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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef CEPH_CRUSH_CRUSH_H
 #define CEPH_CRUSH_CRUSH_H
 
 #ifdef __KERNEL__
 # include <linux/rbtree.h>
 # include <linux/types.h>
 #else
 # include "crush_compat.h"
 #endif
 
 /*
  * CRUSH is a pseudo-random data distribution algorithm that
  * efficiently distributes input values (typically, data objects)
  * across a heterogeneous, structured storage cluster.
  *
  * The algorithm was originally described in detail in this paper
  * (although the algorithm has evolved somewhat since then):
  *
  *     https://www.ssrc.ucsc.edu/Papers/weil-sc06.pdf
  *
  * LGPL2
  */
 
 
 #define CRUSH_MAGIC 0x00010000ul   /* for detecting algorithm revisions */
 
 #define CRUSH_MAX_DEPTH 10  /* max crush hierarchy depth */
 #define CRUSH_MAX_RULESET (1<<8)  /* max crush ruleset number */
 #define CRUSH_MAX_RULES CRUSH_MAX_RULESET  /* should be the same as max rulesets */
 
 #define CRUSH_MAX_DEVICE_WEIGHT (100u * 0x10000u)
 #define CRUSH_MAX_BUCKET_WEIGHT (65535u * 0x10000u)
 
 #define CRUSH_ITEM_UNDEF  0x7ffffffe  /* undefined result (internal use only) */
 #define CRUSH_ITEM_NONE   0x7fffffff  /* no result */
 
 /*
  * CRUSH uses user-defined "rules" to describe how inputs should be
  * mapped to devices.  A rule consists of sequence of steps to perform
  * to generate the set of output devices.
  */
 struct crush_rule_step {
     __u32 op;
     __s32 arg1;
     __s32 arg2;
 };
 
 /* step op codes */
 enum {
     CRUSH_RULE_NOOP = 0,
     CRUSH_RULE_TAKE = 1,          /* arg1 = value to start with */
     CRUSH_RULE_CHOOSE_FIRSTN = 2, /* arg1 = num items to pick */
                       /* arg2 = type */
     CRUSH_RULE_CHOOSE_INDEP = 3,  /* same */
     CRUSH_RULE_EMIT = 4,          /* no args */
     CRUSH_RULE_CHOOSELEAF_FIRSTN = 6,
     CRUSH_RULE_CHOOSELEAF_INDEP = 7,
 
     CRUSH_RULE_SET_CHOOSE_TRIES = 8, /* override choose_total_tries */
     CRUSH_RULE_SET_CHOOSELEAF_TRIES = 9, /* override chooseleaf_descend_once */
     CRUSH_RULE_SET_CHOOSE_LOCAL_TRIES = 10,
     CRUSH_RULE_SET_CHOOSE_LOCAL_FALLBACK_TRIES = 11,
     CRUSH_RULE_SET_CHOOSELEAF_VARY_R = 12,
     CRUSH_RULE_SET_CHOOSELEAF_STABLE = 13
 };
 
 /*
  * for specifying choose num (arg1) relative to the max parameter
  * passed to do_rule
  */
 #define CRUSH_CHOOSE_N            0
 #define CRUSH_CHOOSE_N_MINUS(x)   (-(x))
 
 /*
  * The rule mask is used to describe what the rule is intended for.
  * Given a ruleset and size of output set, we search through the
  * rule list for a matching rule_mask.
  */
 struct crush_rule_mask {
     __u8 ruleset;
     __u8 type;
     __u8 min_size;
     __u8 max_size;
 };
 
 struct crush_rule {
     __u32 len;
     struct crush_rule_mask mask;
     struct crush_rule_step steps[];
 };
 
 #define crush_rule_size(len) (sizeof(struct crush_rule) + \
                   (len)*sizeof(struct crush_rule_step))
 
 
 
 /*
  * A bucket is a named container of other items (either devices or
  * other buckets).  Items within a bucket are chosen using one of a
  * few different algorithms.  The table summarizes how the speed of
  * each option measures up against mapping stability when items are
  * added or removed.
  *
  *  Bucket Alg     Speed       Additions    Removals
  *  ------------------------------------------------
  *  uniform         O(1)       poor         poor
  *  list            O(n)       optimal      poor
  *  tree            O(log n)   good         good
  *  straw           O(n)       better       better
  *  straw2          O(n)       optimal      optimal
  */
 enum {
     CRUSH_BUCKET_UNIFORM = 1,
     CRUSH_BUCKET_LIST = 2,
     CRUSH_BUCKET_TREE = 3,
     CRUSH_BUCKET_STRAW = 4,
     CRUSH_BUCKET_STRAW2 = 5,
 };
 extern const char *crush_bucket_alg_name(int alg);
 
 /*
  * although tree was a legacy algorithm, it has been buggy, so
  * exclude it.
  */
 #define CRUSH_LEGACY_ALLOWED_BUCKET_ALGS (  \
         (1 << CRUSH_BUCKET_UNIFORM) |   \
         (1 << CRUSH_BUCKET_LIST) |  \
         (1 << CRUSH_BUCKET_STRAW))
 
 struct crush_bucket {
     __s32 id;        /* this'll be negative */
     __u16 type;      /* non-zero; type=0 is reserved for devices */
     __u8 alg;        /* one of CRUSH_BUCKET_* */
     __u8 hash;       /* which hash function to use, CRUSH_HASH_* */
     __u32 weight;    /* 16-bit fixed point */
     __u32 size;      /* num items */
     __s32 *items;
 
 };
 
 /** @ingroup API
  *
  * Replacement weights for each item in a bucket. The size of the
  * array must be exactly the size of the straw2 bucket, just as the
  * item_weights array.
  *
  */
 struct crush_weight_set {
     __u32 *weights; /*!< 16.16 fixed point weights
                              in the same order as items */
     __u32 size;     /*!< size of the __weights__ array */
 };
 
 /** @ingroup API
  *
  * Replacement weights and ids for a given straw2 bucket, for
  * placement purposes.
  *
  * When crush_do_rule() chooses the Nth item from a straw2 bucket, the
  * replacement weights found at __weight_set[N]__ are used instead of
  * the weights from __item_weights__. If __N__ is greater than
  * __weight_set_size__, the weights found at __weight_set_size-1__ are
  * used instead. For instance if __weight_set__ is:
  *
  *    [ [ 0x10000, 0x20000 ],   // position 0
  *      [ 0x20000, 0x40000 ] ]  // position 1
  *
  * choosing the 0th item will use position 0 weights [ 0x10000, 0x20000 ]
  * choosing the 1th item will use position 1 weights [ 0x20000, 0x40000 ]
  * choosing the 2th item will use position 1 weights [ 0x20000, 0x40000 ]
  * etc.
  *
  */
 struct crush_choose_arg {
     __s32 *ids;            /*!< values to use instead of items */
     __u32 ids_size;        /*!< size of the __ids__ array */
     struct crush_weight_set *weight_set; /*!< weight replacements for
                                                   a given position */
     __u32 weight_set_size; /*!< size of the __weight_set__ array */
 };
 
 /** @ingroup API
  *
  * Replacement weights and ids for each bucket in the crushmap. The
  * __size__ of the __args__ array must be exactly the same as the
  * __map->max_buckets__.
  *
  * The __crush_choose_arg__ at index N will be used when choosing
  * an item from the bucket __map->buckets[N]__ bucket, provided it
  * is a straw2 bucket.
  *
  */
 struct crush_choose_arg_map {
 #ifdef __KERNEL__
     struct rb_node node;
     s64 choose_args_index;
 #endif
     struct crush_choose_arg *args; /*!< replacement for each bucket
                                             in the crushmap */
     __u32 size;                    /*!< size of the __args__ array */
 };
 
 struct crush_bucket_uniform {
     struct crush_bucket h;
     __u32 item_weight;  /* 16-bit fixed point; all items equally weighted */
 };
 
 struct crush_bucket_list {
     struct crush_bucket h;
     __u32 *item_weights;  /* 16-bit fixed point */
     __u32 *sum_weights;   /* 16-bit fixed point.  element i is sum
                  of weights 0..i, inclusive */
 };
 
 struct crush_bucket_tree {
     struct crush_bucket h;  /* note: h.size is _tree_ size, not number of
                    actual items */
     __u8 num_nodes;
     __u32 *node_weights;
 };
 
 struct crush_bucket_straw {
     struct crush_bucket h;
     __u32 *item_weights;   /* 16-bit fixed point */
     __u32 *straws;         /* 16-bit fixed point */
 };
 
 struct crush_bucket_straw2 {
     struct crush_bucket h;
     __u32 *item_weights;   /* 16-bit fixed point */
 };
 
 
 
 /*
  * CRUSH map includes all buckets, rules, etc.
  */
 struct crush_map {
     struct crush_bucket **buckets;
     struct crush_rule **rules;
 
     __s32 max_buckets;
     __u32 max_rules;
     __s32 max_devices;
 
     /* choose local retries before re-descent */
     __u32 choose_local_tries;
     /* choose local attempts using a fallback permutation before
      * re-descent */
     __u32 choose_local_fallback_tries;
     /* choose attempts before giving up */
     __u32 choose_total_tries;
     /* attempt chooseleaf inner descent once for firstn mode; on
      * reject retry outer descent.  Note that this does *not*
      * apply to a collision: in that case we will retry as we used
      * to. */
     __u32 chooseleaf_descend_once;
 
     /* if non-zero, feed r into chooseleaf, bit-shifted right by (r-1)
      * bits.  a value of 1 is best for new clusters.  for legacy clusters
      * that want to limit reshuffling, a value of 3 or 4 will make the
      * mappings line up a bit better with previous mappings. */
     __u8 chooseleaf_vary_r;
 
     /* if true, it makes chooseleaf firstn to return stable results (if
      * no local retry) so that data migrations would be optimal when some
      * device fails. */
     __u8 chooseleaf_stable;
 
     /*
      * This value is calculated after decode or construction by
      * the builder. It is exposed here (rather than having a
      * 'build CRUSH working space' function) so that callers can
      * reserve a static buffer, allocate space on the stack, or
      * otherwise avoid calling into the heap allocator if they
      * want to. The size of the working space depends on the map,
      * while the size of the scratch vector passed to the mapper
      * depends on the size of the desired result set.
      *
      * Nothing stops the caller from allocating both in one swell
      * foop and passing in two points, though.
      */
     size_t working_size;
 
 #ifndef __KERNEL__
     /*
      * version 0 (original) of straw_calc has various flaws.  version 1
      * fixes a few of them.
      */
     __u8 straw_calc_version;
 
     /*
      * allowed bucket algs is a bitmask, here the bit positions
      * are CRUSH_BUCKET_*.  note that these are *bits* and
      * CRUSH_BUCKET_* values are not, so we need to or together (1
      * << CRUSH_BUCKET_WHATEVER).  The 0th bit is not used to
      * minimize confusion (bucket type values start at 1).
      */
     __u32 allowed_bucket_algs;
 
     __u32 *choose_tries;
 #else
     /* device/bucket type id -> type name (CrushWrapper::type_map) */
     struct rb_root type_names;
 
     /* device/bucket id -> name (CrushWrapper::name_map) */
     struct rb_root names;
 
     /* CrushWrapper::choose_args */
     struct rb_root choose_args;
 #endif
 };
 
 
 /* crush.c */
 extern int crush_get_bucket_item_weight(const struct crush_bucket *b, int pos);
 extern void crush_destroy_bucket_uniform(struct crush_bucket_uniform *b);
 extern void crush_destroy_bucket_list(struct crush_bucket_list *b);
 extern void crush_destroy_bucket_tree(struct crush_bucket_tree *b);
 extern void crush_destroy_bucket_straw(struct crush_bucket_straw *b);
 extern void crush_destroy_bucket_straw2(struct crush_bucket_straw2 *b);
 extern void crush_destroy_bucket(struct crush_bucket *b);
 extern void crush_destroy_rule(struct crush_rule *r);
 extern void crush_destroy(struct crush_map *map);
 
 static inline int crush_calc_tree_node(int i)
 {
     return ((i+1) << 1)-1;
 }
 
 /*
  * These data structures are private to the CRUSH implementation. They
  * are exposed in this header file because builder needs their
  * definitions to calculate the total working size.
  *
  * Moving this out of the crush map allow us to treat the CRUSH map as
  * immutable within the mapper and removes the requirement for a CRUSH
  * map lock.
  */
 struct crush_work_bucket {
     __u32 perm_x; /* @x for which *perm is defined */
     __u32 perm_n; /* num elements of *perm that are permuted/defined */
     __u32 *perm;  /* Permutation of the bucket's items */
 };
 
 struct crush_work {
     struct crush_work_bucket **work; /* Per-bucket working store */
 #ifdef __KERNEL__
     struct list_head item;
 #endif
 };
 
 #ifdef __KERNEL__
 /* osdmap.c */
 void clear_crush_names(struct rb_root *root);
 void clear_choose_args(struct crush_map *c);
 #endif
 
 #endif

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