bsg: add io_uring command support to generic layer

Add an io_uring command handler to the generic BSG layer. The new
.uring_cmd file operation validates io_uring features and delegates
handling to a per-queue bsg_uring_cmd_fn callback.

Extend bsg_register_queue() so transport drivers can register both
sg_io and io_uring command handlers.

Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260317072226.2598233-3-yangxiuwei@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 20cd0ef3c394b4b73fa3841cddcfbcab6d6fe7d8..fdb4b290ca689182baf58c5beb033c23438c8c8f 100644 (file)
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -393,7 +393,7 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
 
        blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
 
-       bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn);
+       bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn, NULL);
        if (IS_ERR(bset->bd)) {
                ret = PTR_ERR(bset->bd);
                goto out_cleanup_queue;

diff --git a/block/bsg.c b/block/bsg.c
index e0af6206ed2873f0a223ad973f50723fff4da708..82aaf3cee582509ca0529be9cdbd717e17e54a9b 100644 (file)
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -12,6 +12,7 @@
 #include <linux/idr.h>
 #include <linux/bsg.h>
 #include <linux/slab.h>
+#include <linux/io_uring/cmd.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_ioctl.h>
@@ -28,6 +29,7 @@ struct bsg_device {
        unsigned int timeout;
        unsigned int reserved_size;
        bsg_sg_io_fn *sg_io_fn;
+       bsg_uring_cmd_fn *uring_cmd_fn;
 };
 
 static inline struct bsg_device *to_bsg_device(struct inode *inode)
@@ -158,11 +160,38 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        }
 }
 
+static int bsg_check_uring_features(unsigned int issue_flags)
+{
+       /* BSG passthrough requires big SQE/CQE support */
+       if ((issue_flags & (IO_URING_F_SQE128|IO_URING_F_CQE32)) !=
+           (IO_URING_F_SQE128|IO_URING_F_CQE32))
+               return -EOPNOTSUPP;
+       return 0;
+}
+
+static int bsg_uring_cmd(struct io_uring_cmd *ioucmd, unsigned int issue_flags)
+{
+       struct bsg_device *bd = to_bsg_device(file_inode(ioucmd->file));
+       bool open_for_write = ioucmd->file->f_mode & FMODE_WRITE;
+       struct request_queue *q = bd->queue;
+       int ret;
+
+       ret = bsg_check_uring_features(issue_flags);
+       if (ret)
+               return ret;
+
+       if (!bd->uring_cmd_fn)
+               return -EOPNOTSUPP;
+
+       return bd->uring_cmd_fn(q, ioucmd, issue_flags, open_for_write);
+}
+
 static const struct file_operations bsg_fops = {
        .open           =       bsg_open,
        .release        =       bsg_release,
        .unlocked_ioctl =       bsg_ioctl,
        .compat_ioctl   =       compat_ptr_ioctl,
+       .uring_cmd      =       bsg_uring_cmd,
        .owner          =       THIS_MODULE,
        .llseek         =       default_llseek,
 };
@@ -187,7 +216,8 @@ void bsg_unregister_queue(struct bsg_device *bd)
 EXPORT_SYMBOL_GPL(bsg_unregister_queue);
 
 struct bsg_device *bsg_register_queue(struct request_queue *q,
-               struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn)
+               struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn,
+               bsg_uring_cmd_fn *uring_cmd_fn)
 {
        struct bsg_device *bd;
        int ret;
@@ -199,6 +229,7 @@ struct bsg_device *bsg_register_queue(struct request_queue *q,
        bd->reserved_size = INT_MAX;
        bd->queue = q;
        bd->sg_io_fn = sg_io_fn;
+       bd->uring_cmd_fn = uring_cmd_fn;
 
        ret = ida_alloc_max(&bsg_minor_ida, BSG_MAX_DEVS - 1, GFP_KERNEL);
        if (ret < 0) {

diff --git a/drivers/scsi/scsi_bsg.c b/drivers/scsi/scsi_bsg.c
index a9a9ec086a7e3f2ac13a05f80fe3a04bec976a3a..4d57e524e1415b4312b4a0b35b732fd5ec881092 100644 (file)
--- a/drivers/scsi/scsi_bsg.c
+++ b/drivers/scsi/scsi_bsg.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/bsg.h>
+#include <linux/io_uring/cmd.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsi_cmnd.h>
@@ -9,6 +10,12 @@
 
 #define uptr64(val) ((void __user *)(uintptr_t)(val))
 
+static int scsi_bsg_uring_cmd(struct request_queue *q, struct io_uring_cmd *ioucmd,
+                              unsigned int issue_flags, bool open_for_write)
+{
+       return -EOPNOTSUPP;
+}
+
 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
                bool open_for_write, unsigned int timeout)
 {
@@ -99,5 +106,6 @@ out_put_request:
 struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
 {
        return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
-                       dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
+                       dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn,
+                       scsi_bsg_uring_cmd);
 }

diff --git a/include/linux/bsg.h b/include/linux/bsg.h
index ee2df73edf83f8e1925bf50f9f1c0403bd51ba14..162730bfc2d8d5a360e49b7556581c74d31407c5 100644 (file)
--- a/include/linux/bsg.h
+++ b/include/linux/bsg.h
@@ -7,13 +7,17 @@
 struct bsg_device;
 struct device;
 struct request_queue;
+struct io_uring_cmd;
 
 typedef int (bsg_sg_io_fn)(struct request_queue *, struct sg_io_v4 *hdr,
                bool open_for_write, unsigned int timeout);
 
+typedef int (bsg_uring_cmd_fn)(struct request_queue *q, struct io_uring_cmd *ioucmd,
+                              unsigned int issue_flags, bool open_for_write);
+
 struct bsg_device *bsg_register_queue(struct request_queue *q,
                struct device *parent, const char *name,
-               bsg_sg_io_fn *sg_io_fn);
+               bsg_sg_io_fn *sg_io_fn, bsg_uring_cmd_fn *uring_cmd_fn);
 void bsg_unregister_queue(struct bsg_device *bcd);
 
 #endif /* _LINUX_BSG_H */