linux_dsm_epyc7002/fs/btrfs
Filipe Manana 501fdd1cef btrfs: fix race between writes to swap files and scrub
commit 195a49eaf655eb914896c92cecd96bc863c9feb3 upstream.

When we active a swap file, at btrfs_swap_activate(), we acquire the
exclusive operation lock to prevent the physical location of the swap
file extents to be changed by operations such as balance and device
replace/resize/remove. We also call there can_nocow_extent() which,
among other things, checks if the block group of a swap file extent is
currently RO, and if it is we can not use the extent, since a write
into it would result in COWing the extent.

However we have no protection against a scrub operation running after we
activate the swap file, which can result in the swap file extents to be
COWed while the scrub is running and operating on the respective block
group, because scrub turns a block group into RO before it processes it
and then back again to RW mode after processing it. That means an attempt
to write into a swap file extent while scrub is processing the respective
block group, will result in COWing the extent, changing its physical
location on disk.

Fix this by making sure that block groups that have extents that are used
by active swap files can not be turned into RO mode, therefore making it
not possible for a scrub to turn them into RO mode. When a scrub finds a
block group that can not be turned to RO due to the existence of extents
used by swap files, it proceeds to the next block group and logs a warning
message that mentions the block group was skipped due to active swap
files - this is the same approach we currently use for balance.

Fixes: ed46ff3d42 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-09 11:11:11 +01:00
..
tests btrfs: fix missing delalloc new bit for new delalloc ranges 2020-11-13 22:15:59 +01:00
acl.c
async-thread.c Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
async-thread.h Btrfs: fix crash during unmount due to race with delayed inode workers 2020-03-23 17:01:51 +01:00
backref.c btrfs: do not warn if we can't find the reloc root when looking up backref 2021-03-04 11:38:29 +01:00
backref.h btrfs: add asserts for deleting backref cache nodes 2021-03-04 11:38:29 +01:00
block-group.c btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
block-group.h btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
block-rsv.c btrfs: print the block rsv type when we fail our reservation 2020-11-05 13:02:05 +01:00
block-rsv.h btrfs: Remove __ prefix from btrfs_block_rsv_release 2020-03-23 17:01:55 +01:00
btrfs_inode.h btrfs: fix deadlock when cloning inline extent and low on free metadata space 2021-01-17 14:16:54 +01:00
check-integrity.c btrfs: check-integrity: remove unnecessary failure messages during memory allocation 2020-07-27 12:55:21 +02:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: compression: move declarations to header 2020-10-07 12:06:55 +02:00
compression.h btrfs: compression: move declarations to header 2020-10-07 12:06:55 +02:00
ctree.c btrfs: fix extent buffer leak on failure to copy root 2021-03-04 11:38:30 +01:00
ctree.h btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
delalloc-space.c btrfs: add btrfs_reserve_data_bytes and use it 2020-10-07 12:06:52 +02:00
delalloc-space.h btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
delayed-inode.c btrfs: sink total_data parameter in setup_items_for_insert 2020-10-07 12:13:18 +02:00
delayed-inode.h btrfs: delayed-inode: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
delayed-ref.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-03-04 11:38:30 +01:00
delayed-ref.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-03-04 11:38:30 +01:00
dev-replace.c btrfs: fix deadlock when cloning inline extent and low on free metadata space 2021-01-17 14:16:54 +01:00
dev-replace.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
dir-item.c
discard.c btrfs: merge critical sections of discard lock in workfn 2021-01-19 18:27:24 +01:00
discard.h btrfs: discard: Use the correct style for SPDX License Identifier 2020-04-20 17:43:42 +02:00
disk-io.c btrfs: print the actual offset in btrfs_root_name 2021-01-27 11:55:06 +01:00
disk-io.h btrfs: add a helper to read the tree_root commit root for backref lookup 2020-10-26 15:04:57 +01:00
export.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
export.h btrfs: export helpers for subvolume name/id resolution 2020-03-23 17:01:42 +01:00
extent_io.c btrfs: prevent NULL pointer dereference in extent_io_tree_panic 2021-01-19 18:27:17 +01:00
extent_io.h btrfs: remove struct extent_io_ops 2020-10-07 12:13:25 +02:00
extent_map.c Btrfs: fix race between using extent maps and merging them 2020-02-12 17:16:46 +01:00
extent_map.h btrfs: remove extent_map::bdev 2019-11-18 23:43:44 +01:00
extent-io-tree.h btrfs: remove struct extent_io_ops 2020-10-07 12:13:25 +02:00
extent-tree.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-03-04 11:38:30 +01:00
file-item.c btrfs: make btrfs_find_ordered_sum take btrfs_inode 2020-10-07 12:12:19 +02:00
file.c btrfs: fix missing delalloc new bit for new delalloc ranges 2020-11-13 22:15:59 +01:00
free-space-cache.c btrfs: avoid double put of block group when emptying cluster 2021-03-09 11:11:10 +01:00
free-space-cache.h btrfs: let btrfs_return_cluster_to_free_space() return void 2020-07-27 12:55:21 +02:00
free-space-tree.c btrfs: fix possible free space tree corruption with online conversion 2021-02-03 23:28:40 +01:00
free-space-tree.h btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
inode-item.c btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref 2019-09-09 14:59:16 +02:00
inode-map.c btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
inode-map.h
inode.c btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
ioctl.c btrfs: fix deadlock when cloning inline extent and low on free metadata space 2021-01-17 14:16:54 +01:00
Kconfig btrfs: switch to iomap for direct IO 2020-10-07 12:06:57 +02:00
locking.c btrfs: add nesting tags to the locking helpers 2020-10-07 12:12:16 +02:00
locking.h btrfs: introduce BTRFS_NESTING_NEW_ROOT for adding new roots 2020-10-07 12:12:17 +02:00
lzo.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00
Makefile Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
misc.h btrfs: rename tree_entry to rb_simple_node and export it 2020-05-25 11:25:19 +02:00
ordered-data.c btrfs: remove inode argument from btrfs_start_ordered_extent 2020-10-07 12:13:22 +02:00
ordered-data.h btrfs: remove inode argument from btrfs_start_ordered_extent 2020-10-07 12:13:22 +02:00
orphan.c
print-tree.c btrfs: print the actual offset in btrfs_root_name 2021-01-27 11:55:06 +01:00
print-tree.h btrfs: print the actual offset in btrfs_root_name 2021-01-27 11:55:06 +01:00
props.c btrfs: simplify iget helpers 2020-05-25 11:25:37 +02:00
props.h
qgroup.c btrfs: fix transaction leak and crash after RO remount caused by qgroup rescan 2021-01-19 18:27:24 +01:00
qgroup.h btrfs: qgroup: export qgroups in sysfs 2020-07-27 12:55:37 +02:00
raid56.c btrfs: fix raid6 qstripe kmap 2021-03-09 11:11:10 +01:00
raid56.h
rcu-string.h btrfs: rcu-string: Replace zero-length array with flexible-array member 2020-03-23 17:01:53 +01:00
reada.c btrfs: fix readahead hang and use-after-free after removing a device 2020-10-26 15:03:59 +01:00
ref-verify.c btrfs: ref-verify: fix memory leak in btrfs_ref_tree_mod 2020-11-05 13:03:39 +01:00
ref-verify.h
reflink.c btrfs: fix deadlock when cloning inline extent and low on free metadata space 2021-01-17 14:16:54 +01:00
reflink.h Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
relocation.c btrfs: fix reloc root leak with 0 ref reloc roots on recovery 2021-03-04 11:38:30 +01:00
root-tree.c btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations 2020-10-07 12:12:13 +02:00
scrub.c btrfs: fix race between writes to swap files and scrub 2021-03-09 11:11:11 +01:00
send.c btrfs: send: fix invalid clone operations when cloning from the same file and root 2021-01-27 11:54:53 +01:00
send.h btrfs: send: avoid copying file data 2020-10-07 12:13:17 +02:00
space-info.c btrfs: shrink delalloc pages instead of full inodes 2021-01-17 14:16:54 +01:00
space-info.h btrfs: handle space_info::total_bytes_pinned inside the delayed ref itself 2021-03-04 11:38:30 +01:00
struct-funcs.c btrfs: use unaligned helpers for stack and header set/get helpers 2020-10-07 12:13:23 +02:00
super.c btrfs: fix transaction leak and crash after RO remount caused by qgroup rescan 2021-01-19 18:27:24 +01:00
sysfs.c btrfs: do not create raid sysfs entries under any locks 2020-10-07 12:13:19 +02:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: fix error handling in commit_fs_roots 2021-03-07 12:34:13 +01:00
transaction.h btrfs: dio iomap DSYNC workaround 2020-10-07 12:06:57 +02:00
tree-checker.c btrfs: tree-checker: check if chunk item end overflows 2021-01-19 18:27:22 +01:00
tree-checker.h
tree-defrag.c btrfs: remove unused btrfs_root::defrag_trans_start 2020-07-27 12:55:28 +02:00
tree-log.c btrfs: skip unnecessary searches for xattrs when logging an inode 2021-01-17 14:16:53 +01:00
tree-log.h btrfs: make fast fsyncs wait only for writeback 2020-10-07 12:06:56 +02:00
ulist.c
ulist.h
uuid-tree.c btrfs: simplify root lookup by id 2020-05-25 11:25:36 +02:00
volumes.c btrfs: fix lockdep warning due to seqcount_mutex on 32bit arch 2021-02-03 23:28:40 +01:00
volumes.h btrfs: fix lockdep warning due to seqcount_mutex on 32bit arch 2021-02-03 23:28:40 +01:00
xattr.c btrfs: skip unnecessary searches for xattrs when logging an inode 2021-01-17 14:16:53 +01:00
xattr.h
zlib.c btrfs: use larger zlib buffer for s390 hardware compression 2020-01-31 10:30:40 -08:00
zstd.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00