From 85854b245e1090970d566d6432dabc315e17461c Mon Sep 17 00:00:00 2001

From: Harald Hoyer <harald@redhat.com>

Date: Sat, 30 Jun 2012 09:06:13 +0200

Subject: [PATCH] dracut-install.c: try clone ioctl for more speed

---

 install/dracut-install.c |   64 ++++++++++++++++++++++++++++++++++++++++++----

 1 file changed, 59 insertions(+), 5 deletions(-)

diff --git a/install/dracut-install.c b/install/dracut-install.c

index ccd4ba4..86c32db 100644

--- a/install/dracut-install.c

+++ b/install/dracut-install.c

@@ -39,6 +39,7 @@

 #include <sys/types.h>

 #include <sys/wait.h>

 #include <unistd.h>

+#include <sys/ioctl.h>

 #include "log.h"

 #include "hashmap.h"

@@ -163,25 +164,78 @@ static int ln_r(const char *src, const char *dst)

         return 0;

 }

+/* Perform the O(1) btrfs clone operation, if possible.

+   Upon success, return 0.  Otherwise, return -1 and set errno.  */

+static inline int clone_file(int dest_fd, int src_fd)

+{

+#undef BTRFS_IOCTL_MAGIC

+#define BTRFS_IOCTL_MAGIC 0x94

+#undef BTRFS_IOC_CLONE

+#define BTRFS_IOC_CLONE _IOW (BTRFS_IOCTL_MAGIC, 9, int)

+        return ioctl(dest_fd, BTRFS_IOC_CLONE, src_fd);

+}

+

+static bool use_clone = true;

+

 static int cp(const char *src, const char *dst)

 {

         int pid;

-        int status;

+        int ret;

+

+        if(use_clone) {

+                struct stat sb;

+                int dest_desc, source_desc;

+

+                if (lstat(src, &sb) != 0)

+                        goto normal_copy;

+

+                if (S_ISLNK(sb.st_mode))

+                        goto normal_copy;

+

+                source_desc = open(src, O_RDONLY | O_CLOEXEC);

+                if (source_desc < 0)

+                        goto normal_copy;

+                dest_desc =

+                        open(dst, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC,

+                             (sb.st_mode) & (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO));

+

+                if (dest_desc < 0) {

+                        close(source_desc);

+                        goto normal_copy;

+                }

+

+                ret = clone_file(dest_desc, source_desc);

+                close(source_desc);

+                if (ret == 0) {

+                        if (fchown(dest_desc, sb.st_uid, sb.st_gid) != 0)

+                                fchown(dest_desc, -1, sb.st_gid);

+                        close(dest_desc);

+                        return ret;

+                }

+                close(dest_desc);

+

+                /* clone did not work, remove the file */

+                unlink(dst);

+                /* do not try clone again */

+                use_clone = false;

+        }

+

+ normal_copy:

         pid = fork();

         if (pid == 0) {

                 execlp("cp", "cp", "--reflink=auto", "--sparse=auto", "--preserve=mode", "-fL", src, dst, NULL);

                 _exit(EXIT_FAILURE);

         }

-        while (waitpid(pid, &status, 0) < 0) {

+        while (waitpid(pid, &ret, 0) < 0) {

                 if (errno != EINTR) {

-                        status = -1;

+                        ret = -1;

                         break;

                 }

         }

-        return status;

+        return ret;

 }

 static int resolve_deps(const char *src)

@@ -643,7 +697,7 @@ static int install_all(int argc, char **argv)

                         free(dest);

                 }

-                if ((ret != 0) &&  (!arg_optional)) {

+                if ((ret != 0) && (!arg_optional)) {

                         log_error("ERROR: installing '%s'", argv[i]);

                         r = EXIT_FAILURE;

                 }