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Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Browse Source 
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
This commit is contained in:
Linus Torvalds 2016-10-28 10:07:35 -07:00
commit f6167514c8
2 changed files with 64 additions and 14 deletions
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58
fs/btrfs/send.c
View File

@ -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;
}

20
fs/btrfs/tree-log.c
View File

@ -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);