Commit 80e4f252 authored by Hao Xu's avatar Hao Xu Committed by Miklos Szeredi
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fuse: invalidate page cache pages before direct write 



In FOPEN_DIRECT_IO, page cache may still be there for a file since private
mmap is allowed.  Direct write should respect that and invalidate the
corresponding pages so that page cache readers don't get stale data.

Signed-off-by: default avatarHao Xu <howeyxu@tencent.com>
Tested-by: default avatarJiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent b8bd342d

fs/fuse/file.c

+11 −1
Original line number Diff line number Diff line
@@ -1428,7 +1428,8 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, 
	int write = flags & FUSE_DIO_WRITE;

	int cuse = flags & FUSE_DIO_CUSE;

	struct file *file = io->iocb->ki_filp;

	struct inode *inode = file->f_mapping->host;

	struct address_space *mapping = file->f_mapping;

	struct inode *inode = mapping->host;

	struct fuse_file *ff = file->private_data;

	struct fuse_conn *fc = ff->fm->fc;

	size_t nmax = write ? fc->max_write : fc->max_read;
@@ -1440,6 +1441,7 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, 
	int err = 0;

	struct fuse_io_args *ia;

	unsigned int max_pages;

	bool fopen_direct_io = ff->open_flags & FOPEN_DIRECT_IO;



	max_pages = iov_iter_npages(iter, fc->max_pages);

	ia = fuse_io_alloc(io, max_pages);
@@ -1454,6 +1456,14 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, 
			inode_unlock(inode);

	}



	if (fopen_direct_io && write) {

		res = invalidate_inode_pages2_range(mapping, idx_from, idx_to);

		if (res) {

			fuse_io_free(ia);

			return res;

		}

	}



	io->should_dirty = !write && user_backed_iter(iter);

	while (count) {

		ssize_t nres;