kernel/drivers/usb/gadget/function/f_mass_storage.c, branch linux-4.16.y

Merge tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs

2017-11-14T22:44:04Z

Pull configfs updates from Christoph Hellwig: "A couple of configfs cleanups: - proper use of the bool type (Thomas Meyer) - constification of struct config_item_type (Bhumika Goyal)" * tag 'configfs-for-4.15' of git://git.infradead.org/users/hch/configfs: RDMA/cma: make config_item_type const stm class: make config_item_type const ACPI: configfs: make config_item_type const nvmet: make config_item_type const usb: gadget: configfs: make config_item_type const PCI: endpoint: make config_item_type const iio: make function argument and some structures const usb: gadget: make config_item_type structures const dlm: make config_item_type const netconsole: make config_item_type const nullb: make config_item_type const ocfs2/cluster: make config_item_type const target: make config_item_type const configfs: make ci_type field, some pointers and function arguments const configfs: make config_item_type const configfs: Fix bool initialization/comparison

USB: add SPDX identifiers to all remaining files in drivers/usb/

2017-11-04T10:48:02Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/usb/ and include/linux/usb* files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Acked-by: Felipe Balbi Acked-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

usb: gadget: make config_item_type structures const

2017-10-19T14:15:23Z

Make these structures const as they are only passed to the const argument of the functions config_{group/item}_init_type_name. Signed-off-by: Bhumika Goyal Acked-by: Felipe Balbi Signed-off-by: Christoph Hellwig

USB: g_mass_storage: Fix deadlock when driver is unbound

2017-09-22T16:29:00Z

As a holdover from the old g_file_storage gadget, the g_mass_storage legacy gadget driver attempts to unregister itself when its main operating thread terminates (if it hasn't been unregistered already). This is not strictly necessary; it was never more than an attempt to have the gadget fail cleanly if something went wrong and the main thread was killed. However, now that the UDC core manages gadget drivers independently of UDC drivers, this scheme doesn't work any more. A simple test: modprobe dummy-hcd modprobe g-mass-storage file=... rmmod dummy-hcd ends up in a deadlock with the following backtrace: sysrq: SysRq : Show Blocked State task PC stack pid father file-storage D 0 1130 2 0x00000000 Call Trace: __schedule+0x53e/0x58c schedule+0x6e/0x77 schedule_preempt_disabled+0xd/0xf __mutex_lock.isra.1+0x129/0x224 ? _raw_spin_unlock_irqrestore+0x12/0x14 __mutex_lock_slowpath+0x12/0x14 mutex_lock+0x28/0x2b usb_gadget_unregister_driver+0x29/0x9b [udc_core] usb_composite_unregister+0x10/0x12 [libcomposite] msg_cleanup+0x1d/0x20 [g_mass_storage] msg_thread_exits+0xd/0xdd7 [g_mass_storage] fsg_main_thread+0x1395/0x13d6 [usb_f_mass_storage] ? __schedule+0x573/0x58c kthread+0xd9/0xdb ? do_set_interface+0x25c/0x25c [usb_f_mass_storage] ? init_completion+0x1e/0x1e ret_from_fork+0x19/0x24 rmmod D 0 1155 683 0x00000000 Call Trace: __schedule+0x53e/0x58c schedule+0x6e/0x77 schedule_timeout+0x26/0xbc ? __schedule+0x573/0x58c do_wait_for_common+0xb3/0x128 ? usleep_range+0x81/0x81 ? wake_up_q+0x3f/0x3f wait_for_common+0x2e/0x45 wait_for_completion+0x17/0x19 fsg_common_put+0x34/0x81 [usb_f_mass_storage] fsg_free_inst+0x13/0x1e [usb_f_mass_storage] usb_put_function_instance+0x1a/0x25 [libcomposite] msg_unbind+0x2a/0x42 [g_mass_storage] __composite_unbind+0x4a/0x6f [libcomposite] composite_unbind+0x12/0x14 [libcomposite] usb_gadget_remove_driver+0x4f/0x77 [udc_core] usb_del_gadget_udc+0x52/0xcc [udc_core] dummy_udc_remove+0x27/0x2c [dummy_hcd] platform_drv_remove+0x1d/0x31 device_release_driver_internal+0xe9/0x16d device_release_driver+0x11/0x13 bus_remove_device+0xd2/0xe2 device_del+0x19f/0x221 ? selinux_capable+0x22/0x27 platform_device_del+0x21/0x63 platform_device_unregister+0x10/0x1a cleanup+0x20/0x817 [dummy_hcd] SyS_delete_module+0x10c/0x197 ? ____fput+0xd/0xf ? task_work_run+0x55/0x62 ? prepare_exit_to_usermode+0x65/0x75 do_fast_syscall_32+0x86/0xc3 entry_SYSENTER_32+0x4e/0x7c What happens is that removing the dummy-hcd driver causes the UDC core to unbind the gadget driver, which it does while holding the udc_lock mutex. The unbind routine in g_mass_storage tells the main thread to exit and waits for it to terminate. But as mentioned above, when the main thread exits it tries to unregister the mass-storage function driver. Via the composite framework this ends up calling usb_gadget_unregister_driver(), which tries to acquire the udc_lock mutex. The result is deadlock. The simplest way to fix the problem is not to be so clever: The main thread doesn't have to unregister the function driver. The side effects won't be so terrible; if the gadget is still attached to a USB host when the main thread is killed, it will appear to the host as though the gadget's firmware has crashed -- a reasonably accurate interpretation, and an all-too-common occurrence for USB mass-storage devices. In fact, the code to unregister the driver when the main thread exits is specific to g-mass-storage; it is not used when f-mass-storage is included as a function in a larger composite device. Therefore the entire mechanism responsible for this (the fsg_operations structure with its ->thread_exits method, the fsg_common_set_ops() routine, and the msg_thread_exits() callback routine) can all be eliminated. Even the msg_registered bitflag can be removed, because now the driver is unregistered in only one place rather than in two places. Signed-off-by: Alan Stern CC: Acked-by: Felipe Balbi Acked-by: Michal Nazarewicz Signed-off-by: Greg Kroah-Hartman

gadget/f_mass_storage: stop messing with the address limit

2017-09-04T23:05:16Z

Instead use kernel_read/write consistently, which also makes sparse happy. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

usb: gadget: f_mass_storage: Fix the logic to iterate all common->luns

2017-07-17T08:00:06Z

It is wrong to do --i in the for loop. Fixes: dd02ea5a3305 ("usb: gadget: mass_storage: Use static array for luns") Signed-off-by: Axel Lin Reviewed-by: Krzysztof Opasiak Acked-by: Michal Nazarewicz Signed-off-by: Felipe Balbi

USB: f_mass_storage: improve memory barriers and synchronization

2017-05-16T07:38:33Z

This patch reworks the way f_mass_storage.c handles memory barriers and synchronization: The driver now uses a wait_queue instead of doing its own task-state manipulations (even though only one task will ever use the wait_queue). The thread_wakeup_needed variable is removed. It was only a source of trouble; although it was what the driver tested to see whether it should wake up, what we really wanted to see was whether a USB transfer had completed. All the explicit memory barriers scattered throughout the driver are replaced by a few calls to smp_load_acquire() and smp_store_release(). The inreq_busy and outreq_busy fields are removed. In their place, the driver keeps track of the current I/O direction by splitting BUF_STATE_BUSY into two states: BUF_STATE_SENDING and BUF_STATE_RECEIVING. The buffer states are no longer protected by a lock. Mutual exclusion isn't needed; the state is changed only by the driver's main thread when it owns the buffer, and only by the request completion routine when the gadget core owns the buffer. The do_write() and throw_away_data() routines were reorganized to make efficient use of the new sleeping mechanism. This resulted in the removal of one indentation level in those routines, making the patch appear to be more more complicated than it really is. In a few places, the driver allowed itself to be frozen although it really shouldn't have (in the middle of executing a SCSI command). Those places have been fixed. The logic in the exception handler for aborting transfers and waiting for them to stop has been simplified. Tested-by: Thinh Nguyen Signed-off-by: Alan Stern Signed-off-by: Felipe Balbi

USB: f_mass_storage: improve async notification handling

2017-05-16T07:38:29Z

This patch makes several adjustments to the way f_mass_storage.c handles its internal state and asynchronous notifications (AKA exceptions): A number of states weren't being used for anything. They are removed. The FSG_STATE_IDLE state was renamed to FSG_STATE_NORMAL, because it now applies whenever the gadget is operating normally, not just when the gadget is idle. The FSG_STATE_RESET state was renamed to FSG_STATE_PROTOCOL_RESET, indicating that it represents a Bulk-Only Transport protocol reset and not a general USB reset. When a signal arrives, it's silly for the signal handler to send itself another signal! Now it takes care of everything inline. Along with an assortment of other minor changes in the same category. Tested-by: Thinh Nguyen Signed-off-by: Alan Stern Signed-off-by: Felipe Balbi

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:29Z

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

usb: gadget: Add per-lun inquiry string

2016-08-25T09:13:13Z

Introduce an attribute "inquiry_string" to the lun. In some environments, e. g. BIOS boot menus, the inquiry string is the only information about devices presented to the user. The default string depends on the "cdrom" bit of the first lun as well as the kernel version and allows no further customization. So without access to the client it is not obvious which gadget is active at a given point and what any of the available luns might contain. If "inquiry_string" is ignored or set to the empty string, the old behavior is preserved. Signed-off-by: Philipp Gesang Signed-off-by: Felipe Balbi