common/syscall/statvfs.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Get file system statistics (statvfs and fstatvfs).
 */

#include <sys/types.h>
#include <sys/inttypes.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/fstyp.h>
#include <sys/systm.h>
#include <sys/vfs.h>
#include <sys/statvfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/pathname.h>

#include <vm/page.h>
#include <fs/fs_subr.h>

#define STATVFSCOPY(dst, src)                   \
    (dst)->f_bsize  = (src)->f_bsize;           \
    (dst)->f_frsize = (src)->f_frsize;          \
    (dst)->f_blocks = (src)->f_blocks;          \
    (dst)->f_bfree  = (src)->f_bfree;           \
    (dst)->f_bavail = (src)->f_bavail;          \
    (dst)->f_files  = (src)->f_files;           \
    (dst)->f_ffree  = (src)->f_ffree;           \
    (dst)->f_favail = (src)->f_favail;          \
    (dst)->f_fsid   = (src)->f_fsid;            \
    bcopy((src)->f_basetype, (dst)->f_basetype,     \
        sizeof ((dst)->f_basetype));            \
    (dst)->f_flag   = (src)->f_flag;            \
    (dst)->f_namemax = (src)->f_namemax;            \
    bcopy((src)->f_fstr, (dst)->f_fstr,         \
        sizeof ((dst)->f_fstr))

/*
 * Common routines for statvfs and fstatvfs.
 */

static int
cstatvfs32(struct vfs *vfsp, struct statvfs32 *ubp)
{
    struct statvfs64 ds64;
    struct statvfs32 ds32;
    int error;

#if !defined(lint)
    ASSERT32(sizeof (struct statvfs) == sizeof (struct statvfs32));
    ASSERT32(sizeof (struct statvfs64) == sizeof (struct statvfs64_32));
#endif

    bzero(&ds64, sizeof (ds64));
    if ((error = VFS_STATVFS(vfsp, &ds64)) != 0)
        return (error);

    /*
     * VFS_STATVFS can return data that is incompatible with the space
     * available the 32-bit statvfs structure.  Check here to see if
     * it will fit into the 32-bit structure, if not, return EOVERFLOW.
     *
     * The check for -1 is because some file systems return -1 in the
     * fields that are irrelevant or nonessential, and we do not want
     * to return EOVERFLOW for them.  For example: df is expected to
     * show -1 in the output for some of these fields on NFS mounted
     * filesystems.
     */
    if (ds64.f_files == (fsfilcnt64_t)-1)
        ds64.f_files = UINT32_MAX;
    if (ds64.f_ffree == (fsfilcnt64_t)-1)
        ds64.f_ffree = UINT32_MAX;
    if (ds64.f_favail == (fsfilcnt64_t)-1)
        ds64.f_favail = UINT32_MAX;
    if (ds64.f_bavail == (fsblkcnt64_t)-1)
        ds64.f_bavail = UINT32_MAX;
    if (ds64.f_bfree == (fsblkcnt64_t)-1)
        ds64.f_bfree = UINT32_MAX;

    if (ds64.f_blocks > UINT32_MAX || ds64.f_bfree > UINT32_MAX ||
        ds64.f_bavail > UINT32_MAX || ds64.f_files > UINT32_MAX ||
        ds64.f_ffree > UINT32_MAX || ds64.f_favail > UINT32_MAX)
        return (EOVERFLOW);
#ifdef _LP64
    /*
     * On the 64-bit kernel, even these fields grow to 64-bit
     * quantities in the statvfs64 structure.
     */
    if (ds64.f_namemax == (ulong_t)-1l)
        ds64.f_namemax = UINT32_MAX;

    if (ds64.f_bsize > UINT32_MAX || ds64.f_frsize > UINT32_MAX ||
        ds64.f_fsid > UINT32_MAX || ds64.f_flag > UINT32_MAX ||
        ds64.f_namemax > UINT32_MAX)
        return (EOVERFLOW);
#endif

    bzero(&ds32, sizeof (ds32));
    STATVFSCOPY(&ds32, &ds64);
    if (copyout(&ds32, ubp, sizeof (ds32)) != 0)
        return (EFAULT);
    return (0);
}

static int
cstatvfs64(struct vfs *vfsp, struct statvfs64 *ubp)
{
    struct statvfs64 ds64;
    int error;

#if !defined(lint)
    ASSERT64(sizeof (struct statvfs) == sizeof (struct statvfs64));
#endif
    bzero(&ds64, sizeof (ds64));
    if ((error = VFS_STATVFS(vfsp, &ds64)) != 0)
        return (error);
    if (copyout(&ds64, ubp, sizeof (ds64)) != 0)
        return (EFAULT);
    return (0);
}

/*
 * Native system calls
 */
int
statvfs(char *fname, struct statvfs *sbp)
{
    vnode_t *vp;
    int error;
    int estale_retry = 0;

lookup:
    if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
#ifdef _LP64
    error = cstatvfs64(vp->v_vfsp, (struct statvfs64 *)sbp);
#else
    error = cstatvfs32(vp->v_vfsp, (struct statvfs32 *)sbp);
#endif
    VN_RELE(vp);
    if (error) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    return (0);
}

int
fstatvfs(int fdes, struct statvfs *sbp)
{
    struct file *fp;
    int error;

    if ((fp = getf(fdes)) == NULL)
        return (set_errno(EBADF));
#ifdef _LP64
    error = cstatvfs64(fp->f_vnode->v_vfsp, (struct statvfs64 *)sbp);
#else
    error = cstatvfs32(fp->f_vnode->v_vfsp, (struct statvfs32 *)sbp);
#endif
    releasef(fdes);
    if (error)
        return (set_errno(error));
    return (0);
}

#if defined(_ILP32)

/*
 * Large File system calls.
 *
 * (We deliberately don't have special "large file" system calls in the
 * 64-bit kernel -- we just use the native versions, since they're just
 * as functional.)
 */
int
statvfs64(char *fname, struct statvfs64 *sbp)
{
    vnode_t *vp;
    int error;
    int estale_retry = 0;

lookup:
    if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    error = cstatvfs64(vp->v_vfsp, sbp);
    VN_RELE(vp);
    if (error) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    return (0);
}

int
fstatvfs64(int fdes, struct statvfs64 *sbp)
{
    struct file *fp;
    int error;

    if ((fp = getf(fdes)) == NULL)
        return (set_errno(EBADF));
    error = cstatvfs64(fp->f_vnode->v_vfsp, sbp);
    releasef(fdes);
    if (error)
        return (set_errno(error));
    return (0);
}

#endif  /* _ILP32 */

#ifdef _SYSCALL32_IMPL

static int
cstatvfs64_32(struct vfs *vfsp, struct statvfs64_32 *ubp)
{
    struct statvfs64 ds64;
    struct statvfs64_32 ds64_32;
    int error;

    bzero(&ds64, sizeof (ds64));
    if ((error = VFS_STATVFS(vfsp, &ds64)) != 0)
        return (error);

    /*
     * On the 64-bit kernel, even these fields grow to 64-bit
     * quantities in the statvfs64 structure.
     */
    if (ds64.f_namemax == (ulong_t)-1l)
        ds64.f_namemax = UINT32_MAX;

    if (ds64.f_bsize > UINT32_MAX || ds64.f_frsize > UINT32_MAX ||
        ds64.f_fsid > UINT32_MAX || ds64.f_flag > UINT32_MAX ||
        ds64.f_namemax > UINT32_MAX)
        return (EOVERFLOW);

    STATVFSCOPY(&ds64_32, &ds64);
    if (copyout(&ds64_32, ubp, sizeof (ds64_32)) != 0)
        return (EFAULT);
    return (0);
}

/*
 * ILP32 "small file" system calls on LP64 kernel
 */
int
statvfs32(char *fname, struct statvfs32 *sbp)
{
    vnode_t *vp;
    int error;
    int estale_retry = 0;

lookup:
    if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    error = cstatvfs32(vp->v_vfsp, sbp);
    VN_RELE(vp);
    if (error) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    return (0);
}

int
fstatvfs32(int fdes, struct statvfs32 *sbp)
{
    struct file *fp;
    int error;

    if ((fp = getf(fdes)) == NULL)
        return (set_errno(EBADF));
    error = cstatvfs32(fp->f_vnode->v_vfsp, sbp);
    releasef(fdes);
    if (error)
        return (set_errno(error));
    return (0);
}

/*
 * ILP32 Large File system calls on LP64 kernel
 */
int
statvfs64_32(char *fname, struct statvfs64_32 *sbp)
{
    vnode_t *vp;
    int error;
    int estale_retry = 0;

lookup:
    if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    error = cstatvfs64_32(vp->v_vfsp, sbp);
    VN_RELE(vp);
    if (error) {
        if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
            goto lookup;
        return (set_errno(error));
    }
    return (0);
}

int
fstatvfs64_32(int fdes, struct statvfs64_32 *sbp)
{
    struct file *fp;
    int error;

    if ((fp = getf(fdes)) == NULL)
        return (set_errno(EBADF));
    error = cstatvfs64_32(fp->f_vnode->v_vfsp, sbp);
    releasef(fdes);
    if (error)
        return (set_errno(error));
    return (0);
}

#endif  /* _SYSCALL32_IMPL */