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author | J. Bruce Fields <bfields@redhat.com> | 2019-10-29 21:02:18 +0100 |
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committer | J. Bruce Fields <bfields@redhat.com> | 2019-11-08 18:32:59 +0100 |
commit | cc1ce2f13ea1c13d7f1f322146b01446d9f7ad8b (patch) | |
tree | c1bd2fb9fc35463c37ed2fc58f174badc1718973 /fs/nfsd/nfs4callback.c | |
parent | nfsd: mark cb path down on unknown errors (diff) | |
download | linux-cc1ce2f13ea1c13d7f1f322146b01446d9f7ad8b.tar.xz linux-cc1ce2f13ea1c13d7f1f322146b01446d9f7ad8b.zip |
nfsd: document callback_wq serialization of callback code
The callback code relies on the fact that much of it is only ever called
from the ordered workqueue callback_wq, and this is worth documenting.
Reported-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd/nfs4callback.c')
-rw-r--r-- | fs/nfsd/nfs4callback.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index c94768b096a3..24534db87e86 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1243,6 +1243,12 @@ static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) return NULL; } +/* + * Note there isn't a lot of locking in this code; instead we depend on + * the fact that it is run from the callback_wq, which won't run two + * work items at once. So, for example, callback_wq handles all access + * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client. + */ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) { struct nfs4_cb_conn conn; |