2022-02-22 05:29:53

by Finn Thain

Subject: [PATCH] mesh: Stop using struct scsi_pointer

This driver doesn't use SCp.ptr to save a SCSI command data pointer
which means "scsi pointer" is a complete misnomer here. Only a few
members of struct scsi_pointer are used and the rest waste memory.
Avoid the "struct foo { struct bar; };" silliness.

Signed-off-by: Finn Thain <[email protected]>
---
drivers/scsi/mesh.c | 19 +++++++++----------
drivers/scsi/mesh.h | 10 +++++-----
2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
index de9ae36def42..322d3ad38159 100644
--- a/drivers/scsi/mesh.c
+++ b/drivers/scsi/mesh.c
@@ -586,12 +586,12 @@ static void mesh_done(struct mesh_state *ms, int start_next)
ms->current_req = NULL;
tp->current_req = NULL;
if (cmd) {
- struct scsi_pointer *scsi_pointer = mesh_scsi_pointer(cmd);
+ struct mesh_cmd_priv *mcmd = mesh_priv(cmd);

set_host_byte(cmd, ms->stat);
- set_status_byte(cmd, scsi_pointer->Status);
+ set_status_byte(cmd, mcmd->status);
if (ms->stat == DID_OK)
- scsi_msg_to_host_byte(cmd, scsi_pointer->Message);
+ scsi_msg_to_host_byte(cmd, mcmd->message);
if (DEBUG_TARGET(cmd)) {
printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
cmd->result, ms->data_ptr, scsi_bufflen(cmd));
@@ -605,7 +605,7 @@ static void mesh_done(struct mesh_state *ms, int start_next)
}
#endif
}
- scsi_pointer->this_residual -= ms->data_ptr;
+ mcmd->this_residual -= ms->data_ptr;
scsi_done(cmd);
}
if (start_next) {
@@ -1173,7 +1173,7 @@ static void handle_msgin(struct mesh_state *ms)
if (ms->n_msgin < msgin_length(ms))
goto reject;
if (cmd)
- mesh_scsi_pointer(cmd)->Message = code;
+ mesh_priv(cmd)->message = code;
switch (code) {
case COMMAND_COMPLETE:
break;
@@ -1264,7 +1264,7 @@ static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
if (cmd) {
int nseg;

- mesh_scsi_pointer(cmd)->this_residual = scsi_bufflen(cmd);
+ mesh_priv(cmd)->this_residual = scsi_bufflen(cmd);

nseg = scsi_dma_map(cmd);
BUG_ON(nseg < 0);
@@ -1594,13 +1594,12 @@ static void cmd_complete(struct mesh_state *ms)
break;
case statusing:
if (cmd) {
- struct scsi_pointer *scsi_pointer =
- mesh_scsi_pointer(cmd);
+ struct mesh_cmd_priv *mcmd = mesh_priv(cmd);

- scsi_pointer->Status = mr->fifo;
+ mcmd->status = mr->fifo;
if (DEBUG_TARGET(cmd))
printk(KERN_DEBUG "mesh: status is %x\n",
- scsi_pointer->Status);
+ mcmd->status);
}
ms->msgphase = msg_in;
break;
diff --git a/drivers/scsi/mesh.h b/drivers/scsi/mesh.h
index 1afa8b37295b..f70181acceac 100644
--- a/drivers/scsi/mesh.h
+++ b/drivers/scsi/mesh.h
@@ -9,14 +9,14 @@
#define _MESH_H

struct mesh_cmd_priv {
- struct scsi_pointer scsi_pointer;
+ int this_residual;
+ int message;
+ int status;
};

-static inline struct scsi_pointer *mesh_scsi_pointer(struct scsi_cmnd *cmd)
+static inline struct mesh_cmd_priv *mesh_priv(struct scsi_cmnd *cmd)
{
- struct mesh_cmd_priv *mcmd = scsi_cmd_priv(cmd);
-
- return &mcmd->scsi_pointer;
+ return scsi_cmd_priv(cmd);
}

/*
--
2.32.0

2022-02-22 08:05:00

by Christoph Hellwig

Subject: Re: [PATCH] mesh: Stop using struct scsi_pointer

On Tue, Feb 22, 2022 at 10:09:42AM +1100, Finn Thain wrote:
> This driver doesn't use SCp.ptr to save a SCSI command data pointer
> which means "scsi pointer" is a complete misnomer here. Only a few
> members of struct scsi_pointer are used and the rest waste memory.
> Avoid the "struct foo { struct bar; };" silliness.

Looks good:

Reviewed-by: Christoph Hellwig <[email protected]>

2022-02-28 07:07:01

by Martin K. Petersen

Subject: Re: [PATCH] mesh: Stop using struct scsi_pointer

Finn,

> This driver doesn't use SCp.ptr to save a SCSI command data pointer
> which means "scsi pointer" is a complete misnomer here. Only a few
> members of struct scsi_pointer are used and the rest waste memory.
> Avoid the "struct foo { struct bar; };" silliness.

Applied to 5.18/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering

2022-03-02 10:51:29

by Martin K. Petersen

Subject: Re: [PATCH] mesh: Stop using struct scsi_pointer

On Tue, 22 Feb 2022 10:09:42 +1100, Finn Thain wrote:

> This driver doesn't use SCp.ptr to save a SCSI command data pointer
> which means "scsi pointer" is a complete misnomer here. Only a few
> members of struct scsi_pointer are used and the rest waste memory.
> Avoid the "struct foo { struct bar; };" silliness.
>
>

Applied to 5.18/scsi-queue, thanks!

[1/1] mesh: Stop using struct scsi_pointer
https://git.kernel.org/mkp/scsi/c/2e1b3175f29c

--
Martin K. Petersen Oracle Linux Engineering