diff options
| -rw-r--r-- | fs/namei.c | 53 | ||||
| -rw-r--r-- | include/linux/namei.h | 1 |
2 files changed, 35 insertions, 19 deletions
diff --git a/fs/namei.c b/fs/namei.c index 895733efc6b..88baaf2b916 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -552,6 +552,17 @@ static __always_inline int link_path_walk(const char *name, struct nameidata *nd return result; } +static __always_inline void set_root(struct nameidata *nd) +{ + if (!nd->root.mnt) { + struct fs_struct *fs = current->fs; + read_lock(&fs->lock); + nd->root = fs->root; + path_get(&nd->root); + read_unlock(&fs->lock); + } +} + static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) { int res = 0; @@ -560,14 +571,10 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l goto fail; if (*link == '/') { - struct fs_struct *fs = current->fs; - + set_root(nd); path_put(&nd->path); - - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); + nd->path = nd->root; + path_get(&nd->root); } res = link_path_walk(link, nd); @@ -741,19 +748,16 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry) static __always_inline void follow_dotdot(struct nameidata *nd) { - struct fs_struct *fs = current->fs; + set_root(nd); while(1) { struct vfsmount *parent; struct dentry *old = nd->path.dentry; - read_lock(&fs->lock); - if (nd->path.dentry == fs->root.dentry && - nd->path.mnt == fs->root.mnt) { - read_unlock(&fs->lock); + if (nd->path.dentry == nd->root.dentry && + nd->path.mnt == nd->root.mnt) { break; } - read_unlock(&fs->lock); spin_lock(&dcache_lock); if (nd->path.dentry != nd->path.mnt->mnt_root) { nd->path.dentry = dget(nd->path.dentry->d_parent); @@ -1022,18 +1026,18 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei 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; + nd->root.mnt = NULL; if (*name=='/') { - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); + set_root(nd); + nd->path = nd->root; + path_get(&nd->root); } else if (dfd == AT_FDCWD) { + struct fs_struct *fs = current->fs; read_lock(&fs->lock); nd->path = fs->pwd; path_get(&fs->pwd); @@ -1079,6 +1083,10 @@ static int do_path_lookup(int dfd, const char *name, if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); + if (nd->root.mnt) { + path_put(&nd->root); + nd->root.mnt = NULL; + } return retval; } @@ -1115,6 +1123,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->last_type = LAST_ROOT; nd->flags = flags; nd->depth = 0; + nd->root.mnt = NULL; nd->path.dentry = dentry; nd->path.mnt = mnt; @@ -1125,8 +1134,12 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); - return retval; + if (nd->root.mnt) { + path_put(&nd->root); + nd->root.mnt = NULL; + } + return retval; } /** @@ -1817,6 +1830,8 @@ exit: if (!IS_ERR(nd.intent.open.file)) release_open_intent(&nd); exit_parent: + if (nd.root.mnt) + path_put(&nd.root); path_put(&nd.path); return ERR_PTR(error); diff --git a/include/linux/namei.h b/include/linux/namei.h index 518098fe63a..325dd3ad39a 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -18,6 +18,7 @@ enum { MAX_NESTED_LINKS = 8 }; struct nameidata { struct path path; struct qstr last; + struct path root; unsigned int flags; int last_type; unsigned depth; |