[PATCH for-next 3/4] io_uring: grow a field in struct io_uring_cmd

Kanchan Joshi
2022-07-11T11:08:37Z

Use the leftover space to carve 'next' field that enables linking of
io_uring_cmd structs. Also introduce a list head and few helpers.

This is in preparation to support nvme-mulitpath, allowing multiple
uring passthrough commands to be queued.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
---
include/linux/io_uring.h | 38 ++++++++++++++++++++++++++++++++++++--
1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 54063d67506b..d734599cbcd7 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -22,9 +22,14 @@ struct io_uring_cmd {
const void *cmd;
/* callback to defer completions to task context */
void (*task_work_cb)(struct io_uring_cmd *cmd);
+ struct io_uring_cmd *next;
u32 cmd_op;
- u32 pad;
- u8 pdu[32]; /* available inline for free use */
+ u8 pdu[28]; /* available inline for free use */
+};
+
+struct ioucmd_list {
+ struct io_uring_cmd *head;
+ struct io_uring_cmd *tail;
};

#if defined(CONFIG_IO_URING)
@@ -54,6 +59,27 @@ static inline void io_uring_free(struct task_struct *tsk)
if (tsk->io_uring)
__io_uring_free(tsk);
}
+
+static inline struct io_uring_cmd *ioucmd_list_get(struct ioucmd_list *il)
+{
+ struct io_uring_cmd *ioucmd = il->head;
+
+ il->head = il->tail = NULL;
+
+ return ioucmd;
+}
+
+static inline void ioucmd_list_add(struct ioucmd_list *il,
+ struct io_uring_cmd *ioucmd)
+{
+ ioucmd->next = NULL;
+
+ if (il->tail)
+ il->tail->next = ioucmd;
+ else
+ il->head = ioucmd;
+ il->tail = ioucmd;
+}
#else
static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
ssize_t ret2)
@@ -80,6 +106,14 @@ static inline const char *io_uring_get_opcode(u8 opcode)
{
return "";
}
+static inline struct io_uring_cmd *ioucmd_list_get(struct ioucmd_list *il)
+{
+ return NULL;
+}
+static inline void ioucmd_list_add(struct ioucmd_list *il,
+ struct io_uring_cmd *ioucmd)
+{
+}
#endif

#endif
--
2.25.1