[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>

diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 2fc6d65..3011df9 100644 (file)
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -33,6 +33,7 @@
 #endif
 
 extern struct address_space_operations cifs_addr_ops;
+extern struct address_space_operations cifs_addr_ops_smallbuf;
 
 /* Functions related to super block operations */
 extern struct super_operations cifs_super_ops;

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 379369e..d62e29f 100644 (file)
--- 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 = */
+};

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index a609d26..b88147c 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -180,11 +180,12 @@ int cifs_get_inode_info_unix(struct inode **pinode,
                        else /* not direct, send byte range locks */ 
                                inode->i_fop = &cifs_file_ops;
 
-                       inode->i_data.a_ops = &cifs_addr_ops;
                        /* check if server can support readpages */
                        if(pTcon->ses->server->maxBuf < 
-                           4096 + MAX_CIFS_HDR_SIZE)
-                               inode->i_data.a_ops->readpages = NULL;
+                           PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE)
+                               inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
+                       else
+                               inode->i_data.a_ops = &cifs_addr_ops;
                } else if (S_ISDIR(inode->i_mode)) {
                        cFYI(1, ("Directory inode"));
                        inode->i_op = &cifs_dir_inode_ops;
@@ -519,10 +520,11 @@ int cifs_get_inode_info(struct inode **pinode,
                        else /* not direct, send byte range locks */
                                inode->i_fop = &cifs_file_ops;
 
-                       inode->i_data.a_ops = &cifs_addr_ops;
                        if(pTcon->ses->server->maxBuf < 
-                            4096 + MAX_CIFS_HDR_SIZE)
-                               inode->i_data.a_ops->readpages = NULL;
+                            PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE)
+                               inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
+                       else
+                               inode->i_data.a_ops = &cifs_addr_ops;
                } else if (S_ISDIR(inode->i_mode)) {
                        cFYI(1, ("Directory inode"));
                        inode->i_op = &cifs_dir_inode_ops;

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 53903a2..e3e762d 100644 (file)
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -21,6 +21,7 @@
  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 #include <linux/fs.h>
+#include <linux/pagemap.h>
 #include <linux/stat.h>
 #include <linux/smp_lock.h>
 #include "cifspdu.h"
@@ -216,11 +217,13 @@ static void fill_in_inode(struct inode *tmp_inode,
                else
                        tmp_inode->i_fop = &cifs_file_ops;
 
-               tmp_inode->i_data.a_ops = &cifs_addr_ops;
                if((cifs_sb->tcon) && (cifs_sb->tcon->ses) &&
                   (cifs_sb->tcon->ses->server->maxBuf <
-                       4096 + MAX_CIFS_HDR_SIZE))
-                       tmp_inode->i_data.a_ops->readpages = NULL;
+                       PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE))
+                       tmp_inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
+               else
+                       tmp_inode->i_data.a_ops = &cifs_addr_ops;
+
                if(isNewInode)
                        return; /* No sense invalidating pages for new inode
                                   since have not started caching readahead file
@@ -339,11 +342,12 @@ static void unix_fill_in_inode(struct inode *tmp_inode,
                else
                        tmp_inode->i_fop = &cifs_file_ops;
 
-               tmp_inode->i_data.a_ops = &cifs_addr_ops;
                if((cifs_sb->tcon) && (cifs_sb->tcon->ses) &&
                   (cifs_sb->tcon->ses->server->maxBuf < 
-                       4096 + MAX_CIFS_HDR_SIZE))
-                       tmp_inode->i_data.a_ops->readpages = NULL;
+                       PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE))
+                       tmp_inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
+               else
+                       tmp_inode->i_data.a_ops = &cifs_addr_ops;
 
                if(isNewInode)
                        return; /* No sense invalidating pages for new inode since we