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Kirill Smelkov
linux
Commits
84d17192
Commit
84d17192
authored
Mar 15, 2013
by
Al Viro
Browse files
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Plain Diff
get rid of full-hash scan on detaching vfsmounts
Signed-off-by:
Al Viro
<
viro@zeniv.linux.org.uk
>
parent
e9c5d8a5
Changes
4
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Side-by-side
Showing
4 changed files
with
149 additions
and
97 deletions
+149
-97
fs/mount.h
fs/mount.h
+7
-0
fs/namespace.c
fs/namespace.c
+137
-92
fs/pnode.c
fs/pnode.c
+3
-3
fs/pnode.h
fs/pnode.h
+2
-2
No files found.
fs/mount.h
View file @
84d17192
...
@@ -18,6 +18,12 @@ struct mnt_pcp {
...
@@ -18,6 +18,12 @@ struct mnt_pcp {
int
mnt_writers
;
int
mnt_writers
;
};
};
struct
mountpoint
{
struct
list_head
m_hash
;
struct
dentry
*
m_dentry
;
int
m_count
;
};
struct
mount
{
struct
mount
{
struct
list_head
mnt_hash
;
struct
list_head
mnt_hash
;
struct
mount
*
mnt_parent
;
struct
mount
*
mnt_parent
;
...
@@ -40,6 +46,7 @@ struct mount {
...
@@ -40,6 +46,7 @@ struct mount {
struct
list_head
mnt_slave
;
/* slave list entry */
struct
list_head
mnt_slave
;
/* slave list entry */
struct
mount
*
mnt_master
;
/* slave is on master->mnt_slave_list */
struct
mount
*
mnt_master
;
/* slave is on master->mnt_slave_list */
struct
mnt_namespace
*
mnt_ns
;
/* containing namespace */
struct
mnt_namespace
*
mnt_ns
;
/* containing namespace */
struct
mountpoint
*
mnt_mp
;
/* where is it mounted */
#ifdef CONFIG_FSNOTIFY
#ifdef CONFIG_FSNOTIFY
struct
hlist_head
mnt_fsnotify_marks
;
struct
hlist_head
mnt_fsnotify_marks
;
__u32
mnt_fsnotify_mask
;
__u32
mnt_fsnotify_mask
;
...
...
fs/namespace.c
View file @
84d17192
...
@@ -36,6 +36,7 @@ static int mnt_id_start = 0;
...
@@ -36,6 +36,7 @@ static int mnt_id_start = 0;
static
int
mnt_group_start
=
1
;
static
int
mnt_group_start
=
1
;
static
struct
list_head
*
mount_hashtable
__read_mostly
;
static
struct
list_head
*
mount_hashtable
__read_mostly
;
static
struct
list_head
*
mountpoint_hashtable
__read_mostly
;
static
struct
kmem_cache
*
mnt_cache
__read_mostly
;
static
struct
kmem_cache
*
mnt_cache
__read_mostly
;
static
struct
rw_semaphore
namespace_sem
;
static
struct
rw_semaphore
namespace_sem
;
...
@@ -605,6 +606,51 @@ struct vfsmount *lookup_mnt(struct path *path)
...
@@ -605,6 +606,51 @@ struct vfsmount *lookup_mnt(struct path *path)
}
}
}
}
static
struct
mountpoint
*
new_mountpoint
(
struct
dentry
*
dentry
)
{
struct
list_head
*
chain
=
mountpoint_hashtable
+
hash
(
NULL
,
dentry
);
struct
mountpoint
*
mp
;
list_for_each_entry
(
mp
,
chain
,
m_hash
)
{
if
(
mp
->
m_dentry
==
dentry
)
{
/* might be worth a WARN_ON() */
if
(
d_unlinked
(
dentry
))
return
ERR_PTR
(
-
ENOENT
);
mp
->
m_count
++
;
return
mp
;
}
}
mp
=
kmalloc
(
sizeof
(
struct
mountpoint
),
GFP_KERNEL
);
if
(
!
mp
)
return
ERR_PTR
(
-
ENOMEM
);
spin_lock
(
&
dentry
->
d_lock
);
if
(
d_unlinked
(
dentry
))
{
spin_unlock
(
&
dentry
->
d_lock
);
kfree
(
mp
);
return
ERR_PTR
(
-
ENOENT
);
}
dentry
->
d_flags
|=
DCACHE_MOUNTED
;
spin_unlock
(
&
dentry
->
d_lock
);
mp
->
m_dentry
=
dentry
;
mp
->
m_count
=
1
;
list_add
(
&
mp
->
m_hash
,
chain
);
return
mp
;
}
static
void
put_mountpoint
(
struct
mountpoint
*
mp
)
{
if
(
!--
mp
->
m_count
)
{
struct
dentry
*
dentry
=
mp
->
m_dentry
;
spin_lock
(
&
dentry
->
d_lock
);
dentry
->
d_flags
&=
~
DCACHE_MOUNTED
;
spin_unlock
(
&
dentry
->
d_lock
);
list_del
(
&
mp
->
m_hash
);
kfree
(
mp
);
}
}
static
inline
int
check_mnt
(
struct
mount
*
mnt
)
static
inline
int
check_mnt
(
struct
mount
*
mnt
)
{
{
return
mnt
->
mnt_ns
==
current
->
nsproxy
->
mnt_ns
;
return
mnt
->
mnt_ns
==
current
->
nsproxy
->
mnt_ns
;
...
@@ -632,27 +678,6 @@ static void __touch_mnt_namespace(struct mnt_namespace *ns)
...
@@ -632,27 +678,6 @@ static void __touch_mnt_namespace(struct mnt_namespace *ns)
}
}
}
}
/*
* Clear dentry's mounted state if it has no remaining mounts.
* vfsmount_lock must be held for write.
*/
static
void
dentry_reset_mounted
(
struct
dentry
*
dentry
)
{
unsigned
u
;
for
(
u
=
0
;
u
<
HASH_SIZE
;
u
++
)
{
struct
mount
*
p
;
list_for_each_entry
(
p
,
&
mount_hashtable
[
u
],
mnt_hash
)
{
if
(
p
->
mnt_mountpoint
==
dentry
)
return
;
}
}
spin_lock
(
&
dentry
->
d_lock
);
dentry
->
d_flags
&=
~
DCACHE_MOUNTED
;
spin_unlock
(
&
dentry
->
d_lock
);
}
/*
/*
* vfsmount lock must be held for write
* vfsmount lock must be held for write
*/
*/
...
@@ -664,32 +689,35 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
...
@@ -664,32 +689,35 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
mnt
->
mnt_mountpoint
=
mnt
->
mnt
.
mnt_root
;
mnt
->
mnt_mountpoint
=
mnt
->
mnt
.
mnt_root
;
list_del_init
(
&
mnt
->
mnt_child
);
list_del_init
(
&
mnt
->
mnt_child
);
list_del_init
(
&
mnt
->
mnt_hash
);
list_del_init
(
&
mnt
->
mnt_hash
);
dentry_reset_mounted
(
old_path
->
dentry
);
put_mountpoint
(
mnt
->
mnt_mp
);
mnt
->
mnt_mp
=
NULL
;
}
}
/*
/*
* vfsmount lock must be held for write
* vfsmount lock must be held for write
*/
*/
void
mnt_set_mountpoint
(
struct
mount
*
mnt
,
struct
dentry
*
dentry
,
void
mnt_set_mountpoint
(
struct
mount
*
mnt
,
struct
mountpoint
*
mp
,
struct
mount
*
child_mnt
)
struct
mount
*
child_mnt
)
{
{
mp
->
m_count
++
;
mnt_add_count
(
mnt
,
1
);
/* essentially, that's mntget */
mnt_add_count
(
mnt
,
1
);
/* essentially, that's mntget */
child_mnt
->
mnt_mountpoint
=
dget
(
dentry
);
child_mnt
->
mnt_mountpoint
=
dget
(
mp
->
m_
dentry
);
child_mnt
->
mnt_parent
=
mnt
;
child_mnt
->
mnt_parent
=
mnt
;
spin_lock
(
&
dentry
->
d_lock
);
child_mnt
->
mnt_mp
=
mp
;
dentry
->
d_flags
|=
DCACHE_MOUNTED
;
spin_unlock
(
&
dentry
->
d_lock
);
}
}
/*
/*
* vfsmount lock must be held for write
* vfsmount lock must be held for write
*/
*/
static
void
attach_mnt
(
struct
mount
*
mnt
,
struct
path
*
path
)
static
void
attach_mnt
(
struct
mount
*
mnt
,
struct
mount
*
parent
,
struct
mountpoint
*
mp
)
{
{
mnt_set_mountpoint
(
real_mount
(
path
->
mnt
),
path
->
dentry
,
mnt
);
mnt_set_mountpoint
(
parent
,
mp
,
mnt
);
list_add_tail
(
&
mnt
->
mnt_hash
,
mount_hashtable
+
list_add_tail
(
&
mnt
->
mnt_hash
,
mount_hashtable
+
hash
(
path
->
mnt
,
path
->
dentry
));
hash
(
&
parent
->
mnt
,
mp
->
m_
dentry
));
list_add_tail
(
&
mnt
->
mnt_child
,
&
real_mount
(
path
->
mnt
)
->
mnt_mounts
);
list_add_tail
(
&
mnt
->
mnt_child
,
&
parent
->
mnt_mounts
);
}
}
/*
/*
...
@@ -1138,7 +1166,8 @@ void umount_tree(struct mount *mnt, int propagate, struct list_head *kill)
...
@@ -1138,7 +1166,8 @@ void umount_tree(struct mount *mnt, int propagate, struct list_head *kill)
list_del_init
(
&
p
->
mnt_child
);
list_del_init
(
&
p
->
mnt_child
);
if
(
mnt_has_parent
(
p
))
{
if
(
mnt_has_parent
(
p
))
{
p
->
mnt_parent
->
mnt_ghosts
++
;
p
->
mnt_parent
->
mnt_ghosts
++
;
dentry_reset_mounted
(
p
->
mnt_mountpoint
);
put_mountpoint
(
p
->
mnt_mp
);
p
->
mnt_mp
=
NULL
;
}
}
change_mnt_propagation
(
p
,
MS_PRIVATE
);
change_mnt_propagation
(
p
,
MS_PRIVATE
);
}
}
...
@@ -1323,8 +1352,7 @@ static bool mnt_ns_loop(struct path *path)
...
@@ -1323,8 +1352,7 @@ static bool mnt_ns_loop(struct path *path)
struct
mount
*
copy_tree
(
struct
mount
*
mnt
,
struct
dentry
*
dentry
,
struct
mount
*
copy_tree
(
struct
mount
*
mnt
,
struct
dentry
*
dentry
,
int
flag
)
int
flag
)
{
{
struct
mount
*
res
,
*
p
,
*
q
,
*
r
;
struct
mount
*
res
,
*
p
,
*
q
,
*
r
,
*
parent
;
struct
path
path
;
if
(
!
(
flag
&
CL_COPY_ALL
)
&&
IS_MNT_UNBINDABLE
(
mnt
))
if
(
!
(
flag
&
CL_COPY_ALL
)
&&
IS_MNT_UNBINDABLE
(
mnt
))
return
ERR_PTR
(
-
EINVAL
);
return
ERR_PTR
(
-
EINVAL
);
...
@@ -1351,14 +1379,13 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
...
@@ -1351,14 +1379,13 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
q
=
q
->
mnt_parent
;
q
=
q
->
mnt_parent
;
}
}
p
=
s
;
p
=
s
;
path
.
mnt
=
&
q
->
mnt
;
parent
=
q
;
path
.
dentry
=
p
->
mnt_mountpoint
;
q
=
clone_mnt
(
p
,
p
->
mnt
.
mnt_root
,
flag
);
q
=
clone_mnt
(
p
,
p
->
mnt
.
mnt_root
,
flag
);
if
(
IS_ERR
(
q
))
if
(
IS_ERR
(
q
))
goto
out
;
goto
out
;
br_write_lock
(
&
vfsmount_lock
);
br_write_lock
(
&
vfsmount_lock
);
list_add_tail
(
&
q
->
mnt_list
,
&
res
->
mnt_list
);
list_add_tail
(
&
q
->
mnt_list
,
&
res
->
mnt_list
);
attach_mnt
(
q
,
&
path
);
attach_mnt
(
q
,
parent
,
p
->
mnt_mp
);
br_write_unlock
(
&
vfsmount_lock
);
br_write_unlock
(
&
vfsmount_lock
);
}
}
}
}
...
@@ -1505,11 +1532,11 @@ static int invent_group_ids(struct mount *mnt, bool recurse)
...
@@ -1505,11 +1532,11 @@ static int invent_group_ids(struct mount *mnt, bool recurse)
* in allocations.
* in allocations.
*/
*/
static
int
attach_recursive_mnt
(
struct
mount
*
source_mnt
,
static
int
attach_recursive_mnt
(
struct
mount
*
source_mnt
,
struct
path
*
path
,
struct
path
*
parent_path
)
struct
mount
*
dest_mnt
,
struct
mountpoint
*
dest_mp
,
struct
path
*
parent_path
)
{
{
LIST_HEAD
(
tree_list
);
LIST_HEAD
(
tree_list
);
struct
mount
*
dest_mnt
=
real_mount
(
path
->
mnt
);
struct
dentry
*
dest_dentry
=
path
->
dentry
;
struct
mount
*
child
,
*
p
;
struct
mount
*
child
,
*
p
;
int
err
;
int
err
;
...
@@ -1518,7 +1545,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
...
@@ -1518,7 +1545,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
if
(
err
)
if
(
err
)
goto
out
;
goto
out
;
}
}
err
=
propagate_mnt
(
dest_mnt
,
dest_
dentry
,
source_mnt
,
&
tree_list
);
err
=
propagate_mnt
(
dest_mnt
,
dest_
mp
,
source_mnt
,
&
tree_list
);
if
(
err
)
if
(
err
)
goto
out_cleanup_ids
;
goto
out_cleanup_ids
;
...
@@ -1530,10 +1557,10 @@ static int attach_recursive_mnt(struct mount *source_mnt,
...
@@ -1530,10 +1557,10 @@ static int attach_recursive_mnt(struct mount *source_mnt,
}
}
if
(
parent_path
)
{
if
(
parent_path
)
{
detach_mnt
(
source_mnt
,
parent_path
);
detach_mnt
(
source_mnt
,
parent_path
);
attach_mnt
(
source_mnt
,
path
);
attach_mnt
(
source_mnt
,
dest_mnt
,
dest_mp
);
touch_mnt_namespace
(
source_mnt
->
mnt_ns
);
touch_mnt_namespace
(
source_mnt
->
mnt_ns
);
}
else
{
}
else
{
mnt_set_mountpoint
(
dest_mnt
,
dest_
dentry
,
source_mnt
);
mnt_set_mountpoint
(
dest_mnt
,
dest_
mp
,
source_mnt
);
commit_tree
(
source_mnt
);
commit_tree
(
source_mnt
);
}
}
...
@@ -1552,46 +1579,53 @@ static int attach_recursive_mnt(struct mount *source_mnt,
...
@@ -1552,46 +1579,53 @@ static int attach_recursive_mnt(struct mount *source_mnt,
return
err
;
return
err
;
}
}
static
int
lock_mount
(
struct
path
*
path
)
static
struct
mountpoint
*
lock_mount
(
struct
path
*
path
)
{
{
struct
vfsmount
*
mnt
;
struct
vfsmount
*
mnt
;
struct
dentry
*
dentry
=
path
->
dentry
;
retry:
retry:
mutex_lock
(
&
path
->
dentry
->
d_inode
->
i_mutex
);
mutex_lock
(
&
dentry
->
d_inode
->
i_mutex
);
if
(
unlikely
(
cant_mount
(
path
->
dentry
)))
{
if
(
unlikely
(
cant_mount
(
dentry
)))
{
mutex_unlock
(
&
path
->
dentry
->
d_inode
->
i_mutex
);
mutex_unlock
(
&
dentry
->
d_inode
->
i_mutex
);
return
-
ENOENT
;
return
ERR_PTR
(
-
ENOENT
)
;
}
}
down_write
(
&
namespace_sem
);
down_write
(
&
namespace_sem
);
mnt
=
lookup_mnt
(
path
);
mnt
=
lookup_mnt
(
path
);
if
(
likely
(
!
mnt
))
if
(
likely
(
!
mnt
))
{
return
0
;
struct
mountpoint
*
mp
=
new_mountpoint
(
dentry
);
if
(
IS_ERR
(
mp
))
{
up_write
(
&
namespace_sem
);
mutex_unlock
(
&
dentry
->
d_inode
->
i_mutex
);
return
mp
;
}
return
mp
;
}
up_write
(
&
namespace_sem
);
up_write
(
&
namespace_sem
);
mutex_unlock
(
&
path
->
dentry
->
d_inode
->
i_mutex
);
mutex_unlock
(
&
path
->
dentry
->
d_inode
->
i_mutex
);
path_put
(
path
);
path_put
(
path
);
path
->
mnt
=
mnt
;
path
->
mnt
=
mnt
;
path
->
dentry
=
dget
(
mnt
->
mnt_root
);
dentry
=
path
->
dentry
=
dget
(
mnt
->
mnt_root
);
goto
retry
;
goto
retry
;
}
}
static
void
unlock_mount
(
struct
path
*
path
)
static
void
unlock_mount
(
struct
mountpoint
*
where
)
{
{
struct
dentry
*
dentry
=
where
->
m_dentry
;
put_mountpoint
(
where
);
up_write
(
&
namespace_sem
);
up_write
(
&
namespace_sem
);
mutex_unlock
(
&
path
->
dentry
->
d_inode
->
i_mutex
);
mutex_unlock
(
&
dentry
->
d_inode
->
i_mutex
);
}
}
static
int
graft_tree
(
struct
mount
*
mnt
,
struct
path
*
path
)
static
int
graft_tree
(
struct
mount
*
mnt
,
struct
mount
*
p
,
struct
mountpoint
*
mp
)
{
{
if
(
mnt
->
mnt
.
mnt_sb
->
s_flags
&
MS_NOUSER
)
if
(
mnt
->
mnt
.
mnt_sb
->
s_flags
&
MS_NOUSER
)
return
-
EINVAL
;
return
-
EINVAL
;
if
(
S_ISDIR
(
path
->
dentry
->
d_inode
->
i_mode
)
!=
if
(
S_ISDIR
(
mp
->
m_
dentry
->
d_inode
->
i_mode
)
!=
S_ISDIR
(
mnt
->
mnt
.
mnt_root
->
d_inode
->
i_mode
))
S_ISDIR
(
mnt
->
mnt
.
mnt_root
->
d_inode
->
i_mode
))
return
-
ENOTDIR
;
return
-
ENOTDIR
;
if
(
d_unlinked
(
path
->
dentry
))
return
attach_recursive_mnt
(
mnt
,
p
,
mp
,
NULL
);
return
-
ENOENT
;
return
attach_recursive_mnt
(
mnt
,
path
,
NULL
);
}
}
/*
/*
...
@@ -1654,7 +1688,8 @@ static int do_loopback(struct path *path, const char *old_name,
...
@@ -1654,7 +1688,8 @@ static int do_loopback(struct path *path, const char *old_name,
{
{
LIST_HEAD
(
umount_list
);
LIST_HEAD
(
umount_list
);
struct
path
old_path
;
struct
path
old_path
;
struct
mount
*
mnt
=
NULL
,
*
old
;
struct
mount
*
mnt
=
NULL
,
*
old
,
*
parent
;
struct
mountpoint
*
mp
;
int
err
;
int
err
;
if
(
!
old_name
||
!*
old_name
)
if
(
!
old_name
||
!*
old_name
)
return
-
EINVAL
;
return
-
EINVAL
;
...
@@ -1666,17 +1701,19 @@ static int do_loopback(struct path *path, const char *old_name,
...
@@ -1666,17 +1701,19 @@ static int do_loopback(struct path *path, const char *old_name,
if
(
mnt_ns_loop
(
&
old_path
))
if
(
mnt_ns_loop
(
&
old_path
))
goto
out
;
goto
out
;
err
=
lock_mount
(
path
);
mp
=
lock_mount
(
path
);
if
(
err
)
err
=
PTR_ERR
(
mp
);
if
(
IS_ERR
(
mp
))
goto
out
;
goto
out
;
old
=
real_mount
(
old_path
.
mnt
);
old
=
real_mount
(
old_path
.
mnt
);
parent
=
real_mount
(
path
->
mnt
);
err
=
-
EINVAL
;
err
=
-
EINVAL
;
if
(
IS_MNT_UNBINDABLE
(
old
))
if
(
IS_MNT_UNBINDABLE
(
old
))
goto
out2
;
goto
out2
;
if
(
!
check_mnt
(
real_mount
(
path
->
mnt
)
)
||
!
check_mnt
(
old
))
if
(
!
check_mnt
(
parent
)
||
!
check_mnt
(
old
))
goto
out2
;
goto
out2
;
if
(
recurse
)
if
(
recurse
)
...
@@ -1689,14 +1726,14 @@ static int do_loopback(struct path *path, const char *old_name,
...
@@ -1689,14 +1726,14 @@ static int do_loopback(struct path *path, const char *old_name,
goto
out2
;
goto
out2
;
}
}
err
=
graft_tree
(
mnt
,
pa
th
);
err
=
graft_tree
(
mnt
,
pa
rent
,
mp
);
if
(
err
)
{
if
(
err
)
{
br_write_lock
(
&
vfsmount_lock
);
br_write_lock
(
&
vfsmount_lock
);
umount_tree
(
mnt
,
0
,
&
umount_list
);
umount_tree
(
mnt
,
0
,
&
umount_list
);
br_write_unlock
(
&
vfsmount_lock
);
br_write_unlock
(
&
vfsmount_lock
);
}
}
out2:
out2:
unlock_mount
(
path
);
unlock_mount
(
mp
);
release_mounts
(
&
umount_list
);
release_mounts
(
&
umount_list
);
out:
out:
path_put
(
&
old_path
);
path_put
(
&
old_path
);
...
@@ -1779,6 +1816,7 @@ static int do_move_mount(struct path *path, const char *old_name)
...
@@ -1779,6 +1816,7 @@ static int do_move_mount(struct path *path, const char *old_name)
struct
path
old_path
,
parent_path
;
struct
path
old_path
,
parent_path
;
struct
mount
*
p
;
struct
mount
*
p
;
struct
mount
*
old
;
struct
mount
*
old
;
struct
mountpoint
*
mp
;
int
err
;
int
err
;
if
(
!
old_name
||
!*
old_name
)
if
(
!
old_name
||
!*
old_name
)
return
-
EINVAL
;
return
-
EINVAL
;
...
@@ -1786,8 +1824,9 @@ static int do_move_mount(struct path *path, const char *old_name)
...
@@ -1786,8 +1824,9 @@ static int do_move_mount(struct path *path, const char *old_name)
if
(
err
)
if
(
err
)
return
err
;
return
err
;
err
=
lock_mount
(
path
);
mp
=
lock_mount
(
path
);
if
(
err
<
0
)
err
=
PTR_ERR
(
mp
);
if
(
IS_ERR
(
mp
))
goto
out
;
goto
out
;
old
=
real_mount
(
old_path
.
mnt
);
old
=
real_mount
(
old_path
.
mnt
);
...
@@ -1797,9 +1836,6 @@ static int do_move_mount(struct path *path, const char *old_name)
...
@@ -1797,9 +1836,6 @@ static int do_move_mount(struct path *path, const char *old_name)
if
(
!
check_mnt
(
p
)
||
!
check_mnt
(
old
))
if
(
!
check_mnt
(
p
)
||
!
check_mnt
(
old
))
goto
out1
;
goto
out1
;
if
(
d_unlinked
(
path
->
dentry
))
goto
out1
;
err
=
-
EINVAL
;
err
=
-
EINVAL
;
if
(
old_path
.
dentry
!=
old_path
.
mnt
->
mnt_root
)
if
(
old_path
.
dentry
!=
old_path
.
mnt
->
mnt_root
)
goto
out1
;
goto
out1
;
...
@@ -1826,7 +1862,7 @@ static int do_move_mount(struct path *path, const char *old_name)
...
@@ -1826,7 +1862,7 @@ static int do_move_mount(struct path *path, const char *old_name)
if
(
p
==
old
)
if
(
p
==
old
)
goto
out1
;
goto
out1
;
err
=
attach_recursive_mnt
(
old
,
path
,
&
parent_path
);
err
=
attach_recursive_mnt
(
old
,
real_mount
(
path
->
mnt
),
mp
,
&
parent_path
);
if
(
err
)
if
(
err
)
goto
out1
;
goto
out1
;
...
@@ -1834,7 +1870,7 @@ static int do_move_mount(struct path *path, const char *old_name)
...
@@ -1834,7 +1870,7 @@ static int do_move_mount(struct path *path, const char *old_name)
* automatically */
* automatically */
list_del_init
(
&
old
->
mnt_expire
);
list_del_init
(
&
old
->
mnt_expire
);
out1:
out1:
unlock_mount
(
path
);
unlock_mount
(
mp
);
out:
out:
if
(
!
err
)
if
(
!
err
)
path_put
(
&
parent_path
);
path_put
(
&
parent_path
);
...
@@ -1870,21 +1906,24 @@ static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
...
@@ -1870,21 +1906,24 @@ static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
*/
*/
static
int
do_add_mount
(
struct
mount
*
newmnt
,
struct
path
*
path
,
int
mnt_flags
)
static
int
do_add_mount
(
struct
mount
*
newmnt
,
struct
path
*
path
,
int
mnt_flags
)
{
{
struct
mountpoint
*
mp
;
struct
mount
*
parent
;
int
err
;
int
err
;
mnt_flags
&=
~
(
MNT_SHARED
|
MNT_WRITE_HOLD
|
MNT_INTERNAL
);
mnt_flags
&=
~
(
MNT_SHARED
|
MNT_WRITE_HOLD
|
MNT_INTERNAL
);
err
=
lock_mount
(
path
);
mp
=
lock_mount
(
path
);
if
(
err
)
if
(
IS_ERR
(
mp
)
)
return
err
;
return
PTR_ERR
(
mp
)
;
parent
=
real_mount
(
path
->
mnt
);
err
=
-
EINVAL
;
err
=
-
EINVAL
;
if
(
unlikely
(
!
check_mnt
(
real_mount
(
path
->
mnt
)
)))
{
if
(
unlikely
(
!
check_mnt
(
parent
)))
{
/* that's acceptable only for automounts done in private ns */
/* that's acceptable only for automounts done in private ns */
if
(
!
(
mnt_flags
&
MNT_SHRINKABLE
))
if
(
!
(
mnt_flags
&
MNT_SHRINKABLE
))
goto
unlock
;
goto
unlock
;
/* ... and for those we'd better have mountpoint still alive */
/* ... and for those we'd better have mountpoint still alive */
if
(
!
real_mount
(
path
->
mnt
)
->
mnt_ns
)
if
(
!
parent
->
mnt_ns
)
goto
unlock
;
goto
unlock
;
}
}
...
@@ -1899,10 +1938,10 @@ static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags)
...
@@ -1899,10 +1938,10 @@ static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags)
goto
unlock
;
goto
unlock
;
newmnt
->
mnt
.
mnt_flags
=
mnt_flags
;
newmnt
->
mnt
.
mnt_flags
=
mnt_flags
;
err
=
graft_tree
(
newmnt
,
pa
th
);
err
=
graft_tree
(
newmnt
,
pa
rent
,
mp
);
unlock:
unlock:
unlock_mount
(
path
);
unlock_mount
(
mp
);
return
err
;
return
err
;
}
}
...
@@ -2543,7 +2582,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
...
@@ -2543,7 +2582,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
const
char
__user
*
,
put_old
)
const
char
__user
*
,
put_old
)
{
{
struct
path
new
,
old
,
parent_path
,
root_parent
,
root
;
struct
path
new
,
old
,
parent_path
,
root_parent
,
root
;
struct
mount
*
new_mnt
,
*
root_mnt
;
struct
mount
*
new_mnt
,
*
root_mnt
,
*
old_mnt
;
struct
mountpoint
*
old_mp
,
*
root_mp
;
int
error
;
int
error
;
if
(
!
may_mount
())
if
(
!
may_mount
())
...
@@ -2562,14 +2602,16 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
...
@@ -2562,14 +2602,16 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
goto
out2
;
goto
out2
;
get_fs_root
(
current
->
fs
,
&
root
);
get_fs_root
(
current
->
fs
,
&
root
);
error
=
lock_mount
(
&
old
);
old_mp
=
lock_mount
(
&
old
);
if
(
error
)
error
=
PTR_ERR
(
old_mp
);
if
(
IS_ERR
(
old_mp
))
goto
out3
;
goto
out3
;
error
=
-
EINVAL
;
error
=
-
EINVAL
;
new_mnt
=
real_mount
(
new
.
mnt
);
new_mnt
=
real_mount
(
new
.
mnt
);
root_mnt
=
real_mount
(
root
.
mnt
);
root_mnt
=
real_mount
(
root
.
mnt
);
if
(
IS_MNT_SHARED
(
real_mount
(
old
.
mnt
))
||
old_mnt
=
real_mount
(
old
.
mnt
);
if
(
IS_MNT_SHARED
(
old_mnt
)
||
IS_MNT_SHARED
(
new_mnt
->
mnt_parent
)
||
IS_MNT_SHARED
(
new_mnt
->
mnt_parent
)
||
IS_MNT_SHARED
(
root_mnt
->
mnt_parent
))
IS_MNT_SHARED
(
root_mnt
->
mnt_parent
))
goto
out4
;
goto
out4
;
...
@@ -2578,37 +2620,37 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
...
@@ -2578,37 +2620,37 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
error
=
-
ENOENT
;
error
=
-
ENOENT
;
if
(
d_unlinked
(
new
.
dentry
))
if
(
d_unlinked
(
new
.
dentry
))
goto
out4
;
goto
out4
;
if
(
d_unlinked
(
old
.
dentry
))
goto
out4
;
error
=
-
EBUSY
;
error
=
-
EBUSY
;
if
(
new
.
mnt
==
root
.
mnt
||
if
(
new_mnt
==
root_mnt
||
old_mnt
==
root_mnt
)
old
.
mnt
==
root
.
mnt
)
goto
out4
;
/* loop, on the same file system */
goto
out4
;
/* loop, on the same file system */
error
=
-
EINVAL
;
error
=
-
EINVAL
;
if
(
root
.
mnt
->
mnt_root
!=
root
.
dentry
)
if
(
root
.
mnt
->
mnt_root
!=
root
.
dentry
)
goto
out4
;
/* not a mountpoint */
goto
out4
;
/* not a mountpoint */
if
(
!
mnt_has_parent
(
root_mnt
))
if
(
!
mnt_has_parent
(
root_mnt
))
goto
out4
;
/* not attached */
goto
out4
;
/* not attached */
root_mp
=
root_mnt
->
mnt_mp
;
if
(
new
.
mnt
->
mnt_root
!=
new
.
dentry
)
if
(
new
.
mnt
->
mnt_root
!=
new
.
dentry
)
goto
out4
;
/* not a mountpoint */
goto
out4
;
/* not a mountpoint */
if
(
!
mnt_has_parent
(
new_mnt
))
if
(
!
mnt_has_parent
(
new_mnt
))
goto
out4
;
/* not attached */
goto
out4
;
/* not attached */
/* make sure we can reach put_old from new_root */
/* make sure we can reach put_old from new_root */
if
(
!
is_path_reachable
(
real_mount
(
old
.
mnt
)
,
old
.
dentry
,
&
new
))
if
(
!
is_path_reachable
(
old_mnt
,
old
.
dentry
,
&
new
))
goto
out4
;
goto
out4
;
root_mp
->
m_count
++
;
/* pin it so it won't go away */
br_write_lock
(
&
vfsmount_lock
);
br_write_lock
(
&
vfsmount_lock
);
detach_mnt
(
new_mnt
,
&
parent_path
);
detach_mnt
(
new_mnt
,
&
parent_path
);
detach_mnt
(
root_mnt
,
&
root_parent
);
detach_mnt
(
root_mnt
,
&
root_parent
);
/* mount old root on put_old */
/* mount old root on put_old */
attach_mnt
(
root_mnt
,
&
old
);
attach_mnt
(
root_mnt
,
old_mnt
,
old_mp
);
/* mount new_root on / */
/* mount new_root on / */
attach_mnt
(
new_mnt
,
&
root_parent
);
attach_mnt
(
new_mnt
,
real_mount
(
root_parent
.
mnt
),
root_mp
);
touch_mnt_namespace
(
current
->
nsproxy
->
mnt_ns
);
touch_mnt_namespace
(
current
->
nsproxy
->
mnt_ns
);
br_write_unlock
(
&
vfsmount_lock
);
br_write_unlock
(
&
vfsmount_lock
);
chroot_fs_refs
(
&
root
,
&
new
);
chroot_fs_refs
(
&
root
,
&
new
);
put_mountpoint
(
root_mp
);
error
=
0
;
error
=
0
;
out4:
out4:
unlock_mount
(
&
old
);
unlock_mount
(
old_mp
);
if
(
!
error
)
{
if
(
!
error
)
{
path_put
(
&
root_parent
);
path_put
(
&
root_parent
);
path_put
(
&
parent_path
);
path_put
(
&
parent_path
);
...
@@ -2663,14 +2705,17 @@ void __init mnt_init(void)
...
@@ -2663,14 +2705,17 @@ void __init mnt_init(void)
0
,
SLAB_HWCACHE_ALIGN
|
SLAB_PANIC
,
NULL
);
0
,
SLAB_HWCACHE_ALIGN
|
SLAB_PANIC
,
NULL
);
mount_hashtable
=
(
struct
list_head
*
)
__get_free_page
(
GFP_ATOMIC
);
mount_hashtable
=
(
struct
list_head
*
)
__get_free_page
(
GFP_ATOMIC
);
mountpoint_hashtable
=
(
struct
list_head
*
)
__get_free_page
(
GFP_ATOMIC
);
if
(
!
mount_hashtable
)
if
(
!
mount_hashtable
||
!
mountpoint_hashtable
)
panic
(
"Failed to allocate mount hash table
\n
"
);
panic
(
"Failed to allocate mount hash table
\n
"
);
printk
(
KERN_INFO
"Mount-cache hash table entries: %lu
\n
"
,
HASH_SIZE
);
printk
(
KERN_INFO
"Mount-cache hash table entries: %lu
\n
"
,
HASH_SIZE
);
for
(
u
=
0
;
u
<
HASH_SIZE
;
u
++
)
for
(
u
=
0
;
u
<
HASH_SIZE
;
u
++
)
INIT_LIST_HEAD
(
&
mount_hashtable
[
u
]);
INIT_LIST_HEAD
(
&
mount_hashtable
[
u
]);
for
(
u
=
0
;
u
<
HASH_SIZE
;
u
++
)
INIT_LIST_HEAD
(
&
mountpoint_hashtable
[
u
]);
br_lock_init
(
&
vfsmount_lock
);
br_lock_init
(
&
vfsmount_lock
);
...
...
fs/pnode.c
View file @
84d17192
...
@@ -217,7 +217,7 @@ static struct mount *get_source(struct mount *dest,
...
@@ -217,7 +217,7 @@ static struct mount *get_source(struct mount *dest,
* @source_mnt: source mount.
* @source_mnt: source mount.
* @tree_list : list of heads of trees to be attached.
* @tree_list : list of heads of trees to be attached.
*/
*/
int
propagate_mnt
(
struct
mount
*
dest_mnt
,
struct
dentry
*
dest_dentry
,
int
propagate_mnt
(
struct
mount
*
dest_mnt
,
struct
mountpoint
*
dest_mp
,
struct
mount
*
source_mnt
,
struct
list_head
*
tree_list
)
struct
mount
*
source_mnt
,
struct
list_head
*
tree_list
)
{
{
struct
mount
*
m
,
*
child
;
struct
mount
*
m
,
*
child
;
...
@@ -244,8 +244,8 @@ int propagate_mnt(struct mount *dest_mnt, struct dentry *dest_dentry,
...
@@ -244,8 +244,8 @@ int propagate_mnt(struct mount *dest_mnt, struct dentry *dest_dentry,
goto
out
;
goto
out
;
}
}
if
(
is_subdir
(
dest_dentry
,
m
->
mnt
.
mnt_root
))
{
if
(
is_subdir
(
dest_
mp
->
m_
dentry
,
m
->
mnt
.
mnt_root
))
{
mnt_set_mountpoint
(
m
,
dest_
dentry
,
child
);
mnt_set_mountpoint
(
m
,
dest_
mp
,
child
);
list_add_tail
(
&
child
->
mnt_hash
,
tree_list
);
list_add_tail
(
&
child
->
mnt_hash
,
tree_list
);
}
else
{
}
else
{
/*
/*
...
...
fs/pnode.h
View file @
84d17192
...
@@ -31,14 +31,14 @@ static inline void set_mnt_shared(struct mount *mnt)
...
@@ -31,14 +31,14 @@ static inline void set_mnt_shared(struct mount *mnt)
}
}
void
change_mnt_propagation
(
struct
mount
*
,
int
);
void
change_mnt_propagation
(
struct
mount
*
,
int
);
int
propagate_mnt
(
struct
mount
*
,
struct
dentry
*
,
struct
mount
*
,
int
propagate_mnt
(
struct
mount
*
,
struct
mountpoint
*
,
struct
mount
*
,
struct
list_head
*
);
struct
list_head
*
);
int
propagate_umount
(
struct
list_head
*
);
int
propagate_umount
(
struct
list_head
*
);
int
propagate_mount_busy
(
struct
mount
*
,
int
);
int
propagate_mount_busy
(
struct
mount
*
,
int
);
void
mnt_release_group_id
(
struct
mount
*
);
void
mnt_release_group_id
(
struct
mount
*
);
int
get_dominating_id
(
struct
mount
*
mnt
,
const
struct
path
*
root
);
int
get_dominating_id
(
struct
mount
*
mnt
,
const
struct
path
*
root
);
unsigned
int
mnt_get_count
(
struct
mount
*
mnt
);
unsigned
int
mnt_get_count
(
struct
mount
*
mnt
);
void
mnt_set_mountpoint
(
struct
mount
*
,
struct
dentry
*
,
void
mnt_set_mountpoint
(
struct
mount
*
,
struct
mountpoint
*
,
struct
mount
*
);
struct
mount
*
);
void
release_mounts
(
struct
list_head
*
);
void
release_mounts
(
struct
list_head
*
);
void
umount_tree
(
struct
mount
*
,
int
,
struct
list_head
*
);
void
umount_tree
(
struct
mount
*
,
int
,
struct
list_head
*
);
...
...
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