Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-virtiofs-20200123b' into staging

virtiofsd first pull v2

Import our virtiofsd.
This pulls in the daemon to drive a file system connected to the
existing qemu virtiofsd device.
It's derived from upstream libfuse with lots of changes (and a lot
trimmed out).
The daemon lives in the newly created qemu/tools/virtiofsd

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

v2
  drop the docs while we discuss where they should live
  and we need to redo the manpage in anything but texi

# gpg: Signature made Thu 23 Jan 2020 16:45:18 GMT
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert-gitlab/tags/pull-virtiofs-20200123b: (108 commits)
  virtiofsd: add some options to the help message
  virtiofsd: stop all queue threads on exit in virtio_loop()
  virtiofsd/passthrough_ll: Pass errno to fuse_reply_err()
  virtiofsd: Convert lo_destroy to take the lo->mutex lock itself
  virtiofsd: add --thread-pool-size=NUM option
  virtiofsd: fix lo_destroy() resource leaks
  virtiofsd: prevent FUSE_INIT/FUSE_DESTROY races
  virtiofsd: process requests in a thread pool
  virtiofsd: use fuse_buf_writev to replace fuse_buf_write for better performance
  virtiofsd: add definition of fuse_buf_writev()
  virtiofsd: passthrough_ll: Use cache_readdir for directory open
  virtiofsd: Fix data corruption with O_APPEND write in writeback mode
  virtiofsd: Reset O_DIRECT flag during file open
  virtiofsd: convert more fprintf and perror to use fuse log infra
  virtiofsd: do not always set FUSE_FLOCK_LOCKS
  virtiofsd: introduce inode refcount to prevent use-after-free
  virtiofsd: passthrough_ll: fix refcounting on remove/rename
  libvhost-user: Fix some memtable remap cases
  virtiofsd: rename inode->refcount to inode->nlookup
  virtiofsd: prevent races with lo_dirp_put()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/tools/virtiofsd/fuse_log.h b/tools/virtiofsd/fuse_log.h
new file mode 100644
index 0000000000..bf6c11ff11
--- /dev/null
+++ b/tools/virtiofsd/fuse_log.h
@@ -0,0 +1,74 @@
+/*
+ * FUSE: Filesystem in Userspace
+ * Copyright (C) 2019  Red Hat, Inc.
+ *
+ * This program can be distributed under the terms of the GNU LGPLv2.
+ * See the file COPYING.LIB.
+ */
+
+#ifndef FUSE_LOG_H_
+#define FUSE_LOG_H_
+
+/** @file
+ *
+ * This file defines the logging interface of FUSE
+ */
+
+#include <stdarg.h>
+
+/**
+ * Log severity level
+ *
+ * These levels correspond to syslog(2) log levels since they are widely used.
+ */
+enum fuse_log_level {
+    FUSE_LOG_EMERG,
+    FUSE_LOG_ALERT,
+    FUSE_LOG_CRIT,
+    FUSE_LOG_ERR,
+    FUSE_LOG_WARNING,
+    FUSE_LOG_NOTICE,
+    FUSE_LOG_INFO,
+    FUSE_LOG_DEBUG
+};
+
+/**
+ * Log message handler function.
+ *
+ * This function must be thread-safe.  It may be called from any libfuse
+ * function, including fuse_parse_cmdline() and other functions invoked before
+ * a FUSE filesystem is created.
+ *
+ * Install a custom log message handler function using fuse_set_log_func().
+ *
+ * @param level log severity level
+ * @param fmt sprintf-style format string including newline
+ * @param ap format string arguments
+ */
+typedef void (*fuse_log_func_t)(enum fuse_log_level level, const char *fmt,
+                                va_list ap);
+
+/**
+ * Install a custom log handler function.
+ *
+ * Log messages are emitted by libfuse functions to report errors and debug
+ * information.  Messages are printed to stderr by default but this can be
+ * overridden by installing a custom log message handler function.
+ *
+ * The log message handler function is global and affects all FUSE filesystems
+ * created within this process.
+ *
+ * @param func a custom log message handler function or NULL to revert to
+ *             the default
+ */
+void fuse_set_log_func(fuse_log_func_t func);
+
+/**
+ * Emit a log message
+ *
+ * @param level severity level (FUSE_LOG_ERR, FUSE_LOG_DEBUG, etc)
+ * @param fmt sprintf-style format string including newline
+ */
+void fuse_log(enum fuse_log_level level, const char *fmt, ...);
+
+#endif /* FUSE_LOG_H_ */