USB: g_file_storage: per-LUN ro, removable and cdrom flags handling changed

removable and cdrom flag has been added to the fsg_lun structure
removing any references to mod_data object from storage_common.c.

As of read-only flag, previously it was set if a read-only
backing file was specified (which is good) and remained set
even after the file has been closed (which may be considered an
issue).  Currently, the initial read-only flag is preserved so
if it was unset each time file is opened code will try to open
it read-write even if previous file was opened read-only.

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, 13 insertions, 6 deletions

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 90233f4f3601..ee712a5715e7 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -3138,7 +3138,9 @@ static ssize_t show_ro(struct device *dev, struct device_attribute *attr, char *
 {
         struct fsg_lun  *curlun = fsg_lun_from_dev(dev);
 
-        return sprintf(buf, "%d\n", curlun->ro);
+        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,
@@ -3188,6 +3190,7 @@ static ssize_t store_ro(struct device *dev, struct device_attribute *attr,
                 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);
@@ -3433,9 +3436,10 @@ static int __init fsg_bind(struct usb_gadget *gadget)
 
         for (i = 0; i < fsg->nluns; ++i) {
                 curlun = &fsg->luns[i];
-                curlun->ro = mod_data.ro[i];
-                if (mod_data.cdrom)
-                        curlun->ro = 1;
+                curlun->cdrom = !!mod_data.cdrom;
+                curlun->ro = mod_data.cdrom || mod_data.ro[i];
+                curlun->initially_ro = curlun->ro;
+                curlun->removable = mod_data.removable;
                 curlun->dev.release = lun_release;
                 curlun->dev.parent = &gadget->dev;
                 curlun->dev.driver = &fsg_driver.driver;
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 19bf1e330dd0..affd23b5436f 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -225,7 +225,10 @@ struct fsg_lun {
         loff_t          file_length;
         loff_t          num_sectors;
 
+        unsigned int    initially_ro : 1;
         unsigned int    ro : 1;
+        unsigned int    removable : 1;
+        unsigned int    cdrom : 1;
         unsigned int    prevent_medium_removal : 1;
         unsigned int    registered : 1;
         unsigned int    info_valid : 1;
@@ -478,7 +481,7 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
         loff_t                          min_sectors;
 
         /* R/W if we can, R/O if we must */
-        ro = curlun->ro;
+        ro = curlun->initially_ro;
         if (!ro) {
                 filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0);
                 if (-EROFS == PTR_ERR(filp))
@@ -521,7 +524,7 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
         }
         num_sectors = size >> 9;        // File size in 512-byte blocks
         min_sectors = 1;
-        if (mod_data.cdrom) {
+        if (curlun->cdrom) {
                 num_sectors &= ~3;      // Reduce to a multiple of 2048
                 min_sectors = 300*4;    // Smallest track is 300 frames
                 if (num_sectors >= 256*60*75*4) {