nfsd: Push mnt_want_write() outside of i_mutex
When mnt_want_write() starts to handle freezing it will get a full lock
semantics requiring proper lock ordering. So push mnt_want_write() call
consistently outside of i_mutex.
CC: linux-nfs@vger.kernel.org
CC: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index e15dc45..aad6d45 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -196,6 +196,7 @@
struct dentry *dchild;
int type, mode;
__be32 nfserr;
+ int hosterr;
dev_t rdev = 0, wanted = new_decode_dev(attr->ia_size);
dprintk("nfsd: CREATE %s %.*s\n",
@@ -214,6 +215,12 @@
nfserr = nfserr_exist;
if (isdotent(argp->name, argp->len))
goto done;
+ hosterr = fh_want_write(dirfhp);
+ if (hosterr) {
+ nfserr = nfserrno(hosterr);
+ goto done;
+ }
+
fh_lock_nested(dirfhp, I_MUTEX_PARENT);
dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
if (IS_ERR(dchild)) {
@@ -330,7 +337,7 @@
out_unlock:
/* We don't really need to unlock, as fh_put does it. */
fh_unlock(dirfhp);
-
+ fh_drop_write(dirfhp);
done:
fh_put(dirfhp);
return nfsd_return_dirop(nfserr, resp);