Commit Graph

373 Commits

Author SHA1 Message Date
kib
55fda50177 Do not copy by field when converting struct oexport_args to struct
export_args on mount update, bzero() is consistent with
vfs_oexport_conv().
Make the code structure more explicit by using switch.
Return EINVAL if export option layout (deduced from size) is unknown.

Based on the submission by:	bde
Sponsored by:	The FreeBSD Foundation
2016-02-04 16:32:21 +00:00
trasz
c1207ee9b8 Make vfs_unmountall() unmount /dev after /, not before. The only
reason this didn't result in an unclean shutdown is that devfs ignores
MNT_FORCE flag.

Reviewed by:	kib@
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D3467
2015-08-24 13:18:13 +00:00
kib
f3f63a15ab Vnode is not referenced by the vfs_domount() at the point where
asserts are made.  Remove them, since we might dereference freed
memory.  Leaked locks are asserted by the syscall return code anyway.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-07-02 14:31:47 +00:00
kib
d77dbf3761 Right now, dounmount() is called with unreferenced mount point.
Nothing stops a parallel unmount to suceed before the given call to
dounmount() checks and locks the covered vnode.  Prevent dounmount()
from acting on the freed (although type-stable) memory by changing the
interface to require the mount point to be referenced.  dounmount()
consumes the reference on return, regardless of the sucessfull or
erronous result.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-05-27 09:22:50 +00:00
kib
7a1bb0de5f Mountd iterating over the mount points may race with the parallel
unmount, which causes error from nmount(2) call when performing
MNT_DELEXPORT over the directory which ceased to be a mount point.

The race is legitimate and innocent, but results in the chatty mountd.
Silence it by providing an distinguished error code for the situation,
and ignoring the error in mountd loop.

Based on the patch by:	Andreas Longwitz <longwitz@incore.de>
Prodded and tested by:	bdrewery
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-02-10 18:00:32 +00:00
kib
c1b643c449 Do not call VFS_SYNC() before VFS_UNMOUNT() for forced unmount.
Since VFS does not/cannot stop writes, sync might run indefinitely, or
be a wrong thing to do at all.  E. g. NFS ignores VFS_SYNC() for
forced unmounts, since non-responding server does not allow sync to
finish.  On the other hand, filesystems can and do stop writes using
fs-specific facilities, and should already fully flush caches in
VFS_UNMOUNT() due to the race.

Adjust msdosfs tp sync in unmount for forced call, to accomodate the
new behaviour.  Note that it is still racy, since writes are not
stopped.

Discussed with:	avg, bjk, mckusick
Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2014-12-09 10:00:47 +00:00
trasz
cac9beab7d Bring in the new automounter, similar to what's provided in most other
UNIX systems, eg. MacOS X and Solaris.  It uses Sun-compatible map format,
has proper kernel support, and LDAP integration.

There are still a few outstanding problems; they will be fixed shortly.

Reviewed by:	allanjude@, emaste@, kib@, wblock@ (earlier versions)
Phabric:	D523
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
2014-08-17 09:44:42 +00:00
kib
17b754a026 Remove Giant acquisition from the mount and unmount pathes.
It could be claimed that two things were reasonable protected by
Giant.  One is vfsconf list links, which is converted to the new
dedicated sx vfsconf_sx.  Another is vfsconf.vfc_refcount, which is
now updated with atomics.

Note that vfc_refcount still has the same races now as it has under
the Giant, the unload of filesystem modules can happen while the
module is still in use.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-08-03 03:27:54 +00:00
bdrewery
b749ffee6a Use proper MFSNAMELEN for fs type.
MFC after:	2 weeks
Reviewed by:	rodrigc
Also spotted by:ambrisko
2014-04-12 21:39:17 +00:00
sbruno
6b64ef7266 Change len checks for fstypelen and fspathlen to be against absolute len
not strlen as they are *not* strings.

Discovered by GSOC student, Mike Ma <mikemandarine@gmail.com> during his
fuse.glusterfs port to FreeBSD.

Final patch from mckusick@

Submitted by:	mckusick@
Approved by:	re (hrs)
MFC after:	2 weeks
2013-10-03 22:52:03 +00:00
rmacklem
8d06f831a7 Forced dismounts of NFS mounts can fail when thread(s) are stuck
waiting for an RPC reply from the server while holding the mount
point busy (mnt_lockref incremented). This happens because dounmount()
msleep()s waiting for mnt_lockref to become 0, before calling
VFS_UNMOUNT(). This patch adds a new VFS operation called VFS_PURGE(),
which the NFS client implements as purging RPCs in progress. Making
this call before checking mnt_lockref fixes the problem, by ensuring
that the VOP_xxx() calls will fail and unbusy the mount point.

Reported by:	sbruno
Reviewed by:	kib
MFC after:	2 weeks
2013-09-01 23:02:59 +00:00
marcel
c660176671 Add vfs_mounted and vfs_unmounted events so that components can be informed
about mount and unmount events. This is used by Juniper to implement a more
optimal implementation of NetBSD's veriexec.

This change differs from r253224 in the following way:
o   The vfs_mounted handler is called before mountcheckdirs() and with
    newdp locked. vp is unlocked.
o   The event handlers are declared in <sys/eventhandler.h> and not in
    <sys/mount.h>. The <sys/mount.h> header is used in user land code
    that pretends to be kernel code and as such creates a very convoluted
    environment. It's hard to untangle.

Submitted by:	stevek@juniper.net
Discussed with:	pjd@
Obtained from:	Juniper Networks, Inc.
2013-07-10 15:35:25 +00:00
marcel
ded5e8df05 Revert r251590. It unexpectedly broke the build and there were some
questions on locking. As part of commit-bit grooming, I'd like Steve
to handle this, but can't leave things broken in the mean time.
2013-06-10 15:22:27 +00:00
marcel
ac0545a5fe Add vfs_mounted and vfs_unmounted events so that components can be informed
about mount and unmount events. This is used by Juniper to implement a more
optimal implementation of NetBSD's veriexec.

Submitted by:	stevek@juniper.net
Obtained from:	Juniper Networks, Inc
2013-06-09 23:51:26 +00:00
gabor
d3ee8e3ff6 - Correct mispellings of the word occurrence
Submitted by:	Christoph Mallon <christoph.mallon@gmx.de> (via private mail)
2013-04-17 11:40:10 +00:00
kib
6fbc70a0bc When the journaled FFS volume is suspended due to the journal space
becoming too low, the softdep flush thread processes the workitems,
which frees the space in journal, and then unsuspends the fs.  The
softdep_flush() and other workitem processing functions busy the
filesystem before iterating over the worklist, to prevent the parallel
unmount from freeing the mount data. The vfs_busy() is called with
MBF_NOWAIT flag.

Now, if the unmount is already started and the filesystem is suspended
due to low journal space, the journal is never flushed and filesystem
is never unsuspended, because vfs_busy(MBF_NOWAIT) call cannot succeed
for the unmounting fs, and softdep_flush() does not process the
workitems. Unmount needs to write metadata, where it hangs in the
"suspfs" state.

Move the vn_start_write() call in the dounmount() before setting the
MNTK_UNMOUNT flag. This practically ensures that softdep_flush()
processed the pending journal writes by making dounmount() wait for
the lift of the suspension.

Sponsored by:	The FreeBSD Foundation
Reported and tested by:	pho
MFC after:	2 weeks
2013-03-20 21:07:49 +00:00
davidxu
ab8145269b Revert revision 244760 because strncpy pads trailing space with zero,
this prevents kernel data from being leaked.

Noticed by: Joerg Sonnenberger &lt; joerg at britannica dot bec dot de &gt;
2013-01-04 11:11:12 +00:00
kib
bc62472c88 Remove the deprecated MNT_VNODE_FOREACH interface. Use the
MNT_VNODE_FOREACH_ALL instead.
2013-01-03 19:02:52 +00:00
davidxu
b7760e9ec4 Use strlcpy to NULL-terminate error message even if user provided a short
buffer.
2012-12-28 02:43:33 +00:00
attilio
0d14b65c78 Fixup r218424: uio_yield() was scaling directly to userland priority.
When kern_yield() was introduced with the possibility to specify
a new priority, the behaviour changed by not lowering priority at all
in the consumers, making the yielding mechanism highly ineffective for
high priority kthreads like bufdaemon, syncer, vlrudaemon, etc.
There are no evidences that consumers could bear with such change in
semantic and this situation could finally lead to bugs similar to the
ones fixed in r244240.
Re-specify userland pri for kthreads involved.

Tested by:	pho
Reviewed by:	kib, mdf
MFC after:	1 week
2012-12-21 13:14:12 +00:00
kib
868d4dc870 Fix typo.
MFC after:	3 days
2012-12-09 20:26:51 +00:00
pjd
a3ce94291c IFp4 @208450:
Remove redundant call to AUDIT_ARG_UPATH1().
Path will be remembered by the following NDINIT(AUDITVNODE1) call.

Sponsored by:	FreeBSD Foundation (auditdistd)
MFC after:	2 weeks
2012-11-30 22:49:28 +00:00
kib
560aa751e0 Remove the support for using non-mpsafe filesystem modules.
In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by:	attilio
Tested by:	pho
2012-10-22 17:50:54 +00:00
kib
5a86a6849a Add a facility for vgone() to inform the set of subscribed mounts
about vnode reclamation. Typical use is for the bypass mounts like
nullfs to get a notification about lower vnode going away.

Now, vgone() calls new VFS op vfs_reclaim_lowervp() with an argument
lowervp which is reclaimed. It is possible to register several
reclamation event listeners, to correctly handle the case of several
nullfs mounts over the same directory.

For the filesystem not having nullfs mounts over it, the overhead
added is a single mount interlock lock/unlock in the vnode reclamation
path.

In collaboration with:	pho
MFC after:	3 weeks
2012-09-09 19:17:15 +00:00
mckusick
5b7b29e35b This change creates a new list of active vnodes associated with
a mount point. Active vnodes are those with a non-zero use or hold
count, e.g., those vnodes that are not on the free list. Note that
this list is in addition to the list of all the vnodes associated
with a mount point.

To avoid adding another set of linkage pointers to the vnode
structure, the active list uses the existing linkage pointers
used by the free list (previously named v_freelist, now renamed
v_actfreelist).

This update adds the MNT_VNODE_FOREACH_ACTIVE interface that loops
over just the active vnodes associated with a mount point (typically
less than 1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by:   Peter Holm
MFC after:   2 weeks
2012-04-20 06:50:44 +00:00
mckusick
ffee40eeff Replace the MNT_VNODE_FOREACH interface with MNT_VNODE_FOREACH_ALL.
The primary changes are that the user of the interface no longer
needs to manage the mount-mutex locking and that the vnode that
is returned has its mutex locked (thus avoiding the need to check
to see if its is DOOMED or other possible end of life senarios).

To minimize compatibility issues for third-party developers, the
old MNT_VNODE_FOREACH interface will remain available so that this
change can be MFC'ed to 9. Following the MFC to 9, MNT_VNODE_FOREACH
will be removed in head.

The reason for this update is to prepare for the addition of the
MNT_VNODE_FOREACH_ACTIVE interface that will loop over just the
active vnodes associated with a mount point (typically less than
1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by:   Peter Holm
MFC after:   2 weeks
2012-04-17 16:28:22 +00:00
gleb
fb452e77b0 Add vfs_getopt_size. Support human readable file system options in tmpfs.
Increase maximum tmpfs file system size to 4GB*PAGE_SIZE on 32 bit archs.

Discussed with:	delphij
MFC after:	2 weeks
2012-04-07 15:27:34 +00:00
kib
5abd2bb7cb Decomission mnt_noasync. Introduce MNTK_NOASYNC mnt_kern_flag which
allows a filesystem to request VFS to not allow MNTK_ASYNC.

MFC after:	1 week
2012-03-09 00:12:05 +00:00
mm
8a4156df5d Analogous to r230407 a separate path buffer in vfs_mount.c is required
for r230129. Fixes a out of bounds write to fspath.

MFC after:	10 days
2012-02-05 10:59:50 +00:00
mckusick
af2e331939 Make sure all intermediate variables holding mount flags (mnt_flag)
and that all internal kernel calls passing mount flags are declared
as uint64_t so that flags in the top 32-bits are not lost.

MFC after: 2 weeks
2012-01-17 01:08:01 +00:00
mm
9f44ed5ca8 Introduce vn_path_to_global_path()
This function updates path string to vnode's full global path and checks
the size of the new path string against the pathlen argument.

In vfs_domount(), sys_unmount() and kern_jail_set() this new function
is used to update the supplied path argument to the respective global path.

Unbreaks jailed zfs(8) with enforce_statfs set to 1.

Reviewed by:	kib
MFC after:	1 month
2012-01-15 12:08:20 +00:00
attilio
8e918ec439 Introduce the option VFS_ALLOW_NONMPSAFE and turn it on by default on
all the architectures.
The option allows to mount non-MPSAFE filesystem. Without it, the
kernel will refuse to mount a non-MPSAFE filesytem.

This patch is part of the effort of killing non-MPSAFE filesystems
from the tree.

No MFC is expected for this patch.

Tested by:	gianni
Reviewed by:	kib
2011-11-08 10:18:07 +00:00
ed
e97eae1577 Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.
This means that their use is restricted to a single C file.
2011-11-07 06:44:47 +00:00
mckusick
b6c294da1b When unmounting a filesystem always wait for the vfs_busy lock to clear
so that if no vnodes in the filesystem are actively in use the unmount
will succeed rather than failing with EBUSY.

Reported by: Garrett Cooper
Reviewed by: Attilio Rao and Kostik Belousov
Tested by:   Garrett Cooper
PR:          kern/161016
MFC after:   3 weeks
2011-10-11 18:46:41 +00:00
kmacy
99851f359e In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by:	rwatson
Approved by:	re (bz)
2011-09-16 13:58:51 +00:00
mm
ad65ea8db8 Revert r224655 and r224614 because vn_fullpath* does not always work
on nullfs mounts.

Change shall be reconsidered after 9.0 is released.

Requested by:	re (kib)
Approved by:	re (kib)
2011-08-08 14:02:08 +00:00
mm
8396492933 The change in r224615 didn't take into account that vn_fullpath_global()
doesn't operate on locked vnode. This could cause a panic.

Fix by unlocking vnode, re-locking afterwards and verifying that it wasn't
renamed or deleted. To improve readability and reduce code size, move code
to a new static function vfs_verify_global_path().

In addition, fix missing giant unlock in unmount().

Reported by:	David Wolfskill <david@catwhisker.org>
Reviewed by:	kib
Approved by:	re (bz)
MFC after:	2 weeks
2011-08-05 11:12:50 +00:00
mm
a1639c8fd4 For mount, discover f_mntonname from supplied path argument
using vn_fullpath_global(). This fixes f_mntonname if mounting
inside chroot, jail or with relative path as argument.

For unmount in jail, use vn_fullpath_global() to discover
global path from supplied path argument. This fixes unmount in jail.

Reviewed by:	pjd, kib
Approved by:	re (kib)
MFC after:	2 weeks
2011-08-02 19:13:56 +00:00
mckusick
64e0ba1afe This update changes the mnt_flag field in the mount structure from
32 bits to 64 bits and eliminates the unused mnt_xflag field.  The
existing mnt_flag field is completely out of bits, so this update
gives us room to expand. Note that the f_flags field in the statfs
structure is already 64 bits, so the expanded mnt_flag field can
be exported without having to make any changes in the statfs structure.

Approved by: re (bz)
2011-07-24 17:43:09 +00:00
ae
4b5a09bf21 Include sys/sbuf.h directly. 2011-07-11 05:17:46 +00:00
mdf
bbbc4c5455 Use a name instead of a magic number for kern_yield(9) when the priority
should not change.  Fetch the td_user_pri under the thread lock.  This
is probably not necessary but a magic number also seems preferable to
knowing the implementation details here.

Requested by:	Jason Behmer < jason DOT behmer AT isilon DOT com >
2011-05-13 05:27:58 +00:00
jh
91fe746b18 Utilize vfs_sanitizeopts() in vfs_mergeopts() to merge options. Because
vfs_sanitizeopts() can handle "ro" and "rw" options properly, there is
no more need to add "noro" in vfs_donmount() to cancel "ro".

This also fixes a problem of canceling options beginning with "no".
For example, "noatime" didn't cancel "nonoatime". Thus it was possible
that both "noatime" and "nonoatime" were active at the same time.

Reviewed by:	bde
2011-04-22 07:26:09 +00:00
jh
b6e26fa641 Fix some style issues in r219925.
Reported by:	bde
MFC after:	1 month
2011-03-26 17:17:24 +00:00
jh
fc3bd08464 Recognize "ro", "rdonly", "norw", "rw" and "noro" as equal options in
vfs_equalopts(). This allows vfs_sanitizeopts() to filter redundant
occurrences of these options. It was possible that for example both "ro"
and "rw" options became active concurrently.

PR:		kern/133614
Discussed on:	freebsd-hackers
MFC after:	1 month
2011-03-23 17:56:38 +00:00
jh
d4c0c6675e Don't restore old mount options and flags if VFS_MOUNT(9) succeeds but
vfs_export() fails. Restoring old options and flags after successful
VFS_MOUNT(9) call may cause the file system internal state to become
inconsistent with mount options and flags. Specifically the FFS super
block fs_ronly field and the MNT_RDONLY flag may get out of sync.

PR:		kern/133614
Discussed on:	freebsd-hackers
2011-02-19 14:27:14 +00:00
mdf
33ee365b55 Based on discussions on the svn-src mailing list, rework r218195:
- entirely eliminate some calls to uio_yeild() as being unnecessary,
   such as in a sysctl handler.

 - move should_yield() and maybe_yield() to kern_synch.c and move the
   prototypes from sys/uio.h to sys/proc.h

 - add a slightly more generic kern_yield() that can replace the
   functionality of uio_yield().

 - replace source uses of uio_yield() with the functional equivalent,
   or in some cases do not change the thread priority when switching.

 - fix a logic inversion bug in vlrureclaim(), pointed out by bde@.

 - instead of using the per-cpu last switched ticks, use a per thread
   variable for should_yield().  With PREEMPTION, the only reasonable
   use of this is to determine if a lock has been held a long time and
   relinquish it.  Without PREEMPTION, this is essentially the same as
   the per-cpu variable.
2011-02-08 00:16:36 +00:00
mdf
b291e9a365 Put the general logic for being a CPU hog into a new function
should_yield().  Use this in various places.  Encapsulate the common
case of check-and-yield into a new function maybe_yield().

Change several checks for a magic number of iterations to use
should_yield() instead.

MFC after:	1 week
2011-02-02 16:35:10 +00:00
jh
aec2294356 Replace spaces with tabs. 2011-01-24 17:08:26 +00:00
pluknet
64dd3dbf39 Update MNT_ROOTFS comments after changes in the root mount logic.
Reported by:	arundel
Suggested by:	marcel (phrasing)
Approved by:	kib (mentor)
2010-11-23 13:49:15 +00:00
marcel
f093b8cccc In vfs_filteropt(), only print the errmsg when there's no errmsg
mount option. Otherwise errors tend to get printed multiple times.
2010-10-18 04:34:42 +00:00