diff --git a/sys/fs/tmpfs/tmpfs.h b/sys/fs/tmpfs/tmpfs.h index bb777e29e3d0..99368d67aaaa 100644 --- a/sys/fs/tmpfs/tmpfs.h +++ b/sys/fs/tmpfs/tmpfs.h @@ -1,584 +1,585 @@ /* $NetBSD: tmpfs.h,v 1.26 2007/02/22 06:37:00 thorpej Exp $ */ /*- * SPDX-License-Identifier: BSD-2-Clause-NetBSD * * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Julio M. Merino Vidal, developed as part of Google's Summer of Code * 2005 program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD$ */ #ifndef _FS_TMPFS_TMPFS_H_ #define _FS_TMPFS_TMPFS_H_ #include #include #include #ifdef _SYS_MALLOC_H_ MALLOC_DECLARE(M_TMPFSNAME); #endif #define OBJ_TMPFS OBJ_PAGERPRIV1 /* has tmpfs vnode allocated */ +#define OBJ_TMPFS_VREF OBJ_PAGERPRIV2 /* vnode is referenced */ /* * Internal representation of a tmpfs directory entry. */ LIST_HEAD(tmpfs_dir_duphead, tmpfs_dirent); struct tmpfs_dirent { /* * Depending on td_cookie flag entry can be of 3 types: * - regular -- no hash collisions, stored in RB-Tree * - duphead -- synthetic linked list head for dup entries * - dup -- stored in linked list instead of RB-Tree */ union { /* regular and duphead entry types */ RB_ENTRY(tmpfs_dirent) td_entries; /* dup entry type */ struct { LIST_ENTRY(tmpfs_dirent) entries; LIST_ENTRY(tmpfs_dirent) index_entries; } td_dup; } uh; uint32_t td_cookie; uint32_t td_hash; u_int td_namelen; /* * Pointer to the node this entry refers to. In case this field * is NULL, the node is a whiteout. */ struct tmpfs_node * td_node; union { /* * The name of the entry, allocated from a string pool. This * string is not required to be zero-terminated. */ char * td_name; /* regular, dup */ struct tmpfs_dir_duphead td_duphead; /* duphead */ } ud; }; /* * A directory in tmpfs holds a collection of directory entries, which * in turn point to other files (which can be directories themselves). * * In tmpfs, this collection is managed by a RB-Tree, whose head is * defined by the struct tmpfs_dir type. * * It is important to notice that directories do not have entries for . and * .. as other file systems do. These can be generated when requested * based on information available by other means, such as the pointer to * the node itself in the former case or the pointer to the parent directory * in the latter case. This is done to simplify tmpfs's code and, more * importantly, to remove redundancy. */ RB_HEAD(tmpfs_dir, tmpfs_dirent); /* * Each entry in a directory has a cookie that identifies it. Cookies * supersede offsets within directories because, given how tmpfs stores * directories in memory, there is no such thing as an offset. * * The '.', '..' and the end of directory markers have fixed cookies which * cannot collide with the cookies generated by other entries. The cookies * for the other entries are generated based on the file name hash value or * unique number in case of name hash collision. * * To preserve compatibility cookies are limited to 31 bits. */ #define TMPFS_DIRCOOKIE_DOT 0 #define TMPFS_DIRCOOKIE_DOTDOT 1 #define TMPFS_DIRCOOKIE_EOF 2 #define TMPFS_DIRCOOKIE_MASK ((off_t)0x3fffffffU) #define TMPFS_DIRCOOKIE_MIN ((off_t)0x00000004U) #define TMPFS_DIRCOOKIE_DUP ((off_t)0x40000000U) #define TMPFS_DIRCOOKIE_DUPHEAD ((off_t)0x80000000U) #define TMPFS_DIRCOOKIE_DUP_MIN TMPFS_DIRCOOKIE_DUP #define TMPFS_DIRCOOKIE_DUP_MAX \ (TMPFS_DIRCOOKIE_DUP | TMPFS_DIRCOOKIE_MASK) /* * Internal representation of a tmpfs file system node. * * This structure is splitted in two parts: one holds attributes common * to all file types and the other holds data that is only applicable to * a particular type. The code must be careful to only access those * attributes that are actually allowed by the node's type. * * Below is the key of locks used to protected the fields in the following * structures. * (v) vnode lock in exclusive mode * (vi) vnode lock in exclusive mode, or vnode lock in shared vnode and * tn_interlock * (i) tn_interlock * (m) tmpfs_mount tm_allnode_lock * (c) stable after creation */ struct tmpfs_node { /* * Doubly-linked list entry which links all existing nodes for * a single file system. This is provided to ease the removal * of all nodes during the unmount operation, and to support * the implementation of VOP_VNTOCNP(). tn_attached is false * when the node is removed from list and unlocked. */ LIST_ENTRY(tmpfs_node) tn_entries; /* (m) */ /* Node identifier. */ ino_t tn_id; /* (c) */ /* * The node's type. Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO', * 'VLNK', 'VREG' and 'VSOCK' is allowed. The usage of vnode * types instead of a custom enumeration is to make things simpler * and faster, as we do not need to convert between two types. */ enum vtype tn_type; /* (c) */ /* * See the top comment. Reordered here to fill LP64 hole. */ bool tn_attached; /* (m) */ /* * Node's internal status. This is used by several file system * operations to do modifications to the node in a delayed * fashion. * * tn_accessed has a dedicated byte to allow update by store without * using atomics. This provides a micro-optimization to e.g. * tmpfs_read_pgcache(). */ uint8_t tn_status; /* (vi) */ uint8_t tn_accessed; /* unlocked */ /* * The node size. It does not necessarily match the real amount * of memory consumed by it. */ off_t tn_size; /* (v) */ /* Generic node attributes. */ uid_t tn_uid; /* (v) */ gid_t tn_gid; /* (v) */ mode_t tn_mode; /* (v) */ int tn_links; /* (v) */ u_long tn_flags; /* (v) */ struct timespec tn_atime; /* (vi) */ struct timespec tn_mtime; /* (vi) */ struct timespec tn_ctime; /* (vi) */ struct timespec tn_birthtime; /* (v) */ unsigned long tn_gen; /* (c) */ /* * As there is a single vnode for each active file within the * system, care has to be taken to avoid allocating more than one * vnode per file. In order to do this, a bidirectional association * is kept between vnodes and nodes. * * Whenever a vnode is allocated, its v_data field is updated to * point to the node it references. At the same time, the node's * tn_vnode field is modified to point to the new vnode representing * it. Further attempts to allocate a vnode for this same node will * result in returning a new reference to the value stored in * tn_vnode. * * May be NULL when the node is unused (that is, no vnode has been * allocated for it or it has been reclaimed). */ struct vnode * tn_vnode; /* (i) */ /* * Interlock to protect tn_vpstate, and tn_status under shared * vnode lock. */ struct mtx tn_interlock; /* * Identify if current node has vnode assiocate with * or allocating vnode. */ int tn_vpstate; /* (i) */ /* Transient refcounter on this node. */ u_int tn_refcount; /* 0<->1 (m) + (i) */ /* misc data field for different tn_type node */ union { /* Valid when tn_type == VBLK || tn_type == VCHR. */ dev_t tn_rdev; /* (c) */ /* Valid when tn_type == VDIR. */ struct tn_dir { /* * Pointer to the parent directory. The root * directory has a pointer to itself in this field; * this property identifies the root node. */ struct tmpfs_node * tn_parent; /* * Head of a tree that links the contents of * the directory together. */ struct tmpfs_dir tn_dirhead; /* * Head of a list the contains fake directory entries * heads, i.e. entries with TMPFS_DIRCOOKIE_DUPHEAD * flag. */ struct tmpfs_dir_duphead tn_dupindex; /* * Number and pointer of the first directory entry * returned by the readdir operation if it were * called again to continue reading data from the * same directory as before. This is used to speed * up reads of long directories, assuming that no * more than one read is in progress at a given time. * Otherwise, these values are discarded. */ off_t tn_readdir_lastn; struct tmpfs_dirent * tn_readdir_lastp; } tn_dir; /* Valid when tn_type == VLNK. */ /* The link's target, allocated from a string pool. */ struct tn_link { char * tn_link_target; /* (c) */ char tn_link_smr; /* (c) */ } tn_link; /* Valid when tn_type == VREG. */ struct tn_reg { /* * The contents of regular files stored in a * tmpfs file system are represented by a * single anonymous memory object (aobj, for * short). The aobj provides direct access to * any position within the file. It is a task * of the memory management subsystem to issue * the required page ins or page outs whenever * a position within the file is accessed. */ vm_object_t tn_aobj; /* (c) */ struct tmpfs_mount *tn_tmp; /* (c) */ } tn_reg; } tn_spec; /* (v) */ }; LIST_HEAD(tmpfs_node_list, tmpfs_node); #define tn_rdev tn_spec.tn_rdev #define tn_dir tn_spec.tn_dir #define tn_link_target tn_spec.tn_link.tn_link_target #define tn_link_smr tn_spec.tn_link.tn_link_smr #define tn_reg tn_spec.tn_reg #define tn_fifo tn_spec.tn_fifo #define TMPFS_LINK_MAX INT_MAX #define TMPFS_NODE_LOCK(node) mtx_lock(&(node)->tn_interlock) #define TMPFS_NODE_UNLOCK(node) mtx_unlock(&(node)->tn_interlock) #define TMPFS_NODE_MTX(node) (&(node)->tn_interlock) #define TMPFS_NODE_ASSERT_LOCKED(node) mtx_assert(TMPFS_NODE_MTX(node), \ MA_OWNED) #ifdef INVARIANTS #define TMPFS_ASSERT_LOCKED(node) do { \ MPASS((node) != NULL); \ MPASS((node)->tn_vnode != NULL); \ ASSERT_VOP_LOCKED((node)->tn_vnode, "tmpfs assert"); \ } while (0) #else #define TMPFS_ASSERT_LOCKED(node) (void)0 #endif /* tn_vpstate */ #define TMPFS_VNODE_ALLOCATING 1 #define TMPFS_VNODE_WANT 2 #define TMPFS_VNODE_DOOMED 4 #define TMPFS_VNODE_WRECLAIM 8 /* tn_status */ #define TMPFS_NODE_MODIFIED 0x01 #define TMPFS_NODE_CHANGED 0x02 /* * Internal representation of a tmpfs mount point. */ struct tmpfs_mount { /* * Original value of the "size" parameter, for reference purposes, * mostly. */ off_t tm_size_max; /* * Maximum number of memory pages available for use by the file * system, set during mount time. This variable must never be * used directly as it may be bigger than the current amount of * free memory; in the extreme case, it will hold the ULONG_MAX * value. */ u_long tm_pages_max; /* Number of pages in use by the file system. */ u_long tm_pages_used; /* * Pointer to the node representing the root directory of this * file system. */ struct tmpfs_node * tm_root; /* * Maximum number of possible nodes for this file system; set * during mount time. We need a hard limit on the maximum number * of nodes to avoid allocating too much of them; their objects * cannot be released until the file system is unmounted. * Otherwise, we could easily run out of memory by creating lots * of empty files and then simply removing them. */ ino_t tm_nodes_max; /* unrhdr used to allocate inode numbers */ struct unrhdr64 tm_ino_unr; /* Number of nodes currently that are in use. */ ino_t tm_nodes_inuse; /* Refcounter on this struct tmpfs_mount. */ uint64_t tm_refcount; /* maximum representable file size */ u_int64_t tm_maxfilesize; /* * The used list contains all nodes that are currently used by * the file system; i.e., they refer to existing files. */ struct tmpfs_node_list tm_nodes_used; /* All node lock to protect the node list and tmp_pages_used. */ struct mtx tm_allnode_lock; /* Read-only status. */ bool tm_ronly; /* Do not use namecache. */ bool tm_nonc; /* Do not update mtime on writes through mmaped areas. */ bool tm_nomtime; }; #define TMPFS_LOCK(tm) mtx_lock(&(tm)->tm_allnode_lock) #define TMPFS_UNLOCK(tm) mtx_unlock(&(tm)->tm_allnode_lock) #define TMPFS_MP_ASSERT_LOCKED(tm) mtx_assert(&(tm)->tm_allnode_lock, MA_OWNED) /* * This structure maps a file identifier to a tmpfs node. Used by the * NFS code. */ struct tmpfs_fid_data { ino_t tfd_id; unsigned long tfd_gen; }; _Static_assert(sizeof(struct tmpfs_fid_data) <= MAXFIDSZ, "(struct tmpfs_fid_data) is larger than (struct fid).fid_data"); struct tmpfs_dir_cursor { struct tmpfs_dirent *tdc_current; struct tmpfs_dirent *tdc_tree; }; #ifdef _KERNEL /* * Prototypes for tmpfs_subr.c. */ void tmpfs_ref_node(struct tmpfs_node *node); int tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *, enum vtype, uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *, const char *, dev_t, struct tmpfs_node **); int tmpfs_fo_close(struct file *fp, struct thread *td); void tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *); bool tmpfs_free_node_locked(struct tmpfs_mount *, struct tmpfs_node *, bool); void tmpfs_free_tmp(struct tmpfs_mount *); int tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *, const char *, u_int, struct tmpfs_dirent **); void tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *); void tmpfs_dirent_init(struct tmpfs_dirent *, const char *, u_int); void tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj); int tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, int, struct vnode **); void tmpfs_free_vp(struct vnode *); int tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *, struct componentname *, const char *); void tmpfs_check_mtime(struct vnode *); void tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *); void tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *); void tmpfs_dir_destroy(struct tmpfs_mount *, struct tmpfs_node *); struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, struct componentname *cnp); int tmpfs_dir_getdents(struct tmpfs_mount *, struct tmpfs_node *, struct uio *, int, u_long *, int *); int tmpfs_dir_whiteout_add(struct vnode *, struct componentname *); void tmpfs_dir_whiteout_remove(struct vnode *, struct componentname *); int tmpfs_reg_resize(struct vnode *, off_t, boolean_t); int tmpfs_chflags(struct vnode *, u_long, struct ucred *, struct thread *); int tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct thread *); int tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *, struct thread *); int tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct thread *); int tmpfs_chtimes(struct vnode *, struct vattr *, struct ucred *cred, struct thread *); void tmpfs_itimes(struct vnode *, const struct timespec *, const struct timespec *); void tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node); void tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node, int status); int tmpfs_truncate(struct vnode *, off_t); struct tmpfs_dirent *tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc); struct tmpfs_dirent *tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc); static __inline void tmpfs_update(struct vnode *vp) { tmpfs_itimes(vp, NULL, NULL); } /* * Convenience macros to simplify some logical expressions. */ #define IMPLIES(a, b) (!(a) || (b)) #define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a)) /* * Checks that the directory entry pointed by 'de' matches the name 'name' * with a length of 'len'. */ #define TMPFS_DIRENT_MATCHES(de, name, len) \ (de->td_namelen == len && \ bcmp((de)->ud.td_name, (name), (de)->td_namelen) == 0) /* * Ensures that the node pointed by 'node' is a directory and that its * contents are consistent with respect to directories. */ #define TMPFS_VALIDATE_DIR(node) do { \ MPASS((node)->tn_type == VDIR); \ MPASS((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \ } while (0) /* * Amount of memory pages to reserve for the system (e.g., to not use by * tmpfs). */ #if !defined(TMPFS_PAGES_MINRESERVED) #define TMPFS_PAGES_MINRESERVED (4 * 1024 * 1024 / PAGE_SIZE) #endif size_t tmpfs_mem_avail(void); size_t tmpfs_pages_used(struct tmpfs_mount *tmp); 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. */ static inline struct tmpfs_mount * VFS_TO_TMPFS(struct mount *mp) { struct tmpfs_mount *tmp; MPASS(mp != NULL && mp->mnt_data != NULL); tmp = (struct tmpfs_mount *)mp->mnt_data; return (tmp); } static inline struct tmpfs_node * VP_TO_TMPFS_NODE(struct vnode *vp) { struct tmpfs_node *node; MPASS(vp != NULL && vp->v_data != NULL); node = (struct tmpfs_node *)vp->v_data; return (node); } #define VP_TO_TMPFS_NODE_SMR(vp) \ ((struct tmpfs_node *)vn_load_v_data_smr(vp)) static inline struct tmpfs_node * VP_TO_TMPFS_DIR(struct vnode *vp) { struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); TMPFS_VALIDATE_DIR(node); return (node); } static inline bool tmpfs_use_nc(struct vnode *vp) { return (!(VFS_TO_TMPFS(vp->v_mount)->tm_nonc)); } static inline void tmpfs_update_getattr(struct vnode *vp) { struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); if (__predict_false((node->tn_status & (TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED)) != 0 || node->tn_accessed)) tmpfs_update(vp); } extern struct fileops tmpfs_fnops; #endif /* _KERNEL */ #endif /* _FS_TMPFS_TMPFS_H_ */ diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c index 67eb12598e24..8b75c58d69a2 100644 --- a/sys/fs/tmpfs/tmpfs_subr.c +++ b/sys/fs/tmpfs/tmpfs_subr.c @@ -1,2063 +1,2170 @@ /* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */ /*- * SPDX-License-Identifier: BSD-2-Clause-NetBSD * * Copyright (c) 2005 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Julio M. Merino Vidal, developed as part of Google's Summer of Code * 2005 program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Efficient memory file system supporting functions. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "tmpfs file system"); static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED; 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); } +/* + * Make sure tmpfs vnodes with writable mappings can be found on the lazy list. + * + * This allows for periodic mtime updates while only scanning vnodes which are + * plausibly dirty, see tmpfs_update_mtime_lazy. + */ +static void +tmpfs_pager_writecount_recalc(vm_object_t object, vm_offset_t old, + vm_offset_t new) +{ + struct vnode *vp; + + VM_OBJECT_ASSERT_WLOCKED(object); + + vp = object->un_pager.swp.swp_tmpfs; + + /* + * Forced unmount? + */ + if (vp == NULL) { + KASSERT((object->flags & OBJ_TMPFS_VREF) == 0, + ("object %p with OBJ_TMPFS_VREF but without vnode", object)); + VM_OBJECT_WUNLOCK(object); + return; + } + + if (old == 0) { + VNASSERT((object->flags & OBJ_TMPFS_VREF) == 0, vp, + ("object without writable mappings has a reference")); + VNPASS(vp->v_usecount > 0, vp); + } else { + VNASSERT((object->flags & OBJ_TMPFS_VREF) != 0, vp, + ("object with writable mappings does not have a reference")); + } + + if (old == new) { + VM_OBJECT_WUNLOCK(object); + return; + } + + if (new == 0) { + vm_object_clear_flag(object, OBJ_TMPFS_VREF); + VM_OBJECT_WUNLOCK(object); + vrele(vp); + } else { + if ((object->flags & OBJ_TMPFS_VREF) == 0) { + vref(vp); + vlazy(vp); + vm_object_set_flag(object, OBJ_TMPFS_VREF); + } + VM_OBJECT_WUNLOCK(object); + } +} + +static void +tmpfs_pager_update_writecount(vm_object_t object, vm_offset_t start, + vm_offset_t end) +{ + vm_offset_t new, old; + + VM_OBJECT_WLOCK(object); + KASSERT((object->flags & OBJ_ANON) == 0, + ("%s: object %p with OBJ_ANON", __func__, object)); + old = object->un_pager.swp.writemappings; + object->un_pager.swp.writemappings += (vm_ooffset_t)end - start; + new = object->un_pager.swp.writemappings; + tmpfs_pager_writecount_recalc(object, old, new); + VM_OBJECT_ASSERT_UNLOCKED(object); +} + +static void +tmpfs_pager_release_writecount(vm_object_t object, vm_offset_t start, + vm_offset_t end) +{ + vm_offset_t new, old; + + VM_OBJECT_WLOCK(object); + KASSERT((object->flags & OBJ_ANON) == 0, + ("%s: object %p with OBJ_ANON", __func__, object)); + old = object->un_pager.swp.writemappings; + object->un_pager.swp.writemappings -= (vm_ooffset_t)end - start; + new = object->un_pager.swp.writemappings; + tmpfs_pager_writecount_recalc(object, old, new); + VM_OBJECT_ASSERT_UNLOCKED(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_update_writecount = tmpfs_pager_update_writecount, + .pgo_release_writecount = tmpfs_pager_release_writecount, .pgo_mightbedirty = vm_object_mightbedirty_, .pgo_getvp = tmpfs_pager_getvp, }; static int tmpfs_node_ctor(void *mem, int size, void *arg, int flags) { struct tmpfs_node *node; node = mem; node->tn_gen++; node->tn_size = 0; node->tn_status = 0; node->tn_accessed = false; node->tn_flags = 0; node->tn_links = 0; node->tn_vnode = NULL; node->tn_vpstate = 0; return (0); } static void tmpfs_node_dtor(void *mem, int size, void *arg) { struct tmpfs_node *node; node = mem; node->tn_type = VNON; } static int tmpfs_node_init(void *mem, int size, int flags) { struct tmpfs_node *node; node = mem; node->tn_id = 0; mtx_init(&node->tn_interlock, "tmpfsni", NULL, MTX_DEF); node->tn_gen = arc4random(); return (0); } static void tmpfs_node_fini(void *mem, int size) { struct tmpfs_node *node; node = mem; mtx_destroy(&node->tn_interlock); } 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); } static int sysctl_mem_reserved(SYSCTL_HANDLER_ARGS) { int error; long pages, bytes; pages = *(long *)arg1; bytes = pages * PAGE_SIZE; error = sysctl_handle_long(oidp, &bytes, 0, req); if (error || !req->newptr) return (error); pages = bytes / PAGE_SIZE; if (pages < TMPFS_PAGES_MINRESERVED) return (EINVAL); *(long *)arg1 = pages; return (0); } SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_MPSAFE|CTLFLAG_RW, &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L", "Amount of available memory and swap below which tmpfs growth stops"); static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b); RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); size_t tmpfs_mem_avail(void) { size_t avail; long reserved; avail = swap_pager_avail + vm_free_count(); reserved = atomic_load_long(&tmpfs_pages_reserved); if (__predict_false(avail < reserved)) return (0); return (avail - reserved); } size_t tmpfs_pages_used(struct tmpfs_mount *tmp) { const size_t node_size = sizeof(struct tmpfs_node) + sizeof(struct tmpfs_dirent); size_t meta_pages; meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size, PAGE_SIZE); return (meta_pages + tmp->tm_pages_used); } static size_t tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages) { if (tmpfs_mem_avail() < req_pages) return (0); if (tmp->tm_pages_max != ULONG_MAX && tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp)) return (0); return (1); } void tmpfs_ref_node(struct tmpfs_node *node) { #ifdef INVARIANTS u_int old; old = #endif refcount_acquire(&node->tn_refcount); #ifdef INVARIANTS KASSERT(old > 0, ("node %p zero refcount", node)); #endif } /* * Allocates a new node of type 'type' inside the 'tmp' mount point, with * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', * using the credentials of the process 'p'. * * If the node type is set to 'VDIR', then the parent parameter must point * to the parent directory of the node being created. It may only be NULL * while allocating the root node. * * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter * specifies the device the node represents. * * If the node type is set to 'VLNK', then the parameter target specifies * the file name of the target file for the symbolic link that is being * created. * * Note that new nodes are retrieved from the available list if it has * items or, if it is empty, from the node pool as long as there is enough * space to create them. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type, uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, const char *target, dev_t rdev, struct tmpfs_node **node) { struct tmpfs_node *nnode; vm_object_t obj; char *symlink; char symlink_smr; /* If the root directory of the 'tmp' file system is not yet * allocated, this must be the request to do it. */ MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); MPASS(IFF(type == VLNK, target != NULL)); MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) return (ENOSPC); if (tmpfs_pages_check_avail(tmp, 1) == 0) return (ENOSPC); if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { /* * When a new tmpfs node is created for fully * constructed mount point, there must be a parent * node, which vnode is locked exclusively. As * consequence, if the unmount is executing in * parallel, vflush() cannot reclaim the parent vnode. * Due to this, the check for MNTK_UNMOUNT flag is not * racy: if we did not see MNTK_UNMOUNT flag, then tmp * cannot be destroyed until node construction is * finished and the parent vnode unlocked. * * Tmpfs does not need to instantiate new nodes during * unmount. */ return (EBUSY); } if ((mp->mnt_kern_flag & MNT_RDONLY) != 0) return (EROFS); nnode = uma_zalloc_smr(tmpfs_node_pool, M_WAITOK); /* Generic initialization. */ nnode->tn_type = type; vfs_timestamp(&nnode->tn_atime); nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime; nnode->tn_uid = uid; nnode->tn_gid = gid; nnode->tn_mode = mode; nnode->tn_id = alloc_unr64(&tmp->tm_ino_unr); nnode->tn_refcount = 1; /* Type-specific initialization. */ switch (nnode->tn_type) { case VBLK: case VCHR: nnode->tn_rdev = rdev; break; case VDIR: RB_INIT(&nnode->tn_dir.tn_dirhead); LIST_INIT(&nnode->tn_dir.tn_dupindex); MPASS(parent != nnode); MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; nnode->tn_dir.tn_readdir_lastn = 0; nnode->tn_dir.tn_readdir_lastp = NULL; nnode->tn_links++; TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); nnode->tn_dir.tn_parent->tn_links++; TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); break; case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: MPASS(strlen(target) < MAXPATHLEN); nnode->tn_size = strlen(target); symlink = NULL; if (!tmp->tm_nonc) { symlink = cache_symlink_alloc(nnode->tn_size + 1, M_WAITOK); symlink_smr = true; } if (symlink == NULL) { symlink = malloc(nnode->tn_size + 1, M_TMPFSNAME, M_WAITOK); symlink_smr = false; } memcpy(symlink, target, nnode->tn_size + 1); /* * Allow safe symlink resolving for lockless lookup. * tmpfs_fplookup_symlink references this comment. * * 1. nnode is not yet visible to the world * 2. both tn_link_target and tn_link_smr get populated * 3. release fence publishes their content * 4. tn_link_target content is immutable until node destruction, * where the pointer gets set to NULL * 5. tn_link_smr is never changed once set * * As a result it is sufficient to issue load consume on the node * pointer to also get the above content in a stable manner. * Worst case tn_link_smr flag may be set to true despite being stale, * while the target buffer is already cleared out. */ atomic_store_ptr(&nnode->tn_link_target, symlink); atomic_store_char((char *)&nnode->tn_link_smr, symlink_smr); atomic_thread_fence_rel(); break; case VREG: obj = nnode->tn_reg.tn_aobj = 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 */ nnode->tn_reg.tn_tmp = tmp; break; default: panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); } TMPFS_LOCK(tmp); LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); nnode->tn_attached = true; tmp->tm_nodes_inuse++; tmp->tm_refcount++; TMPFS_UNLOCK(tmp); *node = nnode; return (0); } /* * Destroys the node pointed to by node from the file system 'tmp'. * If the node references a directory, no entries are allowed. */ void tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) { if (refcount_release_if_not_last(&node->tn_refcount)) return; TMPFS_LOCK(tmp); TMPFS_NODE_LOCK(node); if (!tmpfs_free_node_locked(tmp, node, false)) { TMPFS_NODE_UNLOCK(node); TMPFS_UNLOCK(tmp); } } bool tmpfs_free_node_locked(struct tmpfs_mount *tmp, struct tmpfs_node *node, bool detach) { vm_object_t uobj; char *symlink; bool last; TMPFS_MP_ASSERT_LOCKED(tmp); TMPFS_NODE_ASSERT_LOCKED(node); last = refcount_release(&node->tn_refcount); if (node->tn_attached && (detach || last)) { MPASS(tmp->tm_nodes_inuse > 0); tmp->tm_nodes_inuse--; LIST_REMOVE(node, tn_entries); node->tn_attached = false; } if (!last) return (false); #ifdef INVARIANTS MPASS(node->tn_vnode == NULL); MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); #endif TMPFS_NODE_UNLOCK(node); TMPFS_UNLOCK(tmp); switch (node->tn_type) { case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VDIR: /* FALLTHROUGH */ case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: symlink = node->tn_link_target; atomic_store_ptr(&node->tn_link_target, NULL); if (atomic_load_char(&node->tn_link_smr)) { cache_symlink_free(symlink, node->tn_size + 1); } else { free(symlink, M_TMPFSNAME); } break; case VREG: uobj = node->tn_reg.tn_aobj; if (uobj != NULL) { if (uobj->size != 0) atomic_subtract_long(&tmp->tm_pages_used, uobj->size); KASSERT((uobj->flags & OBJ_TMPFS) == 0, ("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj)); vm_object_deallocate(uobj); } break; default: panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); } uma_zfree_smr(tmpfs_node_pool, node); TMPFS_LOCK(tmp); tmpfs_free_tmp(tmp); return (true); } static __inline uint32_t tmpfs_dirent_hash(const char *name, u_int len) { uint32_t hash; hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK; #ifdef TMPFS_DEBUG_DIRCOOKIE_DUP hash &= 0xf; #endif if (hash < TMPFS_DIRCOOKIE_MIN) hash += TMPFS_DIRCOOKIE_MIN; return (hash); } static __inline off_t tmpfs_dirent_cookie(struct tmpfs_dirent *de) { if (de == NULL) return (TMPFS_DIRCOOKIE_EOF); MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN); return (de->td_cookie); } static __inline boolean_t tmpfs_dirent_dup(struct tmpfs_dirent *de) { return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0); } static __inline boolean_t tmpfs_dirent_duphead(struct tmpfs_dirent *de) { return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0); } void tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen) { de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen); memcpy(de->ud.td_name, name, namelen); de->td_namelen = namelen; } /* * Allocates a new directory entry for the node node with a name of name. * The new directory entry is returned in *de. * * The link count of node is increased by one to reflect the new object * referencing it. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, const char *name, u_int len, struct tmpfs_dirent **de) { struct tmpfs_dirent *nde; nde = malloc(sizeof(*nde), M_TMPFSDIR, M_WAITOK); nde->td_node = node; if (name != NULL) { nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK); tmpfs_dirent_init(nde, name, len); } else nde->td_namelen = 0; if (node != NULL) node->tn_links++; *de = nde; return 0; } /* * Frees a directory entry. It is the caller's responsibility to destroy * the node referenced by it if needed. * * The link count of node is decreased by one to reflect the removal of an * object that referenced it. This only happens if 'node_exists' is true; * otherwise the function will not access the node referred to by the * directory entry, as it may already have been released from the outside. */ void tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de) { struct tmpfs_node *node; node = de->td_node; if (node != NULL) { MPASS(node->tn_links > 0); node->tn_links--; } if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL) free(de->ud.td_name, M_TMPFSNAME); free(de, M_TMPFSDIR); } void tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj) { + bool want_vrele; ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject"); if (vp->v_type != VREG || obj == NULL) return; VM_OBJECT_WLOCK(obj); VI_LOCK(vp); + /* + * May be going through forced unmount. + */ + want_vrele = false; + if ((obj->flags & OBJ_TMPFS_VREF) != 0) { + vm_object_clear_flag(obj, OBJ_TMPFS_VREF); + want_vrele = true; + } + vm_object_clear_flag(obj, OBJ_TMPFS); obj->un_pager.swp.swp_tmpfs = NULL; if (vp->v_writecount < 0) vp->v_writecount = 0; VI_UNLOCK(vp); VM_OBJECT_WUNLOCK(obj); + if (want_vrele) { + vrele(vp); + } } /* * Need to clear v_object for insmntque failure. */ static void tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg) { tmpfs_destroy_vobject(vp, vp->v_object); vp->v_object = NULL; vp->v_data = NULL; vp->v_op = &dead_vnodeops; vgone(vp); vput(vp); } /* * Allocates a new vnode for the node node or returns a new reference to * an existing one if the node had already a vnode referencing it. The * resulting locked vnode is returned in *vpp. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, struct vnode **vpp) { struct vnode *vp; enum vgetstate vs; struct tmpfs_mount *tm; vm_object_t object; int error; error = 0; tm = VFS_TO_TMPFS(mp); TMPFS_NODE_LOCK(node); tmpfs_ref_node(node); loop: TMPFS_NODE_ASSERT_LOCKED(node); if ((vp = node->tn_vnode) != NULL) { MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) || (VN_IS_DOOMED(vp) && (lkflag & LK_NOWAIT) != 0)) { TMPFS_NODE_UNLOCK(node); error = ENOENT; vp = NULL; goto out; } if (VN_IS_DOOMED(vp)) { node->tn_vpstate |= TMPFS_VNODE_WRECLAIM; while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) { msleep(&node->tn_vnode, TMPFS_NODE_MTX(node), 0, "tmpfsE", 0); } goto loop; } vs = vget_prep(vp); TMPFS_NODE_UNLOCK(node); error = vget_finish(vp, lkflag, vs); if (error == ENOENT) { TMPFS_NODE_LOCK(node); goto loop; } if (error != 0) { vp = NULL; goto out; } /* * Make sure the vnode is still there after * getting the interlock to avoid racing a free. */ if (node->tn_vnode == NULL || node->tn_vnode != vp) { vput(vp); TMPFS_NODE_LOCK(node); goto loop; } goto out; } if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { TMPFS_NODE_UNLOCK(node); error = ENOENT; vp = NULL; goto out; } /* * otherwise lock the vp list while we call getnewvnode * since that can block. */ if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { node->tn_vpstate |= TMPFS_VNODE_WANT; error = msleep((caddr_t) &node->tn_vpstate, TMPFS_NODE_MTX(node), 0, "tmpfs_alloc_vp", 0); if (error != 0) goto out; goto loop; } else node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; TMPFS_NODE_UNLOCK(node); /* Get a new vnode and associate it with our node. */ error = getnewvnode("tmpfs", mp, VFS_TO_TMPFS(mp)->tm_nonc ? &tmpfs_vnodeop_nonc_entries : &tmpfs_vnodeop_entries, &vp); if (error != 0) goto unlock; MPASS(vp != NULL); /* lkflag is ignored, the lock is exclusive */ (void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_data = node; vp->v_type = node->tn_type; /* Type-specific initialization. */ switch (node->tn_type) { case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VLNK: /* FALLTHROUGH */ case VSOCK: break; case VFIFO: vp->v_op = &tmpfs_fifoop_entries; break; case VREG: object = node->tn_reg.tn_aobj; VM_OBJECT_WLOCK(object); + KASSERT((object->flags & OBJ_TMPFS_VREF) == 0, + ("%s: object %p with OBJ_TMPFS_VREF but without vnode", + __func__, object)); + KASSERT(object->un_pager.swp.writemappings == 0, + ("%s: object %p has writemappings", + __func__, object)); VI_LOCK(vp); KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs")); vp->v_object = object; object->un_pager.swp.swp_tmpfs = vp; vm_object_set_flag(object, OBJ_TMPFS); vn_irflag_set_locked(vp, VIRF_PGREAD); VI_UNLOCK(vp); VM_OBJECT_WUNLOCK(object); break; case VDIR: MPASS(node->tn_dir.tn_parent != NULL); if (node->tn_dir.tn_parent == node) vp->v_vflag |= VV_ROOT; break; default: panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); } if (vp->v_type != VFIFO) VN_LOCK_ASHARE(vp); error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL); if (error != 0) vp = NULL; unlock: TMPFS_NODE_LOCK(node); MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; node->tn_vnode = vp; if (node->tn_vpstate & TMPFS_VNODE_WANT) { node->tn_vpstate &= ~TMPFS_VNODE_WANT; TMPFS_NODE_UNLOCK(node); wakeup((caddr_t) &node->tn_vpstate); } else TMPFS_NODE_UNLOCK(node); out: if (error == 0) { *vpp = vp; #ifdef INVARIANTS MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); TMPFS_NODE_LOCK(node); MPASS(*vpp == node->tn_vnode); TMPFS_NODE_UNLOCK(node); #endif } tmpfs_free_node(tm, node); return (error); } /* * Destroys the association between the vnode vp and the node it * references. */ void tmpfs_free_vp(struct vnode *vp) { struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); TMPFS_NODE_ASSERT_LOCKED(node); node->tn_vnode = NULL; if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) wakeup(&node->tn_vnode); node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM; vp->v_data = NULL; } /* * Allocates a new file of type 'type' and adds it to the parent directory * 'dvp'; this addition is done using the component name given in 'cnp'. * The ownership of the new file is automatically assigned based on the * credentials of the caller (through 'cnp'), the group is set based on * the parent directory and the mode is determined from the 'vap' argument. * If successful, *vpp holds a vnode to the newly created file and zero * is returned. Otherwise *vpp is NULL and the function returns an * appropriate error code. */ int tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, struct componentname *cnp, const char *target) { int error; struct tmpfs_dirent *de; struct tmpfs_mount *tmp; struct tmpfs_node *dnode; struct tmpfs_node *node; struct tmpfs_node *parent; ASSERT_VOP_ELOCKED(dvp, "tmpfs_alloc_file"); MPASS(cnp->cn_flags & HASBUF); tmp = VFS_TO_TMPFS(dvp->v_mount); dnode = VP_TO_TMPFS_DIR(dvp); *vpp = NULL; /* If the entry we are creating is a directory, we cannot overflow * the number of links of its parent, because it will get a new * link. */ if (vap->va_type == VDIR) { /* Ensure that we do not overflow the maximum number of links * imposed by the system. */ MPASS(dnode->tn_links <= TMPFS_LINK_MAX); if (dnode->tn_links == TMPFS_LINK_MAX) { return (EMLINK); } parent = dnode; MPASS(parent != NULL); } else parent = NULL; /* Allocate a node that represents the new file. */ error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type, cnp->cn_cred->cr_uid, dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node); if (error != 0) return (error); /* Allocate a directory entry that points to the new file. */ error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, &de); if (error != 0) { tmpfs_free_node(tmp, node); return (error); } /* Allocate a vnode for the new file. */ error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); if (error != 0) { tmpfs_free_dirent(tmp, de); tmpfs_free_node(tmp, node); return (error); } /* Now that all required items are allocated, we can proceed to * insert the new node into the directory, an operation that * cannot fail. */ if (cnp->cn_flags & ISWHITEOUT) tmpfs_dir_whiteout_remove(dvp, cnp); tmpfs_dir_attach(dvp, de); return (0); } struct tmpfs_dirent * tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) { struct tmpfs_dirent *de; de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead); dc->tdc_tree = de; if (de != NULL && tmpfs_dirent_duphead(de)) de = LIST_FIRST(&de->ud.td_duphead); dc->tdc_current = de; return (dc->tdc_current); } struct tmpfs_dirent * tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) { struct tmpfs_dirent *de; MPASS(dc->tdc_tree != NULL); if (tmpfs_dirent_dup(dc->tdc_current)) { dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries); if (dc->tdc_current != NULL) return (dc->tdc_current); } dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, dc->tdc_tree); if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) { dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); MPASS(dc->tdc_current != NULL); } return (dc->tdc_current); } /* Lookup directory entry in RB-Tree. Function may return duphead entry. */ static struct tmpfs_dirent * tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash) { struct tmpfs_dirent *de, dekey; dekey.td_hash = hash; de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey); return (de); } /* Lookup directory entry by cookie, initialize directory cursor accordingly. */ static struct tmpfs_dirent * tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie, struct tmpfs_dir_cursor *dc) { struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead; struct tmpfs_dirent *de, dekey; MPASS(cookie >= TMPFS_DIRCOOKIE_MIN); if (cookie == node->tn_dir.tn_readdir_lastn && (de = node->tn_dir.tn_readdir_lastp) != NULL) { /* Protect against possible race, tn_readdir_last[pn] * may be updated with only shared vnode lock held. */ if (cookie == tmpfs_dirent_cookie(de)) goto out; } if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) { LIST_FOREACH(de, &node->tn_dir.tn_dupindex, uh.td_dup.index_entries) { MPASS(tmpfs_dirent_dup(de)); if (de->td_cookie == cookie) goto out; /* dupindex list is sorted. */ if (de->td_cookie < cookie) { de = NULL; goto out; } } MPASS(de == NULL); goto out; } if ((cookie & TMPFS_DIRCOOKIE_MASK) != cookie) { de = NULL; } else { dekey.td_hash = cookie; /* Recover if direntry for cookie was removed */ de = RB_NFIND(tmpfs_dir, dirhead, &dekey); } dc->tdc_tree = de; dc->tdc_current = de; if (de != NULL && tmpfs_dirent_duphead(de)) { dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); MPASS(dc->tdc_current != NULL); } return (dc->tdc_current); out: dc->tdc_tree = de; dc->tdc_current = de; if (de != NULL && tmpfs_dirent_dup(de)) dc->tdc_tree = tmpfs_dir_xlookup_hash(node, de->td_hash); return (dc->tdc_current); } /* * Looks for a directory entry in the directory represented by node. * 'cnp' describes the name of the entry to look for. Note that the . * and .. components are not allowed as they do not physically exist * within directories. * * Returns a pointer to the entry when found, otherwise NULL. */ struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, struct componentname *cnp) { struct tmpfs_dir_duphead *duphead; struct tmpfs_dirent *de; uint32_t hash; MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && cnp->cn_nameptr[1] == '.'))); TMPFS_VALIDATE_DIR(node); hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen); de = tmpfs_dir_xlookup_hash(node, hash); if (de != NULL && tmpfs_dirent_duphead(de)) { duphead = &de->ud.td_duphead; LIST_FOREACH(de, duphead, uh.td_dup.entries) { if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, cnp->cn_namelen)) break; } } else if (de != NULL) { if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, cnp->cn_namelen)) de = NULL; } if (de != NULL && f != NULL && de->td_node != f) de = NULL; return (de); } /* * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex * list, allocate new cookie value. */ static void tmpfs_dir_attach_dup(struct tmpfs_node *dnode, struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde) { struct tmpfs_dir_duphead *dupindex; struct tmpfs_dirent *de, *pde; dupindex = &dnode->tn_dir.tn_dupindex; de = LIST_FIRST(dupindex); if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) { if (de == NULL) nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; else nde->td_cookie = de->td_cookie + 1; MPASS(tmpfs_dirent_dup(nde)); LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); return; } /* * Cookie numbers are near exhaustion. Scan dupindex list for unused * numbers. dupindex list is sorted in descending order. Keep it so * after inserting nde. */ while (1) { pde = de; de = LIST_NEXT(de, uh.td_dup.index_entries); if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) { /* * Last element of the index doesn't have minimal cookie * value, use it. */ nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries); LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); return; } else if (de == NULL) { /* * We are so lucky have 2^30 hash duplicates in single * directory :) Return largest possible cookie value. * It should be fine except possible issues with * VOP_READDIR restart. */ nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX; LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); return; } if (de->td_cookie + 1 == pde->td_cookie || de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX) continue; /* No hole or invalid cookie. */ nde->td_cookie = de->td_cookie + 1; MPASS(tmpfs_dirent_dup(nde)); MPASS(pde->td_cookie > nde->td_cookie); MPASS(nde->td_cookie > de->td_cookie); LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries); LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); return; } } /* * Attaches the directory entry de to the directory represented by vp. * Note that this does not change the link count of the node pointed by * the directory entry, as this is done by tmpfs_alloc_dirent. */ void tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) { struct tmpfs_node *dnode; struct tmpfs_dirent *xde, *nde; ASSERT_VOP_ELOCKED(vp, __func__); MPASS(de->td_namelen > 0); MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN); MPASS(de->td_cookie == de->td_hash); dnode = VP_TO_TMPFS_DIR(vp); dnode->tn_dir.tn_readdir_lastn = 0; dnode->tn_dir.tn_readdir_lastp = NULL; MPASS(!tmpfs_dirent_dup(de)); xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); if (xde != NULL && tmpfs_dirent_duphead(xde)) tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); else if (xde != NULL) { /* * Allocate new duphead. Swap xde with duphead to avoid * adding/removing elements with the same hash. */ MPASS(!tmpfs_dirent_dup(xde)); tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0, &nde); /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */ memcpy(nde, xde, sizeof(*xde)); xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD; LIST_INIT(&xde->ud.td_duphead); xde->td_namelen = 0; xde->td_node = NULL; tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde); tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); } dnode->tn_size += sizeof(struct tmpfs_dirent); dnode->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; dnode->tn_accessed = true; tmpfs_update(vp); } /* * Detaches the directory entry de from the directory represented by vp. * Note that this does not change the link count of the node pointed by * the directory entry, as this is done by tmpfs_free_dirent. */ void tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) { struct tmpfs_mount *tmp; struct tmpfs_dir *head; struct tmpfs_node *dnode; struct tmpfs_dirent *xde; ASSERT_VOP_ELOCKED(vp, __func__); dnode = VP_TO_TMPFS_DIR(vp); head = &dnode->tn_dir.tn_dirhead; dnode->tn_dir.tn_readdir_lastn = 0; dnode->tn_dir.tn_readdir_lastp = NULL; if (tmpfs_dirent_dup(de)) { /* Remove duphead if de was last entry. */ if (LIST_NEXT(de, uh.td_dup.entries) == NULL) { xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash); MPASS(tmpfs_dirent_duphead(xde)); } else xde = NULL; LIST_REMOVE(de, uh.td_dup.entries); LIST_REMOVE(de, uh.td_dup.index_entries); if (xde != NULL) { if (LIST_EMPTY(&xde->ud.td_duphead)) { RB_REMOVE(tmpfs_dir, head, xde); tmp = VFS_TO_TMPFS(vp->v_mount); MPASS(xde->td_node == NULL); tmpfs_free_dirent(tmp, xde); } } de->td_cookie = de->td_hash; } else RB_REMOVE(tmpfs_dir, head, de); dnode->tn_size -= sizeof(struct tmpfs_dirent); dnode->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; dnode->tn_accessed = true; tmpfs_update(vp); } void tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode) { struct tmpfs_dirent *de, *dde, *nde; RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) { RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); /* Node may already be destroyed. */ de->td_node = NULL; if (tmpfs_dirent_duphead(de)) { while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) { LIST_REMOVE(dde, uh.td_dup.entries); dde->td_node = NULL; tmpfs_free_dirent(tmp, dde); } } tmpfs_free_dirent(tmp, de); } } /* * Helper function for tmpfs_readdir. Creates a '.' entry for the given * directory and returns it in the uio space. The function returns 0 * on success, -1 if there was not enough space in the uio structure to * hold the directory entry or an appropriate error code if another * error happens. */ static int tmpfs_dir_getdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node, struct uio *uio) { int error; struct dirent dent; TMPFS_VALIDATE_DIR(node); MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); dent.d_fileno = node->tn_id; dent.d_off = TMPFS_DIRCOOKIE_DOTDOT; dent.d_type = DT_DIR; dent.d_namlen = 1; dent.d_name[0] = '.'; dent.d_reclen = GENERIC_DIRSIZ(&dent); dirent_terminate(&dent); if (dent.d_reclen > uio->uio_resid) error = EJUSTRETURN; else error = uiomove(&dent, dent.d_reclen, uio); tmpfs_set_accessed(tm, node); return (error); } /* * Helper function for tmpfs_readdir. Creates a '..' entry for the given * directory and returns it in the uio space. The function returns 0 * on success, -1 if there was not enough space in the uio structure to * hold the directory entry or an appropriate error code if another * error happens. */ static int tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node, struct uio *uio, off_t next) { struct tmpfs_node *parent; struct dirent dent; int error; TMPFS_VALIDATE_DIR(node); MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); /* * Return ENOENT if the current node is already removed. */ TMPFS_ASSERT_LOCKED(node); parent = node->tn_dir.tn_parent; if (parent == NULL) return (ENOENT); TMPFS_NODE_LOCK(parent); dent.d_fileno = parent->tn_id; TMPFS_NODE_UNLOCK(parent); dent.d_off = next; dent.d_type = DT_DIR; dent.d_namlen = 2; dent.d_name[0] = '.'; dent.d_name[1] = '.'; dent.d_reclen = GENERIC_DIRSIZ(&dent); dirent_terminate(&dent); if (dent.d_reclen > uio->uio_resid) error = EJUSTRETURN; else error = uiomove(&dent, dent.d_reclen, uio); tmpfs_set_accessed(tm, node); return (error); } /* * Helper function for tmpfs_readdir. Returns as much directory entries * as can fit in the uio space. The read starts at uio->uio_offset. * The function returns 0 on success, -1 if there was not enough space * in the uio structure to hold the directory entry or an appropriate * error code if another error happens. */ int tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node, struct uio *uio, int maxcookies, u_long *cookies, int *ncookies) { struct tmpfs_dir_cursor dc; struct tmpfs_dirent *de, *nde; off_t off; int error; TMPFS_VALIDATE_DIR(node); off = 0; /* * Lookup the node from the current offset. The starting offset of * 0 will lookup both '.' and '..', and then the first real entry, * or EOF if there are none. Then find all entries for the dir that * fit into the buffer. Once no more entries are found (de == NULL), * the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next * call to return 0. */ switch (uio->uio_offset) { case TMPFS_DIRCOOKIE_DOT: error = tmpfs_dir_getdotdent(tm, node, uio); if (error != 0) return (error); uio->uio_offset = off = TMPFS_DIRCOOKIE_DOTDOT; if (cookies != NULL) cookies[(*ncookies)++] = off; /* FALLTHROUGH */ case TMPFS_DIRCOOKIE_DOTDOT: de = tmpfs_dir_first(node, &dc); off = tmpfs_dirent_cookie(de); error = tmpfs_dir_getdotdotdent(tm, node, uio, off); if (error != 0) return (error); uio->uio_offset = off; if (cookies != NULL) cookies[(*ncookies)++] = off; /* EOF. */ if (de == NULL) return (0); break; case TMPFS_DIRCOOKIE_EOF: return (0); default: de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc); if (de == NULL) return (EINVAL); if (cookies != NULL) off = tmpfs_dirent_cookie(de); } /* * Read as much entries as possible; i.e., until we reach the end of the * directory or we exhaust uio space. */ do { struct dirent d; /* * Create a dirent structure representing the current tmpfs_node * and fill it. */ if (de->td_node == NULL) { d.d_fileno = 1; d.d_type = DT_WHT; } else { d.d_fileno = de->td_node->tn_id; switch (de->td_node->tn_type) { case VBLK: d.d_type = DT_BLK; break; case VCHR: d.d_type = DT_CHR; break; case VDIR: d.d_type = DT_DIR; break; case VFIFO: d.d_type = DT_FIFO; break; case VLNK: d.d_type = DT_LNK; break; case VREG: d.d_type = DT_REG; break; case VSOCK: d.d_type = DT_SOCK; break; default: panic("tmpfs_dir_getdents: type %p %d", de->td_node, (int)de->td_node->tn_type); } } d.d_namlen = de->td_namelen; MPASS(de->td_namelen < sizeof(d.d_name)); (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen); d.d_reclen = GENERIC_DIRSIZ(&d); /* * Stop reading if the directory entry we are treating is bigger * than the amount of data that can be returned. */ if (d.d_reclen > uio->uio_resid) { error = EJUSTRETURN; break; } nde = tmpfs_dir_next(node, &dc); d.d_off = tmpfs_dirent_cookie(nde); dirent_terminate(&d); /* * Copy the new dirent structure into the output buffer and * advance pointers. */ error = uiomove(&d, d.d_reclen, uio); if (error == 0) { de = nde; if (cookies != NULL) { off = tmpfs_dirent_cookie(de); MPASS(*ncookies < maxcookies); cookies[(*ncookies)++] = off; } } } while (error == 0 && uio->uio_resid > 0 && de != NULL); /* Skip setting off when using cookies as it is already done above. */ if (cookies == NULL) off = tmpfs_dirent_cookie(de); /* Update the offset and cache. */ uio->uio_offset = off; node->tn_dir.tn_readdir_lastn = off; node->tn_dir.tn_readdir_lastp = de; tmpfs_set_accessed(tm, node); return (error); } int tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) { struct tmpfs_dirent *de; int error; error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, cnp->cn_nameptr, cnp->cn_namelen, &de); if (error != 0) return (error); tmpfs_dir_attach(dvp, de); return (0); } void tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) { struct tmpfs_dirent *de; de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); MPASS(de != NULL && de->td_node == NULL); tmpfs_dir_detach(dvp, de); tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de); } /* * Resizes the aobj associated with the regular file pointed to by 'vp' to the * size 'newsize'. 'vp' must point to a vnode that represents a regular file. * 'newsize' must be positive. * * Returns zero on success or an appropriate error code on failure. */ 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_page_t m; vm_pindex_t idx, newpages, oldpages; off_t oldsize; int base, rv; MPASS(vp->v_type == VREG); MPASS(newsize >= 0); 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 * store them. It may happen that we do not need to do anything * because the last allocated page can accommodate the change on * its own. */ oldsize = node->tn_size; oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); MPASS(oldpages == uobj->size); newpages = OFF_TO_IDX(newsize + PAGE_MASK); if (__predict_true(newpages == oldpages && newsize >= oldsize)) { node->tn_size = newsize; return (0); } if (newpages > oldpages && tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) return (ENOSPC); VM_OBJECT_WLOCK(uobj); if (newsize < oldsize) { /* * Zero the truncated part of the last page. */ base = newsize & PAGE_MASK; if (base != 0) { idx = OFF_TO_IDX(newsize); retry: m = vm_page_grab(uobj, idx, VM_ALLOC_NOCREAT); if (m != NULL) { MPASS(vm_page_all_valid(m)); } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL | VM_ALLOC_WAITFAIL); if (m == NULL) goto retry; vm_object_pip_add(uobj, 1); VM_OBJECT_WUNLOCK(uobj); rv = vm_pager_get_pages(uobj, &m, 1, NULL, NULL); VM_OBJECT_WLOCK(uobj); vm_object_pip_wakeup(uobj); if (rv == VM_PAGER_OK) { /* * Since the page was not resident, * and therefore not recently * accessed, immediately enqueue it * for asynchronous laundering. The * current operation is not regarded * as an access. */ vm_page_launder(m); } else { vm_page_free(m); if (ignerr) m = NULL; else { VM_OBJECT_WUNLOCK(uobj); return (EIO); } } } if (m != NULL) { pmap_zero_page_area(m, base, PAGE_SIZE - base); vm_page_set_dirty(m); vm_page_xunbusy(m); } } /* * Release any swap space and free any whole pages. */ if (newpages < oldpages) vm_object_page_remove(uobj, newpages, 0, 0); } uobj->size = newpages; VM_OBJECT_WUNLOCK(uobj); atomic_add_long(&tmp->tm_pages_used, newpages - oldpages); node->tn_size = newsize; return (0); } void tmpfs_check_mtime(struct vnode *vp) { struct tmpfs_node *node; struct vm_object *obj; ASSERT_VOP_ELOCKED(vp, "check_mtime"); if (vp->v_type != VREG) return; obj = vp->v_object; KASSERT(obj->type == tmpfs_pager_type && (obj->flags & (OBJ_SWAP | OBJ_TMPFS)) == (OBJ_SWAP | OBJ_TMPFS), ("non-tmpfs obj")); /* unlocked read */ if (obj->generation != obj->cleangeneration) { VM_OBJECT_WLOCK(obj); if (obj->generation != obj->cleangeneration) { obj->cleangeneration = obj->generation; node = VP_TO_TMPFS_NODE(vp); node->tn_status |= TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED; } VM_OBJECT_WUNLOCK(obj); } } /* * Change flags of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; ASSERT_VOP_ELOCKED(vp, "chflags"); node = VP_TO_TMPFS_NODE(vp); if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK | UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP | UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE | UF_SPARSE | UF_SYSTEM)) != 0) return (EOPNOTSUPP); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); /* * Callers may only modify the file flags on objects they * have VADMIN rights for. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * Unprivileged processes are not permitted to unset system * flags, or modify flags if any system flags are set. */ if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS)) { if (node->tn_flags & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { error = securelevel_gt(cred, 0); if (error) return (error); } } else { if (node->tn_flags & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || ((flags ^ node->tn_flags) & SF_SETTABLE)) return (EPERM); } node->tn_flags = flags; node->tn_status |= TMPFS_NODE_CHANGED; ASSERT_VOP_ELOCKED(vp, "chflags2"); return (0); } /* * Change access mode on the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; mode_t newmode; ASSERT_VOP_ELOCKED(vp, "chmod"); ASSERT_VOP_IN_SEQC(vp); node = VP_TO_TMPFS_NODE(vp); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return EPERM; /* * To modify the permissions on a file, must possess VADMIN * for that file. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * Privileged processes may set the sticky bit on non-directories, * as well as set the setgid bit on a file with a group that the * process is not a member of. */ if (vp->v_type != VDIR && (mode & S_ISTXT)) { if (priv_check_cred(cred, PRIV_VFS_STICKYFILE)) return (EFTYPE); } if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { error = priv_check_cred(cred, PRIV_VFS_SETGID); if (error) return (error); } newmode = node->tn_mode & ~ALLPERMS; newmode |= mode & ALLPERMS; atomic_store_short(&node->tn_mode, newmode); node->tn_status |= TMPFS_NODE_CHANGED; ASSERT_VOP_ELOCKED(vp, "chmod2"); return (0); } /* * Change ownership of the given vnode. At least one of uid or gid must * be different than VNOVAL. If one is set to that value, the attribute * is unchanged. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; uid_t ouid; gid_t ogid; mode_t newmode; ASSERT_VOP_ELOCKED(vp, "chown"); ASSERT_VOP_IN_SEQC(vp); node = VP_TO_TMPFS_NODE(vp); /* Assign default values if they are unknown. */ MPASS(uid != VNOVAL || gid != VNOVAL); if (uid == VNOVAL) uid = node->tn_uid; if (gid == VNOVAL) gid = node->tn_gid; MPASS(uid != VNOVAL && gid != VNOVAL); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return (EPERM); /* * To modify the ownership of a file, must possess VADMIN for that * file. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * To change the owner of a file, or change the group of a file to a * group of which we are not a member, the caller must have * privilege. */ if ((uid != node->tn_uid || (gid != node->tn_gid && !groupmember(gid, cred))) && (error = priv_check_cred(cred, PRIV_VFS_CHOWN))) return (error); ogid = node->tn_gid; ouid = node->tn_uid; node->tn_uid = uid; node->tn_gid = gid; node->tn_status |= TMPFS_NODE_CHANGED; if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID)) { newmode = node->tn_mode & ~(S_ISUID | S_ISGID); atomic_store_short(&node->tn_mode, newmode); } } ASSERT_VOP_ELOCKED(vp, "chown2"); return (0); } /* * Change size of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; ASSERT_VOP_ELOCKED(vp, "chsize"); node = VP_TO_TMPFS_NODE(vp); /* Decide whether this is a valid operation based on the file type. */ error = 0; switch (vp->v_type) { case VDIR: return (EISDIR); case VREG: if (vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); break; case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VFIFO: /* * Allow modifications of special files even if in the file * system is mounted read-only (we are not modifying the * files themselves, but the objects they represent). */ return (0); default: /* Anything else is unsupported. */ return (EOPNOTSUPP); } /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return (EPERM); error = tmpfs_truncate(vp, size); /* * tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents * for us, as will update tn_status; no need to do that here. */ ASSERT_VOP_ELOCKED(vp, "chsize2"); return (error); } /* * Change access and modification times of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chtimes(struct vnode *vp, struct vattr *vap, struct ucred *cred, struct thread *l) { int error; struct tmpfs_node *node; ASSERT_VOP_ELOCKED(vp, "chtimes"); node = VP_TO_TMPFS_NODE(vp); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return (EROFS); /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return (EPERM); error = vn_utimes_perm(vp, vap, cred, l); if (error != 0) return (error); if (vap->va_atime.tv_sec != VNOVAL) node->tn_accessed = true; if (vap->va_mtime.tv_sec != VNOVAL) node->tn_status |= TMPFS_NODE_MODIFIED; if (vap->va_birthtime.tv_sec != VNOVAL) node->tn_status |= TMPFS_NODE_MODIFIED; tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime); if (vap->va_birthtime.tv_sec != VNOVAL) node->tn_birthtime = vap->va_birthtime; ASSERT_VOP_ELOCKED(vp, "chtimes2"); return (0); } void tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node, int status) { if ((node->tn_status & status) == status || tm->tm_ronly) return; TMPFS_NODE_LOCK(node); node->tn_status |= status; TMPFS_NODE_UNLOCK(node); } void tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node) { if (node->tn_accessed || tm->tm_ronly) return; atomic_store_8(&node->tn_accessed, true); } /* Sync timestamps */ void tmpfs_itimes(struct vnode *vp, const struct timespec *acc, const struct timespec *mod) { struct tmpfs_node *node; struct timespec now; ASSERT_VOP_LOCKED(vp, "tmpfs_itimes"); node = VP_TO_TMPFS_NODE(vp); if (!node->tn_accessed && (node->tn_status & (TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED)) == 0) return; vfs_timestamp(&now); TMPFS_NODE_LOCK(node); if (node->tn_accessed) { if (acc == NULL) acc = &now; node->tn_atime = *acc; } if (node->tn_status & TMPFS_NODE_MODIFIED) { if (mod == NULL) mod = &now; node->tn_mtime = *mod; } if (node->tn_status & TMPFS_NODE_CHANGED) node->tn_ctime = now; node->tn_status &= ~(TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); node->tn_accessed = false; TMPFS_NODE_UNLOCK(node); /* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */ random_harvest_queue(node, sizeof(*node), RANDOM_FS_ATIME); } int tmpfs_truncate(struct vnode *vp, off_t length) { int error; struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); if (length < 0) { error = EINVAL; goto out; } if (node->tn_size == length) { error = 0; goto out; } if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) return (EFBIG); error = tmpfs_reg_resize(vp, length, FALSE); if (error == 0) node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; out: tmpfs_update(vp); return (error); } static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b) { if (a->td_hash > b->td_hash) return (1); else if (a->td_hash < b->td_hash) return (-1); return (0); } RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); diff --git a/sys/fs/tmpfs/tmpfs_vfsops.c b/sys/fs/tmpfs/tmpfs_vfsops.c index 4f29b5dfc6f0..7dffb9027946 100644 --- a/sys/fs/tmpfs/tmpfs_vfsops.c +++ b/sys/fs/tmpfs/tmpfs_vfsops.c @@ -1,695 +1,698 @@ /* $NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos Exp $ */ /*- * SPDX-License-Identifier: BSD-2-Clause-NetBSD * * Copyright (c) 2005 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Julio M. Merino Vidal, developed as part of Google's Summer of Code * 2005 program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Efficient memory file system. * * tmpfs is a file system that uses FreeBSD's virtual memory * sub-system to store file data and metadata in an efficient way. * This means that it does not follow the structure of an on-disk file * system because it simply does not need to. Instead, it uses * memory-specific data structures and algorithms to automatically * allocate and release resources. */ #include "opt_tmpfs.h" #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Default permission for root node */ #define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) static MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names"); static int tmpfs_mount(struct mount *); static int tmpfs_unmount(struct mount *, int); static int tmpfs_root(struct mount *, int flags, struct vnode **); static int tmpfs_fhtovp(struct mount *, struct fid *, int, struct vnode **); static int tmpfs_statfs(struct mount *, struct statfs *); static const char *tmpfs_opts[] = { "from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export", "union", "nonc", "nomtime", NULL }; static const char *tmpfs_updateopts[] = { "from", "export", "nomtime", "size", NULL }; -/* - * 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 basically OBJT_SWAP. If lazy, only handle - * delayed update of mtime due to the writes to mapped files. - */ +static int +tmpfs_update_mtime_lazy_filter(struct vnode *vp, void *arg) +{ + struct vm_object *obj; + + if (vp->v_type != VREG) + return (0); + + obj = atomic_load_ptr(&vp->v_object); + if (obj == NULL) + return (0); + + return (vm_object_mightbedirty_(obj)); +} + static void -tmpfs_update_mtime(struct mount *mp, bool lazy) +tmpfs_update_mtime_lazy(struct mount *mp) +{ + struct vnode *vp, *mvp; + + MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, tmpfs_update_mtime_lazy_filter, NULL) { + if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) + continue; + tmpfs_check_mtime(vp); + vput(vp); + } +} + +static void +tmpfs_update_mtime_all(struct mount *mp) { struct vnode *vp, *mvp; - struct vm_object *obj; if (VFS_TO_TMPFS(mp)->tm_nomtime) return; MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { if (vp->v_type != VREG) { VI_UNLOCK(vp); continue; } - obj = vp->v_object; - MPASS(obj->type == tmpfs_pager_type); - MPASS((obj->flags & OBJ_TMPFS) != 0); - - /* - * In lazy case, do unlocked read, avoid taking vnode - * lock if not needed. Lost update will be handled on - * the next call. - * For non-lazy case, we must flush all pending - * metadata changes now. - */ - if (!lazy || obj->generation != obj->cleangeneration) { - if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) - continue; - tmpfs_check_mtime(vp); - if (!lazy) - tmpfs_update(vp); - vput(vp); - } else { - VI_UNLOCK(vp); + if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) continue; - } + tmpfs_check_mtime(vp); + tmpfs_update(vp); + vput(vp); } } struct tmpfs_check_rw_maps_arg { bool found; }; static bool tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused, vm_map_entry_t entry __unused, void *arg) { struct tmpfs_check_rw_maps_arg *a; a = arg; a->found = true; return (true); } /* * Revoke write permissions from all mappings of regular files * belonging to the specified tmpfs mount. */ static bool tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map, vm_map_entry_t entry, void *arg __unused) { /* * XXXKIB: might be invalidate the mapping * instead ? The process is not going to be * happy in any case. */ entry->max_protection &= ~VM_PROT_WRITE; if ((entry->protection & VM_PROT_WRITE) != 0) { entry->protection &= ~VM_PROT_WRITE; pmap_protect(map->pmap, entry->start, entry->end, entry->protection); } return (false); } static void tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t, vm_map_entry_t, void *), void *cb_arg) { struct proc *p; struct vmspace *vm; vm_map_t map; vm_map_entry_t entry; vm_object_t object; struct vnode *vp; int gen; bool terminate; terminate = false; sx_slock(&allproc_lock); again: gen = allproc_gen; FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC | P_SYSTEM | P_WEXIT)) != 0) { PROC_UNLOCK(p); continue; } vm = vmspace_acquire_ref(p); _PHOLD_LITE(p); PROC_UNLOCK(p); if (vm == NULL) { PRELE(p); continue; } sx_sunlock(&allproc_lock); map = &vm->vm_map; vm_map_lock(map); if (map->busy) vm_map_wait_busy(map); VM_MAP_ENTRY_FOREACH(entry, map) { if ((entry->eflags & (MAP_ENTRY_GUARD | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 || (entry->max_protection & VM_PROT_WRITE) == 0) continue; object = entry->object.vm_object; if (object == NULL || object->type != tmpfs_pager_type) continue; /* * No need to dig into shadow chain, mapping * of the object not at top is readonly. */ VM_OBJECT_RLOCK(object); if (object->type == OBJT_DEAD) { VM_OBJECT_RUNLOCK(object); continue; } MPASS(object->ref_count > 1); if ((object->flags & OBJ_TMPFS) == 0) { VM_OBJECT_RUNLOCK(object); continue; } vp = object->un_pager.swp.swp_tmpfs; if (vp->v_mount != mp) { VM_OBJECT_RUNLOCK(object); continue; } terminate = cb(mp, map, entry, cb_arg); VM_OBJECT_RUNLOCK(object); if (terminate) break; } vm_map_unlock(map); vmspace_free(vm); sx_slock(&allproc_lock); PRELE(p); if (terminate) break; } if (!terminate && gen != allproc_gen) goto again; sx_sunlock(&allproc_lock); } static bool tmpfs_check_rw_maps(struct mount *mp) { struct tmpfs_check_rw_maps_arg ca; ca.found = false; tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca); return (ca.found); } static int tmpfs_rw_to_ro(struct mount *mp) { int error, flags; bool forced; forced = (mp->mnt_flag & MNT_FORCE) != 0; flags = WRITECLOSE | (forced ? FORCECLOSE : 0); if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0) return (error); error = vfs_write_suspend_umnt(mp); if (error != 0) return (error); if (!forced && tmpfs_check_rw_maps(mp)) { error = EBUSY; goto out; } VFS_TO_TMPFS(mp)->tm_ronly = 1; MNT_ILOCK(mp); mp->mnt_flag |= MNT_RDONLY; MNT_IUNLOCK(mp); for (;;) { tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL); - tmpfs_update_mtime(mp, false); + tmpfs_update_mtime_all(mp); error = vflush(mp, 0, flags, curthread); if (error != 0) { VFS_TO_TMPFS(mp)->tm_ronly = 0; MNT_ILOCK(mp); mp->mnt_flag &= ~MNT_RDONLY; MNT_IUNLOCK(mp); goto out; } if (!tmpfs_check_rw_maps(mp)) break; } out: vfs_write_resume(mp, 0); return (error); } static int tmpfs_mount(struct mount *mp) { const size_t nodes_per_page = howmany(PAGE_SIZE, sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node)); struct tmpfs_mount *tmp; struct tmpfs_node *root; int error; bool nomtime, nonc; /* Size counters. */ u_quad_t pages; off_t nodes_max, size_max, maxfilesize; /* Root node attributes. */ uid_t root_uid; gid_t root_gid; mode_t root_mode; struct vattr va; if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts)) return (EINVAL); if (mp->mnt_flag & MNT_UPDATE) { /* Only support update mounts for certain options. */ if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0) return (EOPNOTSUPP); tmp = VFS_TO_TMPFS(mp); if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) { /* * On-the-fly resizing is not supported (yet). We still * need to have "size" listed as "supported", otherwise * trying to update fs that is listed in fstab with size * parameter, say trying to change rw to ro or vice * versa, would cause vfs_filteropt() to bail. */ if (size_max != tmp->tm_size_max) return (EOPNOTSUPP); } if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && !tmp->tm_ronly) { /* RW -> RO */ return (tmpfs_rw_to_ro(mp)); } else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && tmp->tm_ronly) { /* RO -> RW */ tmp->tm_ronly = 0; MNT_ILOCK(mp); mp->mnt_flag &= ~MNT_RDONLY; MNT_IUNLOCK(mp); } tmp->tm_nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, 0) == 0; MNT_ILOCK(mp); if ((mp->mnt_flag & MNT_UNION) == 0) { mp->mnt_kern_flag |= MNTK_FPLOOKUP; } else { mp->mnt_kern_flag &= ~MNTK_FPLOOKUP; } MNT_IUNLOCK(mp); return (0); } vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); VOP_UNLOCK(mp->mnt_vnodecovered); if (error) return (error); if (mp->mnt_cred->cr_ruid != 0 || vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1) root_gid = va.va_gid; if (mp->mnt_cred->cr_ruid != 0 || vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1) root_uid = va.va_uid; if (mp->mnt_cred->cr_ruid != 0 || vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1) root_mode = va.va_mode; if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0) nodes_max = 0; if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0) size_max = 0; if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0) maxfilesize = 0; nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0; nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, NULL) == 0; /* Do not allow mounts if we do not have enough memory to preserve * the minimum reserved pages. */ if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED) return (ENOSPC); /* Get the maximum number of memory pages this file system is * allowed to use, based on the maximum size the user passed in * the mount structure. A value of zero is treated as if the * maximum available space was requested. */ if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE || (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX)) pages = SIZE_MAX; else { size_max = roundup(size_max, PAGE_SIZE); pages = howmany(size_max, PAGE_SIZE); } MPASS(pages > 0); if (nodes_max <= 3) { if (pages < INT_MAX / nodes_per_page) nodes_max = pages * nodes_per_page; else nodes_max = INT_MAX; } if (nodes_max > INT_MAX) nodes_max = INT_MAX; MPASS(nodes_max >= 3); /* Allocate the tmpfs mount structure and fill it. */ tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), M_TMPFSMNT, M_WAITOK | M_ZERO); mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF); tmp->tm_nodes_max = nodes_max; tmp->tm_nodes_inuse = 0; tmp->tm_refcount = 1; tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX; LIST_INIT(&tmp->tm_nodes_used); tmp->tm_size_max = size_max; tmp->tm_pages_max = pages; tmp->tm_pages_used = 0; new_unrhdr64(&tmp->tm_ino_unr, 2); tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0; tmp->tm_nonc = nonc; tmp->tm_nomtime = nomtime; /* Allocate the root node. */ error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid, root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root); if (error != 0 || root == NULL) { free(tmp, M_TMPFSMNT); return (error); } KASSERT(root->tn_id == 2, ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id)); tmp->tm_root = root; MNT_ILOCK(mp); mp->mnt_flag |= MNT_LOCAL; mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED | MNTK_TEXT_REFS | MNTK_NOMSYNC; if (!nonc && (mp->mnt_flag & MNT_UNION) == 0) mp->mnt_kern_flag |= MNTK_FPLOOKUP; MNT_IUNLOCK(mp); mp->mnt_data = tmp; mp->mnt_stat.f_namemax = MAXNAMLEN; vfs_getnewfsid(mp); vfs_mountedfrom(mp, "tmpfs"); return 0; } /* ARGSUSED2 */ static int tmpfs_unmount(struct mount *mp, int mntflags) { struct tmpfs_mount *tmp; struct tmpfs_node *node; int error, flags; flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0; tmp = VFS_TO_TMPFS(mp); /* Stop writers */ error = vfs_write_suspend_umnt(mp); if (error != 0) return (error); /* * At this point, nodes cannot be destroyed by any other * thread because write suspension is started. */ for (;;) { error = vflush(mp, 0, flags, curthread); if (error != 0) { vfs_write_resume(mp, VR_START_WRITE); return (error); } MNT_ILOCK(mp); if (mp->mnt_nvnodelistsize == 0) { MNT_IUNLOCK(mp); break; } MNT_IUNLOCK(mp); if ((mntflags & MNT_FORCE) == 0) { vfs_write_resume(mp, VR_START_WRITE); return (EBUSY); } } TMPFS_LOCK(tmp); while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) { TMPFS_NODE_LOCK(node); if (node->tn_type == VDIR) tmpfs_dir_destroy(tmp, node); if (tmpfs_free_node_locked(tmp, node, true)) TMPFS_LOCK(tmp); else TMPFS_NODE_UNLOCK(node); } mp->mnt_data = NULL; tmpfs_free_tmp(tmp); vfs_write_resume(mp, VR_START_WRITE); MNT_ILOCK(mp); mp->mnt_flag &= ~MNT_LOCAL; MNT_IUNLOCK(mp); return (0); } void tmpfs_free_tmp(struct tmpfs_mount *tmp) { TMPFS_MP_ASSERT_LOCKED(tmp); MPASS(tmp->tm_refcount > 0); tmp->tm_refcount--; if (tmp->tm_refcount > 0) { TMPFS_UNLOCK(tmp); return; } TMPFS_UNLOCK(tmp); mtx_destroy(&tmp->tm_allnode_lock); MPASS(tmp->tm_pages_used == 0); MPASS(tmp->tm_nodes_inuse == 0); free(tmp, M_TMPFSMNT); } static int tmpfs_root(struct mount *mp, int flags, struct vnode **vpp) { int error; error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp); if (error == 0) (*vpp)->v_vflag |= VV_ROOT; return (error); } static int tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp) { struct tmpfs_fid_data tfd; struct tmpfs_mount *tmp; struct tmpfs_node *node; int error; if (fhp->fid_len != sizeof(tfd)) return (EINVAL); /* * Copy from fid_data onto the stack to avoid unaligned pointer use. * See the comment in sys/mount.h on struct fid for details. */ memcpy(&tfd, fhp->fid_data, fhp->fid_len); tmp = VFS_TO_TMPFS(mp); if (tfd.tfd_id >= tmp->tm_nodes_max) return (EINVAL); TMPFS_LOCK(tmp); LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { if (node->tn_id == tfd.tfd_id && node->tn_gen == tfd.tfd_gen) { tmpfs_ref_node(node); break; } } TMPFS_UNLOCK(tmp); if (node != NULL) { error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp); tmpfs_free_node(tmp, node); } else error = EINVAL; return (error); } /* ARGSUSED2 */ static int tmpfs_statfs(struct mount *mp, struct statfs *sbp) { struct tmpfs_mount *tmp; size_t used; tmp = VFS_TO_TMPFS(mp); sbp->f_iosize = PAGE_SIZE; sbp->f_bsize = PAGE_SIZE; used = tmpfs_pages_used(tmp); if (tmp->tm_pages_max != ULONG_MAX) sbp->f_blocks = tmp->tm_pages_max; else sbp->f_blocks = used + tmpfs_mem_avail(); if (sbp->f_blocks <= used) sbp->f_bavail = 0; else sbp->f_bavail = sbp->f_blocks - used; sbp->f_bfree = sbp->f_bavail; used = tmp->tm_nodes_inuse; sbp->f_files = tmp->tm_nodes_max; if (sbp->f_files <= used) sbp->f_ffree = 0; else sbp->f_ffree = sbp->f_files - used; /* sbp->f_owner = tmp->tn_uid; */ return 0; } static int tmpfs_sync(struct mount *mp, int waitfor) { if (waitfor == MNT_SUSPEND) { MNT_ILOCK(mp); mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED; MNT_IUNLOCK(mp); } else if (waitfor == MNT_LAZY) { - tmpfs_update_mtime(mp, true); + tmpfs_update_mtime_lazy(mp); } return (0); } static int tmpfs_init(struct vfsconf *conf) { 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); } static int tmpfs_uninit(struct vfsconf *conf) { tmpfs_subr_uninit(); return (0); } /* * tmpfs vfs operations. */ struct vfsops tmpfs_vfsops = { .vfs_mount = tmpfs_mount, .vfs_unmount = tmpfs_unmount, .vfs_root = vfs_cache_root, .vfs_cachedroot = tmpfs_root, .vfs_statfs = tmpfs_statfs, .vfs_fhtovp = tmpfs_fhtovp, .vfs_sync = tmpfs_sync, .vfs_init = tmpfs_init, .vfs_uninit = tmpfs_uninit, }; VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);