USB: g_file_storage: more code from file_storage.c moved to storage_common.c

Since storage_common.c no longer references mod_data object
it is now possible to include it before mod_data object is
defined.  This makes it possible to move some defines that
are used as default values of mod_data fields to be defined
in storage_common.c file (where they should be set from
the beginning).

Also, show_ro(), show_file(), store_ro() and store_file()
have been moved to storage_common.c with LUN's device's
drvdata changed from pointing to fsg_dev to pointing to
rw_semaphore (&fsg->filesem).
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/file_storage.c

@@ -278,18 +278,14 @@ static       char fsg_string_serial[13];
 static const char fsg_string_config[] = "Self-powered";
 static const char fsg_string_interface[] = "Mass Storage";
 
+
+#include "storage_common.c"
+
+
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_AUTHOR("Alan Stern");
 MODULE_LICENSE("Dual BSD/GPL");
 
-/* Thanks to NetChip Technologies for donating this product ID.
- *
- * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
- * Instead:  allocate your own, using normal USB-IF procedures. */
-#define FSG_VENDOR_ID	0x0525	// NetChip
-#define FSG_PRODUCT_ID	0xa4a5	// Linux-USB File-backed Storage Gadget
-
-
 /*
  * This driver assumes self-powered hardware and has no way for users to
  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
@@ -302,8 +298,6 @@ MODULE_LICENSE("Dual BSD/GPL");
 
 /* Encapsulate the module parameter settings */
 
-#define FSG_MAX_LUNS	8
-
 static struct {
 	char		*file[FSG_MAX_LUNS];
 	int		ro[FSG_MAX_LUNS];
@@ -408,10 +402,6 @@ MODULE_PARM_DESC(buflen, "I/O buffer size");
 #endif /* CONFIG_USB_FILE_STORAGE_TEST */
 
 
-/*-------------------------------------------------------------------------*/
-
-#include "storage_common.c"
-
 /*-------------------------------------------------------------------------*/
 
 
@@ -3134,107 +3124,10 @@ static int fsg_main_thread(void *fsg_)
 
 /*-------------------------------------------------------------------------*/
 
-static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *buf)
-{
-	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
-
-	return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
-				  ? curlun->ro
-				  : curlun->initially_ro);
-}
-
-static ssize_t show_file(struct device *dev, struct device_attribute *attr,
-		char *buf)
-{
-	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
-	struct fsg_dev	*fsg = dev_get_drvdata(dev);
-	char		*p;
-	ssize_t		rc;
-
-	down_read(&fsg->filesem);
-	if (fsg_lun_is_open(curlun)) {	// Get the complete pathname
-		p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
-		if (IS_ERR(p))
-			rc = PTR_ERR(p);
-		else {
-			rc = strlen(p);
-			memmove(buf, p, rc);
-			buf[rc] = '\n';		// Add a newline
-			buf[++rc] = 0;
-		}
-	} else {				// No file, return 0 bytes
-		*buf = 0;
-		rc = 0;
-	}
-	up_read(&fsg->filesem);
-	return rc;
-}
-
-
-static ssize_t store_ro(struct device *dev, struct device_attribute *attr,
-		const char *buf, size_t count)
-{
-	ssize_t		rc = count;
-	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
-	struct fsg_dev	*fsg = dev_get_drvdata(dev);
-	int		i;
-
-	if (sscanf(buf, "%d", &i) != 1)
-		return -EINVAL;
-
-	/* Allow the write-enable status to change only while the backing file
-	 * is closed. */
-	down_read(&fsg->filesem);
-	if (fsg_lun_is_open(curlun)) {
-		LDBG(curlun, "read-only status change prevented\n");
-		rc = -EBUSY;
-	} else {
-		curlun->ro = !!i;
-		curlun->initially_ro = !!i;
-		LDBG(curlun, "read-only status set to %d\n", curlun->ro);
-	}
-	up_read(&fsg->filesem);
-	return rc;
-}
-
-static ssize_t store_file(struct device *dev, struct device_attribute *attr,
-		const char *buf, size_t count)
-{
-	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
-	struct fsg_dev	*fsg = dev_get_drvdata(dev);
-	int		rc = 0;
-
-	if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
-		LDBG(curlun, "eject attempt prevented\n");
-		return -EBUSY;				// "Door is locked"
-	}
-
-	/* Remove a trailing newline */
-	if (count > 0 && buf[count-1] == '\n')
-		((char *) buf)[count-1] = 0;		// Ugh!
-
-	/* Eject current medium */
-	down_write(&fsg->filesem);
-	if (fsg_lun_is_open(curlun)) {
-		fsg_lun_close(curlun);
-		curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
-	}
-
-	/* Load new medium */
-	if (count > 0 && buf[0]) {
-		rc = fsg_lun_open(curlun, buf);
-		if (rc == 0)
-			curlun->unit_attention_data =
-					SS_NOT_READY_TO_READY_TRANSITION;
-	}
-	up_write(&fsg->filesem);
-	return (rc < 0 ? rc : count);
-}
-
 
 /* The write permissions and store_xxx pointers are set in fsg_bind() */
-static DEVICE_ATTR(ro, 0444, show_ro, NULL);
-static DEVICE_ATTR(file, 0444, show_file, NULL);
+static DEVICE_ATTR(ro, 0444, fsg_show_ro, NULL);
+static DEVICE_ATTR(file, 0444, fsg_show_file, NULL);
 
 
 /*-------------------------------------------------------------------------*/
@@ -3249,7 +3142,9 @@ static void fsg_release(struct kref *ref)
 
 static void lun_release(struct device *dev)
 {
-	struct fsg_dev	*fsg = dev_get_drvdata(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	struct fsg_dev		*fsg =
+		container_of(filesem, struct fsg_dev, filesem);
 
 	kref_put(&fsg->ref, fsg_release);
 }
@@ -3408,10 +3303,10 @@ static int __init fsg_bind(struct usb_gadget *gadget)
 
 	if (mod_data.removable) {	// Enable the store_xxx attributes
 		dev_attr_file.attr.mode = 0644;
-		dev_attr_file.store = store_file;
+		dev_attr_file.store = fsg_store_file;
 		if (!mod_data.cdrom) {
 			dev_attr_ro.attr.mode = 0644;
-			dev_attr_ro.store = store_ro;
+			dev_attr_ro.store = fsg_store_ro;
 		}
 	}
 
@@ -3443,7 +3338,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
 		curlun->dev.release = lun_release;
 		curlun->dev.parent = &gadget->dev;
 		curlun->dev.driver = &fsg_driver.driver;
-		dev_set_drvdata(&curlun->dev, fsg);
+		dev_set_drvdata(&curlun->dev, &fsg->filesem);
 		dev_set_name(&curlun->dev,"%s-lun%d",
 			     dev_name(&gadget->dev), i);
 

drivers/usb/gadget/storage_common.c

@@ -37,6 +37,14 @@
 #include <asm/unaligned.h>
 
 
+/* Thanks to NetChip Technologies for donating this product ID.
+ *
+ * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures. */
+#define FSG_VENDOR_ID	0x0525	// NetChip
+#define FSG_PRODUCT_ID	0xa4a5	// Linux-USB File-backed Storage Gadget
+
+
 /*-------------------------------------------------------------------------*/
 
 
@@ -255,6 +263,12 @@ static struct fsg_lun *fsg_lun_from_dev(struct device *dev)
 /* Number of buffers we will use.  2 is enough for double-buffering */
 #define FSG_NUM_BUFFERS	2
 
+/* Default size of buffer length. */
+#define FSG_BUFLEN	((u32)16384)
+
+/* Maximal number of LUNs supported in mass storage function */
+#define FSG_MAX_LUNS	8
+
 enum fsg_buffer_state {
 	BUF_STATE_EMPTY = 0,
 	BUF_STATE_FULL,
@@ -594,3 +608,105 @@ static void store_cdrom_address(u8 *dest, int msf, u32 addr)
 		put_unaligned_be32(addr, dest);
 	}
 }
+
+
+/*-------------------------------------------------------------------------*/
+
+
+static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+
+	return sprintf(buf, "%d\n", fsg_lun_is_open(curlun)
+				  ? curlun->ro
+				  : curlun->initially_ro);
+}
+
+static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	char		*p;
+	ssize_t		rc;
+
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {	// Get the complete pathname
+		p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1);
+		if (IS_ERR(p))
+			rc = PTR_ERR(p);
+		else {
+			rc = strlen(p);
+			memmove(buf, p, rc);
+			buf[rc] = '\n';		// Add a newline
+			buf[++rc] = 0;
+		}
+	} else {				// No file, return 0 bytes
+		*buf = 0;
+		rc = 0;
+	}
+	up_read(filesem);
+	return rc;
+}
+
+
+static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	ssize_t		rc = count;
+	struct fsg_lun	*curlun = fsg_lun_from_dev(dev);
+	struct rw_semaphore	*filesem = dev_get_drvdata(dev);
+	int		i;
+
+	if (sscanf(buf, "%d", &i) != 1)
+		return -EINVAL;
+
+	/* Allow the write-enable status to change only while the backing file
+	 * is closed. */
+	down_read(filesem);
+	if (fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "read-only status change prevented\n");
+		rc = -EBUSY;
+	} else {
+		curlun->ro = !!i;
+		curlun->initially_ro = !!i;
+		LDBG(curlun, "read-only status set to %d\n", curlun->ro);
+	}
+	up_read(filesem);
+	return rc;
+}
+
+static ssize_t fsg_store_file(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);
+	int		rc = 0;
+
+	if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) {
+		LDBG(curlun, "eject attempt prevented\n");
+		return -EBUSY;				// "Door is locked"
+	}
+
+	/* Remove a trailing newline */
+	if (count > 0 && buf[count-1] == '\n')
+		((char *) buf)[count-1] = 0;		// Ugh!
+
+	/* Eject current medium */
+	down_write(filesem);
+	if (fsg_lun_is_open(curlun)) {
+		fsg_lun_close(curlun);
+		curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
+	}
+
+	/* Load new medium */
+	if (count > 0 && buf[0]) {
+		rc = fsg_lun_open(curlun, buf);
+		if (rc == 0)
+			curlun->unit_attention_data =
+					SS_NOT_READY_TO_READY_TRANSITION;
+	}
+	up_write(filesem);
+	return (rc < 0 ? rc : count);
+}