4.9-stable review patch. If anyone has any objections, please let me know.
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From: piaojun piaojun@huawei.com
commit 3111784bee81591ea2815011688d28b65df03627 upstream.
In my testing, v9fs_fid_xattr_set will return successfully even if the backend ext4 filesystem has no space to store xattr key-value. That will cause inconsistent behavior between front end and back end. The reason is that lsetxattr will be triggered by p9_client_clunk, and unfortunately we did not catch the error. This patch will catch the error to notify upper caller.
p9_client_clunk (in 9p) p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid); v9fs_clunk (in qemu) put_fid free_fid v9fs_xattr_fid_clunk v9fs_co_lsetxattr s->ops->lsetxattr ext4_xattr_user_set (in host ext4 filesystem)
Link: http://lkml.kernel.org/r/5B57EACC.2060900@huawei.com Signed-off-by: Jun Piao piaojun@huawei.com Cc: Eric Van Hensbergen ericvh@gmail.com Cc: Ron Minnich rminnich@sandia.gov Cc: Latchesar Ionkov lucho@ionkov.net Cc: Andrew Morton akpm@linux-foundation.org Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet dominique.martinet@cea.fr Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/9p/xattr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/9p/xattr.c +++ b/fs/9p/xattr.c @@ -105,7 +105,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fi { struct kvec kvec = {.iov_base = (void *)value, .iov_len = value_len}; struct iov_iter from; - int retval; + int retval, err;
iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len);
@@ -126,7 +126,9 @@ int v9fs_fid_xattr_set(struct p9_fid *fi retval); else p9_client_write(fid, 0, &from, &retval); - p9_client_clunk(fid); + err = p9_client_clunk(fid); + if (!retval && err) + retval = err; return retval; }