Filipe Manana e26605497f btrfs: silence lockdep when reading chunk tree during mount ... [ Upstream commit 4d9380e0da ] Often some test cases like btrfs/161 trigger lockdep splats that complain about possible unsafe lock scenario due to the fact that during mount, when reading the chunk tree we end up calling blkdev_get_by_path() while holding a read lock on a leaf of the chunk tree. That produces a lockdep splat like the following: [ 3653.683975] ====================================================== [ 3653.685148] WARNING: possible circular locking dependency detected [ 3653.686301] 5.15.0-rc7-btrfs-next-103 #1 Not tainted [ 3653.687239] ------------------------------------------------------ [ 3653.688400] mount/447465 is trying to acquire lock: [ 3653.689320] ffff8c6b0c76e528 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.691054] but task is already holding lock: [ 3653.692155] ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.693978] which lock already depends on the new lock. [ 3653.695510] the existing dependency chain (in reverse order) is: [ 3653.696915] -> #3 (btrfs-chunk-00){++++}-{3:3}: [ 3653.698053] down_read_nested+0x4b/0x140 [ 3653.698893] __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.699988] btrfs_read_lock_root_node+0x31/0x40 [btrfs] [ 3653.701205] btrfs_search_slot+0x537/0xc00 [btrfs] [ 3653.702234] btrfs_insert_empty_items+0x32/0x70 [btrfs] [ 3653.703332] btrfs_init_new_device+0x563/0x15b0 [btrfs] [ 3653.704439] btrfs_ioctl+0x2110/0x3530 [btrfs] [ 3653.705405] __x64_sys_ioctl+0x83/0xb0 [ 3653.706215] do_syscall_64+0x3b/0xc0 [ 3653.706990] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.708040] -> #2 (sb_internal#2){.+.+}-{0:0}: [ 3653.708994] lock_release+0x13d/0x4a0 [ 3653.709533] up_write+0x18/0x160 [ 3653.710017] btrfs_sync_file+0x3f3/0x5b0 [btrfs] [ 3653.710699] __loop_update_dio+0xbd/0x170 [loop] [ 3653.711360] lo_ioctl+0x3b1/0x8a0 [loop] [ 3653.711929] block_ioctl+0x48/0x50 [ 3653.712442] __x64_sys_ioctl+0x83/0xb0 [ 3653.712991] do_syscall_64+0x3b/0xc0 [ 3653.713519] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.714233] -> #1 (&lo->lo_mutex){+.+.}-{3:3}: [ 3653.715026] __mutex_lock+0x92/0x900 [ 3653.715648] lo_open+0x28/0x60 [loop] [ 3653.716275] blkdev_get_whole+0x28/0x90 [ 3653.716867] blkdev_get_by_dev.part.0+0x142/0x320 [ 3653.717537] blkdev_open+0x5e/0xa0 [ 3653.718043] do_dentry_open+0x163/0x390 [ 3653.718604] path_openat+0x3f0/0xa80 [ 3653.719128] do_filp_open+0xa9/0x150 [ 3653.719652] do_sys_openat2+0x97/0x160 [ 3653.720197] __x64_sys_openat+0x54/0x90 [ 3653.720766] do_syscall_64+0x3b/0xc0 [ 3653.721285] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.721986] -> #0 (&disk->open_mutex){+.+.}-{3:3}: [ 3653.722775] __lock_acquire+0x130e/0x2210 [ 3653.723348] lock_acquire+0xd7/0x310 [ 3653.723867] __mutex_lock+0x92/0x900 [ 3653.724394] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.725041] blkdev_get_by_path+0xb8/0xd0 [ 3653.725614] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.726332] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.726999] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.727739] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.728384] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.729130] legacy_get_tree+0x30/0x50 [ 3653.729676] vfs_get_tree+0x28/0xc0 [ 3653.730192] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.730800] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.731427] legacy_get_tree+0x30/0x50 [ 3653.731970] vfs_get_tree+0x28/0xc0 [ 3653.732486] path_mount+0x2d4/0xbe0 [ 3653.732997] __x64_sys_mount+0x103/0x140 [ 3653.733560] do_syscall_64+0x3b/0xc0 [ 3653.734080] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.734782] other info that might help us debug this: [ 3653.735784] Chain exists of: &disk->open_mutex --> sb_internal#2 --> btrfs-chunk-00 [ 3653.737123] Possible unsafe locking scenario: [ 3653.737865] CPU0 CPU1 [ 3653.738435] ---- ---- [ 3653.739007] lock(btrfs-chunk-00); [ 3653.739449] lock(sb_internal#2); [ 3653.740193] lock(btrfs-chunk-00); [ 3653.740955] lock(&disk->open_mutex); [ 3653.741431] *** DEADLOCK *** [ 3653.742176] 3 locks held by mount/447465: [ 3653.742739] #0: ffff8c6acf85c0e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xd5/0x3b0 [ 3653.744114] #1: ffffffffc0b28f70 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x59/0x870 [btrfs] [ 3653.745563] #2: ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.747066] stack backtrace: [ 3653.747723] CPU: 4 PID: 447465 Comm: mount Not tainted 5.15.0-rc7-btrfs-next-103 #1 [ 3653.748873] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 3653.750592] Call Trace: [ 3653.750967] dump_stack_lvl+0x57/0x72 [ 3653.751526] check_noncircular+0xf3/0x110 [ 3653.752136] ? stack_trace_save+0x4b/0x70 [ 3653.752748] __lock_acquire+0x130e/0x2210 [ 3653.753356] lock_acquire+0xd7/0x310 [ 3653.753898] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.754596] ? lock_is_held_type+0xe8/0x140 [ 3653.755125] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.755729] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.756338] __mutex_lock+0x92/0x900 [ 3653.756794] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.757400] ? do_raw_spin_unlock+0x4b/0xa0 [ 3653.757930] ? _raw_spin_unlock+0x29/0x40 [ 3653.758437] ? bd_prepare_to_claim+0x129/0x150 [ 3653.758999] ? trace_module_get+0x2b/0xd0 [ 3653.759508] ? try_module_get.part.0+0x50/0x80 [ 3653.760072] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.760661] ? devcgroup_check_permission+0xc1/0x1f0 [ 3653.761288] blkdev_get_by_path+0xb8/0xd0 [ 3653.761797] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.762454] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.763055] ? clone_fs_devices+0x8f/0x170 [btrfs] [ 3653.763689] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.764370] ? kvm_sched_clock_read+0x14/0x40 [ 3653.764922] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.765493] ? super_setup_bdi_name+0x79/0xd0 [ 3653.766043] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.766780] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.767488] ? kfree+0x1f2/0x3c0 [ 3653.767979] legacy_get_tree+0x30/0x50 [ 3653.768548] vfs_get_tree+0x28/0xc0 [ 3653.769076] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.769718] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.770381] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.771086] ? kfree+0x1f2/0x3c0 [ 3653.771574] legacy_get_tree+0x30/0x50 [ 3653.772136] vfs_get_tree+0x28/0xc0 [ 3653.772673] path_mount+0x2d4/0xbe0 [ 3653.773201] __x64_sys_mount+0x103/0x140 [ 3653.773793] do_syscall_64+0x3b/0xc0 [ 3653.774333] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.775094] RIP: 0033:0x7f648bc45aaa This happens because through btrfs_read_chunk_tree(), which is called only during mount, ends up acquiring the mutex open_mutex of a block device while holding a read lock on a leaf of the chunk tree while other paths need to acquire other locks before locking extent buffers of the chunk tree. Since at mount time when we call btrfs_read_chunk_tree() we know that we don't have other tasks running in parallel and modifying the chunk tree, we can simply skip locking of chunk tree extent buffers. So do that and move the assertion that checks the fs is not yet mounted to the top block of btrfs_read_chunk_tree(), with a comment before doing it. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-12-08 09:04:39 +01:00
..
9p	9p: Fix a bunch of kerneldoc warnings shown up by W=1	2021-10-04 22:07:46 +01:00
adfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
affs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
afs	netfslib, cachefiles and afs fixes	2021-10-07 11:20:08 -07:00
autofs	autofs: fix wait name hash calculation in autofs_wait()	2021-10-20 21:09:02 -04:00
befs	isystem: ship and use stdarg.h	2021-08-19 09:02:55 +09:00
bfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
btrfs	btrfs: silence lockdep when reading chunk tree during mount	2021-12-08 09:04:39 +01:00
cachefiles	cachefiles: Change %p in format strings to something else	2021-08-27 13:34:02 +01:00
ceph	ceph: properly handle statfs on multifs setups	2021-12-01 09:04:55 +01:00
cifs	cifs: nosharesock should be set on new server	2021-12-01 09:04:56 +01:00
coda	coda: fix reference counting in coda_file_mmap error path	2021-04-23 14:42:39 -07:00
configfs	configfs: fix a race in configfs_lookup()	2021-08-25 07:58:49 +02:00
cramfs
crypto	fscrypt: allow 256-bit master keys with AES-256-XTS	2021-11-18 19:16:11 +01:00
debugfs	debugfs: debugfs_create_file_size(): use IS_ERR to check for error	2021-09-21 09:09:06 +02:00
devpts
dlm	fs: dlm: avoid comms shutdown delay in release_lockspace	2021-09-01 11:29:14 -05:00
ecryptfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
efivarfs	efivars: convert to fileattr	2021-04-12 15:04:29 +02:00
efs
erofs	erofs: fix deadlock when shrink erofs slab	2021-12-01 09:04:50 +01:00
exfat	exfat: fix incorrect loading of i_blocks for large files	2021-11-18 19:15:52 +01:00
exportfs
ext2	ext2: fix sleeping in atomic bugs on error	2021-09-22 13:05:23 +02:00
ext4	ext4: refresh the ext4_ext_path struct after dropping i_data_sem.	2021-11-18 19:15:56 +01:00
f2fs	f2fs: set SBI_NEED_FSCK flag when inconsistent node block found	2021-12-01 09:04:55 +01:00
fat	linux-kselftest-kunit-5.15-rc1	2021-09-02 12:32:12 -07:00
freevxfs
fscache	fscache: Remove an unused static variable	2021-10-04 22:13:12 +01:00
fuse	fuse: release pipe buf after last use	2021-12-01 09:04:42 +01:00
gfs2	gfs2: Fix length of holes reported at end-of-file	2021-12-08 09:04:37 +01:00
hfs	hfs: add lock nesting notation to hfs_find_init	2021-07-15 10:13:49 -07:00
hfsplus	hfsplus: report create_date to kstat.btime	2021-07-01 11:06:06 -07:00
hostfs	hostfs: support splice_write	2021-08-26 22:28:02 +02:00
hpfs	hpfs: use iomap_fiemap to implement ->fiemap	2021-07-27 11:00:36 +02:00
hugetlbfs	hugetlbfs: fix mount mode command line processing	2021-07-23 17:43:28 -07:00
iomap	iomap: Fix inline extent handling in iomap_readpage	2021-12-01 09:04:44 +01:00
isofs	isofs: Fix out of bound access for corrupted isofs image	2021-11-12 15:05:50 +01:00
jbd2	jbd2: add sparse annotations for add_transaction_credits()	2021-08-30 23:36:50 -04:00
jffs2	vfs: add rcu argument to ->get_acl() callback	2021-08-18 22:08:24 +02:00
jfs	JFS: fix memleak in jfs_mount	2021-11-18 19:16:48 +01:00
kernfs	kernfs: don't create a negative dentry if inactive node exists	2021-10-04 10:27:18 +02:00
ksmbd	ksmbd: Fix an error handling path in 'smb2_sess_setup()'	2021-12-01 09:04:55 +01:00
lockd	Critical bug fixes:	2021-09-22 09:21:02 -07:00
minix	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
netfs	netfs: Fix READ/WRITE confusion when calling iov_iter_xarray()	2021-10-05 11:22:06 +01:00
nfs	NFSv42: Don't fail clone() unless the OP_CLONE operation failed	2021-12-01 09:04:47 +01:00
nfs_common	nfs: Fix kerneldoc warning shown up by W=1	2021-10-04 22:02:17 +01:00
nfsd	NFSD: Fix exposure in nfsd4_decode_bitmap()	2021-11-25 09:48:35 +01:00
nilfs2	Merge branch 'akpm' (patches from Andrew)	2021-09-08 12:55:35 -07:00
nls
notify	fsnotify: fix sb_connectors leak	2021-09-10 09:46:48 -07:00
ntfs	Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2021-07-03 11:30:04 -07:00
ntfs3	Fixed xfstests generic/016 generic/021 generic/022 generic/041 generic/274 generic/423,	2021-10-15 09:58:11 -04:00
ocfs2	ocfs2: fix data corruption on truncate	2021-11-18 19:15:51 +01:00
omfs	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
openpromfs
orangefs	fs: orangefs: fix error return code of orangefs_revalidate_lookup()	2021-11-18 19:17:01 +01:00
overlayfs	ovl: fix filattr copy-up failure	2021-11-18 19:16:04 +01:00
proc	proc/vmcore: fix clearing user buffer by properly using clear_user()	2021-12-01 09:04:44 +01:00
pstore	pstore/blk: Use "%lu" to format unsigned long	2021-11-25 09:48:42 +01:00
qnx4	qnx4: work around gcc false positive warning bug	2021-09-21 08:36:48 -07:00
qnx6
quota	quota: correct error number in free_dqentry()	2021-11-18 19:16:05 +01:00
ramfs	fs: move ramfs_aops to libfs	2021-06-29 10:53:48 -07:00
reiserfs	Kbuild updates for v5.15	2021-09-03 15:33:47 -07:00
romfs
smbfs_common	cifs: remove pathname for file from SPDX header	2021-09-13 14:51:10 -05:00
squashfs	squashfs: use bvec_virt	2021-08-16 10:50:32 -06:00
sysfs	sysfs: Allow deferred execution of iomem_get_mapping()	2021-08-06 13:05:28 +02:00
sysv	mm: require ->set_page_dirty to be explicitly wired up	2021-06-29 10:53:48 -07:00
tracefs	tracefs: Have tracefs directories not set OTH permission bits by default	2021-11-18 19:16:15 +01:00
ubifs	ubifs: report correct st_size for encrypted symlinks	2021-07-25 20:01:07 -07:00
udf	udf: Fix crash after seekdir	2021-11-25 09:48:46 +01:00
ufs	isystem: ship and use stdarg.h	2021-08-19 09:02:55 +09:00
unicode	.gitignore: prefix local generated files with a slash	2021-05-02 00:43:35 +09:00
vboxsf	vboxfs: fix broken legacy mount signature checking	2021-09-27 11:26:21 -07:00
verity	fs-verity: fix signed integer overflow with i_size near S64_MAX	2021-09-22 10:56:34 -07:00
xfs	libnvdimm for v5.15	2021-09-09 11:39:57 -07:00
zonefs	\n	2021-08-30 10:24:50 -07:00
aio.c	eventfd: Make signal recursion protection a task bit	2021-08-28 01:33:02 +02:00
anon_inodes.c
attr.c	fs: handle circular mappings correctly	2021-11-25 09:48:46 +01:00
bad_inode.c	vfs: add rcu argument to ->get_acl() callback	2021-08-18 22:08:24 +02:00
binfmt_aout.c	binfmt: a.out: Fix bogus semicolon	2021-09-05 10:15:05 -07:00
binfmt_elf.c	elf: don't use MAP_FIXED_NOREPLACE for elf interpreter mappings	2021-10-03 14:02:58 -07:00
binfmt_elf_fdpic.c	binfmt: remove in-tree usage of MAP_DENYWRITE	2021-09-03 18:42:01 +02:00
binfmt_flat.c	binfmt: remove in-tree usage of MAP_EXECUTABLE	2021-06-29 10:53:50 -07:00
binfmt_misc.c
binfmt_script.c
buffer.c	mm: fs: invalidate bh_lrus for only cold path	2021-09-24 16:13:35 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c	coredump: fix memleak in dump_vma_snapshot()	2021-09-08 11:50:27 -07:00
d_path.c	d_path: make 'prepend()' fill up the buffer exactly on overflow	2021-09-02 10:07:29 -07:00
dax.c	New code for 5.15:	2021-08-31 11:13:35 -07:00
dcache.c	useful constants: struct qstr for ".."	2021-04-15 22:36:45 -04:00
direct-io.c
drop_caches.c	fs: drop_caches: fix skipping over shadow cache inodes	2021-09-03 09:58:10 -07:00
eventfd.c	eventfd: Export eventfd_wake_count to modules	2021-09-06 07:20:56 -04:00
eventpoll.c	ARM development updates for 5.15:	2021-09-09 13:25:49 -07:00
exec.c	signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV)	2021-11-25 09:49:06 +01:00
fcntl.c	Merge branch 'akpm' (patches from Andrew)	2021-09-03 10:08:28 -07:00
fhandle.c
file.c	virtio,vdpa,vhost: features, fixes	2021-09-11 14:48:42 -07:00
file_table.c
filesystems.c	fs: simplify get_filesystem_list / get_all_fs_names	2021-08-23 01:25:40 -04:00
fs-writeback.c	Merge branch 'akpm' (patches from Andrew)	2021-09-03 10:08:28 -07:00
fs_context.c	memcg: charge fs_context and legacy_fs_context	2021-09-03 09:58:12 -07:00
fs_parser.c	namei: Standardize callers of filename_lookup()	2021-09-07 16:07:47 -04:00
fs_pin.c
fs_struct.c
fs_types.c
fsopen.c
init.c
inode.c	fs: export an inode_update_time helper	2021-11-25 09:49:08 +01:00
internal.h	block: move fs/block_dev.c to block/bdev.c	2021-09-07 08:39:40 -06:00
io-wq.c	io-wq: fix max-workers not correctly set on multi-node system	2021-11-18 19:17:05 +01:00
io-wq.h	io-wq: provide a way to limit max number of workers	2021-08-29 07:55:55 -06:00
io_uring.c	io_uring: fix soft lockup when call __io_remove_buffers	2021-12-01 09:04:56 +01:00
ioctl.c	New code for 5.15:	2021-08-31 11:06:32 -07:00
Kconfig	4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate	2021-09-12 10:10:21 -07:00
Kconfig.binfmt	binfmt: remove support for em86 (alpha only)	2021-07-25 22:33:03 -07:00
kernel_read_file.c	vfs: check fd has read access in kernel_read_file_from_fd()	2021-10-18 20:22:03 -10:00
libfs.c	fs: remove noop_set_page_dirty()	2021-06-29 10:53:48 -07:00
locks.c	Revert "memcg: enable accounting for file lock caches"	2021-09-07 11:21:48 -07:00
Makefile	4 cifs/smb3 fixes, one for DFS reconnect, and one to begin creating common headers for server and client and the other two to rename the cifs_common directory to smbfs_common to be more consistent ie change use of the name cifs to smb which is more accurate	2021-09-12 10:10:21 -07:00
mbcache.c
mount.h
mpage.c
namei.c	putname(): IS_ERR_OR_NULL() is wrong here	2021-09-07 16:14:05 -04:00
namespace.c	Merge branch 'akpm' (patches from Andrew)	2021-09-03 10:08:28 -07:00
no-block.c
nsfs.c
open.c	mm, thp: fix incorrect unmap behavior for private pages	2021-11-18 19:17:17 +01:00
pipe.c	Revert "mm/gup: remove try_get_page(), call try_get_compound_head() directly"	2021-09-07 11:03:45 -07:00
pnode.c
pnode.h
posix_acl.c	ovl: enable RCU'd ->get_acl()	2021-08-18 22:08:24 +02:00
proc_namespace.c
read_write.c	fs: clean up after mandatory file locking support removal	2021-08-24 07:52:45 -04:00
readdir.c	readdir: make sure to verify directory entry for legacy interfaces too	2021-04-17 11:39:49 -07:00
remap_range.c	fs: remove mandatory file locking support	2021-08-23 06:15:36 -04:00
select.c	Revert "memcg: enable accounting for pollfd and select bits arrays"	2021-09-07 11:26:23 -07:00
seq_file.c	seq_file: disallow extremely large seq buffer allocations	2021-07-19 17:18:48 -07:00
signalfd.c	signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency	2021-07-23 13:16:43 -05:00
splice.c
stack.c
stat.c	fs: add generic helper for filling statx attribute flags	2021-08-17 11:47:43 +02:00
statfs.c
super.c	block: remove the bd_bdi in struct block_device	2021-08-09 11:53:26 -06:00
sync.c
timerfd.c	timerfd: Provide timerfd_resume()	2021-08-10 17:57:22 +02:00
userfaultfd.c	userfaultfd: fix a race between writeprotect and exit_mmap()	2021-10-18 20:22:02 -10:00
utimes.c
xattr.c