Commit Graph

241 Commits

Author SHA1 Message Date
Konstantin Belousov
555b7bb4c8 Mark pages after EOF as clean after pageout.
Suppose that a file on NFS has partially filled last page, and this
page is dirty.  NFS VOP_PAGEOUT() method only marks the the page clean
up to the block of the last written byte, leaving other blocks dirty.
Also any page which erronously exists in the vnode vm_object past EOF
is also left marked as dirty.

With the introduction of the buf-cache coherent pager, each pass of
syncer over the object with such page results in creation of B_DELWRI
buffer due to VOP_WRITE() call.  This buffer is noted on next syncer
pass, which results e.g. a visible manifestation of shutdown never
finishing vnode sync.  Note that before buf-cache coherency commit, a
dirty page might left never synced to server if a partial writes
occur.

Fix this by clearing dirty bits after EOF.  Only blocks of the partial
page which are completely after EOF are marked clean, to avoid
possible user data loss.

Reported by:	mav
Reviewed by:	alc, markj
Tested by:	mav, pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D11697
2017-07-26 20:07:05 +00:00
John Baldwin
15a88f8158 Consistently use vop_stdpathconf() for default pathconf values.
Update filesystems not currently using vop_stdpathconf() in pathconf
VOPs to use vop_stdpathconf() for any configuration variables that do
not have filesystem-specific values.  vop_stdpathconf() is used for
variables that have system-wide settings as well as providing default
values for some values based on system limits.  Filesystems can still
explicitly override individual settings.

PR:		219851
Reported by:	cem
Reviewed by:	cem, kib, ngie
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D11541
2017-07-11 21:55:20 +00:00
Gleb Smirnoff
83c9dea1ba - Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter
in place.  To do per-cpu stats, convert all fields that previously were
  maintained in the vmmeters that sit in pcpus to counter(9).
- Since some vmmeter stats may be touched at very early stages of boot,
  before we have set up UMA and we can do counter_u64_alloc(), provide an
  early counter mechanism:
  o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter.
  o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter,
    so that at early stages of boot, before counters are allocated we already
    point to a counter that can be safely written to.
  o For sparc64 that required a whole dummy pcpu[MAXCPU] array.

Further related changes:
- Don't include vmmeter.h into pcpu.h.
- vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit,
  to match kernel representation.
- struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion.

This is based on benno@'s 4-year old patch:
https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html

Reviewed by:	kib, gallatin, marius, lidl
Differential Revision:	https://reviews.freebsd.org/D10156
2017-04-17 17:34:47 +00:00
Conrad Meyer
8844e55d4a smbfs: Fix an indentation level
Based on the change in r242386, it seems clear that scred was intended to
be released in all paths at exit.

No functional change.  This line's indent was just the result of a bad copy
paste from the previous free() in an early exit path.

Reported by:	PVS-Studio
Sponsored by:	Dell EMC Isilon
2017-04-06 17:31:58 +00:00
Edward Tomasz Napierala
411455a8fb Replace all remaining calls to vprint(9) with vn_printf(9), and remove
the old macro.

MFC after:	1 month
2016-08-10 16:12:31 +00:00
Pedro F. Giffuni
b3a15ddd5b sys/fs: spelling fixes in comments.
No functional change.
2016-04-29 20:51:24 +00:00
Pedro F. Giffuni
74b8d63dcc Cleanup unnecessary semicolons from the kernel.
Found with devel/coccinelle.
2016-04-10 23:07:00 +00:00
Andrey V. Elsukov
c829016e85 Change the type of newsize argument in the smbfs_smb_setfsize() function
from int to int64.
MSDN says that SMB_SET_FILE_END_OF_FILE_INFO uses signed 64-bit integer
to specify offset, but since smbfs_smb_setfsize() has used plain int,
a value was truncated in case when offset was larger than 2G.
	https://msdn.microsoft.com/en-us/library/ff469975.aspx

In particular, now `truncate -s 10G` will work correctly on the mounted
SMB share.

Reported and tested by:	Eugene Grosbein <eugen at grosbein dot net>
MFC after:	1 week
2016-01-11 18:11:06 +00:00
Gleb Smirnoff
f17f88d3e0 Fix breakage caused by r292373 in ZFS/FUSE/NFS/SMBFS.
With the new VOP_GETPAGES() KPI the "count" argument counts pages already,
and doesn't need to be translated from bytes to pages.

While here make it consistent that *rbehind and *rahead are updated only
if we doesn't return error.

Pointy hat to:	glebius
2015-12-16 23:48:50 +00:00
Gleb Smirnoff
b0cd20172d A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES().
o With new KPI consumers can request contiguous ranges of pages, and
  unlike before, all pages will be kept busied on return, like it was
  done before with the 'reqpage' only. Now the reqpage goes away. With
  new interface it is easier to implement code protected from race
  conditions.

  Such arrayed requests for now should be preceeded by a call to
  vm_pager_haspage() to make sure that request is possible. This
  could be improved later, making vm_pager_haspage() obsolete.

  Strenghtening the promises on the business of the array of pages
  allows us to remove such hacks as swp_pager_free_nrpage() and
  vm_pager_free_nonreq().

o New KPI accepts two integer pointers that may optionally point at
  values for read ahead and read behind, that a pager may do, if it
  can. These pages are completely owned by pager, and not controlled
  by the caller.

  This shifts the UFS-specific readahead logic from vm_fault.c, which
  should be file system agnostic, into vnode_pager.c. It also removes
  one VOP_BMAP() request per hard fault.

Discussed with:	kib, alc, jeff, scottl
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-12-16 21:30:45 +00:00
Dimitry Andric
7f4daa88f1 Fix a -Wcast-qual warning in smbfs_subr.c, by using __DECONST. No
functional change.

MFC after:	3 days
2015-01-30 22:02:32 +00:00
Edward Tomasz Napierala
836856e3e6 Fix smbfs to not zero out statfs f_flags field. Previously, this
made getmntinfo() return empty flags for smbfs filesystems when
called with MNT_WAIT. It's not visible with mount(8), since it uses
MNT_NOWAIT, but broke autounmount(8) operation.

PR:		195161
Differential Revision:	https://reviews.freebsd.org/D1194
Reviewed by:	kib@
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
2014-11-21 06:21:39 +00:00
Gleb Smirnoff
27ad26d8c7 Remove unused arguments for VOP_GETPAGES(), VOP_PUTPAGES(). 2014-09-10 12:36:41 +00:00
Andrey V. Elsukov
14b2dc3952 Use SMB_QUERY_FS_SIZE_INFO request to populate statfs structure.
When server doesn't support this request, try to use SMB_INFO_ALLOCATION.
And use SMB_COM_QUERY_INFORMATION_DISK request as fallback.

MFC after:	2 weeks
2014-04-15 09:10:01 +00:00
Kenneth D. Merry
7da1a731c6 Expand the use of stat(2) flags to allow storing some Windows/DOS
and CIFS file attributes as BSD stat(2) flags.

This work is intended to be compatible with ZFS, the Solaris CIFS
server's interaction with ZFS, somewhat compatible with MacOS X,
and of course compatible with Windows.

The Windows attributes that are implemented were chosen based on
the attributes that ZFS already supports.

The summary of the flags is as follows:

UF_SYSTEM:	Command line name: "system" or "usystem"
		ZFS name: XAT_SYSTEM, ZFS_SYSTEM
		Windows: FILE_ATTRIBUTE_SYSTEM

		This flag means that the file is used by the
		operating system.  FreeBSD does not enforce any
		special handling when this flag is set.

UF_SPARSE:	Command line name: "sparse" or "usparse"
		ZFS name: XAT_SPARSE, ZFS_SPARSE
		Windows: FILE_ATTRIBUTE_SPARSE_FILE

		This flag means that the file is sparse.  Although
		ZFS may modify this in some situations, there is
		not generally any special handling for this flag.

UF_OFFLINE:	Command line name: "offline" or "uoffline"
		ZFS name: XAT_OFFLINE, ZFS_OFFLINE
		Windows: FILE_ATTRIBUTE_OFFLINE

		This flag means that the file has been moved to
		offline storage.  FreeBSD does not have any special
		handling for this flag.

UF_REPARSE:	Command line name: "reparse" or "ureparse"
		ZFS name: XAT_REPARSE, ZFS_REPARSE
		Windows: FILE_ATTRIBUTE_REPARSE_POINT

		This flag means that the file is a Windows reparse
		point.  ZFS has special handling code for reparse
		points, but we don't currently have the other
		supporting infrastructure for them.

UF_HIDDEN:	Command line name: "hidden" or "uhidden"
		ZFS name: XAT_HIDDEN, ZFS_HIDDEN
		Windows: FILE_ATTRIBUTE_HIDDEN

		This flag means that the file may be excluded from
		a directory listing if the application honors it.
		FreeBSD has no special handling for this flag.

		The name and bit definition for UF_HIDDEN are
		identical to the definition in MacOS X.

UF_READONLY:	Command line name: "urdonly", "rdonly", "readonly"
		ZFS name: XAT_READONLY, ZFS_READONLY
		Windows: FILE_ATTRIBUTE_READONLY

		This flag means that the file may not written or
		appended, but its attributes may be changed.

		ZFS currently enforces this flag, but Illumos
		developers have discussed disabling enforcement.

		The behavior of this flag is different than MacOS X.
		MacOS X uses UF_IMMUTABLE to represent the DOS
		readonly permission, but that flag has a stronger
		meaning than the semantics of DOS readonly permissions.

UF_ARCHIVE:	Command line name: "uarch", "uarchive"
		ZFS_NAME: XAT_ARCHIVE, ZFS_ARCHIVE
		Windows name: FILE_ATTRIBUTE_ARCHIVE

		The UF_ARCHIVED flag means that the file has changed and
		needs to be archived.  The meaning is same as
		the Windows FILE_ATTRIBUTE_ARCHIVE attribute, and
		the ZFS XAT_ARCHIVE and ZFS_ARCHIVE attribute.

		msdosfs and ZFS have special handling for this flag.
		i.e. they will set it when the file changes.

sys/param.h:		Bump __FreeBSD_version to 1000047 for the
			addition of new stat(2) flags.

chflags.1:		Document the new command line flag names
			(e.g. "system", "hidden") available to the
			user.

ls.1:			Reference chflags(1) for a list of file flags
			and their meanings.

strtofflags.c:		Implement the mapping between the new
			command line flag names and new stat(2)
			flags.

chflags.2:		Document all of the new stat(2) flags, and
			explain the intended behavior in a little
			more detail.  Explain how they map to
			Windows file attributes.

			Different filesystems behave differently
			with respect to flags, so warn the
			application developer to take care when
			using them.

zfs_vnops.c:		Add support for getting and setting the
			UF_ARCHIVE, UF_READONLY, UF_SYSTEM, UF_HIDDEN,
			UF_REPARSE, UF_OFFLINE, and UF_SPARSE flags.

			All of these flags are implemented using
			attributes that ZFS already supports, so
			the on-disk format has not changed.

			ZFS currently doesn't allow setting the
			UF_REPARSE flag, and we don't really have
			the other infrastructure to support reparse
			points.

msdosfs_denode.c,
msdosfs_vnops.c:	Add support for getting and setting
			UF_HIDDEN, UF_SYSTEM and UF_READONLY
			in MSDOSFS.

			It supported SF_ARCHIVED, but this has been
			changed to be UF_ARCHIVE, which has the same
			semantics as the DOS archive attribute instead
			of inverse semantics like SF_ARCHIVED.

			After discussion with Bruce Evans, change
			several things in the msdosfs behavior:

			Use UF_READONLY to indicate whether a file
			is writeable instead of file permissions, but
			don't actually enforce it.

			Refuse to change attributes on the root
			directory, because it is special in FAT
			filesystems, but allow most other attribute
			changes on directories.

			Don't set the archive attribute on a directory
			when its modification time is updated.
			Windows and DOS don't set the archive attribute
			in that scenario, so we are now bug-for-bug
			compatible.

smbfs_node.c,
smbfs_vnops.c:		Add support for UF_HIDDEN, UF_SYSTEM,
			UF_READONLY and UF_ARCHIVE in SMBFS.

			This is similar to changes that Apple has
			made in their version of SMBFS (as of
			smb-583.8, posted on opensource.apple.com),
			but not quite the same.

			We map SMB_FA_READONLY to UF_READONLY,
			because UF_READONLY is intended to match
			the semantics of the DOS readonly flag.
			The MacOS X code maps both UF_IMMUTABLE
			and SF_IMMUTABLE to SMB_FA_READONLY, but
			the immutable flags have stronger meaning
			than the DOS readonly bit.

stat.h:			Add definitions for UF_SYSTEM, UF_SPARSE,
			UF_OFFLINE, UF_REPARSE, UF_ARCHIVE, UF_READONLY
			and UF_HIDDEN.

			The definition of UF_HIDDEN is the same as
			the MacOS X definition.

			Add commented-out definitions of
			UF_COMPRESSED and UF_TRACKED.  They are
			defined in MacOS X (as of 10.8.2), but we
			do not implement them (yet).

ufs_vnops.c:		Add support for getting and setting
			UF_ARCHIVE, UF_HIDDEN, UF_OFFLINE, UF_READONLY,
			UF_REPARSE, UF_SPARSE, and UF_SYSTEM in UFS.
			Alphabetize the flags that are supported.

			These new flags are only stored, UFS does
			not take any action if the flag is set.

Sponsored by:	Spectra Logic
Reviewed by:	bde (earlier version)
2013-08-21 23:04:48 +00:00
Davide Italiano
9e9421bcdf - Fix double frees/user after free.
- Allocate using smb_rq_alloc() instead of inlining it.

Reported by:	uqs
Found with:	Coverity Scan
2013-07-03 10:31:45 +00:00
Davide Italiano
bbc6d2c1af Properly use v_data field. This magically worked (even if wrong) until
now because v_data is the first field of the structure, but it's not
something we should rely on.
2013-06-28 20:32:48 +00:00
Davide Italiano
189e41259b Garbage collect an useless check. smp should be never NULL. 2013-06-28 20:14:30 +00:00
Davide Italiano
c7d2e4cf9b Plug a couple of leakages in smbfs_lookup(). 2013-06-28 20:07:24 +00:00
Davide Italiano
caa8e38fa6 Change VM_OBJECT_LOCK/UNLOCK() -> VM_OBJECT_WLOCK/WUNLOCK() to reflect
the recent switch of the vm object lock to a rwlock.

Reported by:	attilio
2013-05-04 14:27:28 +00:00
Davide Italiano
a4c059845a Overhaul locking in netsmb, getting rid of the obsolete lockmgr() primitive.
This solves a long standing LOR between smb_conn and smb_vc.

Tested by:	martymac, pho (previous version)
2013-05-04 14:18:10 +00:00
Davide Italiano
92a4d9bcc8 Completely rewrite the interface to smbdev switching from dev_clone
to cdevpriv(9). This commit changes the semantic of mount_smbfs
in userland as well, which now passes file descriptor in order to
to mount a specific filesystem istance.

Reviewed by:	attilio, ed
Tested by:	martymac
2013-05-04 14:03:18 +00:00
Davide Italiano
ce589ae2a7 smbfs_lookup() in the DOTDOT case operates on dvp->n_parent without
proper locking. This doesn't prevent in any case reclaim of the vnode.
Avoid this not going over-the-wire in this case and relying on subsequent
smbfs_getattr() call to restore consistency.
While I'm here, change a couple of SMBVDEBUG() in MPASS().
sbmfs_smb_lookup() doesn't and shouldn't know about '.' and '..'

Reported by:	pho's stress2 suite
2013-03-09 13:25:45 +00:00
Davide Italiano
e346bd8177 - Initialize variable in smbfs_rename() to silent compiler warning
- Fix smbfs_mkdir() return value (in case of error).

Reported by:	pho
2013-03-09 13:05:21 +00:00
Davide Italiano
42039c5bce - smbfs_rename() might return an error value without correctly upgrading
the vnode use count, and this might cause the kernel to panic if compiled
with WITNESS enable.
- Be sure to put the '\0' terminator to the rpath string.

Sponsored by:	iXsystems inc.
2012-11-26 04:29:47 +00:00
Davide Italiano
2c4415419f - Remove reset of vpp pointer in some places as long as it's not really
useful and has the side effect of obfuscating the code a bit.
- Remove spurious references to simple_lock.

Reported by:	attilio [1]
Sponsored by:	iXsystems inc.
2012-11-22 09:13:45 +00:00
Davide Italiano
80704a47af Until now, smbfs_fullpath() computed the full path starting from the
vnode and following back the chain of n_parent pointers up to the root,
without acquiring the locks of the n_parent vnodes analyzed during the
computation. This is immediately wrong because if the vnode lock is not
held there's no guarantee on the validity of the vnode pointer or the data.
In order to fix, store the whole path in the smbnode structure so that
smbfs_fullpath() can use this information.

Discussed with:		kib
Reported and tested by:		pho
Sponsored by:		iXsystems inc.
2012-11-22 08:58:29 +00:00
Davide Italiano
e631d5ab78 Get rid of some old debug code. It provides checks similar to the one
offered by RedZone so there's no need to keep it.

Sponsored by:	iXsystems inc.
2012-11-14 19:10:50 +00:00
Davide Italiano
9dbe0b121c Fix the lookup in the DOTDOT case in the same way as other filesystems do,
i.e. inlining the vn_vget_ino() algorithm.

Sponsored by:	iXsystems inc.
2012-11-14 18:43:58 +00:00
Davide Italiano
8680dc800f - Do not put in the mntqueue half-constructed vnodes.
- Change the code so that it relies on vfs_hash rather than on a
  home-made hashtable.
- There's no need to inline fnv_32_buf().

Reviewed by:	delphij
Tested by:	pho
Sponsored by:	iXsystems inc.
2012-10-31 03:55:33 +00:00
Davide Italiano
afe097512c Fix panic due to page faults while in kernel mode, under conditions of
VM pressure. The reason is that in some codepaths pointers to stack
variables were passed from one thread to another.

In collaboration with:	pho
Reported by:	pho's stress2 suite
Sponsored by:	iXsystems inc.
2012-10-31 03:34:07 +00:00
Davide Italiano
994f027fbc Change the code to use %jd as printf() placeholder for uio_offset and
cast to intmax_t.

Suggested by:	pjd
Sponsored by:	iXsystems inc.
2012-10-31 02:54:44 +00:00
Davide Italiano
469cb18f88 Fix build in case we have SMBVDEBUG turned on.
Reviewed by:	gnn
Approved by:	gnn
Sponsored by:	iXsystems inc.
2012-10-25 21:08:02 +00:00
Davide Italiano
8d9495bb1d - Remove the references to the deprecated zalloc kernel interface
- Use M_ZERO flag in malloc() rather than bzero()
- malloc() with M_NOWAIT can't return NULL so there's no need to check

Reviewed by:	alc
Approved by:	alc
2012-10-25 20:23:04 +00:00
Konstantin Belousov
b6c00483e9 Do not leave invalid pages in the object after the short read for a
network file systems (not only NFS proper). Short reads cause pages
other then the requested one, which were not filled by read response,
to stay invalid.

Change the vm_page_readahead_finish() interface to not take the error
code, but instead to make a decision to free or to (de)activate the
page only by its validity. As result, not requested invalid pages are
freed even if the read RPC indicated success.

Noted and reviewed by:	alc
MFC after:	1 week
2012-08-14 11:45:47 +00:00
Konstantin Belousov
1c771f9222 After the PHYS_TO_VM_PAGE() function was de-inlined, the main reason
to pull vm_param.h was removed.  Other big dependency of vm_page.h on
vm_param.h are PA_LOCK* definitions, which are only needed for
in-kernel code, because modules use KBI-safe functions to lock the
pages.

Stop including vm_param.h into vm_page.h. Include vm_param.h
explicitely for the kernel code which needs it.

Suggested and reviewed by:	alc
MFC after:    2 weeks
2012-08-05 14:11:42 +00:00
Konstantin Belousov
0055cbd3c5 Reduce code duplication and exposure of direct access to struct
vm_page oflags by providing helper function
vm_page_readahead_finish(), which handles completed reads for pages
with indexes other then the requested one, for VOP_GETPAGES().

Reviewed by:	alc
MFC after:	1 week
2012-08-04 18:16:43 +00:00
Christian Brueffer
01cc0b6531 Simply error handling by moving the allocation of np down to where it is
actually used.  While here, improve style a little.

Submitted by:	mjg
MFC after:	2 weeks
2012-07-16 22:07:29 +00:00
Christian Brueffer
9ce63ce2a3 Save a bzero() by using M_ZERO.
Obtained from:	Dragonfly BSD (change 4faaf07c3d7ddd120deed007370aaf4d90b72ebb)
MFC after:	2 weeks
2012-07-15 15:50:12 +00:00
Edward Tomasz Napierala
af6e6b87ad Remove unused thread argument to vrecycle().
Reviewed by:	kib
2012-04-23 14:10:34 +00:00
John Baldwin
bf40d24a3f Rename cache_lookup_times() to cache_lookup() and retire the old API and
ABI stub for cache_lookup().
2012-02-06 17:00:28 +00:00
Kirk McKusick
cc672d3599 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
Ed Schouten
dc15eac046 Use strchr() and strrchr().
It seems strchr() and strrchr() are used more often than index() and
rindex(). Therefore, simply migrate all kernel code to use it.

For the XFS code, remove an empty line to make the code identical to
the code in the Linux kernel.
2012-01-02 12:12:10 +00:00
Konstantin Belousov
dc874f9881 Rename vm_page_set_valid() to vm_page_set_valid_range().
The vm_page_set_valid() is the most reasonable name for the m->valid
accessor.

Reviewed by:	attilio, alc
2011-11-30 17:39:00 +00:00
Kevin Lo
41f1dccceb Add unicode support to msdosfs and smbfs; original pathes from imura,
bug fixes by Kuan-Chung Chiu <buganini at gmail dot com>.

Tested by me in production for several days at work.
2011-11-18 03:05:20 +00:00
Ed Schouten
d745c852be 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
Ed Schouten
8f80f103b4 Remove MALLOC_DECLAREs of nonexisting malloc-pools.
After careful grepping, it seems none of these pools can be found in our
source tree. They are not in use, nor are they defined.
2011-11-06 20:16:50 +00:00
Kirk McKusick
6beb3bb4eb 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
Jonathan Anderson
cd6dac7dff Make a comment more accurate.
This comment refers to CAP_NT_SMBS, which does not exist; it should refer to SMB_CAP_NT_SMBS.
Fixing this comment makes it easier for people interested in Capsicum to grep around for
capability rights, whose identifiers are of the form 'CAP_[A-Z_]'.

Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
2011-07-07 17:00:42 +00:00
Konstantin Belousov
031ec8c10a In the VOP_PUTPAGES() implementations, change the default error from
VM_PAGER_AGAIN to VM_PAGER_ERROR for the uwritten pages. Return
VM_PAGER_AGAIN for the partially written page. Always forward at least
one page in the loop of vm_object_page_clean().

VM_PAGER_ERROR causes the page reactivation and does not clear the
page dirty state, so the write is not lost.

The change fixes an infinite loop in vm_object_page_clean() when the
filesystem returns permanent errors for some page writes.

Reported and tested by:	gavin
Reviewed by:	alc, rmacklem
MFC after:	1 week
2011-06-01 21:00:28 +00:00