Commit Graph

362 Commits

Author SHA1 Message Date
Xin LI
4f9343fc7c Disable timestamping on devfs read/write operations by default.
Currently we update timestamps unconditionally when doing read or
write operations.  This may slow things down on hardware where
reading timestamps is expensive (e.g. HPET, because of the default
vfs.timestamp_precision setting is nanosecond now) with limited
benefit.

A new sysctl variable, vfs.devfs.dotimes is added, which can be
set to non-zero value when the old behavior is desirable.

Differential Revision:	https://reviews.freebsd.org/D2104
Reported by:	Mike Tancsa <mike sentex net>
Reviewed by:	kib
Relnotes:	yes
Sponsored by:	iXsystems, Inc.
MFC after:	2 weeks
2015-03-21 01:14:11 +00:00
Konstantin Belousov
08189ed667 The VNASSERT in vflush() FORCECLOSE case is trying to panic early to
prevent errors from yanking devices out from under filesystems.  Only
care about special vnodes on devfs, special nodes on other kinds of
filesystems do not have special properties.

Sponsored by:  EMC / Isilon Storage Division
Submitted by:   Conrad Meyer
MFC after:	1 week
2015-02-27 16:43:50 +00:00
Konstantin Belousov
3b50dff506 Stop enforcing additional reference on all cdevs, which was introduced
in r277199.  Acquire the neccessary reference in delist_dev_locked()
and inform destroy_devl() about it using CDP_UNREF_DTR flag.

Fix some style nits, add asserts.

Discussed with:	hselasky
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-19 17:36:52 +00:00
Konstantin Belousov
a57a934a38 Ignore devfs directory entries for devices either being destroyed or
delisted.  The check is racy.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-19 17:24:52 +00:00
Hans Petter Selasky
d2955419cd Avoid race with "dev_rel()" when using the recently added
"delist_dev()" function. Make sure the character device structure
doesn't go away until the end of the "destroy_dev()" function due to
concurrently running cleanup code inside "devfs_populate()".

MFC after:	1 week
Reported by:	dchagin@
2015-01-14 22:07:13 +00:00
Mateusz Guzik
4dba07b216 Fix up some session-related races in devfs.
One was introduced with r272596, the rest was there to begin with.

Noted by: jhb
2014-11-03 03:12:15 +00:00
Hans Petter Selasky
f0188618f2 Fix multiple incorrect SYSCTL arguments in the kernel:
- Wrong integer type was specified.

- Wrong or missing "access" specifier. The "access" specifier
sometimes included the SYSCTL type, which it should not, except for
procedural SYSCTL nodes.

- Logical OR where binary OR was expected.

- Properly assert the "access" argument passed to all SYSCTL macros,
using the CTASSERT macro. This applies to both static- and dynamically
created SYSCTLs.

- Properly assert the the data type for both static and dynamic
SYSCTLs. In the case of static SYSCTLs we only assert that the data
pointed to by the SYSCTL data pointer has the correct size, hence
there is no easy way to assert types in the C language outside a
C-function.

- Rewrote some code which doesn't pass a constant "access" specifier
when creating dynamic SYSCTL nodes, which is now a requirement.

- Updated "EXAMPLES" section in SYSCTL manual page.

MFC after:	3 days
Sponsored by:	Mellanox Technologies
2014-10-21 07:31:21 +00:00
Konstantin Belousov
f12aa60c62 When vnode bypass cannot be performed on the cdev file descriptor for
read/write/poll/ioctl, call standard vnode filedescriptor fop.  This
restores the special handling for terminals by calling the deadfs VOP,
instead of always returning ENXIO for destroyed devices or revoked
terminals.

Since destroyed (and not revoked) device would use devfs_specops VOP
vector, make dead_read/write/poll non-static and fill VOP table with
pointers to the functions, to instead of VOP_PANIC.

Noted and reviewed by:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-10-15 13:16:51 +00:00
Mateusz Guzik
3a222fe000 devfs: tidy up after 272596
This moves a var to an if statement, no functional changes.

MFC after:	1 week
2014-10-06 07:22:48 +00:00
Mateusz Guzik
1d1b55fbba devfs: don't take proctree_lock unconditionally in devfs_close
MFC after:	1 week
2014-10-06 06:20:35 +00:00
John Baldwin
9696feebe2 Add a new fo_fill_kinfo fileops method to add type-specific information to
struct kinfo_file.
- Move the various fill_*_info() methods out of kern_descrip.c and into the
  various file type implementations.
- Rework the support for kinfo_ofile to generate a suitable kinfo_file object
  for each file and then convert that to a kinfo_ofile structure rather than
  keeping a second, different set of code that directly manipulates
  type-specific file information.
- Remove the shm_path() and ksem_info() layering violations.

Differential Revision:	https://reviews.freebsd.org/D775
Reviewed by:	kib, glebius (earlier version)
2014-09-22 16:20:47 +00:00
Konstantin Belousov
7b81a399a4 In msdosfs_setattr(), add a check for result of the utimes(2)
permissions test, forgotten in r164033.

Refactor the permission checks for utimes(2) into vnode helper
function vn_utimes_perm(9), and simplify its code comparing with the
UFS origin, by writing the call to VOP_ACCESSX only once.  Use the
helper for UFS(5), tmpfs(5), devfs(5) and msdosfs(5).

Reported by:	bde
Reviewed by:	bde, trasz
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-06-17 07:11:00 +00:00
Alexander Motin
ca187878c0 Fix long known bug with handling device aliases residing not in devfs root.
Historically creation of device aliases created symbolic links using only
name of target device as a link target, not considering current directory.
Fix that by adding number of "../" chunks to the terget device name,
required to get out of the current directory to devfs root first.

MFC after:	1 month
2013-12-12 11:05:48 +00:00
Konstantin Belousov
bf3e483b44 Similar to debug.iosize_max_clamp sysctl, introduce
devfs_iosize_max_clamp sysctl, which allows/disables SSIZE_MAX-sized
i/o requests on the devfs files.

Sponsored by:	The FreeBSD Foundation
Reminded by:	Dmitry Sivachenko <trtrmitya@gmail.com>
MFC after:	1 week
2013-10-15 06:33:10 +00:00
Konstantin Belousov
64548150b6 Remove two instances of ARGSUSED comment, and wrap lines nearby the
code that is to be changed.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2013-10-15 06:28:11 +00:00
Konstantin Belousov
c0a46535c4 Make the seek a method of the struct fileops.
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2013-08-21 17:36:01 +00:00
Konstantin Belousov
b1dd38f408 Restore the previous sendfile(2) behaviour on the block devices.
Provide valid .fo_sendfile method for several missed struct fileops.

Reviewed by:	glebius
Sponsored by:	The FreeBSD Foundation
2013-08-16 14:22:20 +00:00
Andriy Gapon
8e94193e58 make path matching in devfs rules consistent and sane (and safer)
Before this change path matching had the following features:
- for device nodes the patterns were matched against full path
- in the above case '/' in a path could be matched by a wildcard
- for directories and links only the last component was matched

So, for example, a pattern like 're*' could match the following entries:
- re0 device
- responder/u0 device
- zvol/recpool directory

Although it was possible to work around this behavior (once it was spotted
and understood), it was very confusing and contrary to documentation.

Now we always match a full path for all types of devfs entries (devices,
directories, links) and a '/' has to be matched explicitly.
This behavior follows the shell globbing rules.

This change is originally developed by Jaakko Heinonen.
Many thanks!

PR:		kern/122838
Submitted by:	jh
MFC after:	4 weeks
2013-07-26 14:25:58 +00:00
Gabor Kovesdan
a2098fea6d - Correct mispellings of the word necessary
Submitted by:	Christoph Mallon <christoph.mallon@gmx.de> (via private mail)
2013-04-17 11:42:40 +00:00
Konstantin Belousov
2ca4998342 Stop translating the ERESTART error from the open(2) into EINTR.
Posix requires that open(2) is restartable for SA_RESTART.

For non-posix objects, in particular, devfs nodes, still disable
automatic restart of the opens. The open call to a driver could have
significant side effects for the hardware.

Noted and reviewed by:	jilles
Discussed with:	bde
MFC after:	2 weeks
2013-02-07 14:53:33 +00:00
Konstantin Belousov
ad9789f6db Do not force a writer to the devfs file to drain the buffer writes.
Requested and tested by:	Ian Lepore <freebsd@damnhippie.dyndns.org>
MFC after:	2 weeks
2012-12-23 22:43:27 +00:00
Konstantin Belousov
6feceb86ab Remove M_USE_RESERVE from the devfs cdp allocator, which is one of two
uses of M_USE_RESERVE in the kernel. This allocation is not special.

Reviewed by:	alc
Tested by:	pho
MFC after:	2 weeks
2012-11-14 19:50:21 +00:00
Attilio Rao
bc2258da88 Complete MPSAFE VFS interface and remove MNTK_MPSAFE flag.
Porters should refer to __FreeBSD_version 1000021 for this change as
it may have happened at the same timeframe.
2012-11-09 18:02:25 +00:00
Ed Schouten
7cbef24e1a Prefer __containerof() above member2struct().
The first does proper checking of the argument types, while the latter
does not.
2012-09-15 19:28:54 +00:00
Hans Petter Selasky
07da61a6cc Streamline use of cdevpriv and correct some corner cases.
1) It is not useful to call "devfs_clear_cdevpriv()" from
"d_close" callbacks, hence for example read, write, ioctl and
so on might be sleeping at the time of "d_close" being called
and then then freed private data can still be accessed.
Examples: dtrace, linux_compat, ksyms (all fixed by this patch)

2) In sys/dev/drm* there are some cases in which memory will
be freed twice, if open fails, first by code in the open
routine, secondly by the cdevpriv destructor. Move registration
of the cdevpriv to the end of the drm open routines.

3) devfs_clear_cdevpriv() is not called if the "d_open" callback
registered cdevpriv data and the "d_open" callback function
returned an error. Fix this.

Discussed with:	phk
MFC after:	2 weeks
2012-08-15 16:19:39 +00:00
Konstantin Belousov
c5c1199c83 Extend the KPI to lock and unlock f_offset member of struct file. It
now fully encapsulates all accesses to f_offset, and extends f_offset
locking to other consumers that need it, in particular, to lseek() and
variants of getdirentries().

Ensure that on 32bit architectures f_offset, which is 64bit quantity,
always read and written under the mtxpool protection. This fixes
apparently easy to trigger race when parallel lseek()s or lseek() and
read/write could destroy file offset.

The already broken ABI emulations, including iBCS and SysV, are not
converted (yet).

Tested by:	pho
No objections from:	jhb
MFC after:    3 weeks
2012-07-02 21:01:03 +00:00
Alexander Motin
d499701b0c Revert devfs part of r235911. I was unaware about old but unfinished
discussion between kib@ and gibbs@ about it.
2012-05-24 18:19:23 +00:00
Alexander Motin
f6ad3f237a MFprojects/zfsd:
Revamp the CAM enclosure services driver.
This updated driver uses an in-kernel daemon to track state changes and
publishes physical path location information\for disk elements into the
CAM device database.

Sponsored by:   Spectra Logic Corporation
Sponsored by:   iXsystems, Inc.
Submitted by:   gibbs, will, mav
2012-05-24 14:07:44 +00:00
Martin Matuska
b362f0a78b Add "export" to devfs_opts[] and return EOPNOTSUPP if called with it.
Fixes mountd warnings.

Reported by:	kib
MFC after:	1 week
2012-02-29 16:16:36 +00:00
Martin Matuska
bf3db8aa65 To improve control over the use of mount(8) inside a jail(8), introduce
a new jail parameter node with the following parameters:

allow.mount.devfs:
	allow mounting the devfs filesystem inside a jail

allow.mount.nullfs:
	allow mounting the nullfs filesystem inside a jail

Both parameters are disabled by default (equals the behavior before
devfs and nullfs in jails). Administrators have to explicitly allow
mounting devfs and nullfs for each jail. The value "-1" of the
devfs_ruleset parameter is removed in favor of the new allow setting.

Reviewed by:	jamie
Suggested by:	pjd
MFC after:	2 weeks
2012-02-23 18:51:24 +00:00
Konstantin Belousov
526d0bd547 Fix found places where uio_resid is truncated to int.
Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.

Discussed with:	bde, das (previous versions)
MFC after:	1 month
2012-02-21 01:05:12 +00:00
Ed Schouten
8fac9b7b7d 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
Martin Matuska
0cc207a6f5 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
Martin Matuska
17d84d611f 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
John Baldwin
e517e6f12c 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
Konstantin Belousov
f82360acf2 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
Eitan Adler
3b6dc18ef5 - 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
John Baldwin
dccc45e4c0 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
Konstantin Belousov
1fef78c3f0 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
Konstantin Belousov
084e62e91b Export devfs inode number allocator for the kernel consumers.
Reviewed by:	jhb
MFC after:	2 weeks
2011-10-05 16:50:15 +00:00
Konstantin Belousov
9c00bb9190 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
Konstantin Belousov
e047ade947 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
Konstantin Belousov
724ce55b5b 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
Jaakko Heinonen
2d843e7d34 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
Jaakko Heinonen
ef456eec95 - 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
Jaakko Heinonen
2f66e90fc7 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
Jaakko Heinonen
27877c9903 Format prototypes to follow style(9) more closely.
Discussed with:	kib, phk
2010-10-12 15:58:52 +00:00
Jaakko Heinonen
47bcfb6422 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
Jaakko Heinonen
d318c565d7 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
Jaakko Heinonen
6adc52306a 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
Jaakko Heinonen
8570d045e5 - 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
Jaakko Heinonen
89d10571db 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
Jaakko Heinonen
4136388a18 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
Jaakko Heinonen
f5efcd64f4 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
Jaakko Heinonen
0f6bb099ae 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
John Baldwin
3634d5b241 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
Jaakko Heinonen
96835d61b6 Call dev_rel() in error paths.
Reported by:	kib
Reviewed by:	kib
MFC after:	2 weeks
2010-08-19 16:39:00 +00:00
Jaakko Heinonen
64040d3978 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
Konstantin Belousov
d3c5a40780 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
Konstantin Belousov
3979450b4c 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
Konstantin Belousov
9968a42675 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
Konstantin Belousov
3a6fc63c9f 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
Jaakko Heinonen
f40645c83d 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
Jaakko Heinonen
59e0452e82 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
Konstantin Belousov
d2ba618a63 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
Jaakko Heinonen
17f820725e Revert r206560. The change doesn't work correctly in all cases with
multiple devfs mounts.
2010-04-16 07:02:28 +00:00
Jaakko Heinonen
70781bf94e - 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 Schouten
bf2296be8b 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 Schouten
8dc9b4cf04 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 Schouten
f8f6146082 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
Konstantin Belousov
c4df27d5c8 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
Robert Watson
bcf11e8d00 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
Robert Watson
927e0a56ce 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
Konstantin Belousov
0e9bd89d7d 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 Rao
dfd233edd5 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
Robert Watson
885868cd8f 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
Konstantin Belousov
52dc9305aa 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
Konstantin Belousov
125dcf8c7d 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
Bjoern A. Zeeb
7956d34b95 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 Schouten
f3b86a5fd7 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
Edward Tomasz Napierala
71624181c8 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
Konstantin Belousov
c7c7520a95 Do not leak defs_de_interlock on error.
Another pointy hat for my collection.
2008-12-12 11:10:10 +00:00
Joe Marcus Clarke
4c44fd376a Implement VOP_VPTOCNP for devfs. Directory and character device vnodes are
properly translated to their component names.

Reviewed by:	arch
Approved by:	kib
2008-12-12 01:00:38 +00:00
Edward Tomasz Napierala
15bc6b2bd8 Introduce accmode_t. This is required for NFSv4 ACLs - it will be neccessary
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)
2008-10-28 13:44:11 +00:00
Konstantin Belousov
7818e0a545 Save previous content of the td_fpop before storing the current
filedescriptor into it. Make sure that td_fpop is NULL when calling
d_mmap from dev_pager_getpages().

Change guards against td_fpop field being non-NULL with private state
for another device, and against sudden clearing the td_fpop. This
could occur when either a driver method calls another driver through
the filedescriptor operation, or a page fault happen while driver is
writing to a memory backed by another driver.

Noted by:	rwatson
Tested by:	rnoland
MFC after:	3 days
2008-09-26 14:50:49 +00:00
Ed Schouten
219cc94999 Already initialize the vfs timestamps inside the cdev upon allocation.
In the MPSAFE TTY branch I noticed the vfs timestamps inside devfs were
allocated with 0, where the getattr() routine bumps the timestamps to
boottime if the value is below 3600. The reason why it has been designed
like this, is because timestamps during boot are likely to be invalid.

This means that device nodes that are created on demand (posix_openpt())
have timestamps with a value of boottime, which is not what we want.
Solve this by calling vfs_timestamp() inside devfs_alloc().

Discussed with:	kib
2008-09-21 14:02:43 +00:00
Konstantin Belousov
caf8aec886 fdescfs, devfs, mqueuefs, nfs, portalfs, pseudofs, tmpfs and xfs
initialize the vattr structure in VOP_GETATTR() with VATTR_NULL(),
vattr_null() or by zeroing it. Remove these to allow preinitialization
of fields work in vn_stat(). This is needed to get birthtime initialized
correctly.

Submitted by:   Jaakko Heinonen <jh saunalahti fi>
Discussed on:   freebsd-fs
MFC after:	1 month
2008-09-20 19:50:52 +00:00
Attilio Rao
0359a12ead Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread
was always curthread and totally unuseful.

Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
2008-08-28 15:23:18 +00:00
Ed Schouten
bc093719ca Integrate the new MPSAFE TTY layer to the FreeBSD operating system.
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

  The old TTY layer has a driver model that is not abstract enough to
  make it friendly to use. A good example is the output path, where the
  device drivers directly access the output buffers. This means that an
  in-kernel PPP implementation must always convert network buffers into
  TTY buffers.

  If a PPP implementation would be built on top of the new TTY layer
  (still needs a hooks layer, though), it would allow the PPP
  implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

  With the old TTY layer, it isn't entirely safe to destroy TTY's from
  the system. This implementation has a two-step destructing design,
  where the driver first abandons the TTY. After all threads have left
  the TTY, the TTY layer calls a routine in the driver, which can be
  used to free resources (unit numbers, etc).

  The pts(4) driver also implements this feature, which means
  posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

  One of the major improvements is the per-TTY mutex, which is expected
  to improve scalability when compared to the old Giant locking.
  Another change is the unbuffered copying to userspace, which is both
  used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from:		//depot/projects/mpsafetty/...
Approved by:		philip (ex-mentor)
Discussed:		on the lists, at BSDCan, at the DevSummit
Sponsored by:		Snow B.V., the Netherlands
dcons(4) fixed by:	kan
2008-08-20 08:31:58 +00:00
Konstantin Belousov
f35db5f7ca Remove unnecessary locking around pointer fetch.
Requested by:   jhb
2008-08-12 19:34:45 +00:00
Oleksandr Tymoshenko
2da528a74f Get pointer to devfs_ruleset struct after garbage collection has been
performed. Otherwise if ruleset is used by given mountpoint and is empty
it's freed by devfs_ruleset_reap and pointer becomes bogus.

Submitted by:   Mateusz Guzik <mjguzik@gmail.com>
PR:             kern/124853
2008-06-22 14:34:38 +00:00
Konstantin Belousov
05427aafc6 Struct cdev is always the member of the struct cdev_priv. When devfs
needed to promote cdev to cdev_priv, the si_priv pointer was followed.

Use member2struct() to calculate address of the wrapping cdev_priv.
Rename si_priv to __si_reserved.

Tested by:	pho
Reviewed by:	ed
MFC after:	2 weeks
2008-06-16 17:34:59 +00:00
Konstantin Belousov
9e40a5f827 When devfs_allocv() committed to create new vnode, since de_vnode is NULL,
the dm_lock is held while the newly allocated vnode is locked. Since no
other threads may try to lock the new vnode yet, the LOR there cannot
result in the deadlock.

Shut down the witness warning to note this fact.

Tested by:	pho
Prodded by:	attilio
2008-06-05 09:15:47 +00:00
Ed Schouten
16151645c2 Revert the changes I made to devfs_setattr() in r179457.
As discussed with Robert Watson and John Baldwin, it would be better if
PTY's are created with proper permissions, turning grantpt() into a
no-op.

Bypassing security frameworks like MAC by passing NOCRED to
VOP_SETATTR() will only make things more complex.

Approved by:	philip (mentor)
2008-06-01 14:02:46 +00:00
Ed Schouten
34d1dcf0cc Merge back devfs changes from the mpsafetty branch.
In the mpsafetty branch, PTY's are allocated through the posix_openpt()
system call. The controller side of a PTY now uses its own file
descriptor type (just like sockets, vnodes, pipes, etc).

To remain compatible with existing FreeBSD and Linux C libraries, we can
still create PTY's by opening /dev/ptmx or /dev/ptyXX. These nodes
implement d_fdopen(). Devfs has been slightly changed here, to allow
finit() to be called from d_fdopen().

The routine grantpt() has also been moved into the kernel. This routine
is a little odd, because it needs to bypass standard UNIX permissions.
It needs to change the owner/group/mode of the slave device node, which
may often not be possible. The old implementation solved this by
spawning a setuid utility.

When VOP_SETATTR() is called with NOCRED, devfs_setattr() dereferences
ap->a_cred, causing a kernel panic. Change the de_{uid,gid,mode} code to
allow changes when a->a_cred is set to NOCRED.

Approved by:	philip (mentor)
2008-05-31 14:06:37 +00:00
Konstantin Belousov
772e245341 When vget() fails (because the vnode has been reclaimed), there is no
sense to loop trying to vget() the vnode again.

PR:	122977
Submitted by:	Arthur Hartwig <arthur.hartwig nokia com>
Tested by:	pho
Reviewed by:	jhb
MFC after:	1 week
2008-05-23 16:36:39 +00:00
Konstantin Belousov
82f4d64035 Implement the per-open file data for the cdev.
The patch does not change the cdevsw KBI. Management of the data is
provided by the functions
int	devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t dtr);
int	devfs_get_cdevpriv(void **datap);
void	devfs_clear_cdevpriv(void);
All of the functions are supposed to be called from the cdevsw method
contexts.

- devfs_set_cdevpriv assigns the priv as private data for the file
  descriptor which is used to initiate currently performed driver
  operation. dtr is the function that will be called when either the
  last refernce to the file goes away, the device is destroyed  or
  devfs_clear_cdevpriv is called.
- devfs_get_cdevpriv is the obvious accessor.
- devfs_clear_cdevpriv allows to clear the private data for the still
  open file.

Implementation keeps the driver-supplied pointers in the struct
cdev_privdata, that is referenced both from the struct file and struct
cdev, and cannot outlive any of the referee.

Man pages will be provided after the KPI stabilizes.

Reviewed by:	jhb
Useful suggestions from:	jeff, antoine
Debugging help and tested by:	pho
MFC after:	1 month
2008-05-21 09:31:44 +00:00
John Baldwin
06d0d0e274 Don't explicitly drop Giant around d_open/d_fdopen/d_close for MPSAFE
drivers.  Since devfs is already marked MPSAFE it shouldn't be held
anyway.

MFC after:	2 weeks
Discussed with:	phk
2008-05-07 19:03:57 +00:00
Konstantin Belousov
91a35e7870 Do not dereference cdev->si_cdevsw, use the dev_refthread() to properly
obtain the reference. In particular, this fixes the panic reported in
the PR. Remove the comments stating that this needs to be done.

PR:	kern/119422
MFC after:	1 week
2008-03-20 16:08:42 +00:00
Attilio Rao
81c794f998 Axe the 'thread' argument from VOP_ISLOCKED() and lockstatus() as it is
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>
2008-02-25 18:45:57 +00:00