path: root/lib/libalpm/diskspace.c

/*
 *  diskspace.c
 *
 *  Copyright (c) 2010-2014 Pacman Development Team <pacman-dev@archlinux.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <errno.h>

#if defined(HAVE_MNTENT_H)
#include <mntent.h>
#endif
#if defined(HAVE_SYS_MNTTAB_H)
#include <sys/mnttab.h>
#endif
#if defined(HAVE_SYS_STATVFS_H)
#include <sys/statvfs.h>
#endif
#if defined(HAVE_SYS_PARAM_H)
#include <sys/param.h>
#endif
#if defined(HAVE_SYS_MOUNT_H)
#include <sys/mount.h>
#endif
#if defined(HAVE_SYS_UCRED_H)
#include <sys/ucred.h>
#endif
#if defined(HAVE_SYS_TYPES_H)
#include <sys/types.h>
#endif

/* libalpm */
#include "diskspace.h"
#include "alpm_list.h"
#include "util.h"
#include "log.h"
#include "trans.h"
#include "handle.h"

static int mount_point_cmp(const void *p1, const void *p2)
{
  const alpm_mountpoint_t *mp1 = p1;
  const alpm_mountpoint_t *mp2 = p2;
  /* the negation will sort all mountpoints before their parent */
  return -strcmp(mp1->mount_dir, mp2->mount_dir);
}

static void mount_point_list_free(alpm_list_t *mount_points)
{
  alpm_list_t *i;

  for(i = mount_points; i; i = i->next) {
    alpm_mountpoint_t *data = i->data;
    FREE(data->mount_dir);
  }
  FREELIST(mount_points);
}

static int mount_point_load_fsinfo(alpm_handle_t *handle, alpm_mountpoint_t *mountpoint)
{
#if defined(HAVE_GETMNTENT)
  /* grab the filesystem usage */
  if(statvfs(mountpoint->mount_dir, &(mountpoint->fsp)) != 0) {
    _alpm_log(handle, ALPM_LOG_WARNING,
        _("could not get filesystem information for %s: %s\n"),
        mountpoint->mount_dir, strerror(errno));
    mountpoint->fsinfo_loaded = MOUNT_FSINFO_FAIL;
    return -1;
  }

  _alpm_log(handle, ALPM_LOG_DEBUG, "loading fsinfo for %s\n", mountpoint->mount_dir);
  mountpoint->read_only = mountpoint->fsp.f_flag & ST_RDONLY;
  mountpoint->fsinfo_loaded = MOUNT_FSINFO_LOADED;
#endif

  return 0;
}

static alpm_list_t *mount_point_list(alpm_handle_t *handle)
{
  alpm_list_t *mount_points = NULL, *ptr;
  alpm_mountpoint_t *mp;

#if defined(HAVE_GETMNTENT) && defined(HAVE_MNTENT_H)
  /* Linux */
  struct mntent *mnt;
  FILE *fp;

  fp = setmntent(MOUNTED, "r");

  if(fp == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not open file: %s: %s\n"),
        MOUNTED, strerror(errno));
    return NULL;
  }

  while((mnt = getmntent(fp))) {
    CALLOC(mp, 1, sizeof(alpm_mountpoint_t), RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
    mp->mount_dir = strdup(mnt->mnt_dir);
    mp->mount_dir_len = strlen(mp->mount_dir);

    mount_points = alpm_list_add(mount_points, mp);
  }

  endmntent(fp);
#elif defined(HAVE_GETMNTENT) && defined(HAVE_MNTTAB_H)
  /* Solaris, Illumos */
  struct mnttab mnt;
  FILE *fp;
  int ret;

  fp = fopen("/etc/mnttab", "r");

  if(fp == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not open file %s: %s\n"),
        "/etc/mnttab", strerror(errno));
    return NULL;
  }

  while((ret = getmntent(fp, &mnt)) == 0) {
    CALLOC(mp, 1, sizeof(alpm_mountpoint_t), RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
    mp->mount_dir = strdup(mnt->mnt_mountp);
    mp->mount_dir_len = strlen(mp->mount_dir);

    mount_points = alpm_list_add(mount_points, mp);
  }
  /* -1 == EOF */
  if(ret != -1) {
    _alpm_log(handle, ALPM_LOG_WARNING,
        _("could not get filesystem information\n"));
  }

  fclose(fp);
#elif defined(HAVE_GETMNTINFO)
  /* FreeBSD (statfs), NetBSD (statvfs), OpenBSD (statfs), OS X (statfs) */
  int entries;
  FSSTATSTYPE *fsp;

  entries = getmntinfo(&fsp, MNT_NOWAIT);

  if(entries < 0) {
    _alpm_log(handle, ALPM_LOG_ERROR,
        _("could not get filesystem information\n"));
    return NULL;
  }

  for(; entries-- > 0; fsp++) {
    CALLOC(mp, 1, sizeof(alpm_mountpoint_t), RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
    mp->mount_dir = strdup(fsp->f_mntonname);
    mp->mount_dir_len = strlen(mp->mount_dir);
    memcpy(&(mp->fsp), fsp, sizeof(FSSTATSTYPE));
#if defined(HAVE_GETMNTINFO_STATVFS) && defined(HAVE_STRUCT_STATVFS_F_FLAG)
    mp->read_only = fsp->f_flag & ST_RDONLY;
#elif defined(HAVE_GETMNTINFO_STATFS) && defined(HAVE_STRUCT_STATFS_F_FLAGS)
    mp->read_only = fsp->f_flags & MNT_RDONLY;
#endif

    /* we don't support lazy loading on this platform */
    mp->fsinfo_loaded = MOUNT_FSINFO_LOADED;

    mount_points = alpm_list_add(mount_points, mp);
  }
#endif

  mount_points = alpm_list_msort(mount_points, alpm_list_count(mount_points),
      mount_point_cmp);
  for(ptr = mount_points; ptr != NULL; ptr = ptr->next) {
    mp = ptr->data;
    _alpm_log(handle, ALPM_LOG_DEBUG, "discovered mountpoint: %s\n", mp->mount_dir);
  }
  return mount_points;
}

static alpm_mountpoint_t *match_mount_point(const alpm_list_t *mount_points,
    const char *real_path)
{
  const alpm_list_t *mp;

  for(mp = mount_points; mp != NULL; mp = mp->next) {
    alpm_mountpoint_t *data = mp->data;

    /* first, check if the prefix matches */
    if(strncmp(data->mount_dir, real_path, data->mount_dir_len) == 0) {
      /* now, the hard work- a file like '/etc/myconfig' shouldn't map to a
       * mountpoint '/e', but only '/etc'. If the mountpoint ends in a trailing
       * slash, we know we didn't have a mismatch, otherwise we have to do some
       * more sanity checks. */
      if(data->mount_dir[data->mount_dir_len - 1] == '/') {
        return data;
      } else if(strlen(real_path) >= data->mount_dir_len) {
        const char next = real_path[data->mount_dir_len];
        if(next == '/' || next == '\0') {
          return data;
        }
      }
    }
  }

  /* should not get here... */
  return NULL;
}

static int calculate_removed_size(alpm_handle_t *handle,
    const alpm_list_t *mount_points, alpm_pkg_t *pkg)
{
  size_t i;
  alpm_filelist_t *filelist = alpm_pkg_get_files(pkg);

  if(!filelist->count) {
    return 0;
  }

  for(i = 0; i < filelist->count; i++) {
    const alpm_file_t *file = filelist->files + i;
    alpm_mountpoint_t *mp;
    struct stat st;
    char path[PATH_MAX];
    blkcnt_t remove_size;
    const char *filename = file->name;

    snprintf(path, PATH_MAX, "%s%s", handle->root, filename);
    _alpm_lstat(path, &st);

    /* skip directories and symlinks to be consistent with libarchive that
     * reports them to be zero size */
    if(S_ISDIR(st.st_mode) || S_ISLNK(st.st_mode)) {
      continue;
    }

    mp = match_mount_point(mount_points, path);
    if(mp == NULL) {
      _alpm_log(handle, ALPM_LOG_WARNING,
          _("could not determine mount point for file %s\n"), filename);
      continue;
    }

    /* don't check a mount that we know we can't stat */
    if(mp && mp->fsinfo_loaded == MOUNT_FSINFO_FAIL) {
      continue;
    }

    /* lazy load filesystem info */
    if(mp->fsinfo_loaded == MOUNT_FSINFO_UNLOADED) {
      if(mount_point_load_fsinfo(handle, mp) < 0) {
        continue;
      }
    }

    /* the addition of (divisor - 1) performs ceil() with integer division */
    remove_size = (st.st_size + mp->fsp.f_bsize - 1) / mp->fsp.f_bsize;
    mp->blocks_needed -= remove_size;
    mp->used |= USED_REMOVE;
  }

  return 0;
}

static int calculate_installed_size(alpm_handle_t *handle,
    const alpm_list_t *mount_points, alpm_pkg_t *pkg)
{
  size_t i;
  alpm_filelist_t *filelist = alpm_pkg_get_files(pkg);

  if(!filelist->count) {
    return 0;
  }

  for(i = 0; i < filelist->count; i++) {
    const alpm_file_t *file = filelist->files + i;
    alpm_mountpoint_t *mp;
    char path[PATH_MAX];
    blkcnt_t install_size;
    const char *filename = file->name;

    /* libarchive reports these as zero size anyways */
    /* NOTE: if we do start accounting for directory size, a dir matching a
     * mountpoint needs to be attributed to the parent, not the mountpoint. */
    if(S_ISDIR(file->mode) || S_ISLNK(file->mode)) {
      continue;
    }

    /* approximate space requirements for db entries */
    if(filename[0] == '.') {
      filename = handle->dbpath;
    }

    snprintf(path, PATH_MAX, "%s%s", handle->root, filename);

    mp = match_mount_point(mount_points, path);
    if(mp == NULL) {
      _alpm_log(handle, ALPM_LOG_WARNING,
          _("could not determine mount point for file %s\n"), filename);
      continue;
    }

    /* don't check a mount that we know we can't stat */
    if(mp && mp->fsinfo_loaded == MOUNT_FSINFO_FAIL) {
      continue;
    }

    /* lazy load filesystem info */
    if(mp->fsinfo_loaded == MOUNT_FSINFO_UNLOADED) {
      if(mount_point_load_fsinfo(handle, mp) < 0) {
        continue;
      }
    }

    /* the addition of (divisor - 1) performs ceil() with integer division */
    install_size = (file->size + mp->fsp.f_bsize - 1) / mp->fsp.f_bsize;
    mp->blocks_needed += install_size;
    mp->used |= USED_INSTALL;
  }

  return 0;
}

static int check_mountpoint(alpm_handle_t *handle, alpm_mountpoint_t *mp)
{
  /* cushion is roughly min(5% capacity, 20MiB) */
  fsblkcnt_t fivepc = (mp->fsp.f_blocks / 20) + 1;
  fsblkcnt_t twentymb = (20 * 1024 * 1024 / mp->fsp.f_bsize) + 1;
  fsblkcnt_t cushion = fivepc < twentymb ? fivepc : twentymb;
  blkcnt_t needed = mp->max_blocks_needed + cushion;

  _alpm_log(handle, ALPM_LOG_DEBUG,
      "partition %s, needed %jd, cushion %ju, free %ju\n",
      mp->mount_dir, (intmax_t)mp->max_blocks_needed,
      (uintmax_t)cushion, (uintmax_t)mp->fsp.f_bfree);
  if(needed >= 0 && (fsblkcnt_t)needed > mp->fsp.f_bfree) {
    _alpm_log(handle, ALPM_LOG_ERROR,
        _("Partition %s too full: %jd blocks needed, %jd blocks free\n"),
        mp->mount_dir, (intmax_t)needed, (uintmax_t)mp->fsp.f_bfree);
    return 1;
  }
  return 0;
}

int _alpm_check_downloadspace(alpm_handle_t *handle, const char *cachedir,
    size_t num_files, off_t *file_sizes)
{
  alpm_list_t *mount_points;
  alpm_mountpoint_t *cachedir_mp;
  char resolved_cachedir[PATH_MAX];
  size_t j;
  int error = 0;

  /* resolve the cachedir path to ensure we check the right mountpoint. We
   * handle failures silently, and continue to use the possibly unresolved
   * path. */
  if(realpath(cachedir, resolved_cachedir) != NULL) {
    cachedir = resolved_cachedir;
  }

  mount_points = mount_point_list(handle);
  if(mount_points == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not determine filesystem mount points\n"));
    return -1;
  }

  cachedir_mp = match_mount_point(mount_points, cachedir);
  if(cachedir_mp == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not determine cachedir mount point %s\n"),
        cachedir);
    error = 1;
    goto finish;
  }

  if(cachedir_mp->fsinfo_loaded == MOUNT_FSINFO_UNLOADED) {
    if(mount_point_load_fsinfo(handle, cachedir_mp)) {
      error = 1;
      goto finish;
    }
  }

  /* there's no need to check for a R/O mounted filesystem here, as
   * _alpm_filecache_setup will never give us a non-writable directory */

  /* round up the size of each file to the nearest block and accumulate */
  for(j = 0; j < num_files; j++) {
    cachedir_mp->max_blocks_needed += (file_sizes[j] + cachedir_mp->fsp.f_bsize + 1) /
      cachedir_mp->fsp.f_bsize;
  }

  if(check_mountpoint(handle, cachedir_mp)) {
    error = 1;
  }

finish:
  mount_point_list_free(mount_points);

  if(error) {
    RET_ERR(handle, ALPM_ERR_DISK_SPACE, -1);
  }

  return 0;
}

int _alpm_check_diskspace(alpm_handle_t *handle)
{
  alpm_list_t *mount_points, *i;
  alpm_mountpoint_t *root_mp;
  size_t replaces = 0, current = 0, numtargs;
  int error = 0;
  alpm_list_t *targ;
  alpm_trans_t *trans = handle->trans;

  numtargs = alpm_list_count(trans->add);
  mount_points = mount_point_list(handle);
  if(mount_points == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not determine filesystem mount points\n"));
    return -1;
  }
  root_mp = match_mount_point(mount_points, handle->root);
  if(root_mp == NULL) {
    _alpm_log(handle, ALPM_LOG_ERROR, _("could not determine root mount point %s\n"),
        handle->root);
    error = 1;
    goto finish;
  }

  replaces = alpm_list_count(trans->remove);
  if(replaces) {
    numtargs += replaces;
    for(targ = trans->remove; targ; targ = targ->next, current++) {
      alpm_pkg_t *local_pkg;
      int percent = (current * 100) / numtargs;
      PROGRESS(handle, ALPM_PROGRESS_DISKSPACE_START, "", percent,
          numtargs, current);

      local_pkg = targ->data;
      calculate_removed_size(handle, mount_points, local_pkg);
    }
  }

  for(targ = trans->add; targ; targ = targ->next, current++) {
    alpm_pkg_t *pkg, *local_pkg;
    int percent = (current * 100) / numtargs;
    PROGRESS(handle, ALPM_PROGRESS_DISKSPACE_START, "", percent,
        numtargs, current);

    pkg = targ->data;
    /* is this package already installed? */
    local_pkg = _alpm_db_get_pkgfromcache(handle->db_local, pkg->name);
    if(local_pkg) {
      calculate_removed_size(handle, mount_points, local_pkg);
    }
    calculate_installed_size(handle, mount_points, pkg);

    for(i = mount_points; i; i = i->next) {
      alpm_mountpoint_t *data = i->data;
      if(data->blocks_needed > data->max_blocks_needed) {
        data->max_blocks_needed = data->blocks_needed;
      }
    }
  }

  PROGRESS(handle, ALPM_PROGRESS_DISKSPACE_START, "", 100,
      numtargs, current);

  for(i = mount_points; i; i = i->next) {
    alpm_mountpoint_t *data = i->data;
    if(data->used && data->read_only) {
      _alpm_log(handle, ALPM_LOG_ERROR, _("Partition %s is mounted read only\n"),
          data->mount_dir);
      error = 1;
    } else if(data->used & USED_INSTALL && check_mountpoint(handle, data)) {
      error = 1;
    }
  }

finish:
  mount_point_list_free(mount_points);

  if(error) {
    RET_ERR(handle, ALPM_ERR_DISK_SPACE, -1);
  }

  return 0;
}

/* vim: set ts=2 sw=2 noet: */