Date: Wed, 10 Mar 2010 19:49:33 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-7@freebsd.org Subject: svn commit: r204971 - stable/7/sys/kern Message-ID: <201003101949.o2AJnXHR044636@svn.freebsd.org>
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Author: jhb Date: Wed Mar 10 19:49:33 2010 New Revision: 204971 URL: http://svn.freebsd.org/changeset/base/204971 Log: MFC 204638: Allow lseek(SEEK_END) to work on disk devices by using the DIOCGMEDIASIZE to determine the media size. Modified: stable/7/sys/kern/vfs_syscalls.c Directory Properties: stable/7/sys/ (props changed) stable/7/sys/cddl/contrib/opensolaris/ (props changed) stable/7/sys/contrib/dev/acpica/ (props changed) stable/7/sys/contrib/pf/ (props changed) Modified: stable/7/sys/kern/vfs_syscalls.c ============================================================================== --- stable/7/sys/kern/vfs_syscalls.c Wed Mar 10 19:47:05 2010 (r204970) +++ stable/7/sys/kern/vfs_syscalls.c Wed Mar 10 19:49:33 2010 (r204971) @@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$"); #include <sys/systm.h> #include <sys/bio.h> #include <sys/buf.h> +#include <sys/disk.h> #include <sys/sysent.h> #include <sys/malloc.h> #include <sys/mount.h> @@ -1762,7 +1763,7 @@ lseek(td, uap) struct file *fp; struct vnode *vp; struct vattr vattr; - off_t offset; + off_t offset, size; int error, noneg; int vfslocked; @@ -1792,6 +1793,15 @@ lseek(td, uap) VOP_UNLOCK(vp, 0, td); if (error) break; + + /* + * If the file references a disk device, then fetch + * the media size and use that to determine the ending + * offset. + */ + if (vattr.va_size == 0 && vp->v_type == VCHR && + fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0) + vattr.va_size = size; if (noneg && (vattr.va_size > OFF_MAX || (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
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