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2017-11-27lockd: fix "list_add double add" caused by legacy signal interfaceVasily Averin1-1/+5
restart_grace() uses hardcoded init_net. It can cause to "list_add double add" in following scenario: 1) nfsd and lockd was started in several net namespaces 2) nfsd in init_net was stopped (lockd was not stopped because it have users from another net namespaces) 3) lockd got signal, called restart_grace() -> set_grace_period() and enabled lock_manager in hardcoded init_net. 4) nfsd in init_net is started again, its lockd_up() calls set_grace_period() and tries to add lock_manager into init_net 2nd time. Jeff Layton suggest: "Make it safe to call locks_start_grace multiple times on the same lock_manager. If it's already on the global grace_list, then don't try to add it again. (But we don't intentionally add twice, so for now we WARN about that case.) With this change, we also need to ensure that the nfsd4 lock manager initializes the list before we call locks_start_grace. While we're at it, move the rest of the nfsd_net initialization into nfs4_state_create_net. I see no reason to have it spread over two functions like it is today." Suggested patch was updated to generate warning in described situation. Suggested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27grace: replace BUG_ON by WARN_ONCE in exit_net hookVasily Averin1-1/+3
Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-09-26nfs_common: convert int to boolCorentin Labbe1-5/+5
Since __state_in_grace return only true/false, make it return bool instead of int. Same change for the two user of it, locks_in_grace/opens_in_grace Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-09-26nfs_common: move locks_in_grace comment at the right placeCorentin Labbe1-7/+7
Commit c87fb4a378f9 ("lockd: NLM grace period shouldn't block NFSv4 opens") made the locks_in_grace() comment be in the wrong place. This patch move this comment just at the right place. Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-09-26nfs_common: fix build warning in grace.cCorentin Labbe1-1/+1
This fix the following warning fs/nfs_common/grace.c:66:1: warning: no previous prototype for function '__state_in_grace' [-Wmissing-prototypes] by adding the missing static. Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-18netns: make struct pernet_operations::id unsigned intAlexey Dobriyan1-1/+1
Make struct pernet_operations::id unsigned. There are 2 reasons to do so: 1) This field is really an index into an zero based array and thus is unsigned entity. Using negative value is out-of-bound access by definition. 2) On x86_64 unsigned 32-bit data which are mixed with pointers via array indexing or offsets added or subtracted to pointers are preffered to signed 32-bit data. "int" being used as an array index needs to be sign-extended to 64-bit before being used. void f(long *p, int i) { g(p[i]); } roughly translates to movsx rsi, esi mov rdi, [rsi+...] call g MOVSX is 3 byte instruction which isn't necessary if the variable is unsigned because x86_64 is zero extending by default. Now, there is net_generic() function which, you guessed it right, uses "int" as an array index: static inline void *net_generic(const struct net *net, int id) { ... ptr = ng->ptr[id - 1]; ... } And this function is used a lot, so those sign extensions add up. Patch snipes ~1730 bytes on allyesconfig kernel (without all junk messing with code generation): add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) Unfortunately some functions actually grow bigger. This is a semmingly random artefact of code generation with register allocator being used differently. gcc decides that some variable needs to live in new r8+ registers and every access now requires REX prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be used which is longer than [r8] However, overall balance is in negative direction: add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) function old new delta nfsd4_lock 3886 3959 +73 tipc_link_build_proto_msg 1096 1140 +44 mac80211_hwsim_new_radio 2776 2808 +32 tipc_mon_rcv 1032 1058 +26 svcauth_gss_legacy_init 1413 1429 +16 tipc_bcbase_select_primary 379 392 +13 nfsd4_exchange_id 1247 1260 +13 nfsd4_setclientid_confirm 782 793 +11 ... put_client_renew_locked 494 480 -14 ip_set_sockfn_get 730 716 -14 geneve_sock_add 829 813 -16 nfsd4_sequence_done 721 703 -18 nlmclnt_lookup_host 708 686 -22 nfsd4_lockt 1085 1063 -22 nfs_get_client 1077 1050 -27 tcf_bpf_init 1106 1076 -30 nfsd4_encode_fattr 5997 5930 -67 Total: Before=154856051, After=154854321, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-13lockd: NLM grace period shouldn't block NFSv4 opensJ. Bruce Fields1-2/+21
NLM locks don't conflict with NFSv4 share reservations, so we're not going to learn anything new by watiting for them. They do conflict with NFSv4 locks and with delegations. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-17lockd: move lockd's grace period handling into its own moduleJeff Layton1-0/+113
Currently, all of the grace period handling is part of lockd. Eventually though we'd like to be able to build v4-only servers, at which point we'll need to put all of this elsewhere. Move the code itself into fs/nfs_common and have it build a grace.ko module. Then, rejigger the Kconfig options so that both nfsd and lockd enable it automatically. Signed-off-by: Jeff Layton <jlayton@primarydata.com>