Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

[mirror_ubuntu-bionic-kernel.git] / net / ceph / osdmap.c

#include <linux/ceph/ceph_debug.h>

#include <linux/module.h>
#include <linux/slab.h>
#include <asm/div64.h>

#include <linux/ceph/libceph.h>
#include <linux/ceph/osdmap.h>
#include <linux/ceph/decode.h>
#include <linux/crush/hash.h>
#include <linux/crush/mapper.h>

char *ceph_osdmap_state_str(char *str, int len, int state)
{
        int flag = 0;

        if (!len)
                goto done;

        *str = '\0';
        if (state) {
                if (state & CEPH_OSD_EXISTS) {
                        snprintf(str, len, "exists");
                        flag = 1;
                }
                if (state & CEPH_OSD_UP) {
                        snprintf(str, len, "%s%s%s", str, (flag ? ", " : ""),
                                 "up");
                        flag = 1;
                }
        } else {
                snprintf(str, len, "doesn't exist");
        }
done:
        return str;
}

/* maps */

static int calc_bits_of(unsigned int t)
{
        int b = 0;
        while (t) {
                t = t >> 1;
                b++;
        }
        return b;
}

/*
 * the foo_mask is the smallest value 2^n-1 that is >= foo.
 */
static void calc_pg_masks(struct ceph_pg_pool_info *pi)
{
        pi->pg_num_mask = (1 << calc_bits_of(le32_to_cpu(pi->v.pg_num)-1)) - 1;
        pi->pgp_num_mask =
                (1 << calc_bits_of(le32_to_cpu(pi->v.pgp_num)-1)) - 1;
        pi->lpg_num_mask =
                (1 << calc_bits_of(le32_to_cpu(pi->v.lpg_num)-1)) - 1;
        pi->lpgp_num_mask =
                (1 << calc_bits_of(le32_to_cpu(pi->v.lpgp_num)-1)) - 1;
}

/*
 * decode crush map
 */
static int crush_decode_uniform_bucket(void **p, void *end,
                                       struct crush_bucket_uniform *b)
{
        dout("crush_decode_uniform_bucket %p to %p\n", *p, end);
        ceph_decode_need(p, end, (1+b->h.size) * sizeof(u32), bad);
        b->item_weight = ceph_decode_32(p);
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_list_bucket(void **p, void *end,
                                    struct crush_bucket_list *b)
{
        int j;
        dout("crush_decode_list_bucket %p to %p\n", *p, end);
        b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->item_weights == NULL)
                return -ENOMEM;
        b->sum_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->sum_weights == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
        for (j = 0; j < b->h.size; j++) {
                b->item_weights[j] = ceph_decode_32(p);
                b->sum_weights[j] = ceph_decode_32(p);
        }
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_tree_bucket(void **p, void *end,
                                    struct crush_bucket_tree *b)
{
        int j;
        dout("crush_decode_tree_bucket %p to %p\n", *p, end);
        ceph_decode_32_safe(p, end, b->num_nodes, bad);
        b->node_weights = kcalloc(b->num_nodes, sizeof(u32), GFP_NOFS);
        if (b->node_weights == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, b->num_nodes * sizeof(u32), bad);
        for (j = 0; j < b->num_nodes; j++)
                b->node_weights[j] = ceph_decode_32(p);
        return 0;
bad:
        return -EINVAL;
}

static int crush_decode_straw_bucket(void **p, void *end,
                                     struct crush_bucket_straw *b)
{
        int j;
        dout("crush_decode_straw_bucket %p to %p\n", *p, end);
        b->item_weights = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->item_weights == NULL)
                return -ENOMEM;
        b->straws = kcalloc(b->h.size, sizeof(u32), GFP_NOFS);
        if (b->straws == NULL)
                return -ENOMEM;
        ceph_decode_need(p, end, 2 * b->h.size * sizeof(u32), bad);
        for (j = 0; j < b->h.size; j++) {
                b->item_weights[j] = ceph_decode_32(p);
                b->straws[j] = ceph_decode_32(p);
        }
        return 0;
bad:
        return -EINVAL;
}

static struct crush_map *crush_decode(void *pbyval, void *end)
{
        struct crush_map *c;
        int err = -EINVAL;
        int i, j;
        void **p = &pbyval;
        void *start = pbyval;
        u32 magic;

        dout("crush_decode %p to %p len %d\n", *p, end, (int)(end - *p));

        c = kzalloc(sizeof(*c), GFP_NOFS);
        if (c == NULL)
                return ERR_PTR(-ENOMEM);

        ceph_decode_need(p, end, 4*sizeof(u32), bad);
        magic = ceph_decode_32(p);
        if (magic != CRUSH_MAGIC) {
                pr_err("crush_decode magic %x != current %x\n",
                       (unsigned int)magic, (unsigned int)CRUSH_MAGIC);
                goto bad;
        }
        c->max_buckets = ceph_decode_32(p);
        c->max_rules = ceph_decode_32(p);
        c->max_devices = ceph_decode_32(p);

        c->device_parents = kcalloc(c->max_devices, sizeof(u32), GFP_NOFS);
        if (c->device_parents == NULL)
                goto badmem;
        c->bucket_parents = kcalloc(c->max_buckets, sizeof(u32), GFP_NOFS);
        if (c->bucket_parents == NULL)
                goto badmem;

        c->buckets = kcalloc(c->max_buckets, sizeof(*c->buckets), GFP_NOFS);
        if (c->buckets == NULL)
                goto badmem;
        c->rules = kcalloc(c->max_rules, sizeof(*c->rules), GFP_NOFS);
        if (c->rules == NULL)
                goto badmem;

        /* buckets */
        for (i = 0; i < c->max_buckets; i++) {
                int size = 0;
                u32 alg;
                struct crush_bucket *b;

                ceph_decode_32_safe(p, end, alg, bad);
                if (alg == 0) {
                        c->buckets[i] = NULL;
                        continue;
                }
                dout("crush_decode bucket %d off %x %p to %p\n",
                     i, (int)(*p-start), *p, end);

                switch (alg) {
                case CRUSH_BUCKET_UNIFORM:
                        size = sizeof(struct crush_bucket_uniform);
                        break;
                case CRUSH_BUCKET_LIST:
                        size = sizeof(struct crush_bucket_list);
                        break;
                case CRUSH_BUCKET_TREE:
                        size = sizeof(struct crush_bucket_tree);
                        break;
                case CRUSH_BUCKET_STRAW:
                        size = sizeof(struct crush_bucket_straw);
                        break;
                default:
                        err = -EINVAL;
                        goto bad;
                }
                BUG_ON(size == 0);
                b = c->buckets[i] = kzalloc(size, GFP_NOFS);
                if (b == NULL)
                        goto badmem;

                ceph_decode_need(p, end, 4*sizeof(u32), bad);
                b->id = ceph_decode_32(p);
                b->type = ceph_decode_16(p);
                b->alg = ceph_decode_8(p);
                b->hash = ceph_decode_8(p);
                b->weight = ceph_decode_32(p);
                b->size = ceph_decode_32(p);

                dout("crush_decode bucket size %d off %x %p to %p\n",
                     b->size, (int)(*p-start), *p, end);

                b->items = kcalloc(b->size, sizeof(__s32), GFP_NOFS);
                if (b->items == NULL)
                        goto badmem;
                b->perm = kcalloc(b->size, sizeof(u32), GFP_NOFS);
                if (b->perm == NULL)
                        goto badmem;
                b->perm_n = 0;

                ceph_decode_need(p, end, b->size*sizeof(u32), bad);
                for (j = 0; j < b->size; j++)
                        b->items[j] = ceph_decode_32(p);

                switch (b->alg) {
                case CRUSH_BUCKET_UNIFORM:
                        err = crush_decode_uniform_bucket(p, end,
                                  (struct crush_bucket_uniform *)b);
                        if (err < 0)
                                goto bad;
                        break;
                case CRUSH_BUCKET_LIST:
                        err = crush_decode_list_bucket(p, end,
                               (struct crush_bucket_list *)b);
                        if (err < 0)
                                goto bad;
                        break;
                case CRUSH_BUCKET_TREE:
                        err = crush_decode_tree_bucket(p, end,
                                (struct crush_bucket_tree *)b);
                        if (err < 0)
                                goto bad;
                        break;
                case CRUSH_BUCKET_STRAW:
                        err = crush_decode_straw_bucket(p, end,
                                (struct crush_bucket_straw *)b);
                        if (err < 0)
                                goto bad;
                        break;
                }
        }

        /* rules */
        dout("rule vec is %p\n", c->rules);
        for (i = 0; i < c->max_rules; i++) {
                u32 yes;
                struct crush_rule *r;

                ceph_decode_32_safe(p, end, yes, bad);
                if (!yes) {
                        dout("crush_decode NO rule %d off %x %p to %p\n",
                             i, (int)(*p-start), *p, end);
                        c->rules[i] = NULL;
                        continue;
                }

                dout("crush_decode rule %d off %x %p to %p\n",
                     i, (int)(*p-start), *p, end);

                /* len */
                ceph_decode_32_safe(p, end, yes, bad);
#if BITS_PER_LONG == 32
                err = -EINVAL;
                if (yes > (ULONG_MAX - sizeof(*r))
                          / sizeof(struct crush_rule_step))
                        goto bad;
#endif
                r = c->rules[i] = kmalloc(sizeof(*r) +
                                          yes*sizeof(struct crush_rule_step),
                                          GFP_NOFS);
                if (r == NULL)
                        goto badmem;
                dout(" rule %d is at %p\n", i, r);
                r->len = yes;
                ceph_decode_copy_safe(p, end, &r->mask, 4, bad); /* 4 u8's */
                ceph_decode_need(p, end, r->len*3*sizeof(u32), bad);
                for (j = 0; j < r->len; j++) {
                        r->steps[j].op = ceph_decode_32(p);
                        r->steps[j].arg1 = ceph_decode_32(p);
                        r->steps[j].arg2 = ceph_decode_32(p);
                }
        }

        /* ignore trailing name maps. */

        dout("crush_decode success\n");
        return c;

badmem:
        err = -ENOMEM;
bad:
        dout("crush_decode fail %d\n", err);
        crush_destroy(c);
        return ERR_PTR(err);
}

/*
 * rbtree of pg_mapping for handling pg_temp (explicit mapping of pgid
 * to a set of osds)
 */
static int pgid_cmp(struct ceph_pg l, struct ceph_pg r)
{
        u64 a = *(u64 *)&l;
        u64 b = *(u64 *)&r;

        if (a < b)
                return -1;
        if (a > b)
                return 1;
        return 0;
}

static int __insert_pg_mapping(struct ceph_pg_mapping *new,
                               struct rb_root *root)
{
        struct rb_node **p = &root->rb_node;
        struct rb_node *parent = NULL;
        struct ceph_pg_mapping *pg = NULL;
        int c;

        dout("__insert_pg_mapping %llx %p\n", *(u64 *)&new->pgid, new);
        while (*p) {
                parent = *p;
                pg = rb_entry(parent, struct ceph_pg_mapping, node);
                c = pgid_cmp(new->pgid, pg->pgid);
                if (c < 0)
                        p = &(*p)->rb_left;
                else if (c > 0)
                        p = &(*p)->rb_right;
                else
                        return -EEXIST;
        }

        rb_link_node(&new->node, parent, p);
        rb_insert_color(&new->node, root);
        return 0;
}

static struct ceph_pg_mapping *__lookup_pg_mapping(struct rb_root *root,
                                                   struct ceph_pg pgid)
{
        struct rb_node *n = root->rb_node;
        struct ceph_pg_mapping *pg;
        int c;

        while (n) {
                pg = rb_entry(n, struct ceph_pg_mapping, node);
                c = pgid_cmp(pgid, pg->pgid);
                if (c < 0) {
                        n = n->rb_left;
                } else if (c > 0) {
                        n = n->rb_right;
                } else {
                        dout("__lookup_pg_mapping %llx got %p\n",
                             *(u64 *)&pgid, pg);
                        return pg;
                }
        }
        return NULL;
}

static int __remove_pg_mapping(struct rb_root *root, struct ceph_pg pgid)
{
        struct ceph_pg_mapping *pg = __lookup_pg_mapping(root, pgid);

        if (pg) {
                dout("__remove_pg_mapping %llx %p\n", *(u64 *)&pgid, pg);
                rb_erase(&pg->node, root);
                kfree(pg);
                return 0;
        }
        dout("__remove_pg_mapping %llx dne\n", *(u64 *)&pgid);
        return -ENOENT;
}

/*
 * rbtree of pg pool info
 */
static int __insert_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *new)
{
        struct rb_node **p = &root->rb_node;
        struct rb_node *parent = NULL;
        struct ceph_pg_pool_info *pi = NULL;

        while (*p) {
                parent = *p;
                pi = rb_entry(parent, struct ceph_pg_pool_info, node);
                if (new->id < pi->id)
                        p = &(*p)->rb_left;
                else if (new->id > pi->id)
                        p = &(*p)->rb_right;
                else
                        return -EEXIST;
        }

        rb_link_node(&new->node, parent, p);
        rb_insert_color(&new->node, root);
        return 0;
}

static struct ceph_pg_pool_info *__lookup_pg_pool(struct rb_root *root, int id)
{
        struct ceph_pg_pool_info *pi;
        struct rb_node *n = root->rb_node;

        while (n) {
                pi = rb_entry(n, struct ceph_pg_pool_info, node);
                if (id < pi->id)
                        n = n->rb_left;
                else if (id > pi->id)
                        n = n->rb_right;
                else
                        return pi;
        }
        return NULL;
}

int ceph_pg_poolid_by_name(struct ceph_osdmap *map, const char *name)
{
        struct rb_node *rbp;

        for (rbp = rb_first(&map->pg_pools); rbp; rbp = rb_next(rbp)) {
                struct ceph_pg_pool_info *pi =
                        rb_entry(rbp, struct ceph_pg_pool_info, node);
                if (pi->name && strcmp(pi->name, name) == 0)
                        return pi->id;
        }
        return -ENOENT;
}
EXPORT_SYMBOL(ceph_pg_poolid_by_name);

static void __remove_pg_pool(struct rb_root *root, struct ceph_pg_pool_info *pi)
{
        rb_erase(&pi->node, root);
        kfree(pi->name);
        kfree(pi);
}

static int __decode_pool(void **p, void *end, struct ceph_pg_pool_info *pi)
{
        unsigned int n, m;

        ceph_decode_copy(p, &pi->v, sizeof(pi->v));
        calc_pg_masks(pi);

        /* num_snaps * snap_info_t */
        n = le32_to_cpu(pi->v.num_snaps);
        while (n--) {
                ceph_decode_need(p, end, sizeof(u64) + 1 + sizeof(u64) +
                                 sizeof(struct ceph_timespec), bad);
                *p += sizeof(u64) +       /* key */
                        1 + sizeof(u64) + /* u8, snapid */
                        sizeof(struct ceph_timespec);
                m = ceph_decode_32(p);    /* snap name */
                *p += m;
        }

        *p += le32_to_cpu(pi->v.num_removed_snap_intervals) * sizeof(u64) * 2;
        return 0;

bad:
        return -EINVAL;
}

static int __decode_pool_names(void **p, void *end, struct ceph_osdmap *map)
{
        struct ceph_pg_pool_info *pi;
        u32 num, len, pool;

        ceph_decode_32_safe(p, end, num, bad);
        dout(" %d pool names\n", num);
        while (num--) {
                ceph_decode_32_safe(p, end, pool, bad);
                ceph_decode_32_safe(p, end, len, bad);
                dout("  pool %d len %d\n", pool, len);
                pi = __lookup_pg_pool(&map->pg_pools, pool);
                if (pi) {
                        kfree(pi->name);
                        pi->name = kmalloc(len + 1, GFP_NOFS);
                        if (pi->name) {
                                memcpy(pi->name, *p, len);
                                pi->name[len] = '\0';
                                dout("  name is %s\n", pi->name);
                        }
                }
                *p += len;
        }
        return 0;

bad:
        return -EINVAL;
}

/*
 * osd map
 */
void ceph_osdmap_destroy(struct ceph_osdmap *map)
{
        dout("osdmap_destroy %p\n", map);
        if (map->crush)
                crush_destroy(map->crush);
        while (!RB_EMPTY_ROOT(&map->pg_temp)) {
                struct ceph_pg_mapping *pg =
                        rb_entry(rb_first(&map->pg_temp),
                                 struct ceph_pg_mapping, node);
                rb_erase(&pg->node, &map->pg_temp);
                kfree(pg);
        }
        while (!RB_EMPTY_ROOT(&map->pg_pools)) {
                struct ceph_pg_pool_info *pi =
                        rb_entry(rb_first(&map->pg_pools),
                                 struct ceph_pg_pool_info, node);
                __remove_pg_pool(&map->pg_pools, pi);
        }
        kfree(map->osd_state);
        kfree(map->osd_weight);
        kfree(map->osd_addr);
        kfree(map);
}

/*
 * adjust max osd value.  reallocate arrays.
 */
static int osdmap_set_max_osd(struct ceph_osdmap *map, int max)
{
        u8 *state;
        struct ceph_entity_addr *addr;
        u32 *weight;

        state = kcalloc(max, sizeof(*state), GFP_NOFS);
        addr = kcalloc(max, sizeof(*addr), GFP_NOFS);
        weight = kcalloc(max, sizeof(*weight), GFP_NOFS);
        if (state == NULL || addr == NULL || weight == NULL) {
                kfree(state);
                kfree(addr);
                kfree(weight);
                return -ENOMEM;
        }

        /* copy old? */
        if (map->osd_state) {
                memcpy(state, map->osd_state, map->max_osd*sizeof(*state));
                memcpy(addr, map->osd_addr, map->max_osd*sizeof(*addr));
                memcpy(weight, map->osd_weight, map->max_osd*sizeof(*weight));
                kfree(map->osd_state);
                kfree(map->osd_addr);
                kfree(map->osd_weight);
        }

        map->osd_state = state;
        map->osd_weight = weight;
        map->osd_addr = addr;
        map->max_osd = max;
        return 0;
}

/*
 * decode a full map.
 */
struct ceph_osdmap *osdmap_decode(void **p, void *end)
{
        struct ceph_osdmap *map;
        u16 version;
        u32 len, max, i;
        u8 ev;
        int err = -EINVAL;
        void *start = *p;
        struct ceph_pg_pool_info *pi;

        dout("osdmap_decode %p to %p len %d\n", *p, end, (int)(end - *p));

        map = kzalloc(sizeof(*map), GFP_NOFS);
        if (map == NULL)
                return ERR_PTR(-ENOMEM);
        map->pg_temp = RB_ROOT;

        ceph_decode_16_safe(p, end, version, bad);
        if (version > CEPH_OSDMAP_VERSION) {
                pr_warning("got unknown v %d > %d of osdmap\n", version,
                           CEPH_OSDMAP_VERSION);
                goto bad;
        }

        ceph_decode_need(p, end, 2*sizeof(u64)+6*sizeof(u32), bad);
        ceph_decode_copy(p, &map->fsid, sizeof(map->fsid));
        map->epoch = ceph_decode_32(p);
        ceph_decode_copy(p, &map->created, sizeof(map->created));
        ceph_decode_copy(p, &map->modified, sizeof(map->modified));

        ceph_decode_32_safe(p, end, max, bad);
        while (max--) {
                ceph_decode_need(p, end, 4 + 1 + sizeof(pi->v), bad);
                pi = kzalloc(sizeof(*pi), GFP_NOFS);
                if (!pi)
                        goto bad;
                pi->id = ceph_decode_32(p);
                ev = ceph_decode_8(p); /* encoding version */
                if (ev > CEPH_PG_POOL_VERSION) {
                        pr_warning("got unknown v %d > %d of ceph_pg_pool\n",
                                   ev, CEPH_PG_POOL_VERSION);
                        kfree(pi);
                        goto bad;
                }
                err = __decode_pool(p, end, pi);
                if (err < 0) {
                        kfree(pi);
                        goto bad;
                }
                __insert_pg_pool(&map->pg_pools, pi);
        }

        if (version >= 5 && __decode_pool_names(p, end, map) < 0)
                goto bad;

        ceph_decode_32_safe(p, end, map->pool_max, bad);

        ceph_decode_32_safe(p, end, map->flags, bad);

        max = ceph_decode_32(p);

        /* (re)alloc osd arrays */
        err = osdmap_set_max_osd(map, max);
        if (err < 0)
                goto bad;
        dout("osdmap_decode max_osd = %d\n", map->max_osd);

        /* osds */
        err = -EINVAL;
        ceph_decode_need(p, end, 3*sizeof(u32) +
                         map->max_osd*(1 + sizeof(*map->osd_weight) +
                                       sizeof(*map->osd_addr)), bad);
        *p += 4; /* skip length field (should match max) */
        ceph_decode_copy(p, map->osd_state, map->max_osd);

        *p += 4; /* skip length field (should match max) */
        for (i = 0; i < map->max_osd; i++)
                map->osd_weight[i] = ceph_decode_32(p);

        *p += 4; /* skip length field (should match max) */
        ceph_decode_copy(p, map->osd_addr, map->max_osd*sizeof(*map->osd_addr));
        for (i = 0; i < map->max_osd; i++)
                ceph_decode_addr(&map->osd_addr[i]);

        /* pg_temp */
        ceph_decode_32_safe(p, end, len, bad);
        for (i = 0; i < len; i++) {
                int n, j;
                struct ceph_pg pgid;
                struct ceph_pg_mapping *pg;

                ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad);
                ceph_decode_copy(p, &pgid, sizeof(pgid));
                n = ceph_decode_32(p);
                ceph_decode_need(p, end, n * sizeof(u32), bad);
                err = -ENOMEM;
                pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS);
                if (!pg)
                        goto bad;
                pg->pgid = pgid;
                pg->len = n;
                for (j = 0; j < n; j++)
                        pg->osds[j] = ceph_decode_32(p);

                err = __insert_pg_mapping(pg, &map->pg_temp);
                if (err)
                        goto bad;
                dout(" added pg_temp %llx len %d\n", *(u64 *)&pgid, len);
        }

        /* crush */
        ceph_decode_32_safe(p, end, len, bad);
        dout("osdmap_decode crush len %d from off 0x%x\n", len,
             (int)(*p - start));
        ceph_decode_need(p, end, len, bad);
        map->crush = crush_decode(*p, end);
        *p += len;
        if (IS_ERR(map->crush)) {
                err = PTR_ERR(map->crush);
                map->crush = NULL;
                goto bad;
        }

        /* ignore the rest of the map */
        *p = end;

        dout("osdmap_decode done %p %p\n", *p, end);
        return map;

bad:
        dout("osdmap_decode fail\n");
        ceph_osdmap_destroy(map);
        return ERR_PTR(err);
}

/*
 * decode and apply an incremental map update.
 */
struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
                                             struct ceph_osdmap *map,
                                             struct ceph_messenger *msgr)
{
        struct crush_map *newcrush = NULL;
        struct ceph_fsid fsid;
        u32 epoch = 0;
        struct ceph_timespec modified;
        u32 len, pool;
        __s32 new_pool_max, new_flags, max;
        void *start = *p;
        int err = -EINVAL;
        u16 version;

        ceph_decode_16_safe(p, end, version, bad);
        if (version > CEPH_OSDMAP_INC_VERSION) {
                pr_warning("got unknown v %d > %d of inc osdmap\n", version,
                           CEPH_OSDMAP_INC_VERSION);
                goto bad;
        }

        ceph_decode_need(p, end, sizeof(fsid)+sizeof(modified)+2*sizeof(u32),
                         bad);
        ceph_decode_copy(p, &fsid, sizeof(fsid));
        epoch = ceph_decode_32(p);
        BUG_ON(epoch != map->epoch+1);
        ceph_decode_copy(p, &modified, sizeof(modified));
        new_pool_max = ceph_decode_32(p);
        new_flags = ceph_decode_32(p);

        /* full map? */
        ceph_decode_32_safe(p, end, len, bad);
        if (len > 0) {
                dout("apply_incremental full map len %d, %p to %p\n",
                     len, *p, end);
                return osdmap_decode(p, min(*p+len, end));
        }

        /* new crush? */
        ceph_decode_32_safe(p, end, len, bad);
        if (len > 0) {
                dout("apply_incremental new crush map len %d, %p to %p\n",
                     len, *p, end);
                newcrush = crush_decode(*p, min(*p+len, end));
                if (IS_ERR(newcrush))
                        return ERR_CAST(newcrush);
                *p += len;
        }

        /* new flags? */
        if (new_flags >= 0)
                map->flags = new_flags;
        if (new_pool_max >= 0)
                map->pool_max = new_pool_max;

        ceph_decode_need(p, end, 5*sizeof(u32), bad);

        /* new max? */
        max = ceph_decode_32(p);
        if (max >= 0) {
                err = osdmap_set_max_osd(map, max);
                if (err < 0)
                        goto bad;
        }

        map->epoch++;
        map->modified = modified;
        if (newcrush) {
                if (map->crush)
                        crush_destroy(map->crush);
                map->crush = newcrush;
                newcrush = NULL;
        }

        /* new_pool */
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                __u8 ev;
                struct ceph_pg_pool_info *pi;

                ceph_decode_32_safe(p, end, pool, bad);
                ceph_decode_need(p, end, 1 + sizeof(pi->v), bad);
                ev = ceph_decode_8(p);  /* encoding version */
                if (ev > CEPH_PG_POOL_VERSION) {
                        pr_warning("got unknown v %d > %d of ceph_pg_pool\n",
                                   ev, CEPH_PG_POOL_VERSION);
                        goto bad;
                }
                pi = __lookup_pg_pool(&map->pg_pools, pool);
                if (!pi) {
                        pi = kzalloc(sizeof(*pi), GFP_NOFS);
                        if (!pi) {
                                err = -ENOMEM;
                                goto bad;
                        }
                        pi->id = pool;
                        __insert_pg_pool(&map->pg_pools, pi);
                }
                err = __decode_pool(p, end, pi);
                if (err < 0)
                        goto bad;
        }
        if (version >= 5 && __decode_pool_names(p, end, map) < 0)
                goto bad;

        /* old_pool */
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                struct ceph_pg_pool_info *pi;

                ceph_decode_32_safe(p, end, pool, bad);
                pi = __lookup_pg_pool(&map->pg_pools, pool);
                if (pi)
                        __remove_pg_pool(&map->pg_pools, pi);
        }

        /* new_up */
        err = -EINVAL;
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                u32 osd;
                struct ceph_entity_addr addr;
                ceph_decode_32_safe(p, end, osd, bad);
                ceph_decode_copy_safe(p, end, &addr, sizeof(addr), bad);
                ceph_decode_addr(&addr);
                pr_info("osd%d up\n", osd);
                BUG_ON(osd >= map->max_osd);
                map->osd_state[osd] |= CEPH_OSD_UP;
                map->osd_addr[osd] = addr;
        }

        /* new_state */
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                u32 osd;
                u8 xorstate;
                ceph_decode_32_safe(p, end, osd, bad);
                xorstate = **(u8 **)p;
                (*p)++;  /* clean flag */
                if (xorstate == 0)
                        xorstate = CEPH_OSD_UP;
                if (xorstate & CEPH_OSD_UP)
                        pr_info("osd%d down\n", osd);
                if (osd < map->max_osd)
                        map->osd_state[osd] ^= xorstate;
        }

        /* new_weight */
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                u32 osd, off;
                ceph_decode_need(p, end, sizeof(u32)*2, bad);
                osd = ceph_decode_32(p);
                off = ceph_decode_32(p);
                pr_info("osd%d weight 0x%x %s\n", osd, off,
                     off == CEPH_OSD_IN ? "(in)" :
                     (off == CEPH_OSD_OUT ? "(out)" : ""));
                if (osd < map->max_osd)
                        map->osd_weight[osd] = off;
        }

        /* new_pg_temp */
        ceph_decode_32_safe(p, end, len, bad);
        while (len--) {
                struct ceph_pg_mapping *pg;
                int j;
                struct ceph_pg pgid;
                u32 pglen;
                ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
                ceph_decode_copy(p, &pgid, sizeof(pgid));
                pglen = ceph_decode_32(p);

                if (pglen) {
                        /* insert */
                        ceph_decode_need(p, end, pglen*sizeof(u32), bad);
                        pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS);
                        if (!pg) {
                                err = -ENOMEM;
                                goto bad;
                        }
                        pg->pgid = pgid;
                        pg->len = pglen;
                        for (j = 0; j < pglen; j++)
                                pg->osds[j] = ceph_decode_32(p);
                        err = __insert_pg_mapping(pg, &map->pg_temp);
                        if (err) {
                                kfree(pg);
                                goto bad;
                        }
                        dout(" added pg_temp %llx len %d\n", *(u64 *)&pgid,
                             pglen);
                } else {
                        /* remove */
                        __remove_pg_mapping(&map->pg_temp, pgid);
                }
        }

        /* ignore the rest */
        *p = end;
        return map;

bad:
        pr_err("corrupt inc osdmap epoch %d off %d (%p of %p-%p)\n",
               epoch, (int)(*p - start), *p, start, end);
        print_hex_dump(KERN_DEBUG, "osdmap: ",
                       DUMP_PREFIX_OFFSET, 16, 1,
                       start, end - start, true);
        if (newcrush)
                crush_destroy(newcrush);
        return ERR_PTR(err);
}




/*
 * calculate file layout from given offset, length.
 * fill in correct oid, logical length, and object extent
 * offset, length.
 *
 * for now, we write only a single su, until we can
 * pass a stride back to the caller.
 */
void ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
                                   u64 off, u64 *plen,
                                   u64 *ono,
                                   u64 *oxoff, u64 *oxlen)
{
        u32 osize = le32_to_cpu(layout->fl_object_size);
        u32 su = le32_to_cpu(layout->fl_stripe_unit);
        u32 sc = le32_to_cpu(layout->fl_stripe_count);
        u32 bl, stripeno, stripepos, objsetno;
        u32 su_per_object;
        u64 t, su_offset;

        dout("mapping %llu~%llu  osize %u fl_su %u\n", off, *plen,
             osize, su);
        su_per_object = osize / su;
        dout("osize %u / su %u = su_per_object %u\n", osize, su,
             su_per_object);

        BUG_ON((su & ~PAGE_MASK) != 0);
        /* bl = *off / su; */
        t = off;
        do_div(t, su);
        bl = t;
        dout("off %llu / su %u = bl %u\n", off, su, bl);

        stripeno = bl / sc;
        stripepos = bl % sc;
        objsetno = stripeno / su_per_object;

        *ono = objsetno * sc + stripepos;
        dout("objset %u * sc %u = ono %u\n", objsetno, sc, (unsigned int)*ono);

        /* *oxoff = *off % layout->fl_stripe_unit;  # offset in su */
        t = off;
        su_offset = do_div(t, su);
        *oxoff = su_offset + (stripeno % su_per_object) * su;

        /*
         * Calculate the length of the extent being written to the selected
         * object. This is the minimum of the full length requested (plen) or
         * the remainder of the current stripe being written to.
         */
        *oxlen = min_t(u64, *plen, su - su_offset);
        *plen = *oxlen;

        dout(" obj extent %llu~%llu\n", *oxoff, *oxlen);
}
EXPORT_SYMBOL(ceph_calc_file_object_mapping);

/*
 * calculate an object layout (i.e. pgid) from an oid,
 * file_layout, and osdmap
 */
int ceph_calc_object_layout(struct ceph_object_layout *ol,
                            const char *oid,
                            struct ceph_file_layout *fl,
                            struct ceph_osdmap *osdmap)
{
        unsigned int num, num_mask;
        struct ceph_pg pgid;
        s32 preferred = (s32)le32_to_cpu(fl->fl_pg_preferred);
        int poolid = le32_to_cpu(fl->fl_pg_pool);
        struct ceph_pg_pool_info *pool;
        unsigned int ps;

        BUG_ON(!osdmap);

        pool = __lookup_pg_pool(&osdmap->pg_pools, poolid);
        if (!pool)
                return -EIO;
        ps = ceph_str_hash(pool->v.object_hash, oid, strlen(oid));
        if (preferred >= 0) {
                ps += preferred;
                num = le32_to_cpu(pool->v.lpg_num);
                num_mask = pool->lpg_num_mask;
        } else {
                num = le32_to_cpu(pool->v.pg_num);
                num_mask = pool->pg_num_mask;
        }

        pgid.ps = cpu_to_le16(ps);
        pgid.preferred = cpu_to_le16(preferred);
        pgid.pool = fl->fl_pg_pool;
        if (preferred >= 0)
                dout("calc_object_layout '%s' pgid %d.%xp%d\n", oid, poolid, ps,
                     (int)preferred);
        else
                dout("calc_object_layout '%s' pgid %d.%x\n", oid, poolid, ps);

        ol->ol_pgid = pgid;
        ol->ol_stripe_unit = fl->fl_object_stripe_unit;
        return 0;
}
EXPORT_SYMBOL(ceph_calc_object_layout);

/*
 * Calculate raw osd vector for the given pgid.  Return pointer to osd
 * array, or NULL on failure.
 */
static int *calc_pg_raw(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
                        int *osds, int *num)
{
        struct ceph_pg_mapping *pg;
        struct ceph_pg_pool_info *pool;
        int ruleno;
        unsigned int poolid, ps, pps, t;
        int preferred;

        poolid = le32_to_cpu(pgid.pool);
        ps = le16_to_cpu(pgid.ps);
        preferred = (s16)le16_to_cpu(pgid.preferred);

        pool = __lookup_pg_pool(&osdmap->pg_pools, poolid);
        if (!pool)
                return NULL;

        /* pg_temp? */
        if (preferred >= 0)
                t = ceph_stable_mod(ps, le32_to_cpu(pool->v.lpg_num),
                                    pool->lpgp_num_mask);
        else
                t = ceph_stable_mod(ps, le32_to_cpu(pool->v.pg_num),
                                    pool->pgp_num_mask);
        pgid.ps = cpu_to_le16(t);
        pg = __lookup_pg_mapping(&osdmap->pg_temp, pgid);
        if (pg) {
                *num = pg->len;
                return pg->osds;
        }

        /* crush */
        ruleno = crush_find_rule(osdmap->crush, pool->v.crush_ruleset,
                                 pool->v.type, pool->v.size);
        if (ruleno < 0) {
                pr_err("no crush rule pool %d ruleset %d type %d size %d\n",
                       poolid, pool->v.crush_ruleset, pool->v.type,
                       pool->v.size);
                return NULL;
        }

        /* don't forcefeed bad device ids to crush */
        if (preferred >= osdmap->max_osd ||
            preferred >= osdmap->crush->max_devices)
                preferred = -1;

        if (preferred >= 0)
                pps = ceph_stable_mod(ps,
                                      le32_to_cpu(pool->v.lpgp_num),
                                      pool->lpgp_num_mask);
        else
                pps = ceph_stable_mod(ps,
                                      le32_to_cpu(pool->v.pgp_num),
                                      pool->pgp_num_mask);
        pps += poolid;
        *num = crush_do_rule(osdmap->crush, ruleno, pps, osds,
                             min_t(int, pool->v.size, *num),
                             preferred, osdmap->osd_weight);
        return osds;
}

/*
 * Return acting set for given pgid.
 */
int ceph_calc_pg_acting(struct ceph_osdmap *osdmap, struct ceph_pg pgid,
                        int *acting)
{
        int rawosds[CEPH_PG_MAX_SIZE], *osds;
        int i, o, num = CEPH_PG_MAX_SIZE;

        osds = calc_pg_raw(osdmap, pgid, rawosds, &num);
        if (!osds)
                return -1;

        /* primary is first up osd */
        o = 0;
        for (i = 0; i < num; i++)
                if (ceph_osd_is_up(osdmap, osds[i]))
                        acting[o++] = osds[i];
        return o;
}

/*
 * Return primary osd for given pgid, or -1 if none.
 */
int ceph_calc_pg_primary(struct ceph_osdmap *osdmap, struct ceph_pg pgid)
{
        int rawosds[CEPH_PG_MAX_SIZE], *osds;
        int i, num = CEPH_PG_MAX_SIZE;

        osds = calc_pg_raw(osdmap, pgid, rawosds, &num);
        if (!osds)
                return -1;

        /* primary is first up osd */
        for (i = 0; i < num; i++)
                if (ceph_osd_is_up(osdmap, osds[i]))
                        return osds[i];
        return -1;
}
EXPORT_SYMBOL(ceph_calc_pg_primary);