#ident "$Revision: 1.56 $"
/*
* This file contains the implementation of the xfs_buf_log_item.
* It contains the item operations used to manipulate the buf log
* items as well as utility routines used by the buffer specific
* transaction routines.
*/
#include <limits.h>
#ifdef SIM
#define _KERNEL 1
#endif
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/atomic_ops.h>
#include <sys/debug.h>
#ifdef SIM
#undef _KERNEL
#endif
#include <sys/vnode.h>
#include <sys/kmem.h>
#include <sys/errno.h>
#ifdef SIM
#include <bstring.h>
#include <stdio.h>
#else
#include <sys/systm.h>
#endif
#include <sys/ktrace.h>
#include <sys/cmn_err.h>
#include <sys/uuid.h>
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_rw.h"
#include "xfs_bit.h"
#ifdef SIM
#include "sim.h"
#endif
#define ROUNDUPNBWORD(x) (((x) + (NBWORD - 1)) & ~(NBWORD - 1))
zone_t *xfs_buf_item_zone;
#if 0
STATIC void xfs_buf_item_set_bit(uint *, uint, uint);
#endif
#ifdef XFS_TRANS_DEBUG
STATIC void
xfs_buf_item_log_debug(
xfs_buf_log_item_t *bip,
uint first,
uint last);
STATIC void
xfs_buf_item_log_check(
xfs_buf_log_item_t *bip);
#else
#define xfs_buf_item_log_debug(x,y,z)
#define xfs_buf_item_log_check(x)
#endif
STATIC void xfs_buf_error_relse(buf_t *bp);
/*
* This returns the number of log iovecs needed to log the
* given buf log item.
*
* It calculates this as 1 iovec for the buf log format structure
* and 1 or each stretch of non-contiguous chunks to be logged.
* Contiguous chunks are logged in a single iovec.
*
* If the XFS_BLI_STALE flag has been set, then log nothing.
*/
uint
xfs_buf_item_size(
xfs_buf_log_item_t *bip)
{
uint nvecs;
int next_bit;
int last_bit;
ASSERT(bip->bli_refcount > 0);
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* The buffer is stale, so all we need to log
* is the buf log format structure with the
* cancel flag in it.
*/
xfs_buf_item_trace("SIZE STALE", bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
return 1;
}
ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
nvecs = 1;
last_bit = xfs_buf_item_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size, 0);
ASSERT(last_bit != -1);
nvecs++;
while (last_bit != -1) {
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*/
next_bit = xfs_buf_item_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size,
last_bit + 1);
/*
* If we run out of bits, leave the loop,
* else if we find a new set of bits bump the number of vecs,
* else keep scanning the current set of bits.
*/
if (next_bit == -1) {
last_bit = -1;
} else if (next_bit != last_bit + 1) {
last_bit = next_bit;
nvecs++;
} else {
last_bit++;
}
}
xfs_buf_item_trace("SIZE NORM", bip);
return nvecs;
}
/*
* This is called to fill in the vector of log iovecs for the
* given log buf item. It fills the first entry with a buf log
* format structure, and the rest point to contiguous chunks
* within the buffer.
*/
void
xfs_buf_item_format(
xfs_buf_log_item_t *bip,
xfs_log_iovec_t *log_vector)
{
uint base_size;
uint nvecs;
xfs_log_iovec_t *vecp;
buf_t *bp;
int first_bit;
int last_bit;
int next_bit;
uint nbits;
uint buffer_offset;
ASSERT(bip->bli_refcount > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
bp = bip->bli_buf;
ASSERT(BP_ISMAPPED(bp));
vecp = log_vector;
/*
* The size of the base structure is the size of the
* declared structure plus the space for the extra words
* of the bitmap. We subtract one from the map size, because
* the first element of the bitmap is accounted for in the
* size of the base structure.
*/
base_size = sizeof(xfs_buf_log_format_t) +
((bip->bli_format.blf_map_size - 1) * sizeof(uint));
vecp->i_addr = (caddr_t)&bip->bli_format;
vecp->i_len = base_size;
vecp++;
nvecs = 1;
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* The buffer is stale, so all we need to log
* is the buf log format structure with the
* cancel flag in it.
*/
xfs_buf_item_trace("FORMAT STALE", bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
bip->bli_format.blf_size = nvecs;
return;
}
/*
* Fill in an iovec for each set of contiguous chunks.
*/
first_bit = xfs_buf_item_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size, 0);
ASSERT(first_bit != -1);
last_bit = first_bit;
nbits = 1;
for (;;) {
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*/
next_bit = xfs_buf_item_next_bit(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size,
(uint)last_bit + 1);
/*
* If we run out of bits fill in the last iovec and get
* out of the loop.
* Else if we start a new set of bits then fill in the
* iovec for the series we were looking at and start
* counting the bits in the new one.
* Else we're still in the same set of bits so just
* keep counting and scanning.
*/
if (next_bit == -1) {
buffer_offset = first_bit * XFS_BLI_CHUNK;
vecp->i_addr = bp->b_un.b_addr + buffer_offset;
vecp->i_len = nbits * XFS_BLI_CHUNK;
nvecs++;
break;
} else if (next_bit != last_bit + 1) {
buffer_offset = first_bit * XFS_BLI_CHUNK;
vecp->i_addr = bp->b_un.b_addr + buffer_offset;
vecp->i_len = nbits * XFS_BLI_CHUNK;
nvecs++;
vecp++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
} else {
last_bit++;
nbits++;
}
}
bip->bli_format.blf_size = nvecs;
/*
* Check to make sure everything is consistent.
*/
xfs_buf_item_trace("FORMAT NORM", bip);
xfs_buf_item_log_check(bip);
}
/*
* This is called to pin the buffer associated with the buf log
* item in memory so it cannot be written out. Simply call bpin()
* on the buffer to do this.
*/
void
xfs_buf_item_pin(
xfs_buf_log_item_t *bip)
{
buf_t *bp;
bp = bip->bli_buf;
ASSERT(bp->b_flags & B_BUSY);
ASSERT(bip->bli_refcount > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
xfs_buf_item_trace("PIN", bip);
bpin(bp);
}
/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
* Just call bunpin() on the buffer to do this.
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*/
void
xfs_buf_item_unpin(
xfs_buf_log_item_t *bip)
{
xfs_mount_t *mp;
buf_t *bp;
int refcount;
SPLDECL(s);
bp = bip->bli_buf;
ASSERT(bp != NULL);
ASSERT((xfs_buf_log_item_t*)(bp->b_fsprivate) == bip);
ASSERT(bip->bli_refcount > 0);
xfs_buf_item_trace("UNPIN", bip);
refcount = atomicAddInt(&bip->bli_refcount, -1);
mp = bip->bli_item.li_mountp;
bunpin(bp);
if ((refcount == 0) && (bip->bli_flags & XFS_BLI_STALE)) {
ASSERT(!(bp->b_flags & B_DELWRI));
ASSERT(bp->b_flags & B_STALE);
ASSERT(bp->b_pincount == 0);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
xfs_buf_item_trace("UNPIN STALE", bip);
AIL_LOCK(mp,s);
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_delete_ail()
* will take care of that situation.
* xfs_trans_delete_ail() drops the AIL lock.
*/
xfs_trans_delete_ail(mp, (xfs_log_item_t *)bip, s);
xfs_buf_item_relse(bp);
ASSERT(bp->b_fsprivate == NULL);
brelse(bp);
}
}
/*
* This is called to attempt to lock the buffer associated with this
* buf log item. Don't sleep on the buffer lock. If we can't get
* the lock right away, return 0. If we can get the lock, pull the
* buffer from the free list, mark it busy, and return 1.
*/
uint
xfs_buf_item_trylock(
xfs_buf_log_item_t *bip)
{
buf_t *bp;
bp = bip->bli_buf;
if (bp->b_pincount > 0) {
return XFS_ITEM_PINNED;
}
if (!cpsema(&bp->b_lock)) {
return XFS_ITEM_LOCKED;
}
/*
* Remove the buffer from the free list. Only do this
* if it's on the free list. Private buffers like the
* superblock buffer are not.
*/
if (bp->av_forw != NULL) {
notavail(bp);
}
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
xfs_buf_item_trace("TRYLOCK SUCCESS", bip);
return XFS_ITEM_SUCCESS;
}
/*
* Release the buffer associated with the buf log item.
* If there is no dirty logged data associated with the
* buffer recorded in the buf log item, then free the
* buf log item and remove the reference to it in the
* buffer.
*
* This call ignores the recursion count. It is only called
* when the buffer should REALLY be unlocked, regardless
* of the recursion count.
*
* If the XFS_BLI_HOLD flag is set in the buf log item, then
* free the log item if necessary but do not unlock the buffer.
* This is for support of xfs_trans_bhold(). Make sure the
* XFS_BLI_HOLD field is cleared if we don't free the item.
*/
void
xfs_buf_item_unlock(
xfs_buf_log_item_t *bip)
{
buf_t *bp;
uint hold;
bp = bip->bli_buf;
/*
* Clear the buffer's association with this transaction.
*/
#ifndef NO_XFS_PARANOIA
if (bp->b_flags2 & B_XFS_INO) {
/*
* put mount ptr in fsprivate2 if xaction pointer
* is there, otherwise, leave it alone
*/
if (((xfs_trans_t *)(bp->b_fsprivate2))->t_magic ==
XFS_TRANS_HEADER_MAGIC)
bp->b_fsprivate2 =
((xfs_trans_t *) bp->b_fsprivate2)->t_mountp;
} else
bp->b_fsprivate2 = NULL;
#else
bp->b_fsprivate2 = NULL;
#endif
/*
* If the buf item is marked stale, then don't do anything.
* We'll unlock the buffer and free the buf item when the
* buffer is unpinned for the last time.
*/
if (bip->bli_flags & XFS_BLI_STALE) {
bip->bli_flags &= ~XFS_BLI_LOGGED;
xfs_buf_item_trace("UNLOCK STALE", bip);
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
return;
}
/*
* Drop the transaction's reference to the log item if
* it was not logged as part of the transaction. Otherwise
* we'll drop the reference in xfs_buf_item_unpin() when
* the transaction is really through with the buffer.
*/
if (!(bip->bli_flags & XFS_BLI_LOGGED)) {
(void) atomicAddInt(&bip->bli_refcount, -1);
} else {
/*
* Clear the logged flag since this is per
* transaction state.
*/
bip->bli_flags &= ~XFS_BLI_LOGGED;
}
/*
* Before possibly freeing the buf item, determine if we should
* release the buffer at the end of this routine.
*/
hold = bip->bli_flags & XFS_BLI_HOLD;
xfs_buf_item_trace("UNLOCK", bip);
/*
* If the buf item isn't tracking any data, free it.
* Otherwise, if XFS_BLI_HOLD is set clear it.
*/
if (xfs_buf_item_bits(bip->bli_format.blf_data_map,
bip->bli_format.blf_map_size, 0) == 0) {
xfs_buf_item_relse(bp);
} else if (hold) {
bip->bli_flags &= ~XFS_BLI_HOLD;
}
/*
* Release the buffer if XFS_BLI_HOLD was not set.
*/
if (!hold) {
brelse(bp);
}
}
/*
* This is called to find out where the oldest active copy of the
* buf log item in the on disk log resides now that the last log
* write of it completed at the given lsn.
* We always re-log all the dirty data in a buffer, so usually the
* latest copy in the on disk log is the only one that matters. For
* those cases we simply return the given lsn.
*
* The one exception to this is for buffers full of newly allocated
* inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
* flag set, indicating that only the di_next_unlinked fields from the
* inodes in the buffers will be replayed during recovery. If the
* origianal newly allocated inode images have not yet been flushed
* when the buffer is so relogged, then we need to make sure that we
* keep the old images in the 'active' portion of the log. We do this
* by returning the original lsn of that transaction here rather than
* the current one.
*/
xfs_lsn_t
xfs_buf_item_committed(
xfs_buf_log_item_t *bip,
xfs_lsn_t lsn)
/* ARGSUSED */
{
xfs_buf_item_trace("COMMITTED", bip);
if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
(bip->bli_item.li_lsn != 0)) {
return bip->bli_item.li_lsn;
}
return (lsn);
}
/*
* This is called when the transaction holding the buffer is aborted.
* The buffer must not have been dirtied within this transaction. Just
* behave as if the transaction had been cancelled.
*/
void
xfs_buf_item_abort(
xfs_buf_log_item_t *bip)
{
xfs_buf_item_unlock(bip);
return;
}
/*
* This is called to asynchronously write the buffer associated with this
* buf log item out to disk. The buffer will already have been locked by
* a successful call to xfs_buf_item_trylock(). If the buffer still has
* B_DELWRI set, then get it going out to disk with a call to bawrite().
* If not, then just release the buffer.
*/
void
xfs_buf_item_push(
xfs_buf_log_item_t *bip)
{
buf_t *bp;
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
xfs_buf_item_trace("PUSH", bip);
bp = bip->bli_buf;
if (bp->b_flags & B_DELWRI) {
xfs_bawrite(bip->bli_item.li_mountp, bp);
} else {
brelse(bp);
}
}
/*
* This is the ops vector shared by all buf log items.
*/
struct xfs_item_ops xfs_buf_item_ops = {
(uint(*)(xfs_log_item_t*))xfs_buf_item_size,
(void(*)(xfs_log_item_t*, xfs_log_iovec_t*))xfs_buf_item_format,
(void(*)(xfs_log_item_t*))xfs_buf_item_pin,
(void(*)(xfs_log_item_t*))xfs_buf_item_unpin,
(uint(*)(xfs_log_item_t*))xfs_buf_item_trylock,
(void(*)(xfs_log_item_t*))xfs_buf_item_unlock,
(xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))xfs_buf_item_committed,
(void(*)(xfs_log_item_t*))xfs_buf_item_push,
(void(*)(xfs_log_item_t*))xfs_buf_item_abort,
NULL
};
/*
* Allocate a new buf log item to go with the given buffer.
* Set the buffer's b_fsprivate field to point to the new
* buf log item. If there are other item's attached to the
* buffer (see xfs_buf_attach_iodone() below), then put the
* buf log item at the front.
*/
void
xfs_buf_item_init(
buf_t *bp,
xfs_mount_t *mp)
{
xfs_log_item_t *lip;
xfs_buf_log_item_t *bip;
int chunks;
int map_size;
/*
* Check to see if there is already a buf log item for
* this buffer. If there is, it is guaranteed to be
* the first. If we do already have one, there is
* nothing to do here so return.
*/
if (bp->b_fsprivate != NULL) {
lip = (xfs_log_item_t *)bp->b_fsprivate;
if (lip->li_type == XFS_LI_BUF) {
return;
}
}
/*
* chunks is the number of XFS_BLI_CHUNK size pieces
* the buffer can be divided into. Make sure not to
* truncate any pieces. map_size is the size of the
* bitmap needed to describe the chunks of the buffer.
*/
chunks = (int)((bp->b_bcount + (XFS_BLI_CHUNK - 1)) >> XFS_BLI_SHIFT);
map_size = (chunks + NBWORD) >> BIT_TO_WORD_SHIFT;
bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone,
KM_SLEEP);
bip->bli_item.li_type = XFS_LI_BUF;
bip->bli_item.li_ops = &xfs_buf_item_ops;
bip->bli_item.li_mountp = mp;
bip->bli_buf = bp;
bip->bli_format.blf_type = XFS_LI_BUF;
bip->bli_format.blf_blkno = (__int64_t)bp->b_blkno;
bip->bli_format.blf_len = (ushort)BTOBB(bp->b_bcount);
bip->bli_format.blf_map_size = map_size;
#ifdef XFS_BLI_TRACE
bip->bli_trace = ktrace_alloc(XFS_BLI_TRACE_SIZE, 0);
#endif
#ifdef XFS_TRANS_DEBUG
/*
* Allocate the arrays for tracking what needs to be logged
* and what our callers request to be logged. bli_orig
* holds a copy of the original, clean buffer for comparison
* against, and bli_logged keeps a 1 byte flag per byte in
* the buffer to indicate which bytes the callers have asked
* to have logged.
*/
bip->bli_orig = (char *)kmem_alloc(bp->b_bcount, KM_SLEEP);
bcopy(bp->b_un.b_addr, bip->bli_orig, bp->b_bcount);
bip->bli_logged = (char *)kmem_zalloc(bp->b_bcount, KM_SLEEP);
#endif
/*
* Put the buf item into the list of items attached to the
* buffer at the front.
*/
if (bp->b_fsprivate != NULL) {
bip->bli_item.li_bio_list = (xfs_log_item_t *)bp->b_fsprivate;
}
bp->b_fsprivate = bip;
}
/*
* Mark bytes first through last inclusive as dirty in the buf
* item's bitmap.
*/
void
xfs_buf_item_log(
xfs_buf_log_item_t *bip,
uint first,
uint last)
{
uint first_bit;
uint last_bit;
uint bits_to_set;
uint bits_set;
uint word_num;
uint *wordp;
uint bit;
uint end_bit;
uint mask;
/*
* Mark the item as having some dirty data for
* quick reference in xfs_buf_item_dirty.
*/
bip->bli_flags |= XFS_BLI_DIRTY;
/*
* Convert byte offsets to bit numbers.
*/
first_bit = first >> XFS_BLI_SHIFT;
last_bit = last >> XFS_BLI_SHIFT;
/*
* Calculate the total number of bits to be set.
*/
bits_to_set = last_bit - first_bit + 1;
/*
* Get a pointer to the first word in the bitmap
* to set a bit in.
*/
word_num = first_bit >> BIT_TO_WORD_SHIFT;
wordp = &(bip->bli_format.blf_data_map[word_num]);
/*
* Calculate the starting bit in the first word.
*/
bit = first_bit & (NBWORD - 1);
/*
* First set any bits in the first word of our range.
* If it starts at bit 0 of the word, it will be
* set below rather than here. That is what the variable
* bit tells us. The variable bits_set tracks the number
* of bits that have been set so far. End_bit is the number
* of the last bit to be set in this word plus one.
*/
if (bit) {
end_bit = MIN(bit + bits_to_set, NBWORD);
mask = ((1 << (end_bit - bit)) - 1) << bit;
*wordp |= mask;
wordp++;
bits_set = end_bit - bit;
} else {
bits_set = 0;
}
/*
* Now set bits a whole word at a time that are between
* first_bit and last_bit.
*/
while ((bits_to_set - bits_set) >= NBWORD) {
*wordp |= 0xffffffff;
bits_set += NBWORD;
wordp++;
}
/*
* Finally, set any bits left to be set in one last partial word.
*/
end_bit = bits_to_set - bits_set;
if (end_bit) {
mask = (1 << end_bit) - 1;
*wordp |= mask;
}
xfs_buf_item_log_debug(bip, first, last);
}
#ifdef XFS_TRANS_DEBUG
/*
* This function uses an alternate strategy for tracking the bytes
* that the user requests to be logged. This can then be used
* in conjunction with the bli_orig array in the buf log item to
* catch bugs in our callers' code.
*
* We also double check the bits set in xfs_buf_item_log using a
* simple algorithm to check that every byte is accounted for.
*/
STATIC void
xfs_buf_item_log_debug(
xfs_buf_log_item_t *bip,
uint first,
uint last)
{
char *logged;
uint x;
uint byte;
uint nbytes;
uint chunk_num;
uint word_num;
uint bit_num;
uint bit_set;
uint *wordp;
ASSERT(bip->bli_logged != NULL);
logged = bip->bli_logged + first; /* pointer arithmetic */
byte = first;
nbytes = last - first + 1;
for (x = 0; x < nbytes; x++) {
*logged = 1;
chunk_num = byte >> XFS_BLI_SHIFT;
word_num = 0xdeadbeaf;
word_num = chunk_num >> BIT_TO_WORD_SHIFT;
bit_num = chunk_num & (NBWORD - 1);
wordp = &(bip->bli_format.blf_data_map[word_num]);
bit_set = *wordp & (1 << bit_num);
ASSERT(bit_set);
logged++;
byte++;
}
}
/*
* This function is called when we flush something into a buffer without
* logging it. This happens for things like inodes which are logged
* separately from the buffer.
*/
void
xfs_buf_item_flush_log_debug(
buf_t *bp,
uint first,
uint last)
{
xfs_buf_log_item_t *bip;
char *logged;
uint x;
uint nbytes;
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
if ((bip == NULL) || (bip->bli_item.li_type != XFS_LI_BUF)) {
return;
}
ASSERT(bip->bli_logged != NULL);
logged = bip->bli_logged + first; /* pointer arithmetic */
nbytes = last - first + 1;
for (x = 0; x < nbytes; x++) {
*logged = 1;
logged++;
}
}
/*
* This function is called to verify that our caller's have logged
* all the bytes that they changed.
*
* It does this by comparing the original copy of the buffer stored in
* the buf log item's bli_orig array to the current copy of the buffer
* and ensuring that all bytes which miscompare are set in the bli_logged
* array of the buf log item.
*/
STATIC void
xfs_buf_item_log_check(
xfs_buf_log_item_t *bip)
{
char *logged;
char *orig;
char *buffer;
int x;
buf_t *bp;
ASSERT(bip->bli_orig != NULL);
ASSERT(bip->bli_logged != NULL);
bp = bip->bli_buf;
ASSERT(bp->b_bcount > 0);
ASSERT(bp->b_un.b_addr != NULL);
logged = bip->bli_logged;
orig = bip->bli_orig;
buffer = bp->b_un.b_addr;
for (x = 0; x < bp->b_bcount; x++) {
if (*orig != *buffer) {
ASSERT(*logged == 1);
}
orig++;
buffer++;
logged++;
}
}
#endif /* XFS_TRANS_DEBUG */
/*
* Count the number of bits set in the bitmap starting with bit
* start_bit. Size is the size of the bitmap in words.
*
* Do the counting by mapping a byte value to the number of set
* bits for that value using the xfs_countbit array, i.e.
* xfs_countbit[0] == 0, xfs_countbit[1] == 1, xfs_countbit[2] == 1,
* xfs_countbit[3] == 2, etc.
*/
int
xfs_buf_item_bits(
uint *map,
uint size,
uint start_bit)
{
register int bits;
register char *bytep;
register char *end_map;
int byte_bit;
bits = 0;
end_map = (char*)(map + size);
bytep = (char*)(map + (start_bit & ~0x7));
byte_bit = start_bit & 0x7;
/*
* If the caller fell off the end of the map, return 0.
*/
if (bytep >= end_map) {
return (0);
}
/*
* If start_bit is not byte aligned, then process the
* first byte separately.
*/
if (byte_bit != 0) {
/*
* Shift off the bits we don't want to look at,
* before indexing into xfs_countbit.
*/
bits += xfs_countbit[(*bytep >> byte_bit)];
bytep++;
}
/*
* Count the bits in each byte until the end of the bitmap.
*/
while (bytep < end_map) {
bits += xfs_countbit[*bytep];
bytep++;
}
return (bits);
} /* xfs_buf_item_bits */
/*
* Count the number of contiguous bits set in the bitmap starting with bit
* start_bit. Size is the size of the bitmap in words.
*
* Do the counting by mapping a byte value to the number of set
* bits for that value using the xfs_countbit array, i.e.
*/
int
xfs_buf_item_contig_bits(
uint *map,
uint size,
uint start_bit)
{
register int bits;
register uint *wordp;
register uint cwordp;
register uint *end_map;
int word_bit;
int cnt;
bits = 0;
end_map = (uint *)(map + size);
wordp = (uint *)(map + (start_bit >> 5));
word_bit = start_bit & 0x1F;
/*
* If the caller fell off the end of the map, return 0.
*/
if (wordp >= end_map) {
return (0);
}
/*
* If start_bit is not byte aligned, then process just the
* relevant bits.
*/
if (word_bit != 0) {
cwordp = *wordp >> word_bit;
} else {
cwordp = *wordp;
word_bit = 0;
}
/*
* Count the bits in each byte until the end of the bitmap.
*/
while (wordp < end_map) {
/*
* Cycle through bits left in word. If the low bit is
* set, we've found a 'contingous' bit.
*/
for (cnt = NBPW*NBBY-word_bit; cnt > 0; cnt--) {
if (cwordp & 0x1)
bits++;
else
return bits;
cwordp >>= 1;
}
/* Grab another word */
wordp++;
cwordp = *wordp;
word_bit = 0;
}
return (bits);
} /* xfs_buf_item_contig_bits */
/*
* This takes the bit number to start looking from and
* returns the next set bit from there. It returns -1
* if there are no more bits set or the start bit is
* beyond the end of the bitmap.
*
* Size is the number of words, not bytes, in the bitmap.
*/
int
xfs_buf_item_next_bit(
uint *map,
uint size,
uint start_bit)
{
int next_bit;
uint *wordp;
uint *end_map;
int word_bit;
uint word;
end_map = map + size;
wordp = map + (start_bit >> BIT_TO_WORD_SHIFT);
word_bit = start_bit & (NBWORD - 1);
/*
* If the caller has stepped beyond the end of the bitmap,
* return -1.
*/
if (wordp >= end_map) {
return (-1);
}
next_bit = start_bit;
/*
* If the start_bit does not start on a word boundary,
* check the remainder of the starting word first.
*/
if (word_bit != 0) {
word = *wordp >> word_bit;
while (word != 0) {
if (word & 1) {
return (next_bit);
}
word = word >> 1;
next_bit++;
}
/*
* Since we don't know how many bits we looked at before
* word became 0, just set next_bit to the start of the
* next word.
*/
wordp++;
next_bit = ROUNDUPNBWORD(start_bit);
}
/*
* Do word at a time checking for bits until the end of the map.
*/
while (wordp < end_map) {
/*
* If the current word is empty, skip it.
*/
if (*wordp == 0) {
wordp++;
next_bit += NBWORD;
continue;
}
/*
* We know we've got a bit in this word, find it.
*/
word = *wordp;
for (;;) {
if (word & 1) {
return (next_bit);
}
next_bit++;
word = word >> 1;
}
}
/*
* If there were no more bits in the bitmap, return -1.
*/
return (-1);
}
#if 0
/*
* Set the specified bit in the given bitmap.
*/
/*ARGSUSED*/
STATIC void
xfs_buf_item_set_bit(
uint *map,
uint size,
uint bit)
{
uint *wordp;
int word_bit;
wordp = map + (bit >> BIT_TO_WORD_SHIFT);
word_bit = bit & (NBWORD - 1);
*wordp |= 1 << word_bit;
}
#endif
/*
* Return 1 if the buffer has some data that has been logged (at any
* point, not just the current transaction) and 0 if not.
*/
uint
xfs_buf_item_dirty(
xfs_buf_log_item_t *bip)
{
return (bip->bli_flags & XFS_BLI_DIRTY);
}
/*
* This is called when the buf log item is no longer needed. It should
* free the buf log item associated with the given buffer and clear
* the buffer's pointer to the buf log item. If there are no more
* items in the list, clear the b_iodone field of the buffer (see
* xfs_buf_attach_iodone() below).
*/
void
xfs_buf_item_relse(
buf_t *bp)
{
xfs_buf_log_item_t *bip;
bip = (xfs_buf_log_item_t*)bp->b_fsprivate;
bp->b_fsprivate = bip->bli_item.li_bio_list;
if ((bp->b_fsprivate == NULL) && (bp->b_iodone != NULL)) {
bp->b_iodone = NULL;
}
#ifdef XFS_TRANS_DEBUG
kmem_free(bip->bli_orig, bp->b_bcount);
bip->bli_orig = NULL;
kmem_free(bip->bli_logged, bp->b_bcount);
bip->bli_logged = NULL;
#endif /* XFS_TRANS_DEBUG */
#ifdef XFS_BLI_TRACE
ktrace_free(bip->bli_trace);
#endif
kmem_zone_free(xfs_buf_item_zone, bip);
}
/*
* Add the given log item with it's callback to the list of callbacks
* to be called when the buffer's I/O completes. If it is not set
* already, set the buffer's b_iodone() routine to be
* xfs_buf_iodone_callbacks() and link the log item into the list of
* items rooted at b_fsprivate. Items are always added as the second
* entry in the list if there is a first, because the buf item code
* assumes that the buf log item is first.
*/
void
xfs_buf_attach_iodone(
buf_t *bp,
void (*cb)(buf_t *, xfs_log_item_t *),
xfs_log_item_t *lip)
{
xfs_log_item_t *head_lip;
ASSERT(bp->b_flags & B_BUSY);
ASSERT(valusema(&bp->b_lock) <= 0);
lip->li_cb = cb;
if (bp->b_fsprivate != NULL) {
head_lip = (xfs_log_item_t *)bp->b_fsprivate;
lip->li_bio_list = head_lip->li_bio_list;
head_lip->li_bio_list = lip;
} else {
bp->b_fsprivate = lip;
}
ASSERT((bp->b_iodone == xfs_buf_iodone_callbacks) ||
(bp->b_iodone == NULL));
if (bp->b_iodone == NULL) {
bp->b_iodone = xfs_buf_iodone_callbacks;
}
}
STATIC void
xfs_buf_do_callbacks(
buf_t *bp,
xfs_log_item_t *lip)
{
xfs_log_item_t *nlip;
while (lip != NULL) {
nlip = lip->li_bio_list;
ASSERT(lip->li_cb != NULL);
/*
* Clear the next pointer so we don't have any
* confusion if the item is added to another buf.
* Don't touch the log item after calling its
* callback, because it could have freed itself.
*/
lip->li_bio_list = NULL;
lip->li_cb(bp, lip);
lip = nlip;
}
}
/*
* This is the iodone() function for buffers which have had callbacks
* attached to them by xfs_buf_attach_iodone(). It should remove each
* log item from the buffer's list and call the callback of each in turn.
* When done, the buffer's fsprivate field is set to NULL and the buffer
* is unlocked with a call to iodone().
*/
void
xfs_buf_iodone_callbacks(
buf_t *bp)
{
xfs_log_item_t *lip;
static time_t lasttime;
static dev_t lastdev;
ASSERT(bp->b_fsprivate != NULL);
lip = (xfs_log_item_t *)bp->b_fsprivate;
if (geterror(bp) != 0) {
/*
* If we've already decided to shutdown the filesystem
* because of IO errors, there's no point in giving this
* a retry.
*/
if (XFS_FORCED_SHUTDOWN(lip->li_mountp)) {
ASSERT(bp->b_edev == lip->li_mountp->m_dev);
bp->b_flags |= B_STALE;
bp->b_flags &= ~(B_DONE|B_DELWRI);
#ifndef SIM
buftrace("BUF_IODONE_CB", bp);
#endif
xfs_buf_do_callbacks(bp, lip);
bp->b_fsprivate = NULL;
bp->b_iodone = NULL;
/*
* XFS_SHUT flag gets set when we go thru the
* entire buffer cache and deliberately start
* throwing away delayed write buffers.
* Since there's no biowait done on those,
* we should just brelse them.
*/
if (bp->b_flags2 & B_XFS_SHUT) {
bp->b_flags2 &= ~B_XFS_SHUT;
brelse(bp);
} else {
biodone(bp);
}
return;
}
#ifdef XFSERRORDEBUG
printf("Error bp 0x%x, flags 0x%x, mp 0x%x\n",
bp, bp->b_flags,
lip->li_mountp);
#endif
if ((bp->b_edev != lastdev) || ((lbolt - lasttime) > 500)) {
prdev("XFS write error in file system meta-data "
"block 0x%x in %s",
(int)bp->b_edev, bp->b_blkno,
lip->li_mountp->m_fsname);
lasttime = lbolt;
}
lastdev = bp->b_edev;
if (bp->b_flags & B_ASYNC) {
/*
* If the write was asynchronous then noone will be
* looking for the error. Clear the error state
* and write the buffer out again delayed write.
*/
bp->b_error = 0;
bp->b_flags &= ~B_ERROR;
if (!(bp->b_flags & B_STALE)) {
bp->b_flags |= B_DELWRI | B_DONE;
bp->b_start = lbolt;
}
brelse(bp);
} else {
/*
* If the write of the buffer was not asynchronous,
* then we want to make sure to return the error
* to the caller of bwrite(). Because of this we
* cannot clear the B_ERROR state at this point.
* Instead we install a callback function that
* will be called when the buffer is released, and
* that routine will clear the error state and
* set the buffer to be written out again after
* some delay.
*/
ASSERT(bp->b_relse == NULL);
bp->b_relse = xfs_buf_error_relse;
bp->b_flags |= B_DONE;
vsema(&bp->b_iodonesema);
}
return;
}
xfs_buf_do_callbacks(bp, lip);
bp->b_fsprivate = NULL;
bp->b_iodone = NULL;
biodone(bp);
}
/*
* This is a callback routine attached to a buffer which gets an error
* when being written out synchronously. If the buffer is not made stale
* by the code doing the write, then it clears the error state in the buffer
* and writes it out again delayed write. It is up to the code doing the
* bwrite() to clean up the buffer if it marks it stale.
*/
STATIC void
xfs_buf_error_relse(
buf_t *bp)
{
xfs_log_item_t *lip;
lip = (xfs_log_item_t *)bp->b_fsprivate;
ASSERT(bp->b_edev == lip->li_mountp->m_dev);
bioerror(bp, EIO);
bp->b_flags |= B_STALE|B_DONE;
bp->b_flags &= ~(B_DELWRI);
#ifndef SIM
buftrace("BUF_ERROR_RELSE", bp);
#endif
/*
* We have to unpin the pinned buffers so do the
* callbacks.
*/
xfs_buf_do_callbacks(bp, lip);
bp->b_fsprivate = NULL;
bp->b_relse = NULL;
brelse(bp);
return;
}
/*
* This is the iodone() function for buffers which have been
* logged. It is called when they are eventually flushed out.
* It should remove the buf item from the AIL, and free the buf item.
* It is called by xfs_buf_iodone_callbacks() above which will take
* care of cleaning up the buffer itself.
*/
/* ARGSUSED */
void
xfs_buf_iodone(
buf_t *bp,
xfs_buf_log_item_t *bip)
{
struct xfs_mount *mp;
SPLDECL(s);
ASSERT(bip->bli_buf == bp);
mp = bip->bli_item.li_mountp;
#ifdef XFSERRORDEBUG
if (!(((xfs_log_item_t *)bip)->li_flags & XFS_LI_IN_AIL)) {
printf("Not in AIL, bip 0x%x\n", bip);
}
#endif
/*
* If we are forcibly shutting down, this may well be
* off the AIL already. That's because we simulate the
* log-committed callbacks to unpin these buffers.
* xfs_trans_delete_ail() checks for that.
* Either way, AIL is useless if we're forcing a shutdown.
*/
AIL_LOCK(mp,s);
/*
* xfs_trans_delete_ail() drops the AIL lock.
*/
xfs_trans_delete_ail(mp, (xfs_log_item_t *)bip, s);
#ifdef XFS_TRANS_DEBUG
kmem_free(bip->bli_orig, bp->b_bcount);
bip->bli_orig = NULL;
kmem_free(bip->bli_logged, bp->b_bcount);
bip->bli_logged = NULL;
#endif /* XFS_TRANS_DEBUG */
#ifdef XFS_BLI_TRACE
ktrace_free(bip->bli_trace);
#endif
kmem_zone_free(xfs_buf_item_zone, bip);
}
#if defined(XFS_BLI_TRACE)
void
xfs_buf_item_trace(
char *id,
xfs_buf_log_item_t *bip)
{
buf_t *bp;
ASSERT(bip->bli_trace != NULL);
bp = bip->bli_buf;
ktrace_enter(bip->bli_trace,
(void *)id,
(void *)bip->bli_buf,
(void *)((unsigned long)bip->bli_flags),
(void *)((unsigned long)bip->bli_recur),
(void *)((unsigned long)bip->bli_refcount),
(void *)bp->b_blkno,
(void *)((unsigned long)bp->b_bcount),
(void *)((unsigned long)bp->b_flags),
(void *)((unsigned long)bp->b_flags2),
(void *)bp->b_fsprivate,
(void *)bp->b_fsprivate2,
(void *)((unsigned long)bp->b_pincount),
(void *)bp->b_iodone,
(void *)((unsigned long)(valusema(&(bp->b_lock)))),
(void *)bip->bli_item.li_desc,
(void *)((unsigned long)bip->bli_item.li_flags));
}
#endif /* XFS_BLI_TRACE */
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