From f55ab26a8f92a23988c3e6da28dae4741933a4e2 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 21 Feb 2006 12:51:39 +0000 Subject: [GFS2] Use mutices rather than semaphores As well as a number of minor bug fixes, this patch changes GFS to use mutices rather than semaphores. This results in better information in case there are any locking problems. Signed-off-by: Steven Whitehouse --- fs/gfs2/log.c | 54 +++++++++++++++++++----------------------------------- 1 file changed, 19 insertions(+), 35 deletions(-) (limited to 'fs/gfs2/log.c') diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 49190a29dd4..e6acb41332e 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -23,29 +23,16 @@ #define PULL 1 -static inline int is_done(struct gfs2_sbd *sdp, atomic_t *a) -{ - int done; - gfs2_log_lock(sdp); - done = atomic_read(a) ? 0 : 1; - gfs2_log_unlock(sdp); - return done; -} - static void do_lock_wait(struct gfs2_sbd *sdp, wait_queue_head_t *wq, atomic_t *a) { - gfs2_log_unlock(sdp); - wait_event(*wq, is_done(sdp, a)); - gfs2_log_lock(sdp); + wait_event(*wq, atomic_read(a) ? 0 : 1); } static void lock_for_trans(struct gfs2_sbd *sdp) { - gfs2_log_lock(sdp); do_lock_wait(sdp, &sdp->sd_log_trans_wq, &sdp->sd_log_flush_count); atomic_inc(&sdp->sd_log_trans_count); - gfs2_log_unlock(sdp); } static void unlock_from_trans(struct gfs2_sbd *sdp) @@ -55,15 +42,13 @@ static void unlock_from_trans(struct gfs2_sbd *sdp) wake_up(&sdp->sd_log_flush_wq); } -void gfs2_lock_for_flush(struct gfs2_sbd *sdp) +static void gfs2_lock_for_flush(struct gfs2_sbd *sdp) { - gfs2_log_lock(sdp); atomic_inc(&sdp->sd_log_flush_count); do_lock_wait(sdp, &sdp->sd_log_flush_wq, &sdp->sd_log_trans_count); - gfs2_log_unlock(sdp); } -void gfs2_unlock_from_flush(struct gfs2_sbd *sdp) +static void gfs2_unlock_from_flush(struct gfs2_sbd *sdp) { gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_flush_count)); if (atomic_dec_and_test(&sdp->sd_log_flush_count)) @@ -209,7 +194,6 @@ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) for (;;) { gfs2_log_lock(sdp); - if (list_empty(&list)) { list_add_tail(&list, &sdp->sd_log_blks_list); while (sdp->sd_log_blks_list.next != &list) { @@ -225,7 +209,6 @@ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) set_current_state(TASK_RUNNING); } } - /* Never give away the last block so we can always pull the tail if we need to. */ if (sdp->sd_log_blks_free > blks) { @@ -237,14 +220,12 @@ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) } gfs2_log_unlock(sdp); - gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp); if (try++) gfs2_ail1_start(sdp, 0); } - lock_for_trans(sdp); return 0; @@ -512,22 +493,26 @@ void gfs2_log_flush_i(struct gfs2_sbd *sdp, struct gfs2_glock *gl) ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); INIT_LIST_HEAD(&ai->ai_ail1_list); INIT_LIST_HEAD(&ai->ai_ail2_list); - gfs2_lock_for_flush(sdp); - down(&sdp->sd_log_flush_lock); + + if (gl) { + gfs2_log_lock(sdp); + if (list_empty(&gl->gl_le.le_list)) { + gfs2_log_unlock(sdp); + gfs2_unlock_from_flush(sdp); + kfree(ai); + return; + } + gfs2_log_unlock(sdp); + } + + mutex_lock(&sdp->sd_log_flush_lock); gfs2_assert_withdraw(sdp, sdp->sd_log_num_buf == sdp->sd_log_commited_buf); gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); - if (gl && list_empty(&gl->gl_le.le_list)) { - up(&sdp->sd_log_flush_lock); - gfs2_unlock_from_flush(sdp); - kfree(ai); - return; - } - sdp->sd_log_flush_head = sdp->sd_log_head; sdp->sd_log_flush_wrapped = 0; ai->ai_first = sdp->sd_log_flush_head; @@ -538,7 +523,6 @@ void gfs2_log_flush_i(struct gfs2_sbd *sdp, struct gfs2_glock *gl) else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle) log_write_header(sdp, 0, PULL); lops_after_commit(sdp, ai); - sdp->sd_log_head = sdp->sd_log_flush_head; if (sdp->sd_log_flush_wrapped) sdp->sd_log_wraps++; @@ -554,7 +538,7 @@ void gfs2_log_flush_i(struct gfs2_sbd *sdp, struct gfs2_glock *gl) } gfs2_log_unlock(sdp); - up(&sdp->sd_log_flush_lock); + mutex_unlock(&sdp->sd_log_flush_lock); sdp->sd_vfs->s_dirt = 0; gfs2_unlock_from_flush(sdp); @@ -627,7 +611,7 @@ void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) void gfs2_log_shutdown(struct gfs2_sbd *sdp) { - down(&sdp->sd_log_flush_lock); + mutex_lock(&sdp->sd_log_flush_lock); gfs2_assert_withdraw(sdp, !atomic_read(&sdp->sd_log_trans_count)); gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); @@ -654,6 +638,6 @@ void gfs2_log_shutdown(struct gfs2_sbd *sdp) sdp->sd_log_wraps++; sdp->sd_log_tail = sdp->sd_log_head; - up(&sdp->sd_log_flush_lock); + mutex_unlock(&sdp->sd_log_flush_lock); } -- cgit v1.2.3