From 54494f02efee75fa1921d239a47c65d70b7f028c Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Sun, 25 Apr 2021 10:14:43 +0300 Subject: [PATCH] src/t_dir_offset2: Add option to create or unlink file Will be used to test missing/stale entries after modifications to an open dirfd. Signed-off-by: Amir Goldstein Reviewed-by: Eryu Guan Signed-off-by: Eryu Guan --- src/t_dir_offset2.c | 56 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 53 insertions(+), 3 deletions(-) diff --git a/src/t_dir_offset2.c b/src/t_dir_offset2.c index 7af24519..75b41c1a 100644 --- a/src/t_dir_offset2.c +++ b/src/t_dir_offset2.c @@ -34,13 +34,13 @@ static uint64_t d_ino_history[HISTORY_LEN]; void usage() { - fprintf(stderr, "usage: t_dir_offset2: [[bufsize] [-v]]\n"); + fprintf(stderr, "usage: t_dir_offset2: [[bufsize] [-|+] [-v]]\n"); exit(EXIT_FAILURE); } int main(int argc, char *argv[]) { - int fd; + int fd, fd2 = -1; char buf[BUF_SIZE]; int nread, bufsize = BUF_SIZE; struct linux_dirent64 *d; @@ -49,7 +49,7 @@ int main(int argc, char *argv[]) int retval = EXIT_SUCCESS; const char *filename = NULL; int exists = 0, found = 0; - int verbose = 0; + int modify = 0, verbose = 0; if (argc > 2) { bufsize = atoi(argv[2]); @@ -60,6 +60,13 @@ int main(int argc, char *argv[]) if (argc > 3) { filename = argv[3]; + /* + creates, - removes */ + if (filename[0] == '+') + modify = 1; + else if (filename[0] == '-') + modify = -1; + if (modify) + filename++; if (argc > 4 && !strcmp(argv[4], "-v")) verbose = 1; } @@ -89,6 +96,49 @@ int main(int argc, char *argv[]) exit(EXIT_FAILURE); } + if (modify && fd2 < 0 && total == 0) { + printf("getdents at offset 0 returned %d bytes\n", nread); + + /* create/unlink entry after first getdents */ + if (modify > 0) { + if (openat(fd, filename, O_CREAT, 0600) < 0) { + perror("openat"); + exit(EXIT_FAILURE); + } + exists = 1; + printf("created entry %s\n", filename); + } else if (modify < 0) { + if (unlinkat(fd, filename, 0) < 0) { + perror("unlinkat"); + exit(EXIT_FAILURE); + } + exists = 0; + printf("unlinked entry %s\n", filename); + } + + /* + * Old fd may not return new entry and may return stale + * entries which is allowed. Keep old fd open and open + * a new fd to check for stale or missing entries later. + */ + fd2 = open(argv[1], O_RDONLY | O_DIRECTORY); + if (fd2 < 0) { + perror("open fd2"); + exit(EXIT_FAILURE); + } + } + + if (nread == 0) { + if (fd2 < 0 || fd == fd2) + break; + + /* Re-iterate with new fd leaving old fd open */ + fd = fd2; + total = 0; + found = 0; + continue; + } + if (nread == 0) break; -- 2.30.2