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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 13:51:11 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 13:51:11 -0400
commitf539abece1b7e36fae6add4f9ea29203d40badcb (patch)
tree786c08f3131a1871ece13343c3fa3832930c1408
parent3f6f7e6d57b8a0ae2810ae7aac70c51b6f2a6304 (diff)
parent24ff6663ccfdaf088dfa7acae489cb11ed4f43c4 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: fs: call security_d_instantiate in d_obtain_alias V2 lose 'mounting_here' argument in ->d_manage() don't pass 'mounting_here' flag to follow_down() change the locking order for namespace_sem fix deadlock in pivot_root() vfs: split off vfsmount-related parts of vfs_kern_mount() Some fixes for pstore kill simple_set_mnt()
-rw-r--r--Documentation/filesystems/vfs.txt6
-rw-r--r--fs/autofs4/root.c6
-rw-r--r--fs/dcache.c3
-rw-r--r--fs/internal.h5
-rw-r--r--fs/namei.c9
-rw-r--r--fs/namespace.c292
-rw-r--r--fs/nfsd/vfs.c2
-rw-r--r--fs/pstore/inode.c116
-rw-r--r--fs/super.c96
-rw-r--r--include/linux/dcache.h2
-rw-r--r--include/linux/fs.h1
-rw-r--r--include/linux/namei.h2
12 files changed, 271 insertions, 269 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index ef0714aa8e40..306f0ae8df09 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -873,7 +873,7 @@ struct dentry_operations {
873 void (*d_iput)(struct dentry *, struct inode *); 873 void (*d_iput)(struct dentry *, struct inode *);
874 char *(*d_dname)(struct dentry *, char *, int); 874 char *(*d_dname)(struct dentry *, char *, int);
875 struct vfsmount *(*d_automount)(struct path *); 875 struct vfsmount *(*d_automount)(struct path *);
876 int (*d_manage)(struct dentry *, bool, bool); 876 int (*d_manage)(struct dentry *, bool);
877}; 877};
878 878
879 d_revalidate: called when the VFS needs to revalidate a dentry. This 879 d_revalidate: called when the VFS needs to revalidate a dentry. This
@@ -969,10 +969,6 @@ struct dentry_operations {
969 mounted on it and not to check the automount flag. Any other error 969 mounted on it and not to check the automount flag. Any other error
970 code will abort pathwalk completely. 970 code will abort pathwalk completely.
971 971
972 If the 'mounting_here' parameter is true, then namespace_sem is being
973 held by the caller and the function should not initiate any mounts or
974 unmounts that it will then wait for.
975
976 If the 'rcu_walk' parameter is true, then the caller is doing a 972 If the 'rcu_walk' parameter is true, then the caller is doing a
977 pathwalk in RCU-walk mode. Sleeping is not permitted in this mode, 973 pathwalk in RCU-walk mode. Sleeping is not permitted in this mode,
978 and the caller can be asked to leave it and call again by returing 974 and the caller can be asked to leave it and call again by returing
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 014e7aba3b08..e6f84d26f4cf 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -36,7 +36,7 @@ static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
36static int autofs4_dir_open(struct inode *inode, struct file *file); 36static int autofs4_dir_open(struct inode *inode, struct file *file);
37static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); 37static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
38static struct vfsmount *autofs4_d_automount(struct path *); 38static struct vfsmount *autofs4_d_automount(struct path *);
39static int autofs4_d_manage(struct dentry *, bool, bool); 39static int autofs4_d_manage(struct dentry *, bool);
40static void autofs4_dentry_release(struct dentry *); 40static void autofs4_dentry_release(struct dentry *);
41 41
42const struct file_operations autofs4_root_operations = { 42const struct file_operations autofs4_root_operations = {
@@ -446,7 +446,7 @@ done:
446 return NULL; 446 return NULL;
447} 447}
448 448
449int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk) 449int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)
450{ 450{
451 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); 451 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
452 452
@@ -454,7 +454,7 @@ int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk)
454 dentry, dentry->d_name.len, dentry->d_name.name); 454 dentry, dentry->d_name.len, dentry->d_name.name);
455 455
456 /* The daemon never waits. */ 456 /* The daemon never waits. */
457 if (autofs4_oz_mode(sbi) || mounting_here) { 457 if (autofs4_oz_mode(sbi)) {
458 if (!d_mountpoint(dentry)) 458 if (!d_mountpoint(dentry))
459 return -EISDIR; 459 return -EISDIR;
460 return 0; 460 return 0;
diff --git a/fs/dcache.c b/fs/dcache.c
index 8b1f8425549f..ad25c4cec7d5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1612,10 +1612,13 @@ struct dentry *d_obtain_alias(struct inode *inode)
1612 __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first); 1612 __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
1613 spin_unlock(&tmp->d_lock); 1613 spin_unlock(&tmp->d_lock);
1614 spin_unlock(&inode->i_lock); 1614 spin_unlock(&inode->i_lock);
1615 security_d_instantiate(tmp, inode);
1615 1616
1616 return tmp; 1617 return tmp;
1617 1618
1618 out_iput: 1619 out_iput:
1620 if (res && !IS_ERR(res))
1621 security_d_instantiate(res, inode);
1619 iput(inode); 1622 iput(inode);
1620 return res; 1623 return res;
1621} 1624}
diff --git a/fs/internal.h b/fs/internal.h
index f3d15de44b15..17191546d527 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -12,6 +12,7 @@
12#include <linux/lglock.h> 12#include <linux/lglock.h>
13 13
14struct super_block; 14struct super_block;
15struct file_system_type;
15struct linux_binprm; 16struct linux_binprm;
16struct path; 17struct path;
17 18
@@ -61,8 +62,6 @@ extern int check_unsafe_exec(struct linux_binprm *);
61extern int copy_mount_options(const void __user *, unsigned long *); 62extern int copy_mount_options(const void __user *, unsigned long *);
62extern int copy_mount_string(const void __user *, char **); 63extern int copy_mount_string(const void __user *, char **);
63 64
64extern void free_vfsmnt(struct vfsmount *);
65extern struct vfsmount *alloc_vfsmnt(const char *);
66extern unsigned int mnt_get_count(struct vfsmount *mnt); 65extern unsigned int mnt_get_count(struct vfsmount *mnt);
67extern struct vfsmount *__lookup_mnt(struct vfsmount *, struct dentry *, int); 66extern struct vfsmount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
68extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *, 67extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
@@ -99,6 +98,8 @@ extern struct file *get_empty_filp(void);
99extern int do_remount_sb(struct super_block *, int, void *, int); 98extern int do_remount_sb(struct super_block *, int, void *, int);
100extern void __put_super(struct super_block *sb); 99extern void __put_super(struct super_block *sb);
101extern void put_super(struct super_block *sb); 100extern void put_super(struct super_block *sb);
101extern struct dentry *mount_fs(struct file_system_type *,
102 int, const char *, void *);
102 103
103/* 104/*
104 * open.c 105 * open.c
diff --git a/fs/namei.c b/fs/namei.c
index b912b7abe747..5a9a6c3094da 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -933,8 +933,7 @@ static int follow_managed(struct path *path, unsigned flags)
933 if (managed & DCACHE_MANAGE_TRANSIT) { 933 if (managed & DCACHE_MANAGE_TRANSIT) {
934 BUG_ON(!path->dentry->d_op); 934 BUG_ON(!path->dentry->d_op);
935 BUG_ON(!path->dentry->d_op->d_manage); 935 BUG_ON(!path->dentry->d_op->d_manage);
936 ret = path->dentry->d_op->d_manage(path->dentry, 936 ret = path->dentry->d_op->d_manage(path->dentry, false);
937 false, false);
938 if (ret < 0) 937 if (ret < 0)
939 return ret == -EISDIR ? 0 : ret; 938 return ret == -EISDIR ? 0 : ret;
940 } 939 }
@@ -999,7 +998,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
999 struct vfsmount *mounted; 998 struct vfsmount *mounted;
1000 if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) && 999 if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
1001 !reverse_transit && 1000 !reverse_transit &&
1002 path->dentry->d_op->d_manage(path->dentry, false, true) < 0) 1001 path->dentry->d_op->d_manage(path->dentry, true) < 0)
1003 return false; 1002 return false;
1004 mounted = __lookup_mnt(path->mnt, path->dentry, 1); 1003 mounted = __lookup_mnt(path->mnt, path->dentry, 1);
1005 if (!mounted) 1004 if (!mounted)
@@ -1065,7 +1064,7 @@ failed:
1065 * Care must be taken as namespace_sem may be held (indicated by mounting_here 1064 * Care must be taken as namespace_sem may be held (indicated by mounting_here
1066 * being true). 1065 * being true).
1067 */ 1066 */
1068int follow_down(struct path *path, bool mounting_here) 1067int follow_down(struct path *path)
1069{ 1068{
1070 unsigned managed; 1069 unsigned managed;
1071 int ret; 1070 int ret;
@@ -1086,7 +1085,7 @@ int follow_down(struct path *path, bool mounting_here)
1086 BUG_ON(!path->dentry->d_op); 1085 BUG_ON(!path->dentry->d_op);
1087 BUG_ON(!path->dentry->d_op->d_manage); 1086 BUG_ON(!path->dentry->d_op->d_manage);
1088 ret = path->dentry->d_op->d_manage( 1087 ret = path->dentry->d_op->d_manage(
1089 path->dentry, mounting_here, false); 1088 path->dentry, false);
1090 if (ret < 0) 1089 if (ret < 0)
1091 return ret == -EISDIR ? 0 : ret; 1090 return ret == -EISDIR ? 0 : ret;
1092 } 1091 }
diff --git a/fs/namespace.c b/fs/namespace.c
index d7513485c1f3..9263995bf6a1 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -196,7 +196,7 @@ unsigned int mnt_get_count(struct vfsmount *mnt)
196#endif 196#endif
197} 197}
198 198
199struct vfsmount *alloc_vfsmnt(const char *name) 199static struct vfsmount *alloc_vfsmnt(const char *name)
200{ 200{
201 struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL); 201 struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
202 if (mnt) { 202 if (mnt) {
@@ -466,15 +466,7 @@ static void __mnt_unmake_readonly(struct vfsmount *mnt)
466 br_write_unlock(vfsmount_lock); 466 br_write_unlock(vfsmount_lock);
467} 467}
468 468
469void simple_set_mnt(struct vfsmount *mnt, struct super_block *sb) 469static void free_vfsmnt(struct vfsmount *mnt)
470{
471 mnt->mnt_sb = sb;
472 mnt->mnt_root = dget(sb->s_root);
473}
474
475EXPORT_SYMBOL(simple_set_mnt);
476
477void free_vfsmnt(struct vfsmount *mnt)
478{ 470{
479 kfree(mnt->mnt_devname); 471 kfree(mnt->mnt_devname);
480 mnt_free_id(mnt); 472 mnt_free_id(mnt);
@@ -678,6 +670,36 @@ static struct vfsmount *skip_mnt_tree(struct vfsmount *p)
678 return p; 670 return p;
679} 671}
680 672
673struct vfsmount *
674vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
675{
676 struct vfsmount *mnt;
677 struct dentry *root;
678
679 if (!type)
680 return ERR_PTR(-ENODEV);
681
682 mnt = alloc_vfsmnt(name);
683 if (!mnt)
684 return ERR_PTR(-ENOMEM);
685
686 if (flags & MS_KERNMOUNT)
687 mnt->mnt_flags = MNT_INTERNAL;
688
689 root = mount_fs(type, flags, name, data);
690 if (IS_ERR(root)) {
691 free_vfsmnt(mnt);
692 return ERR_CAST(root);
693 }
694
695 mnt->mnt_root = root;
696 mnt->mnt_sb = root->d_sb;
697 mnt->mnt_mountpoint = mnt->mnt_root;
698 mnt->mnt_parent = mnt;
699 return mnt;
700}
701EXPORT_SYMBOL_GPL(vfs_kern_mount);
702
681static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root, 703static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
682 int flag) 704 int flag)
683{ 705{
@@ -1641,9 +1663,35 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
1641 return err; 1663 return err;
1642} 1664}
1643 1665
1666static int lock_mount(struct path *path)
1667{
1668 struct vfsmount *mnt;
1669retry:
1670 mutex_lock(&path->dentry->d_inode->i_mutex);
1671 if (unlikely(cant_mount(path->dentry))) {
1672 mutex_unlock(&path->dentry->d_inode->i_mutex);
1673 return -ENOENT;
1674 }
1675 down_write(&namespace_sem);
1676 mnt = lookup_mnt(path);
1677 if (likely(!mnt))
1678 return 0;
1679 up_write(&namespace_sem);
1680 mutex_unlock(&path->dentry->d_inode->i_mutex);
1681 path_put(path);
1682 path->mnt = mnt;
1683 path->dentry = dget(mnt->mnt_root);
1684 goto retry;
1685}
1686
1687static void unlock_mount(struct path *path)
1688{
1689 up_write(&namespace_sem);
1690 mutex_unlock(&path->dentry->d_inode->i_mutex);
1691}
1692
1644static int graft_tree(struct vfsmount *mnt, struct path *path) 1693static int graft_tree(struct vfsmount *mnt, struct path *path)
1645{ 1694{
1646 int err;
1647 if (mnt->mnt_sb->s_flags & MS_NOUSER) 1695 if (mnt->mnt_sb->s_flags & MS_NOUSER)
1648 return -EINVAL; 1696 return -EINVAL;
1649 1697
@@ -1651,16 +1699,10 @@ static int graft_tree(struct vfsmount *mnt, struct path *path)
1651 S_ISDIR(mnt->mnt_root->d_inode->i_mode)) 1699 S_ISDIR(mnt->mnt_root->d_inode->i_mode))
1652 return -ENOTDIR; 1700 return -ENOTDIR;
1653 1701
1654 err = -ENOENT; 1702 if (d_unlinked(path->dentry))
1655 mutex_lock(&path->dentry->d_inode->i_mutex); 1703 return -ENOENT;
1656 if (cant_mount(path->dentry))
1657 goto out_unlock;
1658 1704
1659 if (!d_unlinked(path->dentry)) 1705 return attach_recursive_mnt(mnt, path, NULL);
1660 err = attach_recursive_mnt(mnt, path, NULL);
1661out_unlock:
1662 mutex_unlock(&path->dentry->d_inode->i_mutex);
1663 return err;
1664} 1706}
1665 1707
1666/* 1708/*
@@ -1723,6 +1765,7 @@ static int do_change_type(struct path *path, int flag)
1723static int do_loopback(struct path *path, char *old_name, 1765static int do_loopback(struct path *path, char *old_name,
1724 int recurse) 1766 int recurse)
1725{ 1767{
1768 LIST_HEAD(umount_list);
1726 struct path old_path; 1769 struct path old_path;
1727 struct vfsmount *mnt = NULL; 1770 struct vfsmount *mnt = NULL;
1728 int err = mount_is_safe(path); 1771 int err = mount_is_safe(path);
@@ -1734,13 +1777,16 @@ static int do_loopback(struct path *path, char *old_name,
1734 if (err) 1777 if (err)
1735 return err; 1778 return err;
1736 1779
1737 down_write(&namespace_sem); 1780 err = lock_mount(path);
1781 if (err)
1782 goto out;
1783
1738 err = -EINVAL; 1784 err = -EINVAL;
1739 if (IS_MNT_UNBINDABLE(old_path.mnt)) 1785 if (IS_MNT_UNBINDABLE(old_path.mnt))
1740 goto out; 1786 goto out2;
1741 1787
1742 if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt)) 1788 if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
1743 goto out; 1789 goto out2;
1744 1790
1745 err = -ENOMEM; 1791 err = -ENOMEM;
1746 if (recurse) 1792 if (recurse)
@@ -1749,20 +1795,18 @@ static int do_loopback(struct path *path, char *old_name,
1749 mnt = clone_mnt(old_path.mnt, old_path.dentry, 0); 1795 mnt = clone_mnt(old_path.mnt, old_path.dentry, 0);
1750 1796
1751 if (!mnt) 1797 if (!mnt)
1752 goto out; 1798 goto out2;
1753 1799
1754 err = graft_tree(mnt, path); 1800 err = graft_tree(mnt, path);
1755 if (err) { 1801 if (err) {
1756 LIST_HEAD(umount_list);
1757
1758 br_write_lock(vfsmount_lock); 1802 br_write_lock(vfsmount_lock);
1759 umount_tree(mnt, 0, &umount_list); 1803 umount_tree(mnt, 0, &umount_list);
1760 br_write_unlock(vfsmount_lock); 1804 br_write_unlock(vfsmount_lock);
1761 release_mounts(&umount_list);
1762 } 1805 }
1763 1806out2:
1807 unlock_mount(path);
1808 release_mounts(&umount_list);
1764out: 1809out:
1765 up_write(&namespace_sem);
1766 path_put(&old_path); 1810 path_put(&old_path);
1767 return err; 1811 return err;
1768} 1812}
@@ -1851,18 +1895,12 @@ static int do_move_mount(struct path *path, char *old_name)
1851 if (err) 1895 if (err)
1852 return err; 1896 return err;
1853 1897
1854 down_write(&namespace_sem); 1898 err = lock_mount(path);
1855 err = follow_down(path, true);
1856 if (err < 0) 1899 if (err < 0)
1857 goto out; 1900 goto out;
1858 1901
1859 err = -EINVAL; 1902 err = -EINVAL;
1860 if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt)) 1903 if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
1861 goto out;
1862
1863 err = -ENOENT;
1864 mutex_lock(&path->dentry->d_inode->i_mutex);
1865 if (cant_mount(path->dentry))
1866 goto out1; 1904 goto out1;
1867 1905
1868 if (d_unlinked(path->dentry)) 1906 if (d_unlinked(path->dentry))
@@ -1904,16 +1942,87 @@ static int do_move_mount(struct path *path, char *old_name)
1904 * automatically */ 1942 * automatically */
1905 list_del_init(&old_path.mnt->mnt_expire); 1943 list_del_init(&old_path.mnt->mnt_expire);
1906out1: 1944out1:
1907 mutex_unlock(&path->dentry->d_inode->i_mutex); 1945 unlock_mount(path);
1908out: 1946out:
1909 up_write(&namespace_sem);
1910 if (!err) 1947 if (!err)
1911 path_put(&parent_path); 1948 path_put(&parent_path);
1912 path_put(&old_path); 1949 path_put(&old_path);
1913 return err; 1950 return err;
1914} 1951}
1915 1952
1916static int do_add_mount(struct vfsmount *, struct path *, int); 1953static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
1954{
1955 int err;
1956 const char *subtype = strchr(fstype, '.');
1957 if (subtype) {
1958 subtype++;
1959 err = -EINVAL;
1960 if (!subtype[0])
1961 goto err;
1962 } else
1963 subtype = "";
1964
1965 mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
1966 err = -ENOMEM;
1967 if (!mnt->mnt_sb->s_subtype)
1968 goto err;
1969 return mnt;
1970
1971 err:
1972 mntput(mnt);
1973 return ERR_PTR(err);
1974}
1975
1976struct vfsmount *
1977do_kern_mount(const char *fstype, int flags, const char *name, void *data)
1978{
1979 struct file_system_type *type = get_fs_type(fstype);
1980 struct vfsmount *mnt;
1981 if (!type)
1982 return ERR_PTR(-ENODEV);
1983 mnt = vfs_kern_mount(type, flags, name, data);
1984 if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
1985 !mnt->mnt_sb->s_subtype)
1986 mnt = fs_set_subtype(mnt, fstype);
1987 put_filesystem(type);
1988 return mnt;
1989}
1990EXPORT_SYMBOL_GPL(do_kern_mount);
1991
1992/*
1993 * add a mount into a namespace's mount tree
1994 */
1995static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
1996{
1997 int err;
1998
1999 mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL);
2000
2001 err = lock_mount(path);
2002 if (err)
2003 return err;
2004
2005 err = -EINVAL;
2006 if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
2007 goto unlock;
2008
2009 /* Refuse the same filesystem on the same mount point */
2010 err = -EBUSY;
2011 if (path->mnt->mnt_sb == newmnt->mnt_sb &&
2012 path->mnt->mnt_root == path->dentry)
2013 goto unlock;
2014
2015 err = -EINVAL;
2016 if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
2017 goto unlock;
2018
2019 newmnt->mnt_flags = mnt_flags;
2020 err = graft_tree(newmnt, path);
2021
2022unlock:
2023 unlock_mount(path);
2024 return err;
2025}
1917 2026
1918/* 2027/*
1919 * create a new mount for userspace and request it to be added into the 2028 * create a new mount for userspace and request it to be added into the
@@ -1973,43 +2082,6 @@ fail:
1973 return err; 2082 return err;
1974} 2083}
1975 2084
1976/*
1977 * add a mount into a namespace's mount tree
1978 */
1979static int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
1980{
1981 int err;
1982
1983 mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL);
1984
1985 down_write(&namespace_sem);
1986 /* Something was mounted here while we slept */
1987 err = follow_down(path, true);
1988 if (err < 0)
1989 goto unlock;
1990
1991 err = -EINVAL;
1992 if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
1993 goto unlock;
1994
1995 /* Refuse the same filesystem on the same mount point */
1996 err = -EBUSY;
1997 if (path->mnt->mnt_sb == newmnt->mnt_sb &&
1998 path->mnt->mnt_root == path->dentry)
1999 goto unlock;
2000
2001 err = -EINVAL;
2002 if (S_ISLNK(newmnt->mnt_root->d_inode->i_mode))
2003 goto unlock;
2004
2005 newmnt->mnt_flags = mnt_flags;
2006 err = graft_tree(newmnt, path);
2007
2008unlock:
2009 up_write(&namespace_sem);
2010 return err;
2011}
2012
2013/** 2085/**
2014 * mnt_set_expiry - Put a mount on an expiration list 2086 * mnt_set_expiry - Put a mount on an expiration list
2015 * @mnt: The mount to list. 2087 * @mnt: The mount to list.
@@ -2510,65 +2582,60 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
2510 error = user_path_dir(new_root, &new); 2582 error = user_path_dir(new_root, &new);
2511 if (error) 2583 if (error)
2512 goto out0; 2584 goto out0;
2513 error = -EINVAL;
2514 if (!check_mnt(new.mnt))
2515 goto out1;
2516 2585
2517 error = user_path_dir(put_old, &old); 2586 error = user_path_dir(put_old, &old);
2518 if (error) 2587 if (error)
2519 goto out1; 2588 goto out1;
2520 2589
2521 error = security_sb_pivotroot(&old, &new); 2590 error = security_sb_pivotroot(&old, &new);
2522 if (error) { 2591 if (error)
2523 path_put(&old); 2592 goto out2;
2524 goto out1;
2525 }
2526 2593
2527 get_fs_root(current->fs, &root); 2594 get_fs_root(current->fs, &root);
2528 down_write(&namespace_sem); 2595 error = lock_mount(&old);
2529 mutex_lock(&old.dentry->d_inode->i_mutex); 2596 if (error)
2597 goto out3;
2598
2530 error = -EINVAL; 2599 error = -EINVAL;
2531 if (IS_MNT_SHARED(old.mnt) || 2600 if (IS_MNT_SHARED(old.mnt) ||
2532 IS_MNT_SHARED(new.mnt->mnt_parent) || 2601 IS_MNT_SHARED(new.mnt->mnt_parent) ||
2533 IS_MNT_SHARED(root.mnt->mnt_parent)) 2602 IS_MNT_SHARED(root.mnt->mnt_parent))
2534 goto out2; 2603 goto out4;
2535 if (!check_mnt(root.mnt)) 2604 if (!check_mnt(root.mnt) || !check_mnt(new.mnt))
2536 goto out2; 2605 goto out4;
2537 error = -ENOENT; 2606 error = -ENOENT;
2538 if (cant_mount(old.dentry))
2539 goto out2;
2540 if (d_unlinked(new.dentry)) 2607 if (d_unlinked(new.dentry))
2541 goto out2; 2608 goto out4;
2542 if (d_unlinked(old.dentry)) 2609 if (d_unlinked(old.dentry))
2543 goto out2; 2610 goto out4;
2544 error = -EBUSY; 2611 error = -EBUSY;
2545 if (new.mnt == root.mnt || 2612 if (new.mnt == root.mnt ||
2546 old.mnt == root.mnt) 2613 old.mnt == root.mnt)
2547 goto out2; /* loop, on the same file system */ 2614 goto out4; /* loop, on the same file system */
2548 error = -EINVAL; 2615 error = -EINVAL;
2549 if (root.mnt->mnt_root != root.dentry) 2616 if (root.mnt->mnt_root != root.dentry)
2550 goto out2; /* not a mountpoint */ 2617 goto out4; /* not a mountpoint */
2551 if (root.mnt->mnt_parent == root.mnt) 2618 if (root.mnt->mnt_parent == root.mnt)
2552 goto out2; /* not attached */ 2619 goto out4; /* not attached */
2553 if (new.mnt->mnt_root != new.dentry) 2620 if (new.mnt->mnt_root != new.dentry)
2554 goto out2; /* not a mountpoint */ 2621 goto out4; /* not a mountpoint */
2555 if (new.mnt->mnt_parent == new.mnt) 2622 if (new.mnt->mnt_parent == new.mnt)
2556 goto out2; /* not attached */ 2623 goto out4; /* not attached */
2557 /* make sure we can reach put_old from new_root */ 2624 /* make sure we can reach put_old from new_root */
2558 tmp = old.mnt; 2625 tmp = old.mnt;
2559 br_write_lock(vfsmount_lock);
2560 if (tmp != new.mnt) { 2626 if (tmp != new.mnt) {
2561 for (;;) { 2627 for (;;) {
2562 if (tmp->mnt_parent == tmp) 2628 if (tmp->mnt_parent == tmp)
2563 goto out3; /* already mounted on put_old */ 2629 goto out4; /* already mounted on put_old */
2564 if (tmp->mnt_parent == new.mnt) 2630 if (tmp->mnt_parent == new.mnt)
2565 break; 2631 break;
2566 tmp = tmp->mnt_parent; 2632 tmp = tmp->mnt_parent;
2567 } 2633 }
2568 if (!is_subdir(tmp->mnt_mountpoint, new.dentry)) 2634 if (!is_subdir(tmp->mnt_mountpoint, new.dentry))
2569 goto out3; 2635 goto out4;
2570 } else if (!is_subdir(old.dentry, new.dentry)) 2636 } else if (!is_subdir(old.dentry, new.dentry))
2571 goto out3; 2637 goto out4;
2638 br_write_lock(vfsmount_lock);
2572 detach_mnt(new.mnt, &parent_path); 2639 detach_mnt(new.mnt, &parent_path);
2573 detach_mnt(root.mnt, &root_parent); 2640 detach_mnt(root.mnt, &root_parent);
2574 /* mount old root on put_old */ 2641 /* mount old root on put_old */
@@ -2578,22 +2645,21 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
2578 touch_mnt_namespace(current->nsproxy->mnt_ns); 2645 touch_mnt_namespace(current->nsproxy->mnt_ns);
2579 br_write_unlock(vfsmount_lock); 2646 br_write_unlock(vfsmount_lock);
2580 chroot_fs_refs(&root, &new); 2647 chroot_fs_refs(&root, &new);
2581
2582 error = 0; 2648 error = 0;
2583 path_put(&root_parent); 2649out4:
2584 path_put(&parent_path); 2650 unlock_mount(&old);
2585out2: 2651 if (!error) {
2586 mutex_unlock(&old.dentry->d_inode->i_mutex); 2652 path_put(&root_parent);
2587 up_write(&namespace_sem); 2653 path_put(&parent_path);
2654 }
2655out3:
2588 path_put(&root); 2656 path_put(&root);
2657out2:
2589 path_put(&old); 2658 path_put(&old);
2590out1: 2659out1:
2591 path_put(&new); 2660 path_put(&new);
2592out0: 2661out0:
2593 return error; 2662 return error;
2594out3:
2595 br_write_unlock(vfsmount_lock);
2596 goto out2;
2597} 2663}
2598 2664
2599static void __init init_mount_tree(void) 2665static void __init init_mount_tree(void)
@@ -2668,3 +2734,9 @@ void put_mnt_ns(struct mnt_namespace *ns)
2668 kfree(ns); 2734 kfree(ns);
2669} 2735}
2670EXPORT_SYMBOL(put_mnt_ns); 2736EXPORT_SYMBOL(put_mnt_ns);
2737
2738struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
2739{
2740 return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
2741}
2742EXPORT_SYMBOL_GPL(kern_mount_data);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index da1d9701f8e4..ff93025ae2f7 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -87,7 +87,7 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
87 .dentry = dget(dentry)}; 87 .dentry = dget(dentry)};
88 int err = 0; 88 int err = 0;
89 89
90 err = follow_down(&path, false); 90 err = follow_down(&path);
91 if (err < 0) 91 if (err < 0)
92 goto out; 92 goto out;
93 93
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 549d245d0b42..08342232cb1c 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -40,9 +40,29 @@
40struct pstore_private { 40struct pstore_private {
41 u64 id; 41 u64 id;
42 int (*erase)(u64); 42 int (*erase)(u64);
43 ssize_t size;
44 char data[];
43}; 45};
44 46
45#define pstore_get_inode ramfs_get_inode 47static int pstore_file_open(struct inode *inode, struct file *file)
48{
49 file->private_data = inode->i_private;
50 return 0;
51}
52
53static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
54 size_t count, loff_t *ppos)
55{
56 struct pstore_private *ps = file->private_data;
57
58 return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size);
59}
60
61static const struct file_operations pstore_file_operations = {
62 .open = pstore_file_open,
63 .read = pstore_file_read,
64 .llseek = default_llseek,
65};
46 66
47/* 67/*
48 * When a file is unlinked from our file system we call the 68 * When a file is unlinked from our file system we call the
@@ -63,6 +83,30 @@ static const struct inode_operations pstore_dir_inode_operations = {
63 .unlink = pstore_unlink, 83 .unlink = pstore_unlink,
64}; 84};
65 85
86static struct inode *pstore_get_inode(struct super_block *sb,
87 const struct inode *dir, int mode, dev_t dev)
88{
89 struct inode *inode = new_inode(sb);
90
91 if (inode) {
92 inode->i_ino = get_next_ino();
93 inode->i_uid = inode->i_gid = 0;
94 inode->i_mode = mode;
95 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
96 switch (mode & S_IFMT) {
97 case S_IFREG:
98 inode->i_fop = &pstore_file_operations;
99 break;
100 case S_IFDIR:
101 inode->i_op = &pstore_dir_inode_operations;
102 inode->i_fop = &simple_dir_operations;
103 inc_nlink(inode);
104 break;
105 }
106 }
107 return inode;
108}
109
66static const struct super_operations pstore_ops = { 110static const struct super_operations pstore_ops = {
67 .statfs = simple_statfs, 111 .statfs = simple_statfs,
68 .drop_inode = generic_delete_inode, 112 .drop_inode = generic_delete_inode,
@@ -70,37 +114,10 @@ static const struct super_operations pstore_ops = {
70}; 114};
71 115
72static struct super_block *pstore_sb; 116static struct super_block *pstore_sb;
73static struct vfsmount *pstore_mnt;
74 117
75int pstore_is_mounted(void) 118int pstore_is_mounted(void)
76{ 119{
77 return pstore_mnt != NULL; 120 return pstore_sb != NULL;
78}
79
80/*
81 * Set up a file structure as if we had opened this file and
82 * write our data to it.
83 */
84static int pstore_writefile(struct inode *inode, struct dentry *dentry,
85 char *data, size_t size)
86{
87 struct file f;
88 ssize_t n;
89 mm_segment_t old_fs = get_fs();
90
91 memset(&f, '0', sizeof f);
92 f.f_mapping = inode->i_mapping;
93 f.f_path.dentry = dentry;
94 f.f_path.mnt = pstore_mnt;
95 f.f_pos = 0;
96 f.f_op = inode->i_fop;
97 set_fs(KERNEL_DS);
98 n = do_sync_write(&f, data, size, &f.f_pos);
99 set_fs(old_fs);
100
101 fsnotify_modify(&f);
102
103 return n == size;
104} 121}
105 122
106/* 123/*
@@ -123,8 +140,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
123 inode = pstore_get_inode(pstore_sb, root->d_inode, S_IFREG | 0444, 0); 140 inode = pstore_get_inode(pstore_sb, root->d_inode, S_IFREG | 0444, 0);
124 if (!inode) 141 if (!inode)
125 goto fail; 142 goto fail;
126 inode->i_uid = inode->i_gid = 0; 143 private = kmalloc(sizeof *private + size, GFP_KERNEL);
127 private = kmalloc(sizeof *private, GFP_KERNEL);
128 if (!private) 144 if (!private)
129 goto fail_alloc; 145 goto fail_alloc;
130 private->id = id; 146 private->id = id;
@@ -152,28 +168,19 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
152 if (IS_ERR(dentry)) 168 if (IS_ERR(dentry))
153 goto fail_lockedalloc; 169 goto fail_lockedalloc;
154 170
155 d_add(dentry, inode); 171 memcpy(private->data, data, size);
156 172 inode->i_size = private->size = size;
157 mutex_unlock(&root->d_inode->i_mutex);
158
159 if (!pstore_writefile(inode, dentry, data, size))
160 goto fail_write;
161 173
162 inode->i_private = private; 174 inode->i_private = private;
163 175
164 if (time.tv_sec) 176 if (time.tv_sec)
165 inode->i_mtime = inode->i_ctime = time; 177 inode->i_mtime = inode->i_ctime = time;
166 178
167 return 0; 179 d_add(dentry, inode);
168 180
169fail_write:
170 kfree(private);
171 inode->i_nlink--;
172 mutex_lock(&root->d_inode->i_mutex);
173 d_delete(dentry);
174 dput(dentry);
175 mutex_unlock(&root->d_inode->i_mutex); 181 mutex_unlock(&root->d_inode->i_mutex);
176 goto fail; 182
183 return 0;
177 184
178fail_lockedalloc: 185fail_lockedalloc:
179 mutex_unlock(&root->d_inode->i_mutex); 186 mutex_unlock(&root->d_inode->i_mutex);
@@ -225,32 +232,21 @@ fail:
225 return err; 232 return err;
226} 233}
227 234
228static int pstore_get_sb(struct file_system_type *fs_type, 235static struct dentry *pstore_mount(struct file_system_type *fs_type,
229 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 236 int flags, const char *dev_name, void *data)
230{ 237{
231 struct dentry *root; 238 return mount_single(fs_type, flags, data, pstore_fill_super);
232
233 root = mount_nodev(fs_type, flags, data, pstore_fill_super);
234 if (IS_ERR(root))
235 return -ENOMEM;
236
237 mnt->mnt_root = root;
238 mnt->mnt_sb = root->d_sb;
239 pstore_mnt = mnt;
240
241 return 0;
242} 239}
243 240
244static void pstore_kill_sb(struct super_block *sb) 241static void pstore_kill_sb(struct super_block *sb)
245{ 242{
246 kill_litter_super(sb); 243 kill_litter_super(sb);
247 pstore_sb = NULL; 244 pstore_sb = NULL;
248 pstore_mnt = NULL;
249} 245}
250 246
251static struct file_system_type pstore_fs_type = { 247static struct file_system_type pstore_fs_type = {
252 .name = "pstore", 248 .name = "pstore",
253 .get_sb = pstore_get_sb, 249 .mount = pstore_mount,
254 .kill_sb = pstore_kill_sb, 250 .kill_sb = pstore_kill_sb,
255}; 251};
256 252
diff --git a/fs/super.c b/fs/super.c
index 4bae0ef6110e..e84864908264 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -910,29 +910,18 @@ struct dentry *mount_single(struct file_system_type *fs_type,
910} 910}
911EXPORT_SYMBOL(mount_single); 911EXPORT_SYMBOL(mount_single);
912 912
913struct vfsmount * 913struct dentry *
914vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data) 914mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
915{ 915{
916 struct vfsmount *mnt;
917 struct dentry *root; 916 struct dentry *root;
917 struct super_block *sb;
918 char *secdata = NULL; 918 char *secdata = NULL;
919 int error; 919 int error = -ENOMEM;
920
921 if (!type)
922 return ERR_PTR(-ENODEV);
923
924 error = -ENOMEM;
925 mnt = alloc_vfsmnt(name);
926 if (!mnt)
927 goto out;
928
929 if (flags & MS_KERNMOUNT)
930 mnt->mnt_flags = MNT_INTERNAL;
931 920
932 if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) { 921 if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
933 secdata = alloc_secdata(); 922 secdata = alloc_secdata();
934 if (!secdata) 923 if (!secdata)
935 goto out_mnt; 924 goto out;
936 925
937 error = security_sb_copy_data(data, secdata); 926 error = security_sb_copy_data(data, secdata);
938 if (error) 927 if (error)
@@ -944,13 +933,12 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
944 error = PTR_ERR(root); 933 error = PTR_ERR(root);
945 goto out_free_secdata; 934 goto out_free_secdata;
946 } 935 }
947 mnt->mnt_root = root; 936 sb = root->d_sb;
948 mnt->mnt_sb = root->d_sb; 937 BUG_ON(!sb);
949 BUG_ON(!mnt->mnt_sb); 938 WARN_ON(!sb->s_bdi);
950 WARN_ON(!mnt->mnt_sb->s_bdi); 939 sb->s_flags |= MS_BORN;
951 mnt->mnt_sb->s_flags |= MS_BORN;
952 940
953 error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata); 941 error = security_sb_kern_mount(sb, flags, secdata);
954 if (error) 942 if (error)
955 goto out_sb; 943 goto out_sb;
956 944
@@ -961,27 +949,21 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
961 * violate this rule. This warning should be either removed or 949 * violate this rule. This warning should be either removed or
962 * converted to a BUG() in 2.6.34. 950 * converted to a BUG() in 2.6.34.
963 */ 951 */
964 WARN((mnt->mnt_sb->s_maxbytes < 0), "%s set sb->s_maxbytes to " 952 WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to "
965 "negative value (%lld)\n", type->name, mnt->mnt_sb->s_maxbytes); 953 "negative value (%lld)\n", type->name, sb->s_maxbytes);
966 954
967 mnt->mnt_mountpoint = mnt->mnt_root; 955 up_write(&sb->s_umount);
968 mnt->mnt_parent = mnt;
969 up_write(&mnt->mnt_sb->s_umount);
970 free_secdata(secdata); 956 free_secdata(secdata);
971 return mnt; 957 return root;
972out_sb: 958out_sb:
973 dput(mnt->mnt_root); 959 dput(root);
974 deactivate_locked_super(mnt->mnt_sb); 960 deactivate_locked_super(sb);
975out_free_secdata: 961out_free_secdata:
976 free_secdata(secdata); 962 free_secdata(secdata);
977out_mnt:
978 free_vfsmnt(mnt);
979out: 963out:
980 return ERR_PTR(error); 964 return ERR_PTR(error);
981} 965}
982 966
983EXPORT_SYMBOL_GPL(vfs_kern_mount);
984
985/** 967/**
986 * freeze_super - lock the filesystem and force it into a consistent state 968 * freeze_super - lock the filesystem and force it into a consistent state
987 * @sb: the super to lock 969 * @sb: the super to lock
@@ -1071,49 +1053,3 @@ out:
1071 return 0; 1053 return 0;
1072} 1054}
1073EXPORT_SYMBOL(thaw_super); 1055EXPORT_SYMBOL(thaw_super);
1074
1075static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
1076{
1077 int err;
1078 const char *subtype = strchr(fstype, '.');
1079 if (subtype) {
1080 subtype++;
1081 err = -EINVAL;
1082 if (!subtype[0])
1083 goto err;
1084 } else
1085 subtype = "";
1086
1087 mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
1088 err = -ENOMEM;
1089 if (!mnt->mnt_sb->s_subtype)
1090 goto err;
1091 return mnt;
1092
1093 err:
1094 mntput(mnt);
1095 return ERR_PTR(err);
1096}
1097
1098struct vfsmount *
1099do_kern_mount(const char *fstype, int flags, const char *name, void *data)
1100{
1101 struct file_system_type *type = get_fs_type(fstype);
1102 struct vfsmount *mnt;
1103 if (!type)
1104 return ERR_PTR(-ENODEV);
1105 mnt = vfs_kern_mount(type, flags, name, data);
1106 if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
1107 !mnt->mnt_sb->s_subtype)
1108 mnt = fs_set_subtype(mnt, fstype);
1109 put_filesystem(type);
1110 return mnt;
1111}
1112EXPORT_SYMBOL_GPL(do_kern_mount);
1113
1114struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
1115{
1116 return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
1117}
1118
1119EXPORT_SYMBOL_GPL(kern_mount_data);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index f958c19e3ca5..1a87760d6532 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -168,7 +168,7 @@ struct dentry_operations {
168 void (*d_iput)(struct dentry *, struct inode *); 168 void (*d_iput)(struct dentry *, struct inode *);
169 char *(*d_dname)(struct dentry *, char *, int); 169 char *(*d_dname)(struct dentry *, char *, int);
170 struct vfsmount *(*d_automount)(struct path *); 170 struct vfsmount *(*d_automount)(struct path *);
171 int (*d_manage)(struct dentry *, bool, bool); 171 int (*d_manage)(struct dentry *, bool);
172} ____cacheline_aligned; 172} ____cacheline_aligned;
173 173
174/* 174/*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 92f7e04aea11..7061a8587ee3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1839,7 +1839,6 @@ extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1839 const struct super_operations *ops, 1839 const struct super_operations *ops,
1840 const struct dentry_operations *dops, 1840 const struct dentry_operations *dops,
1841 unsigned long); 1841 unsigned long);
1842extern void simple_set_mnt(struct vfsmount *mnt, struct super_block *sb);
1843 1842
1844static inline void sb_mark_dirty(struct super_block *sb) 1843static inline void sb_mark_dirty(struct super_block *sb)
1845{ 1844{
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 9c8603872c36..eba45ea10298 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -85,7 +85,7 @@ extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry
85extern struct dentry *lookup_one_len(const char *, struct dentry *, int); 85extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
86 86
87extern int follow_down_one(struct path *); 87extern int follow_down_one(struct path *);
88extern int follow_down(struct path *, bool); 88extern int follow_down(struct path *);
89extern int follow_up(struct path *); 89extern int follow_up(struct path *);
90 90
91extern struct dentry *lock_rename(struct dentry *, struct dentry *); 91extern struct dentry *lock_rename(struct dentry *, struct dentry *);