• Chris Mason's avatar
    Btrfs: fix hash overflow handling · 9c52057c
    Chris Mason authored
    The handling for directory crc hash overflows was fairly obscure,
    split_leaf returns EOVERFLOW when we try to extend the item and that is
    supposed to bubble up to userland.  For a while it did so, but along the
    way we added better handling of errors and forced the FS readonly if we
    hit IO errors during the directory insertion.
    
    Along the way, we started testing only for EEXIST and the EOVERFLOW case
    was dropped.  The end result is that we may force the FS readonly if we
    catch a directory hash bucket overflow.
    
    This fixes a few problem spots.  First I add tests for EOVERFLOW in the
    places where we can safely just return the error up the chain.
    
    btrfs_rename is harder though, because it tries to insert the new
    directory item only after it has already unlinked anything the rename
    was going to overwrite.  Rather than adding very complex logic, I added
    a helper to test for the hash overflow case early while it is still safe
    to bail out.
    
    Snapshot and subvolume creation had a similar problem, so they are using
    the new helper now too.
    Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
    Reported-by: default avatarPascal Junod <pascal@junod.info>
    9c52057c
ctree.h 120 KB