ocfs2: Implement quota recovery

Implement functions for recovery after a crash. Functions just
read local quota file and sync info to global quota file.

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

1 files changed, 417 insertions, 8 deletions

diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index 40e82b4..b985621 100644
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -49,14 +49,25 @@ static unsigned int ol_quota_chunk_block(struct super_block *sb, int c)
 	return 1 + (ol_chunk_blocks(sb) + 1) * c;
 }
 
-/* Offset of the dquot structure in the quota file */
-static loff_t ol_dqblk_off(struct super_block *sb, int c, int off)
+static unsigned int ol_dqblk_block(struct super_block *sb, int c, int off)
+{
+	int epb = ol_quota_entries_per_block(sb);
+
+	return ol_quota_chunk_block(sb, c) + 1 + off / epb;
+}
+
+static unsigned int ol_dqblk_block_off(struct super_block *sb, int c, int off)
 {
 	int epb = ol_quota_entries_per_block(sb);
 
-	return ((ol_quota_chunk_block(sb, c) + 1 + off / epb)
-		<< sb->s_blocksize_bits) +
-		(off % epb) * sizeof(struct ocfs2_local_disk_dqblk);
+	return (off % epb) * sizeof(struct ocfs2_local_disk_dqblk);
+}
+
+/* Offset of the dquot structure in the quota file */
+static loff_t ol_dqblk_off(struct super_block *sb, int c, int off)
+{
+	return (ol_dqblk_block(sb, c, off) << sb->s_blocksize_bits) +
+	       ol_dqblk_block_off(sb, c, off);
 }
 
 /* Compute block number from given offset */
@@ -253,6 +264,379 @@ static void olq_update_info(struct buffer_head *bh, void *private)
 	spin_unlock(&dq_data_lock);
 }
 
+static int ocfs2_add_recovery_chunk(struct super_block *sb,
+				    struct ocfs2_local_disk_chunk *dchunk,
+				    int chunk,
+				    struct list_head *head)
+{
+	struct ocfs2_recovery_chunk *rc;
+
+	rc = kmalloc(sizeof(struct ocfs2_recovery_chunk), GFP_NOFS);
+	if (!rc)
+		return -ENOMEM;
+	rc->rc_chunk = chunk;
+	rc->rc_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
+	if (!rc->rc_bitmap) {
+		kfree(rc);
+		return -ENOMEM;
+	}
+	memcpy(rc->rc_bitmap, dchunk->dqc_bitmap,
+	       (ol_chunk_entries(sb) + 7) >> 3);
+	list_add_tail(&rc->rc_list, head);
+	return 0;
+}
+
+static void free_recovery_list(struct list_head *head)
+{
+	struct ocfs2_recovery_chunk *next;
+	struct ocfs2_recovery_chunk *rchunk;
+
+	list_for_each_entry_safe(rchunk, next, head, rc_list) {
+		list_del(&rchunk->rc_list);
+		kfree(rchunk->rc_bitmap);
+		kfree(rchunk);
+	}
+}
+
+void ocfs2_free_quota_recovery(struct ocfs2_quota_recovery *rec)
+{
+	int type;
+
+	for (type = 0; type < MAXQUOTAS; type++)
+		free_recovery_list(&(rec->r_list[type]));
+	kfree(rec);
+}
+
+/* Load entries in our quota file we have to recover*/
+static int ocfs2_recovery_load_quota(struct inode *lqinode,
+				     struct ocfs2_local_disk_dqinfo *ldinfo,
+				     int type,
+				     struct list_head *head)
+{
+	struct super_block *sb = lqinode->i_sb;
+	struct buffer_head *hbh;
+	struct ocfs2_local_disk_chunk *dchunk;
+	int i, chunks = le32_to_cpu(ldinfo->dqi_chunks);
+	int status = 0;
+
+	for (i = 0; i < chunks; i++) {
+		hbh = ocfs2_read_quota_block(lqinode,
+					     ol_quota_chunk_block(sb, i),
+					     &status);
+		if (!hbh) {
+			mlog_errno(status);
+			break;
+		}
+		dchunk = (struct ocfs2_local_disk_chunk *)hbh->b_data;
+		if (le32_to_cpu(dchunk->dqc_free) < ol_chunk_entries(sb))
+			status = ocfs2_add_recovery_chunk(sb, dchunk, i, head);
+		brelse(hbh);
+		if (status < 0)
+			break;
+	}
+	if (status < 0)
+		free_recovery_list(head);
+	return status;
+}
+
+static struct ocfs2_quota_recovery *ocfs2_alloc_quota_recovery(void)
+{
+	int type;
+	struct ocfs2_quota_recovery *rec;
+
+	rec = kmalloc(sizeof(struct ocfs2_quota_recovery), GFP_NOFS);
+	if (!rec)
+		return NULL;
+	for (type = 0; type < MAXQUOTAS; type++)
+		INIT_LIST_HEAD(&(rec->r_list[type]));
+	return rec;
+}
+
+/* Load information we need for quota recovery into memory */
+struct ocfs2_quota_recovery *ocfs2_begin_quota_recovery(
+						struct ocfs2_super *osb,
+						int slot_num)
+{
+	unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,
+					    OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};
+	unsigned int ino[MAXQUOTAS] = { LOCAL_USER_QUOTA_SYSTEM_INODE,
+					LOCAL_GROUP_QUOTA_SYSTEM_INODE };
+	struct super_block *sb = osb->sb;
+	struct ocfs2_local_disk_dqinfo *ldinfo;
+	struct inode *lqinode;
+	struct buffer_head *bh;
+	int type;
+	int status = 0;
+	struct ocfs2_quota_recovery *rec;
+
+	mlog(ML_NOTICE, "Beginning quota recovery in slot %u\n", slot_num);
+	rec = ocfs2_alloc_quota_recovery();
+	if (!rec)
+		return ERR_PTR(-ENOMEM);
+	/* First init... */
+
+	for (type = 0; type < MAXQUOTAS; type++) {
+		if (!OCFS2_HAS_RO_COMPAT_FEATURE(sb, feature[type]))
+			continue;
+		/* At this point, journal of the slot is already replayed so
+		 * we can trust metadata and data of the quota file */
+		lqinode = ocfs2_get_system_file_inode(osb, ino[type], slot_num);
+		if (!lqinode) {
+			status = -ENOENT;
+			goto out;
+		}
+		status = ocfs2_inode_lock_full(lqinode, NULL, 1,
+					       OCFS2_META_LOCK_RECOVERY);
+		if (status < 0) {
+			mlog_errno(status);
+			goto out_put;
+		}
+		/* Now read local header */
+		bh = ocfs2_read_quota_block(lqinode, 0, &status);
+		if (!bh) {
+			mlog_errno(status);
+			mlog(ML_ERROR, "failed to read quota file info header "
+				"(slot=%d type=%d)\n", slot_num, type);
+			goto out_lock;
+		}
+		ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
+							OCFS2_LOCAL_INFO_OFF);
+		status = ocfs2_recovery_load_quota(lqinode, ldinfo, type,
+						   &rec->r_list[type]);
+		brelse(bh);
+out_lock:
+		ocfs2_inode_unlock(lqinode, 1);
+out_put:
+		iput(lqinode);
+		if (status < 0)
+			break;
+	}
+out:
+	if (status < 0) {
+		ocfs2_free_quota_recovery(rec);
+		rec = ERR_PTR(status);
+	}
+	return rec;
+}
+
+/* Sync changes in local quota file into global quota file and
+ * reinitialize local quota file.
+ * The function expects local quota file to be already locked and
+ * dqonoff_mutex locked. */
+static int ocfs2_recover_local_quota_file(struct inode *lqinode,
+					  int type,
+					  struct ocfs2_quota_recovery *rec)
+{
+	struct super_block *sb = lqinode->i_sb;
+	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
+	struct ocfs2_local_disk_chunk *dchunk;
+	struct ocfs2_local_disk_dqblk *dqblk;
+	struct dquot *dquot;
+	handle_t *handle;
+	struct buffer_head *hbh = NULL, *qbh = NULL;
+	int status = 0;
+	int bit, chunk;
+	struct ocfs2_recovery_chunk *rchunk, *next;
+	qsize_t spacechange, inodechange;
+
+	mlog_entry("ino=%lu type=%u", (unsigned long)lqinode->i_ino, type);
+
+	status = ocfs2_lock_global_qf(oinfo, 1);
+	if (status < 0)
+		goto out;
+
+	list_for_each_entry_safe(rchunk, next, &(rec->r_list[type]), rc_list) {
+		chunk = rchunk->rc_chunk;
+		hbh = ocfs2_read_quota_block(lqinode,
+					     ol_quota_chunk_block(sb, chunk),
+					     &status);
+		if (!hbh) {
+			mlog_errno(status);
+			break;
+		}
+		dchunk = (struct ocfs2_local_disk_chunk *)hbh->b_data;
+		for_each_bit(bit, rchunk->rc_bitmap, ol_chunk_entries(sb)) {
+			qbh = ocfs2_read_quota_block(lqinode,
+						ol_dqblk_block(sb, chunk, bit),
+						&status);
+			if (!qbh) {
+				mlog_errno(status);
+				break;
+			}
+			dqblk = (struct ocfs2_local_disk_dqblk *)(qbh->b_data +
+				ol_dqblk_block_off(sb, chunk, bit));
+			dquot = dqget(sb, le64_to_cpu(dqblk->dqb_id), type);
+			if (!dquot) {
+				status = -EIO;
+				mlog(ML_ERROR, "Failed to get quota structure "
+				     "for id %u, type %d. Cannot finish quota "
+				     "file recovery.\n",
+				     (unsigned)le64_to_cpu(dqblk->dqb_id),
+				     type);
+				goto out_put_bh;
+			}
+			handle = ocfs2_start_trans(OCFS2_SB(sb),
+						   OCFS2_QSYNC_CREDITS);
+			if (IS_ERR(handle)) {
+				status = PTR_ERR(handle);
+				mlog_errno(status);
+				goto out_put_dquot;
+			}
+			mutex_lock(&sb_dqopt(sb)->dqio_mutex);
+			spin_lock(&dq_data_lock);
+			/* Add usage from quota entry into quota changes
+			 * of our node. Auxiliary variables are important
+			 * due to signedness */
+			spacechange = le64_to_cpu(dqblk->dqb_spacemod);
+			inodechange = le64_to_cpu(dqblk->dqb_inodemod);
+			dquot->dq_dqb.dqb_curspace += spacechange;
+			dquot->dq_dqb.dqb_curinodes += inodechange;
+			spin_unlock(&dq_data_lock);
+			/* We want to drop reference held by the crashed
+			 * node. Since we have our own reference we know
+			 * global structure actually won't be freed. */
+			status = ocfs2_global_release_dquot(dquot);
+			if (status < 0) {
+				mlog_errno(status);
+				goto out_commit;
+			}
+			/* Release local quota file entry */
+			status = ocfs2_journal_access(handle, lqinode,
+					qbh, OCFS2_JOURNAL_ACCESS_WRITE);
+			if (status < 0) {
+				mlog_errno(status);
+				goto out_commit;
+			}
+			lock_buffer(qbh);
+			WARN_ON(!ocfs2_test_bit(bit, dchunk->dqc_bitmap));
+			ocfs2_clear_bit(bit, dchunk->dqc_bitmap);
+			le32_add_cpu(&dchunk->dqc_free, 1);
+			unlock_buffer(qbh);
+			status = ocfs2_journal_dirty(handle, qbh);
+			if (status < 0)
+				mlog_errno(status);
+out_commit:
+			mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
+			ocfs2_commit_trans(OCFS2_SB(sb), handle);
+out_put_dquot:
+			dqput(dquot);
+out_put_bh:
+			brelse(qbh);
+			if (status < 0)
+				break;
+		}
+		brelse(hbh);
+		list_del(&rchunk->rc_list);
+		kfree(rchunk->rc_bitmap);
+		kfree(rchunk);
+		if (status < 0)
+			break;
+	}
+	ocfs2_unlock_global_qf(oinfo, 1);
+out:
+	if (status < 0)
+		free_recovery_list(&(rec->r_list[type]));
+	mlog_exit(status);
+	return status;
+}
+
+/* Recover local quota files for given node different from us */
+int ocfs2_finish_quota_recovery(struct ocfs2_super *osb,
+				struct ocfs2_quota_recovery *rec,
+				int slot_num)
+{
+	unsigned int ino[MAXQUOTAS] = { LOCAL_USER_QUOTA_SYSTEM_INODE,
+					LOCAL_GROUP_QUOTA_SYSTEM_INODE };
+	struct super_block *sb = osb->sb;
+	struct ocfs2_local_disk_dqinfo *ldinfo;
+	struct buffer_head *bh;
+	handle_t *handle;
+	int type;
+	int status = 0;
+	struct inode *lqinode;
+	unsigned int flags;
+
+	mlog(ML_NOTICE, "Finishing quota recovery in slot %u\n", slot_num);
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	for (type = 0; type < MAXQUOTAS; type++) {
+		if (list_empty(&(rec->r_list[type])))
+			continue;
+		mlog(0, "Recovering quota in slot %d\n", slot_num);
+		lqinode = ocfs2_get_system_file_inode(osb, ino[type], slot_num);
+		if (!lqinode) {
+			status = -ENOENT;
+			goto out;
+		}
+		status = ocfs2_inode_lock_full(lqinode, NULL, 1,
+						       OCFS2_META_LOCK_NOQUEUE);
+		/* Someone else is holding the lock? Then he must be
+		 * doing the recovery. Just skip the file... */
+		if (status == -EAGAIN) {
+			mlog(ML_NOTICE, "skipping quota recovery for slot %d "
+			     "because quota file is locked.\n", slot_num);
+			status = 0;
+			goto out_put;
+		} else if (status < 0) {
+			mlog_errno(status);
+			goto out_put;
+		}
+		/* Now read local header */
+		bh = ocfs2_read_quota_block(lqinode, 0, &status);
+		if (!bh) {
+			mlog_errno(status);
+			mlog(ML_ERROR, "failed to read quota file info header "
+				"(slot=%d type=%d)\n", slot_num, type);
+			goto out_lock;
+		}
+		ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
+							OCFS2_LOCAL_INFO_OFF);
+		/* Is recovery still needed? */
+		flags = le32_to_cpu(ldinfo->dqi_flags);
+		if (!(flags & OLQF_CLEAN))
+			status = ocfs2_recover_local_quota_file(lqinode,
+								type,
+								rec);
+		/* We don't want to mark file as clean when it is actually
+		 * active */
+		if (slot_num == osb->slot_num)
+			goto out_bh;
+		/* Mark quota file as clean if we are recovering quota file of
+		 * some other node. */
+		handle = ocfs2_start_trans(osb, 1);
+		if (IS_ERR(handle)) {
+			status = PTR_ERR(handle);
+			mlog_errno(status);
+			goto out_bh;
+		}
+		status = ocfs2_journal_access(handle, lqinode, bh,
+					      OCFS2_JOURNAL_ACCESS_WRITE);
+		if (status < 0) {
+			mlog_errno(status);
+			goto out_trans;
+		}
+		lock_buffer(bh);
+		ldinfo->dqi_flags = cpu_to_le32(flags | OLQF_CLEAN);
+		unlock_buffer(bh);
+		status = ocfs2_journal_dirty(handle, bh);
+		if (status < 0)
+			mlog_errno(status);
+out_trans:
+		ocfs2_commit_trans(osb, handle);
+out_bh:
+		brelse(bh);
+out_lock:
+		ocfs2_inode_unlock(lqinode, 1);
+out_put:
+		iput(lqinode);
+		if (status < 0)
+			break;
+	}
+out:
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	kfree(rec);
+	return status;
+}
+
 /* Read information header from quota file */
 static int ocfs2_local_read_info(struct super_block *sb, int type)
 {
@@ -262,6 +646,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	struct inode *lqinode = sb_dqopt(sb)->files[type];
 	int status;
 	struct buffer_head *bh = NULL;
+	struct ocfs2_quota_recovery *rec;
 	int locked = 0;
 
 	info->dqi_maxblimit = 0x7fffffffffffffffLL;
@@ -275,6 +660,7 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	info->dqi_priv = oinfo;
 	oinfo->dqi_type = type;
 	INIT_LIST_HEAD(&oinfo->dqi_chunk);
+	oinfo->dqi_rec = NULL;
 	oinfo->dqi_lqi_bh = NULL;
 	oinfo->dqi_ibh = NULL;
 
@@ -305,10 +691,27 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	oinfo->dqi_ibh = bh;
 
 	/* We crashed when using local quota file? */
-	if (!(info->dqi_flags & OLQF_CLEAN))
-		goto out_err;	/* So far we just bail out. Later we should resync here */
+	if (!(info->dqi_flags & OLQF_CLEAN)) {
+		rec = OCFS2_SB(sb)->quota_rec;
+		if (!rec) {
+			rec = ocfs2_alloc_quota_recovery();
+			if (!rec) {
+				status = -ENOMEM;
+				mlog_errno(status);
+				goto out_err;
+			}
+			OCFS2_SB(sb)->quota_rec = rec;
+		}
 
-	status = ocfs2_load_local_quota_bitmaps(sb_dqopt(sb)->files[type],
+		status = ocfs2_recovery_load_quota(lqinode, ldinfo, type,
+                                                   &rec->r_list[type]);
+		if (status < 0) {
+			mlog_errno(status);
+			goto out_err;
+		}
+	}
+
+	status = ocfs2_load_local_quota_bitmaps(lqinode,
 						ldinfo,
 						&oinfo->dqi_chunk);
 	if (status < 0) {
@@ -394,6 +797,12 @@ static int ocfs2_local_free_info(struct super_block *sb, int type)
 	}
 	ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);
 
+	/* dqonoff_mutex protects us against racing with recovery thread... */
+	if (oinfo->dqi_rec) {
+		ocfs2_free_quota_recovery(oinfo->dqi_rec);
+		mark_clean = 0;
+	}
+
 	if (!mark_clean)
 		goto out;