[PATCH v2 4/7] btrfs: use IO_URING_F_COMPAT for uring encoded iovec import

The uring encoded paths select args32 from IO_URING_F_COMPAT, but then
call import_iovec() for the iovec array. import_iovec() keys off
in_compat_syscall(), which is false when first issued from SQPOLL or
io-wq, so a compat ring can misread the iovec list as native layout.

Pass the same IO_URING_F_COMPAT flag into __import_iovec() instead.

Fixes: 34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Fixes: e32dcdb0af9f ("btrfs: add io_uring interface for encoded writes")
Signed-off-by: Yang Xiuwei <[email protected]>
---
 fs/btrfs/ioctl.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 39bd9788e895..939c4a9d47b6 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4759,9 +4759,10 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue
 		}
 
 		data->iov = data->iovstack;
-		ret = import_iovec(ITER_DEST, data->args.iov, data->args.iovcnt,
-				   ARRAY_SIZE(data->iovstack), &data->iov,
-				   &data->iter);
+		ret = __import_iovec(ITER_DEST, data->args.iov, data->args.iovcnt,
+				     ARRAY_SIZE(data->iovstack), &data->iov,
+				     &data->iter,
+				     !!(issue_flags & IO_URING_F_COMPAT));
 		if (ret < 0)
 			goto out_acct;
 
@@ -4914,9 +4915,10 @@ static int btrfs_uring_encoded_write(struct io_uring_cmd *cmd, unsigned int issu
 			goto out_acct;
 
 		data->iov = data->iovstack;
-		ret = import_iovec(ITER_SOURCE, data->args.iov, data->args.iovcnt,
-				   ARRAY_SIZE(data->iovstack), &data->iov,
-				   &data->iter);
+		ret = __import_iovec(ITER_SOURCE, data->args.iov, data->args.iovcnt,
+				     ARRAY_SIZE(data->iovstack), &data->iov,
+				     &data->iter,
+				     !!(issue_flags & IO_URING_F_COMPAT));
 		if (ret < 0)
 			goto out_acct;
 
-- 
2.25.1