4c3c44cdd8
check hash to cylinder groups. If a check hash fails when a cylinder
group is read, no further allocations are attempted in that cylinder
group until it has been fixed by fsck. This avoids a class of
filesystem panics related to corrupted cylinder group maps. The
hash is done using crc32c.
Check hases are added only to UFS2 and not to UFS1 as UFS1 is primarily
used in embedded systems with small memories and low-powered processors
which need as light-weight a filesystem as possible.
Specifics of the changes:
sys/sys/buf.h:
Add BX_FSPRIV to reserve a set of eight b_xflags that may be used
by individual filesystems for their own purpose. Their specific
definitions are found in the header files for each filesystem
that uses them. Also add fields to struct buf as noted below.
sys/kern/vfs_bio.c:
It is only necessary to compute a check hash for a cylinder
group when it is actually read from disk. When calling bread,
you do not know whether the buffer was found in the cache or
read. So a new flag (GB_CKHASH) and a pointer to a function to
perform the hash has been added to breadn_flags to say that the
function should be called to calculate a hash if the data has
been read. The check hash is placed in b_ckhash and the B_CKHASH
flag is set to indicate that a read was done and a check hash
calculated. Though a rather elaborate mechanism, it should
also work for check hashing other metadata in the future. A
kernel internal API change was to change breada into a static
fucntion and add flags and a function pointer to a check-hash
function.
sys/ufs/ffs/fs.h:
Add flags for types of check hashes; stored in a new word in the
superblock. Define corresponding BX_ flags for the different types
of check hashes. Add a check hash word in the cylinder group.
sys/ufs/ffs/ffs_alloc.c:
In ffs_getcg do the dance with breadn_flags to get a check hash and
if one is provided, check it.
sys/ufs/ffs/ffs_vfsops.c:
Copy across the BX_FFSTYPES flags in background writes.
Update the check hash when writing out buffers that need them.
sys/ufs/ffs/ffs_snapshot.c:
Recompute check hash when updating snapshot cylinder groups.
sys/libkern/crc32.c:
lib/libufs/Makefile:
lib/libufs/libufs.h:
lib/libufs/cgroup.c:
Include libkern/crc32.c in libufs and use it to compute check
hashes when updating cylinder groups.
Four utilities are affected:
sbin/newfs/mkfs.c:
Add the check hashes when building the cylinder groups.
sbin/fsck_ffs/fsck.h:
sbin/fsck_ffs/fsutil.c:
Verify and update check hashes when checking and writing cylinder groups.
sbin/fsck_ffs/pass5.c:
Offer to add check hashes to existing filesystems.
Precompute check hashes when rebuilding cylinder group
(although this will be done when it is written in fsutil.c
it is necessary to do it early before comparing with the old
cylinder group)
sbin/dumpfs/dumpfs.c
Print out the new check hash flag(s)
sbin/fsdb/Makefile:
Needs to add libufs now used by pass5.c imported from fsck_ffs.
Reviewed by: kib
Tested by: Peter Holm (pho)
155 lines
4.2 KiB
C
155 lines
4.2 KiB
C
/*
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* Copyright (c) 2002 Juli Mallett. All rights reserved.
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*
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* This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
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* FreeBSD project. Redistribution and use in source and binary forms, with
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* or without modification, are permitted provided that the following
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* conditions are met:
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*
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* 1. Redistribution of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistribution in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef __LIBUFS_H__
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#define __LIBUFS_H__
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/*
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* libufs structures.
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*/
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/*
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* userland ufs disk.
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*/
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struct uufsd {
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const char *d_name; /* disk name */
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int d_ufs; /* decimal UFS version */
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int d_fd; /* raw device file descriptor */
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long d_bsize; /* device bsize */
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ufs2_daddr_t d_sblock; /* superblock location */
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struct csum *d_sbcsum; /* Superblock summary info */
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caddr_t d_inoblock; /* inode block */
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uint32_t d_inomin; /* low inode (not ino_t for ABI compat) */
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uint32_t d_inomax; /* high inode (not ino_t for ABI compat) */
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union {
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struct fs d_fs; /* filesystem information */
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char d_sb[MAXBSIZE];
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/* superblock as buffer */
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} d_sbunion;
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union {
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struct cg d_cg; /* cylinder group */
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char d_buf[MAXBSIZE];
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/* cylinder group storage */
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} d_cgunion;
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int d_ccg; /* current cylinder group */
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int d_lcg; /* last cylinder group (in d_cg) */
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const char *d_error; /* human readable disk error */
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int d_mine; /* internal flags */
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#define d_fs d_sbunion.d_fs
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#define d_sb d_sbunion.d_sb
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#define d_cg d_cgunion.d_cg
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};
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/*
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* libufs macros (internal, non-exported).
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*/
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#ifdef _LIBUFS
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/*
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* Trace steps through libufs, to be used at entry and erroneous return.
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*/
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static inline void
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ERROR(struct uufsd *u, const char *str)
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{
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#ifdef _LIBUFS_DEBUGGING
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if (str != NULL) {
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fprintf(stderr, "libufs: %s", str);
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if (errno != 0)
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fprintf(stderr, ": %s", strerror(errno));
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fprintf(stderr, "\n");
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}
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#endif
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if (u != NULL)
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u->d_error = str;
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}
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#endif /* _LIBUFS */
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__BEGIN_DECLS
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/*
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* libufs prototypes.
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*/
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/*
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* block.c
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*/
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ssize_t bread(struct uufsd *, ufs2_daddr_t, void *, size_t);
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ssize_t bwrite(struct uufsd *, ufs2_daddr_t, const void *, size_t);
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int berase(struct uufsd *, ufs2_daddr_t, ufs2_daddr_t);
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/*
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* cgroup.c
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*/
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ufs2_daddr_t cgballoc(struct uufsd *);
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int cgbfree(struct uufsd *, ufs2_daddr_t, long);
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ino_t cgialloc(struct uufsd *);
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int cgread(struct uufsd *);
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int cgread1(struct uufsd *, int);
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int cgwrite(struct uufsd *);
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int cgwrite1(struct uufsd *, int);
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/*
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* inode.c
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*/
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int getino(struct uufsd *, void **, ino_t, int *);
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int putino(struct uufsd *);
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/*
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* sblock.c
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*/
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int sbread(struct uufsd *);
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int sbwrite(struct uufsd *, int);
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/*
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* type.c
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*/
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int ufs_disk_close(struct uufsd *);
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int ufs_disk_fillout(struct uufsd *, const char *);
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int ufs_disk_fillout_blank(struct uufsd *, const char *);
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int ufs_disk_write(struct uufsd *);
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/*
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* ffs_subr.c
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*/
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void ffs_clrblock(struct fs *, u_char *, ufs1_daddr_t);
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void ffs_clusteracct(struct fs *, struct cg *, ufs1_daddr_t, int);
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void ffs_fragacct(struct fs *, int, int32_t [], int);
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int ffs_isblock(struct fs *, u_char *, ufs1_daddr_t);
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int ffs_isfreeblock(struct fs *, u_char *, ufs1_daddr_t);
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void ffs_setblock(struct fs *, u_char *, ufs1_daddr_t);
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/*
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* crc32c.c
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*/
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uint32_t calculate_crc32c(uint32_t, const void *, size_t);
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__END_DECLS
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#endif /* __LIBUFS_H__ */
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