From 14320f1e7f93a63a36dd0b005b0fd920d5a965c6 Mon Sep 17 00:00:00 2001 From: Xin LI Date: Thu, 10 Apr 2008 23:49:23 +0000 Subject: [PATCH] Add a new flag, '-C' which enables a special mode that is intended for catastrophic recovery. Currently, this mode only validates whether a cylindergroup has good signature data, and prompts the user to decide whether to clear it as a whole. This mode is useful when there is data damage on a disk and you are working on copy of the original disk, as fsck_ffs(8) tends to abnormally exit in such case, as a last resort to recover data from the disk. --- sbin/fsck_ffs/fsck.h | 2 ++ sbin/fsck_ffs/fsck_ffs.8 | 24 ++++++++++++++++++++++-- sbin/fsck_ffs/fsutil.c | 32 ++++++++++++++++++++++++++++++-- sbin/fsck_ffs/inode.c | 3 +-- sbin/fsck_ffs/main.c | 7 ++++++- 5 files changed, 61 insertions(+), 7 deletions(-) diff --git a/sbin/fsck_ffs/fsck.h b/sbin/fsck_ffs/fsck.h index f9b38e0c27b8..14f49d6d5d5a 100644 --- a/sbin/fsck_ffs/fsck.h +++ b/sbin/fsck_ffs/fsck.h @@ -270,6 +270,7 @@ char yflag; /* assume a yes response */ int bkgrdflag; /* use a snapshot to run on an active system */ int bflag; /* location of alternate super block */ int debug; /* output debugging info */ +char catastrophicflag; /* run in catastrophic mode */ int cvtlevel; /* convert to newer file system format */ int bkgrdcheck; /* determine if background check is possible */ int bkgrdsumadj; /* whether the kernel have ability to adjust superblock summary */ @@ -335,6 +336,7 @@ void cacheino(union dinode *dp, ino_t inumber); void catch(int); void catchquit(int); int changeino(ino_t dir, const char *name, ino_t newnum); +void check_cgmagic(int cg, struct cg *cgp); int chkrange(ufs2_daddr_t blk, int cnt); void ckfini(int markclean); int ckinode(union dinode *dp, struct inodesc *); diff --git a/sbin/fsck_ffs/fsck_ffs.8 b/sbin/fsck_ffs/fsck_ffs.8 index a64c7ce8b5e7..98c97f327c5f 100644 --- a/sbin/fsck_ffs/fsck_ffs.8 +++ b/sbin/fsck_ffs/fsck_ffs.8 @@ -29,7 +29,7 @@ .\" @(#)fsck.8 8.4 (Berkeley) 5/9/95 .\" $FreeBSD$ .\" -.Dd April 24, 2001 +.Dd April 10, 2008 .Dt FSCK_FFS 8 .Os .Sh NAME @@ -38,7 +38,7 @@ .Nd file system consistency check and interactive repair .Sh SYNOPSIS .Nm -.Op Fl BFpfny +.Op Fl BCFpfny .Op Fl b Ar block .Op Fl c Ar level .Op Fl m Ar mode @@ -175,6 +175,26 @@ Use the block specified immediately after the flag as the super block for the file system. An alternate super block is usually located at block 32 for UFS1, and block 160 for UFS2. +.It Fl C +Run +.Nm +in 'catastrophic recovery' mode, which will enable certain aggressive +operations that can make +.Nm +to survive with file systems that has very serious data damage, which +is an useful last resort when on disk data damage is very serious +and causes +.Nm +to crash otherwise. Be +.Em very careful +using this flag, is dangerous if there are data transmission hazards +because a false positive cylinder group magic number mismatch could +cause +.Em irrevertible data loss! +.Pp +This option implies the +.Fl f +flag. .It Fl c Convert the file system to the specified level. Note that the level of a file system can only be raised. diff --git a/sbin/fsck_ffs/fsutil.c b/sbin/fsck_ffs/fsutil.c index 65f996c1ced8..7ca0c44e9f28 100644 --- a/sbin/fsck_ffs/fsutil.c +++ b/sbin/fsck_ffs/fsutil.c @@ -417,6 +417,35 @@ blwrite(int fd, char *buf, ufs2_daddr_t blk, long size) return; } +/* + * Check cg's magic number. If catastrophic mode is enabled and the cg's + * magic number is bad, offer an option to clear the whole cg. + */ +void +check_cgmagic(int cg, struct cg *cgp) +{ + + if (!cg_chkmagic(cgp)) { + pwarn("CG %d: BAD MAGIC NUMBER\n", cg); + if (catastrophicflag) { + if (reply("CLEAR CG")) { + memset(cgp, 0, (size_t)sblock.fs_cgsize); + cgp->cg_initediblk = sblock.fs_ipg; + cgp->cg_old_niblk = sblock.fs_ipg; + cgp->cg_old_ncyl = sblock.fs_old_cpg; + cgp->cg_cgx = cg; + cgp->cg_niblk = sblock.fs_ipg; + cgp->cg_ndblk = sblock.fs_size - cgbase(&sblock, cg); + cgp->cg_magic = CG_MAGIC; + cgdirty(); + printf("PLEASE RERUN FSCK.\n"); + rerun = 1; + } + } else + printf("YOU MAY NEED TO RERUN FSCK WITH -C IF IT CRASHED.\n"); + } +} + /* * allocate a data block with the specified number of fragments */ @@ -441,8 +470,7 @@ allocblk(long frags) } cg = dtog(&sblock, i + j); getblk(&cgblk, cgtod(&sblock, cg), sblock.fs_cgsize); - if (!cg_chkmagic(cgp)) - pfatal("CG %d: BAD MAGIC NUMBER\n", cg); + check_cgmagic(cg, cgp); baseblk = dtogd(&sblock, i + j); for (k = 0; k < frags; k++) { setbmap(i + j + k); diff --git a/sbin/fsck_ffs/inode.c b/sbin/fsck_ffs/inode.c index b41d8430e81b..94c637ef7ae5 100644 --- a/sbin/fsck_ffs/inode.c +++ b/sbin/fsck_ffs/inode.c @@ -617,8 +617,7 @@ allocino(ino_t request, int type) return (0); cg = ino_to_cg(&sblock, ino); getblk(&cgblk, cgtod(&sblock, cg), sblock.fs_cgsize); - if (!cg_chkmagic(cgp)) - pfatal("CG %d: BAD MAGIC NUMBER\n", cg); + check_cgmagic(cg, cgp); setbit(cg_inosused(cgp), ino % sblock.fs_ipg); cgp->cg_cs.cs_nifree--; switch (type & IFMT) { diff --git a/sbin/fsck_ffs/main.c b/sbin/fsck_ffs/main.c index f24d49bdc9f2..7cb20a79f267 100644 --- a/sbin/fsck_ffs/main.c +++ b/sbin/fsck_ffs/main.c @@ -81,7 +81,8 @@ main(int argc, char *argv[]) sync(); skipclean = 1; - while ((ch = getopt(argc, argv, "b:Bc:dfFm:npy")) != -1) { + catastrophicflag = 0; + while ((ch = getopt(argc, argv, "b:Bc:CdfFm:npy")) != -1) { switch (ch) { case 'b': skipclean = 0; @@ -105,6 +106,10 @@ main(int argc, char *argv[]) debug++; break; + case 'C': + catastrophicflag = 1; + /* FALLTHROUGH */ + case 'f': skipclean = 0; break;