Kirk McKusick 8d408dff91 Reported problem: ... Large (60GB) filesystems created using "newfs -U -O 1 -b 65536 -f 8192" show incorrect results from "df" for free and used space when mounted immediately after creation. fsck on the new filesystem (before ever mounting it once) gives a "SUMMARY INFORMATION BAD" error in phase 5. This error hasn't occurred in any runs of fsck immediately after "newfs -U -b 65536 -f 8192" (leaving out the "-O 1" option). Solution: The default UFS1 superblock is located at offset 8K in the filesystem partition; the default UFS2 superblock is located at offset 64K in the filesystem partition. For UFS1 filesystems with a blocksize of 64K, the first alternate superblock resides at 64K which is the the location used for the default UFS2 superblock. By default, the system first checks for a valid superblock at the default location for a UFS2 filoesystem. For a UFS1 filesystem with a blocksize of 64K, there is a valid UFS1 superblock at this location. Thus, even though it is expected to be a backup superblock, the system will use it as its default superblock. So, we have to ensure that all the statistcs on usage are correct in this first alternate superblock as it is the superblock that will actually be used. While tracking down this problem, another limitation of UFS1 became evident. For UFS1, the number of inodes per cylinder group is stored in an int16_t. Thus the maximum number of inodes per cylinder group is limited to 2^15 - 1. This limit can easily be exceeded for block sizes of 32K and above. Thus when building UFS1 filesystems, newfs must limit the number of inodes per cylinder group to 2^15 - 1. Reported by: Guy Helmer<ghelmer@palisadesys.com> Followup by: Bruce Cran <brucec@freebsd.org> PR: 107692 MFC after: 4 weeks		2010-09-24 19:08:56 +00:00
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Makefile
mkfs.c
newfs.8
newfs.c
newfs.h
ref.test
runtest00.sh
runtest01.sh