switch do_filp_open() to struct open_flags

[linux-2.6-block.git] / fs / open.c

diff --git a/fs/open.c b/fs/open.c
index b47aab39c0572242c607495c37c15928fbf8290c..d05e18c60baec9e9b422c57338c01debda07f214 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -890,15 +890,86 @@ void fd_install(unsigned int fd, struct file *file)
 
 EXPORT_SYMBOL(fd_install);
 
+static inline int build_open_flags(int flags, int mode, struct open_flags *op)
+{
+       int lookup_flags = 0;
+       int acc_mode;
+
+       if (!(flags & O_CREAT))
+               mode = 0;
+       op->mode = mode;
+
+       /* Must never be set by userspace */
+       flags &= ~FMODE_NONOTIFY;
+
+       /*
+        * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only
+        * check for O_DSYNC if the need any syncing at all we enforce it's
+        * always set instead of having to deal with possibly weird behaviour
+        * for malicious applications setting only __O_SYNC.
+        */
+       if (flags & __O_SYNC)
+               flags |= O_DSYNC;
+
+       op->open_flag = flags;
+
+       acc_mode = MAY_OPEN | ACC_MODE(flags);
+
+       /* O_TRUNC implies we need access checks for write permissions */
+       if (flags & O_TRUNC)
+               acc_mode |= MAY_WRITE;
+
+       /* Allow the LSM permission hook to distinguish append
+          access from general write access. */
+       if (flags & O_APPEND)
+               acc_mode |= MAY_APPEND;
+
+       op->acc_mode = acc_mode;
+
+       op->intent = LOOKUP_OPEN;
+       if (flags & O_CREAT) {
+               op->intent |= LOOKUP_CREATE;
+               if (flags & O_EXCL)
+                       op->intent |= LOOKUP_EXCL;
+       }
+
+       if (flags & O_DIRECTORY)
+               lookup_flags |= LOOKUP_DIRECTORY;
+       if (!(flags & O_NOFOLLOW))
+               lookup_flags |= LOOKUP_FOLLOW;
+       return lookup_flags;
+}
+
+/**
+ * filp_open - open file and return file pointer
+ *
+ * @filename:  path to open
+ * @flags:     open flags as per the open(2) second argument
+ * @mode:      mode for the new file if O_CREAT is set, else ignored
+ *
+ * This is the helper to open a file from kernelspace if you really
+ * have to.  But in generally you should not do this, so please move
+ * along, nothing to see here..
+ */
+struct file *filp_open(const char *filename, int flags, int mode)
+{
+       struct open_flags op;
+       int lookup = build_open_flags(flags, mode, &op);
+       return do_filp_open(AT_FDCWD, filename, &op, lookup);
+}
+EXPORT_SYMBOL(filp_open);
+
 long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
 {
+       struct open_flags op;
+       int lookup = build_open_flags(flags, mode, &op);
        char *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, flags, mode, 0);
+                       struct file *f = do_filp_open(dfd, tmp, &op, lookup);
                        if (IS_ERR(f)) {
                                put_unused_fd(fd);
                                fd = PTR_ERR(f);