Add UFS writesuspension mechanism, designed to allow userland processes
to modify on-disk metadata for filesystems mounted for write. Reviewed by: kib, mckusick Sponsored by: FreeBSD Foundation
This commit is contained in:
parent
f5d1e6f5a3
commit
1848286ada
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=243245
@ -3578,6 +3578,7 @@ ufs/ffs/ffs_tables.c optional ffs
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ufs/ffs/ffs_vfsops.c optional ffs
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ufs/ffs/ffs_vnops.c optional ffs
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ufs/ffs/ffs_rawread.c optional directio
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ufs/ffs/ffs_suspend.c optional ffs
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ufs/ufs/ufs_acl.c optional ffs
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ufs/ufs/ufs_bmap.c optional ffs
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ufs/ufs/ufs_dirhash.c optional ffs
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@ -79,9 +79,11 @@ int ffs_isfreeblock(struct fs *, u_char *, ufs1_daddr_t);
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void ffs_load_inode(struct buf *, struct inode *, struct fs *, ino_t);
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int ffs_mountroot(void);
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void ffs_oldfscompat_write(struct fs *, struct ufsmount *);
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int ffs_own_mount(const struct mount *mp);
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int ffs_reallocblks(struct vop_reallocblks_args *);
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int ffs_realloccg(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
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ufs2_daddr_t, int, int, int, struct ucred *, struct buf **);
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int ffs_reload(struct mount *, struct thread *, int);
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int ffs_sbupdate(struct ufsmount *, int, int);
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void ffs_setblock(struct fs *, u_char *, ufs1_daddr_t);
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int ffs_snapblkfree(struct fs *, struct vnode *, ufs2_daddr_t, long, ino_t,
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@ -100,6 +102,8 @@ int ffs_valloc(struct vnode *, int, struct ucred *, struct vnode **);
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int ffs_vfree(struct vnode *, ino_t, int);
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vfs_vget_t ffs_vget;
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int ffs_vgetf(struct mount *, ino_t, int, struct vnode **, int);
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void ffs_susp_initialize(void);
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void ffs_susp_uninitialize(void);
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#define FFSV_FORCEINSMQ 0x0001
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338
sys/ufs/ffs/ffs_suspend.c
Normal file
338
sys/ufs/ffs/ffs_suspend.c
Normal file
@ -0,0 +1,338 @@
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/*-
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* Copyright (c) 2012 The FreeBSD Foundation
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* All rights reserved.
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*
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* This software was developed by Edward Tomasz Napierala under sponsorship
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* from the FreeBSD Foundation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/ioccom.h>
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#include <sys/mount.h>
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#include <sys/vnode.h>
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#include <sys/conf.h>
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#include <sys/jail.h>
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#include <sys/sx.h>
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#include <security/mac/mac_framework.h>
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#include <ufs/ufs/extattr.h>
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#include <ufs/ufs/quota.h>
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#include <ufs/ufs/ufsmount.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/ffs/fs.h>
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#include <ufs/ffs/ffs_extern.h>
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static d_open_t ffs_susp_open;
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static d_write_t ffs_susp_rdwr;
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static d_ioctl_t ffs_susp_ioctl;
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static struct cdevsw ffs_susp_cdevsw = {
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.d_version = D_VERSION,
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.d_open = ffs_susp_open,
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.d_read = ffs_susp_rdwr,
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.d_write = ffs_susp_rdwr,
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.d_ioctl = ffs_susp_ioctl,
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.d_name = "ffs_susp",
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};
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static struct cdev *ffs_susp_dev;
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static struct sx ffs_susp_lock;
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static int
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ffs_susp_suspended(struct mount *mp)
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{
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struct ufsmount *ump;
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sx_assert(&ffs_susp_lock, SA_LOCKED);
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ump = VFSTOUFS(mp);
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if (ump->um_writesuspended)
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return (1);
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return (0);
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}
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static int
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ffs_susp_open(struct cdev *dev __unused, int flags __unused,
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int fmt __unused, struct thread *td __unused)
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{
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return (0);
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}
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static int
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ffs_susp_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
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{
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int error, i;
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struct vnode *devvp;
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struct mount *mp;
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struct ufsmount *ump;
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struct buf *bp;
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void *base;
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size_t len;
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ssize_t cnt;
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struct fs *fs;
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sx_slock(&ffs_susp_lock);
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error = devfs_get_cdevpriv((void **)&mp);
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if (error != 0) {
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sx_sunlock(&ffs_susp_lock);
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return (ENXIO);
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}
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ump = VFSTOUFS(mp);
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devvp = ump->um_devvp;
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fs = ump->um_fs;
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if (ffs_susp_suspended(mp) == 0) {
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sx_sunlock(&ffs_susp_lock);
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return (ENXIO);
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}
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KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
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("neither UIO_READ or UIO_WRITE"));
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KASSERT(uio->uio_segflg == UIO_USERSPACE,
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("uio->uio_segflg != UIO_USERSPACE"));
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cnt = uio->uio_resid;
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for (i = 0; i < uio->uio_iovcnt; i++) {
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while (uio->uio_iov[i].iov_len) {
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base = uio->uio_iov[i].iov_base;
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len = uio->uio_iov[i].iov_len;
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if (len > fs->fs_bsize)
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len = fs->fs_bsize;
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if (fragoff(fs, uio->uio_offset) != 0 ||
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fragoff(fs, len) != 0) {
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error = EINVAL;
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goto out;
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}
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error = bread(devvp, btodb(uio->uio_offset), len,
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NOCRED, &bp);
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if (error != 0)
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goto out;
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if (uio->uio_rw == UIO_WRITE) {
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error = copyin(base, bp->b_data, len);
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if (error != 0) {
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bp->b_flags |= B_INVAL | B_NOCACHE;
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brelse(bp);
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goto out;
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}
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error = bwrite(bp);
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if (error != 0)
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goto out;
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} else {
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error = copyout(bp->b_data, base, len);
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brelse(bp);
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if (error != 0)
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goto out;
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}
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uio->uio_iov[i].iov_base =
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(char *)uio->uio_iov[i].iov_base + len;
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uio->uio_iov[i].iov_len -= len;
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uio->uio_resid -= len;
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uio->uio_offset += len;
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}
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}
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out:
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sx_sunlock(&ffs_susp_lock);
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if (uio->uio_resid < cnt)
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return (0);
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return (error);
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}
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static int
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ffs_susp_suspend(struct mount *mp)
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{
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struct fs *fs;
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struct ufsmount *ump;
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int error;
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sx_assert(&ffs_susp_lock, SA_XLOCKED);
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if (!ffs_own_mount(mp))
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return (EINVAL);
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if (ffs_susp_suspended(mp))
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return (EBUSY);
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ump = VFSTOUFS(mp);
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fs = ump->um_fs;
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/*
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* Make sure the calling thread is permitted to access the mounted
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* device. The permissions can change after we unlock the vnode;
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* it's harmless.
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*/
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vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
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error = VOP_ACCESS(ump->um_devvp, VREAD | VWRITE,
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curthread->td_ucred, curthread);
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VOP_UNLOCK(ump->um_devvp, 0);
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if (error != 0)
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return (error);
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#ifdef MAC
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if (mac_mount_check_stat(curthread->td_ucred, mp) != 0)
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return (EPERM);
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#endif
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if ((error = vfs_write_suspend(mp)) != 0)
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return (error);
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ump->um_writesuspended = 1;
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return (0);
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}
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static void
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ffs_susp_dtor(void *data)
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{
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struct fs *fs;
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struct ufsmount *ump;
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struct mount *mp;
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int error;
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sx_xlock(&ffs_susp_lock);
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mp = (struct mount *)data;
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ump = VFSTOUFS(mp);
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fs = ump->um_fs;
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if (ffs_susp_suspended(mp) == 0) {
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sx_xunlock(&ffs_susp_lock);
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return;
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}
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KASSERT((mp->mnt_kern_flag & MNTK_SUSPEND) != 0,
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("MNTK_SUSPEND not set"));
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error = ffs_reload(mp, curthread, 1);
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if (error != 0)
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panic("failed to unsuspend writes on %s", fs->fs_fsmnt);
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/*
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* XXX: The status is kept per-process; the vfs_write_resume() routine
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* asserts that the resuming thread is the same one that called
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* vfs_write_suspend(). The cdevpriv data, however, is attached
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* to the file descriptor, e.g. is inherited during fork. Thus,
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* it's possible that the resuming process will be different from
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* the one that started the suspension.
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*
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* Work around by fooling the check in vfs_write_resume().
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*/
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mp->mnt_susp_owner = curthread;
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vfs_write_resume(mp);
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vfs_unbusy(mp);
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ump->um_writesuspended = 0;
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sx_xunlock(&ffs_susp_lock);
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}
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static int
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ffs_susp_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
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struct thread *td)
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{
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struct mount *mp;
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fsid_t *fsidp;
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int error;
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/*
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* No suspend inside the jail. Allowing it would require making
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* sure that e.g. the devfs ruleset for that jail permits access
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* to the devvp.
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*/
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if (jailed(td->td_ucred))
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return (EPERM);
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sx_xlock(&ffs_susp_lock);
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switch (cmd) {
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case UFSSUSPEND:
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fsidp = (fsid_t *)addr;
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mp = vfs_getvfs(fsidp);
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if (mp == NULL) {
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error = ENOENT;
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break;
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}
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error = vfs_busy(mp, 0);
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vfs_rel(mp);
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if (error != 0)
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break;
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error = ffs_susp_suspend(mp);
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if (error != 0) {
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vfs_unbusy(mp);
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break;
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}
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error = devfs_set_cdevpriv(mp, ffs_susp_dtor);
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KASSERT(error == 0, ("devfs_set_cdevpriv failed"));
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break;
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case UFSRESUME:
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error = devfs_get_cdevpriv((void **)&mp);
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if (error != 0)
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break;
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/*
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* This calls ffs_susp_dtor, which in turn unsuspends the fs.
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* The dtor expects to be called without lock held, because
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* sometimes it's called from here, and sometimes due to the
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* file being closed or process exiting.
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*/
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sx_xunlock(&ffs_susp_lock);
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devfs_clear_cdevpriv();
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return (0);
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default:
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error = ENXIO;
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break;
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}
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sx_xunlock(&ffs_susp_lock);
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return (error);
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}
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void
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ffs_susp_initialize(void)
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{
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sx_init(&ffs_susp_lock, "ffs_susp");
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ffs_susp_dev = make_dev(&ffs_susp_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
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"ufssuspend");
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}
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void
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ffs_susp_uninitialize(void)
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{
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destroy_dev(ffs_susp_dev);
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sx_destroy(&ffs_susp_lock);
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}
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@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$");
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#include <sys/buf.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/ioccom.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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@ -75,7 +76,6 @@ __FBSDID("$FreeBSD$");
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static uma_zone_t uma_inode, uma_ufs1, uma_ufs2;
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static int ffs_reload(struct mount *, struct thread *);
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static int ffs_mountfs(struct vnode *, struct mount *, struct thread *);
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static void ffs_oldfscompat_read(struct fs *, struct ufsmount *,
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ufs2_daddr_t);
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@ -333,7 +333,7 @@ ffs_mount(struct mount *mp)
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vfs_write_resume(mp);
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}
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if ((mp->mnt_flag & MNT_RELOAD) &&
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(error = ffs_reload(mp, td)) != 0)
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(error = ffs_reload(mp, td, 0)) != 0)
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return (error);
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if (fs->fs_ronly &&
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!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
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@ -595,8 +595,8 @@ ffs_cmount(struct mntarg *ma, void *data, uint64_t flags)
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/*
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* Reload all incore data for a filesystem (used after running fsck on
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* the root filesystem and finding things to fix). The filesystem must
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* be mounted read-only.
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* the root filesystem and finding things to fix). If the 'force' flag
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* is 0, the filesystem must be mounted read-only.
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*
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* Things to do to update the mount:
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* 1) invalidate all cached meta-data.
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@ -606,8 +606,8 @@ ffs_cmount(struct mntarg *ma, void *data, uint64_t flags)
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* 5) invalidate all cached file data.
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* 6) re-read inode data for all active vnodes.
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*/
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static int
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ffs_reload(struct mount *mp, struct thread *td)
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int
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ffs_reload(struct mount *mp, struct thread *td, int force)
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{
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struct vnode *vp, *mvp, *devvp;
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struct inode *ip;
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@ -619,9 +619,15 @@ ffs_reload(struct mount *mp, struct thread *td)
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int i, blks, size, error;
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int32_t *lp;
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if ((mp->mnt_flag & MNT_RDONLY) == 0)
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return (EINVAL);
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ump = VFSTOUFS(mp);
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MNT_ILOCK(mp);
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if ((mp->mnt_flag & MNT_RDONLY) == 0 && force == 0) {
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MNT_IUNLOCK(mp);
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return (EINVAL);
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}
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MNT_IUNLOCK(mp);
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/*
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* Step 1: invalidate all cached meta-data.
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*/
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@ -655,8 +661,7 @@ ffs_reload(struct mount *mp, struct thread *td)
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newfs->fs_maxcluster = fs->fs_maxcluster;
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newfs->fs_contigdirs = fs->fs_contigdirs;
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newfs->fs_active = fs->fs_active;
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/* The file system is still read-only. */
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newfs->fs_ronly = 1;
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newfs->fs_ronly = fs->fs_ronly;
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sblockloc = fs->fs_sblockloc;
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bcopy(newfs, fs, (u_int)fs->fs_sbsize);
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brelse(bp);
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@ -710,6 +715,13 @@ ffs_reload(struct mount *mp, struct thread *td)
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loop:
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MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
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/*
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* Skip syncer vnode.
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*/
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if (vp->v_type == VNON) {
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VI_UNLOCK(vp);
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continue;
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}
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/*
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* Step 4: invalidate all cached file data.
|
||||
*/
|
||||
@ -1834,6 +1846,7 @@ ffs_init(vfsp)
|
||||
struct vfsconf *vfsp;
|
||||
{
|
||||
|
||||
ffs_susp_initialize();
|
||||
softdep_initialize();
|
||||
return (ufs_init(vfsp));
|
||||
}
|
||||
@ -1849,6 +1862,7 @@ ffs_uninit(vfsp)
|
||||
|
||||
ret = ufs_uninit(vfsp);
|
||||
softdep_uninitialize();
|
||||
ffs_susp_uninitialize();
|
||||
return (ret);
|
||||
}
|
||||
|
||||
@ -2198,6 +2212,15 @@ ffs_geom_strategy(struct bufobj *bo, struct buf *bp)
|
||||
g_vfs_strategy(bo, bp);
|
||||
}
|
||||
|
||||
int
|
||||
ffs_own_mount(const struct mount *mp)
|
||||
{
|
||||
|
||||
if (mp->mnt_op == &ufs_vfsops)
|
||||
return (1);
|
||||
return (0);
|
||||
}
|
||||
|
||||
#ifdef DDB
|
||||
|
||||
static void
|
||||
|
@ -33,6 +33,8 @@
|
||||
#ifndef _UFS_FFS_FS_H_
|
||||
#define _UFS_FFS_FS_H_
|
||||
|
||||
#include <sys/mount.h>
|
||||
|
||||
/*
|
||||
* Each disk drive contains some number of filesystems.
|
||||
* A filesystem consists of a number of cylinder groups.
|
||||
@ -763,4 +765,10 @@ CTASSERT(sizeof(union jrec) == JREC_SIZE);
|
||||
extern int inside[], around[];
|
||||
extern u_char *fragtbl[];
|
||||
|
||||
/*
|
||||
* IOCTLs used for filesystem write suspension.
|
||||
*/
|
||||
#define UFSSUSPEND _IOW('U', 1, fsid_t)
|
||||
#define UFSRESUME _IO('U', 2)
|
||||
|
||||
#endif
|
||||
|
@ -98,6 +98,7 @@ struct ufsmount {
|
||||
char um_qflags[MAXQUOTAS]; /* quota specific flags */
|
||||
int64_t um_savedmaxfilesize; /* XXX - limit maxfilesize */
|
||||
int um_candelete; /* devvp supports TRIM */
|
||||
int um_writesuspended; /* suspension in progress */
|
||||
int (*um_balloc)(struct vnode *, off_t, int, struct ucred *, int, struct buf **);
|
||||
int (*um_blkatoff)(struct vnode *, off_t, char **, struct buf **);
|
||||
int (*um_truncate)(struct vnode *, off_t, int, struct ucred *);
|
||||
|
Loading…
Reference in New Issue
Block a user