btrfs-progs: add OPEN_CTREE_INVALIDATE_FST flag
[platform/upstream/btrfs-progs.git] / volumes.c
index f7462c5..e39f21e 100644 (file)
--- a/volumes.c
+++ b/volumes.c
@@ -162,6 +162,8 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
        struct btrfs_device *device;
 
 again:
+       if (!fs_devices)
+               return 0;
        while (!list_empty(&fs_devices->devices)) {
                device = list_entry(fs_devices->devices.next,
                                    struct btrfs_device, dev_list);
@@ -198,6 +200,17 @@ again:
        return 0;
 }
 
+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)
 {
        int fd;
@@ -216,6 +229,8 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
                fd = open(device->name, flags);
                if (fd < 0) {
                        ret = -errno;
+                       error("cannot open device '%s': %s", device->name,
+                                       strerror(errno));
                        goto fail;
                }
 
@@ -238,24 +253,17 @@ fail:
 
 int btrfs_scan_one_device(int fd, const char *path,
                          struct btrfs_fs_devices **fs_devices_ret,
-                         u64 *total_devs, u64 super_offset, int super_recover)
+                         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;
 
-       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, super_recover);
-       if (ret < 0) {
-               ret = -EIO;
-               goto error_brelse;
-       }
+       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;
@@ -264,9 +272,6 @@ int btrfs_scan_one_device(int fd, const char *path,
 
        ret = device_list_add(path, disk_super, devid, fs_devices_ret);
 
-error_brelse:
-       free(buf);
-error:
        return ret;
 }
 
@@ -364,7 +369,7 @@ no_more_items:
                                goto check_pending;
                        }
                }
-               if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
+               if (key.type != BTRFS_DEV_EXTENT_KEY) {
                        goto next;
                }
 
@@ -398,7 +403,7 @@ 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)
+                                 u64 num_bytes, u64 *start, int convert)
 {
        int ret;
        struct btrfs_path *path;
@@ -411,9 +416,15 @@ static 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, path, num_bytes,
+                                          start);
+               if (ret)
+                       goto err;
        }
 
        key.objectid = device->devid;
@@ -450,7 +461,8 @@ 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;
@@ -731,7 +743,7 @@ static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
                        goto next;
                if (key.objectid > device->devid)
                        break;
-               if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+               if (key.type != BTRFS_DEV_EXTENT_KEY)
                        goto next;
                if (key.offset > search_end)
                        break;
@@ -972,7 +984,7 @@ 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;
@@ -1028,9 +1040,17 @@ 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;
@@ -1051,10 +1071,24 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
 
        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)
@@ -1079,7 +1113,7 @@ 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;
@@ -1116,7 +1150,8 @@ 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;
@@ -1164,21 +1199,30 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
        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 = search_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;
@@ -1577,7 +1621,92 @@ static struct btrfs_device *fill_missing_device(u64 devid)
 }
 
 /*
- * Slot is used to verfy the chunk item is valid
+ * 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.
  */
@@ -1598,6 +1727,15 @@ 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 = search_cache_extent(&map_tree->cache_tree, logical);
 
@@ -1606,7 +1744,6 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                return 0;
        }
 
-       num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
        map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
        if (!map)
                return -ENOMEM;
@@ -1621,50 +1758,6 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        map->type = btrfs_chunk_type(leaf, chunk);
        map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
 
-       /* Check on chunk item type */
-       if (map->type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
-                         BTRFS_BLOCK_GROUP_PROFILE_MASK)) {
-               fprintf(stderr, "Unknown chunk type bits: %llu\n",
-                       map->type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
-                                     BTRFS_BLOCK_GROUP_PROFILE_MASK));
-               ret = -EIO;
-               goto out;
-       }
-
-       /*
-        * 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))) {
-               fprintf(stderr, "Invalid num_stripes: %u\n",
-                       num_stripes);
-               ret = -EIO;
-               goto out;
-       }
-
-       /*
-        * Device number check against profile
-        */
-       if ((map->type & BTRFS_BLOCK_GROUP_RAID10 && map->sub_stripes == 0) ||
-           (map->type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
-           (map->type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
-           (map->type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
-           (map->type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
-           ((map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
-            num_stripes != 1)) {
-               fprintf(stderr,
-                       "Invalid num_stripes:sub_stripes %u:%u for profile %llu\n",
-                       num_stripes, map->sub_stripes,
-                       map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
-               ret = -EIO;
-               goto out;
-       }
-
        for (i = 0; i < num_stripes; i++) {
                map->stripes[i].physical =
                        btrfs_stripe_offset_nr(leaf, chunk, i);
@@ -1678,6 +1771,8 @@ 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);
                }
 
        }
@@ -1685,9 +1780,6 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
        BUG_ON(ret);
 
        return 0;
-out:
-       free(map);
-       return ret;
 }
 
 static int fill_device_from_item(struct extent_buffer *leaf,
@@ -1773,8 +1865,6 @@ 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 = kzalloc(sizeof(*device), GFP_NOFS);
                if (!device)
                        return -ENOMEM;
@@ -1794,50 +1884,85 @@ int btrfs_read_sys_array(struct btrfs_root *root)
        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;
-       u8 *array_end;
-       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, sizeof(*super_copy));
-       array_end = ((u8 *)super_copy->sys_chunk_array) +
-                   btrfs_super_sys_array_size(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;
+       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 (ptr < array_end) {
-               disk_key = (struct btrfs_disk_key *)ptr;
                btrfs_disk_key_to_cpu(&key, disk_key);
 
-               len = sizeof(*disk_key);
-               ptr += len;
+               array_ptr += len;
+               sb_array_offset += len;
+               cur_offset += len;
 
                if (key.type == BTRFS_CHUNK_ITEM_KEY) {
-                       chunk = (struct btrfs_chunk *)(ptr - (u8 *)super_copy);
+                       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;
-                       num_stripes = btrfs_chunk_num_stripes(sb, chunk);
-                       len = btrfs_chunk_item_size(num_stripes);
                } 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;
+               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)
@@ -1941,26 +2066,39 @@ static int rmw_eb(struct btrfs_fs_info *info,
        return 0;
 }
 
-static void split_eb_for_raid56(struct btrfs_fs_info *info,
-                               struct extent_buffer *orig_eb,
+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 *eb;
+       struct extent_buffer **tmp_ebs;
        u64 start = orig_eb->start;
        u64 this_eb_start;
        int i;
-       int ret;
+       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;
 
-               eb = malloc(sizeof(struct extent_buffer) + stripe_len);
-               if (!eb)
-                       BUG();
-               memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
+               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;
@@ -1974,12 +2112,21 @@ static void split_eb_for_raid56(struct btrfs_fs_info *info,
                if (start > this_eb_start ||
                    start + orig_eb->len < this_eb_start + stripe_len) {
                        ret = rmw_eb(info, eb, orig_eb);
-                       BUG_ON(ret);
+                       if (ret)
+                               goto clean_up;
                } else {
-                       memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
+                       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,
@@ -1992,15 +2139,23 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
        int j;
        int ret;
        int alloc_size = eb->len;
+       void **pointers;
 
-       ebs = kmalloc(sizeof(*ebs) * multi->num_stripes, GFP_NOFS);
-       BUG_ON(!ebs);
+       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;
 
-       split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
-                           multi->num_stripes);
+       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;
@@ -2008,11 +2163,17 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
                        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]);
+                       if (ebs[i]->start != raid_map[i]) {
+                               ret = -EINVAL;
+                               goto out_free_split;
+                       }
                        continue;
                }
-               new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
-               BUG_ON(!new_eb);
+               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++;
@@ -2024,12 +2185,6 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
                        q_eb = new_eb;
        }
        if (q_eb) {
-               void **pointers;
-
-               pointers = kmalloc(sizeof(*pointers) * multi->num_stripes,
-                                  GFP_NOFS);
-               BUG_ON(!pointers);
-
                ebs[multi->num_stripes - 2] = p_eb;
                ebs[multi->num_stripes - 1] = q_eb;
 
@@ -2037,26 +2192,36 @@ int write_raid56_with_parity(struct btrfs_fs_info *info,
                        pointers[i] = ebs[i]->data;
 
                raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
-               kfree(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 < stripe_len; i += sizeof(u64)) {
+                               u64 p_eb_data;
+                               u64 ebs_data;
+
+                               p_eb_data = get_unaligned_64(p_eb->data + i);
+                               ebs_data = get_unaligned_64(ebs[j]->data + i);
+                               p_eb_data ^= ebs_data;
+                               put_unaligned_64(p_eb_data, p_eb->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]);
+               if (ret < 0)
+                       goto out_free_split;
        }
 
-       kfree(ebs);
+out_free_split:
+       for (i = 0; i < multi->num_stripes; i++) {
+               if (ebs[i] != eb)
+                       free(ebs[i]);
+       }
+out:
+       free(ebs);
+       free(pointers);
 
-       return 0;
+       return ret;
 }