From 3c8f24225752fba30f7265202ce6092318ed9fac Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 15 Jul 2013 11:57:06 -0400 Subject: Btrfs: update drop progress before stopping snapshot dropping Alex pointed out a problem and fix that exists in the drop one snapshot at a time patch. If we decide we need to exit for whatever reason (umount for example) we will just exit the snapshot dropping without updating the drop progress. So the next time we go to resume we will BUG_ON() because we can't find the extent we left off at because we never updated it. This patch fixes the problem. Cc: stable@vger.kernel.org Reported-by: Alex Lyakas Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 0236de711989..a429704dd95f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7552,11 +7552,6 @@ int btrfs_drop_snapshot(struct btrfs_root *root, wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root); while (1) { - if (!for_reloc && btrfs_need_cleaner_sleep(root)) { - pr_debug("btrfs: drop snapshot early exit\n"); - err = -EAGAIN; - goto out_end_trans; - } ret = walk_down_tree(trans, root, path, wc); if (ret < 0) { @@ -7584,7 +7579,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root, } BUG_ON(wc->level == 0); - if (btrfs_should_end_transaction(trans, tree_root)) { + if (btrfs_should_end_transaction(trans, tree_root) || + (!for_reloc && btrfs_need_cleaner_sleep(root))) { ret = btrfs_update_root(trans, tree_root, &root->root_key, root_item); @@ -7595,6 +7591,12 @@ int btrfs_drop_snapshot(struct btrfs_root *root, } btrfs_end_transaction_throttle(trans, tree_root); + if (!for_reloc && btrfs_need_cleaner_sleep(root)) { + pr_debug("btrfs: drop snapshot early exit\n"); + err = -EAGAIN; + goto out_free; + } + trans = btrfs_start_transaction(tree_root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); -- cgit v1.2.3 From fec386ac1428f9c0e672df952cbca5cebd4e4e2f Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 15 Jul 2013 12:41:42 -0400 Subject: Btrfs: fix lock leak when resuming snapshot deletion We aren't setting path->locks[level] when we resume a snapshot deletion which means we won't unlock the buffer when we free the path. This causes deadlocks if we happen to re-allocate the block before we've evicted the extent buffer from cache. Thanks, Cc: stable@vger.kernel.org Reported-by: Alex Lyakas Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a429704dd95f..e814b1312511 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7523,6 +7523,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, while (1) { btrfs_tree_lock(path->nodes[level]); btrfs_set_lock_blocking(path->nodes[level]); + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; ret = btrfs_lookup_extent_info(trans, root, path->nodes[level]->start, @@ -7538,6 +7539,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, break; btrfs_tree_unlock(path->nodes[level]); + path->locks[level] = 0; WARN_ON(wc->refs[level] != 1); level--; } -- cgit v1.2.3 From d29a9f629e009c9b90e5859bce581070fd6247fc Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 17 Jul 2013 19:30:20 -0400 Subject: Btrfs: re-add root to dead root list if we stop dropping it If we stop dropping a root for whatever reason we need to add it back to the dead root list so that we will re-start the dropping next transaction commit. The other case this happens is if we recover a drop because we will add a root without adding it to the fs radix tree, so we can leak it's root and commit root extent buffer, adding this to the dead root list makes this cleanup happen. Thanks, Cc: stable@vger.kernel.org Reported-by: Alex Lyakas Signed-off-by: Josef Bacik --- fs/btrfs/extent-tree.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index e814b1312511..1204c8ef6f32 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7466,6 +7466,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int err = 0; int ret; int level; + bool root_dropped = false; path = btrfs_alloc_path(); if (!path) { @@ -7643,12 +7644,22 @@ int btrfs_drop_snapshot(struct btrfs_root *root, free_extent_buffer(root->commit_root); btrfs_put_fs_root(root); } + root_dropped = true; out_end_trans: btrfs_end_transaction_throttle(trans, tree_root); out_free: kfree(wc); btrfs_free_path(path); out: + /* + * So if we need to stop dropping the snapshot for whatever reason we + * need to make sure to add it back to the dead root list so that we + * keep trying to do the work later. This also cleans up roots if we + * don't have it in the radix (like when we recover after a power fail + * or unmount) so we don't leak memory. + */ + if (root_dropped == false) + btrfs_add_dead_root(root); if (err) btrfs_std_error(root->fs_info, err); return err; -- cgit v1.2.3 From 115930cb2d444a684975cf2325759cb48ebf80cc Mon Sep 17 00:00:00 2001 From: Stefan Behrens Date: Thu, 4 Jul 2013 16:14:23 +0200 Subject: Btrfs: fix wrong write offset when replacing a device Miao Xie reported the following issue: The filesystem was corrupted after we did a device replace. Steps to reproduce: # mkfs.btrfs -f -m single -d raid10 .. # mount # btrfs replace start -rfB 1 # umount # btrfsck The reason for the issue is that we changed the write offset by mistake, introduced by commit 625f1c8dc. We read the data from the source device at first, and then write the data into the corresponding place of the new device. In order to implement the "-r" option, the source location is remapped using btrfs_map_block(). The read takes place on the mapped location, and the write needs to take place on the unmapped location. Currently the write is using the mapped location, and this commit changes it back by undoing the change to the write address that the aforementioned commit added by mistake. Reported-by: Miao Xie Cc: # 3.10+ Signed-off-by: Stefan Behrens Signed-off-by: Josef Bacik --- fs/btrfs/scrub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 4ba2a69a60ad..64a157becbe5 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2495,7 +2495,7 @@ again: ret = scrub_extent(sctx, extent_logical, extent_len, extent_physical, extent_dev, flags, generation, extent_mirror_num, - extent_physical); + extent_logical - logical + physical); if (ret) goto out; -- cgit v1.2.3