Author: kib Date: Wed Nov 14 14:18:35 2018 New Revision: 340431 URL: https://svnweb.freebsd.org/changeset/base/340431
Log: Add d_off support for multiple filesystems. The d_off field has been added to the dirent structure recently. Currently filesystems don't support this feature. Support has been added and tested for zfs, ufs, ext2fs, fdescfs, msdosfs and unionfs. A stub implementation is available for cd9660, nandfs, udf and pseudofs but hasn't been tested. Motivation for this feature: our usecase is for a userspace nfs server (nfs-ganesha) with zfs. At the moment we cache direntry offsets by calling lseek once per entry, with this patch we can get the offset directly from getdirentries(2) calls which provides a significant speedup. Submitted by: Jack Halford <j...@gandi.net> Reviewed by: mckusick, pfg, rmacklem (previous versions) Sponsored by: Gandi.net MFC after: 1 week Differential revision: https://reviews.freebsd.org/D17917 Modified: head/lib/libc/sys/getdirentries.2 head/share/man/man5/dir.5 head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c head/sys/fs/cd9660/cd9660_vnops.c head/sys/fs/devfs/devfs_vnops.c head/sys/fs/ext2fs/ext2_lookup.c head/sys/fs/fdescfs/fdesc_vnops.c head/sys/fs/msdosfs/msdosfs_vnops.c head/sys/fs/nandfs/nandfs_vnops.c head/sys/fs/pseudofs/pseudofs_vnops.c head/sys/fs/udf/udf_vnops.c head/sys/ufs/ufs/ufs_vnops.c Modified: head/lib/libc/sys/getdirentries.2 ============================================================================== --- head/lib/libc/sys/getdirentries.2 Wed Nov 14 13:06:48 2018 (r340430) +++ head/lib/libc/sys/getdirentries.2 Wed Nov 14 14:18:35 2018 (r340431) @@ -28,7 +28,7 @@ .\" @(#)getdirentries.2 8.2 (Berkeley) 5/3/95 .\" $FreeBSD$ .\" -.Dd May 28, 2017 +.Dd Nov 14, 2018 .Dt GETDIRENTRIES 2 .Os .Sh NAME @@ -88,6 +88,11 @@ Files that are linked by hard links (see have the same .Fa d_fileno . The +.Fa d_off +field returns a cookie which can be used with +.Xr lseek 2 +to position the directory descriptor to the next entry. +The .Fa d_reclen entry is the length, in bytes, of the directory record. The @@ -140,8 +145,17 @@ a value returned in the location pointed to by .Fa basep .Po Fn getdirentries only -.Pc +.Pc , +a value returned in the +.Fa d_off +field, or zero. +.Sh IMPLEMENTATION NOTES +The +.Fa d_off +field is being used as a cookie to readdir for nfs servers. +These cookies can be cached and allow to read directory entries at a specific +offset on demand. .Sh RETURN VALUES If successful, the number of bytes actually transferred is returned. Otherwise, -1 is returned and the global variable Modified: head/share/man/man5/dir.5 ============================================================================== --- head/share/man/man5/dir.5 Wed Nov 14 13:06:48 2018 (r340430) +++ head/share/man/man5/dir.5 Wed Nov 14 14:18:35 2018 (r340431) @@ -28,7 +28,7 @@ .\" @(#)dir.5 8.3 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd June 20, 2018 +.Dd November 14, 2018 .Dt DIR 5 .Os .Sh NAME @@ -101,7 +101,7 @@ The directory entry format is defined in the file struct dirent { ino_t d_fileno; /* file number of entry */ - off_t d_off; /* directory offset of entry */ + off_t d_off; /* directory offset of the next entry */ __uint16_t d_reclen; /* length of this record */ __uint8_t d_type; /* file type, see below */ __uint8_t d_namlen; /* length of string in d_name */ Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c Wed Nov 14 14:18:35 2018 (r340431) @@ -1097,6 +1097,8 @@ zfsctl_snapdir_readdir(ap) strcpy(entry.d_name, snapname); entry.d_namlen = strlen(entry.d_name); entry.d_reclen = sizeof(entry); + /* NOTE: d_off is the offset for the *next* entry. */ + entry.d_off = cookie + dots_offset; error = vfs_read_dirent(ap, &entry, uio->uio_offset); if (error != 0) { if (error == ENAMETOOLONG) Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -2529,8 +2529,8 @@ zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int * */ eodp->ed_ino = objnum; eodp->ed_reclen = reclen; - /* NOTE: ed_off is the offset for the *next* entry */ - next = &(eodp->ed_off); + /* NOTE: ed_off is the offset for the *next* entry. */ + next = &eodp->ed_off; eodp->ed_eflags = zap.za_normalization_conflict ? ED_CASE_CONFLICT : 0; (void) strncpy(eodp->ed_name, zap.za_name, @@ -2543,6 +2543,8 @@ zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int * odp->d_ino = objnum; odp->d_reclen = reclen; odp->d_namlen = strlen(zap.za_name); + /* NOTE: d_off is the offset for the *next* entry. */ + next = &odp->d_off; (void) strlcpy(odp->d_name, zap.za_name, odp->d_namlen + 1); odp->d_type = type; odp = (dirent64_t *)((intptr_t)odp + reclen); @@ -2567,6 +2569,9 @@ zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int * offset += 1; } + /* Fill the offset right after advancing the cursor. */ + if (next != NULL) + *next = offset; if (cooks != NULL) { *cooks++ = offset; ncooks--; Modified: head/sys/fs/cd9660/cd9660_vnops.c ============================================================================== --- head/sys/fs/cd9660/cd9660_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/cd9660/cd9660_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -576,6 +576,8 @@ cd9660_readdir(ap) entryoffsetinblock; idp->curroff += reclen; + /* NOTE: d_off is the offset of *next* entry. */ + idp->current.d_off = idp->curroff; switch (imp->iso_ftype) { case ISO_FTYPE_RRIP: Modified: head/sys/fs/devfs/devfs_vnops.c ============================================================================== --- head/sys/fs/devfs/devfs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/devfs/devfs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -1381,6 +1381,8 @@ devfs_readdir(struct vop_readdir_args *ap) if (dp->d_reclen > uio->uio_resid) break; dp->d_fileno = de->de_inode; + /* NOTE: d_off is the offset for the *next* entry. */ + dp->d_off = off + dp->d_reclen; if (off >= uio->uio_offset) { error = vfs_read_dirent(ap, dp, off); if (error) Modified: head/sys/fs/ext2fs/ext2_lookup.c ============================================================================== --- head/sys/fs/ext2fs/ext2_lookup.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/ext2fs/ext2_lookup.c Wed Nov 14 14:18:35 2018 (r340431) @@ -224,6 +224,8 @@ ext2_readdir(struct vop_readdir_args *ap) dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen); dstdp.d_name[dstdp.d_namlen] = '\0'; + /* NOTE: d_off is the offset of the *next* entry. */ + dstdp.d_off = offset + dp->e2d_reclen; if (dstdp.d_reclen > uio->uio_resid) { if (uio->uio_resid == startresid) error = EINVAL; Modified: head/sys/fs/fdescfs/fdesc_vnops.c ============================================================================== --- head/sys/fs/fdescfs/fdesc_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/fdescfs/fdesc_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -574,6 +574,8 @@ fdesc_readdir(struct vop_readdir_args *ap) dp->d_fileno = i + FD_DESC; break; } + /* NOTE: d_off is the offset of the *next* entry. */ + dp->d_off = UIO_MX * (i + 1); if (dp->d_namlen != 0) { /* * And ship to userland Modified: head/sys/fs/msdosfs/msdosfs_vnops.c ============================================================================== --- head/sys/fs/msdosfs/msdosfs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/msdosfs/msdosfs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -1558,6 +1558,8 @@ msdosfs_readdir(struct vop_readdir_args *ap) break; } dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf); + /* NOTE: d_off is the offset of the *next* entry. */ + dirbuf.d_off = offset + sizeof(struct direntry); if (uio->uio_resid < dirbuf.d_reclen) goto out; error = uiomove(&dirbuf, dirbuf.d_reclen, uio); @@ -1681,6 +1683,8 @@ msdosfs_readdir(struct vop_readdir_args *ap) mbnambuf_flush(&nb, &dirbuf); chksum = -1; dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf); + /* NOTE: d_off is the offset of the *next* entry. */ + dirbuf.d_off = offset + sizeof(struct direntry); if (uio->uio_resid < dirbuf.d_reclen) { brelse(bp); goto out; Modified: head/sys/fs/nandfs/nandfs_vnops.c ============================================================================== --- head/sys/fs/nandfs/nandfs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/nandfs/nandfs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -1233,6 +1233,8 @@ nandfs_readdir(struct vop_readdir_args *ap) dirent.d_namlen = name_len; strncpy(dirent.d_name, ndirent->name, name_len); dirent.d_reclen = GENERIC_DIRSIZ(&dirent); + /* NOTE: d_off is the offset of the *next* entry. */ + dirent.d_off = diroffset + ndirent->rec_len; DPRINTF(READDIR, ("copying `%*.*s`\n", name_len, name_len, dirent.d_name)); } Modified: head/sys/fs/pseudofs/pseudofs_vnops.c ============================================================================== --- head/sys/fs/pseudofs/pseudofs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/pseudofs/pseudofs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -830,6 +830,8 @@ pfs_readdir(struct vop_readdir_args *va) pfsent->entry.d_name[i] = pn->pn_name[i]; pfsent->entry.d_name[i] = 0; pfsent->entry.d_namlen = i; + /* NOTE: d_off is the offset of the *next* entry. */ + pfsent->entry.d_off = offset + PFS_DELEN; switch (pn->pn_type) { case pfstype_procdir: KASSERT(p != NULL, Modified: head/sys/fs/udf/udf_vnops.c ============================================================================== --- head/sys/fs/udf/udf_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/fs/udf/udf_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -846,6 +846,7 @@ udf_readdir(struct vop_readdir_args *a) dir.d_name[1] = '\0'; dir.d_namlen = 1; dir.d_reclen = GENERIC_DIRSIZ(&dir); + dir.d_off = 1; uiodir.dirent = &dir; error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1); if (error) @@ -858,6 +859,7 @@ udf_readdir(struct vop_readdir_args *a) dir.d_name[2] = '\0'; dir.d_namlen = 2; dir.d_reclen = GENERIC_DIRSIZ(&dir); + dir.d_off = 2; uiodir.dirent = &dir; error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2); } else { @@ -867,6 +869,7 @@ udf_readdir(struct vop_readdir_args *a) dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ? DT_DIR : DT_UNKNOWN; dir.d_reclen = GENERIC_DIRSIZ(&dir); + dir.d_off = ds->this_off; uiodir.dirent = &dir; error = udf_uiodir(&uiodir, dir.d_reclen, uio, ds->this_off); Modified: head/sys/ufs/ufs/ufs_vnops.c ============================================================================== --- head/sys/ufs/ufs/ufs_vnops.c Wed Nov 14 13:06:48 2018 (r340430) +++ head/sys/ufs/ufs/ufs_vnops.c Wed Nov 14 14:18:35 2018 (r340431) @@ -2218,6 +2218,8 @@ ufs_readdir(ap) dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); bcopy(dp->d_name, dstdp.d_name, dstdp.d_namlen); dstdp.d_name[dstdp.d_namlen] = '\0'; + /* NOTE: d_off is the offset of the *next* entry. */ + dstdp.d_off = offset + dp->d_reclen; if (dstdp.d_reclen > uio->uio_resid) { if (uio->uio_resid == startresid) error = EINVAL; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
