of the lower level vnode is incremented to greater than 1 when
the upper level vnode's v_usecount is greater than one. This
is necessary for the NFS clients, so that they will do a silly
rename of the file instead of actually removing it when the
file is still in use. It is "racy", since the v_usecount is
incremented in many places in the kernel with
minimal synchronization, but an extraneous silly rename is
preferred to not doing a silly rename when it is required.
The only other file systems that currently check the value
of v_usecount in their VOP_REMOVE() functions are nwfs and
smbfs. These file systems choose to fail a remove when the
v_usecount is greater than 1 and I believe will function
more correctly with this patch, as well.
Tested by: to.my.trociny at gmail.com
Submitted by: to.my.trociny at gmail.com (earlier version)
Reviewed by: kib
MFC after: 2 weeks
vn_open_cred in default implementation. Valid struct ucred is needed for
audit and MAC, and curthread credentials may be wrong.
This further requires modifying the interface of vn_fullpath(9), but it
is out of scope of this change.
Reviewed by: rwatson
This should not really matter for correctness, since vp->v_lock is
not locked before the call, and null_lock() holds the interlock,
but makes the control flow for reclaim more clear.
Tested by: pho
permissions, such as VWRITE_ACL. For a filsystems that don't
implement it, there is a default implementation, which works
as a wrapper around VOP_ACCESS.
Reviewed by: rwatson@
implementation instead. The bypass does not assume that returned vnode
is only held.
Reported by: Paul B. Mahol <onemda gmail com>, pluknet <pluknet gmail com>
Reviewed by: jhb
Tested by: pho, pluknet <pluknet gmail com>
to add more V* constants, and the variables changed by this patch were often
being assigned to mode_t variables, which is 16 bit.
Approved by: rwatson (mentor)
always curthread.
As KPI gets broken by this patch, manpages and __FreeBSD_version will be
updated by further commits.
Tested by: Andrea Barberio <insomniac at slackware dot it>
- Remove the "thread" argument from the lockmgr() function as it is
always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
present
Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h
KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.
Tested by: matteo
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
function calls are no more generated for vop_lock.
Rename _vop_lock to vop_lock1 to satisfy tools/vnode_if.awk assumption
about vop naming conventions. This restores pre/post-condition calls.
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.
Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.
VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.
Approved by: mckusick
Discussed with: many (on IRC)
Tested with: ufs, msdosfs, cd9660, nullfs and zfs
vop_lock_post do not trigger.
- Rearrange null_inactive to null_hashrem earlier so there is no chance
of finding the null node on the hash list after the locks have been
switched.
- We should never have a NULL lowervp in null_reclaim() so there is
no need to handle this situation. panic instead.
MFC After: 1 week
that they set v->v_vnlock. This is true for all filesystems in the
tree.
- Remove all uses of LK_THISLAYER. If the lower layer is locked, the
null layer is locked. We only use vget() to get a reference now.
null essentially does no locking. This fixes LOOKUP_SHARED with
nullfs.
- Remove the special LK_DRAIN considerations, I do not believe this is
needed now as LK_DRAIN doesn't destroy the lower vnode's lock, and
it's hardly used anymore.
- Add one well commented hack to prevent the lowervp from going away
while we're in it's VOP_LOCK routine. This can only happen if we're
forcibly unmounted while some callers are waiting in the lock. In
this case the lowervp could be recycled after we drop our last ref
in null_reclaim(). Prevent this with a vhold().
the filesystem. Check that rather than VI_XLOCK.
- VOP_INACTIVE should no longer drop the vnode lock.
- The vnode lock is required around calls to vrecycle() and vgone().
Sponsored by: Isilon Systems, Inc.
and KASSERT coverage.
After this check there is only one "nasty" cast in this code but there
is a KASSERT to protect against the wrong argument structure behind
that cast.
Un-inlining the meat of VOP_FOO() saves 35kB of text segment on a typical
kernel with no change in performance.
We also now run the checking and tracing on VOP's which have been layered
by nullfs, umapfs, deadfs or unionfs.
Add new (non-inline) VOP_FOO_AP() functions which take a "struct
foo_args" argument and does everything the VOP_FOO() macros
used to do with checks and debugging code.
Add KASSERT to VOP_FOO_AP() check for argument type being
correct.
Slim down VOP_FOO() inline functions to just stuff arguments
into the struct foo_args and call VOP_FOO_AP().
Put function pointer to VOP_FOO_AP() into vop_foo_desc structure
and make VCALL() use it instead of the current offsetoff() hack.
Retire vcall() which implemented the offsetoff()
Make deadfs and unionfs use VOP_FOO_AP() calls instead of
VCALL(), we know which specific call we want already.
Remove unneeded arguments to VCALL() in nullfs and umapfs bypass
functions.
Remove unused vdesc_offset and VOFFSET().
Generally improve style/readability of the generated code.
initializations but we did have lofty goals and big ideals.
Adjust to more contemporary circumstances and gain type checking.
Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.
Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.
Give coda correct prototypes and function definitions for
all vop_()s.
Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.
Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.
Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.
Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.
Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.
Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)
Null_open() was only here to handle MNT_NODEV, but since that does
not affect any filesystems anymore, it could only have any effect
if you nullfs mounted a devfs but didn't want devices to show up.
If you need that, there are easier ways.
