ANDROID: sdcardfs: add read_iter/write_iter opeations
Adapted from wrapfs
commit f398bf6a7377 ("Wrapfs: add read_iter/write_iter opeations")
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Mengyang Li <li.mengyang@stonybrook.edu>
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 35766959
Change-Id: I2b3de59c9682fc705bf21df0de6df81e76fd2e40
diff --git a/fs/sdcardfs/file.c b/fs/sdcardfs/file.c
index f49df7a..c0146e0 100644
--- a/fs/sdcardfs/file.c
+++ b/fs/sdcardfs/file.c
@@ -338,6 +338,52 @@
return err;
}
+/*
+ * Sdcardfs read_iter, redirect modified iocb to lower read_iter
+ */
+ssize_t sdcardfs_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ int err;
+ struct file *file = iocb->ki_filp, *lower_file;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (!lower_file->f_op->read_iter) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ get_file(lower_file); /* prevent lower_file from being released */
+ iocb->ki_filp = lower_file;
+ err = lower_file->f_op->read_iter(iocb, iter);
+ /* ? wait IO finish to update atime as ecryptfs ? */
+ iocb->ki_filp = file;
+ fput(lower_file);
+out:
+ return err;
+}
+
+/*
+ * Sdcardfs write_iter, redirect modified iocb to lower write_iter
+ */
+ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ int err;
+ struct file *file = iocb->ki_filp, *lower_file;
+
+ lower_file = sdcardfs_lower_file(file);
+ if (!lower_file->f_op->write_iter) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ get_file(lower_file); /* prevent lower_file from being released */
+ iocb->ki_filp = lower_file;
+ err = lower_file->f_op->write_iter(iocb, iter);
+ iocb->ki_filp = file;
+ fput(lower_file);
+out:
+ return err;
+}
const struct file_operations sdcardfs_main_fops = {
.llseek = generic_file_llseek,
@@ -353,6 +399,8 @@
.release = sdcardfs_file_release,
.fsync = sdcardfs_fsync,
.fasync = sdcardfs_fasync,
+ .read_iter = sdcardfs_read_iter,
+ .write_iter = sdcardfs_write_iter,
};
/* trimmed directory options */