1 files changed, 65 insertions, 27 deletions

diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 013146755683..49c844dab33a 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -36,6 +36,7 @@
 struct nilfs_dat_info {
         struct nilfs_mdt_info mi;
         struct nilfs_palloc_cache palloc_cache;
+        struct nilfs_shadow_map shadow;
 };
 
 static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
@@ -102,7 +103,8 @@ void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
         nilfs_palloc_abort_alloc_entry(dat, req);
 }
 
-void nilfs_dat_commit_free(struct inode *dat, struct nilfs_palloc_req *req)
+static void nilfs_dat_commit_free(struct inode *dat,
+                                  struct nilfs_palloc_req *req)
 {
         struct nilfs_dat_entry *entry;
         void *kaddr;
@@ -327,6 +329,23 @@ int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
         ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
         if (ret < 0)
                 return ret;
+
+        /*
+         * The given disk block number (blocknr) is not yet written to
+         * the device at this point.
+         *
+         * To prevent nilfs_dat_translate() from returning the
+         * uncommited block number, this makes a copy of the entry
+         * buffer and redirects nilfs_dat_translate() to the copy.
+         */
+        if (!buffer_nilfs_redirected(entry_bh)) {
+                ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
+                if (ret) {
+                        brelse(entry_bh);
+                        return ret;
+                }
+        }
+
         kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
         entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
         if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
@@ -371,7 +390,7 @@ int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
  */
 int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
 {
-        struct buffer_head *entry_bh;
+        struct buffer_head *entry_bh, *bh;
         struct nilfs_dat_entry *entry;
         sector_t blocknr;
         void *kaddr;
@@ -381,6 +400,15 @@ int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
         if (ret < 0)
                 return ret;
 
+        if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
+                bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
+                if (bh) {
+                        WARN_ON(!buffer_uptodate(bh));
+                        brelse(entry_bh);
+                        entry_bh = bh;
+                }
+        }
+
         kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
         entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
         blocknr = le64_to_cpu(entry->de_blocknr);
@@ -436,38 +464,48 @@ ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
 }
 
 /**
- * nilfs_dat_read - read dat inode
- * @dat: dat inode
- * @raw_inode: on-disk dat inode
- */
-int nilfs_dat_read(struct inode *dat, struct nilfs_inode *raw_inode)
-{
-        return nilfs_read_inode_common(dat, raw_inode);
-}
-
-/**
- * nilfs_dat_new - create dat file
- * @nilfs: nilfs object
+ * nilfs_dat_read - read or get dat inode
+ * @sb: super block instance
  * @entry_size: size of a dat entry
+ * @raw_inode: on-disk dat inode
+ * @inodep: buffer to store the inode
  */
-struct inode *nilfs_dat_new(struct the_nilfs *nilfs, size_t entry_size)
+int nilfs_dat_read(struct super_block *sb, size_t entry_size,
+                   struct nilfs_inode *raw_inode, struct inode **inodep)
 {
         static struct lock_class_key dat_lock_key;
         struct inode *dat;
         struct nilfs_dat_info *di;
         int err;
 
-        dat = nilfs_mdt_new(nilfs, NULL, NILFS_DAT_INO, sizeof(*di));
-        if (dat) {
-                err = nilfs_palloc_init_blockgroup(dat, entry_size);
-                if (unlikely(err)) {
-                        nilfs_mdt_destroy(dat);
-                        return NULL;
-                }
+        dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
+        if (unlikely(!dat))
+                return -ENOMEM;
+        if (!(dat->i_state & I_NEW))
+                goto out;
 
-                di = NILFS_DAT_I(dat);
-                lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
-                nilfs_palloc_setup_cache(dat, &di->palloc_cache);
-        }
-        return dat;
+        err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
+        if (err)
+                goto failed;
+
+        err = nilfs_palloc_init_blockgroup(dat, entry_size);
+        if (err)
+                goto failed;
+
+        di = NILFS_DAT_I(dat);
+        lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
+        nilfs_palloc_setup_cache(dat, &di->palloc_cache);
+        nilfs_mdt_setup_shadow_map(dat, &di->shadow);
+
+        err = nilfs_read_inode_common(dat, raw_inode);
+        if (err)
+                goto failed;
+
+        unlock_new_inode(dat);
+ out:
+        *inodep = dat;
+        return 0;
+ failed:
+        iget_failed(dat);
+        return err;
 }