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/dir.c b/fs/nfs/dir.c
index 2c3eb33..abdf38d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1169,11 +1169,23 @@
iput(inode);
}
+static void nfs_d_release(struct dentry *dentry)
+{
+ /* free cached devname value, if it survived that far */
+ if (unlikely(dentry->d_fsdata)) {
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ WARN_ON(1);
+ else
+ kfree(dentry->d_fsdata);
+ }
+}
+
const struct dentry_operations nfs_dentry_operations = {
.d_revalidate = nfs_lookup_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
};
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
@@ -1248,6 +1260,7 @@
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
};
/*
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 4d6e5a3..1084792 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -82,12 +82,18 @@
struct nfs_fsinfo fsinfo;
struct dentry *ret;
struct inode *inode;
+ void *name = kstrdup(devname, GFP_KERNEL);
int error;
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+
/* get the actual root for this mount */
fsinfo.fattr = nfs_alloc_fattr();
- if (fsinfo.fattr == NULL)
+ if (fsinfo.fattr == NULL) {
+ kfree(name);
return ERR_PTR(-ENOMEM);
+ }
error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
if (error < 0) {
@@ -120,7 +126,15 @@
}
security_d_instantiate(ret, inode);
+ spin_lock(&ret->d_lock);
+ if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
+ ret->d_fsdata = name;
+ name = NULL;
+ }
+ spin_unlock(&ret->d_lock);
out:
+ if (name)
+ kfree(name);
nfs_free_fattr(fsinfo.fattr);
return ret;
}
@@ -177,21 +191,28 @@
struct nfs_fattr *fattr = NULL;
struct dentry *ret;
struct inode *inode;
+ void *name = kstrdup(devname, GFP_KERNEL);
int error;
dprintk("--> nfs4_get_root()\n");
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+
/* get the info about the server and filesystem */
error = nfs4_server_capabilities(server, mntfh);
if (error < 0) {
dprintk("nfs_get_root: getcaps error = %d\n",
-error);
+ kfree(name);
return ERR_PTR(error);
}
fattr = nfs_alloc_fattr();
- if (fattr == NULL)
- return ERR_PTR(-ENOMEM);;
+ if (fattr == NULL) {
+ kfree(name);
+ return ERR_PTR(-ENOMEM);
+ }
/* get the actual root for this mount */
error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
@@ -225,8 +246,15 @@
}
security_d_instantiate(ret, inode);
-
+ spin_lock(&ret->d_lock);
+ if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
+ ret->d_fsdata = name;
+ name = NULL;
+ }
+ spin_unlock(&ret->d_lock);
out:
+ if (name)
+ kfree(name);
nfs_free_fattr(fattr);
dprintk("<-- nfs4_get_root()\n");
return ret;
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;