diff options
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index db03f6f7b5a4..b128aaa9b870 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -877,7 +877,7 @@ restart: * Once we attach the ctx to the iclog, a shutdown can process the * iclog, run the callbacks and free the ctx. The only thing preventing * this potential UAF situation here is that we are holding the - * icloglock. Hence we cannot access the ctx after we have attached the + * icloglock. Hence we cannot access the ctx once we have attached the * callbacks and dropped the icloglock. */ spin_lock(&log->l_icloglock); @@ -900,17 +900,38 @@ restart: spin_unlock(&cil->xc_push_lock); /* - * If the checkpoint spans multiple iclogs, wait for all previous - * iclogs to complete before we submit the commit_iclog. In this case, - * the commit_iclog write needs to issue a pre-flush so that the - * ordering is correctly preserved down to stable storage. + * If the checkpoint spans multiple iclogs, wait for all previous iclogs + * to complete before we submit the commit_iclog. We can't use state + * checks for this - ACTIVE can be either a past completed iclog or a + * future iclog being filled, while WANT_SYNC through SYNC_DONE can be a + * past or future iclog awaiting IO or ordered IO completion to be run. + * In the latter case, if it's a future iclog and we wait on it, the we + * will hang because it won't get processed through to ic_force_wait + * wakeup until this commit_iclog is written to disk. Hence we use the + * iclog header lsn and compare it to the commit lsn to determine if we + * need to wait on iclogs or not. * * NOTE: It is not safe to reference the ctx after this check as we drop * the icloglock if we have to wait for completion of other iclogs. */ if (ctx->start_lsn != commit_lsn) { - xlog_wait_on_iclog(commit_iclog->ic_prev); - spin_lock(&log->l_icloglock); + xfs_lsn_t plsn; + + plsn = be64_to_cpu(commit_iclog->ic_prev->ic_header.h_lsn); + if (plsn && XFS_LSN_CMP(plsn, commit_lsn) < 0) { + /* + * Waiting on ic_force_wait orders the completion of + * iclogs older than ic_prev. Hence we only need to wait + * on the most recent older iclog here. + */ + xlog_wait_on_iclog(commit_iclog->ic_prev); + spin_lock(&log->l_icloglock); + } + + /* + * We need to issue a pre-flush so that the ordering for this + * checkpoint is correctly preserved down to stable storage. + */ commit_iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; } |