Commit ff5d913d authored by Yan, Zheng's avatar Yan, Zheng Committed by Ilya Dryomov
Browse files

ceph: return -EIO if read/write against filp that lost file locks 



After mds evicts session, file locks get lost sliently. It's not safe to
let programs continue to do read/write.

Signed-off-by: default avatar"Yan, Zheng" <zyan@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent d468e729

fs/ceph/caps.c

+22 −6
Original line number Diff line number Diff line
@@ -2570,8 +2570,13 @@ static void __take_cap_refs(struct ceph_inode_info *ci, int got, 
 *

 * FIXME: how does a 0 return differ from -EAGAIN?

 */

enum {

	NON_BLOCKING	= 1,

	CHECK_FILELOCK	= 2,

};



static int try_get_cap_refs(struct inode *inode, int need, int want,

			    loff_t endoff, bool nonblock, int *got)

			    loff_t endoff, int flags, int *got)

{

	struct ceph_inode_info *ci = ceph_inode(inode);

	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
@@ -2586,6 +2591,13 @@ static int try_get_cap_refs(struct inode *inode, int need, int want, 
again:

	spin_lock(&ci->i_ceph_lock);



	if ((flags & CHECK_FILELOCK) &&

	    (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK)) {

		dout("try_get_cap_refs %p error filelock\n", inode);

		ret = -EIO;

		goto out_unlock;

	}



	/* make sure file is actually open */

	file_wanted = __ceph_caps_file_wanted(ci);

	if ((file_wanted & need) != need) {
@@ -2647,7 +2659,7 @@ static int try_get_cap_refs(struct inode *inode, int need, int want, 
					 * we can not call down_read() when

					 * task isn't in TASK_RUNNING state

					 */

					if (nonblock) {

					if (flags & NON_BLOCKING) {

						ret = -EAGAIN;

						goto out_unlock;

					}
@@ -2752,7 +2764,8 @@ int ceph_try_get_caps(struct inode *inode, int need, int want, 
	if (ret < 0)

		return ret;



	ret = try_get_cap_refs(inode, need, want, 0, nonblock, got);

	ret = try_get_cap_refs(inode, need, want, 0,

			       (nonblock ? NON_BLOCKING : 0), got);

	return ret == -EAGAIN ? 0 : ret;

}
@@ -2764,9 +2777,10 @@ int ceph_try_get_caps(struct inode *inode, int need, int want, 
int ceph_get_caps(struct file *filp, int need, int want,

		  loff_t endoff, int *got, struct page **pinned_page)

{

	struct ceph_file_info *fi = filp->private_data;

	struct inode *inode = file_inode(filp);

	struct ceph_inode_info *ci = ceph_inode(inode);

	int _got, ret;

	int ret, _got, flags;



	ret = ceph_pool_perm_check(inode, need);

	if (ret < 0)
@@ -2776,17 +2790,19 @@ int ceph_get_caps(struct file *filp, int need, int want, 
		if (endoff > 0)

			check_max_size(inode, endoff);



		flags = atomic_read(&fi->num_locks) ? CHECK_FILELOCK : 0;

		_got = 0;

		ret = try_get_cap_refs(inode, need, want, endoff,

				       false, &_got);

				       flags, &_got);

		if (ret == -EAGAIN)

			continue;

		if (!ret) {

			DEFINE_WAIT_FUNC(wait, woken_wake_function);

			add_wait_queue(&ci->i_cap_wq, &wait);



			flags |= NON_BLOCKING;

			while (!(ret = try_get_cap_refs(inode, need, want,

							endoff, true, &_got))) {

							endoff, flags, &_got))) {

				if (signal_pending(current)) {

					ret = -ERESTARTSYS;

					break;

fs/ceph/locks.c

+6 −2
Original line number Diff line number Diff line
@@ -32,14 +32,18 @@ void __init ceph_flock_init(void) 


static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src)

{

	struct inode *inode = file_inode(src->fl_file);

	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);
@@ -73,7 +77,7 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, 
		 * window. Caller function will decrease the counter.

		 */

		fl->fl_ops = &ceph_fl_lock_ops;

		atomic_inc(&ceph_inode(inode)->i_filelock_ref);

		fl->fl_ops->fl_copy_lock(fl, NULL);

	}



	if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK)

fs/ceph/super.h

+1 −0
Original line number Diff line number Diff line
@@ -707,6 +707,7 @@ struct ceph_file_info { 
	struct list_head rw_contexts;



	errseq_t meta_err;

	atomic_t num_locks;

};



struct ceph_dir_file_info {