diff options
| author | Filipe Manana <fdmanana@suse.com> | 2023-10-04 11:38:51 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-10-12 16:44:17 +0200 |
| commit | 0124855ff18b9bdfe6aec87f7b29d3fdc6f575db (patch) | |
| tree | 9efcc94b959df93a18e6fecc165546b1f99f3fad /fs/btrfs/tree-checker.c | |
| parent | 4a4f8fe2b0230c22aba40c9f8ea7b9c6fcfc8417 (diff) | |
btrfs: add and use helpers for reading and writing last_trans_committed
Currently the last_trans_committed field of struct btrfs_fs_info is
modified and read without any locking or other protection. For example
early in the fsync path, skip_inode_logging() is called which reads
fs_info->last_trans_committed, but at the same time we can have a
transaction commit completing and updating that field.
In the case of an fsync this is harmless and any data race should be
rare and at most cause an unnecessary logging of an inode.
To avoid data race warnings from tools like KCSAN and other issues such
as load and store tearing (amongst others, see [1]), create helpers to
access the last_trans_committed field of struct btrfs_fs_info using
READ_ONCE() and WRITE_ONCE(), and use these helpers everywhere.
[1] https://lwn.net/Articles/793253/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/tree-checker.c')
| -rw-r--r-- | fs/btrfs/tree-checker.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 1f2c389b0bfa..a416cbea75d1 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -2051,7 +2051,7 @@ int btrfs_verify_level_key(struct extent_buffer *eb, int level, * So we only checks tree blocks which is read from disk, whose * generation <= fs_info->last_trans_committed. */ - if (btrfs_header_generation(eb) > fs_info->last_trans_committed) + if (btrfs_header_generation(eb) > btrfs_get_last_trans_committed(fs_info)) return 0; /* We have @first_key, so this @eb must have at least one item */ |