Merge tag 'fscache-fixes-20200508-2' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

(1) The reorganisation of bmap() use accidentally caused the return value
     of cachefiles_read_or_alloc_pages() to get corrupted.

 (2) The NFS superblock index key accidentally got changed to include a
     number of kernel pointers - meaning that the key isn't matchable after
     a reboot.

 (3) A redundant check in nfs_fscache_get_super_cookie().

 (4) The NFS change_attr sometimes set in the auxiliary data for the
     caching of an file and sometimes not, which causes the cache to get
     discarded when it shouldn't.

 (5) There's a race between cachefiles_read_waiter() and
     cachefiles_read_copier() that causes an occasional assertion failure.
This commit is contained in:
Trond Myklebust 2020-05-10 09:30:42 -04:00
commit 2b666a110b
3 changed files with 24 additions and 28 deletions

View file

@ -60,9 +60,9 @@ static int cachefiles_read_waiter(wait_queue_entry_t *wait, unsigned mode,
object = container_of(op->op.object, struct cachefiles_object, fscache);
spin_lock(&object->work_lock);
list_add_tail(&monitor->op_link, &op->to_do);
fscache_enqueue_retrieval(op);
spin_unlock(&object->work_lock);
fscache_enqueue_retrieval(op);
fscache_put_retrieval(op);
return 0;
}
@ -398,7 +398,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
struct inode *inode;
sector_t block;
unsigned shift;
int ret;
int ret, ret2;
object = container_of(op->op.object,
struct cachefiles_object, fscache);
@ -430,8 +430,8 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
block = page->index;
block <<= shift;
ret = bmap(inode, &block);
ASSERT(ret < 0);
ret2 = bmap(inode, &block);
ASSERT(ret2 == 0);
_debug("%llx -> %llx",
(unsigned long long) (page->index << shift),
@ -739,8 +739,8 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
block = page->index;
block <<= shift;
ret = bmap(inode, &block);
ASSERT(!ret);
ret2 = bmap(inode, &block);
ASSERT(ret2 == 0);
_debug("%llx -> %llx",
(unsigned long long) (page->index << shift),

View file

@ -118,8 +118,6 @@ void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int
nfss->fscache_key = NULL;
nfss->fscache = NULL;
if (!(nfss->options & NFS_OPTION_FSCACHE))
return;
if (!uniq) {
uniq = "";
ulen = 1;
@ -188,7 +186,8 @@ void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int
/* create a cache index for looking up filehandles */
nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
&nfs_fscache_super_index_def,
key, sizeof(*key) + ulen,
&key->key,
sizeof(key->key) + ulen,
NULL, 0,
nfss, 0, true);
dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
@ -226,6 +225,19 @@ void nfs_fscache_release_super_cookie(struct super_block *sb)
}
}
static void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
struct nfs_inode *nfsi)
{
memset(auxdata, 0, sizeof(*auxdata));
auxdata->mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
auxdata->ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
}
/*
* Initialise the per-inode cache cookie pointer for an NFS inode.
*/
@ -239,14 +251,7 @@ void nfs_fscache_init_inode(struct inode *inode)
if (!(nfss->fscache && S_ISREG(inode->i_mode)))
return;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
auxdata.ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
nfs_fscache_update_auxdata(&auxdata, nfsi);
nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
&nfs_fscache_inode_object_def,
@ -266,11 +271,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
memset(&auxdata, 0, sizeof(auxdata));
auxdata.mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
auxdata.ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
nfs_fscache_update_auxdata(&auxdata, nfsi);
fscache_relinquish_cookie(cookie, &auxdata, false);
nfsi->fscache = NULL;
}
@ -310,11 +311,7 @@ void nfs_fscache_open_file(struct inode *inode, struct file *filp)
if (!fscache_cookie_valid(cookie))
return;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
auxdata.ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
nfs_fscache_update_auxdata(&auxdata, nfsi);
if (inode_is_open_for_write(inode)) {
dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);

View file

@ -1189,7 +1189,6 @@ static void nfs_get_cache_cookie(struct super_block *sb,
uniq = ctx->fscache_uniq;
ulen = strlen(ctx->fscache_uniq);
}
return;
}
nfs_fscache_get_super_cookie(sb, uniq, ulen);