On FreeBSD CURRENT, trying to access the mountpoint of a fusefs-lkl mount returns EBADF. I don't know yet whether this is due to a bug in fusefs-lkl, or a bug in the new fusefs(5) driver. > uname -a FreeBSD arginine-fbsd-head 13.0-CURRENT FreeBSD 13.0-CURRENT #7 r350943M: Mon Aug 12 22:46:56 UTC 2019 somers@arginine-fbsd-head:/usr/obj/usr/home/somers/freebsd/base/head/amd64.amd64/sys/GENERIC amd64 > truncate -s 1g /tmp/ext2.img > mkfs.ext2 /tmp/ext2.img mke2fs 1.45.3 (14-Jul-2019) Creating filesystem with 262144 4k blocks and 65536 inodes Filesystem UUID: b6ea7c26-79c2-445c-a128-3c7a2fc4c2c2 Superblock backups stored on blocks: 32768, 98304, 163840, 229376 Allocating group tables: done Writing inode tables: done Writing superblocks and filesystem accounting information: done > lklfuse -o type=ext2,debug /tmp/ext2.img /tmp/mnt FUSE library version: 2.9.9 nullpath_ok: 1 nopath: 1 utime_omit_ok: 1 [ 0.000000] Linux version 4.16.0 (root@head-amd64-default-job-13) (gcc version 9.1.0 (FreeBSD Ports Collection)) #1 Sat Aug 3 20:01:57 UTC 2019 [ 0.000000] bootmem address range: 0x802601000 - 0x806600000 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 16159 [ 0.000000] Kernel command line: mem=64M virtio_mmio.device=292@0x1000000:1 [ 0.000000] Dentry cache hash table entries: 8192 (order: 4, 65536 bytes) [ 0.000000] Inode-cache hash table entries: 4096 (order: 3, 32768 bytes) [ 0.000000] Memory available: 64440k/65532k RAM [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 [ 0.000000] NR_IRQS: 4096 [ 0.000000] lkl: irqs initialized [ 0.000000] clocksource: lkl: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns [ 0.000008] lkl: time and timers initialized (irq2) [ 0.000038] pid_max: default: 4096 minimum: 301 [ 0.000077] Mount-cache hash table entries: 512 (order: 0, 4096 bytes) [ 0.000085] Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes) [ 0.006054] console [lkl_console0] enabled [ 0.006083] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 0.006100] xor: automatically using best checksumming function 8regs [ 0.006181] random: get_random_u32 called from bucket_table_alloc+0x8b/0x240 with crng_init=0 [ 0.006233] NET: Registered protocol family 16 [ 0.341124] raid6: int64x1 gen() 9406 MB/s [ 0.681041] raid6: int64x1 xor() 5210 MB/s [ 1.021097] raid6: int64x2 gen() 11317 MB/s [ 1.361247] raid6: int64x2 xor() 6949 MB/s [ 1.701154] raid6: int64x4 gen() 8793 MB/s [ 2.041063] raid6: int64x4 xor() 5944 MB/s [ 2.381000] raid6: int64x8 gen() 8385 MB/s [ 2.561119] random: fast init done [ 2.721020] raid6: int64x8 xor() 5898 MB/s [ 2.721045] raid6: using algorithm int64x2 gen() 11317 MB/s [ 2.721055] raid6: .... xor() 6949 MB/s, rmw enabled [ 2.721065] raid6: using intx1 recovery algorithm [ 2.721212] clocksource: Switched to clocksource lkl [ 2.721343] NET: Registered protocol family 2 [ 2.721565] tcp_listen_portaddr_hash hash table entries: 256 (order: 0, 4096 bytes) [ 2.721586] TCP established hash table entries: 512 (order: 0, 4096 bytes) [ 2.721597] TCP bind hash table entries: 512 (order: 0, 4096 bytes) [ 2.721608] TCP: Hash tables configured (established 512 bind 512) [ 2.721649] UDP hash table entries: 128 (order: 0, 4096 bytes) [ 2.721660] UDP-Lite hash table entries: 128 (order: 0, 4096 bytes) [ 2.721816] virtio-mmio: Registering device virtio-mmio.0 at 0x1000000-0x1000123, IRQ 1. [ 2.722891] workingset: timestamp_bits=62 max_order=14 bucket_order=0 [ 2.723841] SGI XFS with ACLs, security attributes, no debug enabled [ 2.744209] io scheduler noop registered [ 2.744235] io scheduler deadline registered [ 2.744298] io scheduler cfq registered (default) [ 2.744309] io scheduler mq-deadline registered [ 2.744318] io scheduler kyber registered [ 2.744338] virtio-mmio virtio-mmio.0: Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work. [ 2.746783] virtio_blk virtio0: [vda] 2097152 512-byte logical blocks (1.07 GB/1.00 GiB) [ 2.747978] NET: Registered protocol family 10 [ 2.749093] Segment Routing with IPv6 [ 2.749144] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver [ 2.749526] Btrfs loaded, crc32c=crc32c-generic [ 2.749651] Warning: unable to open an initial console. [ 2.749695] This architecture does not have kernel memory protection. [ 2.751010] EXT4-fs (vda): mounting ext2 file system using the ext4 subsystem [ 2.753282] EXT4-fs (vda): mounted filesystem without journal. Opts: warning: multithreaded mode not supported unique: 1, opcode: INIT (26), nodeid: 0, insize: 56, pid: 1832 INIT: 7.23 flags=0x00010033 max_readahead=0x00010000 INIT: 7.19 flags=0x00000011 max_readahead=0x00010000 max_write=0x00020000 max_background=0 congestion_threshold=0 unique: 1, success, outsize: 40 unique: 2, opcode: GETATTR (3), nodeid: 1, insize: 40, pid: 1836 fgetattr[281694020108288] (null) unique: 2, error: -9 (Bad file descriptor), outsize: 16 The GETATTR operation was triggered by doing "stat /tmp/mnt" in another window. Notice that nodeid is 1. In the FUSE protocol, nodeid 1 always refers to the mountpoint. Obviously, EBADF is not a valid error for that operation. This bug cannot be reproduced in 11.3-RELEASE-p1.
Turns out to be a kernel bug. In FUSE protocol 7.9 and above, FUSE_GETATTR has a larger payload. We aren't sending the entire payload. I never noticed until now, because the extra fields are all always 0. But fusefs-lkl checks the overall size and complains. Most fuse daemons don't.
A commit references this bug: Author: asomers Date: Wed Aug 14 20:45:01 UTC 2019 New revision: 351042 URL: https://svnweb.freebsd.org/changeset/base/351042 Log: fusefs: Fix the size of fuse_getattr_in 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 Changes: head/sys/fs/fuse/fuse_internal.c head/tests/sys/fs/fusefs/getattr.cc head/tests/sys/fs/fusefs/mockfs.cc head/tests/sys/fs/fusefs/mockfs.hh
A commit references this bug: Author: asomers Date: Sun Sep 15 04:14:37 UTC 2019 New revision: 352351 URL: https://svnweb.freebsd.org/changeset/base/352351 Log: MFC the new fusefs driver MFC r350665, r350990, r350992, r351039, r351042, r351061, r351066, r351113, r351560, r351961, r351963, r352021, r352025, r352230 r350665: fusefs: merge from projects/fuse2 This commit imports the new fusefs driver. It raises the protocol level from 7.8 to 7.23, fixes many bugs, adds a test suite for the driver, and adds many new features. New features include: * Optional kernel-side permissions checks (-o default_permissions) * Implement VOP_MKNOD, VOP_BMAP, and VOP_ADVLOCK * Allow interrupting FUSE operations * Support named pipes and unix-domain sockets in fusefs file systems * Forward UTIME_NOW during utimensat(2) to the daemon * kqueue support for /dev/fuse * Allow updating mounts with "mount -u" * Allow exporting fusefs file systems over NFS * Server-initiated invalidation of the name cache or data cache * Respect RLIMIT_FSIZE * Try to support servers as old as protocol 7.4 Performance enhancements include: * Implement FUSE's FOPEN_KEEP_CACHE and FUSE_ASYNC_READ flags * Cache file attributes * Cache lookup entries, both positive and negative * Server-selectable cache modes: writethrough, writeback, or uncached * Write clustering * Readahead * Use counter(9) for statistical reporting PR: 199934 216391 233783 234581 235773 235774 235775 PR: 236226 236231 236236 236291 236329 236381 236405 PR: 236327 236466 236472 236473 236474 236530 236557 PR: 236560 236844 237052 237181 237588 238565 Reviewed by: bcr (man pages) Reviewed by: cem, ngie, rpokala, glebius, kib, bde, emaste (post-commit review on project branch) Relnotes: yes Sponsored by: The FreeBSD Foundation Pull Request: https://reviews.freebsd.org/D21110 r350990: fusefs: add SVN Keywords to the test files Reported by: SVN pre-commit hooks MFC-With: r350665 Sponsored by: The FreeBSD Foundation r350992: fusefs: skip some tests when unsafe aio is disabled MFC-With: r350665 Sponsored by: The FreeBSD Foundation r351039: fusefs: fix intermittency in the default_permissions.Unlink.ok test The test needs to expect a FUSE_FORGET operation. Most of the time the test would pass anyway, because by chance FUSE_FORGET would arrive after the unmount. MFC-With: 350665 Sponsored by: The FreeBSD Foundation r351042: fusefs: Fix the size of fuse_getattr_in 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-With: 350665 Sponsored by: The FreeBSD Foundation r351061: fusefs: fix the 32-bit build after 351042 Reported by: jhb MFC-With: 351042 Sponsored by: The FreeBSD Foundation r351066: fusefs: fix conditional from r351061 The entirety of r351061 was a copy/paste error. I'm sorry I've been comitting so hastily. Reported by: rpokala Reviewed by: rpokala MFC-With: 351061 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21265 r351113: fusefs: don't send the namespace during listextattr 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 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21280 r351560: fusefs: Fix some bugs regarding the size of the LISTXATTR list * 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 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21287 r351961: Coverity fixes in fusefs(5) 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 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21466 r351963: fusefs: coverity cleanup in the tests Address the following defects reported by Coverity: * Structurally dead code (CID 1404366): set m_quit before FAIL, not after * Unchecked return value of sysctlbyname (CID 1404321) * Unchecked return value of stat(2) (CID 1404471) * Unchecked return value of open(2) (CID 1404402, 1404529) * Unchecked return value of dup(2) (CID 1404478) * Buffer overflows. These are all false positives caused by the fact that Coverity thinks I'm using a buffer to store strings, when in fact I'm really just using it to store a byte array that happens to be initialized with a string. I'm changing the type from char to uint8_t in the hopes that it will placate Coverity. (CID 1404338, 1404350, 1404367, 1404376, 1404379, 1404381, 1404388, 1404403, 1404425, 1404433, 1404434, 1404474, 1404480, 1404484, 1404503, 1404505) * False positive file descriptor leak. I'm going to try to fix this with Coverity modeling, but I'll also change an EXPECT to ASSERT so we don't perform meaningless assertions after the failure. (CID 1404320, 1404324, 1404440, 1404445). * Unannotated file descriptor leak. This will be followed up by a Coverity modeling change. (CID 1404326, 1404334, 1404336, 1404357, 1404361, 1404372, 1404391, 1404395, 1404409, 1404430, 1404448, 1404451, 1404455, 1404457, 1404458, 1404460) * Uninitialized variables in C++ constructors (CID 1404327, 1404346). In the case of m_maxphys, this actually led to part of the FUSE_INIT's response being set to stack garbage during the WriteCluster::clustering test. * Uninitialized sun_len field in struct sockaddr_un (CID 1404330, 1404371, 1404429). Reported by: Coverity Reviewed by: emaste Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21457 r352021: fusefs: suppress some Coverity resource leak CIDs in the tests The fusefs tests deliberately leak file descriptors. To do otherwise would add extra complications to the tests' mock FUSE server. This annotation should hopefully convince Coverity to shut up about the leaks. Reviewed by: uqs Sponsored by: The FreeBSD Foundation r352025: mount_fusefs: fix a segfault on memory allocation failure Reported by: Coverity Coverity CID: 1354188 Sponsored by: The FreeBSD Foundation r352230: fusefs: Fix iosize for FUSE_WRITE in 7.8 compat mode 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-With: r350665 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21557 Changes: _U stable/12/ stable/12/MAINTAINERS stable/12/UPDATING stable/12/etc/mtree/BSD.tests.dist stable/12/sbin/mount_fusefs/mount_fusefs.8 stable/12/sbin/mount_fusefs/mount_fusefs.c stable/12/share/man/man5/fusefs.5 stable/12/sys/fs/fuse/fuse.h stable/12/sys/fs/fuse/fuse_device.c stable/12/sys/fs/fuse/fuse_file.c stable/12/sys/fs/fuse/fuse_file.h stable/12/sys/fs/fuse/fuse_internal.c stable/12/sys/fs/fuse/fuse_internal.h stable/12/sys/fs/fuse/fuse_io.c stable/12/sys/fs/fuse/fuse_io.h stable/12/sys/fs/fuse/fuse_ipc.c stable/12/sys/fs/fuse/fuse_ipc.h stable/12/sys/fs/fuse/fuse_kernel.h stable/12/sys/fs/fuse/fuse_main.c stable/12/sys/fs/fuse/fuse_node.c stable/12/sys/fs/fuse/fuse_node.h stable/12/sys/fs/fuse/fuse_param.h stable/12/sys/fs/fuse/fuse_vfsops.c stable/12/sys/fs/fuse/fuse_vnops.c stable/12/sys/sys/param.h stable/12/tests/sys/fs/Makefile stable/12/tests/sys/fs/fusefs/ stable/12/tests/sys/fs/fusefs/access.cc stable/12/tests/sys/fs/fusefs/allow_other.cc stable/12/tests/sys/fs/fusefs/bmap.cc stable/12/tests/sys/fs/fusefs/create.cc stable/12/tests/sys/fs/fusefs/default_permissions.cc stable/12/tests/sys/fs/fusefs/default_permissions_privileged.cc stable/12/tests/sys/fs/fusefs/destroy.cc stable/12/tests/sys/fs/fusefs/dev_fuse_poll.cc stable/12/tests/sys/fs/fusefs/fifo.cc stable/12/tests/sys/fs/fusefs/flush.cc stable/12/tests/sys/fs/fusefs/forget.cc stable/12/tests/sys/fs/fusefs/fsync.cc stable/12/tests/sys/fs/fusefs/fsyncdir.cc stable/12/tests/sys/fs/fusefs/getattr.cc stable/12/tests/sys/fs/fusefs/interrupt.cc stable/12/tests/sys/fs/fusefs/io.cc stable/12/tests/sys/fs/fusefs/link.cc stable/12/tests/sys/fs/fusefs/locks.cc stable/12/tests/sys/fs/fusefs/lookup.cc stable/12/tests/sys/fs/fusefs/mkdir.cc stable/12/tests/sys/fs/fusefs/mknod.cc stable/12/tests/sys/fs/fusefs/mockfs.cc stable/12/tests/sys/fs/fusefs/mockfs.hh stable/12/tests/sys/fs/fusefs/mount.cc stable/12/tests/sys/fs/fusefs/nfs.cc stable/12/tests/sys/fs/fusefs/notify.cc stable/12/tests/sys/fs/fusefs/open.cc stable/12/tests/sys/fs/fusefs/opendir.cc stable/12/tests/sys/fs/fusefs/read.cc stable/12/tests/sys/fs/fusefs/readdir.cc stable/12/tests/sys/fs/fusefs/readlink.cc stable/12/tests/sys/fs/fusefs/release.cc stable/12/tests/sys/fs/fusefs/releasedir.cc stable/12/tests/sys/fs/fusefs/rename.cc stable/12/tests/sys/fs/fusefs/rmdir.cc stable/12/tests/sys/fs/fusefs/setattr.cc stable/12/tests/sys/fs/fusefs/statfs.cc stable/12/tests/sys/fs/fusefs/symlink.cc stable/12/tests/sys/fs/fusefs/unlink.cc stable/12/tests/sys/fs/fusefs/utils.cc stable/12/tests/sys/fs/fusefs/utils.hh stable/12/tests/sys/fs/fusefs/write.cc stable/12/tests/sys/fs/fusefs/xattr.cc
@Alan Will this go to stable/11? I assume it won't because new fusefs driver is only in stable/12, but wanted to check/confirm. If not set mfc-stable11 to -
Correct, koobs. This is only relevant for the new driver, and I have no plans to MFC that to stable/11.