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Date: Wed, 17 Oct 2012 22:22:40 +0530
From: Ashish Sangwan <ashishsangwan2@...il.com>
To: tytso@....edu
Cc: linux-ext4@...r.kernel.org,
Ashish Sangwan <ashish.sangwan2@...il.com>,
Namjae Jeon <linkinjeon@...il.com>
Subject: [PATCH] e4defrag: Add option -m mtab to e4defrag
Currently, e4defrag will not work on machines where /etc/mtab is not present
OR is empty.
This patch does 3 things:
a) Add option "-m mtab" to e4defrag so that user can specify any file to
be scanned for otbtaining mounted filesystems info.
b) If mtab option is not specified, first we try to scan /proc/mounts, if failed
to access this file, we try with /etc/mtab.
c) In function is_ext4, check if the varibale "mnt_type" is null before
calling strcmp, otherwise segfault would occur if mtab is empty.
Signed-off-by: Ashish Sangwan <ashish.sangwan2@...il.com>
Signed-off-by: Namjae Jeon <linkinjeon@...il.com>
---
misc/e4defrag.8.in | 10 ++++++++++
misc/e4defrag.c | 34 ++++++++++++++++++++++------------
2 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/misc/e4defrag.8.in b/misc/e4defrag.8.in
index 75e1bc9..7090e51 100644
--- a/misc/e4defrag.8.in
+++ b/misc/e4defrag.8.in
@@ -9,6 +9,9 @@ e4defrag \- online defragmenter for ext4 filesystem
[
.B \-v
]
+[
+.B \-m mtab
+]
.I target
\&...
.SH DESCRIPTION
@@ -57,6 +60,13 @@ is never defragmented.
.B \-v
Print error messages and the fragmentation count before and after defrag for
each file.
+.TP
+.B \-m mtab
+This option will specify the file to be scanned for obtaining mounted filesystems
+information. If this option is not specified, the default is to use
+.B /proc/mounts .
+If this file is not accessible, e4defrag will try to get required information from
+.B /etc/mtab
.SH NOTES
.B e4defrag
does not support swap file, files in lost+found directory, and files allocated
diff --git a/misc/e4defrag.c b/misc/e4defrag.c
index 4b31d03..3567e9f 100644
--- a/misc/e4defrag.c
+++ b/misc/e4defrag.c
@@ -123,6 +123,7 @@
#define NGMSG_FILE_OPEN "Failed to open"
#define NGMSG_FILE_UNREG "File is not regular file"
#define NGMSG_LOST_FOUND "Can not process \"lost+found\""
+#define _PATH_PROC_MOUNTS "/proc/mounts"
/* Data type for filesystem-wide blocks number */
typedef unsigned long long ext4_fsblk_t;
@@ -262,10 +263,8 @@ static int fallocate64(int fd, int mode, loff_t offset, loff_t len)
* @dir_path_len: the length of directory.
*/
static int get_mount_point(const char *devname, char *mount_point,
- int dir_path_len)
+ int dir_path_len, const char *mtab)
{
- /* Refer to /etc/mtab */
- const char *mtab = MOUNTED;
FILE *fp = NULL;
struct mntent *mnt = NULL;
struct stat64 sb;
@@ -278,7 +277,7 @@ static int get_mount_point(const char *devname, char *mount_point,
fp = setmntent(mtab, "r");
if (fp == NULL) {
- perror("Couldn't access /etc/mtab");
+ printf("Couldn't access %s\n", mtab);
return -1;
}
@@ -313,14 +312,12 @@ static int get_mount_point(const char *devname, char *mount_point,
*
* @file: the file's name.
*/
-static int is_ext4(const char *file, char *devname)
+static int is_ext4(const char *file, char *devname, const char *mtab)
{
int maxlen = 0;
int len, ret;
FILE *fp = NULL;
char *mnt_type = NULL;
- /* Refer to /etc/mtab */
- const char *mtab = MOUNTED;
char file_path[PATH_MAX + 1];
struct mntent *mnt = NULL;
struct statfs64 fsbuf;
@@ -345,7 +342,7 @@ static int is_ext4(const char *file, char *devname)
fp = setmntent(mtab, "r");
if (fp == NULL) {
- perror("Couldn't access /etc/mtab");
+ printf("Couldn't access %s", mtab);
return -1;
}
@@ -374,6 +371,10 @@ static int is_ext4(const char *file, char *devname)
}
endmntent(fp);
+ if (mnt_type == NULL) {
+ printf("Could not get mount information from %s\n", mtab);
+ return -1;
+ }
if (strcmp(mnt_type, FS_EXT4) == 0) {
FREE(mnt_type);
return 0;
@@ -1724,6 +1725,7 @@ int main(int argc, char *argv[])
int success_flag = 0;
char dir_name[PATH_MAX + 1];
char dev_name[PATH_MAX + 1];
+ char *mtab = NULL;
struct stat64 buf;
ext2_filsys fs = NULL;
@@ -1731,7 +1733,7 @@ int main(int argc, char *argv[])
if (argc == 1)
goto out;
- while ((opt = getopt(argc, argv, "vc")) != EOF) {
+ while ((opt = getopt(argc, argv, "vcm:")) != EOF) {
switch (opt) {
case 'v':
mode_flag |= DETAIL;
@@ -1739,11 +1741,19 @@ int main(int argc, char *argv[])
case 'c':
mode_flag |= STATISTIC;
break;
+ case 'm':
+ mtab = optarg;
+ break;
default:
goto out;
}
}
-
+ if (!mtab) {
+ if (access(_PATH_PROC_MOUNTS, R_OK) == 0)
+ mtab = _PATH_PROC_MOUNTS;
+ else
+ mtab = _PATH_MOUNTED;
+ }
if (argc == optind)
goto out;
@@ -1797,7 +1807,7 @@ int main(int argc, char *argv[])
if (S_ISBLK(buf.st_mode)) {
/* Block device */
strncpy(dev_name, argv[i], strnlen(argv[i], PATH_MAX));
- if (get_mount_point(argv[i], dir_name, PATH_MAX) < 0)
+ if (get_mount_point(argv[i], dir_name, PATH_MAX, mtab) < 0)
continue;
if (lstat64(dir_name, &buf) < 0) {
perror(NGMSG_FILE_INFO);
@@ -1833,7 +1843,7 @@ int main(int argc, char *argv[])
* filesystem type checked in get_mount_point()
*/
if (arg_type == FILENAME || arg_type == DIRNAME) {
- if (is_ext4(argv[i], dev_name) < 0)
+ if (is_ext4(argv[i], dev_name, mtab) < 0)
continue;
if (realpath(argv[i], dir_name) == NULL) {
perror("Couldn't get full path");
--
1.7.8.4
--
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