File: [Development] / xfs-linux-nodel / xfs_log.c (download)
Revision 1.136.1.3, Sat Dec 14 01:43:57 1996 UTC (20 years, 10 months ago) by rcc
CVS Tags: DELETE-1
Changes since 1.136.1.2: +24 -4
lines
446511 - choke off all disk I/O for read-only mounts of cleanly
unmounted filesystems
|
#ident "$Revision: 1.139 $"
/*
* High level interface routines for log manager
*/
#include <sys/param.h>
#ifdef SIM
#define _KERNEL 1
#endif
#include <sys/sysmacros.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/sysinfo.h>
#include <sys/ksa.h>
#ifdef SIM
#undef _KERNEL
#include <bstring.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#else
#include <sys/systm.h>
#include <sys/conf.h>
#endif
#include <sys/cmn_err.h>
#include <sys/kmem.h>
#include <sys/ktrace.h>
#include <sys/debug.h>
#include <sys/sema.h>
#include <sys/sysmacros.h>
#include <sys/vfs.h>
#include <sys/uuid.h>
#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_ag.h" /* needed by xfs_sb.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_error.h"
#include "xfs_log_priv.h" /* depends on all above */
#include "xfs_buf_item.h"
#include "xfs_alloc_btree.h"
#include "xfs_log_recover.h"
#include "xfs_bit.h"
#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);}
/* Local miscellaneous function prototypes */
STATIC xfs_lsn_t xlog_commit_record(xfs_mount_t *mp, xlog_ticket_t *ticket);
STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp,
dev_t log_dev,
daddr_t blk_offset,
int num_bblks);
STATIC int xlog_space_left(xlog_t *log, int cycle, int bytes);
STATIC void xlog_sync(xlog_t *log, xlog_in_core_t *iclog, uint flags);
STATIC void xlog_unalloc_log(xlog_t *log);
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, uint flags);
/* 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,
xlog_ticket_t *ticket,
int *continued_write);
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 void xlog_state_switch_iclogs(xlog_t *log,
xlog_in_core_t *iclog,
int eventual_size);
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 functions to manipulate grant head */
STATIC void xlog_grant_log_space(xlog_t *log,
xlog_ticket_t *xtic);
STATIC void xlog_grant_push_ail(xfs_mount_t *mp,
int need_bytes);
STATIC void xlog_regrant_reserve_log_space(xlog_t *log,
xlog_ticket_t *ticket);
STATIC void xlog_regrant_write_log_space(xlog_t *log,
xlog_ticket_t *ticket);
STATIC void xlog_ungrant_log_space(xlog_t *log,
xlog_ticket_t *ticket);
/* local ticket functions */
STATIC void xlog_state_ticket_alloc(xlog_t *log);
STATIC xlog_ticket_t *xlog_ticket_get(xlog_t *log,
int unit_bytes,
int count,
char clientid,
uint flags);
STATIC void xlog_ticket_put(xlog_t *log, xlog_ticket_t *ticket);
/* local debug functions */
STATIC void xlog_verify_dest_ptr(xlog_t *log, __psint_t ptr);
#ifdef XFSDEBUG
STATIC void xlog_verify_disk_cycle_no(xlog_t *log, xlog_in_core_t *iclog);
#endif
STATIC void xlog_verify_grant_head(xlog_t *log, int equals);
STATIC void xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
int count, boolean_t syncing);
STATIC void xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog,
xfs_lsn_t tail_lsn);
/*
* 0 => disable log manager
* 1 => enable log manager
* 2 => enable log manager and log debugging
*/
int xlog_debug = 1;
dev_t xlog_devt = 0;
#if defined(XFS_LOG_TRACE)
void
xlog_trace_loggrant(xlog_t *log, xlog_ticket_t *tic, caddr_t string)
{
if (! log->l_grant_trace)
log->l_grant_trace = ktrace_alloc(1024, 0);
ktrace_enter(log->l_grant_trace,
(void *)tic,
(void *)log->l_reserve_headq,
(void *)log->l_write_headq,
(void *)((unsigned long)log->l_grant_reserve_cycle),
(void *)((unsigned long)log->l_grant_reserve_bytes),
(void *)((unsigned long)log->l_grant_write_cycle),
(void *)((unsigned long)log->l_grant_write_bytes),
(void *)((unsigned long)log->l_curr_cycle),
(void *)((unsigned long)log->l_curr_block),
(void *)((unsigned long)CYCLE_LSN(log->l_tail_lsn)),
(void *)((unsigned long)BLOCK_LSN(log->l_tail_lsn)),
(void *)string,
(void *)((unsigned long)13),
(void *)((unsigned long)14),
(void *)((unsigned long)15),
(void *)((unsigned long)16));
}
void
xlog_trace_tic(xlog_t *log, xlog_ticket_t *tic)
{
if (! log->l_trace)
log->l_trace = ktrace_alloc(256, 0);
ktrace_enter(log->l_trace,
(void *)tic,
(void *)((unsigned long)tic->t_curr_res),
(void *)((unsigned long)tic->t_unit_res),
(void *)((unsigned long)tic->t_ocnt),
(void *)((unsigned long)tic->t_cnt),
(void *)((unsigned long)tic->t_flags),
(void *)((unsigned long)7),
(void *)((unsigned long)8),
(void *)((unsigned long)9),
(void *)((unsigned long)10),
(void *)((unsigned long)11),
(void *)((unsigned long)12),
(void *)((unsigned long)13),
(void *)((unsigned long)14),
(void *)((unsigned long)15),
(void *)((unsigned long)16));
}
void
xlog_trace_iclog(xlog_in_core_t *iclog, uint state)
{
pid_t pid;
pid = current_pid();
if (!iclog->ic_trace)
iclog->ic_trace = ktrace_alloc(256, 0);
ktrace_enter(iclog->ic_trace,
(void *)((unsigned long)state),
(void *)((unsigned long)pid),
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0,
(void *)0);
}
#else
#define xlog_trace_loggrant(log,tic,string)
#define xlog_trace_iclog(iclog,state)
#endif /* XFS_LOG_TRACE */
/*
* 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 xtic,
uint flags)
{
xlog_t *log = mp->m_log;
xlog_ticket_t *ticket = (xfs_log_ticket_t) xtic;
xfs_lsn_t lsn = 0;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (! xlog_debug && xlog_devt == log->l_dev)
return 0;
#endif
/* 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);
if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
(flags & XFS_LOG_REL_PERM_RESERV)) {
/* Release ticket if not permanent reservation or a specifc
* request has been made to release a permanent reservation.
*/
xlog_ungrant_log_space(log, ticket);
xlog_state_put_ticket(log, ticket);
} else {
xlog_regrant_reserve_log_space(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 defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (! xlog_debug && xlog_devt == log->l_dev)
return 0;
#endif
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");
return( 0 );
} /* 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;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (! xlog_debug && xlog_devt == log->l_dev)
return;
#endif
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()
{
return( 0 );
}
/*
* 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,
int unit_bytes,
int cnt,
xfs_log_ticket_t *ticket,
char client,
uint flags)
{
xlog_t *log = mp->m_log;
xlog_ticket_t *internal_ticket;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (! xlog_debug && xlog_devt == log->l_dev)
return 0;
#endif
ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
ASSERT((flags & XFS_LOG_NOSLEEP) == 0);
if (*ticket != NULL) {
ASSERT(flags & XFS_LOG_PERM_RESERV);
internal_ticket = (xlog_ticket_t *)*ticket;
xlog_grant_push_ail(mp, internal_ticket->t_unit_res);
xlog_regrant_write_log_space(log, internal_ticket);
} else {
/* may sleep if need to allocate more tickets */
internal_ticket = xlog_ticket_get(log, unit_bytes, cnt,
client, flags);
*ticket = internal_ticket;
xlog_grant_push_ail(mp,
(internal_ticket->t_unit_res *
internal_ticket->t_cnt));
xlog_grant_log_space(log, internal_ticket);
}
return 0;
} /* xfs_log_reserve */
int
xfs_log_stat(caddr_t mnt_pt, int *log_BBstart, int *log_BBsize)
{
xfs_mount_t *xmp;
vnode_t *vp;
int error, start, size;
extern int xfs_fstype;
if (error = lookupname(mnt_pt, UIO_USERSPACE, NO_FOLLOW, NULLVPP, &vp))
return error;
if (vp->v_vfsp->vfs_fstype != xfs_fstype) {
error = XFS_ENOTXFS;
} else {
bhv_desc_t *bdp = bhv_lookup_unlocked(VFS_BHVHEAD(vp->v_vfsp), &xfs_vfsops);
xmp = XFS_BHVTOM(bdp);
start = XFS_FSB_TO_DADDR(xmp, xmp->m_sb.sb_logstart);
size = XFS_FSB_TO_BB(xmp, xmp->m_sb.sb_logblocks);
if ((error = copyout(&start, log_BBstart, sizeof(int))) == 0)
error = copyout(&size, log_BBsize, sizeof(int));
}
VN_RELE(vp);
return error;
} /* xfs_log_stat */
/*
* Mount a log filesystem
*
* mp - ubiquitous xfs mount point structure
* log_dev - device number of on-disk log device
* blk_offset - Start block # where block size is 512 bytes (BBSIZE)
* num_bblocks - Number of BBSIZE blocks in on-disk log
*
* Return error or zero.
*/
int
xfs_log_mount(xfs_mount_t *mp,
dev_t log_dev,
daddr_t blk_offset,
int num_bblks,
int *clean)
{
xlog_t *log;
int error;
cmn_err(CE_NOTE, "!Start mounting filesystem: %s", mp->m_fsname);
log = xlog_alloc_log(mp, log_dev, blk_offset, num_bblks);
if (! xlog_debug) {
cmn_err(CE_NOTE, "log dev: 0x%x", log_dev);
return 0;
}
if ((error = xlog_recover(log, XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY,
clean)) != NULL) {
xlog_unalloc_log(log);
}
/* Normal transactions can now occur */
log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
/* End mounting message in xfs_log_mount_finish */
return error;
} /* xfs_log_mount */
/*
* Finish the recovery of the file system. This is separate from
* the xfs_log_mount() call, because it depends on the code in
* xfs_mountfs() to read in the root and real-time bitmap inodes
* between calling xfs_log_mount() and here.
*
* mp - ubiquitous xfs mount point structure
*/
int
xfs_log_mount_finish(xfs_mount_t *mp)
{
int error;
int clean;
clean = 0;
error = xlog_recover_finish(mp->m_log, &clean);
/*
* if the fs didn't need recovery and is marked read-only,
* keep it clean.
*/
if (clean && (XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY))
mp->m_flags |= XFS_MOUNT_FS_IS_CLEAN;
return error;
}
/*
* Unmount a log filesystem.
*
* Mark the filesystem clean as unmount happens.
*/
int
xfs_log_unmount(xfs_mount_t *mp)
{
xlog_t *log = mp->m_log;
xlog_in_core_t *iclog;
#ifdef DEBUG
xlog_in_core_t *first_iclog;
#endif
xfs_log_iovec_t reg[1];
xfs_log_ticket_t tic = 0;
xfs_lsn_t lsn;
int error;
int spl;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (! xlog_debug && xlog_devt == log->l_dev)
return 0;
#endif
/*
* don't write out unmount record if the fs was clean when
* mounted (no recovery required) and the fs is readonly
*/
if (mp->m_flags & XFS_MOUNT_FS_IS_CLEAN) {
xlog_unalloc_log(log);
return 0;
}
if (xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC))
xlog_panic("xfs_log_unmount: log force failed");
#ifdef DEBUG
first_iclog = iclog = log->l_iclog;
do {
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
ASSERT(iclog->ic_offset == 0);
iclog = iclog->ic_next;
} while (iclog != first_iclog);
#endif
reg[0].i_addr = "Unmount filesystem--";
reg[0].i_len = 20;
if (xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0) == -1)
xlog_panic("xfs_log_unmount: xfs_log_reserve failed");
((xlog_ticket_t *)tic)->t_flags = 0; /* remove inited flag */
error = xlog_write(mp, reg, 1, tic, &lsn, XLOG_UNMOUNT_TRANS);
if (error)
xlog_panic("xfs_log_unmount: unmount record failed");
spl = LOG_LOCK(log);
iclog = log->l_iclog;
iclog->ic_refcnt++;
LOG_UNLOCK(log, spl);
xlog_state_want_sync(log, iclog);
xlog_state_release_iclog(log, iclog);
spl = LOG_LOCK(log);
if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY))
sv_wait(&iclog->ic_forcesema, PMEM, &log->l_icloglock, spl);
else
LOG_UNLOCK(log, spl);
xlog_state_put_ticket(log, tic);
xlog_unalloc_log(log);
return 0;
} /* xfs_log_unmount */
/*
* 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 defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
xlog_t *log = mp->m_log;
if (! xlog_debug && xlog_devt == log->l_dev) {
*start_lsn = 0;
return 0;
}
#endif
return xlog_write(mp, reg, nentries, tic, start_lsn, 0);
} /* xfs_log_write */
void
xfs_log_move_tail(xfs_mount_t *mp,
xfs_lsn_t tail_lsn)
{
xlog_ticket_t *tic;
xlog_t *log = mp->m_log;
int need_bytes, free_bytes, cycle, bytes, spl;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
if (!xlog_debug && xlog_devt == log->l_dev)
return;
#endif
if (tail_lsn == 0) {
/* needed since sync_lsn is 64 bits */
spl = LOG_LOCK(log);
tail_lsn = log->l_last_sync_lsn;
LOG_UNLOCK(log, spl);
}
spl = GRANT_LOCK(log);
/* Also an illegal lsn. 1 implies that we aren't passing in a legal
* tail_lsn.
*/
if (tail_lsn != 1)
log->l_tail_lsn = tail_lsn;
if (tic = log->l_write_headq) {
#ifdef DEBUG
if (log->l_flags & XLOG_ACTIVE_RECOVERY)
panic("Recovery problem");
#endif
cycle = log->l_grant_write_cycle;
bytes = log->l_grant_write_bytes;
free_bytes = xlog_space_left(log, cycle, bytes);
do {
ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
if (free_bytes < tic->t_unit_res)
break;
free_bytes -= tic->t_unit_res;
sv_signal(&tic->t_sema);
tic = tic->t_next;
} while (tic != log->l_write_headq);
}
if (tic = log->l_reserve_headq) {
#ifdef DEBUG
if (log->l_flags & XLOG_ACTIVE_RECOVERY)
panic("Recovery problem");
#endif
cycle = log->l_grant_reserve_cycle;
bytes = log->l_grant_reserve_bytes;
free_bytes = xlog_space_left(log, cycle, bytes);
do {
if (tic->t_flags & XLOG_TIC_PERM_RESERV)
need_bytes = tic->t_unit_res*tic->t_cnt;
else
need_bytes = tic->t_unit_res;
if (free_bytes < need_bytes)
break;
free_bytes -= need_bytes;
sv_signal(&tic->t_sema);
tic = tic->t_next;
} while (tic != log->l_reserve_headq);
}
GRANT_UNLOCK(log, spl);
} /* xfs_log_move_tail */
/******************************************************************************
*
* local routines
*
******************************************************************************
*/
/* xfs_trans_tail_ail returns 0 when there is nothing in the list.
* The log manager must keep track of the last LR which was committed
* to disk. The lsn of this LR will become the new tail_lsn whenever
* xfs_trans_tail_ail returns 0. If we don't do this, we run into
* the situation where stuff could be written into the log but nothing
* was ever in the AIL when asked. Eventually, we panic since the
* tail hits the head.
*
* We may be holding the log iclog lock upon entering this routine.
*/
xfs_lsn_t
xlog_assign_tail_lsn(xfs_mount_t *mp, xlog_in_core_t *iclog)
{
xfs_lsn_t tail_lsn;
int spl;
xlog_t *log = mp->m_log;
tail_lsn = xfs_trans_tail_ail(mp);
spl = GRANT_LOCK(log);
if (tail_lsn != 0)
log->l_tail_lsn = tail_lsn;
else
tail_lsn = log->l_tail_lsn = log->l_last_sync_lsn;
if (iclog)
iclog->ic_header.h_tail_lsn = tail_lsn;
GRANT_UNLOCK(log, spl);
return tail_lsn;
} /* xlog_assign_tail_lsn */
/*
* Return the space in the log between the tail and the head. The head
* is passed in the cycle/bytes formal parms. In the special case where
* the reserve head has wrapped passed the tail, this calculation is no
* longer valid. In this case, just return 0 which means there is no space
* in the log. This works for all places where this function is called
* with the reserve head. Of course, if the write head were to ever
* wrap the tail, we should blow up. Rather than catch this case here,
* we depend on other ASSERTions in other parts of the code. XXXmiken
*
* This code also handles the case where the reservation head is behind
* the tail. The details of this case are described below, but the end
* result is that we return the size of the log as the amount of space left.
*/
int
xlog_space_left(xlog_t *log, int cycle, int bytes)
{
int free_bytes;
int tail_bytes;
int tail_cycle;
tail_bytes = BBTOB(BLOCK_LSN(log->l_tail_lsn));
tail_cycle = CYCLE_LSN(log->l_tail_lsn);
if ((tail_cycle == cycle) && (bytes >= tail_bytes)) {
free_bytes = log->l_logsize - (bytes - tail_bytes);
} else if ((tail_cycle + 1) < cycle) {
return 0;
} else if (tail_cycle < cycle) {
ASSERT(tail_cycle == (cycle - 1));
free_bytes = tail_bytes - bytes;
} else {
/*
* The reservation head is behind the tail.
* This can only happen when the AIL is empty so the tail
* is equal to the head and the l_roundoff value in the
* log structure is taking up the difference between the
* reservation head and the tail. The bytes accounted for
* by the l_roundoff field are temporarily 'lost' to the
* reservation mechanism, but they are cleaned up when the
* log buffers that created them are reused. These lost
* bytes are what allow the reservation head to fall behind
* the tail in the case that the log is 'empty'.
* In this case we just want to return the size of the
* log as the amount of space left.
*/
ASSERT((tail_cycle == (cycle + 1)) ||
((bytes + log->l_roundoff) >= tail_bytes));
free_bytes = log->l_logsize;
}
return free_bytes;
} /* xlog_space_left */
/*
* 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)
{
ASSERT(bp->b_fsprivate2 == (void *)((unsigned long)2));
bp->b_fsprivate2 = (void *)((unsigned long)1);
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 */
/*
* Return size of each in-core log record buffer.
*
* Low memory machines only get 2 16KB buffers. We don't want to waste
* memory here. However, all other machines get at least 2 32KB buffers.
* The number is hard coded because we don't care about the minimum
* memory size, just 32MB systems.
*
* If the filesystem blocksize is too large, we may need to choose a
* larger size since the directory code currently logs entire blocks.
* XXXmiken XXXcurtis
*/
int xlogs = 0;
int xlogsize = 0;
int xloglog = 0;
STATIC void
xlog_get_iclog_buffer_size(xfs_mount_t *mp,
xlog_t *log)
{
int size;
#if defined(SIM) || defined(DEBUG) || defined(XLOG_NOLOG)
/*
* When logbufs == 0, someone has disabled the log from the FSTAB
* file. This is not a documented feature. We need to set xlog_debug
* to zero (this deactivates the log) and set xlog_devt to the
* appropriate dev_t. Only one filesystem may be affected as such
* since this is just a performance hack to test what we might be able
* to get if the log were not present.
*/
if (mp->m_logbufs == 0) {
xlog_debug = 0;
xlog_devt = log->l_dev;
log->l_iclog_bufs = XLOG_NUM_ICLOGS;
} else
#endif
{
/*
* This is the normal path. If m_logbufs == -1, then the
* admin has chosen to use the system defaults for logbuffers.
*/
if (mp->m_logbufs == -1)
log->l_iclog_bufs = XLOG_NUM_ICLOGS;
else
log->l_iclog_bufs = mp->m_logbufs;
/* We are reactivating a filesystem after it was active */
if (log->l_dev == xlog_devt) {
xlog_devt = 1;
xlog_debug = 1;
}
}
/*
* We can't allow 64k log record sizes because there isn't enough
* room in the log record header for all the cycle numbers.
*/
ASSERT(XLOG_MAX_RECORD_BSIZE == 32*1024);
/*
* Buffer size passed in from mount system call.
*/
if (mp->m_logbsize != -1) {
size = log->l_iclog_size = mp->m_logbsize;
log->l_iclog_size_log = 0;
while (size != 1) {
log->l_iclog_size_log++;
size >>= 1;
}
return;
}
/*
* Special case machines that have less than 32MB of memory.
* All machines with more memory use 32KB buffers.
*/
if (physmem <= btoc(32*1024*1024)) {
/* Don't change; min configuration */
log->l_iclog_size = XLOG_RECORD_BSIZE; /* 16k */
log->l_iclog_size_log = XLOG_RECORD_BSHIFT;
} else {
log->l_iclog_size = XLOG_MAX_RECORD_BSIZE; /* 32k */
log->l_iclog_size_log = XLOG_MAX_RECORD_BSHIFT;
}
/*
* For 16KB, we use 3 32KB buffers. For 32KB block sizes, we use
* 4 32KB buffers. For 64KB block sizes, we use 8 32KB buffers.
*/
if (mp->m_sb.sb_blocksize >= 16*1024) {
log->l_iclog_size = XLOG_MAX_RECORD_BSIZE;
log->l_iclog_size_log = XLOG_MAX_RECORD_BSHIFT;
if (mp->m_logbufs == -1) {
switch (mp->m_sb.sb_blocksize) {
case 16*1024: /* 16 KB */
log->l_iclog_bufs = 3;
break;
case 32*1024: /* 32 KB */
log->l_iclog_bufs = 4;
break;
case 64*1024: /* 64 KB */
log->l_iclog_bufs = 8;
break;
default:
xlog_panic("XFS: Illegal blocksize");
break;
}
}
}
/* DEBUG code */
if (xlogs != 0) {
log->l_iclog_bufs = xlogs;
log->l_iclog_size = xlogsize;
log->l_iclog_size_log = xloglog;
}
} /* xlog_get_iclog_buffer_size */
/*
* This routine initializes some of the log structure for a given mount point.
* Its primary purpose is to fill in enough, so recovery can occur. However,
* some other stuff may be filled in too.
*/
STATIC xlog_t *
xlog_alloc_log(xfs_mount_t *mp,
dev_t log_dev,
daddr_t blk_offset,
int num_bblks)
{
xlog_t *log;
xlog_rec_header_t *head;
xlog_in_core_t **iclogp;
xlog_in_core_t *iclog, *prev_iclog;
buf_t *bp;
int i;
int iclogsize;
log = mp->m_log = (void *)kmem_zalloc(sizeof(xlog_t), 0);
log->l_mp = mp;
log->l_dev = log_dev;
log->l_logsize = BBTOB(num_bblks);
log->l_logBBstart = blk_offset;
log->l_logBBsize = num_bblks;
log->l_roundoff = 0;
log->l_flags |= XLOG_ACTIVE_RECOVERY;
log->l_prev_block = -1;
log->l_tail_lsn = 0x100000000LL; /* cycle = 1; current block = 0 */
log->l_last_sync_lsn = log->l_tail_lsn;
log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
log->l_curr_block = 0; /* filled in by xlog_recover */
log->l_grant_reserve_bytes = 0;
log->l_grant_reserve_cycle = 1;
log->l_grant_write_bytes = 0;
log->l_grant_write_cycle = 1;
log->l_quotaoffs_flag = 0; /* XFS_LI_QUOTAOFF logitems */
xlog_get_iclog_buffer_size(mp, log);
bp = log->l_xbuf = getrbuf(0); /* get my locked buffer */
bp->b_edev = log_dev;
bp->b_bufsize = log->l_iclog_size;
bp->b_iodone = xlog_iodone;
bp->b_fsprivate2 = (void *)((unsigned long)1);
ASSERT(log->l_xbuf->b_flags & B_BUSY);
ASSERT(valusema(&log->l_xbuf->b_lock) <= 0);
spinlock_init(&log->l_icloglock, "iclog");
spinlock_init(&log->l_grant_lock, "grhead_iclog");
initnsema(&log->l_flushsema, 0, "ic-flush");
xlog_state_ticket_alloc(log); /* wait until after icloglock inited */
/* log record size must be multiple of BBSIZE; see xlog_rec_header_t */
ASSERT((bp->b_bufsize & BBMASK) == 0);
iclogp = &log->l_iclog;
/*
* The amount of memory to allocate for the iclog structure is
* rather funky due to the way the structure is defined. It is
* done this way so that we can use different sizes for machines
* with different amounts of memory. See the definition of
* xlog_in_core_t in xfs_log_priv.h for details.
*/
iclogsize = sizeof(xlog_in_core_t) - 1 +
log->l_iclog_size - XLOG_HEADER_SIZE;
ASSERT(log->l_iclog_size >= 4096);
for (i=0; i < log->l_iclog_bufs; i++) {
*iclogp = (xlog_in_core_t *)
kmem_zalloc(iclogsize, VM_CACHEALIGN);
iclog = *iclogp;
iclog->ic_prev = prev_iclog;
prev_iclog = iclog;
log->l_iclog_bak[i] = (caddr_t)&(iclog->ic_header);
head = &iclog->ic_header;
head->h_magicno = XLOG_HEADER_MAGIC_NUM;
head->h_version = 1;
head->h_lsn = 0;
head->h_tail_lsn = 0;
bp = iclog->ic_bp = getrbuf(0); /* my locked buffer */
bp->b_edev = log_dev;
bp->b_bufsize = log->l_iclog_size;
bp->b_iodone = xlog_iodone;
bp->b_fsprivate2 = (void *)((unsigned long)1);
iclog->ic_size = bp->b_bufsize - XLOG_HEADER_SIZE;
iclog->ic_state = XLOG_STATE_ACTIVE;
iclog->ic_log = log;
iclog->ic_refcnt = 0;
iclog->ic_roundoff = 0;
iclog->ic_bwritecnt = 0;
iclog->ic_callback = 0;
iclog->ic_callback_tail = &(iclog->ic_callback);
ASSERT(iclog->ic_bp->b_flags & B_BUSY);
ASSERT(valusema(&iclog->ic_bp->b_lock) <= 0);
sv_init(&iclog->ic_forcesema, SV_DEFAULT, "iclog-force");
iclogp = &iclog->ic_next;
}
*iclogp = log->l_iclog; /* complete ring */
log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
return log;
} /* xlog_alloc_log */
/*
* Write out the commit record of a transaction associated with the given
* ticket. Return the lsn of the commit record.
*/
STATIC 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, XLOG_COMMIT_TRANS);
if (error)
xlog_panic("xlog_commit_record: Can't commit transaction");
return commit_lsn;
} /* xlog_commit_record */
/*
* 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_grant_push_ail(xfs_mount_t *mp,
int need_bytes)
{
xlog_t *log = mp->m_log; /* pointer to the log */
xfs_lsn_t tail_lsn; /* lsn of the log tail */
xfs_lsn_t threshold_lsn = 0; /* lsn we'd like to be at */
int free_blocks; /* free blocks left to write to */
int free_bytes; /* free bytes left to write to */
int threshold_block; /* block in lsn we'd like to be at */
int spl;
int free_threshold;
ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
spl = GRANT_LOCK(log);
free_bytes = xlog_space_left(log,
log->l_grant_reserve_cycle,
log->l_grant_reserve_bytes);
tail_lsn = log->l_tail_lsn;
free_blocks = BTOBBT(free_bytes);
/*
* Set the threshold for the minimum number of free blocks in the
* log to the maximum of what the caller needs, one quarter of the
* log, and 256 blocks.
*/
free_threshold = BTOBB(need_bytes);
free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
free_threshold = MAX(free_threshold, 256);
if (free_blocks < free_threshold) {
threshold_block = BLOCK_LSN(tail_lsn) + free_threshold;
if (threshold_block >= log->l_logBBsize) {
threshold_block -= log->l_logBBsize;
((uint *)&threshold_lsn)[0] = CYCLE_LSN(tail_lsn) +1;
} else {
((uint *)&threshold_lsn)[0] = CYCLE_LSN(tail_lsn);
}
((uint *)&threshold_lsn)[1] = threshold_block;
/* Don't pass in an lsn greater than the lsn of the last
* log record known to be on disk.
*/
if (threshold_lsn > log->l_last_sync_lsn)
threshold_lsn = log->l_last_sync_lsn;
}
GRANT_UNLOCK(log, spl);
if (threshold_lsn)
xfs_trans_push_ail(mp, threshold_lsn);
} /* xlog_grant_push_ail */
/*
* 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 */
XFSSTATS.xs_log_writes++;
ASSERT(iclog->ic_refcnt == 0);
if (flags != 0 && (flags & XFS_LOG_SYNC) )
xlog_panic("xlog_sync: illegal flag");
xlog_pack_data(log, iclog); /* put cycle number in every block */
iclog->ic_header.h_len = iclog->ic_offset; /* real byte length */
bp = iclog->ic_bp;
ASSERT(bp->b_fsprivate2 == (void *)((unsigned long)1));
bp->b_fsprivate2 = (void *)((unsigned long)2);
bp->b_blkno = BLOCK_LSN(iclog->ic_header.h_lsn);
/* Round byte count up to a BBSIZE chunk */
count = BBTOB(BTOBB(iclog->ic_offset));
if (iclog->ic_offset != count) {
/* count of 0 is already accounted for up in
* xlog_state_sync_all(). Once in this rountine, operations
* on the iclog are single threaded.
*
* Difference between rounded up size and size
*/
iclog->ic_roundoff = count - iclog->ic_offset;
log->l_roundoff += iclog->ic_roundoff;
}
/* Add for LR header */
count += XLOG_HEADER_SIZE;
XFSSTATS.xs_log_blocks += BTOBB(count);
/* Do we need to split this write into 2 parts? */
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->ic_header);
bp->b_bcount = count;
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);
xlog_verify_iclog(log, iclog, count, B_TRUE);
/* account for log which don't start at block #0 */
bp->b_blkno += log->l_logBBstart;
bwrite(bp);
if (bp->b_flags & B_ERROR)
xlog_panic("xlog_sync: buffer error");
if (split) {
bp = iclog->ic_log->l_xbuf;
ASSERT(bp->b_fsprivate2 == (void *)((unsigned long)1));
bp->b_fsprivate2 = (void *)((unsigned long)2);
bp->b_blkno = 0; /* logical 0 */
bp->b_bcount = split;
bp->b_dmaaddr = (caddr_t)((__psint_t)&(iclog->ic_header)+
(__psint_t)count);
bp->b_fsprivate = iclog;
if (flags & XFS_LOG_SYNC)
bp->b_flags |= (B_BUSY | B_HOLD);
else
bp->b_flags |= (B_BUSY | B_ASYNC);
dptr = bp->b_dmaaddr;
/*
* Bump the cycle numbers at the start of each block
* since this part of the buffer is at the start of
* a new cycle. Watch out for the header magic number
* case, though.
*/
for (i=0; i<split; i += BBSIZE) {
*(uint *)dptr += 1;
if (*(uint *)dptr == XLOG_HEADER_MAGIC_NUM)
*(uint *)dptr += 1;
dptr += BBSIZE;
}
ASSERT(bp->b_blkno <= log->l_logBBsize-1);
ASSERT(bp->b_blkno + BTOBB(count) <= log->l_logBBsize);
/* account for internal log which does't start at block #0 */
bp->b_blkno += log->l_logBBstart;
bwrite(bp);
if (bp->b_flags & B_ERROR)
xlog_panic("xlog_sync: buffer error");
}
} /* xlog_sync */
/*
* Unallocate a log structure
*/
void
xlog_unalloc_log(xlog_t *log)
{
xlog_in_core_t *iclog, *next_iclog;
xlog_ticket_t *tic, *next_tic;
int i;
iclog = log->l_iclog;
for (i=0; i<log->l_iclog_bufs; i++) {
sv_destroy(&iclog->ic_forcesema);
freerbuf(iclog->ic_bp);
#ifdef DEBUG
if (iclog->ic_trace != NULL) {
ktrace_free(iclog->ic_trace);
}
#endif
next_iclog = iclog->ic_next;
kmem_free(iclog,
(sizeof(xlog_in_core_t) - 1 +
log->l_iclog_size - XLOG_HEADER_SIZE));
iclog = next_iclog;
}
freesema(&log->l_flushsema);
spinlock_destroy(&log->l_icloglock);
spinlock_destroy(&log->l_grant_lock);
if (log->l_ticket_cnt != log->l_ticket_tcnt) {
cmn_err(CE_WARN,
"xlog_unalloc_log: (cnt: %d, total: %d)",
log->l_ticket_cnt, log->l_ticket_tcnt);
ASSERT(log->l_ticket_cnt == log->l_ticket_tcnt);
} else {
tic = log->l_unmount_free;
while (tic) {
next_tic = tic->t_next;
kmem_free(tic, NBPP);
tic = next_tic;
}
}
freerbuf(log->l_xbuf);
#ifdef DEBUG
if (log->l_trace != NULL) {
ktrace_free(log->l_trace);
}
if (log->l_grant_trace != NULL) {
ktrace_free(log->l_grant_trace);
}
#endif
log->l_mp->m_log = NULL;
kmem_free(log, sizeof(xlog_t));
} /* xlog_unalloc_log */
/*
* 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,
uint flags)
{
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_t 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; /* did we split a region? */
int partial_copy_len;/* # 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 contwr; /* continued write of in-core log? */
int firstwr = 0; /* first write of transaction */
partial_copy_len = partial_copy = 0;
/* 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;
}
contwr = *start_lsn = 0;
if (ticket->t_curr_res < len)
xlog_panic("xfs_log_write: reservation ran out. Need to up reservation")
else
ticket->t_curr_res -= len;
for (index = 0; index < nentries; ) {
log_offset =
xlog_state_get_iclog_space(log, len, &iclog, ticket, &contwr);
ASSERT(log_offset <= iclog->ic_size - 1);
ptr = (__psint_t) &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(__int32_t) == 0);
ASSERT((__psint_t)ptr % sizeof(__int32_t) == 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;
logop_head->oh_res2 = 0;
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;
logop_head->oh_res2 = 0;
/* header copied directly */
xlog_write_adv_cnt(ptr, len, log_offset, sizeof(xlog_op_header_t));
/* are we copying a commit or unmount record? */
logop_head->oh_flags = flags;
#ifndef NO_XFS_PARANOIA
switch (logop_head->oh_clientid) {
case XFS_TRANSACTION:
case XFS_VOLUME:
case XFS_LOG:
break;
default:
cmn_err(CE_PANIC,
"Bad XFS transaction clientid 0x%x in ticket 0x%x\n",
logop_head->oh_clientid, tic);
}
#endif
/* 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_len;
copy_off = partial_copy_len;
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|XLOG_WAS_CONT_TRANS);
partial_copy_len = partial_copy = 0;
} else { /* partial write */
copy_len = logop_head->oh_len = iclog->ic_size - log_offset;
logop_head->oh_flags |= XLOG_CONTINUE_TRANS;
if (partial_copy)
logop_head->oh_flags |= XLOG_WAS_CONT_TRANS;
partial_copy_len += copy_len;
partial_copy++;
len += sizeof(xlog_op_header_t); /* from splitting of region */
/* account for new log op header */
ticket->t_curr_res -= sizeof(xlog_op_header_t);
}
xlog_verify_dest_ptr(log, ptr);
/* copy region */
ASSERT(copy_len >= 0);
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, (contwr? 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_len = 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);
if (index == nentries)
return 0; /* we are done */
else
break;
}
} /* if (partial_copy) */
} /* while (index < nentries) */
} /* for (index = 0; index < nentries; ) */
ASSERT(len == 0);
#ifndef _KERNEL
xlog_state_want_sync(log, iclog);
#endif
xlog_state_release_iclog(log, iclog);
return 0;
} /* 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.
*
* State Change: DIRTY -> ACTIVE
*/
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;
} 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 */
STATIC void
xlog_state_do_callback(xlog_t *log)
{
xlog_in_core_t *iclog, *first_iclog;
xfs_log_callback_t *cb, *cb_next;
int spl;
int flushcnt = 0;
spl = LOG_LOCK(log);
first_iclog = iclog = log->l_iclog;
do {
/* skip all iclogs in the ACTIVE & DIRTY states */
if (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY) {
iclog = iclog->ic_next;
continue;
}
/* Can only perform callbacks in order. Since
* this iclog is not in the DONE_SYNC state, we skip
* the rest and just try to clean up.
*/
if (iclog->ic_state != XLOG_STATE_DONE_SYNC)
goto clean;
iclog->ic_state = XLOG_STATE_CALLBACK;
LOG_UNLOCK(log, spl);
/* l_last_sync_lsn field protected by GRANT_LOCK.
* Don't worry about iclog's lsn. No one else can
* be here except us.
*/
spl = GRANT_LOCK(log);
log->l_last_sync_lsn = iclog->ic_header.h_lsn;
GRANT_UNLOCK(log, spl);
/*
* Keep processing entries in the callback list
* until we come around and it is empty. We need
* to atomically see that the list is empty and change
* the state to DIRTY so that we don't miss any more
* callbacks being added.
*/
spl = LOG_LOCK(log);
cb = iclog->ic_callback;
while (cb != 0) {
iclog->ic_callback_tail = &(iclog->ic_callback);
iclog->ic_callback = 0;
LOG_UNLOCK(log, spl);
/* perform callbacks in the order given */
for (; cb != 0; cb = cb_next) {
cb_next = cb->cb_next;
cb->cb_func(cb->cb_arg);
}
spl = LOG_LOCK(log);
cb = iclog->ic_callback;
}
ASSERT(iclog->ic_callback == 0);
iclog->ic_state = XLOG_STATE_DIRTY;
/* wake up threads waiting in xfs_log_force() */
sv_broadcast(&iclog->ic_forcesema);
iclog = iclog->ic_next;
} while (first_iclog != iclog);
clean:
xlog_state_clean_log(log);
if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE) {
flushcnt = log->l_flushcnt;
log->l_flushcnt = 0;
}
LOG_UNLOCK(log, spl);
while (flushcnt--)
vsema(&log->l_flushsema);
#if 0
while (cvsema(&log->l_flushsema));
#endif
} /* xlog_state_do_callback */
/*
* 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;
spl = LOG_LOCK(log);
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) {
LOG_UNLOCK(log, spl);
return;
}
iclog->ic_state = XLOG_STATE_DONE_SYNC;
/*
* Someone could be sleeping on the next iclog even though it is
* in the ACTIVE state. We kick off one thread to force the
* iclog buffer out. See xlog_state_sync() for more details.
*/
if (iclog->ic_next->ic_state == XLOG_STATE_ACTIVE)
sv_signal(&iclog->ic_next->ic_forcesema);
LOG_UNLOCK(log, spl);
xlog_state_do_callback(log); /* also cleans log */
} /* 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 = LOG_LOCK(log);
if (first_write)
iclog->ic_header.h_num_logops++;
iclog->ic_header.h_num_logops++;
iclog->ic_offset += copy_bytes;
LOG_UNLOCK(log, 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,
xlog_ticket_t *ticket,
int *continued_write)
{
int spl;
int log_offset;
xlog_rec_header_t *head;
xlog_in_core_t *iclog;
xlog_state_do_callback(log); /* also cleans log */
restart:
spl = LOG_LOCK(log);
iclog = log->l_iclog;
if (! (iclog->ic_state == XLOG_STATE_ACTIVE)) {
log->l_flushcnt++;
LOG_UNLOCK(log, spl);
xlog_trace_iclog(iclog, XLOG_TRACE_SLEEP_FLUSH);
XFSSTATS.xs_log_noiclogs++;
psema(&log->l_flushsema, PINOD);
goto restart;
}
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
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) {
ticket->t_curr_res -= XLOG_HEADER_SIZE;
head->h_cycle = log->l_curr_cycle;
ASSIGN_LSN(head->h_lsn, log);
ASSERT(log->l_curr_block >= 0);
/* round off error from last write with this iclog */
ticket->t_curr_res -= iclog->ic_roundoff;
log->l_roundoff -= iclog->ic_roundoff;
iclog->ic_roundoff = 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.
*
* 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)) {
xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
/* If I'm the only one writing to this iclog, sync it to disk */
if (iclog->ic_refcnt == 1) {
LOG_UNLOCK(log, spl);
xlog_state_release_iclog(log, iclog);
} else {
iclog->ic_refcnt--;
LOG_UNLOCK(log, spl);
}
goto restart;
}
/* Do we have enough room to write the full amount in the remainder
* of this iclog? Or must we continue a write on the next iclog and
* mark this iclog as completely taken? In the case where we switch
* iclogs (to mark it taken), this particular iclog will release/sync
* to disk in xlog_write().
*/
if (len <= iclog->ic_size - iclog->ic_offset) {
*continued_write = 0;
iclog->ic_offset += len;
} else {
*continued_write = 1;
xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
}
*iclogp = iclog;
ASSERT(iclog->ic_offset <= iclog->ic_size);
LOG_UNLOCK(log, spl);
return log_offset;
} /* xlog_state_get_iclog_space */
/*
* Atomically get the log space required for a log ticket.
*
* Once a ticket gets put onto the reserveq, it will only return after
* the needed reservation is satisfied.
*/
STATIC void
xlog_grant_log_space(xlog_t *log,
xlog_ticket_t *tic)
{
int free_bytes;
int need_bytes;
int spl;
#ifdef DEBUG
xfs_lsn_t tail_lsn;
#endif
#ifdef DEBUG
if (log->l_flags & XLOG_ACTIVE_RECOVERY)
panic("grant Recovery problem");
#endif
/* Is there space or do we need to sleep? */
spl = GRANT_LOCK(log);
xlog_trace_loggrant(log, tic, "xlog_grant_log_space: enter");
/* something is already sleeping; insert new transaction at end */
if (log->l_reserve_headq) {
XLOG_INS_TICKETQ(log->l_reserve_headq, tic);
xlog_trace_loggrant(log, tic,
"xlog_grant_log_space: sleep 1");
sv_wait(&tic->t_sema, PINOD, &log->l_grant_lock, spl);
xlog_trace_loggrant(log, tic,
"xlog_grant_log_space: wake 1");
spl = GRANT_LOCK(log);
}
if (tic->t_flags & XFS_LOG_PERM_RESERV)
need_bytes = tic->t_unit_res*tic->t_ocnt;
else
need_bytes = tic->t_unit_res;
redo:
free_bytes = xlog_space_left(log, log->l_grant_reserve_cycle,
log->l_grant_reserve_bytes);
if (free_bytes < need_bytes) {
if ((tic->t_flags & XLOG_TIC_IN_Q) == 0)
XLOG_INS_TICKETQ(log->l_reserve_headq, tic);
xlog_trace_loggrant(log, tic,
"xlog_grant_log_space: sleep 2");
sv_wait(&tic->t_sema, PINOD, &log->l_grant_lock, spl);
xlog_trace_loggrant(log, tic,
"xlog_grant_log_space: wake 2");
xlog_grant_push_ail(log->l_mp, need_bytes);
spl = GRANT_LOCK(log);
goto redo;
} else if (tic->t_flags & XLOG_TIC_IN_Q)
XLOG_DEL_TICKETQ(log->l_reserve_headq, tic);
/* we've got enough space */
XLOG_GRANT_ADD_SPACE(log, need_bytes, 'w');
XLOG_GRANT_ADD_SPACE(log, need_bytes, 'r');
#ifdef DEBUG
tail_lsn = log->l_tail_lsn;
/*
* Check to make sure the grant write head didn't just over lap the
* tail. If the cycles are the same, we can't be overlapping.
* Otherwise, make sure that the cycles differ by exactly one and
* check the byte count.
*/
if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) {
ASSERT(log->l_grant_write_cycle-1 == CYCLE_LSN(tail_lsn));
ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn)));
}
#endif
xlog_trace_loggrant(log, tic, "xlog_grant_log_space: exit");
xlog_verify_grant_head(log, 1);
GRANT_UNLOCK(log, spl);
return;
} /* xlog_grant_log_space */
/*
* Replenish the byte reservation required by moving the grant write head.
*
*
*/
STATIC void
xlog_regrant_write_log_space(xlog_t *log,
xlog_ticket_t *tic)
{
int spl;
int free_bytes, need_bytes;
#ifdef DEBUG
xfs_lsn_t tail_lsn;
#endif
tic->t_curr_res = tic->t_unit_res;
if (tic->t_cnt > 0)
return;
#ifdef DEBUG
if (log->l_flags & XLOG_ACTIVE_RECOVERY)
panic("regrant Recovery problem");
#endif
spl = GRANT_LOCK(log);
xlog_trace_loggrant(log, tic, "xlog_regrant_write_log_space: enter");
need_bytes = tic->t_unit_res;
redo:
free_bytes = xlog_space_left(log, log->l_grant_write_cycle,
log->l_grant_write_bytes);
if (free_bytes < need_bytes) {
if ((tic->t_flags & XLOG_TIC_IN_Q) == 0)
XLOG_INS_TICKETQ(log->l_write_headq, tic);
sv_wait(&tic->t_sema, PINOD, &log->l_grant_lock, spl);
xlog_trace_loggrant(log, tic,
"xlog_regrant_write_log_space: wake 1");
xlog_grant_push_ail(log->l_mp, need_bytes);
spl = GRANT_LOCK(log);
goto redo;
} else if (tic->t_flags & XLOG_TIC_IN_Q)
XLOG_DEL_TICKETQ(log->l_write_headq, tic);
XLOG_GRANT_ADD_SPACE(log, need_bytes, 'w'); /* we've got enough space */
#ifdef DEBUG
tail_lsn = log->l_tail_lsn;
if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) {
ASSERT(log->l_grant_write_cycle-1 == CYCLE_LSN(tail_lsn));
ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn)));
}
#endif
xlog_trace_loggrant(log, tic, "xlog_regrant_write_log_space: exit");
xlog_verify_grant_head(log, 1);
GRANT_UNLOCK(log, spl);
} /* xlog_regrant_write_log_space */
/* The first cnt-1 times through here we don't need to
* move the grant write head because the permanent
* reservation has reserved cnt times the unit amount.
* Release part of current permanent unit reservation and
* reset current reservation to be one units worth. Also
* move grant reservation head forward.
*/
STATIC void
xlog_regrant_reserve_log_space(xlog_t *log,
xlog_ticket_t *ticket)
{
int spl;
xlog_trace_loggrant(log, ticket,
"xlog_regrant_reserve_log_space: enter");
if (ticket->t_cnt > 0)
ticket->t_cnt--;
spl = GRANT_LOCK(log);
XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'w');
XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'r');
ticket->t_curr_res = ticket->t_unit_res;
xlog_trace_loggrant(log, ticket,
"xlog_regrant_reserve_log_space: sub current res");
xlog_verify_grant_head(log, 1);
/* just return if we still have some of the pre-reserved space */
if (ticket->t_cnt > 0) {
GRANT_UNLOCK(log, spl);
return;
}
XLOG_GRANT_ADD_SPACE(log, ticket->t_unit_res, 'r');
xlog_trace_loggrant(log, ticket,
"xlog_regrant_reserve_log_space: exit");
xlog_verify_grant_head(log, 0);
GRANT_UNLOCK(log, spl);
ticket->t_curr_res = ticket->t_unit_res;
} /* xlog_regrant_reserve_log_space */
/*
* Give back the space left from a reservation.
*
* All the information we need to make a correct determination of space left
* is present. For non-permanent reservations, things are quite easy. The
* count should have been decremented to zero. We only need to deal with the
* space remaining in the current reservation part of the ticket. If the
* ticket contains a permanent reservation, there may be left over space which
* needs to be released. A count of N means that N-1 refills of the current
* reservation can be done before we need to ask for more space. The first
* one goes to fill up the first current reservation. Once we run out of
* space, the count will stay at zero and the only space remaining will be
* in the current reservation field.
*/
STATIC void
xlog_ungrant_log_space(xlog_t *log,
xlog_ticket_t *ticket)
{
int spl;
if (ticket->t_cnt > 0)
ticket->t_cnt--;
spl = GRANT_LOCK(log);
xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: enter");
XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'w');
XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'r');
xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: sub current");
/* If this is a permanent reservation ticket, we may be able to free
* up more space based on the remaining count.
*/
if (ticket->t_cnt > 0) {
ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
XLOG_GRANT_SUB_SPACE(log, ticket->t_unit_res*ticket->t_cnt,'w');
XLOG_GRANT_SUB_SPACE(log, ticket->t_unit_res*ticket->t_cnt,'r');
}
xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: exit");
xlog_verify_grant_head(log, 1);
GRANT_UNLOCK(log, spl);
xfs_log_move_tail(log->l_mp, 1);
} /* xlog_ungrant_log_space */
/*
* 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 end
* 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 = LOG_LOCK(log);
iclog = log->l_iclog;
do {
if (iclog->ic_header.h_lsn != lsn) {
iclog = iclog->ic_next;
continue;
} else {
if (iclog->ic_state == XLOG_STATE_DIRTY) /* call it*/
break;
/* insert callback onto end of list */
cb->cb_next = 0;
*(iclog->ic_callback_tail) = cb;
iclog->ic_callback_tail = &(cb->cb_next);
lsn_is_synced = 0;
break;
}
} while (iclog != log->l_iclog);
LOG_UNLOCK(log, 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 = LOG_LOCK(log);
xlog_ticket_put(log, tic);
LOG_UNLOCK(log, spl);
} /* xlog_state_put_ticket */
/*
* 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? */
xlog_assign_tail_lsn(log->l_mp, 0);
spl = LOG_LOCK(log);
ASSERT(iclog->ic_refcnt > 0);
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE || iclog->ic_state == XLOG_STATE_WANT_SYNC);
if (--iclog->ic_refcnt == 0 &&
iclog->ic_state == XLOG_STATE_WANT_SYNC) {
sync++;
iclog->ic_state = XLOG_STATE_SYNCING;
iclog->ic_header.h_tail_lsn = log->l_tail_lsn;
xlog_verify_tail_lsn(log, iclog, log->l_tail_lsn);
/* cycle incremented when incrementing curr_block */
}
LOG_UNLOCK(log, spl);
if (sync)
xlog_sync(log, iclog, 0);
} /* xlog_state_release_iclog */
/*
* This routine will mark the current iclog in the ring as WANT_SYNC
* and move the current iclog pointer to the next iclog in the ring.
* When this routine is called from xlog_state_get_iclog_space(), the
* exact size of the iclog has not yet been determined. All we know is
* that every data block. We have run out of space in this log record.
*/
STATIC void
xlog_state_switch_iclogs(xlog_t *log,
xlog_in_core_t *iclog,
int eventual_size)
{
ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
if (!eventual_size)
eventual_size = iclog->ic_offset;
iclog->ic_state = XLOG_STATE_WANT_SYNC;
iclog->ic_header.h_prev_block = 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(eventual_size)+1;
if (log->l_curr_block >= log->l_logBBsize) {
log->l_curr_cycle++;
if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
log->l_curr_cycle++;
log->l_curr_block -= log->l_logBBsize;
ASSERT(log->l_curr_block >= 0);
}
ASSERT(iclog == log->l_iclog);
log->l_iclog = iclog->ic_next;
} /* xlog_state_switch_iclogs */
/*
* Write out all data in the in-core log as of this exact moment in time.
*
* Data may be written to the in-core log during this call. However,
* we don't guarantee this data will be written out. A change from past
* implementation means this routine will *not* write out zero length LRs.
*
* Basically, we try and perform an intelligent scan of the in-core logs.
* If we determine there is no flushable data, we just return. There is no
* flushable data if:
*
* 1. the current iclog is active and has no data; the previous iclog
* is in the active or dirty state.
* 2. the current iclog is drity, and the previous iclog is in the
* active or dirty state.
*
* We may sleep (call psema) if:
*
* 1. the current iclog is not in the active nor dirty state.
* 2. the current iclog dirty, and the previous iclog is not in the
* active nor dirty state.
* 3. the current iclog is active, and there is another thread writing
* to this particular iclog.
* 4. a) the current iclog is active and has no other writers
* b) when we return from flushing out this iclog, it is still
* not in the active nor dirty state.
*/
STATIC int
xlog_state_sync_all(xlog_t *log, uint flags)
{
xlog_in_core_t *iclog;
xfs_lsn_t lsn;
int spl;
spl = LOG_LOCK(log);
iclog = log->l_iclog;
/* If the head iclog is not active nor dirty, we just attach
* ourselves to the head and go to sleep.
*/
if (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY) {
/*
* If the head is dirty or (active and empty), then
* we need to look at the previous iclog. If the previous
* iclog is active or dirty we are done. There is nothing
* to sync out. Otherwise, we attach ourselves to the
* previous iclog and go to sleep.
*/
if (iclog->ic_state == XLOG_STATE_DIRTY ||
(iclog->ic_refcnt == 0 && iclog->ic_offset == 0)) {
iclog = iclog->ic_prev;
if (iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY)
goto no_sleep;
else
goto maybe_sleep;
} else {
if (iclog->ic_refcnt == 0) {
/* We are the only one with access to this
* iclog. Flush it out now. There should
* be a roundoff of zero to show that someone
* has already taken care of the roundoff from
* the previous sync.
*/
ASSERT(iclog->ic_roundoff == 0);
iclog->ic_refcnt++;
lsn = iclog->ic_header.h_lsn;
xlog_state_switch_iclogs(log, iclog, 0);
LOG_UNLOCK(log, spl);
xlog_state_release_iclog(log, iclog);
spl = LOG_LOCK(log);
if (iclog->ic_header.h_lsn == lsn &&
iclog->ic_state != XLOG_STATE_DIRTY)
goto maybe_sleep;
else
goto no_sleep;
} else {
/* Someone else is writing to this iclog.
* Use its call to flush out the data. However,
* the other thread may not force out this LR,
* so we mark it WANT_SYNC.
*/
xlog_state_switch_iclogs(log, iclog, 0);
goto maybe_sleep;
}
}
}
/* By the time we come around again, the iclog could been filled
* which would give it another lsn. If we have a new lsn, just
* return because the relevant data has been flushed.
*/
maybe_sleep:
if (flags & XFS_LOG_SYNC) {
sv_wait(&iclog->ic_forcesema, PINOD, &log->l_icloglock, spl);
} else {
no_sleep:
LOG_UNLOCK(log, spl);
}
return 0;
} /* xlog_state_sync_all */
/*
* 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.
*
* If filesystem activity goes to zero, the iclog will get flushed only by
* bdflush().
*/
int
xlog_state_sync(xlog_t *log,
xfs_lsn_t lsn,
uint flags)
{
xlog_in_core_t *iclog;
int spl;
int already_slept = 0;
if (lsn == 0)
return xlog_state_sync_all(log, flags);
try_again:
spl = LOG_LOCK(log);
iclog = log->l_iclog;
do {
if (iclog->ic_header.h_lsn != lsn) {
iclog = iclog->ic_next;
} else {
if (iclog->ic_state == XLOG_STATE_ACTIVE) {
/*
* Need a big comment here.
*/
if (!already_slept &&
(iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
sv_wait(&iclog->ic_forcesema, PSWP, &log->l_icloglock, spl);
already_slept = 1;
goto try_again;
} else {
iclog->ic_refcnt++;
xlog_state_switch_iclogs(log, iclog, 0);
LOG_UNLOCK(log, spl);
xlog_state_release_iclog(log, iclog);
spl = LOG_LOCK(log);
}
} else if (iclog->ic_state == XLOG_STATE_DIRTY) {
LOG_UNLOCK(log, spl);
return 0;
}
if ((flags & XFS_LOG_SYNC) && /* sleep */
!(iclog->ic_state == XLOG_STATE_ACTIVE ||
iclog->ic_state == XLOG_STATE_DIRTY)) {
sv_wait(&iclog->ic_forcesema, PSWP, &log->l_icloglock, spl);
} else { /* just return */
LOG_UNLOCK(log, spl);
}
return 0;
}
} while (iclog != log->l_iclog);
LOG_UNLOCK(log, 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 = LOG_LOCK(log);
if (iclog->ic_state == XLOG_STATE_ACTIVE)
xlog_state_switch_iclogs(log, iclog, 0);
else if (iclog->ic_state != XLOG_STATE_WANT_SYNC)
xlog_panic("xlog_state_want_sync: bad state");
LOG_UNLOCK(log, spl);
} /* xlog_state_want_sync */
/*****************************************************************************
*
* TICKET functions
*
*****************************************************************************
*/
/*
* Algorithm doesn't take into account page size. ;-(
*/
STATIC void
xlog_state_ticket_alloc(xlog_t *log)
{
xlog_ticket_t *t_list;
xlog_ticket_t *next;
caddr_t buf;
int spl;
uint i = (NBPP / sizeof(xlog_ticket_t)) - 2;
/*
* The kmem_zalloc may sleep, so we shouldn't be holding the
* global lock. XXXmiken: may want to use zone allocator.
*/
buf = (caddr_t) kmem_zalloc(NBPP, 0);
spl = LOG_LOCK(log);
/* Attach 1st ticket to Q, so we can keep track of allocated memory */
t_list = (xlog_ticket_t *)buf;
t_list->t_next = log->l_unmount_free;
log->l_unmount_free = t_list++;
log->l_ticket_cnt++;
log->l_ticket_tcnt++;
/* Next ticket becomes first ticket attached to ticket free list */
if (log->l_freelist != NULL) {
ASSERT(log->l_tail != NULL);
log->l_tail->t_next = t_list;
} else {
log->l_freelist = t_list;
}
log->l_ticket_cnt++;
log->l_ticket_tcnt++;
/* Cycle through rest of alloc'ed memory, building up free Q */
for ( ; i > 0; i--) {
next = t_list + 1;
t_list->t_next = next;
t_list = next;
log->l_ticket_cnt++;
log->l_ticket_tcnt++;
}
t_list->t_next = 0;
log->l_tail = t_list;
LOG_UNLOCK(log, spl);
} /* xlog_state_ticket_alloc */
/*
* Put ticket into free list
*
* Assumption: log lock is held around this call.
*/
STATIC void
xlog_ticket_put(xlog_t *log,
xlog_ticket_t *ticket)
{
sv_destroy(&ticket->t_sema);
/*
* Don't think caching will make that much difference. It's
* more important to make debug easier.
*/
#if 0
/* 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;
if (log->l_tail != 0) {
log->l_tail->t_next = ticket;
} else {
ASSERT(log->l_freelist == 0);
log->l_freelist = ticket;
}
log->l_tail = ticket;
#endif /* DEBUG */
log->l_ticket_cnt++;
} /* xlog_ticket_put */
/*
* Grab ticket off freelist or allocation some more
*/
xlog_ticket_t *
xlog_ticket_get(xlog_t *log,
int unit_bytes,
int cnt,
char client,
uint xflags)
{
xlog_ticket_t *tic;
int spl;
alloc:
if (log->l_freelist == NULL)
xlog_state_ticket_alloc(log); /* potentially sleep */
spl = LOG_LOCK(log);
if (log->l_freelist == NULL) {
LOG_UNLOCK(log, spl);
goto alloc;
}
tic = log->l_freelist;
log->l_freelist = tic->t_next;
if (log->l_freelist == NULL)
log->l_tail = NULL;
log->l_ticket_cnt--;
LOG_UNLOCK(log, spl);
/*
* Permanent reservations have up to 'cnt'-1 active log operations
* in the log. A unit in this case is the amount of space for one
* of these log operations. Normal reservations have a cnt of 1
* and their unit amount is the total amount of space required.
* The following line of code adds one log record header length
* for each part of an operation which may fall on a different
* log record.
*
* One more XLOG_HEADER_SIZE is added to account for possible
* round off errors when syncing a LR to disk. The bytes are
* subtracted if the thread using this ticket is the first writer
* to a new LR.
*
* We add an extra log header for the possibility that the commit
* record is the first data written to a new log record. In this
* case it is separate from the rest of the transaction data and
* will be charged for the log record header.
*/
unit_bytes += XLOG_HEADER_SIZE * (XLOG_BTOLRBB(unit_bytes) + 2);
tic->t_unit_res = unit_bytes;
tic->t_curr_res = unit_bytes;
tic->t_cnt = cnt;
tic->t_ocnt = cnt;
tic->t_tid = (xlog_tid_t)((__psint_t)tic & 0xffffffff);
tic->t_clientid = client;
tic->t_flags = XLOG_TIC_INITED;
if (xflags & XFS_LOG_PERM_RESERV)
tic->t_flags |= XLOG_TIC_PERM_RESERV;
sv_init(&(tic->t_sema), SV_DEFAULT, "logtick");
return tic;
} /* xlog_ticket_get */
/******************************************************************************
*
* 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.
*/
/* ARGSUSED */
void
xlog_verify_dest_ptr(xlog_t *log,
__psint_t ptr)
{
#ifdef DEBUG
int i;
int good_ptr = 0;
for (i=0; i < log->l_iclog_bufs; i++) {
if (ptr >= (__psint_t)log->l_iclog_bak[i] &&
ptr <= (__psint_t)log->l_iclog_bak[i]+log->l_iclog_size)
good_ptr++;
}
if (! good_ptr)
xlog_panic("xlog_verify_dest_ptr: invalid ptr");
#endif /* DEBUG */
} /* xlog_verify_dest_ptr */
#ifdef XFSDEBUG
/* check split LR write */
STATIC void
xlog_verify_disk_cycle_no(xlog_t *log,
xlog_in_core_t *iclog)
{
buf_t *bp;
uint cycle_no;
daddr_t i;
if (BLOCK_LSN(iclog->ic_header.h_lsn) < 10) {
cycle_no = CYCLE_LSN(iclog->ic_header.h_lsn);
bp = xlog_get_bp(1);
for (i = 0; i < BLOCK_LSN(iclog->ic_header.h_lsn); i++) {
xlog_bread(log, i, 1, bp);
if (GET_CYCLE(bp->b_dmaaddr) != cycle_no)
xlog_warn("XFS: xlog_verify_disk_cycle_no: bad cycle no");
}
xlog_put_bp(bp);
}
} /* xlog_verify_disk_cycle_no */
#endif
/*ARGSUSED*/
STATIC void
xlog_verify_grant_head(xlog_t *log, int equals)
{
if (log->l_grant_reserve_cycle == log->l_grant_write_cycle) {
if (equals)
ASSERT(log->l_grant_reserve_bytes >= log->l_grant_write_bytes);
else
ASSERT(log->l_grant_reserve_bytes > log->l_grant_write_bytes);
} else {
ASSERT(log->l_grant_reserve_cycle-1 == log->l_grant_write_cycle);
ASSERT(log->l_grant_write_bytes >= log->l_grant_reserve_bytes);
}
} /* xlog_verify_grant_head */
/* check if it will fit */
/*ARGSUSED*/
STATIC void
xlog_verify_tail_lsn(xlog_t *log,
xlog_in_core_t *iclog,
xfs_lsn_t tail_lsn)
{
#ifdef DEBUG
int blocks;
if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
blocks =
log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
if (blocks < BTOBB(iclog->ic_offset)+1)
xlog_panic("xlog_verify_tail_lsn: ran out of log space");
} else {
ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
xlog_panic("xlog_verify_tail_lsn: tail wrapped");
blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
if (blocks < BTOBB(iclog->ic_offset) + 1)
xlog_panic("xlog_verify_tail_lsn: ran out of log space");
}
#endif /* DEBUG */
} /* xlog_verify_tail_lsn */
/*
* 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.
*/
/*ARGSUSED*/
STATIC void
xlog_verify_iclog(xlog_t *log,
xlog_in_core_t *iclog,
int count,
boolean_t syncing)
{
#ifdef DEBUG
xlog_op_header_t *ophead;
xlog_in_core_t *icptr;
#ifndef _KERNEL
xlog_tid_t tid;
#endif
caddr_t ptr;
caddr_t base_ptr;
__psint_t field_offset;
char clientid;
int len, i, op_len, spl;
/* check validity of iclog pointers */
spl = LOG_LOCK(log);
icptr = log->l_iclog;
for (i=0; i < log->l_iclog_bufs; 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");
LOG_UNLOCK(log, spl);
/* check log magic numbers */
ptr = (caddr_t) &(iclog->ic_header);
if (*(uint *)ptr != XLOG_HEADER_MAGIC_NUM)
xlog_panic("xlog_verify_iclog: illegal magic num");
for (ptr += BBSIZE; ptr < ((caddr_t)&(iclog->ic_header))+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;
base_ptr = ptr;
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 */
field_offset = (__psint_t)
((caddr_t)&(ophead->oh_clientid) - base_ptr);
if (syncing == B_FALSE || (field_offset & 0x1ff))
clientid = ophead->oh_clientid;
else
clientid = iclog->ic_header.h_cycle_data[BTOBB(&ophead->oh_clientid - iclog->ic_data)]>>24;
if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
xlog_panic("xlog_verify_iclog: illegal client");
#ifndef _KERNEL
/* check tids */
field_offset = (__psint_t)
((caddr_t)&(ophead->oh_tid) - base_ptr);
if (syncing == B_FALSE || (field_offset & 0x1ff))
tid = ophead->oh_tid;
else
tid = (xlog_tid_t)(iclog->ic_header.h_cycle_data[BTOBB((__psint_t)&ophead->oh_tid - (__psint_t)iclog->ic_data)]);
/* This is a user space check */
if ((__psint_t)tid < 0x10000000 || (__psint_t)tid > 0x20000000)
xlog_panic("xlog_verify_iclog: illegal tid");
#endif
/* check length */
field_offset = (__psint_t)
((caddr_t)&(ophead->oh_len) - base_ptr);
if (syncing == B_FALSE || (field_offset & 0x1ff))
op_len = ophead->oh_len;
else
op_len = iclog->ic_header.h_cycle_data[BTOBB((__psint_t)&ophead->oh_len - (__psint_t)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");
#endif /* DEBUG */
} /* xlog_verify_iclog */
![[BACK]](/icons/back.gif){kind=icon}
Return to xfs_log.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [Development] / xfs-linux-nodel