[CIFS] Do not overwrite aops

cifs should not be overwriting an element of the aops structure, since the
structure is shared by all cifs inodes.  Instead define a separate aops
structure to suit each purpose.

I also took the liberty of replacing a hard-coded 4096 with PAGE_CACHE_SIZE

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 379369ecda96..d62e29fe91f2 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1959,3 +1959,19 @@ struct address_space_operations cifs_addr_ops = {
 	/* .sync_page = cifs_sync_page, */
 	/* .direct_IO = */
 };
+
+/*
+ * cifs_readpages requires the server to support a buffer large enough to
+ * contain the header plus one complete page of data.  Otherwise, we need
+ * to leave cifs_readpages out of the address space operations.
+ */
+struct address_space_operations cifs_addr_ops_smallbuf = {
+	.readpage = cifs_readpage,
+	.writepage = cifs_writepage,
+	.writepages = cifs_writepages,
+	.prepare_write = cifs_prepare_write,
+	.commit_write = cifs_commit_write,
+	.set_page_dirty = __set_page_dirty_nobuffers,
+	/* .sync_page = cifs_sync_page, */
+	/* .direct_IO = */
+};