Author: mjg Date: Fri Aug 7 23:06:40 2020 New Revision: 364044 URL: https://svnweb.freebsd.org/changeset/base/364044
Log: vfs: add VOP_STAT The current scheme of calling VOP_GETATTR adds avoidable overhead. An example with tmpfs doing fstat (ops/s): before: 7488958 after: 7913833 Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D25910 Modified: head/share/man/man9/Makefile head/share/man/man9/VOP_ATTRIB.9 head/sys/compat/linuxkpi/common/src/linux_compat.c head/sys/kern/vfs_default.c head/sys/kern/vfs_syscalls.c head/sys/kern/vfs_vnops.c head/sys/kern/vnode_if.src head/sys/security/audit/audit_arg.c head/sys/sys/vnode.h Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Fri Aug 7 19:58:16 2020 (r364043) +++ head/share/man/man9/Makefile Fri Aug 7 23:06:40 2020 (r364044) @@ -2308,7 +2308,8 @@ MLINKS+=vm_page_insert.9 vm_page_remove.9 MLINKS+=vm_page_wire.9 vm_page_unwire.9 MLINKS+=VOP_ACCESS.9 VOP_ACCESSX.9 MLINKS+=VOP_ATTRIB.9 VOP_GETATTR.9 \ - VOP_ATTRIB.9 VOP_SETATTR.9 + VOP_ATTRIB.9 VOP_SETATTR.9 \ + VOP_ATTRIB.9 VOP_STAT.9 MLINKS+=VOP_CREATE.9 VOP_MKDIR.9 \ VOP_CREATE.9 VOP_MKNOD.9 \ VOP_CREATE.9 VOP_SYMLINK.9 Modified: head/share/man/man9/VOP_ATTRIB.9 ============================================================================== --- head/share/man/man9/VOP_ATTRIB.9 Fri Aug 7 19:58:16 2020 (r364043) +++ head/share/man/man9/VOP_ATTRIB.9 Fri Aug 7 23:06:40 2020 (r364044) @@ -28,7 +28,7 @@ .\" .\" $FreeBSD$ .\" -.Dd August 29, 2008 +.Dd August 8, 2020 .Dt VOP_ATTRIB 9 .Os .Sh NAME @@ -42,21 +42,51 @@ .Fn VOP_GETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" .Ft int .Fn VOP_SETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" +.Ft int +.Fn VOP_STAT "struct vnode *vp" "struct stat *sb" "struct ucred *active_cred" \ +"struct ucred *file_cred" "struct thread *td" .Sh DESCRIPTION These entry points manipulate various attributes of a file or directory, including file permissions, owner, group, size, access time and modification time. .Pp -The arguments are: +.Fn VOP_STAT +returns data in a format suitable for the +.Xr stat 2 +system call and by default is implemented as a wrapper around +.Fn VOP_GETATTR . +Filesystems may want to implement their own variant for performance reasons. +.Pp +For +.Fn VOP_GETATTR +and +.Fn VOP_SETATTR +the arguments are: .Bl -tag -width cred .It Fa vp The vnode of the file. .It Fa vap The attributes of the file. .It Fa cred -The user credentials of the calling process. +The user credentials of the calling thread. .El .Pp +For +.Fn VOP_STAT +the arguments are: +.Bl -tag -width active_cred +.It Fa vp +The vnode of the file. +.It Fa sb +The attributes of the file. +.It Fa active_cred +The user credentials of the calling thread. +.It Fa file_cred +The credentials installed on the file description pointing to the vnode or NOCRED. +.It Fa td +The calling thread. +.El +.Pp Attributes which are not being modified by .Fn VOP_SETATTR should be set to the value @@ -67,8 +97,11 @@ the contents of .Fa *vap prior to setting specific values. .Sh LOCKS +Both .Fn VOP_GETATTR -expects the vnode to be locked on entry and will leave the vnode locked on +and +.Fn VOP_STAT +expect the vnode to be locked on entry and will leave the vnode locked on return. The lock type can be either shared or exclusive. .Pp @@ -84,6 +117,10 @@ otherwise an appropriate error is returned. .Fn VOP_SETATTR returns zero if the attributes were changed successfully, otherwise an appropriate error is returned. +.Fn VOP_STAT +returns 0 if it was able to retrieve the attribute data +.Fa *sb , +otherwise an appropriate error is returned. .Sh ERRORS .Bl -tag -width Er .It Bq Er EPERM Modified: head/sys/compat/linuxkpi/common/src/linux_compat.c ============================================================================== --- head/sys/compat/linuxkpi/common/src/linux_compat.c Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/compat/linuxkpi/common/src/linux_compat.c Fri Aug 7 23:06:40 2020 (r364044) @@ -1691,7 +1691,7 @@ linux_file_stat(struct file *fp, struct stat *sb, stru vp = filp->f_vnode; vn_lock(vp, LK_SHARED | LK_RETRY); - error = vn_stat(vp, sb, td->td_ucred, NOCRED, td); + error = VOP_STAT(vp, sb, td->td_ucred, NOCRED, td); VOP_UNLOCK(vp); return (error); Modified: head/sys/kern/vfs_default.c ============================================================================== --- head/sys/kern/vfs_default.c Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/kern/vfs_default.c Fri Aug 7 23:06:40 2020 (r364044) @@ -57,6 +57,9 @@ __FBSDID("$FreeBSD$"); #include <sys/vnode.h> #include <sys/dirent.h> #include <sys/poll.h> +#include <sys/stat.h> +#include <security/audit/audit.h> +#include <sys/priv.h> #include <security/mac/mac_framework.h> @@ -87,6 +90,7 @@ static int vop_stdadd_writecount(struct vop_add_writec static int vop_stdcopy_file_range(struct vop_copy_file_range_args *ap); static int vop_stdfdatasync(struct vop_fdatasync_args *ap); static int vop_stdgetpages_async(struct vop_getpages_async_args *ap); +static int vop_stdstat(struct vop_stat_args *ap); /* * This vnode table stores what we want to do if the filesystem doesn't @@ -114,6 +118,7 @@ struct vop_vector default_vnodeops = { .vop_bmap = vop_stdbmap, .vop_close = VOP_NULL, .vop_fsync = VOP_NULL, + .vop_stat = vop_stdstat, .vop_fdatasync = vop_stdfdatasync, .vop_getpages = vop_stdgetpages, .vop_getpages_async = vop_stdgetpages_async, @@ -1460,4 +1465,112 @@ vop_sigdefer(struct vop_vector *vop, struct vop_generi rc = bp(a); sigallowstop(prev_stops); return (rc); +} + +static int +vop_stdstat(struct vop_stat_args *a) +{ + struct vattr vattr; + struct vattr *vap; + struct vnode *vp; + struct stat *sb; + int error; + u_short mode; + + vp = a->a_vp; + sb = a->a_sb; + + error = vop_stat_helper_pre(a); + if (error != 0) + return (error); + + vap = &vattr; + + /* + * Initialize defaults for new and unusual fields, so that file + * systems which don't support these fields don't need to know + * about them. + */ + vap->va_birthtime.tv_sec = -1; + vap->va_birthtime.tv_nsec = 0; + vap->va_fsid = VNOVAL; + vap->va_rdev = NODEV; + + error = VOP_GETATTR(vp, vap, a->a_active_cred); + if (error) + goto out; + + /* + * Zero the spare stat fields + */ + bzero(sb, sizeof *sb); + + /* + * Copy from vattr table + */ + if (vap->va_fsid != VNOVAL) + sb->st_dev = vap->va_fsid; + else + sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; + sb->st_ino = vap->va_fileid; + mode = vap->va_mode; + switch (vap->va_type) { + case VREG: + mode |= S_IFREG; + break; + case VDIR: + mode |= S_IFDIR; + break; + case VBLK: + mode |= S_IFBLK; + break; + case VCHR: + mode |= S_IFCHR; + break; + case VLNK: + mode |= S_IFLNK; + break; + case VSOCK: + mode |= S_IFSOCK; + break; + case VFIFO: + mode |= S_IFIFO; + break; + default: + error = EBADF; + goto out; + } + sb->st_mode = mode; + sb->st_nlink = vap->va_nlink; + sb->st_uid = vap->va_uid; + sb->st_gid = vap->va_gid; + sb->st_rdev = vap->va_rdev; + if (vap->va_size > OFF_MAX) { + error = EOVERFLOW; + goto out; + } + sb->st_size = vap->va_size; + sb->st_atim.tv_sec = vap->va_atime.tv_sec; + sb->st_atim.tv_nsec = vap->va_atime.tv_nsec; + sb->st_mtim.tv_sec = vap->va_mtime.tv_sec; + sb->st_mtim.tv_nsec = vap->va_mtime.tv_nsec; + sb->st_ctim.tv_sec = vap->va_ctime.tv_sec; + sb->st_ctim.tv_nsec = vap->va_ctime.tv_nsec; + sb->st_birthtim.tv_sec = vap->va_birthtime.tv_sec; + sb->st_birthtim.tv_nsec = vap->va_birthtime.tv_nsec; + + /* + * According to www.opengroup.org, the meaning of st_blksize is + * "a filesystem-specific preferred I/O block size for this + * object. In some filesystem types, this may vary from file + * to file" + * Use minimum/default of PAGE_SIZE (e.g. for VCHR). + */ + + sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); + sb->st_flags = vap->va_flags; + sb->st_blocks = vap->va_bytes / S_BLKSIZE; + sb->st_gen = vap->va_gen; +out: + return (vop_stat_helper_post(a, error)); } Modified: head/sys/kern/vfs_syscalls.c ============================================================================== --- head/sys/kern/vfs_syscalls.c Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/kern/vfs_syscalls.c Fri Aug 7 23:06:40 2020 (r364044) @@ -1867,7 +1867,7 @@ restart: if (vp->v_type == VDIR && oldinum == 0) { error = EPERM; /* POSIX */ } else if (oldinum != 0 && - ((error = vn_stat(vp, &sb, td->td_ucred, NOCRED, td)) == 0) && + ((error = VOP_STAT(vp, &sb, td->td_ucred, NOCRED, td)) == 0) && sb.st_ino != oldinum) { error = EIDRM; /* Identifier removed */ } else if (fp != NULL && fp->f_vnode != vp) { @@ -2381,7 +2381,7 @@ kern_statat(struct thread *td, int flag, int fd, const if ((error = namei(&nd)) != 0) return (error); - error = vn_stat(nd.ni_vp, sbp, td->td_ucred, NOCRED, td); + error = VOP_STAT(nd.ni_vp, sbp, td->td_ucred, NOCRED, td); if (error == 0) { SDT_PROBE2(vfs, , stat, mode, path, sbp->st_mode); if (S_ISREG(sbp->st_mode)) @@ -4566,7 +4566,7 @@ kern_fhstat(struct thread *td, struct fhandle fh, stru vfs_unbusy(mp); if (error != 0) return (error); - error = vn_stat(vp, sb, td->td_ucred, NOCRED, td); + error = VOP_STAT(vp, sb, td->td_ucred, NOCRED, td); vput(vp); return (error); } Modified: head/sys/kern/vfs_vnops.c ============================================================================== --- head/sys/kern/vfs_vnops.c Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/kern/vfs_vnops.c Fri Aug 7 23:06:40 2020 (r364044) @@ -1455,121 +1455,10 @@ vn_statfile(struct file *fp, struct stat *sb, struct u int error; vn_lock(vp, LK_SHARED | LK_RETRY); - error = vn_stat(vp, sb, active_cred, fp->f_cred, td); + error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td); VOP_UNLOCK(vp); return (error); -} - -/* - * Stat a vnode; implementation for the stat syscall - */ -int -vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, - struct ucred *file_cred, struct thread *td) -{ - struct vattr vattr; - struct vattr *vap; - int error; - u_short mode; - - AUDIT_ARG_VNODE1(vp); -#ifdef MAC - error = mac_vnode_check_stat(active_cred, file_cred, vp); - if (error) - return (error); -#endif - - vap = &vattr; - - /* - * Initialize defaults for new and unusual fields, so that file - * systems which don't support these fields don't need to know - * about them. - */ - vap->va_birthtime.tv_sec = -1; - vap->va_birthtime.tv_nsec = 0; - vap->va_fsid = VNOVAL; - vap->va_rdev = NODEV; - - error = VOP_GETATTR(vp, vap, active_cred); - if (error) - return (error); - - /* - * Zero the spare stat fields - */ - bzero(sb, sizeof *sb); - - /* - * Copy from vattr table - */ - if (vap->va_fsid != VNOVAL) - sb->st_dev = vap->va_fsid; - else - sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; - sb->st_ino = vap->va_fileid; - mode = vap->va_mode; - switch (vap->va_type) { - case VREG: - mode |= S_IFREG; - break; - case VDIR: - mode |= S_IFDIR; - break; - case VBLK: - mode |= S_IFBLK; - break; - case VCHR: - mode |= S_IFCHR; - break; - case VLNK: - mode |= S_IFLNK; - break; - case VSOCK: - mode |= S_IFSOCK; - break; - case VFIFO: - mode |= S_IFIFO; - break; - default: - return (EBADF); - } - sb->st_mode = mode; - sb->st_nlink = vap->va_nlink; - sb->st_uid = vap->va_uid; - sb->st_gid = vap->va_gid; - sb->st_rdev = vap->va_rdev; - if (vap->va_size > OFF_MAX) - return (EOVERFLOW); - sb->st_size = vap->va_size; - sb->st_atim.tv_sec = vap->va_atime.tv_sec; - sb->st_atim.tv_nsec = vap->va_atime.tv_nsec; - sb->st_mtim.tv_sec = vap->va_mtime.tv_sec; - sb->st_mtim.tv_nsec = vap->va_mtime.tv_nsec; - sb->st_ctim.tv_sec = vap->va_ctime.tv_sec; - sb->st_ctim.tv_nsec = vap->va_ctime.tv_nsec; - sb->st_birthtim.tv_sec = vap->va_birthtime.tv_sec; - sb->st_birthtim.tv_nsec = vap->va_birthtime.tv_nsec; - - /* - * According to www.opengroup.org, the meaning of st_blksize is - * "a filesystem-specific preferred I/O block size for this - * object. In some filesystem types, this may vary from file - * to file" - * Use minimum/default of PAGE_SIZE (e.g. for VCHR). - */ - - sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize); - - sb->st_flags = vap->va_flags; - if (priv_check_cred_vfs_generation(td->td_ucred)) - sb->st_gen = 0; - else - sb->st_gen = vap->va_gen; - - sb->st_blocks = vap->va_bytes / S_BLKSIZE; - return (0); } /* Modified: head/sys/kern/vnode_if.src ============================================================================== --- head/sys/kern/vnode_if.src Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/kern/vnode_if.src Fri Aug 7 23:06:40 2020 (r364044) @@ -177,6 +177,17 @@ vop_accessx { }; +%% stat vp L L L + +vop_stat { + IN struct vnode *vp; + OUT struct stat *sb; + IN struct ucred *active_cred; + IN struct ucred *file_cred; + IN struct thread *td; +}; + + %% getattr vp L L L vop_getattr { Modified: head/sys/security/audit/audit_arg.c ============================================================================== --- head/sys/security/audit/audit_arg.c Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/security/audit/audit_arg.c Fri Aug 7 23:06:40 2020 (r364044) @@ -854,7 +854,7 @@ audit_arg_upath2_canon(char *upath) * It is assumed that the caller will hold any vnode locks necessary to * perform a VOP_GETATTR() on the passed vnode. * - * XXX: The attr code is very similar to vfs_vnops.c:vn_stat(), but always + * XXX: The attr code is very similar to vfs_default.c:vop_stdstat(), but always * provides access to the generation number as we need that to construct the * BSM file ID. * Modified: head/sys/sys/vnode.h ============================================================================== --- head/sys/sys/vnode.h Fri Aug 7 19:58:16 2020 (r364043) +++ head/sys/sys/vnode.h Fri Aug 7 23:06:40 2020 (r364044) @@ -737,8 +737,6 @@ int vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, struct thread *td); int vn_rlimit_fsize(const struct vnode *vn, const struct uio *uio, struct thread *td); -int vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred, - struct ucred *file_cred, struct thread *td); int vn_start_write(struct vnode *vp, struct mount **mpp, int flags); int vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags); @@ -892,6 +890,22 @@ void vop_need_inactive_debugpost(void *a, int rc); #endif void vop_rename_fail(struct vop_rename_args *ap); + +#define vop_stat_helper_pre(ap) ({ \ + int _error; \ + AUDIT_ARG_VNODE1(ap->a_vp); \ + _error = mac_vnode_check_stat(ap->a_active_cred, ap->a_file_cred, ap->a_vp);\ + if (__predict_true(_error == 0)) \ + bzero(ap->a_sb, sizeof(*ap->a_sb)); \ + _error; \ +}) + +#define vop_stat_helper_post(ap, error) ({ \ + int _error = (error); \ + if (priv_check_cred_vfs_generation(ap->a_td->td_ucred)) \ + ap->a_sb->st_gen = 0; \ + _error; \ +}) #define VOP_WRITE_PRE(ap) \ struct vattr va; \ _______________________________________________ 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"
