Oct. 5, 2015
3:08 p.m.
Hi, I am trying to understand the path-lookup in linux filesystem and was going through https://www.kernel.org/doc/Documentation/filesystems/path-lookup.txt Under 'Rename' heading, I came across the negative lookup terminology, snapshot below 'Between deleting the dentry from the old hash list, and inserting it on the new hash list, a lookup may find neither 'A' nor 'B' matching the dentry. The same rename seqlock is also used to cover this race in much the same way, by retrying a negative lookup result if a rename was in progress.' Can anyone please help understanding the negative lookup concept and how do we achieve it. Thanks in advance. Regards, ~Praveen.