9549332df4
Implement a register of caches and provide functions to manage it.
Two functions are provided for the cache backend to use:
(1) Acquire a cache cookie:
struct fscache_cache *fscache_acquire_cache(const char *name)
This gets the cache cookie for a cache of the specified name and moves
it to the preparation state. If a nameless cache cookie exists, that
will be given this name and used.
(2) Relinquish a cache cookie:
void fscache_relinquish_cache(struct fscache_cache *cache);
This relinquishes a cache cookie, cleans it and makes it available if
it's still referenced by a network filesystem.
Note that network filesystems don't deal with cache cookies directly, but
rather go straight to the volume registration.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819587157.215744.13523139317322503286.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906889665.143852.10378009165231294456.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967085081.1823006.2218944206363626210.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021494847.640689.10109692261640524343.stgit@warthog.procyon.org.uk/ # v4
47 lines
961 B
C
47 lines
961 B
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* FS-Cache statistics viewing interface
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*
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* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#define FSCACHE_DEBUG_LEVEL CACHE
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#include <linux/module.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include "internal.h"
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/*
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* initialise the /proc/fs/fscache/ directory
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*/
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int __init fscache_proc_init(void)
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{
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if (!proc_mkdir("fs/fscache", NULL))
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goto error_dir;
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if (!proc_create_seq("fs/fscache/caches", S_IFREG | 0444, NULL,
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&fscache_caches_seq_ops))
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goto error;
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#ifdef CONFIG_FSCACHE_STATS
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if (!proc_create_single("fs/fscache/stats", S_IFREG | 0444, NULL,
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fscache_stats_show))
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goto error;
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#endif
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return 0;
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error:
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remove_proc_entry("fs/fscache", NULL);
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error_dir:
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return -ENOMEM;
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}
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/*
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* clean up the /proc/fs/fscache/ directory
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*/
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void fscache_proc_cleanup(void)
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{
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remove_proc_subtree("fs/fscache", NULL);
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}
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