On Feb 10, 2009 10:20 -0500, Theodore Ts'o wrote: > The rec_len field in the directory entry is 16 bits, so there was a > problem representing rec_len for filesystems with a 64k block size in > the case where the directory entry takes the entire 64k block. > Unfortunately, there were two schemes that were proposed; one where > all zeros meant 65536 and one where all ones (65535) meant 65536. > E2fsprogs used 0, whereas the kernel used 65535. Oops. Fortunately > this case happens extremely rarely, with the most common case being > the lost+found directory, created by mke2fs. > > So we will be liberal in what we accept, and accept both encodings, > but we will continue to encode 65536 as 65535. This will require a > change in e2fsprogs, but with fortunately ext4 filesystems normally > have the dir_index feature enabled, which precludes having a > completely empty directory block. I'm glad that the MAX_REC_LEN value is being kept, because "0" is too easily hit due to disk corruption. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
