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authorAndreas Gruenbacher <agruenba@redhat.com>2023-10-30 22:06:05 +0100
committerAndreas Gruenbacher <agruenba@redhat.com>2023-11-06 01:51:26 +0100
commit074d7306a4fe22fcac0b53f699f92757ab1cee99 (patch)
treeaa6eea75aa11b83a3aad36002393aacf7f66ca52 /fs
parentd6fc6c93636ffefd3d209d90a749e4e4ea51d6c1 (diff)
gfs2: Silence "suspicious RCU usage in gfs2_permission" warning
Commit 0abd1557e21c added rcu_dereference() for dereferencing ip->i_gl in gfs2_permission. This now causes lockdep to complain when gfs2_permission is called in non-RCU context: WARNING: suspicious RCU usage in gfs2_permission Switch to rcu_dereference_check() and check for the MAY_NOT_BLOCK flag to shut up lockdep when we know that dereferencing ip->i_gl is safe. Fixes: 0abd1557e21c ("gfs2: fix an oops in gfs2_permission") Reported-by: syzbot+3e5130844b0c0e2b4948@syzkaller.appspotmail.com Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/gfs2/inode.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 79e96130ef9e..425bf4e90448 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1867,6 +1867,7 @@ out:
int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
int mask)
{
+ int may_not_block = mask & MAY_NOT_BLOCK;
struct gfs2_inode *ip;
struct gfs2_holder i_gh;
struct gfs2_glock *gl;
@@ -1874,14 +1875,14 @@ int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
gfs2_holder_mark_uninitialized(&i_gh);
ip = GFS2_I(inode);
- gl = rcu_dereference(ip->i_gl);
+ gl = rcu_dereference_check(ip->i_gl, !may_not_block);
if (unlikely(!gl)) {
/* inode is getting torn down, must be RCU mode */
- WARN_ON_ONCE(!(mask & MAY_NOT_BLOCK));
+ WARN_ON_ONCE(!may_not_block);
return -ECHILD;
}
if (gfs2_glock_is_locked_by_me(gl) == NULL) {
- if (mask & MAY_NOT_BLOCK)
+ if (may_not_block)
return -ECHILD;
error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
if (error)