3742 zfs comments need cleaner, more consistent style

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>

usr/src/uts/common/fs/zfs/arc.c

@@ -58,11 +58,11 @@
  * tight.
  *
  * 3. The Megiddo and Modha model assumes a fixed page size. All
- * elements of the cache are therefor exactly the same size.  So
+ * elements of the cache are therefore exactly the same size.  So
  * when adjusting the cache size following a cache miss, its simply
  * a matter of choosing a single page to evict.  In our model, we
  * have variable sized cache blocks (rangeing from 512 bytes to
- * 128K bytes).  We therefor choose a set of blocks to evict to make
+ * 128K bytes).  We therefore choose a set of blocks to evict to make
  * space for a cache miss that approximates as closely as possible
  * the space used by the new block.
  *
@@ -77,7 +77,7 @@
  * ways: 1) via a hash table lookup using the DVA as a key,
  * or 2) via one of the ARC lists.  The arc_read() interface
  * uses method 1, while the internal arc algorithms for
- * adjusting the cache use method 2.  We therefor provide two
+ * adjusting the cache use method 2.  We therefore provide two
  * types of locks: 1) the hash table lock array, and 2) the
  * arc list locks.
  *
@@ -385,7 +385,7 @@ static arc_stats_t arc_stats = {
 #define	ARCSTAT(stat)	(arc_stats.stat.value.ui64)
 
 #define	ARCSTAT_INCR(stat, val) \
-	atomic_add_64(&arc_stats.stat.value.ui64, (val));
+	atomic_add_64(&arc_stats.stat.value.ui64, (val))
 
 #define	ARCSTAT_BUMP(stat)	ARCSTAT_INCR(stat, 1)
 #define	ARCSTAT_BUMPDOWN(stat)	ARCSTAT_INCR(stat, -1)
@@ -613,9 +613,7 @@ uint64_t zfs_crc64_table[256];
 #define	l2arc_writes_sent	ARCSTAT(arcstat_l2_writes_sent)
 #define	l2arc_writes_done	ARCSTAT(arcstat_l2_writes_done)
 
-/*
- * L2ARC Performance Tunables
- */
+/* L2ARC Performance Tunables */
 uint64_t l2arc_write_max = L2ARC_WRITE_SIZE;	/* default max write size */
 uint64_t l2arc_write_boost = L2ARC_WRITE_SIZE;	/* extra write during warmup */
 uint64_t l2arc_headroom = L2ARC_HEADROOM;	/* number of dev writes */
@@ -3628,7 +3626,7 @@ arc_tempreserve_space(uint64_t reserve, uint64_t txg)
 
 	/*
 	 * Writes will, almost always, require additional memory allocations
-	 * in order to compress/encrypt/etc the data.  We therefor need to
+	 * in order to compress/encrypt/etc the data.  We therefore need to
 	 * make sure that there is sufficient available memory for this.
 	 */
 	if (error = arc_memory_throttle(reserve, anon_size, txg))

usr/src/uts/common/fs/zfs/bptree.c

@@ -43,7 +43,7 @@
  * dsl_scan_sync. This allows the delete operation to finish without traversing
  * all the dataset's blocks.
  *
- * Note that while bt_begin and bt_end are only ever incremented in this code
+ * Note that while bt_begin and bt_end are only ever incremented in this code,
  * they are effectively reset to 0 every time the entire bptree is freed because
  * the bptree's object is destroyed and re-created.
  */

usr/src/uts/common/fs/zfs/dnode.c

@@ -1803,14 +1803,16 @@ dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx)
 }
 
 /*
- * This function scans a block at the indicated "level" looking for
- * a hole or data (depending on 'flags').  If level > 0, then we are
- * scanning an indirect block looking at its pointers.  If level == 0,
- * then we are looking at a block of dnodes.  If we don't find what we
- * are looking for in the block, we return ESRCH.  Otherwise, return
- * with *offset pointing to the beginning (if searching forwards) or
- * end (if searching backwards) of the range covered by the block
- * pointer we matched on (or dnode).
+ * Scans a block at the indicated "level" looking for a hole or data,
+ * depending on 'flags'.
+ *
+ * If level > 0, then we are scanning an indirect block looking at its
+ * pointers.  If level == 0, then we are looking at a block of dnodes.
+ *
+ * If we don't find what we are looking for in the block, we return ESRCH.
+ * Otherwise, return with *offset pointing to the beginning (if searching
+ * forwards) or end (if searching backwards) of the range covered by the
+ * block pointer we matched on (or dnode).
  *
  * The basic search algorithm used below by dnode_next_offset() is to
  * use this function to search up the block tree (widen the search) until

usr/src/uts/common/fs/zfs/dnode_sync.c

@@ -302,7 +302,7 @@ free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc,
 }
 
 /*
- * free_range: Traverse the indicated range of the provided file
+ * Traverse the indicated range of the provided file
  * and "free" all the blocks contained there.
  */
 static void
@@ -370,7 +370,7 @@ dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
 }
 
 /*
- * Try to kick all the dnodes dbufs out of the cache...
+ * Try to kick all the dnode's dbufs out of the cache...
  */
 void
 dnode_evict_dbufs(dnode_t *dn)

usr/src/uts/common/fs/zfs/dsl_prop.c

@@ -380,7 +380,7 @@ dsl_prop_predict(dsl_dir_t *dd, const char *propname,
 
 /*
  * Unregister this callback.  Return 0 on success, ENOENT if ddname is
- * invalid, ENOMSG if no matching callback registered.
+ * invalid, or ENOMSG if no matching callback registered.
  */
 int
 dsl_prop_unregister(dsl_dataset_t *ds, const char *propname,

usr/src/uts/common/fs/zfs/sa.c

@@ -111,6 +111,7 @@
  * location.
  *
  * Byteswap implications:
+ *
  * Since the SA attributes are not entirely self describing we can't do
  * the normal byteswap processing.  The special ZAP layout attribute and
  * attribute registration attributes define the byteswap function and the
@@ -189,7 +190,6 @@ sa_attr_reg_t sa_legacy_attrs[] = {
 };
 
 /*
- * ZPL legacy layout
  * This is only used for objects of type DMU_OT_ZNODE
  */
 sa_attr_type_t sa_legacy_zpl_layout[] = {
@@ -199,7 +199,6 @@ sa_attr_type_t sa_legacy_zpl_layout[] = {
 /*
  * Special dummy layout used for buffers with no attributes.
  */
-
 sa_attr_type_t sa_dummy_zpl_layout[] = { 0 };
 
 static int sa_legacy_attr_count = 16;

usr/src/uts/common/fs/zfs/spa.c

@@ -4516,6 +4516,7 @@ spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
 
 /*
  * Detach a device from a mirror or replacing vdev.
+ *
  * If 'replace_done' is specified, only detach if the parent
  * is a replacing vdev.
  */
@@ -5170,11 +5171,9 @@ spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
  * the spa_vdev_config_[enter/exit] functions which allow us to
  * grab and release the spa_config_lock while still holding the namespace
  * lock.  During each step the configuration is synced out.
- */
-
-/*
- * Remove a device from the pool.  Currently, this supports removing only hot
- * spares, slogs, and level 2 ARC devices.
+ *
+ * Currently, this supports removing only hot spares, slogs, and level 2 ARC
+ * devices.
  */
 int
 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
@@ -5284,7 +5283,7 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
 
 /*
  * Find any device that's done replacing, or a vdev marked 'unspare' that's
- * current spared, so we can detach it.
+ * currently spared, so we can detach it.
  */
 static vdev_t *
 spa_vdev_resilver_done_hunt(vdev_t *vd)

usr/src/uts/common/fs/zfs/spa_config.c

@@ -317,6 +317,7 @@ spa_config_set(spa_t *spa, nvlist_t *config)
 
 /*
  * Generate the pool's configuration based on the current in-core state.
+ *
  * We infer whether to generate a complete config or just one top-level config
  * based on whether vd is the root vdev.
  */

usr/src/uts/common/fs/zfs/spa_misc.c

@@ -1334,7 +1334,7 @@ zfs_panic_recover(const char *fmt, ...)
 
 /*
  * This is a stripped-down version of strtoull, suitable only for converting
- * lowercase hexidecimal numbers that don't overflow.
+ * lowercase hexadecimal numbers that don't overflow.
  */
 uint64_t
 strtonum(const char *str, char **nptr)

usr/src/uts/common/fs/zfs/sys/ddt.h

@@ -63,16 +63,15 @@ enum ddt_class {
  */
 typedef struct ddt_key {
 	zio_cksum_t	ddk_cksum;	/* 256-bit block checksum */
-	uint64_t	ddk_prop;	/* LSIZE, PSIZE, compression */
+	/*
+	 * Encoded with logical & physical size, and compression, as follows:
+	 *   +-------+-------+-------+-------+-------+-------+-------+-------+
+	 *   |   0   |   0   |   0   | comp  |     PSIZE     |     LSIZE     |
+	 *   +-------+-------+-------+-------+-------+-------+-------+-------+
+	 */
+	uint64_t	ddk_prop;
 } ddt_key_t;
 
-/*
- * ddk_prop layout:
- *
- *	+-------+-------+-------+-------+-------+-------+-------+-------+
- *	|   0	|   0	|   0	| comp	|     PSIZE	|     LSIZE	|
- *	+-------+-------+-------+-------+-------+-------+-------+-------+
- */
 #define	DDK_GET_LSIZE(ddk)	\
 	BF64_GET_SB((ddk)->ddk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1)
 #define	DDK_SET_LSIZE(ddk, x)	\

usr/src/uts/common/fs/zfs/sys/dnode.h

@@ -145,9 +145,8 @@ typedef struct dnode_phys {
 
 typedef struct dnode {
 	/*
-	 * dn_struct_rwlock protects the structure of the dnode,
-	 * including the number of levels of indirection (dn_nlevels),
-	 * dn_maxblkid, and dn_next_*
+	 * Protects the structure of the dnode, including the number of levels
+	 * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
 	 */
 	krwlock_t dn_struct_rwlock;
 

usr/src/uts/common/fs/zfs/sys/dsl_pool.h

@@ -110,6 +110,7 @@ typedef struct dsl_pool {
 
 	/*
 	 * Protects administrative changes (properties, namespace)
+	 *
 	 * It is only held for write in syncing context.  Therefore
 	 * syncing context does not need to ever have it for read, since
 	 * nobody else could possibly have it for write.

usr/src/uts/common/fs/zfs/sys/sa_impl.h

@@ -150,6 +150,7 @@ struct sa_os {
 
 /*
  * header for all bonus and spill buffers.
+ *
  * The header has a fixed portion with a variable number
  * of "lengths" depending on the number of variable sized
  * attribues which are determined by the "layout number"
@@ -158,29 +159,27 @@ struct sa_os {
 #define	SA_MAGIC	0x2F505A  /* ZFS SA */
 typedef struct sa_hdr_phys {
 	uint32_t sa_magic;
-	uint16_t sa_layout_info;  /* Encoded with hdrsize and layout number */
+	/*
+	 * Encoded with hdrsize and layout number as follows:
+	 * 16      10       0
+	 * +--------+-------+
+	 * | hdrsz  |layout |
+	 * +--------+-------+
+	 *
+	 * Bits 0-10 are the layout number
+	 * Bits 11-16 are the size of the header.
+	 * The hdrsize is the number * 8
+	 *
+	 * For example.
+	 * hdrsz of 1 ==> 8 byte header
+	 *          2 ==> 16 byte header
+	 *
+	 */
+	uint16_t sa_layout_info;
 	uint16_t sa_lengths[1];	/* optional sizes for variable length attrs */
 	/* ... Data follows the lengths.  */
 } sa_hdr_phys_t;
 
-/*
- * sa_hdr_phys -> sa_layout_info
- *
- * 16      10       0
- * +--------+-------+
- * | hdrsz  |layout |
- * +--------+-------+
- *
- * Bits 0-10 are the layout number
- * Bits 11-16 are the size of the header.
- * The hdrsize is the number * 8
- *
- * For example.
- * hdrsz of 1 ==> 8 byte header
- *          2 ==> 16 byte header
- *
- */
-
 #define	SA_HDR_LAYOUT_NUM(hdr) BF32_GET(hdr->sa_layout_info, 0, 10)
 #define	SA_HDR_SIZE(hdr) BF32_GET_SB(hdr->sa_layout_info, 10, 6, 3, 0)
 #define	SA_HDR_LAYOUT_INFO_ENCODE(x, num, size) \

usr/src/uts/common/fs/zfs/sys/spa_impl.h

@@ -239,7 +239,7 @@ struct spa {
 	kmutex_t	spa_iokstat_lock;	/* protects spa_iokstat_* */
 	struct kstat	*spa_iokstat;		/* kstat of io to this pool */
 	/*
-	 * spa_refcnt & spa_config_lock must be the last elements
+	 * spa_refcount & spa_config_lock must be the last elements
 	 * because 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.

usr/src/uts/common/fs/zfs/sys/space_map.h

@@ -94,7 +94,6 @@ struct space_map_ops {
  *   63  62    60 59        50 49                               0
  *
  *
- *
  * non-debug entry
  *
  *    1               47                   1           15

usr/src/uts/common/fs/zfs/sys/unique.h

@@ -26,8 +26,6 @@
 #ifndef	_SYS_UNIQUE_H
 #define	_SYS_UNIQUE_H
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/zfs_context.h>
 
 #ifdef	__cplusplus
@@ -42,7 +40,7 @@ void unique_fini(void);
 
 /*
  * Return a new unique value (which will not be uniquified against until
- * it is unique_insert()-ed.
+ * it is unique_insert()-ed).
  */
 uint64_t unique_create(void);
 

usr/src/uts/common/fs/zfs/sys/vdev_impl.h

@@ -245,12 +245,13 @@ typedef struct vdev_label {
 #define	VDD_METASLAB	0x01
 #define	VDD_DTL		0x02
 
+/* Offset of embedded boot loader region on each label */
+#define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
 /*
- * Size and offset of embedded boot loader region on each label.
+ * Size of embedded boot loader region on each label.
  * The total size of the first two labels plus the boot area is 4MB.
  */
-#define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
-#define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
+#define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M */
 
 /*
  * Size of label regions at the start and end of each leaf device.
@@ -317,8 +318,9 @@ extern uint64_t vdev_get_min_asize(vdev_t *vd);
 extern void vdev_set_min_asize(vdev_t *vd);
 
 /*
- * zdb uses this tunable, so it must be declared here to make lint happy.
+ * Global variables
  */
+/* zdb uses this tunable, so it must be declared here to make lint happy. */
 extern int zfs_vdev_cache_size;
 
 /*