diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2025-06-22 01:06:19 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2025-06-30 02:03:29 +0300 |
| commit | 406fea79992561f47fd3511dd8b7c8abeeff7045 (patch) | |
| tree | 077af00d0d9850fcfdf1fe0e4a96ebf65c42eed8 /include/linux | |
| parent | 493a4bebf5157a5da64e36f8d468ff80a859b563 (diff) | |
| download | linux-406fea79992561f47fd3511dd8b7c8abeeff7045.tar.xz | |
mount: separate the flags accessed only under namespace_sem
Several flags are updated and checked only under namespace_sem; we are
already making use of that when we are checking them without mount_lock,
but we have to hold mount_lock for all updates, which makes things
clumsier than they have to be.
Take MNT_SHARED, MNT_UNBINDABLE, MNT_MARKED and MNT_UMOUNT_CANDIDATE
into a separate field (->mnt_t_flags), renaming them to T_SHARED,
etc. to avoid confusion. All accesses must be under namespace_sem.
That changes locking requirements for mnt_change_propagation() and
set_mnt_shared() - only namespace_sem is needed now. The same goes
for SET_MNT_MARKED et.al.
There might be more flags moved from ->mnt_flags to that field;
this is just the initial set.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mount.h | 18 |
1 files changed, 2 insertions, 16 deletions
diff --git a/include/linux/mount.h b/include/linux/mount.h index 65fa8442c00a..5f9c053b0897 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -35,12 +35,8 @@ enum mount_flags { MNT_SHRINKABLE = 0x100, MNT_WRITE_HOLD = 0x200, - MNT_SHARED = 0x1000, /* if the vfsmount is a shared mount */ - MNT_UNBINDABLE = 0x2000, /* if the vfsmount is a unbindable mount */ - MNT_INTERNAL = 0x4000, - MNT_UMOUNT_CANDIDATE = 0x020000, MNT_LOCK_ATIME = 0x040000, MNT_LOCK_NOEXEC = 0x080000, MNT_LOCK_NOSUID = 0x100000, @@ -49,25 +45,15 @@ enum mount_flags { MNT_LOCKED = 0x800000, MNT_DOOMED = 0x1000000, MNT_SYNC_UMOUNT = 0x2000000, - MNT_MARKED = 0x4000000, MNT_UMOUNT = 0x8000000, - /* - * MNT_SHARED_MASK is the set of flags that should be cleared when a - * mount becomes shared. Currently, this is only the flag that says a - * mount cannot be bind mounted, since this is how we create a mount - * that shares events with another mount. If you add a new MNT_* - * flag, consider how it interacts with shared mounts. - */ - MNT_SHARED_MASK = MNT_UNBINDABLE, MNT_USER_SETTABLE_MASK = MNT_NOSUID | MNT_NODEV | MNT_NOEXEC | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME | MNT_READONLY | MNT_NOSYMFOLLOW, MNT_ATIME_MASK = MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME, - MNT_INTERNAL_FLAGS = MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | - MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | - MNT_LOCKED | MNT_UMOUNT_CANDIDATE, + MNT_INTERNAL_FLAGS = MNT_WRITE_HOLD | MNT_INTERNAL | MNT_DOOMED | + MNT_SYNC_UMOUNT | MNT_LOCKED }; struct vfsmount { |