btrfs-progs: report I/O errors when closing the filesystem
[platform/upstream/btrfs-progs.git] / volumes.c
index 4c29cef..b350e25 100644 (file)
--- a/volumes.c
+++ b/volumes.c
@@ -15,8 +15,6 @@
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * Boston, MA 021110-1307, USA.
  */
-#define _XOPEN_SOURCE 600
-#define __USE_XOPEN2K
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include "transaction.h"
 #include "print-tree.h"
 #include "volumes.h"
+#include "utils.h"
 
 struct stripe {
        struct btrfs_device *dev;
        u64 physical;
 };
 
-struct map_lookup {
-       struct cache_extent ce;
-       u64 type;
-       int io_align;
-       int io_width;
-       int stripe_len;
-       int sector_size;
-       int num_stripes;
-       int sub_stripes;
-       struct btrfs_bio_stripe stripes[];
-};
+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;
+}
 
-#define map_lookup_size(n) (sizeof(struct map_lookup) + \
-                           (sizeof(struct btrfs_bio_stripe) * (n)))
+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);
 
@@ -111,7 +112,9 @@ 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;
+               device->generation = found_transid;
                memcpy(device->uuid, disk_super->dev_item.uuid,
                       BTRFS_UUID_SIZE);
                device->name = kstrdup(path, GFP_NOFS);
@@ -120,6 +123,11 @@ static int device_list_add(const char *path,
                        return -ENOMEM;
                }
                device->label = kstrdup(disk_super->label, GFP_NOFS);
+               if (!device->label) {
+                       kfree(device->name);
+                       kfree(device);
+                       return -ENOMEM;
+               }
                device->total_devs = btrfs_super_num_devices(disk_super);
                device->super_bytes_used = btrfs_super_bytes_used(disk_super);
                device->total_bytes =
@@ -128,7 +136,14 @@ static int device_list_add(const char *path,
                        btrfs_stack_device_bytes_used(&disk_super->dev_item);
                list_add(&device->dev_list, &fs_devices->devices);
                device->fs_devices = fs_devices;
-       }
+       } else if (!device->name || strcmp(device->name, path)) {
+               char *name = strdup(path);
+                if (!name)
+                        return -ENOMEM;
+                kfree(device->name);
+                device->name = name;
+        }
+
 
        if (found_transid > fs_devices->latest_trans) {
                fs_devices->latest_devid = devid;
@@ -144,24 +159,61 @@ static int device_list_add(const char *path,
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 {
        struct btrfs_fs_devices *seed_devices;
-       struct list_head *cur;
        struct btrfs_device *device;
+       int ret = 0;
+
 again:
-       list_for_each(cur, &fs_devices->devices) {
-               device = list_entry(cur, struct btrfs_device, dev_list);
-               close(device->fd);
-               device->fd = -1;
+       if (!fs_devices)
+               return 0;
+       while (!list_empty(&fs_devices->devices)) {
+               device = list_entry(fs_devices->devices.next,
+                                   struct btrfs_device, dev_list);
+               if (device->fd != -1) {
+                       if (fsync(device->fd) == -1) {
+                               warning("fsync on device %llu failed: %s",
+                                       device->devid, strerror(errno));
+                               ret = -errno;
+                       }
+                       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;
+               list_del(&device->dev_list);
+               /* free the memory */
+               free(device->name);
+               free(device->label);
+               free(device);
        }
 
        seed_devices = fs_devices->seed;
        fs_devices->seed = NULL;
        if (seed_devices) {
+               struct btrfs_fs_devices *orig;
+
+               orig = fs_devices;
                fs_devices = seed_devices;
+               list_del(&orig->list);
+               free(orig);
                goto again;
+       } else {
+               list_del(&fs_devices->list);
+               free(fs_devices);
        }
 
-       return 0;
+       return ret;
+}
+
+void btrfs_close_all_devices(void)
+{
+       struct btrfs_fs_devices *fs_devices;
+
+       while (!list_empty(&fs_uuids)) {
+               fs_devices = list_entry(fs_uuids.next, struct btrfs_fs_devices,
+                                       list);
+               btrfs_close_devices(fs_devices);
+       }
 }
 
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
@@ -174,19 +226,28 @@ 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) {
                        ret = -errno;
+                       error("cannot open device '%s': %s", device->name,
+                                       strerror(errno));
                        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)
                        fs_devices->lowest_bdev = fd;
                device->fd = fd;
-               if (flags == O_RDWR)
+               if (flags & O_RDWR)
                        device->writeable = 1;
        }
        return 0;
@@ -197,86 +258,102 @@ fail:
 
 int btrfs_scan_one_device(int fd, const char *path,
                          struct btrfs_fs_devices **fs_devices_ret,
-                         u64 *total_devs, u64 super_offset)
+                         u64 *total_devs, u64 super_offset, unsigned sbflags)
 {
        struct btrfs_super_block *disk_super;
-       char *buf;
+       char buf[BTRFS_SUPER_INFO_SIZE];
        int ret;
        u64 devid;
-       char uuidbuf[37];
 
-       buf = malloc(4096);
-       if (!buf) {
-               ret = -ENOMEM;
-               goto error;
-       }
        disk_super = (struct btrfs_super_block *)buf;
-       ret = btrfs_read_dev_super(fd, disk_super, super_offset);
-       if (ret < 0) {
-               ret = -EIO;
-               goto error_brelse;
-       }
-       devid = le64_to_cpu(disk_super->dev_item.devid);
+       ret = btrfs_read_dev_super(fd, disk_super, super_offset, sbflags);
+       if (ret < 0)
+               return -EIO;
+       devid = btrfs_stack_device_id(&disk_super->dev_item);
        if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
                *total_devs = 1;
        else
                *total_devs = btrfs_super_num_devices(disk_super);
-       uuid_unparse(disk_super->fsid, uuidbuf);
 
        ret = device_list_add(path, disk_super, devid, fs_devices_ret);
 
-error_brelse:
-       free(buf);
-error:
        return ret;
 }
 
 /*
+ * find_free_dev_extent_start - find free space in the specified device
+ * @device:      the device which we search the free space in
+ * @num_bytes:   the size of the free space that we need
+ * @search_start: the position from which to begin the search
+ * @start:       store the start of the free space.
+ * @len:         the size of the free space. that we find, or the size
+ *               of the max free space if we don't find suitable free space
+ *
  * this uses a pretty simple search, the expectation is that it is
  * called very infrequently and that a given device has a small number
  * of extents
+ *
+ * @start is used to store the start of the free space if we find. But if we
+ * don't find suitable free space, it will be used to store the start position
+ * of the max free space.
+ *
+ * @len is used to store the size of the free space that we find.
+ * But if we don't find suitable free space, it is used to store the size of
+ * the max free space.
  */
-static int find_free_dev_extent(struct btrfs_trans_handle *trans,
-                               struct btrfs_device *device,
-                               struct btrfs_path *path,
-                               u64 num_bytes, u64 *start)
+static int find_free_dev_extent_start(struct btrfs_trans_handle *trans,
+                              struct btrfs_device *device, u64 num_bytes,
+                              u64 search_start, u64 *start, u64 *len)
 {
        struct btrfs_key key;
        struct btrfs_root *root = device->dev_root;
-       struct btrfs_dev_extent *dev_extent = NULL;
-       u64 hole_size = 0;
-       u64 last_byte = 0;
-       u64 search_start = 0;
+       struct btrfs_dev_extent *dev_extent;
+       struct btrfs_path *path;
+       u64 hole_size;
+       u64 max_hole_start;
+       u64 max_hole_size;
+       u64 extent_end;
        u64 search_end = device->total_bytes;
        int ret;
-       int slot = 0;
-       int start_found;
+       int slot;
        struct extent_buffer *l;
+       u64 min_search_start;
 
-       start_found = 0;
-       path->reada = 2;
+       /*
+        * We don't want to overwrite the superblock on the drive nor any area
+        * used by the boot loader (grub for example), so we make sure to start
+        * at an offset of at least 1MB.
+        */
+       min_search_start = max(root->fs_info->alloc_start, (u64)SZ_1M);
+       search_start = max(search_start, min_search_start);
 
-       /* FIXME use last free of some kind */
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
 
-       /* we don't want to overwrite the superblock on the drive,
-        * so we make sure to start at an offset of at least 1MB
-        */
-       search_start = max((u64)1024 * 1024, search_start);
+       max_hole_start = search_start;
+       max_hole_size = 0;
 
-       if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
-               search_start = max(root->fs_info->alloc_start, search_start);
+       if (search_start >= search_end) {
+               ret = -ENOSPC;
+               goto out;
+       }
+
+       path->reada = 2;
 
        key.objectid = device->devid;
        key.offset = search_start;
        key.type = BTRFS_DEV_EXTENT_KEY;
-       ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
-       if (ret < 0)
-               goto error;
-       ret = btrfs_previous_item(root, path, 0, key.type);
+
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
        if (ret < 0)
-               goto error;
-       l = path->nodes[0];
-       btrfs_item_key_to_cpu(l, &key, path->slots[0]);
+               goto out;
+       if (ret > 0) {
+               ret = btrfs_previous_item(root, path, key.objectid, key.type);
+               if (ret < 0)
+                       goto out;
+       }
+
        while (1) {
                l = path->nodes[0];
                slot = path->slots[0];
@@ -285,24 +362,9 @@ static int find_free_dev_extent(struct btrfs_trans_handle *trans,
                        if (ret == 0)
                                continue;
                        if (ret < 0)
-                               goto error;
-no_more_items:
-                       if (!start_found) {
-                               if (search_start >= search_end) {
-                                       ret = -ENOSPC;
-                                       goto error;
-                               }
-                               *start = search_start;
-                               start_found = 1;
-                               goto check_pending;
-                       }
-                       *start = last_byte > search_start ?
-                               last_byte : search_start;
-                       if (search_end <= *start) {
-                               ret = -ENOSPC;
-                               goto error;
-                       }
-                       goto check_pending;
+                               goto out;
+
+                       break;
                }
                btrfs_item_key_to_cpu(l, &key, slot);
 
@@ -310,54 +372,90 @@ no_more_items:
                        goto next;
 
                if (key.objectid > device->devid)
-                       goto no_more_items;
-
-               if (key.offset >= search_start && key.offset > last_byte &&
-                   start_found) {
-                       if (last_byte < search_start)
-                               last_byte = search_start;
-                       hole_size = key.offset - last_byte;
-                       if (key.offset > last_byte &&
-                           hole_size >= num_bytes) {
-                               *start = last_byte;
-                               goto check_pending;
-                       }
-               }
-               if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
+                       break;
+
+               if (key.type != BTRFS_DEV_EXTENT_KEY)
                        goto next;
+
+               if (key.offset > search_start) {
+                       hole_size = key.offset - search_start;
+
+                       /*
+                        * Have to check before we set max_hole_start, otherwise
+                        * we could end up sending back this offset anyway.
+                        */
+                       if (hole_size > max_hole_size) {
+                               max_hole_start = search_start;
+                               max_hole_size = hole_size;
+                       }
+
+                       /*
+                        * If this free space is greater than which we need,
+                        * it must be the max free space that we have found
+                        * until now, so max_hole_start must point to the start
+                        * of this free space and the length of this free space
+                        * is stored in max_hole_size. Thus, we return
+                        * max_hole_start and max_hole_size and go back to the
+                        * caller.
+                        */
+                       if (hole_size >= num_bytes) {
+                               ret = 0;
+                               goto out;
+                       }
                }
 
-               start_found = 1;
                dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
-               last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
+               extent_end = key.offset + btrfs_dev_extent_length(l,
+                                                                 dev_extent);
+               if (extent_end > search_start)
+                       search_start = extent_end;
 next:
                path->slots[0]++;
                cond_resched();
        }
-check_pending:
-       /* we have to make sure we didn't find an extent that has already
-        * been allocated by the map tree or the original allocation
+
+       /*
+        * At this point, search_start should be the end of
+        * allocated dev extents, and when shrinking the device,
+        * search_end may be smaller than search_start.
         */
-       btrfs_release_path(root, path);
-       BUG_ON(*start < search_start);
+       if (search_end > search_start) {
+               hole_size = search_end - search_start;
 
-       if (*start + num_bytes > search_end) {
-               ret = -ENOSPC;
-               goto error;
+               if (hole_size > max_hole_size) {
+                       max_hole_start = search_start;
+                       max_hole_size = hole_size;
+               }
        }
-       /* check for pending inserts here */
-       return 0;
 
-error:
-       btrfs_release_path(root, path);
+       /* See above. */
+       if (max_hole_size < num_bytes)
+               ret = -ENOSPC;
+       else
+               ret = 0;
+
+out:
+       btrfs_free_path(path);
+       *start = max_hole_start;
+       if (len)
+               *len = max_hole_size;
        return ret;
 }
 
-int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
-                          struct btrfs_device *device,
-                          u64 chunk_tree, u64 chunk_objectid,
-                          u64 chunk_offset,
-                          u64 num_bytes, u64 *start)
+int find_free_dev_extent(struct btrfs_trans_handle *trans,
+                        struct btrfs_device *device, u64 num_bytes,
+                        u64 *start)
+{
+       /* FIXME use last free of some kind */
+       return find_free_dev_extent_start(trans, device,
+                                         num_bytes, 0, start, NULL);
+}
+
+static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+                                 struct btrfs_device *device,
+                                 u64 chunk_tree, u64 chunk_objectid,
+                                 u64 chunk_offset,
+                                 u64 num_bytes, u64 *start, int convert)
 {
        int ret;
        struct btrfs_path *path;
@@ -370,9 +468,15 @@ int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
        if (!path)
                return -ENOMEM;
 
-       ret = find_free_dev_extent(trans, device, path, num_bytes, start);
-       if (ret) {
-               goto err;
+       /*
+        * For convert case, just skip search free dev_extent, as caller
+        * is responsible to make sure it's free.
+        */
+       if (!convert) {
+               ret = find_free_dev_extent(trans, device, num_bytes,
+                                          start);
+               if (ret)
+                       goto err;
        }
 
        key.objectid = device->devid;
@@ -409,7 +513,8 @@ static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
        struct btrfs_key found_key;
 
        path = btrfs_alloc_path();
-       BUG_ON(!path);
+       if (!path)
+               return -ENOMEM;
 
        key.objectid = objectid;
        key.offset = (u64)-1;
@@ -470,7 +575,7 @@ static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
        }
        ret = 0;
 error:
-       btrfs_release_path(root, path);
+       btrfs_release_path(path);
        return ret;
 }
 
@@ -584,18 +689,18 @@ out:
        return ret;
 }
 
-int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
-                          struct btrfs_root *root,
+int btrfs_add_system_chunk(struct btrfs_root *root,
                           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;
 
        array_size = btrfs_super_sys_array_size(super_copy);
-       if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+       if (array_size + item_size + sizeof(disk_key)
+                       > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
                return -EFBIG;
 
        ptr = super_copy->sys_chunk_array + array_size;
@@ -608,14 +713,6 @@ 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)
 {
@@ -623,65 +720,179 @@ 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 BTRFS_STRIPE_LEN;
+}
+
+/*
+ * btrfs_device_avail_bytes - count bytes available for alloc_chunk
+ *
+ * It is not equal to "device->total_bytes - device->bytes_used".
+ * We do not allocate any chunk in 1M at beginning of device, and not
+ * allowed to allocate any chunk before alloc_start if it is specified.
+ * So search holes from max(1M, alloc_start) to device->total_bytes.
+ */
+static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
+                                   struct btrfs_device *device,
+                                   u64 *avail_bytes)
+{
+       struct btrfs_path *path;
+       struct btrfs_root *root = device->dev_root;
+       struct btrfs_key key;
+       struct btrfs_dev_extent *dev_extent = NULL;
+       struct extent_buffer *l;
+       u64 search_start = root->fs_info->alloc_start;
+       u64 search_end = device->total_bytes;
+       u64 extent_end = 0;
+       u64 free_bytes = 0;
+       int ret;
+       int slot = 0;
+
+       search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = device->devid;
+       key.offset = root->fs_info->alloc_start;
+       key.type = BTRFS_DEV_EXTENT_KEY;
+
+       path->reada = 2;
+       ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
+       if (ret < 0)
+               goto error;
+       ret = btrfs_previous_item(root, path, 0, key.type);
+       if (ret < 0)
+               goto error;
+
+       while (1) {
+               l = path->nodes[0];
+               slot = path->slots[0];
+               if (slot >= btrfs_header_nritems(l)) {
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret == 0)
+                               continue;
+                       if (ret < 0)
+                               goto error;
+                       break;
+               }
+               btrfs_item_key_to_cpu(l, &key, slot);
+
+               if (key.objectid < device->devid)
+                       goto next;
+               if (key.objectid > device->devid)
+                       break;
+               if (key.type != BTRFS_DEV_EXTENT_KEY)
+                       goto next;
+               if (key.offset > search_end)
+                       break;
+               if (key.offset > search_start)
+                       free_bytes += key.offset - search_start;
+
+               dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+               extent_end = key.offset + btrfs_dev_extent_length(l,
+                                                                 dev_extent);
+               if (extent_end > search_start)
+                       search_start = extent_end;
+               if (search_start > search_end)
+                       break;
+next:
+               path->slots[0]++;
+               cond_resched();
+       }
+
+       if (search_start < search_end)
+               free_bytes += search_end - search_start;
+
+       *avail_bytes = free_bytes;
+       ret = 0;
+error:
+       btrfs_free_path(path);
+       return ret;
+}
+
+#define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r)            \
+                       - sizeof(struct btrfs_item)             \
+                       - sizeof(struct btrfs_chunk))           \
+                       / sizeof(struct btrfs_stripe) + 1)
+
+#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE       \
+                               - 2 * sizeof(struct btrfs_disk_key)     \
+                               - 2 * sizeof(struct btrfs_chunk))       \
+                               / sizeof(struct btrfs_stripe) + 1)
+
 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;
-       u64 calc_size = 8 * 1024 * 1024;
+       int min_stripe_size = SZ_1M;
+       u64 calc_size = SZ_8M;
        u64 min_free;
        u64 max_chunk_size = 4 * calc_size;
-       u64 avail;
+       u64 avail = 0;
        u64 max_avail = 0;
        u64 percent_max;
        int num_stripes = 1;
+       int max_stripes = 0;
        int min_stripes = 1;
        int sub_stripes = 0;
        int looped = 0;
        int ret;
        int index;
-       int stripe_len = 64 * 1024;
+       int stripe_len = BTRFS_STRIPE_LEN;
        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) {
-                       calc_size = 8 * 1024 * 1024;
+                       calc_size = SZ_8M;
                        max_chunk_size = calc_size * 2;
-                       min_stripe_size = 1 * 1024 * 1024;
+                       min_stripe_size = SZ_1M;
+                       max_stripes = BTRFS_MAX_DEVS_SYS_CHUNK;
                } else if (type & BTRFS_BLOCK_GROUP_DATA) {
-                       calc_size = 1024 * 1024 * 1024;
+                       calc_size = SZ_1G;
                        max_chunk_size = 10 * calc_size;
-                       min_stripe_size = 64 * 1024 * 1024;
+                       min_stripe_size = SZ_64M;
+                       max_stripes = BTRFS_MAX_DEVS(chunk_root);
                } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
-                       calc_size = 1024 * 1024 * 1024;
+                       calc_size = SZ_1G;
                        max_chunk_size = 4 * calc_size;
-                       min_stripe_size = 32 * 1024 * 1024;
+                       min_stripe_size = SZ_32M;
+                       max_stripes = BTRFS_MAX_DEVS(chunk_root);
                }
        }
        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;
@@ -691,20 +902,44 @@ 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);
+               if (num_stripes > max_stripes)
+                       num_stripes = max_stripes;
                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 > max_stripes)
+                       num_stripes = max_stripes;
                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 > max_stripes)
+                       num_stripes = max_stripes;
+               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 > max_stripes)
+                       num_stripes = max_stripes;
+               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:
@@ -732,7 +967,9 @@ again:
        /* build a private list of devices we will allocate from */
        while(index < num_stripes) {
                device = list_entry(cur, struct btrfs_device, dev_list);
-               avail = device->total_bytes - device->bytes_used;
+               ret = btrfs_device_avail_bytes(trans, device, &avail);
+               if (ret)
+                       return ret;
                cur = cur->next;
                if (avail >= min_free) {
                        list_move_tail(&device->dev_list, &private_devs);
@@ -762,18 +999,19 @@ 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;
@@ -797,7 +1035,7 @@ again:
                ret = btrfs_alloc_dev_extent(trans, device,
                             info->chunk_root->root_key.objectid,
                             BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
-                            calc_size, &dev_offset);
+                            calc_size, &dev_offset, 0);
                BUG_ON(ret);
 
                device->bytes_used += calc_size;
@@ -840,13 +1078,11 @@ 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) {
-               ret = btrfs_add_system_chunk(trans, chunk_root, &key,
+               ret = btrfs_add_system_chunk(chunk_root, &key,
                                    chunk, btrfs_chunk_item_size(num_stripes));
                BUG_ON(ret);
        }
@@ -855,39 +1091,61 @@ again:
        return ret;
 }
 
+/*
+ * Alloc a DATA chunk with SINGLE profile.
+ *
+ * If 'convert' is set, it will alloc a chunk with 1:1 mapping
+ * (btrfs logical bytenr == on-disk bytenr)
+ * For that case, caller must make sure the chunk and dev_extent are not
+ * occupied.
+ */
 int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
                           struct btrfs_root *extent_root, u64 *start,
-                          u64 num_bytes, u64 type)
+                          u64 num_bytes, u64 type, int convert)
 {
        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;
+       u64 calc_size = SZ_8M;
        int num_stripes = 1;
        int sub_stripes = 0;
        int ret;
        int index;
-       int stripe_len = 64 * 1024;
+       int stripe_len = BTRFS_STRIPE_LEN;
        struct btrfs_key key;
 
        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);
-       if (ret)
-               return ret;
+       if (convert) {
+               if (*start != round_down(*start, extent_root->sectorsize)) {
+                       error("DATA chunk start not sectorsize aligned: %llu",
+                                       (unsigned long long)*start);
+                       return -EINVAL;
+               }
+               key.offset = *start;
+               dev_offset = *start;
+       } else {
+               u64 tmp;
+
+               ret = find_next_chunk(chunk_root,
+                                     BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+                                     &tmp);
+               key.offset = tmp;
+               if (ret)
+                       return ret;
+       }
 
        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;
@@ -906,7 +1164,7 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
                ret = btrfs_alloc_dev_extent(trans, device,
                             info->chunk_root->root_key.objectid,
                             BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
-                            calc_size, &dev_offset);
+                            calc_size, &dev_offset, convert);
                BUG_ON(ret);
 
                device->bytes_used += calc_size;
@@ -943,60 +1201,79 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
        ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
                                btrfs_chunk_item_size(num_stripes));
        BUG_ON(ret);
-       *start = key.offset;
+       if (!convert)
+               *start = key.offset;
 
        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);
        return ret;
 }
 
-void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
-{
-       cache_tree_init(&tree->cache_tree);
-}
-
 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
 {
        struct cache_extent *ce;
        struct map_lookup *map;
        int ret;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, logical);
-       BUG_ON(!ce);
-       BUG_ON(ce->start > logical || ce->start + ce->size < logical);
+       ce = search_cache_extent(&map_tree->cache_tree, logical);
+       if (!ce) {
+               fprintf(stderr, "No mapping for %llu-%llu\n",
+                       (unsigned long long)logical,
+                       (unsigned long long)logical+len);
+               return 1;
+       }
+       if (ce->start > logical || ce->start + ce->size < logical) {
+               fprintf(stderr, "Invalid mapping for %llu-%llu, got "
+                       "%llu-%llu\n", (unsigned long long)logical,
+                       (unsigned long long)logical+len,
+                       (unsigned long long)ce->start,
+                       (unsigned long long)ce->start + ce->size);
+               return 1;
+       }
        map = container_of(ce, struct map_lookup, ce);
 
        if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
                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;
 }
 
-int btrfs_next_metadata(struct btrfs_mapping_tree *map_tree, u64 *logical,
-                       u64 *size)
+int btrfs_next_bg(struct btrfs_mapping_tree *map_tree, u64 *logical,
+                    u64 *size, u64 type)
 {
        struct cache_extent *ce;
        struct map_lookup *map;
+       u64 cur = *logical;
 
-       ce = find_first_cache_extent(&map_tree->cache_tree, *logical);
+       ce = search_cache_extent(&map_tree->cache_tree, cur);
 
        while (ce) {
-               ce = next_cache_extent(ce);
-               if (!ce)
-                       return -ENOENT;
+               /*
+                * only jump to next bg if our cur is not 0
+                * As the initial logical for btrfs_next_bg() is 0, and
+                * if we jump to next bg, we skipped a valid bg.
+                */
+               if (cur) {
+                       ce = next_cache_extent(ce);
+                       if (!ce)
+                               return -ENOENT;
+               }
 
+               cur = ce->start;
                map = container_of(ce, struct map_lookup, ce);
-               if (map->type & BTRFS_BLOCK_GROUP_METADATA) {
+               if (map->type & type) {
                        *logical = ce->start;
                        *size = ce->size;
                        return 0;
@@ -1016,17 +1293,24 @@ 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);
 
@@ -1045,8 +1329,11 @@ 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;
@@ -1057,28 +1344,60 @@ 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;
@@ -1089,15 +1408,15 @@ 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);
+               kfree(multi);
+               *length = (u64)-1;
                return -ENOENT;
        }
-       if (ce->start > logical || ce->start + ce->size < logical) {
-               if (multi)
-                       kfree(multi);
+       if (ce->start > logical) {
+               kfree(multi);
+               *length = ce->start - logical;
                return -ENOENT;
        }
 
@@ -1118,11 +1437,26 @@ 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;
@@ -1139,6 +1473,7 @@ 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 */
@@ -1177,6 +1512,59 @@ 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 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
@@ -1196,8 +1584,14 @@ 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;
 }
@@ -1211,7 +1605,8 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
        cur_devices = root->fs_info->fs_devices;
        while (cur_devices) {
                if (!fsid ||
-                   !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
+                   (!memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE) ||
+                    root->fs_info->ignore_fsid_mismatch)) {
                        device = __find_device(&cur_devices->devices,
                                               devid, uuid);
                        if (device)
@@ -1222,57 +1617,19 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
        return NULL;
 }
 
-int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
-                             struct btrfs_fs_devices *fs_devices)
+struct btrfs_device *
+btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
+                          u64 devid, int instance)
 {
-       struct map_lookup *map;
-       u64 logical = BTRFS_SUPER_INFO_OFFSET;
-       u64 length = BTRFS_SUPER_INFO_SIZE;
-       int num_stripes = 0;
-       int sub_stripes = 0;
-       int ret;
-       int i;
-       struct list_head *cur;
-
-       list_for_each(cur, &fs_devices->devices) {
-               num_stripes++;
-       }
-       map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
-       if (!map)
-               return -ENOMEM;
+       struct list_head *head = &fs_devices->devices;
+       struct btrfs_device *dev;
+       int num_found = 0;
 
-       map->ce.start = logical;
-       map->ce.size = length;
-       map->num_stripes = num_stripes;
-       map->sub_stripes = sub_stripes;
-       map->io_width = length;
-       map->io_align = length;
-       map->sector_size = length;
-       map->stripe_len = length;
-       map->type = BTRFS_BLOCK_GROUP_RAID1;
-
-       i = 0;
-       list_for_each(cur, &fs_devices->devices) {
-               struct btrfs_device *device = list_entry(cur,
-                                                        struct btrfs_device,
-                                                        dev_list);
-               map->stripes[i].physical = logical;
-               map->stripes[i].dev = device;
-               i++;
-       }
-       ret = insert_existing_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_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,
-                                                  &map->ce);
+       list_for_each_entry(dev, head, dev_list) {
+               if (dev->devid == devid && num_found++ == instance)
+                       return dev;
        }
-       BUG_ON(ret);
-       return 0;
+       return NULL;
 }
 
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
@@ -1283,8 +1640,15 @@ 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);
-       BUG_ON(!ce);
+       /*
+        * During chunk recovering, we may fail to find block group's
+        * corresponding chunk, we will rebuild it later
+        */
+       ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
+       if (!root->fs_info->is_chunk_recover)
+               BUG_ON(!ce);
+       else
+               return 0;
 
        map = container_of(ce, struct map_lookup, ce);
        for (i = 0; i < map->num_stripes; i++) {
@@ -1307,9 +1671,99 @@ static struct btrfs_device *fill_missing_device(u64 devid)
        return device;
 }
 
+/*
+ * slot == -1: SYSTEM chunk
+ * return -EIO on error, otherwise return 0
+ */
+int btrfs_check_chunk_valid(struct btrfs_root *root,
+                           struct extent_buffer *leaf,
+                           struct btrfs_chunk *chunk,
+                           int slot, u64 logical)
+{
+       u64 length;
+       u64 stripe_len;
+       u16 num_stripes;
+       u16 sub_stripes;
+       u64 type;
+
+       length = btrfs_chunk_length(leaf, chunk);
+       stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+       num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+       sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+       type = btrfs_chunk_type(leaf, chunk);
+
+       /*
+        * These valid checks may be insufficient to cover every corner cases.
+        */
+       if (!IS_ALIGNED(logical, root->sectorsize)) {
+               error("invalid chunk logical %llu",  logical);
+               return -EIO;
+       }
+       if (btrfs_chunk_sector_size(leaf, chunk) != root->sectorsize) {
+               error("invalid chunk sectorsize %llu", 
+                     (unsigned long long)btrfs_chunk_sector_size(leaf, chunk));
+               return -EIO;
+       }
+       if (!length || !IS_ALIGNED(length, root->sectorsize)) {
+               error("invalid chunk length %llu",  length);
+               return -EIO;
+       }
+       if (stripe_len != BTRFS_STRIPE_LEN) {
+               error("invalid chunk stripe length: %llu", stripe_len);
+               return -EIO;
+       }
+       /* Check on chunk item type */
+       if (slot == -1 && (type & BTRFS_BLOCK_GROUP_SYSTEM) == 0) {
+               error("invalid chunk type %llu", type);
+               return -EIO;
+       }
+       if (type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
+                    BTRFS_BLOCK_GROUP_PROFILE_MASK)) {
+               error("unrecognized chunk type: %llu",
+                     ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
+                       BTRFS_BLOCK_GROUP_PROFILE_MASK) & type);
+               return -EIO;
+       }
+       /*
+        * Btrfs_chunk contains at least one stripe, and for sys_chunk
+        * it can't exceed the system chunk array size
+        * For normal chunk, it should match its chunk item size.
+        */
+       if (num_stripes < 1 ||
+           (slot == -1 && sizeof(struct btrfs_stripe) * num_stripes >
+            BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) ||
+           (slot >= 0 && sizeof(struct btrfs_stripe) * (num_stripes - 1) >
+            btrfs_item_size_nr(leaf, slot))) {
+               error("invalid num_stripes: %u", num_stripes);
+               return -EIO;
+       }
+       /*
+        * Device number check against profile
+        */
+       if ((type & BTRFS_BLOCK_GROUP_RAID10 && sub_stripes == 0) ||
+           (type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
+           (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
+           (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
+           (type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
+           ((type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
+            num_stripes != 1)) {
+               error("Invalid num_stripes:sub_stripes %u:%u for profile %llu",
+                     num_stripes, sub_stripes,
+                     type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+/*
+ * Slot is used to verify the chunk item is valid
+ *
+ * For sys chunk in superblock, pass -1 to indicate sys chunk.
+ */
 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                          struct extent_buffer *leaf,
-                         struct btrfs_chunk *chunk)
+                         struct btrfs_chunk *chunk, int slot)
 {
        struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
        struct map_lookup *map;
@@ -1324,16 +1778,24 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 
        logical = key->offset;
        length = btrfs_chunk_length(leaf, chunk);
+       num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+       /* Validation check */
+       ret = btrfs_check_chunk_valid(root, leaf, chunk, slot, logical);
+       if (ret) {
+               error("%s checksums match, but it has an invalid chunk, %s",
+                     (slot == -1) ? "Superblock" : "Metadata",
+                     (slot == -1) ? "try btrfsck --repair -s <superblock> ie, 0,1,2" : "");
+               return ret;
+       }
 
-       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) {
                return 0;
        }
 
-       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;
 
@@ -1360,10 +1822,12 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                        map->stripes[i].dev = fill_missing_device(devid);
                        printf("warning, device %llu is missing\n",
                               (unsigned long long)devid);
+                       list_add(&map->stripes[i].dev->dev_list,
+                                &root->fs_info->fs_devices->devices);
                }
 
        }
-       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;
@@ -1405,8 +1869,15 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
 
        fs_devices = find_fsid(fsid);
        if (!fs_devices) {
-               ret = -ENOENT;
-               goto out;
+               /* missing all seed devices */
+               fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
+               if (!fs_devices) {
+                       ret = -ENOMEM;
+                       goto out;
+               }
+               INIT_LIST_HEAD(&fs_devices->devices);
+               list_add(&fs_devices->list, &fs_uuids);
+               memcpy(fs_devices->fsid, fsid, BTRFS_FSID_SIZE);
        }
 
        ret = btrfs_open_devices(fs_devices, O_RDONLY);
@@ -1445,12 +1916,10 @@ static int read_one_dev(struct btrfs_root *root,
 
        device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
        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);
        }
@@ -1460,72 +1929,91 @@ 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;
-       struct btrfs_key key;
+       u8 *array_ptr;
+       unsigned long sb_array_offset;
+       int ret = 0;
        u32 num_stripes;
        u32 array_size;
        u32 len = 0;
-       u8 *ptr;
-       unsigned long sb_ptr;
-       u32 cur;
-       int ret = 0;
+       u32 cur_offset;
+       struct btrfs_key key;
 
-       sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
+       sb = btrfs_find_create_tree_block(root->fs_info,
+                                         BTRFS_SUPER_INFO_OFFSET,
                                          BTRFS_SUPER_INFO_SIZE);
        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);
 
-       /*
-        * we do this loop twice, once for the device items and
-        * once for all of the chunks.  This way there are device
-        * structs filled in for every chunk
-        */
-       ptr = super_copy->sys_chunk_array;
-       sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
-       cur = 0;
+       array_ptr = super_copy->sys_chunk_array;
+       sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
+       cur_offset = 0;
+
+       while (cur_offset < array_size) {
+               disk_key = (struct btrfs_disk_key *)array_ptr;
+               len = sizeof(*disk_key);
+               if (cur_offset + len > array_size)
+                       goto out_short_read;
 
-       while (cur < array_size) {
-               disk_key = (struct btrfs_disk_key *)ptr;
                btrfs_disk_key_to_cpu(&key, disk_key);
 
-               len = sizeof(*disk_key);
-               ptr += len;
-               sb_ptr += len;
-               cur += len;
+               array_ptr += len;
+               sb_array_offset += len;
+               cur_offset += len;
 
                if (key.type == BTRFS_CHUNK_ITEM_KEY) {
-                       chunk = (struct btrfs_chunk *)sb_ptr;
-                       ret = read_one_chunk(root, &key, sb, chunk);
-                       if (ret)
-                               break;
+                       chunk = (struct btrfs_chunk *)sb_array_offset;
+                       /*
+                        * At least one btrfs_chunk with one stripe must be
+                        * present, exact stripe count check comes afterwards
+                        */
+                       len = btrfs_chunk_item_size(1);
+                       if (cur_offset + len > array_size)
+                               goto out_short_read;
+
                        num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+                       if (!num_stripes) {
+                               printk(
+           "ERROR: invalid number of stripes %u in sys_array at offset %u\n",
+                                       num_stripes, cur_offset);
+                               ret = -EIO;
+                               break;
+                       }
+
                        len = btrfs_chunk_item_size(num_stripes);
+                       if (cur_offset + len > array_size)
+                               goto out_short_read;
+
+                       ret = read_one_chunk(root, &key, sb, chunk, -1);
+                       if (ret)
+                               break;
                } else {
-                       BUG();
+                       printk(
+               "ERROR: unexpected item type %u in sys_array at offset %u\n",
+                               (u32)key.type, cur_offset);
+                       ret = -EIO;
+                       break;
                }
-               ptr += len;
-               sb_ptr += len;
-               cur += len;
+               array_ptr += len;
+               sb_array_offset += len;
+               cur_offset += len;
        }
        free_extent_buffer(sb);
        return ret;
+
+out_short_read:
+       printk("ERROR: sys_array too short to read %u bytes at offset %u\n",
+                       len, cur_offset);
+       free_extent_buffer(sb);
+       return -EIO;
 }
 
 int btrfs_read_chunk_tree(struct btrfs_root *root)
@@ -1543,15 +2031,18 @@ int btrfs_read_chunk_tree(struct btrfs_root *root)
        if (!path)
                return -ENOMEM;
 
-       /* first we search for all of the device items, and then we
-        * read in all of the chunk items.  This way we can create chunk
-        * mappings that reference all of the devices that are afound
+       /*
+        * Read all device items, and then all the chunk items. All
+        * device items are found before any chunk item (their object id
+        * is smaller than the lowest possible object id for a chunk
+        * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
         */
        key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
        key.offset = 0;
        key.type = 0;
-again:
        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               goto error;
        while(1) {
                leaf = path->nodes[0];
                slot = path->slots[0];
@@ -1564,33 +2055,25 @@ again:
                        break;
                }
                btrfs_item_key_to_cpu(leaf, &found_key, slot);
-               if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
-                       if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
-                               break;
-                       if (found_key.type == BTRFS_DEV_ITEM_KEY) {
-                               struct btrfs_dev_item *dev_item;
-                               dev_item = btrfs_item_ptr(leaf, slot,
+               if (found_key.type == BTRFS_DEV_ITEM_KEY) {
+                       struct btrfs_dev_item *dev_item;
+                       dev_item = btrfs_item_ptr(leaf, slot,
                                                  struct btrfs_dev_item);
-                               ret = read_one_dev(root, leaf, dev_item);
-                               BUG_ON(ret);
-                       }
+                       ret = read_one_dev(root, leaf, dev_item);
+                       BUG_ON(ret);
                } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
                        struct btrfs_chunk *chunk;
                        chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
-                       ret = read_one_chunk(root, &found_key, leaf, chunk);
+                       ret = read_one_chunk(root, &found_key, leaf, chunk,
+                                            slot);
                        BUG_ON(ret);
                }
                path->slots[0]++;
        }
-       if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
-               key.objectid = 0;
-               btrfs_release_path(root, path);
-               goto again;
-       }
 
-       btrfs_free_path(path);
        ret = 0;
 error:
+       btrfs_free_path(path);
        return ret;
 }
 
@@ -1598,3 +2081,191 @@ 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 int 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 **tmp_ebs;
+       u64 start = orig_eb->start;
+       u64 this_eb_start;
+       int i;
+       int ret = 0;
+
+       tmp_ebs = calloc(num_stripes, sizeof(*tmp_ebs));
+       if (!tmp_ebs)
+               return -ENOMEM;
+
+       /* Alloc memory in a row for data stripes */
+       for (i = 0; i < num_stripes; i++) {
+               if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
+                       break;
+
+               tmp_ebs[i] = calloc(1, sizeof(**tmp_ebs) + stripe_len);
+               if (!tmp_ebs[i]) {
+                       ret = -ENOMEM;
+                       goto clean_up;
+               }
+       }
+
+       for (i = 0; i < num_stripes; i++) {
+               struct extent_buffer *eb = tmp_ebs[i];
+
+               if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
+                       break;
+
+               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);
+                       if (ret)
+                               goto clean_up;
+               } else {
+                       memcpy(eb->data, orig_eb->data + eb->start - start,
+                              stripe_len);
+               }
+               ebs[i] = eb;
+       }
+       free(tmp_ebs);
+       return ret;
+clean_up:
+       for (i = 0; i < num_stripes; i++)
+               free(tmp_ebs[i]);
+       free(tmp_ebs);
+       return ret;
+}
+
+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, *p_eb = NULL, *q_eb = NULL;
+       int i;
+       int ret;
+       int alloc_size = eb->len;
+       void **pointers;
+
+       ebs = malloc(sizeof(*ebs) * multi->num_stripes);
+       pointers = malloc(sizeof(*pointers) * multi->num_stripes);
+       if (!ebs || !pointers) {
+               free(ebs);
+               free(pointers);
+               return -ENOMEM;
+       }
+
+       if (stripe_len > alloc_size)
+               alloc_size = stripe_len;
+
+       ret = split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
+                                 multi->num_stripes);
+       if (ret)
+               goto out;
+
+       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++;
+                       if (ebs[i]->start != raid_map[i]) {
+                               ret = -EINVAL;
+                               goto out_free_split;
+                       }
+                       continue;
+               }
+               new_eb = malloc(sizeof(*eb) + alloc_size);
+               if (!new_eb) {
+                       ret = -ENOMEM;
+                       goto out_free_split;
+               }
+               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) {
+               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;
+               for (i = 0; i < multi->num_stripes; i++)
+                       pointers[i] = ebs[i]->data;
+               ret = raid5_gen_result(multi->num_stripes, stripe_len,
+                                      multi->num_stripes - 1, pointers);
+               if (ret < 0)
+                       goto out_free_split;
+       }
+
+       for (i = 0; i < multi->num_stripes; i++) {
+               ret = write_extent_to_disk(ebs[i]);
+               if (ret < 0)
+                       goto out_free_split;
+       }
+
+out_free_split:
+       for (i = 0; i < multi->num_stripes; i++) {
+               if (ebs[i] != eb)
+                       free(ebs[i]);
+       }
+out:
+       free(ebs);
+       free(pointers);
+
+       return ret;
+}