- 25 Oct, 2015 1 commit
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Filipe Manana authored
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: c6fc2454 ("btrfs: delayed-ref: Use list to replace the ref_root in ref_head.") c43d160f ("btrfs: delayed-ref: Cleanup the unneeded functions.") This issue became more exposed after the following change that was added to 4.2 as well: cffc3374 ("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: c6fc2454 ("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:
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>
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- 22 Oct, 2015 35 commits
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Chris Mason authored
Signed-off-by:Chris Mason <clm@fb.com>
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Josef Bacik authored
When we make ctl->unit allocations from a bitmap there is no point in searching for the next 0 in the bitmap. If we've found a bit we're done and can just exit the loop. Thanks, Signed-off-by:
Josef Bacik <jbacik@fb.com> Signed-off-by:
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Josef Bacik authored
We can waste a lot of time searching through bitmaps when we are heavily fragmented trying to find large contiguous areas that don't exist in the bitmap. So keep track of the max extent size when we do a full search of a bitmap so that next time around we can just skip the expensive searching if our max size is less than what we are looking for. Thanks, Signed-off-by:
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Josef Bacik authored
If we are extremely fragmented then we won't be able to create a free_cluster. So if this happens set last_ptr->fragmented so that all future allcations will give up trying to create a cluster. When we unpin extents we will unset ->fragmented if we free up a sufficient amount of space in a block group. Thanks, Signed-off-by:
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Josef Bacik authored
We try really really hard to make allocations, but sometimes it is just not going to happen, especially when free space is extremely fragmented. So add a few short cuts through the looping states. For example if we couldn't allocate a chunk, just go straight to the NO_EMPTY_SIZE loop. If there are no uncached block groups and we've done a full search, go straight to the ALLOC_CHUNK stage. And finally if we already have empty_size and empty_cluster set to 0 go ahead and return -ENOSPC. Thanks, Signed-off-by:
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Josef Bacik authored
If we hit ENOSPC when setting up a space cache don't bother setting up any of the other space cache's in this transaction, it'll just induce unnecessary latency. Thanks, Signed-off-by:
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Josef Bacik authored
When we are heavily fragmented we can induce a lot of latency trying to make an allocation happen that is simply not going to happen. Thankfully we keep track of our max_extent_size when going through the allocator, so if we get to the point where we are exiting find_free_extent with ENOSPC then set our space_info->max_extent_size so we can keep future allocations from having to pay this cost. We reset the max_extent_size whenever we release pinned bytes back into this space info so we can redo all the work. Thanks, Signed-off-by:
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Josef Bacik authored
The space cache needs to have contiguous allocations, and the allocator tries to make allocations by reducing the amount of bytes requested and re-searching. But this just makes us waste time when we are very fragmented, so if we can't find our space just exit, don't bother trying to search again. Thanks, Signed-off-by:
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Josef Bacik authored
I want to set some per transaction flags, so instead of adding yet another int lets just convert the current two int indicators to flags and add a flags field for future use. Thanks, Signed-off-by:
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Josef Bacik authored
If we are heavily fragmented we will continually try to prealloc the largest extent size we can every time we call btrfs_reserve_extent. This can be very expensive when we are heavily fragmented, burning lots of CPU cycles and loops through the allocator. So instead notice when we get a smaller chunk from the allocator than what we specified and use this as the new maximum size we try to allocate. Thanks, Signed-off-by:
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Josef Bacik authored
In tracking down these weird bitmap problems it was helpful to artificially create an extremely fragmented file system. These mount options let us either fragment data or metadata or both. With these options I could reproduce all sorts of weird latencies and hangs that occur under extreme fragmentation and get them fixed. Thanks, Signed-off-by:
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Josef Bacik authored
With my changes to allow us to find old roots when resolving indirect refs I introduced a regression to the sanity tests. Since we don't really care to go down into the fs roots we just need to have the old behavior of returning ENOENT for dummy roots for the sanity tests. In the future if we want to get fancy we can populate the test fs trees with the references as well. Thanks, Signed-off-by:
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Josef Bacik authored
We have a mechanism to make sure we don't lose updates for ordered extents that were logged in the transaction that is currently running. We add the ordered extent to a transaction list and then the transaction waits on all the ordered extents in that list. However are substantially large file systems this list can be extremely large, and can give us soft lockups, since the ordered extents don't remove themselves from the list when they do complete. To fix this we simply add a counter to the transaction that is incremented any time we have a logged extent that needs to be completed in the current transaction. Then when the ordered extent finally completes it decrements the per transaction counter and wakes up the transaction if we are the last ones. This will eliminate the softlockup. Thanks, Signed-off-by:
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Qu Wenruo authored
Add check at btrfs_destroy_inode() time to detect qgroup reserved space leak. Signed-off-by:
Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by:
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Qu Wenruo authored
In clear_bit_hook, qgroup reserved data is already handled quite well, either released by finish_ordered_io or invalidatepage. So calling btrfs_qgroup_free_data() here is completely meaningless, and since btrfs_qgroup_free_data() will lock io_tree, so it can't be called with io_tree lock hold. This patch will add a new function btrfs_free_reserved_data_space_noquota() for clear_bit_hook() to cease the lockdep warning. Signed-off-by:
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Qu Wenruo authored
Now fallocate will do accurate qgroup reserve space check, unlike old method, which will always reserve the whole length of the range. With this patch, fallocate will: 1) Iterate the desired range and mark in data rsv map Only range which is going to be allocated will be recorded in data rsv map and reserve the space. For already allocated range (normal/prealloc extent) they will be skipped. Also, record the marked range into a new list for later use. 2) If 1) succeeded, do real file extent allocate. And at file extent allocation time, corresponding range will be removed from the range in data rsv map. Signed-off-by:
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Qu Wenruo authored
Now each qgroup reserve for data will has its ftrace event for better debugging. Signed-off-by:
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Qu Wenruo authored
For btrfs_invalidatepage() and its variant evict_inode_truncate_page(), there will be pages don't reach disk. In that case, their reserved space won't be release nor freed by finish_ordered_io() nor delayed_ref handler. So we must free their qgroup reserved space, or we will leaking reserved space again. So this will patch will call btrfs_qgroup_free_data() for invalidatepage() and its variant evict_inode_truncate_page(). And due to the nature of new btrfs_qgroup_reserve/free_data() reserved space will only be reserved or freed once, so for pages which are already flushed to disk, their reserved space will be released and freed by delayed_ref handler. Double free won't be a problem. Signed-off-by:
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Qu Wenruo authored
For NOCOW and inline case, there will be no delayed_ref created for them, so we should free their reserved data space at proper time(finish_ordered_io for NOCOW and cow_file_inline for inline). Signed-off-by:
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Qu Wenruo authored
Cleanup the old facilities which use old btrfs_qgroup_reserve() function call, replace them with the newer version, and remove the "__" prefix in them. Also, make btrfs_qgroup_reserve/free() functions private, as they are now only used inside qgroup codes. Now, the whole btrfs qgroup is swithed to use the new reserve facilities. Signed-off-by:
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Qu Wenruo authored
Use new __btrfs_delalloc_reserve_space() and __btrfs_delalloc_release_space() to reserve and release space for delalloc. Signed-off-by:
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Qu Wenruo authored
Add new version of btrfs_delalloc_reserve_space() and btrfs_delalloc_release_space() functions, which supports accurate qgroup reserve. Signed-off-by:
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Qu Wenruo authored
Use new reserve/free for buffered write and inode cache. For buffered write case, as nodatacow write won't increase quota account, so unlike old behavior which does reserve before check nocow, now we check nocow first and then only reserve data if we can't do nocow write. Signed-off-by:
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Qu Wenruo authored
btrfs: extent-tree: Add new version of btrfs_check_data_free_space and btrfs_free_reserved_data_space. Add new functions __btrfs_check_data_free_space() and __btrfs_free_reserved_data_space() to work with new accurate qgroup reserved space framework. The new function will replace old btrfs_check_data_free_space() and btrfs_free_reserved_data_space() respectively, but until all the change is done, let's just use the new name. Also, export internal use function btrfs_alloc_data_chunk_ondemand(), as now qgroup reserve requires precious bytes, some operation can't get the accurate number in advance(like fallocate). But data space info check and data chunk allocate doesn't need to be that accurate, and can be called at the beginning. So export it for later operations. Signed-off-by:
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Qu Wenruo authored
As we have the new metadata reservation functions, use them to replace the old btrfs_qgroup_reserve() call for metadata. Signed-off-by:
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Qu Wenruo authored
Introduce new functions btrfs_qgroup_reserve/free_meta() to reserve/free metadata reserved space. Signed-off-by:
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Qu Wenruo authored
Qgroup reserved space needs to be released from inode dirty map and get freed at different timing: 1) Release when the metadata is written into tree After corresponding metadata is written into tree, any newer write will be COWed(don't include NOCOW case yet). So we must release its range from inode dirty range map, or we will forget to reserve needed range, causing accounting exceeding the limit. 2) Free reserved bytes when delayed ref is run When delayed refs are run, qgroup accounting will follow soon and turn the reserved bytes into rfer/excl numbers. As run_delayed_refs and qgroup accounting are all done at commit_transaction() time, we are safe to free reserved space in run_delayed_ref time(). With these timing to release/free reserved space, we should be able to resolve the long existing qgroup reserve space leak problem. Signed-off-by:
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Qu Wenruo authored
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:
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Qu Wenruo authored
space Introduce functions btrfs_qgroup_release/free_data() to release/free reserved data range. Release means, just remove the data range from io_tree, but doesn't free the reserved space. This is for normal buffered write case, when data is written into disc and its metadata is added into tree, its reserved space should still be kept until commit_trans(). So in that case, we only release dirty range, but keep the reserved space recorded some other place until commit_tran(). Free means not only remove data range, but also free reserved space. This is used for case for cleanup and invalidate page. Signed-off-by:
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Qu Wenruo authored
Introduce a new function, btrfs_qgroup_reserve_data(), which will use io_tree to accurate qgroup reserve, to avoid reserved space leaking. Signed-off-by:
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Qu Wenruo authored
Introduce new function clear_record_extent_bits(), which will clear bits for given range and record the details about which ranges are cleared and how many bytes in total it changes. This provides the basis for later qgroup reserve codes. Signed-off-by:
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Qu Wenruo authored
Introduce new function set_record_extent_bits(), which will not only set given bits, but also record how many bytes are changed, and detailed range info. This is quite important for later qgroup reserve framework. The number of bytes will be used to do qgroup reserve, and detailed range info will be used to cleanup for EQUOT case. Signed-off-by:
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Qu Wenruo authored
Add a new structure, extent_change_set, to record how many bytes are changed in one set/clear_extent_bits() operation, with detailed changed ranges info. This provides the needed facilities for later qgroup reserve framework. Signed-off-by:
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Chris Mason authored
Merge branch 'integration-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.4
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Chris Mason authored
Merge branch 'cleanups/for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.4
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- 21 Oct, 2015 4 commits
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Luis de Bethencourt authored
reada is using -1 instead of the -ENOMEM defined macro to specify that a buffer allocation failed. Since the error number is propagated, the caller will get a -EPERM which is the wrong error condition. Also, updating the caller to return the exact value from reada_add_block. Smatch tool warning: reada_add_block() warn: returning -1 instead of -ENOMEM is sloppy Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by:
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Luis de Bethencourt authored
check-integrity is using -1 instead of the -ENOMEM defined macro to specify that a buffer allocation failed. Since the error number is propagated, the caller will get a -EPERM which is the wrong error condition. Also, the smatch tool complains with the following warnings: btrfsic_process_superblock() warn: returning -1 instead of -ENOMEM is sloppy btrfsic_read_block() warn: returning -1 instead of -ENOMEM is sloppy Reviewed-by:
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Byongho Lee authored
Below variables are defined per compress type. - struct list_head comp_idle_workspace[BTRFS_COMPRESS_TYPES] - spinlock_t comp_workspace_lock[BTRFS_COMPRESS_TYPES] - int comp_num_workspace[BTRFS_COMPRESS_TYPES] - atomic_t comp_alloc_workspace[BTRFS_COMPRESS_TYPES] - wait_queue_head_t comp_workspace_wait[BTRFS_COMPRESS_TYPES] BTW, while accessing one compress type of these variables, the next or before address is other compress types of it. So this patch puts these variables in a struct to make cache friendly. Reviewed-by:
Byongho Lee <bhlee.kernel@gmail.com> Signed-off-by:
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Byongho Lee authored
This patch eliminates the last item of prop_handlers array which is used to check end of array and instead uses ARRAY_SIZE macro. Though this is a very tiny optimization, using ARRAY_SIZE macro is a good practice to iterate array. Reviewed-by:
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