src/t_dir_offset2: Add an option to find file by name
authorAmir Goldstein <amir73il@gmail.com>
Sun, 25 Apr 2021 07:14:42 +0000 (10:14 +0300)
committerEryu Guan <guaneryu@gmail.com>
Sun, 16 May 2021 14:37:20 +0000 (22:37 +0800)
Will be used to check for missing/stale entries.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
src/t_dir_offset2.c

index 7aeb990..7af2451 100644 (file)
@@ -8,11 +8,13 @@
  * that these offsets are seekable to entry with the right inode.
  */
 
+#include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 
@@ -32,7 +34,7 @@ static uint64_t d_ino_history[HISTORY_LEN];
 
 void usage()
 {
-       fprintf(stderr, "usage: t_dir_offset2: <dir> [bufsize]\n");
+       fprintf(stderr, "usage: t_dir_offset2: <dir> [[bufsize] <filename> [-v]]\n");
        exit(EXIT_FAILURE);
 }
 
@@ -45,6 +47,9 @@ int main(int argc, char *argv[])
        int bpos, total, i;
        off_t lret;
        int retval = EXIT_SUCCESS;
+       const char *filename = NULL;
+       int exists = 0, found = 0;
+       int verbose = 0;
 
        if (argc > 2) {
                bufsize = atoi(argv[2]);
@@ -52,6 +57,12 @@ int main(int argc, char *argv[])
                        usage();
                if (bufsize > BUF_SIZE)
                        bufsize = BUF_SIZE;
+
+               if (argc > 3) {
+                       filename = argv[3];
+                       if (argc > 4 && !strcmp(argv[4], "-v"))
+                               verbose = 1;
+               }
        } else if (argc < 2) {
                usage();
        }
@@ -62,6 +73,14 @@ int main(int argc, char *argv[])
                exit(EXIT_FAILURE);
        }
 
+       if (filename) {
+               exists = !faccessat(fd, filename, F_OK, AT_SYMLINK_NOFOLLOW);
+               if (!exists && errno != ENOENT) {
+                       perror("faccessat");
+                       exit(EXIT_FAILURE);
+               }
+       }
+
        total = 0;
        for ( ; ; ) {
                nread = syscall(SYS_getdents64, fd, buf, bufsize);
@@ -91,10 +110,28 @@ int main(int argc, char *argv[])
                        }
                        d_off_history[total] = d->d_off;
                        d_ino_history[total] = d->d_ino;
+                       if (filename) {
+                               if (verbose)
+                                       printf("entry #%d: %s (d_ino=%lld, d_off=%lld)\n",
+                                              i, d->d_name, (long long int)d->d_ino,
+                                              (long long int)d->d_off);
+                               if (!strcmp(filename, d->d_name))
+                                       found = 1;
+                       }
                        bpos += d->d_reclen;
                }
        }
 
+       if (filename) {
+               if (exists == found) {
+                       printf("entry %s %sfound as expected\n", filename, found ? "" : "not ");
+               } else {
+                       fprintf(stderr, "%s entry %s\n",
+                               exists ? "missing" : "stale", filename);
+                       exit(EXIT_FAILURE);
+               }
+       }
+
        /* check if seek works correctly */
        d = (struct linux_dirent64 *)buf;
        for (i = total - 1; i >= 0; i--)