On 2023/6/30 17:46, Hao Xu wrote:
From: Hao Xu <howeyxu@xxxxxxxxxxx>
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: Hao Xu <howeyxu@xxxxxxxxxxx>
---
fs/fuse/file.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index bc4115288eec..7d6dd0e56b73 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1465,7 +1465,8 @@ 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;
@@ -1477,6 +1478,7 @@ 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_write = (ff->open_flags & FOPEN_DIRECT_IO) && write;
max_pages = iov_iter_npages(iter, fc->max_pages);
ia = fuse_io_alloc(io, max_pages);
@@ -1491,6 +1493,14 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
inode_unlock(inode);
}
+ if (fopen_direct_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;
Tested-by: Jiachen Zhang <zhangjiachen.jaycee@xxxxxxxxxxxxx>
Thanks,
Jiachen
