/* $NetBSD: tmpfs.h,v 1.26 2007/02/22 06:37:00 thorpej Exp $ */ /*- * 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: src/sys/fs/tmpfs/tmpfs.h,v 1.18 2009/10/11 07:03:56 delphij Exp $ */ #ifndef _VFS_TMPFS_TMPFS_H_ #define _VFS_TMPFS_TMPFS_H_ /* --------------------------------------------------------------------- * KERNEL-SPECIFIC DEFINITIONS * --------------------------------------------------------------------- */ #include <sys/dirent.h> #include <sys/mount.h> #include <sys/tree.h> #include <sys/vnode.h> #include <sys/file.h> #include <sys/lock.h> #include <sys/lockf.h> #include <sys/mutex.h> /* --------------------------------------------------------------------- */ #include <sys/malloc.h> #ifdef _KERNEL #include <sys/systm.h> #endif #include <sys/vmmeter.h> #include <vm/swap_pager.h> #ifdef MALLOC_DECLARE MALLOC_DECLARE(M_TMPFSMNT); #endif /* --------------------------------------------------------------------- */ /* * Internal representation of a tmpfs directory entry. */ struct tmpfs_dirent { RB_ENTRY(tmpfs_dirent) rb_node; RB_ENTRY(tmpfs_dirent) rb_cookienode; /* Length of the name stored in this directory entry. This avoids * the need to recalculate it every time the name is used. */ uint16_t td_namelen; /* The name of the entry, allocated from a string pool. This * string is not required to be zero-terminated; therefore, the * td_namelen field must always be used when accessing its value. */ char *td_name; /* Pointer to the node this entry refers to. */ struct tmpfs_node *td_node; }; struct tmpfs_dirtree; RB_HEAD(tmpfs_dirtree, tmpfs_dirent); RB_PROTOTYPE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare); RB_HEAD(tmpfs_dirtree_cookie, tmpfs_dirent); RB_PROTOTYPE(tmpfs_dirtree_cookie, tmpfs_dirent, rb_cookienode, tmpfs_dirtree_cookie_compare); /* * A directory in tmpfs holds a set of directory entries, which in * turn point to other files (which can be directories themselves). * * In tmpfs, this set is managed by a red-black tree, whose root is defined * by the struct tmpfs_dirtree 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. * * 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. (Emulating * a real offset could be very difficult.) * * 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 memory address on which * stores their information is stored. * * DragonFly binaries use 64-bit cookies. We mask-off the signed bit to * ensure that cookie 'offsets' are positive. */ #ifdef _KERNEL #define TMPFS_ROOTINO ((ino_t)2) #define TMPFS_DIRCOOKIE_DOT 0 #define TMPFS_DIRCOOKIE_DOTDOT 1 #define TMPFS_DIRCOOKIE_EOF ((off_t)0x7FFFFFFFFFFFFFFFLLU) static __inline off_t tmpfs_dircookie(struct tmpfs_dirent *de) { return ((off_t)((uintptr_t)de >> 1) & 0x7FFFFFFFFFFFFFFFLLU); } /* * WARNING! Caller should never try to actually access a tmpfs dirent * structure from a cookiedir() conversion. It is used strictly * for RBTREE operations. */ static __inline void * tmpfs_cookiedir(off_t off) { return ((void *)((uintptr_t)off << 1)); } #endif /* _KERNEL */ /* --------------------------------------------------------------------- */ /* * 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. */ 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. */ LIST_ENTRY(tmpfs_node) tn_entries; /* 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; /* Node identifier. */ ino_t tn_id; /* Node's internal status. This is used by several file system * operations to do modifications to the node in a delayed * fashion. */ int tn_blksize; /* small file optimization */ int tn_status; #define TMPFS_NODE_ACCESSED (1 << 1) #define TMPFS_NODE_MODIFIED (1 << 2) #define TMPFS_NODE_CHANGED (1 << 3) /* The node size. It does not necessarily match the real amount * of memory consumed by it. */ off_t tn_size; /* Generic node attributes. */ uid_t tn_uid; gid_t tn_gid; mode_t tn_mode; u_int tn_flags; nlink_t tn_links; /* atomic ops req */ long tn_atime; long tn_atimensec; long tn_mtime; long tn_mtimensec; long tn_ctime; long tn_ctimensec; unsigned long tn_gen; struct lockf tn_advlock; /* 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; /* interlock to protect structure */ struct lock tn_interlock; /* * tmpfs vnode state, may specify an allocation in-progress. */ int tn_vpstate; /* misc data field for different tn_type node */ union { /* Valid when tn_type == VBLK || tn_type == VCHR. */ dev_t tn_rdev; /*int32_t ?*/ /* 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; /* * Directory entries are indexed by name and also * indexed by cookie. */ struct tmpfs_dirtree tn_dirtree; struct tmpfs_dirtree_cookie tn_cookietree; } tn_dir; /* Valid when tn_type == VLNK. */ /* The link's target, allocated from a string pool. */ char * tn_link; /* * Valid when tn_type == VREG. * * aobj is used as backing store for the vnode object. It * typically only contains swap assignments, but we also use * it to save the vnode object's vm_page's when the vnode * becomes inactive. */ struct tn_reg { vm_object_t tn_aobj; size_t tn_aobj_pages; int tn_pages_in_aobj; } tn_reg; /* Valid when tn_type = VFIFO */ struct tn_fifo { int (*tn_fo_read) (struct file *fp, struct uio *uio, struct ucred *cred, int flags); int (*tn_fo_write) (struct file *fp, struct uio *uio, struct ucred *cred, int flags); } tn_fifo; } tn_spec; }; /* Only userspace needs this */ #define VTOI(vp) ((struct tmpfs_node *)(vp)->v_data) #ifdef _KERNEL LIST_HEAD(tmpfs_node_list, tmpfs_node); #define tn_rdev tn_spec.tn_rdev #define tn_dir tn_spec.tn_dir #define tn_link tn_spec.tn_link #define tn_reg tn_spec.tn_reg #define tn_fifo tn_spec.tn_fifo #define TMPFS_NODE_LOCK(node) lockmgr(&(node)->tn_interlock, LK_EXCLUSIVE|LK_RETRY) #define TMPFS_NODE_LOCK_SH(node) lockmgr(&(node)->tn_interlock, LK_SHARED|LK_RETRY) #define TMPFS_NODE_UNLOCK(node) lockmgr(&(node)->tn_interlock, LK_RELEASE) #define TMPFS_NODE_MTX(node) (&(node)->tn_interlock) #ifdef INVARIANTS #define TMPFS_ASSERT_LOCKED(node) do { \ KKASSERT(node != NULL); \ KKASSERT(node->tn_vnode != NULL); \ if (!vn_islocked(node->tn_vnode) && \ (lockstatus(TMPFS_NODE_MTX(node), curthread) == LK_EXCLUSIVE )) \ panic("tmpfs: node is not locked: %p", node); \ } while (0) #define TMPFS_ASSERT_ELOCKED(node) do { \ KKASSERT((node) != NULL); \ KKASSERT(lockstatus(TMPFS_NODE_MTX(node), curthread) == LK_EXCLUSIVE); \ } while (0) #else #define TMPFS_ASSERT_LOCKED(node) (void)0 #define TMPFS_ASSERT_ELOCKED(node) (void)0 #endif /* INVARIANTS */ #define TMPFS_VNODE_DOOMED 0x0001 /* --------------------------------------------------------------------- */ /* * Internal representation of a tmpfs mount point. */ struct tmpfs_mount { struct mount *tm_mount; /* 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 SIZE_MAX * value. Instead, use the TMPFS_PAGES_MAX macro. */ long tm_pages_max; /* Number of pages in use by the file system. Cannot be bigger * than the value returned by TMPFS_PAGES_MAX in any case. */ 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; /* Number of nodes currently that are in use. */ ino_t tm_nodes_inuse; /* maximum representable file size */ u_int64_t tm_maxfilesize; /* Nodes are organized in two different lists. The used list * contains all nodes that are currently used by the file system; * i.e., they refer to existing files. The available list contains * all nodes that are currently available for use by new files. * Nodes must be kept in this list (instead of deleting them) * because we need to keep track of their generation number (tn_gen * field). * * Note that nodes are lazily allocated: if the available list is * empty and we have enough space to create more nodes, they will be * created and inserted in the used list. Once these are released, * they will go into the available list, remaining alive until the * file system is unmounted. */ struct tmpfs_node_list tm_nodes_used; /* Per-mount malloc zones for tmpfs nodes, names, and dirents */ struct malloc_type *tm_node_zone_obj; struct malloc_type *tm_dirent_zone_obj; struct malloc_type *tm_name_zone; ino_t tm_ino; int tm_flags; struct netexport tm_export; struct mount *tm_mnt; }; #define TMPFS_LOCK(tm) lwkt_gettoken(&(tm)->tm_mount->mnt_token) #define TMPFS_UNLOCK(tm) lwkt_reltoken(&(tm)->tm_mount->mnt_token) /* --------------------------------------------------------------------- */ /* * This structure maps a file identifier to a tmpfs node. Used by the * NFS code. */ struct tmpfs_fid { uint16_t tf_len; uint16_t tf_pad; ino_t tf_id; unsigned long tf_gen; } __packed; /* --------------------------------------------------------------------- */ /* * Prototypes for tmpfs_subr.c. */ int tmpfs_alloc_node(struct tmpfs_mount *, enum vtype, uid_t uid, gid_t gid, mode_t mode, char *, int, int, struct tmpfs_node **); void tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *); int tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *, const char *, uint16_t, struct tmpfs_dirent **); void tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *); int tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, struct tmpfs_node *, int, struct vnode **); int tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *, struct namecache *, struct ucred *, char *); void tmpfs_dir_attach_locked(struct tmpfs_node *, struct tmpfs_dirent *); void tmpfs_dir_detach_locked(struct tmpfs_node *, struct tmpfs_dirent *); struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, struct namecache *ncp); int tmpfs_dir_getdotdent(struct tmpfs_node *, struct uio *); int tmpfs_dir_getdotdotdent(struct tmpfs_mount *, struct tmpfs_node *, struct uio *); struct tmpfs_dirent * tmpfs_dir_lookupbycookie(struct tmpfs_node *, off_t, int); int tmpfs_dir_getdents(struct tmpfs_node *, struct uio *, off_t *); int tmpfs_reg_resize(struct vnode *, off_t, int); int tmpfs_chflags(struct vnode *, u_long, struct ucred *); int tmpfs_chmod(struct vnode *, mode_t, struct ucred *); int tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *); int tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *); int tmpfs_chtimes(struct vnode *, struct timespec *, struct timespec *, int, struct ucred *); void tmpfs_itimes(struct vnode *, const struct timespec *, const struct timespec *); void tmpfs_node_init(struct tmpfs_node *node); void tmpfs_node_uninit(struct tmpfs_node *node); void tmpfs_update(struct vnode *); int tmpfs_truncate(struct vnode *, off_t); void tmpfs_lock4(struct tmpfs_node *node1, struct tmpfs_node *node2, struct tmpfs_node *node3, struct tmpfs_node *node4); void tmpfs_unlock4(struct tmpfs_node *node1, struct tmpfs_node *node2, struct tmpfs_node *node3, struct tmpfs_node *node4); /* --------------------------------------------------------------------- */ /* * 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 == (uint16_t)len && \ bcmp((de)->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 { \ KKASSERT((node)->tn_type == VDIR); \ KKASSERT((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \ } while(0) /* --------------------------------------------------------------------- */ /* * Macros/functions to convert from generic data structures to tmpfs * specific ones. Kernel code use VP_TO_TMPFS_NODE() instead of VTOI(). */ static inline struct tmpfs_mount * VFS_TO_TMPFS(struct mount *mp) { struct tmpfs_mount *tmp; KKASSERT((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; KKASSERT((vp) != NULL && (vp)->v_data != NULL); node = (struct tmpfs_node *)vp->v_data; return node; } 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; } /* --------------------------------------------------------------------- */ /* * buffer cache size */ #define TMPFS_BLKSIZE 16384 /* buffer cache size*/ #define TMPFS_BLKMASK (TMPFS_BLKSIZE - 1) #define TMPFS_BLKMASK64 ((off_t)(TMPFS_BLKSIZE - 1)) #endif /* _KERNEL */ #endif /* _VFS_TMPFS_TMPFS_H_ */
