Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.
Make b_pages[] array in struct buf flexible. Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*). Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.
Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys. Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight. Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.
Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.
Suggested by: mav (*)
Reviewed by: imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D27225
No functional change intended.
Tracking these structures separately for each proc enables future work to
correctly emulate clone(2) in linux(4).
__FreeBSD_version is bumped (to 1300130) for consumption by, e.g., lsof.
Reviewed by: kib
Discussed with: markj, mjg
Differential Revision: https://reviews.freebsd.org/D27037
from a Linux binary. Should come handy for AppImages.
Reviewed by: asomers
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26959
If a FUSE server returns FOPEN_DIRECT_IO in response to FUSE_OPEN, that
instructs the kernel to bypass the page cache for that file. This feature
is also known by libfuse's name: "direct_io".
However, when accessing a file via mmap, there is no possible way to bypass
the cache completely. This change fixes a deadlock that would happen when
an mmap'd write tried to invalidate a portion of the cache, wrongly assuming
that a write couldn't possibly come from cache if direct_io were set.
Arguably, we could instead disable mmap for files with FOPEN_DIRECT_IO set.
But allowing it is less likely to cause user complaints, and is more in
keeping with the spirit of open(2), where O_DIRECT instructs the kernel to
"reduce", not "eliminate" cache effects.
PR: 247276
Reported by: trapexit@spawn.link
Reviewed by: cem
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D26485
This reapplies logical r360944 and r360946 (reverting r360955), with fixed
copystr() stand-in replacement macro. Eventually the goal is to convert
consumers and kill the macro, but for a first step it helps if the macro is
correct.
Prior commit message:
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults. It's just
an older incarnation of the now-more-common strlcpy().
Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.
Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy (with correction from brooks@ -- thanks).
Remove N redundant MI implementations of copystr. For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.
Reviewed by: jhb (earlier version)
Discussed with: brooks (thanks!)
Differential Revision: https://reviews.freebsd.org/D24672
This patch fixes two issues relating to FUSE_ACCESS when the
default_permissions mount option is disabled:
* VOP_ACCESS() calls with VADMIN set should never be sent to a fuse server
in the form of FUSE_ACCESS operations. The FUSE protocol has no equivalent
of VADMIN, so we must evaluate such things kernel-side, regardless of the
default_permissions setting.
* The FUSE protocol only requires FUSE_ACCESS to be sent for two purposes:
for the access(2) syscall and to check directory permissions for
searchability during lookup. FreeBSD sends it much more frequently, due to
differences between our VFS and Linux's, for which FUSE was designed. But
this patch does eliminate several cases not required by the FUSE protocol:
* for any FUSE_*XATTR operation
* when creating a new file
* when deleting a file
* when setting timestamps, such as by utimensat(2).
* Additionally, when default_permissions is disabled, this patch removes one
FUSE_GETATTR operation when deleting a file.
PR: 245689
Reported by: MooseFS FreeBSD Team <freebsd@moosefs.pro>
Reviewed by: cem
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D24777
Nullfs cacheing can keep a large number of vnodes active. That results in
more active FUSE file handles, causing some FUSE servers to use extra
resources. Disable nullfs cacheing for fusefs, just like we already do for
NFSv4.
PR: 245688
Reported by: MooseFS FreeBSD Team <freebsd@moosefs.pro>
MFC after: 2 weeks
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults. It's just
an older incarnation of the now-more-common strlcpy().
Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.
Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy.
Remove N redundant MI implementations of copystr. For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D24672
The FUSE protocol allows the client (kernel) to cache a file's size, if the
server (userspace daemon) allows it. A well-behaved daemon obviously should
not change a file's size while a client has it cached. But a buggy daemon
might. If the kernel ever detects that that has happened, then it should
invalidate the entire cache for that file. Previously, we would not only
cache stale data, but in the case of a file extension while we had the size
cached, we accidentally extended the cache with zeros.
PR: 244178
Reported by: Ben RUBSON <ben.rubson@gmx.com>
Reviewed by: cem
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D24012
We were reusing a structure for multiple operations, but failing to
reinitialize one member. The result is that a server that cares about FUSE
file handle IDs would see one correct FUSE_FSYNC operation, and one with the
FHID unset.
PR: 244431
Reported by: Agata <chogata@gmail.com>
MFC after: 2 weeks
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Approved by: kib (mentor, blanket)
Differential Revision: https://reviews.freebsd.org/D23627
O_SEARCH is defined by POSIX [0] to open a directory for searching, skipping
permissions checks on the directory itself after the initial open(). This is
close to the semantics we've historically applied for O_EXEC on a directory,
which is UB according to POSIX. Conveniently, O_SEARCH on a file is also
explicitly undefined behavior according to POSIX, so O_EXEC would be a fine
choice. The spec goes on to state that O_SEARCH and O_EXEC need not be
distinct values, but they're not defined to be the same value.
This was pointed out as an incompatibility with other systems that had made
its way into libarchive, which had assumed that O_EXEC was an alias for
O_SEARCH.
This defines compatibility O_SEARCH/FSEARCH (equivalent to O_EXEC and FEXEC
respectively) and expands our UB for O_EXEC on a directory. O_EXEC on a
directory is checked in vn_open_vnode already, so for completeness we add a
NOEXECCHECK when O_SEARCH has been specified on the top-level fd and do not
re-check that when descending in namei.
[0] https://pubs.opengroup.org/onlinepubs/9699919799/
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23247
Filesystems which want to use it in limited capacity can employ the
VOP_UNLOCK_FLAGS macro.
Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D21427
The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.
v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.
Reviewed by: kib, jeff
Differential Revision: https://reviews.freebsd.org/D22715
That revision addressed a Coverity CID that could lead to a buffer overflow,
but it had an off-by-one error in the buffer size check.
Reported by: Coverity
Coverity CID: 1405530
MFC after: 3 days
MFC-With: 351961
Sponsored by: The FreeBSD Foundation
* When unparenting a vnode, actually clear the flag. AFAIK this is basically
a no-op because we only unparent a vnode when reclaiming it or when
unlinking.
* There's no need to call fuse_vnode_setparent during reclaim, because we're
about to free the vnode data anyway.
Reviewed by: emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21630
When communicating with a FUSE server that implements version 7.8 (or older)
of the FUSE protocol, the FUSE_WRITE request structure is 16 bytes shorter
than normal. The protocol version check wasn't applied universally, leading
to an extra 16 bytes being sent to such servers. The extra bytes were
allocated and bzero()d, so there was no information disclosure.
Reviewed by: emaste
MFC after: 3 days
MFC-With: r350665
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21557
CID 1404532 fixes a signed vs unsigned comparison error in fuse_vnop_bmap.
It could potentially have resulted in VOP_BMAP reporting too many
consecutive blocks.
CID 1404364 is much worse. It was an array access by an untrusted,
user-provided variable. It could potentially have resulted in a malicious
file system crashing the kernel or worse.
Reported by: Coverity
Reviewed by: emaste
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21466
Current implementation of vnode_create_vobject() and
vnode_destroy_vobject() is written so that it prepared to handle the
vm object destruction for live vnode. Practically, no filesystems use
this, except for some remnants that were present in UFS till today.
One of the consequences of that model is that each filesystem must
call vnode_destroy_vobject() in VOP_RECLAIM() or earlier, as result
all of them get rid of the v_object in reclaim.
Move the call to vnode_destroy_vobject() to vgonel() before
VOP_RECLAIM(). This makes v_object stable: either the object is NULL,
or it is valid vm object till the vnode reclamation. Remove code from
vnode_create_vobject() to handle races with the parallel destruction.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21412
* A small error in r338152 let to the returned size always being exactly
eight bytes too large.
* The FUSE_LISTXATTR operation works like Linux's listxattr(2): if the
caller does not provide enough space, then the server should return ERANGE
rather than return a truncated list. That's true even though in FUSE's
case the kernel doesn't provide space to the client at all; it simply
requests a maximum size for the list. We previously weren't handling the
case where the server returns ERANGE even though the kernel requested as
much size as the server had told us it needs; that can happen due to a
race.
* We also need to ensure that a pathological server that always returns
ERANGE no matter what size we request in FUSE_LISTXATTR won't cause an
infinite loop in the kernel. As of this commit, it will instead cause an
infinite loop that exits and enters the kernel on each iteration, allowing
signals to be processed.
Reviewed by: cem
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21287
The FUSE_LISTXATTR operation always returns the full list of a file's
extended attributes, in all namespaces. There's no way to filter the list
server-side. However, currently FreeBSD's fusefs driver sends a namespace
string with the FUSE_LISTXATTR request. That behavior was probably copied
from fuse_vnop_getextattr, which has an attribute name argument. It's
been there ever since extended attribute support was added in r324620. This
commit removes it.
Reviewed by: cem
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21280
In FUSE protocol 7.9, the size of the FUSE_GETATTR request has increased.
However, the fusefs driver is currently not sending the additional fields.
In our implementation, the additional fields are always zero, so I there
haven't been any test failures until now. But fusefs-lkl requires the
request's length to be correct.
Fix this bug, and also enhance the test suite to catch similar bugs.
PR: 239830
MFC after: 2 weeks
MFC-With: 350665
Sponsored by: The FreeBSD Foundation
When a fusefs file system is mounted using the writeback cache, the cache
may still be bypassed by opening a file with O_DIRECT. When writing with
O_DIRECT, the cache must be invalidated for the affected portion of the
file. Fix some panics caused by inadvertently invalidating too much.
Sponsored by: The FreeBSD Foundation
FUSE file systems can optionally support interrupting outstanding
operations. However, the file system does not identify to the kernel at
mount time whether it's capable of doing that. Instead it signals its
noncapability by returning ENOSYS to the first FUSE_INTERRUPT operation it
receives. That's a problem for reliable signal delivery, because the kernel
must choose which thread should get a signal before it knows whether the
FUSE server can handle interrupts. The problem is even worse because the
FUSE protocol allows a file system to simply ignore all FUSE_INTERRUPT
operations.
Fix the signal delivery logic by making interruptibility an opt-in mount
option. This will require a corresponding change to libfuse, but not to
most file systems that link to libfuse.
Bump __FreeBSD_version due to the new mount option.
Sponsored by: The FreeBSD Foundation
fticket_wait_answer would spin if it received an unhandled signal whose
default disposition is to terminate. The reason is because msleep(9) would
return EINTR even for a masked signal. One reason is when the thread is
stopped, which happens for example during sigexit(). Fix this bug by
returning immediately if fticket_wait_answer ever gets interrupted a second
time, for any reason.
Sponsored by: The FreeBSD Foundation
1) Don't explicitly not mask SIGKILL. kern_sigprocmask won't allow it to be
masked, anyway.
2) Fix an infinite loop bug. If a process received both a maskable signal
lower than 9 (like SIGINT) and then received SIGKILL,
fticket_wait_answer would spin. msleep would immediately return EINTR,
but cursig would return SIGINT, so the sleep would get retried. Fix it
by explicitly checking whether SIGKILL has been received.
3) Abandon the sig_isfatal optimization introduced by r346357. That
optimization would cause fticket_wait_answer to return immediately,
without waiting for a response from the server, if the process were going
to exit anyway. However, it's vulnerable to a race:
1) fatal signal is received while fticket_wait_answer is sleeping.
2) fticket_wait_answer sends the FUSE_INTERRUPT operation.
3) fticket_wait_answer determines that the signal was fatal and returns
without waiting for a response.
4) Another thread changes the signal to non-fatal.
5) The first thread returns to userspace. Instead of exiting, the
process continues.
6) The application receives EINTR, wrongly believes that the operation
was successfully interrupted, and restarts it. This could cause
problems for non-idempotent operations like FUSE_RENAME.
Reported by: kib (the race part)
Sponsored by: The FreeBSD Foundation
* Fix the kernel build with gcc by removing a redundant extern declaration
* In the tests, fix a printf format specifier that assumed LP64
Sponsored by: The FreeBSD Foundation
We were leaking the fuse ticket if the original operation completed before
the daemon received the INTERRUPT operation. Fixing this was easier than I
expected.
Sponsored by: The FreeBSD Foundation
Previously fusefs would never recycle vnodes. After VOP_INACTIVE, they'd
linger around until unmount or the vnlru reclaimed them. This commit
essentially actives and inlines the old reclaim_revoked sysctl, and fixes
some issues dealing with the attribute cache and multiply linked files.
Sponsored by: The FreeBSD Foundation
counter(9) is more performant than using atomic instructions to update
sysctls that just report statistics to userland.
Sponsored by: The FreeBSD Foundation
