Fix linux_getdents so that it can cope with filesystems which translate
the directory format (ext2fs, cd9660). For these filesystems, it must use cookies to find the correct offset to use for subsequent reads. Without it, linux /bin/ls tends to loop re-reading the same block over and over again. 2.2 candidate.
This commit is contained in:
Doug Rabson
parent
8e71151378
commit
d41979a063
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@ -25,7 +25,7 @@
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $Id: linux_file.c,v 1.11 1997/02/22 09:38:20 peter Exp $
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* $Id: linux_file.c,v 1.12 1997/03/24 11:24:29 bde Exp $
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*/
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#include <sys/param.h>
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@ -414,7 +414,9 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args, int *retval)
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struct vattr va;
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off_t off;
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struct linux_dirent linux_dirent;
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int buflen, error, eofflag, nbytes, justone, blockoff;
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int buflen, error, eofflag, nbytes, justone;
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u_long *cookies = NULL, *cookiep;
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int ncookies;
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#ifdef DEBUG
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printf("Linux-emul(%d): getdents(%d, *, %d)\n",
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@ -445,8 +447,7 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args, int *retval)
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justone = 0;
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off = fp->f_offset;
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blockoff = off % DIRBLKSIZ;
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buflen = max(DIRBLKSIZ, nbytes + blockoff);
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buflen = max(DIRBLKSIZ, nbytes);
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buflen = min(buflen, MAXBSIZE);
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buf = malloc(buflen, M_TEMP, M_WAITOK);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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@ -459,22 +460,47 @@ again:
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auio.uio_segflg = UIO_SYSSPACE;
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auio.uio_procp = p;
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auio.uio_resid = buflen;
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auio.uio_offset = off - (off_t)blockoff;
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auio.uio_offset = off;
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error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL, NULL);
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if (cookies) {
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free(cookies, M_TEMP);
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cookies = NULL;
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}
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error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &ncookies, &cookies);
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if (error) {
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goto out;
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}
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inp = buf;
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inp += blockoff;
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outp = (caddr_t) args->dent;
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resid = nbytes;
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if ((len = buflen - auio.uio_resid - blockoff) == 0) {
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if ((len = buflen - auio.uio_resid) <= 0) {
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goto eof;
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}
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cookiep = cookies;
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if (cookies) {
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/*
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* When using cookies, the vfs has the option of reading from
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* a different offset than that supplied (UFS truncates the
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* offset to a block boundary to make sure that it never reads
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* partway through a directory entry, even if the directory
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* has been compacted).
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*/
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while (len > 0 && ncookies > 0 && *cookiep <= off) {
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bdp = (struct dirent *) inp;
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len -= bdp->d_reclen;
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inp += bdp->d_reclen;
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cookiep++;
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ncookies--;
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}
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}
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while (len > 0) {
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if (cookiep && ncookies == 0)
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break;
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bdp = (struct dirent *) inp;
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reclen = bdp->d_reclen;
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if (reclen & 3) {
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@ -485,7 +511,11 @@ again:
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if (bdp->d_fileno == 0) {
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inp += reclen;
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off += reclen;
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if (cookiep) {
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off = *cookiep++;
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ncookies--;
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} else
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off += reclen;
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len -= reclen;
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continue;
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}
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@ -510,7 +540,11 @@ again:
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goto out;
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}
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inp += reclen;
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off += reclen;
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if (cookiep) {
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off = *cookiep++;
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ncookies--;
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} else
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off += reclen;
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outp += linuxreclen;
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resid -= linuxreclen;
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len -= reclen;
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@ -528,6 +562,8 @@ again:
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eof:
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*retval = nbytes - resid;
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out:
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if (cookies)
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free(cookies, M_TEMP);
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VOP_UNLOCK(vp, 0, p);
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free(buf, M_TEMP);
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return error;
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@ -25,7 +25,7 @@
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $Id: linux_file.c,v 1.11 1997/02/22 09:38:20 peter Exp $
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* $Id: linux_file.c,v 1.12 1997/03/24 11:24:29 bde Exp $
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*/
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#include <sys/param.h>
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@ -414,7 +414,9 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args, int *retval)
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struct vattr va;
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off_t off;
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struct linux_dirent linux_dirent;
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int buflen, error, eofflag, nbytes, justone, blockoff;
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int buflen, error, eofflag, nbytes, justone;
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u_long *cookies = NULL, *cookiep;
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int ncookies;
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#ifdef DEBUG
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printf("Linux-emul(%d): getdents(%d, *, %d)\n",
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@ -445,8 +447,7 @@ linux_getdents(struct proc *p, struct linux_getdents_args *args, int *retval)
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justone = 0;
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off = fp->f_offset;
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blockoff = off % DIRBLKSIZ;
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buflen = max(DIRBLKSIZ, nbytes + blockoff);
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buflen = max(DIRBLKSIZ, nbytes);
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buflen = min(buflen, MAXBSIZE);
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buf = malloc(buflen, M_TEMP, M_WAITOK);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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@ -459,22 +460,47 @@ again:
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auio.uio_segflg = UIO_SYSSPACE;
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auio.uio_procp = p;
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auio.uio_resid = buflen;
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auio.uio_offset = off - (off_t)blockoff;
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auio.uio_offset = off;
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error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL, NULL);
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if (cookies) {
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free(cookies, M_TEMP);
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cookies = NULL;
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}
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error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &ncookies, &cookies);
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if (error) {
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goto out;
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}
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inp = buf;
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inp += blockoff;
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outp = (caddr_t) args->dent;
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resid = nbytes;
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if ((len = buflen - auio.uio_resid - blockoff) == 0) {
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if ((len = buflen - auio.uio_resid) <= 0) {
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goto eof;
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}
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cookiep = cookies;
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if (cookies) {
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/*
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* When using cookies, the vfs has the option of reading from
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* a different offset than that supplied (UFS truncates the
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* offset to a block boundary to make sure that it never reads
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* partway through a directory entry, even if the directory
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* has been compacted).
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*/
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while (len > 0 && ncookies > 0 && *cookiep <= off) {
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bdp = (struct dirent *) inp;
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len -= bdp->d_reclen;
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inp += bdp->d_reclen;
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cookiep++;
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ncookies--;
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}
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}
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while (len > 0) {
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if (cookiep && ncookies == 0)
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break;
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bdp = (struct dirent *) inp;
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reclen = bdp->d_reclen;
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if (reclen & 3) {
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@ -485,7 +511,11 @@ again:
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if (bdp->d_fileno == 0) {
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inp += reclen;
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off += reclen;
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if (cookiep) {
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off = *cookiep++;
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ncookies--;
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} else
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off += reclen;
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len -= reclen;
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continue;
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}
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@ -510,7 +540,11 @@ again:
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goto out;
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}
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inp += reclen;
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off += reclen;
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if (cookiep) {
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off = *cookiep++;
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ncookies--;
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} else
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off += reclen;
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outp += linuxreclen;
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resid -= linuxreclen;
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len -= reclen;
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@ -528,6 +562,8 @@ again:
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eof:
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*retval = nbytes - resid;
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out:
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if (cookies)
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free(cookies, M_TEMP);
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VOP_UNLOCK(vp, 0, p);
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free(buf, M_TEMP);
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return error;
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