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2019-06-11btrfs: Honour FITRIM range constraints during free space trimNikolay Borisov1-6/+19
commit c2d1b3aae33605a61cbab445d8ae1c708ccd2698 upstream. Up until now trimming the freespace was done irrespective of what the arguments of the FITRIM ioctl were. For example fstrim's -o/-l arguments will be entirely ignored. Fix it by correctly handling those paramter. This requires breaking if the found freespace extent is after the end of the passed range as well as completing trim after trimming fstrim_range::len bytes. Fixes: 499f377f49f0 ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17btrfs: Verify that every chunk has corresponding block group at mount timeQu Wenruo1-1/+57
commit 7ef49515fa6727cb4b6f2f5b0ffbc5fc20a9f8c6 upstream. 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> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17btrfs: Check that each block group has corresponding chunk at mount timeQu Wenruo1-1/+27
commit 514c7dca85a0bf40be984dab0b477403a6db901f upstream. 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> [bwh: Backported to 4.4: Use root->fs_info instead of fs_info] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17Btrfs: kill BUG_ON in run_delayed_tree_refLiu Bo1-1/+7
commit 02794222c4132ac003e7281fb71f4ec1645ffc87 upstream. In a corrupted btrfs image, we can come across this BUG_ON and get an unreponsive system, but if we return errors instead, its caller can handle everything gracefully by aborting the current transaction. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17Btrfs: fix em leak in find_first_block_groupJosef Bacik1-0/+1
commit 187ee58c62c1d0d238d3dc4835869d33e1869906 upstream. We need to call free_extent_map() on the em we look up. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17Btrfs: check inconsistence between chunk and block groupLiu Bo1-1/+16
commit 6fb37b756acce6d6e045f79c3764206033f617b4 upstream. With btrfs-corrupt-block, one can drop one chunk item and mounting will end up with a panic in btrfs_full_stripe_len(). This doesn't not remove the BUG_ON, but instead checks it a bit earlier when we find the block group item. 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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-17btrfs: cleanup, stop casting for extent_map->lookup everywhereJeff Mahoney1-1/+1
commit 95617d69326ce386c95e33db7aeb832b45ee9f8f upstream. Overloading extent_map->bdev to struct map_lookup * might have started out as a means to an end, but it's a pattern that's used all over the place now. Let's get rid of the casting and just add a union instead. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-01btrfs: Ensure btrfs_trim_fs can trim the whole filesystemQu Wenruo1-9/+1
commit 6ba9fc8e628becf0e3ec94083450d089b0dec5f5 upstream. [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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: make sure we create all new block groupsJosef Bacik1-2/+5
commit 545e3366db823dc3342ca9d7fea803f829c9062f upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: wait on caching when putting the bg cacheJosef Bacik1-0/+1
commit 3aa7c7a31c26321696b92841d5103461c6f3f517 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: don't attempt to trim devices that don't support itJeff Mahoney1-0/+4
commit 0be88e367fd8fbdb45257615d691f4675dda062f upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: iterate all devices during trim, instead of fs_devices::alloc_listJeff Mahoney1-2/+2
commit d4e329de5e5e21594df2e0dd59da9acee71f133b upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: locking: Add extra check in btrfs_init_new_buffer() to avoid deadlockQu Wenruo1-0/+14
commit b72c3aba09a53fc7c1824250d71180ca154517a7 upstream. [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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21btrfs: Handle owner mismatch gracefully when walking up treeQu Wenruo1-6/+12
commit 65c6e82becec33731f48786e5a30f98662c86b16 upstream. [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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15btrfs: Don't remove block group that still has pinned down bytesQu Wenruo1-1/+1
[ Upstream commit 43794446548730ac8461be30bbe47d5d027d1d16 ] [BUG] Under certain KVM load and LTP tests, it is possible to hit the following calltrace if quota is enabled: BTRFS critical (device vda2): unable to find logical 8820195328 length 4096 BTRFS critical (device vda2): unable to find logical 8820195328 length 4096 WARNING: CPU: 0 PID: 49 at ../block/blk-core.c:172 blk_status_to_errno+0x1a/0x30 CPU: 0 PID: 49 Comm: kworker/u2:1 Not tainted 4.12.14-15-default #1 SLE15 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] task: ffff9f827b340bc0 task.stack: ffffb4f8c0304000 RIP: 0010:blk_status_to_errno+0x1a/0x30 Call Trace: submit_extent_page+0x191/0x270 [btrfs] ? btrfs_create_repair_bio+0x130/0x130 [btrfs] __do_readpage+0x2d2/0x810 [btrfs] ? btrfs_create_repair_bio+0x130/0x130 [btrfs] ? run_one_async_done+0xc0/0xc0 [btrfs] __extent_read_full_page+0xe7/0x100 [btrfs] ? run_one_async_done+0xc0/0xc0 [btrfs] read_extent_buffer_pages+0x1ab/0x2d0 [btrfs] ? run_one_async_done+0xc0/0xc0 [btrfs] btree_read_extent_buffer_pages+0x94/0xf0 [btrfs] read_tree_block+0x31/0x60 [btrfs] read_block_for_search.isra.35+0xf0/0x2e0 [btrfs] btrfs_search_slot+0x46b/0xa00 [btrfs] ? kmem_cache_alloc+0x1a8/0x510 ? btrfs_get_token_32+0x5b/0x120 [btrfs] find_parent_nodes+0x11d/0xeb0 [btrfs] ? leaf_space_used+0xb8/0xd0 [btrfs] ? btrfs_leaf_free_space+0x49/0x90 [btrfs] ? btrfs_find_all_roots_safe+0x93/0x100 [btrfs] btrfs_find_all_roots_safe+0x93/0x100 [btrfs] btrfs_find_all_roots+0x45/0x60 [btrfs] btrfs_qgroup_trace_extent_post+0x20/0x40 [btrfs] btrfs_add_delayed_data_ref+0x1a3/0x1d0 [btrfs] btrfs_alloc_reserved_file_extent+0x38/0x40 [btrfs] insert_reserved_file_extent.constprop.71+0x289/0x2e0 [btrfs] btrfs_finish_ordered_io+0x2f4/0x7f0 [btrfs] ? pick_next_task_fair+0x2cd/0x530 ? __switch_to+0x92/0x4b0 btrfs_worker_helper+0x81/0x300 [btrfs] process_one_work+0x1da/0x3f0 worker_thread+0x2b/0x3f0 ? process_one_work+0x3f0/0x3f0 kthread+0x11a/0x130 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x35/0x40 BTRFS critical (device vda2): unable to find logical 8820195328 length 16384 BTRFS: error (device vda2) in btrfs_finish_ordered_io:3023: errno=-5 IO failure BTRFS info (device vda2): forced readonly BTRFS error (device vda2): pending csums is 2887680 [CAUSE] It's caused by race with block group auto removal: - There is a meta block group X, which has only one tree block The tree block belongs to fs tree 257. - In current transaction, some operation modified fs tree 257 The tree block gets COWed, so the block group X is empty, and marked as unused, queued to be deleted. - Some workload (like fsync) wakes up cleaner_kthread() Which will call btrfs_delete_unused_bgs() to remove unused block groups. So block group X along its chunk map get removed. - Some delalloc work finished for fs tree 257 Quota needs to get the original reference of the extent, which will read tree blocks of commit root of 257. Then since the chunk map gets removed, the above warning gets triggered. [FIX] Just let btrfs_delete_unused_bgs() skip block group which still has pinned bytes. However there is a minor side effect: currently we only queue empty blocks at update_block_group(), and such empty block group with pinned bytes won't go through update_block_group() again, such block group won't be removed, until it gets new extent allocated and removed. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-05btrfs: don't leak ret from do_chunk_allocJosef Bacik1-1/+1
commit 4559b0a71749c442d34f7cfb9e72c9e58db83948 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30btrfs: Fix possible softlock on single core machinesNikolay Borisov1-0/+1
[ Upstream commit 1e1c50a929bc9e49bc3f9935b92450d9e69f8158 ] do_chunk_alloc implements a loop checking whether there is a pending chunk allocation and if so causes the caller do loop. Generally this loop is executed only once, however testing with btrfs/072 on a single core vm machines uncovered an extreme case where the system could loop indefinitely. This is due to a missing cond_resched when loop which doesn't give a chance to the previous chunk allocator finish its job. The fix is to simply add the missing cond_resched. Fixes: 6d74119f1a3e ("Btrfs: avoid taking the chunk_mutex in do_chunk_alloc") Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-05btrfs: clear space cache inode generation alwaysJosef Bacik1-7/+7
commit 8e138e0d92c6c9d3d481674fb14e3439b495be37 upstream. We discovered a box that had double allocations, and suspected the space cache may be to blame. While auditing the write out path I noticed that if we've already setup the space cache we will just carry on. This means that any error we hit after cache_save_setup before we go to actually write the cache out we won't reset the inode generation, so whatever was already written will be considered correct, except it'll be stale. Fix this by _always_ resetting the generation on the block group inode, this way we only ever have valid or invalid cache. With this patch I was no longer able to reproduce cache corruption with dm-log-writes and my bpf error injection tool. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14btrfs: fix memory leak in update_space_info failure pathJeff Mahoney1-0/+1
commit 896533a7da929136d0432713f02a3edffece2826 upstream. If we fail to add the space_info kobject, we'll leak the memory for the percpu counter. Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19btrfs: fix error handling when run_delayed_extent_op failsJeff Mahoney1-0/+3
commit aa7c8da35d1905d80e840d075f07d26ec90144b5 upstream. In __btrfs_run_delayed_refs, the error path when run_delayed_extent_op fails sets locked_ref->processing = 0 but doesn't re-increment delayed_refs->num_heads_ready. As a result, we end up triggering the WARN_ON in btrfs_select_ref_head. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Reported-by: Jon Nelson <jnelson-suse@jamponi.net> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19btrfs: fix locking when we put back a delayed ref that's too newJeff Mahoney1-1/+1
commit d0280996437081dd12ed1e982ac8aeaa62835ec4 upstream. In __btrfs_run_delayed_refs, when we put back a delayed ref that's too new, we have already dropped the lock on locked_ref when we set ->processing = 0. This patch keeps the lock to cover that assignment. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: don't BUG() during drop snapshotJosef Bacik1-11/+27
commit 4867268c57ff709a7b6b86ae6f6537d846d1443a upstream. Really there's lots of things that can go wrong here, kill all the BUG_ON()'s and replace the logic ones with ASSERT()'s and return EIO instead. Signed-off-by: Josef Bacik <jbacik@fb.com> [ switched to btrfs_err, errors go to common label ] Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: fix memory leak in do_walk_downLiu Bo1-0/+1
commit a958eab0ed7fdc1b977bc25d3af6efedaa945488 upstream. The extent buffer 'next' needs to be free'd conditionally. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06Btrfs: bail out if block group has different mixed flagLiu Bo1-0/+14
commit 49303381f19ab16a371a061b67e783d3f570d56e upstream. Currently we allow inconsistence about mixed flag (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA). We'd get ENOSPC if block group has mixed flag and btrfs doesn't. If that happens, we have one space_info with mixed flag and another space_info only with BTRFS_BLOCK_GROUP_METADATA, and global_block_rsv.space_info points to the latter one, but all bytes from block_group contributes to the mixed space_info, thus all the allocation will fail with ENOSPC. This adds a check for the above case. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> [ updated message ] Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-27btrfs: account for non-CoW'd blocks in btrfs_abort_transactionJeff Mahoney1-1/+1
commit 64c12921e11b3a0c10d088606e328c58e29274d8 upstream. The test for !trans->blocks_used in btrfs_abort_transaction is insufficient to determine whether it's safe to drop the transaction handle on the floor. btrfs_cow_block, informed by should_cow_block, can return blocks that have already been CoW'd in the current transaction. trans->blocks_used is only incremented for new block allocations. If an operation overlaps the blocks in the current transaction entirely and must abort the transaction, we'll happily let it clean up the trans handle even though it may have modified the blocks and will commit an incomplete operation. In the long-term, I'd like to do closer tracking of when the fs is actually modified so we can still recover as gracefully as possible, but that approach will need some discussion. In the short term, since this is the only code using trans->blocks_used, let's just switch it to a bool indicating whether any blocks were used and set it when should_cow_block returns false. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-10btrfs: Fix no_space in write and rm loopZhao Lei1-1/+3
commit e1746e8381cd2af421f75557b5cae3604fc18b35 upstream. I see no_space in v4.4-rc1 again in xfstests generic/102. It happened randomly in some node only. (one of 4 phy-node, and a kvm with non-virtio block driver) By bisect, we can found the first-bad is: commit bdced438acd8 ("block: setup bi_phys_segments after splitting")' But above patch only triggered the bug by making bio operation faster(or slower). Main reason is in our space_allocating code, we need to commit page writeback before wait it complish, this patch fixed above bug. BTW, there is another reason for generic/102 fail, caused by disable default mixed-blockgroup, I'll fix it in xfstests. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-10Btrfs: fix deadlock running delayed iputs at transaction commit timeFilipe Manana1-4/+5
commit c2d6cb1636d235257086f939a8194ef0bf93af6e upstream. While running a stress test I ran into a deadlock when running the delayed iputs at transaction time, which produced the following report and trace: [ 886.399989] ============================================= [ 886.400871] [ INFO: possible recursive locking detected ] [ 886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted [ 886.402384] --------------------------------------------- [ 886.403182] fio/8277 is trying to acquire lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] but task is already holding lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] other info that might help us debug this: [ 886.403568] Possible unsafe locking scenario: [ 886.403568] [ 886.403568] CPU0 [ 886.403568] ---- [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] [ 886.403568] *** DEADLOCK *** [ 886.403568] [ 886.403568] May be due to missing lock nesting notation [ 886.403568] [ 886.403568] 3 locks held by fio/8277: [ 886.403568] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0 [ 886.403568] #1: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs] [ 886.403568] #2: (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] stack backtrace: [ 886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 886.403568] 0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0 [ 886.403568] ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290 [ 886.403568] 0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804 [ 886.403568] Call Trace: [ 886.403568] [<ffffffff8125d4fd>] dump_stack+0x4e/0x79 [ 886.403568] [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b [ 886.403568] [<ffffffff810c22db>] ? __module_address+0xdf/0x108 [ 886.403568] [<ffffffff8108eb77>] lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffff8148556b>] down_read+0x3e/0x4d [ 886.489542] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs] [ 886.489542] [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs] [ 886.489542] [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs] [ 886.489542] [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs] [ 886.489542] [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs] [ 886.489542] [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs] [ 886.489542] [<ffffffff81188e31>] evict+0xa7/0x15c [ 886.489542] [<ffffffff81189878>] iput+0x1d3/0x266 [ 886.489542] [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffff81085096>] ? signal_pending_state+0x31/0x31 [ 886.489542] [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs] [ 886.489542] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 886.489542] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 886.489542] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 886.489542] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 886.489542] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 886.489542] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 886.489542] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 886.489542] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 886.489542] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 886.489542] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds. [ 1081.854348] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.863227] fio D ffff880213f9bb28 0 8244 8240 0x00000000 [ 1081.868719] ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240 [ 1081.872499] ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400 [ 1081.876834] ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4 [ 1081.880782] Call Trace: [ 1081.881793] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.883340] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.895525] [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab [ 1081.897419] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1081.899251] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1081.901063] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1081.902365] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1081.903846] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.906078] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.908846] [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c [ 1081.910409] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 1081.912482] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 1081.914597] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 1081.919037] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 1081.920754] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 1081.922496] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 1081.923922] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 1081.925275] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 1081.926584] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 1081.927968] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.985293] INFO: lockdep is turned off. [ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds. [ 1081.987434] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.990147] fio D ffff880218febbb8 0 8249 8240 0x00000000 [ 1081.991626] ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240 [ 1081.993258] ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00 [ 1081.994850] ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4 [ 1081.996485] Call Trace: [ 1081.997037] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.998017] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.999241] [<ffffffff810852a5>] ? finish_wait+0x6d/0x76 [ 1082.000306] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1082.001533] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1082.002776] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1082.003995] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1082.005000] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.007403] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.008988] [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs] [ 1082.010193] [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77 [ 1082.011280] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.012265] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.013021] [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff [ 1082.013738] [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b [ 1082.014778] [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea [ 1082.015778] [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e [ 1082.016806] [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71 [ 1082.017789] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [ 1082.018706] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f This happens because we can recursively acquire the semaphore fs_info->delayed_iput_sem when attempting to allocate space to satisfy a file write request as shown in the first trace above - when committing a transaction we acquire (down_read) the semaphore before running the delayed iputs, and when running a delayed iput() we can end up calling an inode's eviction handler, which in turn commits another transaction and attempts to acquire (down_read) again the semaphore to run more delayed iput operations. This results in a deadlock because if a task acquires multiple times a semaphore it should invoke down_read_nested() with a different lockdep class for each level of recursion. Fix this by simplifying the implementation and use a mutex instead that is acquired by the cleaner kthread before it runs the delayed iputs instead of always acquiring a semaphore before delayed references are run from anywhere. Fixes: d7c151717a1e (btrfs: Fix NO_SPACE bug caused by delayed-iput) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-10Btrfs: fix unprotected list move from unused_bgs to deleted_bgs listFilipe Manana1-3/+7
As of my previous change titled "Btrfs: fix scrub preventing unused block groups from being deleted", the following warning at extent-tree.c:btrfs_delete_unused_bgs() can be hit when we mount the a filesysten with "-o discard": 10263 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) 10264 { (...) 10405 if (trimming) { 10406 WARN_ON(!list_empty(&block_group->bg_list)); 10407 spin_lock(&trans->transaction->deleted_bgs_lock); 10408 list_move(&block_group->bg_list, 10409 &trans->transaction->deleted_bgs); 10410 spin_unlock(&trans->transaction->deleted_bgs_lock); 10411 btrfs_get_block_group(block_group); 10412 } (...) This happens because scrub can now add back the block group to the list of unused block groups (fs_info->unused_bgs). This is dangerous because we are moving the block group from the unused block groups list to the list of deleted block groups without holding the lock that protects the source list (fs_info->unused_bgs_lock). The following diagram illustrates how this happens: CPU 1 CPU 2 cleaner_kthread() btrfs_delete_unused_bgs() sees bg X in list fs_info->unused_bgs deletes bg X from list fs_info->unused_bgs scrub_enumerate_chunks() searches device tree using its commit root finds device extent for block group X gets block group X from the tree fs_info->block_group_cache_tree (via btrfs_lookup_block_group()) sets bg X to RO (again) scrub_chunk(bg X) sets bg X back to RW mode adds bg X to the list fs_info->unused_bgs again, since it's still unused and currently not in that list sets bg X to RO mode btrfs_remove_chunk(bg X) --> discard is enabled and bg X is in the fs_info->unused_bgs list again so the warning is triggered --> we move it from that list into the transaction's delete_bgs list, but we can have another task currently manipulating the first list (fs_info->unused_bgs) Fix this by using the same lock (fs_info->unused_bgs_lock) to protect both the list of unused block groups and the list of deleted block groups. This makes it safe and there's not much worry for more lock contention, as this lock is seldom used and only the cleaner kthread adds elements to the list of deleted block groups. The warning goes away too, as this was previously an impossible case (and would have been better a BUG_ON/ASSERT) but it's not impossible anymore. Reproduced with fstest btrfs/073 (using MOUNT_OPTIONS="-o discard"). Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-11-25btrfs: qgroup: account shared subtree during snapshot deleteMark Fasheh1-7/+40
Commit 0ed4792 ('btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.') removed our qgroup accounting during btrfs_drop_snapshot(). Predictably, this results in qgroup numbers going bad shortly after a snapshot is removed. Fix this by adding a dirty extent record when we encounter extents during our shared subtree walk. This effectively restores the functionality we had with the original shared subtree walking code in 1152651 (btrfs: qgroup: account shared subtrees during snapshot delete). The idea with the original patch (and this one) is that shared subtrees can get skipped during drop_snapshot. The shared subtree walk then allows us a chance to visit those extents and add them to the qgroup work for later processing. This ultimately makes the accounting for drop snapshot work. The new qgroup code nicely handles all the other extents during the tree walk via the ref dec/inc functions so we don't have to add actions beyond what we had originally. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix race between cleaner kthread and space cache writeoutFilipe Manana1-13/+16
When a block group becomes unused and the cleaner kthread is currently running, we can end up getting the current transaction aborted with error -ENOENT when we try to commit the transaction, leading to the following trace: [59779.258768] WARNING: CPU: 3 PID: 5990 at fs/btrfs/extent-tree.c:3740 btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]() [59779.272594] BTRFS: Transaction aborted (error -2) (...) [59779.291137] Call Trace: [59779.291621] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [59779.292543] [<ffffffff8104d0a6>] warn_slowpath_common+0x9f/0xb8 [59779.293435] [<ffffffffa04cb81f>] ? btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [59779.295000] [<ffffffff8104d107>] warn_slowpath_fmt+0x48/0x50 [59779.296138] [<ffffffffa04c2721>] ? write_one_cache_group.isra.32+0x77/0x82 [btrfs] [59779.297663] [<ffffffffa04cb81f>] btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [59779.299141] [<ffffffffa0549b0d>] commit_cowonly_roots+0x1de/0x261 [btrfs] [59779.300359] [<ffffffffa04dd5b6>] btrfs_commit_transaction+0x4c4/0x99c [btrfs] [59779.301805] [<ffffffffa04b5df4>] btrfs_sync_fs+0x145/0x1ad [btrfs] [59779.302893] [<ffffffff81196634>] sync_filesystem+0x7f/0x93 (...) [59779.318186] ---[ end trace 577e2daff90da33a ]--- The following diagram illustrates a sequence of steps leading to this problem: CPU 1 CPU 2 <at transaction N> adds bg A to list fs_info->unused_bgs adds bg B to list fs_info->unused_bgs <transaction kthread commits transaction N and wakes up the cleaner kthread> cleaner kthread delete_unused_bgs() sees bg A in list fs_info->unused_bgs btrfs_start_transaction() <transaction N + 1 starts> deletes bg A update_block_group(bg C) --> adds bg C to list fs_info->unused_bgs deletes bg B sees bg C in the list fs_info->unused_bgs btrfs_remove_chunk(bg C) btrfs_remove_block_group(bg C) --> checks if the block group is in a dirty list, and because it isn't now, it does nothing --> the block group item is deleted from the extent tree --> adds bg C to list transaction->dirty_bgs some task calls btrfs_commit_transaction(t N + 1) commit_cowonly_roots() btrfs_write_dirty_block_groups() --> sees bg C in cur_trans->dirty_bgs --> calls write_one_cache_group() which returns -ENOENT because it did not find the block group item in the extent tree --> transaction aborte with -ENOENT because write_one_cache_group() returned that error So fix this by adding a block group to the list of dirty block groups before adding it to the list of unused block groups. This happened on a stress test using fsstress plus concurrent calls to fallocate 20G and truncate (releasing part of the space allocated with fallocate). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix scrub preventing unused block groups from being deletedFilipe Manana1-1/+1
Currently scrub can race with the cleaner kthread when the later attempts to delete an unused block group, and the result is preventing the cleaner kthread from ever deleting later the block group - unless the block group becomes used and unused again. The following diagram illustrates that race: CPU 1 CPU 2 cleaner kthread btrfs_delete_unused_bgs() gets block group X from fs_info->unused_bgs and removes it from that list scrub_enumerate_chunks() searches device tree using its commit root finds device extent for block group X gets block group X from the tree fs_info->block_group_cache_tree (via btrfs_lookup_block_group()) sets bg X to RO sees the block group is already RO and therefore doesn't delete it nor adds it back to unused list So fix this by making scrub add the block group again to the list of unused block groups if the block group is still unused when it finished scrubbing it and it hasn't been removed already. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: fix the number of transaction units needed to remove a block groupFilipe Manana1-3/+34
We were using only 1 transaction unit when attempting to delete an unused block group but in reality we need 3 + N units, where N corresponds to the number of stripes. We were accounting only for the addition of the orphan item (for the block group's free space cache inode) but we were not accounting that we need to delete one block group item from the extent tree, one free space item from the tree of tree roots and N device extent items from the device tree. While one unit is not enough, it worked most of the time because for each single unit we are too pessimistic and assume an entire tree path, with the highest possible heigth (8), needs to be COWed with eventual node splits at every possible level in the tree, so there was usually enough reserved space for removing all the items and adding the orphan item. However after adding the orphan item, writepages() can by called by the VM subsystem against the btree inode when we are under memory pressure, which causes writeback to start for the nodes we COWed before, this forces the operation to remove the free space item to COW again some (or all of) the same nodes (in the tree of tree roots). Even without writepages() being called, we could fail with ENOSPC because these items are located in multiple trees and one of them might have a higher heigth and require node/leaf splits at many levels, exhausting all the reserved space before removing all the items and adding the orphan. In the kernel 4.0 release, commit 3d84be799194 ("Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group"), we attempted to fix a BUG_ON due to ENOSPC when trying to add the orphan item by making the cleaner kthread reserve one transaction unit before attempting to remove the block group, but this was not enough. We had a couple user reports still hitting the same BUG_ON after 4.0, like Stefan Priebe's report on a 4.2-rc6 kernel for example: http://www.spinics.net/lists/linux-btrfs/msg46070.html So fix this by reserving all the necessary units of metadata. Reported-by: Stefan Priebe <s.priebe@profihost.ag> Fixes: 3d84be799194 ("Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-25Btrfs: use global reserve when deleting unused block group after ENOSPCFilipe Manana1-2/+12
It's possible to reach a state where the cleaner kthread isn't able to start a transaction to delete an unused block group due to lack of enough free metadata space and due to lack of unallocated device space to allocate a new metadata block group as well. If this happens try to use space from the global block group reserve just like we do for unlink operations, so that we don't reach a permanent state where starting a transaction for filesystem operations (file creation, renames, etc) keeps failing with -ENOSPC. Such an unfortunate state was observed on a machine where over a dozen unused data block groups existed and the cleaner kthread was failing to delete them due to ENOSPC error when attempting to start a transaction, and even running balance with a -dusage=0 filter failed with ENOSPC as well. Also unmounting and mounting again the filesystem didn't help. Allowing the cleaner kthread to use the global block reserve to delete the unused data block groups fixed the problem. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-11btrfs: Use fs_info directly in btrfs_delete_unused_bgsZhao Lei1-2/+2
No need to use root->fs_info in btrfs_delete_unused_bgs(), use fs_info directly instead. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-11btrfs: Fix lost-data-profile caused by auto removing bgZhao Lei1-2/+5
Reproduce: (In integration-4.3 branch) TEST_DEV=(/dev/vdg /dev/vdh) TEST_DIR=/mnt/tmp umount "$TEST_DEV" >/dev/null mkfs.btrfs -f -d raid1 "${TEST_DEV[@]}" mount -o nospace_cache "$TEST_DEV" "$TEST_DIR" umount "$TEST_DEV" mount -o nospace_cache "$TEST_DEV" "$TEST_DIR" btrfs filesystem usage $TEST_DIR We can see the data chunk changed from raid1 to single: # btrfs filesystem usage $TEST_DIR Data,single: Size:8.00MiB, Used:0.00B /dev/vdg 8.00MiB # Reason: When a empty filesystem mount with -o nospace_cache, the last data blockgroup will be auto-removed in umount. Then if we mount it again, there is no data chunk in the filesystem, so the only available data profile is 0x0, result is all new chunks are created as single type. Fix: Don't auto-delete last blockgroup for a raid type. Test: Test by above script, and confirmed the logic by debug output. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-11-03Btrfs: find_free_extent: Do not erroneously skip LOOP_CACHING_WAIT statechandan1-1/+6
When executing generic/001 in a loop on a ppc64 machine (with both sectorsize and nodesize set to 64k), the following call trace is observed, WARNING: at /root/repos/linux/fs/btrfs/locking.c:253 Modules linked in: CPU: 2 PID: 8353 Comm: umount Not tainted 4.3.0-rc5-13676-ga5e681d #54 task: c0000000f2b1f560 ti: c0000000f6008000 task.ti: c0000000f6008000 NIP: c000000000520c88 LR: c0000000004a3b34 CTR: 0000000000000000 REGS: c0000000f600a820 TRAP: 0700 Not tainted (4.3.0-rc5-13676-ga5e681d) MSR: 8000000102029032 <SF,VEC,EE,ME,IR,DR,RI> CR: 24444884 XER: 00000000 CFAR: c0000000004a3b30 SOFTE: 1 GPR00: c0000000004a3b34 c0000000f600aaa0 c00000000108ac00 c0000000f5a808c0 GPR04: 0000000000000000 c0000000f600ae60 0000000000000000 0000000000000005 GPR08: 00000000000020a1 0000000000000001 c0000000f2b1f560 0000000000000030 GPR12: 0000000084842882 c00000000fdc0900 c0000000f600ae60 c0000000f070b800 GPR16: 0000000000000000 c0000000f3c8a000 0000000000000000 0000000000000049 GPR20: 0000000000000001 0000000000000001 c0000000f5aa01f8 0000000000000000 GPR24: 0f83e0f83e0f83e1 c0000000f5a808c0 c0000000f3c8d000 c000000000000000 GPR28: c0000000f600ae74 0000000000000001 c0000000f3c8d000 c0000000f5a808c0 NIP [c000000000520c88] .btrfs_tree_lock+0x48/0x2a0 LR [c0000000004a3b34] .btrfs_lock_root_node+0x44/0x80 Call Trace: [c0000000f600aaa0] [c0000000f600ab80] 0xc0000000f600ab80 (unreliable) [c0000000f600ab80] [c0000000004a3b34] .btrfs_lock_root_node+0x44/0x80 [c0000000f600ac00] [c0000000004a99dc] .btrfs_search_slot+0xa8c/0xc00 [c0000000f600ad40] [c0000000004ab878] .btrfs_insert_empty_items+0x98/0x120 [c0000000f600adf0] [c00000000050da44] .btrfs_finish_chunk_alloc+0x1d4/0x620 [c0000000f600af20] [c0000000004be854] .btrfs_create_pending_block_groups+0x1d4/0x2c0 [c0000000f600b020] [c0000000004bf188] .do_chunk_alloc+0x3c8/0x420 [c0000000f600b100] [c0000000004c27cc] .find_free_extent+0xbfc/0x1030 [c0000000f600b260] [c0000000004c2ce8] .btrfs_reserve_extent+0xe8/0x250 [c0000000f600b330] [c0000000004c2f90] .btrfs_alloc_tree_block+0x140/0x590 [c0000000f600b440] [c0000000004a47b4] .__btrfs_cow_block+0x124/0x780 [c0000000f600b530] [c0000000004a4fc0] .btrfs_cow_block+0xf0/0x250 [c0000000f600b5e0] [c0000000004a917c] .btrfs_search_slot+0x22c/0xc00 [c0000000f600b720] [c00000000050aa40] .btrfs_remove_chunk+0x1b0/0x9f0 [c0000000f600b850] [c0000000004c4e04] .btrfs_delete_unused_bgs+0x434/0x570 [c0000000f600b950] [c0000000004d3cb8] .close_ctree+0x2e8/0x3b0 [c0000000f600ba20] [c00000000049d178] .btrfs_put_super+0x18/0x30 [c0000000f600ba90] [c000000000243cd4] .generic_shutdown_super+0xa4/0x1a0 [c0000000f600bb10] [c0000000002441d8] .kill_anon_super+0x18/0x30 [c0000000f600bb90] [c00000000049c898] .btrfs_kill_super+0x18/0xc0 [c0000000f600bc10] [c0000000002444f8] .deactivate_locked_super+0x98/0xe0 [c0000000f600bc90] [c000000000269f94] .cleanup_mnt+0x54/0xa0 [c0000000f600bd10] [c0000000000bd744] .task_work_run+0xc4/0x100 [c0000000f600bdb0] [c000000000016334] .do_notify_resume+0x74/0x80 [c0000000f600be30] [c0000000000098b8] .ret_from_except_lite+0x64/0x68 Instruction dump: fba1ffe8 fbc1fff0 fbe1fff8 7c791b78 f8010010 f821ff21 e94d0290 81030040 812a04e8 7d094a78 7d290034 5529d97e <0b090000> 3b400000 3be30050 3bc3004c The above call trace is seen even on x86_64; albeit very rarely and that too with nodesize set to 64k and with nospace_cache mount option being used. The reason for the above call trace is, btrfs_remove_chunk check_system_chunk Allocate chunk if required For each physical stripe on underlying device, btrfs_free_dev_extent ... Take lock on Device tree's root node btrfs_cow_block("dev tree's root node"); btrfs_reserve_extent find_free_extent index = BTRFS_RAID_DUP; have_caching_bg = false; When in LOOP_CACHING_NOWAIT state, Assume we find a block group which is being cached; Hence have_caching_bg is set to true When repeating the search for the next RAID index, we set have_caching_bg to false. Hence right after completing the LOOP_CACHING_NOWAIT state, we incorrectly skip LOOP_CACHING_WAIT state and move to LOOP_ALLOC_CHUNK state where we allocate a chunk and try to add entries corresponding to the chunk's physical stripe into the device tree. When doing so the task deadlocks itself waiting for the blocking lock on the root node of the device tree. This commit fixes the issue by introducing a new local variable to help indicate as to whether a block group of any RAID type is being cached. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-27btrfs: qgroup: Fix a race in delayed_ref which leads to abort transQu Wenruo1-6/+8
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>
2015-10-25Btrfs: fix regression running delayed references when using qgroupsFilipe Manana1-29/+16
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>
2015-10-25Btrfs: fix regression when running delayed referencesFilipe Manana1-0/+14
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>
2015-10-22Merge branch 'allocator-fixes' into for-linus-4.4Chris Mason1-32/+240
Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: don't keep trying to build clusters if we are fragmentedJosef Bacik1-24/+78
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: cut down on loops through the allocatorJosef Bacik1-3/+36
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: don't continue setting up space cache when enospcJosef Bacik1-0/+19
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: keep track of max_extent_size per space_infoJosef Bacik1-1/+30
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: don't loop in allocator for space cacheJosef Bacik1-1/+1
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: add a flags field to btrfs_transactionJosef Bacik1-2/+3
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22Btrfs: add fragment=* debug mount optionJosef Bacik1-5/+77
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: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22btrfs: qgroup: Avoid calling btrfs_free_reserved_data_space in clear_bit_hookQu Wenruo1-10/+18
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: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22btrfs: qgroup: Add handler for NOCOW and inlineQu Wenruo1-1/+6
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: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-22btrfs: qgroup: Cleanup old inaccurate facilitiesQu Wenruo1-98/+11
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: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
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