add function get_path_block_size and get_device_block_size

HISTORY

@@ -1,7 +1,8 @@
 
-Version 1.52  2021-06-01
+Version 1.52  2021-06-02
   * process_stop more gracefully (kill -9 on timeout)
   * add function fc_queue_pop_to_queue_ex
+  * add function get_path_block_size and get_device_block_size
 
 Version 1.51  2021-05-27
   * fast_mblock.[hc]: support batch alloc and batch free

src/system_info.c

@@ -36,6 +36,7 @@
 #ifdef OS_LINUX
 #include <sys/sysinfo.h>
 #include <sys/vfs.h>
+#include <sys/sysmacros.h>
 #else
 #ifdef OS_FREEBSD
 #include <sys/sysctl.h>
@@ -835,3 +836,124 @@ int get_kernel_version(Version *version)
     version->patch = numbers[1];
     return 0;
 }
+
+#ifdef OS_LINUX
+int get_device_block_size(const char *device, int *block_size)
+{
+    int result;
+    int fd;
+    size_t bs;
+
+    if ((fd=open(device, O_RDONLY)) < 0) {
+        result = errno != 0 ? errno : ENOENT;
+        logError("file: "__FILE__", line: %d, "
+                "open device %s fail, errno: %d, error info: %s",
+                __LINE__, device, result, strerror(result));
+        return result;
+    }
+
+    if (ioctl(fd, BLKSSZGET, &bs) == 0) {
+        *block_size = bs;
+        result = 0;
+    } else {
+        result = errno != 0 ? errno : EPERM;
+        logError("file: "__FILE__", line: %d, "
+                "ioctl device %s fail, errno: %d, error info: %s",
+                __LINE__, device, result, strerror(result));
+    }
+
+    close(fd);
+    return result;
+}
+
+static int get_block_size_by_write(const char *path, int *block_size)
+{
+#define MAX_BLK_SIZE  (128 * 1024)
+    char tmp_filename[PATH_MAX];
+    char *buff;
+    int result;
+    int fd;
+
+    if ((result=posix_memalign((void **)&buff,
+                    MAX_BLK_SIZE, MAX_BLK_SIZE)) != 0)
+    {
+        logError("file: "__FILE__", line: %d, "
+                "posix_memalign %d bytes fail, "
+                "errno: %d, error info: %s", __LINE__,
+                MAX_BLK_SIZE, result, STRERROR(result));
+        return result;
+    }
+
+    snprintf(tmp_filename, sizeof(tmp_filename),
+            "%s/.blksize-test.tmp", path);
+    if ((fd=open(tmp_filename, O_WRONLY | O_CREAT | O_DIRECT)) < 0) {
+        result = errno != 0 ? errno : ENOENT;
+        logError("file: "__FILE__", line: %d, "
+                "open file %s fail, errno: %d, error info: %s",
+                __LINE__, tmp_filename, result, strerror(result));
+        free(buff);
+        return result;
+    }
+
+    result = EINVAL;
+    *block_size = 512;
+    while (*block_size <= MAX_BLK_SIZE) {
+        if (write(fd, buff, *block_size) == *block_size) {
+            result = 0;
+            break;
+        }
+        result = errno != 0 ? errno : EINTR;
+        if (result == EINTR) {
+            continue;
+        }
+
+        if (result != EINVAL) {
+            logError("file: "__FILE__", line: %d, "
+                    "write to file %s fail, errno: %d, error info: %s",
+                    __LINE__, tmp_filename, result, strerror(result));
+            break;
+        }
+
+        *block_size *= 2;
+    }
+
+    free(buff);
+    close(fd);
+    unlink(tmp_filename);
+    return result;
+}
+
+int get_path_block_size(const char *path, int *block_size)
+{
+    char dev_path[64];
+    struct stat statbuf;
+    int result;
+
+    if (stat(path, &statbuf) != 0) {
+        result = errno != 0 ? errno : EPERM;
+        logError("file: "__FILE__", line: %d, "
+                "stat %s fail, errno: %d, error info: %s",
+                __LINE__, path, result, strerror(result));
+        return result;
+    }
+
+    if (S_ISBLK(statbuf.st_mode)) {
+        return get_device_block_size(path, block_size);
+    }
+    if (!S_ISDIR(statbuf.st_mode)) {
+        logError("file: "__FILE__", line: %d, "
+                "%s is NOT a directory!", __LINE__, path);
+        return ENOTDIR;
+    }
+
+    sprintf(dev_path, "/dev/block/%d:%d", (int)major(statbuf.st_dev),
+            (int)minor(statbuf.st_dev));
+    if (access(dev_path, R_OK) == 0) {
+        if ((result=get_device_block_size(dev_path, block_size)) == 0) {
+            return 0;
+        }
+    }
+
+    return get_block_size_by_write(path, block_size);
+}
+#endif

src/system_info.h

@@ -164,6 +164,11 @@ int get_sysinfo(struct fast_sysinfo *info);
 
 int get_kernel_version(Version *version);
 
+#ifdef OS_LINUX
+int get_device_block_size(const char *device, int *block_size);
+int get_path_block_size(const char *path, int *block_size);
+#endif
+
 #endif
 
 #ifdef __cplusplus