kernel/linux.git/fs/btrfs/ctree.c, branch linux-5.3.y

btrfs: Relinquish CPUs in btrfs_compare_trees

2019-10-05T13:12:31+00:00

commit 6af112b11a4bc1b560f60a618ac9c1dcefe9836e upstream. When doing any form of incremental send the parent and the child trees need to be compared via btrfs_compare_trees. This can result in long loop chains without ever relinquishing the CPU. This causes softlockup detector to trigger when comparing trees with a lot of items. Example report: watchdog: BUG: soft lockup - CPU#0 stuck for 24s! [snapperd:16153] CPU: 0 PID: 16153 Comm: snapperd Not tainted 5.2.9-1-default #1 openSUSE Tumbleweed (unreleased) Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40000005 (nZcv daif -PAN -UAO) pc : __ll_sc_arch_atomic_sub_return+0x14/0x20 lr : btrfs_release_extent_buffer_pages+0xe0/0x1e8 [btrfs] sp : ffff00001273b7e0 Call trace: __ll_sc_arch_atomic_sub_return+0x14/0x20 release_extent_buffer+0xdc/0x120 [btrfs] free_extent_buffer.part.0+0xb0/0x118 [btrfs] free_extent_buffer+0x24/0x30 [btrfs] btrfs_release_path+0x4c/0xa0 [btrfs] btrfs_free_path.part.0+0x20/0x40 [btrfs] btrfs_free_path+0x24/0x30 [btrfs] get_inode_info+0xa8/0xf8 [btrfs] finish_inode_if_needed+0xe0/0x6d8 [btrfs] changed_cb+0x9c/0x410 [btrfs] btrfs_compare_trees+0x284/0x648 [btrfs] send_subvol+0x33c/0x520 [btrfs] btrfs_ioctl_send+0x8a0/0xaf0 [btrfs] btrfs_ioctl+0x199c/0x2288 [btrfs] do_vfs_ioctl+0x4b0/0x820 ksys_ioctl+0x84/0xb8 __arm64_sys_ioctl+0x28/0x38 el0_svc_common.constprop.0+0x7c/0x188 el0_svc_handler+0x34/0x90 el0_svc+0x8/0xc Fix this by adding a call to cond_resched at the beginning of the main loop in btrfs_compare_trees. Fixes: 7069830a9e38 ("Btrfs: add btrfs_compare_trees function") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

Btrfs: fix use-after-free when using the tree modification log

2019-10-05T13:12:31+00:00

commit efad8a853ad2057f96664328a0d327a05ce39c76 upstream. At ctree.c:get_old_root(), we are accessing a root's header owner field after we have freed the respective extent buffer. This results in an use-after-free that can lead to crashes, and when CONFIG_DEBUG_PAGEALLOC is set, results in a stack trace like the following: [ 3876.799331] stack segment: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [ 3876.799363] CPU: 0 PID: 15436 Comm: pool Not tainted 5.3.0-rc3-btrfs-next-54 #1 [ 3876.799385] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 3876.799433] RIP: 0010:btrfs_search_old_slot+0x652/0xd80 [btrfs] (...) [ 3876.799502] RSP: 0018:ffff9f08c1a2f9f0 EFLAGS: 00010286 [ 3876.799518] RAX: ffff8dd300000000 RBX: ffff8dd85a7a9348 RCX: 000000038da26000 [ 3876.799538] RDX: 0000000000000000 RSI: ffffe522ce368980 RDI: 0000000000000246 [ 3876.799559] RBP: dae1922adadad000 R08: 0000000008020000 R09: ffffe522c0000000 [ 3876.799579] R10: ffff8dd57fd788c8 R11: 000000007511b030 R12: ffff8dd781ddc000 [ 3876.799599] R13: ffff8dd9e6240578 R14: ffff8dd6896f7a88 R15: ffff8dd688cf90b8 [ 3876.799620] FS: 00007f23ddd97700(0000) GS:ffff8dda20200000(0000) knlGS:0000000000000000 [ 3876.799643] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3876.799660] CR2: 00007f23d4024000 CR3: 0000000710bb0005 CR4: 00000000003606f0 [ 3876.799682] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3876.799703] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3876.799723] Call Trace: [ 3876.799735] ? do_raw_spin_unlock+0x49/0xc0 [ 3876.799749] ? _raw_spin_unlock+0x24/0x30 [ 3876.799779] resolve_indirect_refs+0x1eb/0xc80 [btrfs] [ 3876.799810] find_parent_nodes+0x38d/0x1180 [btrfs] [ 3876.799841] btrfs_check_shared+0x11a/0x1d0 [btrfs] [ 3876.799870] ? extent_fiemap+0x598/0x6e0 [btrfs] [ 3876.799895] extent_fiemap+0x598/0x6e0 [btrfs] [ 3876.799913] do_vfs_ioctl+0x45a/0x700 [ 3876.799926] ksys_ioctl+0x70/0x80 [ 3876.799938] ? trace_hardirqs_off_thunk+0x1a/0x20 [ 3876.799953] __x64_sys_ioctl+0x16/0x20 [ 3876.799965] do_syscall_64+0x62/0x220 [ 3876.799977] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 3876.799993] RIP: 0033:0x7f23e0013dd7 (...) [ 3876.800056] RSP: 002b:00007f23ddd96ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 3876.800078] RAX: ffffffffffffffda RBX: 00007f23d80210f8 RCX: 00007f23e0013dd7 [ 3876.800099] RDX: 00007f23d80210f8 RSI: 00000000c020660b RDI: 0000000000000003 [ 3876.800626] RBP: 000055fa2a2a2440 R08: 0000000000000000 R09: 00007f23ddd96d7c [ 3876.801143] R10: 00007f23d8022000 R11: 0000000000000246 R12: 00007f23ddd96d80 [ 3876.801662] R13: 00007f23ddd96d78 R14: 00007f23d80210f0 R15: 00007f23ddd96d80 (...) [ 3876.805107] ---[ end trace e53161e179ef04f9 ]--- Fix that by saving the root's header owner field into a local variable before freeing the root's extent buffer, and then use that local variable when needed. Fixes: 30b0463a9394d9 ("Btrfs: fix accessing the root pointer in tree mod log functions") CC: stable@vger.kernel.org # 3.10+ Reviewed-by: Nikolay Borisov Reviewed-by: Anand Jain Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: ctree: Dump the leaf before BUG_ON in btrfs_set_item_key_safe

2019-04-29T17:02:52+00:00

We have a long standing problem with reversed keys that's detected by btrfs_set_item_key_safe. This is hard to reproduce so we'd like to capture more information for later analysis. Let's dump the leaf content before triggering BUG_ON() so that we can have some clue on what's going wrong. The output of tree locks should help us to debug such problem. Sample stacktrace: generic/522 [00:07:05] [26946.113381] run fstests generic/522 at 2019-04-16 00:07:05 [27161.474720] kernel BUG at fs/btrfs/ctree.c:3192! [27161.475923] invalid opcode: 0000 [#1] PREEMPT SMP [27161.477167] CPU: 0 PID: 15676 Comm: fsx Tainted: G W 5.1.0-rc5-default+ #562 [27161.478932] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 [27161.481099] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.485369] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.486464] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.487929] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.489289] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.490807] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.492305] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.493845] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.495608] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.496717] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 [27161.498100] Call Trace: [27161.498771] __btrfs_drop_extents+0x6ec/0xdf0 [btrfs] [27161.499872] btrfs_log_changed_extents.isra.26+0x3a2/0x9e0 [btrfs] [27161.501114] btrfs_log_inode+0x7ff/0xdc0 [btrfs] [27161.502114] ? __mutex_unlock_slowpath+0x4b/0x2b0 [27161.503172] btrfs_log_inode_parent+0x237/0x9c0 [btrfs] [27161.504348] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [27161.505374] btrfs_sync_file+0x1b7/0x480 [btrfs] [27161.506371] __x64_sys_msync+0x180/0x210 [27161.507208] do_syscall_64+0x54/0x180 [27161.507932] entry_SYSCALL_64_after_hwframe+0x49/0xbe [27161.508839] RIP: 0033:0x7f8ea5aa9c61 [27161.512616] RSP: 002b:00007ffea2a06498 EFLAGS: 00000246 ORIG_RAX: 000000000000001a [27161.514161] RAX: ffffffffffffffda RBX: 000000000002a938 RCX: 00007f8ea5aa9c61 [27161.515376] RDX: 0000000000000004 RSI: 000000000001c9b2 RDI: 00007f8ea578d000 [27161.516572] RBP: 000000000001c07a R08: fffffffffffffff8 R09: 000000000002a000 [27161.517883] R10: 00007f8ea57a99b2 R11: 0000000000000246 R12: 0000000000000938 [27161.519080] R13: 00007f8ea578d000 R14: 000000000001c9b2 R15: 0000000000000000 [27161.520281] Modules linked in: btrfs libcrc32c xor zstd_decompress zstd_compress xxhash raid6_pq loop [last unloaded: scsi_debug] [27161.522272] ---[ end trace d5afec7ccac6a252 ]--- [27161.523111] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.527253] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.528192] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.529392] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.530607] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.531802] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.533018] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.534405] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.536048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.537210] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from btrfs_set_disk_extent_flags

2019-04-29T17:02:51+00:00

Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from from tree_advance

2019-04-29T17:02:50+00:00

Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from tree_move_down

2019-04-29T17:02:50+00:00

Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from btrfs_extend_item

2019-04-29T17:02:50+00:00

Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from btrfs_truncate_item

2019-04-29T17:02:50+00:00

Signed-off-by: David Sterba

btrfs: remove unused parameter fs_info from split_item

2019-04-29T17:02:50+00:00

Signed-off-by: David Sterba

btrfs: get fs_info from eb in __push_leaf_left

2019-04-29T17:02:47+00:00

We can read fs_info from extent buffer and can drop it from the parameters. Signed-off-by: David Sterba