GFS2: Make rgrp reservations part of the gfs2_inode structure

Before this patch, multi-block reservation structures were allocated
from a special slab. This patch folds the structure into the gfs2_inode
structure. The disadvantage is that the gfs2_inode needs more memory,
even when a file is opened read-only. The advantages are: (a) we don't
need the special slab and the extra time it takes to allocate and
deallocate from it. (b) we no longer need to worry that the structure
exists for things like quota management. (c) This also allows us to
remove the calls to get_write_access and put_write_access since we
know the structure will exist.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

1 files changed, 14 insertions, 38 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index cb30748e7b19..b879925ce134 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -602,28 +602,7 @@ void gfs2_free_clones(struct gfs2_rgrpd *rgd)
  */
 int gfs2_rsqa_alloc(struct gfs2_inode *ip)
 {
-        int error = 0;
-
-        down_write(&ip->i_rw_mutex);
-        if (ip->i_res)
-                goto out;
-
-        ip->i_res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
-        if (!ip->i_res) {
-                error = -ENOMEM;
-                goto out;
-        }
-
-        RB_CLEAR_NODE(&ip->i_res->rs_node);
-        error = gfs2_qa_alloc(ip);
-        if (error) {
-                kmem_cache_free(gfs2_rsrv_cachep, ip->i_res);
-                ip->i_res = NULL;
-        }
-
-out:
-        up_write(&ip->i_rw_mutex);
-        return error;
+        return gfs2_qa_alloc(ip);
 }
 
 static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)
@@ -693,15 +672,12 @@ void gfs2_rs_deltree(struct gfs2_blkreserv *rs)
 void gfs2_rsqa_delete(struct gfs2_inode *ip, atomic_t *wcount)
 {
         down_write(&ip->i_rw_mutex);
-        if (ip->i_res && ((wcount == NULL) || (atomic_read(wcount) <= 1))) {
-                gfs2_rs_deltree(ip->i_res);
-                BUG_ON(ip->i_res->rs_free);
-                kmem_cache_free(gfs2_rsrv_cachep, ip->i_res);
-                ip->i_res = NULL;
-
-                gfs2_qa_delete(ip);
+        if ((wcount == NULL) || (atomic_read(wcount) <= 1)) {
+                gfs2_rs_deltree(&ip->i_res);
+                BUG_ON(ip->i_res.rs_free);
         }
         up_write(&ip->i_rw_mutex);
+        gfs2_qa_delete(ip, wcount);
 }
 
 /**
@@ -1465,7 +1441,7 @@ static void rs_insert(struct gfs2_inode *ip)
 {
         struct rb_node **newn, *parent = NULL;
         int rc;
-        struct gfs2_blkreserv *rs = ip->i_res;
+        struct gfs2_blkreserv *rs = &ip->i_res;
         struct gfs2_rgrpd *rgd = rs->rs_rbm.rgd;
         u64 fsblock = gfs2_rbm_to_block(&rs->rs_rbm);
 
@@ -1512,7 +1488,7 @@ static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
 {
         struct gfs2_rbm rbm = { .rgd = rgd, };
         u64 goal;
-        struct gfs2_blkreserv *rs = ip->i_res;
+        struct gfs2_blkreserv *rs = &ip->i_res;
         u32 extlen;
         u32 free_blocks = rgd->rd_free_clone - rgd->rd_reserved;
         int ret;
@@ -1583,7 +1559,7 @@ static u64 gfs2_next_unreserved_block(struct gfs2_rgrpd *rgd, u64 block,
         }
 
         if (n) {
-                while ((rs_cmp(block, length, rs) == 0) && (ip->i_res != rs)) {
+                while ((rs_cmp(block, length, rs) == 0) && (&ip->i_res != rs)) {
                         block = gfs2_rbm_to_block(&rs->rs_rbm) + rs->rs_free;
                         n = n->rb_right;
                         if (n == NULL)
@@ -1993,7 +1969,7 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
 {
         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_rgrpd *begin = NULL;
-        struct gfs2_blkreserv *rs = ip->i_res;
+        struct gfs2_blkreserv *rs = &ip->i_res;
         int error = 0, rg_locked, flags = 0;
         u64 last_unlinked = NO_BLOCK;
         int loops = 0;
@@ -2122,7 +2098,7 @@ next_rgrp:
 
 void gfs2_inplace_release(struct gfs2_inode *ip)
 {
-        struct gfs2_blkreserv *rs = ip->i_res;
+        struct gfs2_blkreserv *rs = &ip->i_res;
 
         if (rs->rs_rgd_gh.gh_gl)
                 gfs2_glock_dq_uninit(&rs->rs_rgd_gh);
@@ -2276,7 +2252,7 @@ static void gfs2_rgrp_error(struct gfs2_rgrpd *rgd)
 static void gfs2_adjust_reservation(struct gfs2_inode *ip,
                                     const struct gfs2_rbm *rbm, unsigned len)
 {
-        struct gfs2_blkreserv *rs = ip->i_res;
+        struct gfs2_blkreserv *rs = &ip->i_res;
         struct gfs2_rgrpd *rgd = rbm->rgd;
         unsigned rlen;
         u64 block;
@@ -2319,8 +2295,8 @@ static void gfs2_set_alloc_start(struct gfs2_rbm *rbm,
 {
         u64 goal;
 
-        if (gfs2_rs_active(ip->i_res)) {
-                *rbm = ip->i_res->rs_rbm;
+        if (gfs2_rs_active(&ip->i_res)) {
+                *rbm = ip->i_res.rs_rbm;
                 return;
         }
 
@@ -2374,7 +2350,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
         gfs2_alloc_extent(&rbm, dinode, nblocks);
         block = gfs2_rbm_to_block(&rbm);
         rbm.rgd->rd_last_alloc = block - rbm.rgd->rd_data0;
-        if (gfs2_rs_active(ip->i_res))
+        if (gfs2_rs_active(&ip->i_res))
                 gfs2_adjust_reservation(ip, &rbm, *nblocks);
         ndata = *nblocks;
         if (dinode)