From 5cb738b5fbd2f3ebe9dec0e428577a4f2128adbe Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sat, 19 Dec 2020 07:15:17 +0100 Subject: gfs2: Get rid of current_tail() Keep the current value of the updated log tail in the super block as sb_log_flush_tail instead of computing it on the fly. This avoids unnecessary sd_ail_lock taking and cleans up the code. Signed-off-by: Andreas Gruenbacher --- fs/gfs2/log.c | 72 +++++++++++++++++++++++++++++++---------------------------- 1 file changed, 38 insertions(+), 34 deletions(-) (limited to 'fs/gfs2/log.c') diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index ca9fa481913d..6b5584fd8ff7 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -242,6 +242,28 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp) return gfs2_ail1_flush(sdp, &wbc); } +static void gfs2_log_update_flush_tail(struct gfs2_sbd *sdp) +{ + unsigned int new_flush_tail = sdp->sd_log_head; + struct gfs2_trans *tr; + + if (!list_empty(&sdp->sd_ail1_list)) { + tr = list_last_entry(&sdp->sd_ail1_list, + struct gfs2_trans, tr_list); + new_flush_tail = tr->tr_first; + } + sdp->sd_log_flush_tail = new_flush_tail; +} + +static void gfs2_log_update_head(struct gfs2_sbd *sdp) +{ + unsigned int new_head = sdp->sd_log_flush_head; + + if (sdp->sd_log_flush_tail == sdp->sd_log_head) + sdp->sd_log_flush_tail = new_head; + sdp->sd_log_head = new_head; +} + /** * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced * @sdp: the filesystem @@ -317,6 +339,7 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes) else oldest_tr = 0; } + gfs2_log_update_flush_tail(sdp); ret = list_empty(&sdp->sd_ail1_list); spin_unlock(&sdp->sd_ail_lock); @@ -544,30 +567,14 @@ static unsigned int calc_reserved(struct gfs2_sbd *sdp) return reserved; } -static unsigned int current_tail(struct gfs2_sbd *sdp) -{ - struct gfs2_trans *tr; - unsigned int tail; - - spin_lock(&sdp->sd_ail_lock); - - if (list_empty(&sdp->sd_ail1_list)) { - tail = sdp->sd_log_head; - } else { - tr = list_last_entry(&sdp->sd_ail1_list, struct gfs2_trans, - tr_list); - tail = tr->tr_first; - } - - spin_unlock(&sdp->sd_ail_lock); - - return tail; -} - -static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) +static void log_pull_tail(struct gfs2_sbd *sdp) { - unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); + unsigned int new_tail = sdp->sd_log_flush_tail; + unsigned int dist; + if (new_tail == sdp->sd_log_tail) + return; + dist = log_distance(sdp, new_tail, sdp->sd_log_tail); ail2_empty(sdp, new_tail); gfs2_log_release(sdp, dist); sdp->sd_log_tail = new_tail; @@ -822,26 +829,23 @@ void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd, static void log_write_header(struct gfs2_sbd *sdp, u32 flags) { - unsigned int tail; int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC; enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); gfs2_assert_withdraw(sdp, (state != SFS_FROZEN)); - tail = current_tail(sdp); if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) { gfs2_ordered_wait(sdp); log_flush_wait(sdp); op_flags = REQ_SYNC | REQ_META | REQ_PRIO; } - sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); - gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail, - sdp->sd_log_flush_head, flags, op_flags); + sdp->sd_log_idle = (sdp->sd_log_flush_tail == sdp->sd_log_flush_head); + gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, + sdp->sd_log_flush_tail, sdp->sd_log_flush_head, + flags, op_flags); gfs2_log_incr_head(sdp); log_flush_wait(sdp); - - if (sdp->sd_log_tail != tail) - log_pull_tail(sdp, tail); + log_pull_tail(sdp); } /** @@ -991,7 +995,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) if (sdp->sd_log_head != sdp->sd_log_flush_head) { log_flush_wait(sdp); log_write_header(sdp, flags); - } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle) { + } else if (sdp->sd_log_tail != sdp->sd_log_flush_tail && !sdp->sd_log_idle) { atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ trace_gfs2_log_blocks(sdp, -1); log_write_header(sdp, flags); @@ -1001,7 +1005,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) lops_after_commit(sdp, tr); gfs2_log_lock(sdp); - sdp->sd_log_head = sdp->sd_log_flush_head; + gfs2_log_update_head(sdp); sdp->sd_log_blks_reserved = 0; sdp->sd_log_committed_revoke = 0; @@ -1021,7 +1025,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ trace_gfs2_log_blocks(sdp, -1); log_write_header(sdp, flags); - sdp->sd_log_head = sdp->sd_log_flush_head; + gfs2_log_update_head(sdp); } if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN | GFS2_LOG_HEAD_FLUSH_FREEZE)) @@ -1156,7 +1160,7 @@ static void gfs2_log_shutdown(struct gfs2_sbd *sdp) gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); - sdp->sd_log_head = sdp->sd_log_flush_head; + gfs2_log_update_head(sdp); sdp->sd_log_tail = sdp->sd_log_head; } -- cgit v1.2.3