[PATCH AUTOSEL 5.16 03/30] gfs2: Switch lock order of inode and iopen glock

Sasha Levin
2022-04-07T01:14:21Z

From: Andreas Gruenbacher <agruenba@redhat.com>

[ Upstream commit 29464ee36bcaaee2691249f49b9592b8d5c97ece ]

This patch tries to fix the continual ABBA deadlocks we keep having
between the iopen and inode glocks. This switches the lock order in
gfs2_inode_lookup and gfs2_create_inode so the iopen glock is always
locked first.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/gfs2/inode.c | 49 +++++++++++++++++++++++++++----------------------
1 file changed, 27 insertions(+), 22 deletions(-)

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 89905f4f29bb..b30ff50d17f3 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -131,7 +131,21 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct gfs2_glock *io_gl;

- error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
+ error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE,
+ &ip->i_gl);
+ if (unlikely(error))
+ goto fail;
+
+ error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE,
+ &io_gl);
+ if (unlikely(error))
+ goto fail;
+
+ if (blktype != GFS2_BLKST_UNLINKED)
+ gfs2_cancel_delete_work(io_gl);
+ error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT,
+ &ip->i_iopen_gh);
+ gfs2_glock_put(io_gl);
if (unlikely(error))
goto fail;

@@ -161,16 +175,6 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,

set_bit(GLF_INSTANTIATE_NEEDED, &ip->i_gl->gl_flags);

- error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
- if (unlikely(error))
- goto fail;
- if (blktype != GFS2_BLKST_UNLINKED)
- gfs2_cancel_delete_work(io_gl);
- error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
- gfs2_glock_put(io_gl);
- if (unlikely(error))
- goto fail;
-
/* Lowest possible timestamp; will be overwritten in gfs2_dinode_in. */
inode->i_atime.tv_sec = 1LL << (8 * sizeof(inode->i_atime.tv_sec) - 1);
inode->i_atime.tv_nsec = 0;
@@ -716,13 +720,17 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
error = insert_inode_locked4(inode, ip->i_no_addr, iget_test, &ip->i_no_addr);
BUG_ON(error);

- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+ error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
if (error)
goto fail_gunlock2;

+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+ if (error)
+ goto fail_gunlock3;
+
error = gfs2_trans_begin(sdp, blocks, 0);
if (error)
- goto fail_gunlock2;
+ goto fail_gunlock3;

if (blocks > 1) {
ip->i_eattr = ip->i_no_addr + 1;
@@ -731,10 +739,6 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
init_dinode(dip, ip, symname);
gfs2_trans_end(sdp);

- error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
- if (error)
- goto fail_gunlock2;
-
glock_set_object(ip->i_gl, ip);
glock_set_object(io_gl, ip);
gfs2_set_iop(inode);
@@ -745,14 +749,14 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
if (default_acl) {
error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
if (error)
- goto fail_gunlock3;
+ goto fail_gunlock4;
posix_acl_release(default_acl);
default_acl = NULL;
}
if (acl) {
error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
if (error)
- goto fail_gunlock3;
+ goto fail_gunlock4;
posix_acl_release(acl);
acl = NULL;
}
@@ -760,11 +764,11 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
error = security_inode_init_security(&ip->i_inode, &dip->i_inode, name,
&gfs2_initxattrs, NULL);
if (error)
- goto fail_gunlock3;
+ goto fail_gunlock4;

error = link_dinode(dip, name, ip, &da);
if (error)
- goto fail_gunlock3;
+ goto fail_gunlock4;

mark_inode_dirty(inode);
d_instantiate(dentry, inode);
@@ -782,9 +786,10 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
unlock_new_inode(inode);
return error;

-fail_gunlock3:
+fail_gunlock4:
glock_clear_object(ip->i_gl, ip);
glock_clear_object(io_gl, ip);
+fail_gunlock3:
gfs2_glock_dq_uninit(&ip->i_iopen_gh);
fail_gunlock2:
gfs2_glock_put(io_gl);
--
2.35.1