Allow 'zpool replace' to use short device names

The 'zpool replace' command would fail when given a short name
because unlike on other platforms the short name cannot be
deterministically expanded to a single path.  Multiple path
prefixes must be checked and in addition the partition suffix
for whole disks is determined by the prefix.

To handle this complexity a zfs_strcmp_pathname() function was
added which takes either a short or fully qualified device name.
Short names will be expanded using the prefixes in the default
import search path, or the ZPOOL_IMPORT_PATH environment variable
if it's defined.  All posible expansions are then compared against
the comparison path.  Care is taken to strip redundant slashes to
ensure legitimate matches are not missed.

In the context of this work the existing zfs_resolve_shortname()
function was extended to consider the ZPOOL_IMPORT_PATH when set.
The zfs_append_partition() interface was also simplified to take
only a single buffer.

The vast majority of these changes rework existing Linux specific
code which was originally written to accomidate udev.  However,
there is some minimal cleanup which removes Illumos specific code.
This was done to improve readability but the basic flow and intent
of the upstream code was maintained.

These changes are the logical conclusion of the previos work to
adjust the 'zpool import' search behavior, see commit 44867b6a.

Signed-off-by: Brian Behlendorf <[email protected]>
Closes #544
Closes #976

1 files changed, 6 insertions, 16 deletions

diff --git a/include/libzfs.h b/include/libzfs.h
index 75e149334..e59350c9d 100644
--- a/include/libzfs.h
+++ b/include/libzfs.h
@@ -54,22 +54,11 @@ extern "C" {
 /*
  * Default device paths
  */
+#define	DISK_ROOT		"/dev"
+#define	UDISK_ROOT		"/dev/disk"
 
-#if defined(__sun__) || defined(__sun)
-#define	DISK_ROOT	"/dev/dsk"
-#define	RDISK_ROOT	"/dev/rdsk"
-#define	UDISK_ROOT	RDISK_ROOT
-#define	FIRST_SLICE	"s0"
-#define	BACKUP_SLICE	"s2"
-#endif
-
-#ifdef __linux__
-#define	DISK_ROOT	"/dev"
-#define	RDISK_ROOT	DISK_ROOT
-#define	UDISK_ROOT	"/dev/disk"
-#define	FIRST_SLICE	"1"
-#define	BACKUP_SLICE	""
-#endif
+#define	DEFAULT_IMPORT_PATH_SIZE	8
+extern char *zpool_default_import_path[DEFAULT_IMPORT_PATH_SIZE];
 
 /*
  * libzfs errors
@@ -658,8 +647,9 @@ extern zfs_handle_t *zfs_path_to_zhandle(libzfs_handle_t *, char *, zfs_type_t);
 extern boolean_t zfs_dataset_exists(libzfs_handle_t *, const char *,
     zfs_type_t);
 extern int zfs_spa_version(zfs_handle_t *, int *);
-extern void zfs_append_partition(const char *path, char *buf, size_t buflen);
+extern int zfs_append_partition(char *path, size_t max_len);
 extern int zfs_resolve_shortname(const char *name, char *path, size_t pathlen);
+extern int zfs_strcmp_pathname(char *name, char *cmp_name, int wholedisk);
 
 /*
  * Mount support functions.