Turn do_link spaghetty into a normal loop

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2009-12-26 07:16:40 -05:00
parent 10fa8e62f2
commit 806b681cbe
1 changed files with 38 additions and 45 deletions

View File

@ -1844,17 +1844,38 @@ reval:
if (open_flag & O_EXCL)
nd.flags |= LOOKUP_EXCL;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
if (!filp)
goto do_link;
goto out;
exit_dput:
path_put_conditional(&path, &nd);
if (!IS_ERR(nd.intent.open.file))
while (unlikely(!filp)) { /* trailing symlink */
error = -ELOOP;
if ((open_flag & O_NOFOLLOW) || count++ == 32)
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(path.dentry, &nd);
if (error)
goto exit_dput;
error = __do_follow_link(&path, &nd);
path_put(&path);
if (error) {
/* nd.path had been dropped */
release_open_intent(&nd);
exit_parent:
path_put(&nd.path);
filp = ERR_PTR(error);
goto out;
}
nd.flags &= ~LOOKUP_PARENT;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
if (nd.last_type == LAST_NORM)
__putname(nd.last.name);
}
out:
if (nd.root.mnt)
path_put(&nd.root);
@ -1864,43 +1885,15 @@ out:
}
return filp;
do_link:
error = -ELOOP;
if ((open_flag & O_NOFOLLOW) || count++ == 32)
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(path.dentry, &nd);
if (error)
goto exit_dput;
error = __do_follow_link(&path, &nd);
path_put(&path);
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".
*/
exit_dput:
path_put_conditional(&path, &nd);
if (!IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
exit_parent:
path_put(&nd.path);
filp = ERR_PTR(error);
goto out;
}
nd.flags &= ~LOOKUP_PARENT;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
if (nd.last_type == LAST_NORM)
__putname(nd.last.name);
if (!filp)
goto do_link;
goto out;
}
/**
* filp_open - open file and return file pointer