]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - drivers/usb/gadget/f_mass_storage.c
USB: gadget: f_mass_storage: stale common->fsg value bug fix
[net-next-2.6.git] / drivers / usb / gadget / f_mass_storage.c
index f4911c09022e92c2c16cc1b294045a56a0aca231..4ce899c9b1653b2cfd747e65a17b919d0adeae2c 100644 (file)
  * 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
@@ -318,8 +321,8 @@ struct fsg_dev;
 /* Data shared by all the FSG instances. */
 struct fsg_common {
        struct usb_gadget       *gadget;
-       struct fsg_dev          *fsg;
-       struct fsg_dev          *prev_fsg;
+       struct fsg_dev          *fsg, *new_fsg;
+       wait_queue_head_t       fsg_wait;
 
        /* filesem protects: backing files in use */
        struct rw_semaphore     filesem;
@@ -348,7 +351,6 @@ struct fsg_common {
        enum fsg_state          state;          /* For exception handling */
        unsigned int            exception_req_tag;
 
-       u8                      config, new_config;
        enum data_direction     data_dir;
        u32                     data_size;
        u32                     data_size_from_cmnd;
@@ -592,7 +594,7 @@ static int fsg_setup(struct usb_function *f,
        u16                     w_value = le16_to_cpu(ctrl->wValue);
        u16                     w_length = le16_to_cpu(ctrl->wLength);
 
-       if (!fsg->common->config)
+       if (!fsg_is_set(fsg->common))
                return -EOPNOTSUPP;
 
        switch (ctrl->bRequest) {
@@ -1385,12 +1387,50 @@ 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;
 }
 
@@ -2262,24 +2302,20 @@ static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
        return -ENOMEM;
 }
 
-/*
- * Reset interface setting and re-init endpoint state (toggle etc).
- * Call with altsetting < 0 to disable the interface.  The only other
- * available altsetting is 0, which enables the interface.
- */
-static int do_set_interface(struct fsg_common *common, int altsetting)
+/* Reset interface setting and re-init endpoint state (toggle etc). */
+static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
 {
-       int     rc = 0;
-       int     i;
-       const struct usb_endpoint_descriptor    *d;
+       const struct usb_endpoint_descriptor *d;
+       struct fsg_dev *fsg;
+       int i, rc = 0;
 
        if (common->running)
                DBG(common, "reset interface\n");
 
 reset:
        /* Deallocate the requests */
-       if (common->prev_fsg) {
-               struct fsg_dev *fsg = common->prev_fsg;
+       if (common->fsg) {
+               fsg = common->fsg;
 
                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
                        struct fsg_buffhd *bh = &common->buffhds[i];
@@ -2304,88 +2340,53 @@ reset:
                        fsg->bulk_out_enabled = 0;
                }
 
-               common->prev_fsg = 0;
+               common->fsg = NULL;
+               wake_up(&common->fsg_wait);
        }
 
        common->running = 0;
-       if (altsetting < 0 || rc != 0)
+       if (!new_fsg || rc)
                return rc;
 
-       DBG(common, "set interface %d\n", altsetting);
+       common->fsg = new_fsg;
+       fsg = common->fsg;
+
+       /* Enable the endpoints */
+       d = fsg_ep_desc(common->gadget,
+                       &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
+       rc = enable_endpoint(common, fsg->bulk_in, d);
+       if (rc)
+               goto reset;
+       fsg->bulk_in_enabled = 1;
+
+       d = fsg_ep_desc(common->gadget,
+                       &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
+       rc = enable_endpoint(common, fsg->bulk_out, d);
+       if (rc)
+               goto reset;
+       fsg->bulk_out_enabled = 1;
+       common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
+       clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
 
-       if (fsg_is_set(common)) {
-               struct fsg_dev *fsg = common->fsg;
-               common->prev_fsg = common->fsg;
+       /* Allocate the requests */
+       for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+               struct fsg_buffhd       *bh = &common->buffhds[i];
 
-               /* Enable the endpoints */
-               d = fsg_ep_desc(common->gadget,
-                               &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
-               rc = enable_endpoint(common, fsg->bulk_in, d);
+               rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
                if (rc)
                        goto reset;
-               fsg->bulk_in_enabled = 1;
-
-               d = fsg_ep_desc(common->gadget,
-                               &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
-               rc = enable_endpoint(common, fsg->bulk_out, d);
+               rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
                if (rc)
                        goto reset;
-               fsg->bulk_out_enabled = 1;
-               common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
-               clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
-
-               /* Allocate the requests */
-               for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                       struct fsg_buffhd       *bh = &common->buffhds[i];
-
-                       rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
-                       if (rc)
-                               goto reset;
-                       rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
-                       if (rc)
-                               goto reset;
-                       bh->inreq->buf = bh->outreq->buf = bh->buf;
-                       bh->inreq->context = bh->outreq->context = bh;
-                       bh->inreq->complete = bulk_in_complete;
-                       bh->outreq->complete = bulk_out_complete;
-               }
-
-               common->running = 1;
-               for (i = 0; i < common->nluns; ++i)
-                       common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
-               return rc;
-       } else {
-               return -EIO;
+               bh->inreq->buf = bh->outreq->buf = bh->buf;
+               bh->inreq->context = bh->outreq->context = bh;
+               bh->inreq->complete = bulk_in_complete;
+               bh->outreq->complete = bulk_out_complete;
        }
-}
-
-
-/*
- * Change our operational configuration.  This code must agree with the code
- * that returns config descriptors, and with interface altsetting code.
- *
- * It's also responsible for power management interactions.  Some
- * configurations might not work with our current power sources.
- * For now we just assume the gadget is always self-powered.
- */
-static int do_set_config(struct fsg_common *common, u8 new_config)
-{
-       int     rc = 0;
 
-       /* Disable the single interface */
-       if (common->config != 0) {
-               DBG(common, "reset config\n");
-               common->config = 0;
-               rc = do_set_interface(common, -1);
-       }
-
-       /* Enable the interface */
-       if (new_config != 0) {
-               common->config = new_config;
-               rc = do_set_interface(common, 0);
-               if (rc != 0)
-                       common->config = 0;     /* Reset on errors */
-       }
+       common->running = 1;
+       for (i = 0; i < common->nluns; ++i)
+               common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
        return rc;
 }
 
@@ -2396,9 +2397,7 @@ static int do_set_config(struct fsg_common *common, u8 new_config)
 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 {
        struct fsg_dev *fsg = fsg_from_func(f);
-       fsg->common->prev_fsg = fsg->common->fsg;
-       fsg->common->fsg = fsg;
-       fsg->common->new_config = 1;
+       fsg->common->new_fsg = fsg;
        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
        return 0;
 }
@@ -2406,9 +2405,7 @@ static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 static void fsg_disable(struct usb_function *f)
 {
        struct fsg_dev *fsg = fsg_from_func(f);
-       fsg->common->prev_fsg = fsg->common->fsg;
-       fsg->common->fsg = fsg;
-       fsg->common->new_config = 0;
+       fsg->common->new_fsg = NULL;
        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
 }
 
@@ -2418,19 +2415,17 @@ static void fsg_disable(struct usb_function *f)
 static void handle_exception(struct fsg_common *common)
 {
        siginfo_t               info;
-       int                     sig;
        int                     i;
        struct fsg_buffhd       *bh;
        enum fsg_state          old_state;
-       u8                      new_config;
        struct fsg_lun          *curlun;
        unsigned int            exception_req_tag;
-       int                     rc;
 
        /* Clear the existing signals.  Anything but SIGUSR1 is converted
         * into a high-priority EXIT exception. */
        for (;;) {
-               sig = dequeue_signal_lock(current, &current->blocked, &info);
+               int sig =
+                       dequeue_signal_lock(current, &current->blocked, &info);
                if (!sig)
                        break;
                if (sig != SIGUSR1) {
@@ -2441,7 +2436,7 @@ static void handle_exception(struct fsg_common *common)
        }
 
        /* Cancel all the pending transfers */
-       if (fsg_is_set(common)) {
+       if (likely(common->fsg)) {
                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
                        bh = &common->buffhds[i];
                        if (bh->inreq_busy)
@@ -2482,7 +2477,6 @@ static void handle_exception(struct fsg_common *common)
        common->next_buffhd_to_fill = &common->buffhds[0];
        common->next_buffhd_to_drain = &common->buffhds[0];
        exception_req_tag = common->exception_req_tag;
-       new_config = common->new_config;
        old_state = common->state;
 
        if (old_state == FSG_STATE_ABORT_BULK_OUT)
@@ -2532,12 +2526,12 @@ static void handle_exception(struct fsg_common *common)
                break;
 
        case FSG_STATE_CONFIG_CHANGE:
-               rc = do_set_config(common, new_config);
+               do_set_interface(common, common->new_fsg);
                break;
 
        case FSG_STATE_EXIT:
        case FSG_STATE_TERMINATED:
-               do_set_config(common, 0);               /* Free resources */
+               do_set_interface(common, NULL);         /* Free resources */
                spin_lock_irq(&common->lock);
                common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
                spin_unlock_irq(&common->lock);
@@ -2701,10 +2695,8 @@ 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 +2704,9 @@ 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 +2754,19 @@ 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;
 
 
@@ -2818,6 +2816,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
                goto error_release;
        }
        init_completion(&common->thread_notifier);
+       init_waitqueue_head(&common->fsg_wait);
 #undef OR
 
 
@@ -2867,10 +2866,7 @@ 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 +2877,29 @@ 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);
 }
@@ -2903,18 +2911,27 @@ static void fsg_common_release(struct kref *ref)
 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 {
        struct fsg_dev          *fsg = fsg_from_func(f);
+       struct fsg_common       *common = fsg->common;
 
        DBG(fsg, "unbind\n");
-       fsg_common_put(fsg->common);
+       if (fsg->common->fsg == fsg) {
+               fsg->common->new_fsg = NULL;
+               raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
+               /* FIXME: make interruptible or killable somehow? */
+               wait_event(common->fsg_wait, common->fsg != fsg);
+       }
+
+       fsg_common_put(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;
-       int                     rc;
        int                     i;
        struct usb_ep           *ep;
 
@@ -2940,21 +2957,29 @@ static int __init fsg_bind(struct usb_configuration *c, struct usb_function *f)
        ep->driver_data = fsg->common;  /* claim the endpoint */
        fsg->bulk_out = ep;
 
+       /* Copy descriptors */
+       f->descriptors = usb_copy_descriptors(fsg_fs_function);
+       if (unlikely(!f->descriptors))
+               return -ENOMEM;
+
        if (gadget_is_dualspeed(gadget)) {
                /* Assume endpoint addresses are the same for both speeds */
                fsg_hs_bulk_in_desc.bEndpointAddress =
                        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)) {
+                       usb_free_descriptors(f->descriptors);
+                       return -ENOMEM;
+               }
        }
 
        return 0;
 
 autoconf_fail:
        ERROR(fsg, "unable to autoconfigure all endpoints\n");
-       rc = -ENOTSUPP;
-       return rc;
+       return -ENOTSUPP;
 }
 
 
@@ -2978,7 +3003,6 @@ 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.bind        = fsg_bind;
        fsg->function.unbind      = fsg_unbind;
        fsg->function.setup       = fsg_setup;
@@ -2993,12 +3017,10 @@ static int fsg_add(struct usb_composite_dev *cdev,
         * call to usb_add_function() was successful. */
 
        rc = usb_add_function(c, &fsg->function);
-
-       if (likely(rc == 0))
-               fsg_common_get(fsg->common);
-       else
+       if (unlikely(rc))
                kfree(fsg);
-
+       else
+               fsg_common_get(fsg->common);
        return rc;
 }