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2018-12-17Btrfs: allow clear_extent_dirty() to receive a cached extent state recordFilipe Manana1-2/+5
We can have a lot freed extents during the life span of transaction, so the red black tree that keeps track of the ranges of each freed extent (fs_info->freed_extents[]) can get quite big. When finishing a transaction commit we find each range, process it (discard the extents, unpin them) and then remove it from the red black tree. We can use an extent state record as a cache when searching for a range, so that when we clean the range we can use the cached extent state we passed to the search function instead of iterating the red black tree again. Doing things as fast as possible when finishing a transaction (in state TRANS_STATE_UNBLOCKED) is convenient as it reduces the time we block another task that wants to commit the next transaction. So change clear_extent_dirty() to allow an optional extent state record to be passed as an argument, which will be passed down to __clear_extent_bit. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Remove fsid/metadata_fsid fields from btrfs_infoNikolay Borisov1-1/+1
Currently btrfs_fs_info structure contains a copy of the fsid/metadata_uuid fields. Same values are also contained in the btrfs_fs_devices structure which fs_info has a reference to. Let's reduce duplication by removing the fields from fs_info and always refer to the ones in fs_devices. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Introduce support for FSID change without metadata rewriteNikolay Borisov1-1/+1
This field is going to be used when the user wants to change the UUID of the filesystem without having to rewrite all metadata blocks. This field adds another level of indirection such that when the FSID is changed what really happens is the current UUID (the one with which the fs was created) is copied to the 'metadata_uuid' field in the superblock as well as a new incompat flag is set METADATA_UUID. When the kernel detects this flag is set it knows that the superblock in fact has 2 UUIDs: 1. Is the UUID which is user-visible, currently known as FSID. 2. Metadata UUID - this is the UUID which is stamped into all on-disk datastructures belonging to this file system. When the new incompat flag is present device scanning checks whether both fsid/metadata_uuid of the scanned device match any of the registered filesystems. When the flag is not set then both UUIDs are equal and only the FSID is retained on disk, metadata_uuid is set only in-memory during mount. Additionally a new metadata_uuid field is also added to the fs_info struct. It's initialised either with the FSID in case METADATA_UUID incompat flag is not set or with the metdata_uuid of the superblock otherwise. This commit introduces the new fields as well as the new incompat flag and switches all users of the fsid to the new logic. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor updates in comments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Refactor find_free_extent loops update into find_free_extent_update_loopQu Wenruo1-100/+131
We have a complex loop design for find_free_extent(), that has different behavior for each loop, some even includes new chunk allocation. Instead of putting such a long code into find_free_extent() and makes it harder to read, just extract them into find_free_extent_update_loop(). With all the cleanups, the main find_free_extent() should be pretty barebone: find_free_extent() |- Iterate through all block groups | |- Get a valid block group | |- Try to do clustered allocation in that block group | |- Try to do unclustered allocation in that block group | |- Check if the result is valid | | |- If valid, then exit | |- Jump to next block group | |- Push harder to find free extents |- If not found, re-iterate all block groups Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> [ copy callchain from changelog to function comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Refactor unclustered extent allocation into find_free_extent_unclustered()Qu Wenruo1-46/+69
This patch will extract unclsutered extent allocation code into find_free_extent_unclustered(). And this helper function will use return value to indicate what to do next. This should make find_free_extent() a little easier to read. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> [Update merge conflict with fb5c39d7a887 ("btrfs: don't use ctl->free_space for max_extent_size")] Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Refactor clustered extent allocation into find_free_extent_clusteredQu Wenruo1-123/+122
We have two main methods to find free extents inside a block group: 1) clustered allocation 2) unclustered allocation This patch will extract the clustered allocation into find_free_extent_clustered() to make it a little easier to read. Instead of jumping between different labels in find_free_extent(), the helper function will use return value to indicate different behavior. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: Introduce find_free_extent_ctl structure for later reworkQu Wenruo1-95/+170
Instead of tons of different local variables in find_free_extent(), extract them into find_free_extent_ctl structure, and add better explanation for them. Some modification may looks redundant, but will later greatly simplify function parameter list during find_free_extent() refactor. Also add two comments to co-operate with fb5c39d7a887 ("btrfs: don't use ctl->free_space for max_extent_size"), to make ffe_ctl->max_extent_size update more reader-friendly. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: extent-tree: Detect bytes_pinned underflow earlierLu Fengqi1-4/+5
Introduce a new wrapper update_bytes_pinned to replace open coded bytes_pinned modifiers. Now the underflows of space_info::bytes_pinned get detected and reported. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17btrfs: extent-tree: Detect bytes_may_use underflow earlierQu Wenruo1-16/+30
Although we have space_info::bytes_may_use underflow detection in btrfs_free_reserved_data_space_noquota(), we have more callers who are subtracting number from space_info::bytes_may_use. So instead of doing underflow detection for every caller, introduce a new wrapper update_bytes_may_use() to replace open coded bytes_may_use modifiers. This also introduce a macro to declare more wrappers, but currently space_info::bytes_may_use is the mostly interesting one. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19btrfs: fix insert_reserved error handlingJosef Bacik1-8/+4
We were not handling the reserved byte accounting properly for data references. Metadata was fine, if it errored out the error paths would free the bytes_reserved count and pin the extent, but it even missed one of the error cases. So instead move this handling up into run_one_delayed_ref so we are sure that both cases are properly cleaned up in case of a transaction abort. CC: stable@vger.kernel.org # 4.18+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19btrfs: don't use ctl->free_space for max_extent_sizeJosef Bacik1-2/+5
max_extent_size is supposed to be the largest contiguous range for the space info, and ctl->free_space is the total free space in the block group. We need to keep track of these separately and _only_ use the max_free_space if we don't have a max_extent_size, as that means our original request was too large to search any of the block groups for and therefore wouldn't have a max_extent_size set. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-19btrfs: reset max_extent_size properlyJosef Bacik1-0/+2
If we use up our block group before allocating a new one we'll easily get a max_extent_size that's set really really low, which will result in a lot of fragmentation. We need to make sure we're resetting the max_extent_size when we add a new chunk or add new space. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-17Btrfs: fix deadlock when writing out free space cachesFilipe Manana1-10/+6
When writing out a block group free space cache we can end deadlocking with ourselves on an extent buffer lock resulting in a warning like the following: [245043.379979] WARNING: CPU: 4 PID: 2608 at fs/btrfs/locking.c:251 btrfs_tree_lock+0x1be/0x1d0 [btrfs] [245043.392792] CPU: 4 PID: 2608 Comm: btrfs-transacti Tainted: G W I 4.16.8 #1 [245043.395489] RIP: 0010:btrfs_tree_lock+0x1be/0x1d0 [btrfs] [245043.396791] RSP: 0018:ffffc9000424b840 EFLAGS: 00010246 [245043.398093] RAX: 0000000000000a30 RBX: ffff8807e20a3d20 RCX: 0000000000000001 [245043.399414] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8807e20a3d20 [245043.400732] RBP: 0000000000000001 R08: ffff88041f39a700 R09: ffff880000000000 [245043.402021] R10: 0000000000000040 R11: ffff8807e20a3d20 R12: ffff8807cb220630 [245043.403296] R13: 0000000000000001 R14: ffff8807cb220628 R15: ffff88041fbdf000 [245043.404780] FS: 0000000000000000(0000) GS:ffff88082fc80000(0000) knlGS:0000000000000000 [245043.406050] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [245043.407321] CR2: 00007fffdbdb9f10 CR3: 0000000001c09005 CR4: 00000000000206e0 [245043.408670] Call Trace: [245043.409977] btrfs_search_slot+0x761/0xa60 [btrfs] [245043.411278] btrfs_insert_empty_items+0x62/0xb0 [btrfs] [245043.412572] btrfs_insert_item+0x5b/0xc0 [btrfs] [245043.413922] btrfs_create_pending_block_groups+0xfb/0x1e0 [btrfs] [245043.415216] do_chunk_alloc+0x1e5/0x2a0 [btrfs] [245043.416487] find_free_extent+0xcd0/0xf60 [btrfs] [245043.417813] btrfs_reserve_extent+0x96/0x1e0 [btrfs] [245043.419105] btrfs_alloc_tree_block+0xfb/0x4a0 [btrfs] [245043.420378] __btrfs_cow_block+0x127/0x550 [btrfs] [245043.421652] btrfs_cow_block+0xee/0x190 [btrfs] [245043.422979] btrfs_search_slot+0x227/0xa60 [btrfs] [245043.424279] ? btrfs_update_inode_item+0x59/0x100 [btrfs] [245043.425538] ? iput+0x72/0x1e0 [245043.426798] write_one_cache_group.isra.49+0x20/0x90 [btrfs] [245043.428131] btrfs_start_dirty_block_groups+0x102/0x420 [btrfs] [245043.429419] btrfs_commit_transaction+0x11b/0x880 [btrfs] [245043.430712] ? start_transaction+0x8e/0x410 [btrfs] [245043.432006] transaction_kthread+0x184/0x1a0 [btrfs] [245043.433341] kthread+0xf0/0x130 [245043.434628] ? btrfs_cleanup_transaction+0x4e0/0x4e0 [btrfs] [245043.435928] ? kthread_create_worker_on_cpu+0x40/0x40 [245043.437236] ret_from_fork+0x1f/0x30 [245043.441054] ---[ end trace 15abaa2aaf36827f ]--- This is because at write_one_cache_group() when we are COWing a leaf from the extent tree we end up allocating a new block group (chunk) and, because we have hit a threshold on the number of bytes reserved for system chunks, we attempt to finalize the creation of new block groups from the current transaction, by calling btrfs_create_pending_block_groups(). However here we also need to modify the extent tree in order to insert a block group item, and if the location for this new block group item happens to be in the same leaf that we were COWing earlier, we deadlock since btrfs_search_slot() tries to write lock the extent buffer that we locked before at write_one_cache_group(). We have already hit similar cases in the past and commit d9a0540a79f8 ("Btrfs: fix deadlock when finalizing block group creation") fixed some of those cases by delaying the creation of pending block groups at the known specific spots that could lead to a deadlock. This change reworks that commit to be more generic so that we don't have to add similar logic to every possible path that can lead to a deadlock. This is done by making __btrfs_cow_block() disallowing the creation of new block groups (setting the transaction's can_flush_pending_bgs to false) before it attempts to allocate a new extent buffer for either the extent, chunk or device trees, since those are the trees that pending block creation modifies. Once the new extent buffer is allocated, it allows creation of pending block groups to happen again. This change depends on a recent patch from Josef which is not yet in Linus' tree, named "btrfs: make sure we create all new block groups" in order to avoid occasional warnings at btrfs_trans_release_chunk_metadata(). Fixes: d9a0540a79f8 ("Btrfs: fix deadlock when finalizing block group creation") CC: stable@vger.kernel.org # 4.4+ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199753 Link: https://lore.kernel.org/linux-btrfs/CAJtFHUTHna09ST-_EEiyWmDH6gAqS6wa=zMNMBsifj8ABu99cw@mail.gmail.com/ Reported-by: E V <eliventer@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove fs_info from btrfs_should_throttle_delayed_refsLu Fengqi1-3/+2
The avg_delayed_ref_runtime can be referenced from the transaction handle. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove fs_info from btrfs_check_space_for_delayed_refsLu Fengqi1-3/+3
It can be referenced from the transaction handle. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: delayed-ref: pass delayed_refs directly to btrfs_delayed_ref_lockLu Fengqi1-1/+1
Since trans is only used for referring to delayed_refs, there is no need to pass it instead of delayed_refs to btrfs_delayed_ref_lock(). No functional change. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: delayed-ref: pass delayed_refs directly to btrfs_select_ref_headLu Fengqi1-1/+1
Since trans is only used for referring to delayed_refs, there is no need to pass it instead of delayed_refs to btrfs_select_ref_head(). No functional change. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: make sure we create all new block groupsJosef Bacik1-2/+5
Allocating new chunks modifies both the extent and chunk tree, which can trigger new chunk allocations. So instead of doing list_for_each_safe, just do while (!list_empty()) so we make sure we don't exit with other pending bg's still on our list. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: qgroup: Don't trace subtree if we're dropping reloc treeQu Wenruo1-1/+7
Reloc tree doesn't contribute to qgroup numbers, as we have accounted them at balance time (see replace_path()). Skipping the unneeded subtree tracing should reduce the overhead. [[Benchmark]] Hardware: VM 4G vRAM, 8 vCPUs, disk is using 'unsafe' cache mode, backing device is SAMSUNG 850 evo SSD. Host has 16G ram. Mkfs parameter: --nodesize 4K (To bump up tree size) Initial subvolume contents: 4G data copied from /usr and /lib. (With enough regular small files) Snapshots: 16 snapshots of the original subvolume. each snapshot has 3 random files modified. balance parameter: -m So the content should be pretty similar to a real world root fs layout. | v4.19-rc1 | w/ patchset | diff (*) --------------------------------------------------------------- relocated extents | 22929 | 22900 | -0.1% qgroup dirty extents | 227757 | 167139 | -26.6% time (sys) | 65.253s | 50.123s | -23.2% time (real) | 74.032s | 52.551s | -29.0% Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: refactor __btrfs_run_delayed_refs loopNikolay Borisov1-80/+28
Refactor the delayed refs loop by using the newly introduced btrfs_run_delayed_refs_for_head function. This greatly simplifies __btrfs_run_delayed_refs and makes it more obvious what is happening. We now have 1 loop which iterates the existing delayed_heads and then each selected ref head is processed by the new helper. All existing semantics of the code are preserved so no functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Factor out loop processing all refs of a headNikolay Borisov1-0/+77
This patch introduces a new helper encompassing the implicit inner loop in __btrfs_run_delayed_refs which processes all the refs for a given head. The code is mostly copy/paste, the only difference is that if we detect a newer reference then -EAGAIN is returned so that callers can react correctly. Also, at the end of the loop the head is relocked and btrfs_merge_delayed_refs is run again to retain the pre-refactoring semantics. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Factor out ref head locking code in __btrfs_run_delayed_refsNikolay Borisov1-17/+36
This is in preparation to refactor the giant loop in __btrfs_run_delayed_refs. As a first step define a new function which implements acquiring a reference to a btrfs_delayed_refs_head and use it. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: delayed-refs: use rb_first_cached for ref_treeLiu Bo1-6/+7
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating href->ref_tree need to get the first entry, this converts href->ref_tree to use rb_first_cached(). For more details about the optimization see patch "Btrfs: delayed-refs: use rb_first_cached for href_root". Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: delayed-refs: use rb_first_cached for href_rootLiu Bo1-3/+3
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as rb_first() but in O(1). Functions manipulating href_root need to get the first entry, this converts href_root to use rb_first_cached(). This patch is first in the sequenct of similar updates to other rbtrees and this is analysis of the expected behaviour and improvements. There's a common pattern: while (node = rb_first) { entry = rb_entry(node) next = rb_next(node) rb_erase(node) cleanup(entry) } rb_first needs to traverse the tree up to logN depth, rb_erase can completely reshuffle the tree. With the caching we'll skip the traversal in rb_first. That's a cached memory access vs looped pointer dereference trade-off that IMHO has a clear winner. Measurements show there's not much difference in a sample tree with 10000 nodes: 4.5s / rb_first and 4.8s / rb_first_cached. Real effects of caching and pointer chasing are unpredictable though. Further optimzations can be done to avoid the expensive rb_erase step. In some cases it's ok to process the nodes in any order, so the tree can be traversed in post-order, not rebalancing the children nodes and just calling free. Care must be taken regarding the next node. Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog from mail discussions ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: wait on caching when putting the bg cacheJosef Bacik1-0/+1
While testing my backport I noticed there was a panic if I ran generic/416 generic/417 generic/418 all in a row. This just happened to uncover a race where we had outstanding IO after we destroy all of our workqueues, and then we'd go to queue the endio work on those free'd workqueues. This is because we aren't waiting for the caching threads to be done before freeing everything up, so to fix this make sure we wait on any outstanding caching that's being done before we free up the block group, so we're sure to be done with all IO by the time we get to btrfs_stop_all_workers(). This fixes the panic I was seeing consistently in testing. ------------[ cut here ]------------ kernel BUG at fs/btrfs/volumes.c:6112! SMP PTI Modules linked in: CPU: 1 PID: 27165 Comm: kworker/u4:7 Not tainted 4.16.0-02155-g3553e54a578d-dirty #875 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Workqueue: btrfs-cache btrfs_cache_helper RIP: 0010:btrfs_map_bio+0x346/0x370 RSP: 0000:ffffc900061e79d0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff880071542e00 RCX: 0000000000533000 RDX: ffff88006bb74380 RSI: 0000000000000008 RDI: ffff880078160000 RBP: 0000000000000001 R08: ffff8800781cd200 R09: 0000000000503000 R10: ffff88006cd21200 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8800781cd200 R15: ffff880071542e00 FS: 0000000000000000(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000817ffc4 CR3: 0000000078314000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btree_submit_bio_hook+0x8a/0xd0 submit_one_bio+0x5d/0x80 read_extent_buffer_pages+0x18a/0x320 btree_read_extent_buffer_pages+0xbc/0x200 ? alloc_extent_buffer+0x359/0x3e0 read_tree_block+0x3d/0x60 read_block_for_search.isra.30+0x1a5/0x360 btrfs_search_slot+0x41b/0xa10 btrfs_next_old_leaf+0x212/0x470 caching_thread+0x323/0x490 normal_work_helper+0xc5/0x310 process_one_work+0x141/0x340 worker_thread+0x44/0x3c0 kthread+0xf8/0x130 ? process_one_work+0x340/0x340 ? kthread_bind+0x10/0x10 ret_from_fork+0x35/0x40 RIP: btrfs_map_bio+0x346/0x370 RSP: ffffc900061e79d0 ---[ end trace 827eb13e50846033 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: keep trim from interfering with transaction commitsJeff Mahoney1-8/+17
Commit 499f377f49f08 (btrfs: iterate over unused chunk space in FITRIM) fixed free space trimming, but introduced latency when it was running. This is due to it pinning the transaction using both a incremented refcount and holding the commit root sem for the duration of a single trim operation. This was to ensure safety but it's unnecessary. We already hold the the chunk mutex so we know that the chunk we're using can't be allocated while we're trimming it. In order to check against chunks allocated already in this transaction, we need to check the pending chunks list. To to that safely without joining the transaction (or attaching than then having to commit it) we need to ensure that the dev root's commit root doesn't change underneath us and the pending chunk lists stays around until we're done with it. We can ensure the former by holding the commit root sem and the latter by pinning the transaction. We do this now, but the critical section covers the trim operation itself and we don't need to do that. This patch moves the pinning and unpinning logic into helpers and unpins the transaction after performing the search and check for pending chunks. Limiting the critical section of the transaction pinning improves the latency substantially on slower storage (e.g. image files over NFS). Fixes: 499f377f49f08 ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: don't attempt to trim devices that don't support itJeff Mahoney1-0/+4
We check whether any device the file system is using supports discard in the ioctl call, but then we attempt to trim free extents on every device regardless of whether discard is supported. Due to the way we mask off EOPNOTSUPP, we can end up issuing the trim operations on each free range on devices that don't support it, just wasting time. Fixes: 499f377f49f08 ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: iterate all devices during trim, instead of fs_devices::alloc_listJeff Mahoney1-2/+2
btrfs_trim_fs iterates over the fs_devices->alloc_list while holding the device_list_mutex. The problem is that ->alloc_list is protected by the chunk mutex. We don't want to hold the chunk mutex over the trim of the entire file system. Fortunately, the ->dev_list list is protected by the dev_list mutex and while it will give us all devices, including read-only devices, we already just skip the read-only devices. Then we can continue to take and release the chunk mutex while scanning each device. Fixes: 499f377f49f ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Ensure btrfs_trim_fs can trim the whole filesystemQu Wenruo1-9/+1
[BUG] fstrim on some btrfs only trims the unallocated space, not trimming any space in existing block groups. [CAUSE] Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to range [0, super->total_bytes). So later btrfs_trim_fs() will only be able to trim block groups in range [0, super->total_bytes). While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs uses its logical address space, there is nothing limiting the location where we put block groups. For filesystem with frequent balance, it's quite easy to relocate all block groups and bytenr of block groups will start beyond super->total_bytes. In that case, btrfs will not trim existing block groups. [FIX] Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs() can get the unmodified range, which is normally set to [0, U64_MAX]. Reported-by: Chris Murphy <lists@colorremedies.com> Fixes: f4c697e6406d ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl") CC: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Enhance btrfs_trim_fs function to handle error betterQu Wenruo1-11/+38
Function btrfs_trim_fs() doesn't handle errors in a consistent way. If error happens when trimming existing block groups, it will skip the remaining blocks and continue to trim unallocated space for each device. The return value will only reflect the final error from device trimming. This patch will fix such behavior by: 1) Recording the last error from block group or device trimming The return value will also reflect the last error during trimming. Make developer more aware of the problem. 2) Continuing trimming if possible If we failed to trim one block group or device, we could still try the next block group or device. 3) Report number of failures during block group and device trimming It would be less noisy, but still gives user a brief summary of what's going wrong. Such behavior can avoid confusion for cases like failure to trim the first block group and then only unallocated space is trimmed. Reported-by: Chris Murphy <lists@colorremedies.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add bg_ret and dev_ret to the messages ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove redundant variable from btrfs_cross_ref_existMisono Tomohiro1-11/+2
Since commit d7df2c796d7e ("Btrfs attach delayed ref updates to delayed ref heads"), check_delayed_ref() won't return -ENOENT. In btrfs_cross_ref_exist(), two variables 'ret' and 'ret2' are originally used to handle -ENOENT error case. Since the code is not needed anymore, let's just remove 'ret2'. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15Btrfs: remove confusing tracepoint in btrfs_add_reserved_bytesLiu Bo1-4/+0
Here we're not releasing any space, but transferring bytes from ->bytes_may_use to ->bytes_reserved. The last change to the code in commit 18513091af9483ba8 ("btrfs: update btrfs_space_info's bytes_may_use timely") removed a conditional tracepoint and the logic changed too but the tracepiont remained. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: locking: Add extra check in btrfs_init_new_buffer() to avoid deadlockQu Wenruo1-0/+13
[BUG] For certain crafted image, whose csum root leaf has missing backref, if we try to trigger write with data csum, it could cause deadlock with the following kernel WARN_ON(): WARNING: CPU: 1 PID: 41 at fs/btrfs/locking.c:230 btrfs_tree_lock+0x3e2/0x400 CPU: 1 PID: 41 Comm: kworker/u4:1 Not tainted 4.18.0-rc1+ #8 Workqueue: btrfs-endio-write btrfs_endio_write_helper RIP: 0010:btrfs_tree_lock+0x3e2/0x400 Call Trace: btrfs_alloc_tree_block+0x39f/0x770 __btrfs_cow_block+0x285/0x9e0 btrfs_cow_block+0x191/0x2e0 btrfs_search_slot+0x492/0x1160 btrfs_lookup_csum+0xec/0x280 btrfs_csum_file_blocks+0x2be/0xa60 add_pending_csums+0xaf/0xf0 btrfs_finish_ordered_io+0x74b/0xc90 finish_ordered_fn+0x15/0x20 normal_work_helper+0xf6/0x500 btrfs_endio_write_helper+0x12/0x20 process_one_work+0x302/0x770 worker_thread+0x81/0x6d0 kthread+0x180/0x1d0 ret_from_fork+0x35/0x40 [CAUSE] That crafted image has missing backref for csum tree root leaf. And when we try to allocate new tree block, since there is no EXTENT/METADATA_ITEM for csum tree root, btrfs consider it's free slot and use it. The extent tree of the image looks like: Normal image | This fuzzed image ----------------------------------+-------------------------------- BG 29360128 | BG 29360128 One empty slot | One empty slot 29364224: backref to UUID tree | 29364224: backref to UUID tree Two empty slots | Two empty slots 29376512: backref to CSUM tree | One empty slot (bad type) <<< 29380608: backref to D_RELOC tree | 29380608: backref to D_RELOC tree ... | ... Since bytenr 29376512 has no METADATA/EXTENT_ITEM, when btrfs try to alloc tree block, it's an valid slot for btrfs. And for finish_ordered_write, when we need to insert csum, we try to CoW csum tree root. By accident, empty slots at bytenr BG_OFFSET, BG_OFFSET + 8K, BG_OFFSET + 12K is already used by tree block COW for other trees, the next empty slot is BG_OFFSET + 16K, which should be the backref for CSUM tree. But due to the bad type, btrfs can recognize it and still consider it as an empty slot, and will try to use it for csum tree CoW. Then in the following call trace, we will try to lock the new tree block, which turns out to be the old csum tree root which is already locked: btrfs_search_slot() called on csum tree root, which is at 29376512 |- btrfs_cow_block() |- btrfs_set_lock_block() | |- Now locks tree block 29376512 (old csum tree root) |- __btrfs_cow_block() |- btrfs_alloc_tree_block() |- btrfs_reserve_extent() | Now it returns tree block 29376512, which extent tree | shows its empty slot, but it's already hold by csum tree |- btrfs_init_new_buffer() |- btrfs_tree_lock() | Triggers WARN_ON(eb->lock_owner == current->pid) |- wait_event() Wait lock owner to release the lock, but it's locked by ourself, so it will deadlock [FIX] This patch will do the lock_owner and current->pid check at btrfs_init_new_buffer(). So above deadlock can be avoided. Since such problem can only happen in crafted image, we will still trigger kernel warning for later aborted transaction, but with a little more meaningful warning message. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200405 Reported-by: Xu Wen <wen.xu@gatech.edu> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Handle owner mismatch gracefully when walking up treeQu Wenruo1-6/+12
[BUG] When mounting certain crafted image, btrfs will trigger kernel BUG_ON() when trying to recover balance: kernel BUG at fs/btrfs/extent-tree.c:8956! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 662 Comm: mount Not tainted 4.18.0-rc1-custom+ #10 RIP: 0010:walk_up_proc+0x336/0x480 [btrfs] RSP: 0018:ffffb53540c9b890 EFLAGS: 00010202 Call Trace: walk_up_tree+0x172/0x1f0 [btrfs] btrfs_drop_snapshot+0x3a4/0x830 [btrfs] merge_reloc_roots+0xe1/0x1d0 [btrfs] btrfs_recover_relocation+0x3ea/0x420 [btrfs] open_ctree+0x1af3/0x1dd0 [btrfs] btrfs_mount_root+0x66b/0x740 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 btrfs_mount+0x16d/0x890 [btrfs] mount_fs+0x3b/0x16a vfs_kern_mount.part.9+0x54/0x140 do_mount+0x1fd/0xda0 ksys_mount+0xba/0xd0 __x64_sys_mount+0x21/0x30 do_syscall_64+0x60/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] Extent tree corruption. In this particular case, reloc tree root's owner is DATA_RELOC_TREE (should be TREE_RELOC), thus its backref is corrupted and we failed the owner check in walk_up_tree(). [FIX] It's pretty hard to take care of every extent tree corruption, but at least we can remove such BUG_ON() and exit more gracefully. And since in this particular image, DATA_RELOC_TREE and TREE_RELOC share the same root (which is obviously invalid), we needs to make __del_reloc_root() more robust to detect such invalid sharing to avoid possible NULL dereference as root->node can be NULL in this case. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200411 Reported-by: Xu Wen <wen.xu@gatech.edu> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: change btrfs_free_reserved_bytes to return voidzhong jiang1-4/+2
btrfs_free_reserved_bytes uses the variable "ret" for return value, but it is not modified after initialzation. Further, I find that any of the callers do not handle the return value, so it is safe to drop the unneeded "ret" and return void. There are no callees that would need the function to handle or pass the value either. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: Remove 'objectid' member from struct btrfs_rootMisono Tomohiro1-1/+1
There are two members in struct btrfs_root which indicate root's objectid: objectid and root_key.objectid. They are both set to the same value in __setup_root(): static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, u64 objectid) { ... root->objectid = objectid; ... root->root_key.objectid = objecitd; ... } and not changed to other value after initialization. grep in btrfs directory shows both are used in many places: $ grep -rI "root->root_key.objectid" | wc -l 133 $ grep -rI "root->objectid" | wc -l 55 (4.17, inc. some noise) It is confusing to have two similar variable names and it seems that there is no rule about which should be used in a certain case. Since ->root_key itself is needed for tree reloc tree, let's remove 'objecitd' member and unify code to use ->root_key.objectid in all places. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: remove a useless return statement in btrfs_block_rsv_addLu Fengqi1-3/+1
Since ret must be 0 here, don't have to return. No functional change and code readability is not hurt. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-15btrfs: switch update_size to bool in btrfs_block_rsv_migrate and btrfs_rsv_add_bytesLu Fengqi1-8/+8
Using true and false here is closer to the expected semantic than using 0 and 1. No functional change. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-23btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadataLu Fengqi1-9/+8
After btrfs_qgroup_reserve_meta_prealloc(), num_bytes will be assigned again by btrfs_calc_trans_metadata_size(). Once block_rsv fails, we can't properly free the num_bytes of the previous qgroup_reserve. Use a separate variable to store the num_bytes of the qgroup_reserve. Delete the comment for the qgroup_reserved that does not exist and add a comment about use_global_rsv. Fixes: c4c129db5da8 ("btrfs: drop unused parameter qgroup_reserved") CC: stable@vger.kernel.org # 4.18+ Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Verify that every chunk has corresponding block group at mount timeQu Wenruo1-1/+57
If a crafted image has missing block group items, it could cause unexpected behavior and breaks the assumption of 1:1 chunk<->block group mapping. Although we have the block group -> chunk mapping check, we still need chunk -> block group mapping check. This patch will do extra check to ensure each chunk has its corresponding block group. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Check that each block group has corresponding chunk at mount timeQu Wenruo1-1/+27
A crafted btrfs image with incorrect chunk<->block group mapping will trigger a lot of unexpected things as the mapping is essential. Although the problem can be caught by block group item checker added in "btrfs: tree-checker: Verify block_group_item", it's still not sufficient. A sufficiently valid block group item can pass the check added by the mentioned patch but could fail to match the existing chunk. This patch will add extra block group -> chunk mapping check, to ensure we have a completely matching (start, len, flags) chunk for each block group at mount time. Here we reuse the original helper find_first_block_group(), which is already doing the basic bg -> chunk checks, adding further checks of the start/len and type flags. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: extent-tree: Remove unused __btrfs_free_block_rsvMisono Tomohiro1-5/+0
There is no user of this function anymore. This was forgotten to be removed in commit a575ceeb1338 ("Btrfs: get rid of unused orphan infrastructure"). Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Remove fs_info from btrfs_del_rootLu Fengqi1-1/+1
It can be referenced from the passed transaction handle. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: extent-tree: remove unused member walk_control::for_relocDavid Sterba1-3/+0
Leftover after fix e339a6b097c5 ("Btrfs: __btrfs_mod_ref should always use no_quota"), that removed it from the function calls but not the structure. Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: don't leak ret from do_chunk_allocJosef Bacik1-1/+1
If we're trying to make a data reservation and we have to allocate a data chunk we could leak ret == 1, as do_chunk_alloc() will return 1 if it allocated a chunk. Since the end of the function is the success path just return 0. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Remove fs_info from btrfs_finish_chunk_allocNikolay Borisov1-4/+2
It can be referenced from the passed transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: extent-tree: Remove dead alignment checkQu Wenruo1-2/+1
In find_free_extent() under checks: label, we have the following code: search_start = ALIGN(offset, fs_info->stripesize); /* move on to the next group */ if (search_start + num_bytes > block_group->key.objectid + block_group->key.offset) { btrfs_add_free_space(block_group, offset, num_bytes); goto loop; } if (offset < search_start) btrfs_add_free_space(block_group, offset, search_start - offset); BUG_ON(offset > search_start); However ALIGN() is rounding up, thus @search_start >= @offset and that BUG_ON() will never be triggered. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: refactor block group replication factor calculation to a helperDavid Sterba1-28/+8
There are many places that open code the duplicity factor of the block group profiles, create a common helper. This can be easily extended for more copies. Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: qgroup: Drop root parameter from btrfs_qgroup_trace_subtreeLu Fengqi1-1/+1
The fs_info can be fetched from the transaction handle directly. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: qgroup: Drop fs_info parameter from btrfs_qgroup_trace_leaf_itemsLu Fengqi1-1/+1
It can be fetched from the transaction handle. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>