Messages in this thread Patch in this message | | | Date | Mon, 18 Dec 2000 18:31:59 +0000 (GMT) | From | Tigran Aivazian <> | Subject | [final] Re: [patch-2.4.0-test13-pre3] rootfs (2nd attempt) |
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On Mon, 18 Dec 2000, Andreas Dilger wrote: > If I could add one thing here (we have had a 2.2 patch like this for testing > with ext3) - if you specify the rootfstype parameter don't use the "quiet" > option to read_super, so you know why it couldn't mount a specific filesystem > as root, and/or print rootfs type in the panic message.
Agree completely.
Here is the hopefully final version. Sorry, Linus, I thought the first version was final :) Looks like I have missed a couple of very useful things... Thanks to all who commented!
Regards, Tigran
diff -urN -X dontdiff linux/Documentation/kernel-parameters.txt rootfs/Documentation/kernel-parameters.txt --- linux/Documentation/kernel-parameters.txt Tue Sep 5 21:51:14 2000 +++ rootfs/Documentation/kernel-parameters.txt Mon Dec 18 09:04:06 2000 @@ -473,7 +473,10 @@ ro [KNL] Mount root device read-only on boot. - root= [KNL] root filesystem. + root= [KNL] Mount root filesystem on specified (as hex or "/dev/XXX") device. + + rootfs= [KNL] Use filesystem type specified (e.g. rootfs=ext2) for root. + rw [KNL] Mount root device read-write on boot. diff -urN -X dontdiff linux/fs/super.c rootfs/fs/super.c --- linux/fs/super.c Tue Dec 12 09:25:22 2000 +++ rootfs/fs/super.c Mon Dec 18 15:03:44 2000 @@ -18,6 +18,7 @@ * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996. * Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000 + * Added rootfs boot param. used by mount_root(): Tigran Aivazian. Dec 2000. */ #include <linux/config.h> @@ -58,6 +59,12 @@ /* this is initialized in init/main.c */ kdev_t ROOT_DEV; +/* this can be set at boot time, e.g. rootfs=ext2 + * if set to invalid value or if read_super() fails on the specified + * filesystem type then mount_root() will panic + */ +static char rootfs[32] __initdata = ""; + int nr_super_blocks; int max_super_blocks = NR_SUPER; LIST_HEAD(super_blocks); @@ -78,6 +85,17 @@ static struct file_system_type *file_systems; static rwlock_t file_systems_lock = RW_LOCK_UNLOCKED; +static int __init rootfs_setup(char *line) +{ + int n = strlen(line) + 1; + + if (n > 1 && n < 32) + strncpy(rootfs, line, n); + return 1; +} + +__setup("rootfs=", rootfs_setup); + /* WARNING: This can be used only if we _already_ own a reference */ static void get_filesystem(struct file_system_type *fs) { @@ -1579,6 +1597,16 @@ goto mount_it; } + if (*rootfs) { + fs_type = get_fs_type(rootfs); + if (fs_type) { + sb = read_super(ROOT_DEV,bdev,fs_type,root_mountflags,NULL,0); + if (sb) + goto mount_it; + } + /* don't try others if type given explicitly, same behaviour as mount(8) */ + goto fail; + } read_lock(&file_systems_lock); for (fs_type = file_systems ; fs_type ; fs_type = fs_type->next) { if (!(fs_type->fs_flags & FS_REQUIRES_DEV)) @@ -1593,6 +1621,7 @@ put_filesystem(fs_type); } read_unlock(&file_systems_lock); +fail: panic("VFS: Unable to mount root %s on %s", *rootfs ? rootfs : "fs", kdevname(ROOT_DEV)); mount_it: - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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