start adding the tag to iov_iter

For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 21 insertions, 6 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index a7f79e90209c..3aeaf2df4135 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1730,7 +1730,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
         size_t count = iov_length(iov, nr_segs);
         struct iov_iter i;
 
-        iov_iter_init(&i, iov, nr_segs, count, 0);
+        iov_iter_init(&i, READ, iov, nr_segs, count);
         return generic_file_read_iter(iocb, &i);
 }
 EXPORT_SYMBOL(generic_file_aio_read);
@@ -2596,7 +2596,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         if (err)
                 goto out;
 
-        iov_iter_init(&from, iov, nr_segs, count, 0);
+        iov_iter_init(&from, WRITE, iov, nr_segs, count);
 
         /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
         if (unlikely(file->f_flags & O_DIRECT)) {
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 2f762cc21080..e2c9a2db4350 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -220,3 +220,18 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
         return res;
 }
 EXPORT_SYMBOL(iov_iter_alignment);
+
+void iov_iter_init(struct iov_iter *i, int direction,
+                        const struct iovec *iov, unsigned long nr_segs,
+                        size_t count)
+{
+        /* It will get better.  Eventually... */
+        if (segment_eq(get_fs(), KERNEL_DS))
+                direction |= REQ_KERNEL;
+        i->type = direction;
+        i->iov = iov;
+        i->nr_segs = nr_segs;
+        i->iov_offset = 0;
+        i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_init);
diff --git a/mm/page_io.c b/mm/page_io.c
index 0ed0644c73db..313bfedb75d1 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -268,7 +268,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
                 init_sync_kiocb(&kiocb, swap_file);
                 kiocb.ki_pos = page_file_offset(page);
                 kiocb.ki_nbytes = PAGE_SIZE;
-                iov_iter_init(&from, &iov, 1, PAGE_SIZE, 0);
+                iov_iter_init(&from, KERNEL_WRITE, &iov, 1, PAGE_SIZE);
 
                 set_page_writeback(page);
                 unlock_page(page);
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index f32b1fbbfe69..5077afcd9e11 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -274,7 +274,7 @@ static ssize_t process_vm_rw(pid_t pid,
         if (rc <= 0)
                 goto free_iovecs;
 
-        iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
+        iov_iter_init(&iter, vm_write ? WRITE : READ, iov_l, liovcnt, rc);
 
         rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
                                    iovstack_r, &iov_r);
@@ -337,7 +337,7 @@ compat_process_vm_rw(compat_pid_t pid,
                                                   &iov_l);
         if (rc <= 0)
                 goto free_iovecs;
-        iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
+        iov_iter_init(&iter, vm_write ? WRITE : READ, iov_l, liovcnt, rc);
         rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
                                           UIO_FASTIOV, iovstack_r,
                                           &iov_r);
diff --git a/mm/shmem.c b/mm/shmem.c
index 2a93e625adaf..e0b76696c3f9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1417,7 +1417,7 @@ static ssize_t shmem_file_aio_read(struct kiocb *iocb,
         loff_t *ppos = &iocb->ki_pos;
         struct iov_iter iter;
 
-        iov_iter_init(&iter, iov, nr_segs, count, 0);
+        iov_iter_init(&iter, READ, iov, nr_segs, count);
 
         /*
          * Might this read be for a stacking filesystem?  Then when reading