The big lines are:
NODEV -> NULL
NOUDEV -> NODEV
udev_t -> dev_t
udev2dev() -> findcdev()
Various minor adjustments including handling of userland access to kernel
space struct cdev etc.
1. Root from inside a jail was able to unmount any file system
(except /).
2. Unprivileged root was able to unmount file systems mounted by
privileged root (execpt /).
3. User from inside a jail was able to mount file system when
sysctl vfs.usermount was set to 1.
4. User was able to mount file system when vfs.usermount was set to 1
(that's ok) and unmount it even if vfs.usermount was equal to 0
(that's not correct).
Possibility from point 1 was reported by: Dariusz Kowalski <darek@76.pl>
Only a part of this fix will be MFC'ed (if approved).
PR: kern/60149
Reviewed by: rwatson
Approved by: scottl (mentor)
MFC after: 3 days
forced unmount case. Otherwise, a file system that is referenced
only by process fd_cdir/fd_rdir references to the file system root
vnode will be successfully unmounted without the MNT_FORCE flag.
The previous behaviour was not compatible with the unmount semantics
required by amd(8), so file systems could be unexpectedly unmounted
while there were still references to the file system root directory.
Reported by: Erez Zadok <ezk@cs.sunysb.edu>
Approved by: re (scottl)
vfs_mount_alloc/vfs_mount_destroy functions and take care to completely
destroy the mount point along with its locks. Mount struct has grown in
coplexity recently and depending on each failure path to destroy it
completely isn't working anymore.
2. Eliminate largely identical vfs_mount and vfs_unmount question by
moving the code to handle both cases into a newly introduced vfs_domount
function.
3. Simplify nfs_mount_diskless to always expect an allocated mount
struct and never attempt an allocation/destruction itself. The
vfs_allocroot allocation was there to support 'magic' swap space
configuration for diskless clients that was already removed by PHK some
time ago.
4. Include a vfs_buildopts cleanups by Peter Edwards to validate the
sanity of nmount parameters passed from userland.
Submitted by: (4) Peter Edwards <peter.edwards@openet-telecom.com>
Reviewed by: rwatson
Introduce two new macros MNT_ILOCK(mp)/MNT_IUNLOCK(mp) to
operate on this mutex transparently.
Eventually new mutex will be protecting more fields in
struct mount, not only vnode list.
Discussed with: jeff
specified directory is not found in the mount list. Before the
MNT_BYFSID changes, unmount(2) used to return ENOENT for a nonexistent
path and EINVAL for a non-mountpoint, but we can no longer distinguish
between these cases. Of the two error codes, EINVAL was more likely
to occur in practice, and it was the only one of the two that was
documented.
Update the manual page to match the current behaviour.
Suggested by: tjr
Reviewed by: tjr
system by specifying the file system ID instead of a path. Use this
by default in umount(8). This avoids the need to perform any vnode
operations to look up the mount point, so it makes it possible to
unmount a file system whose root vnode cannot be looked up (e.g.
due to a dead NFS server, or a file system that has become detached
from the hierarchy because an underlying file system was unmounted).
It also provides an unambiguous way to specify which file system is
to be unmunted.
Since the ability to unmount using a path name is retained only for
compatibility, that case now just uses a simple string comparison
of the supplied path against f_mntonname of each mounted file system.
Discussed on: freebsd-arch
mdoc help from: ru
barrier between free'ing filedesc structures. Basically if you want to
access another process's filedesc, you want to hold this mutex over the
entire operation.
this was causing filedesc work to be very painful.
In order to make this work split out sigio definitions to thier own header
(sigio.h) which is included from proc.h for the time being.
seem to have all the prerequisites already.
Call g_waitidle() as the first thing in vfs_mountroot() so that we have
it out of the way before we even decide if we should call .._ask() or
.._try().
Call the g_dev_print() function to provide better guidance for the
root-mount prompt.
locks the mount point directory while waiting for vfs_busy to clear.
Meanwhile the unmount which holds the vfs_busy lock tried to lock
the mount point vnode. The fix is to observe that it is safe for the
unmount to remove the vnode from the mount point without locking it.
The lookup will wait for the unmount to complete, then recheck the
mount point when the vfs_busy lock clears.
Sponsored by: DARPA & NAI Labs.
revert to checking the name to determine if our root device is a ramdisk,
md(4) specifically to determine if we should attempt the root-mount RW
Sponsored by: DARPA & NAI Labs.
we can check and use it later on.
Change the pieces of code which relied on mount->mnt_stat.f_owner
to check which user mounted the filesystem.
This became needed as the EA code needs to be able to allocate
blocks for "system" EA users like ACLs.
There seems to be some half-baked (probably only quarter- actually)
notion that the superuser for a given filesystem is the user who
mounted it, but this has far from been carried through. It is
unclear if it should be.
Sponsored by: DARPA & NAI Labs.
- v_vflag is protected by the vnode lock and is used when synchronization
with VOP calls is needed.
- v_iflag is protected by interlock and is used for dealing with vnode
management issues. These flags include X/O LOCK, FREE, DOOMED, etc.
- All accesses to v_iflag and v_vflag have either been locked or marked with
mp_fixme's.
- Many ASSERT_VOP_LOCKED calls have been added where the locking was not
clear.
- Many functions in vfs_subr.c were restructured to provide for stronger
locking.
Idea stolen from: BSD/OS
linker_load_module() instead.
This fixes a bug where the kernel was unable to properly locate and
load a kernel module in vfs_mount() (and probably in the netgraph
code as well since it was using the same function). This is because
the linker_load_file() does not properly search the module path.
Problem found by: peter
Reviewed by: peter
Thanks to: peter
kernel access control.
Invoke the necessary MAC entry points to maintain labels on
mount structures. In particular, invoke entry points for
intialization and destruction in various scenarios (root,
non-root). Also introduce an entry point in the boot procedure
following the mount of the root file system, but prior to the
start of the userland init process to permit policies to
perform further initialization.
Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs
- Sanity check the mount options list (remove duplicates) with
vfs_sanitizeopts().
- Fix some malloc(0)/free(NULL) bugs.
Reviewed by: rwatson (some time ago)
of being correct. None of the root mountable filesystems
do something at VFS_START().
Shorten a comment to fix a style bug while I'm here.
PR: kern/18505
The file vfs_conf.c which was dealing with root mounting has
been repo-copied into vfs_mount.c to preserve history.
This makes nmount related development easier, and help reducing
the size of vfs_syscalls.c, which is still an enormous file.
Reviewed by: rwatson
Repo-copy by: peter
environment needed at boot time to a dynamic subsystem when VM is
up. The dynamic kernel environment is protected by an sx lock.
This adds some new functions to manipulate the kernel environment :
freeenv(), setenv(), unsetenv() and testenv(). freeenv() has to be
called after every getenv() when you have finished using the string.
testenv() only tests if an environment variable is present, and
doesn't require a freeenv() call. setenv() and unsetenv() are self
explanatory.
The kenv(2) syscall exports these new functionalities to userland,
mainly for kenv(1).
Reviewed by: peter
Includes some minor whitespace changes, and re-ordering to be able to document
properly (e.g, grouping of variables and the SYSCTL macro calls for them, where
the documentation has been added.)
Reviewed by: phk (but all errors are mine)
The kernel certainly doesn't use _PATH_DEV or even /dev/ to find the device.
It cannot, since "/" has not been mounted. Maybe the only affect of using
/dev/ is that it gets put in the mounted-from name for "/", so that mount(8),
etc., display an absolute path before "/" has been remounted. Many have
never bothered typing the full path, and code that constructs a path in
rootdevnames[] never bothered to construct a full path, so the example
shouldn't have it.
Submitted by: bde
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
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)
An initial tidyup of the mount() syscall and VFS mount code.
This code replaces the earlier work done by jlemon in an attempt to
make linux_mount() work.
* the guts of the mount work has been moved into vfs_mount().
* move `type', `path' and `flags' from being userland variables into being
kernel variables in vfs_mount(). `data' remains a pointer into
userspace.
* Attempt to verify the `type' and `path' strings passed to vfs_mount()
aren't too long.
* rework mount() and linux_mount() to take the userland parameters
(besides data, as mentioned) and pass kernel variables to vfs_mount().
(linux_mount() already did this, I've just tidied it up a little more.)
* remove the copyin*() stuff for `path'. `data' still requires copyin*()
since its a pointer into userland.
* set `mount->mnt_statf_mntonname' in vfs_mount() rather than in each
filesystem. This variable is generally initialised with `path', and
each filesystem can override it if they want to.
* NOTE: f_mntonname is intiailised with "/" in the case of a root mount.
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
cloning infrastructure standard in kern_conf. Modules are now
the same with or without devfs support.
If you need to detect if devfs is present, in modules or elsewhere,
check the integer variable "devfs_present".
This happily removes an ugly hack from kern/vfs_conf.c.
This forces a rename of the eventhandler and the standard clone
helper function.
Include <sys/eventhandler.h> in <sys/conf.h>: it's a helper #include
like <sys/queue.h>
Remove all #includes of opt_devfs.h they no longer matter.
Implement subdirs.
Build the full "devicename" for cloning functions.
Fix panic when deleted device goes away.
Collaps devfs_dir and devfs_dirent structures.
Add proper cloning to the /dev/fd* "device-"driver.
Fix a bug in make_dev_alias() handling which made aliases appear
multiple times.
Use devfs_clone to implement getdiskbyname()
Make specfs maintain the stat(2) timestamps per dev_t
static int setrootbyname(char *name);
out into
dev_t getdiskbyname(char *name);
This makes it easy to create a new DDB command, which is the big reason
for the change. You can now do the following in DDB:
Example rc.conf entry:
dumpdev="/dev/ad0s1b" # Device name to crashdump to (if enabled).
db> show disk/ad0s1b
dev_t = 0xc0b7ea00
db> p *dumpdev
c0b7ea00
firmware prompt. Several sleepy folk mistook the '>>>' for the SRM
prompt, which was never the desired idea.
Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
Approved by: jkh
what it is.
Be more correct in unbusying the mountpoint (especially before freeing it).
Remove support for mounting 'r' devices as root. You don't mount 'r'
devices anywhere else, and they're going away anyway.
Submitted by: bde
Add MD_ROOT and MD_ROOT_SIZE options to the md driver.
Make the md driver handle MFS_ROOT and MFS_ROOT_SIZE options for compatibility.
Add md driver to GENERIC, PCCARD and LINT.
This is a cleanup which removes the need for some of the worse hacks in
MFS: We really want to have a rootvnode but MFS on a preloaded image
doesn't really have one. md is a true device, so it is less trouble.
This has been tested with make release, and if people remember to add
the "md" pseudo-device to their kernels, PicoBSD should be just fine
as well. If people have no other use for MFS, it can be removed from
the kernel.
We currently only search SCSI and IDE CDROMs; if there's felt to be a
need for supporting the very old and rare soundcard etc. drives for this
application they can be trivially added.
In order to achieve this, root filesystem mount is moved from
SI_ORDER_FIRST to SI_ORDER_SECOND in the SI_SUB_MOUNT_ROOT sysinit
group. Now, modules which wish to usurp the default root mount
can use SI_ORDER_FIRST.
A compiled-in or preloaded MFS filesystem will become the root
filesystem unless the vfs.root.mountfrom environment variable refers
to a valid bootable device. This will normally only be the case when
the kernel and MFS image have been loaded from a disk which has a
valid /etc/fstab file. In this case, the variable should be manually
overridden in the loader, or the kernel booted with -a. In either
case "mfs:" should be supplied as the new value.
Also fix a typo in one DFLTROOT case that would not have compiled.
filesystem is discovered. Preference is given to using the kernel
environment variable vfs.root.mountfrom, which is set by the loader
according to the contents of /etc/fstab. Changes in the MD code
provide fallback mechanisms for systems not using the loader.
A more robust fallback path is also provided, with the last recourse
being to prompt on the console for a root device.
These changes drastically simplify the machine-dependant parts of
the root configuration process. In addition, support for CDROM root
devices has been removed; it was a nasty hack and didn't work.
addaliasu() into addalias() (no operational change) and clarify comments
relating to a trick that vclean() uses.
The fix to BOOTP is yet another hack. Actually, rootfsid handling
is already a major hack. The whole thing needs to be cleaned up.
Reviewed by: David Greenman <dg@root.com>, Alan Cox <alc@cs.rice.edu>
