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freebsd-dev/sys/vm/vm_page.h
Konstantin Belousov b6c00483e9 Do not leave invalid pages in the object after the short read for a 
network file systems (not only NFS proper). Short reads cause pages
other then the requested one, which were not filled by read response,
to stay invalid.

Change the vm_page_readahead_finish() interface to not take the error
code, but instead to make a decision to free or to (de)activate the
page only by its validity. As result, not requested invalid pages are
freed even if the read RPC indicated success.

Noted and reviewed by:	alc
MFC after:	1 week
2012-08-14 11:45:47 +00:00

559 lines
19 KiB
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/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
/*
* Resident memory system definitions.
*/
#ifndef _VM_PAGE_
#define _VM_PAGE_
#include <vm/pmap.h>
/*
* Management of resident (logical) pages.
*
* A small structure is kept for each resident
* page, indexed by page number. Each structure
* is an element of several lists:
*
* A hash table bucket used to quickly
* perform object/offset lookups
*
* A list of all pages for a given object,
* so they can be quickly deactivated at
* time of deallocation.
*
* An ordered list of pages due for pageout.
*
* In addition, the structure contains the object
* and offset to which this page belongs (for pageout),
* and sundry status bits.
*
* In general, operations on this structure's mutable fields are
* synchronized using either one of or a combination of the lock on the
* object that the page belongs to (O), the pool lock for the page (P),
* or the lock for either the free or paging queues (Q). If a field is
* annotated below with two of these locks, then holding either lock is
* sufficient for read access, but both locks are required for write
* access.
*
* In contrast, the synchronization of accesses to the page's
* dirty field is machine dependent (M). In the
* machine-independent layer, the lock on the object that the
* page belongs to must be held in order to operate on the field.
* However, the pmap layer is permitted to set all bits within
* the field without holding that lock. If the underlying
* architecture does not support atomic read-modify-write
* operations on the field's type, then the machine-independent
* layer uses a 32-bit atomic on the aligned 32-bit word that
* contains the dirty field. In the machine-independent layer,
* the implementation of read-modify-write operations on the
* field is encapsulated in vm_page_clear_dirty_mask().
*/
TAILQ_HEAD(pglist, vm_page);
#if PAGE_SIZE == 4096
#define VM_PAGE_BITS_ALL 0xffu
typedef uint8_t vm_page_bits_t;
#elif PAGE_SIZE == 8192
#define VM_PAGE_BITS_ALL 0xffffu
typedef uint16_t vm_page_bits_t;
#elif PAGE_SIZE == 16384
#define VM_PAGE_BITS_ALL 0xffffffffu
typedef uint32_t vm_page_bits_t;
#elif PAGE_SIZE == 32768
#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
typedef uint64_t vm_page_bits_t;
#endif
struct vm_page {
TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (Q) */
TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
struct vm_page *left; /* splay tree link (O) */
struct vm_page *right; /* splay tree link (O) */
vm_object_t object; /* which object am I in (O,P)*/
vm_pindex_t pindex; /* offset into object (O,P) */
vm_paddr_t phys_addr; /* physical address of page */
struct md_page md; /* machine dependant stuff */
uint8_t queue; /* page queue index (P,Q) */
int8_t segind;
short hold_count; /* page hold count (P) */
uint8_t order; /* index of the buddy queue */
uint8_t pool;
u_short cow; /* page cow mapping count (P) */
u_int wire_count; /* wired down maps refs (P) */
uint8_t aflags; /* access is atomic */
uint8_t flags; /* see below, often immutable after alloc */
u_short oflags; /* page flags (O) */
u_char act_count; /* page usage count (O) */
u_char busy; /* page busy count (O) */
/* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
/* so, on normal X86 kernels, they must be at least 8 bits wide */
vm_page_bits_t valid; /* map of valid DEV_BSIZE chunks (O) */
vm_page_bits_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
};
/*
* Page flags stored in oflags:
*
* Access to these page flags is synchronized by the lock on the object
* containing the page (O).
*
* Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
* indicates that the page is not under PV management but
* otherwise should be treated as a normal page. Pages not
* under PV management cannot be paged out via the
* object/vm_page_t because there is no knowledge of their pte
* mappings, and such pages are also not on any PQ queue.
*
*/
#define VPO_BUSY 0x0001 /* page is in transit */
#define VPO_WANTED 0x0002 /* someone is waiting for page */
#define VPO_UNMANAGED 0x0004 /* No PV management for page */
#define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */
#define VPO_NOSYNC 0x0400 /* do not collect for syncer */
#define PQ_NONE 255
#define PQ_INACTIVE 0
#define PQ_ACTIVE 1
#define PQ_HOLD 2
#define PQ_COUNT 3
struct vpgqueues {
struct pglist pl;
int *cnt;
};
extern struct vpgqueues vm_page_queues[PQ_COUNT];
struct vpglocks {
struct mtx data;
char pad[CACHE_LINE_SIZE - sizeof(struct mtx)];
} __aligned(CACHE_LINE_SIZE);
extern struct vpglocks vm_page_queue_free_lock;
extern struct vpglocks pa_lock[];
#if defined(__arm__)
#define PDRSHIFT PDR_SHIFT
#elif !defined(PDRSHIFT)
#define PDRSHIFT 21
#endif
#define pa_index(pa) ((pa) >> PDRSHIFT)
#define PA_LOCKPTR(pa) &pa_lock[pa_index((pa)) % PA_LOCK_COUNT].data
#define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
#define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
#define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
#define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
#define PA_UNLOCK_COND(pa) \
do { \
if ((pa) != 0) { \
PA_UNLOCK((pa)); \
(pa) = 0; \
} \
} while (0)
#define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
#ifdef KLD_MODULE
#define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
#define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
#define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
#if defined(INVARIANTS)
#define vm_page_lock_assert(m, a) \
vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
#else
#define vm_page_lock_assert(m, a)
#endif
#else /* !KLD_MODULE */
#define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
#define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
#define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
#define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
#define vm_page_lock_assert(m, a) mtx_assert(vm_page_lockptr((m)), (a))
#endif
#define vm_page_queue_free_mtx vm_page_queue_free_lock.data
/*
* The vm_page's aflags are updated using atomic operations. To set or clear
* these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
* must be used. Neither these flags nor these functions are part of the KBI.
*
* PGA_REFERENCED may be cleared only if the object containing the page is
* locked. It is set by both the MI and MD VM layers. However, kernel
* loadable modules should not directly set this flag. They should call
* vm_page_reference() instead.
*
* PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it
* does so, the page must be VPO_BUSY. The MI VM layer must never access this
* flag directly. Instead, it should call pmap_page_is_write_mapped().
*
* PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
* at least one executable mapping. It is not consumed by the MI VM layer.
*/
#define PGA_WRITEABLE 0x01 /* page may be mapped writeable */
#define PGA_REFERENCED 0x02 /* page has been referenced */
#define PGA_EXECUTABLE 0x04 /* page may be mapped executable */
/*
* Page flags. If changed at any other time than page allocation or
* freeing, the modification must be protected by the vm_page lock.
*/
#define PG_CACHED 0x01 /* page is cached */
#define PG_FREE 0x02 /* page is free */
#define PG_FICTITIOUS 0x04 /* physical page doesn't exist */
#define PG_ZERO 0x08 /* page is zeroed */
#define PG_MARKER 0x10 /* special queue marker page */
#define PG_SLAB 0x20 /* object pointer is actually a slab */
#define PG_WINATCFLS 0x40 /* flush dirty page on inactive q */
#define PG_NODUMP 0x80 /* don't include this page in a dump */
/*
* Misc constants.
*/
#define ACT_DECLINE 1
#define ACT_ADVANCE 3
#define ACT_INIT 5
#define ACT_MAX 64
#ifdef _KERNEL
#include <sys/systm.h>
#include <machine/atomic.h>
/*
* Each pageable resident page falls into one of five lists:
*
* free
* Available for allocation now.
*
* cache
* Almost available for allocation. Still associated with
* an object, but clean and immediately freeable.
*
* hold
* Will become free after a pending I/O operation
* completes.
*
* The following lists are LRU sorted:
*
* inactive
* Low activity, candidates for reclamation.
* This is the list of pages that should be
* paged out next.
*
* active
* Pages that are "active" i.e. they have been
* recently referenced.
*
*/
extern int vm_page_zero_count;
extern vm_page_t vm_page_array; /* First resident page in table */
extern long vm_page_array_size; /* number of vm_page_t's */
extern long first_page; /* first physical page number */
#define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0)
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa);
vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
extern struct vpglocks vm_page_queue_lock;
#define vm_page_queue_mtx vm_page_queue_lock.data
#define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx)
#define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx)
/* page allocation classes: */
#define VM_ALLOC_NORMAL 0
#define VM_ALLOC_INTERRUPT 1
#define VM_ALLOC_SYSTEM 2
#define VM_ALLOC_CLASS_MASK 3
/* page allocation flags: */
#define VM_ALLOC_WIRED 0x0020 /* non pageable */
#define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
#define VM_ALLOC_RETRY 0x0080 /* Mandatory with vm_page_grab() */
#define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
#define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
#define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
#define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
#define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */
#define VM_ALLOC_NODUMP 0x2000 /* don't include in dump */
#define VM_ALLOC_COUNT_SHIFT 16
#define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
void vm_page_busy(vm_page_t m);
void vm_page_flash(vm_page_t m);
void vm_page_io_start(vm_page_t m);
void vm_page_io_finish(vm_page_t m);
void vm_page_hold(vm_page_t mem);
void vm_page_unhold(vm_page_t mem);
void vm_page_free(vm_page_t m);
void vm_page_free_zero(vm_page_t m);
void vm_page_wakeup(vm_page_t m);
void vm_pageq_remove(vm_page_t m);
void vm_page_activate (vm_page_t);
vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
vm_paddr_t boundary, vm_memattr_t memattr);
vm_page_t vm_page_alloc_freelist(int, int);
vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
void vm_page_cache(vm_page_t);
void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
int vm_page_try_to_cache (vm_page_t);
int vm_page_try_to_free (vm_page_t);
void vm_page_dontneed(vm_page_t);
void vm_page_deactivate (vm_page_t);
vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
boolean_t vm_page_is_cached(vm_object_t object, vm_pindex_t pindex);
vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
vm_page_t vm_page_next(vm_page_t m);
int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *);
vm_page_t vm_page_prev(vm_page_t m);
void vm_page_putfake(vm_page_t m);
void vm_page_readahead_finish(vm_page_t m);
void vm_page_reference(vm_page_t m);
void vm_page_remove (vm_page_t);
void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
void vm_page_requeue(vm_page_t m);
void vm_page_set_valid_range(vm_page_t m, int base, int size);
void vm_page_sleep(vm_page_t m, const char *msg);
vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
vm_offset_t vm_page_startup(vm_offset_t vaddr);
void vm_page_unhold_pages(vm_page_t *ma, int count);
void vm_page_unwire (vm_page_t, int);
void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
void vm_page_wire (vm_page_t);
void vm_page_set_validclean (vm_page_t, int, int);
void vm_page_clear_dirty (vm_page_t, int, int);
void vm_page_set_invalid (vm_page_t, int, int);
int vm_page_is_valid (vm_page_t, int, int);
void vm_page_test_dirty (vm_page_t);
vm_page_bits_t vm_page_bits(int base, int size);
void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
void vm_page_free_toq(vm_page_t m);
void vm_page_zero_idle_wakeup(void);
void vm_page_cowfault (vm_page_t);
int vm_page_cowsetup(vm_page_t);
void vm_page_cowclear (vm_page_t);
void vm_page_dirty_KBI(vm_page_t m);
void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
#endif
#ifdef INVARIANTS
void vm_page_object_lock_assert(vm_page_t m);
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m)
#else
#define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
#endif
/*
* We want to use atomic updates for the aflags field, which is 8 bits wide.
* However, not all architectures support atomic operations on 8-bit
* destinations. In order that we can easily use a 32-bit operation, we
* require that the aflags field be 32-bit aligned.
*/
CTASSERT(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0);
/*
* Clear the given bits in the specified page.
*/
static inline void
vm_page_aflag_clear(vm_page_t m, uint8_t bits)
{
uint32_t *addr, val;
/*
* The PGA_REFERENCED flag can only be cleared if the object
* containing the page is locked.
*/
if ((bits & PGA_REFERENCED) != 0)
VM_PAGE_OBJECT_LOCK_ASSERT(m);
/*
* Access the whole 32-bit word containing the aflags field with an
* atomic update. Parallel non-atomic updates to the other fields
* within this word are handled properly by the atomic update.
*/
addr = (void *)&m->aflags;
KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
("vm_page_aflag_clear: aflags is misaligned"));
val = bits;
#if BYTE_ORDER == BIG_ENDIAN
val <<= 24;
#endif
atomic_clear_32(addr, val);
}
/*
* Set the given bits in the specified page.
*/
static inline void
vm_page_aflag_set(vm_page_t m, uint8_t bits)
{
uint32_t *addr, val;
/*
* The PGA_WRITEABLE flag can only be set if the page is managed and
* VPO_BUSY. Currently, this flag is only set by pmap_enter().
*/
KASSERT((bits & PGA_WRITEABLE) == 0 ||
(m->oflags & (VPO_UNMANAGED | VPO_BUSY)) == VPO_BUSY,
("vm_page_aflag_set: PGA_WRITEABLE and !VPO_BUSY"));
/*
* Access the whole 32-bit word containing the aflags field with an
* atomic update. Parallel non-atomic updates to the other fields
* within this word are handled properly by the atomic update.
*/
addr = (void *)&m->aflags;
KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
("vm_page_aflag_set: aflags is misaligned"));
val = bits;
#if BYTE_ORDER == BIG_ENDIAN
val <<= 24;
#endif
atomic_set_32(addr, val);
}
/*
* vm_page_dirty:
*
* Set all bits in the page's dirty field.
*
* The object containing the specified page must be locked if the
* call is made from the machine-independent layer.
*
* See vm_page_clear_dirty_mask().
*/
static __inline void
vm_page_dirty(vm_page_t m)
{
/* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
#if defined(KLD_MODULE) || defined(INVARIANTS)
vm_page_dirty_KBI(m);
#else
m->dirty = VM_PAGE_BITS_ALL;
#endif
}
/*
* vm_page_sleep_if_busy:
*
* Sleep and release the page queues lock if VPO_BUSY is set or,
* if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the
* thread slept and the page queues lock was released.
* Otherwise, retains the page queues lock and returns FALSE.
*
* The object containing the given page must be locked.
*/
static __inline int
vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg)
{
if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) {
vm_page_sleep(m, msg);
return (TRUE);
}
return (FALSE);
}
/*
* vm_page_undirty:
*
* Set page to not be dirty. Note: does not clear pmap modify bits
*/
static __inline void
vm_page_undirty(vm_page_t m)
{
VM_PAGE_OBJECT_LOCK_ASSERT(m);
m->dirty = 0;
}
#endif /* _KERNEL */
#endif /* !_VM_PAGE_ */
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