xfs: improve shortform attr performance [2/3]

Improve performance of the xattr (and parent pointer) code when the
 attr structure is in short format and we can therefore perform all
 updates in a single transaction.  Avoiding the attr intent code brings
 a very nice speedup in those operations.
 
 With a bit of luck, this should all go splendidly.
 
 Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
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Merge tag 'attr-pptr-speedup-7.0_2026-01-25' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-7.0-merge

xfs: improve shortform attr performance [2/3]

Improve performance of the xattr (and parent pointer) code when the
attr structure is in short format and we can therefore perform all
updates in a single transaction.  Avoiding the attr intent code brings
a very nice speedup in those operations.

With a bit of luck, this should all go splendidly.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

fs/xfs/libxfs/xfs_attr.c

@@ -350,16 +350,14 @@ xfs_attr_set_resv(
  */
 STATIC int
 xfs_attr_try_sf_addname(
-	struct xfs_inode	*dp,
 	struct xfs_da_args	*args)
 {
-
 	int			error;
 
 	/*
 	 * Build initial attribute list (if required).
 	 */
-	if (dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS)
+	if (args->dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS)
 		xfs_attr_shortform_create(args);
 
 	error = xfs_attr_shortform_addname(args);
@@ -371,9 +369,9 @@ xfs_attr_try_sf_addname(
 	 * NOTE: this is also the error path (EEXIST, etc).
 	 */
 	if (!error)
-		xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
+		xfs_trans_ichgtime(args->trans, args->dp, XFS_ICHGTIME_CHG);
 
-	if (xfs_has_wsync(dp->i_mount))
+	if (xfs_has_wsync(args->dp->i_mount))
 		xfs_trans_set_sync(args->trans);
 
 	return error;
@@ -384,10 +382,9 @@ xfs_attr_sf_addname(
 	struct xfs_attr_intent		*attr)
 {
 	struct xfs_da_args		*args = attr->xattri_da_args;
-	struct xfs_inode		*dp = args->dp;
 	int				error = 0;
 
-	error = xfs_attr_try_sf_addname(dp, args);
+	error = xfs_attr_try_sf_addname(args);
 	if (error != -ENOSPC) {
 		ASSERT(!error || error == -EEXIST);
 		attr->xattri_dela_state = XFS_DAS_DONE;
@@ -1031,6 +1028,95 @@ trans_cancel:
 	return error;
 }
 
+/*
+ * Decide if it is theoretically possible to try to bypass the attr intent
+ * mechanism for better performance.  Other constraints (e.g. available space
+ * in the existing structure) are not considered here.
+ */
+static inline bool
+xfs_attr_can_shortcut(
+	const struct xfs_inode	*ip)
+{
+	return xfs_inode_has_attr_fork(ip) && xfs_attr_is_shortform(ip);
+}
+
+/* Try to set an attr in one transaction or fall back to attr intents. */
+int
+xfs_attr_setname(
+	struct xfs_da_args	*args,
+	int			rmt_blks)
+{
+	int			error;
+
+	if (!rmt_blks && xfs_attr_can_shortcut(args->dp)) {
+		args->op_flags |= XFS_DA_OP_ADDNAME;
+
+		error = xfs_attr_try_sf_addname(args);
+		if (error != -ENOSPC)
+			return error;
+	}
+
+	xfs_attr_defer_add(args, XFS_ATTR_DEFER_SET);
+	return 0;
+}
+
+/* Try to remove an attr in one transaction or fall back to attr intents. */
+int
+xfs_attr_removename(
+	struct xfs_da_args	*args)
+{
+	if (xfs_attr_can_shortcut(args->dp))
+		return xfs_attr_sf_removename(args);
+
+	xfs_attr_defer_add(args, XFS_ATTR_DEFER_REMOVE);
+	return 0;
+}
+
+/* Try to replace an attr in one transaction or fall back to attr intents. */
+int
+xfs_attr_replacename(
+	struct xfs_da_args	*args,
+	int			rmt_blks)
+{
+	int			error;
+
+	if (rmt_blks || !xfs_attr_can_shortcut(args->dp)) {
+		xfs_attr_defer_add(args, XFS_ATTR_DEFER_REPLACE);
+		return 0;
+	}
+
+	error = xfs_attr_shortform_replace(args);
+	if (error != -ENOSPC)
+		return error;
+
+	args->op_flags |= XFS_DA_OP_ADDNAME | XFS_DA_OP_REPLACE;
+
+	error = xfs_attr_sf_removename(args);
+	if (error)
+		return error;
+
+	if (args->attr_filter & XFS_ATTR_PARENT) {
+		/*
+		 * Move the new name/value to the regular name/value slots and
+		 * zero out the new name/value slots because we don't need to
+		 * log them for a PPTR_SET operation.
+		 */
+		xfs_attr_update_pptr_replace_args(args);
+		args->new_name = NULL;
+		args->new_namelen = 0;
+		args->new_value = NULL;
+		args->new_valuelen = 0;
+	}
+	args->op_flags &= ~XFS_DA_OP_REPLACE;
+
+	error = xfs_attr_try_sf_addname(args);
+	if (error != -ENOSPC)
+		return error;
+
+	xfs_attr_defer_add(args, XFS_ATTR_DEFER_SET);
+	return 0;
+}
+
 /*
  * Make a change to the xattr structure.
  *
@@ -1111,14 +1197,19 @@ xfs_attr_set(
 	case -EEXIST:
 		if (op == XFS_ATTRUPDATE_REMOVE) {
 			/* if no value, we are performing a remove operation */
-			xfs_attr_defer_add(args, XFS_ATTR_DEFER_REMOVE);
+			error = xfs_attr_removename(args);
+			if (error)
+				goto out_trans_cancel;
 			break;
 		}
 
 		/* Pure create fails if the attr already exists */
 		if (op == XFS_ATTRUPDATE_CREATE)
 			goto out_trans_cancel;
-		xfs_attr_defer_add(args, XFS_ATTR_DEFER_REPLACE);
+
+		error = xfs_attr_replacename(args, rmt_blks);
+		if (error)
+			goto out_trans_cancel;
 		break;
 	case -ENOATTR:
 		/* Can't remove what isn't there. */
@@ -1128,7 +1219,10 @@ xfs_attr_set(
 		/* Pure replace fails if no existing attr to replace. */
 		if (op == XFS_ATTRUPDATE_REPLACE)
 			goto out_trans_cancel;
-		xfs_attr_defer_add(args, XFS_ATTR_DEFER_SET);
+
+		error = xfs_attr_setname(args, rmt_blks);
+		if (error)
+			goto out_trans_cancel;
 		break;
 	default:
 		goto out_trans_cancel;

fs/xfs/libxfs/xfs_attr.h

@@ -573,7 +573,7 @@ struct xfs_trans_res xfs_attr_set_resv(const struct xfs_da_args *args);
  */
 static inline bool
 xfs_attr_is_shortform(
-	struct xfs_inode    *ip)
+	const struct xfs_inode    *ip)
 {
 	return ip->i_af.if_format == XFS_DINODE_FMT_LOCAL ||
 	       (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
@@ -649,4 +649,8 @@ void xfs_attr_intent_destroy_cache(void);
 int xfs_attr_sf_totsize(struct xfs_inode *dp);
 int xfs_attr_add_fork(struct xfs_inode *ip, int size, int rsvd);
 
+int xfs_attr_setname(struct xfs_da_args *args, int rmt_blks);
+int xfs_attr_removename(struct xfs_da_args *args);
+int xfs_attr_replacename(struct xfs_da_args *args, int rmt_blks);
+
 #endif	/* __XFS_ATTR_H__ */

fs/xfs/libxfs/xfs_attr_leaf.c

@@ -842,6 +842,44 @@ xfs_attr_sf_findname(
 	return NULL;
 }
 
+/*
+ * Replace a shortform xattr if it's the right length.  Returns 0 on success,
+ * -ENOSPC if the length is wrong, or -ENOATTR if the attr was not found.
+ */
+int
+xfs_attr_shortform_replace(
+	struct xfs_da_args		*args)
+{
+	struct xfs_attr_sf_entry	*sfe;
+
+	ASSERT(args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL);
+
+	trace_xfs_attr_sf_replace(args);
+
+	sfe = xfs_attr_sf_findname(args);
+	if (!sfe)
+		return -ENOATTR;
+
+	if (args->attr_filter & XFS_ATTR_PARENT) {
+		if (sfe->namelen != args->new_namelen ||
+		    sfe->valuelen != args->new_valuelen)
+			return -ENOSPC;
+
+		memcpy(sfe->nameval, args->new_name, sfe->namelen);
+		memcpy(&sfe->nameval[sfe->namelen], args->new_value,
+				sfe->valuelen);
+	} else {
+		if (sfe->valuelen != args->valuelen)
+			return -ENOSPC;
+		memcpy(&sfe->nameval[sfe->namelen], args->value,
+				sfe->valuelen);
+	}
+
+	xfs_trans_log_inode(args->trans, args->dp,
+			XFS_ILOG_CORE | XFS_ILOG_ADATA);
+	return 0;
+}
+
 /*
  * Add a name/value pair to the shortform attribute list.
  * Overflow from the inode has already been checked for.

fs/xfs/libxfs/xfs_attr_leaf.h

@@ -46,6 +46,7 @@ struct xfs_attr3_icleaf_hdr {
  * Internal routines when attribute fork size < XFS_LITINO(mp).
  */
 void	xfs_attr_shortform_create(struct xfs_da_args *args);
+int	xfs_attr_shortform_replace(struct xfs_da_args *args);
 void	xfs_attr_shortform_add(struct xfs_da_args *args, int forkoff);
 int	xfs_attr_shortform_getvalue(struct xfs_da_args *args);
 int	xfs_attr_shortform_to_leaf(struct xfs_da_args *args);

fs/xfs/libxfs/xfs_parent.c

@@ -29,6 +29,7 @@
 #include "xfs_trans_space.h"
 #include "xfs_attr_item.h"
 #include "xfs_health.h"
+#include "xfs_attr_leaf.h"
 
 struct kmem_cache		*xfs_parent_args_cache;
 
@@ -202,8 +203,8 @@ xfs_parent_addname(
 	xfs_inode_to_parent_rec(&ppargs->rec, dp);
 	xfs_parent_da_args_init(&ppargs->args, tp, &ppargs->rec, child,
 			child->i_ino, parent_name);
-	xfs_attr_defer_add(&ppargs->args, XFS_ATTR_DEFER_SET);
-	return 0;
+
+	return xfs_attr_setname(&ppargs->args, 0);
 }
 
 /* Remove a parent pointer to reflect a dirent removal. */
@@ -224,8 +225,8 @@ xfs_parent_removename(
 	xfs_inode_to_parent_rec(&ppargs->rec, dp);
 	xfs_parent_da_args_init(&ppargs->args, tp, &ppargs->rec, child,
 			child->i_ino, parent_name);
-	xfs_attr_defer_add(&ppargs->args, XFS_ATTR_DEFER_REMOVE);
-	return 0;
+
+	return xfs_attr_removename(&ppargs->args);
 }
 
 /* Replace one parent pointer with another to reflect a rename. */
@@ -250,12 +251,13 @@ xfs_parent_replacename(
 			child->i_ino, old_name);
 
 	xfs_inode_to_parent_rec(&ppargs->new_rec, new_dp);
+
 	ppargs->args.new_name = new_name->name;
 	ppargs->args.new_namelen = new_name->len;
 	ppargs->args.new_value = &ppargs->new_rec;
 	ppargs->args.new_valuelen = sizeof(struct xfs_parent_rec);
-	xfs_attr_defer_add(&ppargs->args, XFS_ATTR_DEFER_REPLACE);
-	return 0;
+
+	return xfs_attr_replacename(&ppargs->args, 0);
 }
 
 /*

fs/xfs/xfs_trace.h

@@ -2413,6 +2413,7 @@ DEFINE_ATTR_EVENT(xfs_attr_sf_addname);
 DEFINE_ATTR_EVENT(xfs_attr_sf_create);
 DEFINE_ATTR_EVENT(xfs_attr_sf_lookup);
 DEFINE_ATTR_EVENT(xfs_attr_sf_remove);
+DEFINE_ATTR_EVENT(xfs_attr_sf_replace);
 DEFINE_ATTR_EVENT(xfs_attr_sf_to_leaf);
 
 DEFINE_ATTR_EVENT(xfs_attr_leaf_add);