diff options
| -rw-r--r-- | sys/compat/linux/linux_getcwd.c | 411 | ||||
| -rw-r--r-- | sys/kern/vfs_cache.c | 378 |
2 files changed, 377 insertions, 412 deletions
diff --git a/sys/compat/linux/linux_getcwd.c b/sys/compat/linux/linux_getcwd.c index bb1c28f..cade9c1 100644 --- a/sys/compat/linux/linux_getcwd.c +++ b/sys/compat/linux/linux_getcwd.c @@ -37,432 +37,25 @@ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ -#include "opt_compat.h" -#include "opt_mac.h" #include <sys/param.h> #include <sys/systm.h> -#include <sys/namei.h> -#include <sys/filedesc.h> -#include <sys/kernel.h> -#include <sys/file.h> -#include <sys/stat.h> #include <sys/syscallsubr.h> -#include <sys/vnode.h> -#include <sys/mount.h> #include <sys/proc.h> -#include <sys/uio.h> -#include <sys/mac.h> -#include <sys/malloc.h> -#include <sys/dirent.h> -#include <ufs/ufs/dir.h> /* XXX only for DIRBLKSIZ */ #include <machine/../linux/linux.h> #include <machine/../linux/linux_proto.h> -#include <compat/linux/linux_util.h> - -static int -linux_getcwd_scandir(struct vnode **, struct vnode **, - char **, char *, struct thread *); -static int -linux_getcwd_common(struct vnode *, struct vnode *, - char **, char *, int, int, struct thread *); - -#define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4) - -/* - * Vnode variable naming conventions in this file: - * - * rvp: the current root we're aiming towards. - * lvp, *lvpp: the "lower" vnode - * uvp, *uvpp: the "upper" vnode. - * - * Since all the vnodes we're dealing with are directories, and the - * lookups are going *up* in the filesystem rather than *down*, the - * usual "pvp" (parent) or "dvp" (directory) naming conventions are - * too confusing. - */ - -/* - * XXX Will infinite loop in certain cases if a directory read reliably - * returns EINVAL on last block. - * XXX is EINVAL the right thing to return if a directory is malformed? - */ - -/* - * XXX Untested vs. mount -o union; probably does the wrong thing. - */ - -/* - * Find parent vnode of *lvpp, return in *uvpp - * - * If we care about the name, scan it looking for name of directory - * entry pointing at lvp. - * - * Place the name in the buffer which starts at bufp, immediately - * before *bpp, and move bpp backwards to point at the start of it. - * - * On entry, *lvpp is a locked vnode reference; on exit, it is vput and NULL'ed - * On exit, *uvpp is either NULL or is a locked vnode reference. - */ -static int -linux_getcwd_scandir(lvpp, uvpp, bpp, bufp, td) - struct vnode **lvpp; - struct vnode **uvpp; - char **bpp; - char *bufp; - struct thread *td; -{ - int error = 0; - int eofflag; - off_t off; - int tries; - struct uio uio; - struct iovec iov; - char *dirbuf = NULL; - int dirbuflen; - ino_t fileno; - struct vattr va; - struct vnode *uvp = NULL; - struct vnode *lvp = *lvpp; - struct componentname cn; - int len, reclen; - tries = 0; - - /* - * If we want the filename, get some info we need while the - * current directory is still locked. - */ - if (bufp != NULL) { - error = VOP_GETATTR(lvp, &va, td->td_ucred, td); - if (error) { - vput(lvp); - *lvpp = NULL; - *uvpp = NULL; - return error; - } - } - - /* - * Ok, we have to do it the hard way.. - * Next, get parent vnode using lookup of .. - */ - cn.cn_nameiop = LOOKUP; - cn.cn_flags = ISLASTCN | ISDOTDOT | RDONLY; - cn.cn_thread = td; - cn.cn_cred = td->td_ucred; - cn.cn_pnbuf = NULL; - cn.cn_nameptr = ".."; - cn.cn_namelen = 2; - cn.cn_consume = 0; - - /* - * At this point, lvp is locked and will be unlocked by the lookup. - * On successful return, *uvpp will be locked - */ - error = VOP_LOOKUP(lvp, uvpp, &cn); - if (error) { - vput(lvp); - *lvpp = NULL; - *uvpp = NULL; - return error; - } - uvp = *uvpp; - - /* If we don't care about the pathname, we're done */ - if (bufp == NULL) { - vrele(lvp); - *lvpp = NULL; - return 0; - } - - fileno = va.va_fileid; - - dirbuflen = DIRBLKSIZ; - if (dirbuflen < va.va_blocksize) - dirbuflen = va.va_blocksize; - dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK); - -#if 0 -unionread: -#endif - off = 0; - do { - /* call VOP_READDIR of parent */ - iov.iov_base = dirbuf; - iov.iov_len = dirbuflen; - - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = off; - uio.uio_resid = dirbuflen; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_READ; - uio.uio_td = td; - - eofflag = 0; - -#ifdef MAC - error = mac_check_vnode_readdir(td->td_ucred, uvp); - if (error == 0) -#endif /* MAC */ - error = VOP_READDIR(uvp, &uio, td->td_ucred, &eofflag, - 0, 0); - - off = uio.uio_offset; - - /* - * Try again if NFS tosses its cookies. - * XXX this can still loop forever if the directory is busted - * such that the second or subsequent page of it always - * returns EINVAL - */ - if ((error == EINVAL) && (tries < 3)) { - off = 0; - tries++; - continue; /* once more, with feeling */ - } - - if (!error) { - char *cpos; - struct dirent *dp; - - cpos = dirbuf; - tries = 0; - - /* scan directory page looking for matching vnode */ - for (len = (dirbuflen - uio.uio_resid); len > 0; len -= reclen) { - dp = (struct dirent *) cpos; - reclen = dp->d_reclen; - - /* check for malformed directory.. */ - if (reclen < DIRENT_MINSIZE) { - error = EINVAL; - goto out; - } - /* - * XXX should perhaps do VOP_LOOKUP to - * check that we got back to the right place, - * but getting the locking games for that - * right would be heinous. - */ - if ((dp->d_type != DT_WHT) && - (dp->d_fileno == fileno)) { - char *bp = *bpp; - bp -= dp->d_namlen; - - if (bp <= bufp) { - error = ERANGE; - goto out; - } - bcopy(dp->d_name, bp, dp->d_namlen); - error = 0; - *bpp = bp; - goto out; - } - cpos += reclen; - } - } - } while (!eofflag); - error = ENOENT; - -out: - vrele(lvp); - *lvpp = NULL; - free(dirbuf, M_TEMP); - return error; -} - - -/* - * common routine shared by sys___getcwd() and linux_vn_isunder() - */ - -#define GETCWD_CHECK_ACCESS 0x0001 - -static int -linux_getcwd_common (lvp, rvp, bpp, bufp, limit, flags, td) - struct vnode *lvp; - struct vnode *rvp; - char **bpp; - char *bufp; - int limit; - int flags; - struct thread *td; -{ - struct filedesc *fdp = td->td_proc->p_fd; - struct vnode *uvp = NULL; - char *bp = NULL; - int error; - int perms = VEXEC; - - if (rvp == NULL) { - rvp = fdp->fd_rdir; - if (rvp == NULL) - rvp = rootvnode; - } - - VREF(rvp); - VREF(lvp); - - /* - * Error handling invariant: - * Before a `goto out': - * lvp is either NULL, or locked and held. - * uvp is either NULL, or locked and held. - */ - - error = vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, td); - if (error) { - vrele(lvp); - lvp = NULL; - goto out; - } - if (bufp) - bp = *bpp; - /* - * this loop will terminate when one of the following happens: - * - we hit the root - * - getdirentries or lookup fails - * - we run out of space in the buffer. - */ - if (lvp == rvp) { - if (bp) - *(--bp) = '/'; - goto out; - } - do { - if (lvp->v_type != VDIR) { - error = ENOTDIR; - goto out; - } - - /* - * access check here is optional, depending on - * whether or not caller cares. - */ - if (flags & GETCWD_CHECK_ACCESS) { - error = VOP_ACCESS(lvp, perms, td->td_ucred, td); - if (error) - goto out; - perms = VEXEC|VREAD; - } - - /* - * step up if we're a covered vnode.. - */ - while (lvp->v_vflag & VV_ROOT) { - struct vnode *tvp; - - if (lvp == rvp) - goto out; - - tvp = lvp; - lvp = lvp->v_mount->mnt_vnodecovered; - vput(tvp); - /* - * hodie natus est radici frater - */ - if (lvp == NULL) { - error = ENOENT; - goto out; - } - VREF(lvp); - error = vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, td); - if (error != 0) { - vrele(lvp); - lvp = NULL; - goto out; - } - } - error = linux_getcwd_scandir(&lvp, &uvp, &bp, bufp, td); - if (error) - goto out; -#if DIAGNOSTIC - if (lvp != NULL) - panic("getcwd: oops, forgot to null lvp"); - if (bufp && (bp <= bufp)) { - panic("getcwd: oops, went back too far"); - } -#endif - if (bp) - *(--bp) = '/'; - lvp = uvp; - uvp = NULL; - limit--; - } while ((lvp != rvp) && (limit > 0)); - -out: - if (bpp) - *bpp = bp; - if (uvp) - vput(uvp); - if (lvp) - vput(lvp); - vrele(rvp); - return error; -} - /* * Find pathname of process's current directory. * * Use vfs vnode-to-name reverse cache; if that fails, fall back - * to reading directory contents. + * to reading directory contents. Use the common routines in vfs_cache.c. */ int linux_getcwd(struct thread *td, struct linux_getcwd_args *args) { - caddr_t bp, bend, path; - int error, len, lenused; - -#ifdef DEBUG - printf("Linux-emul(%ld): getcwd(%p, %ld)\n", (long)td->td_proc->p_pid, - args->buf, (long)args->bufsize); -#endif - - len = args->bufsize; - - if (len > MAXPATHLEN*4) - len = MAXPATHLEN*4; - else if (len < 2) - return ERANGE; - - path = (char *)malloc(len, M_TEMP, M_WAITOK); - - error = kern___getcwd(td, path, UIO_SYSSPACE, len); - if (!error) { - lenused = strlen(path) + 1; - if (lenused <= args->bufsize) { - td->td_retval[0] = lenused; - error = copyout(path, args->buf, lenused); - } - else - error = ERANGE; - } else { - bp = &path[len]; - bend = bp; - *(--bp) = '\0'; - - /* - * 5th argument here is "max number of vnodes to traverse". - * Since each entry takes up at least 2 bytes in the output buffer, - * limit it to N/2 vnodes for an N byte buffer. - */ - - error = linux_getcwd_common (td->td_proc->p_fd->fd_cdir, NULL, - &bp, path, len/2, GETCWD_CHECK_ACCESS, td); - - if (error) - goto out; - lenused = bend - bp; - td->td_retval[0] = lenused; - /* put the result into user buffer */ - error = copyout(bp, args->buf, lenused); - } -out: - free(path, M_TEMP); - return (error); + return (kern___getcwd (td, args->buf, UIO_USERSPACE, args->bufsize)); } diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index cac844e..a2e5d54 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -52,6 +52,8 @@ #include <sys/proc.h> #include <sys/filedesc.h> #include <sys/fnv_hash.h> +#include <ufs/ufs/dir.h> /* XXX only for DIRBLKSIZ */ +#include <sys/dirent.h> /* * This structure describes the elements in the cache of recent @@ -701,6 +703,9 @@ struct __getcwd_args { static int disablecwd; SYSCTL_INT(_debug, OID_AUTO, disablecwd, CTLFLAG_RW, &disablecwd, 0, "Disable the getcwd syscall"); +static int disable_cached_getcwd; +SYSCTL_INT (_debug, OID_AUTO, disable_cached_getcwd, CTLFLAG_RW, + &disable_cached_getcwd, 0, "Disable getcwd using vfs vnode cache"); /* Various statistics for the getcwd syscall */ static u_long numcwdcalls; STATNODE(CTLFLAG_RD, numcwdcalls, &numcwdcalls); @@ -708,20 +713,68 @@ static u_long numcwdfail1; STATNODE(CTLFLAG_RD, numcwdfail1, &numcwdfail1); static u_long numcwdfail2; STATNODE(CTLFLAG_RD, numcwdfail2, &numcwdfail2); static u_long numcwdfail3; STATNODE(CTLFLAG_RD, numcwdfail3, &numcwdfail3); static u_long numcwdfail4; STATNODE(CTLFLAG_RD, numcwdfail4, &numcwdfail4); +static u_long numcwdtraverse; STATNODE(CTLFLAG_RD, numcwdtraverse, &numcwdtraverse); static u_long numcwdfound; STATNODE(CTLFLAG_RD, numcwdfound, &numcwdfound); +#define GETCWD_CHECK_ACCESS 0x0001 + +#define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4) + +static int +kern___getcwd_cached(struct thread *td, u_char *buf, enum uio_seg bufseg, + u_int buflen); +static int +kern___getcwd_traverse(struct vnode *lvp, struct vnode *rvp, char **bpp, + char *bufp, int limit, int flags, struct thread *td); +static int +kern___getcwd_scandir(struct vnode **lvpp, struct vnode **uvpp, + char **bpp, char *bufp, struct thread *td); + /* Implementation of the getcwd syscall */ int __getcwd(td, uap) struct thread *td; struct __getcwd_args *uap; { - return (kern___getcwd(td, uap->buf, UIO_USERSPACE, uap->buflen)); } +/* + * this part mostly from linux_getcwd. use the original kern___getcwd() + * routine first, which uses the vfs vnode-to-name reverse cache. If + * that fails, use the routines originally from linux_getcwd.c to + * traverse the directory contents (much slower!) + */ +int +kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, + u_int buflen) +{ + int error; + char *bp, *bend; + + if (disablecwd) + return (ENODEV); + + if (kern___getcwd_cached (td, buf, bufseg, buflen) == 0) + return 0; + + bp = &buf[buflen]; + bend = bp; + *(--bp) = '\0'; + error = kern___getcwd_traverse (td->td_proc->p_fd->fd_cdir, NULL, &bp, + buf, buflen / 2, GETCWD_CHECK_ACCESS, td); + if (!error) { + if (bufseg == UIO_USERSPACE) + error = copyout (bp, buf, bend - bp); + /* linux_getcwd has this -- needed? */ + td->td_retval[0] = bend - bp; + } + return error; +} + int -kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, u_int buflen) +kern___getcwd_cached (struct thread *td, u_char *buf, enum uio_seg bufseg, + u_int buflen) { char *bp, *tmpbuf; int error, i, slash_prefixed; @@ -730,7 +783,7 @@ kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, u_int buflen) struct vnode *vp; numcwdcalls++; - if (disablecwd) + if (disable_cached_getcwd) return (ENODEV); if (buflen < 2) return (EINVAL); @@ -811,6 +864,325 @@ kern___getcwd(struct thread *td, u_char *buf, enum uio_seg bufseg, u_int buflen) } /* + * Vnode variable naming conventions in this file: + * + * rvp: the current root we're aiming towards. + * lvp, *lvpp: the "lower" vnode + * uvp, *uvpp: the "upper" vnode. + * + * Since all the vnodes we're dealing with are directories, and the + * lookups are going *up* in the filesystem rather than *down*, the + * usual "pvp" (parent) or "dvp" (directory) naming conventions are + * too confusing. + */ + +/* + * XXX Will infinite loop in certain cases if a directory read reliably + * returns EINVAL on last block. + * XXX is EINVAL the right thing to return if a directory is malformed? + */ + +/* + * XXX Untested vs. mount -o union; probably does the wrong thing. + */ + +int +kern___getcwd_traverse (struct vnode *lvp, struct vnode *rvp, char **bpp, + char *bufp, int limit, int flags, struct thread *td) +{ + struct filedesc *fdp = td->td_proc->p_fd; + struct vnode *uvp = NULL; + char *bp = NULL; + int error; + int perms = VEXEC; + + numcwdtraverse++; + + if (rvp == NULL) { + rvp = fdp->fd_rdir; + if (rvp == NULL) + rvp = rootvnode; + } + + VREF(rvp); + VREF(lvp); + + /* + * Error handling invariant: + * Before a `goto out': + * lvp is either NULL, or locked and held. + * uvp is either NULL, or locked and held. + */ + + error = vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, td); + if (error) { + vrele(lvp); + lvp = NULL; + goto out; + } + if (bufp) + bp = *bpp; + /* + * this loop will terminate when one of the following happens: + * - we hit the root + * - getdirentries or lookup fails + * - we run out of space in the buffer. + */ + if (lvp == rvp) { + if (bp) + *(--bp) = '/'; + goto out; + } + do { + if (lvp->v_type != VDIR) { + error = ENOTDIR; + goto out; + } + + /* + * access check here is optional, depending on + * whether or not caller cares. + */ + if (flags & GETCWD_CHECK_ACCESS) { + error = VOP_ACCESS(lvp, perms, td->td_ucred, td); + if (error) + goto out; + perms = VEXEC|VREAD; + } + + /* + * step up if we're a covered vnode.. + */ + while (lvp->v_vflag & VV_ROOT) { + struct vnode *tvp; + + if (lvp == rvp) + goto out; + + tvp = lvp; + lvp = lvp->v_mount->mnt_vnodecovered; + vput(tvp); + /* + * hodie natus est radici frater + */ + if (lvp == NULL) { + error = ENOENT; + goto out; + } + VREF(lvp); + error = vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, td); + if (error != 0) { + vrele(lvp); + lvp = NULL; + goto out; + } + } + error = kern___getcwd_scandir(&lvp, &uvp, &bp, bufp, td); + if (error) + goto out; +#if DIAGNOSTIC + if (lvp != NULL) + panic("getcwd: oops, forgot to null lvp"); + if (bufp && (bp <= bufp)) { + panic("getcwd: oops, went back too far"); + } +#endif + if (bp) + *(--bp) = '/'; + lvp = uvp; + uvp = NULL; + limit--; + } while ((lvp != rvp) && (limit > 0)); + +out: + if (bpp) + *bpp = bp; + if (uvp) + vput(uvp); + if (lvp) + vput(lvp); + vrele(rvp); + return error; +} + + +/* + * Find parent vnode of *lvpp, return in *uvpp + * + * If we care about the name, scan it looking for name of directory + * entry pointing at lvp. + * + * Place the name in the buffer which starts at bufp, immediately + * before *bpp, and move bpp backwards to point at the start of it. + * + * On entry, *lvpp is a locked vnode reference; on exit, it is vput and NULL'ed + * On exit, *uvpp is either NULL or is a locked vnode reference. + */ +static int +kern___getcwd_scandir (struct vnode **lvpp, struct vnode **uvpp, + char **bpp, char *bufp, struct thread *td) +{ + int error = 0; + int eofflag; + off_t off; + int tries; + struct uio uio; + struct iovec iov; + char *dirbuf = NULL; + int dirbuflen; + ino_t fileno; + struct vattr va; + struct vnode *uvp = NULL; + struct vnode *lvp = *lvpp; + struct componentname cn; + int len, reclen; + tries = 0; + + /* + * If we want the filename, get some info we need while the + * current directory is still locked. + */ + if (bufp != NULL) { + error = VOP_GETATTR(lvp, &va, td->td_ucred, td); + if (error) { + vput(lvp); + *lvpp = NULL; + *uvpp = NULL; + return error; + } + } + + /* + * Ok, we have to do it the hard way.. + * Next, get parent vnode using lookup of .. + */ + cn.cn_nameiop = LOOKUP; + cn.cn_flags = ISLASTCN | ISDOTDOT | RDONLY; + cn.cn_thread = td; + cn.cn_cred = td->td_ucred; + cn.cn_pnbuf = NULL; + cn.cn_nameptr = ".."; + cn.cn_namelen = 2; + cn.cn_consume = 0; + + /* + * At this point, lvp is locked and will be unlocked by the lookup. + * On successful return, *uvpp will be locked + */ + error = VOP_LOOKUP(lvp, uvpp, &cn); + if (error) { + vput(lvp); + *lvpp = NULL; + *uvpp = NULL; + return error; + } + uvp = *uvpp; + + /* If we don't care about the pathname, we're done */ + if (bufp == NULL) { + vrele(lvp); + *lvpp = NULL; + return 0; + } + + fileno = va.va_fileid; + + dirbuflen = DIRBLKSIZ; + if (dirbuflen < va.va_blocksize) + dirbuflen = va.va_blocksize; + dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK); + +#if 0 +unionread: +#endif + off = 0; + do { + /* call VOP_READDIR of parent */ + iov.iov_base = dirbuf; + iov.iov_len = dirbuflen; + + uio.uio_iov = &iov; + uio.uio_iovcnt = 1; + uio.uio_offset = off; + uio.uio_resid = dirbuflen; + uio.uio_segflg = UIO_SYSSPACE; + uio.uio_rw = UIO_READ; + uio.uio_td = td; + + eofflag = 0; + +#ifdef MAC + error = mac_check_vnode_readdir(td->td_ucred, uvp); + if (error == 0) +#endif /* MAC */ + error = VOP_READDIR(uvp, &uio, td->td_ucred, &eofflag, + 0, 0); + + off = uio.uio_offset; + + /* + * Try again if NFS tosses its cookies. + * XXX this can still loop forever if the directory is busted + * such that the second or subsequent page of it always + * returns EINVAL + */ + if ((error == EINVAL) && (tries < 3)) { + off = 0; + tries++; + continue; /* once more, with feeling */ + } + + if (!error) { + char *cpos; + struct dirent *dp; + + cpos = dirbuf; + tries = 0; + + /* scan directory page looking for matching vnode */ + for (len = (dirbuflen - uio.uio_resid); len > 0; len -= reclen) { + dp = (struct dirent *) cpos; + reclen = dp->d_reclen; + + /* check for malformed directory.. */ + if (reclen < DIRENT_MINSIZE) { + error = EINVAL; + goto out; + } + /* + * XXX should perhaps do VOP_LOOKUP to + * check that we got back to the right place, + * but getting the locking games for that + * right would be heinous. + */ + if ((dp->d_type != DT_WHT) && + (dp->d_fileno == fileno)) { + char *bp = *bpp; + bp -= dp->d_namlen; + + if (bp <= bufp) { + error = ERANGE; + goto out; + } + bcopy(dp->d_name, bp, dp->d_namlen); + error = 0; + *bpp = bp; + goto out; + } + cpos += reclen; + } + } + } while (!eofflag); + error = ENOENT; + +out: + vrele(lvp); + *lvpp = NULL; + free(dirbuf, M_TEMP); + return error; +} + +/* * Thus begins the fullpath magic. */ |
