OpenZFS 8081 - Compiler warnings in zdb

Fix compiler warnings in zdb.  With these changes, FreeBSD can compile
zdb with all compiler warnings enabled save -Wunused-parameter.

usr/src/cmd/zdb/zdb.c
usr/src/cmd/zdb/zdb_il.c
usr/src/uts/common/fs/zfs/sys/sa.h
usr/src/uts/common/fs/zfs/sys/spa.h
	Fix numerous warnings, including:
	* const-correctness
	* shadowing global definitions
	* signed vs unsigned comparisons
	* missing prototypes, or missing static declarations
	* unused variables and functions
	* Unreadable array initializations
	* Missing struct initializers

usr/src/cmd/zdb/zdb.h
	Add a header file to declare common symbols

usr/src/lib/libzpool/common/sys/zfs_context.h
usr/src/uts/common/fs/zfs/arc.c
usr/src/uts/common/fs/zfs/dbuf.c
usr/src/uts/common/fs/zfs/spa.c
usr/src/uts/common/fs/zfs/txg.c
	Add a function prototype for zk_thread_create, and ensure that every
	callback supplied to this function actually matches the prototype.

usr/src/cmd/ztest/ztest.c
usr/src/uts/common/fs/zfs/sys/zil.h
usr/src/uts/common/fs/zfs/zfs_replay.c
usr/src/uts/common/fs/zfs/zvol.c
	Add a function prototype for zil_replay_func_t, and ensure that
	every function of this type actually matches the prototype.

usr/src/uts/common/fs/zfs/sys/refcount.h
	Change FTAG so it discards any constness of __func__, necessary
	since existing APIs expect it passed as void *.

Porting Notes:
- Many of these fixes have already been applied to Linux.  For
  consistency the OpenZFS version of a change was applied if the
  warning was addressed in an equivalent but different fashion.

Reviewed by: Matthew Ahrens <[email protected]>
Reviewed by: Prakash Surya <[email protected]>
Authored by: Alan Somers <[email protected]>
Approved by: Richard Lowe <[email protected]>
Ported-by: Brian Behlendorf <[email protected]>

OpenZFS-issue: https://www.illumos.org/issues/8081
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/843abe1b8a
Closes #6787 

3 files changed, 4 insertions, 4 deletions

diff --git a/include/sys/refcount.h b/include/sys/refcount.h
index a96220b29..02002ec2f 100644
--- a/include/sys/refcount.h
+++ b/include/sys/refcount.h
@@ -39,7 +39,7 @@ extern "C" {
  * particular object, use FTAG (which is a string) for the holder_tag.
  * Otherwise, use the object that holds the reference.
  */
-#define	FTAG ((char *)__func__)
+#define	FTAG ((char *)(uintptr_t)__func__)
 
 /*
  * Starting with 4.11, torvalds/linux@f405df5, the linux kernel defines a
diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index c292f0373..6a3a3b233 100644
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -352,7 +352,7 @@ extern void zfs_unmap_page(page_t *, caddr_t);
 #endif /* HAVE_UIO_RW */
 
 extern zil_get_data_t zfs_get_data;
-extern zil_replay_func_t zfs_replay_vector[TX_MAX_TYPE];
+extern zil_replay_func_t *zfs_replay_vector[TX_MAX_TYPE];
 extern int zfsfstype;
 
 #endif /* _KERNEL */
diff --git a/include/sys/zil.h b/include/sys/zil.h
index 291728a9d..11c7fb4a2 100644
--- a/include/sys/zil.h
+++ b/include/sys/zil.h
@@ -463,7 +463,7 @@ typedef int zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
     uint64_t txg);
 typedef int zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
     uint64_t txg);
-typedef int (*const zil_replay_func_t)(void *, char *, boolean_t);
+typedef int zil_replay_func_t(void *arg1, void *arg2, boolean_t byteswap);
 typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);
 
 extern int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
@@ -480,7 +480,7 @@ extern zilog_t	*zil_open(objset_t *os, zil_get_data_t *get_data);
 extern void	zil_close(zilog_t *zilog);
 
 extern void	zil_replay(objset_t *os, void *arg,
-    zil_replay_func_t replay_func[TX_MAX_TYPE]);
+    zil_replay_func_t *replay_func[TX_MAX_TYPE]);
 extern boolean_t zil_replaying(zilog_t *zilog, dmu_tx_t *tx);
 extern void	zil_destroy(zilog_t *zilog, boolean_t keep_first);
 extern void	zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx);