diff options
| author | Mark Harmstone <maharmstone@fb.com> | 2024-11-15 16:49:17 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2024-11-29 16:56:38 +0100 |
| commit | 22d2e48e318564f8c9b09faf03ecb4f03fb44dd5 (patch) | |
| tree | 1aa36fc02534dfae195851377a340f5fe993129f /fs/btrfs | |
| parent | btrfs: ref-verify: fix use-after-free after invalid ref action (diff) | |
| download | linux-22d2e48e318564f8c9b09faf03ecb4f03fb44dd5.tar.xz linux-22d2e48e318564f8c9b09faf03ecb4f03fb44dd5.zip | |
btrfs: fix lockdep warnings on io_uring encoded reads
Lockdep doesn't like the fact that btrfs_uring_read_extent() returns to
userspace still holding the inode lock, even though we release it once
the I/O finishes. Add calls to rwsem_release() and rwsem_acquire_read() to
work round this.
Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/ioctl.c | 10 | ||||
| -rw-r--r-- | fs/btrfs/locking.h | 10 |
2 files changed, 20 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 1fdeb216bf6c..f8680e7cc974 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4752,6 +4752,9 @@ static void btrfs_uring_read_finished(struct io_uring_cmd *cmd, unsigned int iss size_t page_offset; ssize_t ret; + /* The inode lock has already been acquired in btrfs_uring_read_extent. */ + btrfs_lockdep_inode_acquire(inode, i_rwsem); + if (priv->err) { ret = priv->err; goto out; @@ -4860,6 +4863,13 @@ static int btrfs_uring_read_extent(struct kiocb *iocb, struct iov_iter *iter, * and inode and freeing the allocations. */ + /* + * We're returning to userspace with the inode lock held, and that's + * okay - it'll get unlocked in a worker thread. Call + * btrfs_lockdep_inode_release() to avoid confusing lockdep. + */ + btrfs_lockdep_inode_release(inode, i_rwsem); + return -EIOCBQUEUED; out_fail: diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h index 46c8be2afab1..35036b151bf5 100644 --- a/fs/btrfs/locking.h +++ b/fs/btrfs/locking.h @@ -129,6 +129,16 @@ enum btrfs_lockdep_trans_states { rwsem_release(&owner->lock##_map, _THIS_IP_) /* + * Used to account for the fact that when doing io_uring encoded I/O, we can + * return to userspace with the inode lock still held. + */ +#define btrfs_lockdep_inode_acquire(owner, lock) \ + rwsem_acquire_read(&owner->vfs_inode.lock.dep_map, 0, 0, _THIS_IP_) + +#define btrfs_lockdep_inode_release(owner, lock) \ + rwsem_release(&owner->vfs_inode.lock.dep_map, _THIS_IP_) + +/* * Macros for the transaction states wait events, similar to the generic wait * event macros. */ |