1 files changed, 104 insertions, 34 deletions

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index f4911c09022e..7d05a0be5c60 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -163,6 +163,10 @@
  * ro setting are not allowed when the medium is loaded or if CD-ROM
  * emulation is being used.
  *
+ * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
+ * if the LUN is removable, the backing file is released to simulate
+ * ejection.
+ *
  *
  * This function is heavily based on "File-backed Storage Gadget" by
  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
@@ -302,7 +306,6 @@ static const char fsg_string_interface[] = "Mass Storage";
 
 
 #define FSG_NO_INTR_EP 1
-#define FSG_BUFFHD_STATIC_BUFFER 1
 #define FSG_NO_DEVICE_STRINGS    1
 #define FSG_NO_OTG               1
 #define FSG_NO_INTR_EP           1
@@ -1385,12 +1388,50 @@ static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
 
 static int do_start_stop(struct fsg_common *common)
 {
-	if (!common->curlun) {
+	struct fsg_lun	*curlun = common->curlun;
+	int		loej, start;
+
+	if (!curlun) {
 		return -EINVAL;
-	} else if (!common->curlun->removable) {
-		common->curlun->sense_data = SS_INVALID_COMMAND;
+	} else if (!curlun->removable) {
+		curlun->sense_data = SS_INVALID_COMMAND;
 		return -EINVAL;
 	}
+
+	loej = common->cmnd[4] & 0x02;
+	start = common->cmnd[4] & 0x01;
+
+	/* eject code from file_storage.c:do_start_stop() */
+
+	if ((common->cmnd[1] & ~0x01) != 0 ||	  /* Mask away Immed */
+		(common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
+		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
+		return -EINVAL;
+	}
+
+	if (!start) {
+		/* Are we allowed to unload the media? */
+		if (curlun->prevent_medium_removal) {
+			LDBG(curlun, "unload attempt prevented\n");
+			curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
+			return -EINVAL;
+		}
+		if (loej) {	/* Simulate an unload/eject */
+			up_read(&common->filesem);
+			down_write(&common->filesem);
+			fsg_lun_close(curlun);
+			up_write(&common->filesem);
+			down_read(&common->filesem);
+		}
+	} else {
+
+		/* Our emulation doesn't support mounting; the medium is
+		 * available for use as soon as it is loaded. */
+		if (!fsg_lun_is_open(curlun)) {
+			curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
+			return -EINVAL;
+		}
+	}
 	return 0;
 }
 
@@ -2701,10 +2742,8 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 	/* Maybe allocate device-global string IDs, and patch descriptors */
 	if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
 		rc = usb_string_id(cdev);
-		if (rc < 0) {
-			kfree(common);
-			return ERR_PTR(rc);
-		}
+		if (unlikely(rc < 0))
+			goto error_release;
 		fsg_strings[FSG_STRING_INTERFACE].id = rc;
 		fsg_intf_desc.iInterface = rc;
 	}
@@ -2712,9 +2751,9 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 	/* Create the LUNs, open their backing files, and register the
 	 * LUN devices in sysfs. */
 	curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
-	if (!curlun) {
-		kfree(common);
-		return ERR_PTR(-ENOMEM);
+	if (unlikely(!curlun)) {
+		rc = -ENOMEM;
+		goto error_release;
 	}
 	common->luns = curlun;
 
@@ -2762,13 +2801,19 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 
 
 	/* Data buffers cyclic list */
-	/* Buffers in buffhds are static -- no need for additional
-	 * allocation. */
 	bh = common->buffhds;
-	i = FSG_NUM_BUFFERS - 1;
+	i = FSG_NUM_BUFFERS;
+	goto buffhds_first_it;
 	do {
 		bh->next = bh + 1;
-	} while (++bh, --i);
+		++bh;
+buffhds_first_it:
+		bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
+		if (unlikely(!bh->buf)) {
+			rc = -ENOMEM;
+			goto error_release;
+		}
+	} while (--i);
 	bh->next = common->buffhds;
 
 
@@ -2867,10 +2912,7 @@ error_release:
 
 static void fsg_common_release(struct kref *ref)
 {
-	struct fsg_common *common =
-		container_of(ref, struct fsg_common, ref);
-	unsigned i = common->nluns;
-	struct fsg_lun *lun = common->luns;
+	struct fsg_common *common = container_of(ref, struct fsg_common, ref);
 
 	/* If the thread isn't already dead, tell it to exit now */
 	if (common->state != FSG_STATE_TERMINATED) {
@@ -2881,17 +2923,29 @@ static void fsg_common_release(struct kref *ref)
 		complete(&common->thread_notifier);
 	}
 
-	/* Beware tempting for -> do-while optimization: when in error
-	 * recovery nluns may be zero. */
+	if (likely(common->luns)) {
+		struct fsg_lun *lun = common->luns;
+		unsigned i = common->nluns;
+
+		/* In error recovery common->nluns may be zero. */
+		for (; i; --i, ++lun) {
+			device_remove_file(&lun->dev, &dev_attr_ro);
+			device_remove_file(&lun->dev, &dev_attr_file);
+			fsg_lun_close(lun);
+			device_unregister(&lun->dev);
+		}
+
+		kfree(common->luns);
+	}
 
-	for (; i; --i, ++lun) {
-		device_remove_file(&lun->dev, &dev_attr_ro);
-		device_remove_file(&lun->dev, &dev_attr_file);
-		fsg_lun_close(lun);
-		device_unregister(&lun->dev);
+	{
+		struct fsg_buffhd *bh = common->buffhds;
+		unsigned i = FSG_NUM_BUFFERS;
+		do {
+			kfree(bh->buf);
+		} while (++bh, --i);
 	}
 
-	kfree(common->luns);
 	if (common->free_storage_on_release)
 		kfree(common);
 }
@@ -2906,11 +2960,13 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	DBG(fsg, "unbind\n");
 	fsg_common_put(fsg->common);
+	usb_free_descriptors(fsg->function.descriptors);
+	usb_free_descriptors(fsg->function.hs_descriptors);
 	kfree(fsg);
 }
 
 
-static int __init fsg_bind(struct usb_configuration *c, struct usb_function *f)
+static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct fsg_dev		*fsg = fsg_from_func(f);
 	struct usb_gadget	*gadget = c->cdev->gadget;
@@ -2946,7 +3002,9 @@ static int __init fsg_bind(struct usb_configuration *c, struct usb_function *f)
 			fsg_fs_bulk_in_desc.bEndpointAddress;
 		fsg_hs_bulk_out_desc.bEndpointAddress =
 			fsg_fs_bulk_out_desc.bEndpointAddress;
-		f->hs_descriptors = fsg_hs_function;
+		f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
+		if (unlikely(!f->hs_descriptors))
+			return -ENOMEM;
 	}
 
 	return 0;
@@ -2978,7 +3036,11 @@ static int fsg_add(struct usb_composite_dev *cdev,
 
 	fsg->function.name        = FSG_DRIVER_DESC;
 	fsg->function.strings     = fsg_strings_array;
-	fsg->function.descriptors = fsg_fs_function;
+	fsg->function.descriptors = usb_copy_descriptors(fsg_fs_function);
+	if (unlikely(!fsg->function.descriptors)) {
+		rc = -ENOMEM;
+		goto error_free_fsg;
+	}
 	fsg->function.bind        = fsg_bind;
 	fsg->function.unbind      = fsg_unbind;
 	fsg->function.setup       = fsg_setup;
@@ -2993,11 +3055,19 @@ static int fsg_add(struct usb_composite_dev *cdev,
 	 * call to usb_add_function() was successful. */
 
 	rc = usb_add_function(c, &fsg->function);
+	if (unlikely(rc))
+		goto error_free_all;
 
-	if (likely(rc == 0))
-		fsg_common_get(fsg->common);
-	else
-		kfree(fsg);
+	fsg_common_get(fsg->common);
+	return 0;
+
+error_free_all:
+	usb_free_descriptors(fsg->function.descriptors);
+	/* fsg_bind() might have copied those; or maybe not? who cares
+	 * -- free it just in case. */
+	usb_free_descriptors(fsg->function.hs_descriptors);
+error_free_fsg:
+	kfree(fsg);
 
 	return rc;
 }