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 40e82b483136..b98562174cd0 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;