提交 deb106c6 编写于 作者: A Al Viro

namei: lift terminate_walk() all the way up

Lift it from link_path_walk(), trailing_symlink(), lookup_last(),
mountpoint_last(), complete_walk() and do_last().  A _lot_ of
those suckers merge.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 3bdba28b
......@@ -563,8 +563,6 @@ static inline int nd_alloc_stack(struct nameidata *nd)
* to restart the path walk from the beginning in ref-walk mode.
*/
static void terminate_walk(struct nameidata *nd);
/**
* unlazy_walk - try to switch to ref-walk mode.
* @nd: nameidata pathwalk data
......@@ -673,10 +671,8 @@ static int complete_walk(struct nameidata *nd)
if (nd->flags & LOOKUP_RCU) {
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
if (unlikely(unlazy_walk(nd, NULL))) {
terminate_walk(nd);
if (unlikely(unlazy_walk(nd, NULL)))
return -ECHILD;
}
}
if (likely(!(nd->flags & LOOKUP_JUMPED)))
......@@ -692,7 +688,6 @@ static int complete_walk(struct nameidata *nd)
if (!status)
status = -ESTALE;
terminate_walk(nd);
return status;
}
......@@ -1858,7 +1853,6 @@ static int link_path_walk(const char *name, struct nameidata *nd)
break;
}
}
terminate_walk(nd);
return err;
}
......@@ -1974,38 +1968,26 @@ static const char *trailing_symlink(struct nameidata *nd)
{
const char *s;
int error = may_follow_link(nd);
if (unlikely(error)) {
terminate_walk(nd);
if (unlikely(error))
return ERR_PTR(error);
}
nd->flags |= LOOKUP_PARENT;
nd->stack[0].name = NULL;
s = get_link(nd);
if (unlikely(IS_ERR(s))) {
terminate_walk(nd);
return s;
}
if (unlikely(!s))
s = "";
return s;
return s ? s : "";
}
static inline int lookup_last(struct nameidata *nd)
{
int err;
if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len])
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
nd->flags &= ~LOOKUP_PARENT;
err = walk_component(nd,
return walk_component(nd,
nd->flags & LOOKUP_FOLLOW
? nd->depth
? WALK_PUT | WALK_GET
: WALK_GET
: 0);
if (err < 0)
terminate_walk(nd);
return err;
}
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
......@@ -2025,16 +2007,14 @@ static int path_lookupat(int dfd, const struct filename *name,
break;
}
}
if (!err)
err = complete_walk(nd);
if (!err && nd->flags & LOOKUP_DIRECTORY) {
if (!d_can_lookup(nd->path.dentry)) {
path_put(&nd->path);
if (!err && nd->flags & LOOKUP_DIRECTORY)
if (!d_can_lookup(nd->path.dentry))
err = -ENOTDIR;
}
}
if (err)
terminate_walk(nd);
path_cleanup(nd);
return err;
......@@ -2069,6 +2049,8 @@ static int path_parentat(int dfd, const struct filename *name,
err = link_path_walk(s, nd);
if (!err)
err = complete_walk(nd);
if (err)
terminate_walk(nd);
path_cleanup(nd);
return err;
}
......@@ -2320,10 +2302,8 @@ mountpoint_last(struct nameidata *nd, struct path *path)
/* If we're in rcuwalk, drop out of it to handle last component */
if (nd->flags & LOOKUP_RCU) {
if (unlazy_walk(nd, NULL)) {
error = -ECHILD;
goto out;
}
if (unlazy_walk(nd, NULL))
return -ECHILD;
}
nd->flags &= ~LOOKUP_PARENT;
......@@ -2331,7 +2311,7 @@ mountpoint_last(struct nameidata *nd, struct path *path)
if (unlikely(nd->last_type != LAST_NORM)) {
error = handle_dots(nd, nd->last_type);
if (error)
goto out;
return error;
dentry = dget(nd->path.dentry);
goto done;
}
......@@ -2346,41 +2326,32 @@ mountpoint_last(struct nameidata *nd, struct path *path)
*/
dentry = d_alloc(dir, &nd->last);
if (!dentry) {
error = -ENOMEM;
mutex_unlock(&dir->d_inode->i_mutex);
goto out;
return -ENOMEM;
}
dentry = lookup_real(dir->d_inode, dentry, nd->flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry)) {
mutex_unlock(&dir->d_inode->i_mutex);
goto out;
return PTR_ERR(dentry);
}
}
mutex_unlock(&dir->d_inode->i_mutex);
done:
if (d_is_negative(dentry)) {
error = -ENOENT;
dput(dentry);
goto out;
return -ENOENT;
}
if (nd->depth)
put_link(nd);
path->dentry = dentry;
path->mnt = nd->path.mnt;
error = should_follow_link(nd, path, nd->flags & LOOKUP_FOLLOW);
if (unlikely(error)) {
if (error < 0)
goto out;
if (unlikely(error))
return error;
}
mntget(path->mnt);
follow_mount(path);
error = 0;
out:
terminate_walk(nd);
return error;
return 0;
}
/**
......@@ -2409,6 +2380,7 @@ path_mountpoint(int dfd, const struct filename *name, struct path *path,
break;
}
}
terminate_walk(nd);
path_cleanup(nd);
return err;
}
......@@ -2982,10 +2954,8 @@ static int do_last(struct nameidata *nd,
if (nd->last_type != LAST_NORM) {
error = handle_dots(nd, nd->last_type);
if (unlikely(error)) {
terminate_walk(nd);
if (unlikely(error))
return error;
}
goto finish_open;
}
......@@ -2998,7 +2968,7 @@ static int do_last(struct nameidata *nd,
goto finish_lookup;
if (error < 0)
goto out;
return error;
BUG_ON(nd->inode != dir->d_inode);
} else {
......@@ -3013,10 +2983,9 @@ static int do_last(struct nameidata *nd,
return error;
audit_inode(name, dir, LOOKUP_PARENT);
error = -EISDIR;
/* trailing slashes? */
if (nd->last.name[nd->last.len])
goto out;
if (unlikely(nd->last.name[nd->last.len]))
return -EISDIR;
}
retry_lookup:
......@@ -3071,35 +3040,31 @@ static int do_last(struct nameidata *nd,
got_write = false;
}
error = -EEXIST;
if ((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))
goto exit_dput;
if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) {
path_to_nameidata(&path, nd);
return -EEXIST;
}
error = follow_managed(&path, nd);
if (error < 0)
goto out;
if (unlikely(error < 0))
return error;
BUG_ON(nd->flags & LOOKUP_RCU);
inode = path.dentry->d_inode;
error = -ENOENT;
if (d_is_negative(path.dentry)) {
if (unlikely(d_is_negative(path.dentry))) {
path_to_nameidata(&path, nd);
goto out;
return -ENOENT;
}
finish_lookup:
if (nd->depth)
put_link(nd);
error = should_follow_link(nd, &path, nd->flags & LOOKUP_FOLLOW);
if (unlikely(error)) {
if (error < 0)
goto out;
if (unlikely(error))
return error;
}
if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
path_to_nameidata(&path, nd);
error = -ELOOP;
goto out;
return -ELOOP;
}
if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
......@@ -3165,12 +3130,8 @@ static int do_last(struct nameidata *nd,
if (got_write)
mnt_drop_write(nd->path.mnt);
path_put(&save_parent);
terminate_walk(nd);
return error;
exit_dput:
path_put_conditional(&path, nd);
goto out;
exit_fput:
fput(file);
goto out;
......@@ -3289,6 +3250,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
break;
}
}
terminate_walk(nd);
path_cleanup(nd);
out2:
if (!(opened & FILE_OPENED)) {
......
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