Export symbols for the VFS API

[zfs.git] / module / zfs / zpl_file.c

diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c
index 0e90b78..af46afd 100644 (file)
--- a/module/zfs/zpl_file.c
+++ b/module/zfs/zpl_file.c
@@ -240,9 +240,15 @@ zpl_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
 static int
 zpl_mmap(struct file *filp, struct vm_area_struct *vma)
 {
-       znode_t *zp = ITOZ(filp->f_mapping->host);
+       struct inode *ip = filp->f_mapping->host;
+       znode_t *zp = ITOZ(ip);
        int error;
 
+       error = -zfs_map(ip, vma->vm_pgoff, (caddr_t *)vma->vm_start,
+           (size_t)(vma->vm_end - vma->vm_start), vma->vm_flags);
+       if (error)
+               return (error);
+
        error = generic_file_mmap(filp, vma);
        if (error)
                return (error);
@@ -254,60 +260,6 @@ zpl_mmap(struct file *filp, struct vm_area_struct *vma)
        return (error);
 }
 
-static struct page **
-pages_vector_from_list(struct list_head *pages, unsigned nr_pages)
-{
-       struct page **pl;
-       struct page *t;
-       unsigned page_idx;
-
-       pl = kmalloc(sizeof(*pl) * nr_pages, GFP_NOFS);
-       if (!pl)
-               return ERR_PTR(-ENOMEM);
-
-       page_idx = 0;
-       list_for_each_entry_reverse(t, pages, lru) {
-               pl[page_idx] = t;
-               page_idx++;
-       }
-
-       return pl;
-}
-
-static int
-zpl_readpages(struct file *file, struct address_space *mapping,
-       struct list_head *pages, unsigned nr_pages)
-{
-       struct inode *ip;
-       struct page  **pl;
-       struct page  *p, *n;
-       int          error;
-
-       ip = mapping->host;
-
-       pl = pages_vector_from_list(pages, nr_pages);
-       if (IS_ERR(pl))
-               return PTR_ERR(pl);
-
-       error = -zfs_getpage(ip, pl, nr_pages);
-       if (error)
-               goto error;
-
-       list_for_each_entry_safe_reverse(p, n, pages, lru) {
-
-               list_del(&p->lru);
-
-               flush_dcache_page(p);
-               SetPageUptodate(p);
-               unlock_page(p);
-               page_cache_release(p);
-       }
-
-error:
-       kfree(pl);
-       return error;
-}
-
 /*
  * Populate a page with data for the Linux page cache.  This function is
  * only used to support mmap(2).  There will be an identical copy of the
@@ -343,24 +295,40 @@ zpl_readpage(struct file *filp, struct page *pp)
        return error;
 }
 
+/*
+ * Populate a set of pages with data for the Linux page cache.  This
+ * function will only be called for read ahead and never for demand
+ * paging.  For simplicity, the code relies on read_cache_pages() to
+ * correctly lock each page for IO and call zpl_readpage().
+ */
+static int
+zpl_readpages(struct file *filp, struct address_space *mapping,
+       struct list_head *pages, unsigned nr_pages)
+{
+       return (read_cache_pages(mapping, pages,
+           (filler_t *)zpl_readpage, filp));
+}
+
 int
 zpl_putpage(struct page *pp, struct writeback_control *wbc, void *data)
 {
-       int error;
-
-       error = -zfs_putpage(pp, wbc, data);
-
-       if (error) {
-               SetPageError(pp);
-               ClearPageUptodate(pp);
-       } else {
-               ClearPageError(pp);
-               SetPageUptodate(pp);
-               flush_dcache_page(pp);
-       }
+       struct address_space *mapping = data;
 
-       unlock_page(pp);
-       return error;
+       ASSERT(PageLocked(pp));
+       ASSERT(!PageWriteback(pp));
+
+       /*
+        * Disable the normal reclaim path for zpl_putpage().  This
+        * ensures that all memory allocations under this call path
+        * will never enter direct reclaim.  If this were to happen
+        * the VM might try to write out additional pages by calling
+        * zpl_putpage() again resulting in a deadlock.
+        */
+       current->flags |= PF_MEMALLOC;
+       (void) zfs_putpage(mapping->host, pp, wbc);
+       current->flags &= ~PF_MEMALLOC;
+
+       return (0);
 }
 
 static int