lvm2/0035-devices-simplify-dev_cache_get_by_devt.patch

From 8552290efae4905fd1a942be8e752842b11f1881 Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Thu, 24 Feb 2022 15:57:29 -0600
Subject: [PATCH 35/54] devices: simplify dev_cache_get_by_devt

remove unused args, and no callers need or want a
repeated dev_cache_scan if there is no dev from the
lookup.
---
 lib/device/dev-cache.c | 60 ++++--------------------------------------
 lib/device/dev-cache.h |  2 +-
 lib/label/label.c      |  2 +-
 tools/pvscan.c         |  6 ++---
 4 files changed, 10 insertions(+), 60 deletions(-)

diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c
index c6e5f68cf..cc1af7c7a 100644
--- a/lib/device/dev-cache.c
+++ b/lib/device/dev-cache.c
@@ -1577,63 +1577,13 @@ struct device *dev_cache_get(struct cmd_context *cmd, const char *name, struct d
 	return dev;
 }
 
-struct device *dev_cache_get_by_devt(struct cmd_context *cmd, dev_t dev, struct dev_filter *f, int *filtered)
+struct device *dev_cache_get_by_devt(struct cmd_context *cmd, dev_t devt)
 {
-	char path[PATH_MAX];
-	const char *sysfs_dir;
-	struct stat info;
-	struct device *d = (struct device *) btree_lookup(_cache.devices, (uint32_t) dev);
-	int ret;
-
-	if (filtered)
-		*filtered = 0;
-
-	if (!d) {
-		sysfs_dir = dm_sysfs_dir();
-		if (sysfs_dir && *sysfs_dir) {
-			/* First check if dev is sysfs to avoid useless scan */
-			if (dm_snprintf(path, sizeof(path), "%sdev/block/%d:%d",
-					sysfs_dir, (int)MAJOR(dev), (int)MINOR(dev)) < 0) {
-				log_error("dm_snprintf partition failed.");
-				return NULL;
-			}
-
-			if (lstat(path, &info)) {
-				log_debug("No sysfs entry for %d:%d errno %d at %s.",
-					  (int)MAJOR(dev), (int)MINOR(dev), errno, path);
-				return NULL;
-			}
-		}
-
-		log_debug_devs("Device num not found in dev_cache repeat dev_cache_scan for %d:%d",
-				(int)MAJOR(dev), (int)MINOR(dev));
-		dev_cache_scan(cmd);
-		d = (struct device *) btree_lookup(_cache.devices, (uint32_t) dev);
-
-		if (!d)
-			return NULL;
-	}
-
-	if (d->flags & DEV_REGULAR)
-		return d;
-
-	if (!f)
-		return d;
-
-	ret = f->passes_filter(cmd, f, d, NULL);
-
-	if (ret == -EAGAIN) {
-		log_debug_devs("get device by number defer filter %s", dev_name(d));
-		d->flags |= DEV_FILTER_AFTER_SCAN;
-		ret = 1;
-	}
-
-	if (ret)
-		return d;
-
-	if (filtered)
-		*filtered = 1;
+	struct device *dev = (struct device *) btree_lookup(_cache.devices, (uint32_t) devt);
 
+	if (dev)
+		return dev;
+	log_debug_devs("No devno %d:%d in dev cache.", (int)MAJOR(devt), (int)MINOR(devt));
 	return NULL;
 }
 
diff --git a/lib/device/dev-cache.h b/lib/device/dev-cache.h
index 635dc4fc9..7305eeb0e 100644
--- a/lib/device/dev-cache.h
+++ b/lib/device/dev-cache.h
@@ -54,7 +54,7 @@ int dev_cache_has_scanned(void);
 int dev_cache_add_dir(const char *path);
 struct device *dev_cache_get(struct cmd_context *cmd, const char *name, struct dev_filter *f);
 
-struct device *dev_cache_get_by_devt(struct cmd_context *cmd, dev_t device, struct dev_filter *f, int *filtered);
+struct device *dev_cache_get_by_devt(struct cmd_context *cmd, dev_t devt);
 
 struct device *dev_hash_get(const char *name);
 
diff --git a/lib/label/label.c b/lib/label/label.c
index 354ab35e2..ffe925254 100644
--- a/lib/label/label.c
+++ b/lib/label/label.c
@@ -1443,7 +1443,7 @@ void label_scan_invalidate_lv(struct cmd_context *cmd, struct logical_volume *lv
 	if (lv_info(cmd, lv, 0, &lvinfo, 0, 0) && lvinfo.exists) {
 		/* FIXME: Still unclear what is it supposed to find */
 		devt = MKDEV(lvinfo.major, lvinfo.minor);
-		if ((dev = dev_cache_get_by_devt(cmd, devt, NULL, NULL)))
+		if ((dev = dev_cache_get_by_devt(cmd, devt)))
 			label_scan_invalidate(dev);
 	}
 }
diff --git a/tools/pvscan.c b/tools/pvscan.c
index f60c4a2ca..160a2c9a0 100644
--- a/tools/pvscan.c
+++ b/tools/pvscan.c
@@ -857,7 +857,7 @@ static int _get_devs_from_saved_vg(struct cmd_context *cmd, const char *vgname,
 
 		devno = MKDEV(file_major, file_minor);
 
-		if (!(dev = dev_cache_get_by_devt(cmd, devno, NULL, NULL))) {
+		if (!(dev = dev_cache_get_by_devt(cmd, devno))) {
 			log_error_pvscan(cmd, "No device found for %d:%d PVID %s", file_major, file_minor, pvid);
 			goto bad;
 		}
@@ -1195,7 +1195,7 @@ static int _get_args_devs(struct cmd_context *cmd, struct dm_list *pvscan_args,
 		if (arg->devname)
 			arg->dev = dev_cache_get(cmd, arg->devname, NULL);
 		else if (arg->devno)
-			arg->dev = dev_cache_get_by_devt(cmd, arg->devno, NULL, NULL);
+			arg->dev = dev_cache_get_by_devt(cmd, arg->devno);
 		else
 			return_0;
 	}
@@ -1257,7 +1257,7 @@ static void _set_pv_devices_online(struct cmd_context *cmd, struct volume_group
 
 		devno = MKDEV(major, minor);
 
-		if (!(dev = dev_cache_get_by_devt(cmd, devno, NULL, NULL))) {
+		if (!(dev = dev_cache_get_by_devt(cmd, devno))) {
 			log_print_pvscan(cmd, "VG %s PV %s no device found for %d:%d",
 					 vg->name, pvid, major, minor);
 			pvl->pv->status |= MISSING_PV;
-- 
2.34.3