commit bbe9051441effce51c9a533d2c56440df64db2d7 upstream. Marc Merlin sent me a broken fs image months ago where it would blow up in the upper->checked BUG_ON() in build_backref_tree. This is because we had a scenario like this block a -- level 4 (not shared) | block b -- level 3 (reloc block, shared) | block c -- level 2 (not shared) | block d -- level 1 (shared) | block e -- level 0 (shared) We go to build a backref tree for block e, we notice block d is shared and add it to the list of blocks to lookup it's backrefs for. Now when we loop around we will check edges for the block, so we will see we looked up block c last time. So we lookup block d and then see that the block that points to it is block c and we can just skip that edge since we've already been up this path. The problem is because we clear need_check when we see block d (as it is shared) we never add block b as needing to be checked. And because block c is in our path already we bail out before we walk up to block b and add it to the backref check list. To fix this we need to reset need_check if we trip over a block that doesn't need to be checked. This will make sure that any subsequent blocks in the path as we're walking up afterwards are added to the list to be processed. With this patch I can now mount Marc's fs image and it'll complete the balance without panicing. Thanks, Reported-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b6c60c8018c4e9beb2f83fc82c09f9d033766571 upstream. Previously we only added blocks to the list to have their backrefs checked if the level of the block is right above the one we are searching for. This is because we want to make sure we don't add the entire path up to the root to the lists to make sure we process things one at a time. This assumes that if any blocks in the path to the root are going to be not checked (shared in other words) then they will be in the level right above the current block on up. This isn't quite right though since we can have blocks higher up the list that are shared because they are attached to a reloc root. But we won't add this block to be checked and then later on we will BUG_ON(!upper->checked). So instead keep track of wether or not we've queued a block to be checked in this current search, and if we haven't go ahead and queue it to be checked. This patch fixed the panic I was seeing where we BUG_ON(!upper->checked). Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dave reported a NULL pointer deref. This is caused because he thought he'd be smart and add sanity checks to the extent_io bit operations, but he didn't expect a tree to have a NULL mapping. To fix this we just need to init the relocation's processed_blocks with the btree_inode->i_mapping. Thanks, Reported-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
It is very likely that there are lots of subvolumes/snapshots in the filesystem, so if we use global block reservation to do inode cache truncation, we may hog all the free space that is reserved in global rsv. So it is better that we do the free space reservation for inode cache truncation by ourselves. Cc: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
In replace_path(), if read_tree_block() fails, we cannot return directly, we should free some allocated memory otherwise memory leak happens. Similar to Wang's "Btrfs: fix possible memory leak in the find_parent_nodes()" patch, the current commit fixes an issue that is related to the "Btrfs: fix all callers of read_tree_block" commit. Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: David Sterba <dsterba@suse.cz> Reviewed-by: Zach Brown <zab@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Big patch, but all it does is add statics to functions which are in fact static, then remove the associated dead-code fallout. removed functions: btrfs_iref_to_path() __btrfs_lookup_delayed_deletion_item() __btrfs_search_delayed_insertion_item() __btrfs_search_delayed_deletion_item() find_eb_for_page() btrfs_find_block_group() range_straddles_pages() extent_range_uptodate() btrfs_file_extent_length() btrfs_scrub_cancel_devid() btrfs_start_transaction_lflush() btrfs_print_tree() is left because it is used for debugging. btrfs_start_transaction_lflush() and btrfs_reada_detach() are left for symmetry. ulist.c functions are left, another patch will take care of those. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We kept leaking extent buffers when mounting a broken file system and it turns out it's because not everybody uses read_tree_block properly. You need to check and make sure the extent_buffer is uptodate before you use it. This patch fixes everybody who calls read_tree_block directly to make sure they check that it is uptodate and free it and return an error if it is not. With this we no longer leak EB's when things go horribly wrong. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
A user sent me a btrfs-image of a file system that was panicing on mount during the log recovery. I had originally thought these problems were from a bug in the free space cache code, but that was just a symptom of the problem. The problem is if your application does something like this [prealloc][prealloc][prealloc] the internal extent maps will merge those all together into one extent map, even though on disk they are 3 separate extents. So if you go to write into one of these ranges the extent map will be right since we use the physical extent when doing the write, but when we log the extents they will use the wrong sizes for the remainder prealloc space. If this doesn't happen to trip up the free space cache (which it won't in a lot of cases) then you will get bogus entries in your extent tree which will screw stuff up later. The data and such will still work, but everything else is broken. This patch fixes this by not allowing extents that are on the modified list to be merged. This has the side effect that we are no longer adding everything to the modified list all the time, which means we now have to call btrfs_drop_extents every time we log an extent into the tree. So this allows me to drop all this speciality code I was using to get around calling btrfs_drop_extents. With this patch the testcase I've created no longer creates a bogus file system after replaying the log. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Each time pick one dead root from the list and let the caller know if it's needed to continue. This should improve responsiveness during umount and balance which at some point waits for cleaning all currently queued dead roots. A new dead root is added to the end of the list, so the snapshots disappear in the order of deletion. The snapshot cleaning work is now done only from the cleaner thread and the others wake it if needed. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fusionio.com>