nilfs2: get rid of GCDAT inode

This applies prepared rollback function and redirect function of
metadata file to DAT file, and eliminates GCDAT inode.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

diff --git a/fs/nilfs2/Makefile b/fs/nilfs2/Makefile
index df3e62c..85c9873 100644 (file)
--- a/fs/nilfs2/Makefile
+++ b/fs/nilfs2/Makefile
@@ -2,4 +2,4 @@ obj-$(CONFIG_NILFS2_FS) += nilfs2.o
 nilfs2-y := inode.o file.o dir.o super.o namei.o page.o mdt.o \
        btnode.o bmap.o btree.o direct.o dat.o recovery.o \
        the_nilfs.o segbuf.o segment.o cpfile.o sufile.o \
-       ifile.o alloc.o gcinode.o ioctl.o gcdat.o
+       ifile.o alloc.o gcinode.o ioctl.o

diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 0024440..8b782b0 100644 (file)
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -533,22 +533,6 @@ void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
        nilfs_btree_init_gc(bmap);
 }
 
-void nilfs_bmap_init_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
-{
-       memcpy(gcbmap, bmap, sizeof(*bmap));
-       init_rwsem(&gcbmap->b_sem);
-       lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
-       gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
-}
-
-void nilfs_bmap_commit_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
-{
-       memcpy(bmap, gcbmap, sizeof(*bmap));
-       init_rwsem(&bmap->b_sem);
-       lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
-       bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
-}
-
 void nilfs_bmap_save(const struct nilfs_bmap *bmap,
                     struct nilfs_bmap_store *store)
 {

diff --git a/fs/nilfs2/bmap.h b/fs/nilfs2/bmap.h
index 5f3339e..bde1c0a 100644 (file)
--- a/fs/nilfs2/bmap.h
+++ b/fs/nilfs2/bmap.h
@@ -159,8 +159,6 @@ int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
 int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
 
 void nilfs_bmap_init_gc(struct nilfs_bmap *);
-void nilfs_bmap_init_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
-void nilfs_bmap_commit_gcdat(struct nilfs_bmap *, struct nilfs_bmap *);
 
 void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
 void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);

diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 0131467..7091c4e 100644 (file)
--- 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)
@@ -327,6 +328,23 @@ 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 +389,7 @@ 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 +399,15 @@ 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);
@@ -468,6 +495,7 @@ struct inode *nilfs_dat_new(struct the_nilfs *nilfs, size_t entry_size)
                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);
        }
        return dat;
 }

diff --git a/fs/nilfs2/gcdat.c b/fs/nilfs2/gcdat.c
deleted file mode 100644 (file)
index 84a45d1..0000000
--- a/fs/nilfs2/gcdat.c
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
- * gcdat.c - NILFS shadow DAT inode for GC
- *
- * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Written by Seiji Kihara <kihara@osrg.net>, Amagai Yoshiji <amagai@osrg.net>,
- *            and Ryusuke Konishi <ryusuke@osrg.net>.
- *
- */
-
-#include <linux/buffer_head.h>
-#include "nilfs.h"
-#include "page.h"
-#include "mdt.h"
-
-int nilfs_init_gcdat_inode(struct the_nilfs *nilfs)
-{
-       struct inode *dat = nilfs->ns_dat, *gcdat = nilfs->ns_gc_dat;
-       struct nilfs_inode_info *dii = NILFS_I(dat), *gii = NILFS_I(gcdat);
-       int err;
-
-       gcdat->i_state = 0;
-       gcdat->i_blocks = dat->i_blocks;
-       gii->i_flags = dii->i_flags;
-       gii->i_state = dii->i_state | (1 << NILFS_I_GCDAT);
-       gii->i_cno = 0;
-       nilfs_bmap_init_gcdat(gii->i_bmap, dii->i_bmap);
-       err = nilfs_copy_dirty_pages(gcdat->i_mapping, dat->i_mapping);
-       if (unlikely(err))
-               return err;
-
-       return nilfs_copy_dirty_pages(&gii->i_btnode_cache,
-                                     &dii->i_btnode_cache);
-}
-
-void nilfs_commit_gcdat_inode(struct the_nilfs *nilfs)
-{
-       struct inode *dat = nilfs->ns_dat, *gcdat = nilfs->ns_gc_dat;
-       struct nilfs_inode_info *dii = NILFS_I(dat), *gii = NILFS_I(gcdat);
-       struct address_space *mapping = dat->i_mapping;
-       struct address_space *gmapping = gcdat->i_mapping;
-
-       down_write(&NILFS_MDT(dat)->mi_sem);
-       dat->i_blocks = gcdat->i_blocks;
-       dii->i_flags = gii->i_flags;
-       dii->i_state = gii->i_state & ~(1 << NILFS_I_GCDAT);
-
-       nilfs_bmap_commit_gcdat(gii->i_bmap, dii->i_bmap);
-
-       nilfs_palloc_clear_cache(dat);
-       nilfs_palloc_clear_cache(gcdat);
-       nilfs_clear_dirty_pages(mapping);
-       nilfs_copy_back_pages(mapping, gmapping);
-       /* note: mdt dirty flags should be cleared by segctor. */
-
-       nilfs_clear_dirty_pages(&dii->i_btnode_cache);
-       nilfs_copy_back_pages(&dii->i_btnode_cache, &gii->i_btnode_cache);
-
-       up_write(&NILFS_MDT(dat)->mi_sem);
-}
-
-void nilfs_clear_gcdat_inode(struct the_nilfs *nilfs)
-{
-       struct inode *gcdat = nilfs->ns_gc_dat;
-       struct nilfs_inode_info *gii = NILFS_I(gcdat);
-
-       gcdat->i_state = I_FREEING | I_CLEAR;
-       gii->i_flags = 0;
-
-       nilfs_palloc_clear_cache(gcdat);
-       truncate_inode_pages(gcdat->i_mapping, 0);
-       truncate_inode_pages(&gii->i_btnode_cache, 0);
-}

diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index 532f85a..3bbd340 100644 (file)
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -414,8 +414,6 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
        sb = inode->i_sb;
        nilfs = NILFS_MDT(inode)->mi_nilfs;
 
-       if (page->mapping->assoc_mapping)
-               return 0; /* Do not request flush for shadow page cache */
        if (!sb) {
                down_read(&nilfs->ns_writer_sem);
                writer = nilfs->ns_writer;
@@ -566,13 +564,6 @@ void nilfs_mdt_set_entry_size(struct inode *inode, unsigned entry_size,
        mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
 }
 
-void nilfs_mdt_set_shadow(struct inode *orig, struct inode *shadow)
-{
-       shadow->i_mapping->assoc_mapping = orig->i_mapping;
-       NILFS_I(shadow)->i_btnode_cache.assoc_mapping =
-               &NILFS_I(orig)->i_btnode_cache;
-}
-
 static const struct address_space_operations shadow_map_aops = {
        .sync_page              = block_sync_page,
 };

diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h
index e60bbfe..1e0901c 100644 (file)
--- a/fs/nilfs2/mdt.h
+++ b/fs/nilfs2/mdt.h
@@ -93,7 +93,6 @@ struct inode *nilfs_mdt_new_common(struct the_nilfs *, struct super_block *,
                                   ino_t);
 void nilfs_mdt_destroy(struct inode *);
 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
-void nilfs_mdt_set_shadow(struct inode *, struct inode *);
 
 int nilfs_mdt_setup_shadow_map(struct inode *inode,
                               struct nilfs_shadow_map *shadow);

diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index cf5507a..e9f4579 100644 (file)
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -101,7 +101,6 @@ enum {
        NILFS_I_INODE_DIRTY,            /* write_inode is requested */
        NILFS_I_BMAP,                   /* has bmap and btnode_cache */
        NILFS_I_GCINODE,                /* inode for GC, on memory only */
-       NILFS_I_GCDAT,                  /* shadow DAT, on memory only */
 };
 
 /*
@@ -193,7 +192,7 @@ static inline int nilfs_doing_construction(void)
 
 static inline struct inode *nilfs_dat_inode(const struct the_nilfs *nilfs)
 {
-       return nilfs_doing_gc() ? nilfs->ns_gc_dat : nilfs->ns_dat;
+       return nilfs->ns_dat;
 }
 
 /*
@@ -294,11 +293,6 @@ int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *);
 int nilfs_init_gcinode(struct inode *inode);
 void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs);
 
-/* gcdat.c */
-int nilfs_init_gcdat_inode(struct the_nilfs *);
-void nilfs_commit_gcdat_inode(struct the_nilfs *);
-void nilfs_clear_gcdat_inode(struct the_nilfs *);
-
 /*
  * Inodes and files operations
  */

diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index 7083344..a6c3c2e 100644 (file)
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -79,8 +79,8 @@ struct buffer_head *nilfs_grab_buffer(struct inode *inode,
 {
        int blkbits = inode->i_blkbits;
        pgoff_t index = blkoff >> (PAGE_CACHE_SHIFT - blkbits);
-       struct page *page, *opage;
-       struct buffer_head *bh, *obh;
+       struct page *page;
+       struct buffer_head *bh;
 
        page = grab_cache_page(mapping, index);
        if (unlikely(!page))
@@ -92,30 +92,6 @@ struct buffer_head *nilfs_grab_buffer(struct inode *inode,
                page_cache_release(page);
                return NULL;
        }
-       if (!buffer_uptodate(bh) && mapping->assoc_mapping != NULL) {
-               /*
-                * Shadow page cache uses assoc_mapping to point its original
-                * page cache.  The following code tries the original cache
-                * if the given cache is a shadow and it didn't hit.
-                */
-               opage = find_lock_page(mapping->assoc_mapping, index);
-               if (!opage)
-                       return bh;
-
-               obh = __nilfs_get_page_block(opage, blkoff, index, blkbits,
-                                            b_state);
-               if (buffer_uptodate(obh)) {
-                       nilfs_copy_buffer(bh, obh);
-                       if (buffer_dirty(obh)) {
-                               nilfs_mark_buffer_dirty(bh);
-                               if (!buffer_nilfs_node(bh) && NILFS_MDT(inode))
-                                       nilfs_mdt_mark_dirty(inode);
-                       }
-               }
-               brelse(obh);
-               unlock_page(opage);
-               page_cache_release(opage);
-       }
        return bh;
 }
 

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 91dc066..b0c5e08 100644 (file)
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1945,11 +1945,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 
        nilfs_drop_collected_inodes(&sci->sc_dirty_files);
 
-       if (nilfs_doing_gc()) {
+       if (nilfs_doing_gc())
                nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
-               if (update_sr)
-                       nilfs_commit_gcdat_inode(nilfs);
-       } else
+       else
                nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
 
        sci->sc_nblk_inc += sci->sc_nblk_this_inc;
@@ -2472,13 +2470,15 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
 
        nilfs_transaction_lock(sbi, &ti, 1);
 
-       err = nilfs_init_gcdat_inode(nilfs);
+       err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
        if (unlikely(err))
                goto out_unlock;
 
        err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
-       if (unlikely(err))
+       if (unlikely(err)) {
+               nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
                goto out_unlock;
+       }
 
        sci->sc_freesegs = kbufs[4];
        sci->sc_nfreesegs = argv[4].v_nmembs;
@@ -2510,7 +2510,7 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
  out_unlock:
        sci->sc_freesegs = NULL;
        sci->sc_nfreesegs = 0;
-       nilfs_clear_gcdat_inode(nilfs);
+       nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
        nilfs_transaction_unlock(sbi);
        return err;
 }

diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 6eeb4f0..b7666bc 100644 (file)
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -96,7 +96,6 @@ void destroy_nilfs(struct the_nilfs *nilfs)
                nilfs_mdt_destroy(nilfs->ns_sufile);
                nilfs_mdt_destroy(nilfs->ns_cpfile);
                nilfs_mdt_destroy(nilfs->ns_dat);
-               nilfs_mdt_destroy(nilfs->ns_gc_dat);
        }
        if (nilfs_init(nilfs)) {
                brelse(nilfs->ns_sbh[0]);
@@ -131,20 +130,14 @@ static int nilfs_load_super_root(struct the_nilfs *nilfs, sector_t sr_block)
        if (unlikely(!nilfs->ns_dat))
                goto failed;
 
-       nilfs->ns_gc_dat = nilfs_dat_new(nilfs, dat_entry_size);
-       if (unlikely(!nilfs->ns_gc_dat))
-               goto failed_dat;
-
        nilfs->ns_cpfile = nilfs_cpfile_new(nilfs, checkpoint_size);
        if (unlikely(!nilfs->ns_cpfile))
-               goto failed_gc_dat;
+               goto failed_dat;
 
        nilfs->ns_sufile = nilfs_sufile_new(nilfs, segment_usage_size);
        if (unlikely(!nilfs->ns_sufile))
                goto failed_cpfile;
 
-       nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
-
        err = nilfs_dat_read(nilfs->ns_dat, (void *)bh_sr->b_data +
                             NILFS_SR_DAT_OFFSET(inode_size));
        if (unlikely(err))
@@ -173,9 +166,6 @@ static int nilfs_load_super_root(struct the_nilfs *nilfs, sector_t sr_block)
  failed_cpfile:
        nilfs_mdt_destroy(nilfs->ns_cpfile);
 
- failed_gc_dat:
-       nilfs_mdt_destroy(nilfs->ns_gc_dat);
-
  failed_dat:
        nilfs_mdt_destroy(nilfs->ns_dat);
        goto failed;
@@ -371,7 +361,6 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
        nilfs_mdt_destroy(nilfs->ns_cpfile);
        nilfs_mdt_destroy(nilfs->ns_sufile);
        nilfs_mdt_destroy(nilfs->ns_dat);
-       nilfs_mdt_destroy(nilfs->ns_gc_dat);
 
  failed:
        nilfs_clear_recovery_info(&ri);

diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 1908dc7..a5178dc 100644 (file)
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -74,7 +74,6 @@ enum {
  * @ns_dat: DAT file inode
  * @ns_cpfile: checkpoint file inode
  * @ns_sufile: segusage file inode
- * @ns_gc_dat: shadow inode of the DAT file inode for GC
  * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)
  * @ns_cptree_lock: lock protecting @ns_cptree
  * @ns_gc_inodes: dummy inodes to keep live blocks
@@ -149,7 +148,6 @@ struct the_nilfs {
        struct inode           *ns_dat;
        struct inode           *ns_cpfile;
        struct inode           *ns_sufile;
-       struct inode           *ns_gc_dat;
 
        /* Checkpoint tree */
        struct rb_root          ns_cptree;