Hi,
In some cases, using resize2fs to resize one fs will return "fail".
Reproduce steps are as follows,
1. create 2 folders, for example "mnt" and "tmp"
2. mount /dev/sdb onto tmp as tmpfs
3. mount /dev/sdb onto mnt as ext4 or other normal file system 4. try to resize /dev/sdb, it FAILED! -> "Couldn't find valid filesystem superblock."
5. if mount mnt firstly, resize2fs command will succeed.
In check_mntent_file func, firstly try to find out the input device name in mtab_file line by line, and it will leave from loop once one item matched.
Then, check the mount point's st_dev of matched item, if it is not same with the input device's st_dev, it will return fail.
In this case, the first matched item in mtab_file is "tmp" mount point, it is only named as "/dev/sdb", which actually is not sdb's real mount point.
Finally, the name is matched, but st_dev is not matched, and then resize command fails.
Here, we check the st_dev immediately once the name is matched.
If st_dev not same, continue to next loop.
Signed-off-by: GuiYao <guiyao@xxxxxxxxxx>
---
lib/ext2fs/ismounted.c | 49 +++++++++++++++++-------------------------
1 file changed, 20 insertions(+), 29 deletions(-)
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c index 6cd497dc..265d27f7 100644
--- a/lib/ext2fs/ismounted.c
+++ b/lib/ext2fs/ismounted.c
@@ -98,6 +98,9 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file, {
struct mntent *mnt;
struct stat st_buf;
+#ifndef __GNU__
+ struct stat dir_st_buf;
+#endif /* __GNU__ */
errcode_t retval = 0;
dev_t file_dev=0, file_rdev=0;
ino_t file_ino=0;
@@ -128,13 +131,26 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
while ((mnt = getmntent (f)) != NULL) {
if (mnt->mnt_fsname[0] != '/')
continue;
- if (strcmp(file, mnt->mnt_fsname) == 0)
+#ifndef __GNU__
+ if (stat(mnt->mnt_dir, &dir_st_buf) != 0)
+ continue;
+#endif /* __GNU__ */
+ if (strcmp(file, mnt->mnt_fsname) == 0) { #ifndef __GNU__
+ if (file_rdev && (file_rdev == dir_st_buf.st_dev))
+ break;
+ continue;
+#else
break;
+#endif /* __GNU__ */
+ }
if (stat(mnt->mnt_fsname, &st_buf) == 0) {
if (ext2fsP_is_disk_device(st_buf.st_mode)) { #ifndef __GNU__
- if (file_rdev && (file_rdev == st_buf.st_rdev))
- break;
+ if (file_rdev && (file_rdev == st_buf.st_rdev)) {
+ if (file_rdev == dir_st_buf.st_dev)
+ break;
+ }
if (check_loop_mounted(mnt->mnt_fsname,
st_buf.st_rdev, file_dev,
file_ino) == 1)
@@ -168,32 +184,7 @@ static errcode_t check_mntent_file(const char *mtab_file, const char *file,
#endif /* __GNU__ */
goto errout;
}
-#ifndef __GNU__ /* The GNU hurd is deficient; what else is new? */
- /* Validate the entry in case /etc/mtab is out of date */
- /*
- * We need to be paranoid, because some broken distributions
- * (read: Slackware) don't initialize /etc/mtab before checking
- * all of the non-root filesystems on the disk.
- */
- if (stat(mnt->mnt_dir, &st_buf) < 0) {
- retval = errno;
- if (retval == ENOENT) {
-#ifdef DEBUG
- printf("Bogus entry in %s! (%s does not exist)\n",
- mtab_file, mnt->mnt_dir);
-#endif /* DEBUG */
- retval = 0;
- }
- goto errout;
- }
- if (file_rdev && (st_buf.st_dev != file_rdev)) {
-#ifdef DEBUG
- printf("Bogus entry in %s! (%s not mounted on %s)\n",
- mtab_file, file, mnt->mnt_dir);
-#endif /* DEBUG */
- goto errout;
- }
-#endif /* __GNU__ */
+
*mount_flags = EXT2_MF_MOUNTED;
#ifdef MNTOPT_RO
--
1.8.3.1
