allow build_open_flags() to return an error

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 41 insertions, 31 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 643019585574..0f6c96c57b2f 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -110,13 +110,14 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
         static const struct open_flags uselib_flags = {
                 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
                 .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN,
-                .intent = LOOKUP_OPEN
+                .intent = LOOKUP_OPEN,
+                .lookup_flags = LOOKUP_FOLLOW,
         };
 
         if (IS_ERR(tmp))
                 goto out;
 
-        file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW);
+        file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
         putname(tmp);
         error = PTR_ERR(file);
         if (IS_ERR(file))
@@ -756,10 +757,11 @@ struct file *open_exec(const char *name)
         static const struct open_flags open_exec_flags = {
                 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
                 .acc_mode = MAY_EXEC | MAY_OPEN,
-                .intent = LOOKUP_OPEN
+                .intent = LOOKUP_OPEN,
+                .lookup_flags = LOOKUP_FOLLOW,
         };
 
-        file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags, LOOKUP_FOLLOW);
+        file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags);
         if (IS_ERR(file))
                 goto out;
 
diff --git a/fs/internal.h b/fs/internal.h
index 68121584ae37..f6ad34362823 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -96,11 +96,12 @@ struct open_flags {
         umode_t mode;
         int acc_mode;
         int intent;
+        int lookup_flags;
 };
 extern struct file *do_filp_open(int dfd, struct filename *pathname,
-                const struct open_flags *op, int flags);
+                const struct open_flags *op);
 extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
-                const char *, const struct open_flags *, int lookup_flags);
+                const char *, const struct open_flags *);
 
 extern long do_handle_open(int mountdirfd,
                            struct file_handle __user *ufh, int open_flag);
diff --git a/fs/namei.c b/fs/namei.c
index 1bc7b7582a66..402eda351d07 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2969,9 +2969,10 @@ out:
 }
 
 struct file *do_filp_open(int dfd, struct filename *pathname,
-                const struct open_flags *op, int flags)
+                const struct open_flags *op)
 {
         struct nameidata nd;
+        int flags = op->lookup_flags;
         struct file *filp;
 
         filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU);
@@ -2983,17 +2984,16 @@ struct file *do_filp_open(int dfd, struct filename *pathname,
 }
 
 struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
-                const char *name, const struct open_flags *op, int flags)
+                const char *name, const struct open_flags *op)
 {
         struct nameidata nd;
         struct file *file;
         struct filename filename = { .name = name };
+        int flags = op->lookup_flags | LOOKUP_ROOT;
 
         nd.root.mnt = mnt;
         nd.root.dentry = dentry;
 
-        flags |= LOOKUP_ROOT;
-
         if (dentry->d_inode->i_op->follow_link && op->intent & LOOKUP_OPEN)
                 return ERR_PTR(-ELOOP);
 
diff --git a/fs/open.c b/fs/open.c
index 8c741002f947..5a40a4a51757 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -876,7 +876,8 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o
                 lookup_flags |= LOOKUP_DIRECTORY;
         if (!(flags & O_NOFOLLOW))
                 lookup_flags |= LOOKUP_FOLLOW;
-        return lookup_flags;
+        op->lookup_flags = lookup_flags;
+        return 0;
 }
 
 /**
@@ -893,8 +894,8 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o
 struct file *file_open_name(struct filename *name, int flags, umode_t mode)
 {
         struct open_flags op;
-        int lookup = build_open_flags(flags, mode, &op);
-        return do_filp_open(AT_FDCWD, name, &op, lookup);
+        int err = build_open_flags(flags, mode, &op);
+        return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op);
 }
 
 /**
@@ -919,37 +920,43 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
                             const char *filename, int flags)
 {
         struct open_flags op;
-        int lookup = build_open_flags(flags, 0, &op);
+        int err = build_open_flags(flags, 0, &op);
+        if (err)
+                return ERR_PTR(err);
         if (flags & O_CREAT)
                 return ERR_PTR(-EINVAL);
         if (!filename && (flags & O_DIRECTORY))
                 if (!dentry->d_inode->i_op->lookup)
                         return ERR_PTR(-ENOTDIR);
-        return do_file_open_root(dentry, mnt, filename, &op, lookup);
+        return do_file_open_root(dentry, mnt, filename, &op);
 }
 EXPORT_SYMBOL(file_open_root);
 
 long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
 {
         struct open_flags op;
-        int lookup = build_open_flags(flags, mode, &op);
-        struct filename *tmp = getname(filename);
-        int fd = PTR_ERR(tmp);
-
-        if (!IS_ERR(tmp)) {
-                fd = get_unused_fd_flags(flags);
-                if (fd >= 0) {
-                        struct file *f = do_filp_open(dfd, tmp, &op, lookup);
-                        if (IS_ERR(f)) {
-                                put_unused_fd(fd);
-                                fd = PTR_ERR(f);
-                        } else {
-                                fsnotify_open(f);
-                                fd_install(fd, f);
-                        }
+        int fd = build_open_flags(flags, mode, &op);
+        struct filename *tmp;
+
+        if (fd)
+                return fd;
+
+        tmp = getname(filename);
+        if (IS_ERR(tmp))
+                return PTR_ERR(tmp);
+
+        fd = get_unused_fd_flags(flags);
+        if (fd >= 0) {
+                struct file *f = do_filp_open(dfd, tmp, &op);
+                if (IS_ERR(f)) {
+                        put_unused_fd(fd);
+                        fd = PTR_ERR(f);
+                } else {
+                        fsnotify_open(f);
+                        fd_install(fd, f);
                 }
-                putname(tmp);
         }
+        putname(tmp);
         return fd;
 }