zfs_enter rework

Replace ZFS_ENTER and ZFS_VERIFY_ZP, which have hidden returns, with
functions that return error code. The reason we want to do this is
because hidden returns are not obvious and had caused some missing fail
path unwinding.

This patch changes the common, linux, and freebsd parts. Also fixes
fail path unwinding in zfs_fsync, zpl_fsync, zpl_xattr_{list,get,set}, and
zfs_lookup().

Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Ryan Moeller <[email protected]>
Signed-off-by: Chunwei Chen <[email protected]>
Closes #13831 

1 files changed, 26 insertions, 18 deletions

diff --git a/module/os/linux/zfs/zfs_ctldir.c b/module/os/linux/zfs/zfs_ctldir.c
index 32342d25c..4ae0a6537 100644
--- a/module/os/linux/zfs/zfs_ctldir.c
+++ b/module/os/linux/zfs/zfs_ctldir.c
@@ -673,17 +673,19 @@ zfsctl_fid(struct inode *ip, fid_t *fidp)
 	uint64_t	object = zp->z_id;
 	zfid_short_t	*zfid;
 	int		i;
+	int		error;
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	if (zfsctl_is_snapdir(ip)) {
-		ZFS_EXIT(zfsvfs);
+		zfs_exit(zfsvfs, FTAG);
 		return (zfsctl_snapdir_fid(ip, fidp));
 	}
 
 	if (fidp->fid_len < SHORT_FID_LEN) {
 		fidp->fid_len = SHORT_FID_LEN;
-		ZFS_EXIT(zfsvfs);
+		zfs_exit(zfsvfs, FTAG);
 		return (SET_ERROR(ENOSPC));
 	}
 
@@ -698,7 +700,7 @@ zfsctl_fid(struct inode *ip, fid_t *fidp)
 	for (i = 0; i < sizeof (zfid->zf_gen); i++)
 		zfid->zf_gen[i] = 0;
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 	return (0);
 }
 
@@ -776,7 +778,8 @@ zfsctl_root_lookup(struct inode *dip, const char *name, struct inode **ipp,
 	zfsvfs_t *zfsvfs = ITOZSB(dip);
 	int error = 0;
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	if (strcmp(name, "..") == 0) {
 		*ipp = dip->i_sb->s_root->d_inode;
@@ -793,7 +796,7 @@ zfsctl_root_lookup(struct inode *dip, const char *name, struct inode **ipp,
 	if (*ipp == NULL)
 		error = SET_ERROR(ENOENT);
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }
@@ -810,11 +813,12 @@ zfsctl_snapdir_lookup(struct inode *dip, const char *name, struct inode **ipp,
 	uint64_t id;
 	int error;
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	error = dmu_snapshot_lookup(zfsvfs->z_os, name, &id);
 	if (error) {
-		ZFS_EXIT(zfsvfs);
+		zfs_exit(zfsvfs, FTAG);
 		return (error);
 	}
 
@@ -823,7 +827,7 @@ zfsctl_snapdir_lookup(struct inode *dip, const char *name, struct inode **ipp,
 	if (*ipp == NULL)
 		error = SET_ERROR(ENOENT);
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }
@@ -844,7 +848,8 @@ zfsctl_snapdir_rename(struct inode *sdip, const char *snm,
 	if (!zfs_admin_snapshot)
 		return (SET_ERROR(EACCES));
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	to = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
 	from = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
@@ -902,7 +907,7 @@ out:
 	kmem_free(real, ZFS_MAX_DATASET_NAME_LEN);
 	kmem_free(fsname, ZFS_MAX_DATASET_NAME_LEN);
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }
@@ -922,7 +927,8 @@ zfsctl_snapdir_remove(struct inode *dip, const char *name, cred_t *cr,
 	if (!zfs_admin_snapshot)
 		return (SET_ERROR(EACCES));
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	snapname = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
 	real = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
@@ -951,7 +957,7 @@ out:
 	kmem_free(snapname, ZFS_MAX_DATASET_NAME_LEN);
 	kmem_free(real, ZFS_MAX_DATASET_NAME_LEN);
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }
@@ -1076,7 +1082,8 @@ zfsctl_snapshot_mount(struct path *path, int flags)
 		return (SET_ERROR(EISDIR));
 
 	zfsvfs = ITOZSB(ip);
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	full_name = kmem_zalloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
 	full_path = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
@@ -1164,7 +1171,7 @@ error:
 	kmem_free(full_name, ZFS_MAX_DATASET_NAME_LEN);
 	kmem_free(full_path, MAXPATHLEN);
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }
@@ -1228,10 +1235,11 @@ zfsctl_shares_lookup(struct inode *dip, char *name, struct inode **ipp,
 	znode_t *dzp;
 	int error;
 
-	ZFS_ENTER(zfsvfs);
+	if ((error = zfs_enter(zfsvfs, FTAG)) != 0)
+		return (error);
 
 	if (zfsvfs->z_shares_dir == 0) {
-		ZFS_EXIT(zfsvfs);
+		zfs_exit(zfsvfs, FTAG);
 		return (SET_ERROR(ENOTSUP));
 	}
 
@@ -1240,7 +1248,7 @@ zfsctl_shares_lookup(struct inode *dip, char *name, struct inode **ipp,
 		zrele(dzp);
 	}
 
-	ZFS_EXIT(zfsvfs);
+	zfs_exit(zfsvfs, FTAG);
 
 	return (error);
 }