[PATCH 5.6 099/194] NFSv4: Fix fscache cookie aux_data to ensure change_attr is included

Greg Kroah-Hartman
2020-05-18T18:12:19Z

From: Dave Wysochanski <dwysocha@redhat.com>

[ Upstream commit 50eaa652b54df1e2b48dc398d9e6114c9ed080eb ]

Commit 402cb8dda949 ("fscache: Attach the index key and aux data to
the cookie") added the aux_data and aux_data_len to parameters to
fscache_acquire_cookie(), and updated the callers in the NFS client.
In the process it modified the aux_data to include the change_attr,
but missed adding change_attr to a couple places where aux_data was
used. Specifically, when opening a file and the change_attr is not
added, the following attempt to lookup an object will fail inside
cachefiles_check_object_xattr() = -116 due to
nfs_fscache_inode_check_aux() failing memcmp on auxdata and returning
FSCACHE_CHECKAUX_OBSOLETE.

Fix this by adding nfs_fscache_update_auxdata() to set the auxdata
from all relevant fields in the inode, including the change_attr.

Fixes: 402cb8dda949 ("fscache: Attach the index key and aux data to the cookie")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/fscache.c | 34 ++++++++++++++++------------------
1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index f517184156068..a60df88efc404 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -225,6 +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.
*/
@@ -238,14 +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,
@@ -265,11 +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;
}
@@ -309,11 +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);
--
2.20.1