diff options
| -rw-r--r-- | sbin/fsck_ffs/setup.c | 105 | ||||
| -rw-r--r-- | sbin/newfs/mkfs.c | 20 | ||||
| -rw-r--r-- | sys/ufs/ffs/fs.h | 14 |
3 files changed, 135 insertions, 4 deletions
diff --git a/sbin/fsck_ffs/setup.c b/sbin/fsck_ffs/setup.c index c77f7d01cf4e..f97a3fed0f83 100644 --- a/sbin/fsck_ffs/setup.c +++ b/sbin/fsck_ffs/setup.c @@ -58,6 +58,10 @@ struct bufarea asblk; #define altsblock (*asblk.b_un.b_fs) #define POWEROF2(num) (((num) & ((num) - 1)) == 0) +static int calcsb(char *dev, int devfd, struct fs *fs); +static void saverecovery(int readfd, int writefd); +static int chkrecovery(int devfd); + /* * Read in a superblock finding an alternate if necessary. * Return 1 if successful, 0 if unsuccessful, -1 if file system @@ -66,9 +70,10 @@ struct bufarea asblk; int setup(char *dev) { - long asked, i, j; + long cg, asked, i, j; long bmapsize; struct stat statb; + struct fs proto; size_t size; havesb = 0; @@ -173,10 +178,28 @@ setup(char *dev) */ if (readsb(1) == 0) { skipclean = 0; - if (bflag || preen) + if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0) return(0); - /* Looking for alternates is hard punt for now but retain structure */ - return (0); + if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0) + return (0); + for (cg = 0; cg < proto.fs_ncg; cg++) { + bflag = fsbtodb(&proto, cgsblock(&proto, cg)); + if (readsb(0) != 0) + break; + } + if (cg >= proto.fs_ncg) { + printf("%s %s\n%s %s\n%s %s\n", + "SEARCH FOR ALTERNATE SUPER-BLOCK", + "FAILED. YOU MUST USE THE", + "-b OPTION TO FSCK TO SPECIFY THE", + "LOCATION OF AN ALTERNATE", + "SUPER-BLOCK TO SUPPLY NEEDED", + "INFORMATION; SEE fsck_ffs(8)."); + bflag = 0; + return(0); + } + pwarn("USING ALTERNATE SUPERBLOCK AT %jd\n", bflag); + bflag = 0; } if (skipclean && ckclean && sblock.fs_clean) { pwarn("FILE SYSTEM CLEAN; SKIPPING CHECKS\n"); @@ -213,6 +236,10 @@ setup(char *dev) memmove(&altsblock, &sblock, (size_t)sblock.fs_sbsize); flush(fswritefd, &asblk); } + if (preen == 0 && yflag == 0 && sblock.fs_magic == FS_UFS2_MAGIC && + fswritefd != -1 && chkrecovery(fsreadfd) == 0 && + reply("SAVE DATA TO FIND ALTERNATE SUPERBLOCKS") != 0) + saverecovery(fsreadfd, fswritefd); /* * read in the summary info. */ @@ -428,3 +455,73 @@ sblock_init(void) errx(EEXIT, "cannot allocate space for superblock"); dev_bsize = secsize = DEV_BSIZE; } + +/* + * Calculate a prototype superblock based on information in the boot area. + * When done the cgsblock macro can be calculated and the fs_ncg field + * can be used. Do NOT attempt to use other macros without verifying that + * their needed information is available! + */ +static int +calcsb(char *dev, int devfd, struct fs *fs) +{ + struct fsrecovery fsr; + + /* + * We need fragments-per-group and the partition-size. + * + * Newfs stores these details at the end of the boot block area + * at the start of the filesystem partition. If they have been + * overwritten by a boot block, we fail. But usually they are + * there and we can use them. + */ + if (blread(devfd, (char *)&fsr, + (SBLOCK_UFS2 - sizeof(fsr)) / dev_bsize, sizeof(fsr)) || + fsr.fsr_magic != FS_UFS2_MAGIC) + return (0); + memset(fs, 0, sizeof(struct fs)); + fs->fs_fpg = fsr.fsr_fpg; + fs->fs_fsbtodb = fsr.fsr_fsbtodb; + fs->fs_sblkno = fsr.fsr_sblkno; + fs->fs_magic = fsr.fsr_magic; + fs->fs_ncg = fsr.fsr_ncg; + return (1); +} + +/* + * Check to see if recovery information exists. + */ +static int +chkrecovery(int devfd) +{ + struct fsrecovery fsr; + + if (blread(devfd, (char *)&fsr, + (SBLOCK_UFS2 - sizeof(fsr)) / dev_bsize, sizeof(fsr)) || + fsr.fsr_magic != FS_UFS2_MAGIC) + return (0); + return (1); +} + +/* + * Read the last sector of the boot block, replace the last + * 20 bytes with the recovery information, then write it back. + * The recovery information only works for UFS2 filesystems. + */ +static void +saverecovery(int readfd, int writefd) +{ + struct fsrecovery fsr; + + if (sblock.fs_magic != FS_UFS2_MAGIC || + blread(readfd, (char *)&fsr, + (SBLOCK_UFS2 - sizeof(fsr)) / dev_bsize, sizeof(fsr))) + return; + fsr.fsr_magic = sblock.fs_magic; + fsr.fsr_fpg = sblock.fs_fpg; + fsr.fsr_fsbtodb = sblock.fs_fsbtodb; + fsr.fsr_sblkno = sblock.fs_sblkno; + fsr.fsr_ncg = sblock.fs_ncg; + blwrite(writefd, (char *)&fsr, (SBLOCK_UFS2 - sizeof(fsr)) / dev_bsize, + sizeof(fsr)); +} diff --git a/sbin/newfs/mkfs.c b/sbin/newfs/mkfs.c index b89ffa12f746..3cbfad8c49d7 100644 --- a/sbin/newfs/mkfs.c +++ b/sbin/newfs/mkfs.c @@ -121,6 +121,7 @@ mkfs(struct partition *pp, char *fsys) ino_t maxinum; int minfragsperinode; /* minimum ratio of frags to inodes */ char tmpbuf[100]; /* XXX this will break in about 2,500 years */ + struct fsrecovery fsr; union { struct fs fdummy; char cdummy[SBLOCKSIZE]; @@ -617,6 +618,25 @@ restart: MIN(sblock.fs_cssize - i, sblock.fs_bsize), ((char *)fscs) + i); /* + * Read the last sector of the boot block, replace the last + * 20 bytes with the recovery information, then write it back. + * The recovery information only works for UFS2 filesystems. + */ + if (sblock.fs_magic == FS_UFS2_MAGIC) { + i = bread(&disk, + part_ofs + (SBLOCK_UFS2 - sizeof(fsr)) / disk.d_bsize, + (char *)&fsr, sizeof(fsr)); + if (i == -1) + err(1, "can't read recovery area: %s", disk.d_error); + fsr.fsr_magic = sblock.fs_magic; + fsr.fsr_fpg = sblock.fs_fpg; + fsr.fsr_fsbtodb = sblock.fs_fsbtodb; + fsr.fsr_sblkno = sblock.fs_sblkno; + fsr.fsr_ncg = sblock.fs_ncg; + wtfs((SBLOCK_UFS2 - sizeof(fsr)) / disk.d_bsize, sizeof(fsr), + (char *)&fsr); + } + /* * Update information about this partition in pack * label, to that it may be updated on disk. */ diff --git a/sys/ufs/ffs/fs.h b/sys/ufs/ffs/fs.h index 4d08210cb522..8de35ffbbd74 100644 --- a/sys/ufs/ffs/fs.h +++ b/sys/ufs/ffs/fs.h @@ -234,6 +234,20 @@ struct fsck_cmd { }; /* + * A recovery structure placed at the end of the boot block area by newfs + * that can be used by fsck to search for alternate superblocks. + */ +#define RESID (4096 - 20) /* disk sector size minus recovery area size */ +struct fsrecovery { + char block[RESID]; /* unused part of sector */ + int32_t fsr_magic; /* magic number */ + int32_t fsr_fsbtodb; /* fsbtodb and dbtofsb shift constant */ + int32_t fsr_sblkno; /* offset of super-block in filesys */ + int32_t fsr_fpg; /* blocks per group * fs_frag */ + u_int32_t fsr_ncg; /* number of cylinder groups */ +}; + +/* * Per cylinder group information; summarized in blocks allocated * from first cylinder group data blocks. These blocks have to be * read in from fs_csaddr (size fs_cssize) in addition to the |