Show First 20 Lines • Show All 220 Lines • ▼ Show 20 Lines	#define mnt_endzero mnt_gjprovider
struct mtx mnt_listmtx;		struct mtx mnt_listmtx;
struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */		struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */
int mnt_activevnodelistsize;/* (l) # of active vnodes */		int mnt_activevnodelistsize;/* (l) # of active vnodes */
struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */		struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */
int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */		int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */
struct lock mnt_explock; /* vfs_export walkers lock */		struct lock mnt_explock; /* vfs_export walkers lock */
TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */		TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */
TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/		TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/
		int mnt_vfs_ops; /* (i) pending vfs ops */
		int *mnt_thread_in_ops_pcpu;
};		};

/*		/*
* Definitions for MNT_VNODE_FOREACH_ALL.		* Definitions for MNT_VNODE_FOREACH_ALL.
*/		*/
struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);
struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);
void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);		void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);
Show All 23 Lines

#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \		#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \
__mnt_vnode_markerfree_active(&(mvp), (mp))		__mnt_vnode_markerfree_active(&(mvp), (mp))

#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)		#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)
#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)		#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)		#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)
#define MNT_MTX(mp) (&(mp)->mnt_mtx)		#define MNT_MTX(mp) (&(mp)->mnt_mtx)

		#define MNT_REF_FASTPATH(mp) do { \
		kibUnsubmitted Not Done Inline Actions I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions right now to replace it. kib: I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions…
		mjgAuthorUnsubmitted Done Inline Actions _UNLOCKED or (later) _PCPU? mjg: _UNLOCKED or (later) _PCPU?
		kibUnsubmitted Not Done Inline Actions unlocked sounds fine kib: unlocked sounds fine
		atomic_add_int(&(mp)->mnt_ref, 1); \
		} while (0)
		#define MNT_REL_FASTPATH(mp) do { \
		int _c; \
		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
		} while (0)

#define MNT_REF(mp) do { \		#define MNT_REF(mp) do { \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
(mp)->mnt_ref++; \		atomic_add_int(&(mp)->mnt_ref, 1); \
		kibUnsubmitted Not Done Inline Actions This should be MNT_REF_FASTPATH() ? kib: This should be MNT_REF_FASTPATH() ?
		mjgAuthorUnsubmitted Done Inline Actions See below. mjg: See below.
} while (0)		} while (0)
#define MNT_REL(mp) do { \		#define MNT_REL(mp) do { \
		int _c; \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
KASSERT((mp)->mnt_ref > 0, ("negative mnt_ref")); \		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
(mp)->mnt_ref--; \		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
if ((mp)->mnt_ref == 0) \		if (_c == 0) \
		kibUnsubmitted Not Done Inline Actions If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it there too. Can these four macros changed to inline functions ? kib: If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it…
		mjgAuthorUnsubmitted Done Inline Actions I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a meaningful value so this will have to go back to doing work on its own. In order to keep things consistent I would prefer avoid changing the _REF_ variant either. But I don't have a strong opinion here. As for inline, this requires adding several headers to struct mount.h and despite them being gated with _KERNEL it causes a lot of breakage during buildworld, e.g.: /usr/src/lib/libprocstat/common_kvm.h:34: error: conflicting types for 'dev2udev' /usr/obj/usr/src/sparc64.sparc64/tmp/usr/include/sys/systm.h:499: error: previous declaration of 'dev2udev' was here I think conversion to inlines should be a separate effort, if done at all. mjg: I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a…
		kibUnsubmitted Not Done Inline Actions Ok. You might move that to a new header. kib: Ok. You might move that to a new header.
wakeup((mp)); \		wakeup((mp)); \
} while (0)		} while (0)

#endif /* _KERNEL */		#endif /* _KERNEL */

/*		/*
* User specifiable flags, stored in mnt_flag.		* User specifiable flags, stored in mnt_flag.
*/		*/
▲ Show 20 Lines • Show All 650 Lines • ▼ Show 20 Lines
vfs_checkexp_t vfs_stdcheckexp;		vfs_checkexp_t vfs_stdcheckexp;
vfs_init_t vfs_stdinit;		vfs_init_t vfs_stdinit;
vfs_uninit_t vfs_stduninit;		vfs_uninit_t vfs_stduninit;
vfs_extattrctl_t vfs_stdextattrctl;		vfs_extattrctl_t vfs_stdextattrctl;
vfs_sysctl_t vfs_stdsysctl;		vfs_sysctl_t vfs_stdsysctl;

void syncer_suspend(void);		void syncer_suspend(void);
void syncer_resume(void);		void syncer_resume(void);

		void vfs_op_barrier_wait(struct mount *);
		void vfs_op_enter(struct mount *);
		void vfs_op_exit_locked(struct mount *);
		void vfs_op_exit(struct mount *);

		jeffUnsubmitted Not Done Inline Actions Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop to handle the whole business? If you wanted to do it with multiple cpus you need only set the bit in each counter. jeff: Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop…
		mjgAuthorUnsubmitted Done Inline Actions Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a discussion on whether given per-cpu routine works and/or is a good idea. Whatever ends up protecting the fast path is trivially replaceable. Main point of this review is to (dis)agree on the general approach - that is wrapping all code which requires an exact value with fast path enable/disable routines, with a guarantee everyone executing after the disabling routine returns goes for the current code. Assuming this is fine, I'll post an equivalent for busy/unbusy and write suspension. With this in in place we can discuss how to handle per-cpu, unless you are very opposed to rmlocks showing up in the first place even if temporarily (in which case I can elaborate on what scheme I had in mind). mjg: Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a…
		mjgAuthorUnsubmitted Done Inline Actions Perhaps I should add I do think making the counters atomic in initial commits is an important logical step, especially when it comes to write suspension -- it required a little patching in SU code. It really just needs something to keep the fast path. You can see the previous iteration here https://people.freebsd.org/~mjg/patches/atomic-mnt-counters.diff But again, if the intermediate work is not seen as necessary, I would be more than happy to go straight to per-cpu variants. mjg: Perhaps I should add I do think making the counters atomic in initial commits is an important…
		/*
		* We mark ourselves as entering the section and post a sequentially consistent
		kibUnsubmitted Not Done Inline Actions Please use the 'sequentially consistent fence' and not 'full barrier' term. kib: Please use the 'sequentially consistent fence' and not 'full barrier' term.
		* fence, meaning the store is completed before we get into the section and
		* mnt_vfs_ops is only read afterwards.
		*
		* Any thread transitioning the ops counter 0->1 does things in the opposite
		* order - first bumps the count, posts a sequentially consistent fence and to
		* observes all CPUs not executing within the section.
		*
		* This provides an invariant that by the time the last CPU is observed not
		* executing, everyone else entering will see the counter > 0 and exit.
		*
		* Note there is no barrier between vfs_ops and the rest of the code in the
		* section. It is not necessary as the writer has to wait for everyone to drain
		* before making any changes or only make safe changes.
		*/

		#define vfs_op_thread_enter(mp) ({ \
		kibUnsubmitted Not Done Inline Actions Can this be inline function ? kib: Can this be inline function ?
		struct mount *_mp = (mp); \
		bool _retval = true; \
		critical_enter(); \
		(int )zpcpu_get(_mp->mnt_thread_in_ops_pcpu) = 1; \
		atomic_thread_fence_seq_cst(); \
		if (__predict_false(_mp->mnt_vfs_ops > 0)) { \
		vfs_op_thread_exit(_mp); \
		_retval = false; \
		} \
		_retval; \
		})

		#define vfs_op_thread_exit(mp) do { \
		atomic_thread_fence_rel(); \
		(int )zpcpu_get(mp->mnt_thread_in_ops_pcpu) = 0; \
		critical_exit(); \
		} while (0)

#else /* !_KERNEL */		#else /* !_KERNEL */

#include <sys/cdefs.h>		#include <sys/cdefs.h>

struct stat;		struct stat;

__BEGIN_DECLS		__BEGIN_DECLS
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sys/compat/linux/linux_file.c

Show First 20 Lines • Show All 220 Lines • ▼ Show 20 Lines	#define mnt_endzero mnt_gjprovider
struct mtx mnt_listmtx;		struct mtx mnt_listmtx;
struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */		struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */
int mnt_activevnodelistsize;/* (l) # of active vnodes */		int mnt_activevnodelistsize;/* (l) # of active vnodes */
struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */		struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */
int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */		int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */
struct lock mnt_explock; /* vfs_export walkers lock */		struct lock mnt_explock; /* vfs_export walkers lock */
TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */		TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */
TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/		TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/
		int mnt_vfs_ops; /* (i) pending vfs ops */
		int *mnt_thread_in_ops_pcpu;
};		};

/*		/*
* Definitions for MNT_VNODE_FOREACH_ALL.		* Definitions for MNT_VNODE_FOREACH_ALL.
*/		*/
struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);
struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);
void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);		void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);
Show All 23 Lines

#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \		#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \
__mnt_vnode_markerfree_active(&(mvp), (mp))		__mnt_vnode_markerfree_active(&(mvp), (mp))

#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)		#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)
#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)		#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)		#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)
#define MNT_MTX(mp) (&(mp)->mnt_mtx)		#define MNT_MTX(mp) (&(mp)->mnt_mtx)

		#define MNT_REF_FASTPATH(mp) do { \
		kibUnsubmitted Not Done Inline Actions I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions right now to replace it. kib: I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions…
		mjgAuthorUnsubmitted Done Inline Actions _UNLOCKED or (later) _PCPU? mjg: _UNLOCKED or (later) _PCPU?
		kibUnsubmitted Not Done Inline Actions unlocked sounds fine kib: unlocked sounds fine
		atomic_add_int(&(mp)->mnt_ref, 1); \
		} while (0)
		#define MNT_REL_FASTPATH(mp) do { \
		int _c; \
		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
		} while (0)

#define MNT_REF(mp) do { \		#define MNT_REF(mp) do { \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
(mp)->mnt_ref++; \		atomic_add_int(&(mp)->mnt_ref, 1); \
		kibUnsubmitted Not Done Inline Actions This should be MNT_REF_FASTPATH() ? kib: This should be MNT_REF_FASTPATH() ?
		mjgAuthorUnsubmitted Done Inline Actions See below. mjg: See below.
} while (0)		} while (0)
#define MNT_REL(mp) do { \		#define MNT_REL(mp) do { \
		int _c; \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
KASSERT((mp)->mnt_ref > 0, ("negative mnt_ref")); \		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
(mp)->mnt_ref--; \		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
if ((mp)->mnt_ref == 0) \		if (_c == 0) \
		kibUnsubmitted Not Done Inline Actions If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it there too. Can these four macros changed to inline functions ? kib: If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it…
		mjgAuthorUnsubmitted Done Inline Actions I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a meaningful value so this will have to go back to doing work on its own. In order to keep things consistent I would prefer avoid changing the _REF_ variant either. But I don't have a strong opinion here. As for inline, this requires adding several headers to struct mount.h and despite them being gated with _KERNEL it causes a lot of breakage during buildworld, e.g.: /usr/src/lib/libprocstat/common_kvm.h:34: error: conflicting types for 'dev2udev' /usr/obj/usr/src/sparc64.sparc64/tmp/usr/include/sys/systm.h:499: error: previous declaration of 'dev2udev' was here I think conversion to inlines should be a separate effort, if done at all. mjg: I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a…
		kibUnsubmitted Not Done Inline Actions Ok. You might move that to a new header. kib: Ok. You might move that to a new header.
wakeup((mp)); \		wakeup((mp)); \
} while (0)		} while (0)

#endif /* _KERNEL */		#endif /* _KERNEL */

/*		/*
* User specifiable flags, stored in mnt_flag.		* User specifiable flags, stored in mnt_flag.
*/		*/
▲ Show 20 Lines • Show All 650 Lines • ▼ Show 20 Lines
vfs_checkexp_t vfs_stdcheckexp;		vfs_checkexp_t vfs_stdcheckexp;
vfs_init_t vfs_stdinit;		vfs_init_t vfs_stdinit;
vfs_uninit_t vfs_stduninit;		vfs_uninit_t vfs_stduninit;
vfs_extattrctl_t vfs_stdextattrctl;		vfs_extattrctl_t vfs_stdextattrctl;
vfs_sysctl_t vfs_stdsysctl;		vfs_sysctl_t vfs_stdsysctl;

void syncer_suspend(void);		void syncer_suspend(void);
void syncer_resume(void);		void syncer_resume(void);

		void vfs_op_barrier_wait(struct mount *);
		void vfs_op_enter(struct mount *);
		void vfs_op_exit_locked(struct mount *);
		void vfs_op_exit(struct mount *);

		jeffUnsubmitted Not Done Inline Actions Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop to handle the whole business? If you wanted to do it with multiple cpus you need only set the bit in each counter. jeff: Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop…
		mjgAuthorUnsubmitted Done Inline Actions Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a discussion on whether given per-cpu routine works and/or is a good idea. Whatever ends up protecting the fast path is trivially replaceable. Main point of this review is to (dis)agree on the general approach - that is wrapping all code which requires an exact value with fast path enable/disable routines, with a guarantee everyone executing after the disabling routine returns goes for the current code. Assuming this is fine, I'll post an equivalent for busy/unbusy and write suspension. With this in in place we can discuss how to handle per-cpu, unless you are very opposed to rmlocks showing up in the first place even if temporarily (in which case I can elaborate on what scheme I had in mind). mjg: Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a…
		mjgAuthorUnsubmitted Done Inline Actions Perhaps I should add I do think making the counters atomic in initial commits is an important logical step, especially when it comes to write suspension -- it required a little patching in SU code. It really just needs something to keep the fast path. You can see the previous iteration here https://people.freebsd.org/~mjg/patches/atomic-mnt-counters.diff But again, if the intermediate work is not seen as necessary, I would be more than happy to go straight to per-cpu variants. mjg: Perhaps I should add I do think making the counters atomic in initial commits is an important…
		/*
		* We mark ourselves as entering the section and post a sequentially consistent
		kibUnsubmitted Not Done Inline Actions Please use the 'sequentially consistent fence' and not 'full barrier' term. kib: Please use the 'sequentially consistent fence' and not 'full barrier' term.
		* fence, meaning the store is completed before we get into the section and
		* mnt_vfs_ops is only read afterwards.
		*
		* Any thread transitioning the ops counter 0->1 does things in the opposite
		* order - first bumps the count, posts a sequentially consistent fence and to
		* observes all CPUs not executing within the section.
		*
		* This provides an invariant that by the time the last CPU is observed not
		* executing, everyone else entering will see the counter > 0 and exit.
		*
		* Note there is no barrier between vfs_ops and the rest of the code in the
		* section. It is not necessary as the writer has to wait for everyone to drain
		* before making any changes or only make safe changes.
		*/

		#define vfs_op_thread_enter(mp) ({ \
		kibUnsubmitted Not Done Inline Actions Can this be inline function ? kib: Can this be inline function ?
		struct mount *_mp = (mp); \
		bool _retval = true; \
		critical_enter(); \
		(int )zpcpu_get(_mp->mnt_thread_in_ops_pcpu) = 1; \
		atomic_thread_fence_seq_cst(); \
		if (__predict_false(_mp->mnt_vfs_ops > 0)) { \
		vfs_op_thread_exit(_mp); \
		_retval = false; \
		} \
		_retval; \
		})

		#define vfs_op_thread_exit(mp) do { \
		atomic_thread_fence_rel(); \
		(int )zpcpu_get(mp->mnt_thread_in_ops_pcpu) = 0; \
		critical_exit(); \
		} while (0)

#else /* !_KERNEL */		#else /* !_KERNEL */

#include <sys/cdefs.h>		#include <sys/cdefs.h>

struct stat;		struct stat;

__BEGIN_DECLS		__BEGIN_DECLS
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sys/compat/linux/linux_futex.c

Show First 20 Lines • Show All 220 Lines • ▼ Show 20 Lines	#define mnt_endzero mnt_gjprovider
struct mtx mnt_listmtx;		struct mtx mnt_listmtx;
struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */		struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */
int mnt_activevnodelistsize;/* (l) # of active vnodes */		int mnt_activevnodelistsize;/* (l) # of active vnodes */
struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */		struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */
int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */		int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */
struct lock mnt_explock; /* vfs_export walkers lock */		struct lock mnt_explock; /* vfs_export walkers lock */
TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */		TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */
TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/		TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/
		int mnt_vfs_ops; /* (i) pending vfs ops */
		int *mnt_thread_in_ops_pcpu;
};		};

/*		/*
* Definitions for MNT_VNODE_FOREACH_ALL.		* Definitions for MNT_VNODE_FOREACH_ALL.
*/		*/
struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);
struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);
void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);		void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);
Show All 23 Lines

#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \		#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \
__mnt_vnode_markerfree_active(&(mvp), (mp))		__mnt_vnode_markerfree_active(&(mvp), (mp))

#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)		#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)
#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)		#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)		#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)
#define MNT_MTX(mp) (&(mp)->mnt_mtx)		#define MNT_MTX(mp) (&(mp)->mnt_mtx)

		#define MNT_REF_FASTPATH(mp) do { \
		kibUnsubmitted Not Done Inline Actions I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions right now to replace it. kib: I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions…
		mjgAuthorUnsubmitted Done Inline Actions _UNLOCKED or (later) _PCPU? mjg: _UNLOCKED or (later) _PCPU?
		kibUnsubmitted Not Done Inline Actions unlocked sounds fine kib: unlocked sounds fine
		atomic_add_int(&(mp)->mnt_ref, 1); \
		} while (0)
		#define MNT_REL_FASTPATH(mp) do { \
		int _c; \
		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
		} while (0)

#define MNT_REF(mp) do { \		#define MNT_REF(mp) do { \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
(mp)->mnt_ref++; \		atomic_add_int(&(mp)->mnt_ref, 1); \
		kibUnsubmitted Not Done Inline Actions This should be MNT_REF_FASTPATH() ? kib: This should be MNT_REF_FASTPATH() ?
		mjgAuthorUnsubmitted Done Inline Actions See below. mjg: See below.
} while (0)		} while (0)
#define MNT_REL(mp) do { \		#define MNT_REL(mp) do { \
		int _c; \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
KASSERT((mp)->mnt_ref > 0, ("negative mnt_ref")); \		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
(mp)->mnt_ref--; \		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
if ((mp)->mnt_ref == 0) \		if (_c == 0) \
		kibUnsubmitted Not Done Inline Actions If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it there too. Can these four macros changed to inline functions ? kib: If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it…
		mjgAuthorUnsubmitted Done Inline Actions I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a meaningful value so this will have to go back to doing work on its own. In order to keep things consistent I would prefer avoid changing the _REF_ variant either. But I don't have a strong opinion here. As for inline, this requires adding several headers to struct mount.h and despite them being gated with _KERNEL it causes a lot of breakage during buildworld, e.g.: /usr/src/lib/libprocstat/common_kvm.h:34: error: conflicting types for 'dev2udev' /usr/obj/usr/src/sparc64.sparc64/tmp/usr/include/sys/systm.h:499: error: previous declaration of 'dev2udev' was here I think conversion to inlines should be a separate effort, if done at all. mjg: I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a…
		kibUnsubmitted Not Done Inline Actions Ok. You might move that to a new header. kib: Ok. You might move that to a new header.
wakeup((mp)); \		wakeup((mp)); \
} while (0)		} while (0)

#endif /* _KERNEL */		#endif /* _KERNEL */

/*		/*
* User specifiable flags, stored in mnt_flag.		* User specifiable flags, stored in mnt_flag.
*/		*/
▲ Show 20 Lines • Show All 650 Lines • ▼ Show 20 Lines
vfs_checkexp_t vfs_stdcheckexp;		vfs_checkexp_t vfs_stdcheckexp;
vfs_init_t vfs_stdinit;		vfs_init_t vfs_stdinit;
vfs_uninit_t vfs_stduninit;		vfs_uninit_t vfs_stduninit;
vfs_extattrctl_t vfs_stdextattrctl;		vfs_extattrctl_t vfs_stdextattrctl;
vfs_sysctl_t vfs_stdsysctl;		vfs_sysctl_t vfs_stdsysctl;

void syncer_suspend(void);		void syncer_suspend(void);
void syncer_resume(void);		void syncer_resume(void);

		void vfs_op_barrier_wait(struct mount *);
		void vfs_op_enter(struct mount *);
		void vfs_op_exit_locked(struct mount *);
		void vfs_op_exit(struct mount *);

		jeffUnsubmitted Not Done Inline Actions Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop to handle the whole business? If you wanted to do it with multiple cpus you need only set the bit in each counter. jeff: Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop…
		mjgAuthorUnsubmitted Done Inline Actions Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a discussion on whether given per-cpu routine works and/or is a good idea. Whatever ends up protecting the fast path is trivially replaceable. Main point of this review is to (dis)agree on the general approach - that is wrapping all code which requires an exact value with fast path enable/disable routines, with a guarantee everyone executing after the disabling routine returns goes for the current code. Assuming this is fine, I'll post an equivalent for busy/unbusy and write suspension. With this in in place we can discuss how to handle per-cpu, unless you are very opposed to rmlocks showing up in the first place even if temporarily (in which case I can elaborate on what scheme I had in mind). mjg: Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a…
		mjgAuthorUnsubmitted Done Inline Actions Perhaps I should add I do think making the counters atomic in initial commits is an important logical step, especially when it comes to write suspension -- it required a little patching in SU code. It really just needs something to keep the fast path. You can see the previous iteration here https://people.freebsd.org/~mjg/patches/atomic-mnt-counters.diff But again, if the intermediate work is not seen as necessary, I would be more than happy to go straight to per-cpu variants. mjg: Perhaps I should add I do think making the counters atomic in initial commits is an important…
		/*
		* We mark ourselves as entering the section and post a sequentially consistent
		kibUnsubmitted Not Done Inline Actions Please use the 'sequentially consistent fence' and not 'full barrier' term. kib: Please use the 'sequentially consistent fence' and not 'full barrier' term.
		* fence, meaning the store is completed before we get into the section and
		* mnt_vfs_ops is only read afterwards.
		*
		* Any thread transitioning the ops counter 0->1 does things in the opposite
		* order - first bumps the count, posts a sequentially consistent fence and to
		* observes all CPUs not executing within the section.
		*
		* This provides an invariant that by the time the last CPU is observed not
		* executing, everyone else entering will see the counter > 0 and exit.
		*
		* Note there is no barrier between vfs_ops and the rest of the code in the
		* section. It is not necessary as the writer has to wait for everyone to drain
		* before making any changes or only make safe changes.
		*/

		#define vfs_op_thread_enter(mp) ({ \
		kibUnsubmitted Not Done Inline Actions Can this be inline function ? kib: Can this be inline function ?
		struct mount *_mp = (mp); \
		bool _retval = true; \
		critical_enter(); \
		(int )zpcpu_get(_mp->mnt_thread_in_ops_pcpu) = 1; \
		atomic_thread_fence_seq_cst(); \
		if (__predict_false(_mp->mnt_vfs_ops > 0)) { \
		vfs_op_thread_exit(_mp); \
		_retval = false; \
		} \
		_retval; \
		})

		#define vfs_op_thread_exit(mp) do { \
		atomic_thread_fence_rel(); \
		(int )zpcpu_get(mp->mnt_thread_in_ops_pcpu) = 0; \
		critical_exit(); \
		} while (0)

#else /* !_KERNEL */		#else /* !_KERNEL */

#include <sys/cdefs.h>		#include <sys/cdefs.h>

struct stat;		struct stat;

__BEGIN_DECLS		__BEGIN_DECLS
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sys/compat/linux/linux_getcwd.c

Show First 20 Lines • Show All 220 Lines • ▼ Show 20 Lines	#define mnt_endzero mnt_gjprovider
struct mtx mnt_listmtx;		struct mtx mnt_listmtx;
struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */		struct vnodelst mnt_activevnodelist; /* (l) list of active vnodes */
int mnt_activevnodelistsize;/* (l) # of active vnodes */		int mnt_activevnodelistsize;/* (l) # of active vnodes */
struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */		struct vnodelst mnt_tmpfreevnodelist; /* (l) list of free vnodes */
int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */		int mnt_tmpfreevnodelistsize;/* (l) # of free vnodes */
struct lock mnt_explock; /* vfs_export walkers lock */		struct lock mnt_explock; /* vfs_export walkers lock */
TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */		TAILQ_ENTRY(mount) mnt_upper_link; /* (m) we in the all uppers */
TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/		TAILQ_HEAD(, mount) mnt_uppers; /* (m) upper mounts over us*/
		int mnt_vfs_ops; /* (i) pending vfs ops */
		int *mnt_thread_in_ops_pcpu;
};		};

/*		/*
* Definitions for MNT_VNODE_FOREACH_ALL.		* Definitions for MNT_VNODE_FOREACH_ALL.
*/		*/
struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_next_all(struct vnode mvp, struct mount mp);
struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);		struct vnode __mnt_vnode_first_all(struct vnode mvp, struct mount mp);
void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);		void __mnt_vnode_markerfree_all(struct vnode *mvp, struct mount mp);
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#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \		#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp) \
__mnt_vnode_markerfree_active(&(mvp), (mp))		__mnt_vnode_markerfree_active(&(mvp), (mp))

#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)		#define MNT_ILOCK(mp) mtx_lock(&(mp)->mnt_mtx)
#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)		#define MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)		#define MNT_IUNLOCK(mp) mtx_unlock(&(mp)->mnt_mtx)
#define MNT_MTX(mp) (&(mp)->mnt_mtx)		#define MNT_MTX(mp) (&(mp)->mnt_mtx)

		#define MNT_REF_FASTPATH(mp) do { \
		kibUnsubmitted Not Done Inline Actions I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions right now to replace it. kib: I should admit that I dislike the _FASTPATH() suffix on principle, but I have no suggestions…
		mjgAuthorUnsubmitted Done Inline Actions _UNLOCKED or (later) _PCPU? mjg: _UNLOCKED or (later) _PCPU?
		kibUnsubmitted Not Done Inline Actions unlocked sounds fine kib: unlocked sounds fine
		atomic_add_int(&(mp)->mnt_ref, 1); \
		} while (0)
		#define MNT_REL_FASTPATH(mp) do { \
		int _c; \
		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
		} while (0)

#define MNT_REF(mp) do { \		#define MNT_REF(mp) do { \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
(mp)->mnt_ref++; \		atomic_add_int(&(mp)->mnt_ref, 1); \
		kibUnsubmitted Not Done Inline Actions This should be MNT_REF_FASTPATH() ? kib: This should be MNT_REF_FASTPATH() ?
		mjgAuthorUnsubmitted Done Inline Actions See below. mjg: See below.
} while (0)		} while (0)
#define MNT_REL(mp) do { \		#define MNT_REL(mp) do { \
		int _c; \
mtx_assert(MNT_MTX(mp), MA_OWNED); \		mtx_assert(MNT_MTX(mp), MA_OWNED); \
KASSERT((mp)->mnt_ref > 0, ("negative mnt_ref")); \		_c = atomic_fetchadd_int(&(mp)->mnt_ref, -1) - 1; \
(mp)->mnt_ref--; \		KASSERT(_c >= 0, ("negative mnt_ref %d", _c)); \
if ((mp)->mnt_ref == 0) \		if (_c == 0) \
		kibUnsubmitted Not Done Inline Actions If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it there too. Can these four macros changed to inline functions ? kib: If you change MNT_REL_FASTPATH into ext macro that returns a value, I think you can use it…
		mjgAuthorUnsubmitted Done Inline Actions I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a meaningful value so this will have to go back to doing work on its own. In order to keep things consistent I would prefer avoid changing the _REF_ variant either. But I don't have a strong opinion here. As for inline, this requires adding several headers to struct mount.h and despite them being gated with _KERNEL it causes a lot of breakage during buildworld, e.g.: /usr/src/lib/libprocstat/common_kvm.h:34: error: conflicting types for 'dev2udev' /usr/obj/usr/src/sparc64.sparc64/tmp/usr/include/sys/systm.h:499: error: previous declaration of 'dev2udev' was here I think conversion to inlines should be a separate effort, if done at all. mjg: I don't think changing this is worthwhile. The per-cpu variant will not have a way to return a…
		kibUnsubmitted Not Done Inline Actions Ok. You might move that to a new header. kib: Ok. You might move that to a new header.
wakeup((mp)); \		wakeup((mp)); \
} while (0)		} while (0)

#endif /* _KERNEL */		#endif /* _KERNEL */

/*		/*
* User specifiable flags, stored in mnt_flag.		* User specifiable flags, stored in mnt_flag.
*/		*/
▲ Show 20 Lines • Show All 650 Lines • ▼ Show 20 Lines
vfs_checkexp_t vfs_stdcheckexp;		vfs_checkexp_t vfs_stdcheckexp;
vfs_init_t vfs_stdinit;		vfs_init_t vfs_stdinit;
vfs_uninit_t vfs_stduninit;		vfs_uninit_t vfs_stduninit;
vfs_extattrctl_t vfs_stdextattrctl;		vfs_extattrctl_t vfs_stdextattrctl;
vfs_sysctl_t vfs_stdsysctl;		vfs_sysctl_t vfs_stdsysctl;

void syncer_suspend(void);		void syncer_suspend(void);
void syncer_resume(void);		void syncer_resume(void);

		void vfs_op_barrier_wait(struct mount *);
		void vfs_op_enter(struct mount *);
		void vfs_op_exit_locked(struct mount *);
		void vfs_op_exit(struct mount *);

		jeffUnsubmitted Not Done Inline Actions Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop to handle the whole business? If you wanted to do it with multiple cpus you need only set the bit in each counter. jeff: Instead of rmlock could we not encode the flag bits in the counter field and use a cmpset loop…
		mjgAuthorUnsubmitted Done Inline Actions Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a discussion on whether given per-cpu routine works and/or is a good idea. Whatever ends up protecting the fast path is trivially replaceable. Main point of this review is to (dis)agree on the general approach - that is wrapping all code which requires an exact value with fast path enable/disable routines, with a guarantee everyone executing after the disabling routine returns goes for the current code. Assuming this is fine, I'll post an equivalent for busy/unbusy and write suspension. With this in in place we can discuss how to handle per-cpu, unless you are very opposed to rmlocks showing up in the first place even if temporarily (in which case I can elaborate on what scheme I had in mind). mjg: Note I said I don't want rmlocks later, they are here specifically because I wanted to avoid a…
		mjgAuthorUnsubmitted Done Inline Actions Perhaps I should add I do think making the counters atomic in initial commits is an important logical step, especially when it comes to write suspension -- it required a little patching in SU code. It really just needs something to keep the fast path. You can see the previous iteration here https://people.freebsd.org/~mjg/patches/atomic-mnt-counters.diff But again, if the intermediate work is not seen as necessary, I would be more than happy to go straight to per-cpu variants. mjg: Perhaps I should add I do think making the counters atomic in initial commits is an important…
		/*
		* We mark ourselves as entering the section and post a sequentially consistent
		kibUnsubmitted Not Done Inline Actions Please use the 'sequentially consistent fence' and not 'full barrier' term. kib: Please use the 'sequentially consistent fence' and not 'full barrier' term.
		* fence, meaning the store is completed before we get into the section and
		* mnt_vfs_ops is only read afterwards.
		*
		* Any thread transitioning the ops counter 0->1 does things in the opposite
		* order - first bumps the count, posts a sequentially consistent fence and to
		* observes all CPUs not executing within the section.
		*
		* This provides an invariant that by the time the last CPU is observed not
		* executing, everyone else entering will see the counter > 0 and exit.
		*
		* Note there is no barrier between vfs_ops and the rest of the code in the
		* section. It is not necessary as the writer has to wait for everyone to drain
		* before making any changes or only make safe changes.
		*/

		#define vfs_op_thread_enter(mp) ({ \
		kibUnsubmitted Not Done Inline Actions Can this be inline function ? kib: Can this be inline function ?
		struct mount *_mp = (mp); \
		bool _retval = true; \
		critical_enter(); \
		(int )zpcpu_get(_mp->mnt_thread_in_ops_pcpu) = 1; \
		atomic_thread_fence_seq_cst(); \
		if (__predict_false(_mp->mnt_vfs_ops > 0)) { \
		vfs_op_thread_exit(_mp); \
		_retval = false; \
		} \
		_retval; \
		})

		#define vfs_op_thread_exit(mp) do { \
		atomic_thread_fence_rel(); \
		(int )zpcpu_get(mp->mnt_thread_in_ops_pcpu) = 0; \
		critical_exit(); \
		} while (0)

#else /* !_KERNEL */		#else /* !_KERNEL */

#include <sys/cdefs.h>		#include <sys/cdefs.h>

struct stat;		struct stat;

__BEGIN_DECLS		__BEGIN_DECLS
Show All 24 Lines