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>

1 files changed, 35 insertions, 22 deletions

diff --git a/fs/namei.c b/fs/namei.c
index e0f59031be87..5e4206f45371 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2169,17 +2169,26 @@ exit:
         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 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                 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 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                 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 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
         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 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
         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 file *do_filp_open(int dfd, const char *pathname,
         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 @@ struct file *do_filp_open(int dfd, const char *pathname,
         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 @@ struct file *do_filp_open(int dfd, const char *pathname,
         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 @@ struct file *do_filp_open(int dfd, const char *pathname,
                 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 @@ out_filp2:
 
 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 @@ reval:
         /*
          * 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 @@ reval:
                  * 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);