* [PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime
@ 2020-09-30 14:58 Darrick J. Wong
2020-09-30 15:31 ` Eric Sandeen
0 siblings, 1 reply; 3+ messages in thread
From: Darrick J. Wong @ 2020-09-30 14:58 UTC (permalink / raw)
To: Eric Sandeen; +Cc: xfs
From: Darrick J. Wong <darrick.wong@oracle.com>
Neither the kernel nor the code in xfsprogs support filesystems that
have (either reverse mapping btrees or reflink) enabled and a realtime
volume configured. The kernel rejects such combinations and mkfs
refuses to format such a config, but xfsprogs doesn't check and can do
Bad Things, so port those checks before someone shreds their filesystem.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
libxfs/init.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/libxfs/init.c b/libxfs/init.c
index cb8967bc77d4..1a966084ffea 100644
--- a/libxfs/init.c
+++ b/libxfs/init.c
@@ -724,6 +724,20 @@ libxfs_mount(
exit(1);
}
+ if (xfs_sb_version_hasreflink(sbp) && sbp->sb_rblocks) {
+ fprintf(stderr,
+ _("%s: Reflink not compatible with realtime device. Please try a newer xfsprogs.\n"),
+ progname);
+ exit(1);
+ }
+
+ if (xfs_sb_version_hasrmapbt(sbp) && sbp->sb_rblocks) {
+ fprintf(stderr,
+ _("%s: Reverse mapping btree not compatible with realtime device. Please try a newer xfsprogs.\n"),
+ progname);
+ exit(1);
+ }
+
xfs_da_mount(mp);
if (xfs_sb_version_hasattr2(&mp->m_sb))
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime
2020-09-30 14:58 [PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime Darrick J. Wong
@ 2020-09-30 15:31 ` Eric Sandeen
2020-09-30 15:52 ` Darrick J. Wong
0 siblings, 1 reply; 3+ messages in thread
From: Eric Sandeen @ 2020-09-30 15:31 UTC (permalink / raw)
To: Darrick J. Wong, Eric Sandeen; +Cc: xfs
On 9/30/20 9:58 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Neither the kernel nor the code in xfsprogs support filesystems that
> have (either reverse mapping btrees or reflink) enabled and a realtime
> volume configured. The kernel rejects such combinations and mkfs
> refuses to format such a config, but xfsprogs doesn't check and can do
> Bad Things, so port those checks before someone shreds their filesystem.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
seems fine in general but a couple thoughts...
> ---
> libxfs/init.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/libxfs/init.c b/libxfs/init.c
> index cb8967bc77d4..1a966084ffea 100644
> --- a/libxfs/init.c
> +++ b/libxfs/init.c
> @@ -724,6 +724,20 @@ libxfs_mount(
> exit(1);
> }
>
> + if (xfs_sb_version_hasreflink(sbp) && sbp->sb_rblocks) {
Hm, we really don't use xfs_sb_version_hasrealtime() very consistently, but it might
be worth doing here?
I wish we had a feature flag to cross-ref against, a corruption in sb_rblocks will lead
to an untouchable filesystem, but I guess there's nothing we can do about that.
Actually, would it help to cross-check against the rtdev arg as well? Should we do anything
different if the user actually specified a realtime device on the commandline?
I mean, I suppose
> + fprintf(stderr,
> + _("%s: Reflink not compatible with realtime device. Please try a newer xfsprogs.\n"),
I like this optimism. ;)
> + progname);
> + exit(1);
> + }
> +
> + if (xfs_sb_version_hasrmapbt(sbp) && sbp->sb_rblocks) {
> + fprintf(stderr,
> + _("%s: Reverse mapping btree not compatible with realtime device. Please try a newer xfsprogs.\n"),
> + progname);
> + exit(1);
> + }
> +
> xfs_da_mount(mp);
>
> if (xfs_sb_version_hasattr2(&mp->m_sb))
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime
2020-09-30 15:31 ` Eric Sandeen
@ 2020-09-30 15:52 ` Darrick J. Wong
0 siblings, 0 replies; 3+ messages in thread
From: Darrick J. Wong @ 2020-09-30 15:52 UTC (permalink / raw)
To: Eric Sandeen; +Cc: Eric Sandeen, xfs
On Wed, Sep 30, 2020 at 10:31:21AM -0500, Eric Sandeen wrote:
> On 9/30/20 9:58 AM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> >
> > Neither the kernel nor the code in xfsprogs support filesystems that
> > have (either reverse mapping btrees or reflink) enabled and a realtime
> > volume configured. The kernel rejects such combinations and mkfs
> > refuses to format such a config, but xfsprogs doesn't check and can do
> > Bad Things, so port those checks before someone shreds their filesystem.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
>
> seems fine in general but a couple thoughts...
>
> > ---
> > libxfs/init.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/libxfs/init.c b/libxfs/init.c
> > index cb8967bc77d4..1a966084ffea 100644
> > --- a/libxfs/init.c
> > +++ b/libxfs/init.c
> > @@ -724,6 +724,20 @@ libxfs_mount(
> > exit(1);
> > }
> >
> > + if (xfs_sb_version_hasreflink(sbp) && sbp->sb_rblocks) {
>
> Hm, we really don't use xfs_sb_version_hasrealtime() very
> consistently, but it might be worth doing here?
Nah, I'll move it to rtmount_init.
> I wish we had a feature flag to cross-ref against, a corruption in
> sb_rblocks will lead to an untouchable filesystem, but I guess there's
> nothing we can do about that.
I guess xfs_repair could add a -E killrt=1 flag that would read the sb,
zero out sb_rblocks, and pass that to libxfs_mount.
> Actually, would it help to cross-check against the rtdev arg as well?
> Should we do anything different if the user actually specified a
> realtime device on the commandline?
I doubt it? I mean, the fs allege it has an rt volume and some
unsupported feature; it doesn't matter if the user did or didn't pass an
rtdev.
> I mean, I suppose
you suppose...?
>
> > + fprintf(stderr,
> > + _("%s: Reflink not compatible with realtime device. Please try a newer xfsprogs.\n"),
>
> I like this optimism. ;)
Optimism?
/me now has an xfsprogs that /does/ support rt rmap and reflink, though
at current patch review rates it won't hit the list until 2024, and
that's assuming I can keep ahead of all the bitrot in rtrmap...
--D
>
>
> > + progname);
> > + exit(1);
> > + }
> > +
> > + if (xfs_sb_version_hasrmapbt(sbp) && sbp->sb_rblocks) {
> > + fprintf(stderr,
> > + _("%s: Reverse mapping btree not compatible with realtime device. Please try a newer xfsprogs.\n"),
> > + progname);
> > + exit(1);
> > + }
> > +
> > xfs_da_mount(mp);
> >
> > if (xfs_sb_version_hasattr2(&mp->m_sb))
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-09-30 15:52 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-09-30 14:58 [PATCH] libxfs: disallow filesystems with reverse mapping and reflink and realtime Darrick J. Wong
2020-09-30 15:31 ` Eric Sandeen
2020-09-30 15:52 ` Darrick J. Wong
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