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path: root/drivers/usb/gadget/f_mass_storage.c
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Diffstat (limited to 'drivers/usb/gadget/f_mass_storage.c')
-rw-r--r--drivers/usb/gadget/f_mass_storage.c138
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;
}
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