Fix issue #48: sar skips long filesystem names

If a filesystem had more than MAX_FS_LEN characters in length, sar
didn't display it.
This patch fixes the problem.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>

diff --git a/rd_stats.c b/rd_stats.c
index 67fc244c6915d0a0b0e21e074ff09104931a7869..4d75fa580b63467a3756a531fa5324c995806475 100644 (file)
--- a/rd_stats.c
+++ b/rd_stats.c
@@ -2071,7 +2071,7 @@ void read_bus_usb_dev(struct stats_pwr_usb *st_pwr_usb, int nbr)
 void read_filesystem(struct stats_filesystem *st_filesystem, int nbr)
 {
        FILE *fp;
-       char line[256], fs_name[MAX_FS_LEN], mountp[MAX_FS_LEN];
+       char line[512], fs_name[MAX_FS_LEN], mountp[256];
        int fs = 0;
        struct stats_filesystem *st_filesystem_i;
        struct statvfs buf;
@@ -2082,12 +2082,26 @@ void read_filesystem(struct stats_filesystem *st_filesystem, int nbr)
        while ((fgets(line, sizeof(line), fp) != NULL) && (fs < nbr)) {
                if (line[0] == '/') {
 
-                       /* Read current filesystem name and mount point */
-                       sscanf(line, "%127s %127s", fs_name, mountp);
+                       /* Read current filesystem name */
+                       sscanf(line, "%127s", fs_name);
+                       /*
+                        * And now read the corresponding mount point.
+                        * Read fs name and mount point in two distinct operations.
+                        * Indeed, if fs name length is greater than 127 chars,
+                        * previous scanf() will read only the first 127 chars, and
+                        * mount point name will be read using the remaining chars
+                        * from the fs name. This will result in a bogus name
+                        * and following statvfs() function will always fail.
+                        */
+                       sscanf(strchr(line, ' ') + 1, "%255s", mountp);
 
                        /* Replace octal codes */
                        oct2chr(mountp);
 
+                       /*
+                        * It's important to have read the whole mount point name
+                        * for statvfs() to work properly (see above).
+                        */
                        if ((statvfs(mountp, &buf) < 0) || (!buf.f_blocks))
                                continue;