diff options
Diffstat (limited to 'fs/gfs2')
| -rw-r--r-- | fs/gfs2/log.c | 74 |
1 files changed, 36 insertions, 38 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 584bb7ce15bf..578c1e0cd415 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -191,11 +191,13 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp) /** * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced * @sdp: the filesystem - * @ai: the AIL entry + * @tr: the transaction + * @max_revokes: If nonzero, issue revokes for the bd items for written buffers * */ -static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr, + int *max_revokes) { struct gfs2_bufdata *bd, *s; struct buffer_head *bh; @@ -220,6 +222,17 @@ static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) gfs2_io_error_bh(sdp, bh); gfs2_withdraw_delayed(sdp); } + /* + * If we have space for revokes and the bd is no longer on any + * buf list, we can just add a revoke for it immediately and + * avoid having to put it on the ail2 list, where it would need + * to be revoked later. + */ + if (*max_revokes && list_empty(&bd->bd_list)) { + gfs2_add_revoke(sdp, bd); + (*max_revokes)--; + continue; + } list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); } } @@ -227,11 +240,12 @@ static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) /** * gfs2_ail1_empty - Try to empty the ail1 lists * @sdp: The superblock + * @max_revokes: If non-zero, add revokes where appropriate * * Tries to empty the ail1 lists, starting with the oldest first */ -static int gfs2_ail1_empty(struct gfs2_sbd *sdp) +static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes) { struct gfs2_trans *tr, *s; int oldest_tr = 1; @@ -239,7 +253,7 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp) spin_lock(&sdp->sd_ail_lock); list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) { - gfs2_ail1_empty_one(sdp, tr); + gfs2_ail1_empty_one(sdp, tr, &max_revokes); if (list_empty(&tr->tr_ail1_list) && oldest_tr) list_move(&tr->tr_list, &sdp->sd_ail2_list); else @@ -627,27 +641,24 @@ void gfs2_glock_remove_revoke(struct gfs2_glock *gl) } } +/** + * gfs2_write_revokes - Add as many revokes to the system transaction as we can + * @sdp: The GFS2 superblock + * + * Our usual strategy is to defer writing revokes as much as we can in the hope + * that we'll eventually overwrite the journal, which will make those revokes + * go away. This changes when we flush the log: at that point, there will + * likely be some left-over space in the last revoke block of that transaction. + * We can fill that space with additional revokes for blocks that have already + * been written back. This will basically come at no cost now, and will save + * us from having to keep track of those blocks on the AIL2 list later. + */ void gfs2_write_revokes(struct gfs2_sbd *sdp) { - struct gfs2_trans *tr; - struct gfs2_bufdata *bd, *tmp; - int have_revokes = 0; + /* number of revokes we still have room for */ int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64); - gfs2_ail1_empty(sdp); - spin_lock(&sdp->sd_ail_lock); - list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) { - list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) { - if (list_empty(&bd->bd_list)) { - have_revokes = 1; - goto done; - } - } - } -done: - spin_unlock(&sdp->sd_ail_lock); - if (have_revokes == 0) - return; + gfs2_log_lock(sdp); while (sdp->sd_log_num_revoke > max_revokes) max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64); max_revokes -= sdp->sd_log_num_revoke; @@ -658,20 +669,7 @@ done: if (!sdp->sd_log_blks_reserved) atomic_dec(&sdp->sd_log_blks_free); } - gfs2_log_lock(sdp); - spin_lock(&sdp->sd_ail_lock); - list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) { - list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) { - if (max_revokes == 0) - goto out_of_blocks; - if (!list_empty(&bd->bd_list)) - continue; - gfs2_add_revoke(sdp, bd); - max_revokes--; - } - } -out_of_blocks: - spin_unlock(&sdp->sd_ail_lock); + gfs2_ail1_empty(sdp, max_revokes); gfs2_log_unlock(sdp); if (!sdp->sd_log_num_revoke) { @@ -870,7 +868,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) for (;;) { gfs2_ail1_start(sdp); gfs2_ail1_wait(sdp); - if (gfs2_ail1_empty(sdp)) + if (gfs2_ail1_empty(sdp, 0)) break; } if (gfs2_withdrawn(sdp)) @@ -1040,7 +1038,7 @@ int gfs2_logd(void *data) did_flush = false; if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { - gfs2_ail1_empty(sdp); + gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_LOGD_JFLUSH_REQD); did_flush = true; @@ -1049,7 +1047,7 @@ int gfs2_logd(void *data) if (gfs2_ail_flush_reqd(sdp)) { gfs2_ail1_start(sdp); gfs2_ail1_wait(sdp); - gfs2_ail1_empty(sdp); + gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_LOGD_AIL_FLUSH_REQD); did_flush = true; |