Btrfs: Don't drop extent_map cache during releasepage on the btree inode
The btree inode should only have a single extent_map in the cache,
it doesn't make sense to ever drop it.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 76ee7a4..2de2b00 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -76,13 +76,12 @@
struct extent_map *em;
int ret;
-again:
spin_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
spin_unlock(&em_tree->lock);
- if (em) {
+ if (em)
goto out;
- }
+
em = alloc_extent_map(GFP_NOFS);
if (!em) {
em = ERR_PTR(-ENOMEM);
@@ -95,15 +94,21 @@
spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
- spin_unlock(&em_tree->lock);
-
if (ret == -EEXIST) {
free_extent_map(em);
- em = NULL;
- goto again;
+ em = lookup_extent_mapping(em_tree, start, len);
+ if (em)
+ ret = 0;
+ else
+ ret = -EIO;
} else if (ret) {
- em = ERR_PTR(ret);
+ free_extent_map(em);
+ em = NULL;
}
+ spin_unlock(&em_tree->lock);
+
+ if (ret)
+ em = ERR_PTR(ret);
out:
return em;
}
@@ -496,7 +501,7 @@
}
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
- ret = try_release_extent_mapping(map, tree, page, gfp_flags);
+ ret = try_release_extent_state(map, tree, page, gfp_flags);
if (ret == 1) {
invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
ClearPagePrivate(page);
