if (major(st.st_dev) == 0)
return false;
- if (!(udev = udev_new()))
+ udev = udev_new();
+ if (!udev)
return -ENOMEM;
- if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev)))
+ udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev);
+ if (!udev_device)
goto finish;
- if ((devtype = udev_device_get_property_value(udev_device, "DEVTYPE")) &&
- streq(devtype, "partition"))
+ devtype = udev_device_get_property_value(udev_device, "DEVTYPE");
+ if (devtype && streq(devtype, "partition"))
look_at = udev_device_get_parent(udev_device);
else
look_at = udev_device;
goto finish;
/* First, try high-level property */
- if ((id = udev_device_get_property_value(look_at, "ID_SSD"))) {
+ id = udev_device_get_property_value(look_at, "ID_SSD");
+ if (id) {
b = streq(id, "1");
goto finish;
}
/* Second, try kernel attribute */
- if ((rotational = udev_device_get_sysattr_value(look_at, "queue/rotational")))
+ rotational = udev_device_get_sysattr_value(look_at, "queue/rotational");
+ if (rotational)
if ((b = streq(rotational, "0")))
goto finish;
/* Finally, fallback to heuristics */
- if (!(look_at = udev_device_get_parent(look_at)))
+ look_at = udev_device_get_parent(look_at);
+ if (!look_at)
goto finish;
- if ((model = udev_device_get_sysattr_value(look_at, "model")))
+ model = udev_device_get_sysattr_value(look_at, "model");
+ if (model)
b = !!strstr(model, "SSD");
finish:
return m;
}
-#define BUMP_REQUEST_NR (16*1024)
+/* We use 20K instead of the more human digestable 16K here. Why?
+ Simply so that it is more unlikely that users end up picking this
+ value too so that we can recognize better whether the user changed
+ the value while we had it temporarily bumped. */
+#define BUMP_REQUEST_NR (20*1024)
-int bump_request_nr(const char *p) {
+int block_bump_request_nr(const char *p) {
struct stat st;
uint64_t u;
char *ap = NULL, *line = NULL;
return r;
}
+
+int block_get_readahead(const char *p, uint64_t *bytes) {
+ struct stat st;
+ char *ap = NULL, *line = NULL;
+ int r;
+ dev_t d;
+ uint64_t u;
+
+ assert(p);
+ assert(bytes);
+
+ if (stat(p, &st) < 0)
+ return -errno;
+
+ if (major(st.st_dev) == 0)
+ return 0;
+
+ d = st.st_dev;
+ block_get_whole_disk(d, &d);
+
+ if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ r = read_one_line_file(ap, &line);
+ if (r < 0)
+ goto finish;
+
+ r = safe_atou64(line, &u);
+ if (r < 0)
+ goto finish;
+
+ *bytes = u * 1024ULL;
+
+finish:
+ free(ap);
+ free(line);
+
+ return r;
+}
+
+int block_set_readahead(const char *p, uint64_t bytes) {
+ struct stat st;
+ char *ap = NULL, *line = NULL;
+ int r;
+ dev_t d;
+
+ assert(p);
+ assert(bytes);
+
+ if (stat(p, &st) < 0)
+ return -errno;
+
+ if (major(st.st_dev) == 0)
+ return 0;
+
+ d = st.st_dev;
+ block_get_whole_disk(d, &d);
+
+ if (asprintf(&ap, "/sys/dev/block/%u:%u/bdi/read_ahead_kb", major(d), minor(d)) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (asprintf(&line, "%llu", (unsigned long long) bytes / 1024ULL) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ r = write_one_line_file(ap, line);
+ if (r < 0)
+ goto finish;
+
+finish:
+ free(ap);
+ free(line);
+
+ return r;
+}