From 977e5f8ed0ab2786755f8d2a96b78a3c7320f7c4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 17 Apr 2020 17:31:26 +0100 Subject: afs: Split the usage count on struct afs_server Split the usage count on the afs_server struct to have an active count that registers who's actually using it separately from the reference count on the object. This allows a future patch to dispatch polling probes without advancing the "unuse" time into the future each time we emit a probe, which would otherwise prevent unused server records from expiring. Included in this: (1) The latter part of afs_destroy_server() in which the RCU destruction of afs_server objects is invoked and the outstanding server count is decremented is split out into __afs_put_server(). (2) afs_put_server() now calls __afs_put_server() rather then setting the management timer. (3) The calls begun by afs_fs_give_up_all_callbacks() and afs_fs_get_capabilities() can now take a ref on the server record, so afs_destroy_server() can just drop its ref and needn't wait for the completion of these calls. They'll put the ref when they're done. (4) Because of (3), afs_fs_probe_done() no longer needs to wake up afs_destroy_server() with server->probe_outstanding. (5) afs_gc_servers can be simplified. It only needs to check if server->active is 0 rather than playing games with the refcount. (6) afs_manage_servers() can propose a server for gc if usage == 0 rather than if ref == 1. The gc is effected by (5). Signed-off-by: David Howells --- fs/afs/internal.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'fs/afs/internal.h') diff --git a/fs/afs/internal.h b/fs/afs/internal.h index ee17c868ad2c..cb70e1c234cc 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -498,7 +498,7 @@ struct afs_server { struct hlist_node addr6_link; /* Link in net->fs_addresses6 */ struct hlist_node proc_link; /* Link in net->fs_proc */ struct afs_server *gc_next; /* Next server in manager's list */ - time64_t put_time; /* Time at which last put */ + time64_t unuse_time; /* Time at which last unused */ unsigned long flags; #define AFS_SERVER_FL_NOT_READY 1 /* The record is not ready for use */ #define AFS_SERVER_FL_NOT_FOUND 2 /* VL server says no such server */ @@ -512,7 +512,8 @@ struct afs_server { #define AFS_SERVER_FL_NO_RM2 10 /* Fileserver doesn't support YFS.RemoveFile2 */ #define AFS_SERVER_FL_HAVE_EPOCH 11 /* ->epoch is valid */ #define AFS_SERVER_FL_NEEDS_UPDATE 12 /* Fileserver address list is out of date */ - atomic_t usage; + atomic_t ref; /* Object refcount */ + atomic_t active; /* Active user count */ u32 addr_version; /* Address list version */ u32 cm_epoch; /* Server RxRPC epoch */ unsigned int debug_id; /* Debugging ID for traces */ @@ -1244,6 +1245,9 @@ extern struct afs_server *afs_find_server(struct afs_net *, extern struct afs_server *afs_find_server_by_uuid(struct afs_net *, const uuid_t *); extern struct afs_server *afs_lookup_server(struct afs_cell *, struct key *, const uuid_t *, u32); extern struct afs_server *afs_get_server(struct afs_server *, enum afs_server_trace); +extern struct afs_server *afs_use_server(struct afs_server *, enum afs_server_trace); +extern void afs_unuse_server(struct afs_net *, struct afs_server *, enum afs_server_trace); +extern void afs_unuse_server_notime(struct afs_net *, struct afs_server *, enum afs_server_trace); extern void afs_put_server(struct afs_net *, struct afs_server *, enum afs_server_trace); extern void afs_manage_servers(struct work_struct *); extern void afs_servers_timer(struct timer_list *); -- cgit v1.2.3