loff_t current_index;
decode_dirent_t decode;
+ unsigned long dir_verifier;
unsigned long timestamp;
unsigned long gencount;
unsigned int cache_entry_index;
again:
timestamp = jiffies;
gencount = nfs_inc_attr_generation_counter();
+ desc->dir_verifier = nfs_save_change_attribute(inode);
error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages,
NFS_SERVER(inode)->dtsize, desc->plus);
if (error < 0) {
}
static
-void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry,
+ unsigned long dir_verifier)
{
struct qstr filename = QSTR_INIT(entry->name, entry->len);
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
struct dentry *dentry;
struct dentry *alias;
- struct inode *dir = d_inode(parent);
struct inode *inode;
int status;
if (nfs_same_file(dentry, entry)) {
if (!entry->fh->size)
goto out;
- nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ nfs_set_verifier(dentry, dir_verifier);
status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
if (!status)
nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label);
dput(dentry);
dentry = alias;
}
- nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ nfs_set_verifier(dentry, dir_verifier);
out:
dput(dentry);
}
count++;
if (desc->plus)
- nfs_prime_dcache(file_dentry(desc->file), entry);
+ nfs_prime_dcache(file_dentry(desc->file), entry,
+ desc->dir_verifier);
status = nfs_readdir_add_to_array(entry, page);
if (status != 0)
* full lookup on all child dentries of 'dir' whenever a change occurs
* on the server that might have invalidated our dcache.
*
+ * Note that we reserve bit '0' as a tag to let us know when a dentry
+ * was revalidated while holding a delegation on its inode.
+ *
* The caller should be holding dir->i_lock
*/
void nfs_force_lookup_revalidate(struct inode *dir)
{
- NFS_I(dir)->cache_change_attribute++;
+ NFS_I(dir)->cache_change_attribute += 2;
}
EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
+/**
+ * nfs_verify_change_attribute - Detects NFS remote directory changes
+ * @dir: pointer to parent directory inode
+ * @verf: previously saved change attribute
+ *
+ * Return "false" if the verifiers doesn't match the change attribute.
+ * This would usually indicate that the directory contents have changed on
+ * the server, and that any dentries need revalidating.
+ */
+static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf)
+{
+ return (verf & ~1UL) == nfs_save_change_attribute(dir);
+}
+
+static void nfs_set_verifier_delegated(unsigned long *verf)
+{
+ *verf |= 1UL;
+}
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void nfs_unset_verifier_delegated(unsigned long *verf)
+{
+ *verf &= ~1UL;
+}
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
+
+static bool nfs_test_verifier_delegated(unsigned long verf)
+{
+ return verf & 1;
+}
+
+static bool nfs_verifier_is_delegated(struct dentry *dentry)
+{
+ return nfs_test_verifier_delegated(dentry->d_time);
+}
+
+static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf)
+{
+ struct inode *inode = d_inode(dentry);
+
+ if (!nfs_verifier_is_delegated(dentry) &&
+ !nfs_verify_change_attribute(d_inode(dentry->d_parent), verf))
+ goto out;
+ if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+ nfs_set_verifier_delegated(&verf);
+out:
+ dentry->d_time = verf;
+}
+
+/**
+ * nfs_set_verifier - save a parent directory verifier in the dentry
+ * @dentry: pointer to dentry
+ * @verf: verifier to save
+ *
+ * Saves the parent directory verifier in @dentry. If the inode has
+ * a delegation, we also tag the dentry as having been revalidated
+ * while holding a delegation so that we know we don't have to
+ * look it up again after a directory change.
+ */
+void nfs_set_verifier(struct dentry *dentry, unsigned long verf)
+{
+
+ spin_lock(&dentry->d_lock);
+ nfs_set_verifier_locked(dentry, verf);
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_set_verifier);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+/**
+ * nfs_clear_verifier_delegated - clear the dir verifier delegation tag
+ * @inode: pointer to inode
+ *
+ * Iterates through the dentries in the inode alias list and clears
+ * the tag used to indicate that the dentry has been revalidated
+ * while holding a delegation.
+ * This function is intended for use when the delegation is being
+ * returned or revoked.
+ */
+void nfs_clear_verifier_delegated(struct inode *inode)
+{
+ struct dentry *alias;
+
+ if (!inode)
+ return;
+ spin_lock(&inode->i_lock);
+ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
+ spin_lock(&alias->d_lock);
+ nfs_unset_verifier_delegated(&alias->d_time);
+ spin_unlock(&alias->d_lock);
+ }
+ spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
+
/*
* A check for whether or not the parent directory has changed.
* In the case it has, we assume that the dentries are untrustworthy
struct nfs_fh *fhandle;
struct nfs_fattr *fattr;
struct nfs4_label *label;
+ unsigned long dir_verifier;
int ret;
ret = -ENOMEM;
if (fhandle == NULL || fattr == NULL || IS_ERR(label))
goto out;
+ dir_verifier = nfs_save_change_attribute(dir);
ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
if (ret < 0) {
switch (ret) {
goto out;
nfs_setsecurity(inode, fattr, label);
- nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ nfs_set_verifier(dentry, dir_verifier);
/* set a readdirplus hint that we had a cache miss */
nfs_force_use_readdirplus(dir);
goto out_bad;
}
- if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
+ if (nfs_verifier_is_delegated(dentry))
return nfs_lookup_revalidate_delegated(dir, dentry, inode);
/* Force a full look up iff the parent directory has changed */
struct nfs_fh *fhandle = NULL;
struct nfs_fattr *fattr = NULL;
struct nfs4_label *label = NULL;
+ unsigned long dir_verifier;
int error;
dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
if (IS_ERR(label))
goto out;
+ dir_verifier = nfs_save_change_attribute(dir);
trace_nfs_lookup_enter(dir, dentry, flags);
error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
if (error == -ENOENT)
goto out_label;
dentry = res;
}
- nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ nfs_set_verifier(dentry, dir_verifier);
out_label:
trace_nfs_lookup_exit(dir, dentry, flags, error);
nfs4_label_free(label);
if (inode == NULL)
goto full_reval;
- if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
+ if (nfs_verifier_is_delegated(dentry))
return nfs_lookup_revalidate_delegated(dir, dentry, inode);
/* NFS only supports OPEN on regular files */
projects / linux.git / blobdiff