linux/fs/btrfs
Anand Jain 6605fd2f39 btrfs: use latest_dev in btrfs_show_devname
The test case btrfs/238 reports the warning below:

 WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs]
 CPU: 2 PID: 1 Comm: systemd Tainted: G        W  O 5.14.0-rc1-custom #72
 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
 Call trace:
   btrfs_show_devname+0x108/0x1b4 [btrfs]
   show_mountinfo+0x234/0x2c4
   m_show+0x28/0x34
   seq_read_iter+0x12c/0x3c4
   vfs_read+0x29c/0x2c8
   ksys_read+0x80/0xec
   __arm64_sys_read+0x28/0x34
   invoke_syscall+0x50/0xf8
   do_el0_svc+0x88/0x138
   el0_svc+0x2c/0x8c
   el0t_64_sync_handler+0x84/0xe4
   el0t_64_sync+0x198/0x19c

Reason:
While btrfs_prepare_sprout() moves the fs_devices::devices into
fs_devices::seed_list, the btrfs_show_devname() searches for the devices
and found none, leading to the warning as in above.

Fix:
latest_dev is updated according to the changes to the device list.
That means we could use the latest_dev->name to show the device name in
/proc/self/mounts, the pointer will be always valid as it's assigned
before the device is deleted from the list in remove or replace.
The RCU protection is sufficient as the device structure is freed after
synchronization.

Reported-by: Su Yue <l@damenly.su>
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26 19:08:00 +02:00
..
tests btrfs: remove ignore_offset argument from btrfs_find_all_roots() 2021-08-23 13:19:01 +02:00
acl.c overlayfs update for 5.15 2021-09-02 09:21:27 -07:00
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: remove ignore_offset argument from btrfs_find_all_roots() 2021-08-23 13:19:01 +02:00
backref.h btrfs: remove ignore_offset argument from btrfs_find_all_roots() 2021-08-23 13:19:01 +02:00
block-group.c btrfs: zoned: activate new block group 2021-10-26 19:07:59 +02:00
block-group.h btrfs: zoned: implement active zone tracking 2021-10-26 19:07:59 +02:00
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: initial fsverity support 2021-08-23 13:19:09 +02:00
check-integrity.c btrfs: check-integrity: drop kmap/kunmap for block pages 2021-08-23 13:19:00 +02:00
check-integrity.h btrfs: remove btrfsic_submit_bh() 2020-03-23 17:01:39 +01:00
compression.c btrfs: rework btrfs_decompress_buf2page() 2021-08-23 13:19:04 +02:00
compression.h btrfs: rework btrfs_decompress_buf2page() 2021-08-23 13:19:04 +02:00
ctree.c btrfs: introduce btrfs_search_backwards function 2021-08-23 13:19:09 +02:00
ctree.h btrfs: zoned: implement active zone tracking 2021-10-26 19:07:59 +02:00
delalloc-space.c btrfs: fix typos in comments 2021-06-22 14:11:57 +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: add ro compat flags to inodes 2021-08-23 13:19:09 +02:00
delayed-inode.h btrfs: make btrfs_delayed_update_inode take btrfs_inode 2020-12-08 15:54:10 +01:00
delayed-ref.c btrfs: fix lock inversion problem when doing qgroup extent tracing 2021-07-22 15:50:07 +02:00
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: fix typos in comments 2021-06-22 14:11:57 +02:00
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: unify lookup return value when dir entry is missing 2021-10-07 22:06:32 +02:00
discard.c btrfs: fix typos in comments 2021-06-22 14:11:57 +02:00
discard.h btrfs: cleanup btrfs_discard_update_discardable usage 2020-12-08 15:54:02 +01:00
disk-io.c btrfs: convert latest_bdev type to btrfs_device and rename 2021-10-26 19:08:00 +02:00
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: convert latest_bdev type to btrfs_device and rename 2021-10-26 19:08:00 +02:00
extent_io.h btrfs: zoned: finish fully written block group 2021-10-26 19:08:00 +02:00
extent_map.c btrfs: fix parameter description of btrfs_add_extent_mapping 2021-02-08 22:58:53 +01:00
extent_map.h btrfs: remove extent_map::bdev 2019-11-18 23:43:44 +01:00
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: avoid chunk allocation if active block group has enough space 2021-10-26 19:07:59 +02:00
file-item.c btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handling 2021-09-17 19:29:38 +02:00
file.c btrfs: fix abort logic in btrfs_replace_file_extents 2021-10-07 22:08:06 +02:00
free-space-cache.c btrfs: zoned: implement active zone tracking 2021-10-26 19:07:59 +02:00
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 btrfs: rename btrfs_block_group_cache 2019-11-18 17:51:51 +01:00
inode-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
inode.c btrfs: convert latest_bdev type to btrfs_device and rename 2021-10-26 19:08:00 +02:00
ioctl.c btrfs: defrag: enable defrag for subpage case 2021-10-26 19:07:58 +02:00
Kconfig btrfs: disable build on platforms having page size 256K 2021-06-22 14:11:57 +02:00
locking.c btrfs: fix typos in comments 2021-06-22 14:11:57 +02:00
locking.h btrfs: remove the recurse parameter from __btrfs_tree_read_lock 2020-12-08 15:54:09 +01:00
lzo.c btrfs: rework lzo_decompress_bio() to make it subpage compatible 2021-08-23 13:19:04 +02:00
Makefile btrfs: initial fsverity support 2021-08-23 13:19:09 +02:00
misc.h btrfs: use correct header for div_u64 in misc.h 2021-09-07 14:29:50 +02:00
ordered-data.c btrfs: zoned: fix double counting of split ordered extent 2021-09-07 14:30:41 +02:00
ordered-data.h btrfs: remove uptodate parameter from btrfs_dec_test_first_ordered_pending 2021-08-23 13:19:02 +02:00
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: props: change how empty value is interpreted 2021-06-22 14:11:58 +02:00
props.h
qgroup.c btrfs: remove ignore_offset argument from btrfs_find_all_roots() 2021-08-23 13:19:01 +02:00
qgroup.h btrfs: fix lock inversion problem when doing qgroup extent tracing 2021-07-22 15:50:07 +02:00
raid56.c btrfs: constify and cleanup variables in comparators 2021-08-23 13:19:03 +02:00
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: subpage: make readahead work properly 2021-03-16 11:06:21 +01:00
ref-verify.c btrfs: stop doing GFP_KERNEL memory allocations in the ref verify tool 2021-08-23 13:19:00 +02:00
ref-verify.h
reflink.c btrfs: reflink: initialize return value to 0 in btrfs_extent_same() 2021-10-26 19:03:57 +02:00
reflink.h Btrfs: move all reflink implementation code into its own file 2020-03-23 17:01:54 +01:00
relocation.c btrfs: zoned: finish relocating block group 2021-10-26 19:08:00 +02:00
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 typos in comments 2021-06-22 14:11:57 +02:00
send.c btrfs: send: simplify send_create_inode_if_needed 2021-10-25 21:17:16 +02:00
send.h btrfs: send: avoid copying file data 2020-10-07 12:13:17 +02:00
space-info.c btrfs: prevent __btrfs_dump_space_info() to underflow its free space 2021-09-17 19:29:54 +02:00
space-info.h btrfs: rip out btrfs_space_info::total_bytes_pinned 2021-06-22 14:55:25 +02:00
struct-funcs.c btrfs: add special case to setget helpers for 64k pages 2021-08-23 13:18:58 +02:00
subpage.c btrfs: subpage: pack all subpage bitmaps into a larger bitmap 2021-10-26 19:03:55 +02:00
subpage.h btrfs: subpage: pack all subpage bitmaps into a larger bitmap 2021-10-26 19:03:55 +02:00
super.c btrfs: use latest_dev in btrfs_show_devname 2021-10-26 19:08:00 +02:00
sysfs.c btrfs: sysfs: document structures and their associated files 2021-08-23 13:19:12 +02:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: rework chunk allocation to avoid exhaustion of the system chunk array 2021-07-07 17:42:41 +02:00
transaction.h btrfs: rework chunk allocation to avoid exhaustion of the system chunk array 2021-07-07 17:42:41 +02:00
tree-checker.c btrfs: add ro compat flags to inodes 2021-08-23 13:19:09 +02:00
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: check for error when looking up inode during dir entry replay 2021-10-07 22:06:34 +02:00
tree-log.h btrfs: make fast fsyncs wait only for writeback 2020-10-07 12:06:56 +02:00
tree-mod-log.c btrfs: fix race when picking most recent mod log operation for an old root 2021-04-20 19:27:17 +02:00
tree-mod-log.h btrfs: add and use helper to get lowest sequence number for the tree mod log 2021-04-19 17:25:17 +02:00
ulist.c
ulist.h
uuid-tree.c btrfs: remove unnecessary casts in printk 2020-12-08 15:53:52 +01:00
verity.c btrfs: fix transaction handle leak after verity rollback failure 2021-09-17 19:29:41 +02:00
volumes.c btrfs: convert latest_bdev type to btrfs_device and rename 2021-10-26 19:08:00 +02:00
volumes.h btrfs: convert latest_bdev type to btrfs_device and rename 2021-10-26 19:08:00 +02:00
xattr.c for-5.12-rc1-tag 2021-03-05 12:21:14 -08:00
xattr.h
zlib.c btrfs: rework btrfs_decompress_buf2page() 2021-08-23 13:19:04 +02:00
zoned.c btrfs: zoned: finish fully written block group 2021-10-26 19:08:00 +02:00
zoned.h btrfs: zoned: finish fully written block group 2021-10-26 19:08:00 +02:00
zstd.c btrfs: rework btrfs_decompress_buf2page() 2021-08-23 13:19:04 +02:00