[PATCH] uml: build host-binaries with the native host arch again
[safe/jmp/linux-2.6] / fs / namei.c
index e252b12..c5769c4 100644 (file)
@@ -28,6 +28,7 @@
 #include <linux/syscalls.h>
 #include <linux/mount.h>
 #include <linux/audit.h>
+#include <linux/file.h>
 #include <asm/namei.h>
 #include <asm/uaccess.h>
 
@@ -317,6 +318,18 @@ void path_release_on_umount(struct nameidata *nd)
        mntput_no_expire(nd->mnt);
 }
 
+/**
+ * release_open_intent - free up open intent resources
+ * @nd: pointer to nameidata
+ */
+void release_open_intent(struct nameidata *nd)
+{
+       if (nd->intent.open.file->f_dentry == NULL)
+               put_filp(nd->intent.open.file);
+       else
+               fput(nd->intent.open.file);
+}
+
 /*
  * Internal lookup() using the new generic dcache.
  * SMP-safe
@@ -501,6 +514,7 @@ struct path {
 static inline int __do_follow_link(struct path *path, struct nameidata *nd)
 {
        int error;
+       void *cookie;
        struct dentry *dentry = path->dentry;
 
        touch_atime(path->mnt, dentry);
@@ -508,13 +522,15 @@ static inline int __do_follow_link(struct path *path, struct nameidata *nd)
 
        if (path->mnt == nd->mnt)
                mntget(path->mnt);
-       error = dentry->d_inode->i_op->follow_link(dentry, nd);
-       if (!error) {
+       cookie = dentry->d_inode->i_op->follow_link(dentry, nd);
+       error = PTR_ERR(cookie);
+       if (!IS_ERR(cookie)) {
                char *s = nd_get_link(nd);
+               error = 0;
                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);
+                       dentry->d_inode->i_op->put_link(dentry, nd, cookie);
        }
        dput(dentry);
        mntput(path->mnt);
@@ -522,6 +538,22 @@ static inline int __do_follow_link(struct path *path, struct nameidata *nd)
        return error;
 }
 
+static inline void dput_path(struct path *path, struct nameidata *nd)
+{
+       dput(path->dentry);
+       if (path->mnt != nd->mnt)
+               mntput(path->mnt);
+}
+
+static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
+{
+       dput(nd->dentry);
+       if (nd->mnt != path->mnt)
+               mntput(nd->mnt);
+       nd->mnt = path->mnt;
+       nd->dentry = path->dentry;
+}
+
 /*
  * This limits recursive symlink follows to 8, while
  * limiting consecutive symlinks to 40.
@@ -549,9 +581,7 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd)
        nd->depth--;
        return err;
 loop:
-       dput(path->dentry);
-       if (path->mnt != nd->mnt)
-               mntput(path->mnt);
+       dput_path(path, nd);
        path_release(nd);
        return err;
 }
@@ -733,6 +763,7 @@ static fastcall int __link_path_walk(const char * name, struct nameidata *nd)
                struct qstr this;
                unsigned int c;
 
+               nd->flags |= LOOKUP_CONTINUE;
                err = exec_permission_lite(inode, nd);
                if (err == -EAGAIN) { 
                        err = permission(inode, MAY_EXEC, nd);
@@ -785,7 +816,6 @@ static fastcall int __link_path_walk(const char * name, struct nameidata *nd)
                        if (err < 0)
                                break;
                }
-               nd->flags |= LOOKUP_CONTINUE;
                /* This does the actual lookups.. */
                err = do_lookup(nd, &this, &next);
                if (err)
@@ -810,13 +840,8 @@ static fastcall int __link_path_walk(const char * name, struct nameidata *nd)
                        err = -ENOTDIR; 
                        if (!inode->i_op)
                                break;
-               } else {
-                       dput(nd->dentry);
-                       if (nd->mnt != next.mnt)
-                               mntput(nd->mnt);
-                       nd->mnt = next.mnt;
-                       nd->dentry = next.dentry;
-               }
+               } else
+                       path_to_nameidata(&next, nd);
                err = -ENOTDIR; 
                if (!inode->i_op->lookup)
                        break;
@@ -856,13 +881,8 @@ last_component:
                        if (err)
                                goto return_err;
                        inode = nd->dentry->d_inode;
-               } else {
-                       dput(nd->dentry);
-                       if (nd->mnt != next.mnt)
-                               mntput(nd->mnt);
-                       nd->mnt = next.mnt;
-                       nd->dentry = next.dentry;
-               }
+               } else
+                       path_to_nameidata(&next, nd);
                err = -ENOENT;
                if (!inode)
                        break;
@@ -898,9 +918,7 @@ return_reval:
 return_base:
                return 0;
 out_dput:
-               dput(next.dentry);
-               if (nd->mnt != next.mnt)
-                       mntput(next.mnt);
+               dput_path(&next, nd);
                break;
        }
        path_release(nd);
@@ -1047,6 +1065,70 @@ out:
        return retval;
 }
 
+static int __path_lookup_intent_open(const char *name, unsigned int lookup_flags,
+               struct nameidata *nd, int open_flags, int create_mode)
+{
+       struct file *filp = get_empty_filp();
+       int err;
+
+       if (filp == NULL)
+               return -ENFILE;
+       nd->intent.open.file = filp;
+       nd->intent.open.flags = open_flags;
+       nd->intent.open.create_mode = create_mode;
+       err = path_lookup(name, lookup_flags|LOOKUP_OPEN, nd);
+       if (IS_ERR(nd->intent.open.file)) {
+               if (err == 0) {
+                       err = PTR_ERR(nd->intent.open.file);
+                       path_release(nd);
+               }
+       } else if (err != 0)
+               release_open_intent(nd);
+       return err;
+}
+
+/**
+ * path_lookup_open - lookup a file path with open intent
+ * @name: pointer to file name
+ * @lookup_flags: lookup intent flags
+ * @nd: pointer to nameidata
+ * @open_flags: open intent flags
+ */
+int path_lookup_open(const char *name, unsigned int lookup_flags,
+               struct nameidata *nd, int open_flags)
+{
+       return __path_lookup_intent_open(name, lookup_flags, nd,
+                       open_flags, 0);
+}
+
+/**
+ * path_lookup_create - lookup a file path with open + create intent
+ * @name: pointer to file name
+ * @lookup_flags: lookup intent flags
+ * @nd: pointer to nameidata
+ * @open_flags: open intent flags
+ * @create_mode: create intent flags
+ */
+int path_lookup_create(const char *name, unsigned int lookup_flags,
+               struct nameidata *nd, int open_flags, int create_mode)
+{
+       return __path_lookup_intent_open(name, lookup_flags|LOOKUP_CREATE, nd,
+                       open_flags, create_mode);
+}
+
+int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags,
+               struct nameidata *nd, int open_flags)
+{
+       char *tmp = getname(name);
+       int err = PTR_ERR(tmp);
+
+       if (!IS_ERR(tmp)) {
+               err = __path_lookup_intent_open(tmp, lookup_flags, nd, open_flags, 0);
+               putname(tmp);
+       }
+       return err;
+}
+
 /*
  * Restricted form of lookup. Doesn't follow links, single-component only,
  * needs parent already locked. Doesn't follow mounts.
@@ -1229,9 +1311,6 @@ static inline int may_create(struct inode *dir, struct dentry *child,
 }
 
 /* 
- * 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)
@@ -1241,9 +1320,6 @@ static inline int lookup_flags(unsigned int f)
        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;
 
@@ -1311,10 +1387,8 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
                return error;
        DQUOT_INIT(dir);
        error = dir->i_op->create(dir, dentry, mode, nd);
-       if (!error) {
+       if (!error)
                fsnotify_create(dir, dentry->d_name.name);
-               security_inode_post_create(dir, dentry, mode);
-       }
        return error;
 }
 
@@ -1413,27 +1487,27 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
  */
 int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
 {
-       int acc_mode, error = 0;
+       int acc_mode, error;
        struct path path;
        struct dentry *dir;
        int count = 0;
 
        acc_mode = ACC_MODE(flag);
 
+       /* O_TRUNC implies we need access checks for write permissions */
+       if (flag & O_TRUNC)
+               acc_mode |= MAY_WRITE;
+
        /* 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);
+               error = path_lookup_open(pathname, lookup_flags(flag), nd, flag);
                if (error)
                        return error;
                goto ok;
@@ -1442,7 +1516,7 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd)
        /*
         * Create - we need to know the parent.
         */
-       error = path_lookup(pathname, LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE, nd);
+       error = path_lookup_create(pathname, LOOKUP_PARENT, nd, flag, mode);
        if (error)
                return error;
 
@@ -1504,11 +1578,7 @@ do_last:
        if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link)
                goto do_link;
 
-       dput(nd->dentry);
-       nd->dentry = path.dentry;
-       if (nd->mnt != path.mnt)
-               mntput(nd->mnt);
-       nd->mnt = path.mnt;
+       path_to_nameidata(&path, nd);
        error = -EISDIR;
        if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode))
                goto exit;
@@ -1519,10 +1589,10 @@ ok:
        return 0;
 
 exit_dput:
-       dput(path.dentry);
-       if (nd->mnt != path.mnt)
-               mntput(path.mnt);
+       dput_path(&path, nd);
 exit:
+       if (!IS_ERR(nd->intent.open.file))
+               release_open_intent(nd);
        path_release(nd);
        return error;
 
@@ -1554,19 +1624,19 @@ do_link:
        if (nd->last_type != LAST_NORM)
                goto exit;
        if (nd->last.name[nd->last.len]) {
-               putname(nd->last.name);
+               __putname(nd->last.name);
                goto exit;
        }
        error = -ELOOP;
        if (count++==32) {
-               putname(nd->last.name);
+               __putname(nd->last.name);
                goto exit;
        }
        dir = nd->dentry;
        down(&dir->d_inode->i_sem);
        path.dentry = __lookup_hash(&nd->last, nd->dentry, nd);
        path.mnt = nd->mnt;
-       putname(nd->last.name);
+       __putname(nd->last.name);
        goto do_last;
 }
 
@@ -1636,10 +1706,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 
        DQUOT_INIT(dir);
        error = dir->i_op->mknod(dir, dentry, mode, dev);
-       if (!error) {
+       if (!error)
                fsnotify_create(dir, dentry->d_name.name);
-               security_inode_post_mknod(dir, dentry, mode, dev);
-       }
        return error;
 }
 
@@ -1709,10 +1777,8 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
        DQUOT_INIT(dir);
        error = dir->i_op->mkdir(dir, dentry, mode);
-       if (!error) {
+       if (!error)
                fsnotify_mkdir(dir, dentry->d_name.name);
-               security_inode_post_mkdir(dir,dentry, mode);
-       }
        return error;
 }
 
@@ -1801,7 +1867,6 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
        }
        up(&dentry->d_inode->i_sem);
        if (!error) {
-               fsnotify_rmdir(dentry, dentry->d_inode, dir);
                d_delete(dentry);
        }
        dput(dentry);
@@ -1874,7 +1939,6 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
 
        /* We don't d_delete() NFS sillyrenamed files--they still exist. */
        if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
-               fsnotify_unlink(dentry, dir);
                d_delete(dentry);
        }
 
@@ -1950,10 +2014,8 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, i
 
        DQUOT_INIT(dir);
        error = dir->i_op->symlink(dir, dentry, oldname);
-       if (!error) {
+       if (!error)
                fsnotify_create(dir, dentry->d_name.name);
-               security_inode_post_symlink(dir, dentry, oldname);
-       }
        return error;
 }
 
@@ -2023,10 +2085,8 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
        DQUOT_INIT(dir);
        error = dir->i_op->link(old_dentry, dir, new_dentry);
        up(&old_dentry->d_inode->i_sem);
-       if (!error) {
+       if (!error)
                fsnotify_create(dir, new_dentry->d_name.name);
-               security_inode_post_link(old_dentry, dir, new_dentry);
-       }
        return error;
 }
 
@@ -2145,11 +2205,8 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
                        d_rehash(new_dentry);
                dput(new_dentry);
        }
-       if (!error) {
+       if (!error)
                d_move(old_dentry,new_dentry);
-               security_inode_post_rename(old_dir, old_dentry,
-                                          new_dir, new_dentry);
-       }
        return error;
 }
 
@@ -2175,7 +2232,6 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
                /* 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);
@@ -2218,7 +2274,8 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
                error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
        if (!error) {
                const char *new_name = old_dentry->d_name.name;
-               fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir);
+               fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir,
+                             new_dentry->d_inode, old_dentry->d_inode);
        }
        fsnotify_oldname_free(old_name);
 
@@ -2345,15 +2402,17 @@ out:
 int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 {
        struct nameidata nd;
-       int res;
+       void *cookie;
+
        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));
+       cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
+       if (!IS_ERR(cookie)) {
+               int 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);
+                       dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
+               cookie = ERR_PTR(res);
        }
-       return res;
+       return PTR_ERR(cookie);
 }
 
 int vfs_follow_link(struct nameidata *nd, const char *link)
@@ -2396,23 +2455,20 @@ int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
        return res;
 }
 
-int page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
+void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
 {
-       struct page *page;
+       struct page *page = NULL;
        nd_set_link(nd, page_getlink(dentry, &page));
-       return 0;
+       return page;
 }
 
-void page_put_link(struct dentry *dentry, struct nameidata *nd)
+void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
 {
-       if (!IS_ERR(nd_get_link(nd))) {
-               struct page *page;
-               page = find_get_page(dentry->d_inode->i_mapping, 0);
-               if (!page)
-                       BUG();
+       struct page *page = cookie;
+
+       if (page) {
                kunmap(page);
                page_cache_release(page);
-               page_cache_release(page);
        }
 }