From: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx>
Moved code initialising fsg_common structure to fsg_common_init()
function which is called from fsg_bind(). Moreover, changed
reference counting mechanism: fsg_common has a reference counter
which counts how many fsg_dev structures uses it. When this
reaches zero fsg_common_release() is run which unregisters
LUN devices and frees memory.
fsg_common_init() takes pointer to fsg_common structure as an
argument. If it is NULL function allocates storage otherwise
uses pointed to memory (handy if fsg_common is a field of another
structure or a static variable).
fsg_common_release() will free storage only if
free_storage_on_release is set -- it is initialised by
fsg_common_init(): set if allocation was done, unset
otherwise (one may overwrite it of course).
Signed-off-by: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/gadget/f_mass_storage.c | 361 +++++++++++++++++++----------------
1 files changed, 199 insertions(+), 162 deletions(-)
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index b4ec76a..5a0f570 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -323,6 +323,8 @@ MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
/* Data shared by all the FSG instances. */
struct fsg_common {
+ struct usb_gadget *gadget;
+
/* filesem protects: backing files in use */
struct rw_semaphore filesem;
@@ -337,6 +339,10 @@ struct fsg_common {
unsigned int lun;
struct fsg_lun *luns;
struct fsg_lun *curlun;
+
+ unsigned int free_storage_on_release:1;
+
+ struct kref ref;
};
@@ -347,9 +353,6 @@ struct fsg_dev {
spinlock_t lock;
struct usb_gadget *gadget;
- /* reference counting: wait until all LUNs are released */
- struct kref ref;
-
struct usb_ep *ep0; // Handy copy of gadget->ep0
struct usb_request *ep0req; // For control responses
unsigned int ep0_req_tag;
@@ -2757,7 +2760,7 @@ static int fsg_main_thread(void *fsg_)
}
-/*-------------------------------------------------------------------------*/
+/*************************** DEVICE ATTRIBUTES ***************************/
/* The write permissions and store_xxx pointers are set in fsg_bind() */
@@ -2765,40 +2768,190 @@ static DEVICE_ATTR(ro, 0444, fsg_show_ro, NULL);
static DEVICE_ATTR(file, 0444, fsg_show_file, NULL);
-/*-------------------------------------------------------------------------*/
+/****************************** FSG COMMON ******************************/
+
+static void fsg_common_release(struct kref *ref);
-static void fsg_release(struct fsg_dev *fsg)
+static void fsg_lun_release(struct device *dev)
{
- kfree(fsg->common->luns);
- kfree(fsg);
+ /* Nothing needs to be done */
}
-static void lun_release(struct device *dev)
+static inline void fsg_common_get(struct fsg_common *common)
{
+ kref_get(&common->ref);
}
+static inline void fsg_common_put(struct fsg_common *common)
+{
+ kref_put(&common->ref, fsg_common_release);
+}
+
+
+static struct fsg_common *fsg_common_init(struct fsg_common *common,
+ struct usb_gadget *gadget)
+{
+ struct fsg_buffhd *bh;
+ struct fsg_lun *curlun;
+ int nluns, i, rc;
+
+ /* Find out how many LUNs there should be */
+ nluns = mod_data.nluns;
+ if (nluns == 0)
+ nluns = max(mod_data.num_filenames, 1u);
+ if (nluns < 1 || nluns > FSG_MAX_LUNS) {
+ dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Allocate? */
+ if (!common) {
+ common = kzalloc(sizeof *common, GFP_KERNEL);
+ if (!common)
+ return ERR_PTR(-ENOMEM);
+ common->free_storage_on_release = 1;
+ } else {
+ memset(common, 0, sizeof common);
+ common->free_storage_on_release = 0;
+ }
+ common->gadget = gadget;
+
+ /* 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);
+ }
+ common->luns = curlun;
+
+ init_rwsem(&common->filesem);
+
+ for (i = 0; i < nluns; ++i, ++curlun) {
+ curlun->cdrom = !!mod_data.cdrom;
+ curlun->ro = mod_data.cdrom || mod_data.ro[i];
+ curlun->removable = mod_data.removable;
+ curlun->dev.release = fsg_lun_release;
+ curlun->dev.parent = &gadget->dev;
+ curlun->dev.driver = &fsg_driver.driver;
+ dev_set_drvdata(&curlun->dev, &common->filesem);
+ dev_set_name(&curlun->dev,"%s-lun%d",
+ dev_name(&gadget->dev), i);
+
+ rc = device_register(&curlun->dev);
+ if (rc) {
+ INFO(common, "failed to register LUN%d: %d\n", i, rc);
+ common->nluns = i;
+ goto error_release;
+ }
+
+ rc = device_create_file(&curlun->dev, &dev_attr_ro);
+ if (rc)
+ goto error_luns;
+ rc = device_create_file(&curlun->dev, &dev_attr_file);
+ if (rc)
+ goto error_luns;
+
+ if (mod_data.file[i] && *mod_data.file[i]) {
+ rc = fsg_lun_open(curlun, mod_data.file[i]);
+ if (rc)
+ goto error_luns;
+ } else if (!mod_data.removable) {
+ ERROR(common, "no file given for LUN%d\n", i);
+ rc = -EINVAL;
+ goto error_luns;
+ }
+ }
+ common->nluns = nluns;
+
+
+ /* Data buffers cyclic list */
+ /* Buffers in buffhds are static -- no need for additional
+ * allocation. */
+ bh = common->buffhds;
+ i = FSG_NUM_BUFFERS - 1;
+ do {
+ bh->next = bh + 1;
+ } while (++bh, --i);
+ bh->next = common->buffhds;
+
+
+ /* Release */
+ if (mod_data.release == 0xffff) { // Parameter wasn't set
+ int gcnum;
+
+ /* The sa1100 controller is not supported */
+ if (gadget_is_sa1100(gadget))
+ gcnum = -1;
+ else
+ gcnum = usb_gadget_controller_number(gadget);
+ if (gcnum >= 0)
+ mod_data.release = 0x0300 + gcnum;
+ else {
+ WARNING(common, "controller '%s' not recognized\n",
+ gadget->name);
+ WARNING(common, "controller '%s' not recognized\n",
+ gadget->name);
+ mod_data.release = 0x0399;
+ }
+ }
+
+
+ /* Some peripheral controllers are known not to be able to
+ * halt bulk endpoints correctly. If one of them is present,
+ * disable stalls.
+ */
+ if (gadget_is_sh(fsg->gadget) || gadget_is_at91(fsg->gadget))
+ mod_data.can_stall = 0;
+
+
+ kref_init(&common->ref);
+ return common;
+
+
+error_luns:
+ common->nluns = i + 1;
+error_release:
+ /* Call fsg_common_release() directly, ref is not initialised */
+ fsg_common_release(&common->ref);
+ return ERR_PTR(rc);
+}
+
+
+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;
+
+ /* Beware tempting for -> do-while optimization: when in error
+ * recovery 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);
+ if (common->free_storage_on_release)
+ kfree(common);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+
static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
{
struct fsg_dev *fsg = get_gadget_data(gadget);
- int i;
- struct fsg_lun *curlun;
struct usb_request *req = fsg->ep0req;
DBG(fsg, "unbind\n");
clear_bit(REGISTERED, &fsg->atomic_bitflags);
- /* Unregister the sysfs attribute files and the LUNs */
- for (i = 0; i < fsg->common->nluns; ++i) {
- curlun = &fsg->common->luns[i];
- if (curlun->registered) {
- device_remove_file(&curlun->dev, &dev_attr_ro);
- device_remove_file(&curlun->dev, &dev_attr_file);
- fsg_lun_close(curlun);
- device_unregister(&curlun->dev);
- curlun->registered = 0;
- }
- }
-
/* If the thread isn't already dead, tell it to exit now */
if (fsg->state != FSG_STATE_TERMINATED) {
raise_exception(fsg, FSG_STATE_EXIT);
@@ -2814,43 +2967,15 @@ static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
usb_ep_free_request(fsg->ep0, req);
}
+ fsg_common_put(fsg->common);
+ kfree(fsg);
set_gadget_data(gadget, NULL);
}
-static int __init check_parameters(struct fsg_dev *fsg)
-{
- int gcnum;
-
- /* Some peripheral controllers are known not to be able to
- * halt bulk endpoints correctly. If one of them is present,
- * disable stalls.
- */
- if (gadget_is_sh(fsg->gadget) || gadget_is_at91(fsg->gadget))
- mod_data.can_stall = 0;
-
- if (mod_data.release == 0xffff) { // Parameter wasn't set
- /* The sa1100 controller is not supported */
- if (gadget_is_sa1100(fsg->gadget))
- gcnum = -1;
- else
- gcnum = usb_gadget_controller_number(fsg->gadget);
- if (gcnum >= 0)
- mod_data.release = 0x0300 + gcnum;
- else {
- WARNING(fsg, "controller '%s' not recognized\n",
- fsg->gadget->name);
- mod_data.release = 0x0399;
- }
- }
-
- return 0;
-}
-
-
static int __init fsg_bind(struct usb_gadget *gadget)
{
- struct fsg_dev *fsg = the_fsg;
+ struct fsg_dev *fsg;
int rc;
int i;
struct fsg_lun *curlun;
@@ -2858,15 +2983,27 @@ static int __init fsg_bind(struct usb_gadget *gadget)
struct usb_request *req;
char *pathbuf, *p;
+ /* Allocate */
+ fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
+ if (!fsg)
+ return -ENOMEM;
+
+ /* Initialise common */
+ fsg->common = fsg_common_init(0, gadget);
+ if (IS_ERR(fsg->common))
+ return PTR_ERR(fsg->common);
+
+ /* Basic parameters */
fsg->gadget = gadget;
set_gadget_data(gadget, fsg);
fsg->ep0 = gadget->ep0;
fsg->ep0->driver_data = fsg;
- if ((rc = check_parameters(fsg)) != 0)
- goto out;
+ spin_lock_init(&fsg->lock);
+ init_completion(&fsg->thread_notifier);
- if (mod_data.removable) { // Enable the store_xxx attributes
+ /* Enable the store_xxx attributes */
+ if (mod_data.removable) {
dev_attr_file.attr.mode = 0644;
dev_attr_file.store = fsg_store_file;
if (!mod_data.cdrom) {
@@ -2875,62 +3012,6 @@ static int __init fsg_bind(struct usb_gadget *gadget)
}
}
- /* Find out how many LUNs there should be */
- i = mod_data.nluns;
- if (i == 0)
- i = max(mod_data.num_filenames, 1u);
- if (i > FSG_MAX_LUNS) {
- ERROR(fsg, "invalid number of LUNs: %d\n", i);
- rc = -EINVAL;
- goto out;
- }
-
- /* Create the LUNs, open their backing files, and register the
- * LUN devices in sysfs. */
- fsg->common->luns = kzalloc(i * sizeof(struct fsg_lun), GFP_KERNEL);
- if (!fsg->common->luns) {
- rc = -ENOMEM;
- goto out;
- }
- fsg->common->nluns = i;
-
- for (i = 0; i < fsg->common->nluns; ++i) {
- curlun = &fsg->common->luns[i];
- 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;
- dev_set_drvdata(&curlun->dev, &fsg->common->filesem);
- dev_set_name(&curlun->dev,"%s-lun%d",
- dev_name(&gadget->dev), i);
-
- if ((rc = device_register(&curlun->dev)) != 0) {
- INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
- goto out;
- }
- if ((rc = device_create_file(&curlun->dev,
- &dev_attr_ro)) != 0 ||
- (rc = device_create_file(&curlun->dev,
- &dev_attr_file)) != 0) {
- device_unregister(&curlun->dev);
- goto out;
- }
- curlun->registered = 1;
-
- if (mod_data.file[i] && *mod_data.file[i]) {
- if ((rc = fsg_lun_open(curlun,
- mod_data.file[i])) != 0)
- goto out;
- } else if (!mod_data.removable) {
- ERROR(fsg, "no file given for LUN%d\n", i);
- rc = -EINVAL;
- goto out;
- }
- }
-
/* Find all the endpoints we will use */
usb_ep_autoconfig_reset(gadget);
ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
@@ -3028,6 +3109,8 @@ static int __init fsg_bind(struct usb_gadget *gadget)
/* Tell the thread to start working */
wake_up_process(fsg->thread_task);
+
+ the_fsg = fsg;
return 0;
autoconf_fail:
@@ -3066,64 +3149,18 @@ static struct usb_gadget_driver fsg_driver = {
};
-static int __init fsg_alloc(void)
-{
- struct fsg_dev *fsg;
- struct fsg_buffhd *bh;
- unsigned i;
-
- fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
- if (!fsg)
- return -ENOMEM;
-
- fsg->common = kzalloc(sizeof *fsg->common, GFP_KERNEL);
- if (!fsg->common) {
- kfree(fsg);
- return -ENOMEM;
- }
-
- bh = fsg->common->buffhds;
- i = FSG_NUM_BUFFERS - 1;
- do {
- bh->next = bh + 1;
- } while (++bh, --i);
- bh->next = fsg->common->buffhds;
-
- spin_lock_init(&fsg->lock);
- init_rwsem(&fsg->common->filesem);
- init_completion(&fsg->thread_notifier);
-
- the_fsg = fsg;
- return 0;
-}
-
-
static int __init fsg_init(void)
{
- int rc;
- struct fsg_dev *fsg;
-
- if ((rc = fsg_alloc()) != 0)
- return rc;
- fsg = the_fsg;
- if ((rc = usb_gadget_register_driver(&fsg_driver)) != 0)
- fsg_release(fsg);
- return rc;
+ return usb_gadget_register_driver(&fsg_driver);
}
module_init(fsg_init);
static void __exit fsg_cleanup(void)
{
- struct fsg_dev *fsg = the_fsg;
-
/* Unregister the driver iff the thread hasn't already done so */
- if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
+ if (the_fsg &&
+ test_and_clear_bit(REGISTERED, &the_fsg->atomic_bitflags))
usb_gadget_unregister_driver(&fsg_driver);
-
- /* Wait for the thread to finish up */
- wait_for_completion(&fsg->thread_notifier);
-
- fsg_release(fsg);
}
module_exit(fsg_cleanup);
--
1.6.5.5
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