ext3: new export ops
[safe/jmp/linux-2.6] / fs / namei.c
index c9750d7..3b993db 100644 (file)
@@ -22,7 +22,6 @@
 #include <linux/quotaops.h>
 #include <linux/pagemap.h>
 #include <linux/fsnotify.h>
-#include <linux/smp_lock.h>
 #include <linux/personality.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
@@ -31,7 +30,6 @@
 #include <linux/capability.h>
 #include <linux/file.h>
 #include <linux/fcntl.h>
-#include <linux/namei.h>
 #include <asm/namei.h>
 #include <asm/uaccess.h>
 
  * any extra contention...
  */
 
+static int fastcall link_path_walk(const char *name, struct nameidata *nd);
+
 /* 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..
@@ -159,7 +159,7 @@ char * getname(const char __user * filename)
 #ifdef CONFIG_AUDITSYSCALL
 void putname(const char *name)
 {
-       if (unlikely(current->audit_context))
+       if (unlikely(!audit_dummy_context()))
                audit_putname(name);
        else
                __putname(name);
@@ -228,6 +228,10 @@ int generic_permission(struct inode *inode, int mask,
 int permission(struct inode *inode, int mask, struct nameidata *nd)
 {
        int retval, submask;
+       struct vfsmount *mnt = NULL;
+
+       if (nd)
+               mnt = nd->mnt;
 
        if (mask & MAY_WRITE) {
                umode_t mode = inode->i_mode;
@@ -246,13 +250,34 @@ int permission(struct inode *inode, int mask, struct nameidata *nd)
                        return -EACCES;
        }
 
+       if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
+               /*
+                * MAY_EXEC on regular files is denied if the fs is mounted
+                * with the "noexec" flag.
+                */
+               if (mnt && (mnt->mnt_flags & MNT_NOEXEC))
+                       return -EACCES;
+       }
 
        /* Ordinary permission routines do not understand MAY_APPEND. */
        submask = mask & ~MAY_APPEND;
-       if (inode->i_op && inode->i_op->permission)
+       if (inode->i_op && inode->i_op->permission) {
                retval = inode->i_op->permission(inode, submask, nd);
-       else
+               if (!retval) {
+                       /*
+                        * Exec permission on a regular file is denied if none
+                        * of the execute bits are set.
+                        *
+                        * This check should be done by the ->permission()
+                        * method.
+                        */
+                       if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) &&
+                           !(inode->i_mode & S_IXUGO))
+                               return -EACCES;
+               }
+       } else {
                retval = generic_permission(inode, submask, NULL);
+       }
        if (retval)
                return retval;
 
@@ -288,7 +313,7 @@ int vfs_permission(struct nameidata *nd, int mask)
  */
 int file_permission(struct file *file, int mask)
 {
-       return permission(file->f_dentry->d_inode, mask, NULL);
+       return permission(file->f_path.dentry->d_inode, mask, NULL);
 }
 
 /*
@@ -324,7 +349,7 @@ int get_write_access(struct inode * inode)
 
 int deny_write_access(struct file * file)
 {
-       struct inode *inode = file->f_dentry->d_inode;
+       struct inode *inode = file->f_path.dentry->d_inode;
 
        spin_lock(&inode->i_lock);
        if (atomic_read(&inode->i_writecount) > 0) {
@@ -359,12 +384,36 @@ void path_release_on_umount(struct nameidata *nd)
  */
 void release_open_intent(struct nameidata *nd)
 {
-       if (nd->intent.open.file->f_dentry == NULL)
+       if (nd->intent.open.file->f_path.dentry == NULL)
                put_filp(nd->intent.open.file);
        else
                fput(nd->intent.open.file);
 }
 
+static inline struct dentry *
+do_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+       int status = dentry->d_op->d_revalidate(dentry, nd);
+       if (unlikely(status <= 0)) {
+               /*
+                * The dentry failed validation.
+                * If d_revalidate returned 0 attempt to invalidate
+                * the dentry otherwise d_revalidate is asking us
+                * to return a fail status.
+                */
+               if (!status) {
+                       if (!d_invalidate(dentry)) {
+                               dput(dentry);
+                               dentry = NULL;
+                       }
+               } else {
+                       dput(dentry);
+                       dentry = ERR_PTR(status);
+               }
+       }
+       return dentry;
+}
+
 /*
  * Internal lookup() using the new generic dcache.
  * SMP-safe
@@ -379,12 +428,9 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name,
        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;
-               }
-       }
+       if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+               dentry = do_revalidate(dentry, nd);
+
        return dentry;
 }
 
@@ -477,10 +523,9 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s
         */
        mutex_unlock(&dir->i_mutex);
        if (result->d_op && result->d_op->d_revalidate) {
-               if (!result->d_op->d_revalidate(result, nd) && !d_invalidate(result)) {
-                       dput(result);
+               result = do_revalidate(result, nd);
+               if (!result)
                        result = ERR_PTR(-ENOENT);
-               }
        }
        return result;
 }
@@ -491,18 +536,20 @@ static int __emul_lookup_dentry(const char *, struct nameidata *);
 static __always_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);
+       struct fs_struct *fs = current->fs;
+
+       read_lock(&fs->lock);
+       if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+               nd->mnt = mntget(fs->altrootmnt);
+               nd->dentry = dget(fs->altroot);
+               read_unlock(&fs->lock);
                if (__emul_lookup_dentry(name,nd))
                        return 0;
-               read_lock(&current->fs->lock);
+               read_lock(&fs->lock);
        }
-       nd->mnt = mntget(current->fs->rootmnt);
-       nd->dentry = dget(current->fs->root);
-       read_unlock(&current->fs->lock);
+       nd->mnt = mntget(fs->rootmnt);
+       nd->dentry = dget(fs->root);
+       read_unlock(&fs->lock);
        return 1;
 }
 
@@ -541,11 +588,6 @@ fail:
        return PTR_ERR(link);
 }
 
-struct path {
-       struct vfsmount *mnt;
-       struct dentry *dentry;
-};
-
 static inline void dput_path(struct path *path, struct nameidata *nd)
 {
        dput(path->dentry);
@@ -697,17 +739,19 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry)
 
 static __always_inline void follow_dotdot(struct nameidata *nd)
 {
+       struct fs_struct *fs = current->fs;
+
        while(1) {
                struct vfsmount *parent;
                struct dentry *old = nd->dentry;
 
-                read_lock(&current->fs->lock);
-               if (nd->dentry == current->fs->root &&
-                   nd->mnt == current->fs->rootmnt) {
-                        read_unlock(&current->fs->lock);
+                read_lock(&fs->lock);
+               if (nd->dentry == fs->root &&
+                   nd->mnt == fs->rootmnt) {
+                        read_unlock(&fs->lock);
                        break;
                }
-                read_unlock(&current->fs->lock);
+                read_unlock(&fs->lock);
                spin_lock(&dcache_lock);
                if (nd->dentry != nd->mnt->mnt_root) {
                        nd->dentry = dget(nd->dentry->d_parent);
@@ -760,12 +804,12 @@ need_lookup:
        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;
+       dentry = do_revalidate(dentry, nd);
+       if (!dentry)
+               goto need_lookup;
+       if (IS_ERR(dentry))
+               goto fail;
+       goto done;
 
 fail:
        return PTR_ERR(dentry);
@@ -971,7 +1015,7 @@ return_err:
  * 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)
+static int fastcall link_path_walk(const char *name, struct nameidata *nd)
 {
        struct nameidata save = *nd;
        int result;
@@ -995,7 +1039,7 @@ int fastcall link_path_walk(const char *name, struct nameidata *nd)
        return result;
 }
 
-int fastcall path_walk(const char * name, struct nameidata *nd)
+static int fastcall path_walk(const char * name, struct nameidata *nd)
 {
        current->total_link_count = 0;
        return link_path_walk(name, nd);
@@ -1015,15 +1059,17 @@ static int __emul_lookup_dentry(const char *name, struct nameidata *nd)
                struct vfsmount *old_mnt = nd->mnt;
                struct qstr last = nd->last;
                int last_type = nd->last_type;
+               struct fs_struct *fs = current->fs;
+
                /*
-                * NAME was not found in alternate root or it's a directory.  Try to find
-                * it in the normal root:
+                * 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);
+               read_lock(&fs->lock);
+               nd->mnt = mntget(fs->rootmnt);
+               nd->dentry = dget(fs->root);
+               read_unlock(&fs->lock);
                if (path_walk(name, nd) == 0) {
                        if (nd->dentry->d_inode) {
                                dput(old_dentry);
@@ -1047,6 +1093,7 @@ void set_fs_altroot(void)
        struct vfsmount *mnt = NULL, *oldmnt;
        struct dentry *dentry = NULL, *olddentry;
        int err;
+       struct fs_struct *fs = current->fs;
 
        if (!emul)
                goto set_it;
@@ -1056,12 +1103,12 @@ void set_fs_altroot(void)
                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);
+       write_lock(&fs->lock);
+       oldmnt = fs->altrootmnt;
+       olddentry = fs->altroot;
+       fs->altrootmnt = mnt;
+       fs->altroot = dentry;
+       write_unlock(&fs->lock);
        if (olddentry) {
                dput(olddentry);
                mntput(oldmnt);
@@ -1075,29 +1122,30 @@ static int fastcall do_path_lookup(int dfd, const char *name,
        int retval = 0;
        int fput_needed;
        struct file *file;
+       struct fs_struct *fs = current->fs;
 
        nd->last_type = LAST_ROOT; /* if there are only slashes... */
        nd->flags = flags;
        nd->depth = 0;
 
        if (*name=='/') {
-               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);
+               read_lock(&fs->lock);
+               if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) {
+                       nd->mnt = mntget(fs->altrootmnt);
+                       nd->dentry = dget(fs->altroot);
+                       read_unlock(&fs->lock);
                        if (__emul_lookup_dentry(name,nd))
                                goto out; /* found in altroot */
-                       read_lock(&current->fs->lock);
+                       read_lock(&fs->lock);
                }
-               nd->mnt = mntget(current->fs->rootmnt);
-               nd->dentry = dget(current->fs->root);
-               read_unlock(&current->fs->lock);
+               nd->mnt = mntget(fs->rootmnt);
+               nd->dentry = dget(fs->root);
+               read_unlock(&fs->lock);
        } else if (dfd == AT_FDCWD) {
-               read_lock(&current->fs->lock);
-               nd->mnt = mntget(current->fs->pwdmnt);
-               nd->dentry = dget(current->fs->pwd);
-               read_unlock(&current->fs->lock);
+               read_lock(&fs->lock);
+               nd->mnt = mntget(fs->pwdmnt);
+               nd->dentry = dget(fs->pwd);
+               read_unlock(&fs->lock);
        } else {
                struct dentry *dentry;
 
@@ -1106,7 +1154,7 @@ static int fastcall do_path_lookup(int dfd, const char *name,
                if (!file)
                        goto out_fail;
 
-               dentry = file->f_dentry;
+               dentry = file->f_path.dentry;
 
                retval = -ENOTDIR;
                if (!S_ISDIR(dentry->d_inode->i_mode))
@@ -1116,19 +1164,17 @@ static int fastcall do_path_lookup(int dfd, const char *name,
                if (retval)
                        goto fput_fail;
 
-               nd->mnt = mntget(file->f_vfsmnt);
+               nd->mnt = mntget(file->f_path.mnt);
                nd->dentry = dget(dentry);
 
                fput_light(file, fput_needed);
        }
-       current->total_link_count = 0;
-       retval = link_path_walk(name, nd);
+
+       retval = path_walk(name, nd);
 out:
-       if (likely(retval == 0)) {
-               if (unlikely(current->audit_context && nd && nd->dentry &&
+       if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
                                nd->dentry->d_inode))
-               audit_inode(name, nd->dentry->d_inode);
-       }
+               audit_inode(name, nd->dentry);
 out_fail:
        return retval;
 
@@ -1143,6 +1189,37 @@ int fastcall path_lookup(const char *name, unsigned int flags,
        return do_path_lookup(AT_FDCWD, name, flags, nd);
 }
 
+/**
+ * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
+ * @dentry:  pointer to dentry of the base directory
+ * @mnt: pointer to vfs mount of the base directory
+ * @name: pointer to file name
+ * @flags: lookup flags
+ * @nd: pointer to nameidata
+ */
+int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
+                   const char *name, unsigned int flags,
+                   struct nameidata *nd)
+{
+       int retval;
+
+       /* same as do_path_lookup */
+       nd->last_type = LAST_ROOT;
+       nd->flags = flags;
+       nd->depth = 0;
+
+       nd->mnt = mntget(mnt);
+       nd->dentry = dget(dentry);
+
+       retval = path_walk(name, nd);
+       if (unlikely(!retval && !audit_dummy_context() && nd->dentry &&
+                               nd->dentry->d_inode))
+               audit_inode(name, nd->dentry);
+
+       return retval;
+
+}
+
 static int __path_lookup_intent_open(int dfd, const char *name,
                unsigned int lookup_flags, struct nameidata *nd,
                int open_flags, int create_mode)
@@ -1211,22 +1288,14 @@ int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags,
        return err;
 }
 
-/*
- * 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)
+static struct dentry *__lookup_hash(struct qstr *name,
+               struct dentry *base, struct nameidata *nd)
 {
-       struct dentry * dentry;
+       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
@@ -1255,48 +1324,91 @@ out:
        return dentry;
 }
 
+/*
+ * 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 nameidata *nd)
 {
+       int err;
+
+       err = permission(nd->dentry->d_inode, MAY_EXEC, nd);
+       if (err)
+               return ERR_PTR(err);
        return __lookup_hash(&nd->last, nd->dentry, nd);
 }
 
-/* SMP-safe */
-struct dentry * lookup_one_len(const char * name, struct dentry * base, int len)
+static int __lookup_one_len(const char *name, struct qstr *this,
+               struct dentry *base, int len)
 {
        unsigned long hash;
-       struct qstr this;
        unsigned int c;
 
-       this.name = name;
-       this.len = len;
+       this->name = name;
+       this->len = len;
        if (!len)
-               goto access;
+               return -EACCES;
 
        hash = init_name_hash();
        while (len--) {
                c = *(const unsigned char *)name++;
                if (c == '/' || c == '\0')
-                       goto access;
+                       return -EACCES;
                hash = partial_name_hash(c, hash);
        }
-       this.hash = end_name_hash(hash);
+       this->hash = end_name_hash(hash);
+       return 0;
+}
 
+/**
+ * lookup_one_len:  filesystem helper to lookup single pathname component
+ * @name:      pathname component to lookup
+ * @base:      base directory to lookup from
+ * @len:       maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem useage and should
+ * not be called by generic code.  Also note that by using this function to
+ * nameidata argument is passed to the filesystem methods and a filesystem
+ * using this helper needs to be prepared for that.
+ */
+struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
+{
+       int err;
+       struct qstr this;
+
+       err = __lookup_one_len(name, &this, base, len);
+       if (err)
+               return ERR_PTR(err);
+
+       err = permission(base->d_inode, MAY_EXEC, NULL);
+       if (err)
+               return ERR_PTR(err);
        return __lookup_hash(&this, base, NULL);
-access:
-       return ERR_PTR(-EACCES);
 }
 
-/*
- *     namei()
+/**
+ * lookup_one_noperm - bad hack for sysfs
+ * @name:      pathname component to lookup
+ * @base:      base directory to lookup from
  *
- * 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.
+ * This is a variant of lookup_one_len that doesn't perform any permission
+ * checks.   It's a horrible hack to work around the braindead sysfs
+ * architecture and should not be used anywhere else.
  *
- * namei exists in two versions: namei/lnamei. The only difference is
- * that namei follows links, while lnamei does not.
- * SMP-safe
+ * DON'T USE THIS FUNCTION EVER, thanks.
  */
+struct dentry *lookup_one_noperm(const char *name, struct dentry *base)
+{
+       int err;
+       struct qstr this;
+
+       err = __lookup_one_len(name, &this, base, strlen(name));
+       if (err)
+               return ERR_PTR(err);
+       return __lookup_hash(&this, base, NULL);
+}
+
 int fastcall __user_walk_fd(int dfd, const char __user *name, unsigned flags,
                            struct nameidata *nd)
 {
@@ -1357,7 +1469,7 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir)
                return -ENOENT;
 
        BUG_ON(victim->d_parent->d_inode != dir);
-       audit_inode_child(victim->d_name.name, victim->d_inode, dir->i_ino);
+       audit_inode_child(victim->d_name.name, victim, dir);
 
        error = permission(dir,MAY_WRITE | MAY_EXEC, NULL);
        if (error)
@@ -1496,10 +1608,6 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
        if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE))
                return -EISDIR;
 
-       error = vfs_permission(nd, acc_mode);
-       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
@@ -1514,6 +1622,10 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
                flag &= ~O_TRUNC;
        } else if (IS_RDONLY(inode) && (flag & FMODE_WRITE))
                return -EROFS;
+
+       error = vfs_permission(nd, acc_mode);
+       if (error)
+               return error;
        /*
         * An append-only file must be opened in append mode for writing.
         */
@@ -1526,7 +1638,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
 
        /* O_NOATIME can only be set by the owner or superuser */
        if (flag & O_NOATIME)
-               if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
+               if (!is_owner_or_cap(inode))
                        return -EPERM;
 
        /*
@@ -1547,8 +1659,10 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
                error = locks_verify_locked(inode);
                if (!error) {
                        DQUOT_INIT(inode);
-                       
-                       error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL);
+
+                       error = do_truncate(dentry, 0,
+                                           ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
+                                           NULL);
                }
                put_write_access(inode);
                if (error)
@@ -1560,6 +1674,24 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
        return 0;
 }
 
+static int open_namei_create(struct nameidata *nd, struct path *path,
+                               int flag, int mode)
+{
+       int error;
+       struct dentry *dir = nd->dentry;
+
+       if (!IS_POSIXACL(dir->d_inode))
+               mode &= ~current->fs->umask;
+       error = vfs_create(dir->d_inode, path->dentry, mode, nd);
+       mutex_unlock(&dir->d_inode->i_mutex);
+       dput(nd->dentry);
+       nd->dentry = path->dentry;
+       if (error)
+               return error;
+       /* Don't check for write permission, don't truncate */
+       return may_open(nd, 0, flag & ~O_TRUNC);
+}
+
 /*
  *     open_namei()
  *
@@ -1641,24 +1773,17 @@ do_last:
 
        /* Negative dentry, just create the file */
        if (!path.dentry->d_inode) {
-               if (!IS_POSIXACL(dir->d_inode))
-                       mode &= ~current->fs->umask;
-               error = vfs_create(dir->d_inode, path.dentry, mode, nd);
-               mutex_unlock(&dir->d_inode->i_mutex);
-               dput(nd->dentry);
-               nd->dentry = path.dentry;
+               error = open_namei_create(nd, &path, flag, mode);
                if (error)
                        goto exit;
-               /* Don't check for write permission, don't truncate */
-               acc_mode = 0;
-               flag &= ~O_TRUNC;
-               goto ok;
+               return 0;
        }
 
        /*
         * It already exists.
         */
        mutex_unlock(&dir->d_inode->i_mutex);
+       audit_inode(pathname, path.dentry);
 
        error = -EEXIST;
        if (flag & O_EXCL)
@@ -1669,6 +1794,7 @@ do_last:
                if (flag & O_NOFOLLOW)
                        goto exit_dput;
        }
+
        error = -ENOENT;
        if (!path.dentry->d_inode)
                goto exit_dput;
@@ -1712,8 +1838,14 @@ do_link:
        if (error)
                goto exit_dput;
        error = __do_follow_link(&path, nd);
-       if (error)
+       if (error) {
+               /* Does someone understand code flow here? Or it is only
+                * me so stupid? Anathema to whoever designed this non-sense
+                * with "intent.open".
+                */
+               release_open_intent(nd);
                return error;
+       }
        nd->flags &= ~LOOKUP_PARENT;
        if (nd->last_type == LAST_BIND)
                goto ok;
@@ -1759,6 +1891,8 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
        if (nd->last_type != LAST_NORM)
                goto fail;
        nd->flags &= ~LOOKUP_PARENT;
+       nd->flags |= LOOKUP_CREATE;
+       nd->intent.open.flags = O_EXCL;
 
        /*
         * Do the final lookup.
@@ -1889,30 +2023,32 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
 {
        int error = 0;
        char * tmp;
+       struct dentry *dentry;
+       struct nameidata nd;
 
        tmp = getname(pathname);
        error = PTR_ERR(tmp);
-       if (!IS_ERR(tmp)) {
-               struct dentry *dentry;
-               struct nameidata nd;
+       if (IS_ERR(tmp))
+               goto out_err;
 
-               error = do_path_lookup(dfd, 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);
-               }
-               mutex_unlock(&nd.dentry->d_inode->i_mutex);
-               path_release(&nd);
-out:
-               putname(tmp);
-       }
+       error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
+       if (error)
+               goto out;
+       dentry = lookup_create(&nd, 1);
+       error = PTR_ERR(dentry);
+       if (IS_ERR(dentry))
+               goto out_unlock;
 
+       if (!IS_POSIXACL(nd.dentry->d_inode))
+               mode &= ~current->fs->umask;
+       error = vfs_mkdir(nd.dentry->d_inode, dentry, mode);
+       dput(dentry);
+out_unlock:
+       mutex_unlock(&nd.dentry->d_inode->i_mutex);
+       path_release(&nd);
+out:
+       putname(tmp);
+out_err:
        return error;
 }
 
@@ -1939,8 +2075,7 @@ asmlinkage long sys_mkdir(const char __user *pathname, int mode)
 void dentry_unhash(struct dentry *dentry)
 {
        dget(dentry);
-       if (atomic_read(&dentry->d_count))
-               shrink_dcache_parent(dentry);
+       shrink_dcache_parent(dentry);
        spin_lock(&dcache_lock);
        spin_lock(&dentry->d_lock);
        if (atomic_read(&dentry->d_count) == 2)
@@ -2011,10 +2146,11 @@ static long do_rmdir(int dfd, const char __user *pathname)
        mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
        dentry = lookup_hash(&nd);
        error = PTR_ERR(dentry);
-       if (!IS_ERR(dentry)) {
-               error = vfs_rmdir(nd.dentry->d_inode, dentry);
-               dput(dentry);
-       }
+       if (IS_ERR(dentry))
+               goto exit2;
+       error = vfs_rmdir(nd.dentry->d_inode, dentry);
+       dput(dentry);
+exit2:
        mutex_unlock(&nd.dentry->d_inode->i_mutex);
 exit1:
        path_release(&nd);
@@ -2154,30 +2290,33 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
        int error = 0;
        char * from;
        char * to;
+       struct dentry *dentry;
+       struct nameidata nd;
 
        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;
+       if (IS_ERR(to))
+               goto out_putname;
 
-               error = do_path_lookup(newdfd, 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);
-               }
-               mutex_unlock(&nd.dentry->d_inode->i_mutex);
-               path_release(&nd);
+       error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
+       if (error)
+               goto out;
+       dentry = lookup_create(&nd, 0);
+       error = PTR_ERR(dentry);
+       if (IS_ERR(dentry))
+               goto out_unlock;
+
+       error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO);
+       dput(dentry);
+out_unlock:
+       mutex_unlock(&nd.dentry->d_inode->i_mutex);
+       path_release(&nd);
 out:
-               putname(to);
-       }
+       putname(to);
+out_putname:
        putname(from);
        return error;
 }
@@ -2263,10 +2402,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
                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);
-       }
+       if (IS_ERR(new_dentry))
+               goto out_unlock;
+       error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry);
+       dput(new_dentry);
+out_unlock:
        mutex_unlock(&nd.dentry->d_inode->i_mutex);
 out_release:
        path_release(&nd);
@@ -2353,7 +2493,8 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
                dput(new_dentry);
        }
        if (!error)
-               d_move(old_dentry,new_dentry);
+               if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
+                       d_move(old_dentry,new_dentry);
        return error;
 }
 
@@ -2376,8 +2517,7 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
        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))
+               if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
                        d_move(old_dentry, new_dentry);
        }
        if (target)
@@ -2422,7 +2562,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (!error) {
                const char *new_name = old_dentry->d_name.name;
                fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir,
-                             new_dentry->d_inode, old_dentry->d_inode);
+                             new_dentry->d_inode, old_dentry);
        }
        fsnotify_oldname_free(old_name);
 
@@ -2581,19 +2721,9 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage)
        struct address_space *mapping = dentry->d_inode->i_mapping;
        page = read_mapping_page(mapping, 0, NULL);
        if (IS_ERR(page))
-               goto sync_fail;
-       wait_on_page_locked(page);
-       if (!PageUptodate(page))
-               goto async_fail;
+               return (char*)page;
        *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)
@@ -2630,52 +2760,29 @@ int __page_symlink(struct inode *inode, const char *symname, int len,
 {
        struct address_space *mapping = inode->i_mapping;
        struct page *page;
-       int err = -ENOMEM;
+       void *fsdata;
+       int err;
        char *kaddr;
 
 retry:
-       page = find_or_create_page(mapping, 0, gfp_mask);
-       if (!page)
-               goto fail;
-       err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);
-       if (err == AOP_TRUNCATED_PAGE) {
-               page_cache_release(page);
-               goto retry;
-       }
+       err = pagecache_write_begin(NULL, mapping, 0, len-1,
+                               AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
        if (err)
-               goto fail_map;
+               goto fail;
+
        kaddr = kmap_atomic(page, KM_USER0);
        memcpy(kaddr, symname, len-1);
        kunmap_atomic(kaddr, KM_USER0);
-       err = mapping->a_ops->commit_write(NULL, page, 0, len-1);
-       if (err == AOP_TRUNCATED_PAGE) {
-               page_cache_release(page);
-               goto retry;
-       }
-       if (err)
-               goto fail_map;
-       /*
-        * 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);
-               if (err != AOP_TRUNCATED_PAGE)
-                       wait_on_page_locked(page);
-       } else {
-               unlock_page(page);
-       }
-       page_cache_release(page);
+
+       err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
+                                                       page, fsdata);
        if (err < 0)
                goto fail;
+       if (err < len-1)
+               goto retry;
+
        mark_inode_dirty(inode);
        return 0;
-fail_map:
-       unlock_page(page);
-       page_cache_release(page);
 fail:
        return err;
 }
@@ -2686,7 +2793,7 @@ int page_symlink(struct inode *inode, const char *symname, int len)
                        mapping_gfp_mask(inode->i_mapping));
 }
 
-struct inode_operations page_symlink_inode_operations = {
+const struct inode_operations page_symlink_inode_operations = {
        .readlink       = generic_readlink,
        .follow_link    = page_follow_link_light,
        .put_link       = page_put_link,
@@ -2707,8 +2814,8 @@ EXPORT_SYMBOL(__page_symlink);
 EXPORT_SYMBOL(page_symlink);
 EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(vfs_path_lookup);
 EXPORT_SYMBOL(path_release);
-EXPORT_SYMBOL(path_walk);
 EXPORT_SYMBOL(permission);
 EXPORT_SYMBOL(vfs_permission);
 EXPORT_SYMBOL(file_permission);