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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 09:40:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 09:40:34 -0700
commite1ec517e18acc0aa9795ff92c15f0adabcb12db9 (patch)
treef3f135b962b3044e48784d061fdccdf561eae80d /fs/namespace.c
parentMerge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs (diff)
parentinit: add an init_dup helper (diff)
downloadlinux-dev-e1ec517e18acc0aa9795ff92c15f0adabcb12db9.tar.xz
linux-dev-e1ec517e18acc0aa9795ff92c15f0adabcb12db9.zip
Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull init and set_fs() cleanups from Al Viro: "Christoph's 'getting rid of ksys_...() uses under KERNEL_DS' series" * 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (50 commits) init: add an init_dup helper init: add an init_utimes helper init: add an init_stat helper init: add an init_mknod helper init: add an init_mkdir helper init: add an init_symlink helper init: add an init_link helper init: add an init_eaccess helper init: add an init_chmod helper init: add an init_chown helper init: add an init_chroot helper init: add an init_chdir helper init: add an init_rmdir helper init: add an init_unlink helper init: add an init_umount helper init: add an init_mount helper init: mark create_dev as __init init: mark console_on_rootfs as __init init: initialize ramdisk_execute_command at compile time devtmpfs: refactor devtmpfsd() ...
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c107
1 files changed, 53 insertions, 54 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 4a0f600a3328..016553d0f925 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)
+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;
}
+static 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);
@@ -3116,12 +3112,11 @@ char *copy_mount_string(const void __user *data)
* Therefore, if this magic number is present, it carries no information
* and must be discarded.
*/
-long do_mount(const char *dev_name, const char __user *dir_name,
+int path_mount(const char *dev_name, struct path *path,
const char *type_page, unsigned long flags, void *data_page)
{
- struct path path;
unsigned int mnt_flags = 0, sb_flags;
- int retval = 0;
+ int ret;
/* Discard magic */
if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
@@ -3134,19 +3129,13 @@ long do_mount(const char *dev_name, const char __user *dir_name,
if (flags & MS_NOUSER)
return -EINVAL;
- /* ... and get the mountpoint */
- retval = user_path_at(AT_FDCWD, dir_name, LOOKUP_FOLLOW, &path);
- if (retval)
- return retval;
-
- retval = security_sb_mount(dev_name, &path,
- type_page, flags, data_page);
- if (!retval && !may_mount())
- retval = -EPERM;
- if (!retval && (flags & SB_MANDLOCK) && !may_mandlock())
- retval = -EPERM;
- if (retval)
- goto dput_out;
+ ret = security_sb_mount(dev_name, path, type_page, flags, data_page);
+ if (ret)
+ return ret;
+ if (!may_mount())
+ return -EPERM;
+ if ((flags & SB_MANDLOCK) && !may_mandlock())
+ return -EPERM;
/* Default to relatime unless overriden */
if (!(flags & MS_NOATIME))
@@ -3173,7 +3162,7 @@ long do_mount(const char *dev_name, const char __user *dir_name,
((flags & (MS_NOATIME | MS_NODIRATIME | MS_RELATIME |
MS_STRICTATIME)) == 0)) {
mnt_flags &= ~MNT_ATIME_MASK;
- mnt_flags |= path.mnt->mnt_flags & MNT_ATIME_MASK;
+ mnt_flags |= path->mnt->mnt_flags & MNT_ATIME_MASK;
}
sb_flags = flags & (SB_RDONLY |
@@ -3186,22 +3175,32 @@ long do_mount(const char *dev_name, const char __user *dir_name,
SB_I_VERSION);
if ((flags & (MS_REMOUNT | MS_BIND)) == (MS_REMOUNT | MS_BIND))
- retval = do_reconfigure_mnt(&path, mnt_flags);
- else if (flags & MS_REMOUNT)
- retval = do_remount(&path, flags, sb_flags, mnt_flags,
- data_page);
- else if (flags & MS_BIND)
- retval = do_loopback(&path, dev_name, flags & MS_REC);
- else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
- retval = do_change_type(&path, flags);
- else if (flags & MS_MOVE)
- retval = do_move_mount_old(&path, dev_name);
- else
- retval = do_new_mount(&path, type_page, sb_flags, mnt_flags,
- dev_name, data_page);
-dput_out:
+ return do_reconfigure_mnt(path, mnt_flags);
+ if (flags & MS_REMOUNT)
+ return do_remount(path, flags, sb_flags, mnt_flags, data_page);
+ if (flags & MS_BIND)
+ return do_loopback(path, dev_name, flags & MS_REC);
+ if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
+ return do_change_type(path, flags);
+ if (flags & MS_MOVE)
+ return do_move_mount_old(path, dev_name);
+
+ return do_new_mount(path, type_page, sb_flags, mnt_flags, dev_name,
+ data_page);
+}
+
+long do_mount(const char *dev_name, const char __user *dir_name,
+ const char *type_page, unsigned long flags, void *data_page)
+{
+ struct path path;
+ int ret;
+
+ ret = user_path_at(AT_FDCWD, dir_name, LOOKUP_FOLLOW, &path);
+ if (ret)
+ return ret;
+ ret = path_mount(dev_name, &path, type_page, flags, data_page);
path_put(&path);
- return retval;
+ return ret;
}
static struct ucounts *inc_mnt_namespaces(struct user_namespace *ns)