diff options
author | Christoph Hellwig <hch@lst.de> | 2018-03-13 23:15:29 -0700 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-03-14 11:12:52 -0700 |
commit | e6b965705685c7fc2f24a68410529f86c08c7277 (patch) | |
tree | 0e34740ae42c3c3fc783a5a5d95e2094783e4640 /fs/xfs/xfs_log.c | |
parent | 656de4ffaffd921e1b45de4150c86ba50da135e9 (diff) | |
download | blackbird-op-linux-e6b965705685c7fc2f24a68410529f86c08c7277.tar.gz blackbird-op-linux-e6b965705685c7fc2f24a68410529f86c08c7277.zip |
xfs: refactor xfs_log_force
Streamline the conditionals so that it is more obvious which specific case
form the top of the function comments is being handled. Use gotos only
for early returns.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/xfs_log.c')
-rw-r--r-- | fs/xfs/xfs_log.c | 144 |
1 files changed, 63 insertions, 81 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index cb50dd72a3f3..2a0f882e7f7e 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3318,99 +3318,81 @@ xfs_log_force( xlog_cil_force(log); spin_lock(&log->l_icloglock); - iclog = log->l_iclog; - if (iclog->ic_state & XLOG_STATE_IOERROR) { - spin_unlock(&log->l_icloglock); - return -EIO; - } + if (iclog->ic_state & XLOG_STATE_IOERROR) + goto out_error; - /* If the head iclog is not active nor dirty, we just attach - * ourselves to the head and go to sleep. - */ - if (iclog->ic_state == XLOG_STATE_ACTIVE || - iclog->ic_state == XLOG_STATE_DIRTY) { + if (iclog->ic_state == XLOG_STATE_DIRTY || + (iclog->ic_state == XLOG_STATE_ACTIVE && + atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) { /* - * If the head is dirty or (active and empty), then - * we need to look at the previous iclog. If the previous - * iclog is active or dirty we are done. There is nothing - * to sync out. Otherwise, we attach ourselves to the + * If the head is dirty or (active and empty), then we need to + * look at the previous iclog. + * + * If the previous iclog is active or dirty we are done. There + * is nothing to sync out. Otherwise, we attach ourselves to the * previous iclog and go to sleep. */ - if (iclog->ic_state == XLOG_STATE_DIRTY || - (atomic_read(&iclog->ic_refcnt) == 0 - && iclog->ic_offset == 0)) { - iclog = iclog->ic_prev; - if (iclog->ic_state == XLOG_STATE_ACTIVE || - iclog->ic_state == XLOG_STATE_DIRTY) - goto no_sleep; - else - goto maybe_sleep; - } else { - if (atomic_read(&iclog->ic_refcnt) == 0) { - /* We are the only one with access to this - * iclog. Flush it out now. There should - * be a roundoff of zero to show that someone - * has already taken care of the roundoff from - * the previous sync. - */ - atomic_inc(&iclog->ic_refcnt); - lsn = be64_to_cpu(iclog->ic_header.h_lsn); - xlog_state_switch_iclogs(log, iclog, 0); - spin_unlock(&log->l_icloglock); - - if (xlog_state_release_iclog(log, iclog)) - return -EIO; + iclog = iclog->ic_prev; + if (iclog->ic_state == XLOG_STATE_ACTIVE || + iclog->ic_state == XLOG_STATE_DIRTY) + goto out_unlock; + } else if (iclog->ic_state == XLOG_STATE_ACTIVE) { + if (atomic_read(&iclog->ic_refcnt) == 0) { + /* + * We are the only one with access to this iclog. + * + * Flush it out now. There should be a roundoff of zero + * to show that someone has already taken care of the + * roundoff from the previous sync. + */ + atomic_inc(&iclog->ic_refcnt); + lsn = be64_to_cpu(iclog->ic_header.h_lsn); + xlog_state_switch_iclogs(log, iclog, 0); + spin_unlock(&log->l_icloglock); - spin_lock(&log->l_icloglock); - if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn && - iclog->ic_state != XLOG_STATE_DIRTY) - goto maybe_sleep; - else - goto no_sleep; - } else { - /* Someone else is writing to this iclog. - * Use its call to flush out the data. However, - * the other thread may not force out this LR, - * so we mark it WANT_SYNC. - */ - xlog_state_switch_iclogs(log, iclog, 0); - goto maybe_sleep; - } - } - } + if (xlog_state_release_iclog(log, iclog)) + return -EIO; - /* By the time we come around again, the iclog could've been filled - * which would give it another lsn. If we have a new lsn, just - * return because the relevant data has been flushed. - */ -maybe_sleep: - if (flags & XFS_LOG_SYNC) { - /* - * We must check if we're shutting down here, before - * we wait, while we're holding the l_icloglock. - * Then we check again after waking up, in case our - * sleep was disturbed by a bad news. - */ - if (iclog->ic_state & XLOG_STATE_IOERROR) { - spin_unlock(&log->l_icloglock); - return -EIO; + spin_lock(&log->l_icloglock); + if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn || + iclog->ic_state == XLOG_STATE_DIRTY) + goto out_unlock; + } else { + /* + * Someone else is writing to this iclog. + * + * Use its call to flush out the data. However, the + * other thread may not force out this LR, so we mark + * it WANT_SYNC. + */ + xlog_state_switch_iclogs(log, iclog, 0); } - XFS_STATS_INC(mp, xs_log_force_sleep); - xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); + } else { /* - * No need to grab the log lock here since we're - * only deciding whether or not to return EIO - * and the memory read should be atomic. + * If the head iclog is not active nor dirty, we just attach + * ourselves to the head and go to sleep if necessary. */ - if (iclog->ic_state & XLOG_STATE_IOERROR) - return -EIO; - } else { - -no_sleep: - spin_unlock(&log->l_icloglock); + ; } + + if (!(flags & XFS_LOG_SYNC)) + goto out_unlock; + + if (iclog->ic_state & XLOG_STATE_IOERROR) + goto out_error; + XFS_STATS_INC(mp, xs_log_force_sleep); + xlog_wait(&iclog->ic_force_wait, &log->l_icloglock); + if (iclog->ic_state & XLOG_STATE_IOERROR) + return -EIO; return 0; + +out_unlock: + spin_unlock(&log->l_icloglock); + return 0; +out_error: + spin_unlock(&log->l_icloglock); + return -EIO; } /* |