mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-22 11:58:21 +07:00
3cb29d1117
The limit equals 32 and is imposed by the number of entries in the
fs_poolid_map and shared_fs_poolid_map. Nowadays it is insufficient,
because with containers on board a Linux host can have hundreds of
active fs mounts.
These maps were introduced by commit 49a9ab815a ("mm: cleancache:
lazy initialization to allow tmem backends to build/run as modules") in
order to allow compiling cleancache drivers as modules. Real pool ids
are stored in these maps while super_block->cleancache_poolid points to
an entry in the map, so that on cleancache registration we can walk over
all (if there are <= 32 of them, of course) cleancache-enabled super
blocks and assign real pool ids.
Actually, there is absolutely no need in these maps, because we can
iterate over all super blocks immediately using iterate_supers. This is
not racy, because cleancache_init_ops is called from mount_fs with
super_block->s_umount held for writing, while iterate_supers takes this
semaphore for reading, so if we call iterate_supers after setting
cleancache_ops, all super blocks that had been created before
cleancache_register_ops was called will be assigned pool ids by the
action function of iterate_supers while all newer super blocks will
receive it in cleancache_init_fs.
This patch therefore removes the maps and hence the artificial limit on
the number of cleancache enabled filesystems.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
126 lines
3.9 KiB
C
126 lines
3.9 KiB
C
#ifndef _LINUX_CLEANCACHE_H
|
|
#define _LINUX_CLEANCACHE_H
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/exportfs.h>
|
|
#include <linux/mm.h>
|
|
|
|
#define CLEANCACHE_NO_POOL -1
|
|
#define CLEANCACHE_NO_BACKEND -2
|
|
#define CLEANCACHE_NO_BACKEND_SHARED -3
|
|
|
|
#define CLEANCACHE_KEY_MAX 6
|
|
|
|
/*
|
|
* cleancache requires every file with a page in cleancache to have a
|
|
* unique key unless/until the file is removed/truncated. For some
|
|
* filesystems, the inode number is unique, but for "modern" filesystems
|
|
* an exportable filehandle is required (see exportfs.h)
|
|
*/
|
|
struct cleancache_filekey {
|
|
union {
|
|
ino_t ino;
|
|
__u32 fh[CLEANCACHE_KEY_MAX];
|
|
u32 key[CLEANCACHE_KEY_MAX];
|
|
} u;
|
|
};
|
|
|
|
struct cleancache_ops {
|
|
int (*init_fs)(size_t);
|
|
int (*init_shared_fs)(char *uuid, size_t);
|
|
int (*get_page)(int, struct cleancache_filekey,
|
|
pgoff_t, struct page *);
|
|
void (*put_page)(int, struct cleancache_filekey,
|
|
pgoff_t, struct page *);
|
|
void (*invalidate_page)(int, struct cleancache_filekey, pgoff_t);
|
|
void (*invalidate_inode)(int, struct cleancache_filekey);
|
|
void (*invalidate_fs)(int);
|
|
};
|
|
|
|
extern int cleancache_register_ops(struct cleancache_ops *ops);
|
|
extern void __cleancache_init_fs(struct super_block *);
|
|
extern void __cleancache_init_shared_fs(struct super_block *);
|
|
extern int __cleancache_get_page(struct page *);
|
|
extern void __cleancache_put_page(struct page *);
|
|
extern void __cleancache_invalidate_page(struct address_space *, struct page *);
|
|
extern void __cleancache_invalidate_inode(struct address_space *);
|
|
extern void __cleancache_invalidate_fs(struct super_block *);
|
|
|
|
#ifdef CONFIG_CLEANCACHE
|
|
#define cleancache_enabled (1)
|
|
static inline bool cleancache_fs_enabled(struct page *page)
|
|
{
|
|
return page->mapping->host->i_sb->cleancache_poolid >= 0;
|
|
}
|
|
static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping)
|
|
{
|
|
return mapping->host->i_sb->cleancache_poolid >= 0;
|
|
}
|
|
#else
|
|
#define cleancache_enabled (0)
|
|
#define cleancache_fs_enabled(_page) (0)
|
|
#define cleancache_fs_enabled_mapping(_page) (0)
|
|
#endif
|
|
|
|
/*
|
|
* The shim layer provided by these inline functions allows the compiler
|
|
* to reduce all cleancache hooks to nothingness if CONFIG_CLEANCACHE
|
|
* is disabled, to a single global variable check if CONFIG_CLEANCACHE
|
|
* is enabled but no cleancache "backend" has dynamically enabled it,
|
|
* and, for the most frequent cleancache ops, to a single global variable
|
|
* check plus a superblock element comparison if CONFIG_CLEANCACHE is enabled
|
|
* and a cleancache backend has dynamically enabled cleancache, but the
|
|
* filesystem referenced by that cleancache op has not enabled cleancache.
|
|
* As a result, CONFIG_CLEANCACHE can be enabled by default with essentially
|
|
* no measurable performance impact.
|
|
*/
|
|
|
|
static inline void cleancache_init_fs(struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_init_fs(sb);
|
|
}
|
|
|
|
static inline void cleancache_init_shared_fs(struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_init_shared_fs(sb);
|
|
}
|
|
|
|
static inline int cleancache_get_page(struct page *page)
|
|
{
|
|
int ret = -1;
|
|
|
|
if (cleancache_enabled && cleancache_fs_enabled(page))
|
|
ret = __cleancache_get_page(page);
|
|
return ret;
|
|
}
|
|
|
|
static inline void cleancache_put_page(struct page *page)
|
|
{
|
|
if (cleancache_enabled && cleancache_fs_enabled(page))
|
|
__cleancache_put_page(page);
|
|
}
|
|
|
|
static inline void cleancache_invalidate_page(struct address_space *mapping,
|
|
struct page *page)
|
|
{
|
|
/* careful... page->mapping is NULL sometimes when this is called */
|
|
if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
|
|
__cleancache_invalidate_page(mapping, page);
|
|
}
|
|
|
|
static inline void cleancache_invalidate_inode(struct address_space *mapping)
|
|
{
|
|
if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
|
|
__cleancache_invalidate_inode(mapping);
|
|
}
|
|
|
|
static inline void cleancache_invalidate_fs(struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_invalidate_fs(sb);
|
|
}
|
|
|
|
#endif /* _LINUX_CLEANCACHE_H */
|