linux/fs/cifs/fscache.h
David Howells 874c8ca1e6 netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_context
While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled.  This was causing the
following complaint[1] from gcc v12:

  In file included from include/linux/string.h:253,
                   from include/linux/ceph/ceph_debug.h:7,
                   from fs/ceph/inode.c:2:
  In function 'fortify_memset_chk',
      inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
      inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
  include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    242 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode).  The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.

Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).

Most of the changes were done with:

  perl -p -i -e 's/vfs_inode/netfs.inode/'g \
        `git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`

Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.

Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].

Version #2:
 - Fix a couple of missed name changes due to a disabled cifs option.
 - Rename nfs_i_context to nfs_inode
 - Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
   structs.

[ This also undoes commit 507160f46c ("netfs: gcc-12: temporarily
  disable '-Wattribute-warning' for now") that is no longer needed ]

Fixes: bc899ee1c8 ("netfs: Add a netfs inode context")
Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
cc: Jonathan Corbet <corbet@lwn.net>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Steve French <smfrench@gmail.com>
cc: William Kucharski <william.kucharski@oracle.com>
cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
cc: Dave Chinner <david@fromorbit.com>
cc: linux-doc@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: samba-technical@lists.samba.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3]
Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-09 13:55:00 -07:00

165 lines
4.7 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 */
/*
* CIFS filesystem cache interface definitions
*
* Copyright (c) 2010 Novell, Inc.
* Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
*
*/
#ifndef _CIFS_FSCACHE_H
#define _CIFS_FSCACHE_H
#include <linux/swap.h>
#include <linux/fscache.h>
#include "cifsglob.h"
/*
* Coherency data attached to CIFS volume within the cache
*/
struct cifs_fscache_volume_coherency_data {
__le64 resource_id; /* unique server resource id */
__le64 vol_create_time;
__le32 vol_serial_number;
} __packed;
/*
* Coherency data attached to CIFS inode within the cache.
*/
struct cifs_fscache_inode_coherency_data {
__le64 last_write_time_sec;
__le64 last_change_time_sec;
__le32 last_write_time_nsec;
__le32 last_change_time_nsec;
};
#ifdef CONFIG_CIFS_FSCACHE
/*
* fscache.c
*/
extern int cifs_fscache_get_super_cookie(struct cifs_tcon *);
extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
extern void cifs_fscache_get_inode_cookie(struct inode *inode);
extern void cifs_fscache_release_inode_cookie(struct inode *);
extern void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update);
static inline
void cifs_fscache_fill_coherency(struct inode *inode,
struct cifs_fscache_inode_coherency_data *cd)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
memset(cd, 0, sizeof(*cd));
cd->last_write_time_sec = cpu_to_le64(cifsi->netfs.inode.i_mtime.tv_sec);
cd->last_write_time_nsec = cpu_to_le32(cifsi->netfs.inode.i_mtime.tv_nsec);
cd->last_change_time_sec = cpu_to_le64(cifsi->netfs.inode.i_ctime.tv_sec);
cd->last_change_time_nsec = cpu_to_le32(cifsi->netfs.inode.i_ctime.tv_nsec);
}
static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
{
return netfs_i_cookie(inode);
}
static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags)
{
struct cifs_fscache_inode_coherency_data cd;
cifs_fscache_fill_coherency(inode, &cd);
fscache_invalidate(cifs_inode_cookie(inode), &cd,
i_size_read(inode), flags);
}
extern int __cifs_fscache_query_occupancy(struct inode *inode,
pgoff_t first, unsigned int nr_pages,
pgoff_t *_data_first,
unsigned int *_data_nr_pages);
static inline int cifs_fscache_query_occupancy(struct inode *inode,
pgoff_t first, unsigned int nr_pages,
pgoff_t *_data_first,
unsigned int *_data_nr_pages)
{
if (!cifs_inode_cookie(inode))
return -ENOBUFS;
return __cifs_fscache_query_occupancy(inode, first, nr_pages,
_data_first, _data_nr_pages);
}
extern int __cifs_readpage_from_fscache(struct inode *pinode, struct page *ppage);
extern void __cifs_readpage_to_fscache(struct inode *pinode, struct page *ppage);
static inline int cifs_readpage_from_fscache(struct inode *inode,
struct page *page)
{
if (cifs_inode_cookie(inode))
return __cifs_readpage_from_fscache(inode, page);
return -ENOBUFS;
}
static inline void cifs_readpage_to_fscache(struct inode *inode,
struct page *page)
{
if (cifs_inode_cookie(inode))
__cifs_readpage_to_fscache(inode, page);
}
static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
{
if (PageFsCache(page)) {
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
wait_on_page_fscache(page);
fscache_note_page_release(cifs_inode_cookie(page->mapping->host));
}
return true;
}
#else /* CONFIG_CIFS_FSCACHE */
static inline
void cifs_fscache_fill_coherency(struct inode *inode,
struct cifs_fscache_inode_coherency_data *cd)
{
}
static inline int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) { return 0; }
static inline void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
static inline void cifs_fscache_get_inode_cookie(struct inode *inode) {}
static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update) {}
static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {}
static inline int cifs_fscache_query_occupancy(struct inode *inode,
pgoff_t first, unsigned int nr_pages,
pgoff_t *_data_first,
unsigned int *_data_nr_pages)
{
*_data_first = ULONG_MAX;
*_data_nr_pages = 0;
return -ENOBUFS;
}
static inline int
cifs_readpage_from_fscache(struct inode *inode, struct page *page)
{
return -ENOBUFS;
}
static inline
void cifs_readpage_to_fscache(struct inode *inode, struct page *page) {}
static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
{
return true; /* May release page */
}
#endif /* CONFIG_CIFS_FSCACHE */
#endif /* _CIFS_FSCACHE_H */