r346162 factored out v_inval_buf_range from vtruncbuf, but it made an error
in the interface between the two. The result was a failure to remove
buffers past the first. Surprisingly, I couldn't reproduce the failure with
file systems other than fuse.
Also, modify fusefs's truncate_discards_cached_data test to catch this bug.
PR: 346162
Sponsored by: The FreeBSD Foundation
When interrupting a FUSE operation, send the FUSE_INTERRUPT op to the daemon
ASAP, ahead of other unrelated operations.
PR: 236530
Sponsored by: The FreeBSD Foundation
fusefs's VOP_SETEXTATTR calls uiomove(9) before blocking, so it can't be
restarted. It must be interrupted instead.
PR: 236530
Sponsored by: The FreeBSD Foundation
If a pending FUSE operation hasn't yet been sent to the daemon, then there's
no reason to inform the daemon that it's been interrupted. Instead, simply
remove it from the fuse message queue and set its status to EINTR or
ERESTART as appropriate.
PR: 346357
Sponsored by: The FreeBSD Foundation
* If a process receives a fatal signal while blocked on a fuse operation,
return ASAP without waiting for the operation to complete. But still send
the FUSE_INTERRUPT op to the daemon.
* Plug memory leaks from r346339
Interruptibility is now fully functional, but it could be better:
* Operations that haven't been sent to the server yet should be aborted
without sending FUSE_INTERRUPT.
* It would be great if write operations could be made restartable.
That would require delaying uiomove until the last possible moment, which
would be sometime during fuse_device_read.
* It would be nice if we didn't have to guess which EAGAIN responses were
for FUSE_INTERRUPT operations.
PR: 236530
Sponsored by: The FreeBSD Foundation
The fuse protocol includes a FUSE_INTERRUPT operation that the client can
send to the server to indicate that it wants to abort an in-progress
operation. It's required to interrupt any syscall that is blocking on a
fuse operation.
This commit adds basic FUSE_INTERRUPT support. If a process receives any
signal while it's blocking on a FUSE operation, it will send a
FUSE_INTERRUPT and wait for the original operation to complete. But there
is still much to do:
* The current code will leak memory if the server ignores FUSE_INTERRUPT,
which many do. It will also leak memory if the server completes the
original operation before it receives the FUSE_INTERRUPT.
* An interrupted read(2) will incorrectly appear to be successful.
* fusefs should return immediately for fatal signals.
* Operations that haven't been sent to the server yet should be aborted
without sending FUSE_INTERRUPT.
* Test coverage should be better.
* It would be great if write operations could be made restartable.
That would require delaying uiomove until the last possible moment, which
would be sometime during fuse_device_read.
PR: 236530
Sponsored by: The FreeBSD Foundation
fusefs's default cache mode is "writethrough", although it currently works
more like "write-around"; writes bypass the cache completely. Since writes
bypass the cache, they were leaving stale previously-read data in the cache.
This commit invalidates that stale data. It also adds a new global
v_inval_buf_range method, like vtruncbuf but for a range of a file.
PR: 235774
Reported by: cem
Sponsored by: The FreeBSD Foundation
For many FUSE opcodes, an error of ENOSYS has special meaning. fusefs
already handled some of those; this commit adds handling for the remainder:
* FUSE_FSYNC, FUSE_FSYNCDIR: ENOSYS means "success, and automatically return
success without calling the daemon from now on"
* All extattr operations: ENOSYS means "fail EOPNOTSUPP, and automatically
do it without calling the daemon from now on"
PR: 236557
Sponsored by: The FreeBSD Foundation
The fuse protocol is designed with security in mind. It prevents users from
spying on each others' activities. And it doesn't grant users any
privileges that they didn't already have. So it's appropriate to make it
available to everyone. Plus, it's necessary in order for kyua to run tests
as an unprivileged user.
Sponsored by: The FreeBSD Foundation
fusefs tracks each vnode's parent. The rename code was already correctly
updating it. Delete a comment that said otherwise, and add a regression
test for it.
Sponsored by: The FreeBSD Foundation
Don't panic if the server changes the file type of a file without us first
deleting it. That could indicate a buggy server, but it could also be the
result of one of several race conditions. Return EAGAIN as we do elsewhere.
Sponsored by: The FreeBSD Foundation
When the entry cache expires, it's only necessary to purge the cache.
Disappearing a vnode also purges the attribute cache, which is unnecessary,
and invalidates the data cache, which could be harmful.
Sponsored by: The FreeBSD Foundation
I got most of -o default_permissions working in r346088. This commit adds
sticky bit checks. One downside is that sometimes there will be an extra
FUSE_GETATTR call for the parent directory during unlink or rename. But in
actual use I think those attributes will almost always be cached.
PR: 216391
Sponsored by: The FreeBSD Foundation
fuse_vnop_lookup was using a FUSE_GETATTR operation when looking up "." and
"..", even though the only information it needed was the file type and file
size. "." and ".." are obviously always going to be directories; there's no
need to double check.
Sponsored by: The FreeBSD Foundation
fuse_vnop_lookup contained an awkward hack meant to reduce daemon activity
during long lookup chains. However, the hack is no longer necessary now
that we properly cache file attributes. Also, I'm 99% certain that it
could've bypassed permission checks when using openat to open a file
relative to a directory that lacks execute permission.
Sponsored by: The FreeBSD Foundation
* Eliminate fuse_access_param. Whatever it was supposed to do, it seems
like it was never complete. The only real function it ever seems to have
had was a minor performance optimization, which I've already eliminated.
* Make extended attribute operations obey the allow_other mount option.
* Allow unprivileged access to the SYSTEM extattr namespace when
-o default_permissions is not in use.
* Disallow setextattr and deleteextattr on read-only mounts.
* Add tests for a few more error cases.
Sponsored by: The FreeBSD Foundation
Normally all permission checking is done in the fuse server. But when -o
default_permissions is used, it should be done in the kernel instead. This
commit adds appropriate permission checks through fusefs when -o
default_permissions is used. However, sticky bit checks aren't working yet.
I'll handle those in a follow-up commit.
There are no checks for file flags, because those aren't supported by our
version of the FUSE protocol. Nor is there any support for ACLs, though
that could be added if there were any demand.
PR: 216391
Reported by: hiyorin@gmail.com
Sponsored by: The FreeBSD Foundation
The FUSE protocol includes a way for a server to tell the client that a
negative lookup response is cacheable for a certain amount of time.
PR: 236226
Sponsored by: The FreeBSD Foundation
Follow-up to r346046. These two commits implement fuse cache timeouts for
both entries and attributes. They also remove the vfs.fusefs.lookup_cache
enable sysctl, which is no longer needed now that cache timeouts are
honored.
PR: 235773
Sponsored by: The FreeBSD Foundation
The FUSE protocol allows the server to specify the timeout period for the
client's attribute and entry caches. This commit implements the timeout
period for the attribute cache. The entry cache's timeout period is
currently disabled because it panics, and is guarded by the
vfs.fusefs.lookup_cache_expire sysctl.
PR: 235773
Reported by: cem
Sponsored by: The FreeBSD Foundation
FUSE_LOOKUP, FUSE_GETATTR, FUSE_SETATTR, FUSE_MKDIR, FUSE_LINK,
FUSE_SYMLINK, FUSE_MKNOD, and FUSE_CREATE all return file attributes with a
cache validity period. fusefs will now cache the attributes, if the server
returns a non-zero cache validity period.
This change does _not_ implement finite attr cache timeouts. That will
follow as part of PR 235773.
PR: 235775
Reported by: cem
Sponsored by: The FreeBSD Foundation
VOP_ACCESS was never fully implemented in fusefs. This change:
* Removes the FACCESS_DO_ACCESS flag, which pretty much disabled the whole
vop.
* Removes a quixotic special case for VEXEC on regular files. I don't know
why that was in there.
* Removes another confusing special case for VADMIN.
* Removes the FACCESS_NOCHECKSPY flag. It seemed to be a performance
optimization, but I'm unconvinced that it was a net positive.
* Updates test cases.
This change does NOT implement -o default_permissions. That will be handled
separately.
PR: 236291
Sponsored by: The FreeBSD Foundation
When -o allow_other is not in use, fusefs is supposed to prevent access to
the filesystem by any user other than the one who owns the daemon. Our
fusefs implementation was only enforcing that restriction at the mountpoint
itself. That was usually good enough because lookup usually descends from
the mountpoint. However, there are cases when it doesn't, such as when
using openat relative to a file beneath the mountpoint.
PR: 237052
Sponsored by: The FreeBSD Foundation
These tests were actually fixed by r345398, r345390 and r345392, but I
neglected to reenable them. Too bad googletest doesn't have the notion of
an Expected Failure like ATF does.
PR: 236474, 236473
Sponsored by: The FreeBSD Foundation
There's no reason to order based on strcmp of ASCII digests instead of
memcmp of the raw digests.
While here, remove collision fallback. If you collide two MD5s, they're
probably the same string anyway. If robustness against MD5 collisions is
desired, maybe we shouldn't use MD5.
None of the behavior of sort -R is specified by POSIX, so we're free to
implement this however we like. E.g., using a 128-bit counter and block cipher
to generate unique indices for each line of input.
PR: 230792 (2/many)
Relnotes: This will change the sort order for a given dataset with a
given seed. Other similarly breaking changes are planned.
Sponsored by: Dell EMC Isilon
r338192 reverted the changes to nfsuserd so that it could use an AF_LOCAL
socket, since it resulted in a vnode locking panic().
Post r338192 nfsuserd daemons use the old AF_INET socket for upcalls and
do not use these kernel changes.
I left them in for a while, so that nfsuserd daemons built from head sources
between r320757 (Jul. 6, 2017) and r338192 (Aug. 22, 2018) would need them
by default.
This only affects head, since the changes were never MFC'd.
I will add an UPDATING entry, since an nfsuserd daemon built from head
sources between r320757 and r338192 will not run unless the "-use-udpsock"
option is specified. (This command line option is only in the affected
revisions of the nfsuserd daemon.)
I suspect few will be affected by this, since most who run systems built
from head sources (not stable or releases) will have rebuilt their nfsuserd
daemon from sources post r338192 (Aug. 22, 2018)
This is being reverted in preparation for an update to include AF_INET6
support to the code.
If a fuse file system returne FOPEN_KEEP_CACHE in the open or create
response, then the client is supposed to _not_ clear its caches for that
file. I don't know why clearing the caches would be the default given that
there's a separate flag to bypass the cache altogether, but that's the way
it is. fusefs(5) will now honor this flag.
Our behavior is slightly different than Linux's because we reuse file
handles. That means that open(2) wont't clear the cache if there's a
reusable file handle, even if the file server wouldn't have sent
FOPEN_KEEP_CACHE had we opened a new file handle like Linux does.
PR: 236560
Sponsored by: The FreeBSD Foundation
This bug was long present, but was exacerbated by r345876.
The problem is that fiov_refresh was bzero()ing a buffer _before_ it
reallocated that buffer. That's obviously the wrong order. I fixed the
order in r345876, which exposed the main problem. Previously, the first 160
bytes of the buffer were getting bzero()ed when it was first allocated in
fiov_init. Subsequently, as that buffer got recycled between callers, the
portion used by the _previous_ caller was getting bzero()ed by the current
caller in fiov_refresh. The problem was never visible simply because no
caller was trying to use more than 160 bytes.
Now the buffer gets properly bzero()ed both at initialization time and any
time it gets enlarged or reallocated.
Sponsored by: The FreeBSD Foundation
There are a few places that use hand crafted versions of the macros
from sys/netinet/in.h making it difficult to actually alter the
values in use by these macros. Correct that by replacing handcrafted
code with proper macro usage.
Reviewed by: karels, kristof
Approved by: bde (mentor)
MFC after: 3 weeks
Sponsored by: John Gilmore
Differential Revision: https://reviews.freebsd.org/D19317
- Remove issues that no longer apply thanks to devfs
- Add language pointing out devfs's role and referencing its config
- Add a "historical notes" section and move discussion of block vs character devs to it, including pointing out the removal of block devs
- Modernize some examples
MFC after: 1 week
PR: 236970
Submitted by: andrew@tao173.riddles.org.uk
Reviewed by: 0mp
Differential Revision: https://reviews.freebsd.org/D19799
