xfs: merge xfs_attr_remove into xfs_attr_set

The Linux xattr and acl APIs use a single call for set and remove.
Modify the high-level XFS API to match that and let xfs_attr_set handle
removing attributes as well.  With a little bit of reordering this
removes a lot of code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_attr.c

@@ -336,6 +336,10 @@ xfs_attr_remove_args(
 	return error;
 }
 
+/*
+ * Note: If value is NULL the attribute will be removed, just like the
+ * Linux ->setattr API.
+ */
 int
 xfs_attr_set(
 	struct xfs_inode	*dp,
@@ -350,66 +354,91 @@ xfs_attr_set(
 	struct xfs_trans_res	tres;
 	int			rsvd = (flags & ATTR_ROOT) != 0;
 	int			error, local;
-
+	unsigned int		total;
-	XFS_STATS_INC(mp, xs_attr_set);
 
 	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
 		return -EIO;
 
+	error = xfs_qm_dqattach(dp);
+	if (error)
+		return error;
+
 	error = xfs_attr_args_init(&args, dp, name, namelen, flags);
 	if (error)
 		return error;
 
 	args.value = value;
 	args.valuelen = valuelen;
-	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
-	args.total = xfs_attr_calc_size(&args, &local);
-
-	error = xfs_qm_dqattach(dp);
-	if (error)
-		return error;
 
 	/*
-	 * If the inode doesn't have an attribute fork, add one.
+	 * We have no control over the attribute names that userspace passes us
-	 * (inode must not be locked when we call this routine)
+	 * to remove, so we have to allow the name lookup prior to attribute
+	 * removal to fail as well.
 	 */
-	if (XFS_IFORK_Q(dp) == 0) {
+	args.op_flags = XFS_DA_OP_OKNOENT;
-		int sf_size = sizeof(xfs_attr_sf_hdr_t) +
-			XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen, valuelen);
 
-		error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
+	if (value) {
-		if (error)
+		XFS_STATS_INC(mp, xs_attr_set);
-			return error;
+
+		args.op_flags |= XFS_DA_OP_ADDNAME;
+		args.total = xfs_attr_calc_size(&args, &local);
+
+		/*
+		 * If the inode doesn't have an attribute fork, add one.
+		 * (inode must not be locked when we call this routine)
+		 */
+		if (XFS_IFORK_Q(dp) == 0) {
+			int sf_size = sizeof(struct xfs_attr_sf_hdr) +
+				XFS_ATTR_SF_ENTSIZE_BYNAME(args.namelen,
+						valuelen);
+
+			error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
+			if (error)
+				return error;
+		}
+
+		tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
+				 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
+		tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
+		tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
+		total = args.total;
+	} else {
+		XFS_STATS_INC(mp, xs_attr_remove);
+
+		tres = M_RES(mp)->tr_attrrm;
+		total = XFS_ATTRRM_SPACE_RES(mp);
 	}
 
-	tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
-			 M_RES(mp)->tr_attrsetrt.tr_logres * args.total;
-	tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
-	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
-
 	/*
 	 * Root fork attributes can use reserved data blocks for this
 	 * operation if necessary
 	 */
-	error = xfs_trans_alloc(mp, &tres, args.total, 0,
+	error = xfs_trans_alloc(mp, &tres, total, 0,
 			rsvd ? XFS_TRANS_RESERVE : 0, &args.trans);
 	if (error)
 		return error;
 
 	xfs_ilock(dp, XFS_ILOCK_EXCL);
-	error = xfs_trans_reserve_quota_nblks(args.trans, dp, args.total, 0,
-				rsvd ? XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
-				       XFS_QMOPT_RES_REGBLKS);
-	if (error)
-		goto out_trans_cancel;
-
 	xfs_trans_ijoin(args.trans, dp, 0);
-	error = xfs_attr_set_args(&args);
+	if (value) {
-	if (error)
+		unsigned int	quota_flags = XFS_QMOPT_RES_REGBLKS;
-		goto out_trans_cancel;
+
-	if (!args.trans) {
+		if (rsvd)
+			quota_flags |= XFS_QMOPT_FORCE_RES;
+		error = xfs_trans_reserve_quota_nblks(args.trans, dp,
+				args.total, 0, quota_flags);
+		if (error)
+			goto out_trans_cancel;
+		error = xfs_attr_set_args(&args);
+		if (error)
+			goto out_trans_cancel;
 		/* shortform attribute has already been committed */
-		goto out_unlock;
+		if (!args.trans)
+			goto out_unlock;
+	} else {
+		error = xfs_attr_remove_args(&args);
+		if (error)
+			goto out_trans_cancel;
 	}
 
 	/*
@@ -437,89 +466,6 @@ out_trans_cancel:
 	goto out_unlock;
 }
 
-/*
- * Generic handler routine to remove a name from an attribute list.
- * Transitions attribute list from Btree to shortform as necessary.
- */
-int
-xfs_attr_remove(
-	struct xfs_inode	*dp,
-	const unsigned char	*name,
-	size_t			namelen,
-	int			flags)
-{
-	struct xfs_mount	*mp = dp->i_mount;
-	struct xfs_da_args	args;
-	int			error;
-
-	XFS_STATS_INC(mp, xs_attr_remove);
-
-	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
-		return -EIO;
-
-	error = xfs_attr_args_init(&args, dp, name, namelen, flags);
-	if (error)
-		return error;
-
-	/*
-	 * we have no control over the attribute names that userspace passes us
-	 * to remove, so we have to allow the name lookup prior to attribute
-	 * removal to fail.
-	 */
-	args.op_flags = XFS_DA_OP_OKNOENT;
-
-	error = xfs_qm_dqattach(dp);
-	if (error)
-		return error;
-
-	/*
-	 * Root fork attributes can use reserved data blocks for this
-	 * operation if necessary
-	 */
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrrm,
-			XFS_ATTRRM_SPACE_RES(mp), 0,
-			(flags & ATTR_ROOT) ? XFS_TRANS_RESERVE : 0,
-			&args.trans);
-	if (error)
-		return error;
-
-	xfs_ilock(dp, XFS_ILOCK_EXCL);
-	/*
-	 * No need to make quota reservations here. We expect to release some
-	 * blocks not allocate in the common case.
-	 */
-	xfs_trans_ijoin(args.trans, dp, 0);
-
-	error = xfs_attr_remove_args(&args);
-	if (error)
-		goto out;
-
-	/*
-	 * If this is a synchronous mount, make sure that the
-	 * transaction goes to disk before returning to the user.
-	 */
-	if (mp->m_flags & XFS_MOUNT_WSYNC)
-		xfs_trans_set_sync(args.trans);
-
-	if ((flags & ATTR_KERNOTIME) == 0)
-		xfs_trans_ichgtime(args.trans, dp, XFS_ICHGTIME_CHG);
-
-	/*
-	 * Commit the last in the sequence of transactions.
-	 */
-	xfs_trans_log_inode(args.trans, dp, XFS_ILOG_CORE);
-	error = xfs_trans_commit(args.trans);
-	xfs_iunlock(dp, XFS_ILOCK_EXCL);
-
-	return error;
-
-out:
-	if (args.trans)
-		xfs_trans_cancel(args.trans);
-	xfs_iunlock(dp, XFS_ILOCK_EXCL);
-	return error;
-}
-
 /*========================================================================
  * External routines when attribute list is inside the inode
  *========================================================================*/

fs/xfs/libxfs/xfs_attr.h

@@ -152,8 +152,6 @@ int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name,
 int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
 		 size_t namelen, unsigned char *value, int valuelen, int flags);
 int xfs_attr_set_args(struct xfs_da_args *args);
-int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name,
-		    size_t namelen, int flags);
 int xfs_attr_remove_args(struct xfs_da_args *args);
 int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
 		  int flags, struct attrlist_cursor_kern *cursor);

fs/xfs/xfs_acl.c

@@ -172,6 +172,8 @@ __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
 	struct xfs_inode *ip = XFS_I(inode);
 	unsigned char *ea_name;
+	struct xfs_acl *xfs_acl = NULL;
+	int len = 0;
 	int error;
 
 	switch (type) {
@@ -188,9 +190,7 @@ __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	}
 
 	if (acl) {
-		struct xfs_acl *xfs_acl;
+		len = XFS_ACL_MAX_SIZE(ip->i_mount);
-		int len = XFS_ACL_MAX_SIZE(ip->i_mount);
-
 		xfs_acl = kmem_zalloc_large(len, 0);
 		if (!xfs_acl)
 			return -ENOMEM;
@@ -200,26 +200,17 @@ __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 		/* subtract away the unused acl entries */
 		len -= sizeof(struct xfs_acl_entry) *
 			 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
-
-		error = xfs_attr_set(ip, ea_name, strlen(ea_name),
-				     (unsigned char *)xfs_acl, len, ATTR_ROOT);
-
-		kmem_free(xfs_acl);
-	} else {
-		/*
-		 * A NULL ACL argument means we want to remove the ACL.
-		 */
-		error = xfs_attr_remove(ip, ea_name,
-					strlen(ea_name),
-					ATTR_ROOT);
-
-		/*
-		 * If the attribute didn't exist to start with that's fine.
-		 */
-		if (error == -ENOATTR)
-			error = 0;
 	}
 
+	error = xfs_attr_set(ip, ea_name, strlen(ea_name),
+			(unsigned char *)xfs_acl, len, ATTR_ROOT);
+	kmem_free(xfs_acl);
+
+	/*
+	 * If the attribute didn't exist to start with that's fine.
+	 */
+	if (!acl && error == -ENOATTR)
+		error = 0;
 	if (!error)
 		set_cached_acl(inode, type, acl);
 	return error;

fs/xfs/xfs_ioctl.c

@@ -417,12 +417,10 @@ xfs_attrmulti_attr_remove(
 	uint32_t		flags)
 {
 	int			error;
-	size_t			namelen;
 
 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 		return -EPERM;
-	namelen = strlen(name);
+	error = xfs_attr_set(XFS_I(inode), name, strlen(name), NULL, 0, flags);
-	error = xfs_attr_remove(XFS_I(inode), name, namelen, flags);
 	if (!error)
 		xfs_forget_acl(inode, name, flags);
 	return error;

fs/xfs/xfs_xattr.c

@@ -69,7 +69,6 @@ xfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused,
 	int			xflags = handler->flags;
 	struct xfs_inode	*ip = XFS_I(inode);
 	int			error;
-	size_t			namelen = strlen(name);
 
 	/* Convert Linux syscall to XFS internal ATTR flags */
 	if (flags & XATTR_CREATE)
@@ -77,14 +76,10 @@ xfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused,
 	if (flags & XATTR_REPLACE)
 		xflags |= ATTR_REPLACE;
 
-	if (value)
+	error = xfs_attr_set(ip, (unsigned char *)name, strlen(name),
-		error = xfs_attr_set(ip, name, namelen, (void *)value, size,
+				(void *)value, size, xflags);
-				xflags);
-	else
-		error = xfs_attr_remove(ip, name, namelen, xflags);
 	if (!error)
 		xfs_forget_acl(inode, name, xflags);
-
 	return error;
 }