ceph: quota: report root dir quota usage in statfs

This commit changes statfs default behaviour when reporting usage
statistics.  Instead of using the overall filesystem usage, statfs now
reports the quota for the filesystem root, if ceph.quota.max_bytes has
been set for this inode.  If quota hasn't been set, it falls back to the
old statfs behaviour.

A new mount option is also added ('noquotadf') to disable this behaviour.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt
index 094772481263852df643546bc91bf9ca633eb968..d7f011ddc1500cdf8e705430c90ed60deb7a2ecc 100644 (file)
--- a/Documentation/filesystems/ceph.txt
+++ b/Documentation/filesystems/ceph.txt
@@ -149,6 +149,10 @@ Mount Options
   noasyncreaddir
        Do not use the dcache as above for readdir.
 
+  noquotadf
+        Report overall filesystem usage in statfs instead of using the root
+        directory quota.
+
 More Information
 ================
 

diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 588744b4665fe7a66b8a8be7695fe37a0017ec21..242bfa5c0539ba3ba49bcca9f17760a6346688ea 100644 (file)
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -18,6 +18,8 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/statfs.h>
+
 #include "super.h"
 #include "mds_client.h"
 
@@ -303,3 +305,57 @@ bool ceph_quota_is_max_bytes_approaching(struct inode *inode, loff_t newsize)
        return check_quota_exceeded(inode, QUOTA_CHECK_MAX_BYTES_APPROACHING_OP,
                                    (newsize - size));
 }
+
+/*
+ * ceph_quota_update_statfs - if root has quota update statfs with quota status
+ * @fsc:       filesystem client instance
+ * @buf:       statfs to update
+ *
+ * If the mounted filesystem root has max_bytes quota set, update the filesystem
+ * statistics with the quota status.
+ *
+ * This function returns true if the stats have been updated, false otherwise.
+ */
+bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
+{
+       struct ceph_mds_client *mdsc = fsc->mdsc;
+       struct ceph_inode_info *ci;
+       struct ceph_snap_realm *realm;
+       struct inode *in;
+       u64 total = 0, used, free;
+       bool is_updated = false;
+
+       down_read(&mdsc->snap_rwsem);
+       realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root));
+       up_read(&mdsc->snap_rwsem);
+       if (!realm)
+               return false;
+
+       spin_lock(&realm->inodes_with_caps_lock);
+       in = realm->inode ? igrab(realm->inode) : NULL;
+       spin_unlock(&realm->inodes_with_caps_lock);
+       if (in) {
+               ci = ceph_inode(in);
+               spin_lock(&ci->i_ceph_lock);
+               if (ci->i_max_bytes) {
+                       total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT;
+                       used = ci->i_rbytes >> CEPH_BLOCK_SHIFT;
+                       /* It is possible for a quota to be exceeded.
+                        * Report 'zero' in that case
+                        */
+                       free = total > used ? total - used : 0;
+               }
+               spin_unlock(&ci->i_ceph_lock);
+               if (total) {
+                       buf->f_blocks = total;
+                       buf->f_bfree = free;
+                       buf->f_bavail = free;
+                       is_updated = true;
+               }
+               iput(in);
+       }
+       ceph_put_snap_realm(mdsc, realm);
+
+       return is_updated;
+}
+

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 0fc03c456c502a64a50f4b9bb2a54dff8c76eb4d..b33082e6878f1ca1ba8820716dafb1924d77855d 100644 (file)
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -76,9 +76,18 @@ static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
         */
        buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
        buf->f_frsize = 1 << CEPH_BLOCK_SHIFT;
-       buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
-       buf->f_bfree = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
-       buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
+
+       /*
+        * By default use root quota for stats; fallback to overall filesystem
+        * usage if using 'noquotadf' mount option or if the root dir doesn't
+        * have max_bytes quota set.
+        */
+       if (ceph_test_mount_opt(fsc, NOQUOTADF) ||
+           !ceph_quota_update_statfs(fsc, buf)) {
+               buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
+               buf->f_bfree = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
+               buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
+       }
 
        buf->f_files = le64_to_cpu(st.num_objects);
        buf->f_ffree = -1;
@@ -151,6 +160,8 @@ enum {
        Opt_acl,
 #endif
        Opt_noacl,
+       Opt_quotadf,
+       Opt_noquotadf,
 };
 
 static match_table_t fsopt_tokens = {
@@ -187,6 +198,8 @@ static match_table_t fsopt_tokens = {
        {Opt_acl, "acl"},
 #endif
        {Opt_noacl, "noacl"},
+       {Opt_quotadf, "quotadf"},
+       {Opt_noquotadf, "noquotadf"},
        {-1, NULL}
 };
 
@@ -334,6 +347,12 @@ static int parse_fsopt_token(char *c, void *private)
        case Opt_norequire_active_mds:
                fsopt->flags |= CEPH_MOUNT_OPT_MOUNTWAIT;
                break;
+       case Opt_quotadf:
+               fsopt->flags &= ~CEPH_MOUNT_OPT_NOQUOTADF;
+               break;
+       case Opt_noquotadf:
+               fsopt->flags |= CEPH_MOUNT_OPT_NOQUOTADF;
+               break;
 #ifdef CONFIG_CEPH_FS_POSIX_ACL
        case Opt_acl:
                fsopt->sb_flags |= SB_POSIXACL;
@@ -520,6 +539,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
        }
        if (fsopt->flags & CEPH_MOUNT_OPT_NOPOOLPERM)
                seq_puts(m, ",nopoolperm");
+       if (fsopt->flags & CEPH_MOUNT_OPT_NOQUOTADF)
+               seq_puts(m, ",noquotadf");
 
 #ifdef CONFIG_CEPH_FS_POSIX_ACL
        if (fsopt->sb_flags & SB_POSIXACL)

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 1321a6749953cc16caea86a6403e698a73d211a2..a7077a0c989fb33cde837a41e6b4d8b9951d2c43 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -39,6 +39,7 @@
 #define CEPH_MOUNT_OPT_FSCACHE         (1<<10) /* use fscache */
 #define CEPH_MOUNT_OPT_NOPOOLPERM      (1<<11) /* no pool permission check */
 #define CEPH_MOUNT_OPT_MOUNTWAIT       (1<<12) /* mount waits if no mds is up */
+#define CEPH_MOUNT_OPT_NOQUOTADF       (1<<13) /* no root dir quota in statfs */
 
 #define CEPH_MOUNT_OPT_DEFAULT    CEPH_MOUNT_OPT_DCACHE
 
@@ -1104,5 +1105,7 @@ extern bool ceph_quota_is_max_bytes_exceeded(struct inode *inode,
                                             loff_t newlen);
 extern bool ceph_quota_is_max_bytes_approaching(struct inode *inode,
                                                loff_t newlen);
+extern bool ceph_quota_update_statfs(struct ceph_fs_client *fsc,
+                                    struct kstatfs *buf);
 
 #endif /* _FS_CEPH_SUPER_H */