usb: gadget: f_mass_storage: forced_eject attribute
PATCH 1/1 usb: gadget: f_mass_storage: forced_eject attribute
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.
--- 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(+)
drivers/usb/gadget/function/f_mass_storage.c +25 -0
@@ -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, };
drivers/usb/gadget/function/storage_common.c +11 -0
@@ -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" );
drivers/usb/gadget/function/storage_common.h +2 -0
@@ -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 */
Signature · 1 line
2.37.0
В Wed, 6 Jul 2022 20:46:34 +0300
Quoted 3 lines · Maxim Devaev
The patch is a completely alternative implementation of the previously proposed [1], the idea of which was born after the mentioned discussion.
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.
Greg KH
maintainerQuoted 26 lines · Maxim Devaev
It allows to reset
prevent_medium_removalflag 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]>--- 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(+)drivers/usb/gadget/function/f_mass_storage.c +5
-0@@ -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);
drivers/usb/gadget/function/f_mass_storage.c static ssize_t file_store(struct device *dev, struct device_attribute *attr, · line 2537
Quoted 10 lines
drivers/usb/gadget/function/f_mass_storage.c +6
-0+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
Quoted 2 lines · Greg KH
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.