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path: root/fs/btrfs/relocation.c
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2020-10-07btrfs: introduce BTRFS_NESTING_COW for cow'ing blocksJosef Bacik
When we COW a block we are holding a lock on the original block, and then we lock the new COW block. Because our lockdep maps are based on root + level, this will make lockdep complain. We need a way to indicate a subclass for locking the COW'ed block, so plumb through our btrfs_lock_nesting from btrfs_cow_block down to the btrfs_init_buffer, and then introduce BTRFS_NESTING_COW to be used for cow'ing blocks. The reason I've added all this extra infrastructure is because there will be need of different nesting classes in follow up patches. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: relocation: review the call sites which can be interrupted by signalQu Wenruo
Since most metadata reservation calls can return -EINTR when get interrupted by fatal signal, we need to review the all the metadata reservation call sites. In relocation code, the metadata reservation happens in the following sites: - btrfs_block_rsv_refill() in merge_reloc_root() merge_reloc_root() is a pretty critical section, we don't want to be interrupted by signal, so change the flush status to BTRFS_RESERVE_FLUSH_LIMIT, so it won't get interrupted by signal. Since such change can be ENPSPC-prone, also shrink the amount of metadata to reserve least amount avoid deadly ENOSPC there. - btrfs_block_rsv_refill() in reserve_metadata_space() It calls with BTRFS_RESERVE_FLUSH_LIMIT, which won't get interrupted by signal. - btrfs_block_rsv_refill() in prepare_to_relocate() - btrfs_block_rsv_add() in prepare_to_relocate() - btrfs_block_rsv_refill() in relocate_block_group() - btrfs_delalloc_reserve_metadata() in relocate_file_extent_cluster() - btrfs_start_transaction() in relocate_block_group() - btrfs_start_transaction() in create_reloc_inode() Can be interrupted by fatal signal and we can handle it easily. For these call sites, just catch the -EINTR value in btrfs_balance() and count them as canceled. CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: relocation: allow signal to cancel balanceQu Wenruo
Although btrfs balance can be canceled with "btrfs balance cancel" command, it's still almost muscle memory to press Ctrl-C to cancel a long running btrfs balance. So allow btrfs balance to check signal to determine if it should exit. The cancellation points are in known location and we're only adding one more reason, so this should be safe. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: make prealloc_file_extent_cluster take btrfs_inodeNikolay Borisov
The vfs inode is only used for a pair of inode_lock/unlock calls all other uses call for btrfs_inode. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: make btrfs_free_reserved_data_space_noquota take btrfs_fs_infoNikolay Borisov
No point in taking an inode only to get btrfs_fs_info from it, instead take btrfs_fs_info directly. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: make btrfs_set_extent_delalloc take btrfs_inodeNikolay Borisov
Preparation to make btrfs_dirty_pages take btrfs_inode as parameter. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: use for loop in prealloc_file_extent_clusterNikolay Borisov
This function iterates all extents in the extent cluster, make this intention obvious by using a for loop. No functional chanes. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: perform data management operations outside of inode lockNikolay Borisov
btrfs_alloc_data_chunk_ondemand and btrfs_free_reserved_data_space_noquota don't really use the guts of the inodes being passed to them. This implies it's not required to call them under extent lock. Move code around in prealloc_file_extent_cluster to do the heavy, data alloc/free operations outside of the lock. This also makes the 'out' label unnecessary, so remove it. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: remove hole check in prealloc_file_extent_clusterNikolay Borisov
Extents in the extent cluster are guaranteed to be contiguous as such the hole check inside the loop can never trigger. In fact this check was never functional since it was added in 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely") which came after the commit introducing clustered/contiguous extents 0257bb82d21b ("Btrfs: relocate file extents in clusters"). Let's just remove it as it adds noise to the source. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: make btrfs_reloc_clone_csums take btrfs_inodeNikolay Borisov
It really wants btrfs_inode and not a vfs inode. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: make btrfs_lookup_ordered_extent take btrfs_inodeNikolay Borisov
It doesn't use the generic vfs inode for anything use btrfs_inode directly. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27btrfs: use btrfs_alloc_data_chunk_ondemand() when allocating space for ↵Filipe Manana
relocation We currently use btrfs_check_data_free_space() when allocating space for relocating data extents, but that is not necessary because that function combines btrfs_alloc_data_chunk_ondemand(), which does the actual space reservation, and btrfs_qgroup_reserve_data(). We can use btrfs_alloc_data_chunk_ondemand() directly because we know we do not need to reserve qgroup space since we are dealing with a relocation tree, which can never have qgroups (btrfs_qgroup_reserve_data() does nothing as is_fstree() returns false for a relocation tree). Conversely we can use btrfs_free_reserved_data_space_noquota() directly instead of btrfs_free_reserved_data_space(), since we had no qgroup reservation when allocating space. This change is preparatory work for another patch in this series that makes relocation reserve the exact amount of space it needs to relocate a data block group. The function btrfs_check_data_free_space() has the incovenient of requiring a start offset argument and we will want to be able to allocate space for multiple ranges, which are not consecutive, at once. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: simplify iget helpersDavid Sterba
The inode lookup starting at btrfs_iget takes the full location key, while only the objectid is used to match the inode, because the lookup happens inside the given root thus the inode number is unique. The entire location key is properly set up in btrfs_init_locked_inode. Simplify the helpers and pass only inode number, renaming it to 'ino' instead of 'objectid'. This allows to remove temporary variables key, saving some stack space. Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: open code read_fs_rootDavid Sterba
After the update to btrfs_get_fs_root, read_fs_root has become trivial wrapper that can be open coded. Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: simplify root lookup by idDavid Sterba
The main function to lookup a root by its id btrfs_get_fs_root takes the whole key, while only using the objectid. The value of offset is preset to (u64)-1 but not actually used until btrfs_find_root that does the actual search. Switch btrfs_get_fs_root to use only objectid and remove all local variables that existed just for the lookup. The actual key for search is set up in btrfs_get_fs_root, reusing another key variable. Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: clear DEAD_RELOC_TREE bit for orphan roots to prevent runaway ↵Qu Wenruo
balance [BUG] There are several reported runaway balance, that balance is flooding the log with "found X extents" where the X never changes. [CAUSE] Commit d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots") introduced BTRFS_ROOT_DEAD_RELOC_TREE bit to indicate that one subvolume has finished its tree blocks swap with its reloc tree. However if balance is canceled or hits ENOSPC halfway, we didn't clear the BTRFS_ROOT_DEAD_RELOC_TREE bit, leaving that bit hanging forever until unmount. Any subvolume root with that bit, would cause backref cache to skip this tree block, as it has finished its tree block swap. This would cause all tree blocks of that root be ignored by balance, leading to runaway balance. [FIX] Fix the problem by also clearing the BTRFS_ROOT_DEAD_RELOC_TREE bit for the original subvolume of orphan reloc root. Add an umount check for the stale bit still set. Fixes: d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: fix reloc root leak and NULL pointer dereferenceQu Wenruo
[BUG] When balance is canceled, there is a pretty high chance that unmounting the fs can lead to lead the NULL pointer dereference: BTRFS warning (device dm-3): page private not zero on page 223158272 ... BTRFS warning (device dm-3): page private not zero on page 223162368 BTRFS error (device dm-3): leaked root 18446744073709551608-304 refcount 1 BUG: kernel NULL pointer dereference, address: 0000000000000168 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 2 PID: 5793 Comm: umount Tainted: G O 5.7.0-rc5-custom+ #53 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:__lock_acquire+0x5dc/0x24c0 Call Trace: lock_acquire+0xab/0x390 _raw_spin_lock+0x39/0x80 btrfs_release_extent_buffer_pages+0xd7/0x200 [btrfs] release_extent_buffer+0xb2/0x170 [btrfs] free_extent_buffer+0x66/0xb0 [btrfs] btrfs_put_root+0x8e/0x130 [btrfs] btrfs_check_leaked_roots.cold+0x5/0x5d [btrfs] btrfs_free_fs_info+0xe5/0x120 [btrfs] btrfs_kill_super+0x1f/0x30 [btrfs] deactivate_locked_super+0x3b/0x80 deactivate_super+0x3e/0x50 cleanup_mnt+0x109/0x160 __cleanup_mnt+0x12/0x20 task_work_run+0x67/0xa0 exit_to_usermode_loop+0xc5/0xd0 syscall_return_slowpath+0x205/0x360 do_syscall_64+0x6e/0xb0 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fd028ef740b [CAUSE] When balance is canceled, all reloc roots are marked as orphan, and orphan reloc roots are going to be cleaned up. However for orphan reloc roots and merged reloc roots, their lifespan are quite different: Merged reloc roots | Orphan reloc roots by cancel -------------------------------------------------------------------- create_reloc_root() | create_reloc_root() |- refs == 1 | |- refs == 1 | btrfs_grab_root(reloc_root); | btrfs_grab_root(reloc_root); |- refs == 2 | |- refs == 2 | root->reloc_root = reloc_root; | root->reloc_root = reloc_root; >>> No difference so far <<< | prepare_to_merge() | prepare_to_merge() |- btrfs_set_root_refs(item, 1);| |- if (!err) (err == -EINTR) | merge_reloc_roots() | merge_reloc_roots() |- merge_reloc_root() | |- Doing nothing to put reloc root |- insert_dirty_subvol() | |- refs == 2 |- __del_reloc_root() | |- btrfs_put_root() | |- refs == 1 | >>> Now orphan reloc roots still have refs 2 <<< | clean_dirty_subvols() | clean_dirty_subvols() |- btrfs_drop_snapshot() | |- btrfS_drop_snapshot() |- reloc_root get freed | |- reloc_root still has refs 2 | related ebs get freed, but | reloc_root still recorded in | allocated_roots btrfs_check_leaked_roots() | btrfs_check_leaked_roots() |- No leaked roots | |- Leaked reloc_roots detected | |- btrfs_put_root() | |- free_extent_buffer(root->node); | |- eb already freed, caused NULL | pointer dereference [FIX] The fix is to clear fs_root->reloc_root and put it at merge_reloc_roots() time, so that we won't leak reloc roots. Fixes: d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots") CC: stable@vger.kernel.org # 5.1+ Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: don't set SHAREABLE flag for data reloc treeQu Wenruo
SHAREABLE flag is set for subvolumes because users can create snapshot for subvolumes, thus sharing tree blocks of them. But data reloc tree is not exposed to user space, as it's only an internal tree for data relocation, thus it doesn't need the full path replacement handling at all. This patch will make data reloc tree a non-shareable tree, and add btrfs_fs_info::data_reloc_root for data reloc tree, so relocation code can grab it from fs_info directly. This would slightly improve tree relocation, as now data reloc tree can go through regular COW routine to get relocated, without bothering the complex tree reloc tree routine. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLEQu Wenruo
The name BTRFS_ROOT_REF_COWS is not very clear about the meaning. In fact, that bit can only be set to those trees: - Subvolume roots - Data reloc root - Reloc roots for above roots All other trees won't get this bit set. So just by the result, it is obvious that, roots with this bit set can have tree blocks shared with other trees. Either shared by snapshots, or by reloc roots (an special snapshot created by relocation). This patch will rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE to make it easier to understand, and update all comment mentioning "reference counted" to follow the rename. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: remove the redundant parameter level in btrfs_bin_search()Qu Wenruo
All callers pass the eb::level so we can get read it directly inside the btrfs_bin_search and key_search. This is inspired by the work of Marek in U-boot. CC: Marek Behun <marek.behun@nic.cz> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: use list_for_each_entry_safe in free_reloc_rootsNikolay Borisov
The function always works on a local copy of the reloc root list, which cannot be modified outside of it so using list_for_each_entry is fine. Additionally the macro handles empty lists so drop list_empty checks of callers. No semantic changes. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: move error handling of build_backref_tree() to backref.cQu Wenruo
The error cleanup will be extracted as a new function, btrfs_backref_error_cleanup(), and moved to backref.c and exported for later usage. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move finish_upper_links()Qu Wenruo
This the the 2nd major part of generic backref cache. Move it to backref.c so we can reuse it. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move handle_one_tree_block()Qu Wenruo
This function is the major part of backref cache build process, move it to backref.c so we can reuse it later. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: open code read_fs_root() for handle_indirect_tree_backref()Qu Wenruo
The backref code is going to be moved to backref.c, and read_fs_root() is just a simple wrapper, open-code it to prepare to the incoming code move. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move should_ignore_root()Qu Wenruo
This function is mostly single purpose to relocation backref cache, but since we're moving the main part of backref cache to backref.c, we need to export such function. And to avoid confusion, rename the function to btrfs_should_ignore_reloc_root() make the name a little more clear. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move backref_tree_panic()Qu Wenruo
Also change the parameter, since all callers can easily grab an fs_info, there is no need for all the pointer chasing. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move backref_cache_cleanup()Qu Wenruo
Since we're releasing all existing nodes/edges, other than cleanup the mess after error, "release" is a more proper naming here. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move remove_backref_node()Qu Wenruo
Also add comment explaining the cleanup progress, to differ it from btrfs_backref_drop_node(). Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move drop_backref_node()Qu Wenruo
With extra comment for drop_backref_node() as it has some similarity with remove_backref_node(), thus we need extra comment explaining the difference. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move free_backref_(node|edge)Qu Wenruo
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move link_backref_edge()Qu Wenruo
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move alloc_backref_edge()Qu Wenruo
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move alloc_backref_node()Qu Wenruo
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: rename and move backref_cache_init()Qu Wenruo
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: rename tree_entry to rb_simple_node and export itQu Wenruo
Structure tree_entry provides a very simple rb_tree which only uses bytenr as search index. That tree_entry is used in 3 structures: backref_node, mapping_node and tree_block. Since we're going to make backref_node independnt from relocation, it's a good time to extract the tree_entry into rb_simple_node, and export it into misc.h. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: backref: move btrfs_backref_(node|edge|cache) structures to backref.hQu Wenruo
These 3 structures are the main part of btrfs backref cache, move them to backref.h to build the basis for later reuse. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: add btrfs_ prefix for backref_node/edge/cacheQu Wenruo
Those three structures are the main elements of backref cache. Add the "btrfs_" prefix for later export. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: refactor useless nodes handling into its own functionQu Wenruo
This patch will also add some comment for the cleanup. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: refactor finishing part of upper linkage into finish_upper_links()Qu Wenruo
After handle_one_tree_backref(), all newly added (not cached) edges and nodes have the following features: - Only backref_edge::list[LOWER] is linked. This means, we can only iterate from botton to top, not the other direction. - Newly added nodes are not added to cache rb_tree yet So to finish the backref cache, we still need to finish the links and add all nodes into backref cache rb_tree. This patch will refactor the existing code into finish_upper_links(), add more comments of each branch, and why we need to do all the work. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: remove the open-coded goto loop for breadth-first searchQu Wenruo
build_backref_tree() uses "goto again;" to implement a breadth-first search to build backref cache. This patch will extract most of its work into a wrapper, handle_one_tree_block(), and use a do {} while() loop to implement the same thing. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: pass essential members for alloc_backref_node()Qu Wenruo
Bytenr and level are essential parameters for backref_node, thus it makes sense to initialize them at allocation time. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: use wrapper to replace open-coded edge linkingQu Wenruo
Since backref_edge is used to connect upper and lower backref nodes, and needs to access both nodes, some code can look pretty nasty: list_add_tail(&edge->list[LOWER], &cur->upper); The above code will link @cur to the LOWER side of the edge, while both "LOWER" and "upper" words show up. This can sometimes be very confusing for reader to grasp. This patch introduces a new wrapper, link_backref_edge(), to handle the linking behavior. Which also has extra ASSERT() to ensure caller won't pass wrong nodes. Also, this updates the comment of related lists of backref_node and backref_edge, to make it more clear that each list points to what. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: refactor indirect tree backref processing into its own functionQu Wenruo
The processing of indirect tree backref (TREE_BLOCK_REF) is the most complex work. We need to grab the fs root, do a tree search to locate all its parent nodes, link all needed edges, and put all uncached edges to pending edge list. This is definitely worth a helper function. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: refactor direct tree backref processing into its own functionQu Wenruo
For BTRFS_SHARED_BLOCK_REF_KEY, its processing is straightforward, as we now the parent node bytenr directly. If the parent is already cached, or a root, call it a day. If the parent is not cached, add it pending list. This patch will just refactor this part into its own function, handle_direct_tree_backref() and add some comment explaining the @ref_key parameter. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: make reloc root search-specific for relocation backref cacheQu Wenruo
find_reloc_root() searches reloc_control::reloc_root_tree to find the reloc root. This behavior is only useful for relocation backref cache. For the incoming more generic purpose backref cache, we don't care about who owns the reloc root, but only care if it's a reloc root. So this patch makes the following modifications to make the reloc root search more specific to relocation backref: - Add backref_node::is_reloc_root This will be an extra indicator for generic purposed backref cache. User doesn't need to read root key from backref_node::root to determine if it's a reloc root. Also for reloc tree root, it's useless and will be queued to useless list. - Add backref_cache::is_reloc This will allow backref cache code to do different behavior for generic purpose backref cache and relocation backref cache. - Pass fs_info to find_reloc_root() - Export find_reloc_root() So backref.c can utilize this function. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: add backref_cache::fs_info memberQu Wenruo
Add this member so that we can grab fs_info without the help from reloc_control. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: add backref_cache::pending_edge and backref_cache::useless_nodeQu Wenruo
These two new members will act the same as the existing local lists, @useless and @list in build_backref_tree(). Currently build_backref_tree() is only executed serially, thus moving such local list into backref_cache is still safe. Also since we're here, use list_first_entry() to replace a lot of list_entry() calls after !list_empty(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: rename mark_block_processed and __mark_block_processedQu Wenruo
These two functions are weirdly named, mark_block_processed() in fact just marks a range dirty unconditionally, while __mark_block_processed() does extra check before doing the marking. This patch will open code old mark_block_processed, and rename __mark_block_processed() to remove the "__" prefix. Since we're here, also kill the forward declaration, which could also kill in_block_group() with in_range() macro. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25btrfs: reloc: use btrfs_backref_iter infrastructureQu Wenruo
In the core function of relocation, build_backref_tree, it needs to iterate all backref items of one tree block. Use btrfs_backref_iter infrastructure to do the loop and make the code more readable. The backref items look would be much more easier to read: ret = btrfs_backref_iter_start(iter, cur->bytenr); for (; ret == 0; ret = btrfs_backref_iter_next(iter)) { /* The really important work */ } Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>