diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 148 |
1 files changed, 56 insertions, 92 deletions
diff --git a/fs/namei.c b/fs/namei.c index 8c704465f6ce..f5de5bb1a61f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1520,59 +1520,6 @@ return_err: return err; } -static inline int path_walk_rcu(const char *name, struct nameidata *nd) -{ - current->total_link_count = 0; - - return link_path_walk(name, nd); -} - -static inline int path_walk_simple(const char *name, struct nameidata *nd) -{ - current->total_link_count = 0; - - return link_path_walk(name, nd); -} - -static int path_walk(const char *name, struct nameidata *nd) -{ - struct path save = nd->path; - int result; - - current->total_link_count = 0; - - /* make sure the stuff we saved doesn't go away */ - path_get(&save); - - result = link_path_walk(name, nd); - if (result == -ESTALE) { - /* nd->path had been dropped */ - current->total_link_count = 0; - nd->path = save; - nd->inode = save.dentry->d_inode; - path_get(&nd->path); - nd->flags |= LOOKUP_REVAL; - result = link_path_walk(name, nd); - } - - path_put(&save); - - return result; -} - -static void path_finish_rcu(struct nameidata *nd) -{ - if (nd->flags & LOOKUP_RCU) { - /* RCU dangling. Cancel it. */ - nd->flags &= ~LOOKUP_RCU; - nd->root.mnt = NULL; - rcu_read_unlock(); - br_read_unlock(vfsmount_lock); - } - if (nd->file) - fput(nd->file); -} - static int path_init_rcu(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { int retval = 0; @@ -1697,7 +1644,7 @@ out_fail: } /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ -static int do_path_lookup(int dfd, const char *name, +static int path_lookupat(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { int retval; @@ -1716,29 +1663,45 @@ static int do_path_lookup(int dfd, const char *name, * be handled by restarting a traditional ref-walk (which will always * be able to complete). */ - retval = path_init_rcu(dfd, name, flags, nd); + if (flags & LOOKUP_RCU) + retval = path_init_rcu(dfd, name, flags, nd); + else + retval = path_init(dfd, name, flags, nd); + if (unlikely(retval)) return retval; - retval = path_walk_rcu(name, nd); - path_finish_rcu(nd); + + current->total_link_count = 0; + retval = link_path_walk(name, nd); + + if (nd->flags & LOOKUP_RCU) { + /* RCU dangling. Cancel it. */ + nd->flags &= ~LOOKUP_RCU; + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + } + + if (nd->file) { + fput(nd->file); + nd->file = NULL; + } + if (nd->root.mnt) { path_put(&nd->root); nd->root.mnt = NULL; } + return retval; +} - if (unlikely(retval == -ECHILD || retval == -ESTALE)) { - /* slower, locked walk */ - if (retval == -ESTALE) - flags |= LOOKUP_REVAL; - retval = path_init(dfd, name, flags, nd); - if (unlikely(retval)) - return retval; - retval = path_walk(name, nd); - if (nd->root.mnt) { - path_put(&nd->root); - nd->root.mnt = NULL; - } - } +static int do_path_lookup(int dfd, const char *name, + unsigned int flags, struct nameidata *nd) +{ + int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd); + if (unlikely(retval == -ECHILD)) + retval = path_lookupat(dfd, name, flags, nd); + if (unlikely(retval == -ESTALE)) + retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd); if (likely(!retval)) { if (unlikely(!audit_dummy_context())) { @@ -1746,7 +1709,6 @@ static int do_path_lookup(int dfd, const char *name, audit_inode(name, nd->path.dentry); } } - return retval; } @@ -1776,7 +1738,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, const char *name, unsigned int flags, struct nameidata *nd) { - int retval; + int result; /* same as do_path_lookup */ nd->last_type = LAST_ROOT; @@ -1790,15 +1752,27 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, path_get(&nd->root); nd->inode = nd->path.dentry->d_inode; - retval = path_walk(name, nd); - if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && + current->total_link_count = 0; + + result = link_path_walk(name, nd); + if (result == -ESTALE) { + /* nd->path had been dropped */ + current->total_link_count = 0; + nd->path.dentry = dentry; + nd->path.mnt = mnt; + nd->inode = dentry->d_inode; + path_get(&nd->path); + nd->flags |= LOOKUP_REVAL; + result = link_path_walk(name, nd); + } + if (unlikely(!result && !audit_dummy_context() && nd->path.dentry && nd->inode)) audit_inode(name, nd->path.dentry); path_put(&nd->root); nd->root.mnt = NULL; - return retval; + return result; } static struct dentry *__lookup_hash(struct qstr *name, @@ -2483,24 +2457,14 @@ out_filp2: creat: /* OK, have to create the file. Find the parent. */ - error = path_init_rcu(dfd, pathname, - LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); - if (error) - goto out_filp; - error = path_walk_rcu(pathname, &nd); - path_finish_rcu(&nd); - if (unlikely(error == -ECHILD || error == -ESTALE)) { - /* slower, locked walk */ - if (error == -ESTALE) { + error = path_lookupat(dfd, pathname, LOOKUP_PARENT | LOOKUP_RCU, &nd); + if (unlikely(error == -ECHILD)) + error = path_lookupat(dfd, pathname, LOOKUP_PARENT, &nd); + if (unlikely(error == -ESTALE)) { reval: - flags |= LOOKUP_REVAL; - } - error = path_init(dfd, pathname, - LOOKUP_PARENT | (flags & LOOKUP_REVAL), &nd); - if (error) - goto out_filp; - - error = path_walk_simple(pathname, &nd); + flags |= LOOKUP_REVAL; + error = path_lookupat(dfd, pathname, + LOOKUP_PARENT | LOOKUP_REVAL, &nd); } if (unlikely(error)) goto out_filp; |