git: 23c8b19c1d13 - main - Drop checks with last alternate superblock in fsck_ffs(8).

The branch main has been updated by mckusick:

URL: https://cgit.FreeBSD.org/src/commit/?id=23c8b19c1d13b8fbd10c5941de0f2618f59db1c9

commit 23c8b19c1d13b8fbd10c5941de0f2618f59db1c9
Author:     Kirk McKusick <mckusick@FreeBSD.org>
AuthorDate: 2022-08-04 23:06:43 +0000
Commit:     Kirk McKusick <mckusick@FreeBSD.org>
CommitDate: 2022-08-04 23:08:18 +0000

    Drop checks with last alternate superblock in fsck_ffs(8).
    
    The fsck_ffs(8) utility made sanity checks of critical superblock
    fields by comparing the values of those fields in the standard
    superblock againt the values of those fields in the last alternate
    superblock. The code for validating a superblock now cover all the
    checked fields as well as many more. Further the checks done are
    far more comprehensive. So we now drop the alternate superblock
    checks as they no longer provide value. Dropping these checks also
    eliminates the need to read the alternate superblock.
---
 sbin/fsck_ffs/setup.c | 64 ++-------------------------------------------------
 1 file changed, 2 insertions(+), 62 deletions(-)

diff --git a/sbin/fsck_ffs/setup.c b/sbin/fsck_ffs/setup.c
index 0daac100499a..cb95d18859b0 100644
--- a/sbin/fsck_ffs/setup.c
+++ b/sbin/fsck_ffs/setup.c
@@ -60,8 +60,6 @@ __FBSDID("$FreeBSD$");
 
 struct inoinfo **inphead, **inpsort;	/* info about all inodes */
 
-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);
@@ -163,10 +161,6 @@ setup(char *dev)
 		pfatal("from before 2002 with the command ``fsck -c 2''\n");
 		exit(EEXIT);
 	}
-	if ((asblk.b_flags & B_DIRTY) != 0 && !bflag) {
-		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)
@@ -252,7 +246,7 @@ int
 readsb(int listerr)
 {
 	off_t super;
-	int bad, ret, flags;
+	int ret, flags;
 	struct fs *fs;
 
 	super = bflag ? bflag * dev_bsize : UFS_STDSB;
@@ -293,58 +287,6 @@ readsb(int listerr)
 	dev_bsize = sblock.fs_fsize / fsbtodb(&sblock, 1);
 	sblk.b_bno = sblock.fs_sblockactualloc / dev_bsize;
 	sblk.b_size = SBLOCKSIZE;
-	/*
-	 * Compare all fields that should not differ in alternate super block.
-	 * When an alternate super-block is specified this check is skipped.
-	 */
-	if (bflag)
-		goto out;
-	getblk(&asblk, cgsblock(&sblock, sblock.fs_ncg - 1), sblock.fs_sbsize);
-	if (asblk.b_errs)
-		return (0);
-	bad = 0;
-#define CHK(x, y)				\
-	if (altsblock.x != sblock.x) {		\
-		bad++;				\
-		if (listerr && debug)		\
-			printf("SUPER BLOCK VS ALTERNATE MISMATCH %s: " y " vs " y "\n", \
-			    #x, (intmax_t)sblock.x, (intmax_t)altsblock.x); \
-	}
-	CHK(fs_sblkno, "%jd");
-	CHK(fs_cblkno, "%jd");
-	CHK(fs_iblkno, "%jd");
-	CHK(fs_dblkno, "%jd");
-	CHK(fs_ncg, "%jd");
-	CHK(fs_bsize, "%jd");
-	CHK(fs_fsize, "%jd");
-	CHK(fs_frag, "%jd");
-	CHK(fs_bmask, "%#jx");
-	CHK(fs_fmask, "%#jx");
-	CHK(fs_bshift, "%jd");
-	CHK(fs_fshift, "%jd");
-	CHK(fs_fragshift, "%jd");
-	CHK(fs_fsbtodb, "%jd");
-	CHK(fs_sbsize, "%jd");
-	CHK(fs_nindir, "%jd");
-	CHK(fs_inopb, "%jd");
-	CHK(fs_cssize, "%jd");
-	CHK(fs_ipg, "%jd");
-	CHK(fs_fpg, "%jd");
-	CHK(fs_magic, "%#jx");
-#undef CHK
-	if (bad) {
-		if (listerr == 0)
-			return (0);
-		if (preen)
-			printf("%s: ", cdevname);
-		printf(
-		    "VALUES IN SUPER BLOCK LSB=%jd DISAGREE WITH THOSE IN\n"
-		    "LAST ALTERNATE LSB=%jd\n",
-		    sblk.b_bno, asblk.b_bno);
-		if (reply("IGNORE ALTERNATE SUPER BLOCK") == 0)
-			return (0);
-	}
-out:
 	/*
 	 * If not yet done, update UFS1 superblock with new wider fields.
 	 */
@@ -373,10 +315,8 @@ sblock_init(void)
 	fsmodified = 0;
 	lfdir = 0;
 	initbarea(&sblk, BT_SUPERBLK);
-	initbarea(&asblk, BT_SUPERBLK);
 	sblk.b_un.b_buf = Malloc(SBLOCKSIZE);
-	asblk.b_un.b_buf = Malloc(SBLOCKSIZE);
-	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
+	if (sblk.b_un.b_buf == NULL)
 		errx(EEXIT, "cannot allocate space for superblock");
 	dev_bsize = secsize = DEV_BSIZE;
 }