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Commit d6a3f017 authored by Felix Fietkau's avatar Felix Fietkau Committed by Brian Norris
Browse files

mtd: block2mtd: wait until block devices are presented 



Ensures that block2mtd is triggered after the block devices are enumerated
at boot time.
This issue is seen on BCM2835 (Raspberry Pi) systems when mounting JFFS2
block2mtd filesystems, probably because of the delay on enumerating a USB
MMC card reader.

Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarRodrigo Freire <rfreire@redhat.com>
Signed-off-by: default avatarHerton Krzesinski <herton@redhat.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent c517d838

drivers/mtd/devices/block2mtd.c

+43 −15
Original line number Diff line number Diff line
@@ -9,7 +9,15 @@ 


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



/*

 * When the first attempt at device initialization fails, we may need to

 * wait a little bit and retry. This timeout, by default 3 seconds, gives

 * device time to start up. Required on BCM2708 and a few other chipsets.

 */

#define MTD_DEFAULT_TIMEOUT	3



#include <linux/module.h>

#include <linux/delay.h>

#include <linux/fs.h>

#include <linux/blkdev.h>

#include <linux/bio.h>
@@ -209,10 +217,14 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) 
}





static struct block2mtd_dev *add_device(char *devname, int erase_size)

static struct block2mtd_dev *add_device(char *devname, int erase_size,

		int timeout)

{

#ifndef MODULE

	int i;

#endif

	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;

	struct block_device *bdev;

	struct block_device *bdev = ERR_PTR(-ENODEV);

	struct block2mtd_dev *dev;

	char *name;
@@ -225,14 +237,27 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) 


	/* Get a handle on the device */

	bdev = blkdev_get_by_path(devname, mode, dev);



#ifndef MODULE

	if (IS_ERR(bdev)) {

	/*

	 * We might not have the root device mounted at this point.

	 * Try to resolve the device name by other means.

	 */

	for (i = 0; IS_ERR(bdev) && i <= timeout; i++) {

		dev_t devt;



		/* We might not have rootfs mounted at this point. Try

		   to resolve the device name by other means. */

		if (i)

			/*

			 * Calling wait_for_device_probe in the first loop

			 * was not enough, sleep for a bit in subsequent

			 * go-arounds.

			 */

			msleep(1000);

		wait_for_device_probe();



		dev_t devt = name_to_dev_t(devname);

		if (devt)

		devt = name_to_dev_t(devname);

		if (!devt)

			continue;

		bdev = blkdev_get_by_dev(devt, mode, dev);

	}

#endif
@@ -280,6 +305,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) 
		/* Device didn't get added, so free the entry */

		goto err_destroy_mutex;

	}



	list_add(&dev->list, &blkmtd_device_list);

	pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n",

		dev->mtd.index,
@@ -348,16 +374,19 @@ static inline void kill_final_newline(char *str) 


#ifndef MODULE

static int block2mtd_init_called = 0;

static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */

/* 80 for device, 12 for erase size */

static char block2mtd_paramline[80 + 12];

#endif



static int block2mtd_setup2(const char *val)

{

	char buf[80 + 12]; /* 80 for device, 12 for erase size */

	/* 80 for device, 12 for erase size, 80 for name, 8 for timeout */

	char buf[80 + 12 + 80 + 8];

	char *str = buf;

	char *token[2];

	char *name;

	size_t erase_size = PAGE_SIZE;

	unsigned long timeout = MTD_DEFAULT_TIMEOUT;

	int i, ret;



	if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
@@ -395,7 +424,7 @@ static int block2mtd_setup2(const char *val) 
		}

	}



	add_device(name, erase_size);

	add_device(name, erase_size, timeout);



	return 0;

}
@@ -463,8 +492,7 @@ static void block2mtd_exit(void) 
	}

}





module_init(block2mtd_init);

late_initcall(block2mtd_init);

module_exit(block2mtd_exit);



MODULE_LICENSE("GPL");