[DRAFT UNTESTED] fs: try an opportunistic lookup for O_CREAT opens too
Today, when opening a file we'll typically do a fast lookup, but if
O_CREAT is set, the kernel always takes the exclusive inode lock. I
assume this was done with the expectation that O_CREAT means that we
always expect to do the create, but that's often not the case. Many
programs set O_CREAT even in scenarios where the file already exists.
This patch rearranges the pathwalk-for-open code to also attempt a
fast_lookup in certain O_CREAT cases. If a positive dentry is found, the
inode_lock can be avoided altogether and we can stay in rcuwalk mode for
the last step_into.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240806-openfast-v2-1-42da45981811@kernel.org
[brauner: don't call audit on parent when file existed]
Signed-off-by: Christian Brauner <brauner@kernel.org>
1 file changed
