Release 4.11 mm/cleancache.c
/*
* Cleancache frontend
*
* This code provides the generic "frontend" layer to call a matching
* "backend" driver implementation of cleancache. See
* Documentation/vm/cleancache.txt for more information.
*
* Copyright (C) 2009-2010 Oracle Corp. All rights reserved.
* Author: Dan Magenheimer
*
* This work is licensed under the terms of the GNU GPL, version 2.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/exportfs.h>
#include <linux/mm.h>
#include <linux/debugfs.h>
#include <linux/cleancache.h>
/*
* cleancache_ops is set by cleancache_register_ops to contain the pointers
* to the cleancache "backend" implementation functions.
*/
static const struct cleancache_ops *cleancache_ops __read_mostly;
/*
* Counters available via /sys/kernel/debug/cleancache (if debugfs is
* properly configured. These are for information only so are not protected
* against increment races.
*/
static u64 cleancache_succ_gets;
static u64 cleancache_failed_gets;
static u64 cleancache_puts;
static u64 cleancache_invalidates;
static void cleancache_register_ops_sb(struct super_block *sb, void *unused)
{
switch (sb->cleancache_poolid) {
case CLEANCACHE_NO_BACKEND:
__cleancache_init_fs(sb);
break;
case CLEANCACHE_NO_BACKEND_SHARED:
__cleancache_init_shared_fs(sb);
break;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Vladimir Davydov | 36 | 87.80% | 1 | 50.00% |
| Dan Magenheimer | 5 | 12.20% | 1 | 50.00% |
| Total | 41 | 100.00% | 2 | 100.00% |
/*
* Register operations for cleancache. Returns 0 on success.
*/
int cleancache_register_ops(const struct cleancache_ops *ops)
{
if (cmpxchg(&cleancache_ops, NULL, ops))
return -EBUSY;
/*
* A cleancache backend can be built as a module and hence loaded after
* a cleancache enabled filesystem has called cleancache_init_fs. To
* handle such a scenario, here we call ->init_fs or ->init_shared_fs
* for each active super block. To differentiate between local and
* shared filesystems, we temporarily initialize sb->cleancache_poolid
* to CLEANCACHE_NO_BACKEND or CLEANCACHE_NO_BACKEND_SHARED
* respectively in case there is no backend registered at the time
* cleancache_init_fs or cleancache_init_shared_fs is called.
*
* Since filesystems can be mounted concurrently with cleancache
* backend registration, we have to be careful to guarantee that all
* cleancache enabled filesystems that has been mounted by the time
* cleancache_register_ops is called has got and all mounted later will
* get cleancache_poolid. This is assured by the following statements
* tied together:
*
* a) iterate_supers skips only those super blocks that has started
* ->kill_sb
*
* b) if iterate_supers encounters a super block that has not finished
* ->mount yet, it waits until it is finished
*
* c) cleancache_init_fs is called from ->mount and
* cleancache_invalidate_fs is called from ->kill_sb
*
* d) we call iterate_supers after cleancache_ops has been set
*
* From a) it follows that if iterate_supers skips a super block, then
* either the super block is already dead, in which case we do not need
* to bother initializing cleancache for it, or it was mounted after we
* initiated iterate_supers. In the latter case, it must have seen
* cleancache_ops set according to d) and initialized cleancache from
* ->mount by itself according to c). This proves that we call
* ->init_fs at least once for each active super block.
*
* From b) and c) it follows that if iterate_supers encounters a super
* block that has already started ->init_fs, it will wait until ->mount
* and hence ->init_fs has finished, then check cleancache_poolid, see
* that it has already been set and therefore do nothing. This proves
* that we call ->init_fs no more than once for each super block.
*
* Combined together, the last two paragraphs prove the function
* correctness.
*
* Note that various cleancache callbacks may proceed before this
* function is called or even concurrently with it, but since
* CLEANCACHE_NO_BACKEND is negative, they will all result in a noop
* until the corresponding ->init_fs has been actually called and
* cleancache_ops has been set.
*/
iterate_supers(cleancache_register_ops_sb, NULL);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Vladimir Davydov | 22 | 57.89% | 2 | 40.00% |
| Dan Magenheimer | 15 | 39.47% | 2 | 40.00% |
| Julia Lawall | 1 | 2.63% | 1 | 20.00% |
| Total | 38 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL(cleancache_register_ops);
/* Called by a cleancache-enabled filesystem at time of mount */
void __cleancache_init_fs(struct super_block *sb)
{
int pool_id = CLEANCACHE_NO_BACKEND;
if (cleancache_ops) {
pool_id = cleancache_ops->init_fs(PAGE_SIZE);
if (pool_id < 0)
pool_id = CLEANCACHE_NO_POOL;
}
sb->cleancache_poolid = pool_id;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 26 | 56.52% | 2 | 50.00% |
| Vladimir Davydov | 18 | 39.13% | 1 | 25.00% |
| Konrad Rzeszutek Wilk | 2 | 4.35% | 1 | 25.00% |
| Total | 46 | 100.00% | 4 | 100.00% |
EXPORT_SYMBOL(__cleancache_init_fs);
/* Called by a cleancache-enabled clustered filesystem at time of mount */
void __cleancache_init_shared_fs(struct super_block *sb)
{
int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
if (cleancache_ops) {
pool_id = cleancache_ops->init_shared_fs(sb->s_uuid, PAGE_SIZE);
if (pool_id < 0)
pool_id = CLEANCACHE_NO_POOL;
}
sb->cleancache_poolid = pool_id;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 27 | 54.00% | 2 | 40.00% |
| Vladimir Davydov | 21 | 42.00% | 2 | 40.00% |
| Konrad Rzeszutek Wilk | 2 | 4.00% | 1 | 20.00% |
| Total | 50 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL(__cleancache_init_shared_fs);
/*
* If the filesystem uses exportable filehandles, use the filehandle as
* the key, else use the inode number.
*/
static int cleancache_get_key(struct inode *inode,
struct cleancache_filekey *key)
{
int (*fhfn)(struct inode *, __u32 *fh, int *, struct inode *);
int len = 0, maxlen = CLEANCACHE_KEY_MAX;
struct super_block *sb = inode->i_sb;
key->u.ino = inode->i_ino;
if (sb->s_export_op != NULL) {
fhfn = sb->s_export_op->encode_fh;
if (fhfn) {
len = (*fhfn)(inode, &key->u.fh[0], &maxlen, NULL);
if (len <= FILEID_ROOT || len == FILEID_INVALID)
return -1;
if (maxlen > CLEANCACHE_KEY_MAX)
return -1;
}
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 134 | 94.37% | 1 | 33.33% |
| Al Viro | 6 | 4.23% | 1 | 33.33% |
| Namjae Jeon | 2 | 1.41% | 1 | 33.33% |
| Total | 142 | 100.00% | 3 | 100.00% |
/*
* "Get" data from cleancache associated with the poolid/inode/index
* that were specified when the data was put to cleanache and, if
* successful, use it to fill the specified page with data and return 0.
* The pageframe is unchanged and returns -1 if the get fails.
* Page must be locked by caller.
*
* The function has two checks before any action is taken - whether
* a backend is registered and whether the sb->cleancache_poolid
* is correct.
*/
int __cleancache_get_page(struct page *page)
{
int ret = -1;
int pool_id;
struct cleancache_filekey key = { .u.key = { 0 } };
if (!cleancache_ops) {
cleancache_failed_gets++;
goto out;
}
VM_BUG_ON_PAGE(!PageLocked(page), page);
pool_id = page->mapping->host->i_sb->cleancache_poolid;
if (pool_id < 0)
goto out;
if (cleancache_get_key(page->mapping->host, &key) < 0)
goto out;
ret = cleancache_ops->get_page(pool_id, key, page->index, page);
if (ret == 0)
cleancache_succ_gets++;
else
cleancache_failed_gets++;
out:
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 126 | 94.74% | 2 | 40.00% |
| Sasha Levin | 3 | 2.26% | 1 | 20.00% |
| Konrad Rzeszutek Wilk | 2 | 1.50% | 1 | 20.00% |
| Vladimir Davydov | 2 | 1.50% | 1 | 20.00% |
| Total | 133 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL(__cleancache_get_page);
/*
* "Put" data from a page to cleancache and associate it with the
* (previously-obtained per-filesystem) poolid and the page's,
* inode and page index. Page must be locked. Note that a put_page
* always "succeeds", though a subsequent get_page may succeed or fail.
*
* The function has two checks before any action is taken - whether
* a backend is registered and whether the sb->cleancache_poolid
* is correct.
*/
void __cleancache_put_page(struct page *page)
{
int pool_id;
struct cleancache_filekey key = { .u.key = { 0 } };
if (!cleancache_ops) {
cleancache_puts++;
return;
}
VM_BUG_ON_PAGE(!PageLocked(page), page);
pool_id = page->mapping->host->i_sb->cleancache_poolid;
if (pool_id >= 0 &&
cleancache_get_key(page->mapping->host, &key) >= 0) {
cleancache_ops->put_page(pool_id, key, page->index, page);
cleancache_puts++;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 96 | 94.12% | 2 | 40.00% |
| Sasha Levin | 3 | 2.94% | 1 | 20.00% |
| Konrad Rzeszutek Wilk | 2 | 1.96% | 1 | 20.00% |
| Vladimir Davydov | 1 | 0.98% | 1 | 20.00% |
| Total | 102 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL(__cleancache_put_page);
/*
* Invalidate any data from cleancache associated with the poolid and the
* page's inode and page index so that a subsequent "get" will fail.
*
* The function has two checks before any action is taken - whether
* a backend is registered and whether the sb->cleancache_poolid
* is correct.
*/
void __cleancache_invalidate_page(struct address_space *mapping,
struct page *page)
{
/* careful... page->mapping is NULL sometimes when this is called */
int pool_id = mapping->host->i_sb->cleancache_poolid;
struct cleancache_filekey key = { .u.key = { 0 } };
if (!cleancache_ops)
return;
if (pool_id >= 0) {
VM_BUG_ON_PAGE(!PageLocked(page), page);
if (cleancache_get_key(mapping->host, &key) >= 0) {
cleancache_ops->invalidate_page(pool_id,
key, page->index);
cleancache_invalidates++;
}
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 93 | 93.94% | 5 | 62.50% |
| Sasha Levin | 3 | 3.03% | 1 | 12.50% |
| Konrad Rzeszutek Wilk | 2 | 2.02% | 1 | 12.50% |
| Vladimir Davydov | 1 | 1.01% | 1 | 12.50% |
| Total | 99 | 100.00% | 8 | 100.00% |
EXPORT_SYMBOL(__cleancache_invalidate_page);
/*
* Invalidate all data from cleancache associated with the poolid and the
* mappings's inode so that all subsequent gets to this poolid/inode
* will fail.
*
* The function has two checks before any action is taken - whether
* a backend is registered and whether the sb->cleancache_poolid
* is correct.
*/
void __cleancache_invalidate_inode(struct address_space *mapping)
{
int pool_id = mapping->host->i_sb->cleancache_poolid;
struct cleancache_filekey key = { .u.key = { 0 } };
if (!cleancache_ops)
return;
if (pool_id >= 0 && cleancache_get_key(mapping->host, &key) >= 0)
cleancache_ops->invalidate_inode(pool_id, key);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 67 | 97.10% | 4 | 80.00% |
| Konrad Rzeszutek Wilk | 2 | 2.90% | 1 | 20.00% |
| Total | 69 | 100.00% | 5 | 100.00% |
EXPORT_SYMBOL(__cleancache_invalidate_inode);
/*
* Called by any cleancache-enabled filesystem at time of unmount;
* note that pool_id is surrendered and may be returned by a subsequent
* cleancache_init_fs or cleancache_init_shared_fs.
*/
void __cleancache_invalidate_fs(struct super_block *sb)
{
int pool_id;
pool_id = sb->cleancache_poolid;
sb->cleancache_poolid = CLEANCACHE_NO_POOL;
if (cleancache_ops && pool_id >= 0)
cleancache_ops->invalidate_fs(pool_id);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 29 | 72.50% | 4 | 66.67% |
| Vladimir Davydov | 9 | 22.50% | 1 | 16.67% |
| Konrad Rzeszutek Wilk | 2 | 5.00% | 1 | 16.67% |
| Total | 40 | 100.00% | 6 | 100.00% |
EXPORT_SYMBOL(__cleancache_invalidate_fs);
static int __init init_cleancache(void)
{
#ifdef CONFIG_DEBUG_FS
struct dentry *root = debugfs_create_dir("cleancache", NULL);
if (root == NULL)
return -ENXIO;
debugfs_create_u64("succ_gets", S_IRUGO, root, &cleancache_succ_gets);
debugfs_create_u64("failed_gets", S_IRUGO,
root, &cleancache_failed_gets);
debugfs_create_u64("puts", S_IRUGO, root, &cleancache_puts);
debugfs_create_u64("invalidates", S_IRUGO,
root, &cleancache_invalidates);
#endif
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 87 | 100.00% | 2 | 100.00% |
| Total | 87 | 100.00% | 2 | 100.00% |
module_init(init_cleancache)
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Dan Magenheimer | 798 | 84.44% | 6 | 40.00% |
| Vladimir Davydov | 112 | 11.85% | 3 | 20.00% |
| Konrad Rzeszutek Wilk | 15 | 1.59% | 1 | 6.67% |
| Sasha Levin | 9 | 0.95% | 1 | 6.67% |
| Al Viro | 6 | 0.63% | 1 | 6.67% |
| Julia Lawall | 2 | 0.21% | 1 | 6.67% |
| Namjae Jeon | 2 | 0.21% | 1 | 6.67% |
| Marcin Jabrzyk | 1 | 0.11% | 1 | 6.67% |
| Total | 945 | 100.00% | 15 | 100.00% |
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