On Mon, 2019-06-24 at 10:44 -0700, Darrick J. Wong wrote:
> On Mon, Jun 24, 2019 at 10:58:50AM +0800, Ian Kent wrote:
> > Add the fs_context_operations method .get_tree that validates
> > mount options and fills the super block as previously done
> > by the file_system_type .mount method.
> >
> > Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
> > ---
> > fs/xfs/xfs_super.c | 139
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 139 insertions(+)
> >
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index cf8efb465969..0ec0142b94e1 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -1629,6 +1629,98 @@ xfs_fs_remount(
> > return 0;
> > }
> >
> > +STATIC int
> > +xfs_validate_params(
> > + struct xfs_mount *mp,
> > + struct xfs_fs_context *ctx,
> > + enum fs_context_purpose purpose)
>
> Tabs here, please:
>
> struct xfs_mount *mp,
> struct xfs_fs_context *ctx,
> enum fs_context_purpose purpose)
Oops, my bad, will fix.
>
> > +{
> > + /*
> > + * no recovery flag requires a read-only mount
> > + */
> > + if ((mp->m_flags & XFS_MOUNT_NORECOVERY) &&
> > + !(mp->m_flags & XFS_MOUNT_RDONLY)) {
> > + xfs_warn(mp, "no-recovery mounts must be read-only.");
> > + return -EINVAL;
> > + }
> > +
> > + 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;
> > + }
> > +
> > + if (ctx->dsunit && !(mp->m_flags & XFS_MOUNT_NOALIGN)) {
> > + /*
> > + * At this point the superblock has not been read
> > + * in, therefore we do not know the block size.
> > + * Before the mount call ends we will convert
> > + * these to FSBs.
> > + */
> > + if (purpose == FS_CONTEXT_FOR_MOUNT) {
> > + mp->m_dalign = ctx->dsunit;
> > + mp->m_swidth = ctx->dswidth;
> > + }
> > + }
> > +
> > + if (mp->m_logbufs != -1 &&
> > + mp->m_logbufs != 0 &&
> > + (mp->m_logbufs < XLOG_MIN_ICLOGS ||
> > + mp->m_logbufs > XLOG_MAX_ICLOGS)) {
> > + xfs_warn(mp, "invalid logbufs value: %d [not %d-%d]",
> > + mp->m_logbufs, XLOG_MIN_ICLOGS, XLOG_MAX_ICLOGS);
> > + return -EINVAL;
> > + }
> > + if (mp->m_logbsize != -1 &&
> > + mp->m_logbsize != 0 &&
> > + (mp->m_logbsize < XLOG_MIN_RECORD_BSIZE ||
> > + mp->m_logbsize > XLOG_MAX_RECORD_BSIZE ||
> > + !is_power_of_2(mp->m_logbsize))) {
> > + xfs_warn(mp,
> > + "invalid logbufsize: %d [not 16k,32k,64k,128k or 256k]",
> > + mp->m_logbsize);
> > + return -EINVAL;
> > + }
> > +
> > + if (ctx->iosizelog) {
> > + if (ctx->iosizelog > XFS_MAX_IO_LOG ||
> > + ctx->iosizelog < XFS_MIN_IO_LOG) {
> > + xfs_warn(mp, "invalid log iosize: %d [not %d-%d]",
> > + ctx->iosizelog, XFS_MIN_IO_LOG,
> > + XFS_MAX_IO_LOG);
> > + return -EINVAL;
> > + }
> > +
> > + if (purpose == FS_CONTEXT_FOR_MOUNT) {
> > + mp->m_flags |= XFS_MOUNT_DFLT_IOSIZE;
> > + mp->m_readio_log = ctx->iosizelog;
> > + mp->m_writeio_log = ctx->iosizelog;
> > + }
> > + }
>
> Ugggh, I don't wanna have to compare the old xfs_parseargs code with
> this new xfs_validate_params code to make sure nothing got screwed up.
> :)
>
> Can this code be broken out of the existing parseargs (instead of added
> further down in the file) to minimize the diff? You're getting rid of
> the old option processing code at the end of the series anyway so I
> don't mind creating temporary struct xfs_fs_context structures in
> xfs_parseargs if that makes it much more obvious that the validation
> code itself isn't changing.
Both you, Dave, and myself agree but ...
The indentation is different between the two functions resulting
in an even harder to understand patch.
I will have another go at it and see if I can come up with a
re-factoring that helps.
>
> --D
>
> > +
> > + return 0;
> > +}
> > +
> > /*
> > * Second stage of a freeze. The data is already frozen so we only
> > * need to take care of the metadata. Once that's done sync the superblock
> > @@ -2035,6 +2127,52 @@ xfs_fs_fill_super(
> > return error;
> > }
> >
> > +STATIC int
> > +xfs_fill_super(
> > + struct super_block *sb,
> > + struct fs_context *fc)
> > +{
> > + struct xfs_fs_context *ctx = fc->fs_private;
> > + struct xfs_mount *mp = sb->s_fs_info;
> > + int silent = fc->sb_flags & SB_SILENT;
> > + int error = -ENOMEM;
> > +
> > + mp->m_super = sb;
> > +
> > + /*
> > + * 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;
> > +
> > + error = xfs_validate_params(mp, ctx, fc->purpose);
> > + 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_get_tree(
> > + struct fs_context *fc)
> > +{
> > + return vfs_get_block_super(fc, xfs_fill_super);
> > +}
> > +
> > STATIC void
> > xfs_fs_put_super(
> > struct super_block *sb)
> > @@ -2107,6 +2245,7 @@ static const struct super_operations
> > xfs_super_operations = {
> >
> > static const struct fs_context_operations xfs_context_ops = {
> > .parse_param = xfs_parse_param,
> > + .get_tree = xfs_get_tree,
> > };
> >
> > static struct file_system_type xfs_fs_type = {
> >
