allow build_open_flags() to return an error

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

allow build_open_flags() to return an error
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro
1 parent 50cd2c5776
Showing 4 changed files with 41 additions and 31 deletions Side-by-side Diff
fs/exec.c
fs/internal.h
fs/namei.c
fs/open.c
@@ -110,13 +110,14 @@
 	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 @@
 	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;
  
@@ -96,11 +96,12 @@
 	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);
@@ -2969,9 +2969,10 @@
 }
  
 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);
  
  
@@ -2983,16 +2984,15 @@
 }
  
 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);
@@ -876,7 +876,8 @@
 		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 @@
 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 @@
 			    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);
+	int fd = build_open_flags(flags, mode, &op);
+	struct filename *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);
-			}
+	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;
 }
...	...	@@ -110,13 +110,14 @@
110	110	static const struct open_flags uselib_flags = {
111	111	.open_flag = O_LARGEFILE \| O_RDONLY \| __FMODE_EXEC,
112	112	.acc_mode = MAY_READ \| MAY_EXEC \| MAY_OPEN,
113		- .intent = LOOKUP_OPEN
	113	+ .intent = LOOKUP_OPEN,
	114	+ .lookup_flags = LOOKUP_FOLLOW,
114	115	};
115	116
116	117	if (IS_ERR(tmp))
117	118	goto out;
118	119
119		- file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW);
	120	+ file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
120	121	putname(tmp);
121	122	error = PTR_ERR(file);
122	123	if (IS_ERR(file))
123	124
...	...	@@ -756,10 +757,11 @@
756	757	static const struct open_flags open_exec_flags = {
757	758	.open_flag = O_LARGEFILE \| O_RDONLY \| __FMODE_EXEC,
758	759	.acc_mode = MAY_EXEC \| MAY_OPEN,
759		- .intent = LOOKUP_OPEN
	760	+ .intent = LOOKUP_OPEN,
	761	+ .lookup_flags = LOOKUP_FOLLOW,
760	762	};
761	763
762		- file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags, LOOKUP_FOLLOW);
	764	+ file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags);
763	765	if (IS_ERR(file))
764	766	goto out;
765	767
...	...	@@ -96,11 +96,12 @@
96	96	umode_t mode;
97	97	int acc_mode;
98	98	int intent;
	99	+ int lookup_flags;
99	100	};
100	101	extern struct file do_filp_open(int dfd, struct filename pathname,
101		- const struct open_flags *op, int flags);
	102	+ const struct open_flags *op);
102	103	extern struct file do_file_open_root(struct dentry , struct vfsmount *,
103		- const char , const struct open_flags , int lookup_flags);
	104	+ const char , const struct open_flags );
104	105
105	106	extern long do_handle_open(int mountdirfd,
106	107	struct file_handle __user *ufh, int open_flag);
...	...	@@ -2969,9 +2969,10 @@
2969	2969	}
2970	2970
2971	2971	struct file do_filp_open(int dfd, struct filename pathname,
2972		- const struct open_flags *op, int flags)
	2972	+ const struct open_flags *op)
2973	2973	{
2974	2974	struct nameidata nd;
	2975	+ int flags = op->lookup_flags;
2975	2976	struct file *filp;
2976	2977
2977	2978	filp = path_openat(dfd, pathname, &nd, op, flags \| LOOKUP_RCU);
2978	2979
2979	2980
...	...	@@ -2983,16 +2984,15 @@
2983	2984	}
2984	2985
2985	2986	struct file do_file_open_root(struct dentry dentry, struct vfsmount *mnt,
2986		- const char name, const struct open_flags op, int flags)
	2987	+ const char name, const struct open_flags op)
2987	2988	{
2988	2989	struct nameidata nd;
2989	2990	struct file *file;
2990	2991	struct filename filename = { .name = name };
	2992	+ int flags = op->lookup_flags \| LOOKUP_ROOT;
2991	2993
2992	2994	nd.root.mnt = mnt;
2993	2995	nd.root.dentry = dentry;
2994		-
2995		- flags \|= LOOKUP_ROOT;
2996	2996
2997	2997	if (dentry->d_inode->i_op->follow_link && op->intent & LOOKUP_OPEN)
2998	2998	return ERR_PTR(-ELOOP);
...	...	@@ -876,7 +876,8 @@
876	876	lookup_flags \|= LOOKUP_DIRECTORY;
877	877	if (!(flags & O_NOFOLLOW))
878	878	lookup_flags \|= LOOKUP_FOLLOW;
879		- return lookup_flags;
	879	+ op->lookup_flags = lookup_flags;
	880	+ return 0;
880	881	}
881	882
882	883	/**
...	...	@@ -893,8 +894,8 @@
893	894	struct file file_open_name(struct filename name, int flags, umode_t mode)
894	895	{
895	896	struct open_flags op;
896		- int lookup = build_open_flags(flags, mode, &op);
897		- return do_filp_open(AT_FDCWD, name, &op, lookup);
	897	+ int err = build_open_flags(flags, mode, &op);
	898	+ return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op);
898	899	}
899	900
900	901	/**
901	902
902	903
903	904
904	905
905	906
...	...	@@ -919,37 +920,43 @@
919	920	const char *filename, int flags)
920	921	{
921	922	struct open_flags op;
922		- int lookup = build_open_flags(flags, 0, &op);
	923	+ int err = build_open_flags(flags, 0, &op);
	924	+ if (err)
	925	+ return ERR_PTR(err);
923	926	if (flags & O_CREAT)
924	927	return ERR_PTR(-EINVAL);
925	928	if (!filename && (flags & O_DIRECTORY))
926	929	if (!dentry->d_inode->i_op->lookup)
927	930	return ERR_PTR(-ENOTDIR);
928		- return do_file_open_root(dentry, mnt, filename, &op, lookup);
	931	+ return do_file_open_root(dentry, mnt, filename, &op);
929	932	}
930	933	EXPORT_SYMBOL(file_open_root);
931	934
932	935	long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
933	936	{
934	937	struct open_flags op;
935		- int lookup = build_open_flags(flags, mode, &op);
936		- struct filename *tmp = getname(filename);
937		- int fd = PTR_ERR(tmp);
	938	+ int fd = build_open_flags(flags, mode, &op);
	939	+ struct filename *tmp;
938	940
939		- if (!IS_ERR(tmp)) {
940		- fd = get_unused_fd_flags(flags);
941		- if (fd >= 0) {
942		- struct file *f = do_filp_open(dfd, tmp, &op, lookup);
943		- if (IS_ERR(f)) {
944		- put_unused_fd(fd);
945		- fd = PTR_ERR(f);
946		- } else {
947		- fsnotify_open(f);
948		- fd_install(fd, f);
949		- }
	941	+ if (fd)
	942	+ return fd;
	943	+
	944	+ tmp = getname(filename);
	945	+ if (IS_ERR(tmp))
	946	+ return PTR_ERR(tmp);
	947	+
	948	+ fd = get_unused_fd_flags(flags);
	949	+ if (fd >= 0) {
	950	+ struct file *f = do_filp_open(dfd, tmp, &op);
	951	+ if (IS_ERR(f)) {
	952	+ put_unused_fd(fd);
	953	+ fd = PTR_ERR(f);
	954	+ } else {
	955	+ fsnotify_open(f);
	956	+ fd_install(fd, f);
950	957	}
951		- putname(tmp);
952	958	}
	959	+ putname(tmp);
953	960	return fd;
954	961	}
955	962