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authorVille Herva <vherva@vianova.fi>2006-07-13 17:31:16 -0400
committerDavid Woodhouse <dwmw2@infradead.org>2006-07-15 08:39:10 -0400
commitc4e7fb313771ac03dfdca26d30e8b721731c562b (patch)
treece57227007ea980dcd37e5f7af3bc6b83a91a3bf /drivers/mtd
parent9a909867d2eca7727d0d5884df96e791e3531f24 (diff)
block2mtd.c: Make kernel boot command line arguments work (try 4)
Trying to pass kernel command line arguments to block2mtd at boot-time does not work currently. block2mtd_setup() is called so early that kmalloc() fails nevermind being able to do open_bdev_excl() (which requires rootfs to be mounted. This patch only saves the option string at the early boot stage, and parses them later when block2mtd_init() is called. If open_bdev_excl() fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it possible to initialize the driver before rootfs has been mounted. Also gets rid of the superfluous parse_name() that only checks if name is longer than 80 chars and copies it to a string that is not kfreed. With this patch, I can boot statically compiled block2mtd, and mount jffs2 as rootfs (without modules or initrd), with lilo config like this: root=/dev/mtdblock0 append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536" (Note that rootfstype=jffs2 is required, since the kernel only tries filesystems without "nodev" attribute by default, and jffs is "nodev"). Compared to first version of this patch, this one does not copy the parameters to the global buffer if init has already been called, and the global array is marked as __initdata. Compared to the second version of this patch, module build is fixed. Compared to the third version of this patch, statically compiled block2mtd driver with no boot-time parameter no longer gives spurious error 'cannot open device ""' Signed-off-by: Ville Herva <vherva@vianova.fi> Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/devices/block2mtd.c93
1 files changed, 63 insertions, 30 deletions
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index ede3561be870..401c6a294baa 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -18,6 +18,7 @@
18#include <linux/mtd/mtd.h> 18#include <linux/mtd/mtd.h>
19#include <linux/buffer_head.h> 19#include <linux/buffer_head.h>
20#include <linux/mutex.h> 20#include <linux/mutex.h>
21#include <linux/mount.h>
21 22
22#define VERSION "$Revision: 1.30 $" 23#define VERSION "$Revision: 1.30 $"
23 24
@@ -236,6 +237,8 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
236 } 237 }
237 return 0; 238 return 0;
238} 239}
240
241
239static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len, 242static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
240 size_t *retlen, const u_char *buf) 243 size_t *retlen, const u_char *buf)
241{ 244{
@@ -299,6 +302,19 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
299 302
300 /* Get a handle on the device */ 303 /* Get a handle on the device */
301 bdev = open_bdev_excl(devname, O_RDWR, NULL); 304 bdev = open_bdev_excl(devname, O_RDWR, NULL);
305#ifndef MODULE
306 if (IS_ERR(bdev)) {
307
308 /* We might not have rootfs mounted at this point. Try
309 to resolve the device name by other means. */
310
311 dev_t dev = name_to_dev_t(devname);
312 if (dev != 0) {
313 bdev = open_by_devnum(dev, FMODE_WRITE | FMODE_READ);
314 }
315 }
316#endif
317
302 if (IS_ERR(bdev)) { 318 if (IS_ERR(bdev)) {
303 ERROR("error: cannot open device %s", devname); 319 ERROR("error: cannot open device %s", devname);
304 goto devinit_err; 320 goto devinit_err;
@@ -393,26 +409,6 @@ static int parse_num(size_t *num, const char *token)
393} 409}
394 410
395 411
396static int parse_name(char **pname, const char *token, size_t limit)
397{
398 size_t len;
399 char *name;
400
401 len = strlen(token) + 1;
402 if (len > limit)
403 return -ENOSPC;
404
405 name = kmalloc(len, GFP_KERNEL);
406 if (!name)
407 return -ENOMEM;
408
409 strcpy(name, token);
410
411 *pname = name;
412 return 0;
413}
414
415
416static inline void kill_final_newline(char *str) 412static inline void kill_final_newline(char *str)
417{ 413{
418 char *newline = strrchr(str, '\n'); 414 char *newline = strrchr(str, '\n');
@@ -426,9 +422,15 @@ static inline void kill_final_newline(char *str)
426 return 0; \ 422 return 0; \
427} while (0) 423} while (0)
428 424
429static int block2mtd_setup(const char *val, struct kernel_param *kp) 425#ifndef MODULE
426static int block2mtd_init_called = 0;
427static __initdata char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
428#endif
429
430
431static int block2mtd_setup2(const char *val)
430{ 432{
431 char buf[80+12]; /* 80 for device, 12 for erase size */ 433 char buf[80 + 12]; /* 80 for device, 12 for erase size */
432 char *str = buf; 434 char *str = buf;
433 char *token[2]; 435 char *token[2];
434 char *name; 436 char *name;
@@ -450,13 +452,9 @@ static int block2mtd_setup(const char *val, struct kernel_param *kp)
450 if (!token[0]) 452 if (!token[0])
451 parse_err("no argument"); 453 parse_err("no argument");
452 454
453 ret = parse_name(&name, token[0], 80); 455 name = token[0];
454 if (ret == -ENOMEM) 456 if (strlen(name) + 1 > 80)
455 parse_err("out of memory"); 457 parse_err("device name too long");
456 if (ret == -ENOSPC)
457 parse_err("name too long");
458 if (ret)
459 return 0;
460 458
461 if (token[1]) { 459 if (token[1]) {
462 ret = parse_num(&erase_size, token[1]); 460 ret = parse_num(&erase_size, token[1]);
@@ -472,13 +470,48 @@ static int block2mtd_setup(const char *val, struct kernel_param *kp)
472} 470}
473 471
474 472
473static int block2mtd_setup(const char *val, struct kernel_param *kp)
474{
475#ifdef MODULE
476 return block2mtd_setup2(val);
477#else
478 /* If more parameters are later passed in via
479 /sys/module/block2mtd/parameters/block2mtd
480 and block2mtd_init() has already been called,
481 we can parse the argument now. */
482
483 if (block2mtd_init_called)
484 return block2mtd_setup2(val);
485
486 /* During early boot stage, we only save the parameters
487 here. We must parse them later: if the param passed
488 from kernel boot command line, block2mtd_setup() is
489 called so early that it is not possible to resolve
490 the device (even kmalloc() fails). Deter that work to
491 block2mtd_setup2(). */
492
493 strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
494
495 return 0;
496#endif
497}
498
499
475module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200); 500module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
476MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\""); 501MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
477 502
478static int __init block2mtd_init(void) 503static int __init block2mtd_init(void)
479{ 504{
505 int ret = 0;
480 INFO("version " VERSION); 506 INFO("version " VERSION);
481 return 0; 507
508#ifndef MODULE
509 if (strlen(block2mtd_paramline))
510 ret = block2mtd_setup2(block2mtd_paramline);
511 block2mtd_init_called = 1;
512#endif
513
514 return ret;
482} 515}
483 516
484 517