[PATCH v4 16/17] xfs: mount-api - switch to new mount-api

[Ian Kent <raven@themaw.net>]

The infrastructure needed to use the new mount api is now
in place, switch over to use it.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/xfs/xfs_super.c |  321 ++++++++--------------------------------------------
 1 file changed, 49 insertions(+), 272 deletions(-)

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 919afd7082b7..93f42160aa6f 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -439,132 +439,6 @@ xfs_validate_params(
 	return 0;
 }
 
-/*
- * This function fills in xfs_mount_t fields based on mount args.
- * Note: the superblock has _not_ yet been read in.
- *
- * Note that this function leaks the various device name allocations on
- * failure.  The caller takes care of them.
- *
- * *sb is const because this is also used to test options on the remount
- * path, and we don't want this to have any side effects at remount time.
- * Today this function does not change *sb, but just to future-proof...
- */
-STATIC int
-xfs_parseargs(
-	struct xfs_mount	*mp,
-	char			*options)
-{
-	const struct super_block *sb = mp->m_super;
-	char			*p;
-	struct fs_context	fc;
-	struct xfs_fs_context	context;
-	struct xfs_fs_context	*ctx;
-	int			ret;
-
-	memset(&fc, 0, sizeof(fc));
-	memset(&context, 0, sizeof(context));
-	fc.fs_private = &context;
-	ctx = &context;
-	fc.s_fs_info = mp;
-
-	/*
-	 * set up the mount name first so all the errors will refer to the
-	 * correct device.
-	 */
-	mp->m_fsname = kstrndup(sb->s_id, MAXNAMELEN, GFP_KERNEL);
-	if (!mp->m_fsname)
-		return -ENOMEM;
-	mp->m_fsname_len = strlen(mp->m_fsname) + 1;
-
-	/*
-	 * Copy binary VFS mount flags we are interested in.
-	 */
-	if (sb_rdonly(sb))
-		mp->m_flags |= XFS_MOUNT_RDONLY;
-	if (sb->s_flags & SB_DIRSYNC)
-		mp->m_flags |= XFS_MOUNT_DIRSYNC;
-	if (sb->s_flags & SB_SYNCHRONOUS)
-		mp->m_flags |= XFS_MOUNT_WSYNC;
-
-	/*
-	 * Set some default flags that could be cleared by the mount option
-	 * parsing.
-	 */
-	mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
-
-	/*
-	 * These can be overridden by the mount option parsing.
-	 */
-	mp->m_logbufs = -1;
-	mp->m_logbsize = -1;
-
-	if (!options)
-		goto done;
-
-	while ((p = strsep(&options, ",")) != NULL) {
-		struct fs_parameter	param;
-		char			*value;
-
-		if (!*p)
-			continue;
-
-		param.key = p;
-		param.type = fs_value_is_string;
-		param.string = NULL;
-		param.size = 0;
-
-		value = strchr(p, '=');
-		if (value) {
-			*value++ = 0;
-			param.size = strlen(value);
-			if (param.size > 0) {
-				param.string = kmemdup_nul(value,
-							   param.size,
-							   GFP_KERNEL);
-				if (!param.string)
-					return -ENOMEM;
-			}
-		}
-
-		ret = xfs_parse_param(&fc, &param);
-		kfree(param.string);
-		if (ret < 0)
-			return ret;
-	}
-
-	if ((mp->m_flags & XFS_MOUNT_NOALIGN) &&
-	    (ctx->dsunit || ctx->dswidth)) {
-		xfs_warn(mp,
-	"sunit and swidth options incompatible with the noalign option");
-		return -EINVAL;
-	}
-
-#ifndef CONFIG_XFS_QUOTA
-	if (XFS_IS_QUOTA_RUNNING(mp)) {
-		xfs_warn(mp, "quota support not available in this kernel.");
-		return -EINVAL;
-	}
-#endif
-
-	if ((ctx->dsunit && !ctx->dswidth) || (!ctx->dsunit && ctx->dswidth)) {
-		xfs_warn(mp, "sunit and swidth must be specified together");
-		return -EINVAL;
-	}
-
-	if (ctx->dsunit && (ctx->dswidth % ctx->dsunit != 0)) {
-		xfs_warn(mp,
-	"stripe width (%d) must be a multiple of the stripe unit (%d)",
-			ctx->dswidth, ctx->dsunit);
-		return -EINVAL;
-	}
-
-done:
-	ret = xfs_validate_params(mp, &context, false);
-
-	return ret;
-}
-
 struct proc_xfs_info {
 	uint64_t	flag;
 	char		*str;
@@ -1343,26 +1217,6 @@ xfs_quiesce_attr(
 	xfs_log_quiesce(mp);
 }
 
-STATIC int
-xfs_test_remount_options(
-	struct super_block	*sb,
-	char			*options)
-{
-	int			error = 0;
-	struct xfs_mount	*tmp_mp;
-
-	tmp_mp = kmem_zalloc(sizeof(*tmp_mp), KM_MAYFAIL);
-	if (!tmp_mp)
-		return -ENOMEM;
-
-	tmp_mp->m_super = sb;
-	error = xfs_parseargs(tmp_mp, options);
-	xfs_free_fsname(tmp_mp);
-	kmem_free(tmp_mp);
-
-	return error;
-}
-
 STATIC int
 xfs_remount_rw(
 	struct xfs_mount	*mp)
@@ -1466,84 +1320,6 @@ xfs_remount_ro(
 	return 0;
 }
 
-STATIC int
-xfs_fs_remount(
-	struct super_block	*sb,
-	int			*flags,
-	char			*options)
-{
-	struct xfs_mount	*mp = XFS_M(sb);
-	xfs_sb_t		*sbp = &mp->m_sb;
-	substring_t		args[MAX_OPT_ARGS];
-	char			*p;
-	int			error;
-
-	/* First, check for complete junk; i.e. invalid options */
-	error = xfs_test_remount_options(sb, options);
-	if (error)
-		return error;
-
-	sync_filesystem(sb);
-	while ((p = strsep(&options, ",")) != NULL) {
-		int token;
-
-		if (!*p)
-			continue;
-
-		token = match_token(p, tokens, args);
-		switch (token) {
-		case Opt_inode64:
-			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;
-			mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
-			break;
-		case Opt_inode32:
-			mp->m_flags |= XFS_MOUNT_SMALL_INUMS;
-			mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount);
-			break;
-		default:
-			/*
-			 * Logically we would return an error here to prevent
-			 * users from believing they might have changed
-			 * mount options using remount which can't be changed.
-			 *
-			 * But unfortunately mount(8) adds all options from
-			 * mtab and fstab to the mount arguments in some cases
-			 * so we can't blindly reject options, but have to
-			 * check for each specified option if it actually
-			 * differs from the currently set option and only
-			 * reject it if that's the case.
-			 *
-			 * Until that is implemented we return success for
-			 * every remount request, and silently ignore all
-			 * options that we can't actually change.
-			 */
-#if 0
-			xfs_info(mp,
-		"mount option \"%s\" not supported for remount", p);
-			return -EINVAL;
-#else
-			break;
-#endif
-		}
-	}
-
-	/* ro -> rw */
-	if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & SB_RDONLY)) {
-		error = xfs_remount_rw(mp);
-		if (error)
-			return error;
-	}
-
-	/* rw -> ro */
-	if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & SB_RDONLY)) {
-		error = xfs_remount_ro(mp);
-		if (error)
-			return error;
-	}
-
-	return 0;
-}
-
 /*
  * There can be problems with options passed from mount(8) when
  * only the mount point path is given. The options are a merge
@@ -1981,42 +1757,6 @@ __xfs_fs_fill_super(
 	goto out_free_sb;
 }
 
-STATIC int
-xfs_fs_fill_super(
-	struct super_block	*sb,
-	void			*data,
-	int			silent)
-{
-	struct xfs_mount	*mp;
-	int			error;
-
-	/*
-	 * allocate mp and do all low-level struct initializations before we
-	 * attach it to the super
-	 */
-	mp = xfs_mount_alloc();
-	if (!mp)
-		return -ENOMEM;
-	mp->m_super = sb;
-	sb->s_fs_info = mp;
-
-	error = xfs_parseargs(mp, (char *)data);
-	if (error)
-		goto out_free_fsname;
-
-	error = __xfs_fs_fill_super(mp, silent);
-	if (error)
-		goto out_free_fsname;
-
-	return 0;
-
- out_free_fsname:
-	sb->s_fs_info = NULL;
-	xfs_free_fsname(mp);
-	kfree(mp);
-	return error;
-}
-
 STATIC int
 xfs_fill_super(
 	struct super_block	*sb,
@@ -2087,16 +1827,6 @@ xfs_fs_put_super(
 	kfree(mp);
 }
 
-STATIC struct dentry *
-xfs_fs_mount(
-	struct file_system_type	*fs_type,
-	int			flags,
-	const char		*dev_name,
-	void			*data)
-{
-	return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super);
-}
-
 static long
 xfs_fs_nr_cached_objects(
 	struct super_block	*sb,
@@ -2126,7 +1856,6 @@ static const struct super_operations xfs_super_operations = {
 	.freeze_fs		= xfs_fs_freeze,
 	.unfreeze_fs		= xfs_fs_unfreeze,
 	.statfs			= xfs_fs_statfs,
-	.remount_fs		= xfs_fs_remount,
 	.show_options		= xfs_fs_show_options,
 	.nr_cached_objects	= xfs_fs_nr_cached_objects,
 	.free_cached_objects	= xfs_fs_free_cached_objects,
@@ -2164,10 +1893,58 @@ static const struct fs_context_operations xfs_context_ops = {
 	.free        = xfs_fc_free,
 };
 
+/*
+ * Set up the filesystem mount context.
+ */
+int xfs_init_fs_context(struct fs_context *fc)
+{
+	struct xfs_fs_context	*ctx;
+	struct xfs_mount	*mp;
+
+	ctx = kzalloc(sizeof(struct xfs_fs_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	mp = xfs_mount_alloc();
+	if (!mp) {
+		kfree(ctx);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Set some default flags that could be cleared by the mount option
+	 * parsing.
+	 */
+	mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;
+
+	/*
+	 * These can be overridden by the mount option parsing.
+	 */
+	mp->m_logbufs = -1;
+	mp->m_logbsize = -1;
+
+	/*
+	 * Copy binary VFS mount flags we are interested in.
+	 */
+	if (fc->sb_flags & SB_RDONLY)
+		mp->m_flags |= XFS_MOUNT_RDONLY;
+	if (fc->sb_flags & SB_DIRSYNC)
+		mp->m_flags |= XFS_MOUNT_DIRSYNC;
+	if (fc->sb_flags & SB_SYNCHRONOUS)
+		mp->m_flags |= XFS_MOUNT_WSYNC;
+
+	fc->fs_private = ctx;
+	fc->s_fs_info = mp;
+	fc->ops = &xfs_context_ops;
+
+	return 0;
+}
+
 static struct file_system_type xfs_fs_type = {
 	.owner			= THIS_MODULE,
 	.name			= "xfs",
-	.mount			= xfs_fs_mount,
+	.init_fs_context	= xfs_init_fs_context,
+	.parameters		= &xfs_fs_parameters,
 	.kill_sb		= kill_block_super,
 	.fs_flags		= FS_REQUIRES_DEV,
 };