Linux 4.19-rc3+ compat: Remove refcount_t compat

torvalds/linux@59b57717f ("blkcg: delay blkg destruction until
after writeback has finished") added a refcount_t to the blkcg
structure. Due to the refcount_t compatibility code, zfs_refcount_t
was used by mistake.

Resolve this by removing the compatibility code and replacing the
occurrences of refcount_t with zfs_refcount_t.

Reviewed-by: Franz Pletz <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tim Schumacher <[email protected]>
Closes #7885 
Closes #7932 

16 files changed, 48 insertions, 59 deletions

diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
index 90b3cca78..c01f58508 100644
--- a/include/linux/vfs_compat.h
+++ b/include/linux/vfs_compat.h
@@ -297,9 +297,6 @@ lseek_execute(
  * This is several orders of magnitude larger than expected grace period.
  * At 60 seconds the kernel will also begin issuing RCU stall warnings.
  */
-#ifdef refcount_t
-#undef refcount_t
-#endif
 
 #include <linux/posix_acl.h>
 
@@ -430,8 +427,6 @@ typedef mode_t zpl_equivmode_t;
 #define	zpl_posix_acl_valid(ip, acl)  posix_acl_valid(acl)
 #endif
 
-#define	refcount_t	zfs_refcount_t
-
 #endif /* CONFIG_FS_POSIX_ACL */
 
 /*
diff --git a/include/sys/abd.h b/include/sys/abd.h
index 077bb9d17..3d9fdbf10 100644
--- a/include/sys/abd.h
+++ b/include/sys/abd.h
@@ -51,7 +51,7 @@ typedef struct abd {
 	abd_flags_t	abd_flags;
 	uint_t		abd_size;	/* excludes scattered abd_offset */
 	struct abd	*abd_parent;
-	refcount_t	abd_children;
+	zfs_refcount_t	abd_children;
 	union {
 		struct abd_scatter {
 			uint_t		abd_offset;
diff --git a/include/sys/arc.h b/include/sys/arc.h
index a5bdefb56..dc2fd0364 100644
--- a/include/sys/arc.h
+++ b/include/sys/arc.h
@@ -87,7 +87,7 @@ struct arc_prune {
 	void			*p_private;
 	uint64_t		p_adjust;
 	list_node_t		p_node;
-	refcount_t		p_refcnt;
+	zfs_refcount_t		p_refcnt;
 };
 
 typedef enum arc_strategy {
diff --git a/include/sys/arc_impl.h b/include/sys/arc_impl.h
index 52863bba4..cd42c0c01 100644
--- a/include/sys/arc_impl.h
+++ b/include/sys/arc_impl.h
@@ -75,12 +75,12 @@ typedef struct arc_state {
 	/*
 	 * total amount of evictable data in this state
 	 */
-	refcount_t arcs_esize[ARC_BUFC_NUMTYPES];
+	zfs_refcount_t arcs_esize[ARC_BUFC_NUMTYPES];
 	/*
 	 * total amount of data in this state; this includes: evictable,
 	 * non-evictable, ARC_BUFC_DATA, and ARC_BUFC_METADATA.
 	 */
-	refcount_t arcs_size;
+	zfs_refcount_t arcs_size;
 	/*
 	 * supports the "dbufs" kstat
 	 */
@@ -168,7 +168,7 @@ typedef struct l1arc_buf_hdr {
 	uint32_t		b_l2_hits;
 
 	/* self protecting */
-	refcount_t		b_refcnt;
+	zfs_refcount_t		b_refcnt;
 
 	arc_callback_t		*b_acb;
 	abd_t			*b_pabd;
@@ -215,7 +215,7 @@ typedef struct l2arc_dev {
 	kmutex_t		l2ad_mtx;	/* lock for buffer list */
 	list_t			l2ad_buflist;	/* buffer list */
 	list_node_t		l2ad_node;	/* device list node */
-	refcount_t		l2ad_alloc;	/* allocated bytes */
+	zfs_refcount_t		l2ad_alloc;	/* allocated bytes */
 } l2arc_dev_t;
 
 typedef struct l2arc_buf_hdr {
diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h
index ab0950c83..eea9e265b 100644
--- a/include/sys/dbuf.h
+++ b/include/sys/dbuf.h
@@ -230,7 +230,7 @@ typedef struct dmu_buf_impl {
 	 * If nonzero, the buffer can't be destroyed.
 	 * Protected by db_mtx.
 	 */
-	refcount_t db_holds;
+	zfs_refcount_t db_holds;
 
 	/* buffer holding our data */
 	arc_buf_t *db_buf;
diff --git a/include/sys/dmu_tx.h b/include/sys/dmu_tx.h
index 6a4bd3fac..36d205e95 100644
--- a/include/sys/dmu_tx.h
+++ b/include/sys/dmu_tx.h
@@ -97,8 +97,8 @@ typedef struct dmu_tx_hold {
 	dmu_tx_t *txh_tx;
 	list_node_t txh_node;
 	struct dnode *txh_dnode;
-	refcount_t txh_space_towrite;
-	refcount_t txh_memory_tohold;
+	zfs_refcount_t txh_space_towrite;
+	zfs_refcount_t txh_memory_tohold;
 	enum dmu_tx_hold_type txh_type;
 	uint64_t txh_arg1;
 	uint64_t txh_arg2;
diff --git a/include/sys/dnode.h b/include/sys/dnode.h
index 0774e663f..48ef927d4 100644
--- a/include/sys/dnode.h
+++ b/include/sys/dnode.h
@@ -335,8 +335,8 @@ struct dnode {
 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
 
 	/* protected by own devices */
-	refcount_t dn_tx_holds;
-	refcount_t dn_holds;
+	zfs_refcount_t dn_tx_holds;
+	zfs_refcount_t dn_holds;
 
 	kmutex_t dn_dbufs_mtx;
 	/*
diff --git a/include/sys/dsl_crypt.h b/include/sys/dsl_crypt.h
index 8766ce51e..c6d2b0a16 100644
--- a/include/sys/dsl_crypt.h
+++ b/include/sys/dsl_crypt.h
@@ -62,7 +62,7 @@ typedef struct dsl_wrapping_key {
 	crypto_key_t wk_key;
 
 	/* refcount of number of dsl_crypto_key_t's holding this struct */
-	refcount_t wk_refcnt;
+	zfs_refcount_t wk_refcnt;
 
 	/* dsl directory object that owns this wrapping key */
 	uint64_t wk_ddobj;
@@ -112,7 +112,7 @@ typedef struct dsl_crypto_key {
 	avl_node_t dck_avl_link;
 
 	/* refcount of dsl_key_mapping_t's holding this key */
-	refcount_t dck_holds;
+	zfs_refcount_t dck_holds;
 
 	/* master key used to derive encryption keys */
 	zio_crypt_key_t dck_key;
@@ -134,7 +134,7 @@ typedef struct dsl_key_mapping {
 	avl_node_t km_avl_link;
 
 	/* refcount of how many users are depending on this mapping */
-	refcount_t km_refcnt;
+	zfs_refcount_t km_refcnt;
 
 	/* dataset this crypto key belongs to (index) */
 	uint64_t km_dsobj;
diff --git a/include/sys/dsl_dataset.h b/include/sys/dsl_dataset.h
index dbe4cb706..768241483 100644
--- a/include/sys/dsl_dataset.h
+++ b/include/sys/dsl_dataset.h
@@ -211,7 +211,7 @@ typedef struct dsl_dataset {
 	 * Owning counts as a long hold.  See the comments above
 	 * dsl_pool_hold() for details.
 	 */
-	refcount_t ds_longholds;
+	zfs_refcount_t ds_longholds;
 
 	/* no locking; only for making guesses */
 	uint64_t ds_trysnap_txg;
diff --git a/include/sys/metaslab_impl.h b/include/sys/metaslab_impl.h
index cc6e8b796..aa1c82a02 100644
--- a/include/sys/metaslab_impl.h
+++ b/include/sys/metaslab_impl.h
@@ -184,7 +184,7 @@ struct metaslab_class {
 	 * number of allocations allowed.
 	 */
 	uint64_t		*mc_alloc_max_slots;
-	refcount_t		*mc_alloc_slots;
+	zfs_refcount_t		*mc_alloc_slots;
 
 	uint64_t		mc_alloc_groups; /* # of allocatable groups */
 
@@ -256,7 +256,7 @@ struct metaslab_group {
 	 */
 	uint64_t		mg_max_alloc_queue_depth;
 	uint64_t		*mg_cur_max_alloc_queue_depth;
-	refcount_t		*mg_alloc_queue_depth;
+	zfs_refcount_t		*mg_alloc_queue_depth;
 	int			mg_allocators;
 	/*
 	 * A metalab group that can no longer allocate the minimum block
diff --git a/include/sys/refcount.h b/include/sys/refcount.h
index 02002ec2f..e20ffbc30 100644
--- a/include/sys/refcount.h
+++ b/include/sys/refcount.h
@@ -41,17 +41,6 @@ extern "C" {
  */
 #define	FTAG ((char *)(uintptr_t)__func__)
 
-/*
- * Starting with 4.11, torvalds/linux@f405df5, the linux kernel defines a
- * refcount_t type of its own.  The macro below effectively changes references
- * in the ZFS code from refcount_t to zfs_refcount_t at compile time, so that
- * existing code need not be altered, reducing conflicts when landing openZFS
- * patches.
- */
-
-#define	refcount_t	zfs_refcount_t
-#define	refcount_add	zfs_refcount_add
-
 #ifdef	ZFS_DEBUG
 typedef struct reference {
 	list_node_t ref_link;
@@ -69,23 +58,28 @@ typedef struct refcount {
 	uint64_t rc_removed_count;
 } zfs_refcount_t;
 
-/* Note: refcount_t must be initialized with refcount_create[_untracked]() */
-
-void refcount_create(refcount_t *rc);
-void refcount_create_untracked(refcount_t *rc);
-void refcount_create_tracked(refcount_t *rc);
-void refcount_destroy(refcount_t *rc);
-void refcount_destroy_many(refcount_t *rc, uint64_t number);
-int refcount_is_zero(refcount_t *rc);
-int64_t refcount_count(refcount_t *rc);
-int64_t zfs_refcount_add(refcount_t *rc, void *holder_tag);
-int64_t refcount_remove(refcount_t *rc, void *holder_tag);
-int64_t refcount_add_many(refcount_t *rc, uint64_t number, void *holder_tag);
-int64_t refcount_remove_many(refcount_t *rc, uint64_t number, void *holder_tag);
-void refcount_transfer(refcount_t *dst, refcount_t *src);
-void refcount_transfer_ownership(refcount_t *, void *, void *);
-boolean_t refcount_held(refcount_t *, void *);
-boolean_t refcount_not_held(refcount_t *, void *);
+/*
+ * Note: zfs_refcount_t must be initialized with
+ * refcount_create[_untracked]()
+ */
+
+void refcount_create(zfs_refcount_t *rc);
+void refcount_create_untracked(zfs_refcount_t *rc);
+void refcount_create_tracked(zfs_refcount_t *rc);
+void refcount_destroy(zfs_refcount_t *rc);
+void refcount_destroy_many(zfs_refcount_t *rc, uint64_t number);
+int refcount_is_zero(zfs_refcount_t *rc);
+int64_t refcount_count(zfs_refcount_t *rc);
+int64_t zfs_refcount_add(zfs_refcount_t *rc, void *holder_tag);
+int64_t refcount_remove(zfs_refcount_t *rc, void *holder_tag);
+int64_t refcount_add_many(zfs_refcount_t *rc, uint64_t number,
+    void *holder_tag);
+int64_t refcount_remove_many(zfs_refcount_t *rc, uint64_t number,
+    void *holder_tag);
+void refcount_transfer(zfs_refcount_t *dst, zfs_refcount_t *src);
+void refcount_transfer_ownership(zfs_refcount_t *, void *, void *);
+boolean_t refcount_held(zfs_refcount_t *, void *);
+boolean_t refcount_not_held(zfs_refcount_t *, void *);
 
 void refcount_init(void);
 void refcount_fini(void);
@@ -94,7 +88,7 @@ void refcount_fini(void);
 
 typedef struct refcount {
 	uint64_t rc_count;
-} refcount_t;
+} zfs_refcount_t;
 
 #define	refcount_create(rc) ((rc)->rc_count = 0)
 #define	refcount_create_untracked(rc) ((rc)->rc_count = 0)
diff --git a/include/sys/rrwlock.h b/include/sys/rrwlock.h
index 7a328fd68..e1c1756cf 100644
--- a/include/sys/rrwlock.h
+++ b/include/sys/rrwlock.h
@@ -57,8 +57,8 @@ typedef struct rrwlock {
 	kmutex_t	rr_lock;
 	kcondvar_t	rr_cv;
 	kthread_t	*rr_writer;
-	refcount_t	rr_anon_rcount;
-	refcount_t	rr_linked_rcount;
+	zfs_refcount_t	rr_anon_rcount;
+	zfs_refcount_t	rr_linked_rcount;
 	boolean_t	rr_writer_wanted;
 	boolean_t	rr_track_all;
 } rrwlock_t;
diff --git a/include/sys/sa_impl.h b/include/sys/sa_impl.h
index b68b7610b..7eddd8750 100644
--- a/include/sys/sa_impl.h
+++ b/include/sys/sa_impl.h
@@ -110,7 +110,7 @@ typedef struct sa_idx_tab {
 	list_node_t	sa_next;
 	sa_lot_t	*sa_layout;
 	uint16_t	*sa_variable_lengths;
-	refcount_t	sa_refcount;
+	zfs_refcount_t	sa_refcount;
 	uint32_t	*sa_idx_tab;	/* array of offsets */
 } sa_idx_tab_t;
 
diff --git a/include/sys/spa_impl.h b/include/sys/spa_impl.h
index 676e8b8a2..9dbdcfcf5 100644
--- a/include/sys/spa_impl.h
+++ b/include/sys/spa_impl.h
@@ -139,7 +139,7 @@ typedef struct spa_config_lock {
 	kthread_t	*scl_writer;
 	int		scl_write_wanted;
 	kcondvar_t	scl_cv;
-	refcount_t	scl_count;
+	zfs_refcount_t	scl_count;
 } spa_config_lock_t;
 
 typedef struct spa_config_dirent {
@@ -387,12 +387,12 @@ struct spa {
 
 	/*
 	 * spa_refcount & spa_config_lock must be the last elements
-	 * because refcount_t changes size based on compilation options.
+	 * because zfs_refcount_t changes size based on compilation options.
 	 * In order for the MDB module to function correctly, the other
 	 * fields must remain in the same location.
 	 */
 	spa_config_lock_t spa_config_lock[SCL_LOCKS]; /* config changes */
-	refcount_t	spa_refcount;		/* number of opens */
+	zfs_refcount_t	spa_refcount;		/* number of opens */
 
 	taskq_t		*spa_upgrade_taskq;	/* taskq for upgrade jobs */
 };
diff --git a/include/sys/zap.h b/include/sys/zap.h
index 43b7fbd26..7acc3becb 100644
--- a/include/sys/zap.h
+++ b/include/sys/zap.h
@@ -226,7 +226,7 @@ int zap_lookup_norm_by_dnode(dnode_t *dn, const char *name,
     boolean_t *ncp);
 
 int zap_count_write_by_dnode(dnode_t *dn, const char *name,
-    int add, refcount_t *towrite, refcount_t *tooverwrite);
+    int add, zfs_refcount_t *towrite, zfs_refcount_t *tooverwrite);
 
 /*
  * Create an attribute with the given name and value.
diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index e82ac9941..01f4328f0 100644
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -223,7 +223,7 @@ typedef struct znode_hold {
 	uint64_t	zh_obj;		/* object id */
 	kmutex_t	zh_lock;	/* lock serializing object access */
 	avl_node_t	zh_node;	/* avl tree linkage */
-	refcount_t	zh_refcount;	/* active consumer reference count */
+	zfs_refcount_t	zh_refcount;	/* active consumer reference count */
 } znode_hold_t;
 
 static inline uint64_t