Btrfs: fix wrong reservation of csums

[~andy/linux] / fs / btrfs / file-item.c

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index bd38cef4235882425c08eb6a5d10306736a14237..b7e529d2860f2f42e3a826593359419a4e5f4111 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -460,8 +460,8 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
                if (!contig)
                        offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 
-               if (!contig && (offset >= ordered->file_offset + ordered->len ||
-                   offset < ordered->file_offset)) {
+               if (offset >= ordered->file_offset + ordered->len ||
+                   offset < ordered->file_offset) {
                        unsigned long bytes_left;
                        sums->len = this_sum_bytes;
                        this_sum_bytes = 0;
@@ -684,6 +684,24 @@ out:
        return ret;
 }
 
+static u64 btrfs_sector_sum_left(struct btrfs_ordered_sum *sums,
+                                struct btrfs_sector_sum *sector_sum,
+                                u64 total_bytes, u64 sectorsize)
+{
+       u64 tmp = sectorsize;
+       u64 next_sector = sector_sum->bytenr;
+       struct btrfs_sector_sum *next = sector_sum + 1;
+
+       while ((tmp + total_bytes) < sums->len) {
+               if (next_sector + sectorsize != next->bytenr)
+                       break;
+               tmp += sectorsize;
+               next_sector = next->bytenr;
+               next++;
+       }
+       return tmp;
+}
+
 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           struct btrfs_ordered_sum *sums)
@@ -710,7 +728,6 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
                return -ENOMEM;
 
        sector_sum = sums->sums;
-       trans->adding_csums = 1;
 again:
        next_offset = (u64)-1;
        found_next = 0;
@@ -789,20 +806,32 @@ again:
                goto insert;
        }
 
-       if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
+       if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) /
            csum_size) {
-               u32 diff = (csum_offset + 1) * csum_size;
+               int extend_nr;
+               u64 tmp;
+               u32 diff;
+               u32 free_space;
 
-               /*
-                * is the item big enough already?  we dropped our lock
-                * before and need to recheck
-                */
-               if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
-                       goto csum;
+               if (btrfs_leaf_free_space(root, leaf) <
+                                sizeof(struct btrfs_item) + csum_size * 2)
+                       goto insert;
+
+               free_space = btrfs_leaf_free_space(root, leaf) -
+                                        sizeof(struct btrfs_item) - csum_size;
+               tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
+                                           root->sectorsize);
+               tmp >>= root->fs_info->sb->s_blocksize_bits;
+               WARN_ON(tmp < 1);
+
+               extend_nr = max_t(int, 1, (int)tmp);
+               diff = (csum_offset + extend_nr) * csum_size;
+               diff = min(diff, MAX_CSUM_ITEMS(root, csum_size) * csum_size);
 
                diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
-               if (diff != csum_size)
-                       goto insert;
+               diff = min(free_space, diff);
+               diff /= csum_size;
+               diff *= csum_size;
 
                btrfs_extend_item(trans, root, path, diff);
                goto csum;
@@ -812,19 +841,14 @@ insert:
        btrfs_release_path(path);
        csum_offset = 0;
        if (found_next) {
-               u64 tmp = total_bytes + root->sectorsize;
-               u64 next_sector = sector_sum->bytenr;
-               struct btrfs_sector_sum *next = sector_sum + 1;
+               u64 tmp;
 
-               while (tmp < sums->len) {
-                       if (next_sector + root->sectorsize != next->bytenr)
-                               break;
-                       tmp += root->sectorsize;
-                       next_sector = next->bytenr;
-                       next++;
-               }
-               tmp = min(tmp, next_offset - file_key.offset);
+               tmp = btrfs_sector_sum_left(sums, sector_sum, total_bytes,
+                                           root->sectorsize);
                tmp >>= root->fs_info->sb->s_blocksize_bits;
+               tmp = min(tmp, (next_offset - file_key.offset) >>
+                                        root->fs_info->sb->s_blocksize_bits);
+
                tmp = max((u64)1, tmp);
                tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
                ins_size = csum_size * tmp;
@@ -874,7 +898,6 @@ next_sector:
                goto again;
        }
 out:
-       trans->adding_csums = 0;
        btrfs_free_path(path);
        return ret;