#ident "$Revision: 1.39 $"
/*
* High level interface routines for log manager
*/
#include <sys/types.h>
#include <sys/param.h>
#ifdef SIM
#define _KERNEL
#endif
#include <sys/sysmacros.h>
#include <sys/buf.h>
#ifdef SIM
#undef _KERNEL
#include <bstring.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#else
#include <sys/systm.h>
#endif
#include <sys/kmem.h>
#include <sys/debug.h>
#include <sys/sema.h>
#include <sys/uuid.h>
#include <sys/vnode.h>
#include "xfs_inum.h"
#include "xfs_types.h"
#include "xfs_sb.h" /* depends on xfs_types.h & xfs_inum.h */
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_mount.h" /* depends on xfs_trans.h & xfs_sb.h */
#include "xfs_log_priv.h" /* depends on all above */
#ifdef SIM
#include "sim.h" /* must be last include file */
#endif
#define xlog_write_adv_cnt(ptr, len, off, bytes) \
{ (ptr) += (bytes); \
(len) -= (bytes); \
(off) += (bytes);}
#define GET_CYCLE(ptr) (*(uint *)(ptr) == XLOG_HEADER_MAGIC_NUM ? *((uint *)(ptr)+1) : *(uint *)(ptr))
#define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1)
/* Local miscellaneous function prototypes */
STATIC void xlog_alloc(xfs_mount_t *mp, dev_t log_dev, uint block_offset,
uint num_bblocks);
STATIC xfs_lsn_t xlog_commit_record(xfs_mount_t *mp, xlog_ticket_t *ticket);
STATIC uint xlog_find_end(dev_t log_dev, uint block_offset,
uint log_bbnum);
uint xlog_find_start(dev_t log_dev, uint log_bbnum);
STATIC int xlog_find_zeroed(dev_t log_dev, uint blk_offset,
uint log_bbnum, uint* blk_no);
STATIC void xlog_push_buffers_to_disk(xfs_mount_t *mp, xlog_t *log);
STATIC void xlog_sync(xlog_t *log, xlog_in_core_t *iclog, uint flags);
STATIC void xlog_unalloc(void);
STATIC int xlog_write(xfs_mount_t *mp, xfs_log_iovec_t region[],
int nentries, xfs_log_ticket_t tic,
xfs_lsn_t *start_lsn, int commit);
/* local state machine functions */
STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog);
STATIC void xlog_state_finish_copy(xlog_t *log,
xlog_in_core_t *iclog,
int first_write, int bytes);
STATIC int xlog_state_get_iclog_space(xlog_t *log, int len,
xlog_in_core_t **iclog,
int *continued_write);
STATIC xfs_log_ticket_t xlog_state_get_ticket(xlog_t *log, int len,
char log_client, uint flags);
STATIC int xlog_state_lsn_is_synced(xlog_t *log, xfs_lsn_t lsn,
xfs_log_callback_t *cb);
STATIC void xlog_state_put_ticket(xlog_t *log, xlog_ticket_t *tic);
STATIC void xlog_state_release_iclog(xlog_t *log,
xlog_in_core_t *iclog);
STATIC int xlog_state_sync(xlog_t *log, xfs_lsn_t lsn, uint flags);
STATIC void xlog_state_want_sync(xlog_t *log,
xlog_in_core_t *iclog);
/* local ticket functions */
STATIC xfs_log_ticket_t *xlog_maketicket(xlog_t *log, int len, char clientid);
STATIC void xlog_alloc_tickets(xlog_t *log);
STATIC void xlog_putticket(xlog_t *log, xlog_ticket_t *ticket);
STATIC void xlog_relticket(xlog_ticket_t *ticket);
STATIC uint xlog_recover(struct xfs_mount *mp, dev_t log_dev,
uint block_offset, uint num_bblocks);
STATIC void xlog_verify_dest_ptr(xlog_t *log, psint ptr);
STATIC void xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
int count);
/*
* 0 => disable log manager
* 1 => enable log manager
* 2 => enable log manager and log debugging
*/
int xlog_debug = 0;
#ifdef DEBUG
int bytes_of_ticket_used;
#endif
/*
* NOTES:
*
* 1. currblock field gets updated at startup and after in-core logs
* marked as with WANT_SYNC.
*/
/*
* This routine is called when a user of a log manager ticket is done with
* the reservation. If the ticket was ever used, then a commit record for
* the associated transaction is written out as a log operation header with
* no data. The flag XLOG_TIC_INITED is set when the first write occurs with
* a given ticket. If the ticket was one with a permanent reservation, then
* a few operations are done differently. Permanent reservation tickets by
* default don't release the reservation. They just commit the current
* transaction with the belief that the reservation is still needed. A flag
* must be passed in before permanent reservations are actually released.
* When these type of tickets are not released, they need to be set into
* the inited state again. By doing this, a start record will be written
* out when the next write occurs.
*/
xfs_lsn_t
xfs_log_done(xfs_mount_t *mp,
xfs_log_ticket_t tic,
uint flags)
{
xlog_t *log = mp->m_log;
xlog_ticket_t *ticket = (xfs_log_ticket_t) tic;
xfs_lsn_t lsn;
if (! xlog_debug)
return 0;
/* If nothing was ever written, don't write out commit record */
if ((ticket->t_flags & XLOG_TIC_INITED) == 0)
lsn = xlog_commit_record(mp, ticket);
/* Release ticket if not permanent reservation or a specifc
* request has been made to release a permanent reservation.
*/
if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
(flags & XFS_LOG_REL_PERM_RESERV))
xlog_state_put_ticket(log, ticket);
/* If this ticket was a permanent reservation and we aren't
* trying to release it, reset the inited flags; so next time
* we write, a start record will be written out.
*/
if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) &&
(flags & XFS_LOG_REL_PERM_RESERV) == 0)
ticket->t_flags |= XLOG_TIC_INITED;
return lsn;
} /* xfs_log_done */
/*
* Force the in-core log to disk. If flags == XFS_LOG_SYNC,
* the force is done synchronously.
*
* Asynchronous forces are implemented by setting the WANT_SYNC
* bit in the appropriate in-core log and then returning.
*
* Synchronous forces are implemented with a semaphore. All callers
* to force a given lsn to disk will wait on a semaphore attached to the
* specific in-core log. When given in-core log finally completes its
* write to disk, that thread will wake up all threads waiting on the
* semaphore.
*/
int
xfs_log_force(xfs_mount_t *mp,
xfs_lsn_t lsn,
uint flags)
{
xlog_t *log = mp->m_log;
if (flags & XFS_LOG_FORCE) {
return(xlog_state_sync(log, lsn, flags));
} else if (flags & XFS_LOG_URGE) {
xlog_panic("xfs_log_force: not yet implemented");
return -1;
} else
xlog_panic("xfs_log_force: illegal flags");
} /* xfs_log_force */
/*
* This function will take a log sequence number and check to see if that
* lsn has been flushed to disk. If it has, then the callback function is
* called with the callback argument. If the relevant in-core log has not
* been synced to disk, we add the callback to the callback list of the
* in-core log.
*/
void
xfs_log_notify(xfs_mount_t *mp, /* mount of partition */
xfs_lsn_t lsn, /* lsn looking for */
xfs_log_callback_t *cb)
{
xlog_t *log = mp->m_log;
cb->cb_next = 0;
if (xlog_state_lsn_is_synced(log, lsn, cb))
cb->cb_func(cb->cb_arg);
} /* xfs_log_notify */
/*
* Initialize log manager data. This routine is intended to be called when
* a system boots up. It is not a per filesystem initialization.
*
* As you can see, we currently do nothing.
*/
int
xfs_log_init()
{
}
/*
* 1. Reserve an amount of on-disk log space and return a ticket corresponding
* to the reservation.
* 2. Potentially, push buffers at tail of log to disk.
*
* Each reservation is going to reserve extra space for a log record header.
* When writes happen to the on-disk log, we don't subtract the length of the
* log record header from any reservation. By wasting space in each
* reservation, we prevent over allocation problems.
*/
int
xfs_log_reserve(xfs_mount_t *mp,
uint len,
xfs_log_ticket_t *ticket,
char client,
uint flags)
{
xlog_t *log = mp->m_log;
if (! xlog_debug)
return 0;
if (client != XFS_TRANSACTION)
return -1;
if (flags & XFS_LOG_SLEEP) {
xlog_panic("xfs_log_reserve: not implemented");
return XFS_ENOTSUP;
}
/*
* Permanent reservations always have at least two active log
* operations in the log. Other reservations may need one log
* record header for each part of an operation which falls in
* a different log record. This is a gross over estimate.
*/
if (flags & XFS_LOG_PERM_RESERV)
len += 2*XLOG_HEADER_SIZE;
else {
len += XLOG_HEADER_SIZE *
((len + XLOG_RECORD_BSIZE - 1) >> XLOG_RECORD_BSHIFT);
}
log->l_sync_lsn = xfs_trans_tail_ail(mp);
xlog_push_buffers_to_disk(mp, log);
if ((int)(*ticket = xlog_state_get_ticket(log,len,client,flags)) == -1)
return XFS_ENOLOGSPACE;
if (flags & XFS_LOG_PERM_RESERV)
((xlog_ticket_t *)ticket)->t_flags |= XLOG_TIC_PERM_RESERV;
return 0;
} /* xfs_log_reserve */
/*
* Mount a log filesystem.
*
* mp - ubiquitous xfs mount point structure
* log_dev - device number of on-disk log device
* block_offset - Start block # where block size is 512 bytes (BBSIZE)
* num_bblocks - Number of BBSIZE blocks in on-disk log
* flags -
*
*/
int
xfs_log_mount(xfs_mount_t *mp,
dev_t log_dev,
int block_offset,
int num_bblocks,
uint flags)
{
xlog_t *log;
if (! xlog_debug)
return 0;
if (xlog_recover(mp, log_dev, block_offset, num_bblocks) != 0) {
return XFS_ERECOVER;
}
xlog_alloc(mp, log_dev, block_offset, num_bblocks);
return 0;
} /* xfs_log_mount */
/*
* Unmount a log filesystem.
*
* Mark the filesystem clean as unmount happens.
*/
int
xfs_log_unmount(xfs_mount_t *mp)
{
xlog_unalloc();
return 0;
}
/*
* Write region vectors to log. The write happens using the space reservation
* of the ticket (tic). It is not a requirement that all writes for a given
* transaction occur with one call to xfs_log_write().
*/
int
xfs_log_write(xfs_mount_t * mp,
xfs_log_iovec_t reg[],
int nentries,
xfs_log_ticket_t tic,
xfs_lsn_t *start_lsn)
{
if (! xlog_debug) {
*start_lsn = 0;
return 0;
}
xlog_write(mp, reg, nentries, tic, start_lsn, 0);
} /* xfs_log_write */
/******************************************************************************
*
* local routines
*
******************************************************************************
*/
/*
* Allocate a log
*
* Perform all the specific initialization required during a log mount.
*/
void
xlog_alloc(xfs_mount_t *mp,
dev_t log_dev,
uint block_offset,
uint num_bblocks)
{
xlog_t *log;
xlog_rec_header_t *head;
xlog_in_core_t **iclogp;
xlog_in_core_t *iclog;
int i;
caddr_t unaligned;
/* XLOG_RECORD_BSIZE must be mult of BBSIZE; see xlog_rec_header_t */
ASSERT((XLOG_RECORD_BSIZE & BBMASK) == 0);
log = mp->m_log = (void *)kmem_zalloc(sizeof(xlog_t), 0);
xlog_alloc_tickets(log);
log->l_mp = mp;
log->l_dev = log_dev;
log->l_logreserved = 0;
log->l_prev_block = -1;
log->l_sync_lsn = 0x100000000LL; /* cycle = 1; current block = 0 */
log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
log->l_xbuf = getrbuf(0); /* get my locked buffer */
log->l_curr_block = xlog_find_end(log_dev, block_offset, num_bblocks);
ASSERT(log->l_xbuf->b_flags & B_BUSY);
ASSERT(valusema(&log->l_xbuf->b_lock) <= 0);
initnlock(&log->l_icloglock, "iclog");
initnsema(&log->l_flushsema, XLOG_NUM_ICLOGS, "iclog-flush");
log->l_logsize = BBTOB(num_bblocks);
log->l_logBBstart = block_offset;
log->l_logBBsize = BTOBB(log->l_logsize);
iclogp = &log->l_iclog;
for (i=0; i < XLOG_NUM_ICLOGS; i++) {
unaligned = kmem_zalloc(sizeof(xlog_in_core_t)+4096, 0);
*iclogp =(xlog_in_core_t *)(((psint)unaligned+4095) & ~0xfff);
iclog = *iclogp;
log->l_iclog_bak[i] = iclog;
head = &iclog->ic_header;
head->h_magicno = XLOG_HEADER_MAGIC_NUM;
head->h_version = 1;
/* head->h_lsn = 0;*/
/* head->h_sync_lsn = 0;*/
/* XXXmiken: Need to make the size of an iclog at least 2x the size of
* a filesystem block. This means some code will not be
* compilable. Additional fields may be needed to precompute
* values.
*/
iclog->ic_size = XLOG_RECORD_BSIZE - XLOG_HEADER_SIZE;
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_log = log;
/* iclog->ic_refcnt = 0; */
/* iclog->ic_callback = 0; */
iclog->ic_bp = getrbuf(0); /* my locked buffer */
ASSERT(iclog->ic_bp->b_flags & B_BUSY);
ASSERT(valusema(&iclog->ic_bp->b_lock) <= 0);
initnsema(&iclog->ic_forcesema, 0, "iclog-force");
iclogp = &iclog->ic_next;
}
log->l_iclog_bak[i] = 0;
log->l_iclog_size = XLOG_RECORD_BSIZE;
*iclogp = log->l_iclog; /* complete ring */
} /* xlog_alloc */
/*
* Write out the commit record of a transaction associated with the given
* ticket. Return the lsn of the commit record.
*/
xfs_lsn_t
xlog_commit_record(xfs_mount_t *mp,
xlog_ticket_t *ticket)
{
int error;
xfs_log_iovec_t reg[1];
xfs_lsn_t commit_lsn;
reg[0].i_addr = 0;
reg[0].i_len = 0;
error = xlog_write(mp, reg, 1, ticket, &commit_lsn, 1);
if (error)
xlog_panic("xlog_commit_record: Can't commit transaction");
return commit_lsn;
} /* xlog_commit_record */
buf_t *
xlog_find_bread(dev_t log_dev,
uint blk_no)
{
buf_t *bp;
bp = bread(log_dev, blk_no, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_bread: bread error");
}
return bp;
} /* xlog_find_bread */
/*
*
*/
uint
xlog_find_end(dev_t log_dev,
uint blk_offset,
uint log_bbnum)
{
#ifdef OLD_LINEAR_SEARCH
uint blk_no = 0; /* current block number */
uint cycle_no = 0; /* current cycle number */
xlog_rec_header_t *head; /* ptr to log record header */
uint start_block = 0; /* block to start writing at */
uint log_rec_block_no = 0; /* last start of log record */
uint log_rec_bblocks; /* num of bblocks in log rec */
int skip_first_part_of_log;
int i;
buf_t *bp;
int *int_ptr;
#else
buf_t *bp;
uint first_blk;
uint mid_blk;
uint last_blk;
uint first_half_cycle;
uint mid_cycle;
uint last_half_cycle;
#endif /* OLD_LINEAR_SEARCH */
/* special case freshly mkfs'ed filesystem */
if (xlog_find_zeroed(log_dev, blk_offset, log_bbnum, &first_blk))
return first_blk;
/* first block */
first_blk = 0;
bp = xlog_find_bread(log_dev, blk_offset);
first_half_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
/* last block */
last_blk = log_bbnum;
bp = xlog_find_bread(log_dev, last_blk+blk_offset);
last_half_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
ASSERT(last_half_cycle != 0);
/* all cycle numbers are identical */
if (first_half_cycle == last_half_cycle)
return 0;
/* have 1st and last; look for middle cycle */
mid_blk = BLK_AVG(first_blk, last_blk);
while (mid_blk != first_blk && mid_blk != last_blk) {
bp = xlog_find_bread(log_dev, mid_blk+blk_offset);
mid_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
if (mid_cycle == first_half_cycle) {
first_blk = mid_blk;
/* first_half_cycle == mid_cycle */
} else {
last_blk = mid_blk;
/* last_half_cycle == mid_cycle */
}
mid_blk = BLK_AVG(first_blk, last_blk);
}
ASSERT((mid_blk == first_blk && mid_blk+1 == last_blk) ||
(mid_blk == last_blk && mid_blk-1 == first_blk));
return last_blk;
#ifdef OLD_LINEAR_SEARCH
skip_first_part_of_log = 1;
while (blk_no < log_bbnum) {
bp = bread(log_dev, blk_no+blk_offset, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_end");
}
head = (xlog_rec_header_t *)bp->b_dmaaddr;
if (head->h_magicno != XLOG_HEADER_MAGIC_NUM) {
if (skip_first_part_of_log) {
blk_no++;
brelse(bp);
continue;
} else {
brelse(bp);
goto end;
}
}
skip_first_part_of_log = 0;
if (cycle_no == 0) {
cycle_no = CYCLE_LSN(head->h_lsn);
start_block = log_rec_block_no = blk_no;
log_rec_bblocks = BTOBB(head->h_len);
} else if (CYCLE_LSN(head->h_lsn) < cycle_no) {
cycle_no = CYCLE_LSN(head->h_lsn);
log_rec_block_no = blk_no;
goto end;
} else { /* cycle num equal */
ASSERT(CYCLE_LSN(head->h_lsn) == cycle_no);
log_rec_block_no = blk_no;
log_rec_bblocks = BTOBB(head->h_len);
}
brelse(bp);
blk_no++;
/* verify log record data cycle numbers */
for (i=0; i<log_rec_bblocks; i++) {
bp = bread(log_dev, blk_no+blk_offset, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_end");
}
int_ptr = (int *)bp->b_dmaaddr;
if (*int_ptr != cycle_no) { /* invalid data blk */
brelse(bp);
goto end;
}
brelse(bp);
}
blk_no += log_rec_bblocks;
log_rec_block_no = blk_no; /* OK to this point */
}
end:
start_block = log_rec_block_no;
return (uint)start_block;
#endif /* OLD_LINEAR_SEARCH */
} /* xlog_find_end */
/*
*/
uint
xlog_find_start(dev_t log_dev, uint log_bbnum)
{
xlog_rec_header_t *head;
int block_start = 0;
int block_no = 0;
int cycle_no = 0;
int binary_block_start = 0;
buf_t *bp;
/* read through all blocks to find start of on-disk log */
while (block_no < log_bbnum) {
bp = bread(log_dev, block_no, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_start");
}
head = (xlog_rec_header_t *)bp->b_dmaaddr;
if (head->h_magicno != XLOG_HEADER_MAGIC_NUM) {
block_no++;
brelse(bp);
continue;
}
if (cycle_no == 0) {
cycle_no = CYCLE_LSN(head->h_lsn);
block_start = block_no;
} else if (CYCLE_LSN(head->h_lsn) < cycle_no) {
cycle_no = CYCLE_LSN(head->h_lsn);
block_start = block_no;
brelse(bp);
break;
}
block_no++;
brelse(bp);
}
return (uint)block_start;
} /* xlog_find_start */
/*
* Find the sync block number
*
* This will be the block number of the last record to have its
* associated buffers synced to disk. Every log record header has
* a sync lsn embedded in it. LSNs hold block numbers, so it is easy
* to get a sync block number. The only concern is to figure out which
* log record header to believe.
*
* The following algorithm uses the log record header with the largest
* lsn. The entire log record does not need to be valid. We only care
* that the header is valid.
*
* NOTE: we also scan the log sequentially. this will need to be changed
* to a binary search.
*/
uint
xlog_find_sync(dev_t log_dev,
uint block_offset,
uint log_bbnum)
{
xlog_rec_header_t *head;
uint block_start = 0;
uint block_no = 0;
uint cycle_no = 0;
uint binary_block_start = 0;
uint last_log_rec_blk = 0;
buf_t *bp;
/* read through all blocks to find start of on-disk log */
while (block_no < log_bbnum) {
bp = bread(log_dev, block_no+block_offset, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_sync");
}
head = (xlog_rec_header_t *)bp->b_dmaaddr;
if (head->h_magicno != XLOG_HEADER_MAGIC_NUM) {
block_no++;
if (cycle_no == 0) {
cycle_no = *(uint *)head;
} else if (*(uint *)head < cycle_no) {
brelse(bp);
break;
}
} else {
if (cycle_no == 0) {
cycle_no = CYCLE_LSN(head->h_lsn);
last_log_rec_blk = block_no;
} else if (CYCLE_LSN(head->h_lsn) < cycle_no) {
brelse(bp);
break;
} else {
last_log_rec_blk = block_no;
}
}
block_no++;
brelse(bp);
}
bp = bread(log_dev, last_log_rec_blk+block_offset, 1);
if (bp->b_flags & B_ERROR) {
brelse(bp);
xlog_panic("xlog_find_sync");
}
brelse(bp);
head = (xlog_rec_header_t *)bp->b_dmaaddr;
return (uint)BLOCK_LSN(head->h_sync_lsn);
} /* xlog_find_sync */
/*
* Is the log zeroed at all?
*
* The last binary search should be changed to perform an X block read
* once X becomes small enough. You can then search linearly through
* the X blocks. This will cut down on the number of reads we need to do.
*/
int
xlog_find_zeroed(dev_t log_dev,
uint blk_offset,
uint log_bbnum,
uint *blk_no)
{
buf_t *bp;
uint first_cycle;
uint mid_cycle;
uint last_cycle;
uint first_blk;
uint mid_blk;
uint last_blk;
/* check totally zeroed log */
bp = xlog_find_bread(log_dev, blk_offset);
first_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
if (first_cycle == 0) { /* completely zeroed log */
*blk_no = 0;
return 1;
}
/* check not zeroed log */
bp = xlog_find_bread(log_dev, log_bbnum+blk_offset-1);
last_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
if (last_cycle != 0) /* log completely written to */
return 0;
/* we have a partially zeroed log */
first_blk = 0;
last_blk = log_bbnum-1;
mid_blk = BLK_AVG(last_blk, first_blk);
while (mid_blk != first_blk && mid_blk != last_blk) {
bp = xlog_find_bread(log_dev, mid_blk + blk_offset);
mid_cycle = GET_CYCLE(bp->b_dmaaddr);
brelse(bp);
if (mid_cycle == 0) {
last_blk = mid_blk;
/* last_cycle == mid_cycle */
} else {
first_blk = mid_blk;
/* first_cycle == mid_cycle */
}
mid_blk = BLK_AVG(last_blk, first_blk);
}
ASSERT((mid_blk == first_blk && mid_blk+1 == last_blk) ||
(mid_blk == last_blk && mid_blk-1 == first_blk));
*blk_no = last_blk;
return 1;
} /* xlog_find_zeroed */
/*
* Log function which is called when an io completes.
*
* The log manager needs its own routine, in order to control what
* happens with the buffer after the write completes.
*/
void
xlog_iodone(buf_t *bp)
{
xlog_state_done_syncing((xlog_in_core_t *)(bp->b_fsprivate));
if ( !(bp->b_flags & B_ASYNC) ) {
/* Corresponding psema() will be done in bwrite(). If we don't
* vsema() here, panic.
*/
vsema(&bp->b_iodonesema);
}
} /* xlog_iodone */
/*
* Push on the buffer cache code if we ever use more than 75% of the on-disk
* log space. This code pushes on the lsn which would supposedly free up
* the 25% which we want to leave free. We may need to adopt a policy which
* pushes on an lsn which is further along in the log once we reach the high
* water mark. In this manner, we would be creating a low water mark.
*/
void
xlog_push_buffers_to_disk(xfs_mount_t *mp, xlog_t *log)
{
int blocks; /* valid blocks left to write to */
xfs_lsn_t sync_lsn;
xfs_lsn_t threshhold_lsn;
int threshhold_block;
sync_lsn = log->l_sync_lsn;
if (CYCLE_LSN(sync_lsn) == log->l_curr_cycle) {
blocks = log->l_logBBsize - (log->l_curr_block - BLOCK_LSN(sync_lsn));
} else {
ASSERT(CYCLE_LSN(sync_lsn) + 1 == log->l_curr_cycle);
blocks = BLOCK_LSN(sync_lsn) - log->l_curr_block;
}
if (blocks < (log->l_logBBsize >> 2)) {
threshhold_block = BLOCK_LSN(sync_lsn) + (log->l_logBBsize >> 2);
if (threshhold_block >= log->l_logBBsize) {
threshhold_block -= log->l_logBBsize;
((uint *)&(threshhold_lsn))[0] = CYCLE_LSN(sync_lsn) +1;
} else {
((uint *)&(threshhold_lsn))[0] = CYCLE_LSN(sync_lsn);
}
((uint *)&(threshhold_lsn))[1] = threshhold_block;
xfs_trans_push_ail(mp, threshhold_lsn);
}
} /* xlog_push_buffers_to_disk */
/*
* Flush out the in-core log (iclog) to the on-disk log in a synchronous or
* asynchronous fashion. Previously, we should have moved the current iclog
* ptr in the log to point to the next available iclog. This allows further
* write to continue while this code syncs out an iclog ready to go.
* Before an in-core log can be written out, the data section must be scanned
* to save away the 1st word of each BBSIZE block into the header. We replace
* it with the current cycle count. Each BBSIZE block is tagged with the
* cycle count because there in an implicit assumption that drives will
* guarantee that entire 512 byte blocks get written at once. In other words,
* we can't have part of a 512 byte block written and part not written. By
* tagging each block, we will know which blocks are valid when recovering
* after an unclean shutdown.
*
* This routine is single threaded on the iclog. No other thread can be in
* this routine with the same iclog. Changing contents of iclog can there-
* fore be done without grabbing the state machine lock. Updating the global
* log will require grabbing the lock though.
*
* The entire log manager uses a logical block numbering scheme. Only
* log_sync (and then only bwrite()) know about the fact that the log may
* not start with block zero on a given device. The log block start offset
* is added immediately before calling bwrite().
*/
void
xlog_sync(xlog_t *log,
xlog_in_core_t *iclog,
uint flags)
{
caddr_t dptr; /* pointer to byte sized element */
buf_t *bp;
int i;
uint count; /* byte count of bwrite */
int split = 0; /* split write into two regions */
ASSERT(iclog->ic_refcnt == 0);
if (flags != 0 && ((flags & XFS_LOG_SYNC) != XFS_LOG_SYNC))
xlog_panic("xlog_sync: illegal flag");
/* put cycle number in every block */
for (i = 0,
dptr = (caddr_t)iclog->ic_data;
dptr < (caddr_t)iclog->ic_data + iclog->ic_offset;
dptr += BBSIZE, i++) {
iclog->ic_header.h_cycle_data[i] = *(uint *)dptr;
*(uint *)dptr = log->l_curr_cycle;
}
iclog->ic_header.h_len = iclog->ic_offset; /* real byte length */
bp = iclog->ic_bp;
bp->b_blkno = BLOCK_LSN(iclog->ic_header.h_lsn);
/* Round byte count up to a XLOG_BBSIZE chunk */
count = BBTOB(BTOBB(iclog->ic_offset)) + XLOG_HEADER_SIZE;
if (bp->b_blkno + BTOBB(count) > log->l_logBBsize) {
split = count - (BBTOB(log->l_logBBsize - bp->b_blkno));
count = BBTOB(log->l_logBBsize - bp->b_blkno);
iclog->ic_bwritecnt = 2; /* split into 2 writes */
} else {
iclog->ic_bwritecnt = 1;
}
bp->b_dmaaddr = (caddr_t) iclog;
bp->b_bcount = bp->b_bufsize = count;
bp->b_iodone = xlog_iodone;
bp->b_edev = log->l_dev;
bp->b_fsprivate = iclog; /* save for later */
if (flags & XFS_LOG_SYNC)
bp->b_flags |= (B_BUSY | B_HOLD);
else
bp->b_flags |= (B_BUSY | B_ASYNC);
ASSERT(bp->b_blkno <= log->l_logBBsize-1);
ASSERT(bp->b_blkno + BTOBB(count) <= log->l_logBBsize);
if (xlog_debug > 1)
xlog_verify_iclog(log, iclog, count);
/* account for log which don't start at block #0 */
bp->b_blkno += log->l_logBBstart;
bwrite(bp);
if (bp->b_flags & B_ERROR == B_ERROR)
xlog_panic("xlog_sync: buffer error");
if (split) {
bp = iclog->ic_log->l_xbuf;
bp->b_blkno = 0; /* XXXmiken assumes 0 */
bp->b_bcount = bp->b_bufsize = split;
bp->b_dmaaddr = (caddr_t)((psint)iclog+(psint)count);
bp->b_iodone = xlog_iodone;
bp->b_edev = log->l_dev;
bp->b_fsprivate = iclog;
if (flags & XFS_LOG_SYNC)
bp->b_flags |= (B_BUSY | B_HOLD);
else
bp->b_flags |= (B_BUSY | B_ASYNC);
ASSERT(bp->b_blkno <= log->l_logBBsize-1);
ASSERT(bp->b_blkno + BTOBB(count) <= log->l_logBBsize);
/* account for log which don't start at block #0 */
bp->b_blkno += log->l_logBBstart;
bwrite(bp);
if (bp->b_flags & B_ERROR == B_ERROR)
xlog_panic("xlog_sync: buffer error");
}
} /* xlog_sync */
/*
* Unallocate a log
*
* What to do... sigh.
*/
void
xlog_unalloc(void)
{
} /* xlog_unalloc */
/*
* Write some region out to in-core log
*
* This will be called when writing externally provided regions or when
* writing out a commit record for a given transaction.
*
* General algorithm:
* 1. Find total length of this write. This may include adding to the
* lengths passed in.
* 2. Check whether we violate the tickets reservation.
* 3. While writing to this iclog
* A. Reserve as much space in this iclog as can get
* B. If this is first write, save away start lsn
* C. While writing this region:
* 1. If first write of transaction, write start record
* 2. Write log operation header (header per region)
* 3. Find out if we can fit entire region into this iclog
* 4. Potentially, verify destination bcopy ptr
* 5. Bcopy (partial) region
* 6. If partial copy, release iclog; otherwise, continue
* copying more regions into current iclog
* 4. Mark want sync bit (in simulation mode)
* 5. Release iclog for potential flush to on-disk log.
*
* ERRORS:
* 1. Panic if reservation is overrun. This should never happen since
* reservation amounts are generated internal to the filesystem.
* NOTES:
* 1. Tickets are single threaded data structures.
* 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
* syncing routine. When a single log_write region needs to span
* multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
* on all log operation writes which don't contain the end of the
* region. The XLOG_END_TRANS bit is used for the in-core log
* operation which contains the end of the continued log_write region.
* 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
* we don't really know exactly how much space will be used. As a result,
* we don't update ic_offset until the end when we know exactly how many
* bytes have been written out.
*/
int
xlog_write(xfs_mount_t * mp,
xfs_log_iovec_t reg[],
int nentries,
xfs_log_ticket_t tic,
xfs_lsn_t *start_lsn,
int commit)
{
xlog_t *log = mp->m_log;
xlog_ticket_t *ticket = (xlog_ticket_t *)tic;
xlog_op_header_t *logop_head; /* ptr to log operation header */
xlog_in_core_t *iclog; /* ptr to current in-core log */
psint ptr; /* copy address into data region */
int len; /* # xlog_write() bytes 2 still copy */
int index; /* region index currently copying */
int log_offset; /* offset (from 0) into data region */
int start_rec_copy; /* # bytes to copy for start record */
int partial_copy=0; /* # bytes copied if split region */
int need_copy; /* # bytes need to bcopy this region */
int copy_len; /* # bytes actually bcopy'ing */
int copy_off; /* # bytes from entry start */
int continuedwr; /* continued write of in-core log? */
int firstwr = 0; /* first write of transaction */
/* Calculate potential maximum space. Each region gets its own
* xlog_op_header_t and may need to be double word aligned.
*/
len = 0;
if (ticket->t_flags & XLOG_TIC_INITED) /* acct for start rec of xact */
len += sizeof(xlog_op_header_t);
for (index = 0; index < nentries; index++) {
len += sizeof(xlog_op_header_t); /* each region gets >= 1 */
len += reg[index].i_len;
}
*start_lsn = 0;
if (ticket->t_curr_reserv < len)
xlog_panic("xfs_log_write: reservation ran out. Need to up reservation")
else if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0)
ticket->t_curr_reserv -= len;
for (index = 0; index < nentries; ) {
log_offset = xlog_state_get_iclog_space(log,len, &iclog, &continuedwr);
ptr = (psint) &iclog->ic_data[log_offset];
/* start_lsn is the first lsn written to. That's all we need. */
if (! *start_lsn)
*start_lsn = iclog->ic_header.h_lsn;
/* This loop writes out as many regions as can fit in the amount
* of space which was allocated by xlog_state_get_iclog_space().
*/
while (index < nentries) {
ASSERT(reg[index].i_len % sizeof(long) == 0);
ASSERT((psint)ptr % sizeof(long) == 0);
start_rec_copy = 0;
/*
* If first write for transaction, insert start record.
* We can't be trying to commit if we are inited. We can't
* have any "partial_copy" if we are inited.
*/
if (ticket->t_flags & XLOG_TIC_INITED) {
logop_head = (xlog_op_header_t *)ptr;
logop_head->oh_tid = ticket->t_tid;
logop_head->oh_clientid = ticket->t_clientid;
logop_head->oh_len = 0;
logop_head->oh_flags = XLOG_START_TRANS;
ticket->t_flags &= ~XLOG_TIC_INITED; /* clear bit */
firstwr++; /* increment log ops below */
start_rec_copy = sizeof(xlog_op_header_t);
xlog_write_adv_cnt(ptr, len, log_offset, start_rec_copy);
}
/* Copy log operation header directly into data section */
logop_head = (xlog_op_header_t *)ptr;
logop_head->oh_tid = ticket->t_tid;
logop_head->oh_clientid = ticket->t_clientid;
/* header copied directly */
xlog_write_adv_cnt(ptr, len, log_offset, sizeof(xlog_op_header_t));
/* commit record? */
logop_head->oh_flags = (commit ? XLOG_COMMIT_TRANS : 0);
/* Partial write last time? => (partial_copy != 0)
* need_copy is the amount we'd like to copy if everything could
* fit in the current bcopy.
*/
need_copy = reg[index].i_len - partial_copy;
copy_off = partial_copy;
if (need_copy <= iclog->ic_size - log_offset) { /*complete write */
logop_head->oh_len = copy_len = need_copy;
if (partial_copy)
logop_head->oh_flags |= XLOG_END_TRANS;
partial_copy = 0;
} else { /* partial write */
copy_len = logop_head->oh_len = iclog->ic_size - log_offset;
partial_copy += copy_len;
logop_head->oh_flags |= XLOG_CONTINUE_TRANS;
len += sizeof(xlog_op_header_t); /* from splitting of region */
}
if (xlog_debug > 1) {
ASSERT(copy_len >= 0);
xlog_verify_dest_ptr(log, ptr);
}
/* copy region */
bcopy(reg[index].i_addr + copy_off, (caddr_t)ptr, copy_len);
xlog_write_adv_cnt(ptr, len, log_offset, copy_len);
/* make copy_len total bytes copied, including headers */
copy_len += start_rec_copy + sizeof(xlog_op_header_t);
xlog_state_finish_copy(log, iclog, firstwr,
(continuedwr ? copy_len : 0));
firstwr = 0;
if (partial_copy) { /* copied partial region */
/* already marked WANT_SYNC */
xlog_state_release_iclog(log, iclog);
break; /* don't increment index */
} else { /* copied entire region */
index++;
partial_copy = 0;
if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
xlog_state_want_sync(log, iclog);
xlog_state_release_iclog(log, iclog);
break;
}
}
}
}
xlog_state_want_sync(log, iclog); /* not needed for kernel XXXmiken */
xlog_state_release_iclog(log, iclog);
} /* xlog_write */
/*****************************************************************************
*
* State Machine functions
*
*****************************************************************************
*/
/* Clean iclogs starting from the head. This ordering must be
* maintained, so an iclog doesn't become ACTIVE beyond one that
* is SYNCING. This is also required to maintain the notion that we use
* a counting semaphore to hold off would be writers to the log when every
* iclog is trying to sync to disk.
*/
void
xlog_state_clean_log(xlog_t *log)
{
xlog_in_core_t *iclog;
iclog = log->l_iclog;
do {
if (iclog->ic_state == XLOG_STATE_DIRTY) {
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_offset = 0;
iclog->ic_callback = 0; /* don't need to free */
iclog->ic_header.h_num_logops = 0;
bzero(iclog->ic_header.h_cycle_data,
sizeof(iclog->ic_header.h_cycle_data));
iclog->ic_header.h_lsn = 0;
vsema(&log->l_flushsema);
} else if (iclog->ic_state == XLOG_STATE_ACTIVE)
/* do nothing */;
else
break; /* stop cleaning */
iclog = iclog->ic_next;
} while (iclog != log->l_iclog);
} /* xlog_state_clean_log */
/*
* Finish transitioning this iclog to the dirty state.
*
* Make sure that we completely execute this routine only when this is
* the last call to the iclog. There is a good chance that iclog flushes,
* when we reach the end of the physical log, get turned into 2 separate
* calls to bwrite. Hence, one iclog flush could generate two calls to this
* routine. By using the reference count bwritecnt, we guarantee that only
* the second completion goes through.
*
* Callbacks could take time, so they are done outside the scope of the
* global state machine log lock. Assume that the calls to cvsema won't
* take a long time. At least we know it won't sleep.
*/
void
xlog_state_done_syncing(xlog_in_core_t *iclog)
{
int spl;
xlog_t *log = iclog->ic_log;
xlog_in_core_t *iclogp;
xfs_log_callback_t *cb, *cb_next;
spl = splockspl(log->l_icloglock, splhi);
ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
ASSERT(iclog->ic_refcnt == 0);
ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
if (--iclog->ic_bwritecnt == 1) {
spunlockspl(log->l_icloglock, spl);
return;
}
iclog->ic_state = XLOG_STATE_CALLBACK;
spunlockspl(log->l_icloglock, spl);
/* perform callbacks XXXmiken */
for (cb = iclog->ic_callback; cb != 0; cb = cb_next) {
cb_next = cb->cb_next;
cb->cb_func(cb->cb_arg);
}
spl = splockspl(log->l_icloglock, splhi);
ASSERT(iclog->ic_state == XLOG_STATE_CALLBACK);
iclog->ic_state = XLOG_STATE_DIRTY;
/* wake up threads waiting in xfs_log_force() */
while (cvsema(&iclog->ic_forcesema));
xlog_state_clean_log(log);
spunlockspl(log->l_icloglock, spl);
} /* xlog_state_done_syncing */
/*
* Update counters atomically now that bcopy is done.
*/
void
xlog_state_finish_copy(xlog_t *log,
xlog_in_core_t *iclog,
int first_write,
int copy_bytes)
{
int spl;
spl = splockspl(log->l_icloglock, splhi);
if (first_write)
iclog->ic_header.h_num_logops++;
iclog->ic_header.h_num_logops++;
iclog->ic_offset += copy_bytes;
spunlockspl(log->l_icloglock, spl);
} /* xlog_state_finish_copy */
/*
* If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
* sleep. The flush semaphore is set to the number of in-core buffers and
* decremented around disk syncing. Therefore, if all buffers are syncing,
* this semaphore will cause new writes to sleep until a sync completes.
* Otherwise, this code just does p() followed by v(). This approximates
* a sleep/wakeup except we can't race.
*
* The in-core logs are used in a circular fashion. They are not used
* out-of-order even when an iclog past the head is free.
*
* return:
* * log_offset where xlog_write() can start writing into the in-core
* log's data space.
* * in-core log pointer to which xlog_write() should write.
* * boolean indicating this is a continued write to an in-core log.
* If this is the last write, then the in-core log's offset field
* needs to be incremented, depending on the amount of data which
* is copied.
*/
int
xlog_state_get_iclog_space(xlog_t *log,
int len,
xlog_in_core_t **iclogp,
int *continued_write)
{
int spl;
int log_offset;
xlog_rec_header_t *head;
xlog_in_core_t *iclog;
restart:
spl = splockspl(log->l_icloglock, splhi);
iclog = log->l_iclog;
if (! (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY) ) {
spunlockspl(log->l_icloglock, spl);
psema(&log->l_flushsema, PINOD);
vsema(&log->l_flushsema);
goto restart;
}
xlog_state_clean_log(log);
head = &iclog->ic_header;
iclog->ic_refcnt++; /* prevents sync */
log_offset = iclog->ic_offset;
/* On the 1st write to an iclog, figure out lsn. This works
* if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
* committing to. If the offset is set, that's how many blocks
* must be written.
*/
if (log_offset == 0) {
head->h_cycle = log->l_curr_cycle;
ASSIGN_LSN(head->h_lsn, log);
ASSERT(log->l_curr_block >= 0);
}
/* If there is enough room to write everything, then do it. Otherwise,
* claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
* bit is on, so this will get flushed out. Don't update ic_offset
* until you know exactly how many bytes get copied. Therefore, wait
* until later to update ic_offset.
*/
if (len <= iclog->ic_size - iclog->ic_offset) {
iclog->ic_offset += len;
*continued_write = 0;
} else {
*continued_write = 1;
if (iclog->ic_state != XLOG_STATE_WANT_SYNC) {
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_offset = log->l_prev_block;
log->l_prev_block = log->l_curr_block;
log->l_prev_cycle = log->l_curr_cycle;
/* roll log?: ic_offset changed later */
log->l_curr_block += BTOBB(iclog->ic_size)+1;
if (log->l_curr_block >= log->l_logBBsize) {
log->l_curr_cycle++;
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
}
log->l_iclog = iclog->ic_next;
psema(&log->l_flushsema, PINOD);
}
/* xlog_write() algorithm assumes that at least 2
* xlog_op_header_t's can fit into remaining data section.
*/
if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)){
iclog->ic_refcnt--;
spunlockspl(log->l_icloglock, spl);
goto restart;
}
}
*iclogp = iclog;
spunlockspl(log->l_icloglock, spl);
return log_offset;
} /* xlog_state_get_iclog_space */
/*
* Atomically get ticket. Usually, don't return until one is available.
*/
xfs_log_ticket_t
xlog_state_get_ticket(xlog_t *log,
int len,
char log_client,
uint flags)
{
int spl;
xfs_log_ticket_t tic;
spl = splockspl(log->l_icloglock, splhi);
/* Eventually force out buffers */
if (log->l_logreserved + len > log->l_logsize) {
if (flags & XFS_LOG_NOSLEEP)
return (xfs_log_ticket_t)-1;
else
xlog_panic("xlog_state_get_ticket: over reserved");
}
log->l_logreserved += len;
tic = xlog_maketicket(log, len, log_client);
spunlockspl(log->l_icloglock, spl);
return tic;
} /* xlog_state_get_ticket */
/*
* If the lsn is not found or the iclog with the lsn is in the callback
* state, we need to call the function directly. This is done outside
* this function's scope. Otherwise, we insert the callback at the front
* of the iclog's callback list.
*/
int
xlog_state_lsn_is_synced(xlog_t *log,
xfs_lsn_t lsn,
xfs_log_callback_t *cb)
{
xlog_in_core_t *iclog;
int spl;
int lsn_is_synced = 1;
spl = splockspl(log->l_icloglock, splhi);
iclog = log->l_iclog;
do {
if (iclog->ic_header.h_lsn != lsn) {
iclog = iclog->ic_next;
continue;
} else {
if ((iclog->ic_state == XLOG_STATE_CALLBACK) ||
(iclog->ic_state == XLOG_STATE_DIRTY)) /*call it*/
break;
/* insert callback into list */
cb->cb_next = iclog->ic_callback;
iclog->ic_callback = cb;
lsn_is_synced = 0;
break;
}
} while (iclog != log->l_iclog);
spunlockspl(log->l_icloglock, spl);
return lsn_is_synced;
} /* xlog_state_lsn_is_synced */
/*
* Atomically put back used ticket.
*/
void
xlog_state_put_ticket(xlog_t *log,
xlog_ticket_t *tic)
{
int spl;
spl = splockspl(log->l_icloglock, splhi);
#ifdef DEBUG
bytes_of_ticket_used = tic->t_orig_reserv - tic->t_curr_reserv;
#endif
log->l_logreserved -= tic->t_orig_reserv;
xlog_putticket(log, tic);
spunlockspl(log->l_icloglock, spl);
} /* xlog_state_reserve_space */
/*
* Flush iclog to disk if this is the last reference to the given iclog and
* the WANT_SYNC bit is set.
*
* When this function is entered, the iclog is not necessarily in the
* WANT_SYNC state. It may be sitting around waiting to get filled.
*
*
*/
void
xlog_state_release_iclog(xlog_t *log,
xlog_in_core_t *iclog)
{
int spl;
int sync = 0; /* do we sync? */
xfs_lsn_t sync_lsn;
int blocks;
spl = splockspl(log->l_icloglock, splhi);
ASSERT(iclog->ic_refcnt > 0);
if (--iclog->ic_refcnt == 0 && iclog->ic_state == XLOG_STATE_WANT_SYNC) {
sync++;
iclog->ic_state = XLOG_STATE_SYNCING;
if ((sync_lsn = xfs_trans_tail_ail(log->l_mp)) == 0)
sync_lsn = iclog->ic_header.h_sync_lsn = log->l_sync_lsn;
else
iclog->ic_header.h_sync_lsn = log->l_sync_lsn = sync_lsn;
/* check if it will fit */
if (xlog_debug > 1) {
if (CYCLE_LSN(sync_lsn) == log->l_prev_cycle) {
blocks =
log->l_logBBsize - (log->l_prev_block -BLOCK_LSN(sync_lsn));
if (blocks < BTOBB(iclog->ic_offset)+1)
xlog_panic("ran out of log space");
} else {
ASSERT(CYCLE_LSN(sync_lsn)+1 == log->l_prev_cycle);
if (BLOCK_LSN(sync_lsn) == log->l_prev_block)
xlog_panic("ran out of log space");
blocks = BLOCK_LSN(sync_lsn) - log->l_prev_block;
if (blocks < BTOBB(iclog->ic_offset) + 1)
xlog_panic("ran out of log space");
}
}
/* cycle incremented when incrementing curr_block */
}
spunlockspl(log->l_icloglock, spl);
if (sync)
xlog_sync(log, iclog, 0);
} /* xlog_state_release_iclog */
/*
* Used by code which implements synchronous log forces.
*
* Find in-core log with lsn.
* If it is in the DIRTY state, just return.
* If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
* state and go to sleep or return.
* If it is in any other state, go to sleep or return.
*/
int
xlog_state_sync(xlog_t *log, xfs_lsn_t lsn, uint flags)
{
xlog_in_core_t *iclog;
int spl;
spl = splockspl(log->l_icloglock, splhi);
iclog = log->l_iclog;
do {
if (iclog->ic_header.h_lsn != lsn) {
iclog = iclog->ic_next;
} else {
if (iclog->ic_state == XLOG_STATE_ACTIVE) {
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_offset = log->l_prev_block;
log->l_prev_block = log->l_curr_block;
log->l_prev_cycle = log->l_curr_cycle;
/* roll log?: ic_offset changed later */
log->l_curr_block += BTOBB(iclog->ic_offset)+1;
if (log->l_curr_block >= log->l_logBBsize) {
log->l_curr_cycle++;
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
}
log->l_iclog = iclog->ic_next;
psema(&log->l_flushsema, PINOD);
} else if (iclog->ic_state == XLOG_STATE_DIRTY) {
spunlockspl(log->l_icloglock, spl);
return 0;
}
if (flags & XFS_LOG_SYNC) /* sleep */
spunlockspl_psema(log->l_icloglock, spl,
&iclog->ic_forcesema, 0);
else /* just return*/
spunlockspl(log->l_icloglock, spl);
return 0;
}
} while (iclog != log->l_iclog);
spunlockspl(log->l_icloglock, spl);
return XFS_ENOTFOUND;
} /* xlog_state_sync */
/*
* Called when we want to mark the current iclog as being ready to sync to
* disk.
*/
void
xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog)
{
int spl;
spl = splockspl(log->l_icloglock, splhi);
if (iclog->ic_state == XLOG_STATE_ACTIVE) {
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_offset = log->l_prev_block;
log->l_prev_block = log->l_curr_block;
log->l_prev_cycle = log->l_curr_cycle;
/* roll log?: ic_offset changed later */
log->l_curr_block += BTOBB(iclog->ic_offset)+1;
if (log->l_curr_block >= log->l_logBBsize){
log->l_curr_cycle++;
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
}
log->l_iclog = log->l_iclog->ic_next;
ASSERT(valusema(&log->l_flushsema) > 0);
psema(&log->l_flushsema, PINOD);
} else if (iclog->ic_state != XLOG_STATE_WANT_SYNC)
xlog_panic("xlog_state_want_sync: bad state");
spunlockspl(log->l_icloglock, spl);
} /* xlog_state_want_sync */
/*****************************************************************************
*
* TICKET functions
*
*****************************************************************************
*/
/*
* Algorithm doesn't take into account page size. ;-(
*/
void
xlog_alloc_tickets(xlog_t *log)
{
caddr_t buf;
xlog_ticket_t *t_list;
uint i = (4096 / sizeof(xlog_ticket_t))-1; /* XXXmiken */
/*
* XXXmiken: may want to account for differing sizes of pointers
* or allocate one page at a time.
*/
buf = (caddr_t) kmem_zalloc(4096, 0);
t_list = log->l_freelist = (xlog_ticket_t *)buf;
for ( ; i > 0; i--) {
t_list->t_next = t_list+1;
t_list = t_list->t_next;
}
t_list->t_next = 0;
log->l_tail = t_list;
} /* xlog_alloc_tickets */
/*
* Put ticket into free list
*/
void xlog_putticket(xlog_t *log,
xlog_ticket_t *ticket)
{
xlog_ticket_t *t_list;
#ifndef DEBUG
/* real code will want to use LIFO for caching */
ticket->t_next = log->l_freelist;
log->l_freelist = ticket;
/* no need to clear fields */
#else
/* When we debug, it is easier if tickets are cycled */
ticket->t_next = 0;
log->l_tail->t_next = ticket;
log->l_tail = ticket;
#endif
} /* xlog_putticket */
/*
* Grab ticket off freelist or allocation some more
*/
xfs_log_ticket_t *
xlog_maketicket(xlog_t *log,
int len,
char log_clientid)
{
xlog_ticket_t *tic;
if (log->l_freelist == NULL) {
xlog_panic("xfs_log_ticket: ran out of tickets"); /* XXXmiken */
/* just call xlog_alloc_tickets */
}
tic = log->l_freelist;
log->l_freelist = tic->t_next;
tic->t_orig_reserv = tic->t_curr_reserv = len;
tic->t_tid = (xlog_tid_t)tic;
tic->t_clientid = log_clientid;
tic->t_flags = XLOG_TIC_INITED;
return (xfs_log_ticket_t)tic;
} /* xlog_maketicket */
/******************************************************************************
*
* Log recover routines
*
******************************************************************************
*/
uint
xlog_recover(struct xfs_mount *mp,
dev_t log_dev,
uint block_offset,
uint num_bblocks)
{
int blkno;
blkno = xlog_find_sync(log_dev, block_offset, num_bblocks);
return 0;
}
/******************************************************************************
*
* Log debug routines
*
******************************************************************************
*/
/*
* Make sure that the destination ptr is within the valid data region of
* one of the iclogs. This uses backup pointers stored in a different
* part of the log in case we trash the log structure.
*/
void
xlog_verify_dest_ptr(xlog_t *log,
psint ptr)
{
int i;
int good_ptr = 0;
for (i=0; i < XLOG_NUM_ICLOGS; i++) {
if (ptr >= (psint)log->l_iclog_bak[i] &&
ptr <= (psint)log->l_iclog_bak[i]+log->l_iclog_size)
good_ptr++;
}
if (! good_ptr)
xlog_panic("xlog_verify_dest_ptr: invalid ptr");
} /* xlog_verify_dest_ptr */
/*
* Perform a number of checks on the iclog before writing to disk.
*
* 1. Make sure the iclogs are still circular
* 2. Make sure we have a good magic number
* 3. Make sure we don't have magic numbers in the data
* 4. Check fields of each log operation header for:
* A. Valid client identifier
* B. tid ptr value falls in valid ptr space (user space code)
* C. Length in log record header is correct according to the
* individual operation headers within record.
* 5. When a bwrite will occur within 5 blocks of the front of the physical
* log, check the preceding blocks of the physical log to make sure all
* the cycle numbers agree with the current cycle number.
*/
void
xlog_verify_iclog(xlog_t *log,
xlog_in_core_t *iclog,
int count)
{
xlog_op_header_t *ophead;
xlog_rec_header_t *rec;
xlog_in_core_t *icptr;
xlog_tid_t tid;
caddr_t ptr;
char clientid;
char buf[XLOG_HEADER_SIZE];
int len;
int fd;
int i;
int op_len;
int cycle_no;
/* check validity of iclog pointers */
icptr = log->l_iclog;
for (i=0; i < XLOG_NUM_ICLOGS; i++) {
if (icptr == 0)
xlog_panic("xlog_verify_iclog: illegal ptr");
icptr = icptr->ic_next;
}
if (icptr != log->l_iclog)
xlog_panic("xlog_verify_iclog: corrupt iclog ring");
/* check log magic numbers */
ptr = (caddr_t) iclog;
if (*(uint *)ptr != XLOG_HEADER_MAGIC_NUM)
xlog_panic("xlog_verify_iclog: illegal magic num");
for (ptr += BBSIZE; ptr < (caddr_t)iclog+count; ptr += BBSIZE) {
if (*(uint *)ptr == XLOG_HEADER_MAGIC_NUM)
xlog_panic("xlog_verify_iclog: unexpected magic num");
}
/* check fields */
len = iclog->ic_header.h_len;
ptr = iclog->ic_data;
ophead = (xlog_op_header_t *)ptr;
for (i=0; i<iclog->ic_header.h_num_logops; i++) {
ophead = (xlog_op_header_t *)ptr;
/* clientid is only 1 byte */
if (((psint)&ophead->oh_clientid & 0x1ff) != 0)
clientid = ophead->oh_clientid;
else
clientid = iclog->ic_header.h_cycle_data[BTOBB(&ophead->oh_clientid - iclog->ic_data)]>>24;
if (clientid != XFS_TRANSACTION)
xlog_panic("xlog_verify_iclog: illegal client");
/* check tids */
if (((psint)&ophead->oh_tid & 0x1ff) != 0)
tid = ophead->oh_tid;
else
tid = (xlog_tid_t)iclog->ic_header.h_cycle_data[BTOBB((psint)&ophead->oh_tid - (psint)iclog->ic_data)];
#ifndef _KERNEL
/* This is a user space check */
if ((psint)tid < 0x10000000 || (psint)tid > 0x20000000)
xlog_panic("xlog_verify_iclog: illegal tid");
#endif
/* check length */
if (((psint)&ophead->oh_len & 0x1ff) != 0)
op_len = ophead->oh_len;
else
op_len = iclog->ic_header.h_cycle_data[BTOBB((psint)&ophead->oh_len - (psint)iclog->ic_data)];
len -= sizeof(xlog_op_header_t) + op_len;
ptr += sizeof(xlog_op_header_t) + op_len;
}
if (len != 0)
xlog_panic("xlog_verify_iclog: illegal iclog");
#ifndef _KERNEL
/* check wrapping log */
if (BLOCK_LSN(iclog->ic_header.h_lsn) < 5) {
cycle_no = CYCLE_LSN(iclog->ic_header.h_lsn);
fd = bmajor(log->l_dev);
if (lseek(fd, 0, SEEK_SET) < 0)
xlog_panic("xlog_verify_iclog: lseek 0 failed");
for (i = 0; i < BLOCK_LSN(iclog->ic_header.h_lsn); i++) {
if (read(fd, buf, XLOG_HEADER_SIZE) == 0)
xlog_panic("xlog_verify_iclog: bad read");
rec = (xlog_rec_header_t *)buf;
if (rec->h_magicno == XLOG_HEADER_MAGIC_NUM &&
CYCLE_LSN(rec->h_lsn) < cycle_no)
xlog_panic("xlog_verify_iclog: bad cycle no");
}
}
#endif
} /* xlog_verify_iclog */
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