Instead of manual device_create_file() and device_remove_file() calls,
assign the static attribute groups to the lun device to register.
The RO or RW permissions for some entries are decided in is_visible
callback. This simplifies the code (also the logic) and avoids the
possible races, too.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
drivers/usb/gadget/function/f_mass_storage.c | 107 +++++++++------------------
1 file changed, 33 insertions(+), 74 deletions(-)
diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 811929cd4c9e..49a2f19c2b87 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2624,13 +2624,10 @@ static ssize_t file_store(struct device *dev, struct device_attribute *attr,
return fsg_store_file(curlun, filesem, buf, count);
}
-static DEVICE_ATTR_RW(ro);
static DEVICE_ATTR_RW(nofua);
-static DEVICE_ATTR_RW(file);
-
-static struct device_attribute dev_attr_ro_cdrom = __ATTR_RO(ro);
-static struct device_attribute dev_attr_file_nonremovable = __ATTR_RO(file);
-
+/* 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);
/****************************** FSG COMMON ******************************/
@@ -2745,40 +2742,10 @@ error_release:
}
EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers);
-static inline void fsg_common_remove_sysfs(struct fsg_lun *lun)
-{
- device_remove_file(&lun->dev, &dev_attr_nofua);
- /*
- * device_remove_file() =>
- *
- * here the attr (e.g. dev_attr_ro) is only used to be passed to:
- *
- * sysfs_remove_file() =>
- *
- * here e.g. both dev_attr_ro_cdrom and dev_attr_ro are in
- * the same namespace and
- * from here only attr->name is passed to:
- *
- * sysfs_hash_and_remove()
- *
- * attr->name is the same for dev_attr_ro_cdrom and
- * dev_attr_ro
- * attr->name is the same for dev_attr_file and
- * dev_attr_file_nonremovable
- *
- * so we don't differentiate between removing e.g. dev_attr_ro_cdrom
- * and dev_attr_ro
- */
- device_remove_file(&lun->dev, &dev_attr_ro);
- device_remove_file(&lun->dev, &dev_attr_file);
-}
-
void fsg_common_remove_lun(struct fsg_lun *lun, bool sysfs)
{
- if (sysfs) {
- fsg_common_remove_sysfs(lun);
+ if (sysfs)
device_unregister(&lun->dev);
- }
fsg_lun_close(lun);
kfree(lun);
}
@@ -2877,41 +2844,35 @@ int fsg_common_set_cdev(struct fsg_common *common,
}
EXPORT_SYMBOL_GPL(fsg_common_set_cdev);
-static inline int fsg_common_add_sysfs(struct fsg_common *common,
- struct fsg_lun *lun)
-{
- int rc;
+static struct attribute *fsg_lun_dev_attrs[] = {
+ &dev_attr_ro.attr,
+ &dev_attr_file.attr,
+ &dev_attr_nofua.attr,
+ NULL
+};
- rc = device_register(&lun->dev);
- if (rc) {
- put_device(&lun->dev);
- return rc;
- }
+static umode_t fsg_lun_dev_is_visible(struct kobject *kobj,
+ struct attribute *attr, int idx)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct fsg_lun *lun = fsg_lun_from_dev(dev);
- rc = device_create_file(&lun->dev,
- lun->cdrom
- ? &dev_attr_ro_cdrom
- : &dev_attr_ro);
- if (rc)
- goto error;
- rc = device_create_file(&lun->dev,
- lun->removable
- ? &dev_attr_file
- : &dev_attr_file_nonremovable);
- if (rc)
- goto error;
- rc = device_create_file(&lun->dev, &dev_attr_nofua);
- if (rc)
- goto error;
+ if (attr == &dev_attr_ro.attr)
+ return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO);
+ if (attr == &dev_attr_file.attr)
+ return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO;
+ return attr->mode;
+}
- return 0;
+static const struct attribute_group fsg_lun_dev_group = {
+ .attrs = fsg_lun_dev_attrs,
+ .is_visible = fsg_lun_dev_is_visible,
+};
-error:
- /* removing nonexistent files is a no-op */
- fsg_common_remove_sysfs(lun);
- device_unregister(&lun->dev);
- return rc;
-}
+static const struct attribute_group *fsg_lun_dev_groups[] = {
+ &fsg_lun_dev_group,
+ NULL
+};
int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
unsigned int id, const char *name,
@@ -2949,13 +2910,15 @@ int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
} else {
lun->dev.release = fsg_lun_release;
lun->dev.parent = &common->gadget->dev;
+ lun->dev.groups = fsg_lun_dev_groups;
dev_set_drvdata(&lun->dev, &common->filesem);
dev_set_name(&lun->dev, "%s", name);
lun->name = dev_name(&lun->dev);
- rc = fsg_common_add_sysfs(common, lun);
+ rc = device_register(&lun->dev);
if (rc) {
pr_info("failed to register LUN%d: %d\n", id, rc);
+ put_device(&lun->dev);
goto error_sysfs;
}
}
@@ -2988,10 +2951,8 @@ int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
return 0;
error_lun:
- if (common->sysfs) {
- fsg_common_remove_sysfs(lun);
+ if (common->sysfs)
device_unregister(&lun->dev);
- }
fsg_lun_close(lun);
common->luns[id] = NULL;
error_sysfs:
@@ -3077,8 +3038,6 @@ static void fsg_common_release(struct kref *ref)
struct fsg_lun *lun = *lun_it;
if (!lun)
continue;
- if (common->sysfs)
- fsg_common_remove_sysfs(lun);
fsg_lun_close(lun);
if (common->sysfs)
device_unregister(&lun->dev);
--
2.2.2
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