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authorDavid Howells <dhowells@redhat.com>2017-11-02 18:27:49 +0300
committerDavid Howells <dhowells@redhat.com>2017-11-13 18:38:18 +0300
commitbe080a6f43c40976afc950ee55e9b7f8e2b53525 (patch)
tree066232ba94227d23335f5691fff4b697273a7d47 /fs/afs/afs.h
parentc435ee34551e1f5a02a253ca8e235287efd2727c (diff)
downloadlinux-be080a6f43c40976afc950ee55e9b7f8e2b53525.tar.xz
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit lists where possible. When most of the fileserver operations are called, they return a status structure indicating the (revised) details of the vnode or vnodes involved in the operation. This includes the access mark derived from the ACL (named CallerAccess in the protocol definition file). This is cacheable and if the ACL changes, the server will tell us that it is breaking the callback promise, at which point we can discard the currently cached permits. With this patch, the afs_permits structure has, at the end, an array of { key, CallerAccess } elements, sorted by key pointer. This is then cached in a hash table so that it can be shared between vnodes with the same access permits. Permit lists can only be shared if they contain the exact same set of key->CallerAccess mappings. Note that that table is global rather than being per-net_ns. If the keys in a permit list cross net_ns boundaries, there is no problem sharing the cached permits, since the permits are just integer masks. Since permit lists pin keys, the permit cache also makes it easier for a future patch to find all occurrences of a key and remove them by means of setting the afs_permits::invalidated flag and then clearing the appropriate key pointer. In such an event, memory barriers will need adding. Lastly, the permit caching is skipped if the server has sent either a vnode-specific or an entire-server callback since the start of the operation. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/afs.h')
-rw-r--r--fs/afs/afs.h1
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index 2e2887a7d331..b94d0edc2b78 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -136,7 +136,6 @@ struct afs_file_status {
afs_access_t caller_access; /* access rights for authenticated caller */
afs_access_t anon_access; /* access rights for unauthenticated caller */
umode_t mode; /* UNIX mode */
- struct afs_fid parent; /* parent dir ID for non-dirs only */
time_t mtime_client; /* last time client changed data */
time_t mtime_server; /* last time server changed data */
s32 lock_count; /* file lock count (0=UNLK -1=WRLCK +ve=#RDLCK */