unify xarray_get_pages() and xarray_get_pages_alloc()

same as for pipes

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 916c628f80a075cc8f5ffda183d4c43930bbab6e..6904a1cc36f26413c35a590bb57ea87ec63e6b2e 100644 (file)
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1373,7 +1373,7 @@ static ssize_t iter_xarray_populate_pages(struct page **pages, struct xarray *xa
 }
 
 static ssize_t iter_xarray_get_pages(struct iov_iter *i,
-                                    struct page **pages, size_t maxsize,
+                                    struct page ***pages, size_t maxsize,
                                     unsigned maxpages, size_t *_start_offset)
 {
        unsigned nr, offset;
@@ -1398,7 +1398,13 @@ static ssize_t iter_xarray_get_pages(struct iov_iter *i,
        if (count > maxpages)
                count = maxpages;
 
-       nr = iter_xarray_populate_pages(pages, i->xarray, index, count);
+       if (!*pages) {
+               *pages = get_pages_array(count);
+               if (!*pages)
+                       return -ENOMEM;
+       }
+
+       nr = iter_xarray_populate_pages(*pages, i->xarray, index, count);
        if (nr == 0)
                return 0;
 
@@ -1490,46 +1496,11 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
        if (iov_iter_is_pipe(i))
                return pipe_get_pages(i, &pages, maxsize, maxpages, start);
        if (iov_iter_is_xarray(i))
-               return iter_xarray_get_pages(i, pages, maxsize, maxpages, start);
+               return iter_xarray_get_pages(i, &pages, maxsize, maxpages, start);
        return -EFAULT;
 }
 EXPORT_SYMBOL(iov_iter_get_pages);
 
-static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i,
-                                          struct page ***pages, size_t maxsize,
-                                          size_t *_start_offset)
-{
-       struct page **p;
-       unsigned nr, offset;
-       pgoff_t index, count;
-       size_t size = maxsize;
-       loff_t pos;
-
-       pos = i->xarray_start + i->iov_offset;
-       index = pos >> PAGE_SHIFT;
-       offset = pos & ~PAGE_MASK;
-       *_start_offset = offset;
-
-       count = 1;
-       if (size > PAGE_SIZE - offset) {
-               size -= PAGE_SIZE - offset;
-               count += size >> PAGE_SHIFT;
-               size &= ~PAGE_MASK;
-               if (size)
-                       count++;
-       }
-
-       *pages = p = get_pages_array(count);
-       if (!p)
-               return -ENOMEM;
-
-       nr = iter_xarray_populate_pages(p, i->xarray, index, count);
-       if (nr == 0)
-               return 0;
-
-       return min_t(size_t, nr * PAGE_SIZE - offset, maxsize);
-}
-
 static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
                   struct page ***pages, size_t maxsize,
                   size_t *start)
@@ -1580,7 +1551,7 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
        if (iov_iter_is_pipe(i))
                return pipe_get_pages(i, pages, maxsize, ~0U, start);
        if (iov_iter_is_xarray(i))
-               return iter_xarray_get_pages_alloc(i, pages, maxsize, start);
+               return iter_xarray_get_pages(i, pages, maxsize, ~0U, start);
        return -EFAULT;
 }