`fsparam_bdev` uses `fs_param_is_blockdev` to parse the option, but it
is currently empty. Filesystems like ext4 use the `fsparam_bdev` to
parse `journal_path` into the block device. This general logic should
be moved to the vfs layer, not the specific filesystem. Therefore, we
implement block device parser in `fs_param_is_blockdev`. And the logic
is similar with `fs_lookup_param`.
Signed-off-by: Hongbo Li <lihongbo22@xxxxxxxxxx>
---
fs/fs_parser.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 50 insertions(+), 1 deletion(-)
diff --git a/fs/fs_parser.c b/fs/fs_parser.c
index a4d6ca0b8971..48f60ecfcca0 100644
--- a/fs/fs_parser.c
+++ b/fs/fs_parser.c
@@ -311,7 +311,56 @@ EXPORT_SYMBOL(fs_param_is_fd);
int fs_param_is_blockdev(struct p_log *log, const struct fs_parameter_spec *p,
struct fs_parameter *param, struct fs_parse_result *result)
{
- return 0;
+ int ret;
+ int dfd;
+ struct filename *f;
+ struct inode *dev_inode;
+ struct path path;
+ bool put_f;
+
+ switch (param->type) {
+ case fs_value_is_string:
+ if (!*param->string) {
+ if (p->flags & fs_param_can_be_empty)
+ return 0;
+ break;
+ }
+ f = getname_kernel(param->string);
+ if (IS_ERR(f))
+ return fs_param_bad_value(log, param);
+ dfd = AT_FDCWD;
+ put_f = true;
+ break;
+ case fs_value_is_filename:
+ f = param->name;
+ dfd = param->dirfd;
+ put_f = false;
+ break;
+ default:
+ return fs_param_bad_value(log, param);
+ }
+
+ ret = filename_lookup(dfd, f, LOOKUP_FOLLOW, &path, NULL);
+ if (ret < 0) {
+ error_plog(log, "%s: Lookup failure for '%s'", param->key, f->name);
+ goto out_putname;
+ }
+
+ dev_inode = d_backing_inode(path.dentry);
+ if (!S_ISBLK(dev_inode->i_mode)) {
+ error_plog(log, "%s: Non-blockdev passed as '%s'", param->key, f->name);
+ ret = -1;
+ goto out_putpath;
+ }
+ result->uint_32 = new_encode_dev(dev_inode->i_rdev);
+
+out_putpath:
+ path_put(&path);
+out_putname:
+ if (put_f)
+ putname(f);
+
+ return (ret < 0) ? fs_param_bad_value(log, param) : 0;
}
EXPORT_SYMBOL(fs_param_is_blockdev);
--
2.34.1
