superblock that is already set up to handle pointer types. This
fixes an accidental change in the superblock size on 64-bit platforms
caused by revision 1.24.
when taking a snapshot. The two time consuming operations are
scanning all the filesystem bitmaps to determine which blocks
are in use and scanning all the other snapshots so as to be able
to expunge their blocks from the view of the current snapshot.
The bitmap scanning is broken into two passes. Before suspending
the filesystem all bitmaps are scanned. After the suspension,
those bitmaps that changed after being scanned the first time
are rescanned. Typically there are few bitmaps that need to be
rescanned. The expunging of other snapshots is now done after
the suspension is released by observing that we can easily
identify any blocks that were allocated to them after the
suspension (they will be maked as `not needing to be copied'
in the just created snapshot). For all the gory details, see
the ``Running fsck in the Background'' paper in the Usenix
BSDCon 2002 Conference Proceedings, pages 55-64.
new file end will land in the middle of a file hole. Since the last
block of a file must always be allocated, the hole is filled by
allocating a block at that location. If the hole being filled is
a direct block, then the truncation may eventually reduce the
full sized block down to a fragment. When running with soft
updates, it is necessary to FSYNC the file after allocating the
block and before creating the fragment to avoid triggering a
soft updates inconsistency when the block unexpectedly shrinks.
Found by: Matthew Dillon <dillon@apollo.backplane.com>
MFC after: 1 week
compare the slot offset against the predicted offset, not a boolean
flag. This typo effectively disabled the sequential optimisation,
but was otherwise harmless.
Not surprisingly, fixing this improves performance in the sequential
access case. I am seeing a 7% speedup on one machine here; using
dirhash when sequentially looking up directory entries is now about
5% faster instead of 2% slower than the non-dirhash case.
Submitted by: KOIE Hidetaka <koie@suri.co.jp>
MFC after: 1 week
in wdrain during a write. This flag needs to be used in devices whos
strategy routines turn-around and issue another high level I/O, such as
when MD turns around and issues a VOP_WRITE to vnode backing store, in order
to avoid deadlocking the dirty buffer draining code.
Remove a vprintf() warning from MD when the backing vnode is found to be
in-use. The syncer of buf_daemon could be flushing the backing vnode at
the time of an MD operation so the warning is not correct.
MFC after: 1 week
o Add reference to TrustedBSD Project in license header.
o Update dated comments, including comment in extattr.h claiming that
no file systems support extended attributes.
o Improve comment consistency.
coerces the deletion of a default ACL on a directory when no default
ACL EA is present to success. Because the UFS EA implementation doesn't
disinguish the EA failure modes "that EA name has not been
administratively enabled" from "that EA name has no defined data",
there's a potential conflict in error return values. Normally, the
lack of administratively configured EA support is coerced to
EOPNOTSUPP to indicate that ACLs are not available; in this case,
it is possible to get a successful return, even if ACLs are not
available because EA support for them has not been enabled.
Expand the comment in ufs_setacl() to identify this case.
Obtained from: TrustedBSD Project
from ufs_extattr_enable_with_open().
o Print auto-start notifications if (bootverbose). This was previously
commented out since it didn't know how to check for bootverbose.
o Drop in comments throughout indicating where ENOENT should be replaced
with ENOATTR once that is available.
Obtained from: TrustedBSD Project
implementation to replace single-character namespace prefixes, '$' is no
longer an invalid attribute name, and the namespace is relevant to
validity determination.
o Remove '$' case from ufs_extattr_valid_attrname()
o Add attrnamespace argument to ufs_extattr_valid_attrname(), and
fill out appropriately.
Currently no decisions are made based on the namespace argument, but
may be in the future.
Obtained from: TrustedBSD Project
real effect.
Optimize vfs_msync(). Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list. Improves looping case by 500%.
Optimize ffs_sync(). Avoid having to continually drop and re-obtain
mutexes when scanning the vnode list. This makes a couple of assumptions,
which I believe are ok, in regards to vnode stability when the mount list
mutex is held. Improves looping case by 500%.
(more optimization work is needed on top of these fixes)
MFC after: 1 week
sanity check after every directory modification. This check can be
re-enabled at any time by setting the sysctl "vfs.ufs.dirhash_docheck"
to 1.
This group of sanity tests was there to ensure that any UFS_DIRHASH
bugs could be caught by a panic before a potentially corrupted
directory block would be written to disk. It has served its main
purpose now, so disable it in the interest of performance.
MFC after: 1 week
- crhold() returns a reference to the ucred whose refcount it bumps.
- crcopy() now simply copies the credentials from one credential to
another and has no return value.
- a new crshared() primitive is added which returns true if a ucred's
refcount is > 1 and false (0) otherwise.
because the IN_RENAME flag only fixes a few of the huge number of race
conditions that can result in the source path becoming invalid even
prior to the VOP_RENAME() call. The panics created a serious security
issue whereby an attacker could fairly easily cause the panic to
occur, crashing the machine.
The correct solution requires a great deal of work in the namei
path cache code.
MFC after: 0 days
first thought and may require serious work to the VOP_RENAME() api itself.
Basically, by the time the VOP_RENAME() function is called, it's already
too late.
- Move the SPECIAL_FLAG #define up next to the NOHOLDER #define and fix a
little nit that caused it to be defined as -(sizeof (struct thread) + 1)
instead of -2.
PRISON_ROOT to the suser_xxx() check. Since securelevels may now
be raised in specific jails, use of system flags can still be
restricted in jail(), but in a more configurable way.
o Users of jail() expecting system flags (such as schg) to restrict
jail()'s should be sure to set the securelevel appropriately in
jail()'s.
o This fixes activities involving automated system flag removal in
jail(), including installkernel and friends.
Obtained from: TrustedBSD Project
refering to securelevels; also, update the unprivileged process text
to better indicate the scope of actions permittable when any system
flags are already set (limited).
Submitted by: Udo Schweigert <udo.schweigert@siemens.com>
sizeof(struct inode) into a new malloc bucket on the i386. This
didn't happen in -current due to the removal of i_lock, but it does
no harm to apply the workaround to -current first.
Reduce the size of the i_spare[] array in struct inode from 4 to
3 entries, and change ext2fs to use i_din.di_spare[1] so that it
does not need i_spare[3].
Reviewed by: bde
MFC after: 3 days
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
an array "fs_contigdirs[]" to avoid too many directories getting
created in each cylinder group. The memory required for this and
two other arrays (fs_csp[] and fs_maxcluster[]) is allocated with
a single malloc() call, and divided up afterwards. However, the
'space' pointer is not advanced correctly, so fs_contigdirs and
fs_maxcluster end up pointing to the same address.
Add the missing code to advance the 'space' pointer, and remove
an unnecessary update of the pointer that follows.
This is likely to fix the "ffs_clusteralloc: map mismatch" panics
that have been reported recently.
Submitted by: Luke Mewburn <lukem@wasabisystems.com>
in got a bit broken, when ufs_extattr_stop() was called and failed,
ufs_extattr_destroy() would panic. This makes the call to destroy()
conditional on the success of stop().
Submitted by: Christian Carstensen <cc@devcon.net>
Obtained from: TrustedBSD Project
file. ffs will discard any pending dirty pages when it is closed,
so we may as well not waste time trying to clean them. This doesn't
stop other things from writing it out, eg: pageout, fsync(2) etc.
never attempt to hash directories once they are deleted. This fixes
a problem where operations on a deleted directory could trigger
dirhash sanity panics.
to supply the number of bytes to be bcopy()'d to move an entry. If
d_ino == 0 however, DIRSIZ() is not guaranteed to return a sensible
length, so ufs_direnter could end up corrupting a directory during
compaction. In practice I believe this can only happen after fsck_ffs
has fixed a previously-corrupted directory.
We now deal with any mid-block unused entries specially to avoid
using DIRSIZ() or bcopy() on such entries. We also ensure that the
variables 'dsize' and 'spacefree' contain meaningful values at all
times. Add a few comments to describe better this intricate piece
of code.
The special handling of mid-block unused entries makes the dirhash-
specific bugfix in the previous revision (1.53) now uncecessary,
so this change removes it.
Reviewed by: mckusick
that the directory entry was in use before attempting to find it
in the hash structures to change its offset. Normally, unused
entries do not need to be moved, but fsck can leave behind some
unused entries that do. A dirhash sanity panic resulted when the
entry to be moved was not found. Add a check that stops entries
with d_ino == 0 from being passed to ufsdirhash_move().
because it shares ufs code. In ufs_fhtovp(), the test on i_effnlink
is invalid because ext2fs does not maintain this field. In ufs_close(),
i_effnlink is also tested, to determines whether or not to call
vn_start_write(). The ufs_fhtovp issue breaks NFS exporting of
ext2fs filesystems; I believe the other is harmless.
Fix both cases by checking um_i_effnlink_valid in the ufsmount
struct, and use i_nlink if necessary.
Noticed by: bde
Reviewed by: mckusick, bde
entry (d_ino == 0) is found in a position that is not the start of
a DIRBLKSIZ block.
While such entries cannot occur normally (ufs always extends the
previous entry to cover the free space instead), they do not cause
problems and fsck does not fix them, so panicking is bad.
extra getblk/brelse sequence for each lookup. We already had this
buf in ufsdirhash_lookup(), so there was no point in brelse'ing it
only to have the caller immediately reaquire the same buffer.
This should make the case of sequential lookups marginally faster;
in my tests, sequential lookups with dirhash enabled are now only
around 1% slower than without dirhash.
directories. When enabled via "options UFS_DIRHASH", in-core hash
arrays are maintained for large directories. These allow all
directory operations to take place quickly instead of requiring
long linear searches. For now anyway, dirhash is not enabled by
default.
The in-core hash arrays have a memory requirement that is approximately
half the size of the size of the on-disk directory file. A number
of new sysctl variables allow control over which directories get
hashed and over the maximum amount of memory that dirhash will use:
vfs.ufs.dirhash_minsize
The minimum on-disk directory size for which hashing should be
used. The default is 2560 (2.5k).
vfs.ufs.dirhash_maxmem
The system-wide maximum total memory to be used by dirhash data
structures. The default is 2097152 (2MB).
The current amount of memory being used by dirhash is visible
through the read-only sysctl variable vfs.ufs.dirhash_maxmem.
Finally, some extra sanity checks that are enabled by default, but
which may have an impact on performance, can be disabled by setting
vfs.ufs.dirhash_docheck to 0.
Discussed on: -fs, -hackers
(this commit is just the first stage). Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
