linux/fs/btrfs
Filipe Manana 195a49eaf6 btrfs: fix race between writes to swap files and scrub
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>
2021-02-22 18:07:15 +01:00
..
tests btrfs: extend btrfs_rmap_block for specifying a device 2021-02-09 02:46:05 +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 2021-02-08 22:58:56 +01:00
backref.h btrfs: add asserts for deleting backref cache nodes 2021-02-08 22:58:56 +01:00
block-group.c btrfs: fix race between writes to swap files and scrub 2021-02-22 18:07:15 +01:00
block-group.h btrfs: fix race between writes to swap files and scrub 2021-02-22 18:07:15 +01:00
block-rsv.c btrfs: introduce mount option rescue=ignorebadroots 2020-12-08 15:53:41 +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: make btrfs_dio_private::bytes u32 2021-02-08 22:58:51 +01:00
check-integrity.c btrfs: drop casts of bio bi_sector 2020-12-09 19:16:05 +01:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: make check_compressed_csum() to be subpage compatible 2021-02-22 17:15:27 +01:00
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 2021-02-08 22:59:04 +01:00
ctree.h btrfs: fix race between writes to swap files and scrub 2021-02-22 18:07:15 +01:00
delalloc-space.c btrfs: fix parameter description of btrfs_inode_rsv_release/btrfs_delalloc_release_space 2021-02-08 22:58:54 +01:00
delalloc-space.h btrfs: make btrfs_delalloc_reserve_space take btrfs_inode 2020-07-27 12:55:36 +02:00
delayed-inode.c btrfs: simplify condition in __btrfs_run_delayed_items 2021-02-08 22:58:59 +01:00
delayed-inode.h btrfs: make btrfs_delayed_update_inode take btrfs_inode 2020-12-08 15:54:10 +01:00
delayed-ref.c btrfs: account for new extents being deleted in total_bytes_pinned 2021-02-08 22:58:55 +01:00
delayed-ref.h btrfs: only let one thread pre-flush delayed refs in commit 2021-02-08 22:58:56 +01:00
dev-replace.c btrfs: zoned: mark block groups to copy for device-replace 2021-02-09 02:46:07 +01:00
dev-replace.h btrfs: zoned: mark block groups to copy for device-replace 2021-02-09 02:46:07 +01:00
dir-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
discard.c btrfs: document now parameter of peek_discard_list 2021-02-08 22:58:53 +01:00
discard.h btrfs: cleanup btrfs_discard_update_discardable usage 2020-12-08 15:54:02 +01:00
disk-io.c btrfs: zoned: reorder log node allocation on zoned filesystem 2021-02-09 02:48:41 +01:00
disk-io.h btrfs: split alloc_log_tree() 2021-02-09 02:46:07 +01:00
export.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
export.h btrfs: export helpers for subvolume name/id resolution 2020-03-23 17:01:42 +01:00
extent_io.c btrfs: zoned: relocate block group to repair IO failure in zoned filesystems 2021-02-09 02:46:07 +01:00
extent_io.h btrfs: zoned: redirty released extent buffers 2021-02-09 02:46:04 +01:00
extent_map.c btrfs: fix parameter description of btrfs_add_extent_mapping 2021-02-08 22:58:53 +01:00
extent_map.h
extent-io-tree.h btrfs: use fixed width int type for extent_state::state 2020-12-08 15:54:13 +01:00
extent-tree.c btrfs: zoned: extend zoned allocator to use dedicated tree-log block group 2021-02-09 02:46:08 +01:00
file-item.c btrfs: fix function description formats in file-item.c 2021-02-08 22:58:53 +01:00
file.c btrfs: zoned: use ZONE_APPEND write for zoned mode 2021-02-09 02:46:06 +01:00
free-space-cache.c btrfs: fix race between extent freeing/allocation when using bitmaps 2021-02-22 17:15:31 +01:00
free-space-cache.h btrfs: zoned: track unusable bytes for zones 2021-02-09 02:46:03 +01:00
free-space-tree.c btrfs: fix possible free space tree corruption with online conversion 2021-01-25 18:44:37 +01:00
free-space-tree.h
inode-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
inode.c btrfs: fix race between writes to swap files and scrub 2021-02-22 18:07:15 +01:00
ioctl.c btrfs: zoned: disallow fitrim on zoned filesystems 2021-02-09 02:32:20 +01:00
Kconfig btrfs: switch to iomap for direct IO 2020-10-07 12:06:57 +02:00
locking.c btrfs: remove the recurse parameter from __btrfs_tree_read_lock 2020-12-08 15:54:09 +01:00
locking.h btrfs: remove the recurse parameter from __btrfs_tree_read_lock 2020-12-08 15:54:09 +01:00
lzo.c
Makefile btrfs: introduce the skeleton of btrfs_subpage structure 2021-02-08 22:59:01 +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: zoned: use ZONE_APPEND write for zoned mode 2021-02-09 02:46:06 +01:00
ordered-data.h btrfs: zoned: use ZONE_APPEND write for zoned mode 2021-02-09 02:46:06 +01:00
orphan.c
print-tree.c btrfs: print the actual offset in btrfs_root_name 2021-01-07 17:25:05 +01:00
print-tree.h btrfs: print the actual offset in btrfs_root_name 2021-01-07 17:25:05 +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 2020-12-18 14:59:57 +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 2021-02-22 17:15:21 +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: pass the owner_root and level to alloc_extent_buffer 2020-12-08 15:54:07 +01:00
ref-verify.c btrfs: ref-verify: make sure owner is set for all refs 2021-02-08 22:58:50 +01:00
ref-verify.h
reflink.c btrfs: introduce btrfs_subpage for data inodes 2021-02-08 22:59:03 +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: zoned: enable relocation on a zoned filesystem 2021-02-09 02:46:07 +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 2021-02-22 18:07:15 +01:00
send.c btrfs: send: use struct send_ctx *sctx for btrfs_compare_trees and changed_cb 2021-02-08 22:58:57 +01:00
send.h btrfs: send: avoid copying file data 2020-10-07 12:13:17 +02:00
space-info.c btrfs: zoned: track unusable bytes for zones 2021-02-09 02:46:03 +01:00
space-info.h btrfs: zoned: track unusable bytes for zones 2021-02-09 02:46:03 +01:00
struct-funcs.c btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors 2020-12-09 19:16:10 +01:00
subpage.c btrfs: integrate page status update for data read path into begin/end_page_read 2021-02-08 22:59:03 +01:00
subpage.h btrfs: integrate page status update for data read path into begin/end_page_read 2021-02-08 22:59:03 +01:00
super.c btrfs: allow read-only mount of 4K sector size fs on 64K page system 2021-02-08 22:59:03 +01:00
sysfs.c btrfs: zoned: track unusable bytes for zones 2021-02-09 02:46:03 +01:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: zoned: redirty released extent buffers 2021-02-09 02:46:04 +01:00
transaction.h btrfs: zoned: redirty released extent buffers 2021-02-09 02:46:04 +01:00
tree-checker.c btrfs: tree-checker: check if chunk item end overflows 2021-01-07 17:25:05 +01:00
tree-checker.h
tree-defrag.c btrfs: locking: remove all the blocking helpers 2020-12-08 15:54:01 +01:00
tree-log.c btrfs: zoned: deal with holes writing out tree-log pages 2021-02-09 02:52:24 +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: remove unnecessary casts in printk 2020-12-08 15:53:52 +01:00
volumes.c btrfs: zoned: relocate block group to repair IO failure in zoned filesystems 2021-02-09 02:46:07 +01:00
volumes.h btrfs: zoned: relocate block group to repair IO failure in zoned filesystems 2021-02-09 02:46:07 +01:00
xattr.c btrfs: skip unnecessary searches for xattrs when logging an inode 2020-12-08 15:54:12 +01:00
xattr.h
zlib.c btrfs: use larger zlib buffer for s390 hardware compression 2020-01-31 10:30:40 -08:00
zoned.c btrfs: zoned: support dev-replace in zoned filesystems 2021-02-09 02:46:07 +01:00
zoned.h btrfs: zoned: extend zoned allocator to use dedicated tree-log block group 2021-02-09 02:46:08 +01:00
zstd.c