X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_trans_ail.c;h=2ffc570679bef017199f59fafa64b9e9c9433797;hb=fd45e4784164d1017521086524e3442318c67370;hp=7bc5eab4c2c19cb703cb09539fe627a55383f6dd;hpb=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 7bc5eab..2ffc570 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -1,57 +1,43 @@ /* - * Copyright (c) 2000-2002 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. + * Copyright (c) 2008 Dave Chinner + * All Rights Reserved. * - * This program is free software; you can redistribute it and/or modify it - * under the terms of version 2 of the GNU General Public License as + * 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. + * 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. * - * Further, this software is distributed without any warranty that it is - * free of the rightful claim of any third person regarding infringement - * or the like. Any license provided herein, whether implied or - * otherwise, applies only to this software file. Patent licenses, if - * any, provided herein do not apply to combinations of this program with - * other software, or any other product whatsoever. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write the Free Software Foundation, Inc., 59 - * Temple Place - Suite 330, Boston MA 02111-1307, USA. - * - * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, - * Mountain View, CA 94043, or: - * - * http://www.sgi.com - * - * For further information regarding this notice, see: - * - * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + * 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_macros.h" +#include "xfs_fs.h" #include "xfs_types.h" -#include "xfs_inum.h" #include "xfs_log.h" +#include "xfs_inum.h" #include "xfs_trans.h" #include "xfs_sb.h" -#include "xfs_dir.h" +#include "xfs_ag.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 *); +STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *); +STATIC xfs_log_item_t * xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *); +STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *); +STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *); #ifdef DEBUG -STATIC void xfs_ail_check(xfs_ail_entry_t *); +STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *); #else -#define xfs_ail_check(a) +#define xfs_ail_check(a,l) #endif /* DEBUG */ @@ -65,21 +51,20 @@ STATIC void xfs_ail_check(xfs_ail_entry_t *); * lsn of the last item in the AIL. */ xfs_lsn_t -xfs_trans_tail_ail( - xfs_mount_t *mp) +xfs_trans_ail_tail( + struct xfs_ail *ailp) { xfs_lsn_t lsn; xfs_log_item_t *lip; - SPLDECL(s); - AIL_LOCK(mp,s); - lip = xfs_ail_min(&(mp->m_ail)); + spin_lock(&ailp->xa_lock); + lip = xfs_ail_min(ailp); if (lip == NULL) { lsn = (xfs_lsn_t)0; } else { lsn = lip->li_lsn; } - AIL_UNLOCK(mp, s); + spin_unlock(&ailp->xa_lock); return lsn; } @@ -87,120 +72,297 @@ xfs_trans_tail_ail( /* * 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. + * 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 push is run asynchronously in a separate thread, so we return the tail + * of the log right now instead of the tail after the push. This means we will + * either continue right away, or we will sleep waiting on the async thread to + * do its work. * - * The routine returns the lsn of the tail of the log. + * We do this unlocked - we only need to know whether there is anything in the + * AIL at the time we are called. We don't need to access the contents of + * any of the objects, so the lock is not needed. */ -xfs_lsn_t -xfs_trans_push_ail( - xfs_mount_t *mp, - xfs_lsn_t threshold_lsn) +void +xfs_trans_ail_push( + struct xfs_ail *ailp, + xfs_lsn_t threshold_lsn) +{ + xfs_log_item_t *lip; + + lip = xfs_ail_min(ailp); + if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { + if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0) + xfsaild_wakeup(ailp, threshold_lsn); + } +} + +/* + * AIL traversal cursor initialisation. + * + * The cursor keeps track of where our current traversal is up + * to by tracking the next ƣtem in the list for us. However, for + * this to be safe, removing an object from the AIL needs to invalidate + * any cursor that points to it. hence the traversal cursor needs to + * be linked to the struct xfs_ail so that deletion can search all the + * active cursors for invalidation. + * + * We don't link the push cursor because it is embedded in the struct + * xfs_ail and hence easily findable. + */ +STATIC void +xfs_trans_ail_cursor_init( + struct xfs_ail *ailp, + struct xfs_ail_cursor *cur) +{ + cur->item = NULL; + if (cur == &ailp->xa_cursors) + return; + + cur->next = ailp->xa_cursors.next; + ailp->xa_cursors.next = cur; +} + +/* + * Set the cursor to the next item, because when we look + * up the cursor the current item may have been freed. + */ +STATIC void +xfs_trans_ail_cursor_set( + struct xfs_ail *ailp, + struct xfs_ail_cursor *cur, + struct xfs_log_item *lip) +{ + if (lip) + cur->item = xfs_ail_next(ailp, lip); +} + +/* + * Get the next item in the traversal and advance the cursor. + * If the cursor was invalidated (inidicated by a lip of 1), + * restart the traversal. + */ +struct xfs_log_item * +xfs_trans_ail_cursor_next( + struct xfs_ail *ailp, + struct xfs_ail_cursor *cur) +{ + struct xfs_log_item *lip = cur->item; + + if ((__psint_t)lip & 1) + lip = xfs_ail_min(ailp); + xfs_trans_ail_cursor_set(ailp, cur, lip); + return lip; +} + +/* + * Now that the traversal is complete, we need to remove the cursor + * from the list of traversing cursors. Avoid removing the embedded + * push cursor, but use the fact it is always present to make the + * list deletion simple. + */ +void +xfs_trans_ail_cursor_done( + struct xfs_ail *ailp, + struct xfs_ail_cursor *done) +{ + struct xfs_ail_cursor *prev = NULL; + struct xfs_ail_cursor *cur; + + done->item = NULL; + if (done == &ailp->xa_cursors) + return; + prev = &ailp->xa_cursors; + for (cur = prev->next; cur; prev = cur, cur = prev->next) { + if (cur == done) { + prev->next = cur->next; + break; + } + } + ASSERT(cur); +} + +/* + * Invalidate any cursor that is pointing to this item. This is + * called when an item is removed from the AIL. Any cursor pointing + * to this object is now invalid and the traversal needs to be + * terminated so it doesn't reference a freed object. We set the + * cursor item to a value of 1 so we can distinguish between an + * invalidation and the end of the list when getting the next item + * from the cursor. + */ +STATIC void +xfs_trans_ail_cursor_clear( + struct xfs_ail *ailp, + struct xfs_log_item *lip) +{ + struct xfs_ail_cursor *cur; + + /* need to search all cursors */ + for (cur = &ailp->xa_cursors; cur; cur = cur->next) { + if (cur->item == lip) + cur->item = (struct xfs_log_item *) + ((__psint_t)cur->item | 1); + } +} + +/* + * Return the item in the AIL with the current lsn. + * Return the current tree generation number for use + * in calls to xfs_trans_next_ail(). + */ +xfs_log_item_t * +xfs_trans_ail_cursor_first( + struct xfs_ail *ailp, + struct xfs_ail_cursor *cur, + xfs_lsn_t 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 + xfs_trans_ail_cursor_init(ailp, cur); + lip = xfs_ail_min(ailp); + if (lsn == 0) + goto out; - AIL_LOCK(mp,s); - lip = xfs_trans_first_ail(mp, &gen); - if (lip == NULL || XFS_FORCED_SHUTDOWN(mp)) { + list_for_each_entry(lip, &ailp->xa_ail, li_ail) { + if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) + goto out; + } + lip = NULL; +out: + xfs_trans_ail_cursor_set(ailp, cur, lip); + return lip; +} + +/* + * Function that does the work of pushing on the AIL + */ +long +xfsaild_push( + struct xfs_ail *ailp, + xfs_lsn_t *last_lsn) +{ + long tout = 1000; /* milliseconds */ + xfs_lsn_t last_pushed_lsn = *last_lsn; + xfs_lsn_t target = ailp->xa_target; + xfs_lsn_t lsn; + xfs_log_item_t *lip; + int flush_log, count, stuck; + xfs_mount_t *mp = ailp->xa_mount; + struct xfs_ail_cursor *cur = &ailp->xa_cursors; + + spin_lock(&ailp->xa_lock); + xfs_trans_ail_cursor_init(ailp, cur); + lip = xfs_trans_ail_cursor_first(ailp, cur, *last_lsn); + if (!lip || XFS_FORCED_SHUTDOWN(mp)) { /* - * Just return if the AIL is empty. + * AIL is empty or our push has reached the end. */ - AIL_UNLOCK(mp, s); - return (xfs_lsn_t)0; + xfs_trans_ail_cursor_done(ailp, cur); + spin_unlock(&ailp->xa_lock); + last_pushed_lsn = 0; + return tout; } 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 + * try to flush it out. 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. + * the given threshold. + * + * However, we will stop after a certain number of pushes and wait + * for a reduced timeout to fire before pushing further. This + * prevents use from spinning when we can't do anything or there is + * lots of contention on the AIL lists. */ - flush_log = 0; - restarts = 0; - while (((restarts < XFS_TRANS_PUSH_AIL_RESTARTS) && - (XFS_LSN_CMP(lip->li_lsn, threshold_lsn) < 0))) { + tout = 10; + lsn = lip->li_lsn; + flush_log = stuck = count = 0; + while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { + int lock_result; /* - * 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 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. List changes are + * handled by the AIL lookup functions internally * - * 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. + * 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); + spin_unlock(&ailp->xa_lock); switch (lock_result) { - case XFS_ITEM_SUCCESS: - AIL_UNLOCK(mp, s); + case XFS_ITEM_SUCCESS: XFS_STATS_INC(xs_push_ail_success); IOP_PUSH(lip); - AIL_LOCK(mp,s); + last_pushed_lsn = lsn; break; - case XFS_ITEM_PUSHBUF: - AIL_UNLOCK(mp, s); + case XFS_ITEM_PUSHBUF: 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); + last_pushed_lsn = lsn; break; - case XFS_ITEM_PINNED: + case XFS_ITEM_PINNED: XFS_STATS_INC(xs_push_ail_pinned); + stuck++; flush_log = 1; break; - case XFS_ITEM_LOCKED: + case XFS_ITEM_LOCKED: XFS_STATS_INC(xs_push_ail_locked); + last_pushed_lsn = lsn; + stuck++; break; - case XFS_ITEM_FLUSHING: + case XFS_ITEM_FLUSHING: XFS_STATS_INC(xs_push_ail_flushing); + last_pushed_lsn = lsn; + stuck++; break; - default: + default: ASSERT(0); break; } - lip = xfs_trans_next_ail(mp, lip, &gen, &restarts); - if (lip == NULL) { + spin_lock(&ailp->xa_lock); + /* should we bother continuing? */ + if (XFS_FORCED_SHUTDOWN(mp)) 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; - } + ASSERT(mp->m_log); + count++; + + /* + * Are there too many items we can't do anything with? + * If we we are skipping too many items because we can't flush + * them or they are already being flushed, we back off and + * given them time to complete whatever operation is being + * done. i.e. remove pressure from the AIL while we can't make + * progress so traversals don't slow down further inserts and + * removals to/from the AIL. + * + * The value of 100 is an arbitrary magic number based on + * observation. + */ + if (stuck > 100) + break; + + lip = xfs_trans_ail_cursor_next(ailp, cur); + if (lip == NULL) + break; + lsn = lip->li_lsn; } + xfs_trans_ail_cursor_done(ailp, cur); + spin_unlock(&ailp->xa_lock); if (flush_log) { /* @@ -208,22 +370,36 @@ xfs_trans_push_ail( * 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; + if (!count) { + /* We're past our target or empty, so idle */ + tout = 1000; + } else if (XFS_LSN_CMP(lsn, target) >= 0) { + /* + * We reached the target so wait a bit longer for I/O to + * complete and remove pushed items from the AIL before we + * start the next scan from the start of the AIL. + */ + tout += 20; + last_pushed_lsn = 0; + } else if ((stuck * 100) / count > 90) { + /* + * Either there is a lot of contention on the AIL or we + * are stuck due to operations in progress. "Stuck" in this + * case is defined as >90% of the items we tried to push + * were stuck. + * + * Backoff a bit more to allow some I/O to complete before + * continuing from where we were. + */ + tout += 10; } - - AIL_UNLOCK(mp, s); - return lsn; -} /* xfs_trans_push_ail */ + *last_lsn = last_pushed_lsn; + return tout; +} /* xfsaild_push */ /* @@ -236,7 +412,7 @@ xfs_trans_push_ail( */ void xfs_trans_unlocked_item( - xfs_mount_t *mp, + struct xfs_ail *ailp, xfs_log_item_t *lip) { xfs_log_item_t *min_lip; @@ -248,7 +424,7 @@ xfs_trans_unlocked_item( * over some potentially valid data. */ if (!(lip->li_flags & XFS_LI_IN_AIL) || - XFS_FORCED_SHUTDOWN(mp)) { + XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { return; } @@ -264,10 +440,10 @@ xfs_trans_unlocked_item( * 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); + min_lip = xfs_ail_min(ailp); if (min_lip == lip) - xfs_log_move_tail(mp, 1); + xfs_log_move_tail(ailp->xa_mount, 1); } /* xfs_trans_unlocked_item */ @@ -280,45 +456,46 @@ xfs_trans_unlocked_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. + * is dropped before returning. */ void -xfs_trans_update_ail( - xfs_mount_t *mp, +xfs_trans_ail_update( + struct xfs_ail *ailp, xfs_log_item_t *lip, - xfs_lsn_t lsn, - unsigned long s) + xfs_lsn_t lsn) __releases(ailp->xa_lock) { - xfs_ail_entry_t *ailp; - xfs_log_item_t *dlip=NULL; + xfs_log_item_t *dlip = NULL; xfs_log_item_t *mlip; /* ptr to minimum lip */ + xfs_lsn_t tail_lsn; - 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); + xfs_trans_ail_cursor_clear(ailp, dlip); } 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); + mlip = xfs_ail_min(ailp); + /* + * It is not safe to access mlip after the AIL lock is + * dropped, so we must get a copy of li_lsn before we do + * so. This is especially important on 32-bit platforms + * where accessing and updating 64-bit values like li_lsn + * is not atomic. + */ + tail_lsn = mlip->li_lsn; + spin_unlock(&ailp->xa_lock); + xfs_log_move_tail(ailp->xa_mount, tail_lsn); } else { - AIL_UNLOCK(mp, s); + spin_unlock(&ailp->xa_lock); } @@ -337,36 +514,41 @@ xfs_trans_update_ail( * 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. + * is dropped before returning. */ void -xfs_trans_delete_ail( - xfs_mount_t *mp, - xfs_log_item_t *lip, - unsigned long s) +xfs_trans_ail_delete( + struct xfs_ail *ailp, + xfs_log_item_t *lip) __releases(ailp->xa_lock) { - xfs_ail_entry_t *ailp; xfs_log_item_t *dlip; xfs_log_item_t *mlip; + xfs_lsn_t tail_lsn; 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); + xfs_trans_ail_cursor_clear(ailp, dlip); 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)); + mlip = xfs_ail_min(ailp); + /* + * It is not safe to access mlip after the AIL lock + * is dropped, so we must get a copy of li_lsn + * before we do so. This is especially important + * on 32-bit platforms where accessing and updating + * 64-bit values like li_lsn is not atomic. + */ + tail_lsn = mlip ? mlip->li_lsn : 0; + spin_unlock(&ailp->xa_lock); + xfs_log_move_tail(ailp->xa_mount, tail_lsn); } else { - AIL_UNLOCK(mp, s); + spin_unlock(&ailp->xa_lock); } } else { @@ -374,13 +556,14 @@ xfs_trans_delete_ail( * 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 { + struct xfs_mount *mp = ailp->xa_mount; + + spin_unlock(&ailp->xa_lock); + if (!XFS_FORCED_SHUTDOWN(mp)) { xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp, - "xfs_trans_delete_ail: attempting to delete a log item that is not in the AIL"); - xfs_force_shutdown(mp, XFS_CORRUPT_INCORE); - AIL_UNLOCK(mp, s); + "%s: attempting to delete a log item that is not in the AIL", + __func__); + xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); } } } @@ -388,56 +571,6 @@ xfs_trans_delete_ail( /* - * 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. @@ -451,12 +584,39 @@ xfs_trans_next_ail( /* * Initialize the doubly linked list to point only to itself. */ -void +int 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); + struct xfs_ail *ailp; + int error; + + ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); + if (!ailp) + return ENOMEM; + + ailp->xa_mount = mp; + INIT_LIST_HEAD(&ailp->xa_ail); + spin_lock_init(&ailp->xa_lock); + error = xfsaild_start(ailp); + if (error) + goto out_free_ailp; + mp->m_ail = ailp; + return 0; + +out_free_ailp: + kmem_free(ailp); + return error; +} + +void +xfs_trans_ail_destroy( + xfs_mount_t *mp) +{ + struct xfs_ail *ailp = mp->m_ail; + + xfsaild_stop(ailp); + kmem_free(ailp); } /* @@ -467,7 +627,7 @@ xfs_trans_ail_init( */ STATIC void xfs_ail_insert( - xfs_ail_entry_t *base, + struct xfs_ail *ailp, xfs_log_item_t *lip) /* ARGSUSED */ { @@ -476,27 +636,22 @@ xfs_ail_insert( /* * 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; + if (list_empty(&ailp->xa_ail)) { + list_add(&lip->li_ail, &ailp->xa_ail); 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; + list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) { + if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0) + break; } - ASSERT((next_lip == (xfs_log_item_t*)base) || + + ASSERT((&next_lip->li_ail == &ailp->xa_ail) || (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); + list_add(&lip->li_ail, &next_lip->li_ail); + + xfs_ail_check(ailp, lip); return; } @@ -506,16 +661,14 @@ xfs_ail_insert( /*ARGSUSED*/ STATIC xfs_log_item_t * xfs_ail_delete( - xfs_ail_entry_t *base, + struct xfs_ail *ailp, 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(ailp, lip); + + list_del(&lip->li_ail); - xfs_ail_check(base); return lip; } @@ -525,14 +678,13 @@ xfs_ail_delete( */ STATIC xfs_log_item_t * xfs_ail_min( - xfs_ail_entry_t *base) + struct xfs_ail *ailp) /* ARGSUSED */ { - register xfs_log_item_t *forw = base->ail_forw; - if (forw == (xfs_log_item_t*)base) { + if (list_empty(&ailp->xa_ail)) return NULL; - } - return forw; + + return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); } /* @@ -542,15 +694,14 @@ xfs_ail_min( */ STATIC xfs_log_item_t * xfs_ail_next( - xfs_ail_entry_t *base, + struct xfs_ail *ailp, xfs_log_item_t *lip) /* ARGSUSED */ { - if (lip->li_ail.ail_forw == (xfs_log_item_t*)base) { + if (lip->li_ail.next == &ailp->xa_ail) return NULL; - } - return lip->li_ail.ail_forw; + return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); } #ifdef DEBUG @@ -559,38 +710,40 @@ xfs_ail_next( */ STATIC void xfs_ail_check( - xfs_ail_entry_t *base) + struct xfs_ail *ailp, + xfs_log_item_t *lip) { - 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); + if (list_empty(&ailp->xa_ail)) return; - } /* - * Walk the list checking forward and backward pointers, - * lsn ordering, and that every entry has the XFS_LI_IN_AIL - * flag set. + * Check the next and previous entries are valid. */ - 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((lip->li_flags & XFS_LI_IN_AIL) != 0); + prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); + if (&prev_lip->li_ail != &ailp->xa_ail) + ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); + + prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); + if (&prev_lip->li_ail != &ailp->xa_ail) + ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); + + +#ifdef XFS_TRANS_DEBUG + /* + * Walk the list checking lsn ordering, and that every entry has the + * XFS_LI_IN_AIL flag set. This is really expensive, so only do it + * when specifically debugging the transaction subsystem. + */ + prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); + list_for_each_entry(lip, &ailp->xa_ail, li_ail) { + if (&prev_lip->li_ail != &ailp->xa_ail) 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 /* XFS_TRANS_DEBUG */ } #endif /* DEBUG */