bitkeeper revision 1.1159.1.272 (417d33eaZEb_tnkLdhSsCNFpEXrEiw)

Update to Linux 2.6.9.

linux-2.6.9-xen-sparse/include/linux/bio.h

@@ -0,0 +1,328 @@
+/*
+ * 2.5 block I/O model
+ *
+ * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
+ */
+#ifndef __LINUX_BIO_H
+#define __LINUX_BIO_H
+
+#include <linux/highmem.h>
+#include <linux/mempool.h>
+
+/* Platforms may set this to teach the BIO layer about IOMMU hardware. */
+#include <asm/io.h>
+
+#if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY)
+#define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1))
+#define BIOVEC_VIRT_OVERSIZE(x)	((x) > BIO_VMERGE_MAX_SIZE)
+#else
+#define BIOVEC_VIRT_START_SIZE(x)	0
+#define BIOVEC_VIRT_OVERSIZE(x)		0
+#endif
+
+#ifndef BIO_VMERGE_BOUNDARY
+#define BIO_VMERGE_BOUNDARY	0
+#endif
+
+#define BIO_DEBUG
+
+#ifdef BIO_DEBUG
+#define BIO_BUG_ON	BUG_ON
+#else
+#define BIO_BUG_ON
+#endif
+
+#define BIO_MAX_PAGES		(256)
+#define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
+#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)
+
+/*
+ * was unsigned short, but we might as well be ready for > 64kB I/O pages
+ */
+struct bio_vec {
+	struct page	*bv_page;
+	unsigned int	bv_len;
+	unsigned int	bv_offset;
+};
+
+struct bio;
+typedef int (bio_end_io_t) (struct bio *, unsigned int, int);
+typedef void (bio_destructor_t) (struct bio *);
+
+/*
+ * main unit of I/O for the block layer and lower layers (ie drivers and
+ * stacking drivers)
+ */
+struct bio {
+	sector_t		bi_sector;
+	struct bio		*bi_next;	/* request queue link */
+	struct block_device	*bi_bdev;
+	unsigned long		bi_flags;	/* status, command, etc */
+	unsigned long		bi_rw;		/* bottom bits READ/WRITE,
+						 * top bits priority
+						 */
+
+	unsigned short		bi_vcnt;	/* how many bio_vec's */
+	unsigned short		bi_idx;		/* current index into bvl_vec */
+
+	/* Number of segments in this BIO after
+	 * physical address coalescing is performed.
+	 */
+	unsigned short		bi_phys_segments;
+
+	/* Number of segments after physical and DMA remapping
+	 * hardware coalescing is performed.
+	 */
+	unsigned short		bi_hw_segments;
+
+	unsigned int		bi_size;	/* residual I/O count */
+
+	/*
+	 * To keep track of the max hw size, we account for the
+	 * sizes of the first and last virtually mergeable segments
+	 * in this bio
+	 */
+	unsigned int		bi_hw_front_size;
+	unsigned int		bi_hw_back_size;
+
+	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */
+
+	struct bio_vec		*bi_io_vec;	/* the actual vec list */
+
+	bio_end_io_t		*bi_end_io;
+	atomic_t		bi_cnt;		/* pin count */
+
+	void			*bi_private;
+
+	bio_destructor_t	*bi_destructor;	/* destructor */
+};
+
+/*
+ * bio flags
+ */
+#define BIO_UPTODATE	0	/* ok after I/O completion */
+#define BIO_RW_BLOCK	1	/* RW_AHEAD set, and read/write would block */
+#define BIO_EOF		2	/* out-out-bounds error */
+#define BIO_SEG_VALID	3	/* nr_hw_seg valid */
+#define BIO_CLONED	4	/* doesn't own data */
+#define BIO_BOUNCED	5	/* bio is a bounce bio */
+#define BIO_USER_MAPPED 6	/* contains user pages */
+#define BIO_EOPNOTSUPP	7	/* not supported */
+#define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
+
+/*
+ * top 4 bits of bio flags indicate the pool this bio came from
+ */
+#define BIO_POOL_BITS		(4)
+#define BIO_POOL_OFFSET		(BITS_PER_LONG - BIO_POOL_BITS)
+#define BIO_POOL_MASK		(1UL << BIO_POOL_OFFSET)
+#define BIO_POOL_IDX(bio)	((bio)->bi_flags >> BIO_POOL_OFFSET)	
+
+/*
+ * bio bi_rw flags
+ *
+ * bit 0 -- read (not set) or write (set)
+ * bit 1 -- rw-ahead when set
+ * bit 2 -- barrier
+ * bit 3 -- fail fast, don't want low level driver retries
+ * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
+ */
+#define BIO_RW		0
+#define BIO_RW_AHEAD	1
+#define BIO_RW_BARRIER	2
+#define BIO_RW_FAILFAST	3
+#define BIO_RW_SYNC	4
+
+/*
+ * various member access, note that bio_data should of course not be used
+ * on highmem page vectors
+ */
+#define bio_iovec_idx(bio, idx)	(&((bio)->bi_io_vec[(idx)]))
+#define bio_iovec(bio)		bio_iovec_idx((bio), (bio)->bi_idx)
+#define bio_page(bio)		bio_iovec((bio))->bv_page
+#define bio_offset(bio)		bio_iovec((bio))->bv_offset
+#define bio_segments(bio)	((bio)->bi_vcnt - (bio)->bi_idx)
+#define bio_sectors(bio)	((bio)->bi_size >> 9)
+#define bio_cur_sectors(bio)	(bio_iovec(bio)->bv_len >> 9)
+#define bio_data(bio)		(page_address(bio_page((bio))) + bio_offset((bio)))
+#define bio_barrier(bio)	((bio)->bi_rw & (1 << BIO_RW_BARRIER))
+#define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
+#define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
+#define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
+
+/*
+ * will die
+ */
+#define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
+#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
+
+/*
+ * queues that have highmem support enabled may still need to revert to
+ * PIO transfers occasionally and thus map high pages temporarily. For
+ * permanent PIO fall back, user is probably better off disabling highmem
+ * I/O completely on that queue (see ide-dma for example)
+ */
+#define __bio_kmap_atomic(bio, idx, kmtype)				\
+	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +	\
+		bio_iovec_idx((bio), (idx))->bv_offset)
+
+#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
+
+/*
+ * merge helpers etc
+ */
+
+#define __BVEC_END(bio)		bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
+#define __BVEC_START(bio)	bio_iovec_idx((bio), (bio)->bi_idx)
+/* Platforms may set this to restrict multi-page buffer merging. */
+#ifndef BIOVEC_PHYS_MERGEABLE
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
+	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
+#endif
+#define BIOVEC_VIRT_MERGEABLE(vec1, vec2)	\
+	((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0)
+#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
+	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
+#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
+	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
+#define BIO_SEG_BOUNDARY(q, b1, b2) \
+	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
+
+#define bio_io_error(bio, bytes) bio_endio((bio), (bytes), -EIO)
+
+/*
+ * drivers should not use the __ version unless they _really_ want to
+ * run through the entire bio and not just pending pieces
+ */
+#define __bio_for_each_segment(bvl, bio, i, start_idx)			\
+	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);	\
+	     i < (bio)->bi_vcnt;					\
+	     bvl++, i++)
+
+#define bio_for_each_segment(bvl, bio, i)				\
+	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
+
+/*
+ * get a reference to a bio, so it won't disappear. the intended use is
+ * something like:
+ *
+ * bio_get(bio);
+ * submit_bio(rw, bio);
+ * if (bio->bi_flags ...)
+ *	do_something
+ * bio_put(bio);
+ *
+ * without the bio_get(), it could potentially complete I/O before submit_bio
+ * returns. and then bio would be freed memory when if (bio->bi_flags ...)
+ * runs
+ */
+#define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)
+
+
+/*
+ * A bio_pair is used when we need to split a bio.
+ * This can only happen for a bio that refers to just one
+ * page of data, and in the unusual situation when the
+ * page crosses a chunk/device boundary
+ *
+ * The address of the master bio is stored in bio1.bi_private
+ * The address of the pool the pair was allocated from is stored
+ *   in bio2.bi_private
+ */
+struct bio_pair {
+	struct bio	bio1, bio2;
+	struct bio_vec	bv1, bv2;
+	atomic_t	cnt;
+	int		error;
+};
+extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
+				  int first_sectors);
+extern mempool_t *bio_split_pool;
+extern void bio_pair_release(struct bio_pair *dbio);
+
+extern struct bio *bio_alloc(int, int);
+extern void bio_put(struct bio *);
+
+extern void bio_endio(struct bio *, unsigned int, int);
+struct request_queue;
+extern int bio_phys_segments(struct request_queue *, struct bio *);
+extern int bio_hw_segments(struct request_queue *, struct bio *);
+
+extern void __bio_clone(struct bio *, struct bio *);
+extern struct bio *bio_clone(struct bio *, int);
+
+extern void bio_init(struct bio *);
+
+extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
+extern int bio_get_nr_vecs(struct block_device *);
+extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
+				unsigned long, unsigned int, int);
+extern void bio_unmap_user(struct bio *);
+extern void bio_set_pages_dirty(struct bio *bio);
+extern void bio_check_pages_dirty(struct bio *bio);
+extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int);
+extern int bio_uncopy_user(struct bio *);
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * remember to add offset! and never ever reenable interrupts between a
+ * bvec_kmap_irq and bvec_kunmap_irq!!
+ *
+ * This function MUST be inlined - it plays with the CPU interrupt flags.
+ * Hence the `extern inline'.
+ */
+extern inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
+{
+	unsigned long addr;
+
+	/*
+	 * might not be a highmem page, but the preempt/irq count
+	 * balancing is a lot nicer this way
+	 */
+	local_irq_save(*flags);
+	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
+
+	BUG_ON(addr & ~PAGE_MASK);
+
+	return (char *) addr + bvec->bv_offset;
+}
+
+extern inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
+{
+	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
+
+	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
+	local_irq_restore(*flags);
+}
+
+#else
+#define bvec_kmap_irq(bvec, flags)	(page_address((bvec)->bv_page) + (bvec)->bv_offset)
+#define bvec_kunmap_irq(buf, flags)	do { *(flags) = 0; } while (0)
+#endif
+
+extern inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
+				   unsigned long *flags)
+{
+	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
+}
+#define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)
+
+#define bio_kmap_irq(bio, flags) \
+	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
+#define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
+
+#endif /* __LINUX_BIO_H */

linux-2.6.9-xen-sparse/include/linux/page-flags.h

@@ -0,0 +1,338 @@
+/*
+ * Macros for manipulating and testing page->flags
+ */
+
+#ifndef PAGE_FLAGS_H
+#define PAGE_FLAGS_H
+
+#include <linux/percpu.h>
+#include <linux/cache.h>
+#include <asm/pgtable.h>
+
+/*
+ * Various page->flags bits:
+ *
+ * PG_reserved is set for special pages, which can never be swapped out. Some
+ * of them might not even exist (eg empty_bad_page)...
+ *
+ * The PG_private bitflag is set if page->private contains a valid value.
+ *
+ * During disk I/O, PG_locked is used. This bit is set before I/O and
+ * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks
+ * waiting for the I/O on this page to complete.
+ *
+ * PG_uptodate tells whether the page's contents is valid.  When a read
+ * completes, the page becomes uptodate, unless a disk I/O error happened.
+ *
+ * For choosing which pages to swap out, inode pages carry a PG_referenced bit,
+ * which is set any time the system accesses that page through the (mapping,
+ * index) hash table.  This referenced bit, together with the referenced bit
+ * in the page tables, is used to manipulate page->age and move the page across
+ * the active, inactive_dirty and inactive_clean lists.
+ *
+ * Note that the referenced bit, the page->lru list_head and the active,
+ * inactive_dirty and inactive_clean lists are protected by the
+ * zone->lru_lock, and *NOT* by the usual PG_locked bit!
+ *
+ * PG_error is set to indicate that an I/O error occurred on this page.
+ *
+ * PG_arch_1 is an architecture specific page state bit.  The generic code
+ * guarantees that this bit is cleared for a page when it first is entered into
+ * the page cache.
+ *
+ * PG_highmem pages are not permanently mapped into the kernel virtual address
+ * space, they need to be kmapped separately for doing IO on the pages.  The
+ * struct page (these bits with information) are always mapped into kernel
+ * address space...
+ */
+
+/*
+ * Don't use the *_dontuse flags.  Use the macros.  Otherwise you'll break
+ * locked- and dirty-page accounting.  The top eight bits of page->flags are
+ * used for page->zone, so putting flag bits there doesn't work.
+ */
+#define PG_locked	 	 0	/* Page is locked. Don't touch. */
+#define PG_error		 1
+#define PG_referenced		 2
+#define PG_uptodate		 3
+
+#define PG_dirty	 	 4
+#define PG_lru			 5
+#define PG_active		 6
+#define PG_slab			 7	/* slab debug (Suparna wants this) */
+
+#define PG_highmem		 8
+#define PG_checked		 9	/* kill me in 2.5.<early>. */
+#define PG_arch_1		10
+#define PG_reserved		11
+
+#define PG_private		12	/* Has something at ->private */
+#define PG_writeback		13	/* Page is under writeback */
+#define PG_nosave		14	/* Used for system suspend/resume */
+#define PG_compound		15	/* Part of a compound page */
+
+#define PG_swapcache		16	/* Swap page: swp_entry_t in private */
+#define PG_mappedtodisk		17	/* Has blocks allocated on-disk */
+#define PG_reclaim		18	/* To be reclaimed asap */
+
+#define PG_foreign		21	/* Page belongs to foreign allocator */
+
+
+/*
+ * Global page accounting.  One instance per CPU.  Only unsigned longs are
+ * allowed.
+ */
+struct page_state {
+	unsigned long nr_dirty;		/* Dirty writeable pages */
+	unsigned long nr_writeback;	/* Pages under writeback */
+	unsigned long nr_unstable;	/* NFS unstable pages */
+	unsigned long nr_page_table_pages;/* Pages used for pagetables */
+	unsigned long nr_mapped;	/* mapped into pagetables */
+	unsigned long nr_slab;		/* In slab */
+#define GET_PAGE_STATE_LAST nr_slab
+
+	/*
+	 * The below are zeroed by get_page_state().  Use get_full_page_state()
+	 * to add up all these.
+	 */
+	unsigned long pgpgin;		/* Disk reads */
+	unsigned long pgpgout;		/* Disk writes */
+	unsigned long pswpin;		/* swap reads */
+	unsigned long pswpout;		/* swap writes */
+	unsigned long pgalloc_high;	/* page allocations */
+
+	unsigned long pgalloc_normal;
+	unsigned long pgalloc_dma;
+	unsigned long pgfree;		/* page freeings */
+	unsigned long pgactivate;	/* pages moved inactive->active */
+	unsigned long pgdeactivate;	/* pages moved active->inactive */
+
+	unsigned long pgfault;		/* faults (major+minor) */
+	unsigned long pgmajfault;	/* faults (major only) */
+	unsigned long pgrefill_high;	/* inspected in refill_inactive_zone */
+	unsigned long pgrefill_normal;
+	unsigned long pgrefill_dma;
+
+	unsigned long pgsteal_high;	/* total highmem pages reclaimed */
+	unsigned long pgsteal_normal;
+	unsigned long pgsteal_dma;
+	unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
+	unsigned long pgscan_kswapd_normal;
+
+	unsigned long pgscan_kswapd_dma;
+	unsigned long pgscan_direct_high;/* total highmem pages scanned */
+	unsigned long pgscan_direct_normal;
+	unsigned long pgscan_direct_dma;
+	unsigned long pginodesteal;	/* pages reclaimed via inode freeing */
+
+	unsigned long slabs_scanned;	/* slab objects scanned */
+	unsigned long kswapd_steal;	/* pages reclaimed by kswapd */
+	unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
+	unsigned long pageoutrun;	/* kswapd's calls to page reclaim */
+	unsigned long allocstall;	/* direct reclaim calls */
+
+	unsigned long pgrotated;	/* pages rotated to tail of the LRU */
+};
+
+DECLARE_PER_CPU(struct page_state, page_states);
+
+extern void get_page_state(struct page_state *ret);
+extern void get_full_page_state(struct page_state *ret);
+extern unsigned long __read_page_state(unsigned offset);
+
+#define read_page_state(member) \
+	__read_page_state(offsetof(struct page_state, member))
+
+#define mod_page_state(member, delta)					\
+	do {								\
+		unsigned long flags;					\
+		local_irq_save(flags);					\
+		__get_cpu_var(page_states).member += (delta);		\
+		local_irq_restore(flags);				\
+	} while (0)
+
+
+#define inc_page_state(member)	mod_page_state(member, 1UL)
+#define dec_page_state(member)	mod_page_state(member, 0UL - 1)
+#define add_page_state(member,delta) mod_page_state(member, (delta))
+#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
+
+#define mod_page_state_zone(zone, member, delta)			\
+	do {								\
+		unsigned long flags;					\
+		local_irq_save(flags);					\
+		if (is_highmem(zone))					\
+			__get_cpu_var(page_states).member##_high += (delta);\
+		else if (is_normal(zone))				\
+			__get_cpu_var(page_states).member##_normal += (delta);\
+		else							\
+			__get_cpu_var(page_states).member##_dma += (delta);\
+		local_irq_restore(flags);				\
+	} while (0)
+
+/*
+ * Manipulation of page state flags
+ */
+#define PageLocked(page)		\
+		test_bit(PG_locked, &(page)->flags)
+#define SetPageLocked(page)		\
+		set_bit(PG_locked, &(page)->flags)
+#define TestSetPageLocked(page)		\
+		test_and_set_bit(PG_locked, &(page)->flags)
+#define ClearPageLocked(page)		\
+		clear_bit(PG_locked, &(page)->flags)
+#define TestClearPageLocked(page)	\
+		test_and_clear_bit(PG_locked, &(page)->flags)
+
+#define PageError(page)		test_bit(PG_error, &(page)->flags)
+#define SetPageError(page)	set_bit(PG_error, &(page)->flags)
+#define ClearPageError(page)	clear_bit(PG_error, &(page)->flags)
+
+#define PageReferenced(page)	test_bit(PG_referenced, &(page)->flags)
+#define SetPageReferenced(page)	set_bit(PG_referenced, &(page)->flags)
+#define ClearPageReferenced(page)	clear_bit(PG_referenced, &(page)->flags)
+#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
+
+#define PageUptodate(page)	test_bit(PG_uptodate, &(page)->flags)
+#ifndef SetPageUptodate
+#define SetPageUptodate(page)	set_bit(PG_uptodate, &(page)->flags)
+#endif
+#define ClearPageUptodate(page)	clear_bit(PG_uptodate, &(page)->flags)
+
+#define PageDirty(page)		test_bit(PG_dirty, &(page)->flags)
+#define SetPageDirty(page)	set_bit(PG_dirty, &(page)->flags)
+#define TestSetPageDirty(page)	test_and_set_bit(PG_dirty, &(page)->flags)
+#define ClearPageDirty(page)	clear_bit(PG_dirty, &(page)->flags)
+#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
+
+#define SetPageLRU(page)	set_bit(PG_lru, &(page)->flags)
+#define PageLRU(page)		test_bit(PG_lru, &(page)->flags)
+#define TestSetPageLRU(page)	test_and_set_bit(PG_lru, &(page)->flags)
+#define TestClearPageLRU(page)	test_and_clear_bit(PG_lru, &(page)->flags)
+
+#define PageActive(page)	test_bit(PG_active, &(page)->flags)
+#define SetPageActive(page)	set_bit(PG_active, &(page)->flags)
+#define ClearPageActive(page)	clear_bit(PG_active, &(page)->flags)
+#define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags)
+#define TestSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags)
+
+#define PageSlab(page)		test_bit(PG_slab, &(page)->flags)
+#define SetPageSlab(page)	set_bit(PG_slab, &(page)->flags)
+#define ClearPageSlab(page)	clear_bit(PG_slab, &(page)->flags)
+#define TestClearPageSlab(page)	test_and_clear_bit(PG_slab, &(page)->flags)
+#define TestSetPageSlab(page)	test_and_set_bit(PG_slab, &(page)->flags)
+
+#ifdef CONFIG_HIGHMEM
+#define PageHighMem(page)	test_bit(PG_highmem, &(page)->flags)
+#else
+#define PageHighMem(page)	0 /* needed to optimize away at compile time */
+#endif
+
+#define PageChecked(page)	test_bit(PG_checked, &(page)->flags)
+#define SetPageChecked(page)	set_bit(PG_checked, &(page)->flags)
+#define ClearPageChecked(page)	clear_bit(PG_checked, &(page)->flags)
+
+#define PageReserved(page)	test_bit(PG_reserved, &(page)->flags)
+#define SetPageReserved(page)	set_bit(PG_reserved, &(page)->flags)
+#define ClearPageReserved(page)	clear_bit(PG_reserved, &(page)->flags)
+#define __ClearPageReserved(page)	__clear_bit(PG_reserved, &(page)->flags)
+
+#define SetPagePrivate(page)	set_bit(PG_private, &(page)->flags)
+#define ClearPagePrivate(page)	clear_bit(PG_private, &(page)->flags)
+#define PagePrivate(page)	test_bit(PG_private, &(page)->flags)
+
+#define PageWriteback(page)	test_bit(PG_writeback, &(page)->flags)
+#define SetPageWriteback(page)						\
+	do {								\
+		if (!test_and_set_bit(PG_writeback,			\
+				&(page)->flags))			\
+			inc_page_state(nr_writeback);			\
+	} while (0)
+#define TestSetPageWriteback(page)					\
+	({								\
+		int ret;						\
+		ret = test_and_set_bit(PG_writeback,			\
+					&(page)->flags);		\
+		if (!ret)						\
+			inc_page_state(nr_writeback);			\
+		ret;							\
+	})
+#define ClearPageWriteback(page)					\
+	do {								\
+		if (test_and_clear_bit(PG_writeback,			\
+				&(page)->flags))			\
+			dec_page_state(nr_writeback);			\
+	} while (0)
+#define TestClearPageWriteback(page)					\
+	({								\
+		int ret;						\
+		ret = test_and_clear_bit(PG_writeback,			\
+				&(page)->flags);			\
+		if (ret)						\
+			dec_page_state(nr_writeback);			\
+		ret;							\
+	})
+
+#define PageNosave(page)	test_bit(PG_nosave, &(page)->flags)
+#define SetPageNosave(page)	set_bit(PG_nosave, &(page)->flags)
+#define TestSetPageNosave(page)	test_and_set_bit(PG_nosave, &(page)->flags)
+#define ClearPageNosave(page)		clear_bit(PG_nosave, &(page)->flags)
+#define TestClearPageNosave(page)	test_and_clear_bit(PG_nosave, &(page)->flags)
+
+#define PageMappedToDisk(page)	test_bit(PG_mappedtodisk, &(page)->flags)
+#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
+#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
+
+#define PageReclaim(page)	test_bit(PG_reclaim, &(page)->flags)
+#define SetPageReclaim(page)	set_bit(PG_reclaim, &(page)->flags)
+#define ClearPageReclaim(page)	clear_bit(PG_reclaim, &(page)->flags)
+#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
+
+#define PageCompound(page)	test_bit(PG_compound, &(page)->flags)
+#define SetPageCompound(page)	set_bit(PG_compound, &(page)->flags)
+#define ClearPageCompound(page)	clear_bit(PG_compound, &(page)->flags)
+
+/* A foreign page uses a custom destructor rather than the buddy allocator. */
+#ifdef CONFIG_FOREIGN_PAGES
+#define PageForeign(page)	test_bit(PG_foreign, &(page)->flags)
+#define SetPageForeign(page, dtor) do {		\
+	set_bit(PG_foreign, &(page)->flags);	\
+	(page)->mapping = (void *)dtor;		\
+} while (0)
+#define ClearPageForeign(page) do {		\
+	clear_bit(PG_foreign, &(page)->flags);	\
+	(page)->mapping = NULL;			\
+} while (0)
+#define PageForeignDestructor(page)	\
+	( (void (*) (struct page *)) (page)->mapping )
+#else
+#define PageForeign(page)	0
+#define PageForeignDestructor(page)	void
+#endif
+
+#ifdef CONFIG_SWAP
+#define PageSwapCache(page)	test_bit(PG_swapcache, &(page)->flags)
+#define SetPageSwapCache(page)	set_bit(PG_swapcache, &(page)->flags)
+#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
+#else
+#define PageSwapCache(page)	0
+#endif
+
+struct page;	/* forward declaration */
+
+int test_clear_page_dirty(struct page *page);
+int __clear_page_dirty(struct page *page);
+int test_clear_page_writeback(struct page *page);
+int test_set_page_writeback(struct page *page);
+
+static inline void clear_page_dirty(struct page *page)
+{
+	test_clear_page_dirty(page);
+}
+
+static inline void set_page_writeback(struct page *page)
+{
+	test_set_page_writeback(page);
+}
+
+#endif	/* PAGE_FLAGS_H */