| Message ID | 20220207224024.87745-7-wwcohen@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | 9p: Add support for darwin | expand |
On Montag, 7. Februar 2022 23:40:19 CET Will Cohen wrote: > From: Keno Fischer <keno@juliacomputing.com> > > Signed-off-by: Keno Fischer <keno@juliacomputing.com> > Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> > > Because XATTR_SIZE_MAX is not defined on Darwin, > create a cross-platform P9_XATTR_SIZE_MAX instead. > > [Will Cohen: - Adjust coding style > - Lower XATTR_SIZE_MAX to 64k > - Add explanatory context related to XATTR_SIZE_MAX] > [Fabian Franz: - Move XATTR_SIZE_MAX reference from 9p.c to > P9_XATTR_SIZE_MAX in 9p.h] > Signed-off-by: Will Cohen <wwcohen@gmail.com> > Signed-off-by: Fabian Franz <fabianfranz.oss@gmail.com> > --- > hw/9pfs/9p.c | 2 +- > hw/9pfs/9p.h | 11 +++++++++++ > 2 files changed, 12 insertions(+), 1 deletion(-) > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > index 14e84c3bcf..7405352c37 100644 > --- a/hw/9pfs/9p.c > +++ b/hw/9pfs/9p.c > @@ -3949,7 +3949,7 @@ static void coroutine_fn v9fs_xattrcreate(void > *opaque) rflags |= XATTR_REPLACE; > } > > - if (size > XATTR_SIZE_MAX) { > + if (size > P9_XATTR_SIZE_MAX) { > err = -E2BIG; > goto out_nofid; > } > diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h > index 1567b67841..6a1856b4dc 100644 > --- a/hw/9pfs/9p.h > +++ b/hw/9pfs/9p.h > @@ -479,4 +479,15 @@ struct V9fsTransport { > void (*push_and_notify)(V9fsPDU *pdu); > }; > > +/* > + * Darwin doesn't seem to define a maximum xattr size in its user > + * space header, so manually configure it across platforms as 64k. > + * > + * Having no limit at all can lead to QEMU crashing during large g_malloc() > + * calls. Because QEMU does not currently support macOS guests, the below > + * preliminary solution only works due to its being a reflection of the limit of > + * Linux guests. > + */ > +#define P9_XATTR_SIZE_MAX 65536 It would be cleaner in a way like this: #if defined(XATTR_SIZE_MAX) /* Linux */ #define P9_XATTR_SIZE_MAX XATTR_SIZE_MAX #elif defined(CONFIG_DARWIN) /* darwin comment goes here */ #define P9_XATTR_SIZE_MAX 65536 #else #error Missing definition for P9_XATTR_SIZE_MAX for this host system #endif Sorry, I haven't noticed that before. You actually had that wrapped into some ifdefs in v2 before: #if defined(CONFIG_DARWIN) && !defined(XATTR_SIZE_MAX) ... #endif > + > #endif
On Tue, Feb 8, 2022 at 7:20 AM Christian Schoenebeck <qemu_oss@crudebyte.com> wrote: > On Montag, 7. Februar 2022 23:40:19 CET Will Cohen wrote: > > From: Keno Fischer <keno@juliacomputing.com> > > > > Signed-off-by: Keno Fischer <keno@juliacomputing.com> > > Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com> > > > > Because XATTR_SIZE_MAX is not defined on Darwin, > > create a cross-platform P9_XATTR_SIZE_MAX instead. > > > > [Will Cohen: - Adjust coding style > > - Lower XATTR_SIZE_MAX to 64k > > - Add explanatory context related to XATTR_SIZE_MAX] > > [Fabian Franz: - Move XATTR_SIZE_MAX reference from 9p.c to > > P9_XATTR_SIZE_MAX in 9p.h] > > Signed-off-by: Will Cohen <wwcohen@gmail.com> > > Signed-off-by: Fabian Franz <fabianfranz.oss@gmail.com> > > --- > > hw/9pfs/9p.c | 2 +- > > hw/9pfs/9p.h | 11 +++++++++++ > > 2 files changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > > index 14e84c3bcf..7405352c37 100644 > > --- a/hw/9pfs/9p.c > > +++ b/hw/9pfs/9p.c > > @@ -3949,7 +3949,7 @@ static void coroutine_fn v9fs_xattrcreate(void > > *opaque) rflags |= XATTR_REPLACE; > > } > > > > - if (size > XATTR_SIZE_MAX) { > > + if (size > P9_XATTR_SIZE_MAX) { > > err = -E2BIG; > > goto out_nofid; > > } > > diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h > > index 1567b67841..6a1856b4dc 100644 > > --- a/hw/9pfs/9p.h > > +++ b/hw/9pfs/9p.h > > @@ -479,4 +479,15 @@ struct V9fsTransport { > > void (*push_and_notify)(V9fsPDU *pdu); > > }; > > > > +/* > > + * Darwin doesn't seem to define a maximum xattr size in its user > > + * space header, so manually configure it across platforms as 64k. > > + * > > + * Having no limit at all can lead to QEMU crashing during large > g_malloc() > > + * calls. Because QEMU does not currently support macOS guests, the > below > > + * preliminary solution only works due to its being a reflection of the > limit of > > + * Linux guests. > > + */ > > +#define P9_XATTR_SIZE_MAX 65536 > > It would be cleaner in a way like this: > > #if defined(XATTR_SIZE_MAX) > /* Linux */ > #define P9_XATTR_SIZE_MAX XATTR_SIZE_MAX > #elif defined(CONFIG_DARWIN) > /* darwin comment goes here */ > #define P9_XATTR_SIZE_MAX 65536 > #else > #error Missing definition for P9_XATTR_SIZE_MAX for this host system > #endif > > Sorry, I haven't noticed that before. You actually had that wrapped into > some > ifdefs in v2 before: > > #if defined(CONFIG_DARWIN) && !defined(XATTR_SIZE_MAX) > ... > #endif > > > + > > #endif > > Agreed, that is cleaner. Adjusting for the next round.
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 14e84c3bcf..7405352c37 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -3949,7 +3949,7 @@ static void coroutine_fn v9fs_xattrcreate(void *opaque) rflags |= XATTR_REPLACE; } - if (size > XATTR_SIZE_MAX) { + if (size > P9_XATTR_SIZE_MAX) { err = -E2BIG; goto out_nofid; } diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h index 1567b67841..6a1856b4dc 100644 --- a/hw/9pfs/9p.h +++ b/hw/9pfs/9p.h @@ -479,4 +479,15 @@ struct V9fsTransport { void (*push_and_notify)(V9fsPDU *pdu); }; +/* + * Darwin doesn't seem to define a maximum xattr size in its user + * space header, so manually configure it across platforms as 64k. + * + * Having no limit at all can lead to QEMU crashing during large g_malloc() + * calls. Because QEMU does not currently support macOS guests, the below + * preliminary solution only works due to its being a reflection of the limit of + * Linux guests. + */ +#define P9_XATTR_SIZE_MAX 65536 + #endif