info,
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struct reserve_ticket *ticket)
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{
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if (!list_empty(&ticket->list)) {
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list_del_init(&ticket->list);
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ASSERT(space_info->reclaim_size >= ticket->bytes);
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space_info->reclaim_size -= ticket->bytes;
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}
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}
|
|
|
|
/*
|
|
* This is for space we already have accounted in space_info->bytes_may_use, so
|
|
* basically when we're returning space from block_rsv's.
|
|
*/
|
|
void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info)
|
|
{
|
|
struct list_head *head;
|
|
enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_NO_FLUSH;
|
|
|
|
lockdep_assert_held(&space_info->lock);
|
|
|
|
head = &space_info->priority_tickets;
|
|
again:
|
|
while (!list_empty(head)) {
|
|
struct reserve_ticket *ticket;
|
|
u64 used = btrfs_space_info_used(space_info, true);
|
|
|
|
ticket = list_first_entry(head, struct reserve_ticket, list);
|
|
|
|
/* Check and see if our ticket can be satisfied now. */
|
|
if ((used + ticket->bytes <= space_info->total_bytes) ||
|
|
btrfs_can_overcommit(fs_info, space_info, ticket->bytes,
|
|
flush)) {
|
|
btrfs_space_info_update_bytes_may_use(fs_info,
|
|
space_info,
|
|
ticket->bytes);
|
|
remove_ticket(space_info, ticket);
|
|
ticket->bytes = 0;
|
|
space_info->tickets_id++;
|
|
wake_up(&ticket->wait);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (head == &space_info->priority_tickets) {
|
|
head = &space_info->tickets;
|
|
flush = BTRFS_RESERVE_FLUSH_ALL;
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
#define DUMP_BLOCK_RSV(fs_info, rsv_name) \
|
|
do { \
|
|
struct btrfs_block_rsv *__rsv = &(fs_info)->rsv_name; \
|
|
spin_lock(&__rsv->lock); \
|
|
btrfs_info(fs_info, #rsv_name ": size %llu reserved %llu", \
|
|
__rsv->size, __rsv->reserved); \
|
|
spin_unlock(&__rsv->lock); \
|
|
} while (0)
|
|
|
|
static const char *space_info_flag_to_str(const struct btrfs_space_info *space_info)
|
|
{
|
|
switch (space_info->flags) {
|
|
case BTRFS_BLOCK_GROUP_SYSTEM:
|
|
return "SYSTEM";
|
|
case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
|
|
return "DATA+METADATA";
|
|
case BTRFS_BLOCK_GROUP_DATA:
|
|
return "DATA";
|
|
case BTRFS_BLOCK_GROUP_METADATA:
|
|
return "METADATA";
|
|
default:
|
|
return "UNKNOWN";
|
|
}
|
|
}
|
|
|
|
static void dump_global_block_rsv(struct btrfs_fs_info *fs_info)
|
|
{
|
|
DUMP_BLOCK_RSV(fs_info, global_block_rsv);
|
|
DUMP_BLOCK_RSV(fs_info, trans_block_rsv);
|
|
DUMP_BLOCK_RSV(fs_info, chunk_block_rsv);
|
|
DUMP_BLOCK_RSV(fs_info, delayed_block_rsv);
|
|
DUMP_BLOCK_RSV(fs_info, delayed_refs_rsv);
|
|
}
|
|
|
|
static void __btrfs_dump_space_info(const struct btrfs_fs_info *fs_info,
|
|
const struct btrfs_space_info *info)
|
|
{
|
|
const char *flag_str = space_info_flag_to_str(info);
|
|
lockdep_assert_held(&info->lock);
|
|
|
|
/* The free space could be negative in case of overcommit */
|
|
btrfs_info(fs_info, "space_info %s has %lld free, is %sfull",
|
|
flag_str,
|
|
(s64)(info->total_bytes - btrfs_space_info_used(info, true)),
|
|
info->full ? "" : "not ");
|
|
btrfs_info(fs_info,
|
|
"space_info total=%llu, used=%llu, pinned=%llu, reserved=%llu, may_use=%llu, readonly=%llu zone_unusable=%llu",
|
|
info->total_bytes, info->bytes_used, info->bytes_pinned,
|
|
info->bytes_reserved, info->bytes_may_use,
|
|
info->bytes_readonly, info->bytes_zone_unusable);
|
|
}
|
|
|
|
void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *info, u64 bytes,
|
|
int dump_block_groups)
|
|
{
|
|
struct btrfs_block_group *cache;
|
|
u64 total_avail = 0;
|
|
int index = 0;
|
|
|
|
spin_lock(&info->lock);
|
|
__btrfs_dump_space_info(fs_info, info);
|
|
dump_global_block_rsv(fs_info);
|
|
spin_unlock(&info->lock);
|
|
|
|
if (!dump_block_groups)
|
|
return;
|
|
|
|
down_read(&info->groups_sem);
|
|
again:
|
|
list_for_each_entry(cache, &info->block_groups[index], list) {
|
|
u64 avail;
|
|
|
|
spin_lock(&cache->lock);
|
|
avail = cache->length - cache->used - cache->pinned -
|
|
cache->reserved - cache->bytes_super - cache->zone_unusable;
|
|
btrfs_info(fs_info,
|
|
"block group %llu has %llu bytes, %llu used %llu pinned %llu reserved %llu delalloc %llu super %llu zone_unusable (%llu bytes available) %s",
|
|
cache->start, cache->length, cache->used, cache->pinned,
|
|
cache->reserved, cache->delalloc_bytes,
|
|
cache->bytes_super, cache->zone_unusable,
|
|
avail, cache->ro ? "[readonly]" : "");
|
|
spin_unlock(&cache->lock);
|
|
btrfs_dump_free_space(cache, bytes);
|
|
total_avail += avail;
|
|
}
|
|
if (++index < BTRFS_NR_RAID_TYPES)
|
|
goto again;
|
|
up_read(&info->groups_sem);
|
|
|
|
btrfs_info(fs_info, "%llu bytes available across all block groups", total_avail);
|
|
}
|
|
|
|
static inline u64 calc_reclaim_items_nr(const struct btrfs_fs_info *fs_info,
|
|
u64 to_reclaim)
|
|
{
|
|
u64 bytes;
|
|
u64 nr;
|
|
|
|
bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
|
|
nr = div64_u64(to_reclaim, bytes);
|
|
if (!nr)
|
|
nr = 1;
|
|
return nr;
|
|
}
|
|
|
|
/*
|
|
* shrink metadata reservation for delalloc
|
|
*/
|
|
static void shrink_delalloc(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
u64 to_reclaim, bool wait_ordered,
|
|
bool for_preempt)
|
|
{
|
|
struct btrfs_trans_handle *trans;
|
|
u64 delalloc_bytes;
|
|
u64 ordered_bytes;
|
|
u64 items;
|
|
long time_left;
|
|
int loops;
|
|
|
|
delalloc_bytes = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
|
|
ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
|
|
if (delalloc_bytes == 0 && ordered_bytes == 0)
|
|
return;
|
|
|
|
/* Calc the number of the pages we need flush for space reservation */
|
|
if (to_reclaim == U64_MAX) {
|
|
items = U64_MAX;
|
|
} else {
|
|
/*
|
|
* to_reclaim is set to however much metadata we need to
|
|
* reclaim, but reclaiming that much data doesn't really track
|
|
* exactly. What we really want to do is reclaim full inode's
|
|
* worth of reservations, however that's not available to us
|
|
* here. We will take a fraction of the delalloc bytes for our
|
|
* flushing loops and hope for the best. Delalloc will expand
|
|
* the amount we write to cover an entire dirty extent, which
|
|
* will reclaim the metadata reservation for that range. If
|
|
* it's not enough subsequent flush stages will be more
|
|
* aggressive.
|
|
*/
|
|
to_reclaim = max(to_reclaim, delalloc_bytes >> 3);
|
|
items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2;
|
|
}
|
|
|
|
trans = current->journal_info;
|
|
|
|
/*
|
|
* If we are doing more ordered than delalloc we need to just wait on
|
|
* ordered extents, otherwise we'll waste time trying to flush delalloc
|
|
* that likely won't give us the space back we need.
|
|
*/
|
|
if (ordered_bytes > delalloc_bytes && !for_preempt)
|
|
wait_ordered = true;
|
|
|
|
loops = 0;
|
|
while ((delalloc_bytes || ordered_bytes) && loops < 3) {
|
|
u64 temp = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
|
|
long nr_pages = min_t(u64, temp, LONG_MAX);
|
|
int async_pages;
|
|
|
|
btrfs_start_delalloc_roots(fs_info, nr_pages, true);
|
|
|
|
/*
|
|
* We need to make sure any outstanding async pages are now
|
|
* processed before we continue. This is because things like
|
|
* sync_inode() try to be smart and skip writing if the inode is
|
|
* marked clean. We don't use filemap_fwrite for flushing
|
|
* because we want to control how many pages we write out at a
|
|
* time, thus this is the only safe way to make sure we've
|
|
* waited for outstanding compressed workers to have started
|
|
* their jobs and thus have ordered extents set up properly.
|
|
*
|
|
* This exists because we do not want to wait for each
|
|
* individual inode to finish its async work, we simply want to
|
|
* start the IO on everybody, and then come back here and wait
|
|
* for all of the async work to catch up. Once we're done with
|
|
* that we know we'll have ordered extents for everything and we
|
|
* can decide if we wait for that or not.
|
|
*
|
|
* If we choose to replace this in the future, make absolutely
|
|
* sure that the proper waiting is being done in the async case,
|
|
* as there have been bugs in that area before.
|
|
*/
|
|
async_pages = atomic_read(&fs_info->async_delalloc_pages);
|
|
if (!async_pages)
|
|
goto skip_async;
|
|
|
|
/*
|
|
* We don't want to wait forever, if we wrote less pages in this
|
|
* loop than we have outstanding, only wait for that number of
|
|
* pages, otherwise we can wait for all async pages to finish
|
|
* before continuing.
|
|
*/
|
|
if (async_pages > nr_pages)
|
|
async_pages -= nr_pages;
|
|
else
|
|
async_pages = 0;
|
|
wait_event(fs_info->async_submit_wait,
|
|
atomic_read(&fs_info->async_delalloc_pages) <=
|
|
async_pages);
|
|
skip_async:
|
|
loops++;
|
|
if (wait_ordered && !trans) {
|
|
btrfs_wait_ordered_roots(fs_info, items, NULL);
|
|
} else {
|
|
time_left = schedule_timeout_killable(1);
|
|
if (time_left)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we are for preemption we just want a one-shot of delalloc
|
|
* flushing so we can stop flushing if we decide we don't need
|
|
* to anymore.
|
|
*/
|
|
if (for_preempt)
|
|
break;
|
|
|
|
spin_lock(&space_info->lock);
|
|
if (list_empty(&space_info->tickets) &&
|
|
list_empty(&space_info->priority_tickets)) {
|
|
spin_unlock(&space_info->lock);
|
|
break;
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
|
|
delalloc_bytes = percpu_counter_sum_positive(
|
|
&fs_info->delalloc_bytes);
|
|
ordered_bytes = percpu_counter_sum_positive(
|
|
&fs_info->ordered_bytes);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Try to flush some data based on policy set by @state. This is only advisory
|
|
* and may fail for various reasons. The caller is supposed to examine the
|
|
* state of @space_info to detect the outcome.
|
|
*/
|
|
static void flush_space(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info, u64 num_bytes,
|
|
enum btrfs_flush_state state, bool for_preempt)
|
|
{
|
|
struct btrfs_root *root = fs_info->tree_root;
|
|
struct btrfs_trans_handle *trans;
|
|
int nr;
|
|
int ret = 0;
|
|
|
|
switch (state) {
|
|
case FLUSH_DELAYED_ITEMS_NR:
|
|
case FLUSH_DELAYED_ITEMS:
|
|
if (state == FLUSH_DELAYED_ITEMS_NR)
|
|
nr = calc_reclaim_items_nr(fs_info, num_bytes) * 2;
|
|
else
|
|
nr = -1;
|
|
|
|
trans = btrfs_join_transaction_nostart(root);
|
|
if (IS_ERR(trans)) {
|
|
ret = PTR_ERR(trans);
|
|
if (ret == -ENOENT)
|
|
ret = 0;
|
|
break;
|
|
}
|
|
ret = btrfs_run_delayed_items_nr(trans, nr);
|
|
btrfs_end_transaction(trans);
|
|
break;
|
|
case FLUSH_DELALLOC:
|
|
case FLUSH_DELALLOC_WAIT:
|
|
case FLUSH_DELALLOC_FULL:
|
|
if (state == FLUSH_DELALLOC_FULL)
|
|
num_bytes = U64_MAX;
|
|
shrink_delalloc(fs_info, space_info, num_bytes,
|
|
state != FLUSH_DELALLOC, for_preempt);
|
|
break;
|
|
case FLUSH_DELAYED_REFS_NR:
|
|
case FLUSH_DELAYED_REFS:
|
|
trans = btrfs_join_transaction_nostart(root);
|
|
if (IS_ERR(trans)) {
|
|
ret = PTR_ERR(trans);
|
|
if (ret == -ENOENT)
|
|
ret = 0;
|
|
break;
|
|
}
|
|
if (state == FLUSH_DELAYED_REFS_NR)
|
|
btrfs_run_delayed_refs(trans, num_bytes);
|
|
else
|
|
btrfs_run_delayed_refs(trans, 0);
|
|
btrfs_end_transaction(trans);
|
|
break;
|
|
case ALLOC_CHUNK:
|
|
case ALLOC_CHUNK_FORCE:
|
|
trans = btrfs_join_transaction(root);
|
|
if (IS_ERR(trans)) {
|
|
ret = PTR_ERR(trans);
|
|
break;
|
|
}
|
|
ret = btrfs_chunk_alloc(trans,
|
|
btrfs_get_alloc_profile(fs_info, space_info->flags),
|
|
(state == ALLOC_CHUNK) ? CHUNK_ALLOC_NO_FORCE :
|
|
CHUNK_ALLOC_FORCE);
|
|
btrfs_end_transaction(trans);
|
|
|
|
if (ret > 0 || ret == -ENOSPC)
|
|
ret = 0;
|
|
break;
|
|
case RUN_DELAYED_IPUTS:
|
|
/*
|
|
* If we have pending delayed iputs then we could free up a
|
|
* bunch of pinned space, so make sure we run the iputs before
|
|
* we do our pinned bytes check below.
|
|
*/
|
|
btrfs_run_delayed_iputs(fs_info);
|
|
btrfs_wait_on_delayed_iputs(fs_info);
|
|
break;
|
|
case COMMIT_TRANS:
|
|
ASSERT(current->journal_info == NULL);
|
|
/*
|
|
* We don't want to start a new transaction, just attach to the
|
|
* current one or wait it fully commits in case its commit is
|
|
* happening at the moment. Note: we don't use a nostart join
|
|
* because that does not wait for a transaction to fully commit
|
|
* (only for it to be unblocked, state TRANS_STATE_UNBLOCKED).
|
|
*/
|
|
ret = btrfs_commit_current_transaction(root);
|
|
break;
|
|
default:
|
|
ret = -ENOSPC;
|
|
break;
|
|
}
|
|
|
|
trace_btrfs_flush_space(fs_info, space_info->flags, num_bytes, state,
|
|
ret, for_preempt);
|
|
return;
|
|
}
|
|
|
|
static u64 btrfs_calc_reclaim_metadata_size(struct btrfs_fs_info *fs_info,
|
|
const struct btrfs_space_info *space_info)
|
|
{
|
|
u64 used;
|
|
u64 avail;
|
|
u64 to_reclaim = space_info->reclaim_size;
|
|
|
|
lockdep_assert_held(&space_info->lock);
|
|
|
|
avail = calc_available_free_space(fs_info, space_info,
|
|
BTRFS_RESERVE_FLUSH_ALL);
|
|
used = btrfs_space_info_used(space_info, true);
|
|
|
|
/*
|
|
* We may be flushing because suddenly we have less space than we had
|
|
* before, and now we're well over-committed based on our current free
|
|
* space. If that's the case add in our overage so we make sure to put
|
|
* appropriate pressure on the flushing state machine.
|
|
*/
|
|
if (space_info->total_bytes + avail < used)
|
|
to_reclaim += used - (space_info->total_bytes + avail);
|
|
|
|
return to_reclaim;
|
|
}
|
|
|
|
static bool need_preemptive_reclaim(struct btrfs_fs_info *fs_info,
|
|
const struct btrfs_space_info *space_info)
|
|
{
|
|
const u64 global_rsv_size = btrfs_block_rsv_reserved(&fs_info->global_block_rsv);
|
|
u64 ordered, delalloc;
|
|
u64 thresh;
|
|
u64 used;
|
|
|
|
thresh = mult_perc(space_info->total_bytes, 90);
|
|
|
|
lockdep_assert_held(&space_info->lock);
|
|
|
|
/* If we're just plain full then async reclaim just slows us down. */
|
|
if ((space_info->bytes_used + space_info->bytes_reserved +
|
|
global_rsv_size) >= thresh)
|
|
return false;
|
|
|
|
used = space_info->bytes_may_use + space_info->bytes_pinned;
|
|
|
|
/* The total flushable belongs to the global rsv, don't flush. */
|
|
if (global_rsv_size >= used)
|
|
return false;
|
|
|
|
/*
|
|
* 128MiB is 1/4 of the maximum global rsv size. If we have less than
|
|
* that devoted to other reservations then there's no sense in flushing,
|
|
* we don't have a lot of things that need flushing.
|
|
*/
|
|
if (used - global_rsv_size <= SZ_128M)
|
|
return false;
|
|
|
|
/*
|
|
* We have tickets queued, bail so we don't compete with the async
|
|
* flushers.
|
|
*/
|
|
if (space_info->reclaim_size)
|
|
return false;
|
|
|
|
/*
|
|
* If we have over half of the free space occupied by reservations or
|
|
* pinned then we want to start flushing.
|
|
*
|
|
* We do not do the traditional thing here, which is to say
|
|
*
|
|
* if (used >= ((total_bytes + avail) / 2))
|
|
* return 1;
|
|
*
|
|
* because this doesn't quite work how we want. If we had more than 50%
|
|
* of the space_info used by bytes_used and we had 0 available we'd just
|
|
* constantly run the background flusher. Instead we want it to kick in
|
|
* if our reclaimable space exceeds our clamped free space.
|
|
*
|
|
* Our clamping range is 2^1 -> 2^8. Practically speaking that means
|
|
* the following:
|
|
*
|
|
* Amount of RAM Minimum threshold Maximum threshold
|
|
*
|
|
* 256GiB 1GiB 128GiB
|
|
* 128GiB 512MiB 64GiB
|
|
* 64GiB 256MiB 32GiB
|
|
* 32GiB 128MiB 16GiB
|
|
* 16GiB 64MiB 8GiB
|
|
*
|
|
* These are the range our thresholds will fall in, corresponding to how
|
|
* much delalloc we need for the background flusher to kick in.
|
|
*/
|
|
|
|
thresh = calc_available_free_space(fs_info, space_info,
|
|
BTRFS_RESERVE_FLUSH_ALL);
|
|
used = space_info->bytes_used + space_info->bytes_reserved +
|
|
space_info->bytes_readonly + global_rsv_size;
|
|
if (used < space_info->total_bytes)
|
|
thresh += space_info->total_bytes - used;
|
|
thresh >>= space_info->clamp;
|
|
|
|
used = space_info->bytes_pinned;
|
|
|
|
/*
|
|
* If we have more ordered bytes than delalloc bytes then we're either
|
|
* doing a lot of DIO, or we simply don't have a lot of delalloc waiting
|
|
* around. Preemptive flushing is only useful in that it can free up
|
|
* space before tickets need to wait for things to finish. In the case
|
|
* of ordered extents, preemptively waiting on ordered extents gets us
|
|
* nothing, if our reservations are tied up in ordered extents we'll
|
|
* simply have to slow down writers by forcing them to wait on ordered
|
|
* extents.
|
|
*
|
|
* In the case that ordered is larger than delalloc, only include the
|
|
* block reserves that we would actually be able to directly reclaim
|
|
* from. In this case if we're heavy on metadata operations this will
|
|
* clearly be heavy enough to warrant preemptive flushing. In the case
|
|
* of heavy DIO or ordered reservations, preemptive flushing will just
|
|
* waste time and cause us to slow down.
|
|
*
|
|
* We want to make sure we truly are maxed out on ordered however, so
|
|
* cut ordered in half, and if it's still higher than delalloc then we
|
|
* can keep flushing. This is to avoid the case where we start
|
|
* flushing, and now delalloc == ordered and we stop preemptively
|
|
* flushing when we could still have several gigs of delalloc to flush.
|
|
*/
|
|
ordered = percpu_counter_read_positive(&fs_info->ordered_bytes) >> 1;
|
|
delalloc = percpu_counter_read_positive(&fs_info->delalloc_bytes);
|
|
if (ordered >= delalloc)
|
|
used += btrfs_block_rsv_reserved(&fs_info->delayed_refs_rsv) +
|
|
btrfs_block_rsv_reserved(&fs_info->delayed_block_rsv);
|
|
else
|
|
used += space_info->bytes_may_use - global_rsv_size;
|
|
|
|
return (used >= thresh && !btrfs_fs_closing(fs_info) &&
|
|
!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
|
|
}
|
|
|
|
static bool steal_from_global_rsv(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
struct reserve_ticket *ticket)
|
|
{
|
|
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
|
|
u64 min_bytes;
|
|
|
|
if (!ticket->steal)
|
|
return false;
|
|
|
|
if (global_rsv->space_info != space_info)
|
|
return false;
|
|
|
|
spin_lock(&global_rsv->lock);
|
|
min_bytes = mult_perc(global_rsv->size, 10);
|
|
if (global_rsv->reserved < min_bytes + ticket->bytes) {
|
|
spin_unlock(&global_rsv->lock);
|
|
return false;
|
|
}
|
|
global_rsv->reserved -= ticket->bytes;
|
|
remove_ticket(space_info, ticket);
|
|
ticket->bytes = 0;
|
|
wake_up(&ticket->wait);
|
|
space_info->tickets_id++;
|
|
if (global_rsv->reserved < global_rsv->size)
|
|
global_rsv->full = 0;
|
|
spin_unlock(&global_rsv->lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* We've exhausted our flushing, start failing tickets.
|
|
*
|
|
* @fs_info - fs_info for this fs
|
|
* @space_info - the space info we were flushing
|
|
*
|
|
* We call this when we've exhausted our flushing ability and haven't made
|
|
* progress in satisfying tickets. The reservation code handles tickets in
|
|
* order, so if there is a large ticket first and then smaller ones we could
|
|
* very well satisfy the smaller tickets. This will attempt to wake up any
|
|
* tickets in the list to catch this case.
|
|
*
|
|
* This function returns true if it was able to make progress by clearing out
|
|
* other tickets, or if it stumbles across a ticket that was smaller than the
|
|
* first ticket.
|
|
*/
|
|
static bool maybe_fail_all_tickets(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info)
|
|
{
|
|
struct reserve_ticket *ticket;
|
|
u64 tickets_id = space_info->tickets_id;
|
|
const bool aborted = BTRFS_FS_ERROR(fs_info);
|
|
|
|
trace_btrfs_fail_all_tickets(fs_info, space_info);
|
|
|
|
if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
|
|
btrfs_info(fs_info, "cannot satisfy tickets, dumping space info");
|
|
__btrfs_dump_space_info(fs_info, space_info);
|
|
}
|
|
|
|
while (!list_empty(&space_info->tickets) &&
|
|
tickets_id == space_info->tickets_id) {
|
|
ticket = list_first_entry(&space_info->tickets,
|
|
struct reserve_ticket, list);
|
|
|
|
if (!aborted && steal_from_global_rsv(fs_info, space_info, ticket))
|
|
return true;
|
|
|
|
if (!aborted && btrfs_test_opt(fs_info, ENOSPC_DEBUG))
|
|
btrfs_info(fs_info, "failing ticket with %llu bytes",
|
|
ticket->bytes);
|
|
|
|
remove_ticket(space_info, ticket);
|
|
if (aborted)
|
|
ticket->error = -EIO;
|
|
else
|
|
ticket->error = -ENOSPC;
|
|
wake_up(&ticket->wait);
|
|
|
|
/*
|
|
* We're just throwing tickets away, so more flushing may not
|
|
* trip over btrfs_try_granting_tickets, so we need to call it
|
|
* here to see if we can make progress with the next ticket in
|
|
* the list.
|
|
*/
|
|
if (!aborted)
|
|
btrfs_try_granting_tickets(fs_info, space_info);
|
|
}
|
|
return (tickets_id != space_info->tickets_id);
|
|
}
|
|
|
|
/*
|
|
* This is for normal flushers, we can wait all goddamned day if we want to. We
|
|
* will loop and continuously try to flush as long as we are making progress.
|
|
* We count progress as clearing off tickets each time we have to loop.
|
|
*/
|
|
static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
|
|
{
|
|
struct btrfs_fs_info *fs_info;
|
|
struct btrfs_space_info *space_info;
|
|
u64 to_reclaim;
|
|
enum btrfs_flush_state flush_state;
|
|
int commit_cycles = 0;
|
|
u64 last_tickets_id;
|
|
|
|
fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
|
|
space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
|
|
|
|
spin_lock(&space_info->lock);
|
|
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info);
|
|
if (!to_reclaim) {
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
last_tickets_id = space_info->tickets_id;
|
|
spin_unlock(&space_info->lock);
|
|
|
|
flush_state = FLUSH_DELAYED_ITEMS_NR;
|
|
do {
|
|
flush_space(fs_info, space_info, to_reclaim, flush_state, false);
|
|
spin_lock(&space_info->lock);
|
|
if (list_empty(&space_info->tickets)) {
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info,
|
|
space_info);
|
|
if (last_tickets_id == space_info->tickets_id) {
|
|
flush_state++;
|
|
} else {
|
|
last_tickets_id = space_info->tickets_id;
|
|
flush_state = FLUSH_DELAYED_ITEMS_NR;
|
|
if (commit_cycles)
|
|
commit_cycles--;
|
|
}
|
|
|
|
/*
|
|
* We do not want to empty the system of delalloc unless we're
|
|
* under heavy pressure, so allow one trip through the flushing
|
|
* logic before we start doing a FLUSH_DELALLOC_FULL.
|
|
*/
|
|
if (flush_state == FLUSH_DELALLOC_FULL && !commit_cycles)
|
|
flush_state++;
|
|
|
|
/*
|
|
* We don't want to force a chunk allocation until we've tried
|
|
* pretty hard to reclaim space. Think of the case where we
|
|
* freed up a bunch of space and so have a lot of pinned space
|
|
* to reclaim. We would rather use that than possibly create a
|
|
* underutilized metadata chunk. So if this is our first run
|
|
* through the flushing state machine skip ALLOC_CHUNK_FORCE and
|
|
* commit the transaction. If nothing has changed the next go
|
|
* around then we can force a chunk allocation.
|
|
*/
|
|
if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles)
|
|
flush_state++;
|
|
|
|
if (flush_state > COMMIT_TRANS) {
|
|
commit_cycles++;
|
|
if (commit_cycles > 2) {
|
|
if (maybe_fail_all_tickets(fs_info, space_info)) {
|
|
flush_state = FLUSH_DELAYED_ITEMS_NR;
|
|
commit_cycles--;
|
|
} else {
|
|
space_info->flush = 0;
|
|
}
|
|
} else {
|
|
flush_state = FLUSH_DELAYED_ITEMS_NR;
|
|
}
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
} while (flush_state <= COMMIT_TRANS);
|
|
}
|
|
|
|
/*
|
|
* This handles pre-flushing of metadata space before we get to the point that
|
|
* we need to start blocking threads on tickets. The logic here is different
|
|
* from the other flush paths because it doesn't rely on tickets to tell us how
|
|
* much we need to flush, instead it attempts to keep us below the 80% full
|
|
* watermark of space by flushing whichever reservation pool is currently the
|
|
* largest.
|
|
*/
|
|
static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
|
|
{
|
|
struct btrfs_fs_info *fs_info;
|
|
struct btrfs_space_info *space_info;
|
|
struct btrfs_block_rsv *delayed_block_rsv;
|
|
struct btrfs_block_rsv *delayed_refs_rsv;
|
|
struct btrfs_block_rsv *global_rsv;
|
|
struct btrfs_block_rsv *trans_rsv;
|
|
int loops = 0;
|
|
|
|
fs_info = container_of(work, struct btrfs_fs_info,
|
|
preempt_reclaim_work);
|
|
space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
|
|
delayed_block_rsv = &fs_info->delayed_block_rsv;
|
|
delayed_refs_rsv = &fs_info->delayed_refs_rsv;
|
|
global_rsv = &fs_info->global_block_rsv;
|
|
trans_rsv = &fs_info->trans_block_rsv;
|
|
|
|
spin_lock(&space_info->lock);
|
|
while (need_preemptive_reclaim(fs_info, space_info)) {
|
|
enum btrfs_flush_state flush;
|
|
u64 delalloc_size = 0;
|
|
u64 to_reclaim, block_rsv_size;
|
|
const u64 global_rsv_size = btrfs_block_rsv_reserved(global_rsv);
|
|
|
|
loops++;
|
|
|
|
/*
|
|
* We don't have a precise counter for the metadata being
|
|
* reserved for delalloc, so we'll approximate it by subtracting
|
|
* out the block rsv's space from the bytes_may_use. If that
|
|
* amount is higher than the individual reserves, then we can
|
|
* assume it's tied up in delalloc reservations.
|
|
*/
|
|
block_rsv_size = global_rsv_size +
|
|
btrfs_block_rsv_reserved(delayed_block_rsv) +
|
|
btrfs_block_rsv_reserved(delayed_refs_rsv) +
|
|
btrfs_block_rsv_reserved(trans_rsv);
|
|
if (block_rsv_size < space_info->bytes_may_use)
|
|
delalloc_size = space_info->bytes_may_use - block_rsv_size;
|
|
|
|
/*
|
|
* We don't want to include the global_rsv in our calculation,
|
|
* because that's space we can't touch. Subtract it from the
|
|
* block_rsv_size for the next checks.
|
|
*/
|
|
block_rsv_size -= global_rsv_size;
|
|
|
|
/*
|
|
* We really want to avoid flushing delalloc too much, as it
|
|
* could result in poor allocation patterns, so only flush it if
|
|
* it's larger than the rest of the pools combined.
|
|
*/
|
|
if (delalloc_size > block_rsv_size) {
|
|
to_reclaim = delalloc_size;
|
|
flush = FLUSH_DELALLOC;
|
|
} else if (space_info->bytes_pinned >
|
|
(btrfs_block_rsv_reserved(delayed_block_rsv) +
|
|
btrfs_block_rsv_reserved(delayed_refs_rsv))) {
|
|
to_reclaim = space_info->bytes_pinned;
|
|
flush = COMMIT_TRANS;
|
|
} else if (btrfs_block_rsv_reserved(delayed_block_rsv) >
|
|
btrfs_block_rsv_reserved(delayed_refs_rsv)) {
|
|
to_reclaim = btrfs_block_rsv_reserved(delayed_block_rsv);
|
|
flush = FLUSH_DELAYED_ITEMS_NR;
|
|
} else {
|
|
to_reclaim = btrfs_block_rsv_reserved(delayed_refs_rsv);
|
|
flush = FLUSH_DELAYED_REFS_NR;
|
|
}
|
|
|
|
spin_unlock(&space_info->lock);
|
|
|
|
/*
|
|
* We don't want to reclaim everything, just a portion, so scale
|
|
* down the to_reclaim by 1/4. If it takes us down to 0,
|
|
* reclaim 1 items worth.
|
|
*/
|
|
to_reclaim >>= 2;
|
|
if (!to_reclaim)
|
|
to_reclaim = btrfs_calc_insert_metadata_size(fs_info, 1);
|
|
flush_space(fs_info, space_info, to_reclaim, flush, true);
|
|
cond_resched();
|
|
spin_lock(&space_info->lock);
|
|
}
|
|
|
|
/* We only went through once, back off our clamping. */
|
|
if (loops == 1 && !space_info->reclaim_size)
|
|
space_info->clamp = max(1, space_info->clamp - 1);
|
|
trace_btrfs_done_preemptive_reclaim(fs_info, space_info);
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
/*
|
|
* FLUSH_DELALLOC_WAIT:
|
|
* Space is freed from flushing delalloc in one of two ways.
|
|
*
|
|
* 1) compression is on and we allocate less space than we reserved
|
|
* 2) we are overwriting existing space
|
|
*
|
|
* For #1 that extra space is reclaimed as soon as the delalloc pages are
|
|
* COWed, by way of btrfs_add_reserved_bytes() which adds the actual extent
|
|
* length to ->bytes_reserved, and subtracts the reserved space from
|
|
* ->bytes_may_use.
|
|
*
|
|
* For #2 this is trickier. Once the ordered extent runs we will drop the
|
|
* extent in the range we are overwriting, which creates a delayed ref for
|
|
* that freed extent. This however is not reclaimed until the transaction
|
|
* commits, thus the next stages.
|
|
*
|
|
* RUN_DELAYED_IPUTS
|
|
* If we are freeing inodes, we want to make sure all delayed iputs have
|
|
* completed, because they could have been on an inode with i_nlink == 0, and
|
|
* thus have been truncated and freed up space. But again this space is not
|
|
* immediately reusable, it comes in the form of a delayed ref, which must be
|
|
* run and then the transaction must be committed.
|
|
*
|
|
* COMMIT_TRANS
|
|
* This is where we reclaim all of the pinned space generated by running the
|
|
* iputs
|
|
*
|
|
* ALLOC_CHUNK_FORCE
|
|
* For data we start with alloc chunk force, however we could have been full
|
|
* before, and then the transaction commit could have freed new block groups,
|
|
* so if we now have space to allocate do the force chunk allocation.
|
|
*/
|
|
static const enum btrfs_flush_state data_flush_states[] = {
|
|
FLUSH_DELALLOC_FULL,
|
|
RUN_DELAYED_IPUTS,
|
|
COMMIT_TRANS,
|
|
ALLOC_CHUNK_FORCE,
|
|
};
|
|
|
|
static void btrfs_async_reclaim_data_space(struct work_struct *work)
|
|
{
|
|
struct btrfs_fs_info *fs_info;
|
|
struct btrfs_space_info *space_info;
|
|
u64 last_tickets_id;
|
|
enum btrfs_flush_state flush_state = 0;
|
|
|
|
fs_info = container_of(work, struct btrfs_fs_info, async_data_reclaim_work);
|
|
space_info = fs_info->data_sinfo;
|
|
|
|
spin_lock(&space_info->lock);
|
|
if (list_empty(&space_info->tickets)) {
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
last_tickets_id = space_info->tickets_id;
|
|
spin_unlock(&space_info->lock);
|
|
|
|
while (!space_info->full) {
|
|
flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false);
|
|
spin_lock(&space_info->lock);
|
|
if (list_empty(&space_info->tickets)) {
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
|
|
/* Something happened, fail everything and bail. */
|
|
if (BTRFS_FS_ERROR(fs_info))
|
|
goto aborted_fs;
|
|
last_tickets_id = space_info->tickets_id;
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
while (flush_state < ARRAY_SIZE(data_flush_states)) {
|
|
flush_space(fs_info, space_info, U64_MAX,
|
|
data_flush_states[flush_state], false);
|
|
spin_lock(&space_info->lock);
|
|
if (list_empty(&space_info->tickets)) {
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
|
|
if (last_tickets_id == space_info->tickets_id) {
|
|
flush_state++;
|
|
} else {
|
|
last_tickets_id = space_info->tickets_id;
|
|
flush_state = 0;
|
|
}
|
|
|
|
if (flush_state >= ARRAY_SIZE(data_flush_states)) {
|
|
if (space_info->full) {
|
|
if (maybe_fail_all_tickets(fs_info, space_info))
|
|
flush_state = 0;
|
|
else
|
|
space_info->flush = 0;
|
|
} else {
|
|
flush_state = 0;
|
|
}
|
|
|
|
/* Something happened, fail everything and bail. */
|
|
if (BTRFS_FS_ERROR(fs_info))
|
|
goto aborted_fs;
|
|
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
return;
|
|
|
|
aborted_fs:
|
|
maybe_fail_all_tickets(fs_info, space_info);
|
|
space_info->flush = 0;
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info)
|
|
{
|
|
INIT_WORK(&fs_info->async_reclaim_work, btrfs_async_reclaim_metadata_space);
|
|
INIT_WORK(&fs_info->async_data_reclaim_work, btrfs_async_reclaim_data_space);
|
|
INIT_WORK(&fs_info->preempt_reclaim_work,
|
|
btrfs_preempt_reclaim_metadata_space);
|
|
}
|
|
|
|
static const enum btrfs_flush_state priority_flush_states[] = {
|
|
FLUSH_DELAYED_ITEMS_NR,
|
|
FLUSH_DELAYED_ITEMS,
|
|
ALLOC_CHUNK,
|
|
};
|
|
|
|
static const enum btrfs_flush_state evict_flush_states[] = {
|
|
FLUSH_DELAYED_ITEMS_NR,
|
|
FLUSH_DELAYED_ITEMS,
|
|
FLUSH_DELAYED_REFS_NR,
|
|
FLUSH_DELAYED_REFS,
|
|
FLUSH_DELALLOC,
|
|
FLUSH_DELALLOC_WAIT,
|
|
FLUSH_DELALLOC_FULL,
|
|
ALLOC_CHUNK,
|
|
COMMIT_TRANS,
|
|
};
|
|
|
|
static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
struct reserve_ticket *ticket,
|
|
const enum btrfs_flush_state *states,
|
|
int states_nr)
|
|
{
|
|
u64 to_reclaim;
|
|
int flush_state = 0;
|
|
|
|
spin_lock(&space_info->lock);
|
|
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info);
|
|
/*
|
|
* This is the priority reclaim path, so to_reclaim could be >0 still
|
|
* because we may have only satisfied the priority tickets and still
|
|
* left non priority tickets on the list. We would then have
|
|
* to_reclaim but ->bytes == 0.
|
|
*/
|
|
if (ticket->bytes == 0) {
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
|
|
while (flush_state < states_nr) {
|
|
spin_unlock(&space_info->lock);
|
|
flush_space(fs_info, space_info, to_reclaim, states[flush_state],
|
|
false);
|
|
flush_state++;
|
|
spin_lock(&space_info->lock);
|
|
if (ticket->bytes == 0) {
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Attempt to steal from the global rsv if we can, except if the fs was
|
|
* turned into error mode due to a transaction abort when flushing space
|
|
* above, in that case fail with the abort error instead of returning
|
|
* success to the caller if we can steal from the global rsv - this is
|
|
* just to have caller fail immeditelly instead of later when trying to
|
|
* modify the fs, making it easier to debug -ENOSPC problems.
|
|
*/
|
|
if (BTRFS_FS_ERROR(fs_info)) {
|
|
ticket->error = BTRFS_FS_ERROR(fs_info);
|
|
remove_ticket(space_info, ticket);
|
|
} else if (!steal_from_global_rsv(fs_info, space_info, ticket)) {
|
|
ticket->error = -ENOSPC;
|
|
remove_ticket(space_info, ticket);
|
|
}
|
|
|
|
/*
|
|
* We must run try_granting_tickets here because we could be a large
|
|
* ticket in front of a smaller ticket that can now be satisfied with
|
|
* the available space.
|
|
*/
|
|
btrfs_try_granting_tickets(fs_info, space_info);
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
static void priority_reclaim_data_space(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
struct reserve_ticket *ticket)
|
|
{
|
|
spin_lock(&space_info->lock);
|
|
|
|
/* We could have been granted before we got here. */
|
|
if (ticket->bytes == 0) {
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
|
|
while (!space_info->full) {
|
|
spin_unlock(&space_info->lock);
|
|
flush_space(fs_info, space_info, U64_MAX, ALLOC_CHUNK_FORCE, false);
|
|
spin_lock(&space_info->lock);
|
|
if (ticket->bytes == 0) {
|
|
spin_unlock(&space_info->lock);
|
|
return;
|
|
}
|
|
}
|
|
|
|
ticket->error = -ENOSPC;
|
|
remove_ticket(space_info, ticket);
|
|
btrfs_try_granting_tickets(fs_info, space_info);
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
static void wait_reserve_ticket(struct btrfs_space_info *space_info,
|
|
struct reserve_ticket *ticket)
|
|
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
int ret = 0;
|
|
|
|
spin_lock(&space_info->lock);
|
|
while (ticket->bytes > 0 && ticket->error == 0) {
|
|
ret = prepare_to_wait_event(&ticket->wait, &wait, TASK_KILLABLE);
|
|
if (ret) {
|
|
/*
|
|
* Delete us from the list. After we unlock the space
|
|
* info, we don't want the async reclaim job to reserve
|
|
* space for this ticket. If that would happen, then the
|
|
* ticket's task would not known that space was reserved
|
|
* despite getting an error, resulting in a space leak
|
|
* (bytes_may_use counter of our space_info).
|
|
*/
|
|
remove_ticket(space_info, ticket);
|
|
ticket->error = -EINTR;
|
|
break;
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
|
|
schedule();
|
|
|
|
finish_wait(&ticket->wait, &wait);
|
|
spin_lock(&space_info->lock);
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
|
|
/*
|
|
* Do the appropriate flushing and waiting for a ticket.
|
|
*
|
|
* @fs_info: the filesystem
|
|
* @space_info: space info for the reservation
|
|
* @ticket: ticket for the reservation
|
|
* @start_ns: timestamp when the reservation started
|
|
* @orig_bytes: amount of bytes originally reserved
|
|
* @flush: how much we can flush
|
|
*
|
|
* This does the work of figuring out how to flush for the ticket, waiting for
|
|
* the reservation, and returning the appropriate error if there is one.
|
|
*/
|
|
static int handle_reserve_ticket(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
struct reserve_ticket *ticket,
|
|
u64 start_ns, u64 orig_bytes,
|
|
enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
int ret;
|
|
|
|
switch (flush) {
|
|
case BTRFS_RESERVE_FLUSH_DATA:
|
|
case BTRFS_RESERVE_FLUSH_ALL:
|
|
case BTRFS_RESERVE_FLUSH_ALL_STEAL:
|
|
wait_reserve_ticket(space_info, ticket);
|
|
break;
|
|
case BTRFS_RESERVE_FLUSH_LIMIT:
|
|
priority_reclaim_metadata_space(fs_info, space_info, ticket,
|
|
priority_flush_states,
|
|
ARRAY_SIZE(priority_flush_states));
|
|
break;
|
|
case BTRFS_RESERVE_FLUSH_EVICT:
|
|
priority_reclaim_metadata_space(fs_info, space_info, ticket,
|
|
evict_flush_states,
|
|
ARRAY_SIZE(evict_flush_states));
|
|
break;
|
|
case BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE:
|
|
priority_reclaim_data_space(fs_info, space_info, ticket);
|
|
break;
|
|
default:
|
|
ASSERT(0);
|
|
break;
|
|
}
|
|
|
|
ret = ticket->error;
|
|
ASSERT(list_empty(&ticket->list));
|
|
/*
|
|
* Check that we can't have an error set if the reservation succeeded,
|
|
* as that would confuse tasks and lead them to error out without
|
|
* releasing reserved space (if an error happens the expectation is that
|
|
* space wasn't reserved at all).
|
|
*/
|
|
ASSERT(!(ticket->bytes == 0 && ticket->error));
|
|
trace_btrfs_reserve_ticket(fs_info, space_info->flags, orig_bytes,
|
|
start_ns, flush, ticket->error);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This returns true if this flush state will go through the ordinary flushing
|
|
* code.
|
|
*/
|
|
static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
return (flush == BTRFS_RESERVE_FLUSH_ALL) ||
|
|
(flush == BTRFS_RESERVE_FLUSH_ALL_STEAL);
|
|
}
|
|
|
|
static inline void maybe_clamp_preempt(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info)
|
|
{
|
|
u64 ordered = percpu_counter_sum_positive(&fs_info->ordered_bytes);
|
|
u64 delalloc = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
|
|
|
|
/*
|
|
* If we're heavy on ordered operations then clamping won't help us. We
|
|
* need to clamp specifically to keep up with dirty'ing buffered
|
|
* writers, because there's not a 1:1 correlation of writing delalloc
|
|
* and freeing space, like there is with flushing delayed refs or
|
|
* delayed nodes. If we're already more ordered than delalloc then
|
|
* we're keeping up, otherwise we aren't and should probably clamp.
|
|
*/
|
|
if (ordered < delalloc)
|
|
space_info->clamp = min(space_info->clamp + 1, 8);
|
|
}
|
|
|
|
static inline bool can_steal(enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
return (flush == BTRFS_RESERVE_FLUSH_ALL_STEAL ||
|
|
flush == BTRFS_RESERVE_FLUSH_EVICT);
|
|
}
|
|
|
|
/*
|
|
* NO_FLUSH and FLUSH_EMERGENCY don't want to create a ticket, they just want to
|
|
* fail as quickly as possible.
|
|
*/
|
|
static inline bool can_ticket(enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
return (flush != BTRFS_RESERVE_NO_FLUSH &&
|
|
flush != BTRFS_RESERVE_FLUSH_EMERGENCY);
|
|
}
|
|
|
|
/*
|
|
* Try to reserve bytes from the block_rsv's space.
|
|
*
|
|
* @fs_info: the filesystem
|
|
* @space_info: space info we want to allocate from
|
|
* @orig_bytes: number of bytes we want
|
|
* @flush: whether or not we can flush to make our reservation
|
|
*
|
|
* This will reserve orig_bytes number of bytes from the space info associated
|
|
* with the block_rsv. If there is not enough space it will make an attempt to
|
|
* flush out space to make room. It will do this by flushing delalloc if
|
|
* possible or committing the transaction. If flush is 0 then no attempts to
|
|
* regain reservations will be made and this will fail if there is not enough
|
|
* space already.
|
|
*/
|
|
static int __reserve_bytes(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info, u64 orig_bytes,
|
|
enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
struct work_struct *async_work;
|
|
struct reserve_ticket ticket;
|
|
u64 start_ns = 0;
|
|
u64 used;
|
|
int ret = -ENOSPC;
|
|
bool pending_tickets;
|
|
|
|
ASSERT(orig_bytes);
|
|
/*
|
|
* If have a transaction handle (current->journal_info != NULL), then
|
|
* the flush method can not be neither BTRFS_RESERVE_FLUSH_ALL* nor
|
|
* BTRFS_RESERVE_FLUSH_EVICT, as we could deadlock because those
|
|
* flushing methods can trigger transaction commits.
|
|
*/
|
|
if (current->journal_info) {
|
|
/* One assert per line for easier debugging. */
|
|
ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL);
|
|
ASSERT(flush != BTRFS_RESERVE_FLUSH_ALL_STEAL);
|
|
ASSERT(flush != BTRFS_RESERVE_FLUSH_EVICT);
|
|
}
|
|
|
|
if (flush == BTRFS_RESERVE_FLUSH_DATA)
|
|
async_work = &fs_info->async_data_reclaim_work;
|
|
else
|
|
async_work = &fs_info->async_reclaim_work;
|
|
|
|
spin_lock(&space_info->lock);
|
|
used = btrfs_space_info_used(space_info, true);
|
|
|
|
/*
|
|
* We don't want NO_FLUSH allocations to jump everybody, they can
|
|
* generally handle ENOSPC in a different way, so treat them the same as
|
|
* normal flushers when it comes to skipping pending tickets.
|
|
*/
|
|
if (is_normal_flushing(flush) || (flush == BTRFS_RESERVE_NO_FLUSH))
|
|
pending_tickets = !list_empty(&space_info->tickets) ||
|
|
!list_empty(&space_info->priority_tickets);
|
|
else
|
|
pending_tickets = !list_empty(&space_info->priority_tickets);
|
|
|
|
/*
|
|
* Carry on if we have enough space (short-circuit) OR call
|
|
* can_overcommit() to ensure we can overcommit to continue.
|
|
*/
|
|
if (!pending_tickets &&
|
|
((used + orig_bytes <= space_info->total_bytes) ||
|
|
btrfs_can_overcommit(fs_info, space_info, orig_bytes, flush))) {
|
|
btrfs_space_info_update_bytes_may_use(fs_info, space_info,
|
|
orig_bytes);
|
|
ret = 0;
|
|
}
|
|
|
|
/*
|
|
* Things are dire, we need to make a reservation so we don't abort. We
|
|
* will let this reservation go through as long as we have actual space
|
|
* left to allocate for the block.
|
|
*/
|
|
if (ret && unlikely(flush == BTRFS_RESERVE_FLUSH_EMERGENCY)) {
|
|
used = btrfs_space_info_used(space_info, false);
|
|
if (used + orig_bytes <= space_info->total_bytes) {
|
|
btrfs_space_info_update_bytes_may_use(fs_info, space_info,
|
|
orig_bytes);
|
|
ret = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we couldn't make a reservation then setup our reservation ticket
|
|
* and kick the async worker if it's not already running.
|
|
*
|
|
* If we are a priority flusher then we just need to add our ticket to
|
|
* the list and we will do our own flushing further down.
|
|
*/
|
|
if (ret && can_ticket(flush)) {
|
|
ticket.bytes = orig_bytes;
|
|
ticket.error = 0;
|
|
space_info->reclaim_size += ticket.bytes;
|
|
init_waitqueue_head(&ticket.wait);
|
|
ticket.steal = can_steal(flush);
|
|
if (trace_btrfs_reserve_ticket_enabled())
|
|
start_ns = ktime_get_ns();
|
|
|
|
if (flush == BTRFS_RESERVE_FLUSH_ALL ||
|
|
flush == BTRFS_RESERVE_FLUSH_ALL_STEAL ||
|
|
flush == BTRFS_RESERVE_FLUSH_DATA) {
|
|
list_add_tail(&ticket.list, &space_info->tickets);
|
|
if (!space_info->flush) {
|
|
/*
|
|
* We were forced to add a reserve ticket, so
|
|
* our preemptive flushing is unable to keep
|
|
* up. Clamp down on the threshold for the
|
|
* preemptive flushing in order to keep up with
|
|
* the workload.
|
|
*/
|
|
maybe_clamp_preempt(fs_info, space_info);
|
|
|
|
space_info->flush = 1;
|
|
trace_btrfs_trigger_flush(fs_info,
|
|
space_info->flags,
|
|
orig_bytes, flush,
|
|
"enospc");
|
|
queue_work(system_unbound_wq, async_work);
|
|
}
|
|
} else {
|
|
list_add_tail(&ticket.list,
|
|
&space_info->priority_tickets);
|
|
}
|
|
} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
|
|
/*
|
|
* We will do the space reservation dance during log replay,
|
|
* which means we won't have fs_info->fs_root set, so don't do
|
|
* the async reclaim as we will panic.
|
|
*/
|
|
if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags) &&
|
|
!work_busy(&fs_info->preempt_reclaim_work) &&
|
|
need_preemptive_reclaim(fs_info, space_info)) {
|
|
trace_btrfs_trigger_flush(fs_info, space_info->flags,
|
|
orig_bytes, flush, "preempt");
|
|
queue_work(system_unbound_wq,
|
|
&fs_info->preempt_reclaim_work);
|
|
}
|
|
}
|
|
spin_unlock(&space_info->lock);
|
|
if (!ret || !can_ticket(flush))
|
|
return ret;
|
|
|
|
return handle_reserve_ticket(fs_info, space_info, &ticket, start_ns,
|
|
orig_bytes, flush);
|
|
}
|
|
|
|
/*
|
|
* Try to reserve metadata bytes from the block_rsv's space.
|
|
*
|
|
* @fs_info: the filesystem
|
|
* @space_info: the space_info we're allocating for
|
|
* @orig_bytes: number of bytes we want
|
|
* @flush: whether or not we can flush to make our reservation
|
|
*
|
|
* This will reserve orig_bytes number of bytes from the space info associated
|
|
* with the block_rsv. If there is not enough space it will make an attempt to
|
|
* flush out space to make room. It will do this by flushing delalloc if
|
|
* possible or committing the transaction. If flush is 0 then no attempts to
|
|
* regain reservations will be made and this will fail if there is not enough
|
|
* space already.
|
|
*/
|
|
int btrfs_reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_space_info *space_info,
|
|
u64 orig_bytes,
|
|
enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
int ret;
|
|
|
|
ret = __reserve_bytes(fs_info, space_info, orig_bytes, flush);
|
|
if (ret == -ENOSPC) {
|
|
trace_btrfs_space_reservation(fs_info, "space_info:enospc",
|
|
space_info->flags, orig_bytes, 1);
|
|
|
|
if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
|
|
btrfs_dump_space_info(fs_info, space_info, orig_bytes, 0);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Try to reserve data bytes for an allocation.
|
|
*
|
|
* @fs_info: the filesystem
|
|
* @bytes: number of bytes we need
|
|
* @flush: how we are allowed to flush
|
|
*
|
|
* This will reserve bytes from the data space info. If there is not enough
|
|
* space then we will attempt to flush space as specified by flush.
|
|
*/
|
|
int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
|
|
enum btrfs_reserve_flush_enum flush)
|
|
{
|
|
struct btrfs_space_info *data_sinfo = fs_info->data_sinfo;
|
|
int ret;
|
|
|
|
ASSERT(flush == BTRFS_RESERVE_FLUSH_DATA ||
|
|
flush == BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE ||
|
|
flush == BTRFS_RESERVE_NO_FLUSH);
|
|
ASSERT(!current->journal_info || flush != BTRFS_RESERVE_FLUSH_DATA);
|
|
|
|
ret = __reserve_bytes(fs_info, data_sinfo, bytes, flush);
|
|
if (ret == -ENOSPC) {
|
|
trace_btrfs_space_reservation(fs_info, "space_info:enospc",
|
|
data_sinfo->flags, bytes, 1);
|
|
if (btrfs_test_opt(fs_info, ENOSPC_DEBUG))
|
|
btrfs_dump_space_info(fs_info, data_sinfo, bytes, 0);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Dump all the space infos when we abort a transaction due to ENOSPC. */
|
|
__cold void btrfs_dump_space_info_for_trans_abort(struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct btrfs_space_info *space_info;
|
|
|
|
btrfs_info(fs_info, "dumping space info:");
|
|
list_for_each_entry(space_info, &fs_info->space_info, list) {
|
|
spin_lock(&space_info->lock);
|
|
__btrfs_dump_space_info(fs_info, space_info);
|
|
spin_unlock(&space_info->lock);
|
|
}
|
|
dump_global_block_rsv(fs_info);
|
|
}
|
|
|
|
/*
|
|
* Account the unused space of all the readonly block group in the space_info.
|
|
* takes mirrors into account.
|
|
*/
|
|
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
|
|
{
|
|
struct btrfs_block_group *block_group;
|
|
u64 free_bytes = 0;
|
|
int factor;
|
|
|
|
/* It's df, we don't care if it's racy */
|
|
if (list_empty(&sinfo->ro_bgs))
|
|
return 0;
|
|
|
|
spin_lock(&sinfo->lock);
|
|
list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
|
|
spin_lock(&block_group->lock);
|
|
|
|
if (!block_group->ro) {
|
|
spin_unlock(&block_group->lock);
|
|
continue;
|
|
}
|
|
|
|
factor = btrfs_bg_type_to_factor(block_group->flags);
|
|
free_bytes += (block_group->length -
|
|
block_group->used) * factor;
|
|
|
|
spin_unlock(&block_group->lock);
|
|
}
|
|
spin_unlock(&sinfo->lock);
|
|
|
|
return free_bytes;
|
|
}
|
|
|
|
static u64 calc_pct_ratio(u64 x, u64 y)
|
|
{
|
|
int err;
|
|
|
|
if (!y)
|
|
return 0;
|
|
again:
|
|
err = check_mul_overflow(100, x, &x);
|
|
if (err)
|
|
goto lose_precision;
|
|
return div64_u64(x, y);
|
|
lose_precision:
|
|
x >>= 10;
|
|
y >>= 10;
|
|
if (!y)
|
|
y = 1;
|
|
goto again;
|
|
}
|
|
|
|
/*
|
|
* A reasonable buffer for unallocated space is 10 data block_groups.
|
|
* If we claw this back repeatedly, we can still achieve efficient
|
|
* utilization when near full, and not do too much reclaim while
|
|
* always maintaining a solid buffer for workloads that quickly
|
|
* allocate and pressure the unallocated space.
|
|
*/
|
|
static u64 calc_unalloc_target(struct btrfs_fs_info *fs_info)
|
|
{
|
|
u64 chunk_sz = calc_effective_data_chunk_size(fs_info);
|
|
|
|
return BTRFS_UNALLOC_BLOCK_GROUP_TARGET * chunk_sz;
|
|
}
|
|
|
|
/*
|
|
* The fundamental goal of automatic reclaim is to protect the filesystem's
|
|
* unallocated space and thus minimize the probability of the filesystem going
|
|
* read only when a metadata allocation failure causes a transaction abort.
|
|
*
|
|
* However, relocations happen into the space_info's unused space, therefore
|
|
* automatic reclaim must also back off as that space runs low. There is no
|
|
* value in doing trivial "relocations" of re-writing the same block group
|
|
* into a fresh one.
|
|
*
|
|
* Furthermore, we want to avoid doing too much reclaim even if there are good
|
|
* candidates. This is because the allocator is pretty good at filling up the
|
|
* holes with writes. So we want to do just enough reclaim to try and stay
|
|
* safe from running out of unallocated space but not be wasteful about it.
|
|
*
|
|
* Therefore, the dynamic reclaim threshold is calculated as follows:
|
|
* - calculate a target unallocated amount of 5 block group sized chunks
|
|
* - ratchet up the intensity of reclaim depending on how far we are from
|
|
* that target by using a formula of unalloc / target to set the threshold.
|
|
*
|
|
* Typically with 10 block groups as the target, the discrete values this comes
|
|
* out to are 0, 10, 20, ... , 80, 90, and 99.
|
|
*/
|
|
static int calc_dynamic_reclaim_threshold(const struct btrfs_space_info *space_info)
|
|
{
|
|
struct btrfs_fs_info *fs_info = space_info->fs_info;
|
|
u64 unalloc = atomic64_read(&fs_info->free_chunk_space);
|
|
u64 target = calc_unalloc_target(fs_info);
|
|
u64 alloc = space_info->total_bytes;
|
|
u64 used = btrfs_space_info_used(space_info, false);
|
|
u64 unused = alloc - used;
|
|
u64 want = target > unalloc ? target - unalloc : 0;
|
|
u64 data_chunk_size = calc_effective_data_chunk_size(fs_info);
|
|
|
|
/* If we have no unused space, don't bother, it won't work anyway. */
|
|
if (unused < data_chunk_size)
|
|
return 0;
|
|
|
|
/* Cast to int is OK because want <= target. */
|
|
return calc_pct_ratio(want, target);
|
|
}
|
|
|
|
int btrfs_calc_reclaim_threshold(const struct btrfs_space_info *space_info)
|
|
{
|
|
lockdep_assert_held(&space_info->lock);
|
|
|
|
if (READ_ONCE(space_info->dynamic_reclaim))
|
|
return calc_dynamic_reclaim_threshold(space_info);
|
|
return READ_ONCE(space_info->bg_reclaim_threshold);
|
|
}
|
|
|
|
/*
|
|
* Under "urgent" reclaim, we will reclaim even fresh block groups that have
|
|
* recently seen successful allocations, as we are desperate to reclaim
|
|
* whatever we can to avoid ENOSPC in a transaction leading to a readonly fs.
|
|
*/
|
|
static bool is_reclaim_urgent(struct btrfs_space_info *space_info)
|
|
{
|
|
struct btrfs_fs_info *fs_info = space_info->fs_info;
|
|
u64 unalloc = atomic64_read(&fs_info->free_chunk_space);
|
|
u64 data_chunk_size = calc_effective_data_chunk_size(fs_info);
|
|
|
|
return unalloc < data_chunk_size;
|
|
}
|
|
|
|
static void do_reclaim_sweep(struct btrfs_space_info *space_info, int raid)
|
|
{
|
|
struct btrfs_block_group *bg;
|
|
int thresh_pct;
|
|
bool try_again = true;
|
|
bool urgent;
|
|
|
|
spin_lock(&space_info->lock);
|
|
urgent = is_reclaim_urgent(space_info);
|
|
thresh_pct = btrfs_calc_reclaim_threshold(space_info);
|
|
spin_unlock(&space_info->lock);
|
|
|
|
down_read(&space_info->groups_sem);
|
|
again:
|
|
list_for_each_entry(bg, &space_info->block_groups[raid], list) {
|
|
u64 thresh;
|
|
bool reclaim = false;
|
|
|
|
btrfs_get_block_group(bg);
|
|
spin_lock(&bg->lock);
|
|
thresh = mult_perc(bg->length, thresh_pct);
|
|
if (bg->used < thresh && bg->reclaim_mark) {
|
|
try_again = false;
|
|
reclaim = true;
|
|
}
|
|
bg->reclaim_mark++;
|
|
spin_unlock(&bg->lock);
|
|
if (reclaim)
|
|
btrfs_mark_bg_to_reclaim(bg);
|
|
btrfs_put_block_group(bg);
|
|
}
|
|
|
|
/*
|
|
* In situations where we are very motivated to reclaim (low unalloc)
|
|
* use two passes to make the reclaim mark check best effort.
|
|
*
|
|
* If we have any staler groups, we don't touch the fresher ones, but if we
|
|
* really need a block group, do take a fresh one.
|
|
*/
|
|
if (try_again && urgent) {
|
|
try_again = false;
|
|
goto again;
|
|
}
|
|
|
|
up_read(&space_info->groups_sem);
|
|
}
|
|
|
|
void btrfs_space_info_update_reclaimable(struct btrfs_space_info *space_info, s64 bytes)
|
|
{
|
|
u64 chunk_sz = calc_effective_data_chunk_size(space_info->fs_info);
|
|
|
|
lockdep_assert_held(&space_info->lock);
|
|
space_info->reclaimable_bytes += bytes;
|
|
|
|
if (space_info->reclaimable_bytes >= chunk_sz)
|
|
btrfs_set_periodic_reclaim_ready(space_info, true);
|
|
}
|
|
|
|
void btrfs_set_periodic_reclaim_ready(struct btrfs_space_info *space_info, bool ready)
|
|
{
|
|
lockdep_assert_held(&space_info->lock);
|
|
if (!READ_ONCE(space_info->periodic_reclaim))
|
|
return;
|
|
if (ready != space_info->periodic_reclaim_ready) {
|
|
space_info->periodic_reclaim_ready = ready;
|
|
if (!ready)
|
|
space_info->reclaimable_bytes = 0;
|
|
}
|
|
}
|
|
|
|
bool btrfs_should_periodic_reclaim(struct btrfs_space_info *space_info)
|
|
{
|
|
bool ret;
|
|
|
|
if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
|
|
return false;
|
|
if (!READ_ONCE(space_info->periodic_reclaim))
|
|
return false;
|
|
|
|
spin_lock(&space_info->lock);
|
|
ret = space_info->periodic_reclaim_ready;
|
|
btrfs_set_periodic_reclaim_ready(space_info, false);
|
|
spin_unlock(&space_info->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void btrfs_reclaim_sweep(const struct btrfs_fs_info *fs_info)
|
|
{
|
|
int raid;
|
|
struct btrfs_space_info *space_info;
|
|
|
|
list_for_each_entry(space_info, &fs_info->space_info, list) {
|
|
if (!btrfs_should_periodic_reclaim(space_info))
|
|
continue;
|
|
for (raid = 0; raid < BTRFS_NR_RAID_TYPES; raid++)
|
|
do_reclaim_sweep(space_info, raid);
|
|
}
|
|
}
|