src/afs/LINUX/osi_misc.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * Linux support routines.
  12  *
  13  */
  14 #include <afsconfig.h>
  15 #include "afs/param.h"
  16
  17
  18 #include <linux/module.h> /* early to avoid printf->printk mapping */
  19 #include <linux/dcache.h>
  20 #include <linux/namei.h>
  21 #include <linux/kthread.h>
  22 #include "afs/sysincludes.h"
  23 #include "afsincludes.h"
  24 #include "afs/afs_stats.h"
  25
  26 #include "osi_compat.h"
  27
  28 int afs_osicred_initialized = 0;
  29 afs_ucred_t afs_osi_cred;
  30
  31 void
  32 osi_linux_mask(void)
  33 {
  34     SIG_LOCK(current);
  35     sigfillset(&current->blocked);
  36     RECALC_SIGPENDING(current);
  37     SIG_UNLOCK(current);
  38 }
  39
  40 void
  41 osi_linux_unmaskrxk(void)
  42 {
  43     extern struct task_struct *rxk_ListenerTask;
  44     /* Note this unblocks signals on the rxk_Listener
  45      * thread from a thread that is stopping rxk */
  46     SIG_LOCK(rxk_ListenerTask);
  47     sigdelset(&rxk_ListenerTask->blocked, SIGKILL);
  48     SIG_UNLOCK(rxk_ListenerTask);
  49 }
  50
  51 /* LOOKUP_POSITIVE is becoming the default */
  52 #ifndef LOOKUP_POSITIVE
  53 #define LOOKUP_POSITIVE 0
  54 #endif
  55 /* Lookup name and return vnode for same. */
  56 int
  57 osi_lookupname_internal(char *aname, int followlink, struct vfsmount **mnt,
  58                         struct dentry **dpp)
  59 {
  60     int code;
  61 #if defined(HAVE_LINUX_PATH_LOOKUP)
  62     struct nameidata path_data;
  63 #else
  64     afs_linux_path_t path_data;
  65 #endif
  66     int flags = LOOKUP_POSITIVE;
  67
  68     if (followlink)
  69        flags |= LOOKUP_FOLLOW;
  70     code = afs_kern_path(aname, flags, &path_data);
  71
  72     if (!code)
  73         afs_get_dentry_ref(&path_data, mnt, dpp);
  74
  75     return code;
  76 }
  77
  78 static char *
  79 afs_getname(char *aname)
  80 {
  81     int len;
  82     char *name = kmem_cache_alloc(names_cachep, GFP_KERNEL);
  83
  84     if (!name)
  85         return ERR_PTR(-ENOMEM);
  86
  87     len = strncpy_from_user(name, aname, PATH_MAX);
  88     if (len < 0)
  89         goto error;
  90     if (len >= PATH_MAX) {
  91         len = -ENAMETOOLONG;
  92         goto error;
  93     }
  94     return name;
  95
  96 error:
  97     kmem_cache_free(names_cachep, name);
  98     return ERR_PTR(len);
  99 }
 100
 101 static void
 102 afs_putname(char *name)
 103 {
 104     kmem_cache_free(names_cachep, name);
 105 }
 106
 107 int
 108 osi_lookupname(char *aname, uio_seg_t seg, int followlink,
 109                struct dentry **dpp)
 110 {
 111     int code;
 112     char *name;
 113
 114     if (seg == AFS_UIOUSER) {
 115         name = afs_getname(aname);
 116         if (IS_ERR(name))
 117             return -PTR_ERR(name);
 118     } else {
 119         name = aname;
 120     }
 121     code = osi_lookupname_internal(name, followlink, NULL, dpp);
 122     if (seg == AFS_UIOUSER) {
 123         afs_putname(name);
 124     }
 125     return code;
 126 }
 127
 128 int osi_abspath(char *aname, char *buf, int buflen,
 129                 int followlink, char **pathp)
 130 {
 131     struct dentry *dp = NULL;
 132     struct vfsmount *mnt = NULL;
 133     char *name, *path;
 134     int code;
 135
 136     name = afs_getname(aname);
 137     if (IS_ERR(name))
 138         return -PTR_ERR(name);
 139     code = osi_lookupname_internal(name, followlink, &mnt, &dp);
 140     if (!code) {
 141 #if defined(D_PATH_TAKES_STRUCT_PATH)
 142         afs_linux_path_t p = { .mnt = mnt, .dentry = dp };
 143         path = d_path(&p, buf, buflen);
 144 #else
 145         path = d_path(dp, mnt, buf, buflen);
 146 #endif
 147
 148         if (IS_ERR(path)) {
 149             code = -PTR_ERR(path);
 150         } else {
 151             *pathp = path;
 152         }
 153
 154         dput(dp);
 155         mntput(mnt);
 156     }
 157
 158     afs_putname(name);
 159     return code;
 160 }
 161
 162
 163 /* This could use some work, and support on more platforms. */
 164 int afs_thread_wrapper(void *rock)
 165 {
 166     void (*proc)(void) = rock;
 167     __module_get(THIS_MODULE);
 168     AFS_GLOCK();
 169     (*proc)();
 170     AFS_GUNLOCK();
 171     module_put(THIS_MODULE);
 172     return 0;
 173 }
 174
 175 void afs_start_thread(void (*proc)(void), char *name)
 176 {
 177     kthread_run(afs_thread_wrapper, proc, "%s", name);
 178 }