1 files changed, 54 insertions, 5 deletions

diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index 1a6d2d5b4b33..1b31481f9e72 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -17,9 +17,11 @@ static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
 struct prop_handler {
 	struct hlist_node node;
 	const char *xattr_name;
-	int (*validate)(const char *value, size_t len);
+	int (*validate)(const struct btrfs_inode *inode, const char *value,
+			size_t len);
 	int (*apply)(struct inode *inode, const char *value, size_t len);
 	const char *(*extract)(struct inode *inode);
+	bool (*ignore)(const struct btrfs_inode *inode);
 	int inheritable;
 };
 
@@ -55,7 +57,8 @@ find_prop_handler(const char *name,
 	return NULL;
 }
 
-int btrfs_validate_prop(const char *name, const char *value, size_t value_len)
+int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
+			const char *value, size_t value_len)
 {
 	const struct prop_handler *handler;
 
@@ -69,7 +72,29 @@ int btrfs_validate_prop(const char *name, const char *value, size_t value_len)
 	if (value_len == 0)
 		return 0;
 
-	return handler->validate(value, value_len);
+	return handler->validate(inode, value, value_len);
+}
+
+/*
+ * Check if a property should be ignored (not set) for an inode.
+ *
+ * @inode:     The target inode.
+ * @name:      The property's name.
+ *
+ * The caller must be sure the given property name is valid, for example by
+ * having previously called btrfs_validate_prop().
+ *
+ * Returns:    true if the property should be ignored for the given inode
+ *             false if the property must not be ignored for the given inode
+ */
+bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
+{
+	const struct prop_handler *handler;
+
+	handler = find_prop_handler(name, NULL);
+	ASSERT(handler != NULL);
+
+	return handler->ignore(inode);
 }
 
 int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
@@ -252,8 +277,12 @@ int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
 	return ret;
 }
 
-static int prop_compression_validate(const char *value, size_t len)
+static int prop_compression_validate(const struct btrfs_inode *inode,
+				     const char *value, size_t len)
 {
+	if (!btrfs_inode_can_compress(inode))
+		return -EINVAL;
+
 	if (!value)
 		return 0;
 
@@ -310,6 +339,22 @@ static int prop_compression_apply(struct inode *inode, const char *value,
 	return 0;
 }
 
+static bool prop_compression_ignore(const struct btrfs_inode *inode)
+{
+	/*
+	 * Compression only has effect for regular files, and for directories
+	 * we set it just to propagate it to new files created inside them.
+	 * Everything else (symlinks, devices, sockets, fifos) is pointless as
+	 * it will do nothing, so don't waste metadata space on a compression
+	 * xattr for anything that is neither a file nor a directory.
+	 */
+	if (!S_ISREG(inode->vfs_inode.i_mode) &&
+	    !S_ISDIR(inode->vfs_inode.i_mode))
+		return true;
+
+	return false;
+}
+
 static const char *prop_compression_extract(struct inode *inode)
 {
 	switch (BTRFS_I(inode)->prop_compress) {
@@ -330,6 +375,7 @@ static struct prop_handler prop_handlers[] = {
 		.validate = prop_compression_validate,
 		.apply = prop_compression_apply,
 		.extract = prop_compression_extract,
+		.ignore = prop_compression_ignore,
 		.inheritable = 1
 	},
 };
@@ -356,6 +402,9 @@ static int inherit_props(struct btrfs_trans_handle *trans,
 		if (!h->inheritable)
 			continue;
 
+		if (h->ignore(BTRFS_I(inode)))
+			continue;
+
 		value = h->extract(parent);
 		if (!value)
 			continue;
@@ -364,7 +413,7 @@ static int inherit_props(struct btrfs_trans_handle *trans,
 		 * This is not strictly necessary as the property should be
 		 * valid, but in case it isn't, don't propagate it further.
 		 */
-		ret = h->validate(value, strlen(value));
+		ret = h->validate(BTRFS_I(inode), value, strlen(value));
 		if (ret)
 			continue;