Red Hat Bugzilla – Bug 1399830
GFS2: fallocate error message during gfs2_grow
Last modified: 2017-08-02 00:53:19 EDT
Description of problem: When I grow a GFS2 file system the successful output includes an error about fallocate not being supported. [root@host-135 ~]# df -h /mnt/growfs0/ Filesystem Size Used Avail Use% Mounted on /dev/mapper/growfs-growfs0 300G 259M 300G 1% /mnt/growfs0 [root@host-135 ~]# lvs growfs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert growfs0 growfs -wi-ao---- 300.00g [root@host-135 ~]# lvextend -L 400G growfs/growfs0 Size of logical volume growfs/growfs0 changed from 300.00 GiB (76800 extents) to 400.00 GiB (102400 extents). Logical volume growfs/growfs0 successfully resized. [root@host-135 ~]# lvs growfs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert growfs0 growfs -wi-ao---- 400.00g [root@host-135 ~]# gfs2_grow /mnt/growfs0/ FS: Mount point: /mnt/growfs0 FS: Device: /dev/mapper/growfs-growfs0 FS: Size: 78643199 (0x4afffff) DEV: Length: 104857600 (0x6400000) The file system will grow by 102400MB. fallocate: Operation not supported <--- HERE gfs2_grow complete. [root@host-135 ~]# echo $? 0 [root@host-135 ~]# df -h /mnt/growfs0/ Filesystem Size Used Avail Use% Mounted on /dev/mapper/growfs-growfs0 400G 259M 400G 1% /mnt/growfs0 I ran the command with strace and found that gfs2_grow is trying to fallocate on the rindex on the gfs2metafs. 18856 open("/tmp/.gfs2meta.xvHEtj/rindex", O_RDWR|O_CLOEXEC) = 6 ... 18856 fallocate(6, 01, 15648, 96) = -1 EOPNOTSUPP (Operation not supported) The file system does grow and appears to be completely usable. Version-Release number of selected component (if applicable): gfs2-utils-3.1.9-3.el7.x86_64 kernel-3.10.0-514.el7.x86_64 How reproducible: Easily Steps to Reproduce: See example above. Actual results: Odd error message is printed Expected results: No odd error message during a successful command. Additional info:
gfs2_grow uses if (fallocate(rindex_fd, FALLOC_FL_KEEP_SIZE, (rindex_size + writelen), entrysize) != 0) perror("fallocate"); to allocate enough space to write an rindex entry if the fs is full when the next grow happens. So, while the grow will succeed, the danger of the fallocate() failing is that a second gfs2_grow could fail if the fs is full. After a recent change to fix bug 1221331, gfs2's fallocate implementation does: if ((mode & ~FALLOC_FL_KEEP_SIZE) || gfs2_is_jdata(ip)) return -EOPNOTSUPP; and since mkfs.gfs2 creates the rindex inode with GFS2_DIF_JDATA set, the gfs2_is_jdata(ip) returns true and we see the bug. So I'm not sure that we can fix this in gfs2_grow. We may need to allow gfs2's fallocate to proceed for the rindex especially, or for all GFS2_DIF_SYSTEM inodes.
I have submitted an upstream patch for this to cluster-devel.
The patch is now upstream and I have sent a RHEL7 version to rhkernel-list.
Patch(es) committed on kernel repository and an interim kernel build is undergoing testing
Patch(es) available on kernel-3.10.0-657.el7
Verified on kernel-3.10.0-679.el7.x86_64 [root@dash-01 ~]# uname -r 3.10.0-679.el7.x86_64 [root@dash-01 ~]# df -Th /mnt/gfs2 Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/fsck-gfs2 gfs2 1.0T 34M 1.0T 1% /mnt/gfs2 [root@dash-01 ~]# lvextend -L +1T /dev/fsck/gfs2 Size of logical volume fsck/gfs2 changed from 1.00 TiB (262144 extents) to 2.00 TiB (524288 extents). Logical volume fsck/gfs2 successfully resized. [root@dash-01 ~]# gfs2_grow /mnt/gfs2 FS: Mount point: /mnt/gfs2 FS: Device: /dev/mapper/fsck-gfs2 FS: Size: 268435454 (0xffffffe) DEV: Length: 536870912 (0x20000000) The file system will grow by 1048576MB. gfs2_grow complete. [root@dash-01 ~]# df -Th /mnt/gfs2 Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/fsck-gfs2 gfs2 2.0T 34M 2.0T 1% /mnt/gfs2
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2017:1842