xfs: merge _xfs_buf_get_pages()

Only called from one place now, so merge it into
xfs_buf_alloc_pages(). Because page array allocation is dependent on
bp->b_pages being null, always ensure that when the pages array is
freed we always set bp->b_pages to null.

Also convert the page array to use kmalloc() rather than
kmem_alloc() so we can use the gfp flags we've already calculated
for the allocation context instead of hard coding KM_NOFS semantics.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 2749bc0..a6fcd82 100644 (file)
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -272,31 +272,6 @@ _xfs_buf_alloc(
        return 0;
 }
 
-/*
- *     Allocate a page array capable of holding a specified number
- *     of pages, and point the page buf at it.
- */
-STATIC int
-_xfs_buf_get_pages(
-       struct xfs_buf          *bp,
-       int                     page_count)
-{
-       /* Make sure that we have a page list */
-       if (bp->b_pages == NULL) {
-               bp->b_page_count = page_count;
-               if (page_count <= XB_PAGES) {
-                       bp->b_pages = bp->b_page_array;
-               } else {
-                       bp->b_pages = kmem_alloc(sizeof(struct page *) *
-                                                page_count, KM_NOFS);
-                       if (bp->b_pages == NULL)
-                               return -ENOMEM;
-               }
-               memset(bp->b_pages, 0, sizeof(struct page *) * page_count);
-       }
-       return 0;
-}
-
 /*
  *     Frees b_pages if it was allocated.
  */
@@ -304,10 +279,9 @@ STATIC void
 _xfs_buf_free_pages(
        struct xfs_buf  *bp)
 {
-       if (bp->b_pages != bp->b_page_array) {
+       if (bp->b_pages != bp->b_page_array)
                kmem_free(bp->b_pages);
-               bp->b_pages = NULL;
-       }
+       bp->b_pages = NULL;
 }
 
 /*
@@ -389,16 +363,22 @@ xfs_buf_alloc_pages(
        long            filled = 0;
        int             error;
 
+       /* Make sure that we have a page list */
+       bp->b_page_count = page_count;
+       if (bp->b_page_count <= XB_PAGES) {
+               bp->b_pages = bp->b_page_array;
+       } else {
+               bp->b_pages = kzalloc(sizeof(struct page *) * bp->b_page_count,
+                                       gfp_mask);
+               if (!bp->b_pages)
+                       return -ENOMEM;
+       }
+       bp->b_flags |= _XBF_PAGES;
+
        /* Assure zeroed buffer for non-read cases. */
        if (!(flags & XBF_READ))
                gfp_mask |= __GFP_ZERO;
 
-       error = _xfs_buf_get_pages(bp, page_count);
-       if (unlikely(error))
-               return error;
-
-       bp->b_flags |= _XBF_PAGES;
-
        /*
         * Bulk filling of pages can take multiple calls. Not filling the entire
         * array is not an allocation failure, so don't back off if we get at