Replaces commit 44e3708cdb204782d728ddd6a40dec230bb9299c

Thanks to ichelm610x for the patch.
I just added memoization to reduce the impact of the many system calls.

diff --git a/src/linux.c b/src/linux.c
index a229809..a41220e 100644 (file)
--- a/src/linux.c
+++ b/src/linux.c
@@ -2246,6 +2246,49 @@ const char *get_disk_protect_queue(const char *disk)
        return (state > 0) ? "frozen" : "free  ";
 }
 
+typedef struct DEV_LIST_TYPE
+{
+       char *dev_name;
+       int memoized;
+       struct DEV_LIST_TYPE *next;
+
+} DEV_LIST, *DEV_LIST_PTR;
+
+/* Same as sf #2942117 but memoized using a linked list */
+int is_disk(char *dev)
+{
+       char syspath[PATH_MAX];
+       char *slash;
+       static DEV_LIST_PTR dev_head = NULL;
+       DEV_LIST_PTR dev_cur, dev_last;
+
+       dev_cur = dev_head;
+
+       while (dev_cur) {
+               if (strcmp(dev_cur->dev_name, dev) == 0)
+                       return dev_cur->memoized;
+               dev_last = dev_cur;
+               dev_cur  = dev_cur->next;
+       }
+
+       dev_cur = (DEV_LIST_PTR)malloc(sizeof(DEV_LIST));
+       dev_cur->dev_name = (char *)malloc((strlen(dev)+1)*sizeof(char));
+       strcpy(dev_cur->dev_name,dev);
+       dev_cur->next = NULL;
+
+       while ((slash = strchr(dev, '/')))
+               *slash = '!';
+       snprintf(syspath, sizeof(syspath), "/sys/block/%s", dev);
+       dev_cur->memoized = !(access(syspath, F_OK));
+
+       if (dev_head)
+               dev_last->next = dev_cur;
+       else
+               dev_head = dev_cur;
+
+       return dev_cur->memoized;
+}
+
 void update_diskio(void)
 {
        FILE *fp;
@@ -2256,7 +2299,6 @@ void update_diskio(void)
        struct diskio_stat *cur;
        unsigned int reads, writes;
        unsigned int total_reads = 0, total_writes = 0;
-       size_t len_devbuf;
 
        stats.current = 0;
        stats.current_read = 0;
@@ -2277,10 +2319,8 @@ void update_diskio(void)
                 * XXX: ignore devices which are part of a SW RAID (MD_MAJOR) */
                if (col_count == 5 && major != LVM_BLK_MAJOR && major != NBD_MAJOR
                                && major != RAMDISK_MAJOR && major != LOOP_MAJOR) {
-                       /* If the last character of the device is a digit we assume
-                        * it is a subdevice (needed for kernel > 2.6.31) */
-                       len_devbuf = strlen(devbuf);
-                       if ((len_devbuf > 0) && !isdigit(devbuf[len_devbuf-1])) {
+                       /* check needed for kernel >= 2.6.31, see sf #2942117 */
+                       if (is_disk(devbuf)) {
                                total_reads += reads;
                                total_writes += writes;
                        }