ceph: switch to vfs_inode_has_locks() to fix file lock bug

[ Upstream commit 461ab10ef7e6ea9b41a0571a7fc6a72af9549a3c ]

For the POSIX locks they are using the same owner, which is the
thread id. And multiple POSIX locks could be merged into single one,
so when checking whether the 'file' has locks may fail.

For a file where some openers use locking and others don't is a
really odd usage pattern though. Locks are like stoplights -- they
only work if everyone pays attention to them.

Just switch ceph_get_caps() to check whether any locks are set on
the inode. If there are POSIX/OFD/FLOCK locks on the file at the
time, we should set CHECK_FILELOCK, regardless of what fd was used
to set the lock.

Fixes: ff5d913dfc71 ("ceph: return -EIO if read/write against filp that lost file locks")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index be96fe6..67b782b 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2872,7 +2872,7 @@ int ceph_get_caps(struct file *filp, int need, int want, loff_t endoff, int *got
 
        while (true) {
                flags &= CEPH_FILE_MODE_MASK;
-               if (atomic_read(&fi->num_locks))
+               if (vfs_inode_has_locks(inode))
                        flags |= CHECK_FILELOCK;
                _got = 0;
                ret = try_get_cap_refs(inode, need, want, endoff,

diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index bdeb271..3e3b8be 100644 (file)
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -32,18 +32,14 @@ void __init ceph_flock_init(void)
 
 static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 {
-       struct ceph_file_info *fi = dst->fl_file->private_data;
        struct inode *inode = file_inode(dst->fl_file);
        atomic_inc(&ceph_inode(inode)->i_filelock_ref);
-       atomic_inc(&fi->num_locks);
 }
 
 static void ceph_fl_release_lock(struct file_lock *fl)
 {
-       struct ceph_file_info *fi = fl->fl_file->private_data;
        struct inode *inode = file_inode(fl->fl_file);
        struct ceph_inode_info *ci = ceph_inode(inode);
-       atomic_dec(&fi->num_locks);
        if (atomic_dec_and_test(&ci->i_filelock_ref)) {
                /* clear error when all locks are released */
                spin_lock(&ci->i_ceph_lock);

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 14f951c..8c9021d 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -773,7 +773,6 @@ struct ceph_file_info {
        struct list_head rw_contexts;
 
        u32 filp_gen;
-       atomic_t num_locks;
 };
 
 struct ceph_dir_file_info {