Commit Graph

281 Commits

Author SHA1 Message Date
ed
2b4f7a9e8a Merge si_name and __si_namebuf.
The si_name pointer always points to the __si_namebuf member inside the
same object. Remove it and rename __si_namebuf to si_name.
2012-02-10 12:40:50 +00:00
mm
1626913ed1 Add support for mounting devfs inside jails.
A new jail(8) option "devfs_ruleset" defines the ruleset enforcement for
mounting devfs inside jails. A value of -1 disables mounting devfs in
jails, a value of zero means no restrictions. Nested jails can only
have mounting devfs disabled or inherit parent's enforcement as jails are
not allowed to view or manipulate devfs(8) rules.

Utilizes new functions introduced in r231265.

Reviewed by:	jamie
MFC after:	1 month
2012-02-09 10:22:08 +00:00
mm
27a58a0dde Introduce the "ruleset=number" option for devfs(5) mounts.
Add support for updating the devfs mount (currently only changing the
ruleset number is supported).
Check mnt_optnew with vfs_filteropt(9).

This new option sets the specified ruleset number as the active ruleset
of the new devfs mount and applies all its rules at mount time. If the
specified ruleset doesn't exist, a new empty ruleset is created.

MFC after:	1 month
2012-02-09 10:09:12 +00:00
jhb
b00203c514 Explicitly use curthread while manipulating td_fpop during last close
of a devfs file descriptor in devfs_close_f().  The passed in td argument
may be NULL if the close was invoked by garbage collection of open
file descriptors in pending control messages in the socket buffer of a
UNIX domain socket after it was closed.

PR:		kern/151758
Submitted by:	Andrey Shidakov  andrey shidakov ru
Submitted by:	Ruben van Staveren  ruben verweg com
Reviewed by:	kib
MFC after:	2 weeks
2011-12-09 17:49:34 +00:00
kib
36fd8d0106 Existing VOP_VPTOCNP() interface has a fatal flow that is critical for
nullfs.  The problem is that resulting vnode is only required to be
held on return from the successfull call to vop, instead of being
referenced.

Nullfs VOP_INACTIVE() method reclaims the vnode, which in combination
with the VOP_VPTOCNP() interface means that the directory vnode
returned from VOP_VPTOCNP() is reclaimed in advance, causing
vn_fullpath() to error with EBADF or like.

Change the interface for VOP_VPTOCNP(), now the dvp must be
referenced. Convert all in-tree implementations of VOP_VPTOCNP(),
which is trivial, because vhold(9) and vref(9) are similar in the
locking prerequisites. Out-of-tree fs implementation of VOP_VPTOCNP(),
if any, should have no trouble with the fix.

Tested by:	pho
Reviewed by:	mckusick
MFC after:	3 weeks (subject of re approval)
2011-11-19 07:50:49 +00:00
eadler
6efa0e7f22 - fix duplicate "a a" in some comments
Submitted by:	eadler
Approved by:	simon
MFC after:	3 days
2011-11-13 17:06:33 +00:00
jhb
1e2d8c9d67 Move the cleanup of f_cdevpriv when the reference count of a devfs
file descriptor drops to zero out of _fdrop() and into devfs_close_f()
as it is only relevant for devfs file descriptors.

Reviewed by:	kib
MFC after:	1 week
2011-11-04 03:39:31 +00:00
kib
5831d7597c Fix kernel panic when d_fdopen csw method is called for NULL fp.
This may happen when kernel consumer calls VOP_OPEN().

Reported by:	Tavis Ormandy <taviso  cmpxchg8b com> through delphij
MFC after:	3 days
2011-11-03 18:55:18 +00:00
kib
12b63c734f Export devfs inode number allocator for the kernel consumers.
Reviewed by:	jhb
MFC after:	2 weeks
2011-10-05 16:50:15 +00:00
kib
011f42054d Add the fo_chown and fo_chmod methods to struct fileops and use them
to implement fchown(2) and fchmod(2) support for several file types
that previously lacked it. Add MAC entries for chown/chmod done on
posix shared memory and (old) in-kernel posix semaphores.

Based on the submission by:	glebius
Reviewed by:	rwatson
Approved by:	re (bz)
2011-08-16 20:07:47 +00:00
kib
3f15a4a91b Do not update mountpoint generation counter to the value which was not
yet acted upon by devfs_populate().

Submitted by:	Kohji Okuno <okuno.kohji jp panasonic com>
Approved by:	re (bz)
MFC after:	1 week
2011-08-09 20:53:33 +00:00
kib
e3d33b853d While fixing the looping of a thread while devfs vnode is reclaimed,
r179247 introduced a possibility of devfs_allocv() returning spurious
ENOENT. If the vnode is selected by vnlru daemon for reclamation, then
devfs_allocv() can get ENOENT from vget() due to devfs_close() dropping
vnode lock around the call to cdevsw d_close method.

Use LK_RETRY in the vget() call, and do some part of the devfs_reclaim()
work in devfs_allocv(), clearing vp->v_data and de->de_vnode. Retry the
allocation of the vnode, now with de->de_vnode == NULL.

The check vp->v_data == NULL at the start of devfs_close() cannot be
affected by the change, since vnode lock must be held while VI_DOOMED
is set, and only dropped after the check.

Reported and tested by:	Kohji Okuno <okuno.kohji jp panasonic com>
Reviewed by:	attilio
MFC after:	3 weeks
2011-07-13 21:07:41 +00:00
jh
dd13f4b76e Don't allow user created symbolic links to cover another entries marked
with DE_USER. If a devfs rule hid such entry, it was possible to create
infinite number of symbolic links with the same name.

Reviewed by:	kib
2010-12-15 16:49:47 +00:00
jh
309885e54e - Assert that dm_lock is exclusively held in devfs_rules_apply() and
in devfs_vmkdir() while adding the entry to de_list of the parent.
- Apply devfs rules to newly created directories and symbolic links.

PR:		kern/125034
Submitted by:	Mateusz Guzik (original version)
2010-12-15 16:42:44 +00:00
jh
bb9ca91194 Handle the special ruleset 0 in devfs_ruleset_use(). An attempt set the
current ruleset to 0 with command "devfs ruleset 0" triggered a KASSERT
in devfs_ruleset_create().

PR:		kern/125030
Submitted by:	Mateusz Guzik
2010-12-12 08:52:13 +00:00
jh
7817d1d259 Format prototypes to follow style(9) more closely.
Discussed with:	kib, phk
2010-10-12 15:58:52 +00:00
jh
400a76c2ba Add a new function devfs_dev_exists() to be able to find out if a
specific devfs path already exists.

The function will be used from kern_conf.c to detect duplicate device
registrations. Callers must hold the devmtx mutex.

Reviewed by:	kib
2010-09-27 18:20:56 +00:00
jh
b6e78e30f2 Add reference counting for devfs paths containing user created symbolic
links. The reference counting is needed to be able to determine if a
specific devfs path exists. For true device file paths we can traverse
the cdevp_list but a separate directory list is needed for user created
symbolic links.

Add a new directory entry flag DE_USER to mark entries which should
unreference their parent directory on deletion.

A new function to traverse cdevp_list and the directory list will be
introduced in a separate commit.

Idea from:	kib
Reviewed by:	kib
2010-09-27 17:47:09 +00:00
jh
4c422ff8ec Modify devfs_fqpn() for future use in devfs path reference counting
code:

- Accept devfs_mount and devfs_dirent as the arguments instead of a
  vnode. This generalizes the function so that it can be used from
  contexts where vnode references are not available.
- Accept NULL cnp argument. No '/' will be appended, if a NULL cnp is
  provided.
- Make the function global and add its prototype to devfs.h.

Reviewed by:	kib
2010-09-21 16:49:02 +00:00
jh
8c48e7bab1 - For consistency, remove "." and ".." entries from de_dlist before
calling devfs_delete() (and thus possibly dropping dm_lock) in
  devfs_rmdir_empty().
- Assert that we don't return doomed entries from devfs_find(). [1]

Suggested by:	kib [1]
Reviewed by:	kib
2010-09-18 18:37:41 +00:00
jh
02ebb2e3c3 Remove empty devfs directories automatically.
devfs_delete() now recursively removes empty parent directories unless
the DEVFS_DEL_NORECURSE flag is specified. devfs_delete() can't be
called anymore with a parent directory vnode lock held because the
possible parent directory deletion needs to lock the vnode. Thus we
unlock the parent directory vnode in devfs_remove() before calling
devfs_delete().

Call devfs_populate_vp() from devfs_symlink() and devfs_vptocnp() as now
directories can get removed.

Add a check for DE_DOOMED flag to devfs_populate_vp() because
devfs_delete() drops dm_lock before the VI_DOOMED vnode flag gets set.
This ensures that devfs_populate_vp() returns an error for directories
which are in progress of deletion.

Reviewed by:	kib
Discussed on:	freebsd-current (mostly silence)
2010-09-15 14:23:55 +00:00
jh
52028f2ca8 Set de_dir for user created symbolic links. This will be needed to be
able to resolve their parent directories.
2010-08-26 16:01:29 +00:00
jh
4a4bf3c511 Call devfs_populate_vp() from devfs_getattr(). It was possible that
fstat(2) returned stale information through an open file descriptor.
2010-08-25 15:29:12 +00:00
jh
6471734221 Introduce and use devfs_populate_vp() to unlock a vnode before calling
devfs_populate(). This is a prerequisite for the automatic removal of
empty directories which will be committed in the future.

Reviewed by:	kib (previous version)
2010-08-22 16:08:12 +00:00
jhb
d4890c88b0 Add dedicated routines to toggle lockmgr flags such as LK_NOSHARE and
LK_CANRECURSE after a lock is created.  Use them to implement macros that
otherwise manipulated the flags directly.  Assert that the associated
lockmgr lock is exclusively locked by the current thread when manipulating
these flags to ensure the flag updates are safe.  This last change required
some minor shuffling in a few filesystems to exclusively lock a brand new
vnode slightly earlier.

Reviewed by:	kib
MFC after:	3 days
2010-08-20 19:46:50 +00:00
jh
61e0ffd171 Call dev_rel() in error paths.
Reported by:	kib
Reviewed by:	kib
MFC after:	2 weeks
2010-08-19 16:39:00 +00:00
jh
2e34ad384b Allow user created symbolic links to cover device files and directories
if the device file appears during or after the link creation.

User created symbolic links are now inserted at the head of the
directory entry list after the "." and ".." entries. A new directory
entry flag DE_COVERED indicates that an entry is covered by a symbolic
link.

PR:		kern/114057
Reviewed by:	kib
Idea from:	kib
Discussed on:	freebsd-current (mostly silence)
2010-08-12 15:29:07 +00:00
kib
d9e9a26839 Enable shared lookups and externed shared ops for devfs.
In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:46:53 +00:00
kib
ba7ee96f4a Add new make_dev_p(9) flag MAKEDEV_ETERNAL to inform devfs that created
cdev will never be destroyed. Propagate the flag to devfs vnodes as
VV_ETERNVALDEV. Use the flags to avoid acquiring devmtx and taking a
thread reference on such nodes.

In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:42:15 +00:00
kib
913fa4ba38 Enable shared locks for the devfs vnodes. Honor the locking mode
requested by lookup(). This should be a nop at the moment.

In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:23:47 +00:00
kib
837d8df157 Initialize VV_ISTTY vnode flag on the devfs vnode creation instead of
doing it on each open.

In collaboration with:	pho
MFC after:	1 month
2010-08-06 09:06:55 +00:00
jh
bc3fa141fa Add a new function devfs_parent_dirent() for resolving devfs parent
directory entry. Use the new function in devfs_fqpn(), devfs_lookupx()
and devfs_vptocnp() instead of manually resolving the parent entry.

Reviewed by:	kib
2010-06-09 15:29:12 +00:00
jh
73a91f4cc7 Don't try to call cdevsw d_close() method when devfs_close() is called
because of insmntque1() failure.

Found with:	stress2
Suggested and reviewed by:	kib
2010-06-01 18:57:21 +00:00
kib
77dcee6926 Add MAKEDEV_NOWAIT flag to make_dev_credf(9), to create a device node
in a no-sleep context. If resource allocation cannot be done without
sleep, make_dev_credf() fails and returns NULL.

Reviewed by:	jh
MFC after:	2 weeks
2010-05-06 19:22:50 +00:00
jh
0cfb62fa2a Revert r206560. The change doesn't work correctly in all cases with
multiple devfs mounts.
2010-04-16 07:02:28 +00:00
jh
7013f95fb6 - Ignore and report duplicate and empty device names in devfs_populate_loop()
instead of causing erratic behavior. Currently make_dev(9) can't fail, so
  there is no way to report an error to make_dev(9) callers.
- Disallow using "." and ".." in device path names. It didn't work previously
  but now it is reported rather than panicing.
- Treat multiple sequential slashes as single in device path names.

Discussed with:	pjd
2010-04-13 18:53:39 +00:00
ed
39978ea638 Properly use dev_refl()/dev_rel() in kern.devname.
While there, perform some clean-up fixes. Update some stale comments on
struct cdev * instead of dev_t and devfs_random(). Also add some missing
whitespace.

MFC after:	1 week
2010-01-31 15:19:16 +00:00
ed
449c6ac843 Let access overriding to TTYs depend on the cdev_priv, not the vnode.
Basically this commit changes two things, which improves access to TTYs
in exceptional conditions. Basically the problem was that when you ran
jexec(8) to attach to a jail, you couldn't use /dev/tty (well, also the
node of the actual TTY, e.g. /dev/pts/X). This is very inconvenient if
you want to attach to screens quickly, use ssh(1), etc.

The fixes:

- Cache the cdev_priv of the controlling TTY in struct session. Change
  devfs_access() to compare against the cdev_priv instead of the vnode.
  This allows you to bypass UNIX permissions, even across different
  mounts of devfs.

- Extend devfs_prison_check() to unconditionally expose the device node
  of the controlling TTY, even if normal prison nesting rules normally
  don't allow this. This actually allows you to interact with this
  device node.

To be honest, I'm not really happy with this solution. We now have to
store three pointers to a controlling TTY (s_ttyp, s_ttyvp, s_ttydp).
In an ideal world, we should just get rid of the latter two and only use
s_ttyp, but this makes certian pieces of code very impractical (e.g.
devfs, kern_exit.c).

Reported by:	Many people
2009-12-19 18:42:12 +00:00
ed
63a4c7f522 Improve nested jail awareness of devfs by handling credentials.
Now that we start to use credentials on character devices more often
(because of MPSAFE TTY), move the prison-checks that are in place in the
TTY code into devfs.

Instead of strictly comparing the prisons, use the more common
prison_check() function to compare credentials. This means that
pseudo-terminals are only visible in devfs by processes within the same
jail and parent jails.

Even though regular users in parent jails can now interact with
pseudo-terminals from child jails, this seems to be the right approach.
These processes are also capable of interacting with the jailed
processes anyway, through signals for example.

Reviewed by:	kib, rwatson (older version)
2009-06-20 14:50:32 +00:00
kib
e0d7459c71 VOP_IOCTL takes unlocked vnode as an argument. Due to this, v_data may
be NULL or derefenced memory may become free at arbitrary moment.

Lock the vnode in cd9660, devfs and pseudofs implementation of VOP_IOCTL
to prevent reclaim; check whether the vnode was already reclaimed after
the lock is granted.

Reported by:	georg at dts su
Reviewed by:	des (pseudofs)
MFC after:	2 weeks
2009-06-10 13:57:36 +00:00
rwatson
f4934662e5 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
rwatson
81b13ff50e Re-add opt_mac.h include, which is required in order for MNT_MULTILABEL
to be set properly on devfs.  Otherwise, it isn't possible to set labels
on /dev nodes.

Reported by:	Sergio Rodriguez <sergiorr at yahoo.com>
MFC after:	3 days
2009-06-04 10:30:18 +00:00
kib
cd869a4a42 Devfs replaces file ops vector with devfs-specific one in devfs_open(),
before the struct file is fully initialized in vn_open(), in particular,
fp->f_vnode is NULL. Other thread calling file operation before f_vnode
is set results in NULL pointer dereference in devvn_refthread().

Initialize f_vnode before calling d_fdopen() cdevsw method, that might
set file ops too.

Reported and tested by:	Chris Timmons <cwt networks cwu edu>
	(RELENG_7 version)
MFC after:	3 days
2009-05-15 19:23:05 +00:00
attilio
1dcb84131b Remove the thread argument from the FSD (File-System Dependent) parts of
the VFS.  Now all the VFS_* functions and relating parts don't want the
context as long as it always refers to curthread.

In some points, in particular when dealing with VOPs and functions living
in the same namespace (eg. vflush) which still need to be converted,
pass curthread explicitly in order to retain the old behaviour.
Such loose ends will be fixed ASAP.

While here fix a bug: now, UFS_EXTATTR can be compiled alone without the
UFS_EXTATTR_AUTOSTART option.

VFS KPI is heavilly changed by this commit so thirdy parts modules needs
to be recompiled.  Bump __FreeBSD_version in order to signal such
situation.
2009-05-11 15:33:26 +00:00
rwatson
fba90f2e03 Remove VOP_LEASE and supporting functions. This hasn't been used since
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.

Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.

Proposed by:    jeff
Reviewed by:    jeff
Discussed with: rmacklem, zach loafman @ isilon
2009-04-10 10:52:19 +00:00
kib
9638e6cef5 Enable advisory file locking for devfs vnodes.
Reported by:	Timothy Redaelli <timothy redaelli eu>
MFC after:	1 week
2009-03-11 12:53:16 +00:00
kib
84bab6f2a5 Extract the no_poll() and vop_nopoll() code into the common routine
poll_no_poll().
Return a poll_no_poll() result from devfs_poll_f() when
filedescriptor does not reference the live cdev, instead of ENXIO.

Noted and tested by:	hps
MFC after:	1 week
2009-03-06 15:35:37 +00:00
bz
9fd12161ca Remove unused local variables.
Submitted by:	Christoph Mallon christoph.mallon@gmx.de
Reviewed by:	kib
MFC after:	2 weeks
2009-01-31 17:36:22 +00:00
ed
50efccc9f0 Mark most often used sysctl's as MPSAFE.
After running a `make buildkernel', I noticed most of the Giant locks in
sysctl are only caused by a very small amount of sysctl's:

- sysctl.name2oid. This one is locked by SYSCTL_LOCK, just like
  sysctl.oidfmt.

- kern.ident, kern.osrelease, kern.version, etc. These are just constant
  strings.

- kern.arandom, used by the stack protector. It is already protected by
  arc4_mtx.

I also saw the following sysctl's show up. Not as often as the ones
above, but still quite often:

- security.jail.jailed. Also mark security.jail.list as MPSAFE. They
  don't need locking or already use allprison_lock.

- kern.devname, used by devname(3), ttyname(3), etc.

This seems to reduce Giant locking inside sysctl by ~75% in my primitive
test setup.
2009-01-28 19:58:05 +00:00
trasz
d72b8ba20f Don't panic with "vinvalbuf: dirty bufs" when the mounted device that was
being written to goes away.

Reviewed by:	kib, scottl
Approved by:	rwatson (mentor)
Sponsored by:	FreeBSD Foundation
2009-01-08 19:13:34 +00:00