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)
variants. This allows usable file system images (i.e. those with both a
shell and an editor) to be created with only one copy of the curses library.
Exp-run: antoine
PR: 189842
Discussed with: bapt
Sponsored by: DARPA, AFRL
and fixing the format string in sbin/fsdb/fsdbutil.c instead.
Note the remark "Work around a problem with format string warnings and
ntohs macros" was actually incorrect. The DIP(dp, di_nlink) macro
invocation actually returned an int, due to its ternary expression, even
though the di_nlink members of struct ufs1_dinode and struct ufs2_dinode
are both defined as int16_t.
MFC after: 2 weeks
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.
Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)
As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:
CC=clang
CXX=clang++
CPP=clang-cpp
MFC after: 2 weeks
- #include <timeconv.h> for _time_to_time32 et al
- use (uintmax_t) and %j
- remove unused variable 'j' (from PR 39866)
PR: 39866
Submitted by: Dan Lukes <dan@obluda.cz>
Tested by: make universe
Approved by: rwatson
Obtained from: NetBSD source tree
Second part of the fsck wrappers commit. This commit enables the new fsck
code (removing the fsck/* code and replacing it with the netbsd fsck
wrapper code), and enabling some FFS-based utilities to compile.
Details:
* quotacheck, fsdb required modification to use the fsck_ffs/ code rather
than fsck/ . This might change later since quotacheck requires preen.c
which should exist in fsck/ rather than fsck_ffs/
* src/Makefile has fsck_ffs added to it so it it built as part of the tree
now
* share/doc/smm/03.fsck/ uses the SMM.doc/ stuff from fsck_ffs, not fsck.
I've tested this, and it shouldn't require any changes on your machine.
The fsck wrapper reads /etc/fsck and is command-line-compatible enough
to not require rc changes (well, most changes unless you want to do
anything nifty by specifying the fs types explicityly, read the man page
if you want further details on what it can do.)
This now allows us to support multiple filesystem types during bootup.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
