/* $NetBSD: lfs_balloc.c,v 1.98 2026/01/05 05:02:47 perseant 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 1.98 2026/01/05 05:02:47 perseant 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) { lfs_fraglock_enter(fs, 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 lfs_fraglock_exit(fs); 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) { lfs_fraglock_exit(fs); } 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; KASSERT(vp != NULL); ip = VTOI(vp); KASSERT(ip != NULL); fs = ip->i_lfs; KASSERT(fs != NULL); /* Don't count metadata */ if (lbn < 0 || vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM) return; mutex_enter(&lfs_lock); if (fs->lfs_sp && (fs->lfs_sp->seg_flags & SEGM_CLEAN)) { mutex_exit(&lfs_lock); return; } 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); }
