(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.
The symptom being treated in 1.98 was to avoid freeing a
pagedep dependency if there was still a newdirblk dependency
referencing it. That change is correct and no longer prints
a warning message when it occurs. The other part of revision
1.98 was to panic when a newdirblk dependency was encountered
during a file truncation. This fix removes that panic and
replaces it with code to find and delete the newdirblk
dependency so that the truncation can succeed.
true. This permits better interoperability with programs which register
filters on their stdin/stdout handles.
Submitted by: Niels Provos <provos@citi.umich.edu>
incorrect due to a missing check for some dependency. This change
avoids the freelist corruption (but not the temporarily inconsistent
state of the file system).
A message is printed as a reminder of the under lying problem when a
pagedep structure is not freed due to the NEWBLOCK flag being set.
Submitted by: Tor.Egge@fast.no
initialized on the file system before trying to grab the lock of the
per-mount extattr structure, as this lock is unitialized in that case.
This is needed because ufs_extattr_vnode_inactive is called from
ufs_inactive, which is also used by EA-unaware file systems such as
ext2fs.
Reviewed by: rwatson
real uid, saved uid, real gid, and saved gid to ucred, as well as the
pcred->pc_uidinfo, which was associated with the real uid, only rename
it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
original macro that pointed.
p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
we figure out locking and optimizations; generally speaking, this
means moving to a structure like this:
newcred = crdup(oldcred);
...
p->p_ucred = newcred;
crfree(oldcred);
It's not race-free, but better than nothing. There are also races
in sys_process.c, all inter-process authorization, fork, exec, and
exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
allocation.
o Clean up ktrcanset() to take into account changes, and move to using
suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
calls to better document current behavior. In a couple of places,
current behavior is a little questionable and we need to check
POSIX.1 to make sure it's "right". More commenting work still
remains to be done.
o Update credential management calls, such as crfree(), to take into
account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
change_euid()
change_egid()
change_ruid()
change_rgid()
change_svuid()
change_svgid()
In each case, the call now acts on a credential not a process, and as
such no longer requires more complicated process locking/etc. They
now assume the caller will do any necessary allocation of an
exclusive credential reference. Each is commented to document its
reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
processes and pcreds. Note that this authorization, as well as
CANSIGIO(), needs to be updated to use the p_cansignal() and
p_cansched() centralized authorization routines, as they currently
do not take into account some desirable restrictions that are handled
by the centralized routines, as well as being inconsistent with other
similar authorization instances.
o Update libkvm to take these changes into account.
Obtained from: TrustedBSD Project
Reviewed by: green, bde, jhb, freebsd-arch, freebsd-audit
Tor created a while ago, removes the raw I/O piece (that has cache coherency
problems), and adds a buffer cache / VM freeing piece.
Essentially this patch causes O_DIRECT I/O to not be left in the cache, but
does not prevent it from going through the cache, hence the 80%. For
the last 20% we need a method by which the I/O can be issued directly to
buffer supplied by the user process and bypass the buffer cache entirely,
but still maintain cache coherency.
I also have the code working under -stable but the changes made to sys/file.h
may not be MFCable, so an MFC is not on the table yet.
Submitted by: tegge, dillon
systems were repo-copied from sys/miscfs to sys/fs.
- Renamed the following file systems and their modules:
fdesc -> fdescfs, portal -> portalfs, union -> unionfs.
- Renamed corresponding kernel options:
FDESC -> FDESCFS, PORTAL -> PORTALFS, UNION -> UNIONFS.
- Install header files for the above file systems.
- Removed bogus -I${.CURDIR}/../../sys CFLAGS from userland
Makefiles.
committed to disk before clearing them. More specifically, when
free_newdirblk is called, we know that the inode claims the new
directory block. However, if the associated pagedep is still linked
onto the directory buffer dependency chain, then some of the entries
on the pd_pendinghd list may not be committed to disk yet. In this
case, we will simply note that the inode claims the block and let
the pd_pendinghd list be processed when the pagedep is next written.
If the pagedep is no longer on the buffer dependency chain, then
all the entries on the pd_pending list are committed to disk and
we can free them in free_newdirblk. This corrects a window of
vulnerability introduced in the code added in version 1.95.
vm_mtx does not recurse and is required for most low level
vm operations.
faults can not be taken without holding Giant.
Memory subsystems can now call the base page allocators safely.
Almost all atomic ops were removed as they are covered under the
vm mutex.
Alpha and ia64 now need to catch up to i386's trap handlers.
FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).
Reviewed (partially) by: jake, jhb
whose name is within that block must ensure not only that the block
containing the file name has been written, but also that the on-disk
directory inode references that block. When a new directory block
is created, we allocate a newdirblk structure which is linked to
the associated allocdirect (on its ad_newdirblk list). When the
allocdirect has been satisfied, the newdirblk structure is moved
to the inodedep id_bufwait list of its directory to await the inode
being written. When the inode is written, the directory entries
are fully committed and can be deleted from their pagedep->id_pendinghd
and inodedep->id_pendinghd lists.
the number of references on the filesystem root vnode to be both
expected and released. Many filesystems hold an extra reference on
the filesystem root vnode, which must be accounted for when
determining if the filesystem is busy and then released if it isn't
busy. The old `skipvp' approach required individual filesystem
xxx_unmount functions to re-implement much of vflush()'s logic to
deal with the root vnode.
All 9 filesystems that hold an extra reference on the root vnode
got the logic wrong in the case of forced unmounts, so `umount -f'
would always fail if there were any extra root vnode references.
Fix this issue centrally in vflush(), now that we can.
This commit also fixes a vnode reference leak in devfs, which could
result in idle devfs filesystems that refuse to unmount.
Reviewed by: phk, bp
comes in for it, the file is really gone, so return ESTALE.
The problem arises when the last reference to an FFS file is
released because soft-updates may delay the actual freeing of the
inode for some time. Since there are no filesystem links or open
file descriptors referencing the inode, from the point of view of
the system, the file is inaccessible. However, if the filesystem
is NFS exported, then the remote client can still access the inode
via ufs_fhtovp() until the inode really goes away. To prevent this
anomoly, it is necessary to begin returning ESTALE at the same time
that the file ceases to be accessible to the local filesystem.
Obtained from: Ian Dowse <iedowse@maths.tcd.ie>
that are committed to being freed and reflect these blocks in the
counts returned by statfs (and thus also by the `df' command). This
change allows programs such as those that do news expiration to
know when to stop if they are trying to create a certain percentage
of free space. Note that this change does not solve the much harder
problem of making this to-be-freed space available to applications
that want it (thus on a nearly full filesystem, you may still
encounter out-of-space conditions even though the free space will
show up eventually). Hopefully this harder problem will be the
subject of a future enhancement.
1) Do not assume that the superblock will be of size fs->fs_bsize.
This fixes a panic when taking a snapshot on a filesystem with
a block size bigger than 8K.
2) Properly calculate the number of fragments that follow the
superblock summary information. This fixes a bug with inconsistent
snapshots.
3) When cleaning up a snapshot that is about to be removed, properly
calculate the number of blocks that need to be checked. This fixes
a bug that created partially allocated inodes.
4) When moving blocks from a snapshot that is about to be removed
to another snapshot, properly account for the reduced number of
blocks in the snapshot from which they are taken. This fixes a
bug in which the number of blocks released from a snapshot did not
match the number that it claimed to have.
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
Make 7 filesystems which don't really know about VOP_BMAP rely
on the default vector, rather than more or less complete local
vop_nopbmap() implementations.
by the inactive routine. Because the freeing causes the filesystem
to be modified, the close must be held up during periods when the
filesystem is suspended.
For snapshots to be consistent across crashes, they must write
blocks that they copy and claim those written blocks in their
on-disk block pointers before the old blocks that they referenced
can be allowed to be written.
Close a loophole that allowed unwritten blocks to be skipped when
doing ffs_sync with a request to wait for all I/O activity to be
completed.
to struct mount.
This makes the "struct netexport *" paramter to the vfs_export
and vfs_checkexport interface unneeded.
Consequently that all non-stacking filesystems can use
vfs_stdcheckexp().
At the same time, make it a pointer to a struct netexport
in struct mount, so that we can remove the bogus AF_MAX
and #include <net/radix.h> from <sys/mount.h>
fs_contigdirs, fs_avgfilesize and fs_avgfpdir. This could cause
panics if these fields were zeroed while a filesystem was mounted
read-only, and then remounted read-write.
Add code to ffs_reload() which copies the fs_contigdirs pointer
from the previous superblock, and reinitialises fs_avgf* if necessary.
Reviewed by: mckusick
VOP_BWRITE() was a hack which made it possible for NFS client
side to use struct buf with non-bio backing.
This patch takes a more general approach and adds a bp->b_op
vector where more methods can be added.
The success of this patch depends on bp->b_op being initialized
all relevant places for some value of "relevant" which is not
easy to determine. For now the buffers have grown a b_magic
element which will make such issues a tiny bit easier to debug.
sized blocks. To enable this option, use: `sysctl -w debug.bigcgs=1'.
Add debugging option to disable background writes of cylinder
groups. To enable this option, use: `sysctl -w debug.dobkgrdwrite=0'.
These debugging options should be tried on systems that are panicing
with corrupted cylinder group maps to see if it makes the problem
go away. The set of panics in question are:
ffs_clusteralloc: map mismatch
ffs_nodealloccg: map corrupted
ffs_nodealloccg: block not in map
ffs_alloccg: map corrupted
ffs_alloccg: block not in map
ffs_alloccgblk: cyl groups corrupted
ffs_alloccgblk: can't find blk in cyl
ffs_checkblk: partially free fragment
The following panics are less likely to be related to this problem,
but might be helped by these debugging options:
ffs_valloc: dup alloc
ffs_blkfree: freeing free block
ffs_blkfree: freeing free frag
ffs_vfree: freeing free inode
If you try these options, please report whether they helped reduce your
bitmap corruption panics to Kirk McKusick at <mckusick@mckusick.com>
and to Matt Dillon <dillon@earth.backplane.com>.
