Date: Sat, 26 May 2012 05:28:48 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r236043 - in head/sys: kern sys Message-ID: <201205260528.q4Q5Smcv054457@svn.freebsd.org>
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Author: kib Date: Sat May 26 05:28:47 2012 New Revision: 236043 URL: http://svn.freebsd.org/changeset/base/236043 Log: Add a vn_bmap_seekhole(9) vnode helper which can be used by any filesystem which supports VOP_BMAP(9) to implement SEEK_HOLE/SEEK_DATA commands for lseek(2). MFC after: 2 weeks Modified: head/sys/kern/vfs_vnops.c head/sys/sys/vnode.h Modified: head/sys/kern/vfs_vnops.c ============================================================================== --- head/sys/kern/vfs_vnops.c Sat May 26 05:25:55 2012 (r236042) +++ head/sys/kern/vfs_vnops.c Sat May 26 05:28:47 2012 (r236043) @@ -1466,3 +1466,56 @@ vn_pages_remove(struct vnode *vp, vm_pin vm_object_page_remove(object, start, end, 0); VM_OBJECT_UNLOCK(object); } + +int +vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred) +{ + struct vattr va; + daddr_t bn, bnp; + uint64_t bsize; + off_t noff; + int error; + + KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA, + ("Wrong command %lu", cmd)); + + if (vn_lock(vp, LK_SHARED) != 0) + return (EBADF); + if (vp->v_type != VREG) { + error = ENOTTY; + goto unlock; + } + error = VOP_GETATTR(vp, &va, cred); + if (error != 0) + goto unlock; + noff = *off; + if (noff >= va.va_size) { + error = ENXIO; + goto unlock; + } + bsize = vp->v_mount->mnt_stat.f_iosize; + for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) { + error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL); + if (error == EOPNOTSUPP) { + error = ENOTTY; + goto unlock; + } + if ((bnp == -1 && cmd == FIOSEEKHOLE) || + (bnp != -1 && cmd == FIOSEEKDATA)) { + noff = bn * bsize; + if (noff < *off) + noff = *off; + goto unlock; + } + } + if (noff > va.va_size) + noff = va.va_size; + /* noff == va.va_size. There is an implicit hole at the end of file. */ + if (cmd == FIOSEEKDATA) + error = ENXIO; +unlock: + VOP_UNLOCK(vp, 0); + if (error == 0) + *off = noff; + return (error); +} Modified: head/sys/sys/vnode.h ============================================================================== --- head/sys/sys/vnode.h Sat May 26 05:25:55 2012 (r236042) +++ head/sys/sys/vnode.h Sat May 26 05:28:47 2012 (r236043) @@ -640,6 +640,8 @@ void vunref(struct vnode *); void vn_printf(struct vnode *vp, const char *fmt, ...) __printflike(2,3); #define vprint(label, vp) vn_printf((vp), "%s\n", (label)) int vrecycle(struct vnode *vp); +int vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, + struct ucred *cred); int vn_close(struct vnode *vp, int flags, struct ucred *file_cred, struct thread *td); void vn_finished_write(struct mount *mp);
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