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Current File : //usr/src/sys/fs/ext2fs/ext2_inode.c |
/*- * modified for Lites 1.1 * * Aug 1995, Godmar Back (gback@cs.utah.edu) * University of Utah, Department of Computer Science */ /*- * Copyright (c) 1982, 1986, 1989, 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. * 4. 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. * * @(#)ffs_inode.c 8.5 (Berkeley) 12/30/93 * $FreeBSD: release/9.1.0/sys/fs/ext2fs/ext2_inode.c 229549 2012-01-05 01:35:01Z pfg $ */ #include <sys/param.h> #include <sys/systm.h> #include <sys/mount.h> #include <sys/bio.h> #include <sys/buf.h> #include <sys/vnode.h> #include <sys/malloc.h> #include <vm/vm.h> #include <vm/vm_extern.h> #include <fs/ext2fs/inode.h> #include <fs/ext2fs/ext2_mount.h> #include <fs/ext2fs/ext2fs.h> #include <fs/ext2fs/fs.h> #include <fs/ext2fs/ext2_extern.h> static int ext2_indirtrunc(struct inode *, int32_t, int32_t, int32_t, int, long *); /* * Update the access, modified, and inode change times as specified by the * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively. Write the inode * to disk if the IN_MODIFIED flag is set (it may be set initially, or by * the timestamp update). The IN_LAZYMOD flag is set to force a write * later if not now. If we write now, then clear both IN_MODIFIED and * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is * set, then wait for the write to complete. */ int ext2_update(vp, waitfor) struct vnode *vp; int waitfor; { struct m_ext2fs *fs; struct buf *bp; struct inode *ip; int error; ASSERT_VOP_ELOCKED(vp, "ext2_update"); ext2_itimes(vp); ip = VTOI(vp); if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0) return (0); ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED); fs = ip->i_e2fs; if(fs->e2fs_ronly) return (0); if ((error = bread(ip->i_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)), (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) { brelse(bp); return (error); } ext2_i2ei(ip, (struct ext2fs_dinode *)((char *)bp->b_data + EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number))); if (waitfor && !DOINGASYNC(vp)) return (bwrite(bp)); else { bdwrite(bp); return (0); } } #define SINGLE 0 /* index of single indirect block */ #define DOUBLE 1 /* index of double indirect block */ #define TRIPLE 2 /* index of triple indirect block */ /* * Truncate the inode oip to at most length size, freeing the * disk blocks. */ int ext2_truncate(vp, length, flags, cred, td) struct vnode *vp; off_t length; int flags; struct ucred *cred; struct thread *td; { struct vnode *ovp = vp; int32_t lastblock; struct inode *oip; int32_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR]; int32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR]; struct bufobj *bo; struct m_ext2fs *fs; struct buf *bp; int offset, size, level; long count, nblocks, blocksreleased = 0; int error, i, allerror; off_t osize; oip = VTOI(ovp); bo = &ovp->v_bufobj; ASSERT_VOP_LOCKED(vp, "ext2_truncate"); if (length < 0) return (EINVAL); if (ovp->v_type == VLNK && oip->i_size < ovp->v_mount->mnt_maxsymlinklen) { #ifdef DIAGNOSTIC if (length != 0) panic("ext2_truncate: partial truncate of symlink"); #endif bzero((char *)&oip->i_shortlink, (u_int)oip->i_size); oip->i_size = 0; oip->i_flag |= IN_CHANGE | IN_UPDATE; return (ext2_update(ovp, 1)); } if (oip->i_size == length) { oip->i_flag |= IN_CHANGE | IN_UPDATE; return (ext2_update(ovp, 0)); } fs = oip->i_e2fs; osize = oip->i_size; /* * Lengthen the size of the file. We must ensure that the * last byte of the file is allocated. Since the smallest * value of osize is 0, length will be at least 1. */ if (osize < length) { if (length > oip->i_e2fs->e2fs_maxfilesize) return (EFBIG); vnode_pager_setsize(ovp, length); offset = blkoff(fs, length - 1); lbn = lblkno(fs, length - 1); flags |= BA_CLRBUF; error = ext2_balloc(oip, lbn, offset + 1, cred, &bp, flags); if (error) { vnode_pager_setsize(vp, osize); return (error); } oip->i_size = length; if (bp->b_bufsize == fs->e2fs_bsize) bp->b_flags |= B_CLUSTEROK; if (flags & IO_SYNC) bwrite(bp); else if (DOINGASYNC(ovp)) bdwrite(bp); else bawrite(bp); oip->i_flag |= IN_CHANGE | IN_UPDATE; return (ext2_update(ovp, 1)); } /* * Shorten the size of the file. If the file is not being * truncated to a block boundry, the contents of the * partial block following the end of the file must be * zero'ed in case it ever become accessible again because * of subsequent file growth. */ /* I don't understand the comment above */ offset = blkoff(fs, length); if (offset == 0) { oip->i_size = length; } else { lbn = lblkno(fs, length); flags |= BA_CLRBUF; error = ext2_balloc(oip, lbn, offset, cred, &bp, flags); if (error) return (error); oip->i_size = length; size = blksize(fs, oip, lbn); bzero((char *)bp->b_data + offset, (u_int)(size - offset)); allocbuf(bp, size); if (bp->b_bufsize == fs->e2fs_bsize) bp->b_flags |= B_CLUSTEROK; if (flags & IO_SYNC) bwrite(bp); else if (DOINGASYNC(ovp)) bdwrite(bp); else bawrite(bp); } /* * Calculate index into inode's block list of * last direct and indirect blocks (if any) * which we want to keep. Lastblock is -1 when * the file is truncated to 0. */ lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1; lastiblock[SINGLE] = lastblock - NDADDR; lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs); lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs); nblocks = btodb(fs->e2fs_bsize); /* * Update file and block pointers on disk before we start freeing * blocks. If we crash before free'ing blocks below, the blocks * will be returned to the free list. lastiblock values are also * normalized to -1 for calls to ext2_indirtrunc below. */ bcopy((caddr_t)&oip->i_db[0], (caddr_t)oldblks, sizeof(oldblks)); for (level = TRIPLE; level >= SINGLE; level--) if (lastiblock[level] < 0) { oip->i_ib[level] = 0; lastiblock[level] = -1; } for (i = NDADDR - 1; i > lastblock; i--) oip->i_db[i] = 0; oip->i_flag |= IN_CHANGE | IN_UPDATE; allerror = ext2_update(ovp, 1); /* * Having written the new inode to disk, save its new configuration * and put back the old block pointers long enough to process them. * Note that we save the new block configuration so we can check it * when we are done. */ bcopy((caddr_t)&oip->i_db[0], (caddr_t)newblks, sizeof(newblks)); bcopy((caddr_t)oldblks, (caddr_t)&oip->i_db[0], sizeof(oldblks)); oip->i_size = osize; error = vtruncbuf(ovp, cred, td, length, (int)fs->e2fs_bsize); if (error && (allerror == 0)) allerror = error; vnode_pager_setsize(ovp, length); /* * Indirect blocks first. */ indir_lbn[SINGLE] = -NDADDR; indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1; indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1; for (level = TRIPLE; level >= SINGLE; level--) { bn = oip->i_ib[level]; if (bn != 0) { error = ext2_indirtrunc(oip, indir_lbn[level], fsbtodb(fs, bn), lastiblock[level], level, &count); if (error) allerror = error; blocksreleased += count; if (lastiblock[level] < 0) { oip->i_ib[level] = 0; ext2_blkfree(oip, bn, fs->e2fs_fsize); blocksreleased += nblocks; } } if (lastiblock[level] >= 0) goto done; } /* * All whole direct blocks or frags. */ for (i = NDADDR - 1; i > lastblock; i--) { long bsize; bn = oip->i_db[i]; if (bn == 0) continue; oip->i_db[i] = 0; bsize = blksize(fs, oip, i); ext2_blkfree(oip, bn, bsize); blocksreleased += btodb(bsize); } if (lastblock < 0) goto done; /* * Finally, look for a change in size of the * last direct block; release any frags. */ bn = oip->i_db[lastblock]; if (bn != 0) { long oldspace, newspace; /* * Calculate amount of space we're giving * back as old block size minus new block size. */ oldspace = blksize(fs, oip, lastblock); oip->i_size = length; newspace = blksize(fs, oip, lastblock); if (newspace == 0) panic("itrunc: newspace"); if (oldspace - newspace > 0) { /* * Block number of space to be free'd is * the old block # plus the number of frags * required for the storage we're keeping. */ bn += numfrags(fs, newspace); ext2_blkfree(oip, bn, oldspace - newspace); blocksreleased += btodb(oldspace - newspace); } } done: #ifdef DIAGNOSTIC for (level = SINGLE; level <= TRIPLE; level++) if (newblks[NDADDR + level] != oip->i_ib[level]) panic("itrunc1"); for (i = 0; i < NDADDR; i++) if (newblks[i] != oip->i_db[i]) panic("itrunc2"); BO_LOCK(bo); if (length == 0 && (bo->bo_dirty.bv_cnt != 0 || bo->bo_clean.bv_cnt != 0)) panic("itrunc3"); BO_UNLOCK(bo); #endif /* DIAGNOSTIC */ /* * Put back the real size. */ oip->i_size = length; oip->i_blocks -= blocksreleased; if (oip->i_blocks < 0) /* sanity */ oip->i_blocks = 0; oip->i_flag |= IN_CHANGE; vnode_pager_setsize(ovp, length); return (allerror); } /* * Release blocks associated with the inode ip and stored in the indirect * block bn. Blocks are free'd in LIFO order up to (but not including) * lastbn. If level is greater than SINGLE, the block is an indirect block * and recursive calls to indirtrunc must be used to cleanse other indirect * blocks. * * NB: triple indirect blocks are untested. */ static int ext2_indirtrunc(ip, lbn, dbn, lastbn, level, countp) struct inode *ip; int32_t lbn, lastbn; int32_t dbn; int level; long *countp; { struct buf *bp; struct m_ext2fs *fs = ip->i_e2fs; struct vnode *vp; int32_t *bap, *copy, nb, nlbn, last; long blkcount, factor; int i, nblocks, blocksreleased = 0; int error = 0, allerror = 0; /* * Calculate index in current block of last * block to be kept. -1 indicates the entire * block so we need not calculate the index. */ factor = 1; for (i = SINGLE; i < level; i++) factor *= NINDIR(fs); last = lastbn; if (lastbn > 0) last /= factor; nblocks = btodb(fs->e2fs_bsize); /* * Get buffer of block pointers, zero those entries corresponding * to blocks to be free'd, and update on disk copy first. Since * double(triple) indirect before single(double) indirect, calls * to bmap on these blocks will fail. However, we already have * the on disk address, so we have to set the b_blkno field * explicitly instead of letting bread do everything for us. */ vp = ITOV(ip); bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0, 0); if (bp->b_flags & (B_DONE | B_DELWRI)) { } else { bp->b_iocmd = BIO_READ; if (bp->b_bcount > bp->b_bufsize) panic("ext2_indirtrunc: bad buffer size"); bp->b_blkno = dbn; vfs_busy_pages(bp, 0); bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); error = bufwait(bp); } if (error) { brelse(bp); *countp = 0; return (error); } bap = (int32_t *)bp->b_data; copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK); bcopy((caddr_t)bap, (caddr_t)copy, (u_int)fs->e2fs_bsize); bzero((caddr_t)&bap[last + 1], (u_int)(NINDIR(fs) - (last + 1)) * sizeof(int32_t)); if (last == -1) bp->b_flags |= B_INVAL; error = bwrite(bp); if (error) allerror = error; bap = copy; /* * Recursively free totally unused blocks. */ for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last; i--, nlbn += factor) { nb = bap[i]; if (nb == 0) continue; if (level > SINGLE) { if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb), (int32_t)-1, level - 1, &blkcount)) != 0) allerror = error; blocksreleased += blkcount; } ext2_blkfree(ip, nb, fs->e2fs_bsize); blocksreleased += nblocks; } /* * Recursively free last partial block. */ if (level > SINGLE && lastbn >= 0) { last = lastbn % factor; nb = bap[i]; if (nb != 0) { if ((error = ext2_indirtrunc(ip, nlbn, fsbtodb(fs, nb), last, level - 1, &blkcount)) != 0) allerror = error; blocksreleased += blkcount; } } free(copy, M_TEMP); *countp = blocksreleased; return (allerror); } /* * discard preallocated blocks */ int ext2_inactive(ap) struct vop_inactive_args /* { struct vnode *a_vp; struct thread *a_td; } */ *ap; { struct vnode *vp = ap->a_vp; struct inode *ip = VTOI(vp); struct thread *td = ap->a_td; int mode, error = 0; /* * Ignore inodes related to stale file handles. */ if (ip->i_mode == 0) goto out; if (ip->i_nlink <= 0) { error = ext2_truncate(vp, (off_t)0, 0, NOCRED, td); ip->i_rdev = 0; mode = ip->i_mode; ip->i_mode = 0; ip->i_flag |= IN_CHANGE | IN_UPDATE; ext2_vfree(vp, ip->i_number, mode); } if (ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) ext2_update(vp, 0); out: /* * If we are done with the inode, reclaim it * so that it can be reused immediately. */ if (ip->i_mode == 0) vrecycle(vp, td); return (error); } /* * Reclaim an inode so that it can be used for other purposes. */ int ext2_reclaim(ap) struct vop_reclaim_args /* { struct vnode *a_vp; struct thread *a_td; } */ *ap; { struct inode *ip; struct vnode *vp = ap->a_vp; ip = VTOI(vp); if (ip->i_flag & IN_LAZYMOD) { ip->i_flag |= IN_MODIFIED; ext2_update(vp, 0); } vfs_hash_remove(vp); free(vp->v_data, M_EXT2NODE); vp->v_data = 0; vnode_destroy_vobject(vp); return (0); }