src/home/homework-quota.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #include <sys/quota.h>
   3
   4 #include "blockdev-util.h"
   5 #include "btrfs-util.h"
   6 #include "errno-util.h"
   7 #include "format-util.h"
   8 #include "homework-quota.h"
   9 #include "missing_magic.h"
  10 #include "quota-util.h"
  11 #include "stat-util.h"
  12 #include "user-util.h"
  13
  14 int home_update_quota_btrfs(UserRecord *h, const char *path) {
  15         int r;
  16
  17         assert(h);
  18         assert(path);
  19
  20         if (h->disk_size == UINT64_MAX)
  21                 return 0;
  22
  23         /* If the user wants quota, enable it */
  24         r = btrfs_quota_enable(path, true);
  25         if (r == -ENOTTY)
  26                 return log_error_errno(r, "No btrfs quota support on subvolume %s.", path);
  27         if (r < 0)
  28                 return log_error_errno(r, "Failed to enable btrfs quota support on %s.", path);
  29
  30         r = btrfs_qgroup_set_limit(path, 0, h->disk_size);
  31         if (r < 0)
  32                 return log_error_errno(r, "Failed to set disk quota on subvolume %s: %m", path);
  33
  34         log_info("Set btrfs quota.");
  35
  36         return 0;
  37 }
  38
  39 int home_update_quota_classic(UserRecord *h, const char *path) {
  40         struct dqblk req;
  41         dev_t devno;
  42         int r;
  43
  44         assert(h);
  45         assert(uid_is_valid(h->uid));
  46         assert(path);
  47
  48         if (h->disk_size == UINT64_MAX)
  49                 return 0;
  50
  51         r = get_block_device(path, &devno);
  52         if (r < 0)
  53                 return log_error_errno(r, "Failed to determine block device of %s: %m", path);
  54         if (devno == 0)
  55                 return log_error_errno(SYNTHETIC_ERRNO(ENODEV), "File system %s not backed by a block device.", path);
  56
  57         r = quotactl_devnum(QCMD_FIXED(Q_GETQUOTA, USRQUOTA), devno, h->uid, &req);
  58         if (r == -ESRCH)
  59                 zero(req);
  60         else if (ERRNO_IS_NEG_NOT_SUPPORTED(r))
  61                 return log_error_errno(r, "No UID quota support on %s.", path);
  62         else if (r < 0)
  63                 return log_error_errno(r, "Failed to query disk quota for UID " UID_FMT ": %m", h->uid);
  64         else if (FLAGS_SET(req.dqb_valid, QIF_BLIMITS) && h->disk_size / QIF_DQBLKSIZE == req.dqb_bhardlimit) {
  65                 /* Shortcut things if everything is set up properly already */
  66                 log_info("Configured quota already matches the intended setting, not updating quota.");
  67                 return 0;
  68         }
  69
  70         req.dqb_valid = QIF_BLIMITS;
  71         req.dqb_bsoftlimit = req.dqb_bhardlimit = h->disk_size / QIF_DQBLKSIZE;
  72
  73         r = quotactl_devnum(QCMD_FIXED(Q_SETQUOTA, USRQUOTA), devno, h->uid, &req);
  74         if (r == -ESRCH)
  75                 return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "UID quota not available on %s.", path);
  76         if (r < 0)
  77                 return log_error_errno(r, "Failed to set disk quota for UID " UID_FMT ": %m", h->uid);
  78
  79         log_info("Updated per-UID quota.");
  80
  81         return 0;
  82 }
  83
  84 int home_update_quota_auto(UserRecord *h, const char *path) {
  85         struct statfs sfs;
  86         int r;
  87
  88         assert(h);
  89
  90         if (h->disk_size == UINT64_MAX)
  91                 return 0;
  92
  93         if (!path) {
  94                 path = user_record_image_path(h);
  95                 if (!path)
  96                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Home record lacks image path.");
  97         }
  98
  99         if (statfs(path, &sfs) < 0)
 100                 return log_error_errno(errno, "Failed to statfs() file system: %m");
 101
 102         if (is_fs_type(&sfs, XFS_SB_MAGIC) ||
 103             is_fs_type(&sfs, EXT4_SUPER_MAGIC))
 104                 return home_update_quota_classic(h, path);
 105
 106         if (is_fs_type(&sfs, BTRFS_SUPER_MAGIC)) {
 107
 108                 r = btrfs_is_subvol(path);
 109                 if (r < 0)
 110                         return log_error_errno(errno, "Failed to test if %s is a subvolume: %m", path);
 111                 if (r == 0)
 112                         return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Directory %s is not a subvolume, cannot apply quota.", path);
 113
 114                 return home_update_quota_btrfs(h, path);
 115         }
 116
 117         return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Type of directory %s not known, cannot apply quota.", path);
 118 }