Add missing checks to zpl_xattr_* functions

Linux specific zpl_* entry points, such as xattrs, must include
the same unmounted and sa handle checks as the common zfs_ entry
points. The additional ZPL_* wrappers are identical to their
ZFS_ counterparts except the errno is negated since they are
expected to be used at the zpl_ layer.

Reviewed by: Matthew Ahrens <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: John Gallagher <[email protected]>
Closes #5866 
Closes #7761 

2 files changed, 38 insertions, 28 deletions

diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index a34d24532..e82ac9941 100644
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -259,28 +259,35 @@ zfs_inherit_projid(znode_t *dzp)
 
 #define	S_ISDEV(mode)	(S_ISCHR(mode) || S_ISBLK(mode) || S_ISFIFO(mode))
 
-/* Called on entry to each ZFS vnode and vfs operation  */
-#define	ZFS_ENTER(zfsvfs) \
-	{ \
-		rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG); \
-		if ((zfsvfs)->z_unmounted) { \
-			ZFS_EXIT(zfsvfs); \
-			return (EIO); \
-		} \
-	}
-
-/* Must be called before exiting the vop */
-#define	ZFS_EXIT(zfsvfs) \
-	{ \
-		rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG); \
-	}
-
-/* Verifies the znode is valid */
-#define	ZFS_VERIFY_ZP(zp) \
-	if ((zp)->z_sa_hdl == NULL) { \
-		ZFS_EXIT(ZTOZSB(zp)); \
-		return (EIO); \
-	}
+/* Called on entry to each ZFS inode and vfs operation. */
+#define	ZFS_ENTER_ERROR(zfsvfs, error)				\
+do {								\
+	rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG);	\
+	if ((zfsvfs)->z_unmounted) {				\
+		ZFS_EXIT(zfsvfs);				\
+		return (error);					\
+	}							\
+} while (0)
+#define	ZFS_ENTER(zfsvfs)	ZFS_ENTER_ERROR(zfsvfs, EIO)
+#define	ZPL_ENTER(zfsvfs)	ZFS_ENTER_ERROR(zfsvfs, -EIO)
+
+/* Must be called before exiting the operation. */
+#define	ZFS_EXIT(zfsvfs)					\
+do {								\
+	rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);		\
+} while (0)
+#define	ZPL_EXIT(zfsvfs)	ZFS_EXIT(zfsvfs)
+
+/* Verifies the znode is valid. */
+#define	ZFS_VERIFY_ZP_ERROR(zp, error)				\
+do {								\
+	if ((zp)->z_sa_hdl == NULL) {				\
+		ZFS_EXIT(ZTOZSB(zp));				\
+		return (error);					\
+	}							\
+} while (0)
+#define	ZFS_VERIFY_ZP(zp)	ZFS_VERIFY_ZP_ERROR(zp, EIO)
+#define	ZPL_VERIFY_ZP(zp)	ZFS_VERIFY_ZP_ERROR(zp, -EIO)
 
 /*
  * Macros for dealing with dmu_buf_hold
diff --git a/module/zfs/zpl_xattr.c b/module/zfs/zpl_xattr.c
index 09e38ee8b..8ee6e9a97 100644
--- a/module/zfs/zpl_xattr.c
+++ b/module/zfs/zpl_xattr.c
@@ -245,7 +245,8 @@ zpl_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 
 	crhold(cr);
 	cookie = spl_fstrans_mark();
-	rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_ENTER(zfsvfs);
+	ZPL_VERIFY_ZP(zp);
 	rw_enter(&zp->z_xattr_lock, RW_READER);
 
 	if (zfsvfs->z_use_sa && zp->z_is_sa) {
@@ -262,7 +263,7 @@ zpl_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 out:
 
 	rw_exit(&zp->z_xattr_lock);
-	rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_EXIT(zfsvfs);
 	spl_fstrans_unmark(cookie);
 	crfree(cr);
 
@@ -418,11 +419,12 @@ zpl_xattr_get(struct inode *ip, const char *name, void *value, size_t size)
 
 	crhold(cr);
 	cookie = spl_fstrans_mark();
-	rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_ENTER(zfsvfs);
+	ZPL_VERIFY_ZP(zp);
 	rw_enter(&zp->z_xattr_lock, RW_READER);
 	error = __zpl_xattr_get(ip, name, value, size, cr);
 	rw_exit(&zp->z_xattr_lock);
-	rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_EXIT(zfsvfs);
 	spl_fstrans_unmark(cookie);
 	crfree(cr);
 
@@ -590,7 +592,8 @@ zpl_xattr_set(struct inode *ip, const char *name, const void *value,
 
 	crhold(cr);
 	cookie = spl_fstrans_mark();
-	rrm_enter_read(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_ENTER(zfsvfs);
+	ZPL_VERIFY_ZP(zp);
 	rw_enter(&ITOZ(ip)->z_xattr_lock, RW_WRITER);
 
 	/*
@@ -643,7 +646,7 @@ zpl_xattr_set(struct inode *ip, const char *name, const void *value,
 		zpl_xattr_set_sa(ip, name, NULL, 0, 0, cr);
 out:
 	rw_exit(&ITOZ(ip)->z_xattr_lock);
-	rrm_exit(&(zfsvfs)->z_teardown_lock, FTAG);
+	ZPL_EXIT(zfsvfs);
 	spl_fstrans_unmark(cookie);
 	crfree(cr);
 	ASSERT3S(error, <=, 0);