Changeset 2325

Timestamp:

12/12/11 07:28:56 (18 months ago)

Author:

jkoshy

Message:

Simplify the implementation of elfcopy by using the
elftc_copyfile() helper function.

Reviewed and revised by: kaiwang27
Ticket: #284

Files:

• trunk/elfcopy/main.c (modified) (4 diffs)

trunk/elfcopy/main.c

@@ -210 +210 @@
 };
 
-static int      copy_tempfile(int fd, const char *out);
+static int      copy_from_tempfile(const char *src, const char *dst,
+    int infd, int *outfd);
 static void     create_file(struct elfcopy *ecp, const char *src,
     const char *dst);
@@ -493 +494 @@
 
 static int
-copy_tempfile(int fd, const char *out)
-{
-        struct stat sb;
-        char *buf;
-        int out_fd, bytes;
-
-        if (fstat(fd, &sb) == -1)
-                err(EXIT_FAILURE, "fstat tmpfile failed");
-        if ((buf = malloc((size_t) sb.st_blksize)) == NULL)
-                err(EXIT_FAILURE, "malloc failed");
-        if (unlink(out) < 0)
-                err(EXIT_FAILURE, "unlink %s failed", out);
-        if ((out_fd = open(out, O_CREAT | O_WRONLY, 0755)) == -1)
-                err(EXIT_FAILURE, "create %s failed", out);
-
-        if (lseek(fd, 0, SEEK_SET) < 0)
-                err(EXIT_FAILURE, "lseek tmpfile failed");
-        while ((bytes = read(fd, buf, sb.st_blksize)) > 0) {
-                if (write(out_fd, buf, (size_t) bytes) != bytes) {
-                        (void) unlink(out);
-                        err(EXIT_FAILURE, "write %s failed", out);
-                }
-        }
-        if (bytes < 0) {
-                (void) unlink(out);
-                err(EXIT_FAILURE, "read failed");
-        }
-
-        free(buf);
-        close(fd);
-
-        return (out_fd);
+copy_from_tempfile(const char *src, const char *dst, int infd, int *outfd)
+{
+        int tmpfd;
+
+        /*
+         * First, check if we can use rename().
+         */
+        if (rename(src, dst) >= 0) {
+                *outfd = infd;
+                return (0);
+        } else if (errno != EXDEV)
+                return (-1);
+
+        /*
+         * If the rename() failed due to 'src' and 'dst' residing in
+         * two different file systems, invoke a helper function in
+         * libelftc to do the copy.
+         */
+
+        if (unlink(dst) < 0)
+                return (-1);
+
+        if ((tmpfd = open(dst, O_CREAT | O_WRONLY, 0755)) < 0)
+                return (-1);
+
+        if (lseek(infd, 0, SEEK_SET) < 0)
+                return (-1);
+
+        if (elftc_copyfile(infd, tmpfd) < 0)
+                return (-1);
+
+        /*
+         * Remove the temporary file from the file system
+         * namespace, and close its file descriptor.
+         */
+        if (unlink(src) < 0)
+                return (-1);
+
+        (void) close(infd);
+
+        /*
+         * Return the file descriptor for the destination.
+         */
+        *outfd = tmpfd;
+
+        return (0);
 }
 
@@ -533 +548 @@
         struct timeval   tv[2];
         char            *tempfile, *elftemp;
-        int              ifd, ofd, ofd0, efd;
+        int              efd, ifd, ofd, ofd0, tfd;
 
         tempfile = NULL;
@@ -668 +683 @@
                 if (dst == NULL)
                         dst = src;
-                if (rename(tempfile, dst) == -1) {
-                        if (errno == EXDEV) {
-                                ofd = copy_tempfile(ofd, dst);
-                                if (unlink(tempfile) < 0)
-                                        err(EXIT_FAILURE, "unlink %s failed",
-                                            tempfile);
-                        } else
-                                err(EXIT_FAILURE, "rename %s to %s failed",
-                                    tempfile, dst);
-                }
+
+                if (copy_from_tempfile(tempfile, dst, ofd, &tfd) < 0)
+                        err(EXIT_FAILURE, "creation of %s failed", dst);
+
                 free(tempfile);
+                tempfile = NULL;
+
+                ofd = tfd;
         }