From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Miklos Szeredi To: David Howells Cc: Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/6] mount: fix regression in setting "subtype" from legacy API Date: Thu, 20 Sep 2018 17:12:11 +0200 Message-Id: <20180920151214.15484-4-mszeredi@redhat.com> In-Reply-To: <20180920151214.15484-1-mszeredi@redhat.com> References: <20180920151214.15484-1-mszeredi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Subtype was initilized at the wrong place from the wrong source (fstype->fs_type->name, which does not ever contain a subtype). Set subtype from do_new_mount(), where it actually does something. Verified with fuse. Signed-off-by: Miklos Szeredi --- fs/fs_context.c | 34 ---------------------------------- fs/namespace.c | 21 +++++++++++++++++++++ 2 files changed, 21 insertions(+), 34 deletions(-) diff --git a/fs/fs_context.c b/fs/fs_context.c index ceaf42559016..c0ecbb1ecdfe 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -684,27 +684,6 @@ static int legacy_validate(struct fs_context *fc) ctx->secdata); } -/* - * Determine the superblock subtype. - */ -static int legacy_set_subtype(struct fs_context *fc) -{ - const char *subtype = strchr(fc->fs_type->name, '.'); - - if (subtype) { - subtype++; - if (!subtype[0]) - return -EINVAL; - } else { - subtype = ""; - } - - fc->subtype = kstrdup(subtype, GFP_KERNEL); - if (!fc->subtype) - return -ENOMEM; - return 0; -} - /* * Get a mountable root with the legacy mount command. */ @@ -713,7 +692,6 @@ static int legacy_get_tree(struct fs_context *fc) struct legacy_fs_context *ctx = fc->fs_private; struct super_block *sb; struct dentry *root; - int ret; root = fc->fs_type->mount(fc->fs_type, fc->sb_flags, fc->source, ctx->legacy_data, @@ -724,20 +702,8 @@ static int legacy_get_tree(struct fs_context *fc) sb = root->d_sb; BUG_ON(!sb); - if ((fc->fs_type->fs_flags & FS_HAS_SUBTYPE) && - !fc->subtype) { - ret = legacy_set_subtype(fc); - if (ret < 0) - goto err_sb; - } - fc->root = root; return 0; - -err_sb: - dput(root); - deactivate_locked_super(sb); - return ret; } /* diff --git a/fs/namespace.c b/fs/namespace.c index 865b6f2c5e7d..7671c1f6fc22 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2617,6 +2617,7 @@ static int do_new_mount(struct path *mountpoint, const char *fstype, { struct file_system_type *fs_type; struct fs_context *fc; + const char *subtype = NULL; int err; if (!fstype) @@ -2627,6 +2628,19 @@ static int do_new_mount(struct path *mountpoint, const char *fstype, if (!fs_type) goto out; + if (fs_type->fs_flags & FS_HAS_SUBTYPE) { + subtype = strchr(fstype, '.'); + if (subtype) { + subtype++; + if (!subtype[0]) { + put_filesystem(fs_type); + return -EINVAL; + } + } else { + subtype = ""; + } + } + fc = vfs_new_fs_context(fs_type, NULL, sb_flags, sb_flags, FS_CONTEXT_FOR_USER_MOUNT); put_filesystem(fs_type); @@ -2635,6 +2649,13 @@ static int do_new_mount(struct path *mountpoint, const char *fstype, goto out; } + if (subtype) { + fc->subtype = kstrdup(subtype, GFP_KERNEL); + err = -ENOMEM; + if (!fc->subtype) + goto out; + } + if (name) { err = vfs_parse_fs_string(fc, "source", name, strlen(name)); if (err < 0) -- 2.14.3