xfs: Set up infrastructure for log attribute replay

Currently attributes are modified directly across one or more
transactions. But they are not logged or replayed in the event of an
error. The goal of log attr replay is to enable logging and replaying
of attribute operations using the existing delayed operations
infrastructure.  This will later enable the attributes to become part of
larger multi part operations that also must first be recorded to the
log.  This is mostly of interest in the scheme of parent pointers which
would need to maintain an attribute containing parent inode information
any time an inode is moved, created, or removed.  Parent pointers would
then be of interest to any feature that would need to quickly derive an
inode path from the mount point. Online scrub, nfs lookups and fs grow
or shrink operations are all features that could take advantage of this.

This patch adds two new log item types for setting or removing
attributes as deferred operations.  The xfs_attri_log_item will log an
intent to set or remove an attribute.  The corresponding
xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is
freed once the transaction is done.  Both log items use a generic
xfs_attr_log_format structure that contains the attribute name, value,
flags, inode, and an op_flag that indicates if the operations is a set
or remove.

[dchinner: added extra little bits needed for intent whiteouts]

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 5e71f719bdd5..80b6f28b0d1a 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -28,6 +28,11 @@ struct xfs_attr_list_context;
  */
 #define	ATTR_MAX_VALUELEN	(64*1024)	/* max length of a value */
 
+static inline bool xfs_has_larp(struct xfs_mount *mp)
+{
+	return false;
+}
+
 /*
  * Kernel-internal version of the attrlist cursor.
  */
@@ -461,6 +466,11 @@ enum xfs_delattr_state {
 struct xfs_delattr_context {
 	struct xfs_da_args      *da_args;
 
+	/*
+	 * Used by xfs_attr_set to hold a leaf buffer across a transaction roll
+	 */
+	struct xfs_buf		*leaf_bp;
+
 	/* Used in xfs_attr_rmtval_set_blk to roll through allocating blocks */
 	struct xfs_bmbt_irec	map;
 	xfs_dablk_t		lblkno;
@@ -474,6 +484,23 @@ struct xfs_delattr_context {
 	enum xfs_delattr_state  dela_state;
 };
 
+/*
+ * List of attrs to commit later.
+ */
+struct xfs_attr_item {
+	struct xfs_delattr_context	xattri_dac;
+
+	/*
+	 * Indicates if the attr operation is a set or a remove
+	 * XFS_ATTR_OP_FLAGS_{SET,REMOVE}
+	 */
+	unsigned int			xattri_op_flags;
+
+	/* used to log this item to an intent */
+	struct list_head		xattri_list;
+};
+
+
 /*========================================================================
  * Function prototypes for the kernel.
  *========================================================================*/
@@ -490,10 +517,21 @@ int xfs_attr_get_ilocked(struct xfs_da_args *args);
 int xfs_attr_get(struct xfs_da_args *args);
 int xfs_attr_set(struct xfs_da_args *args);
 int xfs_attr_set_args(struct xfs_da_args *args);
+int xfs_attr_set_iter(struct xfs_delattr_context *dac,
+		      struct xfs_buf **leaf_bp);
 int xfs_attr_remove_args(struct xfs_da_args *args);
 int xfs_attr_remove_iter(struct xfs_delattr_context *dac);
 bool xfs_attr_namecheck(const void *name, size_t length);
 void xfs_delattr_context_init(struct xfs_delattr_context *dac,
 			      struct xfs_da_args *args);
+int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
+
+extern struct kmem_cache	*xfs_attri_cache;
+extern struct kmem_cache	*xfs_attrd_cache;
+
+int __init xfs_attri_init_cache(void);
+void xfs_attri_destroy_cache(void);
+int __init xfs_attrd_init_cache(void);
+void xfs_attrd_destroy_cache(void);
 
 #endif	/* __XFS_ATTR_H__ */