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* btrfs: split delayed ref head initialization and additionNikolay Borisov2018-05-281-25/+22
| | | | | | | | | | | | | | | | | | | | | | | | add_delayed_ref_head really performed 2 independent operations - initialisting the ref head and adding it to a list. Now that the init part is in a separate function let's complete the separation between both operations. This results in a lot simpler interface for add_delayed_ref_head since the function now deals solely with either adding the newly initialised delayed ref head or merging it into an existing delayed ref head. This results in vastly simplified function signature since 5 arguments are dropped. The only other thing worth mentioning is that due to this split the WARN_ON catching reinit of existing. In this patch the condition is extended such that: qrecord && head_ref->qgroup_ref_root && head_ref->qgroup_reserved is added. This is done because the two qgroup_* prefixed member are set only if both ref_root and reserved are passed. So functionally it's equivalent to the old WARN_ON and allows to remove the two args from add_delayed_ref_head. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Use init_delayed_ref_head in add_delayed_ref_headNikolay Borisov2018-05-281-59/+4
| | | | | | | | | Use the newly introduced function when initialising the head_ref in add_delayed_ref_head. 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>
* btrfs: Introduce init_delayed_ref_headNikolay Borisov2018-05-281-0/+65
| | | | | | | | | | | | | | add_delayed_ref_head implements the logic to both initialize a head_ref structure as well as perform the necessary operations to add it to the delayed ref machinery. This has resulted in a very cumebrsome interface with loads of parameters and code, which at first glance, looks very unwieldy. Begin untangling it by first extracting the initialization only code in its own function. It's more or less verbatim copy of the first part of add_delayed_ref_head. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Open-code add_delayed_data_refNikolay Borisov2018-05-281-40/+22
| | | | | | | | | | | | | | | | | | | | | Now that the initialization part and the critical section code have been split it's a lot easier to open code add_delayed_data_ref. Do so in the following manner: 1. The common init function is put immediately after memory-to-be-initialized is allocated, followed by the specific data ref initialization. 2. The only piece of code that remains in the critical section is insert_delayed_ref call. 3. Tracing and memory freeing code is moved outside of the critical section. No functional changes, just an overall shorter critical section. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Open-code add_delayed_tree_refNikolay Borisov2018-05-281-45/+20
| | | | | | | | | | | | | | | | | | | | | | | Now that the initialization part and the critical section code have been split it's a lot easier to open code add_delayed_tree_ref. Do so in the following manner: 1. The comming init code is put immediately after memory-to-be-initialized is allocated, followed by the ref-specific member initialization. 2. The only piece of code that remains in the critical section is insert_delayed_ref call. 3. Tracing and memory freeing code is put outside of the critical section as well. The only real change here is an overall shorter critical section when dealing with delayed tree refs. From functional point of view - the code is unchanged. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Use init_delayed_ref_common in add_delayed_data_refNikolay Borisov2018-05-281-25/+10
| | | | | | | | | Use the newly introduced helper and remove the duplicate code. 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>
* btrfs: Use init_delayed_ref_common in add_delayed_tree_refNikolay Borisov2018-05-281-24/+11
| | | | | | | | Use the newly introduced common helper. 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>
* btrfs: Factor out common delayed refs init codeNikolay Borisov2018-05-281-0/+51
| | | | | | | | | | | THe majority of the init code for struct btrfs_delayed_ref_node is duplicated in add_delayed_data_ref and add_delayed_tree_ref. Factor out the common bits in init_delayed_ref_common. This function is going to be used in future patches to clean that up. 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>
* btrfs: Drop fs_info parameter from btrfs_merge_delayed_refsNikolay Borisov2018-05-281-1/+1
| | | | | | | It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Drop fs_info parameter from add_delayed_data_refNikolay Borisov2018-05-281-7/+5
| | | | | | | It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Drop add_delayed_ref_head fs_info parameterNikolay Borisov2018-05-281-11/+10
| | | | | | | It's provided by the transaction handle. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Drop delayed_refs argument from btrfs_check_delayed_seqNikolay Borisov2018-05-281-6/+3
| | | | | | | | | It's used to print its pointer in a debug statement but doesn't really bring any useful information to the error message. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Fix race condition between delayed refs and blockgroup removalNikolay Borisov2018-04-201-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the delayed refs for a head are all run, eventually cleanup_ref_head is called which (in case of deletion) obtains a reference for the relevant btrfs_space_info struct by querying the bg for the range. This is problematic because when the last extent of a bg is deleted a race window emerges between removal of that bg and the subsequent invocation of cleanup_ref_head. This can result in cache being null and either a null pointer dereference or assertion failure. task: ffff8d04d31ed080 task.stack: ffff9e5dc10cc000 RIP: 0010:assfail.constprop.78+0x18/0x1a [btrfs] RSP: 0018:ffff9e5dc10cfbe8 EFLAGS: 00010292 RAX: 0000000000000044 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8d04ffc1f868 RSI: ffff8d04ffc178c8 RDI: ffff8d04ffc178c8 RBP: ffff8d04d29e5ea0 R08: 00000000000001f0 R09: 0000000000000001 R10: ffff9e5dc0507d58 R11: 0000000000000001 R12: ffff8d04d29e5ea0 R13: ffff8d04d29e5f08 R14: ffff8d04efe29b40 R15: ffff8d04efe203e0 FS: 00007fbf58ead500(0000) GS:ffff8d04ffc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe6c6975648 CR3: 0000000013b2a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __btrfs_run_delayed_refs+0x10e7/0x12c0 [btrfs] btrfs_run_delayed_refs+0x68/0x250 [btrfs] btrfs_should_end_transaction+0x42/0x60 [btrfs] btrfs_truncate_inode_items+0xaac/0xfc0 [btrfs] btrfs_evict_inode+0x4c6/0x5c0 [btrfs] evict+0xc6/0x190 do_unlinkat+0x19c/0x300 do_syscall_64+0x74/0x140 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7fbf589c57a7 To fix this, introduce a new flag "is_system" to head_ref structs, which is populated at insertion time. This allows to decouple the querying for the spaceinfo from querying the possibly deleted bg. Fixes: d7eae3403f46 ("Btrfs: rework delayed ref total_bytes_pinned accounting") CC: stable@vger.kernel.org # 4.14+ Suggested-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: replace GPL boilerplate by SPDX -- sourcesDavid Sterba2018-04-121-14/+1
| | | | | | | | Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: use lockdep_assert_held for spinlocksDavid Sterba2018-03-311-3/+3
| | | | | | Using lockdep_assert_held is preferred, replace assert_spin_locked. Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: add more __cold annotationsDavid Sterba2018-03-261-1/+1
| | | | | | | | | | | | | | | | The __cold functions are placed to a special section, as they're expected to be called rarely. This could help i-cache prefetches or help compiler to decide which branches are more/less likely to be taken without any other annotations needed. Though we can't add more __exit annotations, it's still possible to add __cold (that's also added with __exit). That way the following function categories are tagged: - printf wrappers, error messages - exit helpers Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: Ignore errors from btrfs_qgroup_trace_extent_postNikolay Borisov2018-02-021-1/+2
| | | | | | | | | | | | | | | | | | Running generic/019 with qgroups on the scratch device enabled is almost guaranteed to trigger the BUG_ON in btrfs_free_tree_block. It's supposed to trigger only on -ENOMEM, in reality, however, it's possible to get -EIO from btrfs_qgroup_trace_extent_post. This function just finds the roots of the extent being tracked and sets the qrecord->old_roots list. If this operation fails nothing critical happens except the quota accounting can be considered wrong. In such case just set the INCONSISTENT flag for the quota and print a warning, rather than killing off the system. Additionally, it's possible to trigger a BUG_ON in btrfs_truncate_inode_items as well. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> [ error message adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: add __init macro to btrfs init functionsLiu Bo2018-01-221-1/+1
| | | | | | | | | | Adding __init macro gives kernel a hint that this function is only used during the initialization phase and its memory resources can be freed up after. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: track refs in a rb_tree instead of a listJosef Bacik2017-11-011-52/+56
| | | | | | | | | | | | | | | | | | If we get a significant amount of delayed refs for a single block (think modifying multiple snapshots) we can end up spending an ungodly amount of time looping through all of the entries trying to see if they can be merged. This is because we only add them to a list, so we have O(2n) for every ref head. This doesn't make any sense as we likely have refs for different roots, and so they cannot be merged. Tracking in a tree will allow us to break as soon as we hit an entry that doesn't match, making our worst case O(n). With this we can also merge entries more easily. Before we had to hope that matching refs were on the ends of our list, but with the tree we can search down to exact matches and merge them at insert time. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: add a comp_refs() helperJosef Bacik2017-11-011-24/+30
| | | | | | | | | Instead of open-coding the delayed ref comparisons, add a helper to do the comparisons generically and use that everywhere. We compare sequence numbers last for following patches. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: switch args for comp_*_refsJosef Bacik2017-11-011-4/+4
| | | | | | | | | | Make it more consistent, we want the inserted ref to be compared against what's already in there. This will make the order go from lowest seq -> highest seq, which will make us more likely to make forward progress if there's a seqlock currently held. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove type argument from comp_tree_refsJosef Bacik2017-10-301-6/+4
| | | | | | | | We can get this from the ref we've passed in. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: remove delayed_ref_node from ref_headJosef Bacik2017-10-301-72/+54
| | | | | | | | | | | This is just excessive information in the ref_head, and makes the code complicated. It is a relic from when we had the heads and the refs in the same tree, which is no longer the case. With this removal I've cleaned up a bunch of the cruft around this old assumption as well. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: return old and new total ref mods when adding delayed refsOmar Sandoval2017-06-291-8/+21
| | | | | | | | We need this to decide when to account pinned bytes. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: convert btrfs_delayed_ref_node.refs from atomic_t to refcount_tElena Reshetova2017-04-181-4/+4
| | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: qgroup: Move half of the qgroup accounting time out of commit transQu Wenruo2017-02-171-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just as Filipe pointed out, the most time consuming parts of qgroup are btrfs_qgroup_account_extents() and btrfs_qgroup_prepare_account_extents(). Which both call btrfs_find_all_roots() to get old_roots and new_roots ulist. What makes things worse is, we're calling that expensive btrfs_find_all_roots() at transaction committing time with TRANS_STATE_COMMIT_DOING, which will blocks all incoming transaction. Such behavior is necessary for @new_roots search as current btrfs_find_all_roots() can't do it correctly so we do call it just before switch commit roots. However for @old_roots search, it's not necessary as such search is based on commit_root, so it will always be correct and we can move it out of transaction committing. This patch moves the @old_roots search part out of commit_transaction(), so in theory we can half the time qgroup time consumption at commit_transaction(). But please note that, this won't speedup qgroup overall, the total time consumption is still the same, just reduce the performance stall. Cc: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: pass delayed_refs directly to btrfs_find_delayed_ref_headLiu Bo2017-02-141-4/+1
| | | | | | | | | | All we need is @delayed_refs, all callers have get it ahead of calling btrfs_find_delayed_ref_head since lock needs to be acquired firstly, there is no reason to deference it again inside the function. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: drop unused extent_op arg from btrfs_add_delayed_data_refJeff Mahoney2017-02-141-4/+2
| | | | | | | | | btrfs_add_delayed_data_ref is always called with a NULL extent_op, so let's drop the argument. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: improve delayed refs iterationsWang Xiaoguang2016-11-301-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This issue was found when I tried to delete a heavily reflinked file, when deleting such files, other transaction operation will not have a chance to make progress, for example, start_transaction() will blocked in wait_current_trans(root) for long time, sometimes it even triggers soft lockups, and the time taken to delete such heavily reflinked file is also very large, often hundreds of seconds. Using perf top, it reports that: PerfTop: 7416 irqs/sec kernel:99.8% exact: 0.0% [4000Hz cpu-clock], (all, 4 CPUs) --------------------------------------------------------------------------------------- 84.37% [btrfs] [k] __btrfs_run_delayed_refs.constprop.80 11.02% [kernel] [k] delay_tsc 0.79% [kernel] [k] _raw_spin_unlock_irq 0.78% [kernel] [k] _raw_spin_unlock_irqrestore 0.45% [kernel] [k] do_raw_spin_lock 0.18% [kernel] [k] __slab_alloc It seems __btrfs_run_delayed_refs() took most cpu time, after some debug work, I found it's select_delayed_ref() causing this issue, for a delayed head, in our case, it'll be full of BTRFS_DROP_DELAYED_REF nodes, but select_delayed_ref() will firstly try to iterate node list to find BTRFS_ADD_DELAYED_REF nodes, obviously it's a disaster in this case, and waste much time. To fix this issue, we introduce a new ref_add_list in struct btrfs_delayed_ref_head, then in select_delayed_ref(), if this list is not empty, we can directly use nodes in this list. With this patch, it just took about 10~15 seconds to delte the same file. Now using perf top, it reports that: PerfTop: 2734 irqs/sec kernel:99.5% exact: 0.0% [4000Hz cpu-clock], (all, 4 CPUs) ---------------------------------------------------------------------------------------- 20.74% [kernel] [k] _raw_spin_unlock_irqrestore 16.33% [kernel] [k] __slab_alloc 5.41% [kernel] [k] lock_acquired 4.42% [kernel] [k] lock_acquire 4.05% [kernel] [k] lock_release 3.37% [kernel] [k] _raw_spin_unlock_irq For normal files, this patch also gives help, at least we do not need to iterate whole list to found BTRFS_ADD_DELAYED_REF nodes. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: qgroup: Rename functions to make it follow reserve,trace,account stepsQu Wenruo2016-11-301-1/+1
| | | | | | | | | | Rename btrfs_qgroup_insert_dirty_extent(_nolock) to btrfs_qgroup_trace_extent(_nolock), according to the new reserve/trace/account naming schema. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: convert pr_* to btrfs_* where possibleJeff Mahoney2016-09-261-4/+5
| | | | | | | | | | | | | | For many printks, we want to know which file system issued the message. This patch converts most pr_* calls to use the btrfs_* versions instead. In some cases, this means adding plumbing to allow call sites access to an fs_info pointer. fs/btrfs/check-integrity.c is left alone for another day. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* Btrfs: add a flags field to btrfs_fs_infoJosef Bacik2016-09-261-2/+4
| | | | | | | | | | | We have a lot of random ints in btrfs_fs_info that can be put into flags. This is mostly equivalent with the exception of how we deal with quota going on or off, now instead we set a flag when we are turning it on or off and deal with that appropriately, rather than just having a pending state that the current quota_enabled gets set to. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent()Qu Wenruo2016-08-251-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor btrfs_qgroup_insert_dirty_extent() function, to two functions: 1. btrfs_qgroup_insert_dirty_extent_nolock() Almost the same with original code. For delayed_ref usage, which has delayed refs locked. Change the return value type to int, since caller never needs the pointer, but only needs to know if they need to free the allocated memory. 2. btrfs_qgroup_insert_dirty_extent() The more encapsulated version. Will do the delayed_refs lock, memory allocation, quota enabled check and other things. The original design is to keep exported functions to minimal, but since more btrfs hacks exposed, like replacing path in balance, we need to record dirty extents manually, so we have to add such functions. Also, add comment for both functions, to info developers how to keep qgroup correct when doing hacks. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* Merge branch 'integration-4.8' of ↵Chris Mason2016-08-051-27/+0
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.8
| * Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve()Filipe Manana2016-08-031-27/+0
| | | | | | | | | | | | | | No longer used as of commit 5846a3c26873 ("btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans"). Signed-off-by: Filipe Manana <fdmanana@suse.com>
* | btrfs: prefix fsid to all trace eventsJeff Mahoney2016-07-261-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | When using trace events to debug a problem, it's impossible to determine which file system generated a particular event. This patch adds a macro to prefix standard information to the head of a trace event. The extent_state alloc/free events are all that's left without an fs_info available. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | btrfs: Fix slab accounting flagsNikolay Borisov2016-07-261-4/+4
|/ | | | | | | | | | | | | | | | | | | BTRFS is using a variety of slab caches to satisfy internal needs. Those slab caches are always allocated with the SLAB_RECLAIM_ACCOUNT, meaning allocations from the caches are going to be accounted as SReclaimable. At the same time btrfs is not registering any shrinkers whatsoever, thus preventing memory from the slabs to be shrunk. This means those caches are not in fact reclaimable. To fix this remove the SLAB_RECLAIM_ACCOUNT on all caches apart from the inode cache, since this one is being freed by the generic VFS super_block shrinker. Also set the transaction related caches as SLAB_TEMPORARY, to better document the lifetime of the objects (it just translates to SLAB_RECLAIM_ACCOUNT). Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: drop null testing before destroy functionsKinglong Mee2016-02-181-8/+4
| | | | | | | | | | Cleanup. kmem_cache_destroy has support NULL argument checking, so drop the double null testing before calling it. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: better packing of btrfs_delayed_extent_opDavid Sterba2016-01-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | btrfs_delayed_extent_op can be packed in a better way, it's 40 bytes now and has 8 unused bytes. Reducing the level type to u8 makes it possible to squeeze it to the padding byte after key. The bitfields were switched to bool as there's space to store the full byte without increasing the whole structure, besides that the generated assembly is smaller. struct btrfs_delayed_extent_op { struct btrfs_disk_key key; /* 0 17 */ u8 level; /* 17 1 */ bool update_key; /* 18 1 */ bool update_flags; /* 19 1 */ bool is_data; /* 20 1 */ /* XXX 3 bytes hole, try to pack */ u64 flags_to_set; /* 24 8 */ /* size: 32, cachelines: 1, members: 6 */ /* sum members: 29, holes: 1, sum holes: 3 */ /* last cacheline: 32 bytes */ }; The final size is 32 bytes which gives +26 object per slab page. text data bss dec hex filename 938811 43670 23144 1005625 f5839 fs/btrfs/btrfs.ko.before 938747 43670 23144 1005561 f57f9 fs/btrfs/btrfs.ko.after Signed-off-by: David Sterba <dsterba@suse.com>
* btrfs: qgroup: Fix a race in delayed_ref which leads to abort transQu Wenruo2015-10-261-5/+17
| | | | | | | | | | | | | | | | | Between btrfs_allocerved_file_extent() and btrfs_add_delayed_qgroup_reserve(), there is a window that delayed_refs are run and delayed ref head maybe freed before btrfs_add_delayed_qgroup_reserve(). This will cause btrfs_dad_delayed_qgroup_reserve() to return -ENOENT, and cause transaction to be aborted. This patch will record qgroup reserve space info into delayed_ref_head at btrfs_add_delayed_ref(), to eliminate the race window. Reported-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix regression running delayed references when using qgroupsFilipe Manana2015-10-251-20/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the kernel 4.2 merge window we had a big changes to the implementation of delayed references and qgroups which made the no_quota field of delayed references not used anymore. More specifically the no_quota field is not used anymore as of: commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.") Leaving the no_quota field actually prevents delayed references from getting merged, which in turn cause the following BUG_ON(), at fs/btrfs/extent-tree.c, to be hit when qgroups are enabled: static int run_delayed_tree_ref(...) { (...) BUG_ON(node->ref_mod != 1); (...) } This happens on a scenario like the following: 1) Ref1 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. 2) Ref2 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with Ref1 because Ref1->no_quota != Ref2->no_quota. 3) Ref3 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref2 is incompatible due to Ref2->no_quota != Ref3->no_quota. 4) Ref4 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref3 is incompatible due to Ref3->no_quota != Ref4->no_quota. 5) We run delayed references, trigger merging of delayed references, through __btrfs_run_delayed_refs() -> btrfs_merge_delayed_refs(). 6) Ref1 and Ref3 are merged as Ref1->no_quota = Ref3->no_quota and all other conditions are satisfied too. So Ref1 gets a ref_mod value of 2. 7) Ref2 and Ref4 are merged as Ref2->no_quota = Ref4->no_quota and all other conditions are satisfied too. So Ref2 gets a ref_mod value of 2. 8) Ref1 and Ref2 aren't merged, because they have different values for their no_quota field. 9) Delayed reference Ref1 is picked for running (select_delayed_ref() always prefers references with an action == BTRFS_ADD_DELAYED_REF). So run_delayed_tree_ref() is called for Ref1 which triggers the BUG_ON because Ref1->red_mod != 1 (equals 2). So fix this by removing the no_quota field, as it's not used anymore as of commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism."). The use of no_quota was also buggy in at least two places: 1) At delayed-refs.c:btrfs_add_delayed_tree_ref() - we were setting no_quota to 0 instead of 1 when the following condition was true: is_fstree(ref_root) || !fs_info->quota_enabled 2) At extent-tree.c:__btrfs_inc_extent_ref() - we were attempting to reset a node's no_quota when the condition "!is_fstree(root_objectid) || !root->fs_info->quota_enabled" was true but we did it only in an unused local stack variable, that is, we never reset the no_quota value in the node itself. This fixes the remainder of problems several people have been having when running delayed references, mostly while a balance is running in parallel, on a 4.2+ kernel. Very special thanks to Stéphane Lesimple for helping debugging this issue and testing this fix on his multi terabyte filesystem (which took more than one day to balance alone, plus fsck, etc). Also, this fixes deadlock issue when using the clone ioctl with qgroups enabled, as reported by Elias Probst in the mailing list. The deadlock happens because after calling btrfs_insert_empty_item we have our path holding a write lock on a leaf of the fs/subvol tree and then before releasing the path we called check_ref() which did backref walking, when qgroups are enabled, and tried to read lock the same leaf. The trace for this case is the following: INFO: task systemd-nspawn:6095 blocked for more than 120 seconds. (...) Call Trace: [<ffffffff86999201>] schedule+0x74/0x83 [<ffffffff863ef64c>] btrfs_tree_read_lock+0xc0/0xea [<ffffffff86137ed7>] ? wait_woken+0x74/0x74 [<ffffffff8639f0a7>] btrfs_search_old_slot+0x51a/0x810 [<ffffffff863a129b>] btrfs_next_old_leaf+0xdf/0x3ce [<ffffffff86413a00>] ? ulist_add_merge+0x1b/0x127 [<ffffffff86411688>] __resolve_indirect_refs+0x62a/0x667 [<ffffffff863ef546>] ? btrfs_clear_lock_blocking_rw+0x78/0xbe [<ffffffff864122d3>] find_parent_nodes+0xaf3/0xfc6 [<ffffffff86412838>] __btrfs_find_all_roots+0x92/0xf0 [<ffffffff864128f2>] btrfs_find_all_roots+0x45/0x65 [<ffffffff8639a75b>] ? btrfs_get_tree_mod_seq+0x2b/0x88 [<ffffffff863e852e>] check_ref+0x64/0xc4 [<ffffffff863e9e01>] btrfs_clone+0x66e/0xb5d [<ffffffff863ea77f>] btrfs_ioctl_clone+0x48f/0x5bb [<ffffffff86048a68>] ? native_sched_clock+0x28/0x77 [<ffffffff863ed9b0>] btrfs_ioctl+0xabc/0x25cb (...) The problem goes away by eleminating check_ref(), which no longer is needed as its purpose was to get a value for the no_quota field of a delayed reference (this patch removes the no_quota field as mentioned earlier). Reported-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Tested-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Reported-by: Elias Probst <mail@eliasprobst.eu> Reported-by: Peter Becker <floyd.net@gmail.com> Reported-by: Malte Schröder <malte@tnxip.de> Reported-by: Derek Dongray <derek@valedon.co.uk> Reported-by: Erkki Seppala <flux-btrfs@inside.org> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
* Btrfs: fix regression when running delayed referencesFilipe Manana2015-10-251-0/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the kernel 4.2 merge window we had a refactoring/rework of the delayed references implementation in order to fix certain problems with qgroups. However that rework introduced one more regression that leads to the following trace when running delayed references for metadata: [35908.064664] kernel BUG at fs/btrfs/extent-tree.c:1832! [35908.065201] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [35908.065201] Modules linked in: dm_flakey dm_mod btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc psmouse i2 [35908.065201] CPU: 14 PID: 15014 Comm: kworker/u32:9 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [35908.065201] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [35908.065201] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs] [35908.065201] task: ffff880114b7d780 ti: ffff88010c4c8000 task.ti: ffff88010c4c8000 [35908.065201] RIP: 0010:[<ffffffffa04928b5>] [<ffffffffa04928b5>] insert_inline_extent_backref+0x52/0xb1 [btrfs] [35908.065201] RSP: 0018:ffff88010c4cbb08 EFLAGS: 00010293 [35908.065201] RAX: 0000000000000000 RBX: ffff88008a661000 RCX: 0000000000000000 [35908.065201] RDX: ffffffffa04dd58f RSI: 0000000000000001 RDI: 0000000000000000 [35908.065201] RBP: ffff88010c4cbb40 R08: 0000000000001000 R09: ffff88010c4cb9f8 [35908.065201] R10: 0000000000000000 R11: 000000000000002c R12: 0000000000000000 [35908.065201] R13: ffff88020a74c578 R14: 0000000000000000 R15: 0000000000000000 [35908.065201] FS: 0000000000000000(0000) GS:ffff88023edc0000(0000) knlGS:0000000000000000 [35908.065201] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [35908.065201] CR2: 00000000015e8708 CR3: 0000000102185000 CR4: 00000000000006e0 [35908.065201] Stack: [35908.065201] ffff88010c4cbb18 0000000000000f37 ffff88020a74c578 ffff88015a408000 [35908.065201] ffff880154a44000 0000000000000000 0000000000000005 ffff88010c4cbbd8 [35908.065201] ffffffffa0492b9a 0000000000000005 0000000000000000 0000000000000000 [35908.065201] Call Trace: [35908.065201] [<ffffffffa0492b9a>] __btrfs_inc_extent_ref+0x8b/0x208 [btrfs] [35908.065201] [<ffffffffa0497117>] ? __btrfs_run_delayed_refs+0x4d4/0xd33 [btrfs] [35908.065201] [<ffffffffa049773d>] __btrfs_run_delayed_refs+0xafa/0xd33 [btrfs] [35908.065201] [<ffffffffa04a976a>] ? join_transaction.isra.10+0x25/0x41f [btrfs] [35908.065201] [<ffffffffa04a97ed>] ? join_transaction.isra.10+0xa8/0x41f [btrfs] [35908.065201] [<ffffffffa049914d>] btrfs_run_delayed_refs+0x75/0x1dd [btrfs] [35908.065201] [<ffffffffa04992f1>] delayed_ref_async_start+0x3c/0x7b [btrfs] [35908.065201] [<ffffffffa04d4b4f>] normal_work_helper+0x14c/0x32a [btrfs] [35908.065201] [<ffffffffa04d4e93>] btrfs_extent_refs_helper+0x12/0x14 [btrfs] [35908.065201] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac [35908.065201] [<ffffffff81064285>] worker_thread+0x206/0x2c2 [35908.065201] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [35908.065201] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb [35908.065201] [<ffffffff8106904d>] kthread+0xef/0xf7 [35908.065201] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [35908.065201] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70 [35908.065201] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24 [35908.065201] Code: 6a 01 41 56 41 54 ff 75 10 41 51 4d 89 c1 49 89 c8 48 8d 4d d0 e8 f6 f1 ff ff 48 83 c4 28 85 c0 75 2c 49 81 fc ff 00 00 00 77 02 <0f> 0b 4c 8b 45 30 8b 4d 28 45 31 [35908.065201] RIP [<ffffffffa04928b5>] insert_inline_extent_backref+0x52/0xb1 [btrfs] [35908.065201] RSP <ffff88010c4cbb08> [35908.310885] ---[ end trace fe4299baf0666457 ]--- This happens because the new delayed references code no longer merges delayed references that have different sequence values. The following steps are an example sequence leading to this issue: 1) Transaction N starts, fs_info->tree_mod_seq has value 0; 2) Extent buffer (btree node) A is allocated, delayed reference Ref1 for bytenr A is created, with a value of 1 and a seq value of 0; 3) fs_info->tree_mod_seq is incremented to 1; 4) Extent buffer A is deleted through btrfs_del_items(), which calls btrfs_del_leaf(), which in turn calls btrfs_free_tree_block(). The later returns the metadata extent associated to extent buffer A to the free space cache (the range is not pinned), because the extent buffer was created in the current transaction (N) and writeback never happened for the extent buffer (flag BTRFS_HEADER_FLAG_WRITTEN not set in the extent buffer). This creates the delayed reference Ref2 for bytenr A, with a value of -1 and a seq value of 1; 5) Delayed reference Ref2 is not merged with Ref1 when we create it, because they have different sequence numbers (decided at add_delayed_ref_tail_merge()); 6) fs_info->tree_mod_seq is incremented to 2; 7) Some task attempts to allocate a new extent buffer (done at extent-tree.c:find_free_extent()), but due to heavy fragmentation and running low on metadata space the clustered allocation fails and we fall back to unclustered allocation, which finds the extent at offset A, so a new extent buffer at offset A is allocated. This creates delayed reference Ref3 for bytenr A, with a value of 1 and a seq value of 2; 8) Ref3 is not merged neither with Ref2 nor Ref1, again because they all have different seq values; 9) We start running the delayed references (__btrfs_run_delayed_refs()); 10) The delayed Ref1 is the first one being applied, which ends up creating an inline extent backref in the extent tree; 10) Next the delayed reference Ref3 is selected for execution, and not Ref2, because select_delayed_ref() always gives a preference for positive references (that have an action of BTRFS_ADD_DELAYED_REF); 11) When running Ref3 we encounter alreay the inline extent backref in the extent tree at insert_inline_extent_backref(), which makes us hit the following BUG_ON: BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID); This is always true because owner corresponds to the level of the extent buffer/btree node in the btree. For the scenario described above we hit the BUG_ON because we never merge references that have different seq values. We used to do the merging before the 4.2 kernel, more specifically, before the commmits: c6fc24549960 ("btrfs: delayed-ref: Use list to replace the ref_root in ref_head.") c43d160fcd5e ("btrfs: delayed-ref: Cleanup the unneeded functions.") This issue became more exposed after the following change that was added to 4.2 as well: cffc3374e567 ("Btrfs: fix order by which delayed references are run") Which in turn fixed another regression by the two commits previously mentioned. So fix this by bringing back the delayed reference merge code, with the proper adaptations so that it operates against the new data structure (linked list vs old red black tree implementation). This issue was hit running fstest btrfs/063 in a loop. Several people have reported this issue in the mailing list when running on kernels 4.2+. Very special thanks to Stéphane Lesimple for helping debugging this issue and testing this fix on his multi terabyte filesystem (which took more than one day to balance alone, plus fsck, etc). Fixes: c6fc24549960 ("btrfs: delayed-ref: Use list to replace the ref_root in ref_head.") Reported-by: Peter Becker <floyd.net@gmail.com> Reported-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Tested-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Reported-by: Malte Schröder <malte@tnxip.de> Reported-by: Derek Dongray <derek@valedon.co.uk> Reported-by: Erkki Seppala <flux-btrfs@inside.org> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
* btrfs: delayed_ref: Add new function to record reserved space into delayed refQu Wenruo2015-10-211-0/+29
| | | | | | | | | | | | | Add new function btrfs_add_delayed_qgroup_reserve() function to record how much space is reserved for that extent. As btrfs only accounts qgroup at run_delayed_refs() time, so newly allocated extent should keep the reserved space until then. So add needed function with related members to do it. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref()Dan Carpenter2015-06-241-9/+11
| | | | | | | | | There is a cut and paste error so instead of freeing "head_ref", we free "ref" twice. Fixes: 3368d001ba5d ('btrfs: qgroup: Record possible quota-related extent for qgroup.') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: qgroup: Record possible quota-related extent for qgroup.Qu Wenruo2015-06-101-7/+43
| | | | | | | | | Add hook in add_delayed_ref_head() to record quota-related extent record into delayed_ref_root->dirty_extent_record rb-tree for later qgroup accounting. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: delayed-ref: Cleanup the unneeded functions.Qu Wenruo2015-06-101-174/+0
| | | | | | | | Cleanup the rb_tree merge/insert/update functions, since now we use list instead of rb_tree now. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: delayed-ref: Use list to replace the ref_root in ref_head.Qu Wenruo2015-06-101-74/+82
| | | | | | | | | | | | | This patch replace the rbtree used in ref_head to list. This has the following advantage: 1) Easier merge logic. With the new list implement, we only need to care merging the tail ref_node with the new ref_node. And this can be done quite easy at insert time, no need to do a indicated merge at run_delayed_refs(). Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: account for crcs in delayed ref processingJosef Bacik2015-04-101-2/+20
| | | | | | | | | | | | | As we delete large extents, we end up doing huge amounts of COW in order to delete the corresponding crcs. This adds accounting so that we keep track of that space and flushing of delayed refs so that we don't build up too much delayed crc work. This helps limit the delayed work that must be done at commit time and tries to avoid ENOSPC aborts because the crcs eat all the global reserves. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: rework qgroup accountingJosef Bacik2014-06-091-16/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently qgroups account for space by intercepting delayed ref updates to fs trees. It does this by adding sequence numbers to delayed ref updates so that it can figure out how the tree looked before the update so we can adjust the counters properly. The problem with this is that it does not allow delayed refs to be merged, so if you say are defragging an extent with 5k snapshots pointing to it we will thrash the delayed ref lock because we need to go back and manually merge these things together. Instead we want to process quota changes when we know they are going to happen, like when we first allocate an extent, we free a reference for an extent, we add new references etc. This patch accomplishes this by only adding qgroup operations for real ref changes. We only modify the sequence number when we need to lookup roots for bytenrs, this reduces the amount of churn on the sequence number and allows us to merge delayed refs as we add them most of the time. This patch encompasses a bunch of architectural changes 1) qgroup ref operations: instead of tracking qgroup operations through the delayed refs we simply add new ref operations whenever we notice that we need to when we've modified the refs themselves. 2) tree mod seq: we no longer have this separation of major/minor counters. this makes the sequence number stuff much more sane and we can remove some locking that was needed to protect the counter. 3) delayed ref seq: we now read the tree mod seq number and use that as our sequence. This means each new delayed ref doesn't have it's own unique sequence number, rather whenever we go to lookup backrefs we inc the sequence number so we can make sure to keep any new operations from screwing up our world view at that given point. This allows us to merge delayed refs during runtime. With all of these changes the delayed ref stuff is a little saner and the qgroup accounting stuff no longer goes negative in some cases like it was before. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix race when updating existing ref headFilipe Manana2014-03-201-1/+1
| | | | | | | | | | | While we update an existing ref head's extent_op, we're not holding its spinlock, so while we're updating its extent_op contents (key, flags) we can have a task running __btrfs_run_delayed_refs() that holds the ref head's lock and sets its extent_op to NULL right after the task updating the ref head just checked its extent_op was not NULL. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-27 12:22:07 +0000