btrfs-progs: add dev maxs limit for btrfs_alloc_chunk in user space

For RAID0,5,6,10,
For system chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds BTRFS_SYSTEM_CHUNK_ARRAY_SIZE
For data/meta chunk, there shouldn't be too many stripes to
make a btrfs_chunk that exceeds a leaf.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/volumes.c b/volumes.c
index b39f374..a61928c 100644 (file)
--- a/volumes.c
+++ b/volumes.c
@@ -754,6 +754,16 @@ error:
        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)
@@ -776,6 +786,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        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;
@@ -797,14 +808,17 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                        calc_size = 8 * 1024 * 1024;
                        max_chunk_size = calc_size * 2;
                        min_stripe_size = 1 * 1024 * 1024;
+                       max_stripes = BTRFS_MAX_DEVS_SYS_CHUNK;
                } else if (type & BTRFS_BLOCK_GROUP_DATA) {
                        calc_size = 1024 * 1024 * 1024;
                        max_chunk_size = 10 * calc_size;
                        min_stripe_size = 64 * 1024 * 1024;
+                       max_stripes = BTRFS_MAX_DEVS(chunk_root);
                } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
                        calc_size = 1024 * 1024 * 1024;
                        max_chunk_size = 4 * calc_size;
                        min_stripe_size = 32 * 1024 * 1024;
+                       max_stripes = BTRFS_MAX_DEVS(chunk_root);
                }
        }
        if (type & BTRFS_BLOCK_GROUP_RAID1) {
@@ -820,10 +834,14 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        }
        if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
                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);
+               if (num_stripes > max_stripes)
+                       num_stripes = max_stripes;
                if (num_stripes < 4)
                        return -ENOSPC;
                num_stripes &= ~(u32)1;
@@ -832,6 +850,8 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        }
        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;
@@ -840,6 +860,8 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        }
        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;