NetBSD/sys/ufs/lfs/lfs_balloc.c

722 lines
20 KiB
C

/* $NetBSD: lfs_balloc.c,v 1.96 2020/09/05 16:30:13 riastradh Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Konrad E. Schroder <perseant@hhhh.org>.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1989, 1991, 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.
*
* @(#)lfs_balloc.c 8.4 (Berkeley) 5/8/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lfs_balloc.c,v 1.96 2020/09/05 16:30:13 riastradh Exp $");
#if defined(_KERNEL_OPT)
#include "opt_quota.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/resourcevar.h>
#include <sys/tree.h>
#include <sys/trace.h>
#include <sys/kauth.h>
#include <miscfs/specfs/specdev.h>
#include <ufs/lfs/ulfs_quotacommon.h>
#include <ufs/lfs/ulfs_inode.h>
#include <ufs/lfs/ulfsmount.h>
#include <ufs/lfs/ulfs_extern.h>
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_accessors.h>
#include <ufs/lfs/lfs_extern.h>
#include <ufs/lfs/lfs_kernel.h>
#include <uvm/uvm_extern.h>
static int lfs_fragextend(struct vnode *, int, int, daddr_t, struct buf **,
kauth_cred_t);
u_int64_t locked_fakequeue_count;
/*
* Allocate a block, and do inode and filesystem block accounting for
* it and for any indirect blocks that may need to be created in order
* to handle this block.
*
* Blocks which have never been accounted for (i.e., which "do not
* exist") have disk address 0, which is translated by ulfs_bmap to
* the special value UNASSIGNED == -1, as in historical FFS-related
* code.
*
* Blocks which have been accounted for but which have not yet been
* written to disk are given the new special disk address UNWRITTEN ==
* -2, so that they can be differentiated from completely new blocks.
*
* Note: it seems that bpp is passed as NULL for blocks that are file
* pages that will be handled by UVM and not the buffer cache.
*
* XXX: locking?
*/
/* VOP_BWRITE ULFS_NIADDR+2 times */
int
lfs_balloc(struct vnode *vp, off_t startoffset, int iosize, kauth_cred_t cred,
int flags, struct buf **bpp)
{
int offset;
daddr_t daddr, idaddr;
struct buf *ibp, *bp;
struct inode *ip;
struct lfs *fs;
struct indir indirs[ULFS_NIADDR+2], *idp;
daddr_t lbn, lastblock;
int bcount;
int error, frags, i, nsize, osize, num;
ip = VTOI(vp);
fs = ip->i_lfs;
/* Declare to humans that we might have the seglock here */
ASSERT_MAYBE_SEGLOCK(fs);
/* offset within block */
offset = lfs_blkoff(fs, startoffset);
/* This is usually but not always exactly the block size */
KASSERT(iosize <= lfs_sb_getbsize(fs));
/* block number (within file) */
lbn = lfs_lblkno(fs, startoffset);
/*
* This checks for whether pending stuff needs to be flushed
* out and potentially waits. It's been disabled since UBC
* support was added to LFS in 2003. -- dholland 20160806
*/
/* (void)lfs_check(vp, lbn, 0); */
/*
* Three cases: it's a block beyond the end of file, it's a block in
* the file that may or may not have been assigned a disk address or
* we're writing an entire block.
*
* Note, if the daddr is UNWRITTEN, the block already exists in
* the cache (it was read or written earlier). If so, make sure
* we don't count it as a new block or zero out its contents. If
* it did not, make sure we allocate any necessary indirect
* blocks.
*
* If we are writing a block beyond the end of the file, we need to
* check if the old last block was a fragment. If it was, we need
* to rewrite it.
*/
if (bpp)
*bpp = NULL;
/* Last block number in file */
lastblock = lfs_lblkno(fs, ip->i_size);
if (lastblock < ULFS_NDADDR && lastblock < lbn) {
/*
* The file is small enough to have fragments, and we're
* allocating past EOF.
*
* If the last block was a fragment we need to rewrite it
* as a full block.
*/
osize = lfs_blksize(fs, ip, lastblock);
if (osize < lfs_sb_getbsize(fs) && osize > 0) {
if ((error = lfs_fragextend(vp, osize, lfs_sb_getbsize(fs),
lastblock,
(bpp ? &bp : NULL), cred)))
return (error);
/* Update the file size with what we just did (only) */
ip->i_size = (lastblock + 1) * lfs_sb_getbsize(fs);
lfs_dino_setsize(fs, ip->i_din, ip->i_size);
uvm_vnp_setsize(vp, ip->i_size);
ip->i_state |= IN_CHANGE | IN_UPDATE;
/* if we got a buffer for this, write it out now */
if (bpp)
(void) VOP_BWRITE(bp->b_vp, bp);
}
}
/*
* If the block we are writing is a direct block, it's the last
* block in the file, and offset + iosize is less than a full
* block, we can write one or more fragments. There are two cases:
* the block is brand new and we should allocate it the correct
* size or it already exists and contains some fragments and
* may need to extend it.
*/
if (lbn < ULFS_NDADDR && lfs_lblkno(fs, ip->i_size) <= lbn) {
osize = lfs_blksize(fs, ip, lbn);
nsize = lfs_fragroundup(fs, offset + iosize);
if (lfs_lblktosize(fs, lbn) >= ip->i_size) {
/* Brand new block or fragment */
frags = lfs_numfrags(fs, nsize);
if (!ISSPACE(fs, frags, cred))
return ENOSPC;
if (bpp) {
*bpp = bp = getblk(vp, lbn, nsize, 0, 0);
bp->b_blkno = UNWRITTEN;
if (flags & B_CLRBUF)
clrbuf(bp);
}
/*
* Update the effective block count (this count
* includes blocks that don't have an on-disk
* presence or location yet)
*/
ip->i_lfs_effnblks += frags;
/* account for the space we're taking */
mutex_enter(&lfs_lock);
lfs_sb_subbfree(fs, frags);
mutex_exit(&lfs_lock);
/* update the inode */
lfs_dino_setdb(fs, ip->i_din, lbn, UNWRITTEN);
} else {
/* extending a block that already has fragments */
if (nsize <= osize) {
/* No need to extend */
if (bpp && (error = bread(vp, lbn, osize,
0, &bp)))
return error;
} else {
/* Extend existing block */
if ((error =
lfs_fragextend(vp, osize, nsize, lbn,
(bpp ? &bp : NULL), cred)))
return error;
}
if (bpp)
*bpp = bp;
}
return 0;
}
/*
* Look up what's already here.
*/
error = ulfs_bmaparray(vp, lbn, &daddr, &indirs[0], &num, NULL, NULL);
if (error)
return (error);
KASSERT(daddr <= LFS_MAX_DADDR(fs));
/*
* Do byte accounting all at once, so we can gracefully fail *before*
* we start assigning blocks.
*/
frags = fs->um_seqinc;
bcount = 0; /* number of frags we need */
if (daddr == UNASSIGNED) {
/* no block yet, going to need a whole block */
bcount = frags;
}
for (i = 1; i < num; ++i) {
if (!indirs[i].in_exists) {
/* need an indirect block at this level */
bcount += frags;
}
}
if (ISSPACE(fs, bcount, cred)) {
/* update the superblock's free block count */
mutex_enter(&lfs_lock);
lfs_sb_subbfree(fs, bcount);
mutex_exit(&lfs_lock);
/* update the file's effective block count */
ip->i_lfs_effnblks += bcount;
} else {
/* whoops, no can do */
return ENOSPC;
}
if (daddr == UNASSIGNED) {
/*
* There is nothing here yet.
*/
/*
* If there's no indirect block in the inode, change it
* to UNWRITTEN to indicate that it exists but doesn't
* have an on-disk address yet.
*
* (Question: where's the block data initialized?)
*/
if (num > 0 && lfs_dino_getib(fs, ip->i_din, indirs[0].in_off) == 0) {
lfs_dino_setib(fs, ip->i_din, indirs[0].in_off, UNWRITTEN);
}
/*
* If we need more layers of indirect blocks, create what
* we need.
*/
if (num > 1) {
/*
* The outermost indirect block address is the one
* in the inode, so fetch that.
*/
idaddr = lfs_dino_getib(fs, ip->i_din, indirs[0].in_off);
/*
* For each layer of indirection...
*/
for (i = 1; i < num; ++i) {
/*
* Get a buffer for the indirect block data.
*
* (XXX: the logic here seems twisted. What's
* wrong with testing in_exists first and then
* doing either bread or getblk to get a
* buffer?)
*/
ibp = getblk(vp, indirs[i].in_lbn,
lfs_sb_getbsize(fs), 0,0);
if (!indirs[i].in_exists) {
/*
* There isn't actually a block here,
* so clear the buffer data and mark
* the address of the block as
* UNWRITTEN.
*/
clrbuf(ibp);
ibp->b_blkno = UNWRITTEN;
} else if (!(ibp->b_oflags & (BO_DELWRI | BO_DONE))) {
/*
* Otherwise read it in.
*/
ibp->b_blkno = LFS_FSBTODB(fs, idaddr);
ibp->b_flags |= B_READ;
VOP_STRATEGY(vp, ibp);
biowait(ibp);
}
/*
* Now this indirect block exists, but
* the next one down may not yet. If
* so, set it to UNWRITTEN. This keeps
* the accounting straight.
*/
if (lfs_iblock_get(fs, ibp->b_data, indirs[i].in_off) == 0)
lfs_iblock_set(fs, ibp->b_data, indirs[i].in_off,
UNWRITTEN);
/* get the block for the next iteration */
idaddr = lfs_iblock_get(fs, ibp->b_data, indirs[i].in_off);
if (vp == fs->lfs_ivnode) {
LFS_ENTER_LOG("balloc", __FILE__,
__LINE__, indirs[i].in_lbn,
ibp->b_flags, curproc->p_pid);
}
/*
* Write out the updated indirect block. Note
* that this writes it out even if we didn't
* modify it - ultimately because the final
* block didn't exist we'll need to write a
* new version of all the blocks that lead to
* it. Hopefully all that gets in before any
* actual disk I/O so we don't end up writing
* any of them twice... this is currently not
* very clear.
*/
if ((error = VOP_BWRITE(ibp->b_vp, ibp)))
return error;
}
}
}
/*
* Get the existing block from the cache, if requested.
*/
if (bpp)
*bpp = bp = getblk(vp, lbn, lfs_blksize(fs, ip, lbn), 0, 0);
/*
* Do accounting on blocks that represent pages.
*/
if (!bpp)
lfs_register_block(vp, lbn);
/*
* The block we are writing may be a brand new block
* in which case we need to do accounting.
*
* We can tell a truly new block because ulfs_bmaparray will say
* it is UNASSIGNED. Once we allocate it we will assign it the
* disk address UNWRITTEN.
*/
if (daddr == UNASSIGNED) {
if (bpp) {
if (flags & B_CLRBUF)
clrbuf(bp);
/* Note the new address */
bp->b_blkno = UNWRITTEN;
}
switch (num) {
case 0:
/* direct block - update the inode */
lfs_dino_setdb(fs, ip->i_din, lbn, UNWRITTEN);
break;
case 1:
/*
* using a single indirect block - update the inode
*
* XXX: is this right? We already set this block
* pointer above. I think we want to be writing *in*
* the single indirect block and this case shouldn't
* exist. (just case 0 and default)
* -- dholland 20160806
*/
lfs_dino_setib(fs, ip->i_din, indirs[0].in_off, UNWRITTEN);
break;
default:
/*
* using multiple indirect blocks - update the
* innermost one
*/
idp = &indirs[num - 1];
if (bread(vp, idp->in_lbn, lfs_sb_getbsize(fs),
B_MODIFY, &ibp))
panic("lfs_balloc: bread bno %lld",
(long long)idp->in_lbn);
lfs_iblock_set(fs, ibp->b_data, idp->in_off, UNWRITTEN);
if (vp == fs->lfs_ivnode) {
LFS_ENTER_LOG("balloc", __FILE__,
__LINE__, idp->in_lbn,
ibp->b_flags, curproc->p_pid);
}
VOP_BWRITE(ibp->b_vp, ibp);
}
} else if (bpp && !(bp->b_oflags & (BO_DONE|BO_DELWRI))) {
/*
* Not a brand new block, also not in the cache;
* read it in from disk.
*/
if (iosize == lfs_sb_getbsize(fs))
/* Optimization: I/O is unnecessary. */
bp->b_blkno = daddr;
else {
/*
* We need to read the block to preserve the
* existing bytes.
*/
bp->b_blkno = daddr;
bp->b_flags |= B_READ;
VOP_STRATEGY(vp, bp);
return (biowait(bp));
}
}
return (0);
}
/*
* Extend a file that uses fragments with more fragments.
*
* XXX: locking?
*/
/* VOP_BWRITE 1 time */
static int
lfs_fragextend(struct vnode *vp, int osize, int nsize, daddr_t lbn,
struct buf **bpp, kauth_cred_t cred)
{
struct inode *ip;
struct lfs *fs;
long frags;
int error;
size_t obufsize;
/* XXX move this to a header file */
/* (XXX: except it's not clear what purpose it serves) */
extern long locked_queue_bytes;
ip = VTOI(vp);
fs = ip->i_lfs;
/*
* XXX: is there some reason we know more about the seglock
* state here than at the top of lfs_balloc?
*/
ASSERT_NO_SEGLOCK(fs);
/* number of frags we're adding */
frags = (long)lfs_numfrags(fs, nsize - osize);
error = 0;
/*
* Get the seglock so we don't enlarge blocks while a segment
* is being written. If we're called with bpp==NULL, though,
* we are only pretending to change a buffer, so we don't have to
* lock.
*
* XXX: the above comment is lying, as fs->lfs_fraglock is not
* the segment lock.
*/
top:
if (bpp) {
rw_enter(&fs->lfs_fraglock, RW_READER);
}
/* check if we actually have enough frags available */
if (!ISSPACE(fs, frags, cred)) {
error = ENOSPC;
goto out;
}
/*
* If we are not asked to actually return the block, all we need
* to do is allocate space for it. UBC will handle dirtying the
* appropriate things and making sure it all goes to disk.
* Don't bother to read in that case.
*/
if (bpp && (error = bread(vp, lbn, osize, 0, bpp))) {
goto out;
}
#if defined(LFS_QUOTA) || defined(LFS_QUOTA2)
if ((error = lfs_chkdq(ip, frags, cred, 0))) {
if (bpp)
brelse(*bpp, 0);
goto out;
}
#endif
/*
* Adjust accounting for lfs_avail. If there's not enough room,
* we will have to wait for the cleaner, which we can't do while
* holding a block busy or while holding the seglock. In that case,
* release both and start over after waiting.
*/
if (bpp && ((*bpp)->b_oflags & BO_DELWRI)) {
if (!lfs_fits(fs, frags)) {
if (bpp)
brelse(*bpp, 0);
#if defined(LFS_QUOTA) || defined(LFS_QUOTA2)
lfs_chkdq(ip, -frags, cred, 0);
#endif
rw_exit(&fs->lfs_fraglock);
lfs_availwait(fs, frags);
goto top;
}
lfs_sb_subavail(fs, frags);
}
/* decrease the free block count in the superblock */
mutex_enter(&lfs_lock);
lfs_sb_subbfree(fs, frags);
mutex_exit(&lfs_lock);
/* increase the file's effective block count */
ip->i_lfs_effnblks += frags;
/* mark the inode dirty */
ip->i_state |= IN_CHANGE | IN_UPDATE;
if (bpp) {
obufsize = (*bpp)->b_bufsize;
allocbuf(*bpp, nsize, 1);
/* Adjust locked-list accounting */
if (((*bpp)->b_flags & B_LOCKED) != 0 &&
(*bpp)->b_iodone == NULL) {
mutex_enter(&lfs_lock);
locked_queue_bytes += (*bpp)->b_bufsize - obufsize;
mutex_exit(&lfs_lock);
}
/* zero the new space */
memset((char *)((*bpp)->b_data) + osize, 0, (u_int)(nsize - osize));
}
out:
if (bpp) {
rw_exit(&fs->lfs_fraglock);
}
return (error);
}
static inline int
lge(struct lbnentry *a, struct lbnentry *b)
{
return a->lbn - b->lbn;
}
SPLAY_PROTOTYPE(lfs_splay, lbnentry, entry, lge);
SPLAY_GENERATE(lfs_splay, lbnentry, entry, lge);
/*
* Record this lbn as being "write pending". We used to have this information
* on the buffer headers, but since pages don't have buffer headers we
* record it here instead.
*/
void
lfs_register_block(struct vnode *vp, daddr_t lbn)
{
struct lfs *fs;
struct inode *ip;
struct lbnentry *lbp;
ip = VTOI(vp);
/* Don't count metadata */
if (lbn < 0 || vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM)
return;
fs = ip->i_lfs;
ASSERT_NO_SEGLOCK(fs);
/* If no space, wait for the cleaner */
lfs_availwait(fs, lfs_btofsb(fs, 1 << lfs_sb_getbshift(fs)));
lbp = (struct lbnentry *)pool_get(&lfs_lbnentry_pool, PR_WAITOK);
lbp->lbn = lbn;
mutex_enter(&lfs_lock);
if (SPLAY_INSERT(lfs_splay, &ip->i_lfs_lbtree, lbp) != NULL) {
mutex_exit(&lfs_lock);
/* Already there */
pool_put(&lfs_lbnentry_pool, lbp);
return;
}
++ip->i_lfs_nbtree;
fs->lfs_favail += lfs_btofsb(fs, (1 << lfs_sb_getbshift(fs)));
fs->lfs_pages += lfs_sb_getbsize(fs) >> PAGE_SHIFT;
++locked_fakequeue_count;
lfs_subsys_pages += lfs_sb_getbsize(fs) >> PAGE_SHIFT;
mutex_exit(&lfs_lock);
}
static void
lfs_do_deregister(struct lfs *fs, struct inode *ip, struct lbnentry *lbp)
{
KASSERT(mutex_owned(&lfs_lock));
ASSERT_MAYBE_SEGLOCK(fs);
--ip->i_lfs_nbtree;
SPLAY_REMOVE(lfs_splay, &ip->i_lfs_lbtree, lbp);
if (fs->lfs_favail > lfs_btofsb(fs, (1 << lfs_sb_getbshift(fs))))
fs->lfs_favail -= lfs_btofsb(fs, (1 << lfs_sb_getbshift(fs)));
fs->lfs_pages -= lfs_sb_getbsize(fs) >> PAGE_SHIFT;
if (locked_fakequeue_count > 0)
--locked_fakequeue_count;
lfs_subsys_pages -= lfs_sb_getbsize(fs) >> PAGE_SHIFT;
mutex_exit(&lfs_lock);
pool_put(&lfs_lbnentry_pool, lbp);
mutex_enter(&lfs_lock);
KASSERT(mutex_owned(&lfs_lock));
}
void
lfs_deregister_block(struct vnode *vp, daddr_t lbn)
{
struct lfs *fs;
struct inode *ip;
struct lbnentry *lbp;
struct lbnentry tmp;
ip = VTOI(vp);
/* Don't count metadata */
if (lbn < 0 || vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM)
return;
mutex_enter(&lfs_lock);
fs = ip->i_lfs;
tmp.lbn = lbn;
if ((lbp = SPLAY_FIND(lfs_splay, &ip->i_lfs_lbtree, &tmp)) != NULL)
lfs_do_deregister(fs, ip, lbp);
mutex_exit(&lfs_lock);
}
void
lfs_deregister_all(struct vnode *vp)
{
struct lbnentry *lbp;
struct lfs_splay *hd;
struct lfs *fs;
struct inode *ip;
ip = VTOI(vp);
fs = ip->i_lfs;
hd = &ip->i_lfs_lbtree;
mutex_enter(&lfs_lock);
while ((lbp = SPLAY_MIN(lfs_splay, hd)) != NULL)
lfs_do_deregister(fs, ip, lbp);
mutex_exit(&lfs_lock);
}