virtiofsd: print log only when priority is high enough

Introduce "-o log_level=" command line option to specify current log
level (priority), valid values are "debug info warn err", e.g.

    ./virtiofsd -o log_level=debug ...

So only log priority higher than "debug" will be printed to
stderr/syslog. And the default level is info.

The "-o debug"/"-d" options are kept, and imply debug log level.

Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
dgilbert: Reworked for libfuse's log_func
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
with fix by:
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

4 files changed, 87 insertions, 115 deletions

diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 6ceb33d913..a7a19685b5 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -158,19 +158,17 @@ static int fuse_send_msg(struct fuse_session *se, struct fuse_chan *ch,
     struct fuse_out_header *out = iov[0].iov_base;
 
     out->len = iov_length(iov, count);
-    if (se->debug) {
-        if (out->unique == 0) {
-            fuse_log(FUSE_LOG_DEBUG, "NOTIFY: code=%d length=%u\n", out->error,
-                     out->len);
-        } else if (out->error) {
-            fuse_log(FUSE_LOG_DEBUG,
-                     "   unique: %llu, error: %i (%s), outsize: %i\n",
-                     (unsigned long long)out->unique, out->error,
-                     strerror(-out->error), out->len);
-        } else {
-            fuse_log(FUSE_LOG_DEBUG, "   unique: %llu, success, outsize: %i\n",
-                     (unsigned long long)out->unique, out->len);
-        }
+    if (out->unique == 0) {
+        fuse_log(FUSE_LOG_DEBUG, "NOTIFY: code=%d length=%u\n", out->error,
+                 out->len);
+    } else if (out->error) {
+        fuse_log(FUSE_LOG_DEBUG,
+                 "   unique: %llu, error: %i (%s), outsize: %i\n",
+                 (unsigned long long)out->unique, out->error,
+                 strerror(-out->error), out->len);
+    } else {
+        fuse_log(FUSE_LOG_DEBUG, "   unique: %llu, success, outsize: %i\n",
+                 (unsigned long long)out->unique, out->len);
     }
 
     if (fuse_lowlevel_is_virtio(se)) {
@@ -1662,10 +1660,8 @@ static void do_interrupt(fuse_req_t req, fuse_ino_t nodeid,
         return;
     }
 
-    if (se->debug) {
-        fuse_log(FUSE_LOG_DEBUG, "INTERRUPT: %llu\n",
-                 (unsigned long long)arg->unique);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "INTERRUPT: %llu\n",
+             (unsigned long long)arg->unique);
 
     req->u.i.unique = arg->unique;
 
@@ -1901,13 +1897,10 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
         }
     }
 
-    if (se->debug) {
-        fuse_log(FUSE_LOG_DEBUG, "INIT: %u.%u\n", arg->major, arg->minor);
-        if (arg->major == 7 && arg->minor >= 6) {
-            fuse_log(FUSE_LOG_DEBUG, "flags=0x%08x\n", arg->flags);
-            fuse_log(FUSE_LOG_DEBUG, "max_readahead=0x%08x\n",
-                     arg->max_readahead);
-        }
+    fuse_log(FUSE_LOG_DEBUG, "INIT: %u.%u\n", arg->major, arg->minor);
+    if (arg->major == 7 && arg->minor >= 6) {
+        fuse_log(FUSE_LOG_DEBUG, "flags=0x%08x\n", arg->flags);
+        fuse_log(FUSE_LOG_DEBUG, "max_readahead=0x%08x\n", arg->max_readahead);
     }
     se->conn.proto_major = arg->major;
     se->conn.proto_minor = arg->minor;
@@ -2116,19 +2109,14 @@ 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->debug) {
-        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);
-        fuse_log(FUSE_LOG_DEBUG, "   max_write=0x%08x\n", outarg.max_write);
-        fuse_log(FUSE_LOG_DEBUG, "   max_background=%i\n",
-                 outarg.max_background);
-        fuse_log(FUSE_LOG_DEBUG, "   congestion_threshold=%i\n",
-                 outarg.congestion_threshold);
-        fuse_log(FUSE_LOG_DEBUG, "   time_gran=%u\n", outarg.time_gran);
-    }
+    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);
+    fuse_log(FUSE_LOG_DEBUG, "   max_write=0x%08x\n", outarg.max_write);
+    fuse_log(FUSE_LOG_DEBUG, "   max_background=%i\n", outarg.max_background);
+    fuse_log(FUSE_LOG_DEBUG, "   congestion_threshold=%i\n",
+             outarg.congestion_threshold);
+    fuse_log(FUSE_LOG_DEBUG, "   time_gran=%u\n", outarg.time_gran);
 
     send_reply_ok(req, &outarg, outargsize);
 }
@@ -2407,14 +2395,11 @@ void fuse_session_process_buf_int(struct fuse_session *se,
     in = fuse_mbuf_iter_advance(&iter, sizeof(*in));
     assert(in); /* caller guarantees the input buffer is large enough */
 
-    if (se->debug) {
-        fuse_log(FUSE_LOG_DEBUG,
-                 "unique: %llu, opcode: %s (%i), nodeid: %llu, insize: %zu, "
-                 "pid: %u\n",
-                 (unsigned long long)in->unique,
-                 opname((enum fuse_opcode)in->opcode), in->opcode,
-                 (unsigned long long)in->nodeid, buf->size, in->pid);
-    }
+    fuse_log(
+        FUSE_LOG_DEBUG,
+        "unique: %llu, opcode: %s (%i), nodeid: %llu, insize: %zu, pid: %u\n",
+        (unsigned long long)in->unique, opname((enum fuse_opcode)in->opcode),
+        in->opcode, (unsigned long long)in->nodeid, buf->size, in->pid);
 
     req = fuse_ll_alloc_req(se);
     if (req == NULL) {
diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
index f2750bc189..138041e5f1 100644
--- a/tools/virtiofsd/fuse_lowlevel.h
+++ b/tools/virtiofsd/fuse_lowlevel.h
@@ -1796,6 +1796,7 @@ struct fuse_cmdline_opts {
     int show_help;
     int print_capabilities;
     int syslog;
+    int log_level;
     unsigned int max_idle_threads;
 };
 
diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c
index 9692ef9f1f..6d50a46a7e 100644
--- a/tools/virtiofsd/helper.c
+++ b/tools/virtiofsd/helper.c
@@ -34,7 +34,6 @@
         t, offsetof(struct fuse_cmdline_opts, p), v \
     }
 
-
 static const struct fuse_opt fuse_helper_opts[] = {
     FUSE_HELPER_OPT("-h", show_help),
     FUSE_HELPER_OPT("--help", show_help),
@@ -55,6 +54,10 @@ static const struct fuse_opt fuse_helper_opts[] = {
     FUSE_OPT_KEY("subtype=", FUSE_OPT_KEY_KEEP),
     FUSE_HELPER_OPT("max_idle_threads=%u", max_idle_threads),
     FUSE_HELPER_OPT("--syslog", syslog),
+    FUSE_HELPER_OPT_VALUE("log_level=debug", log_level, FUSE_LOG_DEBUG),
+    FUSE_HELPER_OPT_VALUE("log_level=info", log_level, FUSE_LOG_INFO),
+    FUSE_HELPER_OPT_VALUE("log_level=warn", log_level, FUSE_LOG_WARNING),
+    FUSE_HELPER_OPT_VALUE("log_level=err", log_level, FUSE_LOG_ERR),
     FUSE_OPT_END
 };
 
@@ -142,6 +145,9 @@ void fuse_cmdline_help(void)
            "    --syslog                   log to syslog (default stderr)\n"
            "    -f                         foreground operation\n"
            "    --daemonize                run in background\n"
+           "    -o log_level=<level>       log level, default to \"info\"\n"
+           "                               level could be one of \"debug, "
+           "info, warn, err\"\n"
            "    -o max_idle_threads        the maximum number of idle worker "
            "threads\n"
            "                               allowed (default: 10)\n"
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 0372aca143..ff6910fd73 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -37,6 +37,7 @@
 
 #include "qemu/osdep.h"
 #include "fuse_virtio.h"
+#include "fuse_log.h"
 #include "fuse_lowlevel.h"
 #include <assert.h>
 #include <cap-ng.h>
@@ -140,6 +141,7 @@ static const struct fuse_opt lo_opts[] = {
     FUSE_OPT_END
 };
 static bool use_syslog = false;
+static int current_log_level;
 
 static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n);
 
@@ -458,11 +460,6 @@ static int lo_fd(fuse_req_t req, fuse_ino_t ino)
     return inode ? inode->fd : -1;
 }
 
-static bool lo_debug(fuse_req_t req)
-{
-    return lo_data(req)->debug != 0;
-}
-
 static void lo_init(void *userdata, struct fuse_conn_info *conn)
 {
     struct lo_data *lo = (struct lo_data *)userdata;
@@ -472,15 +469,11 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn)
     }
 
     if (lo->writeback && conn->capable & FUSE_CAP_WRITEBACK_CACHE) {
-        if (lo->debug) {
-            fuse_log(FUSE_LOG_DEBUG, "lo_init: activating writeback\n");
-        }
+        fuse_log(FUSE_LOG_DEBUG, "lo_init: activating writeback\n");
         conn->want |= FUSE_CAP_WRITEBACK_CACHE;
     }
     if (lo->flock && conn->capable & FUSE_CAP_FLOCK_LOCKS) {
-        if (lo->debug) {
-            fuse_log(FUSE_LOG_DEBUG, "lo_init: activating flock locks\n");
-        }
+        fuse_log(FUSE_LOG_DEBUG, "lo_init: activating flock locks\n");
         conn->want |= FUSE_CAP_FLOCK_LOCKS;
     }
 }
@@ -823,10 +816,8 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
     }
     e->ino = inode->fuse_ino;
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n",
-                 (unsigned long long)parent, name, (unsigned long long)e->ino);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n", (unsigned long long)parent,
+             name, (unsigned long long)e->ino);
 
     return 0;
 
@@ -843,10 +834,8 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
     struct fuse_entry_param e;
     int err;
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "lo_lookup(parent=%" PRIu64 ", name=%s)\n",
-                 parent, name);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "lo_lookup(parent=%" PRIu64 ", name=%s)\n", parent,
+             name);
 
     /*
      * Don't use is_safe_path_component(), allow "." and ".." for NFS export
@@ -971,10 +960,8 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent,
         goto out;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n",
-                 (unsigned long long)parent, name, (unsigned long long)e.ino);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n", (unsigned long long)parent,
+             name, (unsigned long long)e.ino);
 
     fuse_reply_entry(req, &e);
     return;
@@ -1074,10 +1061,8 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t parent,
     pthread_mutex_unlock(&lo->mutex);
     e.ino = inode->fuse_ino;
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n",
-                 (unsigned long long)parent, name, (unsigned long long)e.ino);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n", (unsigned long long)parent,
+             name, (unsigned long long)e.ino);
 
     fuse_reply_entry(req, &e);
     return;
@@ -1171,11 +1156,9 @@ static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup)
         return;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "  forget %lli %lli -%lli\n",
-                 (unsigned long long)ino, (unsigned long long)inode->refcount,
-                 (unsigned long long)nlookup);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "  forget %lli %lli -%lli\n",
+             (unsigned long long)ino, (unsigned long long)inode->refcount,
+             (unsigned long long)nlookup);
 
     unref_inode(lo, inode, nlookup);
 }
@@ -1445,10 +1428,8 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
     int err;
     struct lo_cred old = {};
 
-    if (lo_debug(req)) {
-        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)\n", parent,
+             name);
 
     if (!is_safe_path_component(name)) {
         fuse_reply_err(req, EINVAL);
@@ -1525,10 +1506,8 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
     char buf[64];
     struct lo_data *lo = lo_data(req);
 
-    if (lo_debug(req)) {
-        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)\n", ino,
+             fi->flags);
 
     /*
      * With writeback cache, kernel may send read requests even
@@ -1644,12 +1623,10 @@ static void lo_read(fuse_req_t req, fuse_ino_t ino, size_t size, off_t offset,
 {
     struct fuse_bufvec buf = FUSE_BUFVEC_INIT(size);
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG,
-                 "lo_read(ino=%" PRIu64 ", size=%zd, "
-                 "off=%lu)\n",
-                 ino, size, (unsigned long)offset);
-    }
+    fuse_log(FUSE_LOG_DEBUG,
+             "lo_read(ino=%" PRIu64 ", size=%zd, "
+             "off=%lu)\n",
+             ino, size, (unsigned long)offset);
 
     buf.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
     buf.buf[0].fd = lo_fi_fd(req, fi);
@@ -1671,11 +1648,9 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t ino,
     out_buf.buf[0].fd = lo_fi_fd(req, fi);
     out_buf.buf[0].pos = off;
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG,
-                 "lo_write(ino=%" PRIu64 ", size=%zd, off=%lu)\n", ino,
-                 out_buf.buf[0].size, (unsigned long)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);
 
     /*
      * If kill_priv is set, drop CAP_FSETID which should lead to kernel
@@ -1774,11 +1749,8 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
         goto out;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG,
-                 "lo_getxattr(ino=%" PRIu64 ", name=%s size=%zd)\n", ino, name,
-                 size);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "lo_getxattr(ino=%" PRIu64 ", name=%s size=%zd)\n",
+             ino, name, size);
 
     if (inode->is_symlink) {
         /* Sorry, no race free way to getxattr on symlink. */
@@ -1852,10 +1824,8 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size)
         goto out;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "lo_listxattr(ino=%" PRIu64 ", size=%zd)\n",
-                 ino, size);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "lo_listxattr(ino=%" PRIu64 ", size=%zd)\n", ino,
+             size);
 
     if (inode->is_symlink) {
         /* Sorry, no race free way to listxattr on symlink. */
@@ -1929,11 +1899,8 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
         goto out;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG,
-                 "lo_setxattr(ino=%" PRIu64 ", name=%s value=%s size=%zd)\n",
-                 ino, name, value, size);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "lo_setxattr(ino=%" PRIu64
+             ", name=%s value=%s size=%zd)\n", ino, name, value, size);
 
     if (inode->is_symlink) {
         /* Sorry, no race free way to setxattr on symlink. */
@@ -1978,10 +1945,8 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *name)
         goto out;
     }
 
-    if (lo_debug(req)) {
-        fuse_log(FUSE_LOG_DEBUG, "lo_removexattr(ino=%" PRIu64 ", name=%s)\n",
-                 ino, name);
-    }
+    fuse_log(FUSE_LOG_DEBUG, "lo_removexattr(ino=%" PRIu64 ", name=%s)\n", ino,
+             name);
 
     if (inode->is_symlink) {
         /* Sorry, no race free way to setxattr on symlink. */
@@ -2303,6 +2268,10 @@ static void setup_nofile_rlimit(void)
 
 static void log_func(enum fuse_log_level level, const char *fmt, va_list ap)
 {
+    if (current_log_level < level) {
+        return;
+    }
+
     if (use_syslog) {
         int priority = LOG_ERR;
         switch (level) {
@@ -2401,8 +2370,19 @@ int main(int argc, char *argv[])
         return 1;
     }
 
+    /*
+     * log_level is 0 if not configured via cmd options (0 is LOG_EMERG,
+     * and we don't use this log level).
+     */
+    if (opts.log_level != 0) {
+        current_log_level = opts.log_level;
+    }
     lo.debug = opts.debug;
+    if (lo.debug) {
+        current_log_level = FUSE_LOG_DEBUG;
+    }
     lo.root.refcount = 2;
+
     if (lo.source) {
         struct stat stat;
         int res;