From 0924378a689ccb05f6d60875742dc28f69bf0129 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 8 Mar 2010 11:28:28 +1100 Subject: [PATCH] xfs: split out iclog writing from xfs_trans_commit() Split the the part of xfs_trans_commit() that deals with writing the transaction into the iclog into a separate function. This isolates the physical commit process from the logical commit operation and makes it easier to insert different transaction commit paths without affecting the existing algorithm adversely. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_trans.c | 387 +++++++++++++++++++++++++++-------------------------- 1 file changed, 199 insertions(+), 188 deletions(-) diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 6962f2b..e07b329 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -47,8 +47,6 @@ STATIC void xfs_trans_apply_sb_deltas(xfs_trans_t *); -STATIC uint xfs_trans_count_vecs(xfs_trans_t *); -STATIC void xfs_trans_fill_vecs(xfs_trans_t *, xfs_log_iovec_t *); STATIC void xfs_trans_uncommit(xfs_trans_t *, uint); STATIC void xfs_trans_committed(xfs_trans_t *, int); STATIC void xfs_trans_chunk_committed(xfs_log_item_chunk_t *, xfs_lsn_t, int); @@ -764,94 +762,126 @@ xfs_trans_unreserve_and_mod_sb( } } - /* - * xfs_trans_commit - * - * Commit the given transaction to the log a/synchronously. - * - * XFS disk error handling mechanism is not based on a typical - * transaction abort mechanism. Logically after the filesystem - * gets marked 'SHUTDOWN', we can't let any new transactions - * be durable - ie. committed to disk - because some metadata might - * be inconsistent. In such cases, this returns an error, and the - * caller may assume that all locked objects joined to the transaction - * have already been unlocked as if the commit had succeeded. - * Do not reference the transaction structure after this call. + * Total up the number of log iovecs needed to commit this + * transaction. The transaction itself needs one for the + * transaction header. Ask each dirty item in turn how many + * it needs to get the total. */ - /*ARGSUSED*/ -int -_xfs_trans_commit( - xfs_trans_t *tp, - uint flags, - int *log_flushed) +static uint +xfs_trans_count_vecs( + xfs_trans_t *tp) { - xfs_log_iovec_t *log_vector; - int nvec; - xfs_mount_t *mp; - xfs_lsn_t commit_lsn; - /* REFERENCED */ - int error; - int log_flags; - int sync; -#define XFS_TRANS_LOGVEC_COUNT 16 - xfs_log_iovec_t log_vector_fast[XFS_TRANS_LOGVEC_COUNT]; - struct xlog_in_core *commit_iclog; - int shutdown; + int nvecs; + xfs_log_item_desc_t *lidp; - commit_lsn = -1; + nvecs = 1; + lidp = xfs_trans_first_item(tp); + ASSERT(lidp != NULL); - /* - * Determine whether this commit is releasing a permanent - * log reservation or not. + /* In the non-debug case we need to start bailing out if we + * didn't find a log_item here, return zero and let trans_commit + * deal with it. */ - if (flags & XFS_TRANS_RELEASE_LOG_RES) { - ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); - log_flags = XFS_LOG_REL_PERM_RESERV; - } else { - log_flags = 0; + if (lidp == NULL) + return 0; + + while (lidp != NULL) { + /* + * Skip items which aren't dirty in this transaction. + */ + if (!(lidp->lid_flags & XFS_LID_DIRTY)) { + lidp = xfs_trans_next_item(tp, lidp); + continue; + } + lidp->lid_size = IOP_SIZE(lidp->lid_item); + nvecs += lidp->lid_size; + lidp = xfs_trans_next_item(tp, lidp); } - mp = tp->t_mountp; + + return nvecs; +} + +/* + * Fill in the vector with pointers to data to be logged + * by this transaction. The transaction header takes + * the first vector, and then each dirty item takes the + * number of vectors it indicated it needed in xfs_trans_count_vecs(). + * + * As each item fills in the entries it needs, also pin the item + * so that it cannot be flushed out until the log write completes. + */ +static void +xfs_trans_fill_vecs( + struct xfs_trans *tp, + struct xfs_log_iovec *log_vector) +{ + xfs_log_item_desc_t *lidp; + struct xfs_log_iovec *vecp; + uint nitems; /* - * If there is nothing to be logged by the transaction, - * then unlock all of the items associated with the - * transaction and free the transaction structure. - * Also make sure to return any reserved blocks to - * the free pool. + * Skip over the entry for the transaction header, we'll + * fill that in at the end. */ -shut_us_down: - shutdown = XFS_FORCED_SHUTDOWN(mp) ? EIO : 0; - if (!(tp->t_flags & XFS_TRANS_DIRTY) || shutdown) { - xfs_trans_unreserve_and_mod_sb(tp); + vecp = log_vector + 1; + + nitems = 0; + lidp = xfs_trans_first_item(tp); + ASSERT(lidp); + while (lidp) { + /* Skip items which aren't dirty in this transaction. */ + if (!(lidp->lid_flags & XFS_LID_DIRTY)) { + lidp = xfs_trans_next_item(tp, lidp); + continue; + } + /* - * It is indeed possible for the transaction to be - * not dirty but the dqinfo portion to be. All that - * means is that we have some (non-persistent) quota - * reservations that need to be unreserved. + * The item may be marked dirty but not log anything. This can + * be used to get called when a transaction is committed. */ - xfs_trans_unreserve_and_mod_dquots(tp); - if (tp->t_ticket) { - commit_lsn = xfs_log_done(mp, tp->t_ticket, - NULL, log_flags); - if (commit_lsn == -1 && !shutdown) - shutdown = XFS_ERROR(EIO); - } - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); - xfs_trans_free_items(tp, shutdown? XFS_TRANS_ABORT : 0); - xfs_trans_free_busy(tp); - xfs_trans_free(tp); - XFS_STATS_INC(xs_trans_empty); - return (shutdown); + if (lidp->lid_size) + nitems++; + IOP_FORMAT(lidp->lid_item, vecp); + vecp += lidp->lid_size; + IOP_PIN(lidp->lid_item); + lidp = xfs_trans_next_item(tp, lidp); } - ASSERT(tp->t_ticket != NULL); /* - * If we need to update the superblock, then do it now. + * Now that we've counted the number of items in this transaction, fill + * in the transaction header. Note that the transaction header does not + * have a log item. */ - if (tp->t_flags & XFS_TRANS_SB_DIRTY) - xfs_trans_apply_sb_deltas(tp); - xfs_trans_apply_dquot_deltas(tp); + tp->t_header.th_magic = XFS_TRANS_HEADER_MAGIC; + tp->t_header.th_type = tp->t_type; + tp->t_header.th_num_items = nitems; + log_vector->i_addr = (xfs_caddr_t)&tp->t_header; + log_vector->i_len = sizeof(xfs_trans_header_t); + log_vector->i_type = XLOG_REG_TYPE_TRANSHDR; +} + +/* + * Format the transaction direct to the iclog. This isolates the physical + * transaction commit operation from the logical operation and hence allows + * other methods to be introduced without affecting the existing commit path. + */ +static int +xfs_trans_commit_iclog( + struct xfs_mount *mp, + struct xfs_trans *tp, + xfs_lsn_t *commit_lsn, + int flags) +{ + int shutdown; + int error; + int log_flags = 0; + struct xlog_in_core *commit_iclog; +#define XFS_TRANS_LOGVEC_COUNT 16 + struct xfs_log_iovec log_vector_fast[XFS_TRANS_LOGVEC_COUNT]; + struct xfs_log_iovec *log_vector; + uint nvec; + /* * Ask each log item how many log_vector entries it will @@ -861,8 +891,7 @@ shut_us_down: */ nvec = xfs_trans_count_vecs(tp); if (nvec == 0) { - xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); - goto shut_us_down; + return ENOMEM; /* triggers a shutdown! */ } else if (nvec <= XFS_TRANS_LOGVEC_COUNT) { log_vector = log_vector_fast; } else { @@ -877,6 +906,9 @@ shut_us_down: */ xfs_trans_fill_vecs(tp, log_vector); + if (flags & XFS_TRANS_RELEASE_LOG_RES) + log_flags = XFS_LOG_REL_PERM_RESERV; + error = xfs_log_write(mp, log_vector, nvec, tp->t_ticket, &(tp->t_lsn)); /* @@ -884,18 +916,17 @@ shut_us_down: * at any time after this call. However, all the items associated * with the transaction are still locked and pinned in memory. */ - commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags); + *commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags); - tp->t_commit_lsn = commit_lsn; - if (nvec > XFS_TRANS_LOGVEC_COUNT) { + tp->t_commit_lsn = *commit_lsn; + if (nvec > XFS_TRANS_LOGVEC_COUNT) kmem_free(log_vector); - } /* * If we got a log write error. Unpin the logitems that we * had pinned, clean up, free trans structure, and return error. */ - if (error || commit_lsn == -1) { + if (error || *commit_lsn == -1) { current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); xfs_trans_uncommit(tp, flags|XFS_TRANS_ABORT); return XFS_ERROR(EIO); @@ -909,8 +940,6 @@ shut_us_down: */ xfs_trans_unreserve_and_mod_sb(tp); - sync = tp->t_flags & XFS_TRANS_SYNC; - /* * Tell the LM to call the transaction completion routine * when the log write with LSN commit_lsn completes (e.g. @@ -953,7 +982,7 @@ shut_us_down: * the commit lsn of this transaction for dependency tracking * purposes. */ - xfs_trans_unlock_items(tp, commit_lsn); + xfs_trans_unlock_items(tp, *commit_lsn); /* * If we detected a log error earlier, finish committing @@ -973,7 +1002,92 @@ shut_us_down: * and the items are released we can finally allow the iclog to * go to disk. */ - error = xfs_log_release_iclog(mp, commit_iclog); + return xfs_log_release_iclog(mp, commit_iclog); +} + + +/* + * xfs_trans_commit + * + * Commit the given transaction to the log a/synchronously. + * + * XFS disk error handling mechanism is not based on a typical + * transaction abort mechanism. Logically after the filesystem + * gets marked 'SHUTDOWN', we can't let any new transactions + * be durable - ie. committed to disk - because some metadata might + * be inconsistent. In such cases, this returns an error, and the + * caller may assume that all locked objects joined to the transaction + * have already been unlocked as if the commit had succeeded. + * Do not reference the transaction structure after this call. + */ + /*ARGSUSED*/ +int +_xfs_trans_commit( + xfs_trans_t *tp, + uint flags, + int *log_flushed) +{ + xfs_mount_t *mp = tp->t_mountp; + xfs_lsn_t commit_lsn = -1; + int error; + int log_flags = 0; + int sync = tp->t_flags & XFS_TRANS_SYNC; + int shutdown; + + /* + * Determine whether this commit is releasing a permanent + * log reservation or not. + */ + if (flags & XFS_TRANS_RELEASE_LOG_RES) { + ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); + log_flags = XFS_LOG_REL_PERM_RESERV; + } + + /* + * If there is nothing to be logged by the transaction, + * then unlock all of the items associated with the + * transaction and free the transaction structure. + * Also make sure to return any reserved blocks to + * the free pool. + */ +shut_us_down: + shutdown = XFS_FORCED_SHUTDOWN(mp) ? EIO : 0; + if (!(tp->t_flags & XFS_TRANS_DIRTY) || shutdown) { + xfs_trans_unreserve_and_mod_sb(tp); + /* + * It is indeed possible for the transaction to be + * not dirty but the dqinfo portion to be. All that + * means is that we have some (non-persistent) quota + * reservations that need to be unreserved. + */ + xfs_trans_unreserve_and_mod_dquots(tp); + if (tp->t_ticket) { + commit_lsn = xfs_log_done(mp, tp->t_ticket, + NULL, log_flags); + if (commit_lsn == -1 && !shutdown) + shutdown = XFS_ERROR(EIO); + } + current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + xfs_trans_free_items(tp, shutdown? XFS_TRANS_ABORT : 0); + xfs_trans_free_busy(tp); + xfs_trans_free(tp); + XFS_STATS_INC(xs_trans_empty); + return (shutdown); + } + ASSERT(tp->t_ticket != NULL); + + /* + * If we need to update the superblock, then do it now. + */ + if (tp->t_flags & XFS_TRANS_SB_DIRTY) + xfs_trans_apply_sb_deltas(tp); + xfs_trans_apply_dquot_deltas(tp); + + error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags); + if (error == ENOMEM) { + xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); + goto shut_us_down; + } /* * If the transaction needs to be synchronous, then force the @@ -992,47 +1106,6 @@ shut_us_down: return (error); } - -/* - * Total up the number of log iovecs needed to commit this - * transaction. The transaction itself needs one for the - * transaction header. Ask each dirty item in turn how many - * it needs to get the total. - */ -STATIC uint -xfs_trans_count_vecs( - xfs_trans_t *tp) -{ - int nvecs; - xfs_log_item_desc_t *lidp; - - nvecs = 1; - lidp = xfs_trans_first_item(tp); - ASSERT(lidp != NULL); - - /* In the non-debug case we need to start bailing out if we - * didn't find a log_item here, return zero and let trans_commit - * deal with it. - */ - if (lidp == NULL) - return 0; - - while (lidp != NULL) { - /* - * Skip items which aren't dirty in this transaction. - */ - if (!(lidp->lid_flags & XFS_LID_DIRTY)) { - lidp = xfs_trans_next_item(tp, lidp); - continue; - } - lidp->lid_size = IOP_SIZE(lidp->lid_item); - nvecs += lidp->lid_size; - lidp = xfs_trans_next_item(tp, lidp); - } - - return nvecs; -} - /* * Called from the trans_commit code when we notice that * the filesystem is in the middle of a forced shutdown. @@ -1063,68 +1136,6 @@ xfs_trans_uncommit( } /* - * Fill in the vector with pointers to data to be logged - * by this transaction. The transaction header takes - * the first vector, and then each dirty item takes the - * number of vectors it indicated it needed in xfs_trans_count_vecs(). - * - * As each item fills in the entries it needs, also pin the item - * so that it cannot be flushed out until the log write completes. - */ -STATIC void -xfs_trans_fill_vecs( - xfs_trans_t *tp, - xfs_log_iovec_t *log_vector) -{ - xfs_log_item_desc_t *lidp; - xfs_log_iovec_t *vecp; - uint nitems; - - /* - * Skip over the entry for the transaction header, we'll - * fill that in at the end. - */ - vecp = log_vector + 1; /* pointer arithmetic */ - - nitems = 0; - lidp = xfs_trans_first_item(tp); - ASSERT(lidp != NULL); - while (lidp != NULL) { - /* - * Skip items which aren't dirty in this transaction. - */ - if (!(lidp->lid_flags & XFS_LID_DIRTY)) { - lidp = xfs_trans_next_item(tp, lidp); - continue; - } - /* - * The item may be marked dirty but not log anything. - * This can be used to get called when a transaction - * is committed. - */ - if (lidp->lid_size) { - nitems++; - } - IOP_FORMAT(lidp->lid_item, vecp); - vecp += lidp->lid_size; /* pointer arithmetic */ - IOP_PIN(lidp->lid_item); - lidp = xfs_trans_next_item(tp, lidp); - } - - /* - * Now that we've counted the number of items in this - * transaction, fill in the transaction header. - */ - tp->t_header.th_magic = XFS_TRANS_HEADER_MAGIC; - tp->t_header.th_type = tp->t_type; - tp->t_header.th_num_items = nitems; - log_vector->i_addr = (xfs_caddr_t)&tp->t_header; - log_vector->i_len = sizeof(xfs_trans_header_t); - log_vector->i_type = XLOG_REG_TYPE_TRANSHDR; -} - - -/* * Unlock all of the transaction's items and free the transaction. * The transaction must not have modified any of its items, because * there is no way to restore them to their previous state. -- 1.8.2.3