nfs: store devname at disconnected NFS roots
part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.
Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.
Have ->d_release() free it when dentry goes away.
Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index 6481d53..8d6864c 100644
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -148,6 +148,7 @@
alias = d_lookup(parent, &data->args.name);
if (alias != NULL) {
int ret = 0;
+ void *devname_garbage = NULL;
/*
* Hey, we raced with lookup... See if we need to transfer
@@ -157,6 +158,7 @@
spin_lock(&alias->d_lock);
if (alias->d_inode != NULL &&
!(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+ devname_garbage = alias->d_fsdata;
alias->d_fsdata = data;
alias->d_flags |= DCACHE_NFSFS_RENAMED;
ret = 1;
@@ -164,6 +166,13 @@
spin_unlock(&alias->d_lock);
nfs_dec_sillycount(dir);
dput(alias);
+ /*
+ * If we'd displaced old cached devname, free it. At that
+ * point dentry is definitely not a root, so we won't need
+ * that anymore.
+ */
+ if (devname_garbage)
+ kfree(devname_garbage);
return ret;
}
data->dir = igrab(dir);
@@ -252,6 +261,7 @@
{
struct nfs_unlinkdata *data;
int status = -ENOMEM;
+ void *devname_garbage = NULL;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL)
@@ -269,8 +279,16 @@
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
goto out_unlock;
dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+ devname_garbage = dentry->d_fsdata;
dentry->d_fsdata = data;
spin_unlock(&dentry->d_lock);
+ /*
+ * If we'd displaced old cached devname, free it. At that
+ * point dentry is definitely not a root, so we won't need
+ * that anymore.
+ */
+ if (devname_garbage)
+ kfree(devname_garbage);
return 0;
out_unlock:
spin_unlock(&dentry->d_lock);
@@ -299,6 +317,7 @@
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
data = dentry->d_fsdata;
+ dentry->d_fsdata = NULL;
}
spin_unlock(&dentry->d_lock);
@@ -315,6 +334,7 @@
struct nfs_unlinkdata *data = dentry->d_fsdata;
dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+ dentry->d_fsdata = NULL;
spin_unlock(&dentry->d_lock);
nfs_free_unlinkdata(data);
return;