bail out if the buffer is not already present.
- The buffer returned by incore() is not locked and should not be sent to
brelse(). Use getblk() with the new GB_NOCREAT flag to preserve the
desired semantics.
caller to acquire it. This permits drain_output() to be done atomically
with other operations as well as reducing the number of lock operations.
- Assert that the proper locks are held in drain_output().
- Change getdirtybuf() to accept a mutex as an argument. This mutex is used
to protect the vnode's buf list and the BKGRDWAIT flag. This lock is
dropped when we successfully acquire a buffer and held on return
otherwise. These semantics reduce the number of cumbersome cases in
calling code.
- Pass the mtx from getdirtybuf() into interlocked_sleep() and allow this
mutex to be used as the interlock argument to BUF_LOCK() in the LOCKBUF
case of interlocked_sleep().
- Change the return value of getdirtybuf() to be the resulting locked buffer
or NULL otherwise. This is for callers who pass in a list head that
requires a lock. It is necessary since the lock that protects the list
head must be dropped in getdirtybuf() so that we don't have a lock order
reversal with the buf queues lock in bremfree().
- Adjust all callers of getdirtybuf() to match the new semantics.
- Add a comment in indir_trunc() that points at unlocked access to a buf.
This may also be one of the last instances of incore() in the tree.
- Surround all accesses of the BKGRD{WAIT,INPROG} flags with the vnode
interlock.
- Don't use the B_LOCKED flag and QUEUE_LOCKED for background write
buffers. Check for the BKGRDINPROG flag before recycling or throwing
away a buffer. We do this instead because it is not safe for us to move
the original buffer to a new queue from the callback on the background
write buffer.
- Remove the B_LOCKED flag and the locked buffer queue. They are no longer
used.
- The vnode interlock is used around checks for BKGRDINPROG where it may
not be strictly necessary. If we hold the buf lock the a back-ground
write will not be started without our knowledge, one may only be
completed while we're not looking. Rather than remove the code, Document
two of the places where this extra locking is done. A pass should be
done to verify and minimize the locking later.
get the same value from ip->i_ump->um_devvp.
This saves a pointer in the memory copies of inodes, which can
easily run into several hundred kilobytes.
The extra indirection is unmeasurable in benchmarks.
Approved by: mckusick
generate the inode mode from a default ACL and creation mask,
implement ufs_sync_inode_from_acl() using acl_posix1e_newfilemode().
Since ACL_OVERRIDE_MASK/ACL_PRESERVE_MASK are defined, we no
longer need to explicitly pass in a "preserve_mask" field: this
is implicit in the use of POSIX.1e semantics.
Note: this change contains a semantic bugfix for new file creation:
we now intersect the ACL-generated mode and the cmode requested by
the user process. This means permissions on newly created file
objects will now be more conservative. In the future, we may want
to provide alternative semantics (similar to Solaris and Linux) in
which the ACL mask overrides the umask, permitting ACLs to broaden
the rights beyond the requested umask.
PR: 50148
Reported by: Ritz, Bruno <bruno_ritz@gmx.ch>
Obtained from: TrustedBSD Project
cases:
- Setting sticky bit on non-directory
- Setting setgid on a file with a group that isn't in the effective
or extended groups of the authorizing credential
I.e., test the requirement first, then do the privilege test,
rather than doing the privilege test regardless of the need for
privilege.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
kernel ACL interfaces and system call names.
Break out UFS2 and FFS extattr delete and list vnode operations from
setextattr and getextattr to deleteextattr and listextattr, which
cleans up the implementations, and makes the results more readable,
and makes the APIs more clear.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
contain the filedescriptor number on opens from userland.
The index is used rather than a "struct file *" since it conveys a bit
more information, which may be useful to in particular fdescfs and /dev/fd/*
For now pass -1 all over the place.
UFS quota implementation. Push some quite broken access control
logic out of ufs_quotactl() into the individual command
implementations in ufs_quota.c; fix that logic. Pass in the thread
argument to any quotactl command that will need to perform access
control.
o quotaon() requires privilege (PRISON_ROOT).
o quotaoff() requires privilege (PRISON_ROOT).
o getquota() requires that:
If the type is USRQUOTA, either the effective uid match the
requested quota ID, that the unprivileged_get_quota flag be
set, or that the thread be privileged (PRISON_ROOT).
If the type is GRPQUOTA, require that either the thread be
a member of the group represented by the requested quota ID,
that the unprivileged_get_quota flag be set, or that the
thread be privileged (PRISON_ROOT).
o setquota() requires privilege (PRISON_ROOT).
o setuse() requires privilege (PRISON_ROOT).
o qsync() requires no special privilege (consistent with what
was present before, but probably not very useful).
Add a new sysctl, security.bsd.unprivileged_get_quota, which when
set to a non-zero value, will permit unprivileged users to query user
quotas with non-matching uids and gids. Set this to 0 by default
to be mostly consistent with the previous behavior (the same for
USRQUOTA, but not for GRPQUOTA).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
attribute name of "" from ffs_getextattr(). Invoking VOP_GETETATTR()
with an empty name is now no longer supported; user application
compatibility is provided by a system call level compatibility
wrapper. We make sure to explicitly reject attempts to set an EA
with the name "".
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
extended attribute retrieval code: it's no longer special-cased,
and is caught by the normal UFS1 EA validity checks (and, in
fact, returns the same error, EINVAL).
Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories
if we permit them to occur, the kernel panics due to our performing
EA operations using VOP_STRATEGY on the vnode. This went unnoticed
previously because there are very for users of device nodes on UFS2
due to the introduction of devfs. However, this can come up with
the Linux compat directories and its hard-coded dev nodes (which will
need to go away as we move away from hard-coded device numbers).
This can come up if you use EA-intensive features such as ACLs and
MAC.
The proper fix is pretty complicated, but this band-aid would be
an excellent MFC candidate for the release.
only while holding appropriate vnode locks. This patch slides the lock
release for ufs_extattr_enable() to continue to hold the active vnode lock
on a backing file until after the flag change; it also acquires a vnode
lock when disabling an attribute and hence clearing a flag on the backing
vnode. This permits VFS_DEBUG_LOCKS to run UFS1 extended attributes
without panicking, as well as preventing a potential race and vnode flag
problem.
Approved by: re (jhb)
Pointed out by: DEBUG_VFS_LOCKS
These fields can be left as NULL if ffs_vget() allocates an inode but
fails before the dinode memory has been allocated. There are two cases
when this can occur: when we lose a race and another process has added
the inode to the hash, and when reading the inode off disk fails.
The bug was observed by Kris on one of the package-building machines.
See http://marc.theaimsgroup.com/?l=freebsd-current&m=105172731013411&w=2
In Kris's case, it was the bread() that failed because of a disk error.
The alternative to this patch is to ensure that ffs_vget() does not call
vput() when the inode that hasn't been properly initialised.
kg_nice is now protected by both. Being protected by both means that
other places in the kernel that want to read kg_nice only need one of the
two locks.
requiring locked bufs in vfs_bio_awrite(). Previously the buf could
have been written out by fsync before we acquired the buf lock if it
weren't for giant. The cluster_wbuild() handles this race properly but
the single write at the end of vfs_bio_awrite() would not.
- Modify flushbufqueues() so there is only one copy of the loop. Pass a
parameter in that says whether or not we should sync bufs with deps.
- Call flushbufqueues() a second time and then break if we couldn't find
any bufs without deps.
of a snapshot's copy of a superblock. This patch fixes a panic
when taking a snapshot of a 4096/512 filesystem.
Reported by: Ian Freislich <ianf@za.uu.net>
Sponsored by: DARPA & NAI Labs.
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
flag to the initial BUF_LOCK(). This will eventually be used in cases
were we want to use a buffer only if it is not currently in use.
- Convert all consumers of the getblk() api to use this extra parameter.
Reviwed by: arch
Not objected to by: mckusick
Remove extraneous uses of vop_null, instead defering to the default op.
Rename vnode type "vfs" to the more descriptive "syncer".
Fix formatting for various filesystems that use vop_print.
from the filesystem size field to the filesystem maximum blocksize
field. The problem is that older versions of growfs updated only the
new size field and not the old size field. This resulted in the old
(smaller) size field being copied up to the new size field which
caused the filesystem to appear to fsck to be badly trashed.
This also adds a sanity check to ensure that the superblock is not
being updated when the filesystem is mounted read-only. Obviously
such an update should never happen.
Reported by: Nate Lawson <nate@root.org>
Sponsored by: DARPA & NAI Labs.
- Remove the buftimelock mutex and acquire the buf's interlock to protect
these fields instead.
- Hold the vnode interlock while locking bufs on the clean/dirty queues.
This reduces some cases from one BUF_LOCK with a LK_NOWAIT and another
BUF_LOCK with a LK_TIMEFAIL to a single lock.
Reviewed by: arch, mckusick
