From 5cc8ff22fa0677114bfd33f769881dabb84ca4db Mon Sep 17 00:00:00 2001 From: iedowse Date: Mon, 15 Jan 2001 18:30:40 +0000 Subject: The ffs superblock includes a 128-byte region for use by temporary in-core pointers to summary information. An array in this region (fs_csp) could overflow on filesystems with a very large number of cylinder groups (~16000 on i386 with 8k blocks). When this happens, other fields in the superblock get corrupted, and fsck refuses to check the filesystem. Solve this problem by replacing the fs_csp array in 'struct fs' with a single pointer, and add padding to keep the length of the 128-byte region fixed. Update the kernel and userland utilities to use just this single pointer. With this change, the kernel no longer makes use of the superblock fields 'fs_csshift' and 'fs_csmask'. Add a comment to newfs/mkfs.c to indicate that these fields must be calculated for compatibility with older kernels. Reviewed by: mckusick --- sbin/fsck_ffs/setup.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'sbin/fsck_ffs/setup.c') diff --git a/sbin/fsck_ffs/setup.c b/sbin/fsck_ffs/setup.c index 6c4098c..0c2e8ac 100644 --- a/sbin/fsck_ffs/setup.c +++ b/sbin/fsck_ffs/setup.c @@ -258,11 +258,11 @@ setup(dev) * read in the summary info. */ asked = 0; + sblock.fs_csp = calloc(1, sblock.fs_cssize); for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) { size = sblock.fs_cssize - i < sblock.fs_bsize ? sblock.fs_cssize - i : sblock.fs_bsize; - sblock.fs_csp[j] = (struct csum *)calloc(1, (unsigned)size); - if (bread(fsreadfd, (char *)sblock.fs_csp[j], + if (bread(fsreadfd, (char *)sblock.fs_csp + i, fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag), size) != 0 && !asked) { pfatal("BAD SUMMARY INFORMATION"); @@ -380,7 +380,8 @@ readsb(listerr) altsblock.fs_optim = sblock.fs_optim; altsblock.fs_rotdelay = sblock.fs_rotdelay; altsblock.fs_maxbpg = sblock.fs_maxbpg; - memmove(altsblock.fs_csp, sblock.fs_csp, sizeof sblock.fs_csp); + memmove(altsblock.fs_ocsp, sblock.fs_ocsp, sizeof sblock.fs_ocsp); + altsblock.fs_csp = sblock.fs_csp; altsblock.fs_maxcluster = sblock.fs_maxcluster; memmove(altsblock.fs_fsmnt, sblock.fs_fsmnt, sizeof sblock.fs_fsmnt); memmove(altsblock.fs_snapinum, sblock.fs_snapinum, -- cgit v1.1