[PATCH] PCI/IDE: Fix duplicate stream symlink names for TSM class devices

[Xu Yilun <yilun.xu@linux.intel.com>]

The symlink name streamH.R.E is unique within a specific host bridge but
not across the system. Error occurs e.g. when creating the first stream
on a second host bridge:

[ 1244.034755] sysfs: cannot create duplicate filename '/devices/faux/tdx_host/tsm/tsm0/stream0.0.0'

Fix this by adding host bridge name into symlink name for TSM class
devices. It should be OK to change the uAPI to
/sys/class/tsm/tsmN/pciDDDD:BB:streamH.R.E since it's new and has few
users.

Internally in the IDE library, store the full name in struct pci_ide
so TSM symlinks can use it directly, while PCI host bridge symlinks
can skip the host bridge name to keep concise.

Fixes: a4438f06b1db ("PCI/TSM: Report active IDE streams")
Reported-by: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
---
 Documentation/ABI/testing/sysfs-class-tsm |  2 +-
 drivers/pci/ide.c                         | 12 +++++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-tsm b/Documentation/ABI/testing/sysfs-class-tsm
index 6fc1a5ac6da1..eff71e42c60e 100644
--- a/Documentation/ABI/testing/sysfs-class-tsm
+++ b/Documentation/ABI/testing/sysfs-class-tsm
@@ -8,7 +8,7 @@ Description:
 		link encryption and other device-security features coordinated
 		through a platform tsm.
 
-What:		/sys/class/tsm/tsmN/streamH.R.E
+What:		/sys/class/tsm/tsmN/pciDDDD:BB:streamH.R.E
 Contact:	linux-pci@vger.kernel.org
 Description:
 		(RO) When a host bridge has established a secure connection via
diff --git a/drivers/pci/ide.c b/drivers/pci/ide.c
index f0ef474e1a0d..db1c7423bf39 100644
--- a/drivers/pci/ide.c
+++ b/drivers/pci/ide.c
@@ -425,6 +425,7 @@ int pci_ide_stream_register(struct pci_ide *ide)
 	struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
 	struct pci_ide_stream_id __sid;
 	u8 ep_stream, rp_stream;
+	const char *short_name;
 	int rc;
 
 	if (ide->stream_id < 0 || ide->stream_id > U8_MAX) {
@@ -441,13 +442,16 @@ int pci_ide_stream_register(struct pci_ide *ide)
 
 	ep_stream = ide->partner[PCI_IDE_EP].stream_index;
 	rp_stream = ide->partner[PCI_IDE_RP].stream_index;
-	const char *name __free(kfree) = kasprintf(GFP_KERNEL, "stream%d.%d.%d",
+	const char *name __free(kfree) = kasprintf(GFP_KERNEL, "%s:stream%d.%d.%d",
+						   dev_name(&hb->dev),
 						   ide->host_bridge_stream,
 						   rp_stream, ep_stream);
 	if (!name)
 		return -ENOMEM;
 
-	rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, name);
+	/* Skip host bridge name in the host bridge context */
+	short_name = name + strlen(dev_name(&hb->dev)) + 1;
+	rc = sysfs_create_link(&hb->dev.kobj, &pdev->dev.kobj, short_name);
 	if (rc)
 		return rc;
 
@@ -471,8 +475,10 @@ void pci_ide_stream_unregister(struct pci_ide *ide)
 {
 	struct pci_dev *pdev = ide->pdev;
 	struct pci_host_bridge *hb = pci_find_host_bridge(pdev->bus);
+	const char *short_name;
 
-	sysfs_remove_link(&hb->dev.kobj, ide->name);
+	short_name = ide->name + strlen(dev_name(&hb->dev)) + 1;
+	sysfs_remove_link(&hb->dev.kobj, short_name);
 	kfree(ide->name);
 	ida_free(&hb->ide_stream_ids_ida, ide->stream_id);
 	ide->name = NULL;

base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
-- 
2.25.1