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glibc  2.9
Defines | Functions
internal_statvfs.c File Reference
#include <assert.h>
#include <errno.h>
#include <mntent.h>
#include <paths.h>
#include <stdbool.h>
#include <stdio_ext.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/statvfs.h>
#include "linux_fsinfo.h"
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Go to the source code of this file.

Defines

#define STATFS   statfs
#define STATVFS   statvfs
#define INTERNAL_STATVFS   __internal_statvfs

Functions

int __statvfs_getflags (const char *name, int fstype, struct stat64 *st)
void INTERNAL_STATVFS (const char *name, struct STATVFS *buf, struct STATFS *fsbuf, struct stat64 *st)

Define Documentation

Definition at line 37 of file internal_statvfs.c.

#define STATFS   statfs

Definition at line 35 of file internal_statvfs.c.

#define STATVFS   statvfs

Definition at line 36 of file internal_statvfs.c.


Function Documentation

int __statvfs_getflags ( const char *  name,
int  fstype,
struct stat64 st 
)

Definition at line 41 of file internal_statvfs.c.

{
  if (st == NULL)
    return 0;

  const char *fsname = NULL;
  const char *fsname2 = NULL;

  /* Map the filesystem type we got from the statfs call to a string.  */
  switch (fstype)
    {
    case EXT2_SUPER_MAGIC:
      fsname = "ext3";
      fsname2 = "ext2";
      break;
    case DEVPTS_SUPER_MAGIC:
      fsname= "devpts";
      break;
    case SHMFS_SUPER_MAGIC:
      fsname = "tmpfs";
      break;
    case PROC_SUPER_MAGIC:
      fsname = "proc";
      break;
    case USBDEVFS_SUPER_MAGIC:
      fsname = "usbdevfs";
      break;
    case AUTOFS_SUPER_MAGIC:
      fsname = "autofs";
      break;
    case NFS_SUPER_MAGIC:
      fsname = "nfs";
      break;
    case SYSFS_MAGIC:
      fsname = "sysfs";
      break;
    case REISERFS_SUPER_MAGIC:
      fsname = "reiserfs";
      break;
    case XFS_SUPER_MAGIC:
      fsname = "xfs";
      break;
    case JFS_SUPER_MAGIC:
      fsname = "jfs";
      break;
    case HPFS_SUPER_MAGIC:
      fsname = "hpfs";
      break;
    case DEVFS_SUPER_MAGIC:
      fsname = "devfs";
      break;
    case ISOFS_SUPER_MAGIC:
      fsname = "iso9660";
      break;
    case MSDOS_SUPER_MAGIC:
      fsname = "msdos";
      break;
    case NTFS_SUPER_MAGIC:
      fsname = "ntfs";
      break;
    }

  FILE *mtab = __setmntent ("/proc/mounts", "r");
  if (mtab == NULL)
    mtab = __setmntent (_PATH_MOUNTED, "r");

  int result = 0;
  if (mtab != NULL)
    {
      bool success = false;
      struct mntent mntbuf;
      char tmpbuf[1024];

      /* No locking needed.  */
      (void) __fsetlocking (mtab, FSETLOCKING_BYCALLER);

    again:
      while (__getmntent_r (mtab, &mntbuf, tmpbuf, sizeof (tmpbuf)))
       {
         /* In a first round we look for a given mount point, if
            we have a name.  */
         if (name != NULL && strcmp (name, mntbuf.mnt_dir) != 0)
           continue;
         /* We need to look at the entry only if the filesystem
            name matches.  If we have a filesystem name.  */
         else if (fsname != NULL
                 && strcmp (fsname, mntbuf.mnt_type) != 0
                 && (fsname2 == NULL
                     || strcmp (fsname2, mntbuf.mnt_type) != 0))
           continue;

         /* Find out about the device the current entry is for.  */
         struct stat64 fsst;
         if (stat64 (mntbuf.mnt_dir, &fsst) >= 0
             && st->st_dev == fsst.st_dev)
           {
             /* Bingo, we found the entry for the device FD is on.
               Now interpret the option string.  */
             char *cp = mntbuf.mnt_opts;
             char *opt;

             while ((opt = strsep (&cp, ",")) != NULL)
              if (strcmp (opt, "ro") == 0)
                result |= ST_RDONLY;
              else if (strcmp (opt, "nosuid") == 0)
                result |= ST_NOSUID;
              else if (strcmp (opt, "noexec") == 0)
                result |= ST_NOEXEC;
              else if (strcmp (opt, "nodev") == 0)
                result |= ST_NODEV;
              else if (strcmp (opt, "sync") == 0)
                result |= ST_SYNCHRONOUS;
              else if (strcmp (opt, "mand") == 0)
                result |= ST_MANDLOCK;
              else if (strcmp (opt, "noatime") == 0)
                result |= ST_NOATIME;
              else if (strcmp (opt, "nodiratime") == 0)
                result |= ST_NODIRATIME;
              else if (strcmp (opt, "relatime") == 0)
                result |= ST_RELATIME;

             /* We can stop looking for more entries.  */
             success = true;
             break;
           }
       }
      /* Maybe the kernel names for the filesystems changed or the
        statvfs call got a name which was not the mount point.  Check
        again, this time without checking for name matches first.  */
      if (! success && (name != NULL || fsname != NULL))
       {
         if (name != NULL)
           /* Try without a mount point name.  */
           name = NULL;
         else
           {
             /* Try without a filesystem name.  */
             assert (fsname != NULL);
             fsname = fsname2 = NULL;
           }

         /* It is not strictly allowed to use rewind here.  But
            this code is part of the implementation so it is
            acceptable.  */
         rewind (mtab);

         goto again;
       }

      /* Close the file.  */
      __endmntent (mtab);
    }

  return result;
}

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void INTERNAL_STATVFS ( const char *  name,
struct STATVFS buf,
struct STATFS fsbuf,
struct stat64 st 
)

Definition at line 203 of file internal_statvfs.c.

{
  /* Now fill in the fields we have information for.  */
  buf->f_bsize = fsbuf->f_bsize;
  /* Linux has the f_frsize size only in later version of the kernel.
     If the value is not filled in use f_bsize.  */
  buf->f_frsize = fsbuf->f_frsize ?: fsbuf->f_bsize;
  buf->f_blocks = fsbuf->f_blocks;
  buf->f_bfree = fsbuf->f_bfree;
  buf->f_bavail = fsbuf->f_bavail;
  buf->f_files = fsbuf->f_files;
  buf->f_ffree = fsbuf->f_ffree;
  if (sizeof (buf->f_fsid) == sizeof (fsbuf->f_fsid))
    buf->f_fsid = (fsbuf->f_fsid.__val[0]
                 | ((unsigned long int) fsbuf->f_fsid.__val[1]
                    << (8 * (sizeof (buf->f_fsid)
                            - sizeof (fsbuf->f_fsid.__val[0])))));
  else
    /* We cannot help here.  The statvfs element is not large enough to
       contain both words of the statfs f_fsid field.  */
    buf->f_fsid = fsbuf->f_fsid.__val[0];
#ifdef _STATVFSBUF_F_UNUSED
  buf->__f_unused = 0;
#endif
  buf->f_namemax = fsbuf->f_namelen;
  memset (buf->__f_spare, '\0', sizeof (buf->__f_spare));

  /* What remains to do is to fill the fields f_favail and f_flag.  */

  /* XXX I have no idea how to compute f_favail.  Any idea???  */
  buf->f_favail = buf->f_ffree;

  /* Determining the flags is tricky.  We have to read /proc/mounts or
     the /etc/mtab file and search for the entry which matches the given
     file.  The way we can test for matching filesystem is using the
     device number.  */
  buf->f_flag = __statvfs_getflags (name, fsbuf->f_type, st);
}

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