On Tue, 2019-09-24 at 10:37 -0400, Brian Foster wrote:
> On Tue, Sep 24, 2019 at 09:22:33PM +0800, Ian Kent wrote:
> > Make xfs_parse_param() take arguments of the fs context operation
> > .parse_param() in preparation for switching to use the file system
> > mount context for mount.
> >
> > The function fc_parse() only uses the file system context (fc here)
> > when calling log macros warnf() and invalf() which in turn check
> > only the fc->log field to determine if the message should be saved
> > to a context buffer (for later retrival by userspace) or logged
> > using printk().
> >
> > Also the temporary function match_kstrtoint() is now unused, remove
> > it.
> >
> > Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
> > ---
> > fs/xfs/xfs_super.c | 137 +++++++++++++++++++++++++++++++---------
> > ------------
> > 1 file changed, 81 insertions(+), 56 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index b04aebab69ab..6792d46fa0be 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -191,57 +191,60 @@ suffix_kstrtoint(const char *s, unsigned int
> > base, int *res)
> > return ret;
> > }
> >
> ...
> >
> > STATIC int
> > xfs_parse_param(
> ...
> > - switch (token) {
> > + opt = fs_parse(fc, &xfs_fs_parameters, param, &result);
> > + if (opt < 0) {
> > + /*
> > + * If fs_parse() returns -ENOPARAM and the parameter
> > + * is "source" the VFS needs to handle this option
> > + * in order to boot otherwise use the default case
> > + * below to handle invalid options.
> > + */
> > + if (opt != -ENOPARAM ||
> > + strcmp(param->key, "source") == 0)
> > + return opt;
>
> Same question as before on this bit..
Your comment was:
Why is this not something that is handled in core mount-api code? Every
filesystem needs this logic in order to be a rootfs..?
I looked at the VFS code and was tempted to change it but it's all too
easy to prevent the system from booting.
The way the VFS looks to me it needs to give the file system a chance
to handle the "source" option, if the file system ->parse_param()
doesn't handle the option it "must" return -ENOPARAM so the VFS will
test for and handle the "source" option.
Having returned -ENOPARAM either the option is "source" or it's a
real unknown option.
The choices are:
1) If it is the "source" option we will get a false positive unknown
parameter message logged by our ->parse_param().
2) if it isn't the "source" option we will get an unknown parameter
message from our ->parse_param() and an additional inconsistent
format unknown parameter message from the VFS.
3) Check for the "source" parameter in our ->parse_param() and
return without issuing a message so the VFS can handle the option,
no duplicate message and no inconsistent logging.
Suggestions on how to handle this better, a VFS patch perhaps?
Suggestions David, Al?
> ...
> > @@ -373,10 +374,16 @@ xfs_parseargs(
> > {
> > const struct super_block *sb = mp->m_super;
> > char *p;
> > - substring_t args[MAX_OPT_ARGS];
> > - int dsunit = 0;
> > - int dswidth = 0;
> > - uint8_t iosizelog = 0;
> > + struct fs_context fc;
> > + struct xfs_fs_context context;
> > + struct xfs_fs_context *ctx;
> > + int ret;
> > +
> > + memset(&fc, 0, sizeof(fc));
> > + memset(&context, 0, sizeof(context));
> > + fc.fs_private = &context;
> > + ctx = &context;
>
> I think you mentioned this ctx/context pattern would be removed from
> v2..?
Except that, to minimise code churn the ctx variable is needed
because it will be used in the end result.
I don't much like prefixing those references with &context even
if some happen to go away later on, the additional local variable
is clearer to read and provides usage consistency for the reader
over the changes.
Ian
>
> Brian
>
> > + fc.s_fs_info = mp;
> >
> > /*
> > * set up the mount name first so all the errors will refer to
> > the
> > @@ -413,16 +420,33 @@ xfs_parseargs(
> > goto done;
> >
> > while ((p = strsep(&options, ",")) != NULL) {
> > - int token;
> > - int ret;
> > + struct fs_parameter param;
> > + char *value;
> >
> > if (!*p)
> > continue;
> >
> > - token = match_token(p, tokens, args);
> > - ret = xfs_parse_param(token, p, args, mp,
> > - &dsunit, &dswidth, &iosizelog);
> > - if (ret)
> > + param.key = p;
> > + param.type = fs_value_is_string;
> > + param.string = NULL;
> > + param.size = 0;
> > +
> > + value = strchr(p, '=');
> > + if (value) {
> > + *value++ = 0;
> > + param.size = strlen(value);
> > + if (param.size > 0) {
> > + param.string = kmemdup_nul(value,
> > + param.size,
> > + GFP_KERNEL);
> > + if (!param.string)
> > + return -ENOMEM;
> > + }
> > + }
> > +
> > + ret = xfs_parse_param(&fc, ¶m);
> > + kfree(param.string);
> > + if (ret < 0)
> > return ret;
> > }
> >
> > @@ -435,7 +459,8 @@ xfs_parseargs(
> > return -EINVAL;
> > }
> >
> > - if ((mp->m_flags & XFS_MOUNT_NOALIGN) && (dsunit || dswidth)) {
> > + 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;
> > @@ -448,28 +473,28 @@ xfs_parseargs(
> > }
> > #endif
> >
> > - if ((dsunit && !dswidth) || (!dsunit && dswidth)) {
> > + if ((ctx->dsunit && !ctx->dswidth) || (!ctx->dsunit && ctx-
> > >dswidth)) {
> > xfs_warn(mp, "sunit and swidth must be specified
> > together");
> > return -EINVAL;
> > }
> >
> > - if (dsunit && (dswidth % dsunit != 0)) {
> > + if (ctx->dsunit && (ctx->dswidth % ctx->dsunit != 0)) {
> > xfs_warn(mp,
> > "stripe width (%d) must be a multiple of the stripe unit (%d)",
> > - dswidth, dsunit);
> > + ctx->dswidth, ctx->dsunit);
> > return -EINVAL;
> > }
> >
> > done:
> > - if (dsunit && !(mp->m_flags & XFS_MOUNT_NOALIGN)) {
> > + 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.
> > */
> > - mp->m_dalign = dsunit;
> > - mp->m_swidth = dswidth;
> > + mp->m_dalign = ctx->dsunit;
> > + mp->m_swidth = ctx->dswidth;
> > }
> >
> > if (mp->m_logbufs != -1 &&
> > @@ -491,18 +516,18 @@ xfs_parseargs(
> > return -EINVAL;
> > }
> >
> > - if (iosizelog) {
> > - if (iosizelog > XFS_MAX_IO_LOG ||
> > - iosizelog < XFS_MIN_IO_LOG) {
> > + 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]",
> > - iosizelog, XFS_MIN_IO_LOG,
> > + ctx->iosizelog, XFS_MIN_IO_LOG,
> > XFS_MAX_IO_LOG);
> > return -EINVAL;
> > }
> >
> > mp->m_flags |= XFS_MOUNT_DFLT_IOSIZE;
> > - mp->m_readio_log = iosizelog;
> > - mp->m_writeio_log = iosizelog;
> > + mp->m_readio_log = ctx->iosizelog;
> > + mp->m_writeio_log = ctx->iosizelog;
> > }
> >
> > return 0;
> >
