linux-stable/fs
Qu Wenruo 50f83ffc58 btrfs: scrub: Don't check free space before marking a block group RO
commit b12de52896 upstream.

[BUG]
When running btrfs/072 with only one online CPU, it has a pretty high
chance to fail:

#  btrfs/072 12s ... _check_dmesg: something found in dmesg (see xfstests-dev/results//btrfs/072.dmesg)
#  - output mismatch (see xfstests-dev/results//btrfs/072.out.bad)
#      --- tests/btrfs/072.out     2019-10-22 15:18:14.008965340 +0800
#      +++ /xfstests-dev/results//btrfs/072.out.bad      2019-11-14 15:56:45.877152240 +0800
#      @@ -1,2 +1,3 @@
#       QA output created by 072
#       Silence is golden
#      +Scrub find errors in "-m dup -d single" test
#      ...

And with the following call trace:

  BTRFS info (device dm-5): scrub: started on devid 1
  ------------[ cut here ]------------
  BTRFS: Transaction aborted (error -27)
  WARNING: CPU: 0 PID: 55087 at fs/btrfs/block-group.c:1890 btrfs_create_pending_block_groups+0x3e6/0x470 [btrfs]
  CPU: 0 PID: 55087 Comm: btrfs Tainted: G        W  O      5.4.0-rc1-custom+ #13
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:btrfs_create_pending_block_groups+0x3e6/0x470 [btrfs]
  Call Trace:
   __btrfs_end_transaction+0xdb/0x310 [btrfs]
   btrfs_end_transaction+0x10/0x20 [btrfs]
   btrfs_inc_block_group_ro+0x1c9/0x210 [btrfs]
   scrub_enumerate_chunks+0x264/0x940 [btrfs]
   btrfs_scrub_dev+0x45c/0x8f0 [btrfs]
   btrfs_ioctl+0x31a1/0x3fb0 [btrfs]
   do_vfs_ioctl+0x636/0xaa0
   ksys_ioctl+0x67/0x90
   __x64_sys_ioctl+0x43/0x50
   do_syscall_64+0x79/0xe0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  ---[ end trace 166c865cec7688e7 ]---

[CAUSE]
The error number -27 is -EFBIG, returned from the following call chain:
btrfs_end_transaction()
|- __btrfs_end_transaction()
   |- btrfs_create_pending_block_groups()
      |- btrfs_finish_chunk_alloc()
         |- btrfs_add_system_chunk()

This happens because we have used up all space of
btrfs_super_block::sys_chunk_array.

The root cause is, we have the following bad loop of creating tons of
system chunks:

1. The only SYSTEM chunk is being scrubbed
   It's very common to have only one SYSTEM chunk.
2. New SYSTEM bg will be allocated
   As btrfs_inc_block_group_ro() will check if we have enough space
   after marking current bg RO. If not, then allocate a new chunk.
3. New SYSTEM bg is still empty, will be reclaimed
   During the reclaim, we will mark it RO again.
4. That newly allocated empty SYSTEM bg get scrubbed
   We go back to step 2, as the bg is already mark RO but still not
   cleaned up yet.

If the cleaner kthread doesn't get executed fast enough (e.g. only one
CPU), then we will get more and more empty SYSTEM chunks, using up all
the space of btrfs_super_block::sys_chunk_array.

[FIX]
Since scrub/dev-replace doesn't always need to allocate new extent,
especially chunk tree extent, so we don't really need to do chunk
pre-allocation.

To break above spiral, here we introduce a new parameter to
btrfs_inc_block_group(), @do_chunk_alloc, which indicates whether we
need extra chunk pre-allocation.

For relocation, we pass @do_chunk_alloc=true, while for scrub, we pass
@do_chunk_alloc=false.
This should keep unnecessary empty chunks from popping up for scrub.

Also, since there are two parameters for btrfs_inc_block_group_ro(),
add more comment for it.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-20 10:39:46 +01:00
..
9p 9P: Cast to loff_t before multiplying 2020-11-05 11:43:34 +01:00
adfs
affs fs/affs: release old buffer head on error path 2021-03-04 10:26:48 +01:00
afs rxrpc: Fix deadlock around release of dst cached on udp tunnel 2021-02-10 09:25:27 +01:00
autofs autofs: fix a leak in autofs_expire_indirect() 2019-10-25 00:03:11 -04:00
befs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
bfs bfs: don't use WARNING: string when it's just info. 2021-01-06 14:48:39 +01:00
btrfs btrfs: scrub: Don't check free space before marking a block group RO 2021-03-20 10:39:46 +01:00
cachefiles cachefiles: Handle readpage error correctly 2020-11-05 11:43:36 +01:00
ceph ceph: fix race in concurrent __ceph_remove_cap invocations 2020-12-30 11:51:40 +01:00
cifs cifs: return proper error code in statfs(2) 2021-03-17 17:03:34 +01:00
coda y2038: add inode timestamp clamping 2019-09-19 09:42:37 -07:00
configfs configfs: fix a use-after-free in __configfs_open_file 2021-03-17 17:03:56 +01:00
cramfs cramfs: fix usage on non-MTD device 2019-11-23 21:44:49 -05:00
crypto fscrypt: remove kernel-internal constants from UAPI header 2021-01-06 14:48:35 +01:00
debugfs debugfs: do not attempt to create a new file before the filesystem is initalized 2021-03-04 10:26:10 +01:00
devpts devpts_pty_kill(): don't bother with d_delete() 2019-09-03 09:30:56 -04:00
dlm fs: dlm: fix configfs memory leak 2020-10-29 09:58:03 +01:00
ecryptfs ecryptfs: replace BUG_ON with error handling code 2020-02-28 17:22:26 +01:00
efivarfs efivarfs: revert "fix memory leak in efivarfs_create()" 2020-12-02 08:49:53 +01:00
efs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
erofs erofs: fix shift-out-of-bounds of blkszbits 2021-03-07 12:20:42 +01:00
exportfs exportfs_decode_fh(): negative pinned may become positive without the parent locked 2019-11-10 11:56:05 -05:00
ext2 ext2: don't update mtime on COW faults 2020-09-09 19:12:30 +02:00
ext4 ext4: fix potential htree index checksum corruption 2021-03-04 10:26:37 +01:00
f2fs f2fs: fix to set/clear I_LINKABLE under i_lock 2021-03-07 12:20:46 +01:00
fat fat: don't allow to mount if the FAT length == 0 2020-06-17 16:40:36 +02:00
freevxfs fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
fscache
fuse fuse: fix bad inode 2021-01-09 13:44:54 +01:00
gfs2 gfs2: Recursive gfs2_quota_hold in gfs2_iomap_end 2021-03-04 10:26:51 +01:00
hfs
hfsplus hfsplus: fix crash and filesystem corruption when deleting files 2020-04-17 10:50:22 +02:00
hostfs
hpfs fs: hpfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
hugetlbfs mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page 2021-02-10 09:25:31 +01:00
iomap iomap: fix WARN_ON_ONCE() from unprivileged users 2020-10-29 09:58:06 +01:00
isofs isofs: release buffer head before return 2021-03-04 10:26:30 +01:00
jbd2 jbd2: fix up sparse warnings in checkpoint code 2020-11-18 19:20:30 +01:00
jffs2 jffs2: fix use after free in jffs2_sum_write_data() 2021-03-04 10:26:25 +01:00
jfs JFS: more checks for invalid superblock 2021-03-07 12:20:41 +01:00
kernfs kernfs: do not call fsnotify() with name without a parent 2020-08-19 08:16:12 +02:00
lockd lockd: don't use interval-based rebinding over TCP 2020-12-30 11:51:16 +01:00
minix fs/minix: remove expected error message in block_to_path() 2020-08-21 13:05:37 +02:00
nfs NFSv4.2: fix return value of _nfs4_get_security_label() 2021-03-17 17:03:56 +01:00
nfs_common nfs_common: need lock during iterate through the list 2020-12-30 11:51:22 +01:00
nfsd nfsd: register pernet ops last, unregister first 2021-03-04 10:26:34 +01:00
nilfs2 nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() 2020-06-17 16:40:29 +02:00
nls
notify fanotify: fix ignore mask logic for events on child and on dir 2020-06-17 16:40:24 +02:00
ntfs ntfs: check for valid standard information attribute 2021-02-26 10:10:27 +01:00
ocfs2 ocfs2: fix a use after free on error 2021-03-04 10:26:39 +01:00
omfs fs: omfs: Initialize filesystem timestamp ranges 2019-08-30 08:11:25 -07:00
openpromfs
orangefs orangefs: get rid of knob code... 2020-08-21 13:05:29 +02:00
overlayfs ovl: expand warning in ovl_d_real() 2021-02-17 10:35:19 +01:00
proc proc: fix lookup in /proc/net subdirectories after setns(2) 2021-01-12 20:16:10 +01:00
pstore pstore: Fix typo in compression option name 2021-03-04 10:26:45 +01:00
qnx4 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
qnx6 fs: Fill in max and min timestamps in superblock 2019-08-30 07:27:17 -07:00
quota quota: Fix memory leak when handling corrupted quota file 2021-03-04 10:26:26 +01:00
ramfs ramfs: fix nommu mmap with gaps in the page cache 2020-10-29 09:57:53 +01:00
reiserfs reiserfs: add check for an invalid ih_entry_count 2021-01-06 14:48:38 +01:00
romfs romfs: fix uninitialized memory leak in romfs_dev_read() 2020-08-26 10:40:51 +02:00
squashfs squashfs: add more sanity checks in xattr id lookup 2021-02-13 13:52:57 +01:00
sysfs sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output 2021-03-07 12:20:48 +01:00
sysv fs: sysv: Initialize filesystem timestamp ranges 2019-08-30 07:27:18 -07:00
tracefs tracing: Do not create tracefs files if tracefs lockdown is in effect 2019-10-12 20:49:07 -04:00
ubifs ubifs: Fix error return code in alloc_wbufs() 2021-03-04 10:26:26 +01:00
udf udf: fix silent AED tagLocation corruption 2021-03-17 17:03:41 +01:00
ufs fs/ufs: avoid potential u32 multiplication overflow 2020-08-21 13:05:37 +02:00
unicode unicode: make array 'token' static const, makes object smaller 2019-09-17 11:48:24 -04:00
verity
xfs xfs: Fix assert failure in xfs_setattr_size() 2021-03-07 12:20:42 +01:00
aio.c aio: fix async fsync creds 2020-06-17 16:40:24 +02:00
anon_inodes.c
attr.c utimes: Clamp the timestamps in notify_change() 2020-02-11 04:35:12 -08:00
bad_inode.c
binfmt_aout.c
binfmt_elf.c fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 2020-06-03 08:21:27 +02:00
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c binfmt_flat: revert "binfmt_flat: don't offset the data start" 2020-09-03 11:26:39 +02:00
binfmt_misc.c binfmt_misc: fix possible deadlock in bm_register_write 2021-03-17 17:03:57 +01:00
binfmt_script.c
block_dev.c bdev: Reduce time holding bd_mutex in sync in blkdev_close() 2020-10-01 13:17:55 +02:00
buffer.c fs: Don't invalidate page buffers in block_write_full_page() 2020-11-05 11:43:24 +01:00
char_dev.c chardev: Avoid potential use-after-free in 'chrdev_open()' 2020-01-14 20:08:18 +01:00
compat.c
compat_binfmt_elf.c
compat_ioctl.c fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP 2020-01-09 10:20:05 +01:00
coredump.c coredump: fix core_pattern parse error 2020-12-11 13:23:30 +01:00
d_path.c fs: fix NULL dereference due to data race in prepend_path() 2020-10-29 09:57:45 +01:00
dax.c mm: provide a saner PTE walking API for modules 2021-02-26 10:10:28 +01:00
dcache.c fix dget_parent() fastpath race 2020-10-01 13:17:19 +02:00
dcookies.c
direct-io.c fs/direct-io.c: fix kernel-doc warning 2019-10-14 15:04:01 -07:00
drop_caches.c fs: avoid softlockups in s_inodes iterators 2020-01-12 12:21:37 +01:00
eventfd.c eventfd: track eventfd_signal() recursion depth 2020-02-11 04:35:37 -08:00
eventpoll.c ep_create_wakeup_source(): dentry name can change under you... 2020-10-07 08:01:31 +02:00
exec.c exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:44:55 +01:00
fcntl.c fcntl: Fix potential deadlock in send_sig{io, urg}() 2021-01-06 14:48:39 +01:00
fhandle.c
file.c fix multiplication overflow in copy_fdtable() 2020-05-27 17:46:12 +02:00
file_table.c
filesystems.c fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() 2020-04-17 10:50:21 +02:00
fs-writeback.c fs: fix lazytime expiration handling in __writeback_single_inode() 2021-01-30 13:54:11 +01:00
fs_context.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
fs_parser.c vfs: Make fs_parse() handle fs_param_is_fd-type params better 2019-09-12 21:06:14 -04:00
fs_pin.c
fs_struct.c
fs_types.c
fsopen.c
inode.c futex: Fix inode life-time issue 2020-03-25 08:25:58 +01:00
internal.h fs: move guard_bio_eod() after bio_set_op_attrs 2020-01-17 19:48:21 +01:00
io_uring.c io_uring: Fix current->fs handling in io_sq_wq_submit_work() 2021-01-30 13:54:10 +01:00
ioctl.c compat_ioctl: add compat_ptr_ioctl() 2019-12-17 19:55:30 +01:00
Kconfig fs-verity for 5.4 2019-09-18 16:59:14 -07:00
Kconfig.binfmt
libfs.c libfs: fix error cast of negative value in simple_attr_write() 2020-11-24 13:29:19 +01:00
locks.c locks: reinstate locks_delete_block optimization 2020-03-25 08:25:41 +01:00
Makefile fs-verity for 5.4 2019-09-18 16:59:14 -07:00
mbcache.c
mount.h
mpage.c fs: move guard_bio_eod() after bio_set_op_attrs 2020-01-17 19:48:21 +01:00
namei.c namei: only return -ECHILD from follow_dotdot_rcu() 2020-03-05 16:43:48 +01:00
namespace.c fs/namespace.c: WARN if mnt_count has become negative 2021-01-06 14:48:40 +01:00
no-block.c
nsfs.c
open.c cifs_atomic_open(): fix double-put on late allocation failure 2020-03-18 07:17:51 +01:00
pipe.c
pnode.c propagate_one(): mnt_set_mountpoint() needs mount_lock 2020-05-02 08:48:44 +02:00
pnode.h mount: fix mounting of detached mounts onto targets that reside on shared mounts 2021-03-17 17:03:33 +01:00
posix_acl.c
proc_namespace.c vfs: subtype handling moved to fuse 2019-09-06 21:28:49 +02:00
read_write.c fs: allow deduplication of eof block into the end of the destination file 2020-02-11 04:35:23 -08:00
readdir.c readdir: be more conservative with directory entry names 2020-01-29 16:45:31 +01:00
select.c
seq_file.c
signalfd.c fs/signalfd.c: fix inconsistent return codes for signalfd4 2020-08-26 10:40:58 +02:00
splice.c splice: only read in as much information as there is pipe buffer space 2019-12-17 19:56:52 +01:00
stack.c
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-03 14:21:35 -07:00
super.c vfs: remove lockdep bogosity in __sb_start_write 2020-11-24 13:29:01 +01:00
sync.c
timerfd.c
userfaultfd.c userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK 2020-01-04 19:18:32 +01:00
utimes.c utimes: Clamp the timestamps in notify_change() 2020-02-11 04:35:12 -08:00
xattr.c xattr: break delegations in {set,remove}xattr 2020-08-11 15:33:39 +02:00