Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Cleancache frontend
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * This code provides the generic "frontend" layer to call a matching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * "backend" driver implementation of cleancache.  See
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Documentation/vm/cleancache.rst for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * Copyright (C) 2009-2010 Oracle Corp. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * Author: Dan Magenheimer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/exportfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/debugfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/cleancache.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * cleancache_ops is set by cleancache_register_ops to contain the pointers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * to the cleancache "backend" implementation functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) static const struct cleancache_ops *cleancache_ops __read_mostly;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * Counters available via /sys/kernel/debug/cleancache (if debugfs is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * properly configured.  These are for information only so are not protected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * against increment races.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) static u64 cleancache_succ_gets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) static u64 cleancache_failed_gets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) static u64 cleancache_puts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static u64 cleancache_invalidates;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) static void cleancache_register_ops_sb(struct super_block *sb, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	switch (sb->cleancache_poolid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	case CLEANCACHE_NO_BACKEND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		__cleancache_init_fs(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	case CLEANCACHE_NO_BACKEND_SHARED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		__cleancache_init_shared_fs(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * Register operations for cleancache. Returns 0 on success.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) int cleancache_register_ops(const struct cleancache_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	if (cmpxchg(&cleancache_ops, NULL, ops))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	 * A cleancache backend can be built as a module and hence loaded after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	 * a cleancache enabled filesystem has called cleancache_init_fs. To
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	 * handle such a scenario, here we call ->init_fs or ->init_shared_fs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	 * for each active super block. To differentiate between local and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	 * shared filesystems, we temporarily initialize sb->cleancache_poolid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	 * to CLEANCACHE_NO_BACKEND or CLEANCACHE_NO_BACKEND_SHARED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	 * respectively in case there is no backend registered at the time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	 * cleancache_init_fs or cleancache_init_shared_fs is called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	 * Since filesystems can be mounted concurrently with cleancache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	 * backend registration, we have to be careful to guarantee that all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	 * cleancache enabled filesystems that has been mounted by the time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	 * cleancache_register_ops is called has got and all mounted later will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	 * get cleancache_poolid. This is assured by the following statements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	 * tied together:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	 * a) iterate_supers skips only those super blocks that has started
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	 *    ->kill_sb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	 * b) if iterate_supers encounters a super block that has not finished
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	 *    ->mount yet, it waits until it is finished
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	 * c) cleancache_init_fs is called from ->mount and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	 *    cleancache_invalidate_fs is called from ->kill_sb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	 * d) we call iterate_supers after cleancache_ops has been set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	 * From a) it follows that if iterate_supers skips a super block, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	 * either the super block is already dead, in which case we do not need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	 * to bother initializing cleancache for it, or it was mounted after we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	 * initiated iterate_supers. In the latter case, it must have seen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	 * cleancache_ops set according to d) and initialized cleancache from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	 * ->mount by itself according to c). This proves that we call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	 * ->init_fs at least once for each active super block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	 * From b) and c) it follows that if iterate_supers encounters a super
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	 * block that has already started ->init_fs, it will wait until ->mount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	 * and hence ->init_fs has finished, then check cleancache_poolid, see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	 * that it has already been set and therefore do nothing. This proves
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	 * that we call ->init_fs no more than once for each super block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	 * Combined together, the last two paragraphs prove the function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	 * correctness.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	 * Note that various cleancache callbacks may proceed before this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	 * function is called or even concurrently with it, but since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	 * CLEANCACHE_NO_BACKEND is negative, they will all result in a noop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	 * until the corresponding ->init_fs has been actually called and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	 * cleancache_ops has been set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	iterate_supers(cleancache_register_ops_sb, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) EXPORT_SYMBOL(cleancache_register_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) /* Called by a cleancache-enabled filesystem at time of mount */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) void __cleancache_init_fs(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	int pool_id = CLEANCACHE_NO_BACKEND;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	if (cleancache_ops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		pool_id = cleancache_ops->init_fs(PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		if (pool_id < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 			pool_id = CLEANCACHE_NO_POOL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	sb->cleancache_poolid = pool_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) EXPORT_SYMBOL(__cleancache_init_fs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) /* Called by a cleancache-enabled clustered filesystem at time of mount */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) void __cleancache_init_shared_fs(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	if (cleancache_ops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		if (pool_id < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 			pool_id = CLEANCACHE_NO_POOL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	sb->cleancache_poolid = pool_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) EXPORT_SYMBOL(__cleancache_init_shared_fs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * If the filesystem uses exportable filehandles, use the filehandle as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  * the key, else use the inode number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) static int cleancache_get_key(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			      struct cleancache_filekey *key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	int (*fhfn)(struct inode *, __u32 *fh, int *, struct inode *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	int len = 0, maxlen = CLEANCACHE_KEY_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	key->u.ino = inode->i_ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	if (sb->s_export_op != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		fhfn = sb->s_export_op->encode_fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		if  (fhfn) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 			len = (*fhfn)(inode, &key->u.fh[0], &maxlen, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 			if (len <= FILEID_ROOT || len == FILEID_INVALID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 				return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 			if (maxlen > CLEANCACHE_KEY_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 				return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)  * "Get" data from cleancache associated with the poolid/inode/index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)  * that were specified when the data was put to cleanache and, if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)  * successful, use it to fill the specified page with data and return 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)  * The pageframe is unchanged and returns -1 if the get fails.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)  * Page must be locked by caller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)  * The function has two checks before any action is taken - whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)  * a backend is registered and whether the sb->cleancache_poolid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)  * is correct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) int __cleancache_get_page(struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	int ret = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	int pool_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	struct cleancache_filekey key = { .u.key = { 0 } };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	if (!cleancache_ops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		cleancache_failed_gets++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	VM_BUG_ON_PAGE(!PageLocked(page), page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	pool_id = page->mapping->host->i_sb->cleancache_poolid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	if (pool_id < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	if (cleancache_get_key(page->mapping->host, &key) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	ret = cleancache_ops->get_page(pool_id, key, page->index, page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		cleancache_succ_gets++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		cleancache_failed_gets++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) EXPORT_SYMBOL(__cleancache_get_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)  * "Put" data from a page to cleancache and associate it with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)  * (previously-obtained per-filesystem) poolid and the page's,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)  * inode and page index.  Page must be locked.  Note that a put_page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)  * always "succeeds", though a subsequent get_page may succeed or fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)  * The function has two checks before any action is taken - whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)  * a backend is registered and whether the sb->cleancache_poolid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)  * is correct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) void __cleancache_put_page(struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	int pool_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	struct cleancache_filekey key = { .u.key = { 0 } };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	if (!cleancache_ops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		cleancache_puts++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	VM_BUG_ON_PAGE(!PageLocked(page), page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	pool_id = page->mapping->host->i_sb->cleancache_poolid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (pool_id >= 0 &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		cleancache_get_key(page->mapping->host, &key) >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		cleancache_ops->put_page(pool_id, key, page->index, page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		cleancache_puts++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) EXPORT_SYMBOL(__cleancache_put_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)  * Invalidate any data from cleancache associated with the poolid and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)  * page's inode and page index so that a subsequent "get" will fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)  * The function has two checks before any action is taken - whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)  * a backend is registered and whether the sb->cleancache_poolid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)  * is correct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) void __cleancache_invalidate_page(struct address_space *mapping,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 					struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	/* careful... page->mapping is NULL sometimes when this is called */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	int pool_id = mapping->host->i_sb->cleancache_poolid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	struct cleancache_filekey key = { .u.key = { 0 } };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	if (!cleancache_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	if (pool_id >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		VM_BUG_ON_PAGE(!PageLocked(page), page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		if (cleancache_get_key(mapping->host, &key) >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 			cleancache_ops->invalidate_page(pool_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 					key, page->index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 			cleancache_invalidates++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) EXPORT_SYMBOL(__cleancache_invalidate_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)  * Invalidate all data from cleancache associated with the poolid and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)  * mappings's inode so that all subsequent gets to this poolid/inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)  * will fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269)  * The function has two checks before any action is taken - whether
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)  * a backend is registered and whether the sb->cleancache_poolid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)  * is correct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) void __cleancache_invalidate_inode(struct address_space *mapping)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	int pool_id = mapping->host->i_sb->cleancache_poolid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	struct cleancache_filekey key = { .u.key = { 0 } };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	if (!cleancache_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		cleancache_ops->invalidate_inode(pool_id, key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) EXPORT_SYMBOL(__cleancache_invalidate_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)  * Called by any cleancache-enabled filesystem at time of unmount;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)  * note that pool_id is surrendered and may be returned by a subsequent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)  * cleancache_init_fs or cleancache_init_shared_fs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) void __cleancache_invalidate_fs(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	int pool_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	pool_id = sb->cleancache_poolid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	sb->cleancache_poolid = CLEANCACHE_NO_POOL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 	if (cleancache_ops && pool_id >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 		cleancache_ops->invalidate_fs(pool_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) EXPORT_SYMBOL(__cleancache_invalidate_fs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) static int __init init_cleancache(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) #ifdef CONFIG_DEBUG_FS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	struct dentry *root = debugfs_create_dir("cleancache", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	debugfs_create_u64("succ_gets", 0444, root, &cleancache_succ_gets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	debugfs_create_u64("failed_gets", 0444, root, &cleancache_failed_gets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 	debugfs_create_u64("puts", 0444, root, &cleancache_puts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	debugfs_create_u64("invalidates", 0444, root, &cleancache_invalidates);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) module_init(init_cleancache)