diff options
| -rw-r--r-- | fs/xfs/xfs_log.c | 7 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 245 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 13 |
3 files changed, 147 insertions, 118 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 925d572bf0f..33f718f92a4 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3015,7 +3015,8 @@ _xfs_log_force( XFS_STATS_INC(xs_log_force); - xlog_cil_push(log, 1); + if (log->l_cilp) + xlog_cil_force(log); spin_lock(&log->l_icloglock); @@ -3167,7 +3168,7 @@ _xfs_log_force_lsn( XFS_STATS_INC(xs_log_force); if (log->l_cilp) { - lsn = xlog_cil_push_lsn(log, lsn); + lsn = xlog_cil_force_lsn(log, lsn); if (lsn == NULLCOMMITLSN) return 0; } @@ -3724,7 +3725,7 @@ xfs_log_force_umount( * call below. */ if (!logerror && (mp->m_flags & XFS_MOUNT_DELAYLOG)) - xlog_cil_push(log, 1); + xlog_cil_force(log); /* * We must hold both the GRANT lock and the LOG lock, diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index ef8e7d9f445..9768f2437bb 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -68,6 +68,7 @@ xlog_cil_init( ctx->sequence = 1; ctx->cil = cil; cil->xc_ctx = ctx; + cil->xc_current_sequence = ctx->sequence; cil->xc_log = log; log->l_cilp = cil; @@ -321,94 +322,6 @@ xlog_cil_free_logvec( } /* - * Commit a transaction with the given vector to the Committed Item List. - * - * To do this, we need to format the item, pin it in memory if required and - * account for the space used by the transaction. Once we have done that we - * need to release the unused reservation for the transaction, attach the - * transaction to the checkpoint context so we carry the busy extents through - * to checkpoint completion, and then unlock all the items in the transaction. - * - * For more specific information about the order of operations in - * xfs_log_commit_cil() please refer to the comments in - * xfs_trans_commit_iclog(). - * - * Called with the context lock already held in read mode to lock out - * background commit, returns without it held once background commits are - * allowed again. - */ -int -xfs_log_commit_cil( - struct xfs_mount *mp, - struct xfs_trans *tp, - struct xfs_log_vec *log_vector, - xfs_lsn_t *commit_lsn, - int flags) -{ - struct log *log = mp->m_log; - int log_flags = 0; - int push = 0; - - if (flags & XFS_TRANS_RELEASE_LOG_RES) - log_flags = XFS_LOG_REL_PERM_RESERV; - - if (XLOG_FORCED_SHUTDOWN(log)) { - xlog_cil_free_logvec(log_vector); - return XFS_ERROR(EIO); - } - - /* lock out background commit */ - down_read(&log->l_cilp->xc_ctx_lock); - xlog_cil_format_items(log, log_vector, tp->t_ticket, commit_lsn); - - /* check we didn't blow the reservation */ - if (tp->t_ticket->t_curr_res < 0) - xlog_print_tic_res(log->l_mp, tp->t_ticket); - - /* attach the transaction to the CIL if it has any busy extents */ - if (!list_empty(&tp->t_busy)) { - spin_lock(&log->l_cilp->xc_cil_lock); - list_splice_init(&tp->t_busy, - &log->l_cilp->xc_ctx->busy_extents); - spin_unlock(&log->l_cilp->xc_cil_lock); - } - - tp->t_commit_lsn = *commit_lsn; - xfs_log_done(mp, tp->t_ticket, NULL, log_flags); - xfs_trans_unreserve_and_mod_sb(tp); - - /* - * Once all the items of the transaction have been copied to the CIL, - * the items can be unlocked and freed. - * - * This needs to be done before we drop the CIL context lock because we - * have to update state in the log items and unlock them before they go - * to disk. If we don't, then the CIL checkpoint can race with us and - * we can run checkpoint completion before we've updated and unlocked - * the log items. This affects (at least) processing of stale buffers, - * inodes and EFIs. - */ - xfs_trans_free_items(tp, *commit_lsn, 0); - - /* check for background commit before unlock */ - if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log)) - push = 1; - - up_read(&log->l_cilp->xc_ctx_lock); - - /* - * We need to push CIL every so often so we don't cache more than we - * can fit in the log. The limit really is that a checkpoint can't be - * more than half the log (the current checkpoint is not allowed to - * overwrite the previous checkpoint), but commit latency and memory - * usage limit this to a smaller size in most cases. - */ - if (push) - xlog_cil_push(log, 0); - return 0; -} - -/* * Mark all items committed and clear busy extents. We free the log vector * chains in a separate pass so that we unpin the log items as quickly as * possible. @@ -441,13 +354,23 @@ xlog_cil_committed( } /* - * Push the Committed Item List to the log. If the push_now flag is not set, - * then it is a background flush and so we can chose to ignore it. + * Push the Committed Item List to the log. If @push_seq flag is zero, then it + * is a background flush and so we can chose to ignore it. Otherwise, if the + * current sequence is the same as @push_seq we need to do a flush. If + * @push_seq is less than the current sequence, then it has already been + * flushed and we don't need to do anything - the caller will wait for it to + * complete if necessary. + * + * @push_seq is a value rather than a flag because that allows us to do an + * unlocked check of the sequence number for a match. Hence we can allows log + * forces to run racily and not issue pushes for the same sequence twice. If we + * get a race between multiple pushes for the same sequence they will block on + * the first one and then abort, hence avoiding needless pushes. */ -int +STATIC int xlog_cil_push( struct log *log, - int push_now) + xfs_lsn_t push_seq) { struct xfs_cil *cil = log->l_cilp; struct xfs_log_vec *lv; @@ -467,12 +390,14 @@ xlog_cil_push( if (!cil) return 0; + ASSERT(!push_seq || push_seq <= cil->xc_ctx->sequence); + new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS); new_ctx->ticket = xlog_cil_ticket_alloc(log); /* lock out transaction commit, but don't block on background push */ if (!down_write_trylock(&cil->xc_ctx_lock)) { - if (!push_now) + if (!push_seq) goto out_free_ticket; down_write(&cil->xc_ctx_lock); } @@ -483,7 +408,11 @@ xlog_cil_push( goto out_skip; /* check for spurious background flush */ - if (!push_now && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) + if (!push_seq && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) + goto out_skip; + + /* check for a previously pushed seqeunce */ + if (push_seq < cil->xc_ctx->sequence) goto out_skip; /* @@ -529,6 +458,13 @@ xlog_cil_push( cil->xc_ctx = new_ctx; /* + * mirror the new sequence into the cil structure so that we can do + * unlocked checks against the current sequence in log forces without + * risking deferencing a freed context pointer. + */ + cil->xc_current_sequence = new_ctx->sequence; + + /* * The switch is now done, so we can drop the context lock and move out * of a shared context. We can't just go straight to the commit record, * though - we need to synchronise with previous and future commits so @@ -640,6 +576,94 @@ out_abort: } /* + * Commit a transaction with the given vector to the Committed Item List. + * + * To do this, we need to format the item, pin it in memory if required and + * account for the space used by the transaction. Once we have done that we + * need to release the unused reservation for the transaction, attach the + * transaction to the checkpoint context so we carry the busy extents through + * to checkpoint completion, and then unlock all the items in the transaction. + * + * For more specific information about the order of operations in + * xfs_log_commit_cil() please refer to the comments in + * xfs_trans_commit_iclog(). + * + * Called with the context lock already held in read mode to lock out + * background commit, returns without it held once background commits are + * allowed again. + */ +int +xfs_log_commit_cil( + struct xfs_mount *mp, + struct xfs_trans *tp, + struct xfs_log_vec *log_vector, + xfs_lsn_t *commit_lsn, + int flags) +{ + struct log *log = mp->m_log; + int log_flags = 0; + int push = 0; + + if (flags & XFS_TRANS_RELEASE_LOG_RES) + log_flags = XFS_LOG_REL_PERM_RESERV; + + if (XLOG_FORCED_SHUTDOWN(log)) { + xlog_cil_free_logvec(log_vector); + return XFS_ERROR(EIO); + } + + /* lock out background commit */ + down_read(&log->l_cilp->xc_ctx_lock); + xlog_cil_format_items(log, log_vector, tp->t_ticket, commit_lsn); + + /* check we didn't blow the reservation */ + if (tp->t_ticket->t_curr_res < 0) + xlog_print_tic_res(log->l_mp, tp->t_ticket); + + /* attach the transaction to the CIL if it has any busy extents */ + if (!list_empty(&tp->t_busy)) { + spin_lock(&log->l_cilp->xc_cil_lock); + list_splice_init(&tp->t_busy, + &log->l_cilp->xc_ctx->busy_extents); + spin_unlock(&log->l_cilp->xc_cil_lock); + } + + tp->t_commit_lsn = *commit_lsn; + xfs_log_done(mp, tp->t_ticket, NULL, log_flags); + xfs_trans_unreserve_and_mod_sb(tp); + + /* + * Once all the items of the transaction have been copied to the CIL, + * the items can be unlocked and freed. + * + * This needs to be done before we drop the CIL context lock because we + * have to update state in the log items and unlock them before they go + * to disk. If we don't, then the CIL checkpoint can race with us and + * we can run checkpoint completion before we've updated and unlocked + * the log items. This affects (at least) processing of stale buffers, + * inodes and EFIs. + */ + xfs_trans_free_items(tp, *commit_lsn, 0); + + /* check for background commit before unlock */ + if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log)) + push = 1; + + up_read(&log->l_cilp->xc_ctx_lock); + + /* + * We need to push CIL every so often so we don't cache more than we + * can fit in the log. The limit really is that a checkpoint can't be + * more than half the log (the current checkpoint is not allowed to + * overwrite the previous checkpoint), but commit latency and memory + * usage limit this to a smaller size in most cases. + */ + if (push) + xlog_cil_push(log, 0); + return 0; +} + +/* * Conditionally push the CIL based on the sequence passed in. * * We only need to push if we haven't already pushed the sequence @@ -653,39 +677,34 @@ out_abort: * commit lsn is there. It'll be empty, so this is broken for now. */ xfs_lsn_t -xlog_cil_push_lsn( +xlog_cil_force_lsn( struct log *log, - xfs_lsn_t push_seq) + xfs_lsn_t sequence) { struct xfs_cil *cil = log->l_cilp; struct xfs_cil_ctx *ctx; xfs_lsn_t commit_lsn = NULLCOMMITLSN; -restart: - down_write(&cil->xc_ctx_lock); - ASSERT(push_seq <= cil->xc_ctx->sequence); - - /* check to see if we need to force out the current context */ - if (push_seq == cil->xc_ctx->sequence) { - up_write(&cil->xc_ctx_lock); - xlog_cil_push(log, 1); - goto restart; - } + ASSERT(sequence <= cil->xc_current_sequence); + + /* + * check to see if we need to force out the current context. + * xlog_cil_push() handles racing pushes for the same sequence, + * so no need to deal with it here. + */ + if (sequence == cil->xc_current_sequence) + xlog_cil_push(log, sequence); /* * See if we can find a previous sequence still committing. - * We can drop the flush lock as soon as we have the cil lock - * because we are now only comparing contexts protected by - * the cil lock. - * * We need to wait for all previous sequence commits to complete * before allowing the force of push_seq to go ahead. Hence block * on commits for those as well. */ +restart: spin_lock(&cil->xc_cil_lock); - up_write(&cil->xc_ctx_lock); list_for_each_entry(ctx, &cil->xc_committing, committing) { - if (ctx->sequence > push_seq) + if (ctx->sequence > sequence) continue; if (!ctx->commit_lsn) { /* @@ -695,7 +714,7 @@ restart: sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0); goto restart; } - if (ctx->sequence != push_seq) + if (ctx->sequence != sequence) continue; /* found it! */ commit_lsn = ctx->commit_lsn; diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 8c072618965..ced52b98b32 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -422,6 +422,7 @@ struct xfs_cil { struct rw_semaphore xc_ctx_lock; struct list_head xc_committing; sv_t xc_commit_wait; + xfs_lsn_t xc_current_sequence; }; /* @@ -562,8 +563,16 @@ int xlog_cil_init(struct log *log); void xlog_cil_init_post_recovery(struct log *log); void xlog_cil_destroy(struct log *log); -int xlog_cil_push(struct log *log, int push_now); -xfs_lsn_t xlog_cil_push_lsn(struct log *log, xfs_lsn_t push_sequence); +/* + * CIL force routines + */ +xfs_lsn_t xlog_cil_force_lsn(struct log *log, xfs_lsn_t sequence); + +static inline void +xlog_cil_force(struct log *log) +{ + xlog_cil_force_lsn(log, log->l_cilp->xc_current_sequence); +} /* * Unmount record type is used as a pseudo transaction type for the ticket. |