failtest: rely on the save/restore of files, don't use write cleanup.

diff --git a/ccan/failtest/failtest.c b/ccan/failtest/failtest.c
index 2a39679f4827eadcd05b183587534bb040aa1c8a..56a1ad1872f9f584b9fda6bbf9f21d10e6f3c0b3 100644 (file)
--- a/ccan/failtest/failtest.c
+++ b/ccan/failtest/failtest.c
@@ -235,24 +235,23 @@ struct saved_file {
        struct saved_file *next;
        int fd;
        void *contents;
-       off_t len;
+       off_t off, len;
 };
 
 static struct saved_file *save_file(struct saved_file *next, int fd)
 {
        struct saved_file *s = malloc(sizeof(*s));
-       off_t orig = lseek(fd, 0, SEEK_CUR);
-
-       /* Special file?  Erk... */
-       assert(orig != -1);
 
        s->next = next;
        s->fd = fd;
+       s->off = lseek(fd, 0, SEEK_CUR);
+       /* Special file?  Erk... */
+       assert(s->off != -1);
        s->len = lseek(fd, 0, SEEK_END);
        lseek(fd, 0, SEEK_SET);
        s->contents = malloc(s->len);
        read(fd, s->contents, s->len);
-       lseek(fd, orig, SEEK_SET);
+       lseek(fd, s->off, SEEK_SET);
        return s;
 }
        
@@ -264,34 +263,26 @@ static struct saved_file *save_files(void)
 {
        struct saved_file *files = NULL;
        int i;
-       fd_set closed;
 
        /* Figure out the set of live fds. */
-       FD_ZERO(&closed);
        for (i = history_num - 2; i >= 0; i--) {
-               /* FIXME: Handle dup. */
-               if (history[i].type == FAILTEST_CLOSE) {
-                       assert(!FD_ISSET(history[i].u.close.fd, &closed));
-                       FD_SET(history[i].u.close.fd, &closed);
-               } else if (history[i].type == FAILTEST_OPEN) {
+               if (history[i].type == FAILTEST_OPEN) {
                        int fd = history[i].u.open.ret;
                        /* Only do successful, writable fds. */
                        if (fd < 0)
                                continue;
 
-                       /* If it wasn't closed again... */
-                       if (!FD_ISSET(fd, &closed)) {
-                               if ((history[i].u.open.flags & O_RDWR)
-                                   == O_RDWR) {
-                                       files = save_file(files, fd);
-                               } else if ((history[i].u.open.flags & O_WRONLY)
-                                          == O_WRONLY) {
-                                       /* FIXME: Handle O_WRONLY.  Open with
-                                        * O_RDWR? */
-                                       abort();
-                               }
-                       } else
-                               FD_CLR(history[i].u.open.ret, &closed);
+                       /* If it was closed, cleanup == NULL. */
+                       if (!history[i].cleanup)
+                               continue;
+
+                       if ((history[i].u.open.flags & O_RDWR) == O_RDWR) {
+                               files = save_file(files, fd);
+                       } else if ((history[i].u.open.flags & O_WRONLY)
+                                  == O_WRONLY) {
+                               /* FIXME: Handle O_WRONLY.  Open with O_RDWR? */
+                               abort();
+                       }
                }
        }
 
@@ -302,12 +293,12 @@ static void restore_files(struct saved_file *s)
 {
        while (s) {
                struct saved_file *next = s->next;
-               off_t orig = lseek(s->fd, 0, SEEK_CUR);
 
                lseek(s->fd, 0, SEEK_SET);
                write(s->fd, s->contents, s->len);
+               ftruncate(s->fd, s->len);
                free(s->contents);
-               lseek(s->fd, orig, SEEK_SET);
+               lseek(s->fd, s->off, SEEK_SET);
                free(s);
                s = next;
        }
@@ -604,7 +595,6 @@ int failtest_open(const char *pathname,
        } else {
                p->u.open.ret = open(pathname, call.flags, call.mode);
                set_cleanup(p, cleanup_open, struct open_call);
-               p->u.open.dup_fd = p->u.open.ret;
        }
        errno = p->error;
        return p->u.open.ret;
@@ -639,11 +629,6 @@ int failtest_pipe(int pipefd[2], const char *file, unsigned line)
        return p->u.pipe.ret;
 }
 
-static void cleanup_read(struct read_call *call)
-{
-       lseek(call->fd, call->off, SEEK_SET);
-}
-
 ssize_t failtest_pread(int fd, void *buf, size_t count, off_t off,
                       const char *file, unsigned line)
 {
@@ -661,59 +646,23 @@ ssize_t failtest_pread(int fd, void *buf, size_t count, off_t off,
                p->error = EIO;
        } else {
                p->u.read.ret = pread(fd, buf, count, off);
-               set_cleanup(p, cleanup_read, struct read_call);
        }
        errno = p->error;
        return p->u.read.ret;
 }
 
-static void cleanup_write(struct write_call *call)
-{
-       lseek(call->dup_fd, call->off, SEEK_SET);
-       write(call->dup_fd, call->saved_contents, call->saved_len);
-       lseek(call->dup_fd, call->off, SEEK_SET);
-       ftruncate(call->dup_fd, call->old_filelen);
-       free(call->saved_contents);
-}
-
 ssize_t failtest_pwrite(int fd, const void *buf, size_t count, off_t off,
                        const char *file, unsigned line)
 {
        struct failtest_call *p;
        struct write_call call;
 
-       call.fd = call.dup_fd = fd;
+       call.fd = fd;
        call.buf = buf;
        call.count = count;
        call.off = off;
        p = add_history(FAILTEST_WRITE, file, line, &call);
 
-       /* Save old contents if we can */
-       if (p->u.write.off != -1) {
-               ssize_t ret;
-               p->u.write.old_filelen = lseek(fd, 0, SEEK_END);
-
-               /* Write past end of file?  Nothing to save.*/
-               if (p->u.write.old_filelen <= p->u.write.off)
-                       p->u.write.saved_len = 0;
-               /* Write which goes over end of file?  Partial save. */
-               else if (p->u.write.off + count > p->u.write.old_filelen)
-                       p->u.write.saved_len = p->u.write.old_filelen
-                               - p->u.write.off;
-               /* Full save. */
-               else
-                       p->u.write.saved_len = count;
-
-               p->u.write.saved_contents = malloc(p->u.write.saved_len);
-               lseek(fd, p->u.write.off, SEEK_SET);
-               ret = read(fd, p->u.write.saved_contents, p->u.write.saved_len);
-               if (ret != p->u.write.saved_len)
-                       err(1, "Expected %i bytes, got %i",
-                           (int)p->u.write.saved_len, (int)ret);
-               lseek(fd, p->u.write.off, SEEK_SET);
-               set_cleanup(p, cleanup_write, struct write_call);
-       }
-
        /* If we're a child, tell parent about write. */
        if (control_fd != -1) {
                enum info_type type = WRITE;
@@ -841,49 +790,39 @@ add_lock(struct lock_info *locks, int fd, off_t start, off_t end, int type)
        return locks;
 }
 
-/* We only trap this so we can dup fds in case we need to restore. */
+/* We trap this so we can record it: we don't fail it. */
 int failtest_close(int fd)
 {
-       int new_fd = -1, i;
+       int i;
 
        if (fd < 0)
                return close(fd);
 
-       /* Trace history to find source of fd, and if we need to cleanup writes. */
+       /* Trace history to find source of fd. */
        for (i = history_num-1; i >= 0; i--) {
                switch (history[i].type) {
-               case FAILTEST_WRITE:
-                       if (history[i].u.write.fd != fd)
-                               break;
-                       if (!history[i].cleanup)
-                               break;
-                       /* We need to save fd so we can restore file. */
-                       if (new_fd == -1)
-                               new_fd = dup(fd);
-                       history[i].u.write.dup_fd = new_fd;
-                       break;
-               case FAILTEST_READ:
-                       /* We don't need to cleanup reads on closed fds. */
-                       if (history[i].u.read.fd != fd)
-                               break;
-                       history[i].cleanup = NULL;
-                       break;
                case FAILTEST_PIPE:
-                       /* From a pipe?  We don't ever restore pipes... */
+                       /* From a pipe? */
                        if (history[i].u.pipe.fds[0] == fd) {
-                               assert(new_fd == -1);
+                               assert(!history[i].u.pipe.closed[0]);
                                history[i].u.pipe.closed[0] = true;
+                               if (history[i].u.pipe.closed[1])
+                                       history[i].cleanup = NULL;
                                goto out;
                        }
                        if (history[i].u.pipe.fds[1] == fd) {
-                               assert(new_fd == -1);
+                               assert(!history[i].u.pipe.closed[1]);
                                history[i].u.pipe.closed[1] = true;
+                               if (history[i].u.pipe.closed[0])
+                                       history[i].cleanup = NULL;
                                goto out;
                        }
                        break;
                case FAILTEST_OPEN:
                        if (history[i].u.open.ret == fd) {
-                               history[i].u.open.dup_fd = new_fd;
+                               assert((void *)history[i].cleanup
+                                      == (void *)cleanup_open);
+                               history[i].cleanup = NULL;
                                goto out;
                        }
                        break;

diff --git a/ccan/failtest/failtest.h b/ccan/failtest/failtest.h
index 21bc9f7c59e342fd12dec4140314b252d364763c..473f9e7950fa498e5d56a613353b049e69c82084 100644 (file)
--- a/ccan/failtest/failtest.h
+++ b/ccan/failtest/failtest.h
@@ -64,7 +64,6 @@ struct open_call {
        const char *pathname;
        int flags;
        mode_t mode;
-       int dup_fd;
 };
 
 struct pipe_call {
@@ -87,10 +86,6 @@ struct write_call {
        const void *buf;
        size_t count;
        off_t off;
-       off_t old_filelen;
-       off_t saved_len;
-       void *saved_contents;
-       int dup_fd;
 };
 
 struct fcntl_call {

diff --git a/ccan/failtest/test/run-write.c b/ccan/failtest/test/run-write.c
index 5425517030a5d77f1db0b22926c30956d54bf183..d3d7c6041871c96884e28c488a0f86a1982a9f24 100644 (file)
--- a/ccan/failtest/test/run-write.c
+++ b/ccan/failtest/test/run-write.c
@@ -15,7 +15,11 @@ int main(void)
 
        plan_tests(5);
 
-       fd = open("run-write-scratchpad", O_RDWR|O_CREAT, 0600);
+       fd = failtest_open("run-write-scratchpad", "run-write.c", 1,
+                          O_RDWR|O_CREAT, 0600);
+       /* Child will fail, ignore. */
+       if (fd < 0)
+               failtest_exit(0);
        write(fd, buf, strlen(buf));
        ok1(lseek(fd, 0, SEEK_CUR) == strlen(buf));