From mboxrd@z Thu Jan 1 00:00:00 1970 From: mandeepsandhu.chd@gmail.com (Mandeep Sandhu) Date: Mon, 5 Oct 2015 10:03:25 -0700 Subject: What is negative lookup in linux filesystem In-Reply-To: References: Message-ID: To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org >>From the context of the snippet you posted, it looks like the author implies a "failed lookup" when s/he writes "negative lookup". CMIIW. -mandeep On Mon, Oct 5, 2015 at 8:08 AM, Praveen Kumar wrote: > 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. > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies at kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >