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Commit 86143d8d authored by Azhar Shaikh's avatar Azhar Shaikh
Browse files

usb: f_mass_storage: Add timer to catch VFS read/write/sync stuck issues 



Implement a timer function to print an error message when
the USB mass storage driver is stuck inside a vfs operation.
This helps to catch VFS read/write/sync stuck issues with slower
cards.
By default Configure the timer with 9 sec.
To configure the timer delay from the userspace
echo 9000 >
	/sys/module/usb_f_mass_storage/parameters/msc_vfs_timer_period_ms

Change-Id: I622cd4246eb2abf4d66925240348a39914b7823c
Signed-off-by: default avatarChandanaKishori Chiluveru <cchilu@codeaurora.org>
Signed-off-by: default avatarAzhar Shaikh <azhars@codeaurora.org>
parent e95146f5

drivers/usb/gadget/function/f_mass_storage.c

+53 −1
Original line number Diff line number Diff line
@@ -251,6 +251,16 @@ static struct usb_gadget_strings *fsg_strings_array[] = { 


/*-------------------------------------------------------------------------*/



/*

 * If USB mass storage vfs operation is stuck for more than 10 sec

 * host will initiate the reset. Configure the timer with 9 sec to print

 * the error message before host is intiating the resume on it.

 */

#define MSC_VFS_TIMER_PERIOD_MS	9000

static int msc_vfs_timer_period_ms = MSC_VFS_TIMER_PERIOD_MS;

module_param(msc_vfs_timer_period_ms, int, S_IRUGO | S_IWUSR);

MODULE_PARM_DESC(msc_vfs_timer_period_ms, "Set period for MSC VFS timer");



struct fsg_dev;

struct fsg_common;
@@ -316,6 +326,7 @@ struct fsg_common { 
	/* LUN name for sysfs purpose */

	char name[FSG_MAX_LUNS][LUN_NAME_LEN];

	struct kref		ref;

	struct timer_list	vfs_timer;

};



struct fsg_dev {
@@ -335,6 +346,26 @@ struct fsg_dev { 
	struct usb_ep		*bulk_out;

};



static void msc_usb_vfs_timer_func(unsigned long data)

{

	struct fsg_common *common = (struct fsg_common *) data;



	switch (common->data_dir) {

	case DATA_DIR_FROM_HOST:

		dev_err(&common->curlun->dev,

				"usb mass storage stuck in vfs_write\n");

		break;

	case DATA_DIR_TO_HOST:

		dev_err(&common->curlun->dev,

				"usb mass storage stuck in vfs_read\n");

		break;

	default:

		dev_err(&common->curlun->dev,

				"usb mass storage stuck in vfs_sync\n");

		break;

	}

}



static inline int __fsg_is_set(struct fsg_common *common,

			       const char *func, unsigned line)

{
@@ -703,9 +734,12 @@ static int do_read(struct fsg_common *common) 
		/* Perform the read */

		file_offset_tmp = file_offset;

		start = ktime_get();

		mod_timer(&common->vfs_timer, jiffies +

			msecs_to_jiffies(msc_vfs_timer_period_ms));

		nread = vfs_read(curlun->filp,

				 (char __user *)bh->buf,

				 amount, &file_offset_tmp);

		del_timer_sync(&common->vfs_timer);

		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,

		      (unsigned long long)file_offset, (int)nread);

		diff = ktime_sub(ktime_get(), start);
@@ -901,9 +935,12 @@ static int do_write(struct fsg_common *common) 
			/* Perform the write */

			file_offset_tmp = file_offset;

			start = ktime_get();

			mod_timer(&common->vfs_timer, jiffies +

				msecs_to_jiffies(msc_vfs_timer_period_ms));

			nwritten = vfs_write(curlun->filp,

					     (char __user *)bh->buf,

					     amount, &file_offset_tmp);

			del_timer_sync(&common->vfs_timer);

			VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,

			      (unsigned long long)file_offset, (int)nwritten);

			diff = ktime_sub(ktime_get(), start);
@@ -963,9 +1000,12 @@ static int do_synchronize_cache(struct fsg_common *common) 


	/* We ignore the requested LBA and write out all file's

	 * dirty data buffers. */

	mod_timer(&common->vfs_timer, jiffies +

		msecs_to_jiffies(msc_vfs_timer_period_ms));

	rc = fsg_lun_fsync_sub(curlun);

	if (rc)

		curlun->sense_data = SS_WRITE_ERROR;

	del_timer_sync(&common->vfs_timer);

	return 0;

}
@@ -1021,7 +1061,10 @@ static int do_verify(struct fsg_common *common) 
	file_offset = ((loff_t) lba) << curlun->blkbits;



	/* Write out all the dirty buffers before invalidating them */

	mod_timer(&common->vfs_timer, jiffies +

			msecs_to_jiffies(msc_vfs_timer_period_ms));

	fsg_lun_fsync_sub(curlun);

	del_timer_sync(&common->vfs_timer);

	if (signal_pending(current))

		return -EINTR;
@@ -1051,9 +1094,12 @@ static int do_verify(struct fsg_common *common) 


		/* Perform the read */

		file_offset_tmp = file_offset;

		mod_timer(&common->vfs_timer, jiffies +

				msecs_to_jiffies(msc_vfs_timer_period_ms));

		nread = vfs_read(curlun->filp,

				(char __user *) bh->buf,

				amount, &file_offset_tmp);

		del_timer_sync(&common->vfs_timer);

		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,

				(unsigned long long) file_offset,

				(int) nread);
@@ -1384,8 +1430,12 @@ static int do_prevent_allow(struct fsg_common *common) 
		return -EINVAL;

	}



	if (curlun->prevent_medium_removal && !prevent)

	if (!curlun->nofua && curlun->prevent_medium_removal && !prevent) {

		mod_timer(&common->vfs_timer, jiffies +

			msecs_to_jiffies(msc_vfs_timer_period_ms));

		fsg_lun_fsync_sub(curlun);

		del_timer_sync(&common->vfs_timer);

	}

	curlun->prevent_medium_removal = prevent;

	return 0;

}
@@ -3688,6 +3738,8 @@ static struct usb_function *fsg_alloc(struct usb_function_instance *fi) 
	fsg->function.free_func	= fsg_free;



	fsg->common               = common;

	setup_timer(&common->vfs_timer, msc_usb_vfs_timer_func,

		(unsigned long) common);



	return &fsg->function;

}