GFS2: Use only a single address space for rgrps

Prior to this patch, GFS2 had one address space for each rgrp,
stored in the glock. This patch changes them to use a single
address space in the super block. This therefore saves
(sizeof(struct address_space) * nr_of_rgrps) bytes of memory
and for large filesystems, that can be significant.

It would be nice to be able to do something similar and merge
the inode metadata address space into the same global
address space. However, that is rather more complicated as the
on-disk location doesn't have a 1:1 mapping with the inodes in
general. So while it could be done, it will be a more complicated
operation as it requires changing a lot more code paths.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 1b192c8d404dc228faee9184059502264a915163..b792dbcc83f668b0a4ef304403ccbe89f7556653 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -133,7 +133,8 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
 
 static void rgrp_go_sync(struct gfs2_glock *gl)
 {
-       struct address_space *metamapping = gfs2_glock2aspace(gl);
+       struct gfs2_sbd *sdp = gl->gl_sbd;
+       struct address_space *mapping = &sdp->sd_aspace;
        struct gfs2_rgrpd *rgd;
        int error;
 
@@ -141,10 +142,10 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
                return;
        GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
 
-       gfs2_log_flush(gl->gl_sbd, gl);
-       filemap_fdatawrite_range(metamapping, gl->gl_vm.start, gl->gl_vm.end);
-       error = filemap_fdatawait_range(metamapping, gl->gl_vm.start, gl->gl_vm.end);
-        mapping_set_error(metamapping, error);
+       gfs2_log_flush(sdp, gl);
+       filemap_fdatawrite_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
+       error = filemap_fdatawait_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
+       mapping_set_error(mapping, error);
        gfs2_ail_empty_gl(gl);
 
        spin_lock(&gl->gl_spin);
@@ -166,10 +167,11 @@ static void rgrp_go_sync(struct gfs2_glock *gl)
 
 static void rgrp_go_inval(struct gfs2_glock *gl, int flags)
 {
-       struct address_space *mapping = gfs2_glock2aspace(gl);
+       struct gfs2_sbd *sdp = gl->gl_sbd;
+       struct address_space *mapping = &sdp->sd_aspace;
 
        WARN_ON_ONCE(!(flags & DIO_METADATA));
-       gfs2_assert_withdraw(gl->gl_sbd, !atomic_read(&gl->gl_ail_count));
+       gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
        truncate_inode_pages_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
 
        if (gl->gl_object) {
@@ -558,7 +560,7 @@ const struct gfs2_glock_operations gfs2_rgrp_glops = {
        .go_unlock = gfs2_rgrp_go_unlock,
        .go_dump = gfs2_rgrp_dump,
        .go_type = LM_TYPE_RGRP,
-       .go_flags = GLOF_ASPACE | GLOF_LVB,
+       .go_flags = GLOF_LVB,
 };
 
 const struct gfs2_glock_operations gfs2_trans_glops = {

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index e6544ee0c1379816bf40e8eda1da6eee86093a8d..a99f60c98845db04ccc733feb1a6c0a4e09d4d6e 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -736,6 +736,8 @@ struct gfs2_sbd {
 
        /* Log stuff */
 
+       struct address_space sd_aspace;
+
        spinlock_t sd_log_lock;
 
        struct gfs2_trans *sd_log_tr;

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index cdadb92372f23e9a2d4ce6ed56306b019e7535fb..58f06400b7b8dcece9597b51b05ebf9ebc092396 100644 (file)
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -589,8 +589,12 @@ static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
 static void gfs2_meta_sync(struct gfs2_glock *gl)
 {
        struct address_space *mapping = gfs2_glock2aspace(gl);
+       struct gfs2_sbd *sdp = gl->gl_sbd;
        int error;
 
+       if (mapping == NULL)
+               mapping = &sdp->sd_aspace;
+
        filemap_fdatawrite(mapping);
        error = filemap_fdatawait(mapping);
 

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 52f177be3bf861309ed2439d33da7617bba8dba8..c7f24690ed054b0195568ac1762b4401a2e96ac6 100644 (file)
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -116,6 +116,9 @@ struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
        unsigned long index;
        unsigned int bufnum;
 
+       if (mapping == NULL)
+               mapping = &sdp->sd_aspace;
+
        shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
        index = blkno >> shift;             /* convert block to page */
        bufnum = blkno - (index << shift);  /* block buf index within page */

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 52fa88314f5cdf8ef98ed95e44791a5065cbfccd..94aab31477b688f76ee32ca752c8931203a3161c 100644 (file)
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -36,6 +36,7 @@
 #include "log.h"
 #include "quota.h"
 #include "dir.h"
+#include "meta_io.h"
 #include "trace_gfs2.h"
 
 #define DO 0
@@ -62,6 +63,7 @@ static void gfs2_tune_init(struct gfs2_tune *gt)
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 {
        struct gfs2_sbd *sdp;
+       struct address_space *mapping;
 
        sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
        if (!sdp)
@@ -98,6 +100,16 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
        INIT_LIST_HEAD(&sdp->sd_trunc_list);
        spin_lock_init(&sdp->sd_trunc_lock);
 
+       mapping = &sdp->sd_aspace;
+
+       mapping->a_ops = &gfs2_meta_aops;
+       mapping->host = sb->s_bdev->bd_inode;
+       mapping->flags = 0;
+       mapping_set_gfp_mask(mapping, GFP_NOFS);
+       mapping->private_data = NULL;
+       mapping->backing_dev_info = sb->s_bdi;
+       mapping->writeback_index = 0;
+
        spin_lock_init(&sdp->sd_log_lock);
        atomic_set(&sdp->sd_log_pinned, 0);
        INIT_LIST_HEAD(&sdp->sd_log_le_buf);