skd_main: don't use req->special

[linux.git] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index e4d295d0d23616b29d2d846902531f0749adf2fe..bfcb4ced5664c00f2fab706ba483094a4bc1ca5a 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -331,7 +331,7 @@ COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned i
 }
 #endif
 
-#ifdef __ARCH_WANT_SYS_LLSEEK
+#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT)
 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
                unsigned long, offset_low, loff_t __user *, result,
                unsigned int, whence)
@@ -1407,7 +1407,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
                goto fput_in;
        if (!(out.file->f_mode & FMODE_WRITE))
                goto fput_out;
-       retval = -EINVAL;
        in_inode = file_inode(in.file);
        out_inode = file_inode(out.file);
        out_pos = out.file->f_pos;
@@ -1848,8 +1847,8 @@ static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
  * sense, and then flush all dirty data.  Caller must ensure that the
  * inodes have been locked against any other modifications.
  *
- * Returns: 0 for "nothing to clone", 1 for "something to clone", or
- * the usual negative error code.
+ * If there's an error, then the usual negative error code is returned.
+ * Otherwise returns 0 with *len set to the request length.
  */
 int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
                                  struct file *file_out, loff_t pos_out,
@@ -1945,7 +1944,7 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
                        return ret;
        }
 
-       return 1;
+       return 0;
 }
 EXPORT_SYMBOL(generic_remap_file_range_prep);
 
@@ -2014,6 +2013,20 @@ loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
 }
 EXPORT_SYMBOL(vfs_clone_file_range);
 
+/* Check whether we are allowed to dedupe the destination file */
+static bool allow_file_dedupe(struct file *file)
+{
+       if (capable(CAP_SYS_ADMIN))
+               return true;
+       if (file->f_mode & FMODE_WRITE)
+               return true;
+       if (uid_eq(current_fsuid(), file_inode(file)->i_uid))
+               return true;
+       if (!inode_permission(file_inode(file), MAY_WRITE))
+               return true;
+       return false;
+}
+
 loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
                                 struct file *dst_file, loff_t dst_pos,
                                 loff_t len, unsigned int remap_flags)
@@ -2031,8 +2044,8 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
        if (ret < 0)
                goto out_drop_write;
 
-       ret = -EINVAL;
-       if (!(capable(CAP_SYS_ADMIN) || (dst_file->f_mode & FMODE_WRITE)))
+       ret = -EPERM;
+       if (!allow_file_dedupe(dst_file))
                goto out_drop_write;
 
        ret = -EXDEV;