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| author | jhb <jhb@FreeBSD.org> | 2010-03-03 16:18:04 +0000 |
|---|---|---|
| committer | jhb <jhb@FreeBSD.org> | 2010-03-03 16:18:04 +0000 |
| commit | f9290c7f6d8d1cd09ffc2e4edf2fc35baf783c80 (patch) | |
| tree | 420f28069df7fe97f40e5d6dae2fadac91c2d6e5 /sys/kern/vfs_syscalls.c | |
| parent | c5a3b40d67289d8bb591d76ed3c0d1b8ad5715a8 (diff) | |
| download | FreeBSD-src-f9290c7f6d8d1cd09ffc2e4edf2fc35baf783c80.zip FreeBSD-src-f9290c7f6d8d1cd09ffc2e4edf2fc35baf783c80.tar.gz | |
Allow lseek(SEEK_END) to work on disk devices by using the DIOCGMEDIASIZE
to determine the media size.
Submitted by: nox
MFC after: 1 week
Diffstat (limited to 'sys/kern/vfs_syscalls.c')
| -rw-r--r-- | sys/kern/vfs_syscalls.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c index f1e6ca8..7e70056 100644 --- a/sys/kern/vfs_syscalls.c +++ b/sys/kern/vfs_syscalls.c @@ -45,6 +45,7 @@ __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> @@ -1920,7 +1921,7 @@ lseek(td, uap) struct file *fp; struct vnode *vp; struct vattr vattr; - off_t offset; + off_t offset, size; int error, noneg; int vfslocked; @@ -1951,6 +1952,15 @@ lseek(td, uap) VOP_UNLOCK(vp, 0); 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))) { |
