Collect "operation mode" arguments of do_last() into a structure

No point messing with passing shitloads of "operation mode" arguments to do_open() one by one, especially since they are not going to change during do_filp_open(). Collect them into a struct, fill it and pass to do_last() by reference. Make sure that lookup intent flags are correctly set and removed - we want them for do_last(), but they make no sense for __do_follow_link(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Collect "operation mode" arguments of do_last() into a structure
No point messing with passing shitloads of "operation mode" arguments to do_open() one by one, especially since they are not going to change during do_filp_open(). Collect them into a struct, fill it and pass to do_last() by reference. Make sure that lookup intent flags are correctly set and removed - we want them for do_last(), but they make no sense for __do_follow_link(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro
1 parent f1afe9efc8
Showing 1 changed file with 35 additions and 22 deletions Side-by-side Diff
fs/namei.c
@@ -2169,17 +2169,26 @@
 	return ERR_PTR(error);
 }
  
+struct open_flags {
+	int open_flag;
+	int mode;
+	int acc_mode;
+	int intent;
+};
+
 /*
  * Handle O_CREAT case for do_filp_open
  */
 static struct file *do_last(struct nameidata *nd, struct path *path,
-			    int open_flag, int acc_mode,
-			    int mode, const char *pathname)
+			    const struct open_flags *op, const char *pathname)
 {
 	struct dentry *dir = nd->path.dentry;
 	struct file *filp;
 	int error;
  
+	nd->flags &= ~LOOKUP_PARENT;
+	nd->flags |= op->intent;
+
 	switch (nd->last_type) {
 	case LAST_DOTDOT:
 		follow_dotdot(nd);
@@ -2233,7 +2242,7 @@
 		error = mnt_want_write(nd->path.mnt);
 		if (error)
 			goto exit_mutex_unlock;
-		error = __open_namei_create(nd, path, open_flag, mode);
+		error = __open_namei_create(nd, path, op->open_flag, op->mode);
 		if (error) {
 			mnt_drop_write(nd->path.mnt);
 			goto exit;
@@ -2242,7 +2251,7 @@
 		mnt_drop_write(nd->path.mnt);
 		path_put(&nd->path);
 		if (!IS_ERR(filp)) {
-			error = ima_file_check(filp, acc_mode);
+			error = ima_file_check(filp, op->acc_mode);
 			if (error) {
 				fput(filp);
 				filp = ERR_PTR(error);
@@ -2258,7 +2267,7 @@
 	audit_inode(pathname, path->dentry);
  
 	error = -EEXIST;
-	if (open_flag & O_EXCL)
+	if (op->open_flag & O_EXCL)
 		goto exit_dput;
  
 	error = follow_managed(path, nd->flags);
@@ -2278,7 +2287,7 @@
 	if (S_ISDIR(nd->inode->i_mode))
 		goto exit;
 ok:
-	filp = finish_open(nd, open_flag, acc_mode);
+	filp = finish_open(nd, op->open_flag, op->acc_mode);
 	return filp;
  
 exit_mutex_unlock:
@@ -2304,7 +2313,8 @@
 	struct path path;
 	int count = 0;
 	int flag = open_to_namei_flags(open_flag);
-	int flags;
+	int flags = 0;
+	struct open_flags op;
  
 	if (!(open_flag & O_CREAT))
 		mode = 0;
@@ -2321,6 +2331,8 @@
 	if (open_flag & __O_SYNC)
 		open_flag |= O_DSYNC;
  
+	op.open_flag = open_flag;
+
 	if (!acc_mode)
 		acc_mode = MAY_OPEN | ACC_MODE(open_flag);
  
  
  
  
@@ -2333,12 +2345,15 @@
 	if (open_flag & O_APPEND)
 		acc_mode |= MAY_APPEND;
  
-	flags = LOOKUP_OPEN;
+	op.acc_mode = acc_mode;
+
+	op.intent = LOOKUP_OPEN;
 	if (open_flag & O_CREAT) {
-		flags |= LOOKUP_CREATE;
+		op.intent |= LOOKUP_CREATE;
 		if (open_flag & O_EXCL)
-			flags |= LOOKUP_EXCL;
+			op.intent |= LOOKUP_EXCL;
 	}
+
 	if (open_flag & O_DIRECTORY)
 		flags |= LOOKUP_DIRECTORY;
 	if (!(open_flag & O_NOFOLLOW))
@@ -2357,7 +2372,7 @@
 		goto creat;
  
 	/* !O_CREAT, simple open */
-	error = do_path_lookup(dfd, pathname, flags, &nd);
+	error = do_path_lookup(dfd, pathname, flags | op.intent, &nd);
 	if (unlikely(error))
 		goto out_filp2;
 	error = -ELOOP;
  
  
@@ -2384,14 +2399,14 @@
  
 creat:
 	/* OK, have to create the file. Find the parent. */
-	error = path_lookupat(dfd, pathname, LOOKUP_PARENT | LOOKUP_RCU, &nd);
+	error = path_lookupat(dfd, pathname,
+			LOOKUP_PARENT | LOOKUP_RCU | flags, &nd);
 	if (unlikely(error == -ECHILD))
-		error = path_lookupat(dfd, pathname, LOOKUP_PARENT, &nd);
+		error = path_lookupat(dfd, pathname, LOOKUP_PARENT | flags, &nd);
 	if (unlikely(error == -ESTALE)) {
 reval:
 		flags |= LOOKUP_REVAL;
-		error = path_lookupat(dfd, pathname,
-				LOOKUP_PARENT | LOOKUP_REVAL, &nd);
+		error = path_lookupat(dfd, pathname, LOOKUP_PARENT | flags, &nd);
 	}
 	if (unlikely(error))
 		goto out_filp;
@@ -2401,8 +2416,7 @@
 	/*
 	 * We have the parent and last component.
 	 */
-	nd.flags = (nd.flags & ~LOOKUP_PARENT) | flags;
-	filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
+	filp = do_last(&nd, &path, &op, pathname);
 	while (unlikely(!filp)) { /* trailing symlink */
 		struct path link = path;
 		struct inode *linki = link.dentry->d_inode;
  
  
@@ -2424,13 +2438,12 @@
 		 * just set LAST_BIND.
 		 */
 		nd.flags |= LOOKUP_PARENT;
+		nd.flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
 		error = __do_follow_link(&link, &nd, &cookie);
-		if (unlikely(error)) {
+		if (unlikely(error))
 			filp = ERR_PTR(error);
-		} else {
-			nd.flags &= ~LOOKUP_PARENT;
-			filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
-		}
+		else
+			filp = do_last(&nd, &path, &op, pathname);
 		if (!IS_ERR(cookie) && linki->i_op->put_link)
 			linki->i_op->put_link(link.dentry, &nd, cookie);
 		path_put(&link);
...	...	@@ -2169,17 +2169,26 @@
2169	2169	return ERR_PTR(error);
2170	2170	}
2171	2171
	2172	+struct open_flags {
	2173	+ int open_flag;
	2174	+ int mode;
	2175	+ int acc_mode;
	2176	+ int intent;
	2177	+};
	2178	+
2172	2179	/*
2173	2180	* Handle O_CREAT case for do_filp_open
2174	2181	*/
2175	2182	static struct file do_last(struct nameidata nd, struct path *path,
2176		- int open_flag, int acc_mode,
2177		- int mode, const char *pathname)
	2183	+ const struct open_flags op, const char pathname)
2178	2184	{
2179	2185	struct dentry *dir = nd->path.dentry;
2180	2186	struct file *filp;
2181	2187	int error;
2182	2188
	2189	+ nd->flags &= ~LOOKUP_PARENT;
	2190	+ nd->flags \|= op->intent;
	2191	+
2183	2192	switch (nd->last_type) {
2184	2193	case LAST_DOTDOT:
2185	2194	follow_dotdot(nd);
...	...	@@ -2233,7 +2242,7 @@
2233	2242	error = mnt_want_write(nd->path.mnt);
2234	2243	if (error)
2235	2244	goto exit_mutex_unlock;
2236		- error = __open_namei_create(nd, path, open_flag, mode);
	2245	+ error = __open_namei_create(nd, path, op->open_flag, op->mode);
2237	2246	if (error) {
2238	2247	mnt_drop_write(nd->path.mnt);
2239	2248	goto exit;
...	...	@@ -2242,7 +2251,7 @@
2242	2251	mnt_drop_write(nd->path.mnt);
2243	2252	path_put(&nd->path);
2244	2253	if (!IS_ERR(filp)) {
2245		- error = ima_file_check(filp, acc_mode);
	2254	+ error = ima_file_check(filp, op->acc_mode);
2246	2255	if (error) {
2247	2256	fput(filp);
2248	2257	filp = ERR_PTR(error);
...	...	@@ -2258,7 +2267,7 @@
2258	2267	audit_inode(pathname, path->dentry);
2259	2268
2260	2269	error = -EEXIST;
2261		- if (open_flag & O_EXCL)
	2270	+ if (op->open_flag & O_EXCL)
2262	2271	goto exit_dput;
2263	2272
2264	2273	error = follow_managed(path, nd->flags);
...	...	@@ -2278,7 +2287,7 @@
2278	2287	if (S_ISDIR(nd->inode->i_mode))
2279	2288	goto exit;
2280	2289	ok:
2281		- filp = finish_open(nd, open_flag, acc_mode);
	2290	+ filp = finish_open(nd, op->open_flag, op->acc_mode);
2282	2291	return filp;
2283	2292
2284	2293	exit_mutex_unlock:
...	...	@@ -2304,7 +2313,8 @@
2304	2313	struct path path;
2305	2314	int count = 0;
2306	2315	int flag = open_to_namei_flags(open_flag);
2307		- int flags;
	2316	+ int flags = 0;
	2317	+ struct open_flags op;
2308	2318
2309	2319	if (!(open_flag & O_CREAT))
2310	2320	mode = 0;
...	...	@@ -2321,6 +2331,8 @@
2321	2331	if (open_flag & __O_SYNC)
2322	2332	open_flag \|= O_DSYNC;
2323	2333
	2334	+ op.open_flag = open_flag;
	2335	+
2324	2336	if (!acc_mode)
2325	2337	acc_mode = MAY_OPEN \| ACC_MODE(open_flag);
2326	2338
2327	2339
2328	2340
2329	2341
...	...	@@ -2333,12 +2345,15 @@
2333	2345	if (open_flag & O_APPEND)
2334	2346	acc_mode \|= MAY_APPEND;
2335	2347
2336		- flags = LOOKUP_OPEN;
	2348	+ op.acc_mode = acc_mode;
	2349	+
	2350	+ op.intent = LOOKUP_OPEN;
2337	2351	if (open_flag & O_CREAT) {
2338		- flags \|= LOOKUP_CREATE;
	2352	+ op.intent \|= LOOKUP_CREATE;
2339	2353	if (open_flag & O_EXCL)
2340		- flags \|= LOOKUP_EXCL;
	2354	+ op.intent \|= LOOKUP_EXCL;
2341	2355	}
	2356	+
2342	2357	if (open_flag & O_DIRECTORY)
2343	2358	flags \|= LOOKUP_DIRECTORY;
2344	2359	if (!(open_flag & O_NOFOLLOW))
...	...	@@ -2357,7 +2372,7 @@
2357	2372	goto creat;
2358	2373
2359	2374	/* !O_CREAT, simple open */
2360		- error = do_path_lookup(dfd, pathname, flags, &nd);
	2375	+ error = do_path_lookup(dfd, pathname, flags \| op.intent, &nd);
2361	2376	if (unlikely(error))
2362	2377	goto out_filp2;
2363	2378	error = -ELOOP;
2364	2379
2365	2380
...	...	@@ -2384,14 +2399,14 @@
2384	2399
2385	2400	creat:
2386	2401	/* OK, have to create the file. Find the parent. */
2387		- error = path_lookupat(dfd, pathname, LOOKUP_PARENT \| LOOKUP_RCU, &nd);
	2402	+ error = path_lookupat(dfd, pathname,
	2403	+ LOOKUP_PARENT \| LOOKUP_RCU \| flags, &nd);
2388	2404	if (unlikely(error == -ECHILD))
2389		- error = path_lookupat(dfd, pathname, LOOKUP_PARENT, &nd);
	2405	+ error = path_lookupat(dfd, pathname, LOOKUP_PARENT \| flags, &nd);
2390	2406	if (unlikely(error == -ESTALE)) {
2391	2407	reval:
2392	2408	flags \|= LOOKUP_REVAL;
2393		- error = path_lookupat(dfd, pathname,
2394		- LOOKUP_PARENT \| LOOKUP_REVAL, &nd);
	2409	+ error = path_lookupat(dfd, pathname, LOOKUP_PARENT \| flags, &nd);
2395	2410	}
2396	2411	if (unlikely(error))
2397	2412	goto out_filp;
...	...	@@ -2401,8 +2416,7 @@
2401	2416	/*
2402	2417	* We have the parent and last component.
2403	2418	*/
2404		- nd.flags = (nd.flags & ~LOOKUP_PARENT) \| flags;
2405		- filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
	2419	+ filp = do_last(&nd, &path, &op, pathname);
2406	2420	while (unlikely(!filp)) { /* trailing symlink */
2407	2421	struct path link = path;
2408	2422	struct inode *linki = link.dentry->d_inode;
2409	2423
2410	2424
...	...	@@ -2424,13 +2438,12 @@
2424	2438	* just set LAST_BIND.
2425	2439	*/
2426	2440	nd.flags \|= LOOKUP_PARENT;
	2441	+ nd.flags &= ~(LOOKUP_OPEN\|LOOKUP_CREATE\|LOOKUP_EXCL);
2427	2442	error = __do_follow_link(&link, &nd, &cookie);
2428		- if (unlikely(error)) {
	2443	+ if (unlikely(error))
2429	2444	filp = ERR_PTR(error);
2430		- } else {
2431		- nd.flags &= ~LOOKUP_PARENT;
2432		- filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
2433		- }
	2445	+ else
	2446	+ filp = do_last(&nd, &path, &op, pathname);
2434	2447	if (!IS_ERR(cookie) && linki->i_op->put_link)
2435	2448	linki->i_op->put_link(link.dentry, &nd, cookie);
2436	2449	path_put(&link);