From 648fa8611de3d4d43bbd64af3226679d2d0eb609 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 24 Dec 2009 01:26:48 -0500 Subject: [PATCH] beginning to untangle do_filp_open() That's going to be a long and painful series. The first step: take the stuff reachable from 'ok' label in do_filp_open() into a new helper (finish_open()). Signed-off-by: Al Viro --- fs/namei.c | 106 ++++++++++++++++++++++++++++------------------------- 1 file changed, 56 insertions(+), 50 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 0741c69b3319..60b74b3946a1 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1590,6 +1590,61 @@ static int open_will_truncate(int flag, struct inode *inode) return (flag & O_TRUNC); } +static struct file *finish_open(struct nameidata *nd, + int open_flag, int flag, int acc_mode) +{ + struct file *filp; + int will_truncate; + int error; + + will_truncate = open_will_truncate(flag, nd->path.dentry->d_inode); + if (will_truncate) { + error = mnt_want_write(nd->path.mnt); + if (error) + goto exit; + } + error = may_open(&nd->path, acc_mode, open_flag); + if (error) { + if (will_truncate) + mnt_drop_write(nd->path.mnt); + goto exit; + } + filp = nameidata_to_filp(nd); + if (!IS_ERR(filp)) { + error = ima_file_check(filp, acc_mode); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + if (!IS_ERR(filp)) { + if (acc_mode & MAY_WRITE) + vfs_dq_init(nd->path.dentry->d_inode); + + if (will_truncate) { + error = handle_truncate(&nd->path); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + } + /* + * It is now safe to drop the mnt write + * because the filp has had a write taken + * on its behalf. + */ + if (will_truncate) + mnt_drop_write(nd->path.mnt); + return filp; + +exit: + if (!IS_ERR(nd->intent.open.file)) + release_open_intent(nd); + path_put(&nd->path); + return ERR_PTR(error); +} + /* * Note that the low bits of the passed in "open_flag" * are not the same as in the local variable "flag". See @@ -1604,7 +1659,6 @@ struct file *do_filp_open(int dfd, const char *pathname, struct path path; struct dentry *dir; int count = 0; - int will_truncate; int flag = open_to_namei_flags(open_flag); int force_reval = 0; @@ -1769,55 +1823,7 @@ do_last: if (S_ISDIR(path.dentry->d_inode->i_mode)) goto exit; ok: - /* - * Consider: - * 1. may_open() truncates a file - * 2. a rw->ro mount transition occurs - * 3. nameidata_to_filp() fails due to - * the ro mount. - * That would be inconsistent, and should - * be avoided. Taking this mnt write here - * ensures that (2) can not occur. - */ - will_truncate = open_will_truncate(flag, nd.path.dentry->d_inode); - if (will_truncate) { - error = mnt_want_write(nd.path.mnt); - if (error) - goto exit; - } - error = may_open(&nd.path, acc_mode, open_flag); - if (error) { - if (will_truncate) - mnt_drop_write(nd.path.mnt); - goto exit; - } - filp = nameidata_to_filp(&nd); - if (!IS_ERR(filp)) { - error = ima_file_check(filp, acc_mode); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } - if (!IS_ERR(filp)) { - if (acc_mode & MAY_WRITE) - vfs_dq_init(nd.path.dentry->d_inode); - - if (will_truncate) { - error = handle_truncate(&nd.path); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } - } - /* - * It is now safe to drop the mnt write - * because the filp has had a write taken - * on its behalf. - */ - if (will_truncate) - mnt_drop_write(nd.path.mnt); + filp = finish_open(&nd, open_flag, flag, acc_mode); if (nd.root.mnt) path_put(&nd.root); return filp; -- 2.20.1