Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 528 insertions, 0 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
new file mode 100644
index 0000000..6a64209
--- /dev/null
+++ b/include/linux/bio.h
@@ -0,0 +1,528 @@
+/*
+ * 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>
+#include <linux/ioprio.h>
+
+#ifdef CONFIG_BLOCK
+
+#include <asm/io.h>
+
+#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_set;
+struct bio;
+struct bio_integrity_payload;
+typedef void (bio_end_io_t) (struct bio *, 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;	/* device address in 512 byte
+						   sectors */
+	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 int		bi_phys_segments;
+
+	unsigned int		bi_size;	/* residual I/O count */
+
+	/*
+	 * To keep track of the max segment size, we account for the
+	 * sizes of the first and last mergeable segments in this bio.
+	 */
+	unsigned int		bi_seg_front_size;
+	unsigned int		bi_seg_back_size;
+
+	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */
+
+	unsigned int		bi_comp_cpu;	/* completion CPU */
+
+	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;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	struct bio_integrity_payload *bi_integrity;  /* data integrity */
+#endif
+
+	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	/* bi_phys_segments 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_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
+#define BIO_NULL_MAPPED 9	/* contains invalid user pages */
+#define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
+#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 -- data direction
+ *	If not set, bio is a read from device. If set, it's a write to device.
+ * bit 1 -- rw-ahead when set
+ * bit 2 -- barrier
+ *	Insert a serialization point in the IO queue, forcing previously
+ *	submitted IO to be completed before this oen is issued.
+ * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
+ *	Note that this does NOT indicate that the IO itself is sync, just
+ *	that the block layer will not postpone issue of this IO by plugging.
+ * bit 4 -- metadata request
+ *	Used for tracing to differentiate metadata and data IO. May also
+ *	get some preferential treatment in the IO scheduler
+ * bit 5 -- discard sectors
+ *	Informs the lower level device that this range of sectors is no longer
+ *	used by the file system and may thus be freed by the device. Used
+ *	for flash based storage.
+ * bit 6 -- fail fast device errors
+ * bit 7 -- fail fast transport errors
+ * bit 8 -- fail fast driver errors
+ *	Don't want driver retries for any fast fail whatever the reason.
+ */
+#define BIO_RW		0	/* Must match RW in req flags (blkdev.h) */
+#define BIO_RW_AHEAD	1	/* Must match FAILFAST in req flags */
+#define BIO_RW_BARRIER	2
+#define BIO_RW_SYNC	3
+#define BIO_RW_META	4
+#define BIO_RW_DISCARD	5
+#define BIO_RW_FAILFAST_DEV		6
+#define BIO_RW_FAILFAST_TRANSPORT	7
+#define BIO_RW_FAILFAST_DRIVER		8
+
+/*
+ * upper 16 bits of bi_rw define the io priority of this bio
+ */
+#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
+#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
+#define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))
+
+#define bio_set_prio(bio, prio)		do {			\
+	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
+	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
+	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
+} while (0)
+
+/*
+ * 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_barrier(bio)	((bio)->bi_rw & (1 << BIO_RW_BARRIER))
+#define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
+#define bio_failfast_dev(bio)	((bio)->bi_rw &	(1 << BIO_RW_FAILFAST_DEV))
+#define bio_failfast_transport(bio)	\
+	((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT))
+#define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER))
+#define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
+#define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))
+#define bio_discard(bio)	((bio)->bi_rw & (1 << BIO_RW_DISCARD))
+#define bio_empty_barrier(bio)	(bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
+
+static inline unsigned int bio_cur_sectors(struct bio *bio)
+{
+	if (bio->bi_vcnt)
+		return bio_iovec(bio)->bv_len >> 9;
+	else /* dataless requests such as discard */
+		return bio->bi_size >> 9;
+}
+
+static inline void *bio_data(struct bio *bio)
+{
+	if (bio->bi_vcnt)
+		return page_address(bio_page(bio)) + bio_offset(bio);
+
+	return NULL;
+}
+
+/*
+ * 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)
+
+/* Default implementation of BIOVEC_PHYS_MERGEABLE */
+#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
+	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
+
+/*
+ * allow arch override, for eg virtualized architectures (put in asm/io.h)
+ */
+#ifndef BIOVEC_PHYS_MERGEABLE
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
+	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
+#endif
+
+#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) bio_endio((bio), -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)
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+/*
+ * bio integrity payload
+ */
+struct bio_integrity_payload {
+	struct bio		*bip_bio;	/* parent bio */
+	struct bio_vec		*bip_vec;	/* integrity data vector */
+
+	sector_t		bip_sector;	/* virtual start sector */
+
+	void			*bip_buf;	/* generated integrity data */
+	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
+
+	int			bip_error;	/* saved I/O error */
+	unsigned int		bip_size;
+
+	unsigned short		bip_pool;	/* pool the ivec came from */
+	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
+	unsigned short		bip_idx;	/* current bip_vec index */
+
+	struct work_struct	bip_work;	/* I/O completion */
+};
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+/*
+ * 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;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	struct bio_integrity_payload	bip1, bip2;
+	struct bio_vec			iv1, iv2;
+#endif
+	atomic_t			cnt;
+	int				error;
+};
+extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
+extern void bio_pair_release(struct bio_pair *dbio);
+
+extern struct bio_set *bioset_create(int, int);
+extern void bioset_free(struct bio_set *);
+
+extern struct bio *bio_alloc(gfp_t, int);
+extern struct bio *bio_kmalloc(gfp_t, int);
+extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
+extern void bio_put(struct bio *);
+extern void bio_free(struct bio *, struct bio_set *);
+
+extern void bio_endio(struct bio *, int);
+struct request_queue;
+extern int bio_phys_segments(struct request_queue *, struct bio *);
+
+extern void __bio_clone(struct bio *, struct bio *);
+extern struct bio *bio_clone(struct bio *, gfp_t);
+
+extern void bio_init(struct bio *);
+
+extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
+extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
+			   unsigned int, unsigned int);
+extern int bio_get_nr_vecs(struct block_device *);
+extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
+extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
+				unsigned long, unsigned int, int, gfp_t);
+struct sg_iovec;
+struct rq_map_data;
+extern struct bio *bio_map_user_iov(struct request_queue *,
+				    struct block_device *,
+				    struct sg_iovec *, int, int, gfp_t);
+extern void bio_unmap_user(struct bio *);
+extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
+				gfp_t);
+extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
+				 gfp_t, int);
+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 *, struct rq_map_data *,
+				 unsigned long, unsigned int, int, gfp_t);
+extern struct bio *bio_copy_user_iov(struct request_queue *,
+				     struct rq_map_data *, struct sg_iovec *,
+				     int, int, gfp_t);
+extern int bio_uncopy_user(struct bio *);
+void zero_fill_bio(struct bio *bio);
+extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
+extern unsigned int bvec_nr_vecs(unsigned short idx);
+
+/*
+ * Allow queuer to specify a completion CPU for this bio
+ */
+static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
+{
+	bio->bi_comp_cpu = cpu;
+}
+
+/*
+ * bio_set is used to allow other portions of the IO system to
+ * allocate their own private memory pools for bio and iovec structures.
+ * These memory pools in turn all allocate from the bio_slab
+ * and the bvec_slabs[].
+ */
+#define BIO_POOL_SIZE 2
+#define BIOVEC_NR_POOLS 6
+
+struct bio_set {
+	mempool_t *bio_pool;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	mempool_t *bio_integrity_pool;
+#endif
+	mempool_t *bvec_pools[BIOVEC_NR_POOLS];
+};
+
+struct biovec_slab {
+	int nr_vecs;
+	char *name;
+	struct kmem_cache *slab;
+};
+
+extern struct bio_set *fs_bio_set;
+
+/*
+ * a small number of entries is fine, not going to be performance critical.
+ * basically we just need to survive
+ */
+#define BIO_SPLIT_ENTRIES 2
+
+#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.
+ */
+static 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;
+}
+
+static 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
+
+static 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)
+
+/*
+ * Check whether this bio carries any data or not. A NULL bio is allowed.
+ */
+static inline int bio_has_data(struct bio *bio)
+{
+	return bio && bio->bi_io_vec != NULL;
+}
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+#define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
+#define bip_vec(bip)		bip_vec_idx(bip, 0)
+
+#define __bip_for_each_vec(bvl, bip, i, start_idx)			\
+	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);	\
+	     i < (bip)->bip_vcnt;					\
+	     bvl++, i++)
+
+#define bip_for_each_vec(bvl, bip, i)					\
+	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
+
+#define bio_integrity(bio) (bio->bi_integrity != NULL)
+
+extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
+extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
+extern void bio_integrity_free(struct bio *, struct bio_set *);
+extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
+extern int bio_integrity_enabled(struct bio *bio);
+extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
+extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
+extern int bio_integrity_prep(struct bio *);
+extern void bio_integrity_endio(struct bio *, int);
+extern void bio_integrity_advance(struct bio *, unsigned int);
+extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
+extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
+extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
+extern int bioset_integrity_create(struct bio_set *, int);
+extern void bioset_integrity_free(struct bio_set *);
+extern void bio_integrity_init_slab(void);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+#define bio_integrity(a)		(0)
+#define bioset_integrity_create(a, b)	(0)
+#define bio_integrity_prep(a)		(0)
+#define bio_integrity_enabled(a)	(0)
+#define bio_integrity_clone(a, b, c)	(0)
+#define bioset_integrity_free(a)	do { } while (0)
+#define bio_integrity_free(a, b)	do { } while (0)
+#define bio_integrity_endio(a, b)	do { } while (0)
+#define bio_integrity_advance(a, b)	do { } while (0)
+#define bio_integrity_trim(a, b, c)	do { } while (0)
+#define bio_integrity_split(a, b, c)	do { } while (0)
+#define bio_integrity_set_tag(a, b, c)	do { } while (0)
+#define bio_integrity_get_tag(a, b, c)	do { } while (0)
+#define bio_integrity_init_slab(a)	do { } while (0)
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+#endif /* CONFIG_BLOCK */
+#endif /* __LINUX_BIO_H */