[PATCH 0/4] xfsdump: update to use fallocate

[PATCH 0/4] xfsdump: update to use fallocate

[Darrick J. Wong]

Hi all,

This is a series to update the "create file and preallocate blocks"
code in xfs_restore.

The first patch refactors the existing copy-pasta into a single helper
function to create and preallocate space in files, as well as removing
the totally broken ALLOCSP code.

The next two patches fix unchecked return values and insufficient
unsupported-ioctl code.

The final patch upgrades xfs_restore to try fallocate before RESVSP
simply because it is the newer API.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

[PATCH 1/4] xfs_restore: refactor open-coded file creation code

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Create a helper to unlink, recreate, and reserve space in a file so that
we don't have two open-coded versions.  We lose the broken ALLOCSP code
since it never worked anyway.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 restore/dirattr.c |   97 ++++++++++++++++++-----------------------------------
 restore/dirattr.h |    2 +
 restore/namreg.c  |   70 +++-----------------------------------
 3 files changed, 41 insertions(+), 128 deletions(-)


diff --git a/restore/dirattr.c b/restore/dirattr.c
index 806f282..5cd22a8 100644
--- a/restore/dirattr.c
+++ b/restore/dirattr.c
@@ -55,6 +55,37 @@
 #include "openutil.h"
 #include "mmap.h"
 
+/* Create a file, try to reserve space for it, and return the fd. */
+int
+create_filled_file(
+	const char	*pathname,
+	off64_t		size)
+{
+	struct flock64	fl = {
+		.l_len = size,
+	};
+	int		fd;
+	int		ret;
+
+	(void)unlink(pathname);
+
+	fd = open(pathname, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+	if (fd < 0)
+		return fd;
+
+	ret = ioctl(fd, XFS_IOC_RESVSP64, &fl);
+	if (ret && errno != ENOTTY)
+		mlog(MLOG_VERBOSE | MLOG_NOTE,
+_("attempt to reserve %lld bytes for %s using %s failed: %s (%d)\n"),
+				size, pathname, "XFS_IOC_RESVSP64",
+				strerror(errno), errno);
+	if (ret == 0)
+		goto done;
+
+done:
+	return fd;
+}
+
 /* structure definitions used locally ****************************************/
 
 /* node handle limits
@@ -238,13 +269,8 @@ dirattr_init(char *hkdir, bool_t resume, uint64_t dircnt)
 			return BOOL_FALSE;
 		}
 	} else {
-		/* create the dirattr file, first unlinking any older version
-		 * laying around
-		 */
-		(void)unlink(dtp->dt_pathname);
-		dtp->dt_fd = open(dtp->dt_pathname,
-				   O_RDWR | O_CREAT | O_EXCL,
-				   S_IRUSR | S_IWUSR);
+		dtp->dt_fd = create_filled_file(dtp->dt_pathname,
+			DIRATTR_PERS_SZ + (dircnt * sizeof(struct dirattr)));
 		if (dtp->dt_fd < 0) {
 			mlog(MLOG_NORMAL | MLOG_ERROR, _(
 			      "could not create directory attributes file %s: "
@@ -253,63 +279,6 @@ dirattr_init(char *hkdir, bool_t resume, uint64_t dircnt)
 			      strerror(errno));
 			return BOOL_FALSE;
 		}
-
-		/* reserve space for the backing store. try to use RESVSP64.
-		 * if doesn't work, try ALLOCSP64. the former is faster, as
-		 * it does not zero the space.
-		 */
-		{
-		bool_t successpr;
-		unsigned int ioctlcmd;
-		int loglevel;
-		size_t trycnt;
-
-		for (trycnt = 0,
-		      successpr = BOOL_FALSE,
-		      ioctlcmd = XFS_IOC_RESVSP64,
-		      loglevel = MLOG_VERBOSE
-		      ;
-		      !successpr && trycnt < 2
-		      ;
-		      trycnt++,
-		      ioctlcmd = XFS_IOC_ALLOCSP64,
-		      loglevel = max(MLOG_NORMAL, loglevel - 1)) {
-			off64_t initsz;
-			struct flock64 flock64;
-			int rval;
-
-			if (!ioctlcmd) {
-				continue;
-			}
-
-			initsz = (off64_t)DIRATTR_PERS_SZ
-				 +
-				 ((off64_t)dircnt * sizeof(dirattr_t));
-			flock64.l_whence = 0;
-			flock64.l_start = 0;
-			flock64.l_len = initsz;
-			rval = ioctl(dtp->dt_fd, ioctlcmd, &flock64);
-			if (rval) {
-				if (errno != ENOTTY) {
-					mlog(loglevel | MLOG_NOTE, _(
-					      "attempt to reserve %lld bytes for %s "
-					      "using %s "
-					      "failed: %s (%d)\n"),
-					      initsz,
-					      dtp->dt_pathname,
-					      ioctlcmd == XFS_IOC_RESVSP64
-					      ?
-					      "XFS_IOC_RESVSP64"
-					      :
-					      "XFS_IOC_ALLOCSP64",
-					      strerror(errno),
-					      errno);
-				}
-			} else {
-				successpr = BOOL_TRUE;
-			}
-		}
-		}
 	}
 
 	/* mmap the persistent descriptor
diff --git a/restore/dirattr.h b/restore/dirattr.h
index 232822e..cdfa4fc 100644
--- a/restore/dirattr.h
+++ b/restore/dirattr.h
@@ -88,4 +88,6 @@ extern bool_t dirattr_cb_extattr(dah_t dah,
 				  extattrhdr_t *ahdrp,
 				  void *ctxp);
 
+int create_filled_file(const char *pathname, off64_t size);
+
 #endif /* DIRATTR_H */
diff --git a/restore/namreg.c b/restore/namreg.c
index fe159e4..594e325 100644
--- a/restore/namreg.c
+++ b/restore/namreg.c
@@ -37,6 +37,10 @@
 #include "namreg.h"
 #include "openutil.h"
 #include "mmap.h"
+#include "global.h"
+#include "content.h"
+#include "content_inode.h"
+#include "dirattr.h"
 
 /* structure definitions used locally ****************************************/
 
@@ -153,13 +157,8 @@ namreg_init(char *hkdir, bool_t resume, uint64_t inocnt)
 			return BOOL_FALSE;
 		}
 	} else {
-		/* create the namreg file, first unlinking any older version
-		 * laying around
-		 */
-		(void)unlink(ntp->nt_pathname);
-		ntp->nt_fd = open(ntp->nt_pathname,
-				   O_RDWR | O_CREAT | O_EXCL,
-				   S_IRUSR | S_IWUSR);
+		ntp->nt_fd = create_filled_file(ntp->nt_pathname,
+			NAMREG_PERS_SZ + (inocnt * NAMREG_AVGLEN));
 		if (ntp->nt_fd < 0) {
 			mlog(MLOG_NORMAL | MLOG_ERROR, _(
 			      "could not create name registry file %s: "
@@ -168,63 +167,6 @@ namreg_init(char *hkdir, bool_t resume, uint64_t inocnt)
 			      strerror(errno));
 			return BOOL_FALSE;
 		}
-
-		/* reserve space for the backing store. try to use RESVSP64.
-		 * if doesn't work, try ALLOCSP64. the former is faster, as
-		 * it does not zero the space.
-		 */
-		{
-		bool_t successpr;
-		unsigned int ioctlcmd;
-		int loglevel;
-		size_t trycnt;
-
-		for (trycnt = 0,
-		      successpr = BOOL_FALSE,
-		      ioctlcmd = XFS_IOC_RESVSP64,
-		      loglevel = MLOG_VERBOSE
-		      ;
-		      !successpr && trycnt < 2
-		      ;
-		      trycnt++,
-		      ioctlcmd = XFS_IOC_ALLOCSP64,
-		      loglevel = max(MLOG_NORMAL, loglevel - 1)) {
-			off64_t initsz;
-			struct flock64 flock64;
-			int rval;
-
-			if (!ioctlcmd) {
-				continue;
-			}
-
-			initsz = (off64_t)NAMREG_PERS_SZ
-				 +
-				 ((off64_t)inocnt * NAMREG_AVGLEN);
-			flock64.l_whence = 0;
-			flock64.l_start = 0;
-			flock64.l_len = initsz;
-			rval = ioctl(ntp->nt_fd, ioctlcmd, &flock64);
-			if (rval) {
-				if (errno != ENOTTY) {
-					mlog(loglevel | MLOG_NOTE, _(
-					      "attempt to reserve %lld bytes for %s "
-					      "using %s "
-					      "failed: %s (%d)\n"),
-					      initsz,
-					      ntp->nt_pathname,
-					      ioctlcmd == XFS_IOC_RESVSP64
-					      ?
-					      "XFS_IOC_RESVSP64"
-					      :
-					      "XFS_IOC_ALLOCSP64",
-					      strerror(errno),
-					      errno);
-				}
-			} else {
-				successpr = BOOL_TRUE;
-			}
-		}
-		}
 	}
 
 	/* mmap the persistent descriptor

[PATCH 2/4] xfs_restore: check return value

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Check the return value of the unlink call when creating a new file.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 restore/dirattr.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)


diff --git a/restore/dirattr.c b/restore/dirattr.c
index 5cd22a8..ed7e0b4 100644
--- a/restore/dirattr.c
+++ b/restore/dirattr.c
@@ -67,7 +67,9 @@ create_filled_file(
 	int		fd;
 	int		ret;
 
-	(void)unlink(pathname);
+	ret = unlink(pathname);
+	if (ret && errno != ENOENT)
+		return ret;
 
 	fd = open(pathname, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
 	if (fd < 0)

[PATCH 3/4] xfs_restore: fix unsupported ioctl detection

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Linux ioctls can return ENOTTY or EOPNOTSUPP, so filter both of them
when logging reservation failure.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 restore/dirattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


diff --git a/restore/dirattr.c b/restore/dirattr.c
index ed7e0b4..267bef0 100644
--- a/restore/dirattr.c
+++ b/restore/dirattr.c
@@ -76,7 +76,7 @@ create_filled_file(
 		return fd;
 
 	ret = ioctl(fd, XFS_IOC_RESVSP64, &fl);
-	if (ret && errno != ENOTTY)
+	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
 		mlog(MLOG_VERBOSE | MLOG_NOTE,
 _("attempt to reserve %lld bytes for %s using %s failed: %s (%d)\n"),
 				size, pathname, "XFS_IOC_RESVSP64",

[PATCH 4/4] xfs_restore: support fallocate when reserving space for a file

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Update the file creation helper to try fallocate when restoring a
filesystem before it tries RESVSP.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 configure.ac          |    2 ++
 include/builddefs.in  |    1 +
 m4/Makefile           |    1 +
 m4/package_libcdev.m4 |   15 +++++++++++++++
 restore/Makefile      |    4 ++++
 restore/dirattr.c     |   11 +++++++++++
 6 files changed, 34 insertions(+)
 create mode 100644 m4/package_libcdev.m4


diff --git a/configure.ac b/configure.ac
index a77054c..73dedd7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,6 +84,8 @@ AC_PACKAGE_NEED_ATTRIBUTES_H
 AC_PACKAGE_NEED_ATTRIBUTES_MACROS
 AC_PACKAGE_NEED_ATTRGET_LIBATTR
 
+AC_HAVE_FALLOCATE
+
 AC_MANUAL_FORMAT
 
 AC_CONFIG_FILES([include/builddefs])
diff --git a/include/builddefs.in b/include/builddefs.in
index 269c928..1c7e12f 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -69,6 +69,7 @@ ENABLE_SHARED	= @enable_shared@
 ENABLE_GETTEXT	= @enable_gettext@
 
 HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@
+HAVE_FALLOCATE = @have_fallocate@
 
 GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall 
 #	   -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
diff --git a/m4/Makefile b/m4/Makefile
index 9a35056..ae452f7 100644
--- a/m4/Makefile
+++ b/m4/Makefile
@@ -16,6 +16,7 @@ LSRCFILES = \
 	manual_format.m4 \
 	package_attrdev.m4 \
 	package_globals.m4 \
+	package_libcdev.m4 \
 	package_ncurses.m4 \
 	package_pthread.m4 \
 	package_utilies.m4 \
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
new file mode 100644
index 0000000..050f82c
--- /dev/null
+++ b/m4/package_libcdev.m4
@@ -0,0 +1,15 @@
+#
+# Check if we have a fallocate libc call (Linux)
+#
+AC_DEFUN([AC_HAVE_FALLOCATE],
+  [ AC_MSG_CHECKING([for fallocate])
+    AC_TRY_LINK([
+#include <fcntl.h>
+#include <linux/falloc.h>
+    ], [
+         fallocate(0, 0, 0, 0);
+    ], have_fallocate=yes
+       AC_MSG_RESULT(yes),
+       AC_MSG_RESULT(no))
+    AC_SUBST(have_fallocate)
+  ])
diff --git a/restore/Makefile b/restore/Makefile
index 20c870a..ac3f8c8 100644
--- a/restore/Makefile
+++ b/restore/Makefile
@@ -102,6 +102,10 @@ LTDEPENDENCIES = $(LIBRMT)
 
 LCFLAGS = -DRESTORE
 
+ifeq ($(HAVE_FALLOCATE),yes)
+LCFLAGS += -DHAVE_FALLOCATE
+endif
+
 default: depend $(LTCOMMAND)
 
 include $(BUILDRULES)
diff --git a/restore/dirattr.c b/restore/dirattr.c
index 267bef0..15a16d1 100644
--- a/restore/dirattr.c
+++ b/restore/dirattr.c
@@ -75,6 +75,17 @@ create_filled_file(
 	if (fd < 0)
 		return fd;
 
+#ifdef HAVE_FALLOCATE
+	ret = fallocate(fd, 0, 0, size);
+	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
+		mlog(MLOG_VERBOSE | MLOG_NOTE,
+_("attempt to reserve %lld bytes for %s using %s failed: %s (%d)\n"),
+				size, pathname, "fallocate",
+				strerror(errno), errno);
+	if (ret == 0)
+		goto done;
+#endif
+
 	ret = ioctl(fd, XFS_IOC_RESVSP64, &fl);
 	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
 		mlog(MLOG_VERBOSE | MLOG_NOTE,

Re: [PATCH 0/4] xfsdump: update to use fallocate

[Eric Sandeen]

thanks but I actually merged these back in May :D

https://git.kernel.org/pub/scm/fs/xfs/xfsdump-dev.git/commit/?id=36b5cf95733df250fc4401b6a336b7ffc7567b94

On 8/20/19 3:21 PM, Darrick J. Wong wrote:
> Hi all,
> 
> This is a series to update the "create file and preallocate blocks"
> code in xfs_restore.
> 
> The first patch refactors the existing copy-pasta into a single helper
> function to create and preallocate space in files, as well as removing
> the totally broken ALLOCSP code.
> 
> The next two patches fix unchecked return values and insufficient
> unsupported-ioctl code.
> 
> The final patch upgrades xfs_restore to try fallocate before RESVSP
> simply because it is the newer API.
> 
> This is an extraordinary way to destroy everything.  Enjoy!
> Comments and questions are, as always, welcome.
> 
> --D
> 

Re: [PATCH 4/4] xfs_restore: support fallocate when reserving space for a file

[Allison Collins]

On 2/22/19 9:47 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Update the file creation helper to try fallocate when restoring a
> filesystem before it tries RESVSP.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>   configure.ac          |    2 ++
>   include/builddefs.in  |    1 +
>   m4/Makefile           |    1 +
>   m4/package_libcdev.m4 |   15 +++++++++++++++
>   restore/Makefile      |    4 ++++
>   restore/dirattr.c     |   11 +++++++++++
>   6 files changed, 34 insertions(+)
>   create mode 100644 m4/package_libcdev.m4
> 
> 
> diff --git a/configure.ac b/configure.ac
> index a77054c..73dedd7 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -84,6 +84,8 @@ AC_PACKAGE_NEED_ATTRIBUTES_H
>   AC_PACKAGE_NEED_ATTRIBUTES_MACROS
>   AC_PACKAGE_NEED_ATTRGET_LIBATTR
>   
> +AC_HAVE_FALLOCATE
> +
>   AC_MANUAL_FORMAT
>   
>   AC_CONFIG_FILES([include/builddefs])
> diff --git a/include/builddefs.in b/include/builddefs.in
> index 269c928..1c7e12f 100644
> --- a/include/builddefs.in
> +++ b/include/builddefs.in
> @@ -69,6 +69,7 @@ ENABLE_SHARED	= @enable_shared@
>   ENABLE_GETTEXT	= @enable_gettext@
>   
>   HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@
> +HAVE_FALLOCATE = @have_fallocate@
>   
>   GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
>   #	   -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
> diff --git a/m4/Makefile b/m4/Makefile
> index 9a35056..ae452f7 100644
> --- a/m4/Makefile
> +++ b/m4/Makefile
> @@ -16,6 +16,7 @@ LSRCFILES = \
>   	manual_format.m4 \
>   	package_attrdev.m4 \
>   	package_globals.m4 \
> +	package_libcdev.m4 \
>   	package_ncurses.m4 \
>   	package_pthread.m4 \
>   	package_utilies.m4 \
> diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> new file mode 100644
> index 0000000..050f82c
> --- /dev/null
> +++ b/m4/package_libcdev.m4
> @@ -0,0 +1,15 @@
> +#
> +# Check if we have a fallocate libc call (Linux)
> +#
> +AC_DEFUN([AC_HAVE_FALLOCATE],
> +  [ AC_MSG_CHECKING([for fallocate])
> +    AC_TRY_LINK([
> +#include <fcntl.h>
> +#include <linux/falloc.h>
> +    ], [
> +         fallocate(0, 0, 0, 0);
> +    ], have_fallocate=yes
> +       AC_MSG_RESULT(yes),
> +       AC_MSG_RESULT(no))
> +    AC_SUBST(have_fallocate)
> +  ])
> diff --git a/restore/Makefile b/restore/Makefile
> index 20c870a..ac3f8c8 100644
> --- a/restore/Makefile
> +++ b/restore/Makefile
> @@ -102,6 +102,10 @@ LTDEPENDENCIES = $(LIBRMT)
>   
>   LCFLAGS = -DRESTORE
>   
> +ifeq ($(HAVE_FALLOCATE),yes)
> +LCFLAGS += -DHAVE_FALLOCATE
> +endif
> +
>   default: depend $(LTCOMMAND)
>   
>   include $(BUILDRULES)
> diff --git a/restore/dirattr.c b/restore/dirattr.c
> index 3fa8fb6..82eb1de 100644
> --- a/restore/dirattr.c
> +++ b/restore/dirattr.c
> @@ -75,6 +75,17 @@ create_filled_file(
>   	if (fd < 0)
>   		return fd;
>   
> +#ifdef HAVE_FALLOCATE
> +	ret = fallocate(fd, 0, 0, size);
> +	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
> +		mlog(MLOG_VERBOSE | MLOG_NOTE,
> +_("attempt to reserve %lld bytes for %s using %s failed: %s (%d)\n"),
> +				size, pathname, "fallocate",
> +				strerror(errno), errno);
> +	if (ret == 0)
> +		goto done;
This is the goto I referenced in patch 1.  Otherwise I think the rest is ok.

Reviewed-by: Allison Collins <allison.henderson@oracle.com>

> +#endif
> +
>   	ret = ioctl(fd, XFS_IOC_RESVSP64, &fl);
>   	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
>   		mlog(MLOG_VERBOSE | MLOG_NOTE,
> 

[PATCH 4/4] xfs_restore: support fallocate when reserving space for a file

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Update the file creation helper to try fallocate when restoring a
filesystem before it tries RESVSP.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 configure.ac          |    2 ++
 include/builddefs.in  |    1 +
 m4/Makefile           |    1 +
 m4/package_libcdev.m4 |   15 +++++++++++++++
 restore/Makefile      |    4 ++++
 restore/dirattr.c     |   11 +++++++++++
 6 files changed, 34 insertions(+)
 create mode 100644 m4/package_libcdev.m4


diff --git a/configure.ac b/configure.ac
index a77054c..73dedd7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,6 +84,8 @@ AC_PACKAGE_NEED_ATTRIBUTES_H
 AC_PACKAGE_NEED_ATTRIBUTES_MACROS
 AC_PACKAGE_NEED_ATTRGET_LIBATTR
 
+AC_HAVE_FALLOCATE
+
 AC_MANUAL_FORMAT
 
 AC_CONFIG_FILES([include/builddefs])
diff --git a/include/builddefs.in b/include/builddefs.in
index 269c928..1c7e12f 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -69,6 +69,7 @@ ENABLE_SHARED	= @enable_shared@
 ENABLE_GETTEXT	= @enable_gettext@
 
 HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@
+HAVE_FALLOCATE = @have_fallocate@
 
 GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall 
 #	   -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
diff --git a/m4/Makefile b/m4/Makefile
index 9a35056..ae452f7 100644
--- a/m4/Makefile
+++ b/m4/Makefile
@@ -16,6 +16,7 @@ LSRCFILES = \
 	manual_format.m4 \
 	package_attrdev.m4 \
 	package_globals.m4 \
+	package_libcdev.m4 \
 	package_ncurses.m4 \
 	package_pthread.m4 \
 	package_utilies.m4 \
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
new file mode 100644
index 0000000..050f82c
--- /dev/null
+++ b/m4/package_libcdev.m4
@@ -0,0 +1,15 @@
+#
+# Check if we have a fallocate libc call (Linux)
+#
+AC_DEFUN([AC_HAVE_FALLOCATE],
+  [ AC_MSG_CHECKING([for fallocate])
+    AC_TRY_LINK([
+#include <fcntl.h>
+#include <linux/falloc.h>
+    ], [
+         fallocate(0, 0, 0, 0);
+    ], have_fallocate=yes
+       AC_MSG_RESULT(yes),
+       AC_MSG_RESULT(no))
+    AC_SUBST(have_fallocate)
+  ])
diff --git a/restore/Makefile b/restore/Makefile
index 20c870a..ac3f8c8 100644
--- a/restore/Makefile
+++ b/restore/Makefile
@@ -102,6 +102,10 @@ LTDEPENDENCIES = $(LIBRMT)
 
 LCFLAGS = -DRESTORE
 
+ifeq ($(HAVE_FALLOCATE),yes)
+LCFLAGS += -DHAVE_FALLOCATE
+endif
+
 default: depend $(LTCOMMAND)
 
 include $(BUILDRULES)
diff --git a/restore/dirattr.c b/restore/dirattr.c
index 3fa8fb6..82eb1de 100644
--- a/restore/dirattr.c
+++ b/restore/dirattr.c
@@ -75,6 +75,17 @@ create_filled_file(
 	if (fd < 0)
 		return fd;
 
+#ifdef HAVE_FALLOCATE
+	ret = fallocate(fd, 0, 0, size);
+	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
+		mlog(MLOG_VERBOSE | MLOG_NOTE,
+_("attempt to reserve %lld bytes for %s using %s failed: %s (%d)\n"),
+				size, pathname, "fallocate",
+				strerror(errno), errno);
+	if (ret == 0)
+		goto done;
+#endif
+
 	ret = ioctl(fd, XFS_IOC_RESVSP64, &fl);
 	if (ret && (errno != EOPNOTSUPP && errno != ENOTTY))
 		mlog(MLOG_VERBOSE | MLOG_NOTE,