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 <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 0741c69..60b74b3 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1590,6 +1590,61 @@
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 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 @@
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;