From: Oleg Nesterov Date: Thu, 30 Nov 2023 11:56:14 +0000 (+0100) Subject: afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*() X-Git-Tag: v6.6.17~412 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=08ade0fa61033ab91a740f0ac44874181370eeba;hp=08ade0fa61033ab91a740f0ac44874181370eeba;p=platform%2Fkernel%2Flinux-starfive.git afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*() [ Upstream commit 1702e0654ca9a7bcd7c7619c8a5004db58945b71 ] David Howells says: (5) afs_find_server(). There could be a lot of servers in the list and each server can have multiple addresses, so I think this would be better with an exclusive second pass. The server list isn't likely to change all that often, but when it does change, there's a good chance several servers are going to be added/removed one after the other. Further, this is only going to be used for incoming cache management/callback requests from the server, which hopefully aren't going to happen too often - but it is remotely drivable. (6) afs_find_server_by_uuid(). Similarly to (5), there could be a lot of servers to search through, but they are in a tree not a flat list, so it should be faster to process. Again, it's not likely to change that often and, again, when it does change it's likely to involve multiple changes. This can be driven remotely by an incoming cache management request but is mostly going to be driven by setting up or reconfiguring a volume's server list - something that also isn't likely to happen often. Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock() never takes the lock. Signed-off-by: Oleg Nesterov Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20231130115614.GA21581@redhat.com/ Signed-off-by: Sasha Levin ---