On Fri, 2006-05-12 at 04:20 -0700, Andrew Morton wrote:
> Christoph Hellwig <hch@xxxxxx> wrote:
> >
> > Same as with already do with the file operations:
> > keep them in .rodata and prevents people from doing runtime patching.
>
> It would occasionally be nice to be the second person to compile something.
>
> fs/cifs/inode.c: In function `cifs_get_inode_info_unix':
> fs/cifs/inode.c:187: warning: assignment of read-only member `readpages'
> fs/cifs/inode.c: In function `cifs_get_inode_info':
> fs/cifs/inode.c:525: warning: assignment of read-only member `readpages'
>
> Steve, you should have separate sets of a_ops and select the appropriate
> one for inode->i_data.a_ops, rather than scribbling on cifs_addr_ops.
This patch has been compile-tested only.
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@xxxxxxxxxxxxxx>
diff -urp linux-2.6.17-rc4/fs/cifs/cifsfs.h linux/fs/cifs/cifsfs.h
--- linux-2.6.17-rc4/fs/cifs/cifsfs.h 2006-05-12 12:46:27.000000000 -0500
+++ linux/fs/cifs/cifsfs.h 2006-05-12 12:49:45.000000000 -0500
@@ -33,6 +33,7 @@
#endif
extern const struct address_space_operations cifs_addr_ops;
+extern const struct address_space_operations cifs_addr_ops_smallbuf;
/* Functions related to super block operations */
extern struct super_operations cifs_super_ops;
diff -urp linux-2.6.17-rc4/fs/cifs/file.c linux/fs/cifs/file.c
--- linux-2.6.17-rc4/fs/cifs/file.c 2006-05-12 12:46:27.000000000 -0500
+++ linux/fs/cifs/file.c 2006-05-12 12:50:34.000000000 -0500
@@ -1955,3 +1955,19 @@ const struct address_space_operations ci
/* .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.
+ */
+const 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 -urp linux-2.6.17-rc4/fs/cifs/inode.c linux/fs/cifs/inode.c
--- linux-2.6.17-rc4/fs/cifs/inode.c 2006-05-12 10:31:20.000000000 -0500
+++ linux/fs/cifs/inode.c 2006-05-12 12:52:08.000000000 -0500
@@ -180,11 +180,12 @@ int cifs_get_inode_info_unix(struct inod
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 **p
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 -urp linux-2.6.17-rc4/fs/cifs/readdir.c linux/fs/cifs/readdir.c
--- linux-2.6.17-rc4/fs/cifs/readdir.c 2006-05-12 10:31:20.000000000 -0500
+++ linux/fs/cifs/readdir.c 2006-05-12 13:11:47.000000000 -0500
@@ -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"
@@ -215,11 +216,13 @@ static void fill_in_inode(struct 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
@@ -338,11 +341,12 @@ static void unix_fill_in_inode(struct in
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
--
David Kleikamp
IBM Linux Technology Center
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