* [PATCH v2 1/2] gfs2: replace sd_aspace with sd_inode
2025-04-11 17:38 [PATCH v2 0/2] Fix false warning in inode_to_wb Andreas Gruenbacher
@ 2025-04-11 17:38 ` Andreas Gruenbacher
2025-04-11 17:38 ` [PATCH v2 2/2] writeback: Fix false warning in inode_to_wb() Andreas Gruenbacher
2025-04-12 14:21 ` [PATCH v2 0/2] Fix false warning in inode_to_wb Tetsuo Handa
2 siblings, 0 replies; 5+ messages in thread
From: Andreas Gruenbacher @ 2025-04-11 17:38 UTC (permalink / raw)
To: cgroups
Cc: Andreas Gruenbacher, Tetsuo Handa, Jan Kara, Rafael Aquini, gfs2,
linux-mm, linux-fsdevel, linux-kernel
Currently, sdp->sd_aspace and the per-inode metadata address spaces use
sb->s_bdev->bd_mapping->host as their ->host; folios in those address
spaces will thus appear to be on bdev rather than on gfs2 filesystems.
This is a problem because gfs2 doesn't support cgroup writeback
(SB_I_CGROUPWB), but bdev does.
Fix that by using a "dummy" gfs2 inode as ->host in those address
spaces. When coming from a folio, folio->mapping->host->i_sb will then
be a gfs2 super block and the SB_I_CGROUPWB flag will not be set in
sb->s_iflags.
Based on a previous version from Bob Peterson from several years ago.
Thanks to Tetsuo Handa, Jan Kara, and Rafael Aquini for helping me
figure this out.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
fs/gfs2/glock.c | 3 +--
fs/gfs2/glops.c | 4 ++--
fs/gfs2/incore.h | 9 ++++++++-
fs/gfs2/meta_io.c | 2 +-
fs/gfs2/meta_io.h | 4 +---
fs/gfs2/ops_fstype.c | 31 ++++++++++++++++++-------------
fs/gfs2/super.c | 2 +-
7 files changed, 32 insertions(+), 23 deletions(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index d7220a6fe8f5..ba25b884169e 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1166,7 +1166,6 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
const struct gfs2_glock_operations *glops, int create,
struct gfs2_glock **glp)
{
- struct super_block *s = sdp->sd_vfs;
struct lm_lockname name = { .ln_number = number,
.ln_type = glops->go_type,
.ln_sbd = sdp };
@@ -1229,7 +1228,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
mapping = gfs2_glock2aspace(gl);
if (mapping) {
mapping->a_ops = &gfs2_meta_aops;
- mapping->host = s->s_bdev->bd_mapping->host;
+ mapping->host = sdp->sd_inode;
mapping->flags = 0;
mapping_set_gfp_mask(mapping, GFP_NOFS);
mapping->i_private_data = NULL;
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index eb4714f299ef..116efe335c32 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -168,7 +168,7 @@ void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
static int gfs2_rgrp_metasync(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct address_space *metamapping = &sdp->sd_aspace;
+ struct address_space *metamapping = gfs2_aspace(sdp);
struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(gl);
const unsigned bsize = sdp->sd_sb.sb_bsize;
loff_t start = (rgd->rd_addr * bsize) & PAGE_MASK;
@@ -225,7 +225,7 @@ static int rgrp_go_sync(struct gfs2_glock *gl)
static void rgrp_go_inval(struct gfs2_glock *gl, int flags)
{
struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
- struct address_space *mapping = &sdp->sd_aspace;
+ struct address_space *mapping = gfs2_aspace(sdp);
struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(gl);
const unsigned bsize = sdp->sd_sb.sb_bsize;
loff_t start, end;
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 74abbd4970f8..0a41c4e76b32 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -795,7 +795,7 @@ struct gfs2_sbd {
/* Log stuff */
- struct address_space sd_aspace;
+ struct inode *sd_inode;
spinlock_t sd_log_lock;
@@ -851,6 +851,13 @@ struct gfs2_sbd {
unsigned long sd_glock_dqs_held;
};
+#define GFS2_BAD_INO 1
+
+static inline struct address_space *gfs2_aspace(struct gfs2_sbd *sdp)
+{
+ return sdp->sd_inode->i_mapping;
+}
+
static inline void gfs2_glstats_inc(struct gfs2_glock *gl, int which)
{
gl->gl_stats.stats[which]++;
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 198cc7056637..9dc8885c95d0 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -132,7 +132,7 @@ struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create)
unsigned int bufnum;
if (mapping == NULL)
- mapping = &sdp->sd_aspace;
+ mapping = gfs2_aspace(sdp);
shift = PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift;
index = blkno >> shift; /* convert block to page */
diff --git a/fs/gfs2/meta_io.h b/fs/gfs2/meta_io.h
index 831d988c2ceb..b7c8a6684d02 100644
--- a/fs/gfs2/meta_io.h
+++ b/fs/gfs2/meta_io.h
@@ -44,9 +44,7 @@ static inline struct gfs2_sbd *gfs2_mapping2sbd(struct address_space *mapping)
struct gfs2_glock_aspace *gla =
container_of(mapping, struct gfs2_glock_aspace, mapping);
return gla->glock.gl_name.ln_sbd;
- } else if (mapping->a_ops == &gfs2_rgrp_aops)
- return container_of(mapping, struct gfs2_sbd, sd_aspace);
- else
+ } else
return inode->i_sb->s_fs_info;
}
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index e83d293c3614..dbd6f76bfa2b 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -72,7 +72,6 @@ void free_sbd(struct gfs2_sbd *sdp)
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)
@@ -109,16 +108,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
INIT_LIST_HEAD(&sdp->sd_sc_inodes_list);
- mapping = &sdp->sd_aspace;
-
- address_space_init_once(mapping);
- mapping->a_ops = &gfs2_rgrp_aops;
- mapping->host = sb->s_bdev->bd_mapping->host;
- mapping->flags = 0;
- mapping_set_gfp_mask(mapping, GFP_NOFS);
- mapping->i_private_data = NULL;
- mapping->writeback_index = 0;
-
spin_lock_init(&sdp->sd_log_lock);
atomic_set(&sdp->sd_log_pinned, 0);
INIT_LIST_HEAD(&sdp->sd_log_revokes);
@@ -1135,6 +1124,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
int silent = fc->sb_flags & SB_SILENT;
struct gfs2_sbd *sdp;
struct gfs2_holder mount_gh;
+ struct address_space *mapping;
int error;
sdp = init_sbd(sb);
@@ -1156,6 +1146,19 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_flags |= SB_NOSEC;
sb->s_magic = GFS2_MAGIC;
sb->s_op = &gfs2_super_ops;
+
+ /* Set up an address space for metadata writes */
+ sdp->sd_inode = new_inode(sb);
+ error = -ENOMEM;
+ if (!sdp->sd_inode)
+ goto fail_free;
+ sdp->sd_inode->i_ino = GFS2_BAD_INO;
+ sdp->sd_inode->i_size = OFFSET_MAX;
+
+ mapping = gfs2_aspace(sdp);
+ mapping->a_ops = &gfs2_rgrp_aops;
+ mapping_set_gfp_mask(mapping, GFP_NOFS);
+
sb->s_d_op = &gfs2_dops;
sb->s_export_op = &gfs2_export_ops;
sb->s_qcop = &gfs2_quotactl_ops;
@@ -1183,7 +1186,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
error = init_names(sdp, silent);
if (error)
- goto fail_free;
+ goto fail_iput;
snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s", sdp->sd_table_name);
@@ -1192,7 +1195,7 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_FREEZABLE, 0,
sdp->sd_fsname);
if (!sdp->sd_glock_wq)
- goto fail_free;
+ goto fail_iput;
sdp->sd_delete_wq = alloc_workqueue("gfs2-delete/%s",
WQ_MEM_RECLAIM | WQ_FREEZABLE, 0, sdp->sd_fsname);
@@ -1309,6 +1312,8 @@ static int gfs2_fill_super(struct super_block *sb, struct fs_context *fc)
fail_glock_wq:
if (sdp->sd_glock_wq)
destroy_workqueue(sdp->sd_glock_wq);
+fail_iput:
+ iput(sdp->sd_inode);
fail_free:
free_sbd(sdp);
sb->s_fs_info = NULL;
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 44e5658b896c..4529b7dda8ca 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -648,7 +648,7 @@ static void gfs2_put_super(struct super_block *sb)
gfs2_jindex_free(sdp);
/* Take apart glock structures and buffer lists */
gfs2_gl_hash_clear(sdp);
- truncate_inode_pages_final(&sdp->sd_aspace);
+ iput(sdp->sd_inode);
gfs2_delete_debugfs_file(sdp);
gfs2_sys_fs_del(sdp);
--
2.48.1
^ permalink raw reply [flat|nested] 5+ messages in thread