[PATCH v2 3/7] cifs: invalidate cfid on unlink/rename/rmdir

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

Today we do not invalidate the cached_dirent or the entire
parent cfid when a dentry in a dir has been removed/moved.

This change invalidates the parent cfid so that we don't serve
directory contents from the cache.

Cc: <stable@vger.kernel.org>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/inode.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 888f9e35f14b8..e077df844c819 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -28,6 +28,23 @@
 #include "cached_dir.h"
 #include "reparse.h"
 
+static void cifs_invalidate_cached_dir(struct cifs_tcon *tcon,
+				       struct dentry *parent)
+{
+	struct cached_fid *parent_cfid = NULL;
+
+	if (!tcon || !parent)
+		return;
+
+	if (!open_cached_dir_by_dentry(tcon, parent, &parent_cfid)) {
+		mutex_lock(&parent_cfid->dirents.de_mutex);
+		parent_cfid->dirents.is_valid = false;
+		parent_cfid->dirents.is_failed = true;
+		mutex_unlock(&parent_cfid->dirents.de_mutex);
+		close_cached_dir(parent_cfid);
+	}
+}
+
 /*
  * Set parameters for the netfs library
  */
@@ -322,7 +339,7 @@ cifs_unix_basic_to_fattr(struct cifs_fattr *fattr, FILE_UNIX_BASIC_INFO *info,
 				fattr->cf_uid = uid;
 		}
 	}
-	
+
 	fattr->cf_gid = cifs_sb->ctx->linux_gid;
 	if (!(sbflags & CIFS_MOUNT_OVERR_GID)) {
 		u64 id = le64_to_cpu(info->Gid);
@@ -2067,6 +2084,9 @@ static int __cifs_unlink(struct inode *dir, struct dentry *dentry, bool sillyren
 		cifs_set_file_info(inode, attrs, xid, full_path, origattr);
 
 out_reval:
+	if (!rc && dentry->d_parent)
+		cifs_invalidate_cached_dir(tcon, dentry->d_parent);
+
 	if (inode) {
 		cifs_inode = CIFS_I(inode);
 		cifs_inode->time = 0;	/* will force revalidate to get info
@@ -2378,7 +2398,6 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
 	}
 
 	rc = server->ops->rmdir(xid, tcon, full_path, cifs_sb);
-	cifs_put_tlink(tlink);
 
 	cifsInode = CIFS_I(d_inode(direntry));
 
@@ -2388,6 +2407,8 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
 		i_size_write(d_inode(direntry), 0);
 		clear_nlink(d_inode(direntry));
 		spin_unlock(&d_inode(direntry)->i_lock);
+		if (direntry->d_parent)
+			cifs_invalidate_cached_dir(tcon, direntry->d_parent);
 	}
 
 	/* force revalidate to go get info when needed */
@@ -2402,6 +2423,7 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
 
 	inode_set_ctime_current(d_inode(direntry));
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	cifs_put_tlink(tlink);
 
 rmdir_exit:
 	free_dentry_path(page);
@@ -2501,6 +2523,8 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	struct cifs_sb_info *cifs_sb;
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
+	struct dentry *source_parent;
+	struct dentry *target_parent;
 	bool rehash = false;
 	unsigned int xid;
 	int rc, tmprc;
@@ -2532,6 +2556,8 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
 	tcon = tlink_tcon(tlink);
+	source_parent = source_dentry->d_parent ? dget(source_dentry->d_parent) : NULL;
+	target_parent = target_dentry->d_parent ? dget(target_dentry->d_parent) : NULL;
 	server = tcon->ses->server;
 
 	page1 = alloc_dentry_path();
@@ -2668,11 +2694,21 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
 	}
 
 	/* force revalidate to go get info when needed */
+	if (!rc) {
+		cifs_invalidate_cached_dir(tcon, source_parent);
+		if (target_parent != source_parent)
+			cifs_invalidate_cached_dir(tcon, target_parent);
+	}
+
 	CIFS_I(source_dir)->time = CIFS_I(target_dir)->time = 0;
 
 cifs_rename_exit:
 	if (rehash)
 		d_rehash(target_dentry);
+	if (target_parent)
+		dput(target_parent);
+	if (source_parent)
+		dput(source_parent);
 	kfree(info_buf_source);
 	free_dentry_path(page2);
 	free_dentry_path(page1);
-- 
2.43.0