| Message ID | 20220427100344.700330-1-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] btrfs: improve error reporting in lookup_inline_extent_backref | expand |
On Wed, Apr 27, 2022 at 01:03:44PM +0300, Nikolay Borisov wrote: > When iterating the backrefs in an extent item if the ptr to the > 'current' backref record goes beyond the extent item a warning is > generated and -ENOENT is returned. However what's more appropriate to > debug such cases would be to return EUCLEAN and also print identifying > information about the performed search as well as the current content of > the leaf containing the possibly corrupted extent item. > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> > --- > V2: > * Removed WARN_ON and instead introduced btrfs_crit as an error printing > mechanism > * Now prints a proper error message with information about the searched reference > fs/btrfs/extent-tree.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 963160a0c393..5e29c2cee46e 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -895,7 +895,14 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, > err = -ENOENT; > while (1) { > if (ptr >= end) { > - WARN_ON(ptr > end); > + if (ptr > end) { > + err = -EUCLEAN; > + btrfs_crit(fs_info, > +"overrun extent record at slot %lu [%llu BTRFS_EXTENT_ITEM_KEY %llu] while looking for inline extent for root %llu owner %llu offset %llu", > + path->slots[0], bytenr, num_bytes, > + root_objectid, root_objectid, owner, offset); Printing 'parent' is also needed in order to figure out what type of reference we were looking for. Also, %d can be used to print the slot, as path->slots is an int array. > + btrfs_print_leaf(path->nodes[0]); The leaf should be dumped before printing the message, see: https://btrfs.wiki.kernel.org/index.php/Development_notes#Output Other than that, it looks fine. Thanks. > + } > break; > } > iref = (struct btrfs_extent_inline_ref *)ptr; > -- > 2.25.1 >
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 963160a0c393..5e29c2cee46e 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -895,7 +895,14 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, err = -ENOENT; while (1) { if (ptr >= end) { - WARN_ON(ptr > end); + if (ptr > end) { + err = -EUCLEAN; + btrfs_crit(fs_info, +"overrun extent record at slot %lu [%llu BTRFS_EXTENT_ITEM_KEY %llu] while looking for inline extent for root %llu owner %llu offset %llu", + path->slots[0], bytenr, num_bytes, + root_objectid, root_objectid, owner, offset); + btrfs_print_leaf(path->nodes[0]); + } break; } iref = (struct btrfs_extent_inline_ref *)ptr;
When iterating the backrefs in an extent item if the ptr to the 'current' backref record goes beyond the extent item a warning is generated and -ENOENT is returned. However what's more appropriate to debug such cases would be to return EUCLEAN and also print identifying information about the performed search as well as the current content of the leaf containing the possibly corrupted extent item. Signed-off-by: Nikolay Borisov <nborisov@suse.com> --- V2: * Removed WARN_ON and instead introduced btrfs_crit as an error printing mechanism * Now prints a proper error message with information about the searched reference fs/btrfs/extent-tree.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) -- 2.25.1