[PATCH] gfs2: Fix deadlock between gfs2_create_inode and delete_work_func

[PATCH] gfs2: Fix deadlock between gfs2_create_inode and delete_work_func

[Andreas Gruenbacher]

In gfs2_create_inode, make sure to cancel any pending delete work before
locking the inode glock.  Otherwise, gfs2_cancel_delete_work may block
waiting for delete_work_func to complete, and delete_work_func may block
trying to acquire the inode glock in gfs2_inode_lookup.

Reported-by: Alexander Aring <aahringo@redhat.com>
Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/inode.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index eed1a1bac6f6..3b9e8c99293c 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -725,13 +725,19 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	flush_delayed_work(&ip->i_gl->gl_work);
 	glock_set_object(ip->i_gl, ip);
 
-	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
 	if (error)
 		goto fail_free_inode;
+	gfs2_cancel_delete_work(io_gl);
+	glock_set_object(io_gl, ip);
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+	if (error)
+		goto fail_gunlock2;
 
 	error = gfs2_trans_begin(sdp, blocks, 0);
 	if (error)
-		goto fail_free_inode;
+		goto fail_gunlock2;
 
 	if (blocks > 1) {
 		ip->i_eattr = ip->i_no_addr + 1;
@@ -740,18 +746,12 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	init_dinode(dip, ip, symname);
 	gfs2_trans_end(sdp);
 
-	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
-	if (error)
-		goto fail_free_inode;
-
 	BUG_ON(test_and_set_bit(GLF_INODE_CREATING, &io_gl->gl_flags));
 
 	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
 	if (error)
 		goto fail_gunlock2;
 
-	gfs2_cancel_delete_work(ip->i_iopen_gh.gh_gl);
-	glock_set_object(ip->i_iopen_gh.gh_gl, ip);
 	gfs2_set_iop(inode);
 	insert_inode_hash(inode);
 
@@ -803,6 +803,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 fail_gunlock2:
 	clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
+	glock_clear_object(io_gl, ip);
 	gfs2_glock_put(io_gl);
 fail_free_inode:
 	if (ip->i_gl) {
-- 
2.26.2

[Cluster-devel] [PATCH] gfs2: Fix deadlock between gfs2_create_inode and delete_work_func

[Andreas Gruenbacher]

In gfs2_create_inode, make sure to cancel any pending delete work before
locking the inode glock.  Otherwise, gfs2_cancel_delete_work may block
waiting for delete_work_func to complete, and delete_work_func may block
trying to acquire the inode glock in gfs2_inode_lookup.

Reported-by: Alexander Aring <aahringo@redhat.com>
Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work")
Cc: stable at vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/inode.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index eed1a1bac6f6..3b9e8c99293c 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -725,13 +725,19 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	flush_delayed_work(&ip->i_gl->gl_work);
 	glock_set_object(ip->i_gl, ip);
 
-	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
 	if (error)
 		goto fail_free_inode;
+	gfs2_cancel_delete_work(io_gl);
+	glock_set_object(io_gl, ip);
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
+	if (error)
+		goto fail_gunlock2;
 
 	error = gfs2_trans_begin(sdp, blocks, 0);
 	if (error)
-		goto fail_free_inode;
+		goto fail_gunlock2;
 
 	if (blocks > 1) {
 		ip->i_eattr = ip->i_no_addr + 1;
@@ -740,18 +746,12 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	init_dinode(dip, ip, symname);
 	gfs2_trans_end(sdp);
 
-	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
-	if (error)
-		goto fail_free_inode;
-
 	BUG_ON(test_and_set_bit(GLF_INODE_CREATING, &io_gl->gl_flags));
 
 	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
 	if (error)
 		goto fail_gunlock2;
 
-	gfs2_cancel_delete_work(ip->i_iopen_gh.gh_gl);
-	glock_set_object(ip->i_iopen_gh.gh_gl, ip);
 	gfs2_set_iop(inode);
 	insert_inode_hash(inode);
 
@@ -803,6 +803,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 fail_gunlock2:
 	clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
+	glock_clear_object(io_gl, ip);
 	gfs2_glock_put(io_gl);
 fail_free_inode:
 	if (ip->i_gl) {
-- 
2.26.2

Re: [PATCH] gfs2: Fix deadlock between gfs2_create_inode and delete_work_func

[Andreas Gruenbacher]

On Mon, Nov 30, 2020 at 8:44 PM Andreas Gruenbacher <agruenba@redhat.com> wrote:
> In gfs2_create_inode, make sure to cancel any pending delete work before
> locking the inode glock.  Otherwise, gfs2_cancel_delete_work may block
> waiting for delete_work_func to complete, and delete_work_func may block
> trying to acquire the inode glock in gfs2_inode_lookup.

(Please see version 2 of this patch.)

Thanks,
Andreas

[Cluster-devel] [PATCH] gfs2: Fix deadlock between gfs2_create_inode and delete_work_func

[Andreas Gruenbacher]

On Mon, Nov 30, 2020 at 8:44 PM Andreas Gruenbacher <agruenba@redhat.com> wrote:
> In gfs2_create_inode, make sure to cancel any pending delete work before
> locking the inode glock.  Otherwise, gfs2_cancel_delete_work may block
> waiting for delete_work_func to complete, and delete_work_func may block
> trying to acquire the inode glock in gfs2_inode_lookup.

(Please see version 2 of this patch.)

Thanks,
Andreas