From 4fdccaa0d184c202f98d73b24e3ec8eeee88ab8d Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sat, 24 Jul 2021 12:26:41 +0200 Subject: iomap: Add done_before argument to iomap_dio_rw Add a done_before argument to iomap_dio_rw that indicates how much of the request has already been transferred. When the request succeeds, we report that done_before additional bytes were tranferred. This is useful for finishing a request asynchronously when part of the request has already been completed synchronously. We'll use that to allow iomap_dio_rw to be used with page faults disabled: when a page fault occurs while submitting a request, we synchronously complete the part of the request that has already been submitted. The caller can then take care of the page fault and call iomap_dio_rw again for the rest of the request, passing in the number of bytes already tranferred. Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong --- fs/btrfs/file.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f37211d3bb69..9d41b28c67ba 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1957,7 +1957,7 @@ relock: } dio = __iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dio_ops, - 0); + 0, 0); btrfs_inode_unlock(inode, ilock_flags); @@ -3658,7 +3658,8 @@ static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) return 0; btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED); - ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dio_ops, 0); + ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dio_ops, + 0, 0); btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED); return ret; } -- cgit v1.2.3