Date: Fri, 9 Dec 2022 12:17:40 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 37aea2649ff7 - main - tmpfs: for used pages, account really allocated pages, instead of file sizes Message-ID: <202212091217.2B9CHeCr086490@gitrepo.freebsd.org>
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The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=37aea2649ff707f23d35309d882b38e9ac818e42 commit 37aea2649ff707f23d35309d882b38e9ac818e42 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2022-10-20 13:17:43 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2022-12-09 12:17:12 +0000 tmpfs: for used pages, account really allocated pages, instead of file sizes This makes tmpfs size accounting correct for the sparce files. Also correct report st_blocks/va_bytes. Previously the reported value did not accounted for the swapped out pages. PR: 223015 Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D37097 --- sys/fs/tmpfs/tmpfs.h | 18 ++++++- sys/fs/tmpfs/tmpfs_subr.c | 118 ++++++++++++++++++++++++++++++++++++++++---- sys/fs/tmpfs/tmpfs_vfsops.c | 6 ++- sys/fs/tmpfs/tmpfs_vnops.c | 17 +++++-- sys/kern/uipc_shm.c | 2 +- 5 files changed, 144 insertions(+), 17 deletions(-) diff --git a/sys/fs/tmpfs/tmpfs.h b/sys/fs/tmpfs/tmpfs.h index ad0354f2d474..e9964d7d48af 100644 --- a/sys/fs/tmpfs/tmpfs.h +++ b/sys/fs/tmpfs/tmpfs.h @@ -148,6 +148,7 @@ RB_HEAD(tmpfs_dir, tmpfs_dirent); * (i) tn_interlock * (m) tmpfs_mount tm_allnode_lock * (c) stable after creation + * (v) tn_reg.tn_aobj vm_object lock */ struct tmpfs_node { /* @@ -299,6 +300,7 @@ struct tmpfs_node { */ vm_object_t tn_aobj; /* (c) */ struct tmpfs_mount *tn_tmp; /* (c) */ + vm_pindex_t tn_pages; /* (v) */ } tn_reg; } tn_spec; /* (v) */ }; @@ -533,7 +535,8 @@ VM_TO_TMPFS_VP(vm_object_t obj) { struct tmpfs_node *node; - MPASS((obj->flags & OBJ_TMPFS) != 0); + if ((obj->flags & OBJ_TMPFS) == 0) + return (NULL); /* * swp_priv is the back-pointer to the tmpfs node, if any, @@ -545,6 +548,19 @@ VM_TO_TMPFS_VP(vm_object_t obj) return (node->tn_vnode); } +static inline struct tmpfs_mount * +VM_TO_TMPFS_MP(vm_object_t obj) +{ + struct tmpfs_node *node; + + if ((obj->flags & OBJ_TMPFS) == 0) + return (NULL); + + node = obj->un_pager.swp.swp_priv; + MPASS(node->tn_type == VREG); + return (node->tn_reg.tn_tmp); +} + static inline struct tmpfs_mount * VFS_TO_TMPFS(struct mount *mp) { diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c index 0a7f255a4f74..ef558c424914 100644 --- a/sys/fs/tmpfs/tmpfs_subr.c +++ b/sys/fs/tmpfs/tmpfs_subr.c @@ -214,6 +214,87 @@ tmpfs_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp) VM_OBJECT_RUNLOCK(object); } +static void +tmpfs_pager_freespace(vm_object_t obj, vm_pindex_t start, vm_size_t size) +{ + struct tmpfs_node *node; + struct tmpfs_mount *tm; + vm_size_t c; + + swap_pager_freespace(obj, start, size, &c); + if ((obj->flags & OBJ_TMPFS) == 0 || c == 0) + return; + + node = obj->un_pager.swp.swp_priv; + MPASS(node->tn_type == VREG); + tm = node->tn_reg.tn_tmp; + + KASSERT(tm->tm_pages_used >= c, + ("tmpfs tm %p pages %jd free %jd", tm, + (uintmax_t)tm->tm_pages_used, (uintmax_t)c)); + atomic_add_long(&tm->tm_pages_used, -c); + KASSERT(node->tn_reg.tn_pages >= c, + ("tmpfs node %p pages %jd free %jd", node, + (uintmax_t)node->tn_reg.tn_pages, (uintmax_t)c)); + node->tn_reg.tn_pages -= c; +} + +static void +tmpfs_page_inserted(vm_object_t obj, vm_page_t m) +{ + struct tmpfs_node *node; + struct tmpfs_mount *tm; + + if ((obj->flags & OBJ_TMPFS) == 0) + return; + + node = obj->un_pager.swp.swp_priv; + MPASS(node->tn_type == VREG); + tm = node->tn_reg.tn_tmp; + + if (!vm_pager_has_page(obj, m->pindex, NULL, NULL)) { + atomic_add_long(&tm->tm_pages_used, 1); + node->tn_reg.tn_pages += 1; + } +} + +static void +tmpfs_page_removed(vm_object_t obj, vm_page_t m) +{ + struct tmpfs_node *node; + struct tmpfs_mount *tm; + + if ((obj->flags & OBJ_TMPFS) == 0) + return; + + node = obj->un_pager.swp.swp_priv; + MPASS(node->tn_type == VREG); + tm = node->tn_reg.tn_tmp; + + if (!vm_pager_has_page(obj, m->pindex, NULL, NULL)) { + KASSERT(tm->tm_pages_used >= 1, + ("tmpfs tm %p pages %jd free 1", tm, + (uintmax_t)tm->tm_pages_used)); + atomic_add_long(&tm->tm_pages_used, -1); + KASSERT(node->tn_reg.tn_pages >= 1, + ("tmpfs node %p pages %jd free 1", node, + (uintmax_t)node->tn_reg.tn_pages)); + node->tn_reg.tn_pages -= 1; + } +} + +static boolean_t +tmpfs_can_alloc_page(vm_object_t obj, vm_pindex_t pindex) +{ + struct tmpfs_mount *tm; + + tm = VM_TO_TMPFS_MP(obj); + if (tm == NULL || vm_pager_has_page(obj, pindex, NULL, NULL) || + tm->tm_pages_max == 0) + return (true); + return (tm->tm_pages_max > atomic_load_long(&tm->tm_pages_used)); +} + struct pagerops tmpfs_pager_ops = { .pgo_kvme_type = KVME_TYPE_VNODE, .pgo_alloc = tmpfs_pager_alloc, @@ -222,6 +303,10 @@ struct pagerops tmpfs_pager_ops = { .pgo_release_writecount = tmpfs_pager_release_writecount, .pgo_mightbedirty = vm_object_mightbedirty_, .pgo_getvp = tmpfs_pager_getvp, + .pgo_freespace = tmpfs_pager_freespace, + .pgo_page_inserted = tmpfs_page_inserted, + .pgo_page_removed = tmpfs_page_removed, + .pgo_can_alloc_page = tmpfs_can_alloc_page, }; static int @@ -576,6 +661,7 @@ tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type, nnode->tn_reg.tn_aobj->un_pager.swp.swp_priv = nnode; vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_TMPFS); nnode->tn_reg.tn_tmp = tmp; + nnode->tn_reg.tn_pages = 0; break; default: @@ -665,11 +751,31 @@ tmpfs_free_node_locked(struct tmpfs_mount *tmp, struct tmpfs_node *node, switch (node->tn_type) { case VREG: uobj = node->tn_reg.tn_aobj; - if (uobj != NULL && uobj->size != 0) - atomic_subtract_long(&tmp->tm_pages_used, uobj->size); + node->tn_reg.tn_aobj = NULL; + if (uobj != NULL) { + VM_OBJECT_WLOCK(uobj); + KASSERT((uobj->flags & OBJ_TMPFS) != 0, + ("tmpfs node %p uobj %p not tmpfs", node, uobj)); + vm_object_clear_flag(uobj, OBJ_TMPFS); + KASSERT(tmp->tm_pages_used >= node->tn_reg.tn_pages, + ("tmpfs tmp %p node %p pages %jd free %jd", tmp, + node, (uintmax_t)tmp->tm_pages_used, + (uintmax_t)node->tn_reg.tn_pages)); + atomic_add_long(&tmp->tm_pages_used, + -node->tn_reg.tn_pages); + VM_OBJECT_WUNLOCK(uobj); + } tmpfs_free_tmp(tmp); + + /* + * vm_object_deallocate() must not be called while + * owning tm_allnode_lock, because deallocate might + * sleep. Call it after tmpfs_free_tmp() does the + * unlock. + */ if (uobj != NULL) vm_object_deallocate(uobj); + break; case VLNK: tmpfs_free_tmp(tmp); @@ -1697,7 +1803,6 @@ tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) int tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) { - struct tmpfs_mount *tmp; struct tmpfs_node *node; vm_object_t uobj; vm_pindex_t idx, newpages, oldpages; @@ -1709,7 +1814,6 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) node = VP_TO_TMPFS_NODE(vp); uobj = node->tn_reg.tn_aobj; - tmp = VFS_TO_TMPFS(vp->v_mount); /* * Convert the old and new sizes to the number of pages needed to @@ -1727,10 +1831,6 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) return (0); } - if (newpages > oldpages && - !tmpfs_pages_check_avail(tmp, newpages - oldpages)) - return (ENOSPC); - VM_OBJECT_WLOCK(uobj); if (newsize < oldsize) { /* @@ -1756,8 +1856,6 @@ tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) uobj->size = newpages; VM_OBJECT_WUNLOCK(uobj); - atomic_add_long(&tmp->tm_pages_used, newpages - oldpages); - node->tn_size = newsize; return (0); } diff --git a/sys/fs/tmpfs/tmpfs_vfsops.c b/sys/fs/tmpfs/tmpfs_vfsops.c index ec6120ba72df..de207242b574 100644 --- a/sys/fs/tmpfs/tmpfs_vfsops.c +++ b/sys/fs/tmpfs/tmpfs_vfsops.c @@ -557,7 +557,11 @@ tmpfs_free_tmp(struct tmpfs_mount *tmp) TMPFS_UNLOCK(tmp); mtx_destroy(&tmp->tm_allnode_lock); - MPASS(tmp->tm_pages_used == 0); + /* + * We cannot assert that tmp->tm_pages_used == 0 there, + * because tmpfs vm_objects might be still mapped by some + * process and outlive the mount due to reference counting. + */ MPASS(tmp->tm_nodes_inuse == 0); free(tmp, M_TMPFSMNT); diff --git a/sys/fs/tmpfs/tmpfs_vnops.c b/sys/fs/tmpfs/tmpfs_vnops.c index 6b53f002c8ac..4d95441c05e4 100644 --- a/sys/fs/tmpfs/tmpfs_vnops.c +++ b/sys/fs/tmpfs/tmpfs_vnops.c @@ -437,7 +437,6 @@ tmpfs_stat(struct vop_stat_args *v) { struct vnode *vp = v->a_vp; struct stat *sb = v->a_sb; - vm_object_t obj; struct tmpfs_node *node; int error; @@ -470,8 +469,16 @@ tmpfs_stat(struct vop_stat_args *v) sb->st_flags = node->tn_flags; sb->st_gen = node->tn_gen; if (vp->v_type == VREG) { - obj = node->tn_reg.tn_aobj; - sb->st_blocks = (u_quad_t)obj->resident_page_count * PAGE_SIZE; +#ifdef __ILP32__ + vm_object_t obj = node->tn_reg.tn_aobj; + + /* Handle torn read */ + VM_OBJECT_RLOCK(obj); +#endif + sb->st_blocks = ptoa(node->tn_reg.tn_pages); +#ifdef __ILP32__ + VM_OBJECT_RUNLOCK(obj); +#endif } else { sb->st_blocks = node->tn_size; } @@ -510,7 +517,9 @@ tmpfs_getattr(struct vop_getattr_args *v) node->tn_rdev : NODEV; if (vp->v_type == VREG) { obj = node->tn_reg.tn_aobj; - vap->va_bytes = (u_quad_t)obj->resident_page_count * PAGE_SIZE; + VM_OBJECT_RLOCK(obj); + vap->va_bytes = ptoa(node->tn_reg.tn_pages); + VM_OBJECT_RUNLOCK(obj); } else { vap->va_bytes = node->tn_size; } diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index 07fbc4caa14f..923930a708a3 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -229,7 +229,7 @@ uiomove_object_page(vm_object_t obj, size_t len, struct uio *uio) printf("uiomove_object: vm_obj %p idx %jd " "pager error %d\n", obj, idx, rv); } - return (EIO); + return (rv == VM_PAGER_AGAIN ? ENOSPC : EIO); } VM_OBJECT_WUNLOCK(obj);
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