@@ -6,6 +6,11 @@
#include <linux/idr.h>
#include <linux/uio.h>
+struct fuse_aio_req {
+ struct kiocb iocb;
+ struct kiocb *iocb_fuse;
+};
+
static void fuse_copyattr(struct file *dst_file, struct file *src_file)
{
struct inode *dst = file_inode(dst_file);
@@ -32,6 +37,32 @@ static inline rwf_t iocb_to_rw_flags(int ifl)
return flags;
}
+static void fuse_aio_cleanup_handler(struct fuse_aio_req *aio_req)
+{
+ struct kiocb *iocb = &aio_req->iocb;
+ struct kiocb *iocb_fuse = aio_req->iocb_fuse;
+
+ if (iocb->ki_flags & IOCB_WRITE) {
+ __sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
+ SB_FREEZE_WRITE);
+ file_end_write(iocb->ki_filp);
+ fuse_copyattr(iocb_fuse->ki_filp, iocb->ki_filp);
+ }
+
+ iocb_fuse->ki_pos = iocb->ki_pos;
+ kfree(aio_req);
+}
+
+static void fuse_aio_rw_complete(struct kiocb *iocb, long res, long res2)
+{
+ struct fuse_aio_req *aio_req =
+ container_of(iocb, struct fuse_aio_req, iocb);
+ struct kiocb *iocb_fuse = aio_req->iocb_fuse;
+
+ fuse_aio_cleanup_handler(aio_req);
+ iocb_fuse->ki_complete(iocb_fuse, res, res2);
+}
+
ssize_t fuse_passthrough_read_iter(struct kiocb *iocb_fuse,
struct iov_iter *iter)
{
@@ -43,8 +74,23 @@ ssize_t fuse_passthrough_read_iter(struct kiocb *iocb_fuse,
if (!iov_iter_count(iter))
return 0;
- ret = vfs_iter_read(passthrough_filp, iter, &iocb_fuse->ki_pos,
- iocb_to_rw_flags(iocb_fuse->ki_flags));
+ if (is_sync_kiocb(iocb_fuse)) {
+ ret = vfs_iter_read(passthrough_filp, iter, &iocb_fuse->ki_pos,
+ iocb_to_rw_flags(iocb_fuse->ki_flags));
+ } else {
+ struct fuse_aio_req *aio_req;
+
+ aio_req = kmalloc(sizeof(struct fuse_aio_req), GFP_KERNEL);
+ if (!aio_req)
+ return -ENOMEM;
+
+ aio_req->iocb_fuse = iocb_fuse;
+ kiocb_clone(&aio_req->iocb, iocb_fuse, passthrough_filp);
+ aio_req->iocb.ki_complete = fuse_aio_rw_complete;
+ ret = call_read_iter(passthrough_filp, &aio_req->iocb, iter);
+ if (ret != -EIOCBQUEUED)
+ fuse_aio_cleanup_handler(aio_req);
+ }
return ret;
}
@@ -57,19 +103,40 @@ ssize_t fuse_passthrough_write_iter(struct kiocb *iocb_fuse,
struct fuse_file *ff = fuse_filp->private_data;
struct inode *fuse_inode = file_inode(fuse_filp);
struct file *passthrough_filp = ff->passthrough.filp;
+ struct inode *passthrough_inode = file_inode(passthrough_filp);
if (!iov_iter_count(iter))
return 0;
inode_lock(fuse_inode);
- file_start_write(passthrough_filp);
- ret = vfs_iter_write(passthrough_filp, iter, &iocb_fuse->ki_pos,
- iocb_to_rw_flags(iocb_fuse->ki_flags));
- file_end_write(passthrough_filp);
- if (ret > 0)
- fuse_copyattr(fuse_filp, passthrough_filp);
-
+ if (is_sync_kiocb(iocb_fuse)) {
+ file_start_write(passthrough_filp);
+ ret = vfs_iter_write(passthrough_filp, iter, &iocb_fuse->ki_pos,
+ iocb_to_rw_flags(iocb_fuse->ki_flags));
+ file_end_write(passthrough_filp);
+ if (ret > 0)
+ fuse_copyattr(fuse_filp, passthrough_filp);
+ } else {
+ struct fuse_aio_req *aio_req;
+
+ aio_req = kmalloc(sizeof(struct fuse_aio_req), GFP_KERNEL);
+ if (!aio_req) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ file_start_write(passthrough_filp);
+ __sb_writers_release(passthrough_inode->i_sb, SB_FREEZE_WRITE);
+
+ aio_req->iocb_fuse = iocb_fuse;
+ kiocb_clone(&aio_req->iocb, iocb_fuse, passthrough_filp);
+ aio_req->iocb.ki_complete = fuse_aio_rw_complete;
+ ret = call_write_iter(passthrough_filp, &aio_req->iocb, iter);
+ if (ret != -EIOCBQUEUED)
+ fuse_aio_cleanup_handler(aio_req);
+ }
+out:
inode_unlock(fuse_inode);
return ret;
Extend the passthrough feature by handling asynchronous IO both for read and write operations. When an AIO request is received, if the request targets a FUSE file with the passthrough functionality enabled, a new identical AIO request is created. The new request targets the lower file system file and gets assigned a special FUSE passthrough AIO completion callback. When the lower file system AIO request is completed, the FUSE passthrough AIO completion callback is executed and propagates the completion signal to the FUSE AIO request by triggering its completion callback as well. Signed-off-by: Alessio Balsini <balsini@android.com> --- fs/fuse/passthrough.c | 85 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 76 insertions(+), 9 deletions(-)