90e87c8eb5
- Use vrefcnt().
1740 lines
49 KiB
C
1740 lines
49 KiB
C
/*
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* Copyright 2000 Marshall Kirk McKusick. All Rights Reserved.
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*
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* Further information about snapshots can be obtained from:
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*
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* Marshall Kirk McKusick http://www.mckusick.com/softdep/
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* 1614 Oxford Street mckusick@mckusick.com
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* Berkeley, CA 94709-1608 +1-510-843-9542
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* USA
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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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*
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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 MARSHALL KIRK MCKUSICK ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL MARSHALL KIRK MCKUSICK BE LIABLE FOR
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* 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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* @(#)ffs_snapshot.c 8.11 (McKusick) 7/23/00
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/stdint.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/bio.h>
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#include <sys/buf.h>
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#include <sys/proc.h>
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#include <sys/namei.h>
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#include <sys/stat.h>
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#include <sys/malloc.h>
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#include <sys/mount.h>
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#include <sys/resource.h>
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#include <sys/resourcevar.h>
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#include <sys/vnode.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/ufs/ufs_extern.h>
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#include <ufs/ffs/fs.h>
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#include <ufs/ffs/ffs_extern.h>
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#define KERNCRED thread0.td_ucred
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#define DEBUG 1
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static int cgaccount(int, struct vnode *, struct buf *, int);
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static int expunge_ufs1(struct vnode *, struct inode *, struct fs *,
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int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *,
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ufs_lbn_t, int), int);
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static int indiracct_ufs1(struct vnode *, struct vnode *, int,
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ufs1_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *,
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int (*)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *, struct fs *,
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ufs_lbn_t, int), int);
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static int fullacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int snapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int mapacct_ufs1(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int expunge_ufs2(struct vnode *, struct inode *, struct fs *,
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int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *,
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ufs_lbn_t, int), int);
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static int indiracct_ufs2(struct vnode *, struct vnode *, int,
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ufs2_daddr_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, ufs_lbn_t, struct fs *,
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int (*)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *, struct fs *,
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ufs_lbn_t, int), int);
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static int fullacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int snapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int mapacct_ufs2(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
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struct fs *, ufs_lbn_t, int);
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static int ffs_copyonwrite(struct vnode *, struct buf *);
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static int readblock(struct buf *, ufs2_daddr_t);
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/*
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* To ensure the consistency of snapshots across crashes, we must
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* synchronously write out copied blocks before allowing the
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* originals to be modified. Because of the rather severe speed
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* penalty that this imposes, the following flag allows this
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* crash persistence to be disabled.
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*/
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int dopersistence = 0;
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#ifdef DEBUG
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#include <sys/sysctl.h>
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SYSCTL_INT(_debug, OID_AUTO, dopersistence, CTLFLAG_RW, &dopersistence, 0, "");
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int snapdebug = 0;
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SYSCTL_INT(_debug, OID_AUTO, snapdebug, CTLFLAG_RW, &snapdebug, 0, "");
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int collectsnapstats = 0;
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SYSCTL_INT(_debug, OID_AUTO, collectsnapstats, CTLFLAG_RW, &collectsnapstats,
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0, "");
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#endif /* DEBUG */
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/*
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* Create a snapshot file and initialize it for the filesystem.
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*/
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int
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ffs_snapshot(mp, snapfile)
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struct mount *mp;
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char *snapfile;
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{
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ufs2_daddr_t numblks, blkno;
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int error, cg, snaploc;
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int i, size, len, loc;
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int flag = mp->mnt_flag;
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struct timespec starttime = {0, 0}, endtime;
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char saved_nice = 0;
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long redo = 0;
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int32_t *lp;
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void *space;
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struct fs *copy_fs = NULL, *fs = VFSTOUFS(mp)->um_fs;
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struct snaphead *snaphead;
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struct thread *td = curthread;
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struct inode *ip, *xp;
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struct buf *bp, *nbp, *ibp, *sbp = NULL;
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struct nameidata nd;
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struct mount *wrtmp;
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struct vattr vat;
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struct vnode *vp, *xvp, *nvp;
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/*
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* Need to serialize access to snapshot code per filesystem.
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*/
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/*
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* Assign a snapshot slot in the superblock.
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*/
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for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
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if (fs->fs_snapinum[snaploc] == 0)
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break;
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if (snaploc == FSMAXSNAP)
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return (ENOSPC);
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/*
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* Create the snapshot file.
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*/
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restart:
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NDINIT(&nd, CREATE, LOCKPARENT | LOCKLEAF, UIO_USERSPACE, snapfile, td);
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if ((error = namei(&nd)) != 0)
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return (error);
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if (nd.ni_vp != NULL) {
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vput(nd.ni_vp);
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error = EEXIST;
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}
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if (nd.ni_dvp->v_mount != mp)
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error = EXDEV;
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if (error) {
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NDFREE(&nd, NDF_ONLY_PNBUF);
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if (nd.ni_dvp == nd.ni_vp)
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vrele(nd.ni_dvp);
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else
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vput(nd.ni_dvp);
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return (error);
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}
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VATTR_NULL(&vat);
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vat.va_type = VREG;
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vat.va_mode = S_IRUSR;
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vat.va_vaflags |= VA_EXCLUSIVE;
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if (VOP_GETWRITEMOUNT(nd.ni_dvp, &wrtmp))
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wrtmp = NULL;
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if (wrtmp != mp)
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panic("ffs_snapshot: mount mismatch");
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if (vn_start_write(NULL, &wrtmp, V_NOWAIT) != 0) {
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vput(nd.ni_dvp);
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if ((error = vn_start_write(NULL, &wrtmp,
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V_XSLEEP | PCATCH)) != 0)
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return (error);
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goto restart;
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}
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VOP_LEASE(nd.ni_dvp, td, KERNCRED, LEASE_WRITE);
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error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vat);
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vput(nd.ni_dvp);
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if (error) {
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NDFREE(&nd, NDF_ONLY_PNBUF);
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vn_finished_write(wrtmp);
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return (error);
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}
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vp = nd.ni_vp;
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ip = VTOI(vp);
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/*
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* Allocate and copy the last block contents so as to be able
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* to set size to that of the filesystem.
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*/
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numblks = howmany(fs->fs_size, fs->fs_frag);
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error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(numblks - 1)),
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fs->fs_bsize, KERNCRED, BA_CLRBUF, &bp);
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if (error)
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goto out;
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ip->i_size = lblktosize(fs, (off_t)numblks);
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DIP(ip, i_size) = ip->i_size;
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ip->i_flag |= IN_CHANGE | IN_UPDATE;
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if ((error = readblock(bp, numblks - 1)) != 0)
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goto out;
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bawrite(bp);
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/*
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* Preallocate critical data structures so that we can copy
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* them in without further allocation after we suspend all
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* operations on the filesystem. We would like to just release
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* the allocated buffers without writing them since they will
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* be filled in below once we are ready to go, but this upsets
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* the soft update code, so we go ahead and write the new buffers.
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*
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* Allocate all indirect blocks and mark all of them as not
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* needing to be copied.
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*/
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for (blkno = NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
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error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
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fs->fs_bsize, td->td_ucred, BA_METAONLY, &ibp);
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if (error)
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goto out;
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bdwrite(ibp);
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}
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/*
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* Allocate copies for the superblock and its summary information.
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*/
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error = UFS_BALLOC(vp, lfragtosize(fs, fs->fs_sblockloc),
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fs->fs_sbsize, KERNCRED, 0, &nbp);
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if (error)
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goto out;
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bawrite(nbp);
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blkno = fragstoblks(fs, fs->fs_csaddr);
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len = howmany(fs->fs_cssize, fs->fs_bsize);
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for (loc = 0; loc < len; loc++) {
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error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(blkno + loc)),
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fs->fs_bsize, KERNCRED, 0, &nbp);
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if (error)
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goto out;
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bawrite(nbp);
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}
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/*
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* Allocate all cylinder group blocks.
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*/
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for (cg = 0; cg < fs->fs_ncg; cg++) {
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error = UFS_BALLOC(vp, (off_t)(cgtod(fs, cg)) << fs->fs_fshift,
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fs->fs_bsize, KERNCRED, 0, &nbp);
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if (error)
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goto out;
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bdwrite(nbp);
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}
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/*
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* Copy all the cylinder group maps. Although the
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* filesystem is still active, we hope that only a few
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* cylinder groups will change between now and when we
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* suspend operations. Thus, we will be able to quickly
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* touch up the few cylinder groups that changed during
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* the suspension period.
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*/
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len = howmany(fs->fs_ncg, NBBY);
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MALLOC(fs->fs_active, int *, len, M_DEVBUF, M_WAITOK);
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bzero(fs->fs_active, len);
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for (cg = 0; cg < fs->fs_ncg; cg++) {
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error = bread(vp, fragstoblks(fs, cgtod(fs, cg)), fs->fs_bsize,
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KERNCRED, &nbp);
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if (error) {
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brelse(nbp);
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goto out;
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}
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error = cgaccount(cg, vp, nbp, 1);
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bawrite(nbp);
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if (error)
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goto out;
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}
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/*
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* Change inode to snapshot type file.
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*/
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ip->i_flags |= SF_SNAPSHOT;
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DIP(ip, i_flags) = ip->i_flags;
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ip->i_flag |= IN_CHANGE | IN_UPDATE;
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/*
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* Ensure that the snapshot is completely on disk.
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*/
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if ((error = VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td)) != 0)
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goto out;
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/*
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* All allocations are done, so we can now snapshot the system.
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*
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* Recind nice scheduling while running with the filesystem suspended.
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*/
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if (td->td_ksegrp->kg_nice > 0) {
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saved_nice = td->td_ksegrp->kg_nice;
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td->td_ksegrp->kg_nice = 0;
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}
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/*
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* Suspend operation on filesystem.
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*/
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for (;;) {
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vn_finished_write(wrtmp);
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vfs_write_suspend(vp->v_mount);
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if (mp->mnt_kern_flag & MNTK_SUSPENDED)
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break;
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vn_start_write(NULL, &wrtmp, V_WAIT);
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}
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if (collectsnapstats)
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nanotime(&starttime);
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/*
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* First, copy all the cylinder group maps that have changed.
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*/
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for (cg = 0; cg < fs->fs_ncg; cg++) {
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if ((ACTIVECGNUM(fs, cg) & ACTIVECGOFF(cg)) != 0)
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continue;
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redo++;
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error = bread(vp, fragstoblks(fs, cgtod(fs, cg)), fs->fs_bsize,
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KERNCRED, &nbp);
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if (error) {
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brelse(nbp);
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goto out1;
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}
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error = cgaccount(cg, vp, nbp, 2);
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bawrite(nbp);
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if (error)
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goto out1;
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}
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/*
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* Grab a copy of the superblock and its summary information.
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* We delay writing it until the suspension is released below.
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*/
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error = bread(vp, fragstoblks(fs, fs->fs_sblockloc), fs->fs_bsize,
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KERNCRED, &sbp);
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if (error) {
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brelse(sbp);
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sbp = NULL;
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goto out1;
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}
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loc = blkoff(fs, lfragtosize(fs, fs->fs_sblockloc));
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copy_fs = (struct fs *)(sbp->b_data + loc);
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bcopy(fs, copy_fs, fs->fs_sbsize);
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if ((fs->fs_flags & (FS_UNCLEAN | FS_NEEDSFSCK)) == 0)
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copy_fs->fs_clean = 1;
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if (fs->fs_sbsize < SBLOCKSIZE)
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bzero(&sbp->b_data[loc + fs->fs_sbsize],
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SBLOCKSIZE - fs->fs_sbsize);
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size = blkroundup(fs, fs->fs_cssize);
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if (fs->fs_contigsumsize > 0)
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size += fs->fs_ncg * sizeof(int32_t);
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space = malloc((u_long)size, M_UFSMNT, M_WAITOK);
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copy_fs->fs_csp = space;
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bcopy(fs->fs_csp, copy_fs->fs_csp, fs->fs_cssize);
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(char *)space += fs->fs_cssize;
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loc = howmany(fs->fs_cssize, fs->fs_fsize);
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i = fs->fs_frag - loc % fs->fs_frag;
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len = (i == fs->fs_frag) ? 0 : i * fs->fs_fsize;
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if (len > 0) {
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if ((error = bread(ip->i_devvp,
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fsbtodb(fs, fs->fs_csaddr + loc),
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len, KERNCRED, &bp)) != 0) {
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brelse(bp);
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free(copy_fs->fs_csp, M_UFSMNT);
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bawrite(sbp);
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sbp = NULL;
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goto out1;
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}
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bcopy(bp->b_data, space, (u_int)len);
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(char *)space += len;
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bp->b_flags |= B_INVAL | B_NOCACHE;
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brelse(bp);
|
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}
|
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if (fs->fs_contigsumsize > 0) {
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copy_fs->fs_maxcluster = lp = space;
|
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for (i = 0; i < fs->fs_ncg; i++)
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*lp++ = fs->fs_contigsumsize;
|
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}
|
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/*
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* We must check for active files that have been unlinked
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* (e.g., with a zero link count). We have to expunge all
|
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* trace of these files from the snapshot so that they are
|
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* not reclaimed prematurely by fsck or unnecessarily dumped.
|
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* We turn off the MNTK_SUSPENDED flag to avoid a panic from
|
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* spec_strategy about writing on a suspended filesystem.
|
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*/
|
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mp->mnt_kern_flag &= ~MNTK_SUSPENDED;
|
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mtx_lock(&mntvnode_mtx);
|
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loop:
|
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for (xvp = TAILQ_FIRST(&mp->mnt_nvnodelist); xvp; xvp = nvp) {
|
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/*
|
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* Make sure this vnode wasn't reclaimed in getnewvnode().
|
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* Start over if it has (it won't be on the list anymore).
|
|
*/
|
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if (xvp->v_mount != mp)
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goto loop;
|
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nvp = TAILQ_NEXT(xvp, v_nmntvnodes);
|
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mtx_unlock(&mntvnode_mtx);
|
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mp_fixme("Unlocked GETATTR.");
|
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if (vrefcnt(xvp) == 0 || xvp->v_type == VNON ||
|
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(VOP_GETATTR(xvp, &vat, td->td_proc->p_ucred, td) == 0 &&
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vat.va_nlink > 0)) {
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mtx_lock(&mntvnode_mtx);
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continue;
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}
|
|
if (snapdebug)
|
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vprint("ffs_snapshot: busy vnode", xvp);
|
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if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK, td) != 0)
|
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goto loop;
|
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xp = VTOI(xvp);
|
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/*
|
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* If there is a fragment, clear it here.
|
|
*/
|
|
blkno = 0;
|
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loc = howmany(xp->i_size, fs->fs_bsize) - 1;
|
|
if (loc < NDADDR) {
|
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len = fragroundup(fs, blkoff(fs, xp->i_size));
|
|
if (len < fs->fs_bsize) {
|
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ffs_blkfree(copy_fs, vp, DIP(xp, i_db[loc]),
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len, xp->i_number);
|
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blkno = DIP(xp, i_db[loc]);
|
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DIP(xp, i_db[loc]) = 0;
|
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}
|
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}
|
|
if (xp->i_ump->um_fstype == UFS1)
|
|
error = expunge_ufs1(vp, xp, copy_fs, fullacct_ufs1,
|
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BLK_NOCOPY);
|
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else
|
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error = expunge_ufs2(vp, xp, copy_fs, fullacct_ufs2,
|
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BLK_NOCOPY);
|
|
if (blkno)
|
|
DIP(xp, i_db[loc]) = blkno;
|
|
if (!error)
|
|
error = ffs_freefile(copy_fs, vp, xp->i_number,
|
|
xp->i_mode);
|
|
VOP_UNLOCK(xvp, 0, td);
|
|
if (error) {
|
|
free(copy_fs->fs_csp, M_UFSMNT);
|
|
bawrite(sbp);
|
|
sbp = NULL;
|
|
goto out1;
|
|
}
|
|
mtx_lock(&mntvnode_mtx);
|
|
}
|
|
mtx_unlock(&mntvnode_mtx);
|
|
/*
|
|
* Record snapshot inode. Since this is the newest snapshot,
|
|
* it must be placed at the end of the list.
|
|
*/
|
|
fs->fs_snapinum[snaploc] = ip->i_number;
|
|
if (ip->i_nextsnap.tqe_prev != 0)
|
|
panic("ffs_snapshot: %d already on list", ip->i_number);
|
|
snaphead = &ip->i_devvp->v_rdev->si_snapshots;
|
|
TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
|
|
|
|
ASSERT_VOP_LOCKED(ip->i_devvp, "ffs_snapshot devvp");
|
|
ip->i_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
|
|
ip->i_devvp->v_vflag |= VV_COPYONWRITE;
|
|
ASSERT_VOP_LOCKED(vp, "ffs_snapshot vp");
|
|
vp->v_vflag |= VV_SYSTEM;
|
|
out1:
|
|
/*
|
|
* Resume operation on filesystem.
|
|
*/
|
|
vfs_write_resume(vp->v_mount);
|
|
if (saved_nice > 0)
|
|
td->td_ksegrp->kg_nice = saved_nice;
|
|
vn_start_write(NULL, &wrtmp, V_WAIT);
|
|
if (collectsnapstats && starttime.tv_sec > 0) {
|
|
nanotime(&endtime);
|
|
timespecsub(&endtime, &starttime);
|
|
printf("%s: suspended %d.%03ld sec, redo %ld of %d\n",
|
|
vp->v_mount->mnt_stat.f_mntonname, endtime.tv_sec,
|
|
endtime.tv_nsec / 1000000, redo, fs->fs_ncg);
|
|
}
|
|
if (sbp == NULL)
|
|
goto out;
|
|
/*
|
|
* Copy allocation information from all the snapshots in
|
|
* this snapshot and then expunge them from its view.
|
|
*/
|
|
snaphead = &ip->i_devvp->v_rdev->si_snapshots;
|
|
TAILQ_FOREACH(xp, snaphead, i_nextsnap) {
|
|
if (xp == ip)
|
|
break;
|
|
if (xp->i_ump->um_fstype == UFS1)
|
|
error = expunge_ufs1(vp, xp, fs, snapacct_ufs1,
|
|
BLK_SNAP);
|
|
else
|
|
error = expunge_ufs2(vp, xp, fs, snapacct_ufs2,
|
|
BLK_SNAP);
|
|
if (error) {
|
|
fs->fs_snapinum[snaploc] = 0;
|
|
goto done;
|
|
}
|
|
}
|
|
/*
|
|
* Expunge the blocks used by the snapshots from the set of
|
|
* blocks marked as used in the snapshot bitmaps.
|
|
*/
|
|
if (ip->i_ump->um_fstype == UFS1)
|
|
error = expunge_ufs1(vp, ip, copy_fs, mapacct_ufs1, BLK_SNAP);
|
|
else
|
|
error = expunge_ufs2(vp, ip, copy_fs, mapacct_ufs2, BLK_SNAP);
|
|
if (error) {
|
|
fs->fs_snapinum[snaploc] = 0;
|
|
goto done;
|
|
}
|
|
/*
|
|
* Write the superblock and its summary information
|
|
* to the snapshot.
|
|
*/
|
|
blkno = fragstoblks(fs, fs->fs_csaddr);
|
|
len = howmany(fs->fs_cssize, fs->fs_bsize);
|
|
space = copy_fs->fs_csp;
|
|
for (loc = 0; loc < len; loc++) {
|
|
error = bread(vp, blkno + loc, fs->fs_bsize, KERNCRED, &nbp);
|
|
if (error) {
|
|
brelse(nbp);
|
|
fs->fs_snapinum[snaploc] = 0;
|
|
goto done;
|
|
}
|
|
bcopy(space, nbp->b_data, fs->fs_bsize);
|
|
space = (char *)space + fs->fs_bsize;
|
|
bawrite(nbp);
|
|
}
|
|
done:
|
|
free(copy_fs->fs_csp, M_UFSMNT);
|
|
bawrite(sbp);
|
|
out:
|
|
if (fs->fs_active != 0) {
|
|
FREE(fs->fs_active, M_DEVBUF);
|
|
fs->fs_active = 0;
|
|
}
|
|
mp->mnt_flag = flag;
|
|
if (error)
|
|
(void) UFS_TRUNCATE(vp, (off_t)0, 0, NOCRED, td);
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
if (error)
|
|
vput(vp);
|
|
else
|
|
VOP_UNLOCK(vp, 0, td);
|
|
vn_finished_write(wrtmp);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Copy a cylinder group map. All the unallocated blocks are marked
|
|
* BLK_NOCOPY so that the snapshot knows that it need not copy them
|
|
* if they are later written. If passno is one, then this is a first
|
|
* pass, so only setting needs to be done. If passno is 2, then this
|
|
* is a revision to a previous pass which must be undone as the
|
|
* replacement pass is done.
|
|
*/
|
|
static int
|
|
cgaccount(cg, vp, nbp, passno)
|
|
int cg;
|
|
struct vnode *vp;
|
|
struct buf *nbp;
|
|
int passno;
|
|
{
|
|
struct buf *bp, *ibp;
|
|
struct inode *ip;
|
|
struct cg *cgp;
|
|
struct fs *fs;
|
|
ufs2_daddr_t base, numblks;
|
|
int error, len, loc, indiroff;
|
|
|
|
ip = VTOI(vp);
|
|
fs = ip->i_fs;
|
|
error = bread(ip->i_devvp, fsbtodb(fs, cgtod(fs, cg)),
|
|
(int)fs->fs_cgsize, KERNCRED, &bp);
|
|
if (error) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
cgp = (struct cg *)bp->b_data;
|
|
if (!cg_chkmagic(cgp)) {
|
|
brelse(bp);
|
|
return (EIO);
|
|
}
|
|
atomic_set_int(&ACTIVECGNUM(fs, cg), ACTIVECGOFF(cg));
|
|
bcopy(bp->b_data, nbp->b_data, fs->fs_cgsize);
|
|
if (fs->fs_cgsize < fs->fs_bsize)
|
|
bzero(&nbp->b_data[fs->fs_cgsize],
|
|
fs->fs_bsize - fs->fs_cgsize);
|
|
if (passno == 2)
|
|
nbp->b_flags |= B_VALIDSUSPWRT;
|
|
numblks = howmany(fs->fs_size, fs->fs_frag);
|
|
len = howmany(fs->fs_fpg, fs->fs_frag);
|
|
base = cg * fs->fs_fpg / fs->fs_frag;
|
|
if (base + len >= numblks)
|
|
len = numblks - base - 1;
|
|
loc = 0;
|
|
if (base < NDADDR) {
|
|
for ( ; loc < NDADDR; loc++) {
|
|
if (ffs_isblock(fs, cg_blksfree(cgp), loc))
|
|
DIP(ip, i_db[loc]) = BLK_NOCOPY;
|
|
else if (passno == 2 && DIP(ip, i_db[loc])== BLK_NOCOPY)
|
|
DIP(ip, i_db[loc]) = 0;
|
|
else if (passno == 1 && DIP(ip, i_db[loc])== BLK_NOCOPY)
|
|
panic("ffs_snapshot: lost direct block");
|
|
}
|
|
}
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)(base + loc)),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
if (error) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
indiroff = (base + loc - NDADDR) % NINDIR(fs);
|
|
for ( ; loc < len; loc++, indiroff++) {
|
|
if (indiroff >= NINDIR(fs)) {
|
|
if (passno == 2)
|
|
ibp->b_flags |= B_VALIDSUSPWRT;
|
|
bawrite(ibp);
|
|
error = UFS_BALLOC(vp,
|
|
lblktosize(fs, (off_t)(base + loc)),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
if (error) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
indiroff = 0;
|
|
}
|
|
if (ip->i_ump->um_fstype == UFS1) {
|
|
if (ffs_isblock(fs, cg_blksfree(cgp), loc))
|
|
((ufs1_daddr_t *)(ibp->b_data))[indiroff] =
|
|
BLK_NOCOPY;
|
|
else if (passno == 2 && ((ufs1_daddr_t *)(ibp->b_data))
|
|
[indiroff] == BLK_NOCOPY)
|
|
((ufs1_daddr_t *)(ibp->b_data))[indiroff] = 0;
|
|
else if (passno == 1 && ((ufs1_daddr_t *)(ibp->b_data))
|
|
[indiroff] == BLK_NOCOPY)
|
|
panic("ffs_snapshot: lost indirect block");
|
|
continue;
|
|
}
|
|
if (ffs_isblock(fs, cg_blksfree(cgp), loc))
|
|
((ufs2_daddr_t *)(ibp->b_data))[indiroff] = BLK_NOCOPY;
|
|
else if (passno == 2 &&
|
|
((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY)
|
|
((ufs2_daddr_t *)(ibp->b_data))[indiroff] = 0;
|
|
else if (passno == 1 &&
|
|
((ufs2_daddr_t *)(ibp->b_data)) [indiroff] == BLK_NOCOPY)
|
|
panic("ffs_snapshot: lost indirect block");
|
|
}
|
|
bqrelse(bp);
|
|
if (passno == 2)
|
|
ibp->b_flags |= B_VALIDSUSPWRT;
|
|
bdwrite(ibp);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Before expunging a snapshot inode, note all the
|
|
* blocks that it claims with BLK_SNAP so that fsck will
|
|
* be able to account for those blocks properly and so
|
|
* that this snapshot knows that it need not copy them
|
|
* if the other snapshot holding them is freed. This code
|
|
* is reproduced once each for UFS1 and UFS2.
|
|
*/
|
|
static int
|
|
expunge_ufs1(snapvp, cancelip, fs, acctfunc, expungetype)
|
|
struct vnode *snapvp;
|
|
struct inode *cancelip;
|
|
struct fs *fs;
|
|
int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
|
|
struct fs *, ufs_lbn_t, int);
|
|
int expungetype;
|
|
{
|
|
int i, error, indiroff;
|
|
ufs_lbn_t lbn, rlbn;
|
|
ufs2_daddr_t len, blkno, numblks, blksperindir;
|
|
struct ufs1_dinode *dip;
|
|
struct thread *td = curthread;
|
|
struct buf *bp;
|
|
|
|
numblks = howmany(cancelip->i_size, fs->fs_bsize);
|
|
if ((error = (*acctfunc)(snapvp, &cancelip->i_din1->di_db[0],
|
|
&cancelip->i_din1->di_ib[NIADDR], fs, 0, expungetype)))
|
|
return (error);
|
|
blksperindir = 1;
|
|
lbn = -NDADDR;
|
|
len = numblks - NDADDR;
|
|
rlbn = NDADDR;
|
|
for (i = 0; len > 0 && i < NIADDR; i++) {
|
|
error = indiracct_ufs1(snapvp, ITOV(cancelip), i,
|
|
cancelip->i_din1->di_ib[i], lbn, rlbn, len,
|
|
blksperindir, fs, acctfunc, expungetype);
|
|
if (error)
|
|
return (error);
|
|
blksperindir *= NINDIR(fs);
|
|
lbn -= blksperindir + 1;
|
|
len -= blksperindir;
|
|
rlbn += blksperindir;
|
|
}
|
|
/*
|
|
* Prepare to expunge the inode. If its inode block has not
|
|
* yet been copied, then allocate and fill the copy.
|
|
*/
|
|
lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number));
|
|
blkno = 0;
|
|
if (lbn < NDADDR) {
|
|
blkno = cancelip->i_din1->di_db[lbn];
|
|
} else {
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &bp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
if (error)
|
|
return (error);
|
|
indiroff = (lbn - NDADDR) % NINDIR(fs);
|
|
blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff];
|
|
bqrelse(bp);
|
|
}
|
|
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, 0, &bp);
|
|
if (error)
|
|
return (error);
|
|
if (blkno == 0 && (error = readblock(bp, lbn)))
|
|
return (error);
|
|
/*
|
|
* Set a snapshot inode to be a zero length file, regular files
|
|
* to be completely unallocated.
|
|
*/
|
|
dip = (struct ufs1_dinode *)bp->b_data +
|
|
ino_to_fsbo(fs, cancelip->i_number);
|
|
if (expungetype == BLK_NOCOPY)
|
|
dip->di_mode = 0;
|
|
dip->di_size = 0;
|
|
dip->di_blocks = 0;
|
|
dip->di_flags &= ~SF_SNAPSHOT;
|
|
bzero(&dip->di_db[0], (NDADDR + NIADDR) * sizeof(ufs1_daddr_t));
|
|
bdwrite(bp);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Descend an indirect block chain for vnode cancelvp accounting for all
|
|
* its indirect blocks in snapvp.
|
|
*/
|
|
static int
|
|
indiracct_ufs1(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks,
|
|
blksperindir, fs, acctfunc, expungetype)
|
|
struct vnode *snapvp;
|
|
struct vnode *cancelvp;
|
|
int level;
|
|
ufs1_daddr_t blkno;
|
|
ufs_lbn_t lbn;
|
|
ufs_lbn_t rlbn;
|
|
ufs_lbn_t remblks;
|
|
ufs_lbn_t blksperindir;
|
|
struct fs *fs;
|
|
int (*acctfunc)(struct vnode *, ufs1_daddr_t *, ufs1_daddr_t *,
|
|
struct fs *, ufs_lbn_t, int);
|
|
int expungetype;
|
|
{
|
|
int error, num, i;
|
|
ufs_lbn_t subblksperindir;
|
|
struct indir indirs[NIADDR + 2];
|
|
ufs1_daddr_t last, *bap;
|
|
struct buf *bp;
|
|
|
|
if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0)
|
|
return (error);
|
|
if (lbn != indirs[num - 1 - level].in_lbn || blkno == 0 || num < 2)
|
|
panic("indiracct: botched params");
|
|
/*
|
|
* We have to expand bread here since it will deadlock looking
|
|
* up the block number for any blocks that are not in the cache.
|
|
*/
|
|
bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0);
|
|
bp->b_blkno = fsbtodb(fs, blkno);
|
|
if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 &&
|
|
(error = readblock(bp, fragstoblks(fs, blkno)))) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
/*
|
|
* Account for the block pointers in this indirect block.
|
|
*/
|
|
last = howmany(remblks, blksperindir);
|
|
if (last > NINDIR(fs))
|
|
last = NINDIR(fs);
|
|
MALLOC(bap, ufs1_daddr_t *, fs->fs_bsize, M_DEVBUF, M_WAITOK);
|
|
bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize);
|
|
bqrelse(bp);
|
|
error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, rlbn, expungetype);
|
|
if (error || level == 0)
|
|
goto out;
|
|
/*
|
|
* Account for the block pointers in each of the indirect blocks
|
|
* in the levels below us.
|
|
*/
|
|
subblksperindir = blksperindir / NINDIR(fs);
|
|
for (lbn++, level--, i = 0; i < last; i++) {
|
|
error = indiracct_ufs1(snapvp, cancelvp, level, bap[i], lbn,
|
|
rlbn, remblks, subblksperindir, fs, acctfunc, expungetype);
|
|
if (error)
|
|
goto out;
|
|
rlbn += blksperindir;
|
|
lbn -= blksperindir;
|
|
remblks -= blksperindir;
|
|
}
|
|
out:
|
|
FREE(bap, M_DEVBUF);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Do both snap accounting and map accounting.
|
|
*/
|
|
static int
|
|
fullacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)
|
|
struct vnode *vp;
|
|
ufs1_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int exptype; /* BLK_SNAP or BLK_NOCOPY */
|
|
{
|
|
int error;
|
|
|
|
if ((error = snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype)))
|
|
return (error);
|
|
return (mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, exptype));
|
|
}
|
|
|
|
/*
|
|
* Identify a set of blocks allocated in a snapshot inode.
|
|
*/
|
|
static int
|
|
snapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
|
|
struct vnode *vp;
|
|
ufs1_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int expungetype; /* BLK_SNAP or BLK_NOCOPY */
|
|
{
|
|
struct inode *ip = VTOI(vp);
|
|
ufs1_daddr_t blkno, *blkp;
|
|
ufs_lbn_t lbn;
|
|
struct buf *ibp;
|
|
int error;
|
|
|
|
for ( ; oldblkp < lastblkp; oldblkp++) {
|
|
blkno = *oldblkp;
|
|
if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP)
|
|
continue;
|
|
lbn = fragstoblks(fs, blkno);
|
|
if (lbn < NDADDR) {
|
|
blkp = &ip->i_din1->di_db[lbn];
|
|
ip->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
} else {
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
if (error)
|
|
return (error);
|
|
blkp = &((ufs1_daddr_t *)(ibp->b_data))
|
|
[(lbn - NDADDR) % NINDIR(fs)];
|
|
}
|
|
/*
|
|
* If we are expunging a snapshot vnode and we
|
|
* find a block marked BLK_NOCOPY, then it is
|
|
* one that has been allocated to this snapshot after
|
|
* we took our current snapshot and can be ignored.
|
|
*/
|
|
if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) {
|
|
if (lbn >= NDADDR)
|
|
brelse(ibp);
|
|
} else {
|
|
if (*blkp != 0)
|
|
panic("snapacct: bad block");
|
|
*blkp = expungetype;
|
|
if (lbn >= NDADDR)
|
|
bdwrite(ibp);
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Account for a set of blocks allocated in a snapshot inode.
|
|
*/
|
|
static int
|
|
mapacct_ufs1(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
|
|
struct vnode *vp;
|
|
ufs1_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int expungetype;
|
|
{
|
|
ufs1_daddr_t blkno;
|
|
ino_t inum;
|
|
|
|
inum = VTOI(vp)->i_number;
|
|
for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) {
|
|
blkno = *oldblkp;
|
|
if (blkno == 0 || blkno == BLK_NOCOPY)
|
|
continue;
|
|
if (blkno == BLK_SNAP)
|
|
blkno = blkstofrags(fs, lblkno);
|
|
ffs_blkfree(fs, vp, blkno, fs->fs_bsize, inum);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Before expunging a snapshot inode, note all the
|
|
* blocks that it claims with BLK_SNAP so that fsck will
|
|
* be able to account for those blocks properly and so
|
|
* that this snapshot knows that it need not copy them
|
|
* if the other snapshot holding them is freed. This code
|
|
* is reproduced once each for UFS1 and UFS2.
|
|
*/
|
|
static int
|
|
expunge_ufs2(snapvp, cancelip, fs, acctfunc, expungetype)
|
|
struct vnode *snapvp;
|
|
struct inode *cancelip;
|
|
struct fs *fs;
|
|
int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
|
|
struct fs *, ufs_lbn_t, int);
|
|
int expungetype;
|
|
{
|
|
int i, error, indiroff;
|
|
ufs_lbn_t lbn, rlbn;
|
|
ufs2_daddr_t len, blkno, numblks, blksperindir;
|
|
struct ufs2_dinode *dip;
|
|
struct thread *td = curthread;
|
|
struct buf *bp;
|
|
|
|
numblks = howmany(cancelip->i_size, fs->fs_bsize);
|
|
if ((error = (*acctfunc)(snapvp, &cancelip->i_din2->di_db[0],
|
|
&cancelip->i_din2->di_ib[NIADDR], fs, 0, expungetype)))
|
|
return (error);
|
|
blksperindir = 1;
|
|
lbn = -NDADDR;
|
|
len = numblks - NDADDR;
|
|
rlbn = NDADDR;
|
|
for (i = 0; len > 0 && i < NIADDR; i++) {
|
|
error = indiracct_ufs2(snapvp, ITOV(cancelip), i,
|
|
cancelip->i_din2->di_ib[i], lbn, rlbn, len,
|
|
blksperindir, fs, acctfunc, expungetype);
|
|
if (error)
|
|
return (error);
|
|
blksperindir *= NINDIR(fs);
|
|
lbn -= blksperindir + 1;
|
|
len -= blksperindir;
|
|
rlbn += blksperindir;
|
|
}
|
|
/*
|
|
* Prepare to expunge the inode. If its inode block has not
|
|
* yet been copied, then allocate and fill the copy.
|
|
*/
|
|
lbn = fragstoblks(fs, ino_to_fsba(fs, cancelip->i_number));
|
|
blkno = 0;
|
|
if (lbn < NDADDR) {
|
|
blkno = cancelip->i_din2->di_db[lbn];
|
|
} else {
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &bp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
if (error)
|
|
return (error);
|
|
indiroff = (lbn - NDADDR) % NINDIR(fs);
|
|
blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff];
|
|
bqrelse(bp);
|
|
}
|
|
error = UFS_BALLOC(snapvp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, 0, &bp);
|
|
if (error)
|
|
return (error);
|
|
if (blkno == 0 && (error = readblock(bp, lbn)))
|
|
return (error);
|
|
/*
|
|
* Set a snapshot inode to be a zero length file, regular files
|
|
* to be completely unallocated.
|
|
*/
|
|
dip = (struct ufs2_dinode *)bp->b_data +
|
|
ino_to_fsbo(fs, cancelip->i_number);
|
|
if (expungetype == BLK_NOCOPY)
|
|
dip->di_mode = 0;
|
|
dip->di_size = 0;
|
|
dip->di_blocks = 0;
|
|
dip->di_flags &= ~SF_SNAPSHOT;
|
|
bzero(&dip->di_db[0], (NDADDR + NIADDR) * sizeof(ufs2_daddr_t));
|
|
bdwrite(bp);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Descend an indirect block chain for vnode cancelvp accounting for all
|
|
* its indirect blocks in snapvp.
|
|
*/
|
|
static int
|
|
indiracct_ufs2(snapvp, cancelvp, level, blkno, lbn, rlbn, remblks,
|
|
blksperindir, fs, acctfunc, expungetype)
|
|
struct vnode *snapvp;
|
|
struct vnode *cancelvp;
|
|
int level;
|
|
ufs2_daddr_t blkno;
|
|
ufs_lbn_t lbn;
|
|
ufs_lbn_t rlbn;
|
|
ufs_lbn_t remblks;
|
|
ufs_lbn_t blksperindir;
|
|
struct fs *fs;
|
|
int (*acctfunc)(struct vnode *, ufs2_daddr_t *, ufs2_daddr_t *,
|
|
struct fs *, ufs_lbn_t, int);
|
|
int expungetype;
|
|
{
|
|
int error, num, i;
|
|
ufs_lbn_t subblksperindir;
|
|
struct indir indirs[NIADDR + 2];
|
|
ufs2_daddr_t last, *bap;
|
|
struct buf *bp;
|
|
|
|
if ((error = ufs_getlbns(cancelvp, rlbn, indirs, &num)) != 0)
|
|
return (error);
|
|
if (lbn != indirs[num - 1 - level].in_lbn || blkno == 0 || num < 2)
|
|
panic("indiracct: botched params");
|
|
/*
|
|
* We have to expand bread here since it will deadlock looking
|
|
* up the block number for any blocks that are not in the cache.
|
|
*/
|
|
bp = getblk(cancelvp, lbn, fs->fs_bsize, 0, 0);
|
|
bp->b_blkno = fsbtodb(fs, blkno);
|
|
if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0 &&
|
|
(error = readblock(bp, fragstoblks(fs, blkno)))) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
/*
|
|
* Account for the block pointers in this indirect block.
|
|
*/
|
|
last = howmany(remblks, blksperindir);
|
|
if (last > NINDIR(fs))
|
|
last = NINDIR(fs);
|
|
MALLOC(bap, ufs2_daddr_t *, fs->fs_bsize, M_DEVBUF, M_WAITOK);
|
|
bcopy(bp->b_data, (caddr_t)bap, fs->fs_bsize);
|
|
bqrelse(bp);
|
|
error = (*acctfunc)(snapvp, &bap[0], &bap[last], fs, rlbn, expungetype);
|
|
if (error || level == 0)
|
|
goto out;
|
|
/*
|
|
* Account for the block pointers in each of the indirect blocks
|
|
* in the levels below us.
|
|
*/
|
|
subblksperindir = blksperindir / NINDIR(fs);
|
|
for (lbn++, level--, i = 0; i < last; i++) {
|
|
error = indiracct_ufs2(snapvp, cancelvp, level, bap[i], lbn,
|
|
rlbn, remblks, subblksperindir, fs, acctfunc, expungetype);
|
|
if (error)
|
|
goto out;
|
|
rlbn += blksperindir;
|
|
lbn -= blksperindir;
|
|
remblks -= blksperindir;
|
|
}
|
|
out:
|
|
FREE(bap, M_DEVBUF);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Do both snap accounting and map accounting.
|
|
*/
|
|
static int
|
|
fullacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)
|
|
struct vnode *vp;
|
|
ufs2_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int exptype; /* BLK_SNAP or BLK_NOCOPY */
|
|
{
|
|
int error;
|
|
|
|
if ((error = snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype)))
|
|
return (error);
|
|
return (mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, exptype));
|
|
}
|
|
|
|
/*
|
|
* Identify a set of blocks allocated in a snapshot inode.
|
|
*/
|
|
static int
|
|
snapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
|
|
struct vnode *vp;
|
|
ufs2_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int expungetype; /* BLK_SNAP or BLK_NOCOPY */
|
|
{
|
|
struct inode *ip = VTOI(vp);
|
|
ufs2_daddr_t blkno, *blkp;
|
|
ufs_lbn_t lbn;
|
|
struct buf *ibp;
|
|
int error;
|
|
|
|
for ( ; oldblkp < lastblkp; oldblkp++) {
|
|
blkno = *oldblkp;
|
|
if (blkno == 0 || blkno == BLK_NOCOPY || blkno == BLK_SNAP)
|
|
continue;
|
|
lbn = fragstoblks(fs, blkno);
|
|
if (lbn < NDADDR) {
|
|
blkp = &ip->i_din2->di_db[lbn];
|
|
ip->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
} else {
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
if (error)
|
|
return (error);
|
|
blkp = &((ufs2_daddr_t *)(ibp->b_data))
|
|
[(lbn - NDADDR) % NINDIR(fs)];
|
|
}
|
|
/*
|
|
* If we are expunging a snapshot vnode and we
|
|
* find a block marked BLK_NOCOPY, then it is
|
|
* one that has been allocated to this snapshot after
|
|
* we took our current snapshot and can be ignored.
|
|
*/
|
|
if (expungetype == BLK_SNAP && *blkp == BLK_NOCOPY) {
|
|
if (lbn >= NDADDR)
|
|
brelse(ibp);
|
|
} else {
|
|
if (*blkp != 0)
|
|
panic("snapacct: bad block");
|
|
*blkp = expungetype;
|
|
if (lbn >= NDADDR)
|
|
bdwrite(ibp);
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Account for a set of blocks allocated in a snapshot inode.
|
|
*/
|
|
static int
|
|
mapacct_ufs2(vp, oldblkp, lastblkp, fs, lblkno, expungetype)
|
|
struct vnode *vp;
|
|
ufs2_daddr_t *oldblkp, *lastblkp;
|
|
struct fs *fs;
|
|
ufs_lbn_t lblkno;
|
|
int expungetype;
|
|
{
|
|
ufs2_daddr_t blkno;
|
|
ino_t inum;
|
|
|
|
inum = VTOI(vp)->i_number;
|
|
for ( ; oldblkp < lastblkp; oldblkp++, lblkno++) {
|
|
blkno = *oldblkp;
|
|
if (blkno == 0 || blkno == BLK_NOCOPY)
|
|
continue;
|
|
if (blkno == BLK_SNAP)
|
|
blkno = blkstofrags(fs, lblkno);
|
|
ffs_blkfree(fs, vp, blkno, fs->fs_bsize, inum);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Decrement extra reference on snapshot when last name is removed.
|
|
* It will not be freed until the last open reference goes away.
|
|
*/
|
|
void
|
|
ffs_snapgone(ip)
|
|
struct inode *ip;
|
|
{
|
|
struct inode *xp;
|
|
struct fs *fs;
|
|
int snaploc;
|
|
|
|
/*
|
|
* Find snapshot in incore list.
|
|
*/
|
|
TAILQ_FOREACH(xp, &ip->i_devvp->v_rdev->si_snapshots, i_nextsnap)
|
|
if (xp == ip)
|
|
break;
|
|
if (xp == 0)
|
|
printf("ffs_snapgone: lost snapshot vnode %d\n",
|
|
ip->i_number);
|
|
else
|
|
vrele(ITOV(ip));
|
|
/*
|
|
* Delete snapshot inode from superblock. Keep list dense.
|
|
*/
|
|
fs = ip->i_fs;
|
|
for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++)
|
|
if (fs->fs_snapinum[snaploc] == ip->i_number)
|
|
break;
|
|
if (snaploc < FSMAXSNAP) {
|
|
for (snaploc++; snaploc < FSMAXSNAP; snaploc++) {
|
|
if (fs->fs_snapinum[snaploc] == 0)
|
|
break;
|
|
fs->fs_snapinum[snaploc - 1] = fs->fs_snapinum[snaploc];
|
|
}
|
|
fs->fs_snapinum[snaploc - 1] = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Prepare a snapshot file for being removed.
|
|
*/
|
|
void
|
|
ffs_snapremove(vp)
|
|
struct vnode *vp;
|
|
{
|
|
struct inode *ip;
|
|
struct vnode *devvp;
|
|
struct buf *ibp;
|
|
struct fs *fs;
|
|
ufs2_daddr_t numblks, blkno, dblk;
|
|
int error, loc, last;
|
|
|
|
ip = VTOI(vp);
|
|
fs = ip->i_fs;
|
|
/*
|
|
* If active, delete from incore list (this snapshot may
|
|
* already have been in the process of being deleted, so
|
|
* would not have been active).
|
|
*
|
|
* Clear copy-on-write flag if last snapshot.
|
|
*/
|
|
if (ip->i_nextsnap.tqe_prev != 0) {
|
|
devvp = ip->i_devvp;
|
|
TAILQ_REMOVE(&devvp->v_rdev->si_snapshots, ip, i_nextsnap);
|
|
ip->i_nextsnap.tqe_prev = 0;
|
|
ASSERT_VOP_LOCKED(devvp, "ffs_snapremove devvp");
|
|
if (TAILQ_FIRST(&devvp->v_rdev->si_snapshots) == 0) {
|
|
devvp->v_rdev->si_copyonwrite = 0;
|
|
devvp->v_vflag &= ~VV_COPYONWRITE;
|
|
}
|
|
}
|
|
/*
|
|
* Clear all BLK_NOCOPY fields. Pass any block claims to other
|
|
* snapshots that want them (see ffs_snapblkfree below).
|
|
*/
|
|
for (blkno = 1; blkno < NDADDR; blkno++) {
|
|
dblk = DIP(ip, i_db[blkno]);
|
|
if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
|
|
DIP(ip, i_db[blkno]) = 0;
|
|
else if ((dblk == blkstofrags(fs, blkno) &&
|
|
ffs_snapblkfree(fs, ip->i_devvp, dblk, fs->fs_bsize,
|
|
ip->i_number))) {
|
|
DIP(ip, i_blocks) -= btodb(fs->fs_bsize);
|
|
DIP(ip, i_db[blkno]) = 0;
|
|
}
|
|
}
|
|
numblks = howmany(ip->i_size, fs->fs_bsize);
|
|
for (blkno = NDADDR; blkno < numblks; blkno += NINDIR(fs)) {
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)blkno),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
if (error)
|
|
continue;
|
|
if (fs->fs_size - blkno > NINDIR(fs))
|
|
last = NINDIR(fs);
|
|
else
|
|
last = fs->fs_size - blkno;
|
|
for (loc = 0; loc < last; loc++) {
|
|
if (ip->i_ump->um_fstype == UFS1) {
|
|
dblk = ((ufs1_daddr_t *)(ibp->b_data))[loc];
|
|
if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
|
|
((ufs1_daddr_t *)(ibp->b_data))[loc]= 0;
|
|
else if ((dblk == blkstofrags(fs, blkno) &&
|
|
ffs_snapblkfree(fs, ip->i_devvp, dblk,
|
|
fs->fs_bsize, ip->i_number))) {
|
|
ip->i_din1->di_blocks -=
|
|
btodb(fs->fs_bsize);
|
|
((ufs1_daddr_t *)(ibp->b_data))[loc]= 0;
|
|
}
|
|
continue;
|
|
}
|
|
dblk = ((ufs2_daddr_t *)(ibp->b_data))[loc];
|
|
if (dblk == BLK_NOCOPY || dblk == BLK_SNAP)
|
|
((ufs2_daddr_t *)(ibp->b_data))[loc] = 0;
|
|
else if ((dblk == blkstofrags(fs, blkno) &&
|
|
ffs_snapblkfree(fs, ip->i_devvp, dblk,
|
|
fs->fs_bsize, ip->i_number))) {
|
|
ip->i_din2->di_blocks -= btodb(fs->fs_bsize);
|
|
((ufs2_daddr_t *)(ibp->b_data))[loc] = 0;
|
|
}
|
|
}
|
|
bawrite(ibp);
|
|
}
|
|
/*
|
|
* Clear snapshot flag and drop reference.
|
|
*/
|
|
ip->i_flags &= ~SF_SNAPSHOT;
|
|
DIP(ip, i_flags) = ip->i_flags;
|
|
ip->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
}
|
|
|
|
/*
|
|
* Notification that a block is being freed. Return zero if the free
|
|
* should be allowed to proceed. Return non-zero if the snapshot file
|
|
* wants to claim the block. The block will be claimed if it is an
|
|
* uncopied part of one of the snapshots. It will be freed if it is
|
|
* either a BLK_NOCOPY or has already been copied in all of the snapshots.
|
|
* If a fragment is being freed, then all snapshots that care about
|
|
* it must make a copy since a snapshot file can only claim full sized
|
|
* blocks. Note that if more than one snapshot file maps the block,
|
|
* we can pick one at random to claim it. Since none of the snapshots
|
|
* can change, we are assurred that they will all see the same unmodified
|
|
* image. When deleting a snapshot file (see ffs_snapremove above), we
|
|
* must push any of these claimed blocks to one of the other snapshots
|
|
* that maps it. These claimed blocks are easily identified as they will
|
|
* have a block number equal to their logical block number within the
|
|
* snapshot. A copied block can never have this property because they
|
|
* must always have been allocated from a BLK_NOCOPY location.
|
|
*/
|
|
int
|
|
ffs_snapblkfree(fs, devvp, bno, size, inum)
|
|
struct fs *fs;
|
|
struct vnode *devvp;
|
|
ufs2_daddr_t bno;
|
|
long size;
|
|
ino_t inum;
|
|
{
|
|
struct buf *ibp, *cbp, *savedcbp = 0;
|
|
struct thread *td = curthread;
|
|
struct inode *ip;
|
|
struct vnode *vp;
|
|
ufs_lbn_t lbn;
|
|
ufs2_daddr_t blkno;
|
|
int indiroff = 0, error = 0, claimedblk = 0;
|
|
struct snaphead *snaphead;
|
|
|
|
lbn = fragstoblks(fs, bno);
|
|
snaphead = &devvp->v_rdev->si_snapshots;
|
|
TAILQ_FOREACH(ip, snaphead, i_nextsnap) {
|
|
vp = ITOV(ip);
|
|
/*
|
|
* Lookup block being written.
|
|
*/
|
|
if (lbn < NDADDR) {
|
|
blkno = DIP(ip, i_db[lbn]);
|
|
} else {
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY, &ibp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
VOP_UNLOCK(vp, 0, td);
|
|
if (error)
|
|
break;
|
|
indiroff = (lbn - NDADDR) % NINDIR(fs);
|
|
if (ip->i_ump->um_fstype == UFS1)
|
|
blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff];
|
|
else
|
|
blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff];
|
|
}
|
|
/*
|
|
* Check to see if block needs to be copied.
|
|
*/
|
|
if (blkno == 0) {
|
|
/*
|
|
* A block that we map is being freed. If it has not
|
|
* been claimed yet, we will claim or copy it (below).
|
|
*/
|
|
claimedblk = 1;
|
|
} else if (blkno == BLK_SNAP) {
|
|
/*
|
|
* No previous snapshot claimed the block,
|
|
* so it will be * freed and become a BLK_NOCOPY
|
|
* (don't care) for us.
|
|
*/
|
|
if (claimedblk)
|
|
panic("snapblkfree: inconsistent block type");
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
if (lbn < NDADDR) {
|
|
DIP(ip, i_db[lbn]) = BLK_NOCOPY;
|
|
ip->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
} else if (ip->i_ump->um_fstype == UFS1) {
|
|
((ufs1_daddr_t *)(ibp->b_data))[indiroff] =
|
|
BLK_NOCOPY;
|
|
bdwrite(ibp);
|
|
} else {
|
|
((ufs2_daddr_t *)(ibp->b_data))[indiroff] =
|
|
BLK_NOCOPY;
|
|
bdwrite(ibp);
|
|
}
|
|
VOP_UNLOCK(vp, 0, td);
|
|
continue;
|
|
} else /* BLK_NOCOPY or default */ {
|
|
/*
|
|
* If the snapshot has already copied the block
|
|
* (default), or does not care about the block,
|
|
* it is not needed.
|
|
*/
|
|
if (lbn >= NDADDR)
|
|
bqrelse(ibp);
|
|
continue;
|
|
}
|
|
/*
|
|
* If this is a full size block, we will just grab it
|
|
* and assign it to the snapshot inode. Otherwise we
|
|
* will proceed to copy it. See explanation for this
|
|
* routine as to why only a single snapshot needs to
|
|
* claim this block.
|
|
*/
|
|
if (size == fs->fs_bsize) {
|
|
#ifdef DEBUG
|
|
if (snapdebug)
|
|
printf("%s %d lbn %jd from inum %d\n",
|
|
"Grabonremove: snapino", ip->i_number,
|
|
(intmax_t)lbn, inum);
|
|
#endif
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
if (lbn < NDADDR) {
|
|
DIP(ip, i_db[lbn]) = bno;
|
|
} else if (ip->i_ump->um_fstype == UFS1) {
|
|
((ufs1_daddr_t *)(ibp->b_data))[indiroff] = bno;
|
|
bdwrite(ibp);
|
|
} else {
|
|
((ufs2_daddr_t *)(ibp->b_data))[indiroff] = bno;
|
|
bdwrite(ibp);
|
|
}
|
|
DIP(ip, i_blocks) += btodb(size);
|
|
ip->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
VOP_UNLOCK(vp, 0, td);
|
|
return (1);
|
|
}
|
|
if (lbn >= NDADDR)
|
|
bqrelse(ibp);
|
|
/*
|
|
* Allocate the block into which to do the copy. Note that this
|
|
* allocation will never require any additional allocations for
|
|
* the snapshot inode.
|
|
*/
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, 0, &cbp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
if (error) {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
break;
|
|
}
|
|
#ifdef DEBUG
|
|
if (snapdebug)
|
|
printf("%s%d lbn %jd %s %d size %ld to blkno %jd\n",
|
|
"Copyonremove: snapino ", ip->i_number,
|
|
(intmax_t)lbn, "for inum", inum, size,
|
|
(intmax_t)cbp->b_blkno);
|
|
#endif
|
|
/*
|
|
* If we have already read the old block contents, then
|
|
* simply copy them to the new block. Note that we need
|
|
* to synchronously write snapshots that have not been
|
|
* unlinked, and hence will be visible after a crash,
|
|
* to ensure their integrity.
|
|
*/
|
|
if (savedcbp != 0) {
|
|
bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
|
|
bawrite(cbp);
|
|
if (dopersistence && ip->i_effnlink > 0)
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
continue;
|
|
}
|
|
/*
|
|
* Otherwise, read the old block contents into the buffer.
|
|
*/
|
|
if ((error = readblock(cbp, lbn)) != 0) {
|
|
bzero(cbp->b_data, fs->fs_bsize);
|
|
bawrite(cbp);
|
|
if (dopersistence && ip->i_effnlink > 0)
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
break;
|
|
}
|
|
VOP_UNLOCK(vp, 0, td);
|
|
savedcbp = cbp;
|
|
}
|
|
/*
|
|
* Note that we need to synchronously write snapshots that
|
|
* have not been unlinked, and hence will be visible after
|
|
* a crash, to ensure their integrity.
|
|
*/
|
|
if (savedcbp) {
|
|
vp = savedcbp->b_vp;
|
|
bawrite(savedcbp);
|
|
if (dopersistence && VTOI(vp)->i_effnlink > 0) {
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
}
|
|
}
|
|
/*
|
|
* If we have been unable to allocate a block in which to do
|
|
* the copy, then return non-zero so that the fragment will
|
|
* not be freed. Although space will be lost, the snapshot
|
|
* will stay consistent.
|
|
*/
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Associate snapshot files when mounting.
|
|
*/
|
|
void
|
|
ffs_snapshot_mount(mp)
|
|
struct mount *mp;
|
|
{
|
|
struct ufsmount *ump = VFSTOUFS(mp);
|
|
struct fs *fs = ump->um_fs;
|
|
struct thread *td = curthread;
|
|
struct snaphead *snaphead;
|
|
struct vnode *vp;
|
|
struct inode *ip;
|
|
int error, snaploc, loc;
|
|
|
|
snaphead = &ump->um_devvp->v_rdev->si_snapshots;
|
|
for (snaploc = 0; snaploc < FSMAXSNAP; snaploc++) {
|
|
if (fs->fs_snapinum[snaploc] == 0)
|
|
return;
|
|
if ((error = VFS_VGET(mp, fs->fs_snapinum[snaploc],
|
|
LK_EXCLUSIVE, &vp)) != 0){
|
|
printf("ffs_snapshot_mount: vget failed %d\n", error);
|
|
continue;
|
|
}
|
|
ip = VTOI(vp);
|
|
if ((ip->i_flags & SF_SNAPSHOT) == 0) {
|
|
printf("ffs_snapshot_mount: non-snapshot inode %d\n",
|
|
fs->fs_snapinum[snaploc]);
|
|
vput(vp);
|
|
for (loc = snaploc + 1; loc < FSMAXSNAP; loc++) {
|
|
if (fs->fs_snapinum[loc] == 0)
|
|
break;
|
|
fs->fs_snapinum[loc - 1] = fs->fs_snapinum[loc];
|
|
}
|
|
fs->fs_snapinum[loc - 1] = 0;
|
|
snaploc--;
|
|
continue;
|
|
}
|
|
if (ip->i_nextsnap.tqe_prev != 0)
|
|
panic("ffs_snapshot_mount: %d already on list",
|
|
ip->i_number);
|
|
else
|
|
TAILQ_INSERT_TAIL(snaphead, ip, i_nextsnap);
|
|
vp->v_vflag |= VV_SYSTEM;
|
|
ump->um_devvp->v_rdev->si_copyonwrite = ffs_copyonwrite;
|
|
ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_snapshot_mount");
|
|
ump->um_devvp->v_vflag |= VV_COPYONWRITE;
|
|
VOP_UNLOCK(vp, 0, td);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Disassociate snapshot files when unmounting.
|
|
*/
|
|
void
|
|
ffs_snapshot_unmount(mp)
|
|
struct mount *mp;
|
|
{
|
|
struct ufsmount *ump = VFSTOUFS(mp);
|
|
struct snaphead *snaphead = &ump->um_devvp->v_rdev->si_snapshots;
|
|
struct inode *xp;
|
|
|
|
while ((xp = TAILQ_FIRST(snaphead)) != 0) {
|
|
TAILQ_REMOVE(snaphead, xp, i_nextsnap);
|
|
xp->i_nextsnap.tqe_prev = 0;
|
|
if (xp->i_effnlink > 0)
|
|
vrele(ITOV(xp));
|
|
}
|
|
ASSERT_VOP_LOCKED(ump->um_devvp, "ffs_snapshot_unmount");
|
|
ump->um_devvp->v_rdev->si_copyonwrite = 0;
|
|
ump->um_devvp->v_vflag &= ~VV_COPYONWRITE;
|
|
}
|
|
|
|
/*
|
|
* Check for need to copy block that is about to be written,
|
|
* copying the block if necessary.
|
|
*/
|
|
static int
|
|
ffs_copyonwrite(devvp, bp)
|
|
struct vnode *devvp;
|
|
struct buf *bp;
|
|
{
|
|
struct buf *ibp, *cbp, *savedcbp = 0;
|
|
struct thread *td = curthread;
|
|
struct fs *fs;
|
|
struct inode *ip;
|
|
struct vnode *vp;
|
|
ufs2_daddr_t lbn, blkno;
|
|
int indiroff, error = 0;
|
|
|
|
fs = TAILQ_FIRST(&devvp->v_rdev->si_snapshots)->i_fs;
|
|
lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno));
|
|
if (td->td_proc->p_flag & P_COWINPROGRESS)
|
|
panic("ffs_copyonwrite: recursive call");
|
|
TAILQ_FOREACH(ip, &devvp->v_rdev->si_snapshots, i_nextsnap) {
|
|
vp = ITOV(ip);
|
|
/*
|
|
* We ensure that everything of our own that needs to be
|
|
* copied will be done at the time that ffs_snapshot is
|
|
* called. Thus we can skip the check here which can
|
|
* deadlock in doing the lookup in UFS_BALLOC.
|
|
*/
|
|
if (bp->b_vp == vp)
|
|
continue;
|
|
/*
|
|
* Check to see if block needs to be copied. We have to
|
|
* be able to do the UFS_BALLOC without blocking, otherwise
|
|
* we may get in a deadlock with another process also
|
|
* trying to allocate. If we find outselves unable to
|
|
* get the buffer lock, we unlock the snapshot vnode,
|
|
* sleep briefly, and try again.
|
|
*/
|
|
retry:
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
if (lbn < NDADDR) {
|
|
blkno = DIP(ip, i_db[lbn]);
|
|
} else {
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_METAONLY | BA_NOWAIT, &ibp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
if (error) {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
if (error != EWOULDBLOCK)
|
|
break;
|
|
tsleep(vp, td->td_ksegrp->kg_user_pri, "nap", 1);
|
|
goto retry;
|
|
}
|
|
indiroff = (lbn - NDADDR) % NINDIR(fs);
|
|
if (ip->i_ump->um_fstype == UFS1)
|
|
blkno=((ufs1_daddr_t *)(ibp->b_data))[indiroff];
|
|
else
|
|
blkno=((ufs2_daddr_t *)(ibp->b_data))[indiroff];
|
|
bqrelse(ibp);
|
|
}
|
|
#ifdef DIAGNOSTIC
|
|
if (blkno == BLK_SNAP && bp->b_lblkno >= 0)
|
|
panic("ffs_copyonwrite: bad copy block");
|
|
#endif
|
|
if (blkno != 0) {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
continue;
|
|
}
|
|
/*
|
|
* Allocate the block into which to do the copy. Note that this
|
|
* allocation will never require any additional allocations for
|
|
* the snapshot inode.
|
|
*/
|
|
td->td_proc->p_flag |= P_COWINPROGRESS;
|
|
error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn),
|
|
fs->fs_bsize, KERNCRED, BA_NOWAIT, &cbp);
|
|
td->td_proc->p_flag &= ~P_COWINPROGRESS;
|
|
if (error) {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
if (error != EWOULDBLOCK)
|
|
break;
|
|
tsleep(vp, td->td_ksegrp->kg_user_pri, "nap", 1);
|
|
goto retry;
|
|
}
|
|
#ifdef DEBUG
|
|
if (snapdebug) {
|
|
printf("Copyonwrite: snapino %d lbn %jd for ",
|
|
ip->i_number, (intmax_t)lbn);
|
|
if (bp->b_vp == devvp)
|
|
printf("fs metadata");
|
|
else
|
|
printf("inum %d", VTOI(bp->b_vp)->i_number);
|
|
printf(" lblkno %jd to blkno %jd\n",
|
|
(intmax_t)bp->b_lblkno, (intmax_t)cbp->b_blkno);
|
|
}
|
|
#endif
|
|
/*
|
|
* If we have already read the old block contents, then
|
|
* simply copy them to the new block. Note that we need
|
|
* to synchronously write snapshots that have not been
|
|
* unlinked, and hence will be visible after a crash,
|
|
* to ensure their integrity.
|
|
*/
|
|
if (savedcbp != 0) {
|
|
bcopy(savedcbp->b_data, cbp->b_data, fs->fs_bsize);
|
|
bawrite(cbp);
|
|
if (dopersistence && ip->i_effnlink > 0)
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
continue;
|
|
}
|
|
/*
|
|
* Otherwise, read the old block contents into the buffer.
|
|
*/
|
|
if ((error = readblock(cbp, lbn)) != 0) {
|
|
bzero(cbp->b_data, fs->fs_bsize);
|
|
bawrite(cbp);
|
|
if (dopersistence && ip->i_effnlink > 0)
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
break;
|
|
}
|
|
savedcbp = cbp;
|
|
VOP_UNLOCK(vp, 0, td);
|
|
}
|
|
/*
|
|
* Note that we need to synchronously write snapshots that
|
|
* have not been unlinked, and hence will be visible after
|
|
* a crash, to ensure their integrity.
|
|
*/
|
|
if (savedcbp) {
|
|
vp = savedcbp->b_vp;
|
|
bawrite(savedcbp);
|
|
if (dopersistence && VTOI(vp)->i_effnlink > 0) {
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
(void) VOP_FSYNC(vp, KERNCRED, MNT_WAIT, td);
|
|
VOP_UNLOCK(vp, 0, td);
|
|
}
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Read the specified block into the given buffer.
|
|
* Much of this boiler-plate comes from bwrite().
|
|
*/
|
|
static int
|
|
readblock(bp, lbn)
|
|
struct buf *bp;
|
|
ufs2_daddr_t lbn;
|
|
{
|
|
struct uio auio;
|
|
struct iovec aiov;
|
|
struct thread *td = curthread;
|
|
struct inode *ip = VTOI(bp->b_vp);
|
|
|
|
aiov.iov_base = bp->b_data;
|
|
aiov.iov_len = bp->b_bcount;
|
|
auio.uio_iov = &aiov;
|
|
auio.uio_iovcnt = 1;
|
|
auio.uio_offset = dbtob(fsbtodb(ip->i_fs, blkstofrags(ip->i_fs, lbn)));
|
|
auio.uio_resid = bp->b_bcount;
|
|
auio.uio_rw = UIO_READ;
|
|
auio.uio_segflg = UIO_SYSSPACE;
|
|
auio.uio_td = td;
|
|
return (physio(ip->i_devvp->v_rdev, &auio, 0));
|
|
}
|