From 16615be18cadf53ee6f8a4f0bdd647f0753421b1 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 17 Sep 2007 10:59:52 +0100 Subject: [GFS2] Clean up journaled data writing This patch cleans up the code for writing journaled data into the log. It also removes the need to allocate a small "tag" structure for each block written into the log. Instead we just keep count of the outstanding I/O so that we can be sure that its all been written at the correct time. Another result of this patch is that a number of ll_rw_block() calls have become submit_bh() calls, closing some races at the same time. Signed-off-by: Steven Whitehouse --- fs/gfs2/log.c | 145 +++++++++++++++++++++++++++++++++------------------------- 1 file changed, 83 insertions(+), 62 deletions(-) (limited to 'fs/gfs2/log.c') diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 4d04e6f..ee70467 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -104,11 +104,8 @@ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) gfs2_assert(sdp, bd->bd_ail == ai); if (!buffer_busy(bh)) { - if (!buffer_uptodate(bh)) { - gfs2_log_unlock(sdp); + if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); - gfs2_log_lock(sdp); - } list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); continue; } @@ -118,9 +115,16 @@ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list); + get_bh(bh); gfs2_log_unlock(sdp); - wait_on_buffer(bh); - ll_rw_block(WRITE, 1, &bh); + lock_buffer(bh); + if (test_clear_buffer_dirty(bh)) { + bh->b_end_io = end_buffer_write_sync; + submit_bh(WRITE, bh); + } else { + unlock_buffer(bh); + brelse(bh); + } gfs2_log_lock(sdp); retry = 1; @@ -446,10 +450,10 @@ static unsigned int current_tail(struct gfs2_sbd *sdp) return tail; } -static inline void log_incr_head(struct gfs2_sbd *sdp) +void gfs2_log_incr_head(struct gfs2_sbd *sdp) { if (sdp->sd_log_flush_head == sdp->sd_log_tail) - gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head); + BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head); if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { sdp->sd_log_flush_head = 0; @@ -458,6 +462,23 @@ static inline void log_incr_head(struct gfs2_sbd *sdp) } /** + * gfs2_log_write_endio - End of I/O for a log buffer + * @bh: The buffer head + * @uptodate: I/O Status + * + */ + +static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate) +{ + struct gfs2_sbd *sdp = bh->b_private; + bh->b_private = NULL; + + end_buffer_write_sync(bh, uptodate); + if (atomic_dec_and_test(&sdp->sd_log_in_flight)) + wake_up(&sdp->sd_log_flush_wait); +} + +/** * gfs2_log_get_buf - Get and initialize a buffer to use for log control data * @sdp: The GFS2 superblock * @@ -467,25 +488,42 @@ static inline void log_incr_head(struct gfs2_sbd *sdp) struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp) { u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); - struct gfs2_log_buf *lb; struct buffer_head *bh; - lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL); - list_add(&lb->lb_list, &sdp->sd_log_flush_list); - - bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno); + bh = sb_getblk(sdp->sd_vfs, blkno); lock_buffer(bh); memset(bh->b_data, 0, bh->b_size); set_buffer_uptodate(bh); clear_buffer_dirty(bh); - unlock_buffer(bh); - - log_incr_head(sdp); + gfs2_log_incr_head(sdp); + atomic_inc(&sdp->sd_log_in_flight); + bh->b_private = sdp; + bh->b_end_io = gfs2_log_write_endio; return bh; } /** + * gfs2_fake_write_endio - + * @bh: The buffer head + * @uptodate: The I/O Status + * + */ + +static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate) +{ + struct buffer_head *real_bh = bh->b_private; + struct gfs2_sbd *sdp = GFS2_SB(real_bh->b_page->mapping->host); + + end_buffer_write_sync(bh, uptodate); + free_buffer_head(bh); + unlock_buffer(real_bh); + brelse(real_bh); + if (atomic_dec_and_test(&sdp->sd_log_in_flight)) + wake_up(&sdp->sd_log_flush_wait); +} + +/** * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log * @sdp: the filesystem * @data: the data the buffer_head should point to @@ -497,22 +535,20 @@ struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp, struct buffer_head *real) { u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); - struct gfs2_log_buf *lb; struct buffer_head *bh; - lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL); - list_add(&lb->lb_list, &sdp->sd_log_flush_list); - lb->lb_real = real; - - bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); + bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); atomic_set(&bh->b_count, 1); - bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate); + bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock); set_bh_page(bh, real->b_page, bh_offset(real)); bh->b_blocknr = blkno; bh->b_size = sdp->sd_sb.sb_bsize; bh->b_bdev = sdp->sd_vfs->s_bdev; + bh->b_private = real; + bh->b_end_io = gfs2_fake_write_endio; - log_incr_head(sdp); + gfs2_log_incr_head(sdp); + atomic_inc(&sdp->sd_log_in_flight); return bh; } @@ -579,45 +615,24 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) gfs2_assert_withdraw(sdp, !pull); sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); - log_incr_head(sdp); + gfs2_log_incr_head(sdp); } static void log_flush_commit(struct gfs2_sbd *sdp) { - struct list_head *head = &sdp->sd_log_flush_list; - struct gfs2_log_buf *lb; - struct buffer_head *bh; - int flushcount = 0; - - while (!list_empty(head)) { - lb = list_entry(head->next, struct gfs2_log_buf, lb_list); - list_del(&lb->lb_list); - bh = lb->lb_bh; - - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) - gfs2_io_error_bh(sdp, bh); - if (lb->lb_real) { - while (atomic_read(&bh->b_count) != 1) /* Grrrr... */ - schedule(); - free_buffer_head(bh); - } else - brelse(bh); - kfree(lb); - flushcount++; + DEFINE_WAIT(wait); + + if (atomic_read(&sdp->sd_log_in_flight)) { + do { + prepare_to_wait(&sdp->sd_log_flush_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (atomic_read(&sdp->sd_log_in_flight)) + io_schedule(); + } while(atomic_read(&sdp->sd_log_in_flight)); + finish_wait(&sdp->sd_log_flush_wait, &wait); } - /* If nothing was journaled, the header is unplanned and unwanted. */ - if (flushcount) { - log_write_header(sdp, 0, 0); - } else { - unsigned int tail; - tail = current_tail(sdp); - - gfs2_ail1_empty(sdp, 0); - if (sdp->sd_log_tail != tail) - log_pull_tail(sdp, tail); - } + log_write_header(sdp, 0, 0); } static void gfs2_ordered_write(struct gfs2_sbd *sdp) @@ -698,10 +713,16 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) INIT_LIST_HEAD(&ai->ai_ail1_list); INIT_LIST_HEAD(&ai->ai_ail2_list); - gfs2_assert_withdraw(sdp, - sdp->sd_log_num_buf + sdp->sd_log_num_databuf == - sdp->sd_log_commited_buf + - sdp->sd_log_commited_databuf); + if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) { + printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf, + sdp->sd_log_commited_buf); + gfs2_assert_withdraw(sdp, 0); + } + if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) { + printk(KERN_INFO "GFS2: log databuf %u %u\n", + sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf); + gfs2_assert_withdraw(sdp, 0); + } gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); @@ -713,7 +734,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) lops_before_commit(sdp); gfs2_ordered_wait(sdp); - if (!list_empty(&sdp->sd_log_flush_list)) + if (sdp->sd_log_head != sdp->sd_log_flush_head) log_flush_commit(sdp); else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ gfs2_log_lock(sdp); -- cgit v1.1