Re: [PATCH] e2fsprogs: Fix the overflow in e4defrag with 2GB over file

Ted Ts'o
2010-12-17T04:13:52Z

On Tue, Mar 30, 2010 at 03:35:39PM +0900, Akira Fujita wrote:
> e2fsprogs: Fix the overflow in e4defrag with 2GB over file
>
> From: Akira Fujita <a-fujita@rs.jp.nec.com>
>
> In e4defrag, we use locally defined posix_fallocate interface.
> And its "offset" and "len" are defined as off_t (long) type,
> their upper limit is 2GB -1 byte.
> Thus if we run e4defrag to the file whose size is 2GB over,
> the overflow occurs at calling fallocate syscall.
>
> To fix this issue, I add new define _FILE_OFFSET_BITS 64 to use
> 64bit offset for filesystem related syscalls in e4defrag.c.
> (Also this patch includes open mode fix which has been
> released but not been merged e2fsprogs git tree yet.
> http://lists.openwall.net/linux-ext4/2010/01/19/3)

My apologies for the delay in looking at this patch. The following is
a much smaller patch which fixes the problem, without having to use
the _FILE_OFFSET_BITS 64 kludge. I've checked this into e2fsprogs.

- Ted

commit 30c0529d27edca148a6e5e52bcdd7b38d6cb28b2
Author: Theodore Ts'o <tytso@mit.edu>
Date: Thu Dec 16 22:53:34 2010 -0500

e4defrag: Fix the overflow in e4defrag with > 2GB files

The fallocate() interface on 32-bit machines is defined to use off_t,
not loff_t (even though the system call interface is 64-bit clean).
This causes e4defrag to fail on files greater than 2GB. Fix this by
trying to use fallocate64(), and using the hard-coded syscall if it
does not exist.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/configure b/configure
index 14d9652..2f5515a 100755
--- a/configure
+++ b/configure
@@ -10699,7 +10699,7 @@ if test "$ac_res" != no; then :
fi

fi
-for ac_func in chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit sync_file_range posix_fadvise fallocate blkid_probe_get_topology mbstowcs
+for ac_func in chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit sync_file_range posix_fadvise fallocate fallocate64 blkid_probe_get_topology mbstowcs
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 5e67688..f9fffc1 100644
--- a/configure.in
+++ b/configure.in
@@ -853,7 +853,7 @@ if test -n "$BLKID_CMT"; then
AC_SEARCH_LIBS([blkid_probe_all], [blkid])
fi
dnl
-AC_CHECK_FUNCS(chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit sync_file_range posix_fadvise fallocate blkid_probe_get_topology mbstowcs)
+AC_CHECK_FUNCS(chflags getrusage llseek lseek64 open64 fstat64 ftruncate64 getmntinfo strtoull strcasecmp srandom jrand48 fchown mallinfo fdatasync strnlen strptime strdup sysconf pathconf posix_memalign memalign valloc __secure_getenv prctl mmap utime setresuid setresgid usleep nanosleep getdtablesize getrlimit sync_file_range posix_fadvise fallocate fallocate64 blkid_probe_get_topology mbstowcs)
dnl
dnl Check to see if -lsocket is required (solaris) to make something
dnl that uses socket() to compile; this is needed for the UUID library
diff --git a/misc/e4defrag.c b/misc/e4defrag.c
index 83625fc..e795987 100644
--- a/misc/e4defrag.c
+++ b/misc/e4defrag.c
@@ -327,7 +327,7 @@ int sync_file_range(int fd, loff_t offset, loff_t length, unsigned int flag)
}
#endif /* ! HAVE_SYNC_FILE_RANGE */

-#ifndef HAVE_FALLOCATE
+#ifndef HAVE_FALLOCATE64
#warning Using locally defined fallocate syscall interface.

#ifndef __NR_fallocate
@@ -335,14 +335,14 @@ int sync_file_range(int fd, loff_t offset, loff_t length, unsigned int flag)
#endif

/*
- * fallocate() - Manipulate file space.
+ * fallocate64() - Manipulate file space.
*
* @fd: defrag target file's descriptor.
* @mode: process flag.
* @offset: file offset.
* @len: file size.
*/
-static int fallocate(int fd, int mode, loff_t offset, loff_t len)
+static int fallocate64(int fd, int mode, loff_t offset, loff_t len)
{
return syscall(__NR_fallocate, fd, mode, offset, len);
}
@@ -1738,7 +1738,7 @@ static int file_defrag(const char *file, const struct stat64 *buf,
/* Allocate space for donor inode */
orig_group_tmp = orig_group_head;
do {
- ret = fallocate(donor_fd, 0,
+ ret = fallocate64(donor_fd, 0,
(loff_t)orig_group_tmp->start->data.logical * block_size,
(loff_t)orig_group_tmp->len * block_size);
if (ret < 0) {