582 lines
14 KiB
C
582 lines
14 KiB
C
/*
|
|
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
|
|
* All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include "xfs.h"
|
|
#include "xfs_fs.h"
|
|
#include "xfs_types.h"
|
|
#include "xfs_log.h"
|
|
#include "xfs_inum.h"
|
|
#include "xfs_trans.h"
|
|
#include "xfs_sb.h"
|
|
#include "xfs_dmapi.h"
|
|
#include "xfs_mount.h"
|
|
#include "xfs_trans_priv.h"
|
|
#include "xfs_error.h"
|
|
|
|
STATIC void xfs_ail_insert(xfs_ail_entry_t *, xfs_log_item_t *);
|
|
STATIC xfs_log_item_t * xfs_ail_delete(xfs_ail_entry_t *, xfs_log_item_t *);
|
|
STATIC xfs_log_item_t * xfs_ail_min(xfs_ail_entry_t *);
|
|
STATIC xfs_log_item_t * xfs_ail_next(xfs_ail_entry_t *, xfs_log_item_t *);
|
|
|
|
#ifdef DEBUG
|
|
STATIC void xfs_ail_check(xfs_ail_entry_t *);
|
|
#else
|
|
#define xfs_ail_check(a)
|
|
#endif /* DEBUG */
|
|
|
|
|
|
/*
|
|
* This is called by the log manager code to determine the LSN
|
|
* of the tail of the log. This is exactly the LSN of the first
|
|
* item in the AIL. If the AIL is empty, then this function
|
|
* returns 0.
|
|
*
|
|
* We need the AIL lock in order to get a coherent read of the
|
|
* lsn of the last item in the AIL.
|
|
*/
|
|
xfs_lsn_t
|
|
xfs_trans_tail_ail(
|
|
xfs_mount_t *mp)
|
|
{
|
|
xfs_lsn_t lsn;
|
|
xfs_log_item_t *lip;
|
|
SPLDECL(s);
|
|
|
|
AIL_LOCK(mp,s);
|
|
lip = xfs_ail_min(&(mp->m_ail));
|
|
if (lip == NULL) {
|
|
lsn = (xfs_lsn_t)0;
|
|
} else {
|
|
lsn = lip->li_lsn;
|
|
}
|
|
AIL_UNLOCK(mp, s);
|
|
|
|
return lsn;
|
|
}
|
|
|
|
/*
|
|
* xfs_trans_push_ail
|
|
*
|
|
* This routine is called to move the tail of the AIL
|
|
* forward. It does this by trying to flush items in the AIL
|
|
* whose lsns are below the given threshold_lsn.
|
|
*
|
|
* The routine returns the lsn of the tail of the log.
|
|
*/
|
|
xfs_lsn_t
|
|
xfs_trans_push_ail(
|
|
xfs_mount_t *mp,
|
|
xfs_lsn_t threshold_lsn)
|
|
{
|
|
xfs_lsn_t lsn;
|
|
xfs_log_item_t *lip;
|
|
int gen;
|
|
int restarts;
|
|
int lock_result;
|
|
int flush_log;
|
|
SPLDECL(s);
|
|
|
|
#define XFS_TRANS_PUSH_AIL_RESTARTS 10
|
|
|
|
AIL_LOCK(mp,s);
|
|
lip = xfs_trans_first_ail(mp, &gen);
|
|
if (lip == NULL || XFS_FORCED_SHUTDOWN(mp)) {
|
|
/*
|
|
* Just return if the AIL is empty.
|
|
*/
|
|
AIL_UNLOCK(mp, s);
|
|
return (xfs_lsn_t)0;
|
|
}
|
|
|
|
XFS_STATS_INC(xs_push_ail);
|
|
|
|
/*
|
|
* While the item we are looking at is below the given threshold
|
|
* try to flush it out. Make sure to limit the number of times
|
|
* we allow xfs_trans_next_ail() to restart scanning from the
|
|
* beginning of the list. We'd like not to stop until we've at least
|
|
* tried to push on everything in the AIL with an LSN less than
|
|
* the given threshold. However, we may give up before that if
|
|
* we realize that we've been holding the AIL_LOCK for 'too long',
|
|
* blocking interrupts. Currently, too long is < 500us roughly.
|
|
*/
|
|
flush_log = 0;
|
|
restarts = 0;
|
|
while (((restarts < XFS_TRANS_PUSH_AIL_RESTARTS) &&
|
|
(XFS_LSN_CMP(lip->li_lsn, threshold_lsn) < 0))) {
|
|
/*
|
|
* If we can lock the item without sleeping, unlock
|
|
* the AIL lock and flush the item. Then re-grab the
|
|
* AIL lock so we can look for the next item on the
|
|
* AIL. Since we unlock the AIL while we flush the
|
|
* item, the next routine may start over again at the
|
|
* the beginning of the list if anything has changed.
|
|
* That is what the generation count is for.
|
|
*
|
|
* If we can't lock the item, either its holder will flush
|
|
* it or it is already being flushed or it is being relogged.
|
|
* In any of these case it is being taken care of and we
|
|
* can just skip to the next item in the list.
|
|
*/
|
|
lock_result = IOP_TRYLOCK(lip);
|
|
switch (lock_result) {
|
|
case XFS_ITEM_SUCCESS:
|
|
AIL_UNLOCK(mp, s);
|
|
XFS_STATS_INC(xs_push_ail_success);
|
|
IOP_PUSH(lip);
|
|
AIL_LOCK(mp,s);
|
|
break;
|
|
|
|
case XFS_ITEM_PUSHBUF:
|
|
AIL_UNLOCK(mp, s);
|
|
XFS_STATS_INC(xs_push_ail_pushbuf);
|
|
#ifdef XFSRACEDEBUG
|
|
delay_for_intr();
|
|
delay(300);
|
|
#endif
|
|
ASSERT(lip->li_ops->iop_pushbuf);
|
|
ASSERT(lip);
|
|
IOP_PUSHBUF(lip);
|
|
AIL_LOCK(mp,s);
|
|
break;
|
|
|
|
case XFS_ITEM_PINNED:
|
|
XFS_STATS_INC(xs_push_ail_pinned);
|
|
flush_log = 1;
|
|
break;
|
|
|
|
case XFS_ITEM_LOCKED:
|
|
XFS_STATS_INC(xs_push_ail_locked);
|
|
break;
|
|
|
|
case XFS_ITEM_FLUSHING:
|
|
XFS_STATS_INC(xs_push_ail_flushing);
|
|
break;
|
|
|
|
default:
|
|
ASSERT(0);
|
|
break;
|
|
}
|
|
|
|
lip = xfs_trans_next_ail(mp, lip, &gen, &restarts);
|
|
if (lip == NULL) {
|
|
break;
|
|
}
|
|
if (XFS_FORCED_SHUTDOWN(mp)) {
|
|
/*
|
|
* Just return if we shut down during the last try.
|
|
*/
|
|
AIL_UNLOCK(mp, s);
|
|
return (xfs_lsn_t)0;
|
|
}
|
|
|
|
}
|
|
|
|
if (flush_log) {
|
|
/*
|
|
* If something we need to push out was pinned, then
|
|
* push out the log so it will become unpinned and
|
|
* move forward in the AIL.
|
|
*/
|
|
AIL_UNLOCK(mp, s);
|
|
XFS_STATS_INC(xs_push_ail_flush);
|
|
xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
|
|
AIL_LOCK(mp, s);
|
|
}
|
|
|
|
lip = xfs_ail_min(&(mp->m_ail));
|
|
if (lip == NULL) {
|
|
lsn = (xfs_lsn_t)0;
|
|
} else {
|
|
lsn = lip->li_lsn;
|
|
}
|
|
|
|
AIL_UNLOCK(mp, s);
|
|
return lsn;
|
|
} /* xfs_trans_push_ail */
|
|
|
|
|
|
/*
|
|
* This is to be called when an item is unlocked that may have
|
|
* been in the AIL. It will wake up the first member of the AIL
|
|
* wait list if this item's unlocking might allow it to progress.
|
|
* If the item is in the AIL, then we need to get the AIL lock
|
|
* while doing our checking so we don't race with someone going
|
|
* to sleep waiting for this event in xfs_trans_push_ail().
|
|
*/
|
|
void
|
|
xfs_trans_unlocked_item(
|
|
xfs_mount_t *mp,
|
|
xfs_log_item_t *lip)
|
|
{
|
|
xfs_log_item_t *min_lip;
|
|
|
|
/*
|
|
* If we're forcibly shutting down, we may have
|
|
* unlocked log items arbitrarily. The last thing
|
|
* we want to do is to move the tail of the log
|
|
* over some potentially valid data.
|
|
*/
|
|
if (!(lip->li_flags & XFS_LI_IN_AIL) ||
|
|
XFS_FORCED_SHUTDOWN(mp)) {
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* This is the one case where we can call into xfs_ail_min()
|
|
* without holding the AIL lock because we only care about the
|
|
* case where we are at the tail of the AIL. If the object isn't
|
|
* at the tail, it doesn't matter what result we get back. This
|
|
* is slightly racy because since we were just unlocked, we could
|
|
* go to sleep between the call to xfs_ail_min and the call to
|
|
* xfs_log_move_tail, have someone else lock us, commit to us disk,
|
|
* move us out of the tail of the AIL, and then we wake up. However,
|
|
* the call to xfs_log_move_tail() doesn't do anything if there's
|
|
* not enough free space to wake people up so we're safe calling it.
|
|
*/
|
|
min_lip = xfs_ail_min(&mp->m_ail);
|
|
|
|
if (min_lip == lip)
|
|
xfs_log_move_tail(mp, 1);
|
|
} /* xfs_trans_unlocked_item */
|
|
|
|
|
|
/*
|
|
* Update the position of the item in the AIL with the new
|
|
* lsn. If it is not yet in the AIL, add it. Otherwise, move
|
|
* it to its new position by removing it and re-adding it.
|
|
*
|
|
* Wakeup anyone with an lsn less than the item's lsn. If the item
|
|
* we move in the AIL is the minimum one, update the tail lsn in the
|
|
* log manager.
|
|
*
|
|
* Increment the AIL's generation count to indicate that the tree
|
|
* has changed.
|
|
*
|
|
* This function must be called with the AIL lock held. The lock
|
|
* is dropped before returning, so the caller must pass in the
|
|
* cookie returned by AIL_LOCK.
|
|
*/
|
|
void
|
|
xfs_trans_update_ail(
|
|
xfs_mount_t *mp,
|
|
xfs_log_item_t *lip,
|
|
xfs_lsn_t lsn,
|
|
unsigned long s)
|
|
{
|
|
xfs_ail_entry_t *ailp;
|
|
xfs_log_item_t *dlip=NULL;
|
|
xfs_log_item_t *mlip; /* ptr to minimum lip */
|
|
|
|
ailp = &(mp->m_ail);
|
|
mlip = xfs_ail_min(ailp);
|
|
|
|
if (lip->li_flags & XFS_LI_IN_AIL) {
|
|
dlip = xfs_ail_delete(ailp, lip);
|
|
ASSERT(dlip == lip);
|
|
} else {
|
|
lip->li_flags |= XFS_LI_IN_AIL;
|
|
}
|
|
|
|
lip->li_lsn = lsn;
|
|
|
|
xfs_ail_insert(ailp, lip);
|
|
mp->m_ail_gen++;
|
|
|
|
if (mlip == dlip) {
|
|
mlip = xfs_ail_min(&(mp->m_ail));
|
|
AIL_UNLOCK(mp, s);
|
|
xfs_log_move_tail(mp, mlip->li_lsn);
|
|
} else {
|
|
AIL_UNLOCK(mp, s);
|
|
}
|
|
|
|
|
|
} /* xfs_trans_update_ail */
|
|
|
|
/*
|
|
* Delete the given item from the AIL. It must already be in
|
|
* the AIL.
|
|
*
|
|
* Wakeup anyone with an lsn less than item's lsn. If the item
|
|
* we delete in the AIL is the minimum one, update the tail lsn in the
|
|
* log manager.
|
|
*
|
|
* Clear the IN_AIL flag from the item, reset its lsn to 0, and
|
|
* bump the AIL's generation count to indicate that the tree
|
|
* has changed.
|
|
*
|
|
* This function must be called with the AIL lock held. The lock
|
|
* is dropped before returning, so the caller must pass in the
|
|
* cookie returned by AIL_LOCK.
|
|
*/
|
|
void
|
|
xfs_trans_delete_ail(
|
|
xfs_mount_t *mp,
|
|
xfs_log_item_t *lip,
|
|
unsigned long s)
|
|
{
|
|
xfs_ail_entry_t *ailp;
|
|
xfs_log_item_t *dlip;
|
|
xfs_log_item_t *mlip;
|
|
|
|
if (lip->li_flags & XFS_LI_IN_AIL) {
|
|
ailp = &(mp->m_ail);
|
|
mlip = xfs_ail_min(ailp);
|
|
dlip = xfs_ail_delete(ailp, lip);
|
|
ASSERT(dlip == lip);
|
|
|
|
|
|
lip->li_flags &= ~XFS_LI_IN_AIL;
|
|
lip->li_lsn = 0;
|
|
mp->m_ail_gen++;
|
|
|
|
if (mlip == dlip) {
|
|
mlip = xfs_ail_min(&(mp->m_ail));
|
|
AIL_UNLOCK(mp, s);
|
|
xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0));
|
|
} else {
|
|
AIL_UNLOCK(mp, s);
|
|
}
|
|
}
|
|
else {
|
|
/*
|
|
* If the file system is not being shutdown, we are in
|
|
* serious trouble if we get to this stage.
|
|
*/
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
AIL_UNLOCK(mp, s);
|
|
else {
|
|
xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp,
|
|
"%s: attempting to delete a log item that is not in the AIL",
|
|
__FUNCTION__);
|
|
AIL_UNLOCK(mp, s);
|
|
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Return the item in the AIL with the smallest lsn.
|
|
* Return the current tree generation number for use
|
|
* in calls to xfs_trans_next_ail().
|
|
*/
|
|
xfs_log_item_t *
|
|
xfs_trans_first_ail(
|
|
xfs_mount_t *mp,
|
|
int *gen)
|
|
{
|
|
xfs_log_item_t *lip;
|
|
|
|
lip = xfs_ail_min(&(mp->m_ail));
|
|
*gen = (int)mp->m_ail_gen;
|
|
|
|
return (lip);
|
|
}
|
|
|
|
/*
|
|
* If the generation count of the tree has not changed since the
|
|
* caller last took something from the AIL, then return the elmt
|
|
* in the tree which follows the one given. If the count has changed,
|
|
* then return the minimum elmt of the AIL and bump the restarts counter
|
|
* if one is given.
|
|
*/
|
|
xfs_log_item_t *
|
|
xfs_trans_next_ail(
|
|
xfs_mount_t *mp,
|
|
xfs_log_item_t *lip,
|
|
int *gen,
|
|
int *restarts)
|
|
{
|
|
xfs_log_item_t *nlip;
|
|
|
|
ASSERT(mp && lip && gen);
|
|
if (mp->m_ail_gen == *gen) {
|
|
nlip = xfs_ail_next(&(mp->m_ail), lip);
|
|
} else {
|
|
nlip = xfs_ail_min(&(mp->m_ail));
|
|
*gen = (int)mp->m_ail_gen;
|
|
if (restarts != NULL) {
|
|
XFS_STATS_INC(xs_push_ail_restarts);
|
|
(*restarts)++;
|
|
}
|
|
}
|
|
|
|
return (nlip);
|
|
}
|
|
|
|
|
|
/*
|
|
* The active item list (AIL) is a doubly linked list of log
|
|
* items sorted by ascending lsn. The base of the list is
|
|
* a forw/back pointer pair embedded in the xfs mount structure.
|
|
* The base is initialized with both pointers pointing to the
|
|
* base. This case always needs to be distinguished, because
|
|
* the base has no lsn to look at. We almost always insert
|
|
* at the end of the list, so on inserts we search from the
|
|
* end of the list to find where the new item belongs.
|
|
*/
|
|
|
|
/*
|
|
* Initialize the doubly linked list to point only to itself.
|
|
*/
|
|
void
|
|
xfs_trans_ail_init(
|
|
xfs_mount_t *mp)
|
|
{
|
|
mp->m_ail.ail_forw = (xfs_log_item_t*)&(mp->m_ail);
|
|
mp->m_ail.ail_back = (xfs_log_item_t*)&(mp->m_ail);
|
|
}
|
|
|
|
/*
|
|
* Insert the given log item into the AIL.
|
|
* We almost always insert at the end of the list, so on inserts
|
|
* we search from the end of the list to find where the
|
|
* new item belongs.
|
|
*/
|
|
STATIC void
|
|
xfs_ail_insert(
|
|
xfs_ail_entry_t *base,
|
|
xfs_log_item_t *lip)
|
|
/* ARGSUSED */
|
|
{
|
|
xfs_log_item_t *next_lip;
|
|
|
|
/*
|
|
* If the list is empty, just insert the item.
|
|
*/
|
|
if (base->ail_back == (xfs_log_item_t*)base) {
|
|
base->ail_forw = lip;
|
|
base->ail_back = lip;
|
|
lip->li_ail.ail_forw = (xfs_log_item_t*)base;
|
|
lip->li_ail.ail_back = (xfs_log_item_t*)base;
|
|
return;
|
|
}
|
|
|
|
next_lip = base->ail_back;
|
|
while ((next_lip != (xfs_log_item_t*)base) &&
|
|
(XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) > 0)) {
|
|
next_lip = next_lip->li_ail.ail_back;
|
|
}
|
|
ASSERT((next_lip == (xfs_log_item_t*)base) ||
|
|
(XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0));
|
|
lip->li_ail.ail_forw = next_lip->li_ail.ail_forw;
|
|
lip->li_ail.ail_back = next_lip;
|
|
next_lip->li_ail.ail_forw = lip;
|
|
lip->li_ail.ail_forw->li_ail.ail_back = lip;
|
|
|
|
xfs_ail_check(base);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Delete the given item from the AIL. Return a pointer to the item.
|
|
*/
|
|
/*ARGSUSED*/
|
|
STATIC xfs_log_item_t *
|
|
xfs_ail_delete(
|
|
xfs_ail_entry_t *base,
|
|
xfs_log_item_t *lip)
|
|
/* ARGSUSED */
|
|
{
|
|
lip->li_ail.ail_forw->li_ail.ail_back = lip->li_ail.ail_back;
|
|
lip->li_ail.ail_back->li_ail.ail_forw = lip->li_ail.ail_forw;
|
|
lip->li_ail.ail_forw = NULL;
|
|
lip->li_ail.ail_back = NULL;
|
|
|
|
xfs_ail_check(base);
|
|
return lip;
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to the first item in the AIL.
|
|
* If the AIL is empty, then return NULL.
|
|
*/
|
|
STATIC xfs_log_item_t *
|
|
xfs_ail_min(
|
|
xfs_ail_entry_t *base)
|
|
/* ARGSUSED */
|
|
{
|
|
register xfs_log_item_t *forw = base->ail_forw;
|
|
if (forw == (xfs_log_item_t*)base) {
|
|
return NULL;
|
|
}
|
|
return forw;
|
|
}
|
|
|
|
/*
|
|
* Return a pointer to the item which follows
|
|
* the given item in the AIL. If the given item
|
|
* is the last item in the list, then return NULL.
|
|
*/
|
|
STATIC xfs_log_item_t *
|
|
xfs_ail_next(
|
|
xfs_ail_entry_t *base,
|
|
xfs_log_item_t *lip)
|
|
/* ARGSUSED */
|
|
{
|
|
if (lip->li_ail.ail_forw == (xfs_log_item_t*)base) {
|
|
return NULL;
|
|
}
|
|
return lip->li_ail.ail_forw;
|
|
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
/*
|
|
* Check that the list is sorted as it should be.
|
|
*/
|
|
STATIC void
|
|
xfs_ail_check(
|
|
xfs_ail_entry_t *base)
|
|
{
|
|
xfs_log_item_t *lip;
|
|
xfs_log_item_t *prev_lip;
|
|
|
|
lip = base->ail_forw;
|
|
if (lip == (xfs_log_item_t*)base) {
|
|
/*
|
|
* Make sure the pointers are correct when the list
|
|
* is empty.
|
|
*/
|
|
ASSERT(base->ail_back == (xfs_log_item_t*)base);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Walk the list checking forward and backward pointers,
|
|
* lsn ordering, and that every entry has the XFS_LI_IN_AIL
|
|
* flag set.
|
|
*/
|
|
prev_lip = (xfs_log_item_t*)base;
|
|
while (lip != (xfs_log_item_t*)base) {
|
|
if (prev_lip != (xfs_log_item_t*)base) {
|
|
ASSERT(prev_lip->li_ail.ail_forw == lip);
|
|
ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
|
|
}
|
|
ASSERT(lip->li_ail.ail_back == prev_lip);
|
|
ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
|
|
prev_lip = lip;
|
|
lip = lip->li_ail.ail_forw;
|
|
}
|
|
ASSERT(lip == (xfs_log_item_t*)base);
|
|
ASSERT(base->ail_back == prev_lip);
|
|
}
|
|
#endif /* DEBUG */
|