On Tue, 28 Jul 2020 at 22:04, Christoph Hellwig hch@lst.de wrote:
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@lst.de
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) { return ksys_umount(name, flags);
Regressions on linux next 20200803 tag kernel. LTP syscalls test umount03 mount a path for testing and umount failed and retired for 50 times and test exit with warning and following test cases using that mount path failed.
LTP syscalls tests failed list, * umount03 * umount2_01 * umount2_02 * umount2_03 * utime06 * copy_file_range01
Summary ------------------------------------------------------------------------
kernel: 5.8.0 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git branch: master git describe: next-20200803 Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20200803 ------------------------------------------------------------------------
test failed log: tst_device.c:262: INFO: Using test device LTP_DEV='/dev/loop0' tst_mkfs.c:90: INFO: Formatting /dev/loop0 with ext2 opts='' extra opts='' mke2fs 1.43.8 (1-Jan-2018) tst_test.c:1246: INFO: Timeout per run is 0h 15m 00s [ 870.449934] EXT4-fs (loop0): mounting ext2 file system using the ext4 subsystem [ 870.454338] EXT4-fs (loop0): mounted filesystem without journal. Opts: (null) [ 870.456412] ext2 filesystem being mounted at /tmp/ltp-YQrzWZNEEy/jVhqum/mntpoint supports timestamps until 2038 (0x7fffffff) umount03.c:35: PASS: umount() fails as expected: EPERM (1) tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 1... tst_device.c:388: INFO: Likely gvfsd-trash is probing newly mounted fs, kill it to speed up tests. tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 2... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 3... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 4... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 5... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 6... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 7... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 8... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 9... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 10... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 11... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 12... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 13... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 14... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 15... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 16... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 17... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 18... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 19... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 20... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 21... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 22... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 23... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 24... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 25... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 26... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 27... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 28... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 29... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 30... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 31... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 32... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 33... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 34... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 35... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 36... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 37... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 38... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 39... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 40... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 41... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 42... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 43... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 44... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 45... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 46... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 47... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 48... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 49... tst_device.c:384: INFO: umount('mntpoint') failed with EBUSY, try 50... tst_device.c:394: WARN: Failed to umount('mntpoint') after 50 retries tst_tmpdir.c:337: WARN: tst_rmdir: rmobj(/tmp/ltp-YQrzWZNEEy/jVhqum) failed: remove(/tmp/ltp-YQrzWZNEEy/jVhqum/mntpoint) failed; errno=16: EBUSY Summary: passed 1 failed 0 skipped 0 warnings 1
mke2fs 1.43.8 (1-Jan-2018) /dev/loop0 is mounted; will not make a filesystem here! umount2_01 0 TINFO : Using test device LTP_DEV='/dev/loop0' umount2_01 0 TINFO : Formatting /dev/loop0 with ext2 opts='' extra opts='' umount2_01 1 TBROK : tst_mkfs.c:103: umount2_01.c:81: mkfs.ext2 failed with 1 umount2_01 2 TBROK : tst_mkfs.c:103: Remaining cases broken mke2fs 1.43.8 (1-Jan-2018) /dev/loop0 is mounted; will not make a filesystem here! umount2_02 0 TINFO : Using test device LTP_DEV='/dev/loop0' umount2_02 0 TINFO : Formatting /dev/loop0 with ext2 opts='' extra opts='' umount2_02 1 TBROK : tst_mkfs.c:103: umount2_02.c:121: mkfs.ext2 failed with 1 umount2_02 2 TBROK : tst_mkfs.c:103: Remaining cases broken mke2fs 1.43.8 (1-Jan-2018) /dev/loop0 is mounted; will not make a filesystem here! umount2_03 0 TINFO : Using test device LTP_DEV='/dev/loop0' umount2_03 0 TINFO : Formatting /dev/loop0 with ext2 opts='' extra opts='' umount2_03 1 TBROK : tst_mkfs.c:103: umount2_03.c:101: mkfs.ext2 failed with 1 umount2_03 2 TBROK : tst_mkfs.c:103: Remaining cases broken
mke2fs 1.43.8 (1-Jan-2018) /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:103: utime06.c:122: mkfs.ext2 failed with 1 utime06 2 TBROK : tst_mkfs.c:103: Remaining cases broken
Steps to reproduce: ------------------------- cd /opt/ltp ./runltp -s umount --> FAILS
Above command runs all umount tests.
Test case description, Verify that umount(2) returns -1 and sets errno to EPERM if the user is not the super-user. Test case link, https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/sysca...
full test log, https://lkft.validation.linaro.org/scheduler/job/1642287
-- Linaro LKFT https://lkft.linaro.org
On Thu, 6 Aug 2020 at 20:14, Naresh Kamboju naresh.kamboju@linaro.org wrote:
On Tue, 28 Jul 2020 at 22:04, Christoph Hellwig hch@lst.de wrote:
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@lst.de
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
<trim>
Regressions on linux next 20200803 tag kernel. LTP syscalls test umount03 mount a path for testing and umount failed and retired for 50 times and test exit with warning and following test cases using that mount path failed.
LTP syscalls tests failed list, * umount03 * umount2_01 * umount2_02 * umount2_03 * utime06 * copy_file_range01
The reported issue has been fixed in linux next 20200817 tag by below patch.
fs: fix a struct path leak in path_umount Make sure we also put the dentry and vfsmnt in the illegal flags and !may_umount cases. Fixes: 41525f56e256 ("fs: refactor ksys_umount")
- Naresh
-
Naresh Kamboju