Hi Christoph,
We have seen LTP test(utime06 and umount03) failure in Next Master with
commit Id 41525f56e256("fs: refactor ksys_umount").
I didn't analysis root cause of problem, i am reporting this issue.
---------------------------------------------
LTP Testcase Result Exit Value
----------------------------------- ---------
umount03 FAIL 4
utime06 FAIL 2
--------------------------------------------
LTP utime06 Fail Log:
/dev/loop0 is mounted; will not make a filesystem here!
utime06 0 TINFO : Using test device LTP_DEV='/dev/loop0'
utime06 0 TINFO : Formatting /dev/loop0 with ext2 opts='' extra
opts=''
utime06 1 TBROK : tst_mkfs.c:102: utime06.c:122: mkfs.ext2 failed
with 1
utime06 2 TBROK : tst_mkfs.c:102: Remaining cases broken
LTP umount03 Fail Log:
tst_device.c:262: INFO: Using test device LTP_DEV='/dev/loop0'
tst_mkfs.c:89: INFO: Formatting /dev/loop0 with ext2 opts='' extra opts=''
mke2fs 1.44.5 (15-Dec-2018)
tst_test.c:1244: INFO: Timeout per run is 0h 05m 00s
umount03.c:35: PASS: umount() fails as expected: EPERM (1)
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 1...
tst_device.c:387: INFO: Likely gvfsd-trash is probing newly mounted fs,
kill it to speed up tests.
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 2...
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 3...
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 48...
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 49...
tst_device.c:383: INFO: umount('mntpoint') failed with EBUSY, try 50...
tst_device.c:394: WARN: Failed to umount('mntpoint') after 50 retries
tst_tmpdir.c:336: WARN: tst_rmdir: rmobj(/scratch/ltp-Lnmh7tbxY6/gx0hJU)
failed: remove(/scratch/ltp-Lnmh7tbxY6/gx0hJU/mntpoint) failed;
errno=16: EBUSY
Regards,
Vikas
Below Commit ID 41525f56e256 Bisected for This fail:
commit 41525f56e2564c2feff4fb2824823900efb3a39f
Author: Christoph Hellwig <hch@xxxxxx>
Date: Tue Jul 21 10:54:34 2020 +0200
fs: refactor ksys_umount
Factor out a path_umount helper that takes a struct path * instead
of the
actual file name. This will allow to convert the init and devtmpfs
code
to properly mount based on a kernel pointer instead of relying on the
implicit set_fs(KERNEL_DS) during early init.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/namespace.c | 40 ++++++++++++++++++----------------------
1 file changed, 18 insertions(+), 22 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index 6f8234f74bed90..43834b59eff6c3 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1706,36 +1706,19 @@ static inline bool may_mandlock(void)
}
#endif
-/*
- * Now umount can handle mount points as well as block devices.
- * This is important for filesystems which use unnamed block devices.
- *
- * We now support a flag for forced unmount like the other 'big iron'
- * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD
- */
-
-int ksys_umount(char __user *name, int flags)
+static int path_umount(struct path *path, int flags)
{
- struct path path;
struct mount *mnt;
int retval;
- int lookup_flags = LOOKUP_MOUNTPOINT;
if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))
return -EINVAL;
-
if (!may_mount())
return -EPERM;
- if (!(flags & UMOUNT_NOFOLLOW))
- lookup_flags |= LOOKUP_FOLLOW;
-
- retval = user_path_at(AT_FDCWD, name, lookup_flags, &path);
- if (retval)
- goto out;
- mnt = real_mount(path.mnt);
+ mnt = real_mount(path->mnt);
retval = -EINVAL;
- if (path.dentry != path.mnt->mnt_root)
+ if (path->dentry != path->mnt->mnt_root)
goto dput_and_out;
if (!check_mnt(mnt))
goto dput_and_out;
@@ -1748,12 +1731,25 @@ int ksys_umount(char __user *name, int flags)
retval = do_umount(mnt, flags);
dput_and_out:
/* we mustn't call path_put() as that would clear mnt_expiry_mark */
- dput(path.dentry);
+ dput(path->dentry);
mntput_no_expire(mnt);
-out:
return retval;
}
+int ksys_umount(char __user *name, int flags)
+{
+ int lookup_flags = LOOKUP_MOUNTPOINT;
+ struct path path;
+ int ret;
+
+ if (!(flags & UMOUNT_NOFOLLOW))
+ lookup_flags |= LOOKUP_FOLLOW;
+ ret = user_path_at(AT_FDCWD, name, lookup_flags, &path);
+ if (ret)
+ return ret;
+ return path_umount(&path, flags);
+}
+
SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
{
