kern

annotate src/fs_sys.c @ 95:ec62cbe00b55

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author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 11 Dec 2011 21:15:35 +0200
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nuclear@93 1 /* implementation of the filesystem-related syscalls */
nuclear@93 2
nuclear@93 3 #include <stdio.h>
nuclear@93 4 #include <stdlib.h>
nuclear@93 5 #include <string.h>
nuclear@93 6 #include <assert.h>
nuclear@93 7 #include <errno.h>
nuclear@93 8 #include "fs.h"
nuclear@93 9 #include "part.h"
nuclear@93 10 #include "panic.h"
nuclear@93 11 #include "bdev.h"
nuclear@93 12
nuclear@93 13 static dev_t find_rootfs(void);
nuclear@93 14
nuclear@93 15 /* list of mounted filesystems
nuclear@93 16 * XXX currently only one, the root filesystem
nuclear@93 17 */
nuclear@93 18 static struct filesys *fslist;
nuclear@93 19
nuclear@93 20
nuclear@93 21 int sys_mount(char *mtpt, char *devname, unsigned int flags)
nuclear@93 22 {
nuclear@93 23 dev_t dev;
nuclear@93 24 int err;
nuclear@93 25 struct filesys *fs;
nuclear@93 26
nuclear@93 27 if(strcmp(mtpt, "/") != 0) {
nuclear@93 28 printf("only root can be mounted at the moment\n");
nuclear@93 29 return -EBUG;
nuclear@93 30 }
nuclear@93 31
nuclear@93 32 /* mounting root filesystem */
nuclear@93 33 if(fslist) {
nuclear@93 34 printf("root already mounted\n");
nuclear@93 35 return -EBUSY;
nuclear@93 36 }
nuclear@93 37
nuclear@93 38 if(devname) {
nuclear@93 39 dev = bdev_by_name(devname);
nuclear@93 40 } else {
nuclear@93 41 /* try to autodetect it */
nuclear@93 42 dev = find_rootfs();
nuclear@93 43 }
nuclear@93 44 if(!dev) {
nuclear@93 45 err = -ENOENT;
nuclear@93 46 goto rootfail;
nuclear@93 47 }
nuclear@93 48
nuclear@93 49 if(!(fs = malloc(sizeof *fslist))) {
nuclear@93 50 err = -ENOMEM;
nuclear@93 51 goto rootfail;
nuclear@93 52 }
nuclear@93 53 if((err = openfs(fs, dev)) != 0) {
nuclear@93 54 free(fs);
nuclear@93 55 goto rootfail;
nuclear@93 56 }
nuclear@93 57
nuclear@93 58 fslist = fs;
nuclear@93 59 return 0;
nuclear@93 60
nuclear@93 61 rootfail:
nuclear@93 62 panic("failed to mount root filesystem: %d\n", -err);
nuclear@93 63 return err; /* unreachable */
nuclear@93 64 }
nuclear@93 65
nuclear@93 66 #define PART_TYPE 0xcc
nuclear@93 67 static dev_t find_rootfs(void)
nuclear@93 68 {
nuclear@93 69 dev_t dev = 0;
nuclear@93 70 int i, num_dev, partid;
nuclear@93 71 struct partition *plist, *p;
nuclear@93 72 struct superblock *sb = malloc(BLKSZ);
nuclear@93 73 char name[16];
nuclear@93 74
nuclear@93 75 assert(sb);
nuclear@93 76
nuclear@93 77 num_dev = ata_num_devices();
nuclear@93 78 for(i=0; i<num_dev; i++) {
nuclear@93 79 plist = p = get_part_list(i);
nuclear@93 80
nuclear@93 81 partid = 0;
nuclear@93 82 while(p) {
nuclear@93 83 if(get_part_type(p) == PART_TYPE) {
nuclear@93 84 /* found the correct partition, now read the superblock
nuclear@93 85 * and make sure it's got the correct magic id
nuclear@93 86 */
nuclear@93 87 blk_read(i, p->start_sect / 2 + 1, BLKSZ, sb);
nuclear@93 88
nuclear@93 89 if(sb->magic == MAGIC) {
nuclear@93 90 sprintf(name, "ata%dp%d", i, partid);
nuclear@93 91 printf("found root: %s\n", name);
nuclear@93 92 dev = bdev_by_name(name);
nuclear@93 93 break;
nuclear@93 94 }
nuclear@93 95 }
nuclear@93 96 p = p->next;
nuclear@93 97 partid++;
nuclear@93 98 }
nuclear@93 99 free_part_list(plist);
nuclear@93 100 if(dev) break;
nuclear@93 101 }
nuclear@93 102
nuclear@93 103 free(sb);
nuclear@93 104 return dev;
nuclear@93 105 }