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>

2 files changed, 128 insertions, 117 deletions

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index ee712a5715e7..7998402b1840 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/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];
@@ -410,10 +404,6 @@ MODULE_PARM_DESC(buflen, "I/O buffer size");
 
 /*-------------------------------------------------------------------------*/
 
-#include "storage_common.c"
-
-/*-------------------------------------------------------------------------*/
-
 
 struct fsg_dev {
         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
@@ -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);
 
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index affd23b5436f..6523cb6f4c4d 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/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);
+}