1 files changed, 80 insertions, 25 deletions

diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 04c462ff0ea6..484acfb1a7c5 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -57,10 +57,12 @@
 #include <asm/unaligned.h>
 
 
-/* Thanks to NetChip Technologies for donating this product ID.
+/*
+ * 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. */
+ * 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 */
 
@@ -84,14 +86,27 @@
 #define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
 #define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
 
-/* Keep those macros in sync with thos in
- * include/linux/ubs/composite.h or else GCC will complain.  If they
+/*
+ * Keep those macros in sync with those in
+ * include/linux/usb/composite.h or else GCC will complain.  If they
  * are identical (the same names of arguments, white spaces in the
  * same places) GCC will allow redefinition otherwise (even if some
- * white space is removed or added) warning will be issued.  No
- * checking if those symbols is defined is performed because warning
- * is desired when those macros were defined by someone else to mean
- * something else. */
+ * white space is removed or added) warning will be issued.
+ *
+ * Those macros are needed here because File Storage Gadget does not
+ * include the composite.h header.  For composite gadgets those macros
+ * are redundant since composite.h is included any way.
+ *
+ * One could check whether those macros are already defined (which
+ * would indicate composite.h had been included) or not (which would
+ * indicate we were in FSG) but this is not done because a warning is
+ * desired if definitions here differ from the ones in composite.h.
+ *
+ * We want the definitions to match and be the same in File Storage
+ * Gadget as well as Mass Storage Function (and so composite gadgets
+ * using MSF).  If someone changes them in composite.h it will produce
+ * a warning in this file when building MSF.
+ */
 #define DBG(d, fmt, args...)     dev_dbg(&(d)->gadget->dev , fmt , ## args)
 #define VDBG(d, fmt, args...)    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
 #define ERROR(d, fmt, args...)   dev_err(&(d)->gadget->dev , fmt , ## args)
@@ -269,6 +284,7 @@ struct fsg_lun {
         unsigned int    prevent_medium_removal:1;
         unsigned int    registered:1;
         unsigned int    info_valid:1;
+        unsigned int    nofua:1;
 
         u32             sense_data;
         u32             sense_data_info;
@@ -313,9 +329,11 @@ struct fsg_buffhd {
         enum fsg_buffer_state           state;
         struct fsg_buffhd               *next;
 
-        /* The NetChip 2280 is faster, and handles some protocol faults
+        /*
+         * The NetChip 2280 is faster, and handles some protocol faults
          * better, if we don't submit any short bulk-out read requests.
-         * So we will record the intended request length here. */
+         * So we will record the intended request length here.
+         */
         unsigned int                    bulk_out_intended_length;
 
         struct usb_request              *inreq;
@@ -395,8 +413,10 @@ fsg_intf_desc = {
         .iInterface =           FSG_STRING_INTERFACE,
 };
 
-/* Three full-speed endpoint descriptors: bulk-in, bulk-out,
- * and interrupt-in. */
+/*
+ * Three full-speed endpoint descriptors: bulk-in, bulk-out, and
+ * interrupt-in.
+ */
 
 static struct usb_endpoint_descriptor
 fsg_fs_bulk_in_desc = {
@@ -459,7 +479,7 @@ static struct usb_descriptor_header *fsg_fs_function[] = {
  *
  * That means alternate endpoint descriptors (bigger packets)
  * and a "device qualifier" ... plus more construction options
- * for the config descriptor.
+ * for the configuration descriptor.
  */
 static struct usb_endpoint_descriptor
 fsg_hs_bulk_in_desc = {
@@ -547,8 +567,10 @@ static struct usb_gadget_strings	fsg_stringtab = {
 
  /*-------------------------------------------------------------------------*/
 
-/* If the next two routines are called while the gadget is registered,
- * the caller must own fsg->filesem for writing. */
+/*
+ * If the next two routines are called while the gadget is registered,
+ * the caller must own fsg->filesem for writing.
+ */
 
 static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 {
@@ -587,8 +609,10 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
                 goto out;
         }
 
-        /* If we can't read the file, it's no good.
-         * If we can't write the file, use it read-only. */
+        /*
+         * If we can't read the file, it's no good.
+         * If we can't write the file, use it read-only.
+         */
         if (!filp->f_op || !(filp->f_op->read || filp->f_op->aio_read)) {
                 LINFO(curlun, "file not readable: %s\n", filename);
                 goto out;
@@ -646,8 +670,10 @@ static void fsg_lun_close(struct fsg_lun *curlun)
 
 /*-------------------------------------------------------------------------*/
 
-/* Sync the file data, don't bother with the metadata.
- * This code was copied from fs/buffer.c:sys_fdatasync(). */
+/*
+ * Sync the file data, don't bother with the metadata.
+ * This code was copied from fs/buffer.c:sys_fdatasync().
+ */
 static int fsg_lun_fsync_sub(struct fsg_lun *curlun)
 {
         struct file     *filp = curlun->filp;
@@ -689,6 +715,14 @@ static ssize_t fsg_show_ro(struct device *dev, struct device_attribute *attr,
                                   : curlun->initially_ro);
 }
 
+static ssize_t fsg_show_nofua(struct device *dev, struct device_attribute *attr,
+                              char *buf)
+{
+        struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
+
+        return sprintf(buf, "%u\n", curlun->nofua);
+}
+
 static ssize_t fsg_show_file(struct device *dev, struct device_attribute *attr,
                              char *buf)
 {
@@ -723,26 +757,47 @@ static ssize_t fsg_store_ro(struct device *dev, struct device_attribute *attr,
         ssize_t         rc = count;
         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
-        int             i;
+        unsigned long   ro;
 
-        if (sscanf(buf, "%d", &i) != 1)
+        if (strict_strtoul(buf, 2, &ro))
                 return -EINVAL;
 
-        /* Allow the write-enable status to change only while the backing file
-         * is closed. */
+        /*
+         * 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;
+                curlun->ro = ro;
+                curlun->initially_ro = ro;
                 LDBG(curlun, "read-only status set to %d\n", curlun->ro);
         }
         up_read(filesem);
         return rc;
 }
 
+static ssize_t fsg_store_nofua(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t count)
+{
+        struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
+        unsigned long   nofua;
+
+        if (strict_strtoul(buf, 2, &nofua))
+                return -EINVAL;
+
+        /* Sync data when switching from async mode to sync */
+        if (!nofua && curlun->nofua)
+                fsg_lun_fsync_sub(curlun);
+
+        curlun->nofua = nofua;
+
+        return count;
+}
+
 static ssize_t fsg_store_file(struct device *dev, struct device_attribute *attr,
                               const char *buf, size_t count)
 {