* [PULL 1/6] virtiofsd: Allow to build it without the tools
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 2/6] virtiofsd: vu_dispatch locking should never fail Dr. David Alan Gilbert (git)
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Wainer dos Santos Moschetta <wainersm@redhat.com>
This changed the Meson build script to allow virtiofsd be built even
though the tools build is disabled, thus honoring the --enable-virtiofsd
option.
Fixes: cece116c939d219070b250338439c2d16f94e3da (configure: add option for virtiofsd)
Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20210201211456.1133364-2-wainersm@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/meson.build | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/meson.build b/tools/meson.build
index fdce66857d..3e5a0abfa2 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -10,8 +10,11 @@ if get_option('virtiofsd').enabled()
error('virtiofsd requires Linux')
elif not seccomp.found() or not libcap_ng.found()
error('virtiofsd requires libcap-ng-devel and seccomp-devel')
- elif not have_tools or 'CONFIG_VHOST_USER' not in config_host
- error('virtiofsd needs tools and vhost-user support')
+ elif 'CONFIG_VHOST_USER' not in config_host
+ error('virtiofsd needs vhost-user support')
+ else
+ # Disabled all the tools but virtiofsd.
+ have_virtiofsd = true
endif
endif
elif get_option('virtiofsd').disabled() or not have_system
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PULL 2/6] virtiofsd: vu_dispatch locking should never fail
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 1/6] virtiofsd: Allow to build it without the tools Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 3/6] tools/virtiofsd: Replace the word 'whitelist' Dr. David Alan Gilbert (git)
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Greg Kurz <groug@kaod.org>
pthread_rwlock_rdlock() and pthread_rwlock_wrlock() can fail if a
deadlock condition is detected or the current thread already owns
the lock. They can also fail, like pthread_rwlock_unlock(), if the
mutex wasn't properly initialized. None of these are ever expected
to happen with fv_VuDev::vu_dispatch_rwlock.
Some users already check the return value and assert, some others
don't. Introduce rdlock/wrlock/unlock wrappers that just do the
former and use them everywhere for improved consistency and
robustness.
This is just cleanup. It doesn't fix any actual issue.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210203182434.93870-1-groug@kaod.org>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/virtiofsd/fuse_virtio.c | 49 +++++++++++++++++++++++++----------
1 file changed, 35 insertions(+), 14 deletions(-)
diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
index ddcefee427..523ee64fb7 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -187,6 +187,31 @@ static void copy_iov(struct iovec *src_iov, int src_count,
}
}
+/*
+ * pthread_rwlock_rdlock() and pthread_rwlock_wrlock can fail if
+ * a deadlock condition is detected or the current thread already
+ * owns the lock. They can also fail, like pthread_rwlock_unlock(),
+ * if the mutex wasn't properly initialized. None of these are ever
+ * expected to happen.
+ */
+static void vu_dispatch_rdlock(struct fv_VuDev *vud)
+{
+ int ret = pthread_rwlock_rdlock(&vud->vu_dispatch_rwlock);
+ assert(ret == 0);
+}
+
+static void vu_dispatch_wrlock(struct fv_VuDev *vud)
+{
+ int ret = pthread_rwlock_wrlock(&vud->vu_dispatch_rwlock);
+ assert(ret == 0);
+}
+
+static void vu_dispatch_unlock(struct fv_VuDev *vud)
+{
+ int ret = pthread_rwlock_unlock(&vud->vu_dispatch_rwlock);
+ assert(ret == 0);
+}
+
/*
* Called back by ll whenever it wants to send a reply/message back
* The 1st element of the iov starts with the fuse_out_header
@@ -240,12 +265,12 @@ int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch,
copy_iov(iov, count, in_sg, in_num, tosend_len);
- pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_rdlock(qi->virtio_dev);
pthread_mutex_lock(&qi->vq_lock);
vu_queue_push(dev, q, elem, tosend_len);
vu_queue_notify(dev, q);
pthread_mutex_unlock(&qi->vq_lock);
- pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_unlock(qi->virtio_dev);
req->reply_sent = true;
@@ -403,12 +428,12 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
ret = 0;
- pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_rdlock(qi->virtio_dev);
pthread_mutex_lock(&qi->vq_lock);
vu_queue_push(dev, q, elem, tosend_len);
vu_queue_notify(dev, q);
pthread_mutex_unlock(&qi->vq_lock);
- pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_unlock(qi->virtio_dev);
err:
if (ret == 0) {
@@ -558,12 +583,12 @@ out:
fuse_log(FUSE_LOG_DEBUG, "%s: elem %d no reply sent\n", __func__,
elem->index);
- pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_rdlock(qi->virtio_dev);
pthread_mutex_lock(&qi->vq_lock);
vu_queue_push(dev, q, elem, 0);
vu_queue_notify(dev, q);
pthread_mutex_unlock(&qi->vq_lock);
- pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_unlock(qi->virtio_dev);
}
pthread_mutex_destroy(&req->ch.lock);
@@ -596,7 +621,6 @@ static void *fv_queue_thread(void *opaque)
qi->qidx, qi->kick_fd);
while (1) {
struct pollfd pf[2];
- int ret;
pf[0].fd = qi->kick_fd;
pf[0].events = POLLIN;
@@ -645,8 +669,7 @@ static void *fv_queue_thread(void *opaque)
break;
}
/* Mutual exclusion with virtio_loop() */
- ret = pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
- assert(ret == 0); /* there is no possible error case */
+ vu_dispatch_rdlock(qi->virtio_dev);
pthread_mutex_lock(&qi->vq_lock);
/* out is from guest, in is too guest */
unsigned int in_bytes, out_bytes;
@@ -672,7 +695,7 @@ static void *fv_queue_thread(void *opaque)
}
pthread_mutex_unlock(&qi->vq_lock);
- pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_unlock(qi->virtio_dev);
/* Process all the requests. */
if (!se->thread_pool_size && req_list != NULL) {
@@ -799,7 +822,6 @@ int virtio_loop(struct fuse_session *se)
while (!fuse_session_exited(se)) {
struct pollfd pf[1];
bool ok;
- int ret;
pf[0].fd = se->vu_socketfd;
pf[0].events = POLLIN;
pf[0].revents = 0;
@@ -825,12 +847,11 @@ int virtio_loop(struct fuse_session *se)
assert(pf[0].revents & POLLIN);
fuse_log(FUSE_LOG_DEBUG, "%s: Got VU event\n", __func__);
/* Mutual exclusion with fv_queue_thread() */
- ret = pthread_rwlock_wrlock(&se->virtio_dev->vu_dispatch_rwlock);
- assert(ret == 0); /* there is no possible error case */
+ vu_dispatch_wrlock(se->virtio_dev);
ok = vu_dispatch(&se->virtio_dev->dev);
- pthread_rwlock_unlock(&se->virtio_dev->vu_dispatch_rwlock);
+ vu_dispatch_unlock(se->virtio_dev);
if (!ok) {
fuse_log(FUSE_LOG_ERR, "%s: vu_dispatch failed\n", __func__);
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PULL 3/6] tools/virtiofsd: Replace the word 'whitelist'
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 1/6] virtiofsd: Allow to build it without the tools Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 2/6] virtiofsd: vu_dispatch locking should never fail Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 4/6] virtiofsd: Save error code early at the failure callsite Dr. David Alan Gilbert (git)
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Philippe Mathieu-Daudé <philmd@redhat.com>
Follow the inclusive terminology from the "Conscious Language in your
Open Source Projects" guidelines [*] and replace the words "whitelist"
appropriately.
[*] https://github.com/conscious-lang/conscious-lang-docs/blob/main/faq.md
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210205171817.2108907-3-philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/virtiofsd/passthrough_ll.c | 6 +++---
tools/virtiofsd/passthrough_seccomp.c | 12 ++++++------
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 147b59338a..5f3afe8557 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -3204,7 +3204,7 @@ static void setup_mounts(const char *source)
}
/*
- * Only keep whitelisted capabilities that are needed for file system operation
+ * Only keep capabilities in allowlist that are needed for file system operation
* The (possibly NULL) modcaps_in string passed in is free'd before exit.
*/
static void setup_capabilities(char *modcaps_in)
@@ -3214,8 +3214,8 @@ static void setup_capabilities(char *modcaps_in)
capng_restore_state(&cap.saved);
/*
- * Whitelist file system-related capabilities that are needed for a file
- * server to act like root. Drop everything else like networking and
+ * Add to allowlist file system-related capabilities that are needed for a
+ * file server to act like root. Drop everything else like networking and
* sysadmin capabilities.
*
* Exclusions:
diff --git a/tools/virtiofsd/passthrough_seccomp.c b/tools/virtiofsd/passthrough_seccomp.c
index ea852e2e33..62441cfcdb 100644
--- a/tools/virtiofsd/passthrough_seccomp.c
+++ b/tools/virtiofsd/passthrough_seccomp.c
@@ -21,7 +21,7 @@
#endif
#endif
-static const int syscall_whitelist[] = {
+static const int syscall_allowlist[] = {
/* TODO ireg sem*() syscalls */
SCMP_SYS(brk),
SCMP_SYS(capget), /* For CAP_FSETID */
@@ -117,12 +117,12 @@ static const int syscall_whitelist[] = {
};
/* Syscalls used when --syslog is enabled */
-static const int syscall_whitelist_syslog[] = {
+static const int syscall_allowlist_syslog[] = {
SCMP_SYS(send),
SCMP_SYS(sendto),
};
-static void add_whitelist(scmp_filter_ctx ctx, const int syscalls[], size_t len)
+static void add_allowlist(scmp_filter_ctx ctx, const int syscalls[], size_t len)
{
size_t i;
@@ -153,10 +153,10 @@ void setup_seccomp(bool enable_syslog)
exit(1);
}
- add_whitelist(ctx, syscall_whitelist, G_N_ELEMENTS(syscall_whitelist));
+ add_allowlist(ctx, syscall_allowlist, G_N_ELEMENTS(syscall_allowlist));
if (enable_syslog) {
- add_whitelist(ctx, syscall_whitelist_syslog,
- G_N_ELEMENTS(syscall_whitelist_syslog));
+ add_allowlist(ctx, syscall_allowlist_syslog,
+ G_N_ELEMENTS(syscall_allowlist_syslog));
}
/* libvhost-user calls this for post-copy migration, we don't need it */
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PULL 4/6] virtiofsd: Save error code early at the failure callsite
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
` (2 preceding siblings ...)
2021-02-16 18:37 ` [PULL 3/6] tools/virtiofsd: Replace the word 'whitelist' Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 5/6] viriofsd: Add support for FUSE_HANDLE_KILLPRIV_V2 Dr. David Alan Gilbert (git)
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Vivek Goyal <vgoyal@redhat.com>
Change error code handling slightly in lo_setattr(). Right now we seem
to jump to out_err and assume that "errno" is valid and use that to
send reply.
But if caller has to do some other operations before jumping to out_err,
then it does the dance of first saving errno to saverr and the restore
errno before jumping to out_err. This makes it more confusing.
I am about to make more changes where caller will have to do some
work after error before jumping to out_err. I found it easier to
change the convention a bit. That is caller saves error in "saverr"
before jumping to out_err. And out_err uses "saverr" to send error
back and does not rely on "errno" having actual error.
v3: Resolved conflicts in lo_setattr() due to lo_inode_open() changes.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210208224024.43555-2-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/virtiofsd/passthrough_ll.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 5f3afe8557..216c0bc026 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -698,6 +698,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
res = fchmodat(lo->proc_self_fd, procname, attr->st_mode, 0);
}
if (res == -1) {
+ saverr = errno;
goto out_err;
}
}
@@ -707,6 +708,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
res = fchownat(ifd, "", uid, gid, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
if (res == -1) {
+ saverr = errno;
goto out_err;
}
}
@@ -718,16 +720,15 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
} else {
truncfd = lo_inode_open(lo, inode, O_RDWR);
if (truncfd < 0) {
- errno = -truncfd;
+ saverr = -truncfd;
goto out_err;
}
}
res = ftruncate(truncfd, attr->st_size);
+ saverr = res == -1 ? errno : 0;
if (!fi) {
- saverr = errno;
close(truncfd);
- errno = saverr;
}
if (res == -1) {
goto out_err;
@@ -760,6 +761,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
res = utimensat(lo->proc_self_fd, procname, tv, 0);
}
if (res == -1) {
+ saverr = errno;
goto out_err;
}
}
@@ -768,7 +770,6 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
return lo_getattr(req, ino, fi);
out_err:
- saverr = errno;
lo_inode_put(lo, &inode);
fuse_reply_err(req, saverr);
}
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PULL 5/6] viriofsd: Add support for FUSE_HANDLE_KILLPRIV_V2
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
` (3 preceding siblings ...)
2021-02-16 18:37 ` [PULL 4/6] virtiofsd: Save error code early at the failure callsite Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-16 18:37 ` [PULL 6/6] virtiofsd: Do not use a thread pool by default Dr. David Alan Gilbert (git)
2021-02-17 19:18 ` [PULL 0/6] virtiofs queue Peter Maydell
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Vivek Goyal <vgoyal@redhat.com>
This patch adds basic support for FUSE_HANDLE_KILLPRIV_V2. virtiofsd
can enable/disable this by specifying option "-o killpriv_v2/no_killpriv_v2".
By default this is enabled as long as client supports it
Enabling this option helps with performance in write path. Without this
option, currently every write is first preceeded with a getxattr() operation
to find out if security.capability is set. (Write is supposed to clear
security.capability). With this option enabled, server is signing up for
clearing security.capability on every WRITE and also clearing suid/sgid
subject to certain rules. This gets rid of extra getxattr() call for every
WRITE and improves performance. This is true when virtiofsd is run with
option -o xattr.
What does enabling FUSE_HANDLE_KILLPRIV_V2 mean for file server implementation.
It needs to adhere to following rules. Thanks to Miklos for this summary.
- clear "security.capability" on write, truncate and chown unconditionally
- clear suid/sgid in case of following. Note, sgid is cleared only if
group executable bit is set.
o setattr has FATTR_SIZE and FATTR_KILL_SUIDGID set.
o setattr has FATTR_UID or FATTR_GID
o open has O_TRUNC and FUSE_OPEN_KILL_SUIDGID
o create has O_TRUNC and FUSE_OPEN_KILL_SUIDGID flag set.
o write has FUSE_WRITE_KILL_SUIDGID
>From Linux VFS client perspective, here are the requirements.
- caps are always cleared on chown/write/truncate
- suid is always cleared on chown, while for truncate/write it is cleared
only if caller does not have CAP_FSETID.
- sgid is always cleared on chown, while for truncate/write it is cleared
only if caller does not have CAP_FSETID as well as file has group execute
permission.
virtiofsd implementation has not changed much to adhere to above ruls. And
reason being that current assumption is that we are running on Linux
and on top of filesystems like ext4/xfs which already follow above rules.
On write, truncate, chown, seucurity.capability is cleared. And virtiofsd
drops CAP_FSETID if need be and that will lead to clearing of suid/sgid.
But if virtiofsd is running on top a filesystem which breaks above assumptions,
then it will have to take extra actions to emulate above. That's a TODO
for later when need arises.
Note: create normally is supposed to be called only when file does not
exist. So generally there should not be any question of clearing
setuid/setgid. But it is possible that after client checks that
file is not present, some other client creates file on server
and this race can trigger sending FUSE_CREATE. In that case, if
O_TRUNC is set, we should clear suid/sgid if FUSE_OPEN_KILL_SUIDGID
is also set.
v3:
- Resolved conflicts due to lo_inode_open() changes.
- Moved capability code in lo_do_open() so that both lo_open() and
lo_create() can benefit from common code.
- Dropped changes to kernel headers as these are part of qemu already.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210208224024.43555-3-vgoyal@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/virtiofsd/fuse_common.h | 15 ++++++
tools/virtiofsd/fuse_lowlevel.c | 11 ++++-
tools/virtiofsd/fuse_lowlevel.h | 1 +
tools/virtiofsd/passthrough_ll.c | 84 +++++++++++++++++++++++++++++---
4 files changed, 103 insertions(+), 8 deletions(-)
diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index a090040bb2..fa9671872e 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -357,6 +357,21 @@ struct fuse_file_info {
*/
#define FUSE_CAP_SUBMOUNTS (1 << 27)
+/**
+ * Indicates that the filesystem is responsible for clearing
+ * security.capability xattr and clearing setuid and setgid bits. Following
+ * are the rules.
+ * - clear "security.capability" on write, truncate and chown unconditionally
+ * - clear suid/sgid if following is true. Note, sgid is cleared only if
+ * group executable bit is set.
+ * o setattr has FATTR_SIZE and FATTR_KILL_SUIDGID set.
+ * o setattr has FATTR_UID or FATTR_GID
+ * o open has O_TRUNC and FUSE_OPEN_KILL_SUIDGID
+ * o create has O_TRUNC and FUSE_OPEN_KILL_SUIDGID flag set.
+ * o write has FUSE_WRITE_KILL_SUIDGID
+ */
+#define FUSE_CAP_HANDLE_KILLPRIV_V2 (1 << 28)
+
/**
* Ioctl flags
*
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index e94b71110b..f78692ef66 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -855,7 +855,7 @@ static void do_setattr(fuse_req_t req, fuse_ino_t nodeid,
FUSE_SET_ATTR_GID | FUSE_SET_ATTR_SIZE |
FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME |
FUSE_SET_ATTR_ATIME_NOW | FUSE_SET_ATTR_MTIME_NOW |
- FUSE_SET_ATTR_CTIME;
+ FUSE_SET_ATTR_CTIME | FUSE_SET_ATTR_KILL_SUIDGID;
req->se->op.setattr(req, nodeid, &stbuf, arg->valid, fi);
} else {
@@ -1069,6 +1069,7 @@ static void do_create(fuse_req_t req, fuse_ino_t nodeid,
memset(&fi, 0, sizeof(fi));
fi.flags = arg->flags;
+ fi.kill_priv = arg->open_flags & FUSE_OPEN_KILL_SUIDGID;
req->ctx.umask = arg->umask;
@@ -1092,6 +1093,7 @@ static void do_open(fuse_req_t req, fuse_ino_t nodeid,
memset(&fi, 0, sizeof(fi));
fi.flags = arg->flags;
+ fi.kill_priv = arg->open_flags & FUSE_OPEN_KILL_SUIDGID;
if (req->se->op.open) {
req->se->op.open(req, nodeid, &fi);
@@ -1983,6 +1985,9 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
if (arg->flags & FUSE_SUBMOUNTS) {
se->conn.capable |= FUSE_CAP_SUBMOUNTS;
}
+ if (arg->flags & FUSE_HANDLE_KILLPRIV_V2) {
+ se->conn.capable |= FUSE_CAP_HANDLE_KILLPRIV_V2;
+ }
#ifdef HAVE_SPLICE
#ifdef HAVE_VMSPLICE
se->conn.capable |= FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE;
@@ -2114,6 +2119,10 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
outarg.congestion_threshold = se->conn.congestion_threshold;
outarg.time_gran = se->conn.time_gran;
+ if (se->conn.want & FUSE_CAP_HANDLE_KILLPRIV_V2) {
+ outarg.flags |= FUSE_HANDLE_KILLPRIV_V2;
+ }
+
fuse_log(FUSE_LOG_DEBUG, " INIT: %u.%u\n", outarg.major, outarg.minor);
fuse_log(FUSE_LOG_DEBUG, " flags=0x%08x\n", outarg.flags);
fuse_log(FUSE_LOG_DEBUG, " max_readahead=0x%08x\n", outarg.max_readahead);
diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
index 0e10a14bc9..3bf786b034 100644
--- a/tools/virtiofsd/fuse_lowlevel.h
+++ b/tools/virtiofsd/fuse_lowlevel.h
@@ -143,6 +143,7 @@ struct fuse_forget_data {
#define FUSE_SET_ATTR_ATIME_NOW (1 << 7)
#define FUSE_SET_ATTR_MTIME_NOW (1 << 8)
#define FUSE_SET_ATTR_CTIME (1 << 10)
+#define FUSE_SET_ATTR_KILL_SUIDGID (1 << 11)
/*
* Request methods and replies
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 216c0bc026..58d24c0010 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -168,6 +168,7 @@ struct lo_data {
/* An O_PATH file descriptor to /proc/self/fd/ */
int proc_self_fd;
+ int user_killpriv_v2, killpriv_v2;
};
static const struct fuse_opt lo_opts[] = {
@@ -198,6 +199,8 @@ static const struct fuse_opt lo_opts[] = {
{ "allow_direct_io", offsetof(struct lo_data, allow_direct_io), 1 },
{ "no_allow_direct_io", offsetof(struct lo_data, allow_direct_io), 0 },
{ "announce_submounts", offsetof(struct lo_data, announce_submounts), 1 },
+ { "killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 1 },
+ { "no_killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 0 },
FUSE_OPT_END
};
static bool use_syslog = false;
@@ -630,6 +633,34 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn)
"does not support it\n");
lo->announce_submounts = false;
}
+
+ if (lo->user_killpriv_v2 == 1) {
+ /*
+ * User explicitly asked for this option. Enable it unconditionally.
+ * If connection does not have this capability, it should fail
+ * in fuse_lowlevel.c
+ */
+ fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling killpriv_v2\n");
+ conn->want |= FUSE_CAP_HANDLE_KILLPRIV_V2;
+ lo->killpriv_v2 = 1;
+ } else if (lo->user_killpriv_v2 == -1 &&
+ conn->capable & FUSE_CAP_HANDLE_KILLPRIV_V2) {
+ /*
+ * User did not specify a value for killpriv_v2. By default enable it
+ * if connection offers this capability
+ */
+ fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling killpriv_v2\n");
+ conn->want |= FUSE_CAP_HANDLE_KILLPRIV_V2;
+ lo->killpriv_v2 = 1;
+ } else {
+ /*
+ * Either user specified to disable killpriv_v2, or connection does
+ * not offer this capability. Disable killpriv_v2 in both the cases
+ */
+ fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling killpriv_v2\n");
+ conn->want &= ~FUSE_CAP_HANDLE_KILLPRIV_V2;
+ lo->killpriv_v2 = 0;
+ }
}
static void lo_getattr(fuse_req_t req, fuse_ino_t ino,
@@ -714,7 +745,10 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
}
if (valid & FUSE_SET_ATTR_SIZE) {
int truncfd;
+ bool kill_suidgid;
+ bool cap_fsetid_dropped = false;
+ kill_suidgid = lo->killpriv_v2 && (valid & FUSE_SET_ATTR_KILL_SUIDGID);
if (fi) {
truncfd = fd;
} else {
@@ -725,8 +759,25 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
}
}
+ if (kill_suidgid) {
+ res = drop_effective_cap("FSETID", &cap_fsetid_dropped);
+ if (res != 0) {
+ saverr = res;
+ if (!fi) {
+ close(truncfd);
+ }
+ goto out_err;
+ }
+ }
+
res = ftruncate(truncfd, attr->st_size);
saverr = res == -1 ? errno : 0;
+
+ if (cap_fsetid_dropped) {
+ if (gain_effective_cap("FSETID")) {
+ fuse_log(FUSE_LOG_ERR, "Failed to gain CAP_FSETID\n");
+ }
+ }
if (!fi) {
close(truncfd);
}
@@ -1709,11 +1760,27 @@ static int lo_do_open(struct lo_data *lo, struct lo_inode *inode,
{
ssize_t fh;
int fd = existing_fd;
+ int err;
+ bool cap_fsetid_dropped = false;
+ bool kill_suidgid = lo->killpriv_v2 && fi->kill_priv;
update_open_flags(lo->writeback, lo->allow_direct_io, fi);
if (fd < 0) {
+ if (kill_suidgid) {
+ err = drop_effective_cap("FSETID", &cap_fsetid_dropped);
+ if (err) {
+ return err;
+ }
+ }
+
fd = lo_inode_open(lo, inode, fi->flags);
+
+ if (cap_fsetid_dropped) {
+ if (gain_effective_cap("FSETID")) {
+ fuse_log(FUSE_LOG_ERR, "Failed to gain CAP_FSETID\n");
+ }
+ }
if (fd < 0) {
return -fd;
}
@@ -1747,8 +1814,8 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
int err;
struct lo_cred old = {};
- fuse_log(FUSE_LOG_DEBUG, "lo_create(parent=%" PRIu64 ", name=%s)\n", parent,
- name);
+ fuse_log(FUSE_LOG_DEBUG, "lo_create(parent=%" PRIu64 ", name=%s)"
+ " kill_priv=%d\n", parent, name, fi->kill_priv);
if (!is_safe_path_component(name)) {
fuse_reply_err(req, EINVAL);
@@ -1981,8 +2048,8 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
struct lo_inode *inode = lo_inode(req, ino);
int err;
- fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d)\n", ino,
- fi->flags);
+ fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d, kill_priv=%d)"
+ "\n", ino, fi->flags, fi->kill_priv);
if (!inode) {
fuse_reply_err(req, EBADF);
@@ -2121,12 +2188,14 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t ino,
out_buf.buf[0].pos = off;
fuse_log(FUSE_LOG_DEBUG,
- "lo_write_buf(ino=%" PRIu64 ", size=%zd, off=%lu)\n", ino,
- out_buf.buf[0].size, (unsigned long)off);
+ "lo_write_buf(ino=%" PRIu64 ", size=%zd, off=%lu kill_priv=%d)\n",
+ ino, out_buf.buf[0].size, (unsigned long)off, fi->kill_priv);
/*
* If kill_priv is set, drop CAP_FSETID which should lead to kernel
- * clearing setuid/setgid on file.
+ * clearing setuid/setgid on file. Note, for WRITE, we need to do
+ * this even if killpriv_v2 is not enabled. fuse direct write path
+ * relies on this.
*/
if (fi->kill_priv) {
res = drop_effective_cap("FSETID", &cap_fsetid_dropped);
@@ -3534,6 +3603,7 @@ int main(int argc, char *argv[])
.posix_lock = 0,
.allow_direct_io = 0,
.proc_self_fd = -1,
+ .user_killpriv_v2 = -1,
};
struct lo_map_elem *root_elem;
struct lo_map_elem *reserve_elem;
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PULL 6/6] virtiofsd: Do not use a thread pool by default
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
` (4 preceding siblings ...)
2021-02-16 18:37 ` [PULL 5/6] viriofsd: Add support for FUSE_HANDLE_KILLPRIV_V2 Dr. David Alan Gilbert (git)
@ 2021-02-16 18:37 ` Dr. David Alan Gilbert (git)
2021-02-17 19:18 ` [PULL 0/6] virtiofs queue Peter Maydell
6 siblings, 0 replies; 8+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2021-02-16 18:37 UTC (permalink / raw)
To: qemu-devel, wainersm, groug, philmd, vgoyal; +Cc: virtio-fs
From: Vivek Goyal <vgoyal@redhat.com>
Currently we created a thread pool (With 64 max threads per pool) for
each virtqueue. We hoped that this will provide us with better scalability
and performance.
But in practice, we are getting better numbers in most of the cases
when we don't create a thread pool at all and a single thread per
virtqueue receives the request and processes it.
Hence, I am proposing that we switch to no thread pool by default
(equivalent of --thread-pool-size=0). This will provide out of
box better performance to most of the users. In fact other users
have confirmed that not using a thread pool gives them better
numbers. So why not use this as default. It can be changed when
somebody can fix the issues with thread pool performance.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <20210210182744.27324-2-vgoyal@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
tools/virtiofsd/fuse_lowlevel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index f78692ef66..1aa26c6333 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -18,7 +18,7 @@
#include <sys/file.h>
-#define THREAD_POOL_SIZE 64
+#define THREAD_POOL_SIZE 0
#define OFFSET_MAX 0x7fffffffffffffffLL
--
2.29.2
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PULL 0/6] virtiofs queue
2021-02-16 18:37 [PULL 0/6] virtiofs queue Dr. David Alan Gilbert (git)
` (5 preceding siblings ...)
2021-02-16 18:37 ` [PULL 6/6] virtiofsd: Do not use a thread pool by default Dr. David Alan Gilbert (git)
@ 2021-02-17 19:18 ` Peter Maydell
6 siblings, 0 replies; 8+ messages in thread
From: Peter Maydell @ 2021-02-17 19:18 UTC (permalink / raw)
To: Dr. David Alan Gilbert (git)
Cc: QEMU Developers, Wainer dos Santos Moschetta, Greg Kurz,
virtio-fs, Philippe Mathieu-Daudé, vgoyal
On Tue, 16 Feb 2021 at 18:45, Dr. David Alan Gilbert (git)
<dgilbert@redhat.com> wrote:
>
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The following changes since commit 18543229fd7a2c79dcd6818c7b1f0f62512b5220:
>
> Merge remote-tracking branch 'remotes/cleber-gitlab/tags/python-next-pull-request' into staging (2021-02-16 14:37:57 +0000)
>
> are available in the Git repository at:
>
> https://gitlab.com/dagrh/qemu.git tags/pull-virtiofs-20210216
>
> for you to fetch changes up to 26ec1909648e0c06ff06ebc3ddb2f88ebeeaa6a9:
>
> virtiofsd: Do not use a thread pool by default (2021-02-16 17:54:18 +0000)
>
> ----------------------------------------------------------------
> virtiofsd pull 2021-02-16
>
> Vivek's support for new FUSE KILLPRIV_V2
> and some smaller cleanups.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>
Applied, thanks.
Please update the changelog at https://wiki.qemu.org/ChangeLog/6.0
for any user-visible changes.
-- PMM
^ permalink raw reply [flat|nested] 8+ messages in thread