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Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r--fs/btrfs/ctree.c56
1 files changed, 48 insertions, 8 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e5b2533..fedf8b9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1325,12 +1325,12 @@ static noinline int reada_for_balance(struct btrfs_root *root,
int ret = 0;
int blocksize;
- parent = path->nodes[level - 1];
+ parent = path->nodes[level + 1];
if (!parent)
return 0;
nritems = btrfs_header_nritems(parent);
- slot = path->slots[level];
+ slot = path->slots[level + 1];
blocksize = btrfs_level_size(root, level);
if (slot > 0) {
@@ -1341,7 +1341,7 @@ static noinline int reada_for_balance(struct btrfs_root *root,
block1 = 0;
free_extent_buffer(eb);
}
- if (slot < nritems) {
+ if (slot + 1 < nritems) {
block2 = btrfs_node_blockptr(parent, slot + 1);
gen = btrfs_node_ptr_generation(parent, slot + 1);
eb = btrfs_find_tree_block(root, block2, blocksize);
@@ -1351,7 +1351,11 @@ static noinline int reada_for_balance(struct btrfs_root *root,
}
if (block1 || block2) {
ret = -EAGAIN;
+
+ /* release the whole path */
btrfs_release_path(root, path);
+
+ /* read the blocks */
if (block1)
readahead_tree_block(root, block1, blocksize, 0);
if (block2)
@@ -1361,7 +1365,7 @@ static noinline int reada_for_balance(struct btrfs_root *root,
eb = read_tree_block(root, block1, blocksize, 0);
free_extent_buffer(eb);
}
- if (block1) {
+ if (block2) {
eb = read_tree_block(root, block2, blocksize, 0);
free_extent_buffer(eb);
}
@@ -1465,6 +1469,7 @@ read_block_for_search(struct btrfs_trans_handle *trans,
u32 blocksize;
struct extent_buffer *b = *eb_ret;
struct extent_buffer *tmp;
+ int ret;
blocknr = btrfs_node_blockptr(b, slot);
gen = btrfs_node_ptr_generation(b, slot);
@@ -1472,6 +1477,10 @@ read_block_for_search(struct btrfs_trans_handle *trans,
tmp = btrfs_find_tree_block(root, blocknr, blocksize);
if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+ /*
+ * we found an up to date block without sleeping, return
+ * right away
+ */
*eb_ret = tmp;
return 0;
}
@@ -1479,18 +1488,34 @@ read_block_for_search(struct btrfs_trans_handle *trans,
/*
* reduce lock contention at high levels
* of the btree by dropping locks before
- * we read.
+ * we read. Don't release the lock on the current
+ * level because we need to walk this node to figure
+ * out which blocks to read.
*/
- btrfs_release_path(NULL, p);
+ btrfs_unlock_up_safe(p, level + 1);
+ btrfs_set_path_blocking(p);
+
if (tmp)
free_extent_buffer(tmp);
if (p->reada)
reada_for_search(root, p, level, slot, key->objectid);
+ btrfs_release_path(NULL, p);
+
+ ret = -EAGAIN;
tmp = read_tree_block(root, blocknr, blocksize, gen);
- if (tmp)
+ if (tmp) {
+ /*
+ * If the read above didn't mark this buffer up to date,
+ * it will never end up being up to date. Set ret to EIO now
+ * and give up so that our caller doesn't loop forever
+ * on our EAGAINs.
+ */
+ if (!btrfs_buffer_uptodate(tmp, 0))
+ ret = -EIO;
free_extent_buffer(tmp);
- return -EAGAIN;
+ }
+ return ret;
}
/*
@@ -1689,6 +1714,9 @@ cow_done:
if (ret == -EAGAIN)
goto again;
+ if (ret == -EIO)
+ goto done;
+
if (!p->skip_locking) {
int lret;
@@ -1731,6 +1759,8 @@ done:
*/
if (!p->leave_spinning)
btrfs_set_path_blocking(p);
+ if (ret < 0)
+ btrfs_release_path(root, p);
return ret;
}
@@ -4205,6 +4235,11 @@ again:
if (ret == -EAGAIN)
goto again;
+ if (ret < 0) {
+ btrfs_release_path(root, path);
+ goto done;
+ }
+
if (!path->skip_locking) {
ret = btrfs_try_spin_lock(next);
if (!ret) {
@@ -4239,6 +4274,11 @@ again:
if (ret == -EAGAIN)
goto again;
+ if (ret < 0) {
+ btrfs_release_path(root, path);
+ goto done;
+ }
+
if (!path->skip_locking) {
btrfs_assert_tree_locked(path->nodes[level]);
ret = btrfs_try_spin_lock(next);
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