From c38898116a2737ea168993b9419c4370e7280303 Mon Sep 17 00:00:00 2001 From: Edward Tomasz Napierala Date: Wed, 8 Jul 2009 15:23:18 +0000 Subject: [PATCH] There is an optimization in chmod(1), that makes it not to call chmod(2) if the new file mode is the same as it was before; however, this optimization must be disabled for filesystems that support NFSv4 ACLs. Chmod uses pathconf(2) to determine whether this is the case - however, pathconf(2) always follows symbolic links, while the 'chmod -h' doesn't. This change adds lpathconf(3) to make it possible to solve that problem in a clean way. Reviewed by: rwatson (earlier version) Approved by: re (kib) --- include/unistd.h | 1 + lib/libc/sys/Makefile.inc | 1 + lib/libc/sys/Symbol.map | 1 + lib/libc/sys/pathconf.2 | 28 +++++++++++++++++++++++++--- sys/bsm/audit_kevents.h | 1 + sys/compat/freebsd32/syscalls.master | 1 + sys/compat/svr4/svr4_stat.c | 3 ++- sys/i386/ibcs2/ibcs2_misc.c | 3 ++- sys/kern/syscalls.master | 1 + sys/kern/vfs_syscalls.c | 27 +++++++++++++++++++++++---- sys/sys/syscallsubr.h | 2 +- 11 files changed, 59 insertions(+), 10 deletions(-) diff --git a/include/unistd.h b/include/unistd.h index aa027c21ae72..b4b7516bc6ac 100644 --- a/include/unistd.h +++ b/include/unistd.h @@ -513,6 +513,7 @@ int initgroups(const char *, gid_t); int iruserok(unsigned long, int, const char *, const char *); int iruserok_sa(const void *, int, int, const char *, const char *); int issetugid(void); +long lpathconf(const char *, int); #ifndef _MKDTEMP_DECLARED char *mkdtemp(char *); #define _MKDTEMP_DECLARED diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc index ad6b06e3c002..da4f3c52f308 100644 --- a/lib/libc/sys/Makefile.inc +++ b/lib/libc/sys/Makefile.inc @@ -159,6 +159,7 @@ MLINKS+=mq_send.2 mq_timedsend.2 MLINKS+=ntp_adjtime.2 ntp_gettime.2 MLINKS+=open.2 openat.2 MLINKS+=pathconf.2 fpathconf.2 +MLINKS+=pathconf.2 lpathconf.2 MLINKS+=read.2 pread.2 read.2 preadv.2 read.2 readv.2 MLINKS+=readlink.2 readlinkat.2 MLINKS+=recv.2 recvfrom.2 recv.2 recvmsg.2 diff --git a/lib/libc/sys/Symbol.map b/lib/libc/sys/Symbol.map index 88bc779f2ca6..901b261ab9a0 100644 --- a/lib/libc/sys/Symbol.map +++ b/lib/libc/sys/Symbol.map @@ -346,6 +346,7 @@ FBSD_1.1 { jail_set; jail_remove; linkat; + lpathconf; mkdirat; mkfifoat; mknodat; diff --git a/lib/libc/sys/pathconf.2 b/lib/libc/sys/pathconf.2 index daf95aba7bd2..495bc650f05b 100644 --- a/lib/libc/sys/pathconf.2 +++ b/lib/libc/sys/pathconf.2 @@ -28,11 +28,12 @@ .\" @(#)pathconf.2 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 25, 2009 +.Dd July 7, 2009 .Dt PATHCONF 2 .Os .Sh NAME .Nm pathconf , +.Nm lpathconf , .Nm fpathconf .Nd get configurable pathname variables .Sh LIBRARY @@ -42,10 +43,13 @@ .Ft long .Fn pathconf "const char *path" "int name" .Ft long +.Fn lpathconf "const char *path" "int name" +.Ft long .Fn fpathconf "int fd" "int name" .Sh DESCRIPTION The -.Fn pathconf +.Fn pathconf , +.Fn lpathconf and .Fn fpathconf system calls provide a method for applications to determine the current @@ -53,7 +57,9 @@ value of a configurable system limit or option variable associated with a pathname or file descriptor. .Pp For -.Fn pathconf , +.Fn pathconf +and +.Fn lpathconf , the .Fa path argument is the name of a file or directory. @@ -68,6 +74,18 @@ argument specifies the system variable to be queried. Symbolic constants for each name value are found in the include file .Li . .Pp +The +.Fn lpathconf +system call is like +.Fn pathconf +except in the case where the named file is a symbolic link, +in which case +.Fn lpathconf +returns information about the link, +while +.Fn pathconf +returns information about the file the link references. +.Pp The available values are as follows: .Pp .Bl -tag -width 6n @@ -239,3 +257,7 @@ and .Fn fpathconf system calls first appeared in .Bx 4.4 . +The +.Fn lpathconf +system call first appeared in +.Fx 8.0 . diff --git a/sys/bsm/audit_kevents.h b/sys/bsm/audit_kevents.h index c58371818fa8..880809549e7b 100644 --- a/sys/bsm/audit_kevents.h +++ b/sys/bsm/audit_kevents.h @@ -597,6 +597,7 @@ #define AUE_PWRITE 43193 /* Darwin/FreeBSD. */ #define AUE_FSCTL 43194 /* Darwin. */ #define AUE_FFSCTL 43195 /* Darwin. */ +#define AUE_LPATHCONF 43196 /* FreeBSD. */ /* * Darwin BSM uses a number of AUE_O_* definitions, which are aliased to the diff --git a/sys/compat/freebsd32/syscalls.master b/sys/compat/freebsd32/syscalls.master index 6e0f8864b36f..66731fc5b1e8 100644 --- a/sys/compat/freebsd32/syscalls.master +++ b/sys/compat/freebsd32/syscalls.master @@ -900,3 +900,4 @@ struct msqid_ds32 *buf); } 512 AUE_SHMCTL STD { int freebsd32_shmctl(int shmid, int cmd, \ struct shmid_ds32 *buf); } +513 AUE_LPATHCONF STD { int lpathconf(char *path, int name); } diff --git a/sys/compat/svr4/svr4_stat.c b/sys/compat/svr4/svr4_stat.c index 9ef94be5da1f..cfb8276cee44 100644 --- a/sys/compat/svr4/svr4_stat.c +++ b/sys/compat/svr4/svr4_stat.c @@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -669,7 +670,7 @@ svr4_sys_pathconf(td, uap) return (0); default: CHECKALTEXIST(td, uap->path, &path); - error = kern_pathconf(td, path, UIO_SYSSPACE, name); + error = kern_pathconf(td, path, UIO_SYSSPACE, name, FOLLOW); free(path, M_TEMP); return (error); } diff --git a/sys/i386/ibcs2/ibcs2_misc.c b/sys/i386/ibcs2/ibcs2_misc.c index 94fe50f26570..23c617de6e74 100644 --- a/sys/i386/ibcs2/ibcs2_misc.c +++ b/sys/i386/ibcs2/ibcs2_misc.c @@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$"); #include #include /* Must come after sys/malloc.h */ #include +#include #include #include #include @@ -763,7 +764,7 @@ ibcs2_pathconf(td, uap) CHECKALTEXIST(td, uap->path, &path); uap->name++; /* iBCS2 _PC_* defines are offset by one */ - error = kern_pathconf(td, path, UIO_SYSSPACE, uap->name); + error = kern_pathconf(td, path, UIO_SYSSPACE, uap->name, FOLLOW); free(path, M_TEMP); return (error); } diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master index 940f13da7e4f..4e2e99c09a5f 100644 --- a/sys/kern/syscalls.master +++ b/sys/kern/syscalls.master @@ -910,5 +910,6 @@ struct msqid_ds *buf); } 512 AUE_SHMCTL NOSTD { int shmctl(int shmid, int cmd, \ struct shmid_ds *buf); } +513 AUE_LPATHCONF STD { int lpathconf(char *path, int name); } ; Please copy any additions and changes to the following compatability tables: ; sys/compat/freebsd32/syscalls.master diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c index 7252c4779b3d..28d95e2eb084 100644 --- a/sys/kern/vfs_syscalls.c +++ b/sys/kern/vfs_syscalls.c @@ -2506,17 +2506,36 @@ pathconf(td, uap) } */ *uap; { - return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name)); + return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW)); +} + +#ifndef _SYS_SYSPROTO_H_ +struct lpathconf_args { + char *path; + int name; +}; +#endif +int +lpathconf(td, uap) + struct thread *td; + register struct lpathconf_args /* { + char *path; + int name; + } */ *uap; +{ + + return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, NOFOLLOW)); } int -kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, int name) +kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, int name, + u_long flags) { struct nameidata nd; int error, vfslocked; - NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | MPSAFE | - AUDITVNODE1, pathseg, path, td); + NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | MPSAFE | AUDITVNODE1 | + flags, pathseg, path, td); if ((error = namei(&nd)) != 0) return (error); vfslocked = NDHASGIANT(&nd); diff --git a/sys/sys/syscallsubr.h b/sys/sys/syscallsubr.h index 7e5c15d3f215..d0f209cc5b82 100644 --- a/sys/sys/syscallsubr.h +++ b/sys/sys/syscallsubr.h @@ -145,7 +145,7 @@ int kern_open(struct thread *td, char *path, enum uio_seg pathseg, int kern_openat(struct thread *td, int fd, char *path, enum uio_seg pathseg, int flags, int mode); int kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, - int name); + int name, u_long flags); int kern_pipe(struct thread *td, int fildes[2]); int kern_preadv(struct thread *td, int fd, struct uio *auio, off_t offset); int kern_ptrace(struct thread *td, int req, pid_t pid, void *addr,