1 files changed, 124 insertions, 0 deletions
diff --git a/src/home/homework-quota.c b/src/home/homework-quota.c
new file mode 100644
index 0000000..7001870
--- /dev/null
+++ b/src/home/homework-quota.c
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#include <sys/quota.h>
+
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "errno-util.h"
+#include "format-util.h"
+#include "homework-quota.h"
+#include "missing_magic.h"
+#include "quota-util.h"
+#include "stat-util.h"
+#include "user-util.h"
+
+int home_update_quota_btrfs(UserRecord *h, const char *path) {
+        int r;
+
+        assert(h);
+        assert(path);
+
+        if (h->disk_size == UINT64_MAX)
+                return 0;
+
+        /* If the user wants quota, enable it */
+        r = btrfs_quota_enable(path, true);
+        if (r == -ENOTTY)
+                return log_error_errno(r, "No btrfs quota support on subvolume %s.", path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enable btrfs quota support on %s.", path);
+
+        r = btrfs_qgroup_set_limit(path, 0, h->disk_size);
+        if (r < 0)
+                return log_error_errno(r, "Faled to set disk quota on subvolume %s: %m", path);
+
+        log_info("Set btrfs quota.");
+
+        return 0;
+}
+
+int home_update_quota_classic(UserRecord *h, const char *path) {
+        struct dqblk req;
+        dev_t devno;
+        int r;
+
+        assert(h);
+        assert(uid_is_valid(h->uid));
+        assert(path);
+
+        if (h->disk_size == UINT64_MAX)
+                return 0;
+
+        r = get_block_device(path, &devno);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine block device of %s: %m", path);
+        if (devno == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(ENODEV), "File system %s not backed by a block device.", path);
+
+        r = quotactl_devno(QCMD_FIXED(Q_GETQUOTA, USRQUOTA), devno, h->uid, &req);
+        if (r < 0) {
+                if (ERRNO_IS_NOT_SUPPORTED(r))
+                        return log_error_errno(r, "No UID quota support on %s.", path);
+
+                if (r != -ESRCH)
+                        return log_error_errno(r, "Failed to query disk quota for UID " UID_FMT ": %m", h->uid);
+
+                zero(req);
+        } else {
+                /* Shortcut things if everything is set up properly already */
+                if (FLAGS_SET(req.dqb_valid, QIF_BLIMITS) && h->disk_size / QIF_DQBLKSIZE == req.dqb_bhardlimit) {
+                        log_info("Configured quota already matches the intended setting, not updating quota.");
+                        return 0;
+                }
+        }
+
+        req.dqb_valid = QIF_BLIMITS;
+        req.dqb_bsoftlimit = req.dqb_bhardlimit = h->disk_size / QIF_DQBLKSIZE;
+
+        r = quotactl_devno(QCMD_FIXED(Q_SETQUOTA, USRQUOTA), devno, h->uid, &req);
+        if (r < 0) {
+                if (r == -ESRCH)
+                        return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "UID quota not available on %s.", path);
+
+                return log_error_errno(r, "Failed to set disk quota for UID " UID_FMT ": %m", h->uid);
+        }
+
+        log_info("Updated per-UID quota.");
+
+        return 0;
+}
+
+int home_update_quota_auto(UserRecord *h, const char *path) {
+        struct statfs sfs;
+        int r;
+
+        assert(h);
+
+        if (h->disk_size == UINT64_MAX)
+                return 0;
+
+        if (!path) {
+                path = user_record_image_path(h);
+                if (!path)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Home record lacks image path.");
+        }
+
+        if (statfs(path, &sfs) < 0)
+                return log_error_errno(errno, "Failed to statfs() file system: %m");
+
+        if (is_fs_type(&sfs, XFS_SB_MAGIC) ||
+            is_fs_type(&sfs, EXT4_SUPER_MAGIC))
+                return home_update_quota_classic(h, path);
+
+        if (is_fs_type(&sfs, BTRFS_SUPER_MAGIC)) {
+
+                r = btrfs_is_subvol(path);
+                if (r < 0)
+                        return log_error_errno(errno, "Failed to test if %s is a subvolume: %m", path);
+                if (r == 0)
+                        return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Directory %s is not a subvolume, cannot apply quota.", path);
+
+                return home_update_quota_btrfs(h, path);
+        }
+
+        return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "Type of directory %s not known, cannot apply quota.", path);
+}