/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would 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 License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_BUF_H__
#define __XFS_BUF_H__
#include <linux/config.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/uio.h>
/*
* Base types
*/
#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
#define page_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
#define page_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT)
#define page_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
#define page_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
typedef enum page_buf_rw_e {
PBRW_READ = 1, /* transfer into target memory */
PBRW_WRITE = 2, /* transfer from target memory */
PBRW_ZERO = 3 /* Zero target memory */
} page_buf_rw_t;
typedef enum page_buf_flags_e { /* pb_flags values */
PBF_READ = (1 << 0), /* buffer intended for reading from device */
PBF_WRITE = (1 << 1), /* buffer intended for writing to device */
PBF_MAPPED = (1 << 2), /* buffer mapped (pb_addr valid) */
PBF_ASYNC = (1 << 4), /* initiator will not wait for completion */
PBF_DONE = (1 << 5), /* all pages in the buffer uptodate */
PBF_DELWRI = (1 << 6), /* buffer has dirty pages */
PBF_STALE = (1 << 7), /* buffer has been staled, do not find it */
PBF_FS_MANAGED = (1 << 8), /* filesystem controls freeing memory */
PBF_ORDERED = (1 << 11), /* use ordered writes */
PBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead */
/* flags used only as arguments to access routines */
PBF_LOCK = (1 << 14), /* lock requested */
PBF_TRYLOCK = (1 << 15), /* lock requested, but do not wait */
PBF_DONT_BLOCK = (1 << 16), /* do not block in current thread */
/* flags used only internally */
_PBF_PAGE_CACHE = (1 << 17),/* backed by pagecache */
_PBF_KMEM_ALLOC = (1 << 18),/* backed by kmem_alloc() */
_PBF_RUN_QUEUES = (1 << 19),/* run block device task queue */
_PBF_DELWRI_Q = (1 << 21), /* buffer on delwri queue */
} page_buf_flags_t;
typedef struct xfs_bufhash {
struct list_head bh_list;
spinlock_t bh_lock;
} xfs_bufhash_t;
typedef struct xfs_buftarg {
dev_t pbr_dev;
struct block_device *pbr_bdev;
struct address_space *pbr_mapping;
unsigned int pbr_bsize;
unsigned int pbr_sshift;
size_t pbr_smask;
/* per-device buffer hash table */
uint bt_hashmask;
uint bt_hashshift;
xfs_bufhash_t *bt_hash;
} xfs_buftarg_t;
/*
* xfs_buf_t: Buffer structure for page cache-based buffers
*
* This buffer structure is used by the page cache buffer management routines
* to refer to an assembly of pages forming a logical buffer. The actual I/O
* is performed with buffer_head structures, as required by drivers.
*
* The buffer structure is used on temporary basis only, and discarded when
* released. The real data storage is recorded in the page cache. Metadata is
* hashed to the block device on which the file system resides.
*/
struct xfs_buf;
/* call-back function on I/O completion */
typedef void (*page_buf_iodone_t)(struct xfs_buf *);
/* call-back function on I/O completion */
typedef void (*page_buf_relse_t)(struct xfs_buf *);
/* pre-write function */
typedef int (*page_buf_bdstrat_t)(struct xfs_buf *);
#define PB_PAGES 2
typedef struct xfs_buf {
struct semaphore pb_sema; /* semaphore for lockables */
unsigned long pb_queuetime; /* time buffer was queued */
atomic_t pb_pin_count; /* pin count */
wait_queue_head_t pb_waiters; /* unpin waiters */
struct list_head pb_list;
page_buf_flags_t pb_flags; /* status flags */
struct list_head pb_hash_list; /* hash table list */
xfs_bufhash_t *pb_hash; /* hash table list start */
xfs_buftarg_t *pb_target; /* buffer target (device) */
atomic_t pb_hold; /* reference count */
xfs_daddr_t pb_bn; /* block number for I/O */
loff_t pb_file_offset; /* offset in file */
size_t pb_buffer_length; /* size of buffer in bytes */
size_t pb_count_desired; /* desired transfer size */
void *pb_addr; /* virtual address of buffer */
struct work_struct pb_iodone_work;
atomic_t pb_io_remaining;/* #outstanding I/O requests */
page_buf_iodone_t pb_iodone; /* I/O completion function */
page_buf_relse_t pb_relse; /* releasing function */
page_buf_bdstrat_t pb_strat; /* pre-write function */
struct semaphore pb_iodonesema; /* Semaphore for I/O waiters */
void *pb_fspriv;
void *pb_fspriv2;
void *pb_fspriv3;
unsigned short pb_error; /* error code on I/O */
unsigned short pb_locked; /* page array is locked */
unsigned int pb_page_count; /* size of page array */
unsigned int pb_offset; /* page offset in first page */
struct page **pb_pages; /* array of page pointers */
struct page *pb_page_array[PB_PAGES]; /* inline pages */
#ifdef PAGEBUF_LOCK_TRACKING
int pb_last_holder;
#endif
} xfs_buf_t;
/* Finding and Reading Buffers */
extern xfs_buf_t *_pagebuf_find( /* find buffer for block if */
/* the block is in memory */
xfs_buftarg_t *, /* inode for block */
loff_t, /* starting offset of range */
size_t, /* length of range */
page_buf_flags_t, /* PBF_LOCK */
xfs_buf_t *); /* newly allocated buffer */
#define xfs_incore(buftarg,blkno,len,lockit) \
_pagebuf_find(buftarg, blkno ,len, lockit, NULL)
extern xfs_buf_t *xfs_buf_get_flags( /* allocate a buffer */
xfs_buftarg_t *, /* inode for buffer */
loff_t, /* starting offset of range */
size_t, /* length of range */
page_buf_flags_t); /* PBF_LOCK, PBF_READ, */
/* PBF_ASYNC */
#define xfs_buf_get(target, blkno, len, flags) \
xfs_buf_get_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
extern xfs_buf_t *xfs_buf_read_flags( /* allocate and read a buffer */
xfs_buftarg_t *, /* inode for buffer */
loff_t, /* starting offset of range */
size_t, /* length of range */
page_buf_flags_t); /* PBF_LOCK, PBF_ASYNC */
#define xfs_buf_read(target, blkno, len, flags) \
xfs_buf_read_flags((target), (blkno), (len), PBF_LOCK | PBF_MAPPED)
extern xfs_buf_t *pagebuf_get_empty( /* allocate pagebuf struct with */
/* no memory or disk address */
size_t len,
xfs_buftarg_t *); /* mount point "fake" inode */
extern xfs_buf_t *pagebuf_get_no_daddr(/* allocate pagebuf struct */
/* without disk address */
size_t len,
xfs_buftarg_t *); /* mount point "fake" inode */
extern int pagebuf_associate_memory(
xfs_buf_t *,
void *,
size_t);
extern void pagebuf_hold( /* increment reference count */
xfs_buf_t *); /* buffer to hold */
extern void pagebuf_readahead( /* read ahead into cache */
xfs_buftarg_t *, /* target for buffer (or NULL) */
loff_t, /* starting offset of range */
size_t, /* length of range */
page_buf_flags_t); /* additional read flags */
/* Releasing Buffers */
extern void pagebuf_free( /* deallocate a buffer */
xfs_buf_t *); /* buffer to deallocate */
extern void pagebuf_rele( /* release hold on a buffer */
xfs_buf_t *); /* buffer to release */
/* Locking and Unlocking Buffers */
extern int pagebuf_cond_lock( /* lock buffer, if not locked */
/* (returns -EBUSY if locked) */
xfs_buf_t *); /* buffer to lock */
extern int pagebuf_lock_value( /* return count on lock */
xfs_buf_t *); /* buffer to check */
extern int pagebuf_lock( /* lock buffer */
xfs_buf_t *); /* buffer to lock */
extern void pagebuf_unlock( /* unlock buffer */
xfs_buf_t *); /* buffer to unlock */
/* Buffer Read and Write Routines */
extern void pagebuf_iodone( /* mark buffer I/O complete */
xfs_buf_t *, /* buffer to mark */
int); /* run completion locally, or in
* a helper thread. */
extern void pagebuf_ioerror( /* mark buffer in error (or not) */
xfs_buf_t *, /* buffer to mark */
int); /* error to store (0 if none) */
extern int pagebuf_iostart( /* start I/O on a buffer */
xfs_buf_t *, /* buffer to start */
page_buf_flags_t); /* PBF_LOCK, PBF_ASYNC, */
/* PBF_READ, PBF_WRITE, */
/* PBF_DELWRI */
extern int pagebuf_iorequest( /* start real I/O */
xfs_buf_t *); /* buffer to convey to device */
extern int pagebuf_iowait( /* wait for buffer I/O done */
xfs_buf_t *); /* buffer to wait on */
extern void pagebuf_iomove( /* move data in/out of pagebuf */
xfs_buf_t *, /* buffer to manipulate */
size_t, /* starting buffer offset */
size_t, /* length in buffer */
caddr_t, /* data pointer */
page_buf_rw_t); /* direction */
static inline int pagebuf_iostrategy(xfs_buf_t *pb)
{
return pb->pb_strat ? pb->pb_strat(pb) : pagebuf_iorequest(pb);
}
static inline int pagebuf_geterror(xfs_buf_t *pb)
{
return pb ? pb->pb_error : ENOMEM;
}
/* Buffer Utility Routines */
extern caddr_t pagebuf_offset( /* pointer at offset in buffer */
xfs_buf_t *, /* buffer to offset into */
size_t); /* offset */
/* Pinning Buffer Storage in Memory */
extern void pagebuf_pin( /* pin buffer in memory */
xfs_buf_t *); /* buffer to pin */
extern void pagebuf_unpin( /* unpin buffered data */
xfs_buf_t *); /* buffer to unpin */
extern int pagebuf_ispin( /* check if buffer is pinned */
xfs_buf_t *); /* buffer to check */
/* Delayed Write Buffer Routines */
extern void pagebuf_delwri_dequeue(xfs_buf_t *);
/* Buffer Daemon Setup Routines */
extern int pagebuf_init(void);
extern void pagebuf_terminate(void);
#ifdef PAGEBUF_TRACE
extern ktrace_t *pagebuf_trace_buf;
extern void pagebuf_trace(
xfs_buf_t *, /* buffer being traced */
char *, /* description of operation */
void *, /* arbitrary diagnostic value */
void *); /* return address */
#else
# define pagebuf_trace(pb, id, ptr, ra) do { } while (0)
#endif
#define pagebuf_target_name(target) \
({ char __b[BDEVNAME_SIZE]; bdevname((target)->pbr_bdev, __b); __b; })
/* These are just for xfs_syncsub... it sets an internal variable
* then passes it to VOP_FLUSH_PAGES or adds the flags to a newly gotten buf_t
*/
#define XFS_B_ASYNC PBF_ASYNC
#define XFS_B_DELWRI PBF_DELWRI
#define XFS_B_READ PBF_READ
#define XFS_B_WRITE PBF_WRITE
#define XFS_B_STALE PBF_STALE
#define XFS_BUF_TRYLOCK PBF_TRYLOCK
#define XFS_INCORE_TRYLOCK PBF_TRYLOCK
#define XFS_BUF_LOCK PBF_LOCK
#define XFS_BUF_MAPPED PBF_MAPPED
#define BUF_BUSY PBF_DONT_BLOCK
#define XFS_BUF_BFLAGS(x) ((x)->pb_flags)
#define XFS_BUF_ZEROFLAGS(x) \
((x)->pb_flags &= ~(PBF_READ|PBF_WRITE|PBF_ASYNC|PBF_DELWRI))
#define XFS_BUF_STALE(x) ((x)->pb_flags |= XFS_B_STALE)
#define XFS_BUF_UNSTALE(x) ((x)->pb_flags &= ~XFS_B_STALE)
#define XFS_BUF_ISSTALE(x) ((x)->pb_flags & XFS_B_STALE)
#define XFS_BUF_SUPER_STALE(x) do { \
XFS_BUF_STALE(x); \
pagebuf_delwri_dequeue(x); \
XFS_BUF_DONE(x); \
} while (0)
#define XFS_BUF_MANAGE PBF_FS_MANAGED
#define XFS_BUF_UNMANAGE(x) ((x)->pb_flags &= ~PBF_FS_MANAGED)
#define XFS_BUF_DELAYWRITE(x) ((x)->pb_flags |= PBF_DELWRI)
#define XFS_BUF_UNDELAYWRITE(x) pagebuf_delwri_dequeue(x)
#define XFS_BUF_ISDELAYWRITE(x) ((x)->pb_flags & PBF_DELWRI)
#define XFS_BUF_ERROR(x,no) pagebuf_ioerror(x,no)
#define XFS_BUF_GETERROR(x) pagebuf_geterror(x)
#define XFS_BUF_ISERROR(x) (pagebuf_geterror(x)?1:0)
#define XFS_BUF_DONE(x) ((x)->pb_flags |= PBF_DONE)
#define XFS_BUF_UNDONE(x) ((x)->pb_flags &= ~PBF_DONE)
#define XFS_BUF_ISDONE(x) ((x)->pb_flags & PBF_DONE)
#define XFS_BUF_BUSY(x) do { } while (0)
#define XFS_BUF_UNBUSY(x) do { } while (0)
#define XFS_BUF_ISBUSY(x) (1)
#define XFS_BUF_ASYNC(x) ((x)->pb_flags |= PBF_ASYNC)
#define XFS_BUF_UNASYNC(x) ((x)->pb_flags &= ~PBF_ASYNC)
#define XFS_BUF_ISASYNC(x) ((x)->pb_flags & PBF_ASYNC)
#define XFS_BUF_ORDERED(x) ((x)->pb_flags |= PBF_ORDERED)
#define XFS_BUF_UNORDERED(x) ((x)->pb_flags &= ~PBF_ORDERED)
#define XFS_BUF_ISORDERED(x) ((x)->pb_flags & PBF_ORDERED)
#define XFS_BUF_SHUT(x) printk("XFS_BUF_SHUT not implemented yet\n")
#define XFS_BUF_UNSHUT(x) printk("XFS_BUF_UNSHUT not implemented yet\n")
#define XFS_BUF_ISSHUT(x) (0)
#define XFS_BUF_HOLD(x) pagebuf_hold(x)
#define XFS_BUF_READ(x) ((x)->pb_flags |= PBF_READ)
#define XFS_BUF_UNREAD(x) ((x)->pb_flags &= ~PBF_READ)
#define XFS_BUF_ISREAD(x) ((x)->pb_flags & PBF_READ)
#define XFS_BUF_WRITE(x) ((x)->pb_flags |= PBF_WRITE)
#define XFS_BUF_UNWRITE(x) ((x)->pb_flags &= ~PBF_WRITE)
#define XFS_BUF_ISWRITE(x) ((x)->pb_flags & PBF_WRITE)
#define XFS_BUF_ISUNINITIAL(x) (0)
#define XFS_BUF_UNUNINITIAL(x) (0)
#define XFS_BUF_BP_ISMAPPED(bp) 1
#define XFS_BUF_IODONE_FUNC(buf) (buf)->pb_iodone
#define XFS_BUF_SET_IODONE_FUNC(buf, func) \
(buf)->pb_iodone = (func)
#define XFS_BUF_CLR_IODONE_FUNC(buf) \
(buf)->pb_iodone = NULL
#define XFS_BUF_SET_BDSTRAT_FUNC(buf, func) \
(buf)->pb_strat = (func)
#define XFS_BUF_CLR_BDSTRAT_FUNC(buf) \
(buf)->pb_strat = NULL
#define XFS_BUF_FSPRIVATE(buf, type) \
((type)(buf)->pb_fspriv)
#define XFS_BUF_SET_FSPRIVATE(buf, value) \
(buf)->pb_fspriv = (void *)(value)
#define XFS_BUF_FSPRIVATE2(buf, type) \
((type)(buf)->pb_fspriv2)
#define XFS_BUF_SET_FSPRIVATE2(buf, value) \
(buf)->pb_fspriv2 = (void *)(value)
#define XFS_BUF_FSPRIVATE3(buf, type) \
((type)(buf)->pb_fspriv3)
#define XFS_BUF_SET_FSPRIVATE3(buf, value) \
(buf)->pb_fspriv3 = (void *)(value)
#define XFS_BUF_SET_START(buf)
#define XFS_BUF_SET_BRELSE_FUNC(buf, value) \
(buf)->pb_relse = (value)
#define XFS_BUF_PTR(bp) (xfs_caddr_t)((bp)->pb_addr)
static inline xfs_caddr_t xfs_buf_offset(xfs_buf_t *bp, size_t offset)
{
if (bp->pb_flags & PBF_MAPPED)
return XFS_BUF_PTR(bp) + offset;
return (xfs_caddr_t) pagebuf_offset(bp, offset);
}
#define XFS_BUF_SET_PTR(bp, val, count) \
pagebuf_associate_memory(bp, val, count)
#define XFS_BUF_ADDR(bp) ((bp)->pb_bn)
#define XFS_BUF_SET_ADDR(bp, blk) \
((bp)->pb_bn = (xfs_daddr_t)(blk))
#define XFS_BUF_OFFSET(bp) ((bp)->pb_file_offset)
#define XFS_BUF_SET_OFFSET(bp, off) \
((bp)->pb_file_offset = (off))
#define XFS_BUF_COUNT(bp) ((bp)->pb_count_desired)
#define XFS_BUF_SET_COUNT(bp, cnt) \
((bp)->pb_count_desired = (cnt))
#define XFS_BUF_SIZE(bp) ((bp)->pb_buffer_length)
#define XFS_BUF_SET_SIZE(bp, cnt) \
((bp)->pb_buffer_length = (cnt))
#define XFS_BUF_SET_VTYPE_REF(bp, type, ref)
#define XFS_BUF_SET_VTYPE(bp, type)
#define XFS_BUF_SET_REF(bp, ref)
#define XFS_BUF_ISPINNED(bp) pagebuf_ispin(bp)
#define XFS_BUF_VALUSEMA(bp) pagebuf_lock_value(bp)
#define XFS_BUF_CPSEMA(bp) (pagebuf_cond_lock(bp) == 0)
#define XFS_BUF_VSEMA(bp) pagebuf_unlock(bp)
#define XFS_BUF_PSEMA(bp,x) pagebuf_lock(bp)
#define XFS_BUF_V_IODONESEMA(bp) up(&bp->pb_iodonesema);
/* setup the buffer target from a buftarg structure */
#define XFS_BUF_SET_TARGET(bp, target) \
(bp)->pb_target = (target)
#define XFS_BUF_TARGET(bp) ((bp)->pb_target)
#define XFS_BUFTARG_NAME(target) \
pagebuf_target_name(target)
#define XFS_BUF_SET_VTYPE_REF(bp, type, ref)
#define XFS_BUF_SET_VTYPE(bp, type)
#define XFS_BUF_SET_REF(bp, ref)
static inline int xfs_bawrite(void *mp, xfs_buf_t *bp)
{
bp->pb_fspriv3 = mp;
bp->pb_strat = xfs_bdstrat_cb;
pagebuf_delwri_dequeue(bp);
return pagebuf_iostart(bp, PBF_WRITE | PBF_ASYNC | _PBF_RUN_QUEUES);
}
static inline void xfs_buf_relse(xfs_buf_t *bp)
{
if (!bp->pb_relse)
pagebuf_unlock(bp);
pagebuf_rele(bp);
}
#define xfs_bpin(bp) pagebuf_pin(bp)
#define xfs_bunpin(bp) pagebuf_unpin(bp)
#define xfs_buftrace(id, bp) \
pagebuf_trace(bp, id, NULL, (void *)__builtin_return_address(0))
#define xfs_biodone(pb) \
pagebuf_iodone(pb, 0)
#define xfs_biomove(pb, off, len, data, rw) \
pagebuf_iomove((pb), (off), (len), (data), \
((rw) == XFS_B_WRITE) ? PBRW_WRITE : PBRW_READ)
#define xfs_biozero(pb, off, len) \
pagebuf_iomove((pb), (off), (len), NULL, PBRW_ZERO)
static inline int XFS_bwrite(xfs_buf_t *pb)
{
int iowait = (pb->pb_flags & PBF_ASYNC) == 0;
int error = 0;
if (!iowait)
pb->pb_flags |= _PBF_RUN_QUEUES;
pagebuf_delwri_dequeue(pb);
pagebuf_iostrategy(pb);
if (iowait) {
error = pagebuf_iowait(pb);
xfs_buf_relse(pb);
}
return error;
}
#define XFS_bdwrite(pb) \
pagebuf_iostart(pb, PBF_DELWRI | PBF_ASYNC)
static inline int xfs_bdwrite(void *mp, xfs_buf_t *bp)
{
bp->pb_strat = xfs_bdstrat_cb;
bp->pb_fspriv3 = mp;
return pagebuf_iostart(bp, PBF_DELWRI | PBF_ASYNC);
}
#define XFS_bdstrat(bp) pagebuf_iorequest(bp)
#define xfs_iowait(pb) pagebuf_iowait(pb)
#define xfs_baread(target, rablkno, ralen) \
pagebuf_readahead((target), (rablkno), (ralen), PBF_DONT_BLOCK)
#define xfs_buf_get_empty(len, target) pagebuf_get_empty((len), (target))
#define xfs_buf_get_noaddr(len, target) pagebuf_get_no_daddr((len), (target))
#define xfs_buf_free(bp) pagebuf_free(bp)
/*
* Handling of buftargs.
*/
extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int);
extern void xfs_free_buftarg(xfs_buftarg_t *, int);
extern void xfs_wait_buftarg(xfs_buftarg_t *);
extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
#define xfs_getsize_buftarg(buftarg) \
block_size((buftarg)->pbr_bdev)
#define xfs_readonly_buftarg(buftarg) \
bdev_read_only((buftarg)->pbr_bdev)
#define xfs_binval(buftarg) \
xfs_flush_buftarg(buftarg, 1)
#define XFS_bflush(buftarg) \
xfs_flush_buftarg(buftarg, 1)
#endif /* __XFS_BUF_H__ */
