X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fzpl_file.c;h=af46afddfbbcf0ffcc255d4b40c2ad4fa2b89424;hb=e45aa452988f721e458fa3abe54669bdf9377352;hp=de66ff4b49200f6bf6d997bdfde8f9ced671cb9f;hpb=3117dd0b9005eb76e483b9772c493883b82998bb;p=zfs.git

diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c
index de66ff4..af46afd 100644
--- 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);
@@ -267,33 +273,14 @@ static int
 zpl_readpage(struct file *filp, struct page *pp)
 {
 	struct inode *ip;
-	loff_t off, i_size;
-	size_t len, wrote;
-	cred_t *cr = CRED();
-	void *pb;
+	struct page *pl[1];
 	int error = 0;
 
 	ASSERT(PageLocked(pp));
 	ip = pp->mapping->host;
-	off = page_offset(pp);
-	i_size = i_size_read(ip);
-	ASSERT3S(off, <, i_size);
-
-	crhold(cr);
-	len = MIN(PAGE_CACHE_SIZE, i_size - off);
-
-	pb = kmap(pp);
+	pl[0] = pp;
 
-	/* O_DIRECT is passed to bypass the page cache and avoid deadlock. */
-	wrote = zpl_read_common(ip, pb, len, off, UIO_SYSSPACE, O_DIRECT, cr);
-	if (wrote != len)
-		error = -EIO;
-
-	if (!error && (len < PAGE_CACHE_SIZE))
-		memset(pb + len, 0, PAGE_CACHE_SIZE - len);
-
-	kunmap(pp);
-	crfree(cr);
+	error = -zfs_getpage(ip, pl, 1);
 
 	if (error) {
 		SetPageError(pp);
@@ -305,8 +292,49 @@ zpl_readpage(struct file *filp, struct page *pp)
 	}
 
 	unlock_page(pp);
+	return error;
+}
 
-	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)
+{
+	struct address_space *mapping = data;
+
+	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
+zpl_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+	return write_cache_pages(mapping, wbc, zpl_putpage, mapping);
 }
 
 /*
@@ -314,55 +342,18 @@ zpl_readpage(struct file *filp, struct page *pp)
  * support mmap(2).  Mapped pages may be dirtied by memory operations
  * which never call .write().  These dirty pages are kept in sync with
  * the ARC buffers via this hook.
- *
- * Currently this function relies on zpl_write_common() and the O_DIRECT
- * flag to push out the page.  This works but the more correct way is
- * to update zfs_putapage() to be Linux friendly and use that interface.
  */
 static int
 zpl_writepage(struct page *pp, struct writeback_control *wbc)
 {
-	struct inode *ip;
-	loff_t off, i_size;
-	size_t len, read;
-	cred_t *cr = CRED();
-	void *pb;
-	int error = 0;
-
-	ASSERT(PageLocked(pp));
-	ip = pp->mapping->host;
-	off = page_offset(pp);
-	i_size = i_size_read(ip);
-
-	crhold(cr);
-	len = MIN(PAGE_CACHE_SIZE, i_size - off);
-
-	pb = kmap(pp);
-
-	/* O_DIRECT is passed to bypass the page cache and avoid deadlock. */
-	read = zpl_write_common(ip, pb, len, off, UIO_SYSSPACE, O_DIRECT, cr);
-	if (read != len)
-		error = -EIO;
-
-	kunmap(pp);
-	crfree(cr);
-
-	if (error) {
-		SetPageError(pp);
-		ClearPageUptodate(pp);
-	} else {
-		ClearPageError(pp);
-		SetPageUptodate(pp);
-	}
-
-	unlock_page(pp);
-
-	return (error);
+	return zpl_putpage(pp, wbc, pp->mapping);
 }
 
 const struct address_space_operations zpl_address_space_operations = {
+	.readpages	= zpl_readpages,
 	.readpage	= zpl_readpage,
 	.writepage	= zpl_writepage,
+	.writepages     = zpl_writepages,
 };
 
 const struct file_operations zpl_file_operations = {