- 23 Nov, 2022 3 commits
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Zhen Lei authored
Although kset_unregister() can eventually remove all attribute files, explicitly rolling back with the matching function makes the code logic look clearer. CC: stable@vger.kernel.org # 5.4+ Reviewed-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Filipe Manana authored
When logging an inode in full mode, or when logging xattrs or when logging the dir index items of a directory, we are modifying the log tree while holding a read lock on a leaf from the fs/subvolume tree. This can lead to a deadlock in rare circumstances, but it is a real possibility, and it was recently reported by syzbot with the following trace from lockdep: WARNING: possible circular locking dependency detected 6.1.0-rc5-next-20221116-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/16154 is trying to acquire lock: ffff88807e3084a0 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0xa1/0xf30 fs/btrfs/delayed-inode.c:256 but task is already holding lock: ffff88807df33078 (btrfs-log-00){++++}-{3:3}, at: __btrfs_tree_lock+0x32/0x3d0 fs/btrfs/locking.c:197 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (btrfs-log-00){++++}-{3:3}: down_read_nested+0x9e/0x450 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock+0x32/0x350 fs/btrfs/locking.c:135 btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] btrfs_read_lock_root_node+0x82/0x3a0 fs/btrfs/locking.c:280 btrfs_search_slot_get_root fs/btrfs/ctree.c:1678 [inline] btrfs_search_slot+0x3ca/0x2c70 fs/btrfs/ctree.c:1998 btrfs_lookup_csum+0x116/0x3f0 fs/btrfs/file-item.c:209 btrfs_csum_file_blocks+0x40e/0x1370 fs/btrfs/file-item.c:1021 log_csums.isra.0+0x244/0x2d0 fs/btrfs/tree-log.c:4258 copy_items.isra.0+0xbfb/0xed0 fs/btrfs/tree-log.c:4403 copy_inode_items_to_log+0x13d6/0x1d90 fs/btrfs/tree-log.c:5873 btrfs_log_inode+0xb19/0x4680 fs/btrfs/tree-log.c:6495 btrfs_log_inode_parent+0x890/0x2a20 fs/btrfs/tree-log.c:6982 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7083 btrfs_sync_file+0xa41/0x13c0 fs/btrfs/file.c:1921 vfs_fsync_range+0x13e/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2856 [inline] iomap_dio_complete+0x73a/0x920 fs/iomap/direct-io.c:128 btrfs_direct_write fs/btrfs/file.c:1536 [inline] btrfs_do_write_iter+0xba2/0x1470 fs/btrfs/file.c:1668 call_write_iter include/linux/fs.h:2160 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x745/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:931 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886 do_splice_direct+0x1ab/0x280 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x259/0x2c0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (btrfs-tree-00){++++}-{3:3}: __lock_release kernel/locking/lockdep.c:5382 [inline] lock_release+0x371/0x810 kernel/locking/lockdep.c:5688 up_write+0x2a/0x520 kernel/locking/rwsem.c:1614 btrfs_tree_unlock_rw fs/btrfs/locking.h:189 [inline] btrfs_unlock_up_safe+0x1e3/0x290 fs/btrfs/locking.c:238 search_leaf fs/btrfs/ctree.c:1832 [inline] btrfs_search_slot+0x265e/0x2c70 fs/btrfs/ctree.c:2074 btrfs_insert_empty_items+0xbd/0x1c0 fs/btrfs/ctree.c:4133 btrfs_insert_delayed_item+0x826/0xfa0 fs/btrfs/delayed-inode.c:746 btrfs_insert_delayed_items fs/btrfs/delayed-inode.c:824 [inline] __btrfs_commit_inode_delayed_items fs/btrfs/delayed-inode.c:1111 [inline] __btrfs_run_delayed_items+0x280/0x590 fs/btrfs/delayed-inode.c:1153 flush_space+0x147/0xe90 fs/btrfs/space-info.c:728 btrfs_async_reclaim_metadata_space+0x541/0xc10 fs/btrfs/space-info.c:1086 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (&delayed_node->mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 __btrfs_release_delayed_node.part.0+0xa1/0xf30 fs/btrfs/delayed-inode.c:256 __btrfs_release_delayed_node fs/btrfs/delayed-inode.c:251 [inline] btrfs_release_delayed_node fs/btrfs/delayed-inode.c:281 [inline] btrfs_remove_delayed_node+0x52/0x60 fs/btrfs/delayed-inode.c:1285 btrfs_evict_inode+0x511/0xf30 fs/btrfs/inode.c:5554 evict+0x2ed/0x6b0 fs/inode.c:664 dispose_list+0x117/0x1e0 fs/inode.c:697 prune_icache_sb+0xeb/0x150 fs/inode.c:896 super_cache_scan+0x391/0x590 fs/super.c:106 do_shrink_slab+0x464/0xce0 mm/vmscan.c:843 shrink_slab_memcg mm/vmscan.c:912 [inline] shrink_slab+0x388/0x660 mm/vmscan.c:991 shrink_node_memcgs mm/vmscan.c:6088 [inline] shrink_node+0x93d/0x1f30 mm/vmscan.c:6117 shrink_zones mm/vmscan.c:6355 [inline] do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6417 try_to_free_mem_cgroup_pages+0x3a4/0xa70 mm/vmscan.c:6732 reclaim_high.constprop.0+0x182/0x230 mm/memcontrol.c:2393 mem_cgroup_handle_over_high+0x190/0x520 mm/memcontrol.c:2578 try_charge_memcg+0xe0c/0x12f0 mm/memcontrol.c:2816 try_charge mm/memcontrol.c:2827 [inline] charge_memcg+0x90/0x3b0 mm/memcontrol.c:6889 __mem_cgroup_charge+0x2b/0x90 mm/memcontrol.c:6910 mem_cgroup_charge include/linux/memcontrol.h:667 [inline] __filemap_add_folio+0x615/0xf80 mm/filemap.c:852 filemap_add_folio+0xaf/0x1e0 mm/filemap.c:934 __filemap_get_folio+0x389/0xd80 mm/filemap.c:1976 pagecache_get_page+0x2e/0x280 mm/folio-compat.c:104 find_or_create_page include/linux/pagemap.h:612 [inline] alloc_extent_buffer+0x2b9/0x1580 fs/btrfs/extent_io.c:4588 btrfs_init_new_buffer fs/btrfs/extent-tree.c:4869 [inline] btrfs_alloc_tree_block+0x2e1/0x1320 fs/btrfs/extent-tree.c:4988 __btrfs_cow_block+0x3b2/0x1420 fs/btrfs/ctree.c:440 btrfs_cow_block+0x2fa/0x950 fs/btrfs/ctree.c:595 btrfs_search_slot+0x11b0/0x2c70 fs/btrfs/ctree.c:2038 btrfs_update_root+0xdb/0x630 fs/btrfs/root-tree.c:137 update_log_root fs/btrfs/tree-log.c:2841 [inline] btrfs_sync_log+0xbfb/0x2870 fs/btrfs/tree-log.c:3064 btrfs_sync_file+0xdb9/0x13c0 fs/btrfs/file.c:1947 vfs_fsync_range+0x13e/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2856 [inline] iomap_dio_complete+0x73a/0x920 fs/iomap/direct-io.c:128 btrfs_direct_write fs/btrfs/file.c:1536 [inline] btrfs_do_write_iter+0xba2/0x1470 fs/btrfs/file.c:1668 call_write_iter include/linux/fs.h:2160 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x745/0xc90 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:931 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886 do_splice_direct+0x1ab/0x280 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x259/0x2c0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &delayed_node->mutex --> btrfs-tree-00 --> btrfs-log-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-log-00); lock(btrfs-tree-00); lock(btrfs-log-00); lock(&delayed_node->mutex); Holding a read lock on a leaf from a fs/subvolume tree creates a nasty lock dependency when we are COWing extent buffers for the log tree and we have two tasks modifying the log tree, with each one in one of the following 2 scenarios: 1) Modifying the log tree triggers an extent buffer allocation while holding a write lock on a parent extent buffer from the log tree. Allocating the pages for an extent buffer, or the extent buffer struct, can trigger inode eviction and finally the inode eviction will trigger a release/remove of a delayed node, which requires taking the delayed node's mutex; 2) Allocating a metadata extent for a log tree can trigger the async reclaim thread and make us wait for it to release enough space and unblock our reservation ticket. The reclaim thread can start flushing delayed items, and that in turn results in the need to lock delayed node mutexes and in the need to write lock extent buffers of a subvolume tree - all this while holding a write lock on the parent extent buffer in the log tree. So one task in scenario 1) running in parallel with another task in scenario 2) could lead to a deadlock, one wanting to lock a delayed node mutex while having a read lock on a leaf from the subvolume, while the other is holding the delayed node's mutex and wants to write lock the same subvolume leaf for flushing delayed items. Fix this by cloning the leaf of the fs/subvolume tree, release/unlock the fs/subvolume leaf and use the clone leaf instead. Reported-by: syzbot+9b7c21f486f5e7f8d029@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000ccc93c05edc4d8cf@google.com/ CC: stable@vger.kernel.org # 6.0+ Reviewed-by:Josef Bacik <josef@toxicpanda.com> Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
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Christoph Hellwig authored
Otherwise the kernel memory allocator seems to be unhappy about failing order 6 allocations for the zones array, that cause 100% reproducible mount failures in my qemu setup: [26.078981] mount: page allocation failure: order:6, mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null) [26.079741] CPU: 0 PID: 2965 Comm: mount Not tainted 6.1.0-rc5+ #185 [26.080181] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [26.080950] Call Trace: [26.081132] <TASK> [26.081291] dump_stack_lvl+0x56/0x6f [26.081554] warn_alloc+0x117/0x140 [26.081808] ? __alloc_pages_direct_compact+0x1b5/0x300 [26.082174] __alloc_pages_slowpath.constprop.0+0xd0e/0xde0 [26.082569] __alloc_pages+0x32a/0x340 [26.082836] __kmalloc_large_node+0x4d/0xa0 [26.083133] ? trace_kmalloc+0x29/0xd0 [26.083399] kmalloc_large+0x14/0x60 [26.083654] btrfs_get_dev_zone_info+0x1b9/0xc00 [26.083980] ? _raw_spin_unlock_irqrestore+0x28/0x50 [26.084328] btrfs_get_dev_zone_info_all_devices+0x54/0x80 [26.084708] open_ctree+0xed4/0x1654 [26.084974] btrfs_mount_root.cold+0x12/0xde [26.085288] ? lock_is_held_type+0xe2/0x140 [26.085603] legacy_get_tree+0x28/0x50 [26.085876] vfs_get_tree+0x1d/0xb0 [26.086139] vfs_kern_mount.part.0+0x6c/0xb0 [26.086456] btrfs_mount+0x118/0x3a0 [26.086728] ? lock_is_held_type+0xe2/0x140 [26.087043] legacy_get_tree+0x28/0x50 [26.087323] vfs_get_tree+0x1d/0xb0 [26.087587] path_mount+0x2ba/0xbe0 [26.087850] ? _raw_spin_unlock_irqrestore+0x38/0x50 [26.088217] __x64_sys_mount+0xfe/0x140 [26.088506] do_syscall_64+0x35/0x80 [26.088776] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 5b316468 ("btrfs: get zone information of zoned block devices") CC: stable@vger.kernel.org # 5.15+ Reviewed-by:
Damien Le Moal <damien.lemoal@opensource.wdc.com> Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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- 21 Nov, 2022 3 commits
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ChenXiaoSong authored
Syzkaller reported BUG as follows: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 __might_resched.cold+0x222/0x26b kmem_cache_alloc+0x2e7/0x3c0 update_qgroup_limit_item+0xe1/0x390 btrfs_qgroup_inherit+0x147b/0x1ee0 create_subvol+0x4eb/0x1710 btrfs_mksubvol+0xfe5/0x13f0 __btrfs_ioctl_snap_create+0x2b0/0x430 btrfs_ioctl_snap_create_v2+0x25a/0x520 btrfs_ioctl+0x2a1c/0x5ce0 __x64_sys_ioctl+0x193/0x200 do_syscall_64+0x35/0x80 Fix this by calling qgroup_dirty() on @dstqgroup, and update limit item in btrfs_run_qgroups() later outside of the spinlock context. CC: stable@vger.kernel.org # 4.9+ Reviewed-by:ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by:
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Filipe Manana authored
When trying to see if we can clone a file range, there are cases where we end up sending two write operations in case the inode from the source root has an i_size that is not sector size aligned and the length from the current offset to its i_size is less than the remaining length we are trying to clone. Issuing two write operations when we could instead issue a single write operation is not incorrect. However it is not optimal, specially if the extents are compressed and the flag BTRFS_SEND_FLAG_COMPRESSED was passed to the send ioctl. In that case we can end up sending an encoded write with an offset that is not sector size aligned, which makes the receiver fallback to decompressing the data and writing it using regular buffered IO (so re-compressing the data in case the fs is mounted with compression enabled), because encoded writes fail with -EINVAL when an offset is not sector size aligned. The following example, which triggered a bug in the receiver code for the fallback logic of decompressing + regular buffer IO and is fixed by the patchset referred in a Link at the bottom of this changelog, is an example where we have the non-optimal behaviour due to an unaligned encoded write: $ cat test.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV > /dev/null mount -o compress $DEV $MNT # File foo has a size of 33K, not aligned to the sector size. xfs_io -f -c "pwrite -S 0xab 0 33K" $MNT/foo xfs_io -f -c "pwrite -S 0xcd 0 64K" $MNT/bar # Now clone the first 32K of file bar into foo at offset 0. xfs_io -c "reflink $MNT/bar 0 0 32K" $MNT/foo # Snapshot the default subvolume and create a full send stream (v2). btrfs subvolume snapshot -r $MNT $MNT/snap btrfs send --compressed-data -f /tmp/test.send $MNT/snap echo -e "\nFile bar in the original filesystem:" od -A d -t x1 $MNT/snap/bar umount $MNT mkfs.btrfs -f $DEV > /dev/null mount $DEV $MNT echo -e "\nReceiving stream in a new filesystem..." btrfs receive -f /tmp/test.send $MNT echo -e "\nFile bar in the new filesystem:" od -A d -t x1 $MNT/snap/bar umount $MNT Before this patch, the send stream included one regular write and one encoded write for file 'bar', with the later being not sector size aligned and causing the receiver to fallback to decompression + buffered writes. The output of the btrfs receive command in verbose mode (-vvv): (...) mkfile o258-7-0 rename o258-7-0 -> bar utimes clone bar - source=foo source offset=0 offset=0 length=32768 write bar - offset=32768 length=1024 encoded_write bar - offset=33792, len=4096, unencoded_offset=33792, unencoded_file_len=31744, unencoded_len=65536, compression=1, encryption=0 encoded_write bar - falling back to decompress and write due to errno 22 ("Invalid argument") (...) This patch avoids the regular write followed by an unaligned encoded write so that we end up sending a single encoded write that is aligned. So after this patch the stream content is (output of btrfs receive -vvv): (...) mkfile o258-7-0 rename o258-7-0 -> bar utimes clone bar - source=foo source offset=0 offset=0 length=32768 encoded_write bar - offset=32768, len=4096, unencoded_offset=32768, unencoded_file_len=32768, unencoded_len=65536, compression=1, encryption=0 (...) So we get more optimal behaviour and avoid the silent data loss bug in versions of btrfs-progs affected by the bug referred by the Link tag below (btrfs-progs v5.19, v5.19.1, v6.0 and v6.0.1). Link: https://lore.kernel.org/linux-btrfs/cover.1668529099.git.fdmanana@suse.com/Reviewed-by:Boris Burkov <boris@bur.io> Signed-off-by:
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Christoph Hellwig authored
generation is an on-disk __le64 value, so use btrfs_super_generation to convert it to host endian before comparing it. Fixes: 12659251 ("btrfs: implement log-structured superblock for ZONED mode") CC: stable@vger.kernel.org # 5.15+ Reviewed-by:
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- 15 Nov, 2022 5 commits
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Anand Jain authored
btrfs_ioctl_get_subvol_info() frees the search path after the userspace copy from the temp buffer @subvol_info. This can lead to a lock splat warning. Fix this by freeing the path before we copy it to userspace. CC: stable@vger.kernel.org # 4.19+ Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
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Anand Jain authored
btrfs_ioctl_ino_to_path() frees the search path after the userspace copy from the temp buffer @ipath->fspath. Which potentially can lead to a lock splat warning. Fix this by freeing the path before we copy it to userspace. CC: stable@vger.kernel.org # 4.19+ Signed-off-by:
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Anand Jain authored
btrfs_ioctl_logical_to_ino() frees the search path after the userspace copy from the temp buffer @inodes. Which potentially can lead to a lock splat. Fix this by freeing the path before we copy @inodes to userspace. CC: stable@vger.kernel.org # 4.19+ Signed-off-by:
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Josef Bacik authored
Syzbot reported the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted ------------------------------------------------------ syz-executor307/3029 is trying to acquire lock: ffff0000c02525d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x54/0xb4 mm/memory.c:5576 but task is already holding lock: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1624 __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root+0x74/0x338 fs/btrfs/ctree.c:1637 btrfs_search_slot+0x1b0/0xfd8 fs/btrfs/ctree.c:1944 btrfs_update_root+0x6c/0x5a0 fs/btrfs/root-tree.c:132 commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1459 btrfs_commit_transaction+0x89c/0x12d8 fs/btrfs/transaction.c:2343 flush_space+0x66c/0x738 fs/btrfs/space-info.c:786 btrfs_async_reclaim_metadata_space+0x43c/0x4e0 fs/btrfs/space-info.c:1059 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #2 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 btrfs_record_root_in_trans fs/btrfs/transaction.c:516 [inline] start_transaction+0x248/0x944 fs/btrfs/transaction.c:752 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:781 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6651 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6697 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3688 do_filp_open+0xdc/0x1b8 fs/namei.c:3718 do_sys_openat2+0xb8/0x22c fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1340 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #1 (sb_internal#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:683 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:795 btrfs_dirty_inode+0x50/0x140 fs/btrfs/inode.c:6103 btrfs_update_time+0x1c0/0x1e8 fs/btrfs/inode.c:6145 inode_update_time fs/inode.c:1872 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1945 file_accessed include/linux/fs.h:2516 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2407 call_mmap include/linux/fs.h:2192 [inline] mmap_region+0x7fc/0xc14 mm/mmap.c:1752 do_mmap+0x644/0x97c mm/mmap.c:1540 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:552 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1586 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> &fs_info->reloc_mutex --> btrfs-root-00 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-root-00); lock(&fs_info->reloc_mutex); lock(btrfs-root-00); lock(&mm->mmap_lock); *** DEADLOCK *** 1 lock held by syz-executor307/3029: #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] #0: ffff0000c958a608 (btrfs-root-00){++++}-{3:3}, at: btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 stack backtrace: CPU: 0 PID: 3029 Comm: syz-executor307 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __might_fault+0x7c/0xb4 mm/memory.c:5577 _copy_to_user include/linux/uaccess.h:134 [inline] copy_to_user include/linux/uaccess.h:160 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 We do generally the right thing here, copying the references into a temporary buffer, however we are still holding the path when we do copy_to_user from the temporary buffer. Fix this by freeing the path before we copy to user space. Reported-by: syzbot+4ef9e52e464c6ff47d9d@syzkaller.appspotmail.com CC: stable@vger.kernel.org # 4.19+ Reviewed-by: -
Filipe Manana authored
When doing a nowait buffered write we can trigger the following assertion: [11138.437027] assertion failed: !path->nowait, in fs/btrfs/ctree.c:4658 [11138.438251] ------------[ cut here ]------------ [11138.438254] kernel BUG at fs/btrfs/messages.c:259! [11138.438762] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [11138.439450] CPU: 4 PID: 1091021 Comm: fsstress Not tainted 6.1.0-rc4-btrfs-next-128 #1 [11138.440611] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [11138.442553] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs] [11138.443583] Code: 5b 41 5a 41 (...) [11138.446437] RSP: 0018:ffffbaf0cf05b840 EFLAGS: 00010246 [11138.447235] RAX: 0000000000000039 RBX: ffffbaf0cf05b938 RCX: 0000000000000000 [11138.448303] RDX: 0000000000000000 RSI: ffffffffb2ef59f6 RDI: 00000000ffffffff [11138.449370] RBP: ffff9165f581eb68 R08: 00000000ffffffff R09: 0000000000000001 [11138.450493] R10: ffff9167a88421f8 R11: 0000000000000000 R12: ffff9164981b1000 [11138.451661] R13: 000000008c8f1000 R14: ffff9164991d4000 R15: ffff9164981b1000 [11138.452225] FS: 00007f1438a66440(0000) GS:ffff9167ad600000(0000) knlGS:0000000000000000 [11138.452949] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [11138.453394] CR2: 00007f1438a64000 CR3: 0000000100c36002 CR4: 0000000000370ee0 [11138.454057] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [11138.454879] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [11138.455779] Call Trace: [11138.456211] <TASK> [11138.456598] btrfs_next_old_leaf.cold+0x18/0x1d [btrfs] [11138.457827] ? kmem_cache_alloc+0x18d/0x2a0 [11138.458516] btrfs_lookup_csums_range+0x149/0x4d0 [btrfs] [11138.459407] csum_exist_in_range+0x56/0x110 [btrfs] [11138.460271] can_nocow_file_extent+0x27c/0x310 [btrfs] [11138.461155] can_nocow_extent+0x1ec/0x2e0 [btrfs] [11138.461672] btrfs_check_nocow_lock+0x114/0x1c0 [btrfs] [11138.462951] btrfs_buffered_write+0x44c/0x8e0 [btrfs] [11138.463482] btrfs_do_write_iter+0x42b/0x5f0 [btrfs] [11138.463982] ? lock_release+0x153/0x4a0 [11138.464347] io_write+0x11b/0x570 [11138.464660] ? lock_release+0x153/0x4a0 [11138.465213] ? lock_is_held_type+0xe8/0x140 [11138.466003] io_issue_sqe+0x63/0x4a0 [11138.466339] io_submit_sqes+0x238/0x770 [11138.466741] __do_sys_io_uring_enter+0x37b/0xb10 [11138.467206] ? lock_is_held_type+0xe8/0x140 [11138.467879] ? syscall_enter_from_user_mode+0x1d/0x50 [11138.468688] do_syscall_64+0x38/0x90 [11138.469265] entry_SYSCALL_64_after_hwframe+0x63/0xcd [11138.470017] RIP: 0033:0x7f1438c539e6 This is because to check if we can NOCOW, we check that if we can NOCOW into an extent (it's prealloc extent or the inode has NOCOW attribute), and then check if there are csums for the extent's range in the csum tree. The search may leave us beyond the last slot of a leaf, and then when we call btrfs_next_leaf() we end up at btrfs_next_old_leaf() with a time_seq of 0. This triggers a failure of the first assertion at btrfs_next_old_leaf(), since we have a nowait path. With assertions disabled, we simply don't respect the NOWAIT semantics, allowing the write to block on locks or blocking on IO for reading an extent buffer from disk. Fix this by: 1) Triggering the assertion only if time_seq is not 0, which means that search is being done by a tree mod log user, and in the buffered and direct IO write paths we don't use the tree mod log; 2) Implementing NOWAIT semantics at btrfs_next_old_leaf(). Any failure to lock an extent buffer should return immediately and not retry the search, as well as if we need to do IO to read an extent buffer from disk. Fixes: c922b016 ("btrfs: assert nowait mode is not used for some btree search functions") Signed-off-by:
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- 07 Nov, 2022 7 commits
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Johannes Thumshirn authored
If we're doing device replace on a zoned filesystem and discover in scrub_enumerate_chunks() that we don't have to copy the block group it is unlocked before it gets skipped. But as the block group hasn't yet been locked before it leads to a locking imbalance. To fix this simply remove the unlock. This was uncovered by fstests' testcase btrfs/163. Fixes: 9283b9e0 ("btrfs: remove lock protection for BLOCK_GROUP_FLAG_TO_COPY") Signed-off-by:
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Johannes Thumshirn authored
When performing seeding on a zoned filesystem it is necessary to initialize each zoned device's btrfs_zoned_device_info structure, otherwise mounting the filesystem will cause a NULL pointer dereference. This was uncovered by fstests' testcase btrfs/163. CC: stable@vger.kernel.org # 5.15+ Signed-off-by:
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Johannes Thumshirn authored
When cloning a btrfs_device, we're not cloning the associated btrfs_zoned_device_info structure of the device in case of a zoned filesystem. Later on this leads to a NULL pointer dereference when accessing the device's zone_info for instance when setting a zone as active. This was uncovered by fstests' testcase btrfs/161. CC: stable@vger.kernel.org # 5.15+ Signed-off-by:
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Qu Wenruo authored
This reverts commit 786672e9. [BUG] Since commit 786672e9 ("btrfs: scrub: use larger block size for data extent scrub"), btrfs scrub no longer reports errors if the corruption is not in the first sector of a STRIPE_LEN. The following script can expose the problem: mkfs.btrfs -f $dev mount $dev $mnt xfs_io -f -c "pwrite -S 0xff 0 8k" $mnt/foobar umount $mnt # 13631488 is the logical bytenr of above 8K extent btrfs-map-logical -l 13631488 -b 4096 $dev mirror 1 logical 13631488 physical 13631488 device /dev/test/scratch1 # Corrupt the 2nd sector of that extent xfs_io -f -c "pwrite -S 0x00 13635584 4k" $dev mount $dev $mnt btrfs scrub start -B $mnt scrub done for 54e63f9f-0c30-4c84-a33b-5c56014629b7 Scrub started: Mon Nov 7 07:18:27 2022 Status: finished Duration: 0:00:00 Total to scrub: 536.00MiB Rate: 0.00B/s Error summary: no errors found <<< [CAUSE] That offending commit enlarges the data extent scrub size from sector size to BTRFS_STRIPE_LEN, to avoid extra scrub_block to be allocated. But unfortunately the data extent scrub is still heavily relying on the fact that there is only one scrub_sector per scrub_block. Thus it will only check the first sector, and ignoring the remaining sectors. Furthermore the error reporting is not able to handle multiple sectors either. [FIX] For now just revert the offending commit. The consequence is just extra memory usage during scrub. We will need a proper change to make the remaining data scrub path to handle multiple sectors before we enlarging the data scrub size. Reported-by:
Li Zhang <zhanglikernel@gmail.com> Signed-off-by:
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David Sterba authored
Add ENOMEM among the error codes that don't print stack trace on transaction abort. We've got several reports from syzbot that detects stacks as errors but caused by limiting memory. As this is an artificial condition we don't need to know where exactly the error happens, the abort and error cleanup will continue like e.g. for EIO. As the transaction aborts code needs to be inline in a lot of code, the implementation cases about minimal bloat. The error codes are in a separate function and the WARN uses the condition directly. This increases the code size by 571 bytes on release build. Alternatives considered: add -ENOMEM among the errors, this increases size by 2340 bytes, various attempts to combine the WARN and helper calls, increase by 700 or more bytes. Example syzbot reports (error -12): - https://syzkaller.appspot.com/bug?extid=5244d35be7f589cf093e - https://syzkaller.appspot.com/bug?extid=9c37714c07194d816417Signed-off-by:
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Zhang Xiaoxu authored
The btrfs_alloc_dummy_root() uses ERR_PTR as the error return value rather than NULL, if error happened, there will be a NULL pointer dereference: BUG: KASAN: null-ptr-deref in btrfs_free_dummy_root+0x21/0x50 [btrfs] Read of size 8 at addr 000000000000002c by task insmod/258926 CPU: 2 PID: 258926 Comm: insmod Tainted: G W 6.1.0-rc2+ #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 kasan_report+0xb7/0x140 kasan_check_range+0x145/0x1a0 btrfs_free_dummy_root+0x21/0x50 [btrfs] btrfs_test_free_space_cache+0x1a8c/0x1add [btrfs] btrfs_run_sanity_tests+0x65/0x80 [btrfs] init_btrfs_fs+0xec/0x154 [btrfs] do_one_initcall+0x87/0x2a0 do_init_module+0xdf/0x320 load_module+0x3006/0x3390 __do_sys_finit_module+0x113/0x1b0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: aaedb55b ("Btrfs: add tests for btrfs_get_extent") CC: stable@vger.kernel.org # 4.9+ Reviewed-by:
Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by:
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Liu Shixin authored
syzkaller found a failed assertion: assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921 This can be triggered when we set devid to (u64)-1 by ioctl. In this case, the match of devid will be skipped and the match of device may succeed incorrectly. Patch 562d7b15 introduced this function which is used to match device. This function contains two matching scenarios, we can distinguish them by checking the value of args->missing rather than check whether args->devid and args->uuid is default value. Reported-by: syzbot+031687116258450f9853@syzkaller.appspotmail.com Fixes: 562d7b15 ("btrfs: handle device lookup with btrfs_dev_lookup_args") CC: stable@vger.kernel.org # 5.16+ Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
Liu Shixin <liushixin2@huawei.com> Signed-off-by:
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- 02 Nov, 2022 6 commits
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Filipe Manana authored
During a nowait buffered write, if we fail to balance dirty pages we exit btrfs_buffered_write() without releasing the delalloc space reserved for an extent, resulting in leaking space from the inode's block reserve. So fix that by releasing the delalloc space for the extent when balancing dirty pages fails. Reported-by:
kernel test robot <yujie.liu@intel.com> Link: https://lore.kernel.org/all/202210111304.d369bc32-yujie.liu@intel.com Fixes: 965f47ae ("btrfs: make btrfs_buffered_write nowait compatible") Reviewed-by:
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Filipe Manana authored
If we are doing a buffered write in NOWAIT context and we can't reserve metadata space due to -ENOSPC, then we should return -EAGAIN so that we retry the write in a context allowed to block and do metadata reservation with flushing, which might succeed this time due to the allowed flushing. Returning -ENOSPC while in NOWAIT context simply makes some writes fail with -ENOSPC when they would likely succeed after switching from NOWAIT context to blocking context. That is unexpected behaviour and even fio complains about it with a warning like this: fio: io_u error on file /mnt/sdi/task_0.0.0: No space left on device: write offset=1535705088, buflen=65536 fio: pid=592630, err=28/file:io_u.c:1846, func=io_u error, error=No space left on device The fio's job config is this: [global] bs=64K ioengine=io_uring iodepth=1 size=2236962133 nr_files=1 filesize=2236962133 direct=0 runtime=10 fallocate=posix io_size=2236962133 group_reporting time_based [task_0] rw=randwrite directory=/mnt/sdi numjobs=4 So fix this by returning -EAGAIN if we are in NOWAIT context and the metadata reservation failed with -ENOSPC. Fixes: 304e45ac ("btrfs: plumb NOWAIT through the write path") Reviewed-by:
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Filipe Manana authored
Several places in the qgroup self tests follow the pattern of freeing the ulist pointer they passed to btrfs_find_all_roots() if the call to that function returned an error. That is pointless because that function always frees the ulist in case it returns an error. Also In some places like at test_multiple_refs(), after a call to btrfs_qgroup_account_extent() we also leave "old_roots" and "new_roots" pointing to ulists that were freed, because btrfs_qgroup_account_extent() has freed those ulists, and if after that the next call to btrfs_find_all_roots() fails, we call ulist_free() on the "old_roots" ulist again, resulting in a double free. So remove those calls to reduce the code size and avoid double ulist free in case of an error. Signed-off-by:
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Filipe Manana authored
In the test_no_shared_qgroup() and test_multiple_refs() qgroup self tests, if we fail to add the tree ref, remove the extent item or remove the extent ref, we are returning from the test function without freeing the "old_roots" ulist that was allocated by the previous calls to btrfs_find_all_roots(). Fix that by calling ulist_free() before returning. Fixes: 442244c9 ("btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.") Signed-off-by:
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Filipe Manana authored
During backref walking, at find_parent_nodes(), if we are dealing with a data extent and we get an error while resolving the indirect backrefs, at resolve_indirect_refs(), or in the while loop that iterates over the refs in the direct refs rbtree, we end up leaking the inode lists attached to the direct refs we have in the direct refs rbtree that were not yet added to the refs ulist passed as argument to find_parent_nodes(). Since they were not yet added to the refs ulist and prelim_release() does not free the lists, on error the caller can only free the lists attached to the refs that were added to the refs ulist, all the remaining refs get their inode lists never freed, therefore leaking their memory. Fix this by having prelim_release() always free any attached inode list to each ref found in the rbtree, and have find_parent_nodes() set the ref's inode list to NULL once it transfers ownership of the inode list to a ref added to the refs ulist passed to find_parent_nodes(). Fixes: 86d5f994 ("btrfs: convert prelimary reference tracking to use rbtrees") Signed-off-by:
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Filipe Manana authored
During backref walking, at resolve_indirect_refs(), if we get an error we jump to the 'out' label and call ulist_free() on the 'parents' ulist, which frees all the elements in the ulist - however that does not free any inode lists that may be attached to elements, through the 'aux' field of a ulist node, so we end up leaking lists if we have any attached to the unodes. Fix this by calling free_leaf_list() instead of ulist_free() when we exit from resolve_indirect_refs(). The static function free_leaf_list() is moved up for this to be possible and it's slightly simplified by removing unnecessary code. Fixes: 3301958b ("Btrfs: add inodes before dropping the extent lock in find_all_leafs") Signed-off-by:
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- 31 Oct, 2022 2 commits
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Filipe Manana authored
When doing a direct IO write using a iocb with nowait and dsync set, we end up not syncing the file once the write completes. This is because we tell iomap to not call generic_write_sync(), which would result in calling btrfs_sync_file(), in order to avoid a deadlock since iomap can call it while we are holding the inode's lock and btrfs_sync_file() needs to acquire the inode's lock. The deadlock happens only if the write happens synchronously, when iomap_dio_rw() calls iomap_dio_complete() before it returns. Instead we do the sync ourselves at btrfs_do_write_iter(). For a nowait write however we can end up not doing the sync ourselves at at btrfs_do_write_iter() because the write could have been queued, and therefore we get -EIOCBQUEUED returned from iomap in such case. That makes us skip the sync call at btrfs_do_write_iter(), as we don't do it for any error returned from btrfs_direct_write(). We can't simply do the call even if -EIOCBQUEUED is returned, since that would block the task waiting for IO, both for the data since there are bios still in progress as well as potentially blocking when joining a log transaction and when syncing the log (writing log trees, super blocks, etc). So let iomap do the sync call itself and in order to avoid deadlocks for the case of synchronous writes (without nowait), use __iomap_dio_rw() and have ourselves call iomap_dio_complete() after unlocking the inode. A test case will later be sent for fstests, after this is fixed in Linus' tree. Fixes: 51bd9563 ("btrfs: fix deadlock due to page faults during direct IO reads and writes") Reported-by:
Марк Коренберг <socketpair@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAEmTpZGRKbzc16fWPvxbr6AfFsQoLmz-Lcg-7OgJOZDboJ+SGQ@mail.gmail.com/ CC: stable@vger.kernel.org # 6.0+ Signed-off-by:
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Christophe JAILLET authored
After allocation 'dip' is tested instead of 'dip->csums'. Fix it. Fixes: 642c5d34 ("btrfs: allocate the btrfs_dio_private as part of the iomap dio bio") CC: stable@vger.kernel.org # 5.19+ Reviewed-by:
Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by:
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- 25 Oct, 2022 1 commit
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Qu Wenruo authored
[BUG] There are two reports (the earliest one from LKP, a more recent one from kernel bugzilla) that we can have some chunks with 0 as sub_stripes. This will cause divide-by-zero errors at btrfs_rmap_block, which is introduced by a recent kernel patch ac067734 ("btrfs: merge calculations for simple striped profiles in btrfs_rmap_block"): if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) { stripe_nr = stripe_nr * map->num_stripes + i; stripe_nr = div_u64(stripe_nr, map->sub_stripes); <<< } [CAUSE] From the more recent report, it has been proven that we have some chunks with 0 as sub_stripes, mostly caused by older mkfs. It turns out that the mkfs.btrfs fix is only introduced in 6718ab4d33aa ("btrfs-progs: Initialize sub_stripes to 1 in btrfs_alloc_data_chunk") which is included in v5.4 btrfs-progs release. So there would be quite some old filesystems with such 0 sub_stripes. [FIX] Just don't trust the sub_stripes values from disk. We have a trusted btrfs_raid_array[] to fetch the correct sub_stripes numbers for each profile and that are fixed. By this, we can keep the compatibility with older filesystems while still avoid divide-by-zero bugs. Reported-by:
kernel test robot <oliver.sang@intel.com> Reported-by:
Viktor Kuzmin <kvaster@gmail.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216559 Fixes: ac067734 ("btrfs: merge calculations for simple striped profiles in btrfs_rmap_block") CC: stable@vger.kernel.org # 6.0 Reviewed-by:
Su Yue <glass@fydeos.io> Reviewed-by:
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- 24 Oct, 2022 7 commits
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David Sterba authored
The type of parameter generation has been u32 since the beginning, however all callers pass a u64 generation, so unify the types to prevent potential loss. CC: stable@vger.kernel.org # 4.9+ Reviewed-by:
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BingJing Chang authored
Commit 9ed0a72e ("btrfs: send: fix failures when processing inodes with no links") tries to fix all incremental send cases of orphan inodes the send operation will meet. However, there's still a bug causing the corner subcase fails with a ENOENT error. Here's shortened steps of that subcase: $ btrfs subvolume create vol $ touch vol/foo $ btrfs subvolume snapshot -r vol snap1 $ btrfs subvolume snapshot -r vol snap2 # Turn the second snapshot to RW mode and delete the file while # holding an open file descriptor on it $ btrfs property set snap2 ro false $ exec 73<snap2/foo $ rm snap2/foo # Set the second snapshot back to RO mode and do an incremental send # with an unusal reverse order $ btrfs property set snap2 ro true $ btrfs send -p snap2 snap1 > /dev/null At subvol snap1 ERROR: send ioctl failed with -2: No such file or directory It's subcase 3 of BTRFS_COMPARE_TREE_CHANGED in the commit 9ed0a72e ("btrfs: send: fix failures when processing inodes with no links"). And it's not a common case. We still have not met it in the real world. Theoretically, this case can happen in a batch cascading snapshot backup. In cascading backups, the receive operation in the middle may cause orphan inodes to appear because of the open file descriptors on the snapshot files during receiving. And if we don't do the batch snapshot backups in their creation order, then we can have an inode, which is an orphan in the parent snapshot but refers to a file in the send snapshot. Since an orphan inode has no paths, the send operation will fail with a ENOENT error if it tries to generate a path for it. In that patch, this subcase will be treated as an inode with a new generation. However, when the routine tries to delete the old paths in the parent snapshot, the function process_all_refs() doesn't check whether there are paths recorded or not before it calls the function process_recorded_refs(). And the function process_recorded_refs() try to get the first path in the parent snapshot in the beginning. Since it has no paths in the parent snapshot, the send operation fails. To fix this, we can easily put a link count check to avoid entering the deletion routine like what we do a link count check to avoid creating a new one. Moreover, we can assume that the function process_all_refs() can always collect references to process because we know it has a positive link count. Fixes: 9ed0a72e ("btrfs: send: fix failures when processing inodes with no links") Reviewed-by:
BingJing Chang <bingjingc@synology.com> Signed-off-by:
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Qu Wenruo authored
Previous commit a05d3c91 ("btrfs: check superblock to ensure the fs was not modified at thaw time") only checks the content of the super block, but it doesn't really check if the on-disk super block has a matching checksum. This patch will add the checksum verification to thaw time superblock verification. This involves the following extra changes: - Export btrfs_check_super_csum() As we need to call it in super.c. - Change the argument list of btrfs_check_super_csum() Instead of passing a char *, directly pass struct btrfs_super_block * pointer. - Verify that our checksum type didn't change before checking the checksum value, like it's done at mount time Fixes: a05d3c91 ("btrfs: check superblock to ensure the fs was not modified at thaw time") Reviewed-by:
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Josef Bacik authored
We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba3 ("Btrfs: add tree modification log functions") CC: stable@vger.kernel.org # 3.3+ Reviewed-by: -
David Sterba authored
After changes in commit 917f32a2 ("btrfs: give struct btrfs_bio a real end_io handler") the layout of btrfs_bio can be improved. There are two holes and the structure size is 264 bytes on release build. By reordering the iterator we can get rid of the holes and the size is 256 bytes which fits to slabs much better. Final layout: struct btrfs_bio { unsigned int mirror_num; /* 0 4 */ struct bvec_iter iter; /* 4 20 */ u64 file_offset; /* 24 8 */ struct btrfs_device * device; /* 32 8 */ u8 * csum; /* 40 8 */ u8 csum_inline[64]; /* 48 64 */ /* --- cacheline 1 boundary (64 bytes) was 48 bytes ago --- */ btrfs_bio_end_io_t end_io; /* 112 8 */ void * private; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ struct work_struct end_io_work; /* 128 32 */ struct bio bio; /* 160 96 */ /* size: 256, cachelines: 4, members: 10 */ }; Fixes: 917f32a2 ("btrfs: give struct btrfs_bio a real end_io handler") Signed-off-by:
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Qu Wenruo authored
Currently if full_stripe_write() failed to allocate the pages for parity, it will call __free_raid_bio() first, then return -ENOMEM. But some caller of full_stripe_write() will also call __free_raid_bio() again, this would cause double freeing. And it's not a logically sound either, normally we should either free the memory at the same level where we allocated it, or let endio to handle everything. So this patch will solve the double freeing by make raid56_parity_write() to handle the error and free the rbio. Just like what we do in raid56_parity_recover(). Signed-off-by:
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Qu Wenruo authored
In raid56_alloc_missing_rbio(), if we can not determine where the missing device is inside the full stripe, we just BUG_ON(). This is not necessary especially the only caller inside scrub.c is already properly checking the return value, and will treat it as a memory allocation failure. Fix the error handling by: - Add an extra warning for the reason Although personally speaking it may be better to be an ASSERT(). - Properly free the allocated rbio Signed-off-by:
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- 14 Oct, 2022 1 commit
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David Sterba authored
We have the new documentation hosted on Read The Docs and content is migrated there from the wiki. Also update http to https and add the tracepoint definition header. Signed-off-by:
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- 11 Oct, 2022 5 commits
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Filipe Manana authored
The path cache used during fiemap used to determine the sharedness of extent buffers in a path from a leaf containing a file extent item pointing to our data extent up to the root node of the tree, is meant to be used for a single path. Having a single path is by far the most common case, and therefore worth to optimize for, but it's possible to actually have multiple paths because we have 2 or more leaves. If we have multiple leaves, the 'level' variable keeps getting incremented in each iteration of the while loop at btrfs_is_data_extent_shared(), which means we will treat the second leaf in the 'tmp' ulist as a level 1 node, and so forth. In the worst case this can lead to getting a level greater than or equals to BTRFS_MAX_LEVEL (8), which will trigger a WARN_ON_ONCE() in the functions to lookup from or store in the path cache (lookup_backref_shared_cache() and store_backref_shared_cache()). If the current level never goes beyond 8, due to shared nodes in the paths and a fs tree height smaller than 8, it can still result in incorrectly marking one leaf as shared because some other leaf is shared and is stored one level below that other leaf, as when storing a true sharedness value in the cache results in updating the sharedness to true of all entries in the cache below the current level. Having multiple leaves happens in a case like the following: - We have a file extent item point to data extent at bytenr X, for a file range [0, 1M[ for example; - At this moment we have an extent data ref for the extent, with an offset of 0 and a count of 1; - A write into the middle of the extent happens, file range [64K, 128K) so the file extent item is split into two (at btrfs_drop_extents()): 1) One for file range [0, 64K), with a length (num_bytes field) of 64K and an extent offset of 0; 2) Another one for file range [128K, 1M), with a length of 896K (1M - 128K) and an extent offset of 128K. - At this moment the two file extent items are located in the same leaf; - A new file extent item for the range [64K, 128K), pointing to a new data extent, is inserted in the leaf. This results in a leaf split and now those two file extent items pointing to data extent X end up located in different leaves; - Once delayed refs are run, we still have a single extent data ref item for our data extent at bytenr X, for offset 0, but now with a count of 2 instead of 1; - So during fiemap, at btrfs_is_data_extent_shared(), after we call find_parent_nodes() for the data extent, we get two leaves, since we have two file extent items point to data extent at bytenr X that are located in two different leaves. So skip the use of the path cache when we get more than one leaf. Fixes: 12a824dc ("btrfs: speedup checking for extent sharedness during fiemap") Signed-off-by: -
Filipe Manana authored
During backref walking, when processing a delayed reference with a type of BTRFS_TREE_BLOCK_REF_KEY, we have two bugs there: 1) We are accessing the delayed references extent_op, and its key, without the protection of the delayed ref head's lock; 2) If there's no extent op for the delayed ref head, we end up with an uninitialized key in the stack, variable 'tmp_op_key', and then pass it to add_indirect_ref(), which adds the reference to the indirect refs rb tree. This is wrong, because indirect references should have a NULL key when we don't have access to the key, and in that case they should be added to the indirect_missing_keys rb tree and not to the indirect rb tree. This means that if have BTRFS_TREE_BLOCK_REF_KEY delayed ref resulting from freeing an extent buffer, therefore with a count of -1, it will not cancel out the corresponding reference we have in the extent tree (with a count of 1), since both references end up in different rb trees. When using fiemap, where we often need to check if extents are shared through shared subtrees resulting from snapshots, it means we can incorrectly report an extent as shared when it's no longer shared. However this is temporary because after the transaction is committed the extent is no longer reported as shared, as running the delayed reference results in deleting the tree block reference from the extent tree. Outside the fiemap context, the result is unpredictable, as the key was not initialized but it's used when navigating the rb trees to insert and search for references (prelim_ref_compare()), and we expect all references in the indirect rb tree to have valid keys. The following reproducer triggers the second bug: $ cat test.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount -o compress $DEV $MNT # With a compressed 128M file we get a tree height of 2 (level 1 root). xfs_io -f -c "pwrite -b 1M 0 128M" $MNT/foo btrfs subvolume snapshot $MNT $MNT/snap # Fiemap should output 0x2008 in the flags column. # 0x2000 means shared extent # 0x8 means encoded extent (because it's compressed) echo echo "fiemap after snapshot, range [120M, 120M + 128K):" xfs_io -c "fiemap -v 120M 128K" $MNT/foo echo # Overwrite one extent and fsync to flush delalloc and COW a new path # in the snapshot's tree. # # After this we have a BTRFS_DROP_DELAYED_REF delayed ref of type # BTRFS_TREE_BLOCK_REF_KEY with a count of -1 for every COWed extent # buffer in the path. # # In the extent tree we have inline references of type # BTRFS_TREE_BLOCK_REF_KEY, with a count of 1, for the same extent # buffers, so they should cancel each other, and the extent buffers in # the fs tree should no longer be considered as shared. # echo "Overwriting file range [120M, 120M + 128K)..." xfs_io -c "pwrite -b 128K 120M 128K" $MNT/snap/foo xfs_io -c "fsync" $MNT/snap/foo # Fiemap should output 0x8 in the flags column. The extent in the range # [120M, 120M + 128K) is no longer shared, it's now exclusive to the fs # tree. echo echo "fiemap after overwrite range [120M, 120M + 128K):" xfs_io -c "fiemap -v 120M 128K" $MNT/foo echo umount $MNT Running it before this patch: $ ./test.sh (...) wrote 134217728/134217728 bytes at offset 0 128 MiB, 128 ops; 0.1152 sec (1.085 GiB/sec and 1110.5809 ops/sec) Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap' fiemap after snapshot, range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 Overwriting file range [120M, 120M + 128K)... wrote 131072/131072 bytes at offset 125829120 128 KiB, 1 ops; 0.0001 sec (683.060 MiB/sec and 5464.4809 ops/sec) fiemap after overwrite range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 The extent in the range [120M, 120M + 128K) is still reported as shared (0x2000 bit set) after overwriting that range and flushing delalloc, which is not correct - an entire path was COWed in the snapshot's tree and the extent is now only referenced by the original fs tree. Running it after this patch: $ ./test.sh (...) wrote 134217728/134217728 bytes at offset 0 128 MiB, 128 ops; 0.1198 sec (1.043 GiB/sec and 1068.2067 ops/sec) Create a snapshot of '/mnt/sdj' in '/mnt/sdj/snap' fiemap after snapshot, range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x2008 Overwriting file range [120M, 120M + 128K)... wrote 131072/131072 bytes at offset 125829120 128 KiB, 1 ops; 0.0001 sec (694.444 MiB/sec and 5555.5556 ops/sec) fiemap after overwrite range [120M, 120M + 128K): /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [245760..246015]: 34304..34559 256 0x8 Now the extent is not reported as shared anymore. So fix this by passing a NULL key pointer to add_indirect_ref() when processing a delayed reference for a tree block if there's no extent op for our delayed ref head with a defined key. Also access the extent op only after locking the delayed ref head's lock. The reproducer will be converted later to a test case for fstests. Fixes: 86d5f994 ("btrfs: convert prelimary reference tracking to use rbtrees") Fixes: a6dbceaf ("btrfs: Remove unused op_key var from add_delayed_refs") Signed-off-by: -
Filipe Manana authored
When processing delayed data references during backref walking and we are using a share context (we are being called through fiemap), whenever we find a delayed data reference for an inode different from the one we are interested in, then we immediately exit and consider the data extent as shared. This is wrong, because: 1) This might be a DROP reference that will cancel out a reference in the extent tree; 2) Even if it's an ADD reference, it may be followed by a DROP reference that cancels it out. In either case we should not exit immediately. Fix this by never exiting when we find a delayed data reference for another inode - instead add the reference and if it does not cancel out other delayed reference, we will exit early when we call extent_is_shared() after processing all delayed references. If we find a drop reference, then signal the code that processes references from the extent tree (add_inline_refs() and add_keyed_refs()) to not exit immediately if it finds there a reference for another inode, since we have delayed drop references that may cancel it out. In this later case we exit once we don't have references in the rb trees that cancel out each other and have two references for different inodes. Example reproducer for case 1): $ cat test-1.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT xfs_io -f -c "pwrite 0 64K" $MNT/foo cp --reflink=always $MNT/foo $MNT/bar echo echo "fiemap after cloning:" xfs_io -c "fiemap -v" $MNT/foo rm -f $MNT/bar echo echo "fiemap after removing file bar:" xfs_io -c "fiemap -v" $MNT/foo umount $MNT Running it before this patch, the extent is still listed as shared, it has the flag 0x2000 (FIEMAP_EXTENT_SHARED) set: $ ./test-1.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 Example reproducer for case 2): $ cat test-2.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT xfs_io -f -c "pwrite 0 64K" $MNT/foo cp --reflink=always $MNT/foo $MNT/bar # Flush delayed references to the extent tree and commit current # transaction. sync echo echo "fiemap after cloning:" xfs_io -c "fiemap -v" $MNT/foo rm -f $MNT/bar echo echo "fiemap after removing file bar:" xfs_io -c "fiemap -v" $MNT/foo umount $MNT Running it before this patch, the extent is still listed as shared, it has the flag 0x2000 (FIEMAP_EXTENT_SHARED) set: $ ./test-2.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 After this patch, after deleting bar in both tests, the extent is not reported with the 0x2000 flag anymore, it gets only the flag 0x1 (which is FIEMAP_EXTENT_LAST): $ ./test-1.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x1 $ ./test-2.sh fiemap after cloning: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x2001 fiemap after removing file bar: /mnt/sdj/foo: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 26624..26751 128 0x1 These tests will later be converted to a test case for fstests. Fixes: dc046b10 ("Btrfs: make fiemap not blow when you have lots of snapshots") Signed-off-by: -
David Sterba authored
There are two comments in btrfs_cache_block_group that I left when resolving conflict between commits ced8ecf0 "btrfs: fix space cache corruption and potential double allocations" and 527c490f "btrfs: delete btrfs_wait_space_cache_v1_finished". The former reworked the caching logic to wait until the caching ends in btrfs_cache_block_group while the latter only open coded the waiting. Both removed btrfs_wait_space_cache_v1_finished, the correct code is with the waiting and returning error. Thus the conflict resolution was OK. Signed-off-by:
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Josef Bacik authored
In production we hit the following deadlock task 1 task 2 task 3 ------ ------ ------ fiemap(file) falloc(file) fsync(file) write(0, 1MiB) btrfs_commit_transaction() wait_on(!pending_ordered) lock(512MiB, 1GiB) start_transaction wait_on_transaction lock(0, 1GiB) wait_extent_bit(512MiB) task 4 ------ finish_ordered_extent(0, 1MiB) lock(0, 1MiB) **DEADLOCK** This occurs because when task 1 does it's lock, it locks everything from 0-512MiB, and then waits for the 512MiB chunk to unlock. task 2 will never unlock because it's waiting on the transaction commit to happen, the transaction commit is waiting for the outstanding ordered extents, and then the ordered extent thread is blocked waiting on the 0-1MiB range to unlock. To fix this we have to clear anything we've locked so far, wait for the extent_state that we contended on, and then try to re-lock the entire range again. CC: stable@vger.kernel.org # 5.15+ Reviewed-by:
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