1 files changed, 2454 insertions, 0 deletions

diff --git a/fs/namei.c b/fs/namei.c
new file mode 100644
index 000000000000..9e4aef2a1a21
--- /dev/null
+++ b/fs/namei.c
@@ -0,0 +1,2454 @@
+/*
+ *  linux/fs/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * Some corrections by tytso.
+ */
+
+/* [Feb 1997 T. Schoebel-Theuer] Complete rewrite of the pathname
+ * lookup logic.
+ */
+/* [Feb-Apr 2000, AV] Rewrite to the new namespace architecture.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+#include <linux/pagemap.h>
+#include <linux/dnotify.h>
+#include <linux/smp_lock.h>
+#include <linux/personality.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/mount.h>
+#include <linux/audit.h>
+#include <asm/namei.h>
+#include <asm/uaccess.h>
+
+#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
+
+/* [Feb-1997 T. Schoebel-Theuer]
+ * Fundamental changes in the pathname lookup mechanisms (namei)
+ * were necessary because of omirr.  The reason is that omirr needs
+ * to know the _real_ pathname, not the user-supplied one, in case
+ * of symlinks (and also when transname replacements occur).
+ *
+ * The new code replaces the old recursive symlink resolution with
+ * an iterative one (in case of non-nested symlink chains).  It does
+ * this with calls to <fs>_follow_link().
+ * As a side effect, dir_namei(), _namei() and follow_link() are now 
+ * replaced with a single function lookup_dentry() that can handle all 
+ * the special cases of the former code.
+ *
+ * With the new dcache, the pathname is stored at each inode, at least as
+ * long as the refcount of the inode is positive.  As a side effect, the
+ * size of the dcache depends on the inode cache and thus is dynamic.
+ *
+ * [29-Apr-1998 C. Scott Ananian] Updated above description of symlink
+ * resolution to correspond with current state of the code.
+ *
+ * Note that the symlink resolution is not *completely* iterative.
+ * There is still a significant amount of tail- and mid- recursion in
+ * the algorithm.  Also, note that <fs>_readlink() is not used in
+ * lookup_dentry(): lookup_dentry() on the result of <fs>_readlink()
+ * may return different results than <fs>_follow_link().  Many virtual
+ * filesystems (including /proc) exhibit this behavior.
+ */
+
+/* [24-Feb-97 T. Schoebel-Theuer] Side effects caused by new implementation:
+ * New symlink semantics: when open() is called with flags O_CREAT | O_EXCL
+ * and the name already exists in form of a symlink, try to create the new
+ * name indicated by the symlink. The old code always complained that the
+ * name already exists, due to not following the symlink even if its target
+ * is nonexistent.  The new semantics affects also mknod() and link() when
+ * the name is a symlink pointing to a non-existant name.
+ *
+ * I don't know which semantics is the right one, since I have no access
+ * to standards. But I found by trial that HP-UX 9.0 has the full "new"
+ * semantics implemented, while SunOS 4.1.1 and Solaris (SunOS 5.4) have the
+ * "old" one. Personally, I think the new semantics is much more logical.
+ * Note that "ln old new" where "new" is a symlink pointing to a non-existing
+ * file does succeed in both HP-UX and SunOs, but not in Solaris
+ * and in the old Linux semantics.
+ */
+
+/* [16-Dec-97 Kevin Buhr] For security reasons, we change some symlink
+ * semantics.  See the comments in "open_namei" and "do_link" below.
+ *
+ * [10-Sep-98 Alan Modra] Another symlink change.
+ */
+
+/* [Feb-Apr 2000 AV] Complete rewrite. Rules for symlinks:
+ *      inside the path - always follow.
+ *      in the last component in creation/removal/renaming - never follow.
+ *      if LOOKUP_FOLLOW passed - follow.
+ *      if the pathname has trailing slashes - follow.
+ *      otherwise - don't follow.
+ * (applied in that order).
+ *
+ * [Jun 2000 AV] Inconsistent behaviour of open() in case if flags==O_CREAT
+ * restored for 2.4. This is the last surviving part of old 4.2BSD bug.
+ * During the 2.4 we need to fix the userland stuff depending on it -
+ * hopefully we will be able to get rid of that wart in 2.5. So far only
+ * XEmacs seems to be relying on it...
+ */
+/*
+ * [Sep 2001 AV] Single-semaphore locking scheme (kudos to David Holland)
+ * implemented.  Let's see if raised priority of ->s_vfs_rename_sem gives
+ * any extra contention...
+ */
+
+/* In order to reduce some races, while at the same time doing additional
+ * checking and hopefully speeding things up, we copy filenames to the
+ * kernel data space before using them..
+ *
+ * POSIX.1 2.4: an empty pathname is invalid (ENOENT).
+ * PATH_MAX includes the nul terminator --RR.
+ */
+static inline int do_getname(const char __user *filename, char *page)
+{
+        int retval;
+        unsigned long len = PATH_MAX;
+
+        if (!segment_eq(get_fs(), KERNEL_DS)) {
+                if ((unsigned long) filename >= TASK_SIZE)
+                        return -EFAULT;
+                if (TASK_SIZE - (unsigned long) filename < PATH_MAX)
+                        len = TASK_SIZE - (unsigned long) filename;
+        }
+
+        retval = strncpy_from_user(page, filename, len);
+        if (retval > 0) {
+                if (retval < len)
+                        return 0;
+                return -ENAMETOOLONG;
+        } else if (!retval)
+                retval = -ENOENT;
+        return retval;
+}
+
+char * getname(const char __user * filename)
+{
+        char *tmp, *result;
+
+        result = ERR_PTR(-ENOMEM);
+        tmp = __getname();
+        if (tmp)  {
+                int retval = do_getname(filename, tmp);
+
+                result = tmp;
+                if (retval < 0) {
+                        __putname(tmp);
+                        result = ERR_PTR(retval);
+                }
+        }
+        audit_getname(result);
+        return result;
+}
+
+#ifdef CONFIG_AUDITSYSCALL
+void putname(const char *name)
+{
+        if (unlikely(current->audit_context))
+                audit_putname(name);
+        else
+                __putname(name);
+}
+EXPORT_SYMBOL(putname);
+#endif
+
+
+/**
+ * generic_permission  -  check for access rights on a Posix-like filesystem
+ * @inode:      inode to check access rights for
+ * @mask:       right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
+ * @check_acl:  optional callback to check for Posix ACLs
+ *
+ * Used to check for read/write/execute permissions on a file.
+ * We use "fsuid" for this, letting us set arbitrary permissions
+ * for filesystem access without changing the "normal" uids which
+ * are used for other things..
+ */
+int generic_permission(struct inode *inode, int mask,
+                int (*check_acl)(struct inode *inode, int mask))
+{
+        umode_t                 mode = inode->i_mode;
+
+        if (current->fsuid == inode->i_uid)
+                mode >>= 6;
+        else {
+                if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
+                        int error = check_acl(inode, mask);
+                        if (error == -EACCES)
+                                goto check_capabilities;
+                        else if (error != -EAGAIN)
+                                return error;
+                }
+
+                if (in_group_p(inode->i_gid))
+                        mode >>= 3;
+        }
+
+        /*
+         * If the DACs are ok we don't need any capability check.
+         */
+        if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
+                return 0;
+
+ check_capabilities:
+        /*
+         * Read/write DACs are always overridable.
+         * Executable DACs are overridable if at least one exec bit is set.
+         */
+        if (!(mask & MAY_EXEC) ||
+            (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
+                if (capable(CAP_DAC_OVERRIDE))
+                        return 0;
+
+        /*
+         * Searching includes executable on directories, else just read.
+         */
+        if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
+                if (capable(CAP_DAC_READ_SEARCH))
+                        return 0;
+
+        return -EACCES;
+}
+
+int permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+        int retval, submask;
+
+        if (mask & MAY_WRITE) {
+                umode_t mode = inode->i_mode;
+
+                /*
+                 * Nobody gets write access to a read-only fs.
+                 */
+                if (IS_RDONLY(inode) &&
+                    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
+                        return -EROFS;
+
+                /*
+                 * Nobody gets write access to an immutable file.
+                 */
+                if (IS_IMMUTABLE(inode))
+                        return -EACCES;
+        }
+
+
+        /* Ordinary permission routines do not understand MAY_APPEND. */
+        submask = mask & ~MAY_APPEND;
+        if (inode->i_op && inode->i_op->permission)
+                retval = inode->i_op->permission(inode, submask, nd);
+        else
+                retval = generic_permission(inode, submask, NULL);
+        if (retval)
+                return retval;
+
+        return security_inode_permission(inode, mask, nd);
+}
+
+/*
+ * get_write_access() gets write permission for a file.
+ * put_write_access() releases this write permission.
+ * This is used for regular files.
+ * We cannot support write (and maybe mmap read-write shared) accesses and
+ * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
+ * can have the following values:
+ * 0: no writers, no VM_DENYWRITE mappings
+ * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
+ * > 0: (i_writecount) users are writing to the file.
+ *
+ * Normally we operate on that counter with atomic_{inc,dec} and it's safe
+ * except for the cases where we don't hold i_writecount yet. Then we need to
+ * use {get,deny}_write_access() - these functions check the sign and refuse
+ * to do the change if sign is wrong. Exclusion between them is provided by
+ * the inode->i_lock spinlock.
+ */
+
+int get_write_access(struct inode * inode)
+{
+        spin_lock(&inode->i_lock);
+        if (atomic_read(&inode->i_writecount) < 0) {
+                spin_unlock(&inode->i_lock);
+                return -ETXTBSY;
+        }
+        atomic_inc(&inode->i_writecount);
+        spin_unlock(&inode->i_lock);
+
+        return 0;
+}
+
+int deny_write_access(struct file * file)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+
+        spin_lock(&inode->i_lock);
+        if (atomic_read(&inode->i_writecount) > 0) {
+                spin_unlock(&inode->i_lock);
+                return -ETXTBSY;
+        }
+        atomic_dec(&inode->i_writecount);
+        spin_unlock(&inode->i_lock);
+
+        return 0;
+}
+
+void path_release(struct nameidata *nd)
+{
+        dput(nd->dentry);
+        mntput(nd->mnt);
+}
+
+/*
+ * umount() mustn't call path_release()/mntput() as that would clear
+ * mnt_expiry_mark
+ */
+void path_release_on_umount(struct nameidata *nd)
+{
+        dput(nd->dentry);
+        _mntput(nd->mnt);
+}
+
+/*
+ * Internal lookup() using the new generic dcache.
+ * SMP-safe
+ */
+static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
+{
+        struct dentry * dentry = __d_lookup(parent, name);
+
+        /* lockess __d_lookup may fail due to concurrent d_move() 
+         * in some unrelated directory, so try with d_lookup
+         */
+        if (!dentry)
+                dentry = d_lookup(parent, name);
+
+        if (dentry && dentry->d_op && dentry->d_op->d_revalidate) {
+                if (!dentry->d_op->d_revalidate(dentry, nd) && !d_invalidate(dentry)) {
+                        dput(dentry);
+                        dentry = NULL;
+                }
+        }
+        return dentry;
+}
+
+/*
+ * Short-cut version of permission(), for calling by
+ * path_walk(), when dcache lock is held.  Combines parts
+ * of permission() and generic_permission(), and tests ONLY for
+ * MAY_EXEC permission.
+ *
+ * If appropriate, check DAC only.  If not appropriate, or
+ * short-cut DAC fails, then call permission() to do more
+ * complete permission check.
+ */
+static inline int exec_permission_lite(struct inode *inode,
+                                       struct nameidata *nd)
+{
+        umode_t mode = inode->i_mode;
+
+        if (inode->i_op && inode->i_op->permission)
+                return -EAGAIN;
+
+        if (current->fsuid == inode->i_uid)
+                mode >>= 6;
+        else if (in_group_p(inode->i_gid))
+                mode >>= 3;
+
+        if (mode & MAY_EXEC)
+                goto ok;
+
+        if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE))
+                goto ok;
+
+        if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE))
+                goto ok;
+
+        if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH))
+                goto ok;
+
+        return -EACCES;
+ok:
+        return security_inode_permission(inode, MAY_EXEC, nd);
+}
+
+/*
+ * This is called when everything else fails, and we actually have
+ * to go to the low-level filesystem to find out what we should do..
+ *
+ * We get the directory semaphore, and after getting that we also
+ * make sure that nobody added the entry to the dcache in the meantime..
+ * SMP-safe
+ */
+static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
+{
+        struct dentry * result;
+        struct inode *dir = parent->d_inode;
+
+        down(&dir->i_sem);
+        /*
+         * First re-do the cached lookup just in case it was created
+         * while we waited for the directory semaphore..
+         *
+         * FIXME! This could use version numbering or similar to
+         * avoid unnecessary cache lookups.
+         *
+         * The "dcache_lock" is purely to protect the RCU list walker
+         * from concurrent renames at this point (we mustn't get false
+         * negatives from the RCU list walk here, unlike the optimistic
+         * fast walk).
+         *
+         * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
+         */
+        result = d_lookup(parent, name);
+        if (!result) {
+                struct dentry * dentry = d_alloc(parent, name);
+                result = ERR_PTR(-ENOMEM);
+                if (dentry) {
+                        result = dir->i_op->lookup(dir, dentry, nd);
+                        if (result)
+                                dput(dentry);
+                        else
+                                result = dentry;
+                }
+                up(&dir->i_sem);
+                return result;
+        }
+
+        /*
+         * Uhhuh! Nasty case: the cache was re-populated while
+         * we waited on the semaphore. Need to revalidate.
+         */
+        up(&dir->i_sem);
+        if (result->d_op && result->d_op->d_revalidate) {
+                if (!result->d_op->d_revalidate(result, nd) && !d_invalidate(result)) {
+                        dput(result);
+                        result = ERR_PTR(-ENOENT);
+                }
+        }
+        return result;
+}
+
+static int __emul_lookup_dentry(const char *, struct nameidata *);
+
+/* SMP-safe */
+static inline int
+walk_init_root(const char *name, struct nameidata *nd)
+{
+        read_lock(&current->fs->lock);
+        if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+                nd->mnt = mntget(current->fs->altrootmnt);
+                nd->dentry = dget(current->fs->altroot);
+                read_unlock(&current->fs->lock);
+                if (__emul_lookup_dentry(name,nd))
+                        return 0;
+                read_lock(&current->fs->lock);
+        }
+        nd->mnt = mntget(current->fs->rootmnt);
+        nd->dentry = dget(current->fs->root);
+        read_unlock(&current->fs->lock);
+        return 1;
+}
+
+static inline int __vfs_follow_link(struct nameidata *nd, const char *link)
+{
+        int res = 0;
+        char *name;
+        if (IS_ERR(link))
+                goto fail;
+
+        if (*link == '/') {
+                path_release(nd);
+                if (!walk_init_root(link, nd))
+                        /* weird __emul_prefix() stuff did it */
+                        goto out;
+        }
+        res = link_path_walk(link, nd);
+out:
+        if (nd->depth || res || nd->last_type!=LAST_NORM)
+                return res;
+        /*
+         * If it is an iterative symlinks resolution in open_namei() we
+         * have to copy the last component. And all that crap because of
+         * bloody create() on broken symlinks. Furrfu...
+         */
+        name = __getname();
+        if (unlikely(!name)) {
+                path_release(nd);
+                return -ENOMEM;
+        }
+        strcpy(name, nd->last.name);
+        nd->last.name = name;
+        return 0;
+fail:
+        path_release(nd);
+        return PTR_ERR(link);
+}
+
+static inline int __do_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+        int error;
+
+        touch_atime(nd->mnt, dentry);
+        nd_set_link(nd, NULL);
+        error = dentry->d_inode->i_op->follow_link(dentry, nd);
+        if (!error) {
+                char *s = nd_get_link(nd);
+                if (s)
+                        error = __vfs_follow_link(nd, s);
+                if (dentry->d_inode->i_op->put_link)
+                        dentry->d_inode->i_op->put_link(dentry, nd);
+        }
+
+        return error;
+}
+
+/*
+ * This limits recursive symlink follows to 8, while
+ * limiting consecutive symlinks to 40.
+ *
+ * Without that kind of total limit, nasty chains of consecutive
+ * symlinks can cause almost arbitrarily long lookups. 
+ */
+static inline int do_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+        int err = -ELOOP;
+        if (current->link_count >= MAX_NESTED_LINKS)
+                goto loop;
+        if (current->total_link_count >= 40)
+                goto loop;
+        BUG_ON(nd->depth >= MAX_NESTED_LINKS);
+        cond_resched();
+        err = security_inode_follow_link(dentry, nd);
+        if (err)
+                goto loop;
+        current->link_count++;
+        current->total_link_count++;
+        nd->depth++;
+        err = __do_follow_link(dentry, nd);
+        current->link_count--;
+        nd->depth--;
+        return err;
+loop:
+        path_release(nd);
+        return err;
+}
+
+int follow_up(struct vfsmount **mnt, struct dentry **dentry)
+{
+        struct vfsmount *parent;
+        struct dentry *mountpoint;
+        spin_lock(&vfsmount_lock);
+        parent=(*mnt)->mnt_parent;
+        if (parent == *mnt) {
+                spin_unlock(&vfsmount_lock);
+                return 0;
+        }
+        mntget(parent);
+        mountpoint=dget((*mnt)->mnt_mountpoint);
+        spin_unlock(&vfsmount_lock);
+        dput(*dentry);
+        *dentry = mountpoint;
+        mntput(*mnt);
+        *mnt = parent;
+        return 1;
+}
+
+/* no need for dcache_lock, as serialization is taken care in
+ * namespace.c
+ */
+static int follow_mount(struct vfsmount **mnt, struct dentry **dentry)
+{
+        int res = 0;
+        while (d_mountpoint(*dentry)) {
+                struct vfsmount *mounted = lookup_mnt(*mnt, *dentry);
+                if (!mounted)
+                        break;
+                mntput(*mnt);
+                *mnt = mounted;
+                dput(*dentry);
+                *dentry = dget(mounted->mnt_root);
+                res = 1;
+        }
+        return res;
+}
+
+/* no need for dcache_lock, as serialization is taken care in
+ * namespace.c
+ */
+static inline int __follow_down(struct vfsmount **mnt, struct dentry **dentry)
+{
+        struct vfsmount *mounted;
+
+        mounted = lookup_mnt(*mnt, *dentry);
+        if (mounted) {
+                mntput(*mnt);
+                *mnt = mounted;
+                dput(*dentry);
+                *dentry = dget(mounted->mnt_root);
+                return 1;
+        }
+        return 0;
+}
+
+int follow_down(struct vfsmount **mnt, struct dentry **dentry)
+{
+        return __follow_down(mnt,dentry);
+}
+ 
+static inline void follow_dotdot(struct vfsmount **mnt, struct dentry **dentry)
+{
+        while(1) {
+                struct vfsmount *parent;
+                struct dentry *old = *dentry;
+
+                read_lock(&current->fs->lock);
+                if (*dentry == current->fs->root &&
+                    *mnt == current->fs->rootmnt) {
+                        read_unlock(&current->fs->lock);
+                        break;
+                }
+                read_unlock(&current->fs->lock);
+                spin_lock(&dcache_lock);
+                if (*dentry != (*mnt)->mnt_root) {
+                        *dentry = dget((*dentry)->d_parent);
+                        spin_unlock(&dcache_lock);
+                        dput(old);
+                        break;
+                }
+                spin_unlock(&dcache_lock);
+                spin_lock(&vfsmount_lock);
+                parent = (*mnt)->mnt_parent;
+                if (parent == *mnt) {
+                        spin_unlock(&vfsmount_lock);
+                        break;
+                }
+                mntget(parent);
+                *dentry = dget((*mnt)->mnt_mountpoint);
+                spin_unlock(&vfsmount_lock);
+                dput(old);
+                mntput(*mnt);
+                *mnt = parent;
+        }
+        follow_mount(mnt, dentry);
+}
+
+struct path {
+        struct vfsmount *mnt;
+        struct dentry *dentry;
+};
+
+/*
+ *  It's more convoluted than I'd like it to be, but... it's still fairly
+ *  small and for now I'd prefer to have fast path as straight as possible.
+ *  It _is_ time-critical.
+ */
+static int do_lookup(struct nameidata *nd, struct qstr *name,
+                     struct path *path)
+{
+        struct vfsmount *mnt = nd->mnt;
+        struct dentry *dentry = __d_lookup(nd->dentry, name);
+
+        if (!dentry)
+                goto need_lookup;
+        if (dentry->d_op && dentry->d_op->d_revalidate)
+                goto need_revalidate;
+done:
+        path->mnt = mnt;
+        path->dentry = dentry;
+        return 0;
+
+need_lookup:
+        dentry = real_lookup(nd->dentry, name, nd);
+        if (IS_ERR(dentry))
+                goto fail;
+        goto done;
+
+need_revalidate:
+        if (dentry->d_op->d_revalidate(dentry, nd))
+                goto done;
+        if (d_invalidate(dentry))
+                goto done;
+        dput(dentry);
+        goto need_lookup;
+
+fail:
+        return PTR_ERR(dentry);
+}
+
+/*
+ * Name resolution.
+ *
+ * This is the basic name resolution function, turning a pathname
+ * into the final dentry.
+ *
+ * We expect 'base' to be positive and a directory.
+ */
+static fastcall int __link_path_walk(const char * name, struct nameidata *nd)
+{
+        struct path next;
+        struct inode *inode;
+        int err;
+        unsigned int lookup_flags = nd->flags;
+        
+        while (*name=='/')
+                name++;
+        if (!*name)
+                goto return_reval;
+
+        inode = nd->dentry->d_inode;
+        if (nd->depth)
+                lookup_flags = LOOKUP_FOLLOW;
+
+        /* At this point we know we have a real path component. */
+        for(;;) {
+                unsigned long hash;
+                struct qstr this;
+                unsigned int c;
+
+                err = exec_permission_lite(inode, nd);
+                if (err == -EAGAIN) { 
+                        err = permission(inode, MAY_EXEC, nd);
+                }
+                if (err)
+                        break;
+
+                this.name = name;
+                c = *(const unsigned char *)name;
+
+                hash = init_name_hash();
+                do {
+                        name++;
+                        hash = partial_name_hash(c, hash);
+                        c = *(const unsigned char *)name;
+                } while (c && (c != '/'));
+                this.len = name - (const char *) this.name;
+                this.hash = end_name_hash(hash);
+
+                /* remove trailing slashes? */
+                if (!c)
+                        goto last_component;
+                while (*++name == '/');
+                if (!*name)
+                        goto last_with_slashes;
+
+                /*
+                 * "." and ".." are special - ".." especially so because it has
+                 * to be able to know about the current root directory and
+                 * parent relationships.
+                 */
+                if (this.name[0] == '.') switch (this.len) {
+                        default:
+                                break;
+                        case 2: 
+                                if (this.name[1] != '.')
+                                        break;
+                                follow_dotdot(&nd->mnt, &nd->dentry);
+                                inode = nd->dentry->d_inode;
+                                /* fallthrough */
+                        case 1:
+                                continue;
+                }
+                /*
+                 * See if the low-level filesystem might want
+                 * to use its own hash..
+                 */
+                if (nd->dentry->d_op && nd->dentry->d_op->d_hash) {
+                        err = nd->dentry->d_op->d_hash(nd->dentry, &this);
+                        if (err < 0)
+                                break;
+                }
+                nd->flags |= LOOKUP_CONTINUE;
+                /* This does the actual lookups.. */
+                err = do_lookup(nd, &this, &next);
+                if (err)
+                        break;
+                /* Check mountpoints.. */
+                follow_mount(&next.mnt, &next.dentry);
+
+                err = -ENOENT;
+                inode = next.dentry->d_inode;
+                if (!inode)
+                        goto out_dput;
+                err = -ENOTDIR; 
+                if (!inode->i_op)
+                        goto out_dput;
+
+                if (inode->i_op->follow_link) {
+                        mntget(next.mnt);
+                        err = do_follow_link(next.dentry, nd);
+                        dput(next.dentry);
+                        mntput(next.mnt);
+                        if (err)
+                                goto return_err;
+                        err = -ENOENT;
+                        inode = nd->dentry->d_inode;
+                        if (!inode)
+                                break;
+                        err = -ENOTDIR; 
+                        if (!inode->i_op)
+                                break;
+                } else {
+                        dput(nd->dentry);
+                        nd->mnt = next.mnt;
+                        nd->dentry = next.dentry;
+                }
+                err = -ENOTDIR; 
+                if (!inode->i_op->lookup)
+                        break;
+                continue;
+                /* here ends the main loop */
+
+last_with_slashes:
+                lookup_flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+last_component:
+                nd->flags &= ~LOOKUP_CONTINUE;
+                if (lookup_flags & LOOKUP_PARENT)
+                        goto lookup_parent;
+                if (this.name[0] == '.') switch (this.len) {
+                        default:
+                                break;
+                        case 2: 
+                                if (this.name[1] != '.')
+                                        break;
+                                follow_dotdot(&nd->mnt, &nd->dentry);
+                                inode = nd->dentry->d_inode;
+                                /* fallthrough */
+                        case 1:
+                                goto return_reval;
+                }
+                if (nd->dentry->d_op && nd->dentry->d_op->d_hash) {
+                        err = nd->dentry->d_op->d_hash(nd->dentry, &this);
+                        if (err < 0)
+                                break;
+                }
+                err = do_lookup(nd, &this, &next);
+                if (err)
+                        break;
+                follow_mount(&next.mnt, &next.dentry);
+                inode = next.dentry->d_inode;
+                if ((lookup_flags & LOOKUP_FOLLOW)
+                    && inode && inode->i_op && inode->i_op->follow_link) {
+                        mntget(next.mnt);
+                        err = do_follow_link(next.dentry, nd);
+                        dput(next.dentry);
+                        mntput(next.mnt);
+                        if (err)
+                                goto return_err;
+                        inode = nd->dentry->d_inode;
+                } else {
+                        dput(nd->dentry);
+                        nd->mnt = next.mnt;
+                        nd->dentry = next.dentry;
+                }
+                err = -ENOENT;
+                if (!inode)
+                        break;
+                if (lookup_flags & LOOKUP_DIRECTORY) {
+                        err = -ENOTDIR; 
+                        if (!inode->i_op || !inode->i_op->lookup)
+                                break;
+                }
+                goto return_base;
+lookup_parent:
+                nd->last = this;
+                nd->last_type = LAST_NORM;
+                if (this.name[0] != '.')
+                        goto return_base;
+                if (this.len == 1)
+                        nd->last_type = LAST_DOT;
+                else if (this.len == 2 && this.name[1] == '.')
+                        nd->last_type = LAST_DOTDOT;
+                else
+                        goto return_base;
+return_reval:
+                /*
+                 * We bypassed the ordinary revalidation routines.
+                 * We may need to check the cached dentry for staleness.
+                 */
+                if (nd->dentry && nd->dentry->d_sb &&
+                    (nd->dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) {
+                        err = -ESTALE;
+                        /* Note: we do not d_invalidate() */
+                        if (!nd->dentry->d_op->d_revalidate(nd->dentry, nd))
+                                break;
+                }
+return_base:
+                return 0;
+out_dput:
+                dput(next.dentry);
+                break;
+        }
+        path_release(nd);
+return_err:
+        return err;
+}
+
+/*
+ * Wrapper to retry pathname resolution whenever the underlying
+ * file system returns an ESTALE.
+ *
+ * Retry the whole path once, forcing real lookup requests
+ * instead of relying on the dcache.
+ */
+int fastcall link_path_walk(const char *name, struct nameidata *nd)
+{
+        struct nameidata save = *nd;
+        int result;
+
+        /* make sure the stuff we saved doesn't go away */
+        dget(save.dentry);
+        mntget(save.mnt);
+
+        result = __link_path_walk(name, nd);
+        if (result == -ESTALE) {
+                *nd = save;
+                dget(nd->dentry);
+                mntget(nd->mnt);
+                nd->flags |= LOOKUP_REVAL;
+                result = __link_path_walk(name, nd);
+        }
+
+        dput(save.dentry);
+        mntput(save.mnt);
+
+        return result;
+}
+
+int fastcall path_walk(const char * name, struct nameidata *nd)
+{
+        current->total_link_count = 0;
+        return link_path_walk(name, nd);
+}
+
+/* SMP-safe */
+/* returns 1 if everything is done */
+static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
+{
+        if (path_walk(name, nd))
+                return 0;               /* something went wrong... */
+
+        if (!nd->dentry->d_inode || S_ISDIR(nd->dentry->d_inode->i_mode)) {
+                struct dentry *old_dentry = nd->dentry;
+                struct vfsmount *old_mnt = nd->mnt;
+                struct qstr last = nd->last;
+                int last_type = nd->last_type;
+                /*
+                 * NAME was not found in alternate root or it's a directory.  Try to find
+                 * it in the normal root:
+                 */
+                nd->last_type = LAST_ROOT;
+                read_lock(&current->fs->lock);
+                nd->mnt = mntget(current->fs->rootmnt);
+                nd->dentry = dget(current->fs->root);
+                read_unlock(&current->fs->lock);
+                if (path_walk(name, nd) == 0) {
+                        if (nd->dentry->d_inode) {
+                                dput(old_dentry);
+                                mntput(old_mnt);
+                                return 1;
+                        }
+                        path_release(nd);
+                }
+                nd->dentry = old_dentry;
+                nd->mnt = old_mnt;
+                nd->last = last;
+                nd->last_type = last_type;
+        }
+        return 1;
+}
+
+void set_fs_altroot(void)
+{
+        char *emul = __emul_prefix();
+        struct nameidata nd;
+        struct vfsmount *mnt = NULL, *oldmnt;
+        struct dentry *dentry = NULL, *olddentry;
+        int err;
+
+        if (!emul)
+                goto set_it;
+        err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd);
+        if (!err) {
+                mnt = nd.mnt;
+                dentry = nd.dentry;
+        }
+set_it:
+        write_lock(&current->fs->lock);
+        oldmnt = current->fs->altrootmnt;
+        olddentry = current->fs->altroot;
+        current->fs->altrootmnt = mnt;
+        current->fs->altroot = dentry;
+        write_unlock(&current->fs->lock);
+        if (olddentry) {
+                dput(olddentry);
+                mntput(oldmnt);
+        }
+}
+
+int fastcall path_lookup(const char *name, unsigned int flags, struct nameidata *nd)
+{
+        int retval;
+
+        nd->last_type = LAST_ROOT; /* if there are only slashes... */
+        nd->flags = flags;
+        nd->depth = 0;
+
+        read_lock(&current->fs->lock);
+        if (*name=='/') {
+                if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+                        nd->mnt = mntget(current->fs->altrootmnt);
+                        nd->dentry = dget(current->fs->altroot);
+                        read_unlock(&current->fs->lock);
+                        if (__emul_lookup_dentry(name,nd))
+                                return 0;
+                        read_lock(&current->fs->lock);
+                }
+                nd->mnt = mntget(current->fs->rootmnt);
+                nd->dentry = dget(current->fs->root);
+        } else {
+                nd->mnt = mntget(current->fs->pwdmnt);
+                nd->dentry = dget(current->fs->pwd);
+        }
+        read_unlock(&current->fs->lock);
+        current->total_link_count = 0;
+        retval = link_path_walk(name, nd);
+        if (unlikely(current->audit_context
+                     && nd && nd->dentry && nd->dentry->d_inode))
+                audit_inode(name, nd->dentry->d_inode);
+        return retval;
+}
+
+/*
+ * Restricted form of lookup. Doesn't follow links, single-component only,
+ * needs parent already locked. Doesn't follow mounts.
+ * SMP-safe.
+ */
+static struct dentry * __lookup_hash(struct qstr *name, struct dentry * base, struct nameidata *nd)
+{
+        struct dentry * dentry;
+        struct inode *inode;
+        int err;
+
+        inode = base->d_inode;
+        err = permission(inode, MAY_EXEC, nd);
+        dentry = ERR_PTR(err);
+        if (err)
+                goto out;
+
+        /*
+         * See if the low-level filesystem might want
+         * to use its own hash..
+         */
+        if (base->d_op && base->d_op->d_hash) {
+                err = base->d_op->d_hash(base, name);
+                dentry = ERR_PTR(err);
+                if (err < 0)
+                        goto out;
+        }
+
+        dentry = cached_lookup(base, name, nd);
+        if (!dentry) {
+                struct dentry *new = d_alloc(base, name);
+                dentry = ERR_PTR(-ENOMEM);
+                if (!new)
+                        goto out;
+                dentry = inode->i_op->lookup(inode, new, nd);
+                if (!dentry)
+                        dentry = new;
+                else
+                        dput(new);
+        }
+out:
+        return dentry;
+}
+
+struct dentry * lookup_hash(struct qstr *name, struct dentry * base)
+{
+        return __lookup_hash(name, base, NULL);
+}
+
+/* SMP-safe */
+struct dentry * lookup_one_len(const char * name, struct dentry * base, int len)
+{
+        unsigned long hash;
+        struct qstr this;
+        unsigned int c;
+
+        this.name = name;
+        this.len = len;
+        if (!len)
+                goto access;
+
+        hash = init_name_hash();
+        while (len--) {
+                c = *(const unsigned char *)name++;
+                if (c == '/' || c == '\0')
+                        goto access;
+                hash = partial_name_hash(c, hash);
+        }
+        this.hash = end_name_hash(hash);
+
+        return lookup_hash(&this, base);
+access:
+        return ERR_PTR(-EACCES);
+}
+
+/*
+ *      namei()
+ *
+ * is used by most simple commands to get the inode of a specified name.
+ * Open, link etc use their own routines, but this is enough for things
+ * like 'chmod' etc.
+ *
+ * namei exists in two versions: namei/lnamei. The only difference is
+ * that namei follows links, while lnamei does not.
+ * SMP-safe
+ */
+int fastcall __user_walk(const char __user *name, unsigned flags, struct nameidata *nd)
+{
+        char *tmp = getname(name);
+        int err = PTR_ERR(tmp);
+
+        if (!IS_ERR(tmp)) {
+                err = path_lookup(tmp, flags, nd);
+                putname(tmp);
+        }
+        return err;
+}
+
+/*
+ * It's inline, so penalty for filesystems that don't use sticky bit is
+ * minimal.
+ */
+static inline int check_sticky(struct inode *dir, struct inode *inode)
+{
+        if (!(dir->i_mode & S_ISVTX))
+                return 0;
+        if (inode->i_uid == current->fsuid)
+                return 0;
+        if (dir->i_uid == current->fsuid)
+                return 0;
+        return !capable(CAP_FOWNER);
+}
+
+/*
+ *      Check whether we can remove a link victim from directory dir, check
+ *  whether the type of victim is right.
+ *  1. We can't do it if dir is read-only (done in permission())
+ *  2. We should have write and exec permissions on dir
+ *  3. We can't remove anything from append-only dir
+ *  4. We can't do anything with immutable dir (done in permission())
+ *  5. If the sticky bit on dir is set we should either
+ *      a. be owner of dir, or
+ *      b. be owner of victim, or
+ *      c. have CAP_FOWNER capability
+ *  6. If the victim is append-only or immutable we can't do antyhing with
+ *     links pointing to it.
+ *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
+ *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
+ *  9. We can't remove a root or mountpoint.
+ * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
+ *     nfs_async_unlink().
+ */
+static inline int may_delete(struct inode *dir,struct dentry *victim,int isdir)
+{
+        int error;
+
+        if (!victim->d_inode)
+                return -ENOENT;
+
+        BUG_ON(victim->d_parent->d_inode != dir);
+
+        error = permission(dir,MAY_WRITE | MAY_EXEC, NULL);
+        if (error)
+                return error;
+        if (IS_APPEND(dir))
+                return -EPERM;
+        if (check_sticky(dir, victim->d_inode)||IS_APPEND(victim->d_inode)||
+            IS_IMMUTABLE(victim->d_inode))
+                return -EPERM;
+        if (isdir) {
+                if (!S_ISDIR(victim->d_inode->i_mode))
+                        return -ENOTDIR;
+                if (IS_ROOT(victim))
+                        return -EBUSY;
+        } else if (S_ISDIR(victim->d_inode->i_mode))
+                return -EISDIR;
+        if (IS_DEADDIR(dir))
+                return -ENOENT;
+        if (victim->d_flags & DCACHE_NFSFS_RENAMED)
+                return -EBUSY;
+        return 0;
+}
+
+/*      Check whether we can create an object with dentry child in directory
+ *  dir.
+ *  1. We can't do it if child already exists (open has special treatment for
+ *     this case, but since we are inlined it's OK)
+ *  2. We can't do it if dir is read-only (done in permission())
+ *  3. We should have write and exec permissions on dir
+ *  4. We can't do it if dir is immutable (done in permission())
+ */
+static inline int may_create(struct inode *dir, struct dentry *child,
+                             struct nameidata *nd)
+{
+        if (child->d_inode)
+                return -EEXIST;
+        if (IS_DEADDIR(dir))
+                return -ENOENT;
+        return permission(dir,MAY_WRITE | MAY_EXEC, nd);
+}
+
+/* 
+ * Special case: O_CREAT|O_EXCL implies O_NOFOLLOW for security
+ * reasons.
+ *
+ * O_DIRECTORY translates into forcing a directory lookup.
+ */
+static inline int lookup_flags(unsigned int f)
+{
+        unsigned long retval = LOOKUP_FOLLOW;
+
+        if (f & O_NOFOLLOW)
+                retval &= ~LOOKUP_FOLLOW;
+        
+        if ((f & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+                retval &= ~LOOKUP_FOLLOW;
+        
+        if (f & O_DIRECTORY)
+                retval |= LOOKUP_DIRECTORY;
+
+        return retval;
+}
+
+/*
+ * p1 and p2 should be directories on the same fs.
+ */
+struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
+{
+        struct dentry *p;
+
+        if (p1 == p2) {
+                down(&p1->d_inode->i_sem);
+                return NULL;
+        }
+
+        down(&p1->d_inode->i_sb->s_vfs_rename_sem);
+
+        for (p = p1; p->d_parent != p; p = p->d_parent) {
+                if (p->d_parent == p2) {
+                        down(&p2->d_inode->i_sem);
+                        down(&p1->d_inode->i_sem);
+                        return p;
+                }
+        }
+
+        for (p = p2; p->d_parent != p; p = p->d_parent) {
+                if (p->d_parent == p1) {
+                        down(&p1->d_inode->i_sem);
+                        down(&p2->d_inode->i_sem);
+                        return p;
+                }
+        }
+
+        down(&p1->d_inode->i_sem);
+        down(&p2->d_inode->i_sem);
+        return NULL;
+}
+
+void unlock_rename(struct dentry *p1, struct dentry *p2)
+{
+        up(&p1->d_inode->i_sem);
+        if (p1 != p2) {
+                up(&p2->d_inode->i_sem);
+                up(&p1->d_inode->i_sb->s_vfs_rename_sem);
+        }
+}
+
+int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
+                struct nameidata *nd)
+{
+        int error = may_create(dir, dentry, nd);
+
+        if (error)
+                return error;
+
+        if (!dir->i_op || !dir->i_op->create)
+                return -EACCES; /* shouldn't it be ENOSYS? */
+        mode &= S_IALLUGO;
+        mode |= S_IFREG;
+        error = security_inode_create(dir, dentry, mode);
+        if (error)
+                return error;
+        DQUOT_INIT(dir);
+        error = dir->i_op->create(dir, dentry, mode, nd);
+        if (!error) {
+                inode_dir_notify(dir, DN_CREATE);
+                security_inode_post_create(dir, dentry, mode);
+        }
+        return error;
+}
+
+int may_open(struct nameidata *nd, int acc_mode, int flag)
+{
+        struct dentry *dentry = nd->dentry;
+        struct inode *inode = dentry->d_inode;
+        int error;
+
+        if (!inode)
+                return -ENOENT;
+
+        if (S_ISLNK(inode->i_mode))
+                return -ELOOP;
+        
+        if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE))
+                return -EISDIR;
+
+        error = permission(inode, acc_mode, nd);
+        if (error)
+                return error;
+
+        /*
+         * FIFO's, sockets and device files are special: they don't
+         * actually live on the filesystem itself, and as such you
+         * can write to them even if the filesystem is read-only.
+         */
+        if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+                flag &= ~O_TRUNC;
+        } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
+                if (nd->mnt->mnt_flags & MNT_NODEV)
+                        return -EACCES;
+
+                flag &= ~O_TRUNC;
+        } else if (IS_RDONLY(inode) && (flag & FMODE_WRITE))
+                return -EROFS;
+        /*
+         * An append-only file must be opened in append mode for writing.
+         */
+        if (IS_APPEND(inode)) {
+                if  ((flag & FMODE_WRITE) && !(flag & O_APPEND))
+                        return -EPERM;
+                if (flag & O_TRUNC)
+                        return -EPERM;
+        }
+
+        /* O_NOATIME can only be set by the owner or superuser */
+        if (flag & O_NOATIME)
+                if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
+                        return -EPERM;
+
+        /*
+         * Ensure there are no outstanding leases on the file.
+         */
+        error = break_lease(inode, flag);
+        if (error)
+                return error;
+
+        if (flag & O_TRUNC) {
+                error = get_write_access(inode);
+                if (error)
+                        return error;
+
+                /*
+                 * Refuse to truncate files with mandatory locks held on them.
+                 */
+                error = locks_verify_locked(inode);
+                if (!error) {
+                        DQUOT_INIT(inode);
+                        
+                        error = do_truncate(dentry, 0);
+                }
+                put_write_access(inode);
+                if (error)
+                        return error;
+        } else
+                if (flag & FMODE_WRITE)
+                        DQUOT_INIT(inode);
+
+        return 0;
+}
+
+/*
+ *      open_namei()
+ *
+ * namei for open - this is in fact almost the whole open-routine.
+ *
+ * Note that the low bits of "flag" aren't the same as in the open
+ * system call - they are 00 - no permissions needed
+ *                        01 - read permission needed
+ *                        10 - write permission needed
+ *                        11 - read/write permissions needed
+ * which is a lot more logical, and also allows the "no perm" needed
+ * for symlinks (where the permissions are checked later).
+ * SMP-safe
+ */
+int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
+{
+        int acc_mode, error = 0;
+        struct dentry *dentry;
+        struct dentry *dir;
+        int count = 0;
+
+        acc_mode = ACC_MODE(flag);
+
+        /* Allow the LSM permission hook to distinguish append 
+           access from general write access. */
+        if (flag & O_APPEND)
+                acc_mode |= MAY_APPEND;
+
+        /* Fill in the open() intent data */
+        nd->intent.open.flags = flag;
+        nd->intent.open.create_mode = mode;
+
+        /*
+         * The simplest case - just a plain lookup.
+         */
+        if (!(flag & O_CREAT)) {
+                error = path_lookup(pathname, lookup_flags(flag)|LOOKUP_OPEN, nd);
+                if (error)
+                        return error;
+                goto ok;
+        }
+
+        /*
+         * Create - we need to know the parent.
+         */
+        error = path_lookup(pathname, LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE, nd);
+        if (error)
+                return error;
+
+        /*
+         * We have the parent and last component. First of all, check
+         * that we are not asked to creat(2) an obvious directory - that
+         * will not do.
+         */
+        error = -EISDIR;
+        if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len])
+                goto exit;
+
+        dir = nd->dentry;
+        nd->flags &= ~LOOKUP_PARENT;
+        down(&dir->d_inode->i_sem);
+        dentry = __lookup_hash(&nd->last, nd->dentry, nd);
+
+do_last:
+        error = PTR_ERR(dentry);
+        if (IS_ERR(dentry)) {
+                up(&dir->d_inode->i_sem);
+                goto exit;
+        }
+
+        /* Negative dentry, just create the file */
+        if (!dentry->d_inode) {
+                if (!IS_POSIXACL(dir->d_inode))
+                        mode &= ~current->fs->umask;
+                error = vfs_create(dir->d_inode, dentry, mode, nd);
+                up(&dir->d_inode->i_sem);
+                dput(nd->dentry);
+                nd->dentry = dentry;
+                if (error)
+                        goto exit;
+                /* Don't check for write permission, don't truncate */
+                acc_mode = 0;
+                flag &= ~O_TRUNC;
+                goto ok;
+        }
+
+        /*
+         * It already exists.
+         */
+        up(&dir->d_inode->i_sem);
+
+        error = -EEXIST;
+        if (flag & O_EXCL)
+                goto exit_dput;
+
+        if (d_mountpoint(dentry)) {
+                error = -ELOOP;
+                if (flag & O_NOFOLLOW)
+                        goto exit_dput;
+                while (__follow_down(&nd->mnt,&dentry) && d_mountpoint(dentry));
+        }
+        error = -ENOENT;
+        if (!dentry->d_inode)
+                goto exit_dput;
+        if (dentry->d_inode->i_op && dentry->d_inode->i_op->follow_link)
+                goto do_link;
+
+        dput(nd->dentry);
+        nd->dentry = dentry;
+        error = -EISDIR;
+        if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode))
+                goto exit;
+ok:
+        error = may_open(nd, acc_mode, flag);
+        if (error)
+                goto exit;
+        return 0;
+
+exit_dput:
+        dput(dentry);
+exit:
+        path_release(nd);
+        return error;
+
+do_link:
+        error = -ELOOP;
+        if (flag & O_NOFOLLOW)
+                goto exit_dput;
+        /*
+         * This is subtle. Instead of calling do_follow_link() we do the
+         * thing by hands. The reason is that this way we have zero link_count
+         * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
+         * After that we have the parent and last component, i.e.
+         * we are in the same situation as after the first path_walk().
+         * Well, almost - if the last component is normal we get its copy
+         * stored in nd->last.name and we will have to putname() it when we
+         * are done. Procfs-like symlinks just set LAST_BIND.
+         */
+        nd->flags |= LOOKUP_PARENT;
+        error = security_inode_follow_link(dentry, nd);
+        if (error)
+                goto exit_dput;
+        error = __do_follow_link(dentry, nd);
+        dput(dentry);
+        if (error)
+                return error;
+        nd->flags &= ~LOOKUP_PARENT;
+        if (nd->last_type == LAST_BIND) {
+                dentry = nd->dentry;
+                goto ok;
+        }
+        error = -EISDIR;
+        if (nd->last_type != LAST_NORM)
+                goto exit;
+        if (nd->last.name[nd->last.len]) {
+                putname(nd->last.name);
+                goto exit;
+        }
+        error = -ELOOP;
+        if (count++==32) {
+                putname(nd->last.name);
+                goto exit;
+        }
+        dir = nd->dentry;
+        down(&dir->d_inode->i_sem);
+        dentry = __lookup_hash(&nd->last, nd->dentry, nd);
+        putname(nd->last.name);
+        goto do_last;
+}
+
+/**
+ * lookup_create - lookup a dentry, creating it if it doesn't exist
+ * @nd: nameidata info
+ * @is_dir: directory flag
+ *
+ * Simple function to lookup and return a dentry and create it
+ * if it doesn't exist.  Is SMP-safe.
+ */
+struct dentry *lookup_create(struct nameidata *nd, int is_dir)
+{
+        struct dentry *dentry;
+
+        down(&nd->dentry->d_inode->i_sem);
+        dentry = ERR_PTR(-EEXIST);
+        if (nd->last_type != LAST_NORM)
+                goto fail;
+        nd->flags &= ~LOOKUP_PARENT;
+        dentry = lookup_hash(&nd->last, nd->dentry);
+        if (IS_ERR(dentry))
+                goto fail;
+        if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
+                goto enoent;
+        return dentry;
+enoent:
+        dput(dentry);
+        dentry = ERR_PTR(-ENOENT);
+fail:
+        return dentry;
+}
+
+int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+{
+        int error = may_create(dir, dentry, NULL);
+
+        if (error)
+                return error;
+
+        if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
+                return -EPERM;
+
+        if (!dir->i_op || !dir->i_op->mknod)
+                return -EPERM;
+
+        error = security_inode_mknod(dir, dentry, mode, dev);
+        if (error)
+                return error;
+
+        DQUOT_INIT(dir);
+        error = dir->i_op->mknod(dir, dentry, mode, dev);
+        if (!error) {
+                inode_dir_notify(dir, DN_CREATE);
+                security_inode_post_mknod(dir, dentry, mode, dev);
+        }
+        return error;
+}
+
+asmlinkage long sys_mknod(const char __user * filename, int mode, unsigned dev)
+{
+        int error = 0;
+        char * tmp;
+        struct dentry * dentry;
+        struct nameidata nd;
+
+        if (S_ISDIR(mode))
+                return -EPERM;
+        tmp = getname(filename);
+        if (IS_ERR(tmp))
+                return PTR_ERR(tmp);
+
+        error = path_lookup(tmp, LOOKUP_PARENT, &nd);
+        if (error)
+                goto out;
+        dentry = lookup_create(&nd, 0);
+        error = PTR_ERR(dentry);
+
+        if (!IS_POSIXACL(nd.dentry->d_inode))
+                mode &= ~current->fs->umask;
+        if (!IS_ERR(dentry)) {
+                switch (mode & S_IFMT) {
+                case 0: case S_IFREG:
+                        error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
+                        break;
+                case S_IFCHR: case S_IFBLK:
+                        error = vfs_mknod(nd.dentry->d_inode,dentry,mode,
+                                        new_decode_dev(dev));
+                        break;
+                case S_IFIFO: case S_IFSOCK:
+                        error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
+                        break;
+                case S_IFDIR:
+                        error = -EPERM;
+                        break;
+                default:
+                        error = -EINVAL;
+                }
+                dput(dentry);
+        }
+        up(&nd.dentry->d_inode->i_sem);
+        path_release(&nd);
+out:
+        putname(tmp);
+
+        return error;
+}
+
+int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+        int error = may_create(dir, dentry, NULL);
+
+        if (error)
+                return error;
+
+        if (!dir->i_op || !dir->i_op->mkdir)
+                return -EPERM;
+
+        mode &= (S_IRWXUGO|S_ISVTX);
+        error = security_inode_mkdir(dir, dentry, mode);
+        if (error)
+                return error;
+
+        DQUOT_INIT(dir);
+        error = dir->i_op->mkdir(dir, dentry, mode);
+        if (!error) {
+                inode_dir_notify(dir, DN_CREATE);
+                security_inode_post_mkdir(dir,dentry, mode);
+        }
+        return error;
+}
+
+asmlinkage long sys_mkdir(const char __user * pathname, int mode)
+{
+        int error = 0;
+        char * tmp;
+
+        tmp = getname(pathname);
+        error = PTR_ERR(tmp);
+        if (!IS_ERR(tmp)) {
+                struct dentry *dentry;
+                struct nameidata nd;
+
+                error = path_lookup(tmp, LOOKUP_PARENT, &nd);
+                if (error)
+                        goto out;
+                dentry = lookup_create(&nd, 1);
+                error = PTR_ERR(dentry);
+                if (!IS_ERR(dentry)) {
+                        if (!IS_POSIXACL(nd.dentry->d_inode))
+                                mode &= ~current->fs->umask;
+                        error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+                        dput(dentry);
+                }
+                up(&nd.dentry->d_inode->i_sem);
+                path_release(&nd);
+out:
+                putname(tmp);
+        }
+
+        return error;
+}
+
+/*
+ * We try to drop the dentry early: we should have
+ * a usage count of 2 if we're the only user of this
+ * dentry, and if that is true (possibly after pruning
+ * the dcache), then we drop the dentry now.
+ *
+ * A low-level filesystem can, if it choses, legally
+ * do a
+ *
+ *      if (!d_unhashed(dentry))
+ *              return -EBUSY;
+ *
+ * if it cannot handle the case of removing a directory
+ * that is still in use by something else..
+ */
+void dentry_unhash(struct dentry *dentry)
+{
+        dget(dentry);
+        if (atomic_read(&dentry->d_count))
+                shrink_dcache_parent(dentry);
+        spin_lock(&dcache_lock);
+        spin_lock(&dentry->d_lock);
+        if (atomic_read(&dentry->d_count) == 2)
+                __d_drop(dentry);
+        spin_unlock(&dentry->d_lock);
+        spin_unlock(&dcache_lock);
+}
+
+int vfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+        int error = may_delete(dir, dentry, 1);
+
+        if (error)
+                return error;
+
+        if (!dir->i_op || !dir->i_op->rmdir)
+                return -EPERM;
+
+        DQUOT_INIT(dir);
+
+        down(&dentry->d_inode->i_sem);
+        dentry_unhash(dentry);
+        if (d_mountpoint(dentry))
+                error = -EBUSY;
+        else {
+                error = security_inode_rmdir(dir, dentry);
+                if (!error) {
+                        error = dir->i_op->rmdir(dir, dentry);
+                        if (!error)
+                                dentry->d_inode->i_flags |= S_DEAD;
+                }
+        }
+        up(&dentry->d_inode->i_sem);
+        if (!error) {
+                inode_dir_notify(dir, DN_DELETE);
+                d_delete(dentry);
+        }
+        dput(dentry);
+
+        return error;
+}
+
+asmlinkage long sys_rmdir(const char __user * pathname)
+{
+        int error = 0;
+        char * name;
+        struct dentry *dentry;
+        struct nameidata nd;
+
+        name = getname(pathname);
+        if(IS_ERR(name))
+                return PTR_ERR(name);
+
+        error = path_lookup(name, LOOKUP_PARENT, &nd);
+        if (error)
+                goto exit;
+
+        switch(nd.last_type) {
+                case LAST_DOTDOT:
+                        error = -ENOTEMPTY;
+                        goto exit1;
+                case LAST_DOT:
+                        error = -EINVAL;
+                        goto exit1;
+                case LAST_ROOT:
+                        error = -EBUSY;
+                        goto exit1;
+        }
+        down(&nd.dentry->d_inode->i_sem);
+        dentry = lookup_hash(&nd.last, nd.dentry);
+        error = PTR_ERR(dentry);
+        if (!IS_ERR(dentry)) {
+                error = vfs_rmdir(nd.dentry->d_inode, dentry);
+                dput(dentry);
+        }
+        up(&nd.dentry->d_inode->i_sem);
+exit1:
+        path_release(&nd);
+exit:
+        putname(name);
+        return error;
+}
+
+int vfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+        int error = may_delete(dir, dentry, 0);
+
+        if (error)
+                return error;
+
+        if (!dir->i_op || !dir->i_op->unlink)
+                return -EPERM;
+
+        DQUOT_INIT(dir);
+
+        down(&dentry->d_inode->i_sem);
+        if (d_mountpoint(dentry))
+                error = -EBUSY;
+        else {
+                error = security_inode_unlink(dir, dentry);
+                if (!error)
+                        error = dir->i_op->unlink(dir, dentry);
+        }
+        up(&dentry->d_inode->i_sem);
+
+        /* We don't d_delete() NFS sillyrenamed files--they still exist. */
+        if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
+                d_delete(dentry);
+                inode_dir_notify(dir, DN_DELETE);
+        }
+        return error;
+}
+
+/*
+ * Make sure that the actual truncation of the file will occur outside its
+ * directory's i_sem.  Truncate can take a long time if there is a lot of
+ * writeout happening, and we don't want to prevent access to the directory
+ * while waiting on the I/O.
+ */
+asmlinkage long sys_unlink(const char __user * pathname)
+{
+        int error = 0;
+        char * name;
+        struct dentry *dentry;
+        struct nameidata nd;
+        struct inode *inode = NULL;
+
+        name = getname(pathname);
+        if(IS_ERR(name))
+                return PTR_ERR(name);
+
+        error = path_lookup(name, LOOKUP_PARENT, &nd);
+        if (error)
+                goto exit;
+        error = -EISDIR;
+        if (nd.last_type != LAST_NORM)
+                goto exit1;
+        down(&nd.dentry->d_inode->i_sem);
+        dentry = lookup_hash(&nd.last, nd.dentry);
+        error = PTR_ERR(dentry);
+        if (!IS_ERR(dentry)) {
+                /* Why not before? Because we want correct error value */
+                if (nd.last.name[nd.last.len])
+                        goto slashes;
+                inode = dentry->d_inode;
+                if (inode)
+                        atomic_inc(&inode->i_count);
+                error = vfs_unlink(nd.dentry->d_inode, dentry);
+        exit2:
+                dput(dentry);
+        }
+        up(&nd.dentry->d_inode->i_sem);
+        if (inode)
+                iput(inode);    /* truncate the inode here */
+exit1:
+        path_release(&nd);
+exit:
+        putname(name);
+        return error;
+
+slashes:
+        error = !dentry->d_inode ? -ENOENT :
+                S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
+        goto exit2;
+}
+
+int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode)
+{
+        int error = may_create(dir, dentry, NULL);
+
+        if (error)
+                return error;
+
+        if (!dir->i_op || !dir->i_op->symlink)
+                return -EPERM;
+
+        error = security_inode_symlink(dir, dentry, oldname);
+        if (error)
+                return error;
+
+        DQUOT_INIT(dir);
+        error = dir->i_op->symlink(dir, dentry, oldname);
+        if (!error) {
+                inode_dir_notify(dir, DN_CREATE);
+                security_inode_post_symlink(dir, dentry, oldname);
+        }
+        return error;
+}
+
+asmlinkage long sys_symlink(const char __user * oldname, const char __user * newname)
+{
+        int error = 0;
+        char * from;
+        char * to;
+
+        from = getname(oldname);
+        if(IS_ERR(from))
+                return PTR_ERR(from);
+        to = getname(newname);
+        error = PTR_ERR(to);
+        if (!IS_ERR(to)) {
+                struct dentry *dentry;
+                struct nameidata nd;
+
+                error = path_lookup(to, LOOKUP_PARENT, &nd);
+                if (error)
+                        goto out;
+                dentry = lookup_create(&nd, 0);
+                error = PTR_ERR(dentry);
+                if (!IS_ERR(dentry)) {
+                        error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+                        dput(dentry);
+                }
+                up(&nd.dentry->d_inode->i_sem);
+                path_release(&nd);
+out:
+                putname(to);
+        }
+        putname(from);
+        return error;
+}
+
+int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
+{
+        struct inode *inode = old_dentry->d_inode;
+        int error;
+
+        if (!inode)
+                return -ENOENT;
+
+        error = may_create(dir, new_dentry, NULL);
+        if (error)
+                return error;
+
+        if (dir->i_sb != inode->i_sb)
+                return -EXDEV;
+
+        /*
+         * A link to an append-only or immutable file cannot be created.
+         */
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return -EPERM;
+        if (!dir->i_op || !dir->i_op->link)
+                return -EPERM;
+        if (S_ISDIR(old_dentry->d_inode->i_mode))
+                return -EPERM;
+
+        error = security_inode_link(old_dentry, dir, new_dentry);
+        if (error)
+                return error;
+
+        down(&old_dentry->d_inode->i_sem);
+        DQUOT_INIT(dir);
+        error = dir->i_op->link(old_dentry, dir, new_dentry);
+        up(&old_dentry->d_inode->i_sem);
+        if (!error) {
+                inode_dir_notify(dir, DN_CREATE);
+                security_inode_post_link(old_dentry, dir, new_dentry);
+        }
+        return error;
+}
+
+/*
+ * Hardlinks are often used in delicate situations.  We avoid
+ * security-related surprises by not following symlinks on the
+ * newname.  --KAB
+ *
+ * We don't follow them on the oldname either to be compatible
+ * with linux 2.0, and to avoid hard-linking to directories
+ * and other special files.  --ADM
+ */
+asmlinkage long sys_link(const char __user * oldname, const char __user * newname)
+{
+        struct dentry *new_dentry;
+        struct nameidata nd, old_nd;
+        int error;
+        char * to;
+
+        to = getname(newname);
+        if (IS_ERR(to))
+                return PTR_ERR(to);
+
+        error = __user_walk(oldname, 0, &old_nd);
+        if (error)
+                goto exit;
+        error = path_lookup(to, LOOKUP_PARENT, &nd);
+        if (error)
+                goto out;
+        error = -EXDEV;
+        if (old_nd.mnt != nd.mnt)
+                goto out_release;
+        new_dentry = lookup_create(&nd, 0);
+        error = PTR_ERR(new_dentry);
+        if (!IS_ERR(new_dentry)) {
+                error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+                dput(new_dentry);
+        }
+        up(&nd.dentry->d_inode->i_sem);
+out_release:
+        path_release(&nd);
+out:
+        path_release(&old_nd);
+exit:
+        putname(to);
+
+        return error;
+}
+
+/*
+ * The worst of all namespace operations - renaming directory. "Perverted"
+ * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
+ * Problems:
+ *      a) we can get into loop creation. Check is done in is_subdir().
+ *      b) race potential - two innocent renames can create a loop together.
+ *         That's where 4.4 screws up. Current fix: serialization on
+ *         sb->s_vfs_rename_sem. We might be more accurate, but that's another
+ *         story.
+ *      c) we have to lock _three_ objects - parents and victim (if it exists).
+ *         And that - after we got ->i_sem on parents (until then we don't know
+ *         whether the target exists).  Solution: try to be smart with locking
+ *         order for inodes.  We rely on the fact that tree topology may change
+ *         only under ->s_vfs_rename_sem _and_ that parent of the object we
+ *         move will be locked.  Thus we can rank directories by the tree
+ *         (ancestors first) and rank all non-directories after them.
+ *         That works since everybody except rename does "lock parent, lookup,
+ *         lock child" and rename is under ->s_vfs_rename_sem.
+ *         HOWEVER, it relies on the assumption that any object with ->lookup()
+ *         has no more than 1 dentry.  If "hybrid" objects will ever appear,
+ *         we'd better make sure that there's no link(2) for them.
+ *      d) some filesystems don't support opened-but-unlinked directories,
+ *         either because of layout or because they are not ready to deal with
+ *         all cases correctly. The latter will be fixed (taking this sort of
+ *         stuff into VFS), but the former is not going away. Solution: the same
+ *         trick as in rmdir().
+ *      e) conversion from fhandle to dentry may come in the wrong moment - when
+ *         we are removing the target. Solution: we will have to grab ->i_sem
+ *         in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
+ *         ->i_sem on parents, which works but leads to some truely excessive
+ *         locking].
+ */
+int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
+               struct inode *new_dir, struct dentry *new_dentry)
+{
+        int error = 0;
+        struct inode *target;
+
+        /*
+         * If we are going to change the parent - check write permissions,
+         * we'll need to flip '..'.
+         */
+        if (new_dir != old_dir) {
+                error = permission(old_dentry->d_inode, MAY_WRITE, NULL);
+                if (error)
+                        return error;
+        }
+
+        error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
+        if (error)
+                return error;
+
+        target = new_dentry->d_inode;
+        if (target) {
+                down(&target->i_sem);
+                dentry_unhash(new_dentry);
+        }
+        if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
+                error = -EBUSY;
+        else 
+                error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
+        if (target) {
+                if (!error)
+                        target->i_flags |= S_DEAD;
+                up(&target->i_sem);
+                if (d_unhashed(new_dentry))
+                        d_rehash(new_dentry);
+                dput(new_dentry);
+        }
+        if (!error) {
+                d_move(old_dentry,new_dentry);
+                security_inode_post_rename(old_dir, old_dentry,
+                                           new_dir, new_dentry);
+        }
+        return error;
+}
+
+int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
+               struct inode *new_dir, struct dentry *new_dentry)
+{
+        struct inode *target;
+        int error;
+
+        error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
+        if (error)
+                return error;
+
+        dget(new_dentry);
+        target = new_dentry->d_inode;
+        if (target)
+                down(&target->i_sem);
+        if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
+                error = -EBUSY;
+        else
+                error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
+        if (!error) {
+                /* The following d_move() should become unconditional */
+                if (!(old_dir->i_sb->s_type->fs_flags & FS_ODD_RENAME))
+                        d_move(old_dentry, new_dentry);
+                security_inode_post_rename(old_dir, old_dentry, new_dir, new_dentry);
+        }
+        if (target)
+                up(&target->i_sem);
+        dput(new_dentry);
+        return error;
+}
+
+int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+               struct inode *new_dir, struct dentry *new_dentry)
+{
+        int error;
+        int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
+
+        if (old_dentry->d_inode == new_dentry->d_inode)
+                return 0;
+ 
+        error = may_delete(old_dir, old_dentry, is_dir);
+        if (error)
+                return error;
+
+        if (!new_dentry->d_inode)
+                error = may_create(new_dir, new_dentry, NULL);
+        else
+                error = may_delete(new_dir, new_dentry, is_dir);
+        if (error)
+                return error;
+
+        if (!old_dir->i_op || !old_dir->i_op->rename)
+                return -EPERM;
+
+        DQUOT_INIT(old_dir);
+        DQUOT_INIT(new_dir);
+
+        if (is_dir)
+                error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
+        else
+                error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
+        if (!error) {
+                if (old_dir == new_dir)
+                        inode_dir_notify(old_dir, DN_RENAME);
+                else {
+                        inode_dir_notify(old_dir, DN_DELETE);
+                        inode_dir_notify(new_dir, DN_CREATE);
+                }
+        }
+        return error;
+}
+
+static inline int do_rename(const char * oldname, const char * newname)
+{
+        int error = 0;
+        struct dentry * old_dir, * new_dir;
+        struct dentry * old_dentry, *new_dentry;
+        struct dentry * trap;
+        struct nameidata oldnd, newnd;
+
+        error = path_lookup(oldname, LOOKUP_PARENT, &oldnd);
+        if (error)
+                goto exit;
+
+        error = path_lookup(newname, LOOKUP_PARENT, &newnd);
+        if (error)
+                goto exit1;
+
+        error = -EXDEV;
+        if (oldnd.mnt != newnd.mnt)
+                goto exit2;
+
+        old_dir = oldnd.dentry;
+        error = -EBUSY;
+        if (oldnd.last_type != LAST_NORM)
+                goto exit2;
+
+        new_dir = newnd.dentry;
+        if (newnd.last_type != LAST_NORM)
+                goto exit2;
+
+        trap = lock_rename(new_dir, old_dir);
+
+        old_dentry = lookup_hash(&oldnd.last, old_dir);
+        error = PTR_ERR(old_dentry);
+        if (IS_ERR(old_dentry))
+                goto exit3;
+        /* source must exist */
+        error = -ENOENT;
+        if (!old_dentry->d_inode)
+                goto exit4;
+        /* unless the source is a directory trailing slashes give -ENOTDIR */
+        if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
+                error = -ENOTDIR;
+                if (oldnd.last.name[oldnd.last.len])
+                        goto exit4;
+                if (newnd.last.name[newnd.last.len])
+                        goto exit4;
+        }
+        /* source should not be ancestor of target */
+        error = -EINVAL;
+        if (old_dentry == trap)
+                goto exit4;
+        new_dentry = lookup_hash(&newnd.last, new_dir);
+        error = PTR_ERR(new_dentry);
+        if (IS_ERR(new_dentry))
+                goto exit4;
+        /* target should not be an ancestor of source */
+        error = -ENOTEMPTY;
+        if (new_dentry == trap)
+                goto exit5;
+
+        error = vfs_rename(old_dir->d_inode, old_dentry,
+                                   new_dir->d_inode, new_dentry);
+exit5:
+        dput(new_dentry);
+exit4:
+        dput(old_dentry);
+exit3:
+        unlock_rename(new_dir, old_dir);
+exit2:
+        path_release(&newnd);
+exit1:
+        path_release(&oldnd);
+exit:
+        return error;
+}
+
+asmlinkage long sys_rename(const char __user * oldname, const char __user * newname)
+{
+        int error;
+        char * from;
+        char * to;
+
+        from = getname(oldname);
+        if(IS_ERR(from))
+                return PTR_ERR(from);
+        to = getname(newname);
+        error = PTR_ERR(to);
+        if (!IS_ERR(to)) {
+                error = do_rename(from,to);
+                putname(to);
+        }
+        putname(from);
+        return error;
+}
+
+int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link)
+{
+        int len;
+
+        len = PTR_ERR(link);
+        if (IS_ERR(link))
+                goto out;
+
+        len = strlen(link);
+        if (len > (unsigned) buflen)
+                len = buflen;
+        if (copy_to_user(buffer, link, len))
+                len = -EFAULT;
+out:
+        return len;
+}
+
+/*
+ * A helper for ->readlink().  This should be used *ONLY* for symlinks that
+ * have ->follow_link() touching nd only in nd_set_link().  Using (or not
+ * using) it for any given inode is up to filesystem.
+ */
+int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+        struct nameidata nd;
+        int res;
+        nd.depth = 0;
+        res = dentry->d_inode->i_op->follow_link(dentry, &nd);
+        if (!res) {
+                res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
+                if (dentry->d_inode->i_op->put_link)
+                        dentry->d_inode->i_op->put_link(dentry, &nd);
+        }
+        return res;
+}
+
+int vfs_follow_link(struct nameidata *nd, const char *link)
+{
+        return __vfs_follow_link(nd, link);
+}
+
+/* get the link contents into pagecache */
+static char *page_getlink(struct dentry * dentry, struct page **ppage)
+{
+        struct page * page;
+        struct address_space *mapping = dentry->d_inode->i_mapping;
+        page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage,
+                                NULL);
+        if (IS_ERR(page))
+                goto sync_fail;
+        wait_on_page_locked(page);
+        if (!PageUptodate(page))
+                goto async_fail;
+        *ppage = page;
+        return kmap(page);
+
+async_fail:
+        page_cache_release(page);
+        return ERR_PTR(-EIO);
+
+sync_fail:
+        return (char*)page;
+}
+
+int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
+{
+        struct page *page = NULL;
+        char *s = page_getlink(dentry, &page);
+        int res = vfs_readlink(dentry,buffer,buflen,s);
+        if (page) {
+                kunmap(page);
+                page_cache_release(page);
+        }
+        return res;
+}
+
+int page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
+{
+        struct page *page;
+        nd_set_link(nd, page_getlink(dentry, &page));
+        return 0;
+}
+
+void page_put_link(struct dentry *dentry, struct nameidata *nd)
+{
+        if (!IS_ERR(nd_get_link(nd))) {
+                struct page *page;
+                page = find_get_page(dentry->d_inode->i_mapping, 0);
+                if (!page)
+                        BUG();
+                kunmap(page);
+                page_cache_release(page);
+                page_cache_release(page);
+        }
+}
+
+int page_symlink(struct inode *inode, const char *symname, int len)
+{
+        struct address_space *mapping = inode->i_mapping;
+        struct page *page = grab_cache_page(mapping, 0);
+        int err = -ENOMEM;
+        char *kaddr;
+
+        if (!page)
+                goto fail;
+        err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);
+        if (err)
+                goto fail_map;
+        kaddr = kmap_atomic(page, KM_USER0);
+        memcpy(kaddr, symname, len-1);
+        kunmap_atomic(kaddr, KM_USER0);
+        mapping->a_ops->commit_write(NULL, page, 0, len-1);
+        /*
+         * Notice that we are _not_ going to block here - end of page is
+         * unmapped, so this will only try to map the rest of page, see
+         * that it is unmapped (typically even will not look into inode -
+         * ->i_size will be enough for everything) and zero it out.
+         * OTOH it's obviously correct and should make the page up-to-date.
+         */
+        if (!PageUptodate(page)) {
+                err = mapping->a_ops->readpage(NULL, page);
+                wait_on_page_locked(page);
+        } else {
+                unlock_page(page);
+        }
+        page_cache_release(page);
+        if (err < 0)
+                goto fail;
+        mark_inode_dirty(inode);
+        return 0;
+fail_map:
+        unlock_page(page);
+        page_cache_release(page);
+fail:
+        return err;
+}
+
+struct inode_operations page_symlink_inode_operations = {
+        .readlink       = generic_readlink,
+        .follow_link    = page_follow_link_light,
+        .put_link       = page_put_link,
+};
+
+EXPORT_SYMBOL(__user_walk);
+EXPORT_SYMBOL(follow_down);
+EXPORT_SYMBOL(follow_up);
+EXPORT_SYMBOL(get_write_access); /* binfmt_aout */
+EXPORT_SYMBOL(getname);
+EXPORT_SYMBOL(lock_rename);
+EXPORT_SYMBOL(lookup_hash);
+EXPORT_SYMBOL(lookup_one_len);
+EXPORT_SYMBOL(page_follow_link_light);
+EXPORT_SYMBOL(page_put_link);
+EXPORT_SYMBOL(page_readlink);
+EXPORT_SYMBOL(page_symlink);
+EXPORT_SYMBOL(page_symlink_inode_operations);
+EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(path_release);
+EXPORT_SYMBOL(path_walk);
+EXPORT_SYMBOL(permission);
+EXPORT_SYMBOL(unlock_rename);
+EXPORT_SYMBOL(vfs_create);
+EXPORT_SYMBOL(vfs_follow_link);
+EXPORT_SYMBOL(vfs_link);
+EXPORT_SYMBOL(vfs_mkdir);
+EXPORT_SYMBOL(vfs_mknod);
+EXPORT_SYMBOL(generic_permission);
+EXPORT_SYMBOL(vfs_readlink);
+EXPORT_SYMBOL(vfs_rename);
+EXPORT_SYMBOL(vfs_rmdir);
+EXPORT_SYMBOL(vfs_symlink);
+EXPORT_SYMBOL(vfs_unlink);
+EXPORT_SYMBOL(dentry_unhash);
+EXPORT_SYMBOL(generic_readlink);