tux3: Implement statfs->f_{files,ffree}

To keep track the free inodes, this adds sb->freeinodes.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

4 files changed, 60 insertions, 7 deletions

diff --git a/fs/tux3/commit.c b/fs/tux3/commit.c
index 6160994a062d6b..3f3846bafc3be4 100644
--- a/fs/tux3/commit.c
+++ b/fs/tux3/commit.c
@@ -92,6 +92,7 @@ static void __setup_sb(struct sb *sb, struct disksuper *super)
 	vfs_sb(sb)->s_maxbytes = calc_maxbytes(sb->blocksize);
 
 	/* Probably does not belong here (maybe metablock) */
+	sb->freeinodes = MAX_INODES - be64_to_cpu(super->usedinodes);
 	sb->freeblocks = sb->volblocks;
 	sb->nextalloc = be64_to_cpu(super->nextalloc);
 	sb->atomdictsize = be64_to_cpu(super->atomdictsize);
@@ -100,8 +101,8 @@ static void __setup_sb(struct sb *sb, struct disksuper *super)
 	/* logchain and logcount are read from super directly */
 	trace("blocksize %u, blockbits %u, blockmask %08x",
 	      sb->blocksize, sb->blockbits, sb->blockmask);
-	trace("volblocks %Lu, freeblocks %Lu, nextalloc %Lu",
-	      sb->volblocks, sb->freeblocks, sb->nextalloc);
+	trace("volblocks %Lu, freeblocks %Lu, freeinodes %Lu, nextalloc %Lu",
+	      sb->volblocks, sb->freeblocks, sb->freeinodes, sb->nextalloc);
 	trace("atom_dictsize %Lu, freeatom %u, atomgen %u",
 	      (s64)sb->atomdictsize, sb->freeatom, sb->atomgen);
 	trace("logchain %Lu, logcount %u",
diff --git a/fs/tux3/inode.c b/fs/tux3/inode.c
index 31ce97bfbed030..d99807ad936948 100644
--- a/fs/tux3/inode.c
+++ b/fs/tux3/inode.c
@@ -257,6 +257,17 @@ static int alloc_inum(struct inode *inode, inum_t goal)
 
 	add_defer_alloc_inum(inode);
 
+	/*
+	 * If inum is not reserved area, account it. If inum is
+	 * reserved area, inode might not be written into itable. So,
+	 * we don't include the reserved area into dynamic accounting.
+	 * FIXME: what happen if snapshot was introduced?
+	 */
+	if (goal >= TUX_NORMAL_INO) {
+		assert(sb->freeinodes > TUX_NORMAL_INO);
+		sb->freeinodes--;
+	}
+
 error:
 	up_write(&cursor->btree->lock);
 	free_cursor(cursor);
@@ -458,6 +469,15 @@ static int save_inode(struct inode *inode, struct tux3_iattr_data *idata,
 	if (err)
 		goto error_release;
 
+	/*
+	 * If inode is newly added into itable, account to on-disk usedinodes.
+	 * ->usedinodes is used only by backend, no need lock.
+	 * FIXME: what happen if snapshot was introduced?
+	 */
+	if (is_defer_alloc_inum(inode) && inum >= TUX_NORMAL_INO) {
+		assert(be64_to_cpu(sb->super.usedinodes) < MAX_INODES);
+		be64_add_cpu(&sb->super.usedinodes, 1);
+	}
 	del_defer_alloc_inum(inode);
 
 error_release:
@@ -539,9 +559,21 @@ error:
 /* Remove inode from itable */
 static int purge_inode(struct inode *inode)
 {
-	struct btree *itable = itable_btree(tux_sb(inode->i_sb));
+	struct sb *sb = tux_sb(inode->i_sb);
+	struct btree *itable = itable_btree(sb);
+	int reserved_inum = tux_inode(inode)->inum < TUX_NORMAL_INO;
 
 	down_write(&itable->lock);	/* FIXME: spinlock is enough? */
+
+	/*
+	 * If inum is not reserved area, account it.
+	 * FIXME: what happen if snapshot was introduced?
+	 */
+	if (!reserved_inum) {
+		assert(sb->freeinodes < MAX_INODES);
+		sb->freeinodes++;
+	}
+
 	if (is_defer_alloc_inum(inode)) {
 		del_defer_alloc_inum(inode);
 		up_write(&itable->lock);
@@ -549,6 +581,16 @@ static int purge_inode(struct inode *inode)
 	}
 	up_write(&itable->lock);
 
+	/*
+	 * If inode is deleted from itable, account to on-disk usedinodes.
+	 * ->usedinodes is used only by backend, no need lock.
+	 * FIXME: what happen if snapshot was introduced?
+	 */
+	if (!reserved_inum) {
+		assert(be64_to_cpu(sb->super.usedinodes) > TUX_NORMAL_INO);
+		be64_add_cpu(&sb->super.usedinodes, -1);
+	}
+
 	/* Remove inum from inode btree */
 	return btree_chop(itable, tux_inode(inode)->inum, 1);
 }
diff --git a/fs/tux3/super.c b/fs/tux3/super.c
index 6a1614eccc0bde..428b19742226a4 100644
--- a/fs/tux3/super.c
+++ b/fs/tux3/super.c
@@ -357,9 +357,9 @@ static int tux3_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_blocks = sbi->volblocks;
 	buf->f_bfree = sbi->freeblocks;
 	buf->f_bavail = sbi->freeblocks;
+	buf->f_files = MAX_INODES;
+	buf->f_ffree = sbi->freeinodes;
 #if 0
-	buf->f_files = buf->f_blocks << (sbi->clus_bits - EXFAT_CHUNK_BITS) / 3;
-	buf->f_ffree = buf->f_blocks << (sbi->clus_bits - EXFAT_CHUNK_BITS) / 3;
 	buf->f_fsid.val[0] = sbi->serial_number;
 	/*buf->f_fsid.val[1];*/
 #endif
diff --git a/fs/tux3/tux3.h b/fs/tux3/tux3.h
index 1ffee11312c040..c15b01fab76dec 100644
--- a/fs/tux3/tux3.h
+++ b/fs/tux3/tux3.h
@@ -85,7 +85,7 @@ static inline void *decode48(void *at, u64 *val)
 
 /* Tux3 disk format */
 
-#define TUX3_MAGIC		"tux3" "\x20\x12\x07\x02"
+#define TUX3_MAGIC		"tux3" "\x20\x12\x12\x20"
 /*
  * TUX3_LABEL includes the date of the last incompatible disk format change
  * NOTE: Always update this history for each incompatible change!
@@ -108,9 +108,12 @@ static inline void *decode48(void *at, u64 *val)
 #define TUX3_MAGIC_ILEAF	0x90de
 #define TUX3_MAGIC_OLEAF	0x6eaf
 
+/* Number of available inum ("0" - "((1 << 48) - 1)") */
 #define MAX_INODES_BITS		48
+#define MAX_INODES		((u64)1 << MAX_INODES_BITS)
+/* Maximum number of block address ("0" - "((1 << 48) - 1)") */
 #define MAX_BLOCKS_BITS		48
-#define MAX_BLOCKS		((block_t)1 << 48)
+#define MAX_BLOCKS		((block_t)1 << MAX_BLOCKS_BITS)
 #define MAX_EXTENT		(1 << 6)
 
 #define SB_LOC			(1 << 12)
@@ -141,6 +144,11 @@ struct disksuper {
 	/* The rest should be moved to a "metablock" that is updated frequently */
 	__be64 iroot;		/* Root of the inode table btree */
 	__be64 oroot;		/* Root of the orphan table btree */
+	__be64 usedinodes;	/* Number of using inode numbers.  (Instead of
+				 * free inode numbers).  With this, we can
+				 * change the maximum inodes without changing
+				 * usedinodes on disk.
+				 */
 	__be64 nextalloc;	/* Get rid of this when we have a real allocation policy */
 	__be64 atomdictsize;	/*
 				 * Size of the atom dictionary instead of i_size
@@ -248,6 +256,8 @@ struct sb {
 	struct inode *atable;	/* xattr atom special file */
 
 	unsigned blocksize, blockbits, blockmask;
+	u64 freeinodes;		/* Number of free inode numbers. This is
+				 * including the deferred allocated inodes */
 	block_t volblocks, freeblocks, nextalloc;
 	unsigned entries_per_node; /* must be per-btree type, get rid of this */
 	unsigned version;	/* Currently mounted volume version view */