On 2022/7/22 8:28, Mike Kravetz wrote: > On 07/21/22 21:16, Miaohe Lin wrote: >> When size option is not specified, f_blocks, f_bavail and f_bfree will be >> set to -1 instead of 0. Likewise, when nr_inodes is not specified, f_files >> and f_ffree will be set to -1 too. Check max_hpages and max_inodes against >> -1 first to make sure 0 is reported for max/free/used when no limit is set >> as the comment states. > > Just curious, where are you seeing values reported as -1? The check >From the standard statvfs() function. > for sbinfo->spool was supposed to handle these cases. Seems like it sbinfo->spool could be created when ctx->max_hpages == -1 while ctx->min_hpages != -1 in hugetlbfs_fill_super. > should handle the max_hpages == -1 case. But, it doesn't look like it > considers the max_inodes == -1 case. > > If I create/mount a hugetlb filesystem without specifying size or nr_inodes, > df seems to report zero instead of -1. > > Just want to understand the reasoning behind the change. I wrote a test program: #include <sys/statvfs.h> #include <stdio.h> int main(void) { struct statvfs buf; if (statvfs("/root/huge/", &buf) == -1) { printf("statvfs() error\n"); return -1; } printf("f_blocks %lld, f_bavail %lld, f_bfree %lld, f_files %lld, f_ffree %lld\n", buf.f_blocks, buf.f_bavail, buf.f_bfree, buf.f_files, buf.f_ffree); return 0; } And test it in my env: [root@localhost ~]# mount -t hugetlbfs none /root/huge/ [root@localhost ~]# ./stat f_blocks 0, f_bavail 0, f_bfree 0, f_files 0, f_ffree 0 [root@localhost ~]# umount /root/huge/ [root@localhost ~]# mount -t hugetlbfs -o min_size=32M none /root/huge/ [root@localhost ~]# ./stat f_blocks -1, f_bavail -1, f_bfree -1, f_files -1, f_ffree -1 [root@localhost ~]# umount /root/huge/ [root@localhost ~]# mount -t hugetlbfs -o min_size=32M,size=64M none /root/huge/ [root@localhost ~]# ./stat f_blocks 32, f_bavail 32, f_bfree 32, f_files -1, f_ffree -1 [root@localhost ~]# umount /root/huge/ [root@localhost ~]# mount -t hugetlbfs -o min_size=32M,size=64M,nr_inodes=1024 none /root/huge/ [root@localhost ~]# ./stat f_blocks 32, f_bavail 32, f_bfree 32, f_files 1024, f_ffree 1023 [root@localhost ~]# umount /root/huge/ Or am I miss something? > Thanks.