linux-stable/fs/cifs/fscache.c
David Howells c902ce1bfb FS-Cache: Add a helper to bulk uncache pages on an inode
Add an FS-Cache helper to bulk uncache pages on an inode.  This will
only work for the circumstance where the pages in the cache correspond
1:1 with the pages attached to an inode's page cache.

This is required for CIFS and NFS: When disabling inode cookie, we were
returning the cookie and setting cifsi->fscache to NULL but failed to
invalidate any previously mapped pages.  This resulted in "Bad page
state" errors and manifested in other kind of errors when running
fsstress.  Fix it by uncaching mapped pages when we disable the inode
cookie.

This patch should fix the following oops and "Bad page state" errors
seen during fsstress testing.

  ------------[ cut here ]------------
  kernel BUG at fs/cachefiles/namei.c:201!
  invalid opcode: 0000 [#1] SMP
  Pid: 5, comm: kworker/u:0 Not tainted 2.6.38.7-30.fc15.x86_64 #1 Bochs Bochs
  RIP: 0010: cachefiles_walk_to_object+0x436/0x745 [cachefiles]
  RSP: 0018:ffff88002ce6dd00  EFLAGS: 00010282
  RAX: ffff88002ef165f0 RBX: ffff88001811f500 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000282
  RBP: ffff88002ce6dda0 R08: 0000000000000100 R09: ffffffff81b3a300
  R10: 0000ffff00066c0a R11: 0000000000000003 R12: ffff88002ae54840
  R13: ffff88002ae54840 R14: ffff880029c29c00 R15: ffff88001811f4b0
  FS:  00007f394dd32720(0000) GS:ffff88002ef00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007fffcb62ddf8 CR3: 000000001825f000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process kworker/u:0 (pid: 5, threadinfo ffff88002ce6c000, task ffff88002ce55cc0)
  Stack:
   0000000000000246 ffff88002ce55cc0 ffff88002ce6dd58 ffff88001815dc00
   ffff8800185246c0 ffff88001811f618 ffff880029c29d18 ffff88001811f380
   ffff88002ce6dd50 ffffffff814757e4 ffff88002ce6dda0 ffffffff8106ac56
  Call Trace:
   cachefiles_lookup_object+0x78/0xd4 [cachefiles]
   fscache_lookup_object+0x131/0x16d [fscache]
   fscache_object_work_func+0x1bc/0x669 [fscache]
   process_one_work+0x186/0x298
   worker_thread+0xda/0x15d
   kthread+0x84/0x8c
   kernel_thread_helper+0x4/0x10
  RIP  cachefiles_walk_to_object+0x436/0x745 [cachefiles]
  ---[ end trace 1d481c9af1804caa ]---

I tested the uncaching by the following means:

 (1) Create a big file on my NFS server (104857600 bytes).

 (2) Read the file into the cache with md5sum on the NFS client.  Look in
     /proc/fs/fscache/stats:

	Pages  : mrk=25601 unc=0

 (3) Open the file for read/write ("bash 5<>/warthog/bigfile").  Look in proc
     again:

	Pages  : mrk=25601 unc=25601

Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-07 13:21:56 -07:00

235 lines
6.4 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"
void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
{
server->fscache =
fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
&cifs_fscache_server_index_def, server);
cFYI(1, "%s: (0x%p/0x%p)", __func__, server,
server->fscache);
}
void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
{
cFYI(1, "%s: (0x%p/0x%p)", __func__, server,
server->fscache);
fscache_relinquish_cookie(server->fscache, 0);
server->fscache = NULL;
}
void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
{
struct TCP_Server_Info *server = tcon->ses->server;
tcon->fscache =
fscache_acquire_cookie(server->fscache,
&cifs_fscache_super_index_def, tcon);
cFYI(1, "%s: (0x%p/0x%p)", __func__, server->fscache,
tcon->fscache);
}
void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
{
cFYI(1, "%s: (0x%p)", __func__, tcon->fscache);
fscache_relinquish_cookie(tcon->fscache, 0);
tcon->fscache = NULL;
}
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) {
cifsi->fscache = fscache_acquire_cookie(tcon->fscache,
&cifs_fscache_inode_object_def, cifsi);
cFYI(1, "%s: got FH cookie (0x%p/0x%p)", __func__,
tcon->fscache, cifsi->fscache);
}
}
void cifs_fscache_release_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cFYI(1, "%s: (0x%p)", __func__, cifsi->fscache);
fscache_relinquish_cookie(cifsi->fscache, 0);
cifsi->fscache = NULL;
}
}
static void cifs_fscache_disable_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cFYI(1, "%s: (0x%p)", __func__, cifsi->fscache);
fscache_uncache_all_inode_pages(cifsi->fscache, inode);
fscache_relinquish_cookie(cifsi->fscache, 1);
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 fscache_cookie *old = cifsi->fscache;
if (cifsi->fscache) {
/* retire the current fscache cache and get a new one */
fscache_relinquish_cookie(cifsi->fscache, 1);
cifsi->fscache = fscache_acquire_cookie(
cifs_sb_master_tcon(cifs_sb)->fscache,
&cifs_fscache_inode_object_def,
cifsi);
cFYI(1, "%s: new cookie 0x%p oldcookie 0x%p",
__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);
cFYI(1, "%s: (0x%p/0x%p)", __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)
{
cFYI(1, "%s: (0x%p/%d)", __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;
cFYI(1, "%s: (fsc:%p, p:%p, i:0x%p", __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 */
cFYI(1, "%s: submitted", __func__);
return ret;
case -ENOBUFS: /* page won't be cached */
case -ENODATA: /* page not in cache */
cFYI(1, "%s: %d", __func__, ret);
return 1;
default:
cERROR(1, "unknown error ret = %d", 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;
cFYI(1, "%s: (0x%p/%u/0x%p)", __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 */
cFYI(1, "%s: submitted", __func__);
return ret;
case -ENOBUFS: /* some pages are not cached and can't be */
case -ENODATA: /* some pages are not cached */
cFYI(1, "%s: no page", __func__);
return 1;
default:
cFYI(1, "unknown error ret = %d", ret);
}
return ret;
}
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
int ret;
cFYI(1, "%s: (fsc: %p, p: %p, i: %p)", __func__,
CIFS_I(inode)->fscache, page, inode);
ret = fscache_write_page(CIFS_I(inode)->fscache, page, GFP_KERNEL);
if (ret != 0)
fscache_uncache_page(CIFS_I(inode)->fscache, page);
}
void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct fscache_cookie *cookie = cifsi->fscache;
cFYI(1, "%s: (0x%p/0x%p)", __func__, page, cookie);
fscache_wait_on_page_write(cookie, page);
fscache_uncache_page(cookie, page);
}