Commit de2a4a50 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

Partially revert "locks: fix file locking on overlayfs" 



This partially reverts commit c568d683.

Overlayfs files will now automatically get the correct locks, no need to
hack overlay support in VFS.

It is a partial revert, because it leaves the locks_inode() calls in place
and defines locks_inode() to file_inode().  We could revert those as well,
but it would be unnecessary code churn and it makes sense to document that
we are getting the inode for locking purposes.

Don't revert MS_NOREMOTELOCK yet since that has been part of the userspace
API for some time (though not in a useful way).  Will try to remove
internal flags later when the dust around the new mount API settles.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Acked-by: default avatarJeff Layton <jlayton@kernel.org>
parent 8cf9ee50

fs/locks.c

+6 −11
Original line number Diff line number Diff line
@@ -139,11 +139,6 @@ 
#define IS_OFDLCK(fl)	(fl->fl_flags & FL_OFDLCK)

#define IS_REMOTELCK(fl)	(fl->fl_pid <= 0)



static inline bool is_remote_lock(struct file *filp)

{

	return likely(!(filp->f_path.dentry->d_sb->s_flags & SB_NOREMOTELOCK));

}



static bool lease_breaking(struct file_lock *fl)

{

	return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING);
@@ -1875,7 +1870,7 @@ EXPORT_SYMBOL(generic_setlease); 
int

vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)

{

	if (filp->f_op->setlease && is_remote_lock(filp))

	if (filp->f_op->setlease)

		return filp->f_op->setlease(filp, arg, lease, priv);

	else

		return generic_setlease(filp, arg, lease, priv);
@@ -2022,7 +2017,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) 
	if (error)

		goto out_free;



	if (f.file->f_op->flock && is_remote_lock(f.file))

	if (f.file->f_op->flock)

		error = f.file->f_op->flock(f.file,

					  (can_sleep) ? F_SETLKW : F_SETLK,

					  lock);
@@ -2048,7 +2043,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) 
 */

int vfs_test_lock(struct file *filp, struct file_lock *fl)

{

	if (filp->f_op->lock && is_remote_lock(filp))

	if (filp->f_op->lock)

		return filp->f_op->lock(filp, F_GETLK, fl);

	posix_test_lock(filp, fl);

	return 0;
@@ -2191,7 +2186,7 @@ out: 
 */

int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)

{

	if (filp->f_op->lock && is_remote_lock(filp))

	if (filp->f_op->lock)

		return filp->f_op->lock(filp, cmd, fl);

	else

		return posix_lock_file(filp, fl, conf);
@@ -2513,7 +2508,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx) 
	if (list_empty(&flctx->flc_flock))

		return;



	if (filp->f_op->flock && is_remote_lock(filp))

	if (filp->f_op->flock)

		filp->f_op->flock(filp, F_SETLKW, &fl);

	else

		flock_lock_inode(inode, &fl);
@@ -2600,7 +2595,7 @@ EXPORT_SYMBOL(posix_unblock_lock); 
 */

int vfs_cancel_lock(struct file *filp, struct file_lock *fl)

{

	if (filp->f_op->lock && is_remote_lock(filp))

	if (filp->f_op->lock)

		return filp->f_op->lock(filp, F_CANCELLK, fl);

	return 0;

}

fs/overlayfs/super.c

+1 −1
Original line number Diff line number Diff line
@@ -1456,7 +1456,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	sb->s_op = &ovl_super_operations;

	sb->s_xattr = ovl_xattr_handlers;

	sb->s_fs_info = ofs;

	sb->s_flags |= SB_POSIXACL | SB_NOREMOTELOCK;

	sb->s_flags |= SB_POSIXACL;



	err = -ENOMEM;

	root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));

include/linux/fs.h

+1 −12
Original line number Diff line number Diff line
@@ -1054,17 +1054,7 @@ struct file_lock_context { 


extern void send_sigio(struct fown_struct *fown, int fd, int band);



/*

 * Return the inode to use for locking

 *

 * For overlayfs this should be the overlay inode, not the real inode returned

 * by file_inode().  For any other fs file_inode(filp) and locks_inode(filp) are

 * equal.

 */

static inline struct inode *locks_inode(const struct file *f)

{

	return f->f_path.dentry->d_inode;

}

#define locks_inode(f) file_inode(f)



#ifdef CONFIG_FILE_LOCKING

extern int fcntl_getlk(struct file *, unsigned int, struct flock *);
@@ -1305,7 +1295,6 @@ extern int send_sigurg(struct fown_struct *fown); 


/* These sb flags are internal to the kernel */

#define SB_SUBMOUNT     (1<<26)

#define SB_NOREMOTELOCK	(1<<27)

#define SB_NOSEC	(1<<28)

#define SB_BORN		(1<<29)

#define SB_ACTIVE	(1<<30)

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