It allows to reset prevent_medium_removal flag and "eject" the image.
The patch is a completely alternative implementation of the previously
proposed [1], the idea of which was born after the mentioned discussion.
Signed-off-by: Maxim Devaev <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected] [1]
---
drivers/usb/gadget/function/f_mass_storage.c | 25 ++++++++++++++++++++
drivers/usb/gadget/function/storage_common.c | 11 +++++++++
drivers/usb/gadget/function/storage_common.h | 2 ++
3 files changed, 38 insertions(+)
diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 6ad669dde41c..00cac2a38178 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2520,10 +2520,21 @@ static ssize_t file_store(struct device *dev, struct device_attribute *attr,
return fsg_store_file(curlun, filesem, buf, count);
}
+static ssize_t forced_eject_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct fsg_lun *curlun = fsg_lun_from_dev(dev);
+ struct rw_semaphore *filesem = dev_get_drvdata(dev);
+
+ return fsg_store_forced_eject(curlun, filesem, buf, count);
+}
+
static DEVICE_ATTR_RW(nofua);
/* mode wil be set in fsg_lun_attr_is_visible() */
static DEVICE_ATTR(ro, 0, ro_show, ro_store);
static DEVICE_ATTR(file, 0, file_show, file_store);
+static DEVICE_ATTR_WO(forced_eject);
/****************************** FSG COMMON ******************************/
@@ -2677,6 +2688,7 @@ static struct attribute *fsg_lun_dev_attrs[] = {
&dev_attr_ro.attr,
&dev_attr_file.attr,
&dev_attr_nofua.attr,
+ &dev_attr_forced_eject.attr,
NULL
};
@@ -3090,6 +3102,18 @@ static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
+static ssize_t fsg_lun_opts_forced_eject_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
+ struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
+
+ return fsg_store_forced_eject(opts->lun, &fsg_opts->common->filesem,
+ page, len);
+}
+
+CONFIGFS_ATTR_WO(fsg_lun_opts_, forced_eject);
+
static struct configfs_attribute *fsg_lun_attrs[] = {
&fsg_lun_opts_attr_file,
&fsg_lun_opts_attr_ro,
@@ -3097,6 +3121,7 @@ static struct configfs_attribute *fsg_lun_attrs[] = {
&fsg_lun_opts_attr_cdrom,
&fsg_lun_opts_attr_nofua,
&fsg_lun_opts_attr_inquiry_string,
+ &fsg_lun_opts_attr_forced_eject,
NULL,
};
diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c
index b859a158a414..8cd95bf7831f 100644
--- a/drivers/usb/gadget/function/storage_common.c
+++ b/drivers/usb/gadget/function/storage_common.c
@@ -519,4 +519,15 @@ ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
}
EXPORT_SYMBOL_GPL(fsg_store_inquiry_string);
+ssize_t fsg_store_forced_eject(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ const char *buf, size_t count)
+{
+ int ret;
+
+ curlun->prevent_medium_removal = 0;
+ ret = fsg_store_file(curlun, filesem, "", 0);
+ return ret < 0 ? ret : count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_forced_eject);
+
MODULE_LICENSE("GPL");
diff --git a/drivers/usb/gadget/function/storage_common.h b/drivers/usb/gadget/function/storage_common.h
index bdeb1e233fc9..0a544a82cbf8 100644
--- a/drivers/usb/gadget/function/storage_common.h
+++ b/drivers/usb/gadget/function/storage_common.h
@@ -219,5 +219,7 @@ ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
size_t count);
ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
size_t count);
+ssize_t fsg_store_forced_eject(struct fsg_lun *curlun, struct rw_semaphore *filesem,
+ const char *buf, size_t count);
#endif /* USB_STORAGE_COMMON_H */
--
2.37.0
В Wed, 6 Jul 2022 20:46:34 +0300
Maxim Devaev <[email protected]> wrote:
> The patch is a completely alternative implementation of the previously
> proposed [1], the idea of which was born after the mentioned discussion.
> Link: https://lore.kernel.org/lkml/[email protected] [1]
A small comment after that, which is not worth mentioning in the body of the patch.
As discussed in the previous thread, I made a clean implementation to reset
the prevent_medium_removal flag instead of using SIGUSR1, tested it myself,
and then on several thousand of my users. I haven't received a single complaint
in a few months, so I guess everything is working as intended.
On Wed, Jul 06, 2022 at 08:46:34PM +0300, Maxim Devaev wrote:
> It allows to reset prevent_medium_removal flag and "eject" the image.
>
> The patch is a completely alternative implementation of the previously
> proposed [1], the idea of which was born after the mentioned discussion.
>
> Signed-off-by: Maxim Devaev <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected] [1]
> ---
> drivers/usb/gadget/function/f_mass_storage.c | 25 ++++++++++++++++++++
> drivers/usb/gadget/function/storage_common.c | 11 +++++++++
> drivers/usb/gadget/function/storage_common.h | 2 ++
> 3 files changed, 38 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
> index 6ad669dde41c..00cac2a38178 100644
> --- a/drivers/usb/gadget/function/f_mass_storage.c
> +++ b/drivers/usb/gadget/function/f_mass_storage.c
> @@ -2520,10 +2520,21 @@ static ssize_t file_store(struct device *dev, struct device_attribute *attr,
> return fsg_store_file(curlun, filesem, buf, count);
> }
>
> +static ssize_t forced_eject_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct fsg_lun *curlun = fsg_lun_from_dev(dev);
> + struct rw_semaphore *filesem = dev_get_drvdata(dev);
> +
> + return fsg_store_forced_eject(curlun, filesem, buf, count);
> +}
> +
> static DEVICE_ATTR_RW(nofua);
> /* mode wil be set in fsg_lun_attr_is_visible() */
> static DEVICE_ATTR(ro, 0, ro_show, ro_store);
> static DEVICE_ATTR(file, 0, file_show, file_store);
> +static DEVICE_ATTR_WO(forced_eject);
You have to document sysfs files in Documentation/ABI/ in order for us
to be able to accept them.
thanks,
greg k-h
В Wed, 6 Jul 2022 20:13:54 +0200
Greg KH <[email protected]> wrote:
> You have to document sysfs files in Documentation/ABI/ in order for us
> to be able to accept them.
I've added this and also the documentation for configfs. Submitted as v2 patch.