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NetBSD/sys/ufs/lfs/ulfs_readwrite.c

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/* $NetBSD: ulfs_readwrite.c,v 1.28 2021/10/20 03:08:19 thorpej Exp $ */
/* from NetBSD: ufs_readwrite.c,v 1.120 2015/04/12 22:48:38 riastradh Exp */
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ufs_readwrite.c 8.11 (Berkeley) 5/8/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: ulfs_readwrite.c,v 1.28 2021/10/20 03:08:19 thorpej Exp $");
#define FS struct lfs
#define I_FS i_lfs
#define READ lfs_read
#define READ_S "lfs_read"
#define WRITE lfs_write
#define WRITE_S "lfs_write"
#define BUFRD lfs_bufrd
#define BUFWR lfs_bufwr
#define fs_sb_getbsize(fs) lfs_sb_getbsize(fs)
#define fs_bmask lfs_bmask
static int ulfs_post_read_update(struct vnode *, int, int);
static int ulfs_post_write_update(struct vnode *, struct uio *, int,
kauth_cred_t, off_t, int, int);
/*
* Vnode op for reading.
*/
/* ARGSUSED */
int
READ(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp;
struct inode *ip;
struct uio *uio;
FS *fs;
vsize_t bytelen;
int error, ioflag, advice;
vp = ap->a_vp;
ip = VTOI(vp);
fs = ip->I_FS;
uio = ap->a_uio;
ioflag = ap->a_ioflag;
error = 0;
KASSERT(uio->uio_rw == UIO_READ);
KASSERT(vp->v_type == VREG || vp->v_type == VDIR);
/* XXX Eliminate me by refusing directory reads from userland. */
if (vp->v_type == VDIR)
return BUFRD(vp, uio, ioflag, ap->a_cred);
/* XXX Eliminate me by using ufs_bufio in lfs. */
if (vp->v_type == VREG && ip->i_number == LFS_IFILE_INUM)
return BUFRD(vp, uio, ioflag, ap->a_cred);
if ((u_int64_t)uio->uio_offset > fs->um_maxfilesize)
return (EFBIG);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset >= ip->i_size)
goto out;
KASSERT(vp->v_type == VREG);
advice = IO_ADV_DECODE(ap->a_ioflag);
while (uio->uio_resid > 0) {
if (ioflag & IO_DIRECT) {
genfs_directio(vp, uio, ioflag);
}
bytelen = MIN(ip->i_size - uio->uio_offset, uio->uio_resid);
if (bytelen == 0)
break;
error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice,
UBC_READ | UBC_PARTIALOK | UBC_VNODE_FLAGS(vp));
if (error)
break;
}
out:
error = ulfs_post_read_update(vp, ap->a_ioflag, error);
return (error);
}
/*
* UFS op for reading via the buffer cache
*/
int
BUFRD(struct vnode *vp, struct uio *uio, int ioflag, kauth_cred_t cred)
{
struct inode *ip;
FS *fs;
struct buf *bp;
daddr_t lbn, nextlbn;
off_t bytesinfile;
long size, xfersize, blkoffset;
int error;
KASSERT(VOP_ISLOCKED(vp));
KASSERT(vp->v_type == VDIR || vp->v_type == VLNK ||
vp->v_type == VREG);
KASSERT(uio->uio_rw == UIO_READ);
ip = VTOI(vp);
fs = ip->I_FS;
error = 0;
KASSERT(vp->v_type != VLNK || ip->i_size >= fs->um_maxsymlinklen);
KASSERT(vp->v_type != VLNK || fs->um_maxsymlinklen != 0 ||
DIP(ip, blocks) == 0);
KASSERT(vp->v_type != VREG || vp == fs->lfs_ivnode);
KASSERT(vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM);
if (uio->uio_offset > fs->um_maxfilesize)
return EFBIG;
if (uio->uio_resid == 0)
return 0;
if (uio->uio_offset >= ip->i_size)
goto out;
for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
bytesinfile = ip->i_size - uio->uio_offset;
if (bytesinfile <= 0)
break;
lbn = lfs_lblkno(fs, uio->uio_offset);
nextlbn = lbn + 1;
size = lfs_blksize(fs, ip, lbn);
blkoffset = lfs_blkoff(fs, uio->uio_offset);
xfersize = MIN(MIN(fs_sb_getbsize(fs) - blkoffset, uio->uio_resid),
bytesinfile);
if (lfs_lblktosize(fs, nextlbn) >= ip->i_size)
error = bread(vp, lbn, size, 0, &bp);
else {
int nextsize = lfs_blksize(fs, ip, nextlbn);
error = breadn(vp, lbn,
size, &nextlbn, &nextsize, 1, 0, &bp);
}
if (error)
break;
/*
* We should only get non-zero b_resid when an I/O error
* has occurred, which should cause us to break above.
* However, if the short read did not cause an error,
* then we want to ensure that we do not uiomove bad
* or uninitialized data.
*/
size -= bp->b_resid;
if (size < xfersize) {
if (size == 0)
break;
xfersize = size;
}
error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
if (error)
break;
brelse(bp, 0);
}
if (bp != NULL)
brelse(bp, 0);
out:
error = ulfs_post_read_update(vp, ioflag, error);
return (error);
}
static int
ulfs_post_read_update(struct vnode *vp, int ioflag, int oerror)
{
struct inode *ip = VTOI(vp);
int error = oerror;
if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) {
ip->i_state |= IN_ACCESS;
if ((ioflag & IO_SYNC) == IO_SYNC) {
error = lfs_update(vp, NULL, NULL, UPDATE_WAIT);
}
}
/* Read error overrides any inode update error. */
if (oerror)
error = oerror;
return error;
}
/*
* Vnode op for writing.
*/
int
WRITE(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp;
struct uio *uio;
struct inode *ip;
FS *fs;
kauth_cred_t cred;
off_t osize, origoff, oldoff, preallocoff, endallocoff, nsize;
int blkoffset, error, flags, ioflag, resid;
int aflag;
vsize_t bytelen;
bool async;
cred = ap->a_cred;
ioflag = ap->a_ioflag;
uio = ap->a_uio;
vp = ap->a_vp;
ip = VTOI(vp);
KASSERT(vp->v_size == ip->i_size);
KASSERT(uio->uio_rw == UIO_WRITE);
KASSERT(vp->v_type == VREG);
if (ioflag & IO_APPEND)
uio->uio_offset = ip->i_size;
if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
return (EPERM);
fs = ip->I_FS;
if (uio->uio_offset < 0 ||
(u_int64_t)uio->uio_offset + uio->uio_resid > fs->um_maxfilesize)
return (EFBIG);
/* Disallow writes to the Ifile, even if noschg flag is removed */
/* XXX can this go away when the Ifile is no longer in the namespace? */
if (vp == fs->lfs_ivnode)
return (EPERM);
if (uio->uio_resid == 0)
return (0);
flags = ioflag & IO_SYNC ? B_SYNC : 0;
async = vp->v_mount->mnt_flag & MNT_ASYNC;
origoff = uio->uio_offset;
resid = uio->uio_resid;
osize = ip->i_size;
error = 0;
KASSERT(vp->v_type == VREG);
async = true;
lfs_availwait(fs, lfs_btofsb(fs, uio->uio_resid));
lfs_check(vp, LFS_UNUSED_LBN, 0);
preallocoff = round_page(lfs_blkroundup(fs, MAX(osize, uio->uio_offset)));
aflag = ioflag & IO_SYNC ? B_SYNC : 0;
nsize = MAX(osize, uio->uio_offset + uio->uio_resid);
endallocoff = nsize - lfs_blkoff(fs, nsize);
/*
* if we're increasing the file size, deal with expanding
* the fragment if there is one.
*/
if (nsize > osize && lfs_lblkno(fs, osize) < ULFS_NDADDR &&
lfs_lblkno(fs, osize) != lfs_lblkno(fs, nsize) &&
lfs_blkroundup(fs, osize) != osize) {
off_t eob;
eob = lfs_blkroundup(fs, osize);
uvm_vnp_setwritesize(vp, eob);
error = ulfs_balloc_range(vp, osize, eob - osize, cred, aflag);
if (error)
goto out;
if (flags & B_SYNC) {
rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
VOP_PUTPAGES(vp, trunc_page(osize & lfs_sb_getbmask(fs)),
round_page(eob),
PGO_CLEANIT | PGO_SYNCIO);
}
}
while (uio->uio_resid > 0) {
int ubc_flags = UBC_WRITE;
bool overwrite; /* if we're overwrite a whole block */
off_t newoff;
if (ioflag & IO_DIRECT) {
genfs_directio(vp, uio, ioflag);
}
oldoff = uio->uio_offset;
blkoffset = lfs_blkoff(fs, uio->uio_offset);
bytelen = MIN(fs_sb_getbsize(fs) - blkoffset, uio->uio_resid);
if (bytelen == 0) {
break;
}
/*
* if we're filling in a hole, allocate the blocks now and
* initialize the pages first. if we're extending the file,
* we can safely allocate blocks without initializing pages
* since the new blocks will be inaccessible until the write
* is complete.
*/
overwrite = uio->uio_offset >= preallocoff &&
uio->uio_offset < endallocoff;
if (!overwrite && (vp->v_vflag & VV_MAPPED) == 0 &&
lfs_blkoff(fs, uio->uio_offset) == 0 &&
(uio->uio_offset & PAGE_MASK) == 0) {
vsize_t len;
len = trunc_page(bytelen);
len -= lfs_blkoff(fs, len);
if (len > 0) {
overwrite = true;
bytelen = len;
}
}
newoff = oldoff + bytelen;
if (vp->v_size < newoff) {
uvm_vnp_setwritesize(vp, newoff);
}
if (!overwrite) {
error = ulfs_balloc_range(vp, uio->uio_offset, bytelen,
cred, aflag);
if (error)
break;
} else {
genfs_node_wrlock(vp);
error = GOP_ALLOC(vp, uio->uio_offset, bytelen,
aflag, cred);
genfs_node_unlock(vp);
if (error)
break;
ubc_flags |= UBC_FAULTBUSY;
}
/*
* copy the data.
*/
error = ubc_uiomove(&vp->v_uobj, uio, bytelen,
IO_ADV_DECODE(ioflag), ubc_flags | UBC_VNODE_FLAGS(vp));
/*
* update UVM's notion of the size now that we've
* copied the data into the vnode's pages.
*
* we should update the size even when uiomove failed.
*/
if (vp->v_size < newoff) {
uvm_vnp_setsize(vp, newoff);
}
if (error)
break;
/*
* flush what we just wrote if necessary.
* XXXUBC simplistic async flushing.
*/
__USE(async);
}
if (error == 0 && ioflag & IO_SYNC) {
rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
error = VOP_PUTPAGES(vp, trunc_page(origoff & lfs_sb_getbmask(fs)),
round_page(lfs_blkroundup(fs, uio->uio_offset)),
PGO_CLEANIT | PGO_SYNCIO);
}
out:
error = ulfs_post_write_update(vp, uio, ioflag, cred, osize, resid,
error);
return (error);
}
/*
* UFS op for writing via the buffer cache
*/
int
BUFWR(struct vnode *vp, struct uio *uio, int ioflag, kauth_cred_t cred)
{
struct inode *ip;
FS *fs;
int flags;
struct buf *bp;
off_t osize;
int resid, xfersize, size, blkoffset;
daddr_t lbn;
int error;
bool need_unreserve = false;
KASSERT(ISSET(ioflag, IO_NODELOCKED));
KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
KASSERT(vp->v_type == VDIR || vp->v_type == VLNK);
KASSERT(vp->v_type != VDIR || ISSET(ioflag, IO_SYNC));
KASSERT(uio->uio_rw == UIO_WRITE);
ip = VTOI(vp);
fs = ip->I_FS;
KASSERT(vp->v_size == ip->i_size);
if (uio->uio_offset < 0 ||
uio->uio_resid > fs->um_maxfilesize ||
uio->uio_offset > (fs->um_maxfilesize - uio->uio_resid))
return EFBIG;
KASSERT(vp != fs->lfs_ivnode);
if (uio->uio_resid == 0)
return 0;
flags = ioflag & IO_SYNC ? B_SYNC : 0;
resid = uio->uio_resid;
osize = ip->i_size;
error = 0;
KASSERT(vp->v_type != VREG);
lfs_availwait(fs, lfs_btofsb(fs, uio->uio_resid));
lfs_check(vp, LFS_UNUSED_LBN, 0);
/* XXX Should never have pages cached here. */
KASSERT(vp->v_uobj.uo_npages == 0);
while (uio->uio_resid > 0) {
lbn = lfs_lblkno(fs, uio->uio_offset);
blkoffset = lfs_blkoff(fs, uio->uio_offset);
xfersize = MIN(fs_sb_getbsize(fs) - blkoffset, uio->uio_resid);
if (fs_sb_getbsize(fs) > xfersize)
flags |= B_CLRBUF;
else
flags &= ~B_CLRBUF;
error = lfs_reserve(fs, vp, NULL,
lfs_btofsb(fs, (ULFS_NIADDR + 1) << lfs_sb_getbshift(fs)));
if (error)
break;
need_unreserve = true;
error = lfs_balloc(vp, uio->uio_offset, xfersize, cred, flags,
&bp);
if (error)
break;
if (uio->uio_offset + xfersize > ip->i_size) {
ip->i_size = uio->uio_offset + xfersize;
DIP_ASSIGN(ip, size, ip->i_size);
uvm_vnp_setsize(vp, ip->i_size);
}
size = lfs_blksize(fs, ip, lbn) - bp->b_resid;
if (xfersize > size)
xfersize = size;
error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
/*
* if we didn't clear the block and the uiomove failed,
* the buf will now contain part of some other file,
* so we need to invalidate it.
*/
if (error && (flags & B_CLRBUF) == 0) {
brelse(bp, BC_INVAL);
break;
}
(void)VOP_BWRITE(bp->b_vp, bp);
lfs_reserve(fs, vp, NULL,
-lfs_btofsb(fs, (ULFS_NIADDR + 1) << lfs_sb_getbshift(fs)));
need_unreserve = false;
if (error || xfersize == 0)
break;
}
if (need_unreserve) {
lfs_reserve(fs, vp, NULL,
-lfs_btofsb(fs, (ULFS_NIADDR + 1) << lfs_sb_getbshift(fs)));
}
error = ulfs_post_write_update(vp, uio, ioflag, cred, osize, resid,
error);
return (error);
}
static int
ulfs_post_write_update(struct vnode *vp, struct uio *uio, int ioflag,
kauth_cred_t cred, off_t osize, int resid, int oerror)
{
struct inode *ip = VTOI(vp);
int error = oerror;
/* Trigger ctime and mtime updates, and atime if MNT_RELATIME. */
ip->i_state |= IN_CHANGE | IN_UPDATE;
if (vp->v_mount->mnt_flag & MNT_RELATIME)
ip->i_state |= IN_ACCESS;
/*
* If we successfully wrote any data and we are not the superuser,
* we clear the setuid and setgid bits as a precaution against
* tampering.
*/
if (resid > uio->uio_resid && cred) {
if (ip->i_mode & ISUID) {
if (kauth_authorize_vnode(cred,
KAUTH_VNODE_RETAIN_SUID, vp, NULL, EPERM) != 0) {
ip->i_mode &= ~ISUID;
DIP_ASSIGN(ip, mode, ip->i_mode);
}
}
if (ip->i_mode & ISGID) {
if (kauth_authorize_vnode(cred,
KAUTH_VNODE_RETAIN_SGID, vp, NULL, EPERM) != 0) {
ip->i_mode &= ~ISGID;
DIP_ASSIGN(ip, mode, ip->i_mode);
}
}
}
/*
* Update the size on disk: truncate back to original size on
* error, or reflect the new size on success.
*/
if (error) {
(void) lfs_truncate(vp, osize, ioflag & IO_SYNC, cred);
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
} else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC) {
error = lfs_update(vp, NULL, NULL, UPDATE_WAIT);
} else {
/* nothing */
}
/* Make sure the vnode uvm size matches the inode file size. */
KASSERT(vp->v_size == ip->i_size);
/* Write error overrides any inode update error. */
if (oerror)
error = oerror;
return error;
}
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