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authorMark Fasheh <mark.fasheh@oracle.com>2007-09-16 23:10:16 -0400
committerMark Fasheh <mark.fasheh@oracle.com>2007-09-20 18:06:09 -0400
commit415cb800375cc4e89fb5a6a454e484bd4adbffb4 (patch)
tree816021a5279047702d5fa8180783b1c710f31746 /fs/ocfs2/suballoc.h
parent6d0b842d3bf0cc027dcff57a89fb8a6b1fd610e1 (diff)
ocfs2: Allow smaller allocations during large writes
The ocfs2 write code loops through a page much like the block code, except that ocfs2 allocation units can be any size, including larger than page size. Typically it's equal to or larger than page size - most kernels run 4k pages, the minimum ocfs2 allocation (cluster) size. Some changes introduced during 2.6.23 changed the way writes to pages are handled, and inadvertantly broke support for > 4k page size. Instead of just writing one cluster at a time, we now handle the whole page in one pass. This means that multiple (small) seperate allocations might happen in the same pass. The allocation code howver typically optimizes by getting the maximum which was reserved. This triggered a BUG_ON in the extend code where it'd ask for a single bit (for one part of a > 4k page) and get back more than it asked for. Fix this by providing a variant of the high level allocation function which allows the caller to specify a maximum. The traditional function remains and just calls the new one with a maximum determined from the initial reservation. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'fs/ocfs2/suballoc.h')
-rw-r--r--fs/ocfs2/suballoc.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index f212dc01a84b..cafe93703095 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -85,6 +85,17 @@ int ocfs2_claim_clusters(struct ocfs2_super *osb,
85 u32 min_clusters, 85 u32 min_clusters,
86 u32 *cluster_start, 86 u32 *cluster_start,
87 u32 *num_clusters); 87 u32 *num_clusters);
88/*
89 * Use this variant of ocfs2_claim_clusters to specify a maxiumum
90 * number of clusters smaller than the allocation reserved.
91 */
92int __ocfs2_claim_clusters(struct ocfs2_super *osb,
93 handle_t *handle,
94 struct ocfs2_alloc_context *ac,
95 u32 min_clusters,
96 u32 max_clusters,
97 u32 *cluster_start,
98 u32 *num_clusters);
88 99
89int ocfs2_free_suballoc_bits(handle_t *handle, 100int ocfs2_free_suballoc_bits(handle_t *handle,
90 struct inode *alloc_inode, 101 struct inode *alloc_inode,