Commit f69d6d8e authored Aug 18, 2019 by Jeff Layton Committed by J. Bruce Fields Aug 19, 2019

sunrpc: add a new cache_detail operation for when a cache is flushed

When the exports table is changed, exportfs will usually write a new
time to the "flush" file in the nfsd.export cache procfile. This tells
the kernel to flush any entries that are older than that value.

This gives us a mechanism to tell whether an unexport might have
occurred. Add a new ->flush cache_detail operation that is called after
flushing the cache whenever someone writes to a "flush" file.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

parent 4866073e

include/linux/sunrpc/cache.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ struct cache_detail {
		int has_died);

		struct cache_head * (*alloc)(void);
		void (*flush)(void);
		int (match)(struct cache_head orig, struct cache_head *new);
		void (init)(struct cache_head orig, struct cache_head *new);
		void (update)(struct cache_head orig, struct cache_head *new);

+3 −0

Original line number	Diff line number	Diff line
		@@ -1524,6 +1524,9 @@ static ssize_t write_flush(struct file file, const char __user buf,
		cd->nextcheck = now;
		cache_flush();

		if (cd->flush)
		cd->flush();

		*ppos += count;
		return count;
		}