catastrophic recovery. Currently, this mode only validates whether a
cylindergroup has good signature data, and prompts the user to decide
whether to clear it as a whole.
This mode is useful when there is data damage on a disk and you are
working on copy of the original disk, as fsck_ffs(8) tends to abnormally
exit in such case, as a last resort to recover data from the disk.
doing the MNT_RELOAD, pass in "ro" and "update"
string mount options to nmount() instead of MNT_RDONLY and MNT_UPDATE flags.
Due to the complexity of the mount parsing code especially
with respect to the root file system, passing in MNT_RDONLY and MNT_UPDATE
flags would do weird things and would cause fsck to convert the root
file system from a read-only mount to read-write.
To test:
- boot into single user mode
- show mounted file systems with: mount
- root file system should be mounted read-only
- fsck /
- show mounted file systems with: mount
- root file system should still be mounted read-only
PR: 120319
MFC after: 1 month
Reported by: yar
number read from cylinder group. Chances that we read a smarshed
cylinder group, and we can not 100% trust information it has
supplied. fsck_ffs(8) will crash otherwise for some cases.
processing the information. chk1 is more prone to crash when insane
information is provided by the on-disk inode, and does not even work
if the inode is being smarshed badly.
whether fs_bsize is larger than MINBSIZE, which is larger than the
value that is used to compared with fs_bsize, the sizeof fs, so the
check followed, will be always true.
By inspecting the code and some old commit log, I believe that the
check must be that *fs_sbsize* is larger than sizeof fs. We round
up the size to nearest dev_bsize, as the smallest accepted fs_sbsize,
personally, I think this can be even changed to equal, because this
number is mostly an invariant in file systems.
With this check, fsck_ffs(8) will be more picky and has better
chance rejecting bad first superblock rather than referring to bad
value it supplied, thus gives better chance for it to check the
filesystem carefully.
read-only, so we can't simply exit right after calling gjournal_check(),
instead we need to ask about super block reload.
Submitted by: Niki Denev <niki@totalterror.net>
PR: misc/113889
Approved by: re (kensmith)
and -p flag was given perform fast file system checking (bascially only
garbage collecting of orphaned objects).
Rename bread() to blread() and bwrite() to blwrite() as we now link to
the libufs library, which also implement functions with that names.
Sponsored by: home.pl
initializing the sysctl mibs data before actually using them.
The original patchset (which is the actual version that is running
on my testboxes) have checked whether all of these sysctls and
refuses to do background fsck if we don't have them. Kirk has
pointed out that refusing running fsck on old kernels is pointless,
as old kernels will recompute the summary at mount time, so I
have removed these checks.
Unfortunatelly, as the checks will initialize the mib values of
those sysctl's, and which are vital for the runtime summary
adjustment to work, we can not simply remove the check, which
will lead to problem when running background fsck over a dirty
volume. Add these checks in a different way: give a warning rather
than refusing to work, and complain if the functionality is not
available when adjustments are necessary.
Noticed by: A power failure at my lab
Pointy hat: me
MFC After: 3 days
very slow process, especially for large file systems that is just
recovered from a crash.
Since the summary is already re-sync'ed every 30 second, we will
not lag behind too much after a crash. With this consideration
in mind, it is more reasonable to transfer the responsibility to
background fsck, to reduce the delay after a crash.
Add a new sysctl variable, vfs.ffs.compute_summary_at_mount, to
control this behavior. When set to nonzero, we will get the
"old" behavior, that the summary is computed immediately at mount
time.
Add five new sysctl variables to adjust ndir, nbfree, nifree,
nffree and numclusters respectively. Teach fsck_ffs about these
API, however, intentionally not to check the existence, since
kernels without these sysctls must have recomputed the summary
and hence no adjustments are necessary.
This change has eliminated the usual tens of minutes of delay of
mounting large dirty volumes.
Reviewed by: mckusick
MFC After: 1 week
count of zero and instead encode this information in the inode state.
Pass 4 performed a linear search of this list for each inode in
the file system, which performs poorly if the list is long.
Reviewed by: sam & keramida (an earlier version of the patch), mckusick
MFC after: 1 month
has only been partly initialized via newfs(8) so that it applies to both
UFS1 and UFS2.
Submitted by: "Xin LI" delphij at frontfree dot net
MFC: maybe?
shuffles the timing and sleep calls in bgfsck from:
sleep timer_on io timer_off io io io io io io io
to
sleep io io io io io io io timer_on io timer_off
The original method basically guaranteed that the timed I/O included a
disk seek every time, which made bgfsck sleep for much longer than
necessary.
Submitted by: Dan Nelson
Reviewed by: kirk
original intention of the less restrictive permissions was to allow
users to move or delete recovered files that they own. However, it
is better to not create world-writable directories by default; the
administrator can always pre-create lost+found if different permissions
are desired.
Reviewed by: mckusick
filesystem that is checked in background. Create the snapshot in this
directory rather than in the root. There are two benefits:
1) For terabyte-sized filesystems, the snapshot may require many
minutes to build. Although the filesystem will not be suspended
during most of the snapshot build, the snapshot file itself is
locked during the entire snapshot build period. Thus, if it is
accessed during the period that it is being built, the process
trying to access it will block holding its containing directory
locked. If the snapshot is in the root, the root will lock and
the system will come to a halt until the snapshot finishes. By
putting the snapshot in a subdirectory, it is out of the likely
path of any process traversing through the root and hence much
less likely to cause a lock race to the root.
2) The dump program is usually run by a non-root user running with
operator group privilege. Such a user is typically not permitted
to create files in the root of a filesystem. By having a directory
in group operator with group write access available, such a user
will be able to create a snapshot there. Having the dump program
create its snapshot in a subdirectory below the root will benefit
from point (1) as well.
Sponsored by: DARPA & NAI Labs.
bandwidth for other processes. Since the sleeping is done from
userland, this avoids the locking issues that affected the kernel
version.
The algorithm used here is to measure a moving average of the times
taken by a sample of read operations and then delay 1 in 8 reads
by 16 times the measured average. This should correspond to a factor
of 3 slowdown, but in practice the factor is larger (3.5 to 4) due
to hz rounding effects.
Reviewed by: mckusick
Approved by: re
trying to use them. Set a minimum value for numdirs when using an
alternate superblock to avoid spurious numdirs == 0 error. Calculate
new fields when using an alternate superblock from a UFS1 filesystem
to avoid segment faulting.
Sponsored by: DARPA & NAI Labs.
the old 8-bit fs_old_flags to the new location the first time that the
filesystem is mounted by a new kernel. One of the unused flags in
fs_old_flags is used to indicate that the flags have been moved.
Leave the fs_old_flags word intact so that it will work properly if
used on an old kernel.
Change the fs_sblockloc superblock location field to be in units
of bytes instead of in units of filesystem fragments. The old units
did not work properly when the fragment size exceeeded the superblock
size (8192). Update old fs_sblockloc values at the same time that
the flags are moved.
Suggested by: BOUWSMA Barry <freebsd-misuser@netscum.dyndns.dk>
Sponsored by: DARPA & NAI Labs.
It seems a common corruption to have them -ve (I've seen it several times)
and if fsck doesn't fix it, it leads to a kernel pagefault.
Reviewd by: kirk
Submitted by: Eric Jacobs <eaja@erols.com> and me independently.
MFC in: 2 days
PR: bin/40967
Approved by: re
