linux/fs/cifs/fscache.c
Arnd Bergmann cbedeadf9c cifs: use 64-bit timestamps for fscache
In the fscache, we just need the timestamps as cookies to check for
changes, so we don't really care about the overflow, but it's better
to stop using the deprecated timespec so we don't have to go through
explicit conversion functions.

To avoid comparing uninitialized padding values that are copied
while assigning the timespec values, this rearranges the members of
cifs_fscache_inode_auxdata to avoid padding, and assigns them
individually.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-08-07 14:15:41 -05:00

335 lines
9.4 KiB
C

/*
* fs/cifs/fscache.c - CIFS filesystem cache interface
*
* Copyright (c) 2010 Novell, Inc.
* Author(s): Suresh Jayaraman <sjayaraman@suse.de>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "fscache.h"
#include "cifsglob.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
/*
* Key layout of CIFS server cache index object
*/
struct cifs_server_key {
struct {
uint16_t family; /* address family */
__be16 port; /* IP port */
} hdr;
union {
struct in_addr ipv4_addr;
struct in6_addr ipv6_addr;
};
} __packed;
/*
* Get a cookie for a server object keyed by {IPaddress,port,family} tuple
*/
void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
{
const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
struct cifs_server_key key;
uint16_t key_len = sizeof(key.hdr);
memset(&key, 0, sizeof(key));
/*
* Should not be a problem as sin_family/sin6_family overlays
* sa_family field
*/
key.hdr.family = sa->sa_family;
switch (sa->sa_family) {
case AF_INET:
key.hdr.port = addr->sin_port;
key.ipv4_addr = addr->sin_addr;
key_len += sizeof(key.ipv4_addr);
break;
case AF_INET6:
key.hdr.port = addr6->sin6_port;
key.ipv6_addr = addr6->sin6_addr;
key_len += sizeof(key.ipv6_addr);
break;
default:
cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
server->fscache = NULL;
return;
}
server->fscache =
fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
&cifs_fscache_server_index_def,
&key, key_len,
NULL, 0,
server, 0, true);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server, server->fscache);
}
void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
{
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server, server->fscache);
fscache_relinquish_cookie(server->fscache, NULL, false);
server->fscache = NULL;
}
void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
{
struct TCP_Server_Info *server = tcon->ses->server;
char *sharename;
sharename = extract_sharename(tcon->treeName);
if (IS_ERR(sharename)) {
cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
tcon->fscache = NULL;
return;
}
tcon->fscache =
fscache_acquire_cookie(server->fscache,
&cifs_fscache_super_index_def,
sharename, strlen(sharename),
&tcon->resource_id, sizeof(tcon->resource_id),
tcon, 0, true);
kfree(sharename);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server->fscache, tcon->fscache);
}
void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
{
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
fscache_relinquish_cookie(tcon->fscache, &tcon->resource_id, false);
tcon->fscache = NULL;
}
static void cifs_fscache_acquire_inode_cookie(struct cifsInodeInfo *cifsi,
struct cifs_tcon *tcon)
{
struct cifs_fscache_inode_auxdata auxdata;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.eof = cifsi->server_eof;
auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
cifsi->fscache =
fscache_acquire_cookie(tcon->fscache,
&cifs_fscache_inode_object_def,
&cifsi->uniqueid, sizeof(cifsi->uniqueid),
&auxdata, sizeof(auxdata),
cifsi, cifsi->vfs_inode.i_size, true);
}
static void cifs_fscache_enable_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
if (cifsi->fscache)
return;
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE))
return;
cifs_fscache_acquire_inode_cookie(cifsi, tcon);
cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
__func__, tcon->fscache, cifsi->fscache);
}
void cifs_fscache_release_inode_cookie(struct inode *inode)
{
struct cifs_fscache_inode_auxdata auxdata;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
memset(&auxdata, 0, sizeof(auxdata));
auxdata.eof = cifsi->server_eof;
auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
fscache_relinquish_cookie(cifsi->fscache, &auxdata, false);
cifsi->fscache = NULL;
}
}
static void cifs_fscache_disable_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
fscache_uncache_all_inode_pages(cifsi->fscache, inode);
fscache_relinquish_cookie(cifsi->fscache, NULL, true);
cifsi->fscache = NULL;
}
}
void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
{
if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
cifs_fscache_disable_inode_cookie(inode);
else
cifs_fscache_enable_inode_cookie(inode);
}
void cifs_fscache_reset_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
struct fscache_cookie *old = cifsi->fscache;
if (cifsi->fscache) {
/* retire the current fscache cache and get a new one */
fscache_relinquish_cookie(cifsi->fscache, NULL, true);
cifs_fscache_acquire_inode_cookie(cifsi, tcon);
cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
__func__, cifsi->fscache, old);
}
}
int cifs_fscache_release_page(struct page *page, gfp_t gfp)
{
if (PageFsCache(page)) {
struct inode *inode = page->mapping->host;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, page, cifsi->fscache);
if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
return 0;
}
return 1;
}
static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
int error)
{
cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, page, error);
if (!error)
SetPageUptodate(page);
unlock_page(page);
}
/*
* Retrieve a page from FS-Cache
*/
int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
{
int ret;
cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
__func__, CIFS_I(inode)->fscache, page, inode);
ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
cifs_readpage_from_fscache_complete,
NULL,
GFP_KERNEL);
switch (ret) {
case 0: /* page found in fscache, read submitted */
cifs_dbg(FYI, "%s: submitted\n", __func__);
return ret;
case -ENOBUFS: /* page won't be cached */
case -ENODATA: /* page not in cache */
cifs_dbg(FYI, "%s: %d\n", __func__, ret);
return 1;
default:
cifs_dbg(VFS, "unknown error ret = %d\n", ret);
}
return ret;
}
/*
* Retrieve a set of pages from FS-Cache
*/
int __cifs_readpages_from_fscache(struct inode *inode,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages)
{
int ret;
cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
__func__, CIFS_I(inode)->fscache, *nr_pages, inode);
ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
pages, nr_pages,
cifs_readpage_from_fscache_complete,
NULL,
mapping_gfp_mask(mapping));
switch (ret) {
case 0: /* read submitted to the cache for all pages */
cifs_dbg(FYI, "%s: submitted\n", __func__);
return ret;
case -ENOBUFS: /* some pages are not cached and can't be */
case -ENODATA: /* some pages are not cached */
cifs_dbg(FYI, "%s: no page\n", __func__);
return 1;
default:
cifs_dbg(FYI, "unknown error ret = %d\n", ret);
}
return ret;
}
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
int ret;
cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
__func__, cifsi->fscache, page, inode);
ret = fscache_write_page(cifsi->fscache, page,
cifsi->vfs_inode.i_size, GFP_KERNEL);
if (ret != 0)
fscache_uncache_page(cifsi->fscache, page);
}
void __cifs_fscache_readpages_cancel(struct inode *inode, struct list_head *pages)
{
cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
__func__, CIFS_I(inode)->fscache, inode);
fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
}
void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct fscache_cookie *cookie = cifsi->fscache;
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
fscache_wait_on_page_write(cookie, page);
fscache_uncache_page(cookie, page);
}