fsck: get the fsck tool working

This (with the needed kernel changes) seems to give us the correct behaviour
including handling recovering the live root file system.

If you boot with 'r' as an option or a dirty rootfs you'll now get a r/o
mount and you can fsck /dev/whatever to check it. If it's bad you'll then
get to fix it and it'll reboot.

diff --git a/Applications/util/fsck.c b/Applications/util/fsck.c
index a27c140..f708fd9 100644 (file)
--- a/Applications/util/fsck.c
+++ b/Applications/util/fsck.c
@@ -6,6 +6,8 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 typedef uint16_t       blkno_t;
 
@@ -18,6 +20,8 @@ struct filesys {
     int16_t       s_ninode;
     uint16_t      s_inode[50];
     uint8_t       s_fmod;
+#define FMOD_DIRTY     1
+#define FMOD_CLEAN     2
     uint8_t    s_timeh;        /* top bits of time */
     uint32_t      s_time;
     blkno_t     s_tfree;
@@ -64,6 +68,9 @@ static int swizzling = 0;             /* Wrongendian ? */
 static long offset;
 static int dev_fd;
 static int dev_offset;
+static int error;
+static int rootfs;
+static int aflag;
 
 static unsigned char *bitmap;
 static int16_t *linkmap;
@@ -85,16 +92,25 @@ static void pass3(void);
 static void pass4(void);
 static void pass5(void);
 
-static int yes(void)
+static int yes_noerror(void)
 {
     static char buf[16];
+    fflush(stdout);
     do {
         if (fgets(buf, 15, stdin) == NULL)
             exit(1);
         if (isupper(*buf))
             *buf = tolower(*buf);
     } while(*buf != 'n' && *buf != 'y');
-    return (*buf == 'y') ? 1 : 0;
+    return  (*buf == 'y') ? 1 : 0;
+}
+
+static int yes(void) {
+    int ret = yes_noerror();
+    if (ret)
+        error |= 1;
+    else
+        error |= 4;
 }
 
 static void bitset(uint16_t b)
@@ -112,35 +128,45 @@ static int bittest(uint16_t b)
     return (bitmap[b >> 3] & (1 << (b & 7))) ? 1 : 0;
 }
 
+static void panic(char *s)
+{
+       fprintf(stderr, "panic: %s\n", s);
+       exit(error | 8);
+}
+
 static int fd_open(char *name)
 {
-       char *namecopy, *sd;
+       char *sd;
        int bias = 0;
+       struct stat rootst;
+       struct stat work;
 
-       namecopy = strdup(name);
-       sd = index(namecopy, ':');
+       sd = index(name, ':');
        if (sd) {
                *sd = 0;
                sd++;
                bias = atoi(sd);
        }
 
-       printf("Opening %s (offset %d)\n", namecopy, bias);
+       printf("Opening %s (offset %d)\n", name, bias);
        dev_offset = bias;
-       dev_fd = open(namecopy, O_RDWR | O_CREAT, 0666);
-       free(namecopy);
+       dev_fd = open(name, O_RDWR | O_CREAT, 0666);
 
        if (dev_fd < 0)
                return -1;
        /* printf("fd=%d, dev_offset = %d\n", dev_fd, dev_offset); */
-       return 0;
-}
 
+       if (stat("/", &rootst) == -1)
+           panic("stat /");
+        if (fstat(dev_fd, &work) == -1)
+            panic("statfd");
 
-static void panic(char *s)
-{
-       fprintf(stderr, "panic: %s\n", s);
-       exit(1);
+        if (rootst.st_dev == work.st_rdev) {
+            printf("Checking root file system.\n");
+            rootfs = 1;
+        }
+
+       return 0;
 }
 
 static uint16_t swizzle16(uint32_t v)
@@ -148,7 +174,7 @@ static uint16_t swizzle16(uint32_t v)
         int top = v & 0xFFFF0000UL;
        if (top && top != 0xFFFF0000) {
                fprintf(stderr, "swizzle16 given a 32bit input\n");
-               exit(1);
+               exit(error | 8);
        }
        if (swizzling)
                return (v & 0xFF) << 8 | ((v & 0xFF00) >> 8);
@@ -170,9 +196,15 @@ int main(int argc, char **argv)
     char *buf;
     char *op;
 
+    if (argc == 3 && strcmp(argv[1],"-a") == 0) {
+        argc--;
+        argv++;
+        aflag = 1;
+    }
+
     if(argc != 2){
-        fprintf(stderr, "syntax: fsck [devfile][:offset]\n");
-        return 1;
+        fprintf(stderr, "syntax: fsck[-a] [devfile][:offset]\n");
+        return 16;
     }
     
     op = strchr(argv[1], ':');
@@ -183,12 +215,19 @@ int main(int argc, char **argv)
 
     if(fd_open(argv[1])){
         printf("Cannot open file\n");
-        return -1;
+        return 16;
     }
 
     buf = daread(1);
     bcopy(buf, (char *) &superblock, sizeof(struct filesys));
 
+    if (superblock.s_fmod == FMOD_DIRTY) {
+        printf("Filesystem was not cleanly unmounted.\n");
+        error |= 1;
+    }
+    else if (aflag)
+        return 0;
+
     /* Verify the fsize and isize parameters */
     if (superblock.s_mounted == SMOUNTED_WRONGENDIAN) {
         swizzling = 1;
@@ -198,14 +237,14 @@ int main(int argc, char **argv)
     if (swizzle16(superblock.s_mounted) != SMOUNTED) {
         printf("Device %d has invalid magic number %d. Fix? ", dev, superblock.s_mounted);
         if (!yes())
-            exit(-1);
+            exit(error|32);
         superblock.s_mounted = swizzle16(SMOUNTED);
         dwrite((blkno_t) 1, (char *) &superblock);
     }
     printf("Device %d has fsize = %d and isize = %d. Continue? ",
             dev, swizzle16(superblock.s_fsize), swizzle16(superblock.s_isize));
     if (!yes())
-        exit(-1);
+        exit(error | 32);
 
     bitmap = calloc((swizzle16(superblock.s_fsize) + 7) / 8, sizeof(char));
     linkmap = (int16_t *) calloc(8 * swizzle16(superblock.s_isize), sizeof(int16_t));
@@ -215,7 +254,7 @@ int main(int argc, char **argv)
         swizzle16(superblock.s_fsize + 7) / 8);
     if (!bitmap || !linkmap) {
         fprintf(stderr, "Not enough memory.\n");
-        exit(-1);
+        exit(error | 8);
     }
 
     printf("Pass 1: Checking inodes...\n");
@@ -233,9 +272,22 @@ int main(int argc, char **argv)
     printf("Pass 5: Checking link counts...\n");
     pass5();
 
+    /* If we fixed things, and no errors were left uncorrected */
+    if ((error & 5) == 1) {
+        superblock.s_fmod = FMOD_CLEAN;
+        dwrite((blkno_t) 1, (char *) &superblock);
+        if (rootfs) {
+            error |= 2;
+            printf("**** Root filesystem was modified, immediate reboot required.\n");
+            sleep(5);
+            /* Sync it all out and reboot */
+            uadmin(A_REBOOT, 0, 0);
+        }
+    }
+
     printf("Done.\n");
 
-    exit(0);
+    exit(error);
 }
 
 
@@ -369,12 +421,12 @@ static void pass2(void)
     blkno_t j;
     blkno_t oldtfree;
     int s;
-    int yes();
 
     printf("Rebuild free list? ");
-    if (!yes())
+    if (!yes_noerror())
         return;
 
+    error |= 1;
     oldtfree = swizzle16(superblock.s_tfree);
 
     /* Initialize the superblock-block */
@@ -437,9 +489,10 @@ static void pass3(void)
                             b, n, swizzle16(ino.i_addr[b]));
                     if (yes()) {
                         newno = blk_alloc0(&superblock);
-                        if (newno == 0)
+                        if (newno == 0) {
                             printf("Sorry... No more free blocks.\n");
-                        else {
+                            error |= 4;
+                        } else {
                             dwrite(newno, daread(swizzle16(ino.i_addr[b])));
                             ino.i_addr[b] = swizzle16(newno);
                             iwrite(n, &ino);
@@ -460,9 +513,10 @@ static void pass3(void)
                             bno, n, b);
                     if (yes()) {
                         newno = blk_alloc0(&superblock);
-                        if (newno == 0)
+                        if (newno == 0) {
                             printf("Sorry... No more free blocks.\n");
-                        else {
+                            error |= 4;
+                        } else {
                             dwrite(newno, daread(b));
                             setblkno(&ino, bno, newno);
                             iwrite(n, &ino);
@@ -596,7 +650,6 @@ static void pass5(void)
 {
     uint16_t n;
     struct dinode ino;
-    int yes();
 
     for (n = ROOTINODE; n < 8 * (swizzle16(superblock.s_isize) - 2); ++n) {
         iread(n, &ino);
@@ -689,6 +742,7 @@ static void mkentry(uint16_t inum)
         }
     }
     printf("Sorry... No empty slots in root directory.\n");
+    error |= 4;
 }
 
 /*