[src/trunk]: src/sys expose ksem_t for fstat(8), and implement stat for futur...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b16585247764
branches:  trunk
changeset: 782881:b16585247764
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Nov 25 01:05:04 2012 +0000

description:
expose ksem_t for fstat(8), and implement stat for future reference.

diffstat:

 sys/kern/uipc_sem.c |  73 +++++++++++++++++++++++++++++++++++++++-------------
 sys/sys/ksem.h      |  17 +++++++++++-
 2 files changed, 70 insertions(+), 20 deletions(-)

diffs (145 lines):

diff -r 60619c389d55 -r b16585247764 sys/kern/uipc_sem.c
--- a/sys/kern/uipc_sem.c       Sun Nov 25 01:03:05 2012 +0000
+++ b/sys/kern/uipc_sem.c       Sun Nov 25 01:05:04 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_sem.c,v 1.38 2012/03/13 18:40:55 elad Exp $       */
+/*     $NetBSD: uipc_sem.c,v 1.39 2012/11/25 01:05:04 christos Exp $   */
 
 /*-
  * Copyright (c) 2011 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_sem.c,v 1.38 2012/03/13 18:40:55 elad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_sem.c,v 1.39 2012/11/25 01:05:04 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -88,21 +88,6 @@
 
 #define        KS_UNLINKED             0x01
 
-typedef struct ksem {
-       LIST_ENTRY(ksem)        ks_entry;       /* global list entry */
-       kmutex_t                ks_lock;        /* lock on this ksem */
-       kcondvar_t              ks_cv;          /* condition variable */
-       u_int                   ks_ref;         /* number of references */
-       u_int                   ks_value;       /* current value */
-       u_int                   ks_waiters;     /* number of waiters */
-       char *                  ks_name;        /* name, if named */
-       size_t                  ks_namelen;     /* length of name */
-       int                     ks_flags;       /* for KS_UNLINKED */
-       mode_t                  ks_mode;        /* protection bits */
-       uid_t                   ks_uid;         /* creator uid */
-       gid_t                   ks_gid;         /* creator gid */
-} ksem_t;
-
 static kmutex_t                ksem_lock       __cacheline_aligned;
 static LIST_HEAD(,ksem)        ksem_head       __cacheline_aligned;
 static u_int           nsems_total     __cacheline_aligned;
@@ -114,14 +99,17 @@
 static int             ksem_sysfini(bool);
 static int             ksem_modcmd(modcmd_t, void *);
 static int             ksem_close_fop(file_t *);
+static int             ksem_stat_fop(file_t *, struct stat *);
+static int             ksem_read_fop(file_t *, off_t *, struct uio *,
+    kauth_cred_t, int);
 
 static const struct fileops semops = {
-       .fo_read = fbadop_read,
+       .fo_read = ksem_read_fop,
        .fo_write = fbadop_write,
        .fo_ioctl = fbadop_ioctl,
        .fo_fcntl = fnullop_fcntl,
        .fo_poll = fnullop_poll,
-       .fo_stat = fbadop_stat,
+       .fo_stat = ksem_stat_fop,
        .fo_close = ksem_close_fop,
        .fo_kqfilter = fnullop_kqfilter,
        .fo_restart = fnullop_restart,
@@ -536,6 +524,53 @@
 }
 
 static int
+ksem_read_fop(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
+    int flags)
+{
+       size_t len;
+       char *name;
+       ksem_t *ks = fp->f_data;
+
+       mutex_enter(&ks->ks_lock);
+       len = ks->ks_namelen;
+       name = ks->ks_name;
+       mutex_exit(&ks->ks_lock);
+       if (name == NULL || len == 0)
+               return 0;
+       return uiomove(name, len, uio);
+}
+
+static int
+ksem_stat_fop(file_t *fp, struct stat *ub)
+{
+       ksem_t *ks = fp->f_data;
+
+       mutex_enter(&ks->ks_lock);
+
+       memset(ub, 0, sizeof(*ub));
+
+       ub->st_mode = ks->ks_mode | ((ks->ks_name && ks->ks_namelen)
+           ? _S_IFLNK : _S_IFREG);
+       ub->st_uid = ks->ks_uid;
+       ub->st_gid = ks->ks_gid;
+       ub->st_size = ks->ks_value;
+       ub->st_blocks = (ub->st_size) ? 1 : 0;
+       ub->st_nlink = ks->ks_ref;
+       ub->st_blksize = 4096;
+
+       nanotime(&ub->st_atimespec);
+       ub->st_mtimespec = ub->st_ctimespec = ub->st_birthtimespec =
+           ub->st_atimespec;
+
+       /*
+        * Left as 0: st_dev, st_ino, st_rdev, st_flags, st_gen.
+        * XXX (st_dev, st_ino) should be unique.
+        */
+       mutex_exit(&ks->ks_lock);
+       return 0;
+}
+
+static int
 ksem_close_fop(file_t *fp)
 {
        ksem_t *ks = fp->f_data;
diff -r 60619c389d55 -r b16585247764 sys/sys/ksem.h
--- a/sys/sys/ksem.h    Sun Nov 25 01:03:05 2012 +0000
+++ b/sys/sys/ksem.h    Sun Nov 25 01:05:04 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ksem.h,v 1.13 2012/03/10 21:52:00 joerg Exp $  */
+/*     $NetBSD: ksem.h,v 1.14 2012/11/25 01:05:04 christos Exp $       */
 
 /*
  * Copyright (c) 2002 Alfred Perlstein <alfred%FreeBSD.org@localhost>
@@ -36,6 +36,21 @@
 #ifdef _KERNEL
 #define        KSEM_MAX        128
 
+typedef struct ksem {
+       LIST_ENTRY(ksem)        ks_entry;       /* global list entry */
+       kmutex_t                ks_lock;        /* lock on this ksem */
+       kcondvar_t              ks_cv;          /* condition variable */
+       u_int                   ks_ref;         /* number of references */
+       u_int                   ks_value;       /* current value */
+       u_int                   ks_waiters;     /* number of waiters */
+       char *                  ks_name;        /* name, if named */
+       size_t                  ks_namelen;     /* length of name */
+       int                     ks_flags;       /* for KS_UNLINKED */
+       mode_t                  ks_mode;        /* protection bits */
+       uid_t                   ks_uid;         /* creator uid */
+       gid_t                   ks_gid;         /* creator gid */
+} ksem_t;
+
 int do_ksem_init(struct lwp *, unsigned int, intptr_t *, copyout_t);
 int do_ksem_open(struct lwp *, const char *, int, mode_t, unsigned int,
     intptr_t *, copyout_t);