xfs: move the legacy xfs_attr_list to xfs_ioctl.c

The old xfs_attr_list code is only used by the attrlist by handle
ioctl.  Move it to xfs_ioctl.c with its user.  Also move the
attrlist and attrlist_ent structure to xfs_fs.h, as they are exposed
user ABIs.  They are used through libattr headers with the same name
by at least xfsdump.  Also document this relation so that it doesn't
require a research project to figure out.
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.h

@@ -48,27 +48,6 @@ struct xfs_attr_list_context;
  */
 #define	ATTR_MAX_VALUELEN	(64*1024)	/* max length of a value */
 
-/*
- * Define how lists of attribute names are returned to the user from
- * the attr_list() call.  A large, 32bit aligned, buffer is passed in
- * along with its size.  We put an array of offsets at the top that each
- * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
- */
-typedef struct attrlist {
-	__s32	al_count;	/* number of entries in attrlist */
-	__s32	al_more;	/* T/F: more attrs (do call again) */
-	__s32	al_offset[1];	/* byte offsets of attrs [var-sized] */
-} attrlist_t;
-
-/*
- * Show the interesting info about one attribute.  This is what the
- * al_offset[i] entry points to.
- */
-typedef struct attrlist_ent {	/* data from attr_list() */
-	__u32	a_valuelen;	/* number bytes in value of attr */
-	char	a_name[1];	/* attr name (NULL terminated) */
-} attrlist_ent_t;
-
 /*
  * Kernel-internal version of the attrlist cursor.
  */
@@ -131,8 +110,6 @@ int xfs_attr_get(struct xfs_da_args *args);
 int xfs_attr_set(struct xfs_da_args *args);
 int xfs_attr_set_args(struct xfs_da_args *args);
 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);
 bool xfs_attr_namecheck(const void *name, size_t length);
 
 #endif	/* __XFS_ATTR_H__ */

fs/xfs/libxfs/xfs_fs.h

@@ -572,6 +572,26 @@ typedef struct xfs_attrlist_cursor {
 	__u32		opaque[4];
 } xfs_attrlist_cursor_t;
 
+/*
+ * Define how lists of attribute names are returned to userspace from the
+ * XFS_IOC_ATTRLIST_BY_HANDLE ioctl.  struct xfs_attrlist is the header at the
+ * beginning of the returned buffer, and a each entry in al_offset contains the
+ * relative offset of an xfs_attrlist_ent containing the actual entry.
+ *
+ * NOTE: struct xfs_attrlist must match struct attrlist defined in libattr, and
+ * struct xfs_attrlist_ent must match struct attrlist_ent defined in libattr.
+ */
+struct xfs_attrlist {
+	__s32	al_count;	/* number of entries in attrlist */
+	__s32	al_more;	/* T/F: more attrs (do call again) */
+	__s32	al_offset[1];	/* byte offsets of attrs [var-sized] */
+};
+
+struct xfs_attrlist_ent {	/* data from attr_list() */
+	__u32	a_valuelen;	/* number bytes in value of attr */
+	char	a_name[1];	/* attr name (NULL terminated) */
+};
+
 typedef struct xfs_fsop_attrlist_handlereq {
 	struct xfs_fsop_handlereq	hreq; /* handle interface structure */
 	struct xfs_attrlist_cursor	pos; /* opaque cookie, list offset */

fs/xfs/xfs_attr_list.c

@@ -544,116 +544,3 @@ xfs_attr_list_int(
 	xfs_iunlock(dp, lock_mode);
 	return error;
 }
-
-/*
- * Format an attribute and copy it out to the user's buffer.
- * Take care to check values and protect against them changing later,
- * we may be reading them directly out of a user buffer.
- */
-STATIC void
-xfs_attr_put_listent(
-	struct xfs_attr_list_context	*context,
-	int			flags,
-	unsigned char		*name,
-	int			namelen,
-	int			valuelen)
-{
-	struct attrlist		*alist = context->buffer;
-	struct attrlist_ent	*aep;
-	int			arraytop;
-
-	ASSERT(!context->seen_enough);
-	ASSERT(context->count >= 0);
-	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
-	ASSERT(context->firstu >= sizeof(*alist));
-	ASSERT(context->firstu <= context->bufsize);
-
-	/*
-	 * Only list entries in the right namespace.
-	 */
-	if (((context->flags & ATTR_SECURE) == 0) !=
-	    ((flags & XFS_ATTR_SECURE) == 0))
-		return;
-	if (((context->flags & ATTR_ROOT) == 0) !=
-	    ((flags & XFS_ATTR_ROOT) == 0))
-		return;
-
-	arraytop = sizeof(*alist) +
-			context->count * sizeof(alist->al_offset[0]);
-
-	/* decrement by the actual bytes used by the attr */
-	context->firstu -= round_up(offsetof(struct attrlist_ent, a_name) +
-			namelen + 1, sizeof(uint32_t));
-	if (context->firstu < arraytop) {
-		trace_xfs_attr_list_full(context);
-		alist->al_more = 1;
-		context->seen_enough = 1;
-		return;
-	}
-
-	aep = context->buffer + context->firstu;
-	aep->a_valuelen = valuelen;
-	memcpy(aep->a_name, name, namelen);
-	aep->a_name[namelen] = 0;
-	alist->al_offset[context->count++] = context->firstu;
-	alist->al_count = context->count;
-	trace_xfs_attr_list_add(context);
-	return;
-}
-
-/*
- * Generate a list of extended attribute names and optionally
- * also value lengths.  Positive return value follows the XFS
- * convention of being an error, zero or negative return code
- * is the length of the buffer returned (negated), indicating
- * success.
- */
-int
-xfs_attr_list(
-	struct xfs_inode		*dp,
-	char				*buffer,
-	int				bufsize,
-	int				flags,
-	struct attrlist_cursor_kern	*cursor)
-{
-	struct xfs_attr_list_context	context;
-	struct attrlist			*alist;
-	int				error;
-
-	/*
-	 * Validate the cursor.
-	 */
-	if (cursor->pad1 || cursor->pad2)
-		return -EINVAL;
-	if ((cursor->initted == 0) &&
-	    (cursor->hashval || cursor->blkno || cursor->offset))
-		return -EINVAL;
-
-	/*
-	 * Check for a properly aligned buffer.
-	 */
-	if (((long)buffer) & (sizeof(int)-1))
-		return -EFAULT;
-
-	/*
-	 * Initialize the output buffer.
-	 */
-	memset(&context, 0, sizeof(context));
-	context.dp = dp;
-	context.cursor = cursor;
-	context.resynch = 1;
-	context.flags = flags;
-	context.buffer = buffer;
-	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
-	context.firstu = context.bufsize;
-	context.put_listent = xfs_attr_put_listent;
-
-	alist = context.buffer;
-	alist->al_count = 0;
-	alist->al_more = 0;
-	alist->al_offset[0] = context.bufsize;
-
-	error = xfs_attr_list_int(&context);
-	ASSERT(error <= 0);
-	return error;
-}

fs/xfs/xfs_ioctl.c

@@ -294,6 +294,111 @@ xfs_readlink_by_handle(
 	return error;
 }
 
+/*
+ * Format an attribute and copy it out to the user's buffer.
+ * Take care to check values and protect against them changing later,
+ * we may be reading them directly out of a user buffer.
+ */
+static void
+xfs_ioc_attr_put_listent(
+	struct xfs_attr_list_context *context,
+	int			flags,
+	unsigned char		*name,
+	int			namelen,
+	int			valuelen)
+{
+	struct xfs_attrlist	*alist = context->buffer;
+	struct xfs_attrlist_ent	*aep;
+	int			arraytop;
+
+	ASSERT(!context->seen_enough);
+	ASSERT(context->count >= 0);
+	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
+	ASSERT(context->firstu >= sizeof(*alist));
+	ASSERT(context->firstu <= context->bufsize);
+
+	/*
+	 * Only list entries in the right namespace.
+	 */
+	if (((context->flags & ATTR_SECURE) == 0) !=
+	    ((flags & XFS_ATTR_SECURE) == 0))
+		return;
+	if (((context->flags & ATTR_ROOT) == 0) !=
+	    ((flags & XFS_ATTR_ROOT) == 0))
+		return;
+
+	arraytop = sizeof(*alist) +
+			context->count * sizeof(alist->al_offset[0]);
+
+	/* decrement by the actual bytes used by the attr */
+	context->firstu -= round_up(offsetof(struct xfs_attrlist_ent, a_name) +
+			namelen + 1, sizeof(uint32_t));
+	if (context->firstu < arraytop) {
+		trace_xfs_attr_list_full(context);
+		alist->al_more = 1;
+		context->seen_enough = 1;
+		return;
+	}
+
+	aep = context->buffer + context->firstu;
+	aep->a_valuelen = valuelen;
+	memcpy(aep->a_name, name, namelen);
+	aep->a_name[namelen] = 0;
+	alist->al_offset[context->count++] = context->firstu;
+	alist->al_count = context->count;
+	trace_xfs_attr_list_add(context);
+}
+
+int
+xfs_ioc_attr_list(
+	struct xfs_inode		*dp,
+	char				*buffer,
+	int				bufsize,
+	int				flags,
+	struct attrlist_cursor_kern	*cursor)
+{
+	struct xfs_attr_list_context	context;
+	struct xfs_attrlist		*alist;
+	int				error;
+
+	/*
+	 * Validate the cursor.
+	 */
+	if (cursor->pad1 || cursor->pad2)
+		return -EINVAL;
+	if ((cursor->initted == 0) &&
+	    (cursor->hashval || cursor->blkno || cursor->offset))
+		return -EINVAL;
+
+	/*
+	 * Check for a properly aligned buffer.
+	 */
+	if (((long)buffer) & (sizeof(int)-1))
+		return -EFAULT;
+
+	/*
+	 * Initialize the output buffer.
+	 */
+	memset(&context, 0, sizeof(context));
+	context.dp = dp;
+	context.cursor = cursor;
+	context.resynch = 1;
+	context.flags = flags;
+	context.buffer = buffer;
+	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
+	context.firstu = context.bufsize;
+	context.put_listent = xfs_ioc_attr_put_listent;
+
+	alist = context.buffer;
+	alist->al_count = 0;
+	alist->al_more = 0;
+	alist->al_offset[0] = context.bufsize;
+
+	error = xfs_attr_list_int(&context);
+	ASSERT(error <= 0);
+	return error;
+}
+
 STATIC int
 xfs_attrlist_by_handle(
 	struct file		*parfilp,
@@ -310,7 +415,7 @@ xfs_attrlist_by_handle(
 		return -EPERM;
 	if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
 		return -EFAULT;
-	if (al_hreq.buflen < sizeof(struct attrlist) ||
+	if (al_hreq.buflen < sizeof(struct xfs_attrlist) ||
 	    al_hreq.buflen > XFS_XATTR_LIST_MAX)
 		return -EINVAL;
 
@@ -331,7 +436,7 @@ xfs_attrlist_by_handle(
 		goto out_dput;
 
 	cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
-	error = xfs_attr_list(XFS_I(d_inode(dentry)), kbuf, al_hreq.buflen,
+	error = xfs_ioc_attr_list(XFS_I(d_inode(dentry)), kbuf, al_hreq.buflen,
 					al_hreq.flags, cursor);
 	if (error)
 		goto out_kfree;

fs/xfs/xfs_ioctl.h

@@ -6,6 +6,12 @@
 #ifndef __XFS_IOCTL_H__
 #define __XFS_IOCTL_H__
 
+struct attrlist_cursor_kern;
+struct xfs_bstat;
+struct xfs_ibulk;
+struct xfs_inogrp;
+
+
 extern int
 xfs_ioc_space(
 	struct file		*filp,
@@ -33,6 +39,8 @@ xfs_readlink_by_handle(
 int xfs_ioc_attrmulti_one(struct file *parfilp, struct inode *inode,
 		uint32_t opcode, void __user *uname, void __user *value,
 		uint32_t *len, uint32_t flags);
+int xfs_ioc_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
+	int flags, struct attrlist_cursor_kern *cursor);
 
 extern struct dentry *
 xfs_handle_to_dentry(
@@ -52,10 +60,6 @@ xfs_file_compat_ioctl(
 	unsigned int		cmd,
 	unsigned long		arg);
 
-struct xfs_ibulk;
-struct xfs_bstat;
-struct xfs_inogrp;
-
 int xfs_fsbulkstat_one_fmt(struct xfs_ibulk *breq,
 			   const struct xfs_bulkstat *bstat);
 int xfs_fsinumbers_fmt(struct xfs_ibulk *breq, const struct xfs_inumbers *igrp);

fs/xfs/xfs_ioctl32.c

@@ -366,7 +366,7 @@ xfs_compat_attrlist_by_handle(
 	if (copy_from_user(&al_hreq, arg,
 			   sizeof(compat_xfs_fsop_attrlist_handlereq_t)))
 		return -EFAULT;
-	if (al_hreq.buflen < sizeof(struct attrlist) ||
+	if (al_hreq.buflen < sizeof(struct xfs_attrlist) ||
 	    al_hreq.buflen > XFS_XATTR_LIST_MAX)
 		return -EINVAL;
 
@@ -388,7 +388,7 @@ xfs_compat_attrlist_by_handle(
 		goto out_dput;
 
 	cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
-	error = xfs_attr_list(XFS_I(d_inode(dentry)), kbuf, al_hreq.buflen,
+	error = xfs_ioc_attr_list(XFS_I(d_inode(dentry)), kbuf, al_hreq.buflen,
 					al_hreq.flags, cursor);
 	if (error)
 		goto out_kfree;