/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#include <sys/types.h>
#include <sys/thread.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bitmap.h>
#include <sys/buf.h>
#include <sys/cmn_err.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/fcntl.h>
#include <sys/flock.h>
#include <sys/file.h>
#include <sys/kmem.h>
#include <sys/mman.h>
#include <sys/vmsystm.h>
#include <sys/open.h>
#include <sys/swap.h>
#include <sys/sysmacros.h>
#include <sys/uio.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/poll.h>
#include <sys/zmod.h>
#include <sys/fs/decomp.h>
#include <vm/hat.h>
#include <vm/as.h>
#include <vm/page.h>
#include <vm/pvn.h>
#include <vm/seg_vn.h>
#include <vm/seg_kmem.h>
#include <vm/seg_map.h>
#include <fs/fs_subr.h>
/*
* dcfs - A filesystem for automatic decompressing of fiocompressed files
*
* This filesystem is a layered filesystem that sits on top of a normal
* persistent filesystem and provides automatic decompression of files
* that have been previously compressed and stored on the host file system.
* This is a pseudo filesystem in that it does not persist data, rather it
* intercepts file lookup requests on the host filesystem and provides
* transparent decompression of those files. Currently the only supported
* host filesystem is ufs.
*
* A file is compressed via a userland utility (currently cmd/boot/fiocompress)
* and marked by fiocompress as a compressed file via a flag in the on-disk
* inode (set via a ufs ioctl() - see `ufs_vnops.c`ufs_ioctl()`_FIO_COMPRESSED
* ufs_lookup checks for this flag and if set, passes control to decompvp
* a function defined in this (dcfs) filesystem. decomvp uncompresses the file
* and returns a dcfs vnode to the VFS layer.
*
* dcfs is layered on top of ufs and passes requests involving persistence
* to the underlying ufs filesystem. The compressed files currently cannot be
* written to.
*/
/*
* Define data structures within this file.
*/
#define DCSHFT 5
#define DCTABLESIZE 16
#if ((DCTABLESIZE & (DCTABLESIZE - 1)) == 0)
#define DCHASH(vp) (((uintptr_t)(vp) >> DCSHFT) & (DCTABLESIZE - 1))
#else
#define DCHASH(vp) (((uintptr_t)(vp) >> DCSHFT) % DTABLESIZEC)
#endif
#define DCLRUSIZE 16
#define DCCACHESIZE 4
#define rounddown(x, y) ((x) & ~((y) - 1))
struct dcnode *dctable[DCTABLESIZE];
struct dcnode *dclru;
static int dclru_len;
kmutex_t dctable_lock;
dev_t dcdev;
struct vfs dc_vfs;
struct kmem_cache *dcnode_cache;
struct kmem_cache *dcbuf_cache[DCCACHESIZE];
kmutex_t dccache_lock;
static int dcinit(int, char *);
static struct dcnode *dcnode_alloc(void);
static void dcnode_free(struct dcnode *);
static void dcnode_recycle(struct dcnode *);
static void dcinsert(struct dcnode *);
static void dcdelete(struct dcnode *);
static struct dcnode *dcfind(struct vnode *);
static void dclru_add(struct dcnode *);
static void dclru_sub(struct dcnode *);
/*
* This is the loadable module wrapper.
*/
#include <sys/modctl.h>
struct vfsops *dc_vfsops;
static vfsdef_t vfw = {
VFSDEF_VERSION,
"dcfs",
dcinit,
VSW_ZMOUNT,
NULL
};
/*
* Module linkage information for the kernel.
*/
extern struct mod_ops mod_fsops;
static struct modlfs modlfs = {
&mod_fsops, "compressed filesystem", &vfw
};
static struct modlinkage modlinkage = {
MODREV_1, (void *)&modlfs, NULL
};
int
_init()
{
return (mod_install(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
static int dc_open(struct vnode **, int, struct cred *, caller_context_t *);
static int dc_close(struct vnode *, int, int, offset_t,
struct cred *, caller_context_t *);
static int dc_read(struct vnode *, struct uio *, int, struct cred *,
struct caller_context *);
static int dc_getattr(struct vnode *, struct vattr *, int,
struct cred *, caller_context_t *);
static int dc_setattr(struct vnode *, struct vattr *, int, struct cred *,
struct caller_context *);
static int dc_access(struct vnode *, int, int,
struct cred *, caller_context_t *);
static int dc_fsync(struct vnode *, int, struct cred *, caller_context_t *);
static void dc_inactive(struct vnode *, struct cred *, caller_context_t *);
static int dc_fid(struct vnode *, struct fid *, caller_context_t *);
static int dc_seek(struct vnode *, offset_t, offset_t *, caller_context_t *);
static int dc_frlock(struct vnode *, int, struct flock64 *, int, offset_t,
struct flk_callback *, struct cred *, caller_context_t *);
static int dc_realvp(struct vnode *, struct vnode **, caller_context_t *);
static int dc_getpage(struct vnode *, offset_t, size_t, uint_t *,
struct page **, size_t, struct seg *, caddr_t, enum seg_rw,
struct cred *, caller_context_t *);
static int dc_putpage(struct vnode *, offset_t, size_t, int,
struct cred *, caller_context_t *);
static int dc_map(struct vnode *, offset_t, struct as *, caddr_t *, size_t,
uchar_t, uchar_t, uint_t, struct cred *, caller_context_t *);
static int dc_addmap(struct vnode *, offset_t, struct as *, caddr_t, size_t,
uchar_t, uchar_t, uint_t, struct cred *, caller_context_t *);
static int dc_delmap(struct vnode *, offset_t, struct as *, caddr_t, size_t,
uint_t, uint_t, uint_t, struct cred *, caller_context_t *);
struct vnodeops *dc_vnodeops;
const fs_operation_def_t dc_vnodeops_template[] = {
VOPNAME_OPEN, { .vop_open = dc_open },
VOPNAME_CLOSE, { .vop_close = dc_close },
VOPNAME_READ, { .vop_read = dc_read },
VOPNAME_GETATTR, { .vop_getattr = dc_getattr },
VOPNAME_SETATTR, { .vop_setattr = dc_setattr },
VOPNAME_ACCESS, { .vop_access = dc_access },
VOPNAME_FSYNC, { .vop_fsync = dc_fsync },
VOPNAME_INACTIVE, { .vop_inactive = dc_inactive },
VOPNAME_FID, { .vop_fid = dc_fid },
VOPNAME_SEEK, { .vop_seek = dc_seek },
VOPNAME_FRLOCK, { .vop_frlock = dc_frlock },
VOPNAME_REALVP, { .vop_realvp = dc_realvp },
VOPNAME_GETPAGE, { .vop_getpage = dc_getpage },
VOPNAME_PUTPAGE, { .vop_putpage = dc_putpage },
VOPNAME_MAP, { .vop_map = dc_map },
VOPNAME_ADDMAP, { .vop_addmap = dc_addmap },
VOPNAME_DELMAP, { .vop_delmap = dc_delmap },
NULL, NULL
};
/*ARGSUSED*/
static int
dc_open(struct vnode **vpp, int flag, struct cred *cr, caller_context_t *ctp)
{
return (0);
}
/*ARGSUSED*/
static int
dc_close(struct vnode *vp, int flag, int count, offset_t off,
struct cred *cr, caller_context_t *ctp)
{
(void) cleanlocks(vp, ttoproc(curthread)->p_pid, 0);
cleanshares(vp, ttoproc(curthread)->p_pid);
return (0);
}
/*ARGSUSED*/
static int
dc_read(struct vnode *vp, struct uio *uiop, int ioflag, struct cred *cr,
struct caller_context *ct)
{
struct dcnode *dp = VTODC(vp);
size_t rdsize = MAX(MAXBSIZE, dp->dc_hdr->ch_blksize);
size_t fsize = dp->dc_hdr->ch_fsize;
int error;
/*
* Loop through file with segmap, decompression will occur
* in dc_getapage
*/
do {
caddr_t base;
size_t n;
offset_t mapon;
/*
* read to end of block or file
*/
mapon = uiop->uio_loffset & (rdsize - 1);
n = MIN(rdsize - mapon, uiop->uio_resid);
n = MIN(n, fsize - uiop->uio_loffset);
if (n == 0)
return (0); /* at EOF */
base = segmap_getmapflt(segkmap, vp, uiop->uio_loffset, n, 1,
S_READ);
error = uiomove(base + mapon, n, UIO_READ, uiop);
if (!error) {
uint_t flags;
if (n + mapon == rdsize || uiop->uio_loffset == fsize)
flags = SM_DONTNEED;
else
flags = 0;
error = segmap_release(segkmap, base, flags);
} else
(void) segmap_release(segkmap, base, 0);
} while (!error && uiop->uio_resid);
return (error);
}
static int
dc_getattr(struct vnode *vp, struct vattr *vap, int flags,
cred_t *cred, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct vnode *subvp = dp->dc_subvp;
int error;
error = VOP_GETATTR(subvp, vap, flags, cred, ctp);
/* substitute uncompressed size */
vap->va_size = dp->dc_hdr->ch_fsize;
return (error);
}
static int
dc_setattr(struct vnode *vp, struct vattr *vap, int flags, cred_t *cred,
caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct vnode *subvp = dp->dc_subvp;
return (VOP_SETATTR(subvp, vap, flags, cred, ctp));
}
static int
dc_access(struct vnode *vp, int mode, int flags,
cred_t *cred, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct vnode *subvp = dp->dc_subvp;
return (VOP_ACCESS(subvp, mode, flags, cred, ctp));
}
/*ARGSUSED*/
static int
dc_fsync(vnode_t *vp, int syncflag, cred_t *cred, caller_context_t *ctp)
{
return (0);
}
/*ARGSUSED*/
static void
dc_inactive(struct vnode *vp, cred_t *cr, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
mutex_enter(&dctable_lock);
mutex_enter(&vp->v_lock);
ASSERT(vp->v_count >= 1);
if (--vp->v_count != 0) {
/*
* Somebody accessed the dcnode before we got a chance to
* remove it. They will remove it when they do a vn_rele.
*/
mutex_exit(&vp->v_lock);
mutex_exit(&dctable_lock);
return;
}
mutex_exit(&vp->v_lock);
dcnode_free(dp);
mutex_exit(&dctable_lock);
}
static int
dc_fid(struct vnode *vp, struct fid *fidp, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct vnode *subvp = dp->dc_subvp;
return (VOP_FID(subvp, fidp, ctp));
}
static int
dc_seek(struct vnode *vp, offset_t oof, offset_t *noffp, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct vnode *subvp = dp->dc_subvp;
return (VOP_SEEK(subvp, oof, noffp, ctp));
}
static int
dc_frlock(struct vnode *vp, int cmd, struct flock64 *bfp, int flag,
offset_t offset, struct flk_callback *flk_cbp,
cred_t *cr, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
int error;
struct vattr vattr;
/*
* If file is being mapped, disallow frlock.
*/
vattr.va_mask = AT_MODE;
if (error = VOP_GETATTR(dp->dc_subvp, &vattr, 0, cr, ctp))
return (error);
if (dp->dc_mapcnt > 0 && MANDLOCK(vp, vattr.va_mode))
return (EAGAIN);
return (fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ctp));
}
/*ARGSUSED*/
static int
dc_getblock_miss(struct vnode *vp, offset_t off, size_t len, struct page **ppp,
struct seg *seg, caddr_t addr, enum seg_rw rw, struct cred *cr)
{
struct dcnode *dp = VTODC(vp);
struct comphdr *hdr = dp->dc_hdr;
struct page *pp;
struct buf *bp;
caddr_t saddr;
off_t cblkno;
size_t rdoff, rdsize, dsize;
long xlen;
int error, zerr;
ASSERT(len == hdr->ch_blksize);
/*
* Get destination pages and make them addressable
*/
pp = page_create_va(vp, off, len, PG_WAIT, seg, addr);
bp = pageio_setup(pp, len, vp, B_READ);
bp_mapin(bp);
/*
* read compressed data from subordinate vnode
*/
saddr = kmem_cache_alloc(dp->dc_bufcache, KM_SLEEP);
cblkno = off / len;
rdoff = hdr->ch_blkmap[cblkno];
rdsize = hdr->ch_blkmap[cblkno + 1] - rdoff;
error = vn_rdwr(UIO_READ, dp->dc_subvp, saddr, rdsize, rdoff,
UIO_SYSSPACE, 0, 0, cr, NULL);
if (error)
goto cleanup;
/*
* Uncompress
*/
dsize = len;
zerr = z_uncompress(bp->b_un.b_addr, &dsize, saddr, dp->dc_zmax);
if (zerr != Z_OK) {
error = EIO;
goto cleanup;
}
/*
* Handle EOF
*/
xlen = hdr->ch_fsize - off;
if (xlen < len) {
bzero(bp->b_un.b_addr + xlen, len - xlen);
if (dsize != xlen)
error = EIO;
} else if (dsize != len)
error = EIO;
/*
* Clean up
*/
cleanup:
kmem_cache_free(dp->dc_bufcache, saddr);
pageio_done(bp);
*ppp = pp;
return (error);
}
static int
dc_getblock(struct vnode *vp, offset_t off, size_t len, struct page **ppp,
struct seg *seg, caddr_t addr, enum seg_rw rw, struct cred *cr)
{
struct page *pp, *plist = NULL;
offset_t pgoff;
int rdblk;
/*
* pvn_read_kluster() doesn't quite do what we want, since it
* thinks sub block reads are ok. Here we always decompress
* a full block.
*/
/*
* Check page cache
*/
rdblk = 0;
for (pgoff = off; pgoff < off + len; pgoff += PAGESIZE) {
pp = page_lookup(vp, pgoff, SE_EXCL);
if (pp == NULL) {
rdblk = 1;
break;
}
page_io_lock(pp);
page_add(&plist, pp);
plist = plist->p_next;
}
if (!rdblk) {
*ppp = plist;
return (0); /* all pages in cache */
}
/*
* Undo any locks so getblock_miss has an open field
*/
if (plist != NULL)
pvn_io_done(plist);
return (dc_getblock_miss(vp, off, len, ppp, seg, addr, rw, cr));
}
static int
dc_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
{
struct vnode *rvp;
vp = VTODC(vp)->dc_subvp;
if (VOP_REALVP(vp, &rvp, ct) == 0)
vp = rvp;
*vpp = vp;
return (0);
}
/*ARGSUSED10*/
static int
dc_getpage(struct vnode *vp, offset_t off, size_t len, uint_t *protp,
struct page *pl[], size_t plsz, struct seg *seg, caddr_t addr,
enum seg_rw rw, struct cred *cr, caller_context_t *ctp)
{
struct dcnode *dp = VTODC(vp);
struct comphdr *hdr = dp->dc_hdr;
struct page *pp, *plist = NULL;
caddr_t vp_baddr;
offset_t vp_boff, vp_bend;
size_t bsize = hdr->ch_blksize;
int nblks, error;
/* does not support write */
if (rw == S_WRITE) {
panic("write attempt on compressed file");
/*NOTREACHED*/
}
if (protp)
*protp = PROT_ALL;
/*
* We don't support asynchronous operation at the moment, so
* just pretend we did it. If the pages are ever actually
* needed, they'll get brought in then.
*/
if (pl == NULL)
return (0);
/*
* Calc block start and end offsets
*/
vp_boff = rounddown(off, bsize);
vp_bend = roundup(off + len, bsize);
vp_baddr = (caddr_t)rounddown((uintptr_t)addr, bsize);
nblks = (vp_bend - vp_boff) / bsize;
while (nblks--) {
error = dc_getblock(vp, vp_boff, bsize, &pp, seg, vp_baddr,
rw, cr);
page_list_concat(&plist, &pp);
vp_boff += bsize;
vp_baddr += bsize;
}
if (!error)
pvn_plist_init(plist, pl, plsz, off, len, rw);
else
pvn_read_done(plist, B_ERROR);
return (error);
}
/*
* This function should never be called. We need to have it to pass
* it as an argument to other functions.
*/
/*ARGSUSED*/
static int
dc_putapage(struct vnode *vp, struct page *pp, u_offset_t *offp, size_t *lenp,
int flags, struct cred *cr)
{
/* should never happen */
cmn_err(CE_PANIC, "dcfs: dc_putapage: dirty page");
/*NOTREACHED*/
return (0);
}
/*
* The only flags we support are B_INVAL, B_FREE and B_DONTNEED.
* B_INVAL is set by:
*
* 1) the MC_SYNC command of memcntl(2) to support the MS_INVALIDATE flag.
* 2) the MC_ADVISE command of memcntl(2) with the MADV_DONTNEED advice
* which translates to an MC_SYNC with the MS_INVALIDATE flag.
*
* The B_FREE (as well as the B_DONTNEED) flag is set when the
* MADV_SEQUENTIAL advice has been used. VOP_PUTPAGE is invoked
* from SEGVN to release pages behind a pagefault.
*/
/*ARGSUSED5*/
static int
dc_putpage(struct vnode *vp, offset_t off, size_t len, int flags,
struct cred *cr, caller_context_t *ctp)
{
int error = 0;
if (vp->v_count == 0) {
panic("dcfs_putpage: bad v_count");
/*NOTREACHED*/
}
if (vp->v_flag & VNOMAP)
return (ENOSYS);
if (!vn_has_cached_data(vp)) /* no pages mapped */
return (0);
if (len == 0) /* from 'off' to EOF */
error = pvn_vplist_dirty(vp, off, dc_putapage, flags, cr);
else {
offset_t io_off;
se_t se = (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED;
for (io_off = off; io_off < off + len; io_off += PAGESIZE) {
page_t *pp;
/*
* We insist on getting the page only if we are
* about to invalidate, free or write it and
* the B_ASYNC flag is not set.
*/
if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0))
pp = page_lookup(vp, io_off, se);
else
pp = page_lookup_nowait(vp, io_off, se);
if (pp == NULL)
continue;
/*
* Normally pvn_getdirty() should return 0, which
* impies that it has done the job for us.
* The shouldn't-happen scenario is when it returns 1.
* This means that the page has been modified and
* needs to be put back.
* Since we can't write to a dcfs compressed file,
* we fake a failed I/O and force pvn_write_done()
* to destroy the page.
*/
if (pvn_getdirty(pp, flags) == 1) {
cmn_err(CE_NOTE, "dc_putpage: dirty page");
pvn_write_done(pp, flags |
B_ERROR | B_WRITE | B_INVAL | B_FORCE);
}
}
}
return (error);
}
static int
dc_map(struct vnode *vp, offset_t off, struct as *as, caddr_t *addrp,
size_t len, uchar_t prot, uchar_t maxprot, uint_t flags,
struct cred *cred, caller_context_t *ctp)
{
struct vattr vattr;
struct segvn_crargs vn_a;
int error;
if (vp->v_flag & VNOMAP)
return (ENOSYS);
if (off < (offset_t)0 || (offset_t)(off + len) < (offset_t)0)
return (ENXIO);
/*
* If file is being locked, disallow mapping.
*/
if (error = VOP_GETATTR(VTODC(vp)->dc_subvp, &vattr, 0, cred, ctp))
return (error);
if (vn_has_mandatory_locks(vp, vattr.va_mode))
return (EAGAIN);
as_rangelock(as);
if ((flags & MAP_FIXED) == 0) {
map_addr(addrp, len, off, 1, flags);
if (*addrp == NULL) {
as_rangeunlock(as);
return (ENOMEM);
}
} else {
/*
* User specified address - blow away any previous mappings
*/
(void) as_unmap(as, *addrp, len);
}
vn_a.vp = vp;
vn_a.offset = off;
vn_a.type = flags & MAP_TYPE;
vn_a.prot = prot;
vn_a.maxprot = maxprot;
vn_a.flags = flags & ~MAP_TYPE;
vn_a.cred = cred;
vn_a.amp = NULL;
vn_a.szc = 0;
vn_a.lgrp_mem_policy_flags = 0;
error = as_map(as, *addrp, len, segvn_create, &vn_a);
as_rangeunlock(as);
return (error);
}
/*ARGSUSED*/
static int
dc_addmap(struct vnode *vp, offset_t off, struct as *as, caddr_t addr,
size_t len, uchar_t prot, uchar_t maxprot, uint_t flags,
struct cred *cr, caller_context_t *ctp)
{
struct dcnode *dp;
if (vp->v_flag & VNOMAP)
return (ENOSYS);
dp = VTODC(vp);
mutex_enter(&dp->dc_lock);
dp->dc_mapcnt += btopr(len);
mutex_exit(&dp->dc_lock);
return (0);
}
/*ARGSUSED*/
static int
dc_delmap(struct vnode *vp, offset_t off, struct as *as, caddr_t addr,
size_t len, uint_t prot, uint_t maxprot, uint_t flags,
struct cred *cr, caller_context_t *ctp)
{
struct dcnode *dp;
if (vp->v_flag & VNOMAP)
return (ENOSYS);
dp = VTODC(vp);
mutex_enter(&dp->dc_lock);
dp->dc_mapcnt -= btopr(len);
ASSERT(dp->dc_mapcnt >= 0);
mutex_exit(&dp->dc_lock);
return (0);
}
/*
* Constructor/destructor routines for dcnodes
*/
/*ARGSUSED1*/
static int
dcnode_constructor(void *buf, void *cdrarg, int kmflags)
{
struct dcnode *dp = buf;
struct vnode *vp;
vp = dp->dc_vp = vn_alloc(kmflags);
if (vp == NULL) {
return (-1);
}
vp->v_data = dp;
vp->v_type = VREG;
vp->v_flag = VNOSWAP;
vp->v_vfsp = &dc_vfs;
vn_setops(vp, dc_vnodeops);
vn_exists(vp);
mutex_init(&dp->dc_lock, NULL, MUTEX_DEFAULT, NULL);
dp->dc_mapcnt = 0;
dp->dc_lrunext = dp->dc_lruprev = NULL;
dp->dc_hdr = NULL;
dp->dc_subvp = NULL;
return (0);
}
/*ARGSUSED*/
static void
dcnode_destructor(void *buf, void *cdrarg)
{
struct dcnode *dp = buf;
struct vnode *vp = DCTOV(dp);
mutex_destroy(&dp->dc_lock);
VERIFY(dp->dc_hdr == NULL);
VERIFY(dp->dc_subvp == NULL);
vn_invalid(vp);
vn_free(vp);
}
static struct dcnode *
dcnode_alloc(void)
{
struct dcnode *dp;
/*
* If the free list is above DCLRUSIZE
* re-use one from it
*/
mutex_enter(&dctable_lock);
if (dclru_len < DCLRUSIZE) {
mutex_exit(&dctable_lock);
dp = kmem_cache_alloc(dcnode_cache, KM_SLEEP);
} else {
ASSERT(dclru != NULL);
dp = dclru;
dclru_sub(dp);
dcdelete(dp);
mutex_exit(&dctable_lock);
dcnode_recycle(dp);
}
return (dp);
}
static void
dcnode_free(struct dcnode *dp)
{
struct vnode *vp = DCTOV(dp);
ASSERT(MUTEX_HELD(&dctable_lock));
/*
* If no cached pages, no need to put it on lru
*/
if (!vn_has_cached_data(vp)) {
dcdelete(dp);
dcnode_recycle(dp);
kmem_cache_free(dcnode_cache, dp);
return;
}
/*
* Add to lru, if it's over the limit, free from head
*/
dclru_add(dp);
if (dclru_len > DCLRUSIZE) {
dp = dclru;
dclru_sub(dp);
dcdelete(dp);
dcnode_recycle(dp);
kmem_cache_free(dcnode_cache, dp);
}
}
static void
dcnode_recycle(struct dcnode *dp)
{
struct vnode *vp;
vp = DCTOV(dp);
VN_RELE(dp->dc_subvp);
dp->dc_subvp = NULL;
(void) pvn_vplist_dirty(vp, 0, dc_putapage, B_INVAL, NULL);
kmem_free(dp->dc_hdr, dp->dc_hdrsize);
dp->dc_hdr = NULL;
dp->dc_hdrsize = dp->dc_zmax = 0;
dp->dc_bufcache = NULL;
dp->dc_mapcnt = 0;
vn_reinit(vp);
vp->v_type = VREG;
vp->v_flag = VNOSWAP;
vp->v_vfsp = &dc_vfs;
}
static int
dcinit(int fstype, char *name)
{
static const fs_operation_def_t dc_vfsops_template[] = {
NULL, NULL
};
int error;
major_t dev;
error = vfs_setfsops(fstype, dc_vfsops_template, &dc_vfsops);
if (error) {
cmn_err(CE_WARN, "dcinit: bad vfs ops template");
return (error);
}
VFS_INIT(&dc_vfs, dc_vfsops, NULL);
dc_vfs.vfs_flag = VFS_RDONLY;
dc_vfs.vfs_fstype = fstype;
if ((dev = getudev()) == (major_t)-1)
dev = 0;
dcdev = makedevice(dev, 0);
dc_vfs.vfs_dev = dcdev;
error = vn_make_ops(name, dc_vnodeops_template, &dc_vnodeops);
if (error != 0) {
(void) vfs_freevfsops_by_type(fstype);
cmn_err(CE_WARN, "dcinit: bad vnode ops template");
return (error);
}
mutex_init(&dctable_lock, NULL, MUTEX_DEFAULT, NULL);
mutex_init(&dccache_lock, NULL, MUTEX_DEFAULT, NULL);
dcnode_cache = kmem_cache_create("dcnode_cache", sizeof (struct dcnode),
0, dcnode_constructor, dcnode_destructor, NULL, NULL, NULL, 0);
return (0);
}
/*
* Return shadow vnode with the given vp as its subordinate
*/
struct vnode *
decompvp(struct vnode *vp, cred_t *cred, caller_context_t *ctp)
{
struct dcnode *dp, *ndp;
struct comphdr thdr, *hdr;
struct kmem_cache **cpp;
struct vattr vattr;
size_t hdrsize, bsize;
int error;
/*
* See if we have an existing shadow
* If none, we have to manufacture one
*/
mutex_enter(&dctable_lock);
dp = dcfind(vp);
mutex_exit(&dctable_lock);
if (dp != NULL)
return (DCTOV(dp));
/*
* Make sure it's a valid compressed file
*/
hdr = &thdr;
error = vn_rdwr(UIO_READ, vp, (caddr_t)hdr, sizeof (struct comphdr), 0,
UIO_SYSSPACE, 0, 0, cred, NULL);
if (error || hdr->ch_magic != CH_MAGIC_ZLIB ||
hdr->ch_version != CH_VERSION || hdr->ch_algorithm != CH_ALG_ZLIB ||
hdr->ch_fsize == 0 || hdr->ch_blksize < PAGESIZE ||
hdr->ch_blksize > ptob(DCCACHESIZE) || !ISP2(hdr->ch_blksize))
return (NULL);
/* get underlying file size */
if (VOP_GETATTR(vp, &vattr, 0, cred, ctp) != 0)
return (NULL);
/*
* Re-read entire header
*/
hdrsize = hdr->ch_blkmap[0] + sizeof (uint64_t);
hdr = kmem_alloc(hdrsize, KM_SLEEP);
error = vn_rdwr(UIO_READ, vp, (caddr_t)hdr, hdrsize, 0, UIO_SYSSPACE,
0, 0, cred, NULL);
if (error) {
kmem_free(hdr, hdrsize);
return (NULL);
}
/*
* add extra blkmap entry to make dc_getblock()'s
* life easier
*/
bsize = hdr->ch_blksize;
hdr->ch_blkmap[((hdr->ch_fsize-1) / bsize) + 1] = vattr.va_size;
ndp = dcnode_alloc();
ndp->dc_subvp = vp;
VN_HOLD(vp);
ndp->dc_hdr = hdr;
ndp->dc_hdrsize = hdrsize;
/*
* Allocate kmem cache if none there already
*/
ndp->dc_zmax = ZMAXBUF(bsize);
cpp = &dcbuf_cache[btop(bsize)];
mutex_enter(&dccache_lock);
if (*cpp == NULL)
*cpp = kmem_cache_create("dcbuf_cache", ndp->dc_zmax, 0, NULL,
NULL, NULL, NULL, NULL, 0);
mutex_exit(&dccache_lock);
ndp->dc_bufcache = *cpp;
/*
* Recheck table in case someone else created shadow
* while we were blocked above.
*/
mutex_enter(&dctable_lock);
dp = dcfind(vp);
if (dp != NULL) {
mutex_exit(&dctable_lock);
dcnode_recycle(ndp);
kmem_cache_free(dcnode_cache, ndp);
return (DCTOV(dp));
}
dcinsert(ndp);
mutex_exit(&dctable_lock);
return (DCTOV(ndp));
}
/*
* dcnode lookup table
* These routines maintain a table of dcnodes hashed by their
* subordinate vnode so that they can be found if they already
* exist in the vnode cache
*/
/*
* Put a dcnode in the table.
*/
static void
dcinsert(struct dcnode *newdp)
{
int idx = DCHASH(newdp->dc_subvp);
ASSERT(MUTEX_HELD(&dctable_lock));
newdp->dc_hash = dctable[idx];
dctable[idx] = newdp;
}
/*
* Remove a dcnode from the hash table.
*/
void
dcdelete(struct dcnode *deldp)
{
int idx = DCHASH(deldp->dc_subvp);
struct dcnode *dp, *prevdp;
ASSERT(MUTEX_HELD(&dctable_lock));
dp = dctable[idx];
if (dp == deldp)
dctable[idx] = dp->dc_hash;
else {
for (prevdp = dp, dp = dp->dc_hash; dp != NULL;
prevdp = dp, dp = dp->dc_hash) {
if (dp == deldp) {
prevdp->dc_hash = dp->dc_hash;
break;
}
}
}
ASSERT(dp != NULL);
}
/*
* Find a shadow vnode in the dctable hash list.
*/
static struct dcnode *
dcfind(struct vnode *vp)
{
struct dcnode *dp;
ASSERT(MUTEX_HELD(&dctable_lock));
for (dp = dctable[DCHASH(vp)]; dp != NULL; dp = dp->dc_hash)
if (dp->dc_subvp == vp) {
VN_HOLD(DCTOV(dp));
if (dp->dc_lrunext)
dclru_sub(dp);
return (dp);
}
return (NULL);
}
#ifdef DEBUG
static int
dclru_count(void)
{
struct dcnode *dp;
int i = 0;
if (dclru == NULL)
return (0);
for (dp = dclru; dp->dc_lrunext != dclru; dp = dp->dc_lrunext)
i++;
return (i + 1);
}
#endif
static void
dclru_add(struct dcnode *dp)
{
/*
* Add to dclru as double-link chain
*/
ASSERT(MUTEX_HELD(&dctable_lock));
if (dclru == NULL) {
dclru = dp;
dp->dc_lruprev = dp->dc_lrunext = dp;
} else {
struct dcnode *last = dclru->dc_lruprev;
dclru->dc_lruprev = dp;
last->dc_lrunext = dp;
dp->dc_lruprev = last;
dp->dc_lrunext = dclru;
}
dclru_len++;
ASSERT(dclru_len == dclru_count());
}
static void
dclru_sub(struct dcnode *dp)
{
ASSERT(MUTEX_HELD(&dctable_lock));
dp->dc_lrunext->dc_lruprev = dp->dc_lruprev;
dp->dc_lruprev->dc_lrunext = dp->dc_lrunext;
if (dp == dclru)
dclru = dp->dc_lrunext == dp ? NULL : dp->dc_lrunext;
dp->dc_lrunext = dp->dc_lruprev = NULL;
dclru_len--;
ASSERT(dclru_len == dclru_count());
}