linux-kernel - [PATCH v2 3/4] btrfs: opt-in for IOP_MAY_FAST

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Message-ID: <20251106180103.923856-4-mjguzik@gmail.com>
Date: Thu,  6 Nov 2025 19:01:01 +0100
From: Mateusz Guzik <mjguzik@...il.com>
To: brauner@...nel.org
Cc: viro@...iv.linux.org.uk,
	jack@...e.cz,
	linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org,
	linux-ext4@...r.kernel.org,
	tytso@....edu,
	torvalds@...ux-foundation.org,
	josef@...icpanda.com,
	linux-btrfs@...r.kernel.org,
	Mateusz Guzik <mjguzik@...il.com>
Subject: [PATCH v2 3/4] btrfs: opt-in for IOP_MAY_FAST_EXEC

Signed-off-by: Mateusz Guzik <mjguzik@...il.com>
---
 fs/btrfs/inode.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 42da39c1e5b5..42df687a0126 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5852,6 +5852,8 @@ struct btrfs_inode *btrfs_iget(u64 ino, struct btrfs_root *root)
 	if (ret)
 		return ERR_PTR(ret);
 
+	if (S_ISDIR(inode->vfs_inode.i_mode))
+		inode_enable_fast_may_exec(&inode->vfs_inode);
 	unlock_new_inode(&inode->vfs_inode);
 	return inode;
 }
@@ -6803,8 +6805,11 @@ static int btrfs_create_common(struct inode *dir, struct dentry *dentry,
 	}
 
 	ret = btrfs_create_new_inode(trans, &new_inode_args);
-	if (!ret)
+	if (!ret) {
+		if (S_ISDIR(inode->i_mode))
+			inode_enable_fast_may_exec(inode);
 		d_instantiate_new(dentry, inode);
+	}
 
 	btrfs_end_transaction(trans);
 	btrfs_btree_balance_dirty(fs_info);
@@ -9163,6 +9168,11 @@ int btrfs_prealloc_file_range_trans(struct inode *inode,
 					   min_size, actual_len, alloc_hint, trans);
 }
 
+/*
+ * NOTE: in case you are adding MAY_EXEC check for directories:
+ * inode_enable_fast_may_exec() is issued when inodes get instantiated, meaning
+ * calls to this place can be elided.
+ */
 static int btrfs_permission(struct mnt_idmap *idmap,
 			    struct inode *inode, int mask)
 {
-- 
2.48.1