diff options
| author | Bob Peterson <rpeterso@redhat.com> | 2022-02-11 10:50:08 -0500 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2022-05-24 21:29:14 +0200 |
| commit | 5fcff61eea9efd1f4b60e89d2d686b5feaea100f (patch) | |
| tree | 5ab3319b4416fadfb59ad13992561158fb35c6f4 | |
| parent | f4a47561fcc1494ee3f273163189cf4462b6a245 (diff) | |
| download | linux-5fcff61eea9efd1f4b60e89d2d686b5feaea100f.tar.bz2 | |
gfs2: use i_lock spin_lock for inode qadata
Before this patch, functions gfs2_qa_get and _put used the i_rw_mutex to
prevent simultaneous access to its i_qadata. But i_rw_mutex is now used
for many other things, including iomap_begin and end, which causes a
conflict according to lockdep. We cannot just remove the lock since
simultaneous opens (gfs2_open -> gfs2_open_common -> gfs2_qa_get) can
then stomp on each others values for i_qadata.
This patch solves the conflict by using the i_lock spin_lock in the inode
to prevent simultaneous access.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
| -rw-r--r-- | fs/gfs2/quota.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index ec7e0910b278..390f34ca3bc8 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -528,34 +528,42 @@ static void qdsb_put(struct gfs2_quota_data *qd) */ int gfs2_qa_get(struct gfs2_inode *ip) { - int error = 0; struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct inode *inode = &ip->i_inode; if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF) return 0; - down_write(&ip->i_rw_mutex); + spin_lock(&inode->i_lock); if (ip->i_qadata == NULL) { - ip->i_qadata = kmem_cache_zalloc(gfs2_qadata_cachep, GFP_NOFS); - if (!ip->i_qadata) { - error = -ENOMEM; - goto out; - } + struct gfs2_qadata *tmp; + + spin_unlock(&inode->i_lock); + tmp = kmem_cache_zalloc(gfs2_qadata_cachep, GFP_NOFS); + if (!tmp) + return -ENOMEM; + + spin_lock(&inode->i_lock); + if (ip->i_qadata == NULL) + ip->i_qadata = tmp; + else + kmem_cache_free(gfs2_qadata_cachep, tmp); } ip->i_qadata->qa_ref++; -out: - up_write(&ip->i_rw_mutex); - return error; + spin_unlock(&inode->i_lock); + return 0; } void gfs2_qa_put(struct gfs2_inode *ip) { - down_write(&ip->i_rw_mutex); + struct inode *inode = &ip->i_inode; + + spin_lock(&inode->i_lock); if (ip->i_qadata && --ip->i_qadata->qa_ref == 0) { kmem_cache_free(gfs2_qadata_cachep, ip->i_qadata); ip->i_qadata = NULL; } - up_write(&ip->i_rw_mutex); + spin_unlock(&inode->i_lock); } int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid) |