From dd2a345f8f002845636dbf5d2d768bb5cd8a5f59 Mon Sep 17 00:00:00 2001 From: Dave Gilbert Date: Wed, 9 May 2007 02:33:24 -0700 Subject: [PATCH] Display all possible partitions when the root filesystem failed to mount Display all possible partitions when the root filesystem is not mounted. This helps to track spell'o's and missing drivers. Updated to work with newer kernels. Example output: VFS: Cannot open root device "foobar" or unknown-block(0,0) Please append a correct "root=" boot option; here are the available partitions: 0800 8388608 sda driver: sd 0801 192748 sda1 0802 8193150 sda2 0810 4194304 sdb driver: sd Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [akpm@linux-foundation.org: cleanups, fix printk warnings] Signed-off-by: Jan Engelhardt Cc: Dave Gilbert Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- block/genhd.c | 53 +++++++++++++++++++++++++++++++++++++++++++ include/linux/genhd.h | 1 + init/do_mounts.c | 7 +++++- 3 files changed, 60 insertions(+), 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index b5664440896c..93a2cf654597 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -213,6 +213,59 @@ struct gendisk *get_gendisk(dev_t dev, int *part) return kobj ? to_disk(kobj) : NULL; } +/* + * print a full list of all partitions - intended for places where the root + * filesystem can't be mounted and thus to give the victim some idea of what + * went wrong + */ +void __init printk_all_partitions(void) +{ + int n; + struct gendisk *sgp; + + mutex_lock(&block_subsys_lock); + /* For each block device... */ + list_for_each_entry(sgp, &block_subsys.list, kobj.entry) { + char buf[BDEVNAME_SIZE]; + /* + * Don't show empty devices or things that have been surpressed + */ + if (get_capacity(sgp) == 0 || + (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) + continue; + + /* + * Note, unlike /proc/partitions, I am showing the numbers in + * hex - the same format as the root= option takes. + */ + printk("%02x%02x %10llu %s", + sgp->major, sgp->first_minor, + (unsigned long long)get_capacity(sgp) >> 1, + disk_name(sgp, 0, buf)); + if (sgp->driverfs_dev != NULL && + sgp->driverfs_dev->driver != NULL) + printk(" driver: %s\n", + sgp->driverfs_dev->driver->name); + else + printk(" (driver?)\n"); + + /* now show the partitions */ + for (n = 0; n < sgp->minors - 1; ++n) { + if (sgp->part[n] == NULL) + continue; + if (sgp->part[n]->nr_sects == 0) + continue; + printk(" %02x%02x %10llu %s\n", + sgp->major, n + 1 + sgp->first_minor, + (unsigned long long)sgp->part[n]->nr_sects >> 1, + disk_name(sgp, n + 1, buf)); + } /* partition subloop */ + } /* Block device loop */ + + mutex_unlock(&block_subsys_lock); + return; +} + #ifdef CONFIG_PROC_FS /* iterator */ static void *part_start(struct seq_file *part, loff_t *pos) diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 2c65da7cabb2..f589559cf070 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -413,6 +413,7 @@ char *disk_name (struct gendisk *hd, int part, char *buf); extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev); extern void add_partition(struct gendisk *, int, sector_t, sector_t, int); extern void delete_partition(struct gendisk *, int); +extern void printk_all_partitions(void); extern struct gendisk *alloc_disk_node(int minors, int node_id); extern struct gendisk *alloc_disk(int minors); diff --git a/init/do_mounts.c b/init/do_mounts.c index 3f57ed4599d6..46fe407fb03e 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -308,17 +309,21 @@ void __init mount_block_root(char *name, int flags) /* * Allow the user to distinguish between failed sys_open * and bad superblock on root device. + * and give them a list of the available devices */ #ifdef CONFIG_BLOCK __bdevname(ROOT_DEV, b); #endif printk("VFS: Cannot open root device \"%s\" or %s\n", root_device_name, b); - printk("Please append a correct \"root=\" boot option\n"); + printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); + printk_all_partitions(); panic("VFS: Unable to mount root fs on %s", b); } + printk("List of all partitions:\n"); + printk_all_partitions(); printk("No filesystem could mount root, tried: "); for (p = fs_names; *p; p += strlen(p)+1) printk(" %s", p); -- GitLab