Re: [PATCH 11/11] lpfc: don't use file->f_path.dentry for comparisons

[Al Viro <viro@zeniv.linux.org.uk>]

On Mon, Jul 07, 2025 at 12:29:55PM -0700, Justin Tee wrote:
> > is OK only if all updates of that thing are externally serialized.
> > If they are, we don't need atomic; if they are not, this separation
> > of decrement and test is racy.
> Agreed with this too.  Vport creation and deletion is serialized, so
> we do not need to declare debugfs_vport_count as atomic.
> 
> At this point, cleaning up the lpfc_debugfs_terminate routine may be a
> little more involved.  If it’s alright with you, Broadcom will take up
> the responsibility to clean up the lpfc_debugfs_terminate routine
> during our next driver version update, and we will of course state
> your authorship in that particular clean up patch.
> 
> Regarding this thread’s enum selector patch, I can provide the signed
> off by after we see that the enum declaration is moved to
> lpfc_debugfs.h.

Would this do?

[PATCH v2] lpfc: don't use file->f_path.dentry for comparisons
    
If you want a home-grown switch, at least use enum for selector...
    
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index 3fd1aa5cc78c..42d138ec11b4 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -2375,32 +2375,32 @@ static ssize_t
 lpfc_debugfs_dif_err_read(struct file *file, char __user *buf,
 	size_t nbytes, loff_t *ppos)
 {
-	struct dentry *dent = file->f_path.dentry;
 	struct lpfc_hba *phba = file->private_data;
+	int kind = debugfs_get_aux_num(file);
 	char cbuf[32];
 	uint64_t tmp = 0;
 	int cnt = 0;
 
-	if (dent == phba->debug_writeGuard)
+	if (kind == writeGuard)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_wgrd_cnt);
-	else if (dent == phba->debug_writeApp)
+	else if (kind == writeApp)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_wapp_cnt);
-	else if (dent == phba->debug_writeRef)
+	else if (kind == writeRef)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_wref_cnt);
-	else if (dent == phba->debug_readGuard)
+	else if (kind == readGuard)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_rgrd_cnt);
-	else if (dent == phba->debug_readApp)
+	else if (kind == readApp)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_rapp_cnt);
-	else if (dent == phba->debug_readRef)
+	else if (kind == readRef)
 		cnt = scnprintf(cbuf, 32, "%u\n", phba->lpfc_injerr_rref_cnt);
-	else if (dent == phba->debug_InjErrNPortID)
+	else if (kind == InjErrNPortID)
 		cnt = scnprintf(cbuf, 32, "0x%06x\n",
 				phba->lpfc_injerr_nportid);
-	else if (dent == phba->debug_InjErrWWPN) {
+	else if (kind == InjErrWWPN) {
 		memcpy(&tmp, &phba->lpfc_injerr_wwpn, sizeof(struct lpfc_name));
 		tmp = cpu_to_be64(tmp);
 		cnt = scnprintf(cbuf, 32, "0x%016llx\n", tmp);
-	} else if (dent == phba->debug_InjErrLBA) {
+	} else if (kind == InjErrLBA) {
 		if (phba->lpfc_injerr_lba == (sector_t)(-1))
 			cnt = scnprintf(cbuf, 32, "off\n");
 		else
@@ -2417,8 +2417,8 @@ static ssize_t
 lpfc_debugfs_dif_err_write(struct file *file, const char __user *buf,
 	size_t nbytes, loff_t *ppos)
 {
-	struct dentry *dent = file->f_path.dentry;
 	struct lpfc_hba *phba = file->private_data;
+	int kind = debugfs_get_aux_num(file);
 	char dstbuf[33];
 	uint64_t tmp = 0;
 	int size;
@@ -2428,7 +2428,7 @@ lpfc_debugfs_dif_err_write(struct file *file, const char __user *buf,
 	if (copy_from_user(dstbuf, buf, size))
 		return -EFAULT;
 
-	if (dent == phba->debug_InjErrLBA) {
+	if (kind == InjErrLBA) {
 		if ((dstbuf[0] == 'o') && (dstbuf[1] == 'f') &&
 		    (dstbuf[2] == 'f'))
 			tmp = (uint64_t)(-1);
@@ -2437,23 +2437,23 @@ lpfc_debugfs_dif_err_write(struct file *file, const char __user *buf,
 	if ((tmp == 0) && (kstrtoull(dstbuf, 0, &tmp)))
 		return -EINVAL;
 
-	if (dent == phba->debug_writeGuard)
+	if (kind == writeGuard)
 		phba->lpfc_injerr_wgrd_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_writeApp)
+	else if (kind == writeApp)
 		phba->lpfc_injerr_wapp_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_writeRef)
+	else if (kind == writeRef)
 		phba->lpfc_injerr_wref_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_readGuard)
+	else if (kind == readGuard)
 		phba->lpfc_injerr_rgrd_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_readApp)
+	else if (kind == readApp)
 		phba->lpfc_injerr_rapp_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_readRef)
+	else if (kind == readRef)
 		phba->lpfc_injerr_rref_cnt = (uint32_t)tmp;
-	else if (dent == phba->debug_InjErrLBA)
+	else if (kind == InjErrLBA)
 		phba->lpfc_injerr_lba = (sector_t)tmp;
-	else if (dent == phba->debug_InjErrNPortID)
+	else if (kind == InjErrNPortID)
 		phba->lpfc_injerr_nportid = (uint32_t)(tmp & Mask_DID);
-	else if (dent == phba->debug_InjErrWWPN) {
+	else if (kind == InjErrWWPN) {
 		tmp = cpu_to_be64(tmp);
 		memcpy(&phba->lpfc_injerr_wwpn, &tmp, sizeof(struct lpfc_name));
 	} else
@@ -6160,60 +6160,51 @@ lpfc_debugfs_initialize(struct lpfc_vport *vport)
 			phba->debug_dumpHostSlim = NULL;
 
 		/* Setup DIF Error Injections */
-		snprintf(name, sizeof(name), "InjErrLBA");
 		phba->debug_InjErrLBA =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("InjErrLBA", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, InjErrLBA, &lpfc_debugfs_op_dif_err);
 		phba->lpfc_injerr_lba = LPFC_INJERR_LBA_OFF;
 
-		snprintf(name, sizeof(name), "InjErrNPortID");
 		phba->debug_InjErrNPortID =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("InjErrNPortID", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, InjErrNPortID, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "InjErrWWPN");
 		phba->debug_InjErrWWPN =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("InjErrWWPN", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, InjErrWWPN, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "writeGuardInjErr");
 		phba->debug_writeGuard =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("writeGuardInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, writeGuard, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "writeAppInjErr");
 		phba->debug_writeApp =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("writeAppInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, writeApp, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "writeRefInjErr");
 		phba->debug_writeRef =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("writeRefInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, writeRef, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "readGuardInjErr");
 		phba->debug_readGuard =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("readGuardInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, readGuard, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "readAppInjErr");
 		phba->debug_readApp =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("readAppInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, readApp, &lpfc_debugfs_op_dif_err);
 
-		snprintf(name, sizeof(name), "readRefInjErr");
 		phba->debug_readRef =
-			debugfs_create_file(name, S_IFREG|S_IRUGO|S_IWUSR,
+			debugfs_create_file_aux_num("readRefInjErr", 0644,
 			phba->hba_debugfs_root,
-			phba, &lpfc_debugfs_op_dif_err);
+			phba, readRef, &lpfc_debugfs_op_dif_err);
 
 		/* Setup slow ring trace */
 		if (lpfc_debugfs_max_slow_ring_trc) {
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.h b/drivers/scsi/lpfc/lpfc_debugfs.h
index 8d2e8d05bbc0..f319f3af0400 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.h
+++ b/drivers/scsi/lpfc/lpfc_debugfs.h
@@ -322,6 +322,17 @@ enum {
 						 * discovery */
 #endif /* H_LPFC_DEBUG_FS */
 
+enum {
+	writeGuard = 1,
+	writeApp,
+	writeRef,
+	readGuard,
+	readApp,
+	readRef,
+	InjErrLBA,
+	InjErrNPortID,
+	InjErrWWPN,
+};
 
 /*
  * Driver debug utility routines outside of debugfs. The debug utility