On 7/18/23 21:21, Hao Xu wrote:
From: Hao Xu <howeyxu@xxxxxxxxxxx>
This add support for getdents64 to io_uring, acting exactly like the
syscall: the directory is iterated from it's current's position as
stored in the file struct, and the file's position is updated exactly as
if getdents64 had been called.
For filesystems that support NOWAIT in iterate_shared(), try to use it
first; if a user already knows the filesystem they use do not support
nowait they can force async through IOSQE_ASYNC in the sqe flags,
avoiding the need to bounce back through a useless EAGAIN return.
Co-developed-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Signed-off-by: Hao Xu <howeyxu@xxxxxxxxxxx>
---
include/uapi/linux/io_uring.h | 7 +++++
io_uring/fs.c | 55 +++++++++++++++++++++++++++++++++++
io_uring/fs.h | 3 ++
io_uring/opdef.c | 8 +++++
4 files changed, 73 insertions(+)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 36f9c73082de..b200b2600622 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -65,6 +65,7 @@ struct io_uring_sqe {
__u32 xattr_flags;
__u32 msg_ring_flags;
__u32 uring_cmd_flags;
+ __u32 getdents_flags;
Looks this is not needed anymore, I'll remove this in next version.
};
__u64 user_data; /* data to be passed back at completion time */
/* pack this to avoid bogus arm OABI complaints */
@@ -235,6 +236,7 @@ enum io_uring_op {
IORING_OP_URING_CMD,
IORING_OP_SEND_ZC,
IORING_OP_SENDMSG_ZC,
+ IORING_OP_GETDENTS,
/* this goes last, obviously */
IORING_OP_LAST,
@@ -273,6 +275,11 @@ enum io_uring_op {
*/
#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
+/*
+ * sqe->getdents_flags
+ */
+#define IORING_GETDENTS_REWIND (1U << 0)
ditto
+
/*
* POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
* command flags for POLL_ADD are stored in sqe->len.
diff --git a/io_uring/fs.c b/io_uring/fs.c
index f6a69a549fd4..480f25677fed 100644
--- a/io_uring/fs.c
+++ b/io_uring/fs.c
@@ -47,6 +47,13 @@ struct io_link {
int flags;
};
+struct io_getdents {
+ struct file *file;
+ struct linux_dirent64 __user *dirent;
+ unsigned int count;
+ int flags;
ditto
