ocfs2: Implementation of local and global quota file handling

For each quota type each node has local quota file. In this file it stores
changes users have made to disk usage via this node. Once in a while this
information is synced to global file (and thus with other nodes) so that
limits enforcement at least aproximately works.

Global quota files contain all the information about usage and limits. It's
mostly handled by the generic VFS code (which implements a trie of structures
inside a quota file). We only have to provide functions to convert structures
from on-disk format to in-memory one. We also have to provide wrappers for
various quota functions starting transactions and acquiring necessary cluster
locks before the actual IO is really started.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 146 insertions, 0 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 9f2a7f75d1b3..058aa86490ae 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -32,6 +32,7 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/time.h>
+#include <linux/quotaops.h>
 
 #define MLOG_MASK_PREFIX ML_DLM_GLUE
 #include <cluster/masklog.h>
@@ -51,6 +52,7 @@
 #include "slot_map.h"
 #include "super.h"
 #include "uptodate.h"
+#include "quota.h"
 
 #include "buffer_head_io.h"
 
@@ -68,6 +70,7 @@ struct ocfs2_mask_waiter {
 static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
 static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
 
 /*
  * Return value from ->downconvert_worker functions.
@@ -102,6 +105,7 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
                                      struct ocfs2_lock_res *lockres);
 
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
 
 #define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
 
@@ -258,6 +262,12 @@ static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
         .flags          = 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
+        .set_lvb        = ocfs2_set_qinfo_lvb,
+        .get_osb        = ocfs2_get_qinfo_osb,
+        .flags          = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
+};
+
 static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
 {
         return lockres->l_type == OCFS2_LOCK_TYPE_META ||
@@ -279,6 +289,13 @@ static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res
         return (struct ocfs2_dentry_lock *)lockres->l_priv;
 }
 
+static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
+{
+        BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
+
+        return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
+}
+
 static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
 {
         if (lockres->l_ops->get_osb)
@@ -507,6 +524,13 @@ static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
         return OCFS2_SB(inode->i_sb);
 }
 
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
+{
+        struct ocfs2_mem_dqinfo *info = lockres->l_priv;
+
+        return OCFS2_SB(info->dqi_gi.dqi_sb);
+}
+
 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
 {
         struct ocfs2_file_private *fp = lockres->l_priv;
@@ -609,6 +633,17 @@ void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
         lockres->l_flags |= OCFS2_LOCK_NOCACHE;
 }
 
+void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
+                               struct ocfs2_mem_dqinfo *info)
+{
+        ocfs2_lock_res_init_once(lockres);
+        ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
+                              0, lockres->l_name);
+        ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
+                                   OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
+                                   info);
+}
+
 void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
 {
         mlog_entry_void();
@@ -3445,6 +3480,117 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
         return UNBLOCK_CONTINUE_POST;
 }
 
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
+{
+        struct ocfs2_qinfo_lvb *lvb;
+        struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
+        struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+                                            oinfo->dqi_gi.dqi_type);
+
+        mlog_entry_void();
+
+        lvb = (struct ocfs2_qinfo_lvb *)ocfs2_dlm_lvb(&lockres->l_lksb);
+        lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
+        lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
+        lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
+        lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
+        lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
+        lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
+        lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
+
+        mlog_exit_void();
+}
+
+void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
+{
+        struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+        struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+        int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+        mlog_entry_void();
+        if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
+                ocfs2_cluster_unlock(osb, lockres, level);
+        mlog_exit_void();
+}
+
+static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
+{
+        struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+                                            oinfo->dqi_gi.dqi_type);
+        struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+        struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+        struct buffer_head *bh;
+        struct ocfs2_global_disk_dqinfo *gdinfo;
+        int status = 0;
+
+        if (lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
+                info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
+                info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
+                oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
+                oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
+                oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
+                oinfo->dqi_gi.dqi_free_entry =
+                                        be32_to_cpu(lvb->lvb_free_entry);
+        } else {
+                bh = ocfs2_read_quota_block(oinfo->dqi_gqinode, 0, &status);
+                if (!bh) {
+                        mlog_errno(status);
+                        goto bail;
+                }
+                gdinfo = (struct ocfs2_global_disk_dqinfo *)
+                                        (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
+                info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
+                info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
+                oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
+                oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
+                oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
+                oinfo->dqi_gi.dqi_free_entry =
+                                        le32_to_cpu(gdinfo->dqi_free_entry);
+                brelse(bh);
+                ocfs2_track_lock_refresh(lockres);
+        }
+
+bail:
+        return status;
+}
+
+/* Lock quota info, this function expects at least shared lock on the quota file
+ * so that we can safely refresh quota info from disk. */
+int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
+{
+        struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+        struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+        int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+        int status = 0;
+
+        mlog_entry_void();
+
+        /* On RO devices, locking really isn't needed... */
+        if (ocfs2_is_hard_readonly(osb)) {
+                if (ex)
+                        status = -EROFS;
+                goto bail;
+        }
+        if (ocfs2_mount_local(osb))
+                goto bail;
+
+        status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+        if (status < 0) {
+                mlog_errno(status);
+                goto bail;
+        }
+        if (!ocfs2_should_refresh_lock_res(lockres))
+                goto bail;
+        /* OK, we have the lock but we need to refresh the quota info */
+        status = ocfs2_refresh_qinfo(oinfo);
+        if (status)
+                ocfs2_qinfo_unlock(oinfo, ex);
+        ocfs2_complete_lock_res_refresh(lockres, status);
+bail:
+        mlog_exit(status);
+        return status;
+}
+
 /*
  * This is the filesystem locking protocol.  It provides the lock handling
  * hooks for the underlying DLM.  It has a maximum version number.