(client) fixed race condition between client and kernel in retrieving…

… open file list (FreeBSD only)
moosefs · Sep 14, 2022 · 023198e · 023198e
1 parent cae79a8
commit 023198e
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Showing 2 changed files with 16 additions and 13 deletions.
diff --git a/NEWS b/NEWS
@@ -18,6 +18,7 @@ This file lists noteworthy changes in MooseFS.
   - (all) using SIGUSR1 instead of SIGINFO even on system where SIGINFO is defined
   - (master) changed default ATIME_MODE to 2 (issue #478)
   - (master) fixed atime/mtime/ctime preservation during snapshot (in HA environement upgrade may cause one time desync ; issue #489)
+  - (client) fixed race condition between client and kernel in retrieving open file list (FreeBSD only)
 
 * MooseFS 3.0.116-1 (2021-08-10)
 

diff --git a/mfsclient/sustained_inodes.c b/mfsclient/sustained_inodes.c
@@ -201,7 +201,8 @@ void sinodes_pid_inodes(pid_t pid) {
 #elif defined(__FreeBSD__)
 	struct kinfo_file *kif;
 	uint8_t *p;
-	size_t len, olen;
+	size_t len;
+	int i;
 	int name[4];
 	int error;
 
@@ -211,27 +212,28 @@ void sinodes_pid_inodes(pid_t pid) {
 	name[2] = KERN_PROC_FILEDESC;
 	name[3] = pid;
 	p = NULL;
-	if (sysctl(name, 4, NULL, &len, NULL, 0)<0) {
-		if (errno!=ESRCH && errno!=EBUSY) {
-			mfs_errlog(LOG_NOTICE,"sysctl(kern.proc.filedesc) error");
-		}
-		return;
-	}
-	if (len==0) {
-		return;
-	}
+	i = 0;
 	do {
-		len += len / 10;
+		if (sysctl(name, 4, NULL, &len, NULL, 0)<0) {
+			if (errno!=ESRCH && errno!=EBUSY) {
+				mfs_errlog(LOG_NOTICE,"sysctl(kern.proc.filedesc) error");
+			}
+			return;
+		}
+		if (len==0) {
+			return;
+		}
+		len += len / 2;
 		if (p!=NULL) {
 			free(p);
 		}
 		p = malloc(len);
 		if (p == NULL) {
 			return;
 		}
-		olen = len;
 		error = sysctl(name, 4, p, &len, NULL, 0);
-	} while (error < 0 && errno == ENOMEM && olen == len);
+		i++;
+	} while (error < 0 && errno == ENOMEM && i < 10);
 	if (error<0) {
 		if (errno!=ESRCH && errno!=EBUSY) {
 			mfs_errlog(LOG_NOTICE,"sysctl(kern.proc.filedesc) error");