On 2018年03月28日 23:49, David Sterba wrote: > On Tue, Mar 27, 2018 at 08:44:19PM +0800, Qu Wenruo wrote: >> We have several reports about node pointer points to incorrect child >> tree blocks, which could have even wrong owner and level but still with >> valid generation and checksum. >> >> Although btrfs check could handle it and print error message like: >> leaf parent key incorrect 60670574592 >> >> Kernel doesn't have enough check on this type of corruption correctly. >> At least add such check to read_tree_block() and btrfs_read_buffer(), >> where we need two new parameters @level and @first_key to verify the >> child tree block. >> >> The new @level check is mandatory and all call sites are already >> modified to extract expected level from its call chain. >> >> While @first_key is optional, the following call sites are skipping such >> check: >> 1) Root node/leaf >> As ROOT_ITEM doesn't contain the first key, skip @first_key check. >> 2) Direct backref >> Only parent bytenr and level is known and we need to resolve the key >> all by ourselves, skip @first_key check. >> >> Another note of this verification is, it needs extra info from nodeptr >> or ROOT_ITEM, so it can't fit into current tree-checker framework, which >> is limited to node/leaf boundary. >> >> Signed-off-by: Qu Wenruo <w...@suse.com> >> --- >> changelog: >> v2: >> Make @level check mandatory, suggesed by Jeff and Nikolay. >> Change parameter order as @level is now mandatory, put it in front of >> @first_key. >> Change verify_parent_level() to verify_key_level() to avoid confusion >> on the @level parameter. >> Add btrfs_error() output for CONFIG_BTRFS_DEBUG to help debugging. > > That's much better overall, thanks. Adding it to next.
Nikolay reported a case where @first_key check seems to cause false alert. (Although my xfstests check hasn't exposed it yet) Please discard this patch since it has the possibility to cause false alert for btrfs core functionality. Thanks, Qu > -- > 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 >
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