diff options
Diffstat (limited to 'sys/gnu/fs/ext2fs/ext2_lookup.c')
| -rw-r--r-- | sys/gnu/fs/ext2fs/ext2_lookup.c | 1082 |
1 files changed, 0 insertions, 1082 deletions
diff --git a/sys/gnu/fs/ext2fs/ext2_lookup.c b/sys/gnu/fs/ext2fs/ext2_lookup.c deleted file mode 100644 index 6ab41e5..0000000 --- a/sys/gnu/fs/ext2fs/ext2_lookup.c +++ /dev/null @@ -1,1082 +0,0 @@ -/*- - * modified for Lites 1.1 - * - * Aug 1995, Godmar Back (gback@cs.utah.edu) - * University of Utah, Department of Computer Science - */ -/*- - * Copyright (c) 1989, 1993 - * The Regents of the University of California. All rights reserved. - * (c) UNIX System Laboratories, Inc. - * All or some portions of this file are derived from material licensed - * to the University of California by American Telephone and Telegraph - * Co. or Unix System Laboratories, Inc. and are reproduced herein with - * the permission of UNIX System Laboratories, Inc. - * - * 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. - * - * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94 - * $FreeBSD$ - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/namei.h> -#include <sys/bio.h> -#include <sys/buf.h> -#include <sys/endian.h> -#include <sys/mount.h> -#include <sys/vnode.h> -#include <sys/malloc.h> -#include <sys/dirent.h> -#include <sys/sysctl.h> - -#include <ufs/ufs/dir.h> - -#include <gnu/fs/ext2fs/inode.h> -#include <gnu/fs/ext2fs/ext2_mount.h> -#include <gnu/fs/ext2fs/ext2_extern.h> -#include <gnu/fs/ext2fs/ext2_fs.h> -#include <gnu/fs/ext2fs/ext2_fs_sb.h> - -#ifdef DIAGNOSTIC -static int dirchk = 1; -#else -static int dirchk = 0; -#endif - -static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem"); -SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); - -/* - DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) - while it is the native blocksize in ext2fs - thus, a #define - is no longer appropriate -*/ -#undef DIRBLKSIZ - -static u_char ext2_ft_to_dt[] = { - DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ - DT_REG, /* EXT2_FT_REG_FILE */ - DT_DIR, /* EXT2_FT_DIR */ - DT_CHR, /* EXT2_FT_CHRDEV */ - DT_BLK, /* EXT2_FT_BLKDEV */ - DT_FIFO, /* EXT2_FT_FIFO */ - DT_SOCK, /* EXT2_FT_SOCK */ - DT_LNK, /* EXT2_FT_SYMLINK */ -}; -#define FTTODT(ft) \ - ((ft) > sizeof(ext2_ft_to_dt) / sizeof(ext2_ft_to_dt[0]) ? \ - DT_UNKNOWN : ext2_ft_to_dt[(ft)]) - -static u_char dt_to_ext2_ft[] = { - EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ - EXT2_FT_FIFO, /* DT_FIFO */ - EXT2_FT_CHRDEV, /* DT_CHR */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_DIR, /* DT_DIR */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_BLKDEV, /* DT_BLK */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_REG_FILE, /* DT_REG */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_SYMLINK, /* DT_LNK */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_SOCK, /* DT_SOCK */ - EXT2_FT_UNKNOWN, /* unused */ - EXT2_FT_UNKNOWN, /* DT_WHT */ -}; -#define DTTOFT(dt) \ - ((dt) > sizeof(dt_to_ext2_ft) / sizeof(dt_to_ext2_ft[0]) ? \ - EXT2_FT_UNKNOWN : dt_to_ext2_ft[(dt)]) - -static int ext2_dirbadentry(struct vnode *dp, struct ext2_dir_entry_2 *de, - int entryoffsetinblock); - -/* - * Vnode op for reading directories. - * - * The routine below assumes that the on-disk format of a directory - * is the same as that defined by <sys/dirent.h>. If the on-disk - * format changes, then it will be necessary to do a conversion - * from the on-disk format that read returns to the format defined - * by <sys/dirent.h>. - */ -/* - * this is exactly what we do here - the problem is that the conversion - * will blow up some entries by four bytes, so it can't be done in place. - * This is too bad. Right now the conversion is done entry by entry, the - * converted entry is sent via uiomove. - * - * XXX allocate a buffer, convert as many entries as possible, then send - * the whole buffer to uiomove - */ -int -ext2_readdir(ap) - struct vop_readdir_args /* { - struct vnode *a_vp; - struct uio *a_uio; - struct ucred *a_cred; - } */ *ap; -{ - struct uio *uio = ap->a_uio; - int count, error; - - struct ext2_dir_entry_2 *edp, *dp; - int ncookies; - struct dirent dstdp; - struct uio auio; - struct iovec aiov; - caddr_t dirbuf; - int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->s_blocksize; - int readcnt; - off_t startoffset = uio->uio_offset; - - count = uio->uio_resid; - /* - * Avoid complications for partial directory entries by adjusting - * the i/o to end at a block boundary. Don't give up (like ufs - * does) if the initial adjustment gives a negative count, since - * many callers don't supply a large enough buffer. The correct - * size is a little larger than DIRBLKSIZ to allow for expansion - * of directory entries, but some callers just use 512. - */ - count -= (uio->uio_offset + count) & (DIRBLKSIZ -1); - if (count <= 0) - count += DIRBLKSIZ; - -#ifdef EXT2FS_DEBUG - printf("ext2_readdir: uio_offset = %lld, uio_resid = %d, count = %d\n", - uio->uio_offset, uio->uio_resid, count); -#endif - - auio = *uio; - auio.uio_iov = &aiov; - auio.uio_iovcnt = 1; - auio.uio_resid = count; - auio.uio_segflg = UIO_SYSSPACE; - aiov.iov_len = count; - dirbuf = malloc(count, M_TEMP, M_WAITOK); - aiov.iov_base = dirbuf; - error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred); - if (error == 0) { - readcnt = count - auio.uio_resid; - edp = (struct ext2_dir_entry_2 *)&dirbuf[readcnt]; - ncookies = 0; - bzero(&dstdp, offsetof(struct dirent, d_name)); - for (dp = (struct ext2_dir_entry_2 *)dirbuf; - !error && uio->uio_resid > 0 && dp < edp; ) { - /*- - * "New" ext2fs directory entries differ in 3 ways - * from ufs on-disk ones: - * - the name is not necessarily NUL-terminated. - * - the file type field always exists and always - * follows the name length field. - * - the file type is encoded in a different way. - * - * "Old" ext2fs directory entries need no special - * conversions, since they are binary compatible - * with "new" entries having a file type of 0 (i.e., - * EXT2_FT_UNKNOWN). Splitting the old name length - * field didn't make a mess like it did in ufs, - * because ext2fs uses a machine-independent disk - * layout. - */ - dstdp.d_fileno = dp->inode; - dstdp.d_type = FTTODT(dp->file_type); - dstdp.d_namlen = dp->name_len; - dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); - bcopy(dp->name, dstdp.d_name, dstdp.d_namlen); - bzero(dstdp.d_name + dstdp.d_namlen, - dstdp.d_reclen - offsetof(struct dirent, d_name) - - dstdp.d_namlen); - - if (dp->rec_len > 0) { - if(dstdp.d_reclen <= uio->uio_resid) { - /* advance dp */ - dp = (struct ext2_dir_entry_2 *) - ((char *)dp + dp->rec_len); - error = - uiomove(&dstdp, dstdp.d_reclen, uio); - if (!error) - ncookies++; - } else - break; - } else { - error = EIO; - break; - } - } - /* we need to correct uio_offset */ - uio->uio_offset = startoffset + (caddr_t)dp - dirbuf; - - if (!error && ap->a_ncookies != NULL) { - u_long *cookiep, *cookies, *ecookies; - off_t off; - - if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) - panic("ext2_readdir: unexpected uio from NFS server"); - cookies = malloc(ncookies * sizeof(u_long), M_TEMP, - M_WAITOK); - off = startoffset; - for (dp = (struct ext2_dir_entry_2 *)dirbuf, - cookiep = cookies, ecookies = cookies + ncookies; - cookiep < ecookies; - dp = (struct ext2_dir_entry_2 *)((caddr_t) dp + dp->rec_len)) { - off += dp->rec_len; - *cookiep++ = (u_long) off; - } - *ap->a_ncookies = ncookies; - *ap->a_cookies = cookies; - } - } - free(dirbuf, M_TEMP); - if (ap->a_eofflag) - *ap->a_eofflag = VTOI(ap->a_vp)->i_size <= uio->uio_offset; - return (error); -} - -/* - * Convert a component of a pathname into a pointer to a locked inode. - * This is a very central and rather complicated routine. - * If the file system is not maintained in a strict tree hierarchy, - * this can result in a deadlock situation (see comments in code below). - * - * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending - * on whether the name is to be looked up, created, renamed, or deleted. - * When CREATE, RENAME, or DELETE is specified, information usable in - * creating, renaming, or deleting a directory entry may be calculated. - * If flag has LOCKPARENT or'ed into it and the target of the pathname - * exists, lookup returns both the target and its parent directory locked. - * When creating or renaming and LOCKPARENT is specified, the target may - * not be ".". When deleting and LOCKPARENT is specified, the target may - * be "."., but the caller must check to ensure it does an vrele and vput - * instead of two vputs. - * - * Overall outline of ext2_lookup: - * - * search for name in directory, to found or notfound - * notfound: - * if creating, return locked directory, leaving info on available slots - * else return error - * found: - * if at end of path and deleting, return information to allow delete - * if at end of path and rewriting (RENAME and LOCKPARENT), lock target - * inode and return info to allow rewrite - * if not at end, add name to cache; if at end and neither creating - * nor deleting, add name to cache - */ -int -ext2_lookup(ap) - struct vop_cachedlookup_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - } */ *ap; -{ - struct vnode *vdp; /* vnode for directory being searched */ - struct inode *dp; /* inode for directory being searched */ - struct buf *bp; /* a buffer of directory entries */ - struct ext2_dir_entry_2 *ep; /* the current directory entry */ - int entryoffsetinblock; /* offset of ep in bp's buffer */ - enum {NONE, COMPACT, FOUND} slotstatus; - doff_t slotoffset; /* offset of area with free space */ - int slotsize; /* size of area at slotoffset */ - int slotfreespace; /* amount of space free in slot */ - int slotneeded; /* size of the entry we're seeking */ - int numdirpasses; /* strategy for directory search */ - doff_t endsearch; /* offset to end directory search */ - doff_t prevoff; /* prev entry dp->i_offset */ - struct vnode *pdp; /* saved dp during symlink work */ - struct vnode *tdp; /* returned by VFS_VGET */ - doff_t enduseful; /* pointer past last used dir slot */ - u_long bmask; /* block offset mask */ - int namlen, error; - struct vnode **vpp = ap->a_vpp; - struct componentname *cnp = ap->a_cnp; - struct ucred *cred = cnp->cn_cred; - int flags = cnp->cn_flags; - int nameiop = cnp->cn_nameiop; - ino_t saved_ino; - - int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize; - - bp = NULL; - slotoffset = -1; - *vpp = NULL; - vdp = ap->a_dvp; - dp = VTOI(vdp); - /* - * We now have a segment name to search for, and a directory to search. - */ - - /* - * Suppress search for slots unless creating - * file and at end of pathname, in which case - * we watch for a place to put the new file in - * case it doesn't already exist. - */ - slotstatus = FOUND; - slotfreespace = slotsize = slotneeded = 0; - if ((nameiop == CREATE || nameiop == RENAME) && - (flags & ISLASTCN)) { - slotstatus = NONE; - slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); - /* was - slotneeded = (sizeof(struct direct) - MAXNAMLEN + - cnp->cn_namelen + 3) &~ 3; */ - } - - /* - * If there is cached information on a previous search of - * this directory, pick up where we last left off. - * We cache only lookups as these are the most common - * and have the greatest payoff. Caching CREATE has little - * benefit as it usually must search the entire directory - * to determine that the entry does not exist. Caching the - * location of the last DELETE or RENAME has not reduced - * profiling time and hence has been removed in the interest - * of simplicity. - */ - bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; - if (nameiop != LOOKUP || dp->i_diroff == 0 || - dp->i_diroff > dp->i_size) { - entryoffsetinblock = 0; - dp->i_offset = 0; - numdirpasses = 1; - } else { - dp->i_offset = dp->i_diroff; - if ((entryoffsetinblock = dp->i_offset & bmask) && - (error = ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL, - &bp))) - return (error); - numdirpasses = 2; - nchstats.ncs_2passes++; - } - prevoff = dp->i_offset; - endsearch = roundup(dp->i_size, DIRBLKSIZ); - enduseful = 0; - -searchloop: - while (dp->i_offset < endsearch) { - /* - * If necessary, get the next directory block. - */ - if ((dp->i_offset & bmask) == 0) { - if (bp != NULL) - brelse(bp); - if ((error = - ext2_blkatoff(vdp, (off_t)dp->i_offset, NULL, - &bp)) != 0) - return (error); - entryoffsetinblock = 0; - } - /* - * If still looking for a slot, and at a DIRBLKSIZE - * boundary, have to start looking for free space again. - */ - if (slotstatus == NONE && - (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) { - slotoffset = -1; - slotfreespace = 0; - } - /* - * Get pointer to next entry. - * Full validation checks are slow, so we only check - * enough to insure forward progress through the - * directory. Complete checks can be run by setting - * "vfs.e2fs.dirchk" to be true. - */ - ep = (struct ext2_dir_entry_2 *) - ((char *)bp->b_data + entryoffsetinblock); - if (ep->rec_len == 0 || - (dirchk && ext2_dirbadentry(vdp, ep, entryoffsetinblock))) { - int i; - ext2_dirbad(dp, dp->i_offset, "mangled entry"); - i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)); - dp->i_offset += i; - entryoffsetinblock += i; - continue; - } - - /* - * If an appropriate sized slot has not yet been found, - * check to see if one is available. Also accumulate space - * in the current block so that we can determine if - * compaction is viable. - */ - if (slotstatus != FOUND) { - int size = ep->rec_len; - - if (ep->inode != 0) - size -= EXT2_DIR_REC_LEN(ep->name_len); - if (size > 0) { - if (size >= slotneeded) { - slotstatus = FOUND; - slotoffset = dp->i_offset; - slotsize = ep->rec_len; - } else if (slotstatus == NONE) { - slotfreespace += size; - if (slotoffset == -1) - slotoffset = dp->i_offset; - if (slotfreespace >= slotneeded) { - slotstatus = COMPACT; - slotsize = dp->i_offset + - ep->rec_len - slotoffset; - } - } - } - } - - /* - * Check for a name match. - */ - if (ep->inode) { - namlen = ep->name_len; - if (namlen == cnp->cn_namelen && - !bcmp(cnp->cn_nameptr, ep->name, - (unsigned)namlen)) { - /* - * Save directory entry's inode number and - * reclen in ndp->ni_ufs area, and release - * directory buffer. - */ - dp->i_ino = ep->inode; - dp->i_reclen = ep->rec_len; - goto found; - } - } - prevoff = dp->i_offset; - dp->i_offset += ep->rec_len; - entryoffsetinblock += ep->rec_len; - if (ep->inode) - enduseful = dp->i_offset; - } -/* notfound: */ - /* - * If we started in the middle of the directory and failed - * to find our target, we must check the beginning as well. - */ - if (numdirpasses == 2) { - numdirpasses--; - dp->i_offset = 0; - endsearch = dp->i_diroff; - goto searchloop; - } - if (bp != NULL) - brelse(bp); - /* - * If creating, and at end of pathname and current - * directory has not been removed, then can consider - * allowing file to be created. - */ - if ((nameiop == CREATE || nameiop == RENAME) && - (flags & ISLASTCN) && dp->i_nlink != 0) { - /* - * Access for write is interpreted as allowing - * creation of files in the directory. - */ - if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) - return (error); - /* - * Return an indication of where the new directory - * entry should be put. If we didn't find a slot, - * then set dp->i_count to 0 indicating - * that the new slot belongs at the end of the - * directory. If we found a slot, then the new entry - * can be put in the range from dp->i_offset to - * dp->i_offset + dp->i_count. - */ - if (slotstatus == NONE) { - dp->i_offset = roundup(dp->i_size, DIRBLKSIZ); - dp->i_count = 0; - enduseful = dp->i_offset; - } else { - dp->i_offset = slotoffset; - dp->i_count = slotsize; - if (enduseful < slotoffset + slotsize) - enduseful = slotoffset + slotsize; - } - dp->i_endoff = roundup(enduseful, DIRBLKSIZ); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - /* - * We return with the directory locked, so that - * the parameters we set up above will still be - * valid if we actually decide to do a direnter(). - * We return ni_vp == NULL to indicate that the entry - * does not currently exist; we leave a pointer to - * the (locked) directory inode in ndp->ni_dvp. - * The pathname buffer is saved so that the name - * can be obtained later. - * - * NB - if the directory is unlocked, then this - * information cannot be used. - */ - cnp->cn_flags |= SAVENAME; - return (EJUSTRETURN); - } - /* - * Insert name into cache (as non-existent) if appropriate. - */ - if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) - cache_enter(vdp, *vpp, cnp); - return (ENOENT); - -found: - if (numdirpasses == 2) - nchstats.ncs_pass2++; - /* - * Check that directory length properly reflects presence - * of this entry. - */ - if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->name_len) - > dp->i_size) { - ext2_dirbad(dp, dp->i_offset, "i_size too small"); - dp->i_size = entryoffsetinblock+EXT2_DIR_REC_LEN(ep->name_len); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - } - brelse(bp); - - /* - * Found component in pathname. - * If the final component of path name, save information - * in the cache as to where the entry was found. - */ - if ((flags & ISLASTCN) && nameiop == LOOKUP) - dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1); - - /* - * If deleting, and at end of pathname, return - * parameters which can be used to remove file. - */ - if (nameiop == DELETE && (flags & ISLASTCN)) { - /* - * Write access to directory required to delete files. - */ - if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) - return (error); - /* - * Return pointer to current entry in dp->i_offset, - * and distance past previous entry (if there - * is a previous entry in this block) in dp->i_count. - * Save directory inode pointer in ndp->ni_dvp for dirremove(). - */ - if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) - dp->i_count = 0; - else - dp->i_count = dp->i_offset - prevoff; - if (dp->i_number == dp->i_ino) { - VREF(vdp); - *vpp = vdp; - return (0); - } - if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, - &tdp)) != 0) - return (error); - /* - * If directory is "sticky", then user must own - * the directory, or the file in it, else she - * may not delete it (unless she's root). This - * implements append-only directories. - */ - if ((dp->i_mode & ISVTX) && - cred->cr_uid != 0 && - cred->cr_uid != dp->i_uid && - VTOI(tdp)->i_uid != cred->cr_uid) { - vput(tdp); - return (EPERM); - } - *vpp = tdp; - return (0); - } - - /* - * If rewriting (RENAME), return the inode and the - * information required to rewrite the present directory - * Must get inode of directory entry to verify it's a - * regular file, or empty directory. - */ - if (nameiop == RENAME && (flags & ISLASTCN)) { - if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) - return (error); - /* - * Careful about locking second inode. - * This can only occur if the target is ".". - */ - if (dp->i_number == dp->i_ino) - return (EISDIR); - if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, - &tdp)) != 0) - return (error); - *vpp = tdp; - cnp->cn_flags |= SAVENAME; - return (0); - } - - /* - * Step through the translation in the name. We do not `vput' the - * directory because we may need it again if a symbolic link - * is relative to the current directory. Instead we save it - * unlocked as "pdp". We must get the target inode before unlocking - * the directory to insure that the inode will not be removed - * before we get it. We prevent deadlock by always fetching - * inodes from the root, moving down the directory tree. Thus - * when following backward pointers ".." we must unlock the - * parent directory before getting the requested directory. - * There is a potential race condition here if both the current - * and parent directories are removed before the VFS_VGET for the - * inode associated with ".." returns. We hope that this occurs - * infrequently since we cannot avoid this race condition without - * implementing a sophisticated deadlock detection algorithm. - * Note also that this simple deadlock detection scheme will not - * work if the file system has any hard links other than ".." - * that point backwards in the directory structure. - */ - pdp = vdp; - if (flags & ISDOTDOT) { - saved_ino = dp->i_ino; - VOP_UNLOCK(pdp, 0); /* race to get the inode */ - error = VFS_VGET(vdp->v_mount, saved_ino, LK_EXCLUSIVE, &tdp); - vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY); - if (error != 0) - return (error); - *vpp = tdp; - } else if (dp->i_number == dp->i_ino) { - VREF(vdp); /* we want ourself, ie "." */ - *vpp = vdp; - } else { - if ((error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, - &tdp)) != 0) - return (error); - *vpp = tdp; - } - - /* - * Insert name into cache if appropriate. - */ - if (cnp->cn_flags & MAKEENTRY) - cache_enter(vdp, *vpp, cnp); - return (0); -} - -void -ext2_dirbad(ip, offset, how) - struct inode *ip; - doff_t offset; - char *how; -{ - struct mount *mp; - - mp = ITOV(ip)->v_mount; - (void)printf("%s: bad dir ino %lu at offset %ld: %s\n", - mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how); - if ((mp->mnt_flag & MNT_RDONLY) == 0) - panic("ext2_dirbad: bad dir"); -} - -/* - * Do consistency checking on a directory entry: - * record length must be multiple of 4 - * entry must fit in rest of its DIRBLKSIZ block - * record must be large enough to contain entry - * name is not longer than MAXNAMLEN - * name must be as long as advertised, and null terminated - */ -/* - * changed so that it confirms to ext2_check_dir_entry - */ -static int -ext2_dirbadentry(dp, de, entryoffsetinblock) - struct vnode *dp; - struct ext2_dir_entry_2 *de; - int entryoffsetinblock; -{ - int DIRBLKSIZ = VTOI(dp)->i_e2fs->s_blocksize; - - char * error_msg = NULL; - - if (de->rec_len < EXT2_DIR_REC_LEN(1)) - error_msg = "rec_len is smaller than minimal"; - else if (de->rec_len % 4 != 0) - error_msg = "rec_len % 4 != 0"; - else if (de->rec_len < EXT2_DIR_REC_LEN(de->name_len)) - error_msg = "reclen is too small for name_len"; - else if (entryoffsetinblock + de->rec_len > DIRBLKSIZ) - error_msg = "directory entry across blocks"; - /* else LATER - if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count) - error_msg = "inode out of bounds"; - */ - - if (error_msg != NULL) { - printf("bad directory entry: %s\n", error_msg); - printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n", - entryoffsetinblock, (unsigned long)de->inode, - de->rec_len, de->name_len); - } - return error_msg == NULL ? 0 : 1; -} - -/* - * Write a directory entry after a call to namei, using the parameters - * that it left in nameidata. The argument ip is the inode which the new - * directory entry will refer to. Dvp is a pointer to the directory to - * be written, which was left locked by namei. Remaining parameters - * (dp->i_offset, dp->i_count) indicate how the space for the new - * entry is to be obtained. - */ -int -ext2_direnter(ip, dvp, cnp) - struct inode *ip; - struct vnode *dvp; - struct componentname *cnp; -{ - struct ext2_dir_entry_2 *ep, *nep; - struct inode *dp; - struct buf *bp; - struct ext2_dir_entry_2 newdir; - struct iovec aiov; - struct uio auio; - u_int dsize; - int error, loc, newentrysize, spacefree; - char *dirbuf; - int DIRBLKSIZ = ip->i_e2fs->s_blocksize; - - -#ifdef DIAGNOSTIC - if ((cnp->cn_flags & SAVENAME) == 0) - panic("direnter: missing name"); -#endif - dp = VTOI(dvp); - newdir.inode = ip->i_number; - newdir.name_len = cnp->cn_namelen; - if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, - EXT2_FEATURE_INCOMPAT_FILETYPE)) - newdir.file_type = DTTOFT(IFTODT(ip->i_mode)); - else - newdir.file_type = EXT2_FT_UNKNOWN; - bcopy(cnp->cn_nameptr, newdir.name, (unsigned)cnp->cn_namelen + 1); - newentrysize = EXT2_DIR_REC_LEN(newdir.name_len); - if (dp->i_count == 0) { - /* - * If dp->i_count is 0, then namei could find no - * space in the directory. Here, dp->i_offset will - * be on a directory block boundary and we will write the - * new entry into a fresh block. - */ - if (dp->i_offset & (DIRBLKSIZ - 1)) - panic("ext2_direnter: newblk"); - auio.uio_offset = dp->i_offset; - newdir.rec_len = DIRBLKSIZ; - auio.uio_resid = newentrysize; - aiov.iov_len = newentrysize; - aiov.iov_base = (caddr_t)&newdir; - auio.uio_iov = &aiov; - auio.uio_iovcnt = 1; - auio.uio_rw = UIO_WRITE; - auio.uio_segflg = UIO_SYSSPACE; - auio.uio_td = (struct thread *)0; - error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); - if (DIRBLKSIZ > - VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize) - /* XXX should grow with balloc() */ - panic("ext2_direnter: frag size"); - else if (!error) { - dp->i_size = roundup(dp->i_size, DIRBLKSIZ); - dp->i_flag |= IN_CHANGE; - } - return (error); - } - - /* - * If dp->i_count is non-zero, then namei found space - * for the new entry in the range dp->i_offset to - * dp->i_offset + dp->i_count in the directory. - * To use this space, we may have to compact the entries located - * there, by copying them together towards the beginning of the - * block, leaving the free space in one usable chunk at the end. - */ - - /* - * Increase size of directory if entry eats into new space. - * This should never push the size past a new multiple of - * DIRBLKSIZE. - * - * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. - */ - if (dp->i_offset + dp->i_count > dp->i_size) - dp->i_size = dp->i_offset + dp->i_count; - /* - * Get the block containing the space for the new directory entry. - */ - if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, - &bp)) != 0) - return (error); - /* - * Find space for the new entry. In the simple case, the entry at - * offset base will have the space. If it does not, then namei - * arranged that compacting the region dp->i_offset to - * dp->i_offset + dp->i_count would yield the - * space. - */ - ep = (struct ext2_dir_entry_2 *)dirbuf; - dsize = EXT2_DIR_REC_LEN(ep->name_len); - spacefree = ep->rec_len - dsize; - for (loc = ep->rec_len; loc < dp->i_count; ) { - nep = (struct ext2_dir_entry_2 *)(dirbuf + loc); - if (ep->inode) { - /* trim the existing slot */ - ep->rec_len = dsize; - ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); - } else { - /* overwrite; nothing there; header is ours */ - spacefree += dsize; - } - dsize = EXT2_DIR_REC_LEN(nep->name_len); - spacefree += nep->rec_len - dsize; - loc += nep->rec_len; - bcopy((caddr_t)nep, (caddr_t)ep, dsize); - } - /* - * Update the pointer fields in the previous entry (if any), - * copy in the new entry, and write out the block. - */ - if (ep->inode == 0) { - if (spacefree + dsize < newentrysize) - panic("ext2_direnter: compact1"); - newdir.rec_len = spacefree + dsize; - } else { - if (spacefree < newentrysize) - panic("ext2_direnter: compact2"); - newdir.rec_len = spacefree; - ep->rec_len = dsize; - ep = (struct ext2_dir_entry_2 *)((char *)ep + dsize); - } - bcopy((caddr_t)&newdir, (caddr_t)ep, (u_int)newentrysize); - error = bwrite(bp); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) - error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, - cnp->cn_cred, cnp->cn_thread); - return (error); -} - -/* - * Remove a directory entry after a call to namei, using - * the parameters which it left in nameidata. The entry - * dp->i_offset contains the offset into the directory of the - * entry to be eliminated. The dp->i_count field contains the - * size of the previous record in the directory. If this - * is 0, the first entry is being deleted, so we need only - * zero the inode number to mark the entry as free. If the - * entry is not the first in the directory, we must reclaim - * the space of the now empty record by adding the record size - * to the size of the previous entry. - */ -int -ext2_dirremove(dvp, cnp) - struct vnode *dvp; - struct componentname *cnp; -{ - struct inode *dp; - struct ext2_dir_entry_2 *ep; - struct buf *bp; - int error; - - dp = VTOI(dvp); - if (dp->i_count == 0) { - /* - * First entry in block: set d_ino to zero. - */ - if ((error = - ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, - &bp)) != 0) - return (error); - ep->inode = 0; - error = bwrite(bp); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - return (error); - } - /* - * Collapse new free space into previous entry. - */ - if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), - (char **)&ep, &bp)) != 0) - return (error); - ep->rec_len += dp->i_reclen; - error = bwrite(bp); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - return (error); -} - -/* - * Rewrite an existing directory entry to point at the inode - * supplied. The parameters describing the directory entry are - * set up by a call to namei. - */ -int -ext2_dirrewrite(dp, ip, cnp) - struct inode *dp, *ip; - struct componentname *cnp; -{ - struct buf *bp; - struct ext2_dir_entry_2 *ep; - struct vnode *vdp = ITOV(dp); - int error; - - if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, - &bp)) != 0) - return (error); - ep->inode = ip->i_number; - if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, - EXT2_FEATURE_INCOMPAT_FILETYPE)) - ep->file_type = DTTOFT(IFTODT(ip->i_mode)); - else - ep->file_type = EXT2_FT_UNKNOWN; - error = bwrite(bp); - dp->i_flag |= IN_CHANGE | IN_UPDATE; - return (error); -} - -/* - * Check if a directory is empty or not. - * Inode supplied must be locked. - * - * Using a struct dirtemplate here is not precisely - * what we want, but better than using a struct direct. - * - * NB: does not handle corrupted directories. - */ -int -ext2_dirempty(ip, parentino, cred) - struct inode *ip; - ino_t parentino; - struct ucred *cred; -{ - off_t off; - struct dirtemplate dbuf; - struct ext2_dir_entry_2 *dp = (struct ext2_dir_entry_2 *)&dbuf; - int error, count, namlen; -#define MINDIRSIZ (sizeof (struct dirtemplate) / 2) - - for (off = 0; off < ip->i_size; off += dp->rec_len) { - error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, - off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, - NOCRED, &count, (struct thread *)0); - /* - * Since we read MINDIRSIZ, residual must - * be 0 unless we're at end of file. - */ - if (error || count != 0) - return (0); - /* avoid infinite loops */ - if (dp->rec_len == 0) - return (0); - /* skip empty entries */ - if (dp->inode == 0) - continue; - /* accept only "." and ".." */ - namlen = dp->name_len; - if (namlen > 2) - return (0); - if (dp->name[0] != '.') - return (0); - /* - * At this point namlen must be 1 or 2. - * 1 implies ".", 2 implies ".." if second - * char is also "." - */ - if (namlen == 1) - continue; - if (dp->name[1] == '.' && dp->inode == parentino) - continue; - return (0); - } - return (1); -} - -/* - * Check if source directory is in the path of the target directory. - * Target is supplied locked, source is unlocked. - * The target is always vput before returning. - */ -int -ext2_checkpath(source, target, cred) - struct inode *source, *target; - struct ucred *cred; -{ - struct vnode *vp; - int error, rootino, namlen; - struct dirtemplate dirbuf; - - vp = ITOV(target); - if (target->i_number == source->i_number) { - error = EEXIST; - goto out; - } - rootino = ROOTINO; - error = 0; - if (target->i_number == rootino) - goto out; - - for (;;) { - if (vp->v_type != VDIR) { - error = ENOTDIR; - break; - } - error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, - sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE, - IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, - NULL); - if (error != 0) - break; - namlen = dirbuf.dotdot_type; /* like ufs little-endian */ - if (namlen != 2 || - dirbuf.dotdot_name[0] != '.' || - dirbuf.dotdot_name[1] != '.') { - error = ENOTDIR; - break; - } - if (dirbuf.dotdot_ino == source->i_number) { - error = EINVAL; - break; - } - if (dirbuf.dotdot_ino == rootino) - break; - vput(vp); - if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, - LK_EXCLUSIVE, &vp)) != 0) { - vp = NULL; - break; - } - } - -out: - if (error == ENOTDIR) - printf("checkpath: .. not a directory\n"); - if (vp != NULL) - vput(vp); - return (error); -} |
