Commit Graph

392 Commits

Author SHA1 Message Date
Konstantin Belousov
03311f117b Use whole mnt_stat.f_fsid bits for st_dev.
Since ino64 expanded dev_t to 64bit, make VOP_GETATTR(9) provide all
bits of mnt_stat.f_fsid as va_fsid for vnodes on filesystems which use
f_fsid.  In particular, NFSv3 and sometimes NFSv4, and ZFS use this
method or reporting st_dev by stat(2).

Provide a new helper vn_fsid() to avoid duplicating code to copy
f_fsid to va_fsid.

Note that the change is mostly cosmetic.  Its motivation is to avoid
sign-extension of f_fsid[0] into 64bit dev_t value which happens after
dev_t becomes 64bit..

Reviewed by:	avg(zfs), rmacklem (nfs) (both for previous version)
Sponsored by:	The FreeBSD Foundation
2017-05-27 17:00:30 +00:00
Konstantin Belousov
6992112349 Commit the 64-bit inode project.
Extend the ino_t, dev_t, nlink_t types to 64-bit ints.  Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment.  Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks.  Unfortunately, not everything can be
fixed, especially outside the base system.  For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING.  Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb).  Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver.  Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem).  Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by:	The FreeBSD Foundation (emaste, kib)
Differential revision:	https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
Ed Maste
3e85b721d6 Remove register keyword from sys/ and ANSIfy prototypes
A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by:	cem, jhb
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D10193
2017-05-17 00:34:34 +00:00
Konstantin Belousov
ecc6c515ab Apply noexec mount option for mmap(PROT_EXEC).
Right now the noexec mount option disallows image activators to try
execve the files on the mount point.  Also, after r127187, noexec
also limits max_prot map entries permissions for mappings of files
from such mounts, but not the actual mapping permissions.

As result, the API behaviour is inconsistent.  The files from noexec
mount can be mapped with PROT_EXEC, but if mprotect(2) drops execution
permission, it cannot be re-enabled later.  Make this consistent
logically and aligned with behaviour of other systems, by disallowing
PROT_EXEC for mmap(2).

Note that this change only ensures aligned results from mmap(2) and
mprotect(2), it does not prevent actual code execution from files
coming from noexec mount.  Such files can always be read into
anonymous executable memory and executed from there.

Reported by:	shamaz.mazum@gmail.com
PR:	217062
Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-02-19 20:51:04 +00:00
Konstantin Belousov
987ff18184 Consistently handle negative or wrapping offsets in the mmap(2) syscalls.
For regular files and posix shared memory, POSIX requires that
[offset, offset + size) range is legitimate.  At the maping time,
check that offset is not negative.  Allowing negative offsets might
expose the data that filesystem put into vm_object for internal use,
esp. due to OFF_TO_IDX() signess treatment.  Fault handler verifies
that the mapped range is valid, assuming that mmap(2) checked that
arithmetic gives no undefined results.

For device mappings, leave the semantic of negative offsets to the
driver.  Correct object page index calculation to not erronously
propagate sign.

In either case, disallow overflow of offset + size.

Update mmap(2) man page to explain the requirement of the range
validity, and behaviour when the range becomes invalid after mapping.

Reported and tested by:	royger (previous version)
Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-02-12 21:05:44 +00:00
Konstantin Belousov
e83a71c656 Fix r313495.
The file type DTYPE_VNODE can be assigned as a fallback if VOP_OPEN()
did not initialized file type.  This is a typical code path used by
normal file systems.

Also, change error returned for inappropriate file type used for
O_EXLOCK to EOPNOTSUPP, as declared in the open(2) man page.

Reported by:	cy, dhw, Iblis Lin <iblis@hs.ntnu.edu.tw>
Tested by:	dhw
Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2017-02-10 14:49:04 +00:00
Konstantin Belousov
e628e1b919 Increase a chance of devfs_close() calling d_close cdevsw method.
If a file opened over a vnode has an advisory lock set at close,
vn_closefile() acquires additional vnode use reference to prevent
freeing the vnode in vn_close().  Side effect is that for device
vnodes, devfs_close() sees that vnode reference count is greater than
one and refuses to call d_close().  Create internal version of
vn_close() which can avoid dropping the vnode reference if needed, and
use this to execute VOP_CLOSE() without acquiring a new reference.

Note that any parallel reference to the vnode would still prevent
d_close call, if the reference is not from an opened file, e.g. due to
stat(2).

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-02-09 23:36:50 +00:00
Konstantin Belousov
7903b00087 Do not establish advisory locks when doing open(O_EXLOCK) or open(O_SHLOCK)
for files which do not have DTYPE_VNODE type.

Both flock(2) and fcntl(2) syscalls refuse to acquire advisory lock on
a file which type is not DTYPE_VNODE.  Do the same when lock is
requested from open(2).

Restructure the block in vn_open_vnode() which handles O_EXLOCK and
O_SHLOCK open flags to make it easier to quit its execution earlier
with an error.

Tested by:	pho (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-02-09 23:35:57 +00:00
Mateusz Guzik
f1f7f1cb29 hwpmc: partially depessimize mmap handling if the module is not loaded
In particular this means the pmc sx lock is no longer taken when an
executable mapping succeeds.

MFC after:	1 week
2017-01-27 22:13:15 +00:00
Konstantin Belousov
25c6816845 More style cleanup. Use ANSI C definition for vn_closefile(). Switch
to VNASSERT in _vn_lock(), simplify messages.

Sponsored by:	The FreeBSD Foundation
X-MFC with:	r312600, r312601, r312602, r312606
2017-01-22 19:38:45 +00:00
Mateusz Guzik
eaf0969bda vfs: fix LK_RETRY logic braino in r312600 2017-01-21 20:34:20 +00:00
Mateusz Guzik
829857c893 vfs: __predict_false the need to handle F_HASLOCK
Also reorder the check with DTYPE_VNODE. Passed files are vnodes vast
majority of the time, so it is typically true.
2017-01-21 19:01:42 +00:00
Mateusz Guzik
abbc538d9a vfs: fix whitespace damage in r312600
While here wrap the previously overly long line so that it fits 80 chars.
2017-01-21 18:56:58 +00:00
Mateusz Guzik
1091fb52c1 vfs: refactor _vn_lock
Stop testing for LK_RETRY and error multiple times. Also postpone the
VI_DOOMED until after LK_RETRY was seen as it reads from the vnode.

No functional changes.
2017-01-21 18:38:16 +00:00
Ed Maste
69a2875821 Renumber license clauses in sys/kern to avoid skipping #3 2016-09-15 13:16:20 +00:00
Robert Watson
c3c0088bb0 Audit additional vnode information in the implementation of the
ftruncate(2) system call.  This was not required by the Common
Criteria, which needed only open-time audit.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2016-08-20 18:51:48 +00:00
Conrad Meyer
af326ace9d devfs: Move most ioctl logic down to vnode layer
Devfs' file layer ioctl is now just a thin shim around the vnode layer.

Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D7286
2016-07-25 16:28:02 +00:00
Robert Watson
971711fb7c Call audit hooks to capture vnode attributes for three file-descriptor
method implementations: fstat(2), close(2), and poll(2).  This change
synchronises auditing here with similar auditing for VFS-specific system
calls such as stat(2) that audit more complete vnode information.

Sponsored by:	DARPA, AFRL
Approved by:	re (kib)
MFC after:	1 week
2016-07-05 16:37:01 +00:00
Konstantin Belousov
3f7ca894de Ensure that ftruncate(2) is performed synchronously when file is
opened in O_SYNC mode, at least for UFS.  This also handles
truncation, done due to the O_SYNC | O_TRUNC flags combination to
open(2), in synchronous way.

Noted by:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-05-18 12:03:57 +00:00
Pedro F. Giffuni
31b6732008 sys/kern: spelling fixes.
Mostly on comments but affects some debug messages.

MFC after: 2 weeks
2016-04-29 21:54:28 +00:00
Pedro F. Giffuni
74b8d63dcc Cleanup unnecessary semicolons from the kernel.
Found with devel/coccinelle.
2016-04-10 23:07:00 +00:00
Konstantin Belousov
6adf19481c The struct file f_advice member is overlaid with the devfs f_cdevpriv
data.  If vnode bypass for devfs file failed, vn_read/vn_write are
called and might try to dereference f_advice.  Limit the accesses to
f_advice to VREG vnodes only, which is the type ensured by
posix_fadvise().

The f_advice for regular files is protected by mtxpool lock.  Recheck
that f_advice is not NULL after lock is taken.

Reported and tested by:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2016-01-22 20:35:20 +00:00
Konstantin Belousov
ce958bdefe When cleaning up from failed adv locking and checking for write, do
not call VOP_CLOSE() manually.  Instead, delegate the close to
fo_close() performed as part of the fdrop() on the file failed to
open.  For this, finish constructing file on error, in particular, set
f_vnode and f_ops.

Forcibly resetting f_ops to badfileops disabled additional cleanups
performed by fo_close() for some file types, in this case it was noted
that cdevpriv data was corrupted.  Since fo_close() call must be
enabled for some file types, it makes more sense to enable it for all
files opened through vn_open_cred().

In collaboration with:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-01-17 08:40:51 +00:00
Fabien Thomas
78e79434d2 Fix r283998 that broke mapin events for hwpmc.
Reviewed by:	jhb
Sponsored by:	Stormshield
2015-10-08 09:54:33 +00:00
Mark Johnston
3138cd3670 As a step towards the elimination of PG_CACHED pages, rework the handling
of POSIX_FADV_DONTNEED so that it causes the backing pages to be moved to
the head of the inactive queue instead of being cached.

This affects the implementation of POSIX_FADV_NOREUSE as well, since it
works by applying POSIX_FADV_DONTNEED to file ranges after they have been
read or written.  At that point the corresponding buffers may still be
dirty, so the previous implementation would coalesce successive ranges and
apply POSIX_FADV_DONTNEED to the result, ensuring that pages backing the
dirty buffers would eventually be cached.  To preserve this behaviour in an
efficient manner, this change adds a new buf flag, B_NOREUSE, which causes
the pages backing a VMIO buf to be placed at the head of the inactive queue
when the buf is released.  POSIX_FADV_NOREUSE then works by setting this
flag in bufs that underlie the specified range.

Reviewed by:	alc, kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D3726
2015-09-30 23:06:29 +00:00
Konstantin Belousov
9e18c9eb27 For open("name", O_DIRECTORY | O_CREAT), do not try to create the
named node, open(2) cannot create directories.  But do allow the flag
combination to succeed if the directory already exists.

Declare the open("name", O_DIRECTORY | O_CREAT | O_EXCL) always
invalid for the same reason, since open(2) cannot create directory.

Note that there is an argument that O_DIRECTORY | O_CREAT should be
invalid always, regardless of the target directory existence or
O_EXCL.  The current fix is conservative and allows the call to
succeed in the situation where it succeeded before the patch.

Reported by:	Tom Ridge <freebsd@tom-ridge.com>
Reviewed by:	rwatson
PR:	 202892
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-09-09 19:31:08 +00:00
Conrad Meyer
14bdbaf2e4 Detect badly behaved coredump note helpers
Coredump notes depend on being able to invoke dump routines twice; once
in a dry-run mode to get the size of the note, and another to actually
emit the note to the corefile.

When a note helper emits a different length section the second time
around than the length it requested the first time, the kernel produces
a corrupt coredump.

NT_PROCSTAT_FILES output length, when packing kinfo structs, is tied to
the length of filenames corresponding to vnodes in the process' fd table
via vn_fullpath.  As vnodes may move around during dump, this is racy.

So:

 - Detect badly behaved notes in putnote() and pad underfilled notes.

 - Add a fail point, debug.fail_point.fill_kinfo_vnode__random_path to
   exercise the NT_PROCSTAT_FILES corruption.  It simply picks random
   lengths to expand or truncate paths to in fo_fill_kinfo_vnode().

 - Add a sysctl, kern.coredump_pack_fileinfo, to allow users to
   disable kinfo packing for PROCSTAT_FILES notes.  This should avoid
   both FILES note corruption and truncation, even if filenames change,
   at the cost of about 1 kiB in padding bloat per open fd.  Document
   the new sysctl in core.5.

 - Fix note_procstat_files to self-limit in the 2nd pass.  Since
   sometimes this will result in a short write, pad up to our advertised
   size.  This addresses note corruption, at the risk of sometimes
   truncating the last several fd info entries.

 - Fix NT_PROCSTAT_FILES consumers libutil and libprocstat to grok the
   zero padding.

With suggestions from:	bjk, jhb, kib, wblock
Approved by:	markj (mentor)
Relnotes:	yes
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D3548
2015-09-03 20:32:10 +00:00
Konstantin Belousov
8917728875 vn_io_fault() handling of the LOR for i/o into the file-backed buffers
has observable overhead when the buffer pages are not resident or not
mapped.  The overhead comes at least from two factors, one is the
additional work needed to detect the situation, prepare and execute
the rollbacks.  Another is the consequence of the i/o splitting into
the batches of the held pages, causing filesystems see series of the
smaller i/o requests instead of the single large request.

Note that expected case of the resident i/o buffer does not expose
these issues.  Provide a prefaulting for the userspace i/o buffers,
disabled by default.  I am careful of not enabling prefaulting by
default for now, since it would be detrimental for the applications
which speculatively pass extra-large buffers of anonymous memory to
not deal with buffer sizing (if such apps exist).

Found and tested by:	bde, emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-07-31 04:12:51 +00:00
Mark Johnston
5f34e93c58 Check suspendability on the mountpoint returned by VOP_GETWRITEMOUNT.
This obviates the need for a MNTK_SUSPENDABLE flag, since passthrough
filesystems like nullfs and unionfs no longer need to inherit this
information from their lower layer(s). This change also restores the
pre-r273336 behaviour of using the presence of a susp_clean VFS method to
request suspension support.

Reviewed by:	kib, mjg
Differential Revision:	https://reviews.freebsd.org/D2937
2015-07-05 22:37:33 +00:00
Mateusz Guzik
f6f6d24062 Implement lockless resource limits.
Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
2015-06-10 10:48:12 +00:00
John Baldwin
7077c42623 Add a new file operations hook for mmap operations. File type-specific
logic is now placed in the mmap hook implementation rather than requiring
it to be placed in sys/vm/vm_mmap.c.  This hook allows new file types to
support mmap() as well as potentially allowing mmap() for existing file
types that do not currently support any mapping.

The vm_mmap() function is now split up into two functions.  A new
vm_mmap_object() function handles the "back half" of vm_mmap() and accepts
a referenced VM object to map rather than a (handle, handle_type) tuple.
vm_mmap() is now reduced to converting a (handle, handle_type) tuple to a
a VM object and then calling vm_mmap_object() to handle the actual mapping.
The vm_mmap() function remains for use by other parts of the kernel
(e.g. device drivers and exec) but now only supports mapping vnodes,
character devices, and anonymous memory.

The mmap() system call invokes vm_mmap_object() directly with a NULL object
for anonymous mappings.  For mappings using a file descriptor, the
descriptors fo_mmap() hook is invoked instead.  The fo_mmap() hook is
responsible for performing type-specific checks and adjustments to
arguments as well as possibly modifying mapping parameters such as flags
or the object offset.  The fo_mmap() hook routines then call
vm_mmap_object() to handle the actual mapping.

The fo_mmap() hook is optional.  If it is not set, then fo_mmap() will
fail with ENODEV.  A fo_mmap() hook is implemented for regular files,
character devices, and shared memory objects (created via shm_open()).

While here, consistently use the VM_PROT_* constants for the vm_prot_t
type for the 'prot' variable passed to vm_mmap() and vm_mmap_object()
as well as the vm_mmap_vnode() and vm_mmap_cdev() helper routines.
Previously some places were using the mmap()-specific PROT_* constants
instead.  While this happens to work because PROT_xx == VM_PROT_xx,
using VM_PROT_* is more correct.

Differential Revision:	https://reviews.freebsd.org/D2658
Reviewed by:	alc (glanced over), kib
MFC after:	1 month
Sponsored by:	Chelsio
2015-06-04 19:41:15 +00:00
Konstantin Belousov
2db0e1f50d Add V_MNTREF flag to the vn_start_write(9) and
vn_start_secondary_write(9) functions.  The flag indicates that the
caller already owns a reference on the mount point, and the functions
can consume it.  The reference is released by vn_finished_write(9) and
vn_finished_secondary_write(9) in due course.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-05-27 09:21:47 +00:00
Craig Rodrigues
d5fec48956 Support file verification in MAC.
* Add VCREAT flag to indicate when a new file is being created
* Add VVERIFY to indicate verification is required
* Both VCREAT and VVERIFY are only passed on the MAC method vnode_check_open
  and are removed from the accmode after
* Add O_VERIFY flag to rtld open of objects
* Add 'v' flag to __sflags to set O_VERIFY flag.

Submitted by:		Steve Kiernan <stevek@juniper.net>
Obtained from:		Juniper Networks, Inc.
GitHub Pull Request:	https://github.com/freebsd/freebsd/pull/27
Relnotes:		yes
2015-04-22 01:54:25 +00:00
Konstantin Belousov
8ee9765a9d Add VN_OPEN_NAMECACHE flag for vn_open_cred(9), which requests that
the created file name was cached.  Use the flag for core dumps.

Requested by:	rpaulo
Tested by:	pho (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-12-21 13:32:07 +00:00
Konstantin Belousov
6c21f6edb8 The VOP_LOOKUP() implementations for CREATE op do not put the name
into namecache, to avoid cache trashing when doing large operations.
E.g., tar archive extraction is not usually followed by access to many
of the files created.

Right now, each VOP_LOOKUP() implementation explicitely knowns about
this quirk and tests for both MAKEENTRY flag presence and op != CREATE
to make the call to cache_enter().  Centralize the handling of the
quirk into VFS, by deciding to cache only by MAKEENTRY flag in VOP.
VFS now sets NOCACHE flag for CREATE namei() calls.

Note that the change in semantic is backward-compatible and could be
merged to the stable branch, and is compatible with non-changed
third-party filesystems which correctly handle MAKEENTRY.

Suggested by:	Chris Torek <torek@pi-coral.com>
Reviewed by:	mckusick
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-12-18 10:01:12 +00:00
Konstantin Belousov
0061ddb3ed Only sleep interruptible while waiting for suspension end when
filesystem specified VFCF_SBDRY flag, i.e. for NFS.

There are two issues with the sleeps.  First, applications may get
unexpected EINTR from the disk i/o syscalls.  Second, interruptible
sleep allows the stop of the process, and since mount point is
referenced while thread sleeps, unmount cannot free mount point
structure' memory, blocking unmount indefinitely.

Even for NFS, it is probably only reasonable to enable PCATCH for intr
mounts, but this information is currently not available at VFS level.

Reported and tested by:	pho (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-12-13 16:07:01 +00:00
Konstantin Belousov
5fab60a071 In vfs_write_suspend_umnt(), if suspension cannot be established, do
not forget to restore write ops count when returning the error.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-14 11:31:10 +00:00
Mateusz Guzik
4fce16e4c9 Provide vfs suspension support only for filesystems which need it, take
two.

nullfs and unionfs need to request suspension if underlying filesystem(s)
use it. Utilize mnt_kern_flag for this purpose.

This is a fixup for 273271.

No strong objections from: kib
Pointy hat to: mjg
MFC after:	2 weeks
2014-10-20 18:00:50 +00:00
Mateusz Guzik
020b8f17a0 Provide vfs suspension support only for filesystems which need it.
Need is expressed by providing vfs_susp_clean function in vfsops.

Differential Revision:	D952
Reviewed by:	kib (previous version)
MFC after:	2 weeks
2014-10-19 06:59:33 +00:00
Konstantin Belousov
4142462eeb Slightly reword comment. Move code, which is described by the
comment, after it.

Discussed with:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-10-04 18:51:55 +00:00
Konstantin Belousov
e3d6feceb1 Add IO_RANGELOCKED flag for vn_rdwr(9), which specifies that vnode is
not locked, but range is.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-10-04 18:28:27 +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
Mateusz Guzik
037755fd15 Fix up races with f_seqcount handling.
It was possible that the kernel would overwrite user-supplied hint.

Abuse vnode lock for this purpose.

In collaboration with: kib
MFC after:	1 week
2014-08-26 08:17:22 +00:00
Konstantin Belousov
895b3782c6 Extract the code to put a filesystem into the suspended state (at the
unmount time) in the helper vfs_write_suspend_umnt().  Use it instead
of two inline copies in FFS.

Fix the bug in the FFS unmount, when suspension failed, the ufs
extattrs were not reinitialized.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-07-14 09:10:00 +00:00
Konstantin Belousov
a69452162a Generalize vn_get_ino() to allow filesystems to use custom vnode
producer, instead of hard-coding VFS_VGET().  New function, which
takes callback, is called vn_get_ino_gen(), standard callback for
vn_get_ino() is provided.

Convert inline copies of vn_get_ino() in msdosfs and cd9660 into the
uses of vn_get_ino_gen().

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-07-14 08:34:54 +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
Konstantin Belousov
2e501b0a9e Use vn_io_fault for the writes from core dumping code. Recursing into
VM due to copyin(9) faulting while VFS locks are held is
deadlock-prone there in the same way as for the write(2) syscall.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2014-06-15 04:51:53 +00:00
John-Mark Gurney
6f2b769cac change td_retval into a union w/ off_t, with defines to mask the
change...  This eliminates a cast, and also forces td_retval
(often 2 32-bit registers) to be aligned so that off_t's can be
stored there on arches with strict alignment requirements like
armeb (AVILA)...  On i386, this doesn't change alignment, and on
amd64 it doesn't either, as register_t is already 64bits...

This will also prevent future breakage due to people adding additional
fields to the struct...

This gets AVILA booting a bit farther...

Reviewed by:	bde
2014-03-16 00:53:40 +00:00
Konstantin Belousov
65f05eeb3d If vn_open_vnode() succeeded in opening the vnode, but subsequent
advisory lock cannot be obtained, prevent double-close of the vnode in
vn_close() called from the fdrop(), by resetting file' f_ops methods.

Reported and tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2013-12-17 17:31:16 +00:00
Konstantin Belousov
7e14088d93 Revert back to use int for the page counts. In vn_io_fault(), the i/o
is chunked to pieces limited by integer io_hold_cnt tunable, while
vm_fault_quick_hold_pages() takes integer max_count as the upper bound.

Rearrange the checks to correctly handle overflowing address arithmetic.

Submitted by:	bde
Tested by:	pho
Discussed with:	alc
MFC after:	1 week
2013-11-20 08:45:26 +00:00