diff options
Diffstat (limited to 'sys/gnu/fs/xfs/xfs_trans_ail.c')
-rw-r--r-- | sys/gnu/fs/xfs/xfs_trans_ail.c | 581 |
1 files changed, 0 insertions, 581 deletions
diff --git a/sys/gnu/fs/xfs/xfs_trans_ail.c b/sys/gnu/fs/xfs/xfs_trans_ail.c deleted file mode 100644 index 19ab24a..0000000 --- a/sys/gnu/fs/xfs/xfs_trans_ail.c +++ /dev/null @@ -1,581 +0,0 @@ -/* - * 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_dir.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, - "xfs_trans_delete_ail: attempting to delete a log item that is not in the AIL"); - AIL_UNLOCK(mp, s); - xfs_force_shutdown(mp, XFS_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 */ |