From 75b6c0e045abb7e07773b924237c562ab9920c60 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Thu, 26 May 2016 12:02:12 +0200
Subject: [PATCH 85/86] libblkid: store only canonical devnames to the cache
Let's try to use symlink:
# ls -la /dev/block/8\:1
# lrwxrwxrwx 1 root root 7 May 25 16:42 /dev/block/8:1 -> ../sda1
# blkid /dev/block/8:1
/dev/block/8:3: LABEL="HOME" UUID="196972ad-3b13-4bba-ac54-4cb3f7b409a4" TYPE="ext4" PARTUUID="6073277f-87bc-43ff-bcfd-724c4484a63a"
unfortunately the symlink is stored to the cache:
<device DEVNO="0x0803" TIME="1464253300.715279" LABEL="HOME" UUID="196972ad-3b13-4bba-ac54-4cb3f7b409a4" TYPE="ext4" PARTUUID="6073277f-87bc-43ff-bcfd-724c4484a63a">/dev/block/8:3</device>
next time if you ask for LABEL=HOME the answer will be /dev/block/8:3
rather than /dev/sda3.
It seems better to canonicalize the paths we store to the cache.
Unfortunately if you ask for /dev/block/8:3 then you probably expect
that blkid_dev_devname() returns the same path. This patch introduces
dev->bid_xname, this is the path used by application (and never stored
in the cache).
Upstream: http://github.com/karelzak/util-linux/commit/924c93d9df118338fd54cd73b4a45ccddc4ac103
Addresses: http://bugzilla.redhat.com/show_bug.cgi?id=1007734
Signed-off-by: Karel Zak <kzak@redhat.com>
---
libblkid/src/blkidP.h | 4 +++-
libblkid/src/dev.c | 11 +++++++++--
libblkid/src/devname.c | 43 +++++++++++++++++++++++++++++++++++++------
3 files changed, 49 insertions(+), 9 deletions(-)
diff --git a/libblkid/src/blkidP.h b/libblkid/src/blkidP.h
index 7de84b4..8183c12 100644
--- a/libblkid/src/blkidP.h
+++ b/libblkid/src/blkidP.h
@@ -44,7 +44,7 @@ struct blkid_struct_dev
struct list_head bid_devs; /* All devices in the cache */
struct list_head bid_tags; /* All tags for this device */
blkid_cache bid_cache; /* Dev belongs to this cache */
- char *bid_name; /* Device inode pathname */
+ char *bid_name; /* Device real pathn (as used in cache) */
char *bid_type; /* Preferred device TYPE */
int bid_pri; /* Device priority */
dev_t bid_devno; /* Device major/minor number */
@@ -53,6 +53,8 @@ struct blkid_struct_dev
unsigned int bid_flags; /* Device status bitflags */
char *bid_label; /* Shortcut to device LABEL */
char *bid_uuid; /* Shortcut to binary UUID */
+
+ char *bid_xname; /* Device path as used by application (maybe symlink..) */
};
#define BLKID_BID_FL_VERIFIED 0x0001 /* Device data validated from disk */
diff --git a/libblkid/src/dev.c b/libblkid/src/dev.c
index a4b2aea..d2fd3f4 100644
--- a/libblkid/src/dev.c
+++ b/libblkid/src/dev.c
@@ -60,16 +60,23 @@ void blkid_free_dev(blkid_dev dev)
bit_tags);
blkid_free_tag(tag);
}
+ free(dev->bid_xname);
free(dev->bid_name);
free(dev);
}
/*
- * Given a blkid device, return its name
+ * Given a blkid device, return its name. The function returns the name
+ * previously used for blkid_get_dev(). This name does not have to be canonical
+ * (real path) name, but for example symlink.
*/
const char *blkid_dev_devname(blkid_dev dev)
{
- return dev ? dev->bid_name : NULL;
+ if (!dev)
+ return NULL;
+ if (dev->bid_xname)
+ return dev->bid_xname;
+ return dev->bid_name;
}
#ifdef CONFIG_BLKID_DEBUG
diff --git a/libblkid/src/devname.c b/libblkid/src/devname.c
index 497deaf..55b9594 100644
--- a/libblkid/src/devname.c
+++ b/libblkid/src/devname.c
@@ -51,28 +51,55 @@ blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
{
blkid_dev dev = NULL, tmp;
struct list_head *p, *pnext;
+ char *cn = NULL;
if (!cache || !devname)
return NULL;
+ /* search by name */
list_for_each(p, &cache->bic_devs) {
tmp = list_entry(p, struct blkid_struct_dev, bid_devs);
if (strcmp(tmp->bid_name, devname))
continue;
-
- DBG(DEVNAME, blkid_debug("found devname %s in cache", tmp->bid_name));
dev = tmp;
break;
}
+ /* try canonicalize the name */
+ if (!dev && (cn = canonicalize_path(devname))) {
+ if (strcmp(cn, devname) != 0) {
+ DBG(DEVNAME, blkid_debug("search cannonical %s", cn));
+ list_for_each(p, &cache->bic_devs) {
+ tmp = list_entry(p, struct blkid_struct_dev, bid_devs);
+ if (strcmp(tmp->bid_name, cn))
+ continue;
+ dev = tmp;
+
+ /* update name returned by blkid_dev_devname() */
+ free(dev->bid_xname);
+ dev->bid_xname = strdup(devname);
+ break;
+ }
+ } else {
+ free(cn);
+ cn = NULL;
+ }
+ }
+
if (!dev && (flags & BLKID_DEV_CREATE)) {
if (access(devname, F_OK) < 0)
- return NULL;
+ goto done;
dev = blkid_new_dev();
if (!dev)
- return NULL;
+ goto done;
dev->bid_time = INT_MIN;
- dev->bid_name = strdup(devname);
+ if (cn) {
+ dev->bid_name = cn;
+ dev->bid_xname = strdup(devname);
+ cn = NULL; /* see free() below */
+ } else
+ dev->bid_name = strdup(devname);
+
dev->bid_cache = cache;
list_add_tail(&dev->bid_devs, &cache->bic_devs);
cache->bic_flags |= BLKID_BIC_FL_CHANGED;
@@ -81,7 +108,7 @@ blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
if (flags & BLKID_DEV_VERIFY) {
dev = blkid_verify(cache, dev);
if (!dev || !(dev->bid_flags & BLKID_BID_FL_VERIFIED))
- return dev;
+ goto done;
/*
* If the device is verified, then search the blkid
* cache for any entries that match on the type, uuid,
@@ -112,6 +139,10 @@ blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
blkid_free_dev(dev2);
}
}
+done:
+ if (dev)
+ DBG(DEVNAME, blkid_debug("%s requested, found %s in cache", devname, dev->bid_name));
+ free(cn);
return dev;
}
--
2.7.4