Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (36 commits)
  nilfs2: eliminate sparse warning - "context imbalance"
  nilfs2: eliminate sparse warnings - "symbol not declared"
  nilfs2: get rid of bdi from nilfs object
  nilfs2: change license of exported header file
  nilfs2: add bdev freeze/thaw support
  nilfs2: accept 64-bit checkpoint numbers in cp mount option
  nilfs2: remove own inode allocator and destructor for metadata files
  nilfs2: get rid of back pointer to writable sb instance
  nilfs2: get rid of mi_nilfs back pointer to nilfs object
  nilfs2: see state of root dentry for mount check of snapshots
  nilfs2: use iget for all metadata files
  nilfs2: get rid of GCDAT inode
  nilfs2: add routines to redirect access to buffers of DAT file
  nilfs2: add routines to roll back state of DAT file
  nilfs2: add routines to save and restore bmap state
  nilfs2: do not allocate nilfs_mdt_info structure to gc-inodes
  nilfs2: allow nilfs_clear_inode to clear metadata file inodes
  nilfs2: get rid of snapshot mount flag
  nilfs2: simplify life cycle management of nilfs object
  nilfs2: do not allocate multiple super block instances for a device
  ...

1 files changed, 134 insertions, 33 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index eccb2f2e2315..71d4bc8464e0 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -34,6 +34,12 @@
 #include "cpfile.h"
 #include "ifile.h"
 
+struct nilfs_iget_args {
+        u64 ino;
+        __u64 cno;
+        struct nilfs_root *root;
+        int for_gc;
+};
 
 /**
  * nilfs_get_block() - get a file block on the filesystem (callback function)
@@ -279,6 +285,7 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         struct nilfs_sb_info *sbi = NILFS_SB(sb);
         struct inode *inode;
         struct nilfs_inode_info *ii;
+        struct nilfs_root *root;
         int err = -ENOMEM;
         ino_t ino;
 
@@ -289,15 +296,17 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         mapping_set_gfp_mask(inode->i_mapping,
                              mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
 
+        root = NILFS_I(dir)->i_root;
         ii = NILFS_I(inode);
         ii->i_state = 1 << NILFS_I_NEW;
+        ii->i_root = root;
 
-        err = nilfs_ifile_create_inode(sbi->s_ifile, &ino, &ii->i_bh);
+        err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
         if (unlikely(err))
                 goto failed_ifile_create_inode;
         /* reference count of i_bh inherits from nilfs_mdt_read_block() */
 
-        atomic_inc(&sbi->s_inodes_count);
+        atomic_inc(&root->inodes_count);
         inode_init_owner(inode, dir, mode);
         inode->i_ino = ino;
         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
@@ -320,7 +329,6 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         /* ii->i_file_acl = 0; */
         /* ii->i_dir_acl = 0; */
         ii->i_dir_start_lookup = 0;
-        ii->i_cno = 0;
         nilfs_set_inode_flags(inode);
         spin_lock(&sbi->s_next_gen_lock);
         inode->i_generation = sbi->s_next_generation++;
@@ -350,16 +358,6 @@ struct inode *nilfs_new_inode(struct inode *dir, int mode)
         return ERR_PTR(err);
 }
 
-void nilfs_free_inode(struct inode *inode)
-{
-        struct super_block *sb = inode->i_sb;
-        struct nilfs_sb_info *sbi = NILFS_SB(sb);
-
-        /* XXX: check error code? Is there any thing I can do? */
-        (void) nilfs_ifile_delete_inode(sbi->s_ifile, inode->i_ino);
-        atomic_dec(&sbi->s_inodes_count);
-}
-
 void nilfs_set_inode_flags(struct inode *inode)
 {
         unsigned int flags = NILFS_I(inode)->i_flags;
@@ -410,7 +408,6 @@ int nilfs_read_inode_common(struct inode *inode,
                 0 : le32_to_cpu(raw_inode->i_dir_acl);
 #endif
         ii->i_dir_start_lookup = 0;
-        ii->i_cno = 0;
         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 
         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
@@ -424,7 +421,8 @@ int nilfs_read_inode_common(struct inode *inode,
         return 0;
 }
 
-static int __nilfs_read_inode(struct super_block *sb, unsigned long ino,
+static int __nilfs_read_inode(struct super_block *sb,
+                              struct nilfs_root *root, unsigned long ino,
                               struct inode *inode)
 {
         struct nilfs_sb_info *sbi = NILFS_SB(sb);
@@ -434,11 +432,11 @@ static int __nilfs_read_inode(struct super_block *sb, unsigned long ino,
         int err;
 
         down_read(&NILFS_MDT(dat)->mi_sem);     /* XXX */
-        err = nilfs_ifile_get_inode_block(sbi->s_ifile, ino, &bh);
+        err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
         if (unlikely(err))
                 goto bad_inode;
 
-        raw_inode = nilfs_ifile_map_inode(sbi->s_ifile, ino, bh);
+        raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 
         err = nilfs_read_inode_common(inode, raw_inode);
         if (err)
@@ -461,14 +459,14 @@ static int __nilfs_read_inode(struct super_block *sb, unsigned long ino,
                         inode, inode->i_mode,
                         huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
         }
-        nilfs_ifile_unmap_inode(sbi->s_ifile, ino, bh);
+        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
         brelse(bh);
         up_read(&NILFS_MDT(dat)->mi_sem);       /* XXX */
         nilfs_set_inode_flags(inode);
         return 0;
 
  failed_unmap:
-        nilfs_ifile_unmap_inode(sbi->s_ifile, ino, bh);
+        nilfs_ifile_unmap_inode(root->ifile, ino, bh);
         brelse(bh);
 
  bad_inode:
@@ -476,18 +474,95 @@ static int __nilfs_read_inode(struct super_block *sb, unsigned long ino,
         return err;
 }
 
-struct inode *nilfs_iget(struct super_block *sb, unsigned long ino)
+static int nilfs_iget_test(struct inode *inode, void *opaque)
+{
+        struct nilfs_iget_args *args = opaque;
+        struct nilfs_inode_info *ii;
+
+        if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
+                return 0;
+
+        ii = NILFS_I(inode);
+        if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
+                return !args->for_gc;
+
+        return args->for_gc && args->cno == ii->i_cno;
+}
+
+static int nilfs_iget_set(struct inode *inode, void *opaque)
+{
+        struct nilfs_iget_args *args = opaque;
+
+        inode->i_ino = args->ino;
+        if (args->for_gc) {
+                NILFS_I(inode)->i_state = 1 << NILFS_I_GCINODE;
+                NILFS_I(inode)->i_cno = args->cno;
+                NILFS_I(inode)->i_root = NULL;
+        } else {
+                if (args->root && args->ino == NILFS_ROOT_INO)
+                        nilfs_get_root(args->root);
+                NILFS_I(inode)->i_root = args->root;
+        }
+        return 0;
+}
+
+struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
+                            unsigned long ino)
+{
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = root, .cno = 0, .for_gc = 0
+        };
+
+        return ilookup5(sb, ino, nilfs_iget_test, &args);
+}
+
+struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
+                                unsigned long ino)
+{
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = root, .cno = 0, .for_gc = 0
+        };
+
+        return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
+}
+
+struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
+                         unsigned long ino)
 {
         struct inode *inode;
         int err;
 
-        inode = iget_locked(sb, ino);
+        inode = nilfs_iget_locked(sb, root, ino);
         if (unlikely(!inode))
                 return ERR_PTR(-ENOMEM);
         if (!(inode->i_state & I_NEW))
                 return inode;
 
-        err = __nilfs_read_inode(sb, ino, inode);
+        err = __nilfs_read_inode(sb, root, ino, inode);
+        if (unlikely(err)) {
+                iget_failed(inode);
+                return ERR_PTR(err);
+        }
+        unlock_new_inode(inode);
+        return inode;
+}
+
+struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
+                                __u64 cno)
+{
+        struct nilfs_iget_args args = {
+                .ino = ino, .root = NULL, .cno = cno, .for_gc = 1
+        };
+        struct inode *inode;
+        int err;
+
+        inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
+        if (unlikely(!inode))
+                return ERR_PTR(-ENOMEM);
+        if (!(inode->i_state & I_NEW))
+                return inode;
+
+        err = nilfs_init_gcinode(inode);
         if (unlikely(err)) {
                 iget_failed(inode);
                 return ERR_PTR(err);
@@ -528,21 +603,20 @@ void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh)
 {
         ino_t ino = inode->i_ino;
         struct nilfs_inode_info *ii = NILFS_I(inode);
-        struct super_block *sb = inode->i_sb;
-        struct nilfs_sb_info *sbi = NILFS_SB(sb);
+        struct inode *ifile = ii->i_root->ifile;
         struct nilfs_inode *raw_inode;
 
-        raw_inode = nilfs_ifile_map_inode(sbi->s_ifile, ino, ibh);
+        raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 
         if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
-                memset(raw_inode, 0, NILFS_MDT(sbi->s_ifile)->mi_entry_size);
+                memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
         set_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
 
         nilfs_write_inode_common(inode, raw_inode, 0);
                 /* XXX: call with has_bmap = 0 is a workaround to avoid
                    deadlock of bmap. This delays update of i_bmap to just
                    before writing */
-        nilfs_ifile_unmap_inode(sbi->s_ifile, ino, ibh);
+        nilfs_ifile_unmap_inode(ifile, ino, ibh);
 }
 
 #define NILFS_MAX_TRUNCATE_BLOCKS       16384  /* 64MB for 4KB block */
@@ -617,6 +691,7 @@ void nilfs_truncate(struct inode *inode)
 static void nilfs_clear_inode(struct inode *inode)
 {
         struct nilfs_inode_info *ii = NILFS_I(inode);
+        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
         /*
          * Free resources allocated in nilfs_read_inode(), here.
@@ -625,10 +700,16 @@ static void nilfs_clear_inode(struct inode *inode)
         brelse(ii->i_bh);
         ii->i_bh = NULL;
 
+        if (mdi && mdi->mi_palloc_cache)
+                nilfs_palloc_destroy_cache(inode);
+
         if (test_bit(NILFS_I_BMAP, &ii->i_state))
                 nilfs_bmap_clear(ii->i_bmap);
 
         nilfs_btnode_cache_clear(&ii->i_btnode_cache);
+
+        if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
+                nilfs_put_root(ii->i_root);
 }
 
 void nilfs_evict_inode(struct inode *inode)
@@ -637,7 +718,7 @@ void nilfs_evict_inode(struct inode *inode)
         struct super_block *sb = inode->i_sb;
         struct nilfs_inode_info *ii = NILFS_I(inode);
 
-        if (inode->i_nlink || unlikely(is_bad_inode(inode))) {
+        if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
                 if (inode->i_data.nrpages)
                         truncate_inode_pages(&inode->i_data, 0);
                 end_writeback(inode);
@@ -649,12 +730,16 @@ void nilfs_evict_inode(struct inode *inode)
         if (inode->i_data.nrpages)
                 truncate_inode_pages(&inode->i_data, 0);
 
+        /* TODO: some of the following operations may fail.  */
         nilfs_truncate_bmap(ii, 0);
         nilfs_mark_inode_dirty(inode);
         end_writeback(inode);
+
+        nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
+        atomic_dec(&ii->i_root->inodes_count);
+
         nilfs_clear_inode(inode);
-        nilfs_free_inode(inode);
-        /* nilfs_free_inode() marks inode buffer dirty */
+
         if (IS_SYNC(inode))
                 nilfs_set_transaction_flag(NILFS_TI_SYNC);
         nilfs_transaction_commit(sb);
@@ -700,6 +785,17 @@ out_err:
         return err;
 }
 
+int nilfs_permission(struct inode *inode, int mask)
+{
+        struct nilfs_root *root = NILFS_I(inode)->i_root;
+
+        if ((mask & MAY_WRITE) && root &&
+            root->cno != NILFS_CPTREE_CURRENT_CNO)
+                return -EROFS; /* snapshot is not writable */
+
+        return generic_permission(inode, mask, NULL);
+}
+
 int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
                            struct buffer_head **pbh)
 {
@@ -709,8 +805,8 @@ int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
         spin_lock(&sbi->s_inode_lock);
         if (ii->i_bh == NULL) {
                 spin_unlock(&sbi->s_inode_lock);
-                err = nilfs_ifile_get_inode_block(sbi->s_ifile, inode->i_ino,
-                                                  pbh);
+                err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
+                                                  inode->i_ino, pbh);
                 if (unlikely(err))
                         return err;
                 spin_lock(&sbi->s_inode_lock);
@@ -790,7 +886,7 @@ int nilfs_mark_inode_dirty(struct inode *inode)
         }
         nilfs_update_inode(inode, ibh);
         nilfs_mdt_mark_buffer_dirty(ibh);
-        nilfs_mdt_mark_dirty(sbi->s_ifile);
+        nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
         brelse(ibh);
         return 0;
 }
@@ -808,6 +904,7 @@ int nilfs_mark_inode_dirty(struct inode *inode)
 void nilfs_dirty_inode(struct inode *inode)
 {
         struct nilfs_transaction_info ti;
+        struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 
         if (is_bad_inode(inode)) {
                 nilfs_warning(inode->i_sb, __func__,
@@ -815,6 +912,10 @@ void nilfs_dirty_inode(struct inode *inode)
                 dump_stack();
                 return;
         }
+        if (mdi) {
+                nilfs_mdt_mark_dirty(inode);
+                return;
+        }
         nilfs_transaction_begin(inode->i_sb, &ti, 0);
         nilfs_mark_inode_dirty(inode);
         nilfs_transaction_commit(inode->i_sb); /* never fails */