On 7/27/19 5:37 AM, Douglas Gilbert wrote:
> Add support for the sg v4 interface based on struct sg_io_v4 found
> in include/uapi/linux/bsg.h and only previously supported by the
> bsg driver. Add ioctl(SG_IOSUBMIT) and ioctl(SG_IORECEIVE) for
> async (non-blocking) usage of the sg v4 interface. Do not accept
> the v3 interface with these ioctls. Do not accept the v4
> interface with this driver's existing write() and read()
> system calls.
>
> For sync (blocking) usage expand the existing ioctl(SG_IO)
> to additionally accept the sg v4 interface object.
>
> Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
> ---
> drivers/scsi/sg.c | 489 ++++++++++++++++++++++++++++++++---------
> include/uapi/scsi/sg.h | 37 +++-
> 2 files changed, 420 insertions(+), 106 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 4d6635af7da7..dd779931ada4 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -7,8 +7,9 @@
> *
> * Original driver (sg.c):
> * Copyright (C) 1992 Lawrence Foard
> - * Version 2 and 3 extensions to driver:
> + * Version 2, 3 and 4 extensions to driver:
> * Copyright (C) 1998 - 2019 Douglas Gilbert
> + *
> */
>
> static int sg_version_num = 30901; /* [x]xyyzz where [x] empty when x=0 */
> @@ -40,10 +41,12 @@ static char *sg_version_date = "20190606";
> #include <linux/atomic.h>
> #include <linux/ratelimit.h>
> #include <linux/uio.h>
> -#include <linux/cred.h> /* for sg_check_file_access() */
> +#include <linux/cred.h> /* for sg_check_file_access() */
> +#include <linux/bsg.h>
> #include <linux/proc_fs.h>
>
> -#include "scsi.h"
> +#include <scsi/scsi.h>
> +#include <scsi/scsi_eh.h>
> #include <scsi/scsi_dbg.h>
> #include <scsi/scsi_host.h>
> #include <scsi/scsi_driver.h>
> @@ -99,6 +102,7 @@ enum sg_rq_state {
> #define SG_ADD_RQ_MAX_RETRIES 40 /* to stop infinite _trylock(s) */
>
> /* Bit positions (flags) for sg_request::frq_bm bitmask follow */
> +#define SG_FRQ_IS_V4I 0 /* true (set) when is v4 interface */
> #define SG_FRQ_IS_ORPHAN 1 /* owner of request gone */
> #define SG_FRQ_SYNC_INVOC 2 /* synchronous (blocking) invocation */
> #define SG_FRQ_DIO_IN_USE 3 /* false->indirect_IO,mmap; 1->dio */
> @@ -159,6 +163,15 @@ struct sg_slice_hdr3 {
> void __user *usr_ptr;
> };
>
> +struct sg_slice_hdr4 { /* parts of sg_io_v4 object needed in async usage */
> + void __user *sbp; /* derived from sg_io_v4::response */
> + u64 usr_ptr; /* hold sg_io_v4::usr_ptr as given (u64) */
> + int out_resid;
> + s16 dir; /* data xfer direction; SG_DXFER_* */
> + u16 cmd_len; /* truncated of sg_io_v4::request_len */
> + u16 max_sb_len; /* truncated of sg_io_v4::max_response_len */
> +};
> +
> struct sg_scatter_hold { /* holding area for scsi scatter gather info */
> struct page **pages; /* num_sgat element array of struct page* */
> int buflen; /* capacity in bytes (dlen<=buflen) */
> @@ -175,7 +188,10 @@ struct sg_request { /* active SCSI command or inactive on free list (fl) */
> struct list_head fl_entry; /* member of rq_fl */
> spinlock_t req_lck;
> struct sg_scatter_hold sgat_h; /* hold buffer, perhaps scatter list */
> - struct sg_slice_hdr3 s_hdr3; /* subset of sg_io_hdr */
> + union {
> + struct sg_slice_hdr3 s_hdr3; /* subset of sg_io_hdr */
> + struct sg_slice_hdr4 s_hdr4; /* reduced size struct sg_io_v4 */
> + };
> u32 duration; /* cmd duration in milliseconds */
> u32 rq_flags; /* hold user supplied flags */
> u32 rq_info; /* info supplied by v3 and v4 interfaces */
> @@ -235,7 +251,10 @@ struct sg_device { /* holds the state of each scsi generic device */
> struct sg_comm_wr_t { /* arguments to sg_common_write() */
> int timeout;
> unsigned long frq_bm[1]; /* see SG_FRQ_* defines above */
> - struct sg_io_hdr *h3p;
> + union { /* selector is frq_bm.SG_FRQ_IS_V4I */
> + struct sg_io_hdr *h3p;
> + struct sg_io_v4 *h4p;
> + };
> u8 *cmnd;
> };
>
> @@ -244,12 +263,12 @@ static void sg_rq_end_io(struct request *rq, blk_status_t status);
> /* Declarations of other static functions used before they are defined */
> static int sg_proc_init(void);
> static int sg_start_req(struct sg_request *srp, u8 *cmd, int cmd_len,
> - int dxfer_dir);
> + struct sg_io_v4 *h4p, int dxfer_dir);
> static void sg_finish_scsi_blk_rq(struct sg_request *srp);
> static int sg_mk_sgat(struct sg_request *srp, struct sg_fd *sfp, int minlen);
> -static int sg_submit(struct file *filp, struct sg_fd *sfp,
> - struct sg_io_hdr *hp, bool sync,
> - struct sg_request **o_srp);
> +static int sg_v3_submit(struct file *filp, struct sg_fd *sfp,
> + struct sg_io_hdr *hp, bool sync,
> + struct sg_request **o_srp);
> static struct sg_request *sg_common_write(struct sg_fd *sfp,
> struct sg_comm_wr_t *cwp);
> static int sg_rd_append(struct sg_request *srp, void __user *outp,
> @@ -257,11 +276,11 @@ static int sg_rd_append(struct sg_request *srp, void __user *outp,
> static void sg_remove_sgat(struct sg_request *srp);
> static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
> static void sg_remove_sfp(struct kref *);
> -static struct sg_request *sg_find_srp_by_id(struct sg_fd *sfp, int pack_id);
> +static struct sg_request *sg_find_srp_by_id(struct sg_fd *sfp, int id);
> static struct sg_request *sg_add_request(struct sg_fd *sfp, int dxfr_len,
> struct sg_comm_wr_t *cwrp);
> static void sg_deact_request(struct sg_fd *sfp, struct sg_request *srp);
> -static struct sg_device *sg_get_dev(int dev);
> +static struct sg_device *sg_get_dev(int min_dev);
> static void sg_device_destroy(struct kref *kref);
> static struct sg_request *sg_mk_srp_sgat(struct sg_fd *sfp, bool first,
> int db_len);
> @@ -274,8 +293,11 @@ static void sg_rep_rq_state_fail(struct sg_fd *sfp,
>
> #define SZ_SG_HEADER ((int)sizeof(struct sg_header)) /* v1 and v2 header */
> #define SZ_SG_IO_HDR ((int)sizeof(struct sg_io_hdr)) /* v3 header */
> +#define SZ_SG_IO_V4 ((int)sizeof(struct sg_io_v4)) /* v4 header (in bsg.h) */
> #define SZ_SG_REQ_INFO ((int)sizeof(struct sg_req_info))
>
> +/* There is a assert that SZ_SG_IO_V4 >= SZ_SG_IO_HDR in first function */
> +
> #define SG_IS_DETACHING(sdp) test_bit(SG_FDEV_DETACHING, (sdp)->fdev_bm)
> #define SG_HAVE_EXCLUDE(sdp) test_bit(SG_FDEV_EXCLUDE, (sdp)->fdev_bm)
> #define SG_RS_ACTIVE(srp) (atomic_read(&(srp)->rq_st) != SG_RS_INACTIVE)
> @@ -295,6 +317,7 @@ static void sg_rep_rq_state_fail(struct sg_fd *sfp,
>
> #if IS_ENABLED(CONFIG_SCSI_LOGGING) && IS_ENABLED(SG_DEBUG)
> #define SG_LOG_BUFF_SZ 48
> +#define SG_LOG_ACTIVE 1
>
> #define SG_LOG(depth, sfp, fmt, a...) \
> do { \
> @@ -332,6 +355,10 @@ static void sg_rep_rq_state_fail(struct sg_fd *sfp,
> static int
> sg_check_file_access(struct file *filp, const char *caller)
> {
> + /* can't put following in declarations where it belongs */
> + compiletime_assert(SZ_SG_IO_V4 >= SZ_SG_IO_HDR,
> + "struct sg_io_v4 should be larger than sg_io_hdr");
> +
> if (filp->f_cred != current_real_cred()) {
> pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
> caller, task_tgid_vnr(current), current->comm);
> @@ -347,10 +374,11 @@ sg_check_file_access(struct file *filp, const char *caller)
>
> static int
> sg_wait_open_event(struct sg_device *sdp, bool o_excl)
> + __must_hold(&sdp->open_rel_lock)
This actually has nothing to do with the sg4 interface support.
Please move out locking annotations into a separate patch.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)
