btrfs-progs: update man page for btrfs filesystem label
[platform/upstream/btrfs-progs.git] / volumes.c
index 8dca5e1..10fdc48 100644 (file)
--- a/volumes.c
+++ b/volumes.c
 #include "transaction.h"
 #include "print-tree.h"
 #include "volumes.h"
+#include "math.h"
 
 struct stripe {
        struct btrfs_device *dev;
        u64 physical;
 };
 
-#define map_lookup_size(n) (sizeof(struct map_lookup) + \
-                           (sizeof(struct btrfs_bio_stripe) * (n)))
+static inline int nr_parity_stripes(struct map_lookup *map)
+{
+       if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+               return 1;
+       else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+               return 2;
+       else
+               return 0;
+}
+
+static inline int nr_data_stripes(struct map_lookup *map)
+{
+       return map->num_stripes - nr_parity_stripes(map);
+}
+
+#define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) )
 
 static LIST_HEAD(fs_uuids);
 
@@ -99,6 +114,7 @@ static int device_list_add(const char *path,
                        /* we can safely leave the fs_devices entry around */
                        return -ENOMEM;
                }
+               device->fd = -1;
                device->devid = devid;
                memcpy(device->uuid, disk_super->dev_item.uuid,
                       BTRFS_UUID_SIZE);
@@ -144,8 +160,13 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 again:
        list_for_each(cur, &fs_devices->devices) {
                device = list_entry(cur, struct btrfs_device, dev_list);
-               close(device->fd);
-               device->fd = -1;
+               if (device->fd != -1) {
+                       fsync(device->fd);
+                       if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
+                               fprintf(stderr, "Warning, could not drop caches\n");
+                       close(device->fd);
+                       device->fd = -1;
+               }
                device->writeable = 0;
        }
 
@@ -169,6 +190,10 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
 
        list_for_each(cur, head) {
                device = list_entry(cur, struct btrfs_device, dev_list);
+               if (!device->name) {
+                       printk("no name for device %llu, skip it now\n", device->devid);
+                       continue;
+               }
 
                fd = open(device->name, flags);
                if (fd < 0) {
@@ -176,6 +201,9 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
                        goto fail;
                }
 
+               if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED))
+                       fprintf(stderr, "Warning, could not drop caches\n");
+
                if (device->devid == fs_devices->latest_devid)
                        fs_devices->latest_bdev = fd;
                if (device->devid == fs_devices->lowest_devid)
@@ -584,7 +612,7 @@ int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
                           struct btrfs_key *key,
                           struct btrfs_chunk *chunk, int item_size)
 {
-       struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+       struct btrfs_super_block *super_copy = root->fs_info->super_copy;
        struct btrfs_disk_key disk_key;
        u32 array_size;
        u8 *ptr;
@@ -603,14 +631,6 @@ int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
        return 0;
 }
 
-static u64 div_factor(u64 num, int factor)
-{
-       if (factor == 10)
-               return num;
-       num *= factor;
-       return num / 10;
-}
-
 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
                               int sub_stripes)
 {
@@ -618,23 +638,33 @@ static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
                return calc_size;
        else if (type & BTRFS_BLOCK_GROUP_RAID10)
                return calc_size * (num_stripes / sub_stripes);
+       else if (type & BTRFS_BLOCK_GROUP_RAID5)
+               return calc_size * (num_stripes - 1);
+       else if (type & BTRFS_BLOCK_GROUP_RAID6)
+               return calc_size * (num_stripes - 2);
        else
                return calc_size * num_stripes;
 }
 
 
+static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
+{
+       /* TODO, add a way to store the preferred stripe size */
+       return 64 * 1024;
+}
+
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                      struct btrfs_root *extent_root, u64 *start,
                      u64 *num_bytes, u64 type)
 {
        u64 dev_offset;
        struct btrfs_fs_info *info = extent_root->fs_info;
-       struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
+       struct btrfs_root *chunk_root = info->chunk_root;
        struct btrfs_stripe *stripes;
        struct btrfs_device *device = NULL;
        struct btrfs_chunk *chunk;
        struct list_head private_devs;
-       struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
+       struct list_head *dev_list = &info->fs_devices->devices;
        struct list_head *cur;
        struct map_lookup *map;
        int min_stripe_size = 1 * 1024 * 1024;
@@ -652,12 +682,14 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        int index;
        int stripe_len = 64 * 1024;
        struct btrfs_key key;
+       u64 offset;
 
        if (list_empty(dev_list)) {
                return -ENOSPC;
        }
 
        if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+                   BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
                    BTRFS_BLOCK_GROUP_RAID10 |
                    BTRFS_BLOCK_GROUP_DUP)) {
                if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
@@ -676,7 +708,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        }
        if (type & BTRFS_BLOCK_GROUP_RAID1) {
                num_stripes = min_t(u64, 2,
-                                 btrfs_super_num_devices(&info->super_copy));
+                                 btrfs_super_num_devices(info->super_copy));
                if (num_stripes < 2)
                        return -ENOSPC;
                min_stripes = 2;
@@ -686,20 +718,36 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                min_stripes = 2;
        }
        if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
-               num_stripes = btrfs_super_num_devices(&info->super_copy);
+               num_stripes = btrfs_super_num_devices(info->super_copy);
                min_stripes = 2;
        }
        if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
-               num_stripes = btrfs_super_num_devices(&info->super_copy);
+               num_stripes = btrfs_super_num_devices(info->super_copy);
                if (num_stripes < 4)
                        return -ENOSPC;
                num_stripes &= ~(u32)1;
                sub_stripes = 2;
                min_stripes = 4;
        }
+       if (type & (BTRFS_BLOCK_GROUP_RAID5)) {
+               num_stripes = btrfs_super_num_devices(info->super_copy);
+               if (num_stripes < 2)
+                       return -ENOSPC;
+               min_stripes = 2;
+               stripe_len = find_raid56_stripe_len(num_stripes - 1,
+                                   btrfs_super_stripesize(info->super_copy));
+       }
+       if (type & (BTRFS_BLOCK_GROUP_RAID6)) {
+               num_stripes = btrfs_super_num_devices(info->super_copy);
+               if (num_stripes < 3)
+                       return -ENOSPC;
+               min_stripes = 3;
+               stripe_len = find_raid56_stripe_len(num_stripes - 2,
+                                   btrfs_super_stripesize(info->super_copy));
+       }
 
        /* we don't want a chunk larger than 10% of the FS */
-       percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
+       percent_max = div_factor(btrfs_super_total_bytes(info->super_copy), 1);
        max_chunk_size = min(percent_max, max_chunk_size);
 
 again:
@@ -757,18 +805,19 @@ again:
                }
                return -ENOSPC;
        }
-       key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
-       key.type = BTRFS_CHUNK_ITEM_KEY;
        ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
-                             &key.offset);
+                             &offset);
        if (ret)
                return ret;
+       key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+       key.type = BTRFS_CHUNK_ITEM_KEY;
+       key.offset = offset;
 
        chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
        if (!chunk)
                return -ENOMEM;
 
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map) {
                kfree(chunk);
                return -ENOMEM;
@@ -835,9 +884,7 @@ again:
        map->ce.start = key.offset;
        map->ce.size = *num_bytes;
 
-       ret = insert_existing_cache_extent(
-                          &extent_root->fs_info->mapping_tree.cache_tree,
-                          &map->ce);
+       ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
        BUG_ON(ret);
 
        if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
@@ -856,11 +903,11 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
 {
        u64 dev_offset;
        struct btrfs_fs_info *info = extent_root->fs_info;
-       struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
+       struct btrfs_root *chunk_root = info->chunk_root;
        struct btrfs_stripe *stripes;
        struct btrfs_device *device = NULL;
        struct btrfs_chunk *chunk;
-       struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
+       struct list_head *dev_list = &info->fs_devices->devices;
        struct list_head *cur;
        struct map_lookup *map;
        u64 calc_size = 8 * 1024 * 1024;
@@ -882,7 +929,7 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
        if (!chunk)
                return -ENOMEM;
 
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map) {
                kfree(chunk);
                return -ENOMEM;
@@ -943,9 +990,7 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
        map->ce.start = key.offset;
        map->ce.size = num_bytes;
 
-       ret = insert_existing_cache_extent(
-                          &extent_root->fs_info->mapping_tree.cache_tree,
-                          &map->ce);
+       ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
        BUG_ON(ret);
 
        kfree(chunk);
@@ -963,7 +1008,7 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
        struct map_lookup *map;
        int ret;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, logical);
+       ce = search_cache_extent(&map_tree->cache_tree, logical);
        BUG_ON(!ce);
        BUG_ON(ce->start > logical || ce->start + ce->size < logical);
        map = container_of(ce, struct map_lookup, ce);
@@ -972,6 +1017,10 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
                ret = map->num_stripes;
        else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
                ret = map->sub_stripes;
+       else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
+               ret = 2;
+       else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+               ret = 3;
        else
                ret = 1;
        return ret;
@@ -983,7 +1032,7 @@ int btrfs_next_metadata(struct btrfs_mapping_tree *map_tree, u64 *logical,
        struct cache_extent *ce;
        struct map_lookup *map;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, *logical);
+       ce = search_cache_extent(&map_tree->cache_tree, *logical);
 
        while (ce) {
                ce = next_cache_extent(ce);
@@ -1011,17 +1060,24 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
        u64 bytenr;
        u64 length;
        u64 stripe_nr;
+       u64 rmap_len;
        int i, j, nr = 0;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, chunk_start);
+       ce = search_cache_extent(&map_tree->cache_tree, chunk_start);
        BUG_ON(!ce);
        map = container_of(ce, struct map_lookup, ce);
 
        length = ce->size;
+       rmap_len = map->stripe_len;
        if (map->type & BTRFS_BLOCK_GROUP_RAID10)
                length = ce->size / (map->num_stripes / map->sub_stripes);
        else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
                length = ce->size / map->num_stripes;
+       else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+                             BTRFS_BLOCK_GROUP_RAID6)) {
+               length = ce->size / nr_data_stripes(map);
+               rmap_len = map->stripe_len * nr_data_stripes(map);
+       }
 
        buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
 
@@ -1040,8 +1096,11 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
                                    map->sub_stripes;
                } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                        stripe_nr = stripe_nr * map->num_stripes + i;
-               }
-               bytenr = ce->start + stripe_nr * map->stripe_len;
+               } /* else if RAID[56], multiply by nr_data_stripes().
+                  * Alternatively, just use rmap_len below instead of
+                  * map->stripe_len */
+
+               bytenr = ce->start + stripe_nr * rmap_len;
                for (j = 0; j < nr; j++) {
                        if (buf[j] == bytenr)
                                break;
@@ -1052,28 +1111,60 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 
        *logical = buf;
        *naddrs = nr;
-       *stripe_len = map->stripe_len;
+       *stripe_len = rmap_len;
 
        return 0;
 }
 
+static inline int parity_smaller(u64 a, u64 b)
+{
+       return a > b;
+}
+
+/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
+static void sort_parity_stripes(struct btrfs_multi_bio *bbio, u64 *raid_map)
+{
+       struct btrfs_bio_stripe s;
+       int i;
+       u64 l;
+       int again = 1;
+
+       while (again) {
+               again = 0;
+               for (i = 0; i < bbio->num_stripes - 1; i++) {
+                       if (parity_smaller(raid_map[i], raid_map[i+1])) {
+                               s = bbio->stripes[i];
+                               l = raid_map[i];
+                               bbio->stripes[i] = bbio->stripes[i+1];
+                               raid_map[i] = raid_map[i+1];
+                               bbio->stripes[i+1] = s;
+                               raid_map[i+1] = l;
+                               again = 1;
+                       }
+               }
+       }
+}
+
 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                    u64 logical, u64 *length,
-                   struct btrfs_multi_bio **multi_ret, int mirror_num)
+                   struct btrfs_multi_bio **multi_ret, int mirror_num,
+                   u64 **raid_map_ret)
 {
        return __btrfs_map_block(map_tree, rw, logical, length, NULL,
-                                multi_ret, mirror_num);
+                                multi_ret, mirror_num, raid_map_ret);
 }
 
 int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                    u64 logical, u64 *length, u64 *type,
-                   struct btrfs_multi_bio **multi_ret, int mirror_num)
+                   struct btrfs_multi_bio **multi_ret, int mirror_num,
+                   u64 **raid_map_ret)
 {
        struct cache_extent *ce;
        struct map_lookup *map;
        u64 offset;
        u64 stripe_offset;
        u64 stripe_nr;
+       u64 *raid_map = NULL;
        int stripes_allocated = 8;
        int stripes_required = 1;
        int stripe_index;
@@ -1084,7 +1175,7 @@ int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                stripes_allocated = 1;
        }
 again:
-       ce = find_first_cache_extent(&map_tree->cache_tree, logical);
+       ce = search_cache_extent(&map_tree->cache_tree, logical);
        if (!ce) {
                if (multi)
                        kfree(multi);
@@ -1113,11 +1204,26 @@ again:
                        stripes_required = map->sub_stripes;
                }
        }
+       if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)
+           && multi_ret && ((rw & WRITE) || mirror_num > 1) && raid_map_ret) {
+                   /* RAID[56] write or recovery. Return all stripes */
+                   stripes_required = map->num_stripes;
+
+                   /* Only allocate the map if we've already got a large enough multi_ret */
+                   if (stripes_allocated >= stripes_required) {
+                           raid_map = kmalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
+                           if (!raid_map) {
+                                   kfree(multi);
+                                   return -ENOMEM;
+                           }
+                   }
+       }
+
        /* if our multi bio struct is too small, back off and try again */
-       if (multi_ret && rw == WRITE &&
-           stripes_allocated < stripes_required) {
-               stripes_allocated = map->num_stripes;
+       if (multi_ret && stripes_allocated < stripes_required) {
+               stripes_allocated = stripes_required;
                kfree(multi);
+               multi = NULL;
                goto again;
        }
        stripe_nr = offset;
@@ -1134,6 +1240,7 @@ again:
        stripe_offset = offset - stripe_offset;
 
        if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+                        BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
                         BTRFS_BLOCK_GROUP_RAID10 |
                         BTRFS_BLOCK_GROUP_DUP)) {
                /* we limit the length of each bio to what fits in a stripe */
@@ -1172,6 +1279,59 @@ again:
                        multi->num_stripes = map->num_stripes;
                else if (mirror_num)
                        stripe_index = mirror_num - 1;
+       } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
+                               BTRFS_BLOCK_GROUP_RAID6)) {
+
+               if (raid_map) {
+                       int i, rot;
+                       u64 tmp;
+                       u64 raid56_full_stripe_start;
+                       u64 full_stripe_len = nr_data_stripes(map) * map->stripe_len;
+
+                       /*
+                        * align the start of our data stripe in the logical
+                        * address space
+                        */
+                       raid56_full_stripe_start = offset / full_stripe_len;
+                       raid56_full_stripe_start *= full_stripe_len;
+
+                       /* get the data stripe number */
+                       stripe_nr = raid56_full_stripe_start / map->stripe_len;
+                       stripe_nr = stripe_nr / nr_data_stripes(map);
+
+                       /* Work out the disk rotation on this stripe-set */
+                       rot = stripe_nr % map->num_stripes;
+
+                       /* Fill in the logical address of each stripe */
+                       tmp = stripe_nr * nr_data_stripes(map);
+
+                       for (i = 0; i < nr_data_stripes(map); i++)
+                               raid_map[(i+rot) % map->num_stripes] =
+                                       ce->start + (tmp + i) * map->stripe_len;
+
+                       raid_map[(i+rot) % map->num_stripes] = BTRFS_RAID5_P_STRIPE;
+                       if (map->type & BTRFS_BLOCK_GROUP_RAID6)
+                               raid_map[(i+rot+1) % map->num_stripes] = BTRFS_RAID6_Q_STRIPE;
+
+                       *length = map->stripe_len;
+                       stripe_index = 0;
+                       stripe_offset = 0;
+                       multi->num_stripes = map->num_stripes;
+               } else {
+                       stripe_index = stripe_nr % nr_data_stripes(map);
+                       stripe_nr = stripe_nr / nr_data_stripes(map);
+
+                       /*
+                        * Mirror #0 or #1 means the original data block.
+                        * Mirror #2 is RAID5 parity block.
+                        * Mirror #3 is RAID6 Q block.
+                        */
+                       if (mirror_num > 1)
+                               stripe_index = nr_data_stripes(map) + mirror_num - 2;
+
+                       /* We distribute the parity blocks across stripes */
+                       stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
+               }
        } else {
                /*
                 * after this do_div call, stripe_nr is the number of stripes
@@ -1191,8 +1351,14 @@ again:
                stripe_index++;
        }
        *multi_ret = multi;
+
        if (type)
                *type = map->type;
+
+       if (raid_map) {
+               sort_parity_stripes(multi, raid_map);
+               *raid_map_ret = raid_map;
+       }
 out:
        return 0;
 }
@@ -1217,6 +1383,21 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
        return NULL;
 }
 
+struct btrfs_device *
+btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
+                          u64 devid, int instance)
+{
+       struct list_head *head = &fs_devices->devices;
+       struct btrfs_device *dev;
+       int num_found = 0;
+
+       list_for_each_entry(dev, head, dev_list) {
+               if (dev->devid == devid && num_found++ == instance)
+                       return dev;
+       }
+       return NULL;
+}
+
 int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
                              struct btrfs_fs_devices *fs_devices)
 {
@@ -1232,7 +1413,7 @@ int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
        list_for_each(cur, &fs_devices->devices) {
                num_stripes++;
        }
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map)
                return -ENOMEM;
 
@@ -1255,15 +1436,16 @@ int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
                map->stripes[i].dev = device;
                i++;
        }
-       ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
+       ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
        if (ret == -EEXIST) {
                struct cache_extent *old;
                struct map_lookup *old_map;
-               old = find_cache_extent(&map_tree->cache_tree, logical, length);
+               old = lookup_cache_extent(&map_tree->cache_tree,
+                                         logical, length);
                old_map = container_of(old, struct map_lookup, ce);
                remove_cache_extent(&map_tree->cache_tree, old);
                kfree(old_map);
-               ret = insert_existing_cache_extent(&map_tree->cache_tree,
+               ret = insert_cache_extent(&map_tree->cache_tree,
                                                   &map->ce);
        }
        BUG_ON(ret);
@@ -1278,7 +1460,7 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
        int readonly = 0;
        int i;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, chunk_offset);
+       ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
        BUG_ON(!ce);
 
        map = container_of(ce, struct map_lookup, ce);
@@ -1320,7 +1502,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        logical = key->offset;
        length = btrfs_chunk_length(leaf, chunk);
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, logical);
+       ce = search_cache_extent(&map_tree->cache_tree, logical);
 
        /* already mapped? */
        if (ce && ce->start <= logical && ce->start + ce->size > logical) {
@@ -1328,7 +1510,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        }
 
        num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
+       map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map)
                return -ENOMEM;
 
@@ -1358,7 +1540,7 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                }
 
        }
-       ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
+       ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
        BUG_ON(ret);
 
        return 0;
@@ -1442,10 +1624,10 @@ static int read_one_dev(struct btrfs_root *root,
        if (!device) {
                printk("warning devid %llu not found already\n",
                        (unsigned long long)devid);
-               device = kmalloc(sizeof(*device), GFP_NOFS);
+               device = kzalloc(sizeof(*device), GFP_NOFS);
                if (!device)
                        return -ENOMEM;
-               device->total_ios = 0;
+               device->fd = -1;
                list_add(&device->dev_list,
                         &root->fs_info->fs_devices->devices);
        }
@@ -1455,18 +1637,9 @@ static int read_one_dev(struct btrfs_root *root,
        return ret;
 }
 
-int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
-{
-       struct btrfs_dev_item *dev_item;
-
-       dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
-                                                    dev_item);
-       return read_one_dev(root, buf, dev_item);
-}
-
 int btrfs_read_sys_array(struct btrfs_root *root)
 {
-       struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
+       struct btrfs_super_block *super_copy = root->fs_info->super_copy;
        struct extent_buffer *sb;
        struct btrfs_disk_key *disk_key;
        struct btrfs_chunk *chunk;
@@ -1484,7 +1657,7 @@ int btrfs_read_sys_array(struct btrfs_root *root)
        if (!sb)
                return -ENOMEM;
        btrfs_set_buffer_uptodate(sb);
-       write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
+       write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
        array_size = btrfs_super_sys_array_size(super_copy);
 
        /*
@@ -1583,9 +1756,9 @@ again:
                goto again;
        }
 
-       btrfs_free_path(path);
        ret = 0;
 error:
+       btrfs_free_path(path);
        return ret;
 }
 
@@ -1593,3 +1766,146 @@ struct list_head *btrfs_scanned_uuids(void)
 {
        return &fs_uuids;
 }
+
+static int rmw_eb(struct btrfs_fs_info *info,
+                 struct extent_buffer *eb, struct extent_buffer *orig_eb)
+{
+       int ret;
+       unsigned long orig_off = 0;
+       unsigned long dest_off = 0;
+       unsigned long copy_len = eb->len;
+
+       ret = read_whole_eb(info, eb, 0);
+       if (ret)
+               return ret;
+
+       if (eb->start + eb->len <= orig_eb->start ||
+           eb->start >= orig_eb->start + orig_eb->len)
+               return 0;
+       /*
+        * | ----- orig_eb ------- |
+        *         | ----- stripe -------  |
+        *         | ----- orig_eb ------- |
+        *              | ----- orig_eb ------- |
+        */
+       if (eb->start > orig_eb->start)
+               orig_off = eb->start - orig_eb->start;
+       if (orig_eb->start > eb->start)
+               dest_off = orig_eb->start - eb->start;
+
+       if (copy_len > orig_eb->len - orig_off)
+               copy_len = orig_eb->len - orig_off;
+       if (copy_len > eb->len - dest_off)
+               copy_len = eb->len - dest_off;
+
+       memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
+       return 0;
+}
+
+static void split_eb_for_raid56(struct btrfs_fs_info *info,
+                               struct extent_buffer *orig_eb,
+                              struct extent_buffer **ebs,
+                              u64 stripe_len, u64 *raid_map,
+                              int num_stripes)
+{
+       struct extent_buffer *eb;
+       u64 start = orig_eb->start;
+       u64 this_eb_start;
+       int i;
+       int ret;
+
+       for (i = 0; i < num_stripes; i++) {
+               if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
+                       break;
+
+               eb = malloc(sizeof(struct extent_buffer) + stripe_len);
+               if (!eb)
+                       BUG();
+               memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
+
+               eb->start = raid_map[i];
+               eb->len = stripe_len;
+               eb->refs = 1;
+               eb->flags = 0;
+               eb->fd = -1;
+               eb->dev_bytenr = (u64)-1;
+
+               this_eb_start = raid_map[i];
+
+               if (start > this_eb_start ||
+                   start + orig_eb->len < this_eb_start + stripe_len) {
+                       ret = rmw_eb(info, eb, orig_eb);
+                       BUG_ON(ret);
+               } else {
+                       memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
+               }
+               ebs[i] = eb;
+       }
+}
+
+int write_raid56_with_parity(struct btrfs_fs_info *info,
+                            struct extent_buffer *eb,
+                            struct btrfs_multi_bio *multi,
+                            u64 stripe_len, u64 *raid_map)
+{
+       struct extent_buffer *ebs[multi->num_stripes], *p_eb = NULL, *q_eb = NULL;
+       int i;
+       int j;
+       int ret;
+       int alloc_size = eb->len;
+
+       if (stripe_len > alloc_size)
+               alloc_size = stripe_len;
+
+       split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
+                           multi->num_stripes);
+
+       for (i = 0; i < multi->num_stripes; i++) {
+               struct extent_buffer *new_eb;
+               if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
+                       ebs[i]->dev_bytenr = multi->stripes[i].physical;
+                       ebs[i]->fd = multi->stripes[i].dev->fd;
+                       multi->stripes[i].dev->total_ios++;
+                       BUG_ON(ebs[i]->start != raid_map[i]);
+                       continue;
+               }
+               new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
+               BUG_ON(!new_eb);
+               new_eb->dev_bytenr = multi->stripes[i].physical;
+               new_eb->fd = multi->stripes[i].dev->fd;
+               multi->stripes[i].dev->total_ios++;
+               new_eb->len = stripe_len;
+
+               if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
+                       p_eb = new_eb;
+               else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
+                       q_eb = new_eb;
+       }
+       if (q_eb) {
+               void *pointers[multi->num_stripes];
+               ebs[multi->num_stripes - 2] = p_eb;
+               ebs[multi->num_stripes - 1] = q_eb;
+
+               for (i = 0; i < multi->num_stripes; i++)
+                       pointers[i] = ebs[i]->data;
+
+               raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
+       } else {
+               ebs[multi->num_stripes - 1] = p_eb;
+               memcpy(p_eb->data, ebs[0]->data, stripe_len);
+               for (j = 1; j < multi->num_stripes - 1; j++) {
+                       for (i = 0; i < stripe_len; i += sizeof(unsigned long)) {
+                               *(unsigned long *)(p_eb->data + i) ^=
+                                       *(unsigned long *)(ebs[j]->data + i);
+                       }
+               }
+       }
+
+       for (i = 0; i < multi->num_stripes; i++) {
+               ret = write_extent_to_disk(ebs[i]);
+               BUG_ON(ret);
+               if (ebs[i] != eb)
+                       kfree(ebs[i]);
+       }
+       return 0;
+}