From: Baruch Siach <baruch@tkos.co.il>
Date: Thu, 2 Jan 2014 18:05:37 +0000 (-0500)
Subject: e4defrag: choose the best available posix_fadvise variant
X-Git-Tag: v1.42.9.wc1~135
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=9a3938918545b831b215b2befc2454f7b1a2dd84;p=tools%2Fe2fsprogs.git

e4defrag: choose the best available posix_fadvise variant

Use posix_fadvise64() when available.  This allows 64bit offsets on
32bit systems.

[ Modified by tytso to try to use fadvise64() as well, and to remove
  the attempt to call the syscall directly, since because and
  complexities caused by required dummy arguments on some
  architectures, it's not worth the hair.  ]

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/configure b/configure
index 6f8f1ab..5943849 100755
--- a/configure
+++ b/configure
@@ -11051,7 +11051,7 @@ if test "$ac_res" != no; then :
 fi
 
 fi
-for ac_func in  	__secure_getenv 	backtrace 	blkid_probe_get_topology 	chflags 	fallocate 	fallocate64 	fchown 	fdatasync 	fstat64 	ftruncate64 	futimes 	getdtablesize 	getmntinfo 	getpwuid_r 	getrlimit 	getrusage 	jrand48 	llseek 	lseek64 	mallinfo 	mbstowcs 	memalign 	mmap 	msync 	nanosleep 	open64 	pathconf 	posix_fadvise 	posix_memalign 	prctl 	secure_getenv 	setmntent 	setresgid 	setresuid 	srandom 	strcasecmp 	strdup 	strnlen 	strptime 	strtoull 	sync_file_range 	sysconf 	usleep 	utime 	valloc
+for ac_func in  	__secure_getenv 	backtrace 	blkid_probe_get_topology 	chflags 	fadvise64 	fallocate 	fallocate64 	fchown 	fdatasync 	fstat64 	ftruncate64 	futimes 	getdtablesize 	getmntinfo 	getpwuid_r 	getrlimit 	getrusage 	jrand48 	llseek 	lseek64 	mallinfo 	mbstowcs 	memalign 	mmap 	msync 	nanosleep 	open64 	pathconf 	posix_fadvise 	posix_fadvise64 	posix_memalign 	prctl 	secure_getenv 	setmntent 	setresgid 	setresuid 	srandom 	strcasecmp 	strdup 	strnlen 	strptime 	strtoull 	sync_file_range 	sysconf 	usleep 	utime 	valloc
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index b70a3f9..214d3f6 100644
--- a/configure.in
+++ b/configure.in
@@ -1026,6 +1026,7 @@ AC_CHECK_FUNCS(m4_flatten([
 	backtrace
 	blkid_probe_get_topology
 	chflags
+	fadvise64
 	fallocate
 	fallocate64
 	fchown
@@ -1050,6 +1051,7 @@ AC_CHECK_FUNCS(m4_flatten([
 	open64
 	pathconf
 	posix_fadvise
+	posix_fadvise64
 	posix_memalign
 	prctl
 	secure_getenv
diff --git a/lib/config.h.in b/lib/config.h.in
index ef2e664..0197b56 100644
--- a/lib/config.h.in
+++ b/lib/config.h.in
@@ -103,6 +103,9 @@
 /* Define to 1 if Ext2 ioctls present */
 #undef HAVE_EXT2_IOCTLS
 
+/* Define to 1 if you have the `fadvise64' function. */
+#undef HAVE_FADVISE64
+
 /* Define to 1 if you have the `fallocate' function. */
 #undef HAVE_FALLOCATE
 
@@ -287,6 +290,9 @@
 /* Define to 1 if you have the `posix_fadvise' function. */
 #undef HAVE_POSIX_FADVISE
 
+/* Define to 1 if you have the `posix_fadvise64' function. */
+#undef HAVE_POSIX_FADVISE64
+
 /* Define to 1 if you have the `posix_memalign' function. */
 #undef HAVE_POSIX_MEMALIGN
 
diff --git a/misc/e4defrag.c b/misc/e4defrag.c
index c6a5f0d..c2695e8 100644
--- a/misc/e4defrag.c
+++ b/misc/e4defrag.c
@@ -34,7 +34,6 @@
 #include <unistd.h>
 #include <ext2fs/ext2_types.h>
 #include <ext2fs/ext2fs.h>
-#include <linux/fs.h>
 #include <sys/ioctl.h>
 #include <ext2fs/fiemap.h>
 #include <sys/mman.h>
@@ -183,29 +182,21 @@ static ext4_fsblk_t	files_block_count;
 static struct frag_statistic_ino	frag_rank[SHOW_FRAG_FILES];
 
 
-/* Local definitions of some syscalls glibc may not yet have */
-
-#ifndef HAVE_POSIX_FADVISE
-#warning Using locally defined posix_fadvise interface.
-
-#ifndef __NR_fadvise64_64
-#error Your kernel headers dont define __NR_fadvise64_64
+/*
+ * We prefer posix_fadvise64 when available, as it allows 64bit offset on
+ * 32bit systems
+ */
+#if defined(HAVE_POSIX_FADVISE64)
+#define posix_fadvise	posix_fadvise64
+#elif defined(HAVE_FADVISE64)
+#define posix_fadvise	fadvise64
+#elif !defined(HAVE_POSIX_FADVISE)
+#error posix_fadvise not available!
 #endif
 
 /*
- * fadvise() -		Give advice about file access.
- *
- * @fd:			defrag target file's descriptor.
- * @offset:		file offset.
- * @len:		area length.
- * @advise:		process flag.
+ * Local definitions of some syscalls glibc may not yet have
  */
-static int posix_fadvise(int fd, loff_t offset, size_t len, int advise)
-{
-	return syscall(__NR_fadvise64_64, fd, offset, len, advise);
-}
-#endif /* ! HAVE_FADVISE64_64 */
-
 #ifndef HAVE_SYNC_FILE_RANGE
 #warning Using locally defined sync_file_range interface.