Backport: Add --working-directory options to lttng-relayd

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index 1e52ae0aa073640a34f8b035376bb6b5119d5660..d8a78091a4076fd90bb9d9956286dd1dfb9b8f2b 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -528,7 +528,7 @@ int utils_create_lock_file(const char *filepath)
                S_IRGRP | S_IWGRP);
        if (fd < 0) {
                PERROR("open lock file %s", filepath);
-               ret = -1;
+               fd = -1;
                goto error;
        }
 
@@ -1017,6 +1017,59 @@ static inline unsigned int fls_u32(uint32_t x)
 #define HAS_FLS_U32
 #endif
 
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+       long r;
+
+       asm("bsrq %1,%0\n\t"
+           "jnz 1f\n\t"
+           "movq $-1,%0\n\t"
+           "1:\n\t"
+           : "=r" (r) : "rm" (x));
+       return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+       unsigned int r = 64;
+
+       if (!x)
+               return 0;
+
+       if (!(x & 0xFFFFFFFF00000000ULL)) {
+               x <<= 32;
+               r -= 32;
+       }
+       if (!(x & 0xFFFF000000000000ULL)) {
+               x <<= 16;
+               r -= 16;
+       }
+       if (!(x & 0xFF00000000000000ULL)) {
+               x <<= 8;
+               r -= 8;
+       }
+       if (!(x & 0xF000000000000000ULL)) {
+               x <<= 4;
+               r -= 4;
+       }
+       if (!(x & 0xC000000000000000ULL)) {
+               x <<= 2;
+               r -= 2;
+       }
+       if (!(x & 0x8000000000000000ULL)) {
+               x <<= 1;
+               r -= 1;
+       }
+       return r;
+}
+#endif
+
 #ifndef HAS_FLS_U32
 static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
 {
@@ -1063,6 +1116,20 @@ int utils_get_count_order_u32(uint32_t x)
        return fls_u32(x - 1);
 }
 
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+       if (!x) {
+               return -1;
+       }
+
+       return fls_u64(x - 1);
+}
+
 /**
  * Obtain the value of LTTNG_HOME environment variable, if exists.
  * Otherwise returns the value of HOME.
@@ -1335,15 +1402,17 @@ LTTNG_HIDDEN
 int utils_truncate_stream_file(int fd, off_t length)
 {
        int ret;
+       off_t lseek_ret;
 
        ret = ftruncate(fd, length);
        if (ret < 0) {
                PERROR("ftruncate");
                goto end;
        }
-       ret = lseek(fd, length, SEEK_SET);
-       if (ret < 0) {
+       lseek_ret = lseek(fd, length, SEEK_SET);
+       if (lseek_ret < 0) {
                PERROR("lseek");
+               ret = -1;
                goto end;
        }
 end:
@@ -1375,11 +1444,41 @@ int utils_show_man_page(int section, const char *page_name)
        /*
         * Execute man pager.
         *
-        * We provide --manpath to man here because LTTng-tools can
+        * We provide -M to man here because LTTng-tools can
         * be installed outside /usr, in which case its man pages are
         * not located in the default /usr/share/man directory.
         */
-       ret = execlp(man_bin_path, "man", "--manpath", MANPATH,
+       ret = execlp(man_bin_path, "man", "-M", MANPATH,
                section_string, page_name, NULL);
        return ret;
 }
+
+LTTNG_HIDDEN
+int utils_change_working_dir(const char *path)
+{
+       int ret;
+
+       assert(path);
+
+       ret = chdir(path);
+       if (ret) {
+               PERROR("Failed to change working directory: %s", path);
+               goto end;
+       }
+
+       /* Check for write access */
+       if (access(path, W_OK)) {
+               if (errno == EACCES) {
+                       /*
+                        * Do not treat this as an error since the permission
+                        * might change in the lifetime of the process
+                        */
+                       DBG("Working directory is not writable: %s", path);
+               } else {
+                       PERROR("access");
+               }
+       }
+
+end:
+       return ret;
+}