summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorKrishnan Parthasarathi <kparthas@redhat.com>2013-01-31 10:29:20 +0530
committerAnand Avati <avati@redhat.com>2013-02-03 12:16:07 -0800
commit6b262d20940b088a1d72ad5518cc4908a7316b5a (patch)
treead82bf324c48f6e10c5bb8aa517327d70d75a4d2
parent67d0e72b16104911fef1cebb0b7a1b24d683e899 (diff)
locks: Protected racy (read) access of ext_list
Change-Id: Ibf639695ebd99c11c6960c9be82c0cee71b50744 BUG: 905864 Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com> Reviewed-on: http://review.gluster.org/4458 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Amar Tumballi <amarts@redhat.com> Reviewed-by: Anand Avati <avati@redhat.com>
-rw-r--r--tests/bugs/bug-905864.c82
-rw-r--r--tests/bugs/bug-905864.t29
-rw-r--r--xlators/features/locks/src/common.c28
3 files changed, 129 insertions, 10 deletions
diff --git a/tests/bugs/bug-905864.c b/tests/bugs/bug-905864.c
new file mode 100644
index 00000000000..ed09b6e2bc4
--- /dev/null
+++ b/tests/bugs/bug-905864.c
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <pthread.h>
+
+
+pthread_t th[5] = {0};
+void
+flock_init (struct flock *f, short int type, off_t start, off_t len)
+{
+ f->l_type = type;
+ f->l_start = start;
+ f->l_len = len;
+}
+
+int
+flock_range_in_steps (int fd, int is_set, short l_type,
+ int start, int end, int step)
+{
+ int ret = 0;
+ int i = 0;
+ struct flock f = {0,};
+
+ for (i = start; i+step < end; i += step) {
+ flock_init (&f, l_type, i, step);
+ ret = fcntl (fd, (is_set)? F_SETLKW:F_GETLK, &f);
+ if (ret) {
+ perror ("fcntl");
+ goto out;
+ }
+ }
+out:
+ return ret;
+}
+
+void *
+random_locker (void *arg)
+{
+ int fd = *(int *)arg;
+ int i = 0;
+ int is_set = 0;
+
+ /* use thread id to choose GETLK or SETLK operation*/
+ is_set = pthread_self () % 2;
+ (void)flock_range_in_steps (fd, is_set, F_WRLCK, 0, 400, 1);
+
+ return NULL;
+}
+
+
+int main (int argc, char **argv)
+{
+ int fd = -1;
+ int ret = 1;
+ int i = 0;
+ char *fname = NULL;
+
+ if (argc < 2)
+ goto out;
+
+ fname = argv[1];
+ fd = open (fname, O_RDWR);
+ if (fd == -1) {
+ perror ("open");
+ goto out;
+ }
+
+ ret = flock_range_in_steps (fd, 1, F_WRLCK, 0, 2000, 2);
+ for (i = 0; i < 5; i++) {
+ pthread_create (&th[i], NULL, random_locker, (void *) &fd);
+ }
+ ret = flock_range_in_steps (fd, 1, F_WRLCK, 0, 2000, 2);
+ for (i = 0; i < 5; i++) {
+ pthread_join (th[i], NULL);
+ }
+out:
+ if (fd != -1)
+ close (fd);
+
+ return ret;
+}
diff --git a/tests/bugs/bug-905864.t b/tests/bugs/bug-905864.t
new file mode 100644
index 00000000000..9d18ea1e9ff
--- /dev/null
+++ b/tests/bugs/bug-905864.t
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+
+cleanup;
+
+## Start and create a volume
+TEST glusterd;
+TEST pidof glusterd;
+TEST $CLI volume info;
+
+TEST $CLI volume create $V0 replica 2 stripe 2 $H0:$B0/${V0}{1,2,3,4,5,6,7,8};
+TEST $CLI volume start $V0;
+
+TEST glusterfs --entry-timeout=0 --attribute-timeout=0 -s $H0 --volfile-id $V0 $M0;
+TEST glusterfs --entry-timeout=0 --attribute-timeout=0 -s $H0 --volfile-id $V0 $M1;
+
+TEST touch $M0/file1;
+
+#following C program tries open up race(s) if any, in F_GETLK/F_SETLKW codepaths
+#of locks xlator
+gcc -lpthread -g3 $(dirname $0)/bug-905864.c -o $(dirname $0)/bug-905864
+$(dirname $0)/bug-905864 $M0/file1 &
+$(dirname $0)/bug-905864 $M1/file1;
+wait
+rm -f $(dirname $0)/bug-905864
+
+cleanup
+
diff --git a/xlators/features/locks/src/common.c b/xlators/features/locks/src/common.c
index cfba16ff735..9c21bddb9e0 100644
--- a/xlators/features/locks/src/common.c
+++ b/xlators/features/locks/src/common.c
@@ -718,22 +718,30 @@ static posix_lock_t *
first_conflicting_overlap (pl_inode_t *pl_inode, posix_lock_t *lock)
{
posix_lock_t *l = NULL;
+ posix_lock_t *conf = NULL;
- list_for_each_entry (l, &pl_inode->ext_list, list) {
- if (l->blocked)
- continue;
-
- if (locks_overlap (l, lock)) {
- if (same_owner (l, lock))
+ pthread_mutex_lock (&pl_inode->mutex);
+ {
+ list_for_each_entry (l, &pl_inode->ext_list, list) {
+ if (l->blocked)
continue;
- if ((l->fl_type == F_WRLCK) ||
- (lock->fl_type == F_WRLCK))
- return l;
+ if (locks_overlap (l, lock)) {
+ if (same_owner (l, lock))
+ continue;
+
+ if ((l->fl_type == F_WRLCK) ||
+ (lock->fl_type == F_WRLCK)) {
+ conf = l;
+ goto unlock;
+ }
+ }
}
}
+unlock:
+ pthread_mutex_unlock (&pl_inode->mutex);
- return NULL;
+ return conf;
}
/*