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From: Al Viro <viro@zeniv.linux.org.uk>
To: linux-fsdevel@vger.kernel.org
Cc: torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz,
	raven@themaw.net, miklos@szeredi.hu, a.hindborg@kernel.org,
	linux-mm@kvack.org, linux-efi@vger.kernel.org,
	ocfs2-devel@lists.linux.dev, kees@kernel.org,
	rostedt@goodmis.org, gregkh@linuxfoundation.org,
	linux-usb@vger.kernel.org, paul@paul-moore.com,
	casey@schaufler-ca.com, linuxppc-dev@lists.ozlabs.org,
	borntraeger@linux.ibm.com
Subject: [PATCH 22/39] convert ibmasmfs
Date: Sat, 20 Sep 2025 08:47:41 +0100	[thread overview]
Message-ID: <20250920074759.3564072-22-viro@zeniv.linux.org.uk> (raw)
In-Reply-To: <20250920074759.3564072-1-viro@zeniv.linux.org.uk>

static contents for each "service processor", whatever the fuck it is.
Congruent subdirectories of root, created at mount time, taken out
by kill_litter_super().  All dentries created with d_alloc_name() and are
left pinned.  The odd part is that the list of service providers is
assumed to be unchanging - no locking, nothing to handle removals or
extra elements added later on.

... and it's a PCI device.  If you ever tell it to remove an instance,
you are fucked - it doesn't bother with removing its directory from filesystem,
it has a strange check that presumably wanted to be a check for removed
devices, but it had never been fleshed out.

Anyway, d_add() -> d_make_persistent()+dput() in ibmasmfs_create_dir() and
ibmasmfs_create_file(), and make the latter return int - no need to even
borrow that dentry, callers completely ignore it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 drivers/misc/ibmasm/ibmasmfs.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c
index c44de892a61e..785ce294f4b9 100644
--- a/drivers/misc/ibmasm/ibmasmfs.c
+++ b/drivers/misc/ibmasm/ibmasmfs.c
@@ -103,7 +103,7 @@ static struct file_system_type ibmasmfs_type = {
 	.owner          = THIS_MODULE,
 	.name           = "ibmasmfs",
 	.init_fs_context = ibmasmfs_init_fs_context,
-	.kill_sb        = kill_litter_super,
+	.kill_sb        = kill_anon_super,
 };
 MODULE_ALIAS_FS("ibmasmfs");
 
@@ -144,7 +144,7 @@ static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
 	return ret;
 }
 
-static struct dentry *ibmasmfs_create_file(struct dentry *parent,
+static int ibmasmfs_create_file(struct dentry *parent,
 			const char *name,
 			const struct file_operations *fops,
 			void *data,
@@ -155,19 +155,20 @@ static struct dentry *ibmasmfs_create_file(struct dentry *parent,
 
 	dentry = d_alloc_name(parent, name);
 	if (!dentry)
-		return NULL;
+		return -ENOMEM;
 
 	inode = ibmasmfs_make_inode(parent->d_sb, S_IFREG | mode);
 	if (!inode) {
 		dput(dentry);
-		return NULL;
+		return -ENOMEM;
 	}
 
 	inode->i_fop = fops;
 	inode->i_private = data;
 
-	d_add(dentry, inode);
-	return dentry;
+	d_make_persistent(dentry, inode);
+	dput(dentry);
+	return 0;
 }
 
 static struct dentry *ibmasmfs_create_dir(struct dentry *parent,
@@ -189,8 +190,9 @@ static struct dentry *ibmasmfs_create_dir(struct dentry *parent,
 	inode->i_op = &simple_dir_inode_operations;
 	inode->i_fop = ibmasmfs_dir_ops;
 
-	d_add(dentry, inode);
-	return dentry;
+	d_make_persistent(dentry, inode);
+	dput(dentry);
+	return dentry; // borrowed
 }
 
 int ibmasmfs_register(void)
-- 
2.47.3



  parent reply	other threads:[~2025-09-20  8:11 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-20  7:41 [PATCHES][RFC] the meat of tree-in-dcache series Al Viro
2025-09-20  7:47 ` [PATCH 01/39] new helper: simple_remove_by_name() Al Viro
2025-09-20  7:47   ` [PATCH 02/39] new helper: simple_done_creating() Al Viro
2025-09-20  7:47   ` [PATCH 03/39] introduce a flag for explicitly marking persistently pinned dentries Al Viro
2025-09-20  7:47   ` [PATCH 04/39] primitives for maintaining persisitency Al Viro
2025-09-20  7:47   ` [PATCH 05/39] convert simple_{link,unlink,rmdir,rename,fill_super}() to new primitives Al Viro
2025-09-20  7:47   ` [PATCH 06/39] convert ramfs and tmpfs Al Viro
2025-09-20  7:47   ` [PATCH 07/39] procfs: make /self and /thread_self dentries persistent Al Viro
2025-09-20  7:47   ` [PATCH 08/39] configfs, securityfs: kill_litter_super() not needed Al Viro
2025-09-24 16:56     ` Joel Becker
2025-09-20  7:47   ` [PATCH 09/39] convert xenfs Al Viro
2025-09-20  7:47   ` [PATCH 10/39] convert smackfs Al Viro
2025-09-22 15:11     ` Casey Schaufler
2025-09-20  7:47   ` [PATCH 11/39] convert hugetlbfs Al Viro
2025-09-20  7:47   ` [PATCH 12/39] convert mqueue Al Viro
2025-09-20  7:47   ` [PATCH 13/39] convert bpf Al Viro
2025-09-20  7:47   ` [PATCH 14/39] convert dlmfs Al Viro
2025-09-20  7:47   ` [PATCH 15/39] convert fuse_ctl Al Viro
2025-09-20  7:47   ` [PATCH 16/39] convert pstore Al Viro
2025-09-20  7:47   ` [PATCH 17/39] convert tracefs Al Viro
2025-09-20  7:47   ` [PATCH 18/39] convert debugfs Al Viro
2025-09-23  8:10     ` Greg KH
2025-09-20  7:47   ` [PATCH 19/39] debugfs: remove duplicate checks in callers of start_creating() Al Viro
2025-09-23  8:10     ` Greg KH
2025-09-20  7:47   ` [PATCH 20/39] convert efivarfs Al Viro
2025-09-20  7:47   ` [PATCH 21/39] convert spufs Al Viro
2025-09-20  7:47   ` Al Viro [this message]
2025-09-20  7:47   ` [PATCH 23/39] ibmasmfs: get rid of ibmasmfs_dir_ops Al Viro
2025-09-20  7:47   ` [PATCH 24/39] convert devpts Al Viro
2025-09-20  7:47   ` [PATCH 25/39] binderfs: use simple_start_creating() Al Viro
2025-09-20  7:47   ` [PATCH 26/39] binderfs_binder_ctl_create(): kill a bogus check Al Viro
2025-09-20  7:47   ` [PATCH 27/39] convert binderfs Al Viro
2025-09-20  7:47   ` [PATCH 28/39] autofs_{rmdir,unlink}: dentry->d_fsdata->dentry == dentry there Al Viro
2025-09-20  7:47   ` [PATCH 29/39] convert autofs Al Viro
2025-09-20  7:47   ` [PATCH 30/39] convert binfmt_misc Al Viro
2025-09-20  7:47   ` [PATCH 31/39] convert selinuxfs Al Viro
2025-09-21 20:44     ` Paul Moore
2025-09-21 22:26       ` Al Viro
2025-09-22  2:50         ` Paul Moore
2025-09-22  3:52           ` Al Viro
2025-09-20  7:47   ` [PATCH 32/39] functionfs: switch to simple_remove_by_name() Al Viro
2025-09-20  7:47   ` [PATCH 33/39] convert functionfs Al Viro
2025-09-20  7:47   ` [PATCH 34/39] gadgetfs: switch to simple_remove_by_name() Al Viro
2025-09-20  7:47   ` [PATCH 35/39] convert gadgetfs Al Viro
2025-09-20  7:47   ` [PATCH 36/39] hypfs: don't pin dentries twice Al Viro
2025-09-20  7:47   ` [PATCH 37/39] hypfs: switch hypfs_create_str() to returning int Al Viro
2025-09-20  7:47   ` [PATCH 38/39] hypfs: swich hypfs_create_u64() " Al Viro
2025-09-20  7:47   ` [PATCH 39/39] convert hypfs Al Viro
2025-09-20 16:26 ` [PATCHES][RFC] the meat of tree-in-dcache series Linus Torvalds
2025-09-20 18:09   ` Al Viro

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