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authorJoel Becker <joel.becker@oracle.com>2010-03-26 10:08:27 +0800
committerTao Ma <tao.ma@oracle.com>2010-03-26 10:08:27 +0800
commit13e434cf0cacd2f03a7f4cd077e3e995ef5ef710 (patch)
treee13c0131deb1409c4445242cef52c5fda97a170f /fs/ocfs2
parentaa8f8e93c898a0319bcd6c79a9a42fe52abac7d7 (diff)
downloadblackbird-op-linux-13e434cf0cacd2f03a7f4cd077e3e995ef5ef710.tar.gz
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ocfs2: Trim suballocations if they cross discontiguous regions
A discontiguous block group can find a range of free bits that straddle more than one region of its space. Callers can't handle that, so we trim the returned bits until they fit within one region. Only cluster allocations ask for min_bits>1. Discontiguous block groups are only for block allocations. So min_bits doesn't matter here. Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2')
-rw-r--r--fs/ocfs2/suballoc.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 602c05eae7c5..c9661c477869 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1579,6 +1579,48 @@ out:
return ret;
}
+static int ocfs2_bg_discontig_trim_by_rec(struct ocfs2_suballoc_result *res,
+ struct ocfs2_extent_rec *rec,
+ struct ocfs2_chain_list *cl)
+{
+ unsigned int bpc = le16_to_cpu(cl->cl_bpc);
+ unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
+ unsigned int bitcount = le32_to_cpu(rec->e_leaf_clusters) * bpc;
+
+ if (res->sr_bit_offset < bitoff)
+ return 0;
+ if (res->sr_bit_offset >= (bitoff + bitcount))
+ return 0;
+ if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
+ res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
+ return 1;
+}
+
+static void ocfs2_bg_discontig_trim_result(struct ocfs2_alloc_context *ac,
+ struct ocfs2_group_desc *bg,
+ struct ocfs2_suballoc_result *res)
+{
+ int i;
+ struct ocfs2_extent_rec *rec;
+ struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
+ struct ocfs2_chain_list *cl = &di->id2.i_chain;
+
+ if (!ocfs2_supports_discontig_bh(OCFS2_SB(ac->ac_inode->i_sb)))
+ return;
+
+ if (ocfs2_is_cluster_bitmap(ac->ac_inode))
+ return;
+
+ if (!bg->bg_list.l_next_free_rec)
+ return;
+
+ for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
+ rec = &bg->bg_list.l_recs[i];
+ if (ocfs2_bg_discontig_trim_by_rec(res, rec, cl))
+ break;
+ }
+}
+
static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
handle_t *handle,
u32 bits_wanted,
@@ -1608,6 +1650,9 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
goto out;
}
+ if (!ret)
+ ocfs2_bg_discontig_trim_result(ac, gd, res);
+
ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
res->sr_bits,
le16_to_cpu(gd->bg_chain));
@@ -1697,6 +1742,9 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
BUG_ON(res->sr_bits == 0);
+ if (!status)
+ ocfs2_bg_discontig_trim_result(ac, bg, res);
+
/*
* Keep track of previous block descriptor read. When
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