[PATCH RFC 10/13] usb: gadget: simplify the printing with '%pD' specifier

From: Jia He
Date: Wed Jul 14 2021 - 23:16:34 EST


After the behavior of '%pD' is changed to print the full path of file,
the log printing in fsg_common_create_lun() can be simplified.

Given the space with proper length would be allocated in vprintk_store(),
it is worthy of dropping kmalloc()/kfree() to avoid additional space
allocation. The error case is well handled in d_path_unsafe(), the error
string would be copied in '%pD' buffer, no need to additionally handle
IS_ERR().

Cc: Felipe Balbi <balbi@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: Chen Lin <chen.lin5@xxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Jia He <justin.he@xxxxxxx>
---
drivers/usb/gadget/function/f_mass_storage.c | 28 ++++++++------------
1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 4a4703634a2a..04d4e8a0f6fd 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2738,7 +2738,6 @@ int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
const char **name_pfx)
{
struct fsg_lun *lun;
- char *pathbuf, *p;
int rc = -ENOMEM;

if (id >= ARRAY_SIZE(common->luns))
@@ -2790,22 +2789,17 @@ int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
goto error_lun;
}

- pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
- p = "(no medium)";
- if (fsg_lun_is_open(lun)) {
- p = "(error)";
- if (pathbuf) {
- p = file_path(lun->filp, pathbuf, PATH_MAX);
- if (IS_ERR(p))
- p = "(error)";
- }
- }
- pr_info("LUN: %s%s%sfile: %s\n",
- lun->removable ? "removable " : "",
- lun->ro ? "read only " : "",
- lun->cdrom ? "CD-ROM " : "",
- p);
- kfree(pathbuf);
+ if (fsg_lun_is_open(lun))
+ pr_info("LUN: %s%s%sfile: %pD\n",
+ lun->removable ? "removable " : "",
+ lun->ro ? "read only " : "",
+ lun->cdrom ? "CD-ROM " : "",
+ lun->filp);
+ else
+ pr_info("LUN: %s%s%sfile: (no medium)\n",
+ lun->removable ? "removable " : "",
+ lun->ro ? "read only " : "",
+ lun->cdrom ? "CD-ROM " : "");

return 0;

--
2.17.1