Merge pull request #1641 from poettering/btrfs-quota

btrfs quota beef up and various other unrelated changes

4 files changed, 95 insertions, 20 deletions

diff --git a/src/shared/import-util.c b/src/shared/import-util.c
index 001a8a37e8..56388d5dd6 100644
--- a/src/shared/import-util.c
+++ b/src/shared/import-util.c
@@ -19,6 +19,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "btrfs-util.h"
 #include "util.h"
 #include "import-util.h"
 
@@ -201,3 +202,29 @@ bool dkr_id_is_valid(const char *id) {
 
         return true;
 }
+
+int import_assign_pool_quota_and_warn(const char *path) {
+        int r;
+
+        r = btrfs_subvol_auto_qgroup("/var/lib/machines", 0, true);
+        if (r == -ENOTTY)  {
+                log_debug_errno(r, "Failed to set up default quota hierarchy for /var/lib/machines, as directory is not on btrfs or not a subvolume. Ignoring.");
+                return 0;
+        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to set up default quota hierarchy for /var/lib/machines: %m");
+        if (r > 0)
+                log_info("Set up default quota hierarchy for /var/lib/machines.");
+
+        r = btrfs_subvol_auto_qgroup(path, 0, true);
+        if (r == -ENOTTY) {
+                log_debug_errno(r, "Failed to set up quota hierarchy for %s, as directory is not on btrfs or not a subvolume. Ignoring.", path);
+                return 0;
+        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to set up default quota hierarchy for %s: %m", path);
+        if (r > 0)
+                log_info("Set up default quota hierarchy for %s.", path);
+
+        return 0;
+}
diff --git a/src/shared/import-util.h b/src/shared/import-util.h
index 7bf7d4ca40..9120a5119f 100644
--- a/src/shared/import-util.h
+++ b/src/shared/import-util.h
@@ -47,3 +47,5 @@ bool dkr_id_is_valid(const char *id);
 bool dkr_ref_is_valid(const char *ref);
 bool dkr_digest_is_valid(const char *digest);
 #define dkr_tag_is_valid(tag) filename_is_valid(tag)
+
+int import_assign_pool_quota_and_warn(const char *path);
diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c
index 9c1e4d5e13..8ed3ad7f44 100644
--- a/src/shared/machine-image.c
+++ b/src/shared/machine-image.c
@@ -176,11 +176,10 @@ static int image_make(
                                 return r;
                         if (r) {
                                 BtrfsSubvolInfo info;
-                                BtrfsQuotaInfo quota;
 
                                 /* It's a btrfs subvolume */
 
-                                r = btrfs_subvol_get_info_fd(fd, &info);
+                                r = btrfs_subvol_get_info_fd(fd, 0, &info);
                                 if (r < 0)
                                         return r;
 
@@ -195,13 +194,17 @@ static int image_make(
                                 if (r < 0)
                                         return r;
 
-                                r = btrfs_subvol_get_quota_fd(fd, &quota);
-                                if (r >= 0) {
-                                        (*ret)->usage = quota.referenced;
-                                        (*ret)->usage_exclusive = quota.exclusive;
+                                if (btrfs_quota_scan_ongoing(fd) == 0) {
+                                        BtrfsQuotaInfo quota;
 
-                                        (*ret)->limit = quota.referenced_max;
-                                        (*ret)->limit_exclusive = quota.exclusive_max;
+                                        r = btrfs_subvol_get_subtree_quota_fd(fd, 0, &quota);
+                                        if (r >= 0) {
+                                                (*ret)->usage = quota.referenced;
+                                                (*ret)->usage_exclusive = quota.exclusive;
+
+                                                (*ret)->limit = quota.referenced_max;
+                                                (*ret)->limit_exclusive = quota.exclusive_max;
+                                        }
                                 }
 
                                 return 1;
@@ -397,7 +400,7 @@ int image_remove(Image *i) {
         switch (i->type) {
 
         case IMAGE_SUBVOLUME:
-                r = btrfs_subvol_remove(i->path, true);
+                r = btrfs_subvol_remove(i->path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
                 if (r < 0)
                         return r;
                 break;
@@ -587,7 +590,12 @@ int image_clone(Image *i, const char *new_name, bool read_only) {
         case IMAGE_DIRECTORY:
                 new_path = strjoina("/var/lib/machines/", new_name);
 
-                r = btrfs_subvol_snapshot(i->path, new_path, (read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE);
+                r = btrfs_subvol_snapshot(i->path, new_path, (read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) | BTRFS_SNAPSHOT_FALLBACK_COPY | BTRFS_SNAPSHOT_RECURSIVE | BTRFS_SNAPSHOT_QUOTA);
+
+                /* Enable "subtree" quotas for the copy, if we didn't
+                 * copy any quota from the source. */
+                (void) btrfs_subvol_auto_qgroup(i->path, 0, true);
+
                 break;
 
         case IMAGE_RAW:
@@ -629,6 +637,10 @@ int image_read_only(Image *i, bool b) {
         switch (i->type) {
 
         case IMAGE_SUBVOLUME:
+
+                /* Note that we set the flag only on the top-level
+                 * subvolume of the image. */
+
                 r = btrfs_subvol_set_read_only(i->path, b);
                 if (r < 0)
                         return r;
@@ -729,7 +741,14 @@ int image_set_limit(Image *i, uint64_t referenced_max) {
         if (i->type != IMAGE_SUBVOLUME)
                 return -EOPNOTSUPP;
 
-        return btrfs_quota_limit(i->path, referenced_max);
+        /* We set the quota both for the subvolume as well as for the
+         * subtree. The latter is mostly for historical reasons, since
+         * we didn't use to have a concept of subtree quota, and hence
+         * only modified the subvolume quota. */
+
+        (void) btrfs_qgroup_set_limit(i->path, 0, referenced_max);
+        (void) btrfs_subvol_auto_qgroup(i->path, 0, true);
+        return btrfs_subvol_set_subtree_quota_limit(i->path, 0, referenced_max);
 }
 
 int image_name_lock(const char *name, int operation, LockFile *ret) {
diff --git a/src/shared/machine-pool.c b/src/shared/machine-pool.c
index 8af78f47d5..1da7d0815f 100644
--- a/src/shared/machine-pool.c
+++ b/src/shared/machine-pool.c
@@ -170,7 +170,7 @@ int setup_machine_directory(uint64_t size, sd_bus_error *error) {
         };
         _cleanup_close_ int fd = -1, control = -1, loop = -1;
         _cleanup_free_ char* loopdev = NULL;
-        char tmpdir[] = "/tmp/import-mount.XXXXXX", *mntdir = NULL;
+        char tmpdir[] = "/tmp/machine-pool.XXXXXX", *mntdir = NULL;
         bool tmpdir_made = false, mntdir_made = false, mntdir_mounted = false;
         char buf[FORMAT_BYTES_MAX];
         int r, nr = -1;
@@ -194,14 +194,35 @@ int setup_machine_directory(uint64_t size, sd_bus_error *error) {
 
                 r = btrfs_quota_enable("/var/lib/machines", true);
                 if (r < 0)
-                        log_warning_errno(r, "Failed to enable quota, ignoring: %m");
+                        log_warning_errno(r, "Failed to enable quota for /var/lib/machines, ignoring: %m");
 
+                r = btrfs_subvol_auto_qgroup("/var/lib/machines", 0, true);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to set up default quota hierarchy for /var/lib/machines, ignoring: %m");
+
+                return 1;
+        }
+
+        if (path_is_mount_point("/var/lib/machines", AT_SYMLINK_FOLLOW) > 0) {
+                log_debug("/var/lib/machines is already a mount point, not creating loopback file for it.");
                 return 0;
         }
 
-        if (path_is_mount_point("/var/lib/machines", AT_SYMLINK_FOLLOW) > 0 ||
-            dir_is_empty("/var/lib/machines") == 0)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "/var/lib/machines is not a btrfs file system. Operation is not supported on legacy file systems.");
+        r = dir_is_populated("/var/lib/machines");
+        if (r < 0 && r != -ENOENT)
+                return r;
+        if (r > 0) {
+                log_debug("/var/log/machines is already populated, not creating loopback file for it.");
+                return 0;
+        }
+
+        r = mkfs_exists("btrfs");
+        if (r == -ENOENT) {
+                log_debug("mkfs.btrfs is missing, cannot create loopback file for /var/lib/machines.");
+                return 0;
+        }
+        if (r < 0)
+                return r;
 
         fd = setup_machine_raw(size, error);
         if (fd < 0)
@@ -266,6 +287,10 @@ int setup_machine_directory(uint64_t size, sd_bus_error *error) {
         if (r < 0)
                 log_warning_errno(r, "Failed to enable quota, ignoring: %m");
 
+        r = btrfs_subvol_auto_qgroup(mntdir, 0, true);
+        if (r < 0)
+                log_warning_errno(r, "Failed to set up default quota hierarchy, ignoring: %m");
+
         if (chmod(mntdir, 0700) < 0) {
                 r = sd_bus_error_set_errnof(error, errno, "Failed to fix owner: %m");
                 goto fail;
@@ -286,7 +311,7 @@ int setup_machine_directory(uint64_t size, sd_bus_error *error) {
         (void) rmdir(mntdir);
         (void) rmdir(tmpdir);
 
-        return 0;
+        return 1;
 
 fail:
         if (mntdir_mounted)
@@ -370,9 +395,11 @@ int grow_machine_directory(void) {
         if (r <= 0)
                 return r;
 
-        r = btrfs_quota_limit("/var/lib/machines", new_size);
-        if (r < 0)
-                return r;
+        /* Also bump the quota, of both the subvolume leaf qgroup, as
+         * well as of any subtree quota group by the same id but a
+         * higher level, if it exists. */
+        (void) btrfs_qgroup_set_limit("/var/lib/machines", 0, new_size);
+        (void) btrfs_subvol_set_subtree_quota_limit("/var/lib/machines", 0, new_size);
 
         log_info("Grew /var/lib/machines btrfs loopback file system to %s.", format_bytes(buf, sizeof(buf), new_size));
         return 1;