Re: [PATCH] repair: fix wrong logic when validating node magic number

[Eryu Guan <eguan@xxxxxxxxxx>]

On Thu, Aug 13, 2015 at 03:01:16PM +0800, Eryu Guan wrote:
> Magic number is wrong only when != XFS_DA_NODE_MAGIC and
> != XFS_DA3_NODE_MAGIC.
> 
> This is triggered by shared/002 when testing 512 block size XFS.
> 
>   Phase 1 - find and verify superblock...
>   Phase 2 - using internal log
>           - scan filesystem freespace and inode maps...
>           - found root inode chunk
>   Phase 3 - for each AG...
>           - scan (but don't clear) agi unlinked lists...
>           - process known inodes and perform inode discovery...
>           - agno = 0
>   bad magic number febe in block 64 (108) for directory inode 35
>   ......
> 
> Fix it by changing "||" to "&&".
> 
> Signed-off-by: Eryu Guan <eguan@xxxxxxxxxx>

With this patch applied, shared/002 still fails on 512 block size XFS,
full xfs_repair -n output is                                                    
                                                              
                                                                                
                                                              
*** xfs_repair -n output ***                                                    
                                                              
Phase 1 - find and verify superblock...                                         
                                                              
Phase 2 - using internal log                                                    
                                                              
        - scan filesystem freespace and inode maps...                           
                                                              
        - found root inode chunk                                                
                                                              
Phase 3 - for each AG...                                                        
                                                              
        - scan (but don't clear) agi unlinked lists...                          
                                                              
        - process known inodes and perform inode discovery...                   
                                                              
        - agno = 0                                                              
                                                              
problem with attribute contents in inode 35                                     
                                                              
would clear attr fork                                                           
                                                              
bad nblocks 67 for inode 35, would reset to 0                                   
                                                              
bad anextents 5 for inode 35, would reset to 0                                  
                                                              
        - agno = 1                                                              
                                                              
        - agno = 2                                                              
                                                              
        - agno = 3                                                              
                                                              
        - process newly discovered inodes...                                    
                                                              
Phase 4 - check for duplicate blocks...                                         
                                                              
        - setting up duplicate extent list...                                   
                                                              
        - check for inodes claiming duplicate blocks...                         
                                                              
        - agno = 0                                                              
                                                              
        - agno = 1                                                              
                                                              
        - agno = 2                                                              
                                                              
        - agno = 3                                                              
                                                              
No modify flag set, skipping phase 5                                            
                                                              
Phase 6 - check inode connectivity...                                           
                                                              
        - traversing filesystem ...                                             
                                                              
        - traversal finished ...                                                
                                                              
        - moving disconnected inodes to lost+found ...                          
                                                              
Phase 7 - verify link counts...                                                 
                                                              
No modify flag set, skipping filesystem flush and exiting.                      
                                                              
*** end xfs_repair output

And a simplified reproducer is just adding >= 577 xattrs to file foo on
512 block size XFS, no dmflaky is needed.

num_xattrs=577
for ((i = 1; i <= $num_xattrs; i++)); do
        name="user.attr_$(printf "%04d" $i)"
        $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo
done

And it's easily reproduced.

Thanks,
Eryu