Silence 'old_umask' uninit variable warning

[zfs.git] / lib / libzpool / kernel.c

diff --git a/lib/libzpool/kernel.c b/lib/libzpool/kernel.c
index 002276a..f7aeeb4 100644 (file)
--- a/lib/libzpool/kernel.c
+++ b/lib/libzpool/kernel.c
@@ -141,7 +141,7 @@ zk_thread_helper(void *arg)
 
 kthread_t *
 zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
-             size_t len, proc_t *pp, int state, pri_t pri)
+             size_t len, proc_t *pp, int state, pri_t pri, int detachstate)
 {
        kthread_t *kt;
        pthread_attr_t attr;
@@ -159,9 +159,14 @@ zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
         *
         * We reduce the default stack size in userspace, to ensure
         * we observe stack overruns in user space as well as in
-        * kernel space.  PTHREAD_STACK_MIN is the minimum stack
-        * required for a NULL procedure in user space and is added
-        * in to the stack requirements.
+        * kernel space. In practice we can't set the userspace stack
+        * size to 8k because differences in stack usage between kernel
+        * space and userspace could lead to spurious stack overflows
+        * (especially when debugging is enabled). Nevertheless, we try
+        * to set it to the lowest value that works (currently 8k*4).
+        * PTHREAD_STACK_MIN is the minimum stack required for a NULL
+        * procedure in user space and is added in to the stack
+        * requirements.
         *
         * Some buggy NPTL threading implementations include the
         * guard area within the stack size allocations.  In
@@ -170,12 +175,12 @@ zk_thread_create(caddr_t stk, size_t stksize, thread_func_t func, void *arg,
         * on Linux.
         */
 
-       stack = PTHREAD_STACK_MIN + MAX(stksize, STACK_SIZE) +
-                       EXTRA_GUARD_BYTES;
+       stack = PTHREAD_STACK_MIN + MAX(stksize, STACK_SIZE) * 4;
 
        VERIFY3S(pthread_attr_init(&attr), ==, 0);
        VERIFY3S(pthread_attr_setstacksize(&attr, stack), ==, 0);
        VERIFY3S(pthread_attr_setguardsize(&attr, PAGESIZE), ==, 0);
+       VERIFY3S(pthread_attr_setdetachstate(&attr, detachstate), ==, 0);
 
        VERIFY3S(pthread_create(&kt->t_tid, &attr, &zk_thread_helper, kt),
            ==, 0);
@@ -517,7 +522,7 @@ vn_open(char *path, int x1, int flags, int mode, vnode_t **vpp, int x2, int x3)
 {
        int fd;
        vnode_t *vp;
-       int old_umask;
+       int old_umask = 0;
        char *realpath;
        struct stat64 st;
        int err;
@@ -641,7 +646,9 @@ vn_rdwr(int uio, vnode_t *vp, void *addr, ssize_t len, offset_t offset,
                 * To simulate partial disk writes, we split writes into two
                 * system calls so that the process can be killed in between.
                 */
-               split = (len > 0 ? rand() % len : 0);
+               int sectors = len >> SPA_MINBLOCKSHIFT;
+               split = (sectors > 0 ? rand() % sectors : 0) <<
+                   SPA_MINBLOCKSHIFT;
                rc = pwrite64(vp->v_fd, addr, split, offset);
                if (rc != -1) {
                        done = rc;
@@ -700,8 +707,6 @@ fop_getattr(vnode_t *vp, vattr_t *vap)
        return (0);
 }
 
-#ifdef ZFS_DEBUG
-
 /*
  * =========================================================================
  * Figure out which debugging statements to print
@@ -814,8 +819,6 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...)
        }
 }
 
-#endif /* ZFS_DEBUG */
-
 /*
  * =========================================================================
  * cmn_err() and panic()