git: 28bc23ab92ce - main - tmpfs: dynamically register tmpfs pager
Konstantin Belousov
kib at FreeBSD.org
Thu May 13 17:14:19 UTC 2021
The branch main has been updated by kib:
URL: https://cgit.FreeBSD.org/src/commit/?id=28bc23ab92ce7393aab48da7d71ccde63592ff2d
commit 28bc23ab92ce7393aab48da7d71ccde63592ff2d
Author: Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-05-07 19:42:06 +0000
Commit: Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-05-13 17:13:34 +0000
tmpfs: dynamically register tmpfs pager
Remove OBJT_SWAP_TMPFS. Move tmpfs-specific swap pager bits into
tmpfs_subr.c.
There is no longer any code to directly support tmpfs in sys/vm, most
tmpfs knowledge is shared by non-anon swap object type implementation.
The tmpfs-specific methods are provided by registered tmpfs pager, which
inherits from the swap pager.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D30168
---
sys/fs/tmpfs/tmpfs.h | 6 ++-
sys/fs/tmpfs/tmpfs_subr.c | 70 ++++++++++++++++++++++++++++++++--
sys/fs/tmpfs/tmpfs_vfsops.c | 14 ++++---
sys/fs/tmpfs/tmpfs_vnops.c | 2 +-
sys/vm/swap_pager.c | 93 ++++++++++-----------------------------------
sys/vm/swap_pager.h | 3 +-
sys/vm/vm.h | 1 -
sys/vm/vm_object.c | 1 -
sys/vm/vm_object.h | 2 +-
sys/vm/vm_pager.c | 1 -
10 files changed, 106 insertions(+), 87 deletions(-)
diff --git a/sys/fs/tmpfs/tmpfs.h b/sys/fs/tmpfs/tmpfs.h
index 28493a550252..549339d9b6d1 100644
--- a/sys/fs/tmpfs/tmpfs.h
+++ b/sys/fs/tmpfs/tmpfs.h
@@ -45,6 +45,8 @@
MALLOC_DECLARE(M_TMPFSNAME);
#endif
+#define OBJ_TMPFS OBJ_PAGERPRIV /* has tmpfs vnode allocated */
+
/*
* Internal representation of a tmpfs directory entry.
*/
@@ -514,9 +516,11 @@ tmpfs_update(struct vnode *vp)
size_t tmpfs_mem_avail(void);
size_t tmpfs_pages_used(struct tmpfs_mount *tmp);
-void tmpfs_subr_init(void);
+int tmpfs_subr_init(void);
void tmpfs_subr_uninit(void);
+extern int tmpfs_pager_type;
+
/*
* Macros/functions to convert from generic data structures to tmpfs
* specific ones.
diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c
index 1ea4cf23b314..67eb12598e24 100644
--- a/sys/fs/tmpfs/tmpfs_subr.c
+++ b/sys/fs/tmpfs/tmpfs_subr.c
@@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$");
#include <sys/smr.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
+#include <sys/user.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
@@ -79,6 +80,61 @@ MALLOC_DEFINE(M_TMPFSDIR, "tmpfs dir", "tmpfs dirent structure");
static uma_zone_t tmpfs_node_pool;
VFS_SMR_DECLARE;
+int tmpfs_pager_type = -1;
+
+static vm_object_t
+tmpfs_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
+ vm_ooffset_t offset, struct ucred *cred)
+{
+ vm_object_t object;
+
+ MPASS(handle == NULL);
+ MPASS(offset == 0);
+ object = vm_object_allocate_dyn(tmpfs_pager_type, size,
+ OBJ_COLORED | OBJ_SWAP);
+ if (!swap_pager_init_object(object, NULL, NULL, size, 0)) {
+ vm_object_deallocate(object);
+ object = NULL;
+ }
+ return (object);
+}
+
+static void
+tmpfs_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
+{
+ struct vnode *vp;
+
+ /*
+ * Tmpfs VREG node, which was reclaimed, has tmpfs_pager_type
+ * type, but not OBJ_TMPFS flag. In this case there is no
+ * v_writecount to adjust.
+ */
+ if (vp_heldp != NULL)
+ VM_OBJECT_RLOCK(object);
+ else
+ VM_OBJECT_ASSERT_LOCKED(object);
+ if ((object->flags & OBJ_TMPFS) != 0) {
+ vp = object->un_pager.swp.swp_tmpfs;
+ if (vp != NULL) {
+ *vpp = vp;
+ if (vp_heldp != NULL) {
+ vhold(vp);
+ *vp_heldp = true;
+ }
+ }
+ }
+ if (vp_heldp != NULL)
+ VM_OBJECT_RUNLOCK(object);
+}
+
+struct pagerops tmpfs_pager_ops = {
+ .pgo_kvme_type = KVME_TYPE_VNODE,
+ .pgo_alloc = tmpfs_pager_alloc,
+ .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
+ .pgo_mightbedirty = vm_object_mightbedirty_,
+ .pgo_getvp = tmpfs_pager_getvp,
+};
+
static int
tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
{
@@ -126,18 +182,26 @@ tmpfs_node_fini(void *mem, int size)
mtx_destroy(&node->tn_interlock);
}
-void
+int
tmpfs_subr_init(void)
{
+ tmpfs_pager_type = vm_pager_alloc_dyn_type(&tmpfs_pager_ops,
+ OBJT_SWAP);
+ if (tmpfs_pager_type == -1)
+ return (EINVAL);
tmpfs_node_pool = uma_zcreate("TMPFS node",
sizeof(struct tmpfs_node), tmpfs_node_ctor, tmpfs_node_dtor,
tmpfs_node_init, tmpfs_node_fini, UMA_ALIGN_PTR, 0);
VFS_SMR_ZONE_SET(tmpfs_node_pool);
+ return (0);
}
void
tmpfs_subr_uninit(void)
{
+ if (tmpfs_pager_type != -1)
+ vm_pager_free_dyn_type(tmpfs_pager_type);
+ tmpfs_pager_type = -1;
uma_zdestroy(tmpfs_node_pool);
}
@@ -364,7 +428,7 @@ tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type,
case VREG:
obj = nnode->tn_reg.tn_aobj =
- vm_pager_allocate(OBJT_SWAP_TMPFS, NULL, 0,
+ vm_pager_allocate(tmpfs_pager_type, NULL, 0,
VM_PROT_DEFAULT, 0,
NULL /* XXXKIB - tmpfs needs swap reservation */);
/* OBJ_TMPFS is set together with the setting of vp->v_object */
@@ -1588,7 +1652,7 @@ tmpfs_check_mtime(struct vnode *vp)
if (vp->v_type != VREG)
return;
obj = vp->v_object;
- KASSERT(obj->type == OBJT_SWAP_TMPFS &&
+ KASSERT(obj->type == tmpfs_pager_type &&
(obj->flags & (OBJ_SWAP | OBJ_TMPFS)) ==
(OBJ_SWAP | OBJ_TMPFS), ("non-tmpfs obj"));
/* unlocked read */
diff --git a/sys/fs/tmpfs/tmpfs_vfsops.c b/sys/fs/tmpfs/tmpfs_vfsops.c
index 51d097203135..4f29b5dfc6f0 100644
--- a/sys/fs/tmpfs/tmpfs_vfsops.c
+++ b/sys/fs/tmpfs/tmpfs_vfsops.c
@@ -103,8 +103,8 @@ static const char *tmpfs_updateopts[] = {
* Handle updates of time from writes to mmaped regions, if allowed.
* Use MNT_VNODE_FOREACH_ALL instead of MNT_VNODE_FOREACH_LAZY, since
* unmap of the tmpfs-backed vnode does not call vinactive(), due to
- * vm object type is OBJT_SWAP. If lazy, only handle delayed update
- * of mtime due to the writes to mapped files.
+ * vm object type is basically OBJT_SWAP. If lazy, only handle
+ * delayed update of mtime due to the writes to mapped files.
*/
static void
tmpfs_update_mtime(struct mount *mp, bool lazy)
@@ -120,7 +120,7 @@ tmpfs_update_mtime(struct mount *mp, bool lazy)
continue;
}
obj = vp->v_object;
- MPASS(obj->type == OBJT_SWAP_TMPFS);
+ MPASS(obj->type == tmpfs_pager_type);
MPASS((obj->flags & OBJ_TMPFS) != 0);
/*
@@ -225,7 +225,7 @@ again:
(entry->max_protection & VM_PROT_WRITE) == 0)
continue;
object = entry->object.vm_object;
- if (object == NULL || object->type != OBJT_SWAP_TMPFS)
+ if (object == NULL || object->type != tmpfs_pager_type)
continue;
/*
* No need to dig into shadow chain, mapping
@@ -661,7 +661,11 @@ tmpfs_sync(struct mount *mp, int waitfor)
static int
tmpfs_init(struct vfsconf *conf)
{
- tmpfs_subr_init();
+ int res;
+
+ res = tmpfs_subr_init();
+ if (res != 0)
+ return (res);
memcpy(&tmpfs_fnops, &vnops, sizeof(struct fileops));
tmpfs_fnops.fo_close = tmpfs_fo_close;
return (0);
diff --git a/sys/fs/tmpfs/tmpfs_vnops.c b/sys/fs/tmpfs/tmpfs_vnops.c
index 401ee672b96a..43a2aa77dbbb 100644
--- a/sys/fs/tmpfs/tmpfs_vnops.c
+++ b/sys/fs/tmpfs/tmpfs_vnops.c
@@ -623,7 +623,7 @@ tmpfs_read_pgcache(struct vop_read_pgcache_args *v)
if (object == NULL)
goto out_smr;
- MPASS(object->type == OBJT_SWAP_TMPFS);
+ MPASS(object->type == tmpfs_pager_type);
MPASS((object->flags & (OBJ_ANON | OBJ_DEAD | OBJ_SWAP)) ==
OBJ_SWAP);
if (!VN_IS_DOOMED(vp)) {
diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
index 37db4cbac857..63f0d22ed705 100644
--- a/sys/vm/swap_pager.c
+++ b/sys/vm/swap_pager.c
@@ -419,9 +419,6 @@ static uma_zone_t swpctrie_zone;
static vm_object_t
swap_pager_alloc(void *handle, vm_ooffset_t size,
vm_prot_t prot, vm_ooffset_t offset, struct ucred *);
-static vm_object_t
- swap_tmpfs_pager_alloc(void *handle, vm_ooffset_t size,
- vm_prot_t prot, vm_ooffset_t offset, struct ucred *);
static void swap_pager_dealloc(vm_object_t object);
static int swap_pager_getpages(vm_object_t, vm_page_t *, int, int *,
int *);
@@ -437,8 +434,6 @@ static void swap_pager_update_writecount(vm_object_t object,
vm_offset_t start, vm_offset_t end);
static void swap_pager_release_writecount(vm_object_t object,
vm_offset_t start, vm_offset_t end);
-static void swap_tmpfs_pager_getvp(vm_object_t object, struct vnode **vpp,
- bool *vp_heldp);
static void swap_pager_freespace(vm_object_t object, vm_pindex_t start,
vm_size_t size);
@@ -457,23 +452,6 @@ const struct pagerops swappagerops = {
.pgo_freespace = swap_pager_freespace,
};
-const struct pagerops swaptmpfspagerops = {
- .pgo_kvme_type = KVME_TYPE_VNODE,
- .pgo_alloc = swap_tmpfs_pager_alloc,
- .pgo_dealloc = swap_pager_dealloc,
- .pgo_getpages = swap_pager_getpages,
- .pgo_getpages_async = swap_pager_getpages_async,
- .pgo_putpages = swap_pager_putpages,
- .pgo_haspage = swap_pager_haspage,
- .pgo_pageunswapped = swap_pager_unswapped,
- .pgo_update_writecount = swap_pager_update_writecount,
- .pgo_release_writecount = swap_pager_release_writecount,
- .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
- .pgo_mightbedirty = vm_object_mightbedirty_,
- .pgo_getvp = swap_tmpfs_pager_getvp,
- .pgo_freespace = swap_pager_freespace,
-};
-
/*
* swap_*() routines are externally accessible. swp_*() routines are
* internal.
@@ -681,18 +659,31 @@ swap_pager_swap_init(void)
"reduce kern.maxswzone.\n");
}
-static vm_object_t
-swap_pager_alloc_init(objtype_t otype, void *handle, struct ucred *cred,
+bool
+swap_pager_init_object(vm_object_t object, void *handle, struct ucred *cred,
vm_ooffset_t size, vm_ooffset_t offset)
{
- vm_object_t object;
-
if (cred != NULL) {
if (!swap_reserve_by_cred(size, cred))
- return (NULL);
+ return (false);
crhold(cred);
}
+ object->un_pager.swp.writemappings = 0;
+ object->handle = handle;
+ if (cred != NULL) {
+ object->cred = cred;
+ object->charge = size;
+ }
+ return (true);
+}
+
+static vm_object_t
+swap_pager_alloc_init(objtype_t otype, void *handle, struct ucred *cred,
+ vm_ooffset_t size, vm_ooffset_t offset)
+{
+ vm_object_t object;
+
/*
* The un_pager.swp.swp_blks trie is initialized by
* vm_object_allocate() to ensure the correct order of
@@ -701,11 +692,9 @@ swap_pager_alloc_init(objtype_t otype, void *handle, struct ucred *cred,
object = vm_object_allocate(otype, OFF_TO_IDX(offset +
PAGE_MASK + size));
- object->un_pager.swp.writemappings = 0;
- object->handle = handle;
- if (cred != NULL) {
- object->cred = cred;
- object->charge = size;
+ if (!swap_pager_init_object(object, handle, cred, size, offset)) {
+ vm_object_deallocate(object);
+ return (NULL);
}
return (object);
}
@@ -752,18 +741,6 @@ swap_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
return (object);
}
-static vm_object_t
-swap_tmpfs_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
- vm_ooffset_t offset, struct ucred *cred)
-{
- vm_object_t object;
-
- MPASS(handle == NULL);
- object = swap_pager_alloc_init(OBJT_SWAP_TMPFS, handle, cred,
- size, offset);
- return (object);
-}
-
/*
* SWAP_PAGER_DEALLOC() - remove swap metadata from object
*
@@ -3168,31 +3145,3 @@ swap_pager_release_writecount(vm_object_t object, vm_offset_t start,
object->un_pager.swp.writemappings -= (vm_ooffset_t)end - start;
VM_OBJECT_WUNLOCK(object);
}
-
-static void
-swap_tmpfs_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
-{
- struct vnode *vp;
-
- /*
- * Tmpfs VREG node, which was reclaimed, has OBJT_SWAP_TMPFS
- * type, but not OBJ_TMPFS flag. In this case there is no
- * v_writecount to adjust.
- */
- if (vp_heldp != NULL)
- VM_OBJECT_RLOCK(object);
- else
- VM_OBJECT_ASSERT_LOCKED(object);
- if ((object->flags & OBJ_TMPFS) != 0) {
- vp = object->un_pager.swp.swp_tmpfs;
- if (vp != NULL) {
- *vpp = vp;
- if (vp_heldp != NULL) {
- vhold(vp);
- *vp_heldp = true;
- }
- }
- }
- if (vp_heldp != NULL)
- VM_OBJECT_RUNLOCK(object);
-}
diff --git a/sys/vm/swap_pager.h b/sys/vm/swap_pager.h
index 7a2ea12e887d..20ff70acc3d8 100644
--- a/sys/vm/swap_pager.h
+++ b/sys/vm/swap_pager.h
@@ -82,6 +82,7 @@ int swap_pager_reserve(vm_object_t, vm_pindex_t, vm_size_t);
void swap_pager_status(int *total, int *used);
u_long swap_pager_swapped_pages(vm_object_t object);
void swapoff_all(void);
-
+bool swap_pager_init_object(vm_object_t object, void *handle,
+ struct ucred *cred, vm_ooffset_t size, vm_ooffset_t offset);
#endif /* _KERNEL */
#endif /* _VM_SWAP_PAGER_H_ */
diff --git a/sys/vm/vm.h b/sys/vm/vm.h
index ca310b15b43c..8dce853e684d 100644
--- a/sys/vm/vm.h
+++ b/sys/vm/vm.h
@@ -97,7 +97,6 @@ enum obj_type {
OBJT_DEAD,
OBJT_SG,
OBJT_MGTDEVICE,
- OBJT_SWAP_TMPFS,
OBJT_FIRST_DYN,
};
typedef u_char objtype_t;
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 73cbdfb1ece4..9bd3f416ff94 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -413,7 +413,6 @@ vm_object_allocate(objtype_t type, vm_pindex_t size)
flags = OBJ_COLORED;
break;
case OBJT_SWAP:
- case OBJT_SWAP_TMPFS:
flags = OBJ_COLORED | OBJ_SWAP;
break;
case OBJT_DEVICE:
diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index 7e99288e0ff2..d159c621d2e6 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -207,7 +207,7 @@ struct vm_object {
#define OBJ_COLORED 0x1000 /* pg_color is defined */
#define OBJ_ONEMAPPING 0x2000 /* One USE (a single, non-forked) mapping flag */
#define OBJ_SHADOWLIST 0x4000 /* Object is on the shadow list. */
-#define OBJ_TMPFS 0x8000 /* has tmpfs vnode allocated */
+#define OBJ_PAGERPRIV 0x8000 /* Pager private */
/*
* Helpers to perform conversion between vm_object page indexes and offsets.
diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index 432a948cfe81..640e3d977e99 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -174,7 +174,6 @@ const struct pagerops *pagertab[16] __read_mostly = {
[OBJT_DEAD] = &deadpagerops,
[OBJT_SG] = &sgpagerops,
[OBJT_MGTDEVICE] = &mgtdevicepagerops,
- [OBJT_SWAP_TMPFS] = &swaptmpfspagerops,
};
static struct mtx pagertab_lock;
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