From 6aad1c3d3eba3db38b3a1200e2b02ff3af501c5a Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Mon, 5 Mar 2012 09:20:59 -0500 Subject: [PATCH] GFS2: Eliminate sd_rindex_mutex Over time, we've slowly eliminated the use of sd_rindex_mutex. Up to this point, it was only used in two places: function gfs2_ri_total (which totals the file system size by reading and parsing the rindex file) and function gfs2_rindex_update which updates the rgrps in memory. Both of these functions have the rindex glock to protect them, so the rindex is unnecessary. Since gfs2_grow writes to the rindex via the meta_fs, the mutex is in the wrong order according to the normal rules. This patch eliminates the mutex entirely to avoid the problem. Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/incore.h | 1 - fs/gfs2/ops_fstype.c | 1 - fs/gfs2/rgrp.c | 22 ++++++++++------------ 3 files changed, 10 insertions(+), 14 deletions(-) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 4d546df58ac9..47d0bda5ac2b 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -644,7 +644,6 @@ struct gfs2_sbd { int sd_rindex_uptodate; spinlock_t sd_rindex_spin; - struct mutex sd_rindex_mutex; struct rb_root sd_rindex_tree; unsigned int sd_rgrps; unsigned int sd_max_rg_data; diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index a55baa7f3239..ae5e0a40c9b3 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -83,7 +83,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb) spin_lock_init(&sdp->sd_statfs_spin); spin_lock_init(&sdp->sd_rindex_spin); - mutex_init(&sdp->sd_rindex_mutex); sdp->sd_rindex_tree.rb_node = NULL; INIT_LIST_HEAD(&sdp->sd_jindex_list); diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index e09370eec590..6ff9f17f9ac2 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -540,7 +540,6 @@ u64 gfs2_ri_total(struct gfs2_sbd *sdp) struct file_ra_state ra_state; int error, rgrps; - mutex_lock(&sdp->sd_rindex_mutex); file_ra_state_init(&ra_state, inode->i_mapping); for (rgrps = 0;; rgrps++) { loff_t pos = rgrps * sizeof(struct gfs2_rindex); @@ -553,11 +552,10 @@ u64 gfs2_ri_total(struct gfs2_sbd *sdp) break; total_data += be32_to_cpu(((struct gfs2_rindex *)buf)->ri_data); } - mutex_unlock(&sdp->sd_rindex_mutex); return total_data; } -static void rgd_insert(struct gfs2_rgrpd *rgd) +static int rgd_insert(struct gfs2_rgrpd *rgd) { struct gfs2_sbd *sdp = rgd->rd_sbd; struct rb_node **newn = &sdp->sd_rindex_tree.rb_node, *parent = NULL; @@ -573,11 +571,13 @@ static void rgd_insert(struct gfs2_rgrpd *rgd) else if (rgd->rd_addr > cur->rd_addr) newn = &((*newn)->rb_right); else - return; + return -EEXIST; } rb_link_node(&rgd->rd_node, parent, newn); rb_insert_color(&rgd->rd_node, &sdp->sd_rindex_tree); + sdp->sd_rgrps++; + return 0; } /** @@ -631,10 +631,12 @@ static int read_rindex_entry(struct gfs2_inode *ip, if (rgd->rd_data > sdp->sd_max_rg_data) sdp->sd_max_rg_data = rgd->rd_data; spin_lock(&sdp->sd_rindex_spin); - rgd_insert(rgd); - sdp->sd_rgrps++; + error = rgd_insert(rgd); spin_unlock(&sdp->sd_rindex_spin); - return error; + if (!error) + return 0; + + error = 0; /* someone else read in the rgrp; free it and ignore it */ fail: kfree(rgd->rd_bits); @@ -695,22 +697,18 @@ int gfs2_rindex_update(struct gfs2_sbd *sdp) /* Read new copy from disk if we don't have the latest */ if (!sdp->sd_rindex_uptodate) { - mutex_lock(&sdp->sd_rindex_mutex); if (!gfs2_glock_is_locked_by_me(gl)) { error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, &ri_gh); if (error) - goto out_unlock; + return error; unlock_required = 1; } if (!sdp->sd_rindex_uptodate) error = gfs2_ri_update(ip); if (unlock_required) gfs2_glock_dq_uninit(&ri_gh); -out_unlock: - mutex_unlock(&sdp->sd_rindex_mutex); } - return error; } -- 2.39.5