On Mon, Nov 06, 2017 at 01:47:17PM +0800, Qu Wenruo wrote: > [BUG] > If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will > instantly cause kernel panic like:
Which patch causes that? The selftests used to catch various errors when the original dir_item verification patches were merged. Plus some fstests were failing. I burned a lot of time on that and don't want to repeat that, so I expect that all tree-checker patches pass self-test (incrementally, not just the whole series) and all relevant fstests. > > ------ > ... > assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853 > ... > Call Trace: > btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs] > setup_items_for_insert+0x385/0x650 [btrfs] > __btrfs_drop_extents+0x129a/0x1870 [btrfs] > ... > ----- > > [Cause] > Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check > if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y. > > However quite some btrfs_mark_buffer_dirty() callers(*) don't really > initialize its item data but only initialize its item pointers, leaving > item data uninitialized. > > This makes tree-checker catch uninitialized data as error, causing > such panic. > > *: These callers include but not limited to > setup_items_for_insert() > btrfs_split_item() > btrfs_expand_item() > > [Fix] > Add a new parameter @check_item_data to btrfs_check_leaf(). > With @check_item_data set to false, item data check will be skipped and > fallback to old btrfs_check_leaf() behavior. So this looks like a patch ordering problem. The weaker version of btrfs_check_leaf needs to come first and then the improved checks that cause the crashes. > So we can still get early warning if we screw up item pointers, and > avoid false panic. > > Cc: Filipe Manana <fdman...@gmail.com> > Reported-by: Lakshmipathi.G <lakshmipath...@gmail.com> > Signed-off-by: Qu Wenruo <w...@suse.com> > --- > fs/btrfs/disk-io.c | 5 +++-- > fs/btrfs/tree-checker.c | 16 +++++++++++----- > fs/btrfs/tree-checker.h | 3 ++- > 3 files changed, 16 insertions(+), 8 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index efce9a2fa9be..c65b63d6df27 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -610,7 +610,7 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio > *io_bio, > * that we don't try and read the other copies of this block, just > * return -EIO. > */ > - if (found_level == 0 && btrfs_check_leaf(root, eb)) { > + if (found_level == 0 && btrfs_check_leaf(root, eb, true)) { > set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags); > ret = -EIO; > } > @@ -3848,7 +3848,8 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf) > buf->len, > fs_info->dirty_metadata_batch); > #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY > - if (btrfs_header_level(buf) == 0 && btrfs_check_leaf(root, buf)) { > + if (btrfs_header_level(buf) == 0 && > + btrfs_check_leaf(root, buf, false)) { > btrfs_print_leaf(buf); > ASSERT(0); > } > diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c > index 114fc5f0ecc5..a4c2517fa2a1 100644 > --- a/fs/btrfs/tree-checker.c > +++ b/fs/btrfs/tree-checker.c > @@ -242,7 +242,8 @@ static int check_leaf_item(struct btrfs_root *root, > return ret; > } > > -int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf) > +int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf, > + bool check_item_data) The bool arguments are usally not very descriptive, I suggest to add static inline int btrfs_check_leaf_relaxed(struct btrfs_root *root, struct extent_buffer *leaf) { return btrfs_check_leaf_root, leaf, false); } to tree-check.h and use where appropriate. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html