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| author | Chuck Lever <chuck.lever@oracle.com> | 2022-11-01 13:30:46 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-06 14:45:15 +0000 |
| commit | e62d8c1281662a0cff23df2948162c1fe705d613 (patch) | |
| tree | 1f857fcbfd3a94fb0f80416704f249a331132e24 | |
| parent | 137d20da8ea0daa9e0a2787acc4b66261e8796df (diff) | |
| download | linux-e62d8c1281662a0cff23df2948162c1fe705d613.tar.gz | |
NFSD: Flesh out a documenting comment for filecache.c
[ Upstream commit b3276c1f5b268ff56622e9e125b792b4c3dc03ac ]
Record what we've learned recently about the NFSD filecache in a
documenting comment so our future selves don't forget what all this
is for.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nfsd/filecache.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 5cb8cce153a574..24ed511ed0d389 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -2,6 +2,30 @@ * Open file cache. * * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com> + * + * An nfsd_file object is a per-file collection of open state that binds + * together: + * - a struct file * + * - a user credential + * - a network namespace + * - a read-ahead context + * - monitoring for writeback errors + * + * nfsd_file objects are reference-counted. Consumers acquire a new + * object via the nfsd_file_acquire API. They manage their interest in + * the acquired object, and hence the object's reference count, via + * nfsd_file_get and nfsd_file_put. There are two varieties of nfsd_file + * object: + * + * * non-garbage-collected: When a consumer wants to precisely control + * the lifetime of a file's open state, it acquires a non-garbage- + * collected nfsd_file. The final nfsd_file_put releases the open + * state immediately. + * + * * garbage-collected: When a consumer does not control the lifetime + * of open state, it acquires a garbage-collected nfsd_file. The + * final nfsd_file_put allows the open state to linger for a period + * during which it may be re-used. */ #include <linux/hash.h> |