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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-28 10:07:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-28 10:07:35 -0700
commitf6167514c819cb7794e60cf36b9466598a789013 (patch)
tree53cd063b30ad8314d57f1a58a4c2d27b968a55f2 /fs
parent2cd0b50a189febfe1855b13be98297a621864741 (diff)
parent570dd45042a7c8a7aba1ee029c5dd0f5ccf41b9b (diff)
Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason: "My patch fixes the btrfs list_head abuse that we tracked down during Dave Jones' memory corruption investigation. With both Jens and my patches in place, I'm no longer able to trigger problems. Filipe is fixing a difficult old bug between snapshots, balance and send. Dave is cooking a few more for the next rc, but these are tested and ready" * 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: fix races on root_log_ctx lists btrfs: fix incremental send failure caused by balance
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/send.c58
-rw-r--r--fs/btrfs/tree-log.c20
2 files changed, 64 insertions, 14 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 01bc36cec26e..71261b459863 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -5805,6 +5805,64 @@ static int changed_extent(struct send_ctx *sctx,
int ret = 0;
if (sctx->cur_ino != sctx->cmp_key->objectid) {
+
+ if (result == BTRFS_COMPARE_TREE_CHANGED) {
+ struct extent_buffer *leaf_l;
+ struct extent_buffer *leaf_r;
+ struct btrfs_file_extent_item *ei_l;
+ struct btrfs_file_extent_item *ei_r;
+
+ leaf_l = sctx->left_path->nodes[0];
+ leaf_r = sctx->right_path->nodes[0];
+ ei_l = btrfs_item_ptr(leaf_l,
+ sctx->left_path->slots[0],
+ struct btrfs_file_extent_item);
+ ei_r = btrfs_item_ptr(leaf_r,
+ sctx->right_path->slots[0],
+ struct btrfs_file_extent_item);
+
+ /*
+ * We may have found an extent item that has changed
+ * only its disk_bytenr field and the corresponding
+ * inode item was not updated. This case happens due to
+ * very specific timings during relocation when a leaf
+ * that contains file extent items is COWed while
+ * relocation is ongoing and its in the stage where it
+ * updates data pointers. So when this happens we can
+ * safely ignore it since we know it's the same extent,
+ * but just at different logical and physical locations
+ * (when an extent is fully replaced with a new one, we
+ * know the generation number must have changed too,
+ * since snapshot creation implies committing the current
+ * transaction, and the inode item must have been updated
+ * as well).
+ * This replacement of the disk_bytenr happens at
+ * relocation.c:replace_file_extents() through
+ * relocation.c:btrfs_reloc_cow_block().
+ */
+ if (btrfs_file_extent_generation(leaf_l, ei_l) ==
+ btrfs_file_extent_generation(leaf_r, ei_r) &&
+ btrfs_file_extent_ram_bytes(leaf_l, ei_l) ==
+ btrfs_file_extent_ram_bytes(leaf_r, ei_r) &&
+ btrfs_file_extent_compression(leaf_l, ei_l) ==
+ btrfs_file_extent_compression(leaf_r, ei_r) &&
+ btrfs_file_extent_encryption(leaf_l, ei_l) ==
+ btrfs_file_extent_encryption(leaf_r, ei_r) &&
+ btrfs_file_extent_other_encoding(leaf_l, ei_l) ==
+ btrfs_file_extent_other_encoding(leaf_r, ei_r) &&
+ btrfs_file_extent_type(leaf_l, ei_l) ==
+ btrfs_file_extent_type(leaf_r, ei_r) &&
+ btrfs_file_extent_disk_bytenr(leaf_l, ei_l) !=
+ btrfs_file_extent_disk_bytenr(leaf_r, ei_r) &&
+ btrfs_file_extent_disk_num_bytes(leaf_l, ei_l) ==
+ btrfs_file_extent_disk_num_bytes(leaf_r, ei_r) &&
+ btrfs_file_extent_offset(leaf_l, ei_l) ==
+ btrfs_file_extent_offset(leaf_r, ei_r) &&
+ btrfs_file_extent_num_bytes(leaf_l, ei_l) ==
+ btrfs_file_extent_num_bytes(leaf_r, ei_r))
+ return 0;
+ }
+
inconsistent_snapshot_error(sctx, result, "extent");
return -EIO;
}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 528cae123dc9..3d33c4e41e5f 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2713,14 +2713,12 @@ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
int index, int error)
{
struct btrfs_log_ctx *ctx;
+ struct btrfs_log_ctx *safe;
- if (!error) {
- INIT_LIST_HEAD(&root->log_ctxs[index]);
- return;
- }
-
- list_for_each_entry(ctx, &root->log_ctxs[index], list)
+ list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
+ list_del_init(&ctx->list);
ctx->log_ret = error;
+ }
INIT_LIST_HEAD(&root->log_ctxs[index]);
}
@@ -2961,13 +2959,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
mutex_unlock(&root->log_mutex);
out_wake_log_root:
- /*
- * We needn't get log_mutex here because we are sure all
- * the other tasks are blocked.
- */
+ mutex_lock(&log_root_tree->log_mutex);
btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
- mutex_lock(&log_root_tree->log_mutex);
log_root_tree->log_transid_committed++;
atomic_set(&log_root_tree->log_commit[index2], 0);
mutex_unlock(&log_root_tree->log_mutex);
@@ -2978,10 +2972,8 @@ out_wake_log_root:
if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
wake_up(&log_root_tree->log_commit_wait[index2]);
out:
- /* See above. */
- btrfs_remove_all_log_ctxs(root, index1, ret);
-
mutex_lock(&root->log_mutex);
+ btrfs_remove_all_log_ctxs(root, index1, ret);
root->log_transid_committed++;
atomic_set(&root->log_commit[index1], 0);
mutex_unlock(&root->log_mutex);