3.16.62-rc1 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 Signed-off-by: Dominique Martinet dominique.martinet@cea.fr [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- fs/9p/xattr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/fs/9p/xattr.c +++ b/fs/9p/xattr.c @@ -121,7 +121,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fi const void *value, size_t value_len, int flags) { u64 offset = 0; - int retval, msize, write_count; + int retval, err, msize, write_count;
p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n", name, value_len, flags); @@ -158,7 +158,9 @@ int v9fs_fid_xattr_set(struct p9_fid *fi } retval = 0; err: - p9_client_clunk(fid); + err = p9_client_clunk(fid); + if (!retval && err) + retval = err; return retval; }