ext4: Introduce ext4_lblk_t

This patch adds a new data type ext4_lblk_t to represent
the logical file blocks.

This is the preparatory patch to support large files in ext4
The follow up patch with convert the ext4_inode i_blocks to
represent the number of blocks in file system block size. This
changes makes it possible to have a block number 2**32 -1 which
will result in overflow if the block number is represented by
signed long. This patch convert all the block number to type
ext4_lblk_t which is typedef to __u32

Also remove dead code ext4_ext_walk_space
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>

fs/ext4/dir.c

@@ -124,7 +124,7 @@ static int ext4_readdir(struct file * filp,
 	offset = filp->f_pos & (sb->s_blocksize - 1);
 
 	while (!error && !stored && filp->f_pos < inode->i_size) {
-		unsigned long blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
+		ext4_lblk_t blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
 		struct buffer_head map_bh;
 		struct buffer_head *bh = NULL;
 

fs/ext4/inode.c

@@ -105,7 +105,7 @@ int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
  */
 static unsigned long blocks_for_truncate(struct inode *inode)
 {
-	unsigned long needed;
+	ext4_lblk_t needed;
 
 	needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
 
@@ -282,7 +282,8 @@ static int verify_chain(Indirect *from, Indirect *to)
  */
 
 static int ext4_block_to_path(struct inode *inode,
-			long i_block, int offsets[4], int *boundary)
+			ext4_lblk_t i_block,
+			ext4_lblk_t offsets[4], int *boundary)
 {
 	int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
 	int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
@@ -349,7 +350,8 @@ static int ext4_block_to_path(struct inode *inode,
  *	or when it reads all @depth-1 indirect blocks successfully and finds
  *	the whole chain, all way to the data (returns %NULL, *err == 0).
  */
-static Indirect *ext4_get_branch(struct inode *inode, int depth, int *offsets,
+static Indirect *ext4_get_branch(struct inode *inode, int depth,
+				 ext4_lblk_t  *offsets,
 				 Indirect chain[4], int *err)
 {
 	struct super_block *sb = inode->i_sb;
@@ -445,7 +447,7 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
  *	stores it in *@goal and returns zero.
  */
 
-static ext4_fsblk_t ext4_find_goal(struct inode *inode, long block,
+static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
 		Indirect chain[4], Indirect *partial)
 {
 	struct ext4_block_alloc_info *block_i;
@@ -590,7 +592,7 @@ failed_out:
  */
 static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
 			int indirect_blks, int *blks, ext4_fsblk_t goal,
-			int *offsets, Indirect *branch)
+			ext4_lblk_t *offsets, Indirect *branch)
 {
 	int blocksize = inode->i_sb->s_blocksize;
 	int i, n = 0;
@@ -680,7 +682,7 @@ failed:
  * chain to new block and return 0.
  */
 static int ext4_splice_branch(handle_t *handle, struct inode *inode,
-			long block, Indirect *where, int num, int blks)
+			ext4_lblk_t block, Indirect *where, int num, int blks)
 {
 	int i;
 	int err = 0;
@@ -784,12 +786,12 @@ err_out:
  * return < 0, error case.
  */
 int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
-		sector_t iblock, unsigned long maxblocks,
+		ext4_lblk_t iblock, unsigned long maxblocks,
 		struct buffer_head *bh_result,
 		int create, int extend_disksize)
 {
 	int err = -EIO;
-	int offsets[4];
+	ext4_lblk_t offsets[4];
 	Indirect chain[4];
 	Indirect *partial;
 	ext4_fsblk_t goal;
@@ -803,7 +805,8 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 
 	J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
 	J_ASSERT(handle != NULL || create == 0);
-	depth = ext4_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
+	depth = ext4_block_to_path(inode, iblock, offsets,
+					&blocks_to_boundary);
 
 	if (depth == 0)
 		goto out;
@@ -996,7 +999,7 @@ get_block:
  * `handle' can be NULL if create is zero
  */
 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
-				long block, int create, int *errp)
+				ext4_lblk_t block, int create, int *errp)
 {
 	struct buffer_head dummy;
 	int fatal = 0, err;
@@ -1063,7 +1066,7 @@ err:
 }
 
 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
-			       int block, int create, int *err)
+			       ext4_lblk_t block, int create, int *err)
 {
 	struct buffer_head * bh;
 
@@ -1828,7 +1831,8 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
 {
 	ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
 	unsigned offset = from & (PAGE_CACHE_SIZE-1);
-	unsigned blocksize, iblock, length, pos;
+	unsigned blocksize, length, pos;
+	ext4_lblk_t iblock;
 	struct inode *inode = mapping->host;
 	struct buffer_head *bh;
 	int err = 0;
@@ -1964,7 +1968,7 @@ static inline int all_zeroes(__le32 *p, __le32 *q)
  *			(no partially truncated stuff there).  */
 
 static Indirect *ext4_find_shared(struct inode *inode, int depth,
-			int offsets[4], Indirect chain[4], __le32 *top)
+			ext4_lblk_t offsets[4], Indirect chain[4], __le32 *top)
 {
 	Indirect *partial, *p;
 	int k, err;
@@ -2289,12 +2293,12 @@ void ext4_truncate(struct inode *inode)
 	__le32 *i_data = ei->i_data;
 	int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
 	struct address_space *mapping = inode->i_mapping;
-	int offsets[4];
+	ext4_lblk_t offsets[4];
 	Indirect chain[4];
 	Indirect *partial;
 	__le32 nr = 0;
 	int n;
-	long last_block;
+	ext4_lblk_t last_block;
 	unsigned blocksize = inode->i_sb->s_blocksize;
 	struct page *page;
 

fs/ext4/namei.c

@@ -51,7 +51,7 @@
 
 static struct buffer_head *ext4_append(handle_t *handle,
 					struct inode *inode,
-					u32 *block, int *err)
+					ext4_lblk_t *block, int *err)
 {
 	struct buffer_head *bh;
 
@@ -144,8 +144,8 @@ struct dx_map_entry
 	u16 size;
 };
 
-static inline unsigned dx_get_block (struct dx_entry *entry);
-static void dx_set_block (struct dx_entry *entry, unsigned value);
+static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
+static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 static inline unsigned dx_get_hash (struct dx_entry *entry);
 static void dx_set_hash (struct dx_entry *entry, unsigned value);
 static unsigned dx_get_count (struct dx_entry *entries);
@@ -166,7 +166,8 @@ static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to,
 		struct dx_map_entry *offsets, int count);
 static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size);
-static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block);
+static void dx_insert_block(struct dx_frame *frame,
+					u32 hash, ext4_lblk_t block);
 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 				 struct dx_frame *frame,
 				 struct dx_frame *frames,
@@ -181,12 +182,12 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
  * Mask them off for now.
  */
 
-static inline unsigned dx_get_block (struct dx_entry *entry)
+static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 {
 	return le32_to_cpu(entry->block) & 0x00ffffff;
 }
 
-static inline void dx_set_block (struct dx_entry *entry, unsigned value)
+static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 {
 	entry->block = cpu_to_le32(value);
 }
@@ -243,8 +244,8 @@ static void dx_show_index (char * label, struct dx_entry *entries)
 	int i, n = dx_get_count (entries);
 	printk("%s index ", label);
 	for (i = 0; i < n; i++) {
-		printk("%x->%u ", i? dx_get_hash(entries + i) :
-				0, dx_get_block(entries + i));
+		printk("%x->%lu ", i? dx_get_hash(entries + i) :
+				0, (unsigned long)dx_get_block(entries + i));
 	}
 	printk("\n");
 }
@@ -297,7 +298,8 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 	printk("%i indexed blocks...\n", count);
 	for (i = 0; i < count; i++, entries++)
 	{
-		u32 block = dx_get_block(entries), hash = i? dx_get_hash(entries): 0;
+		ext4_lblk_t block = dx_get_block(entries);
+		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 		struct stats stats;
 		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
@@ -561,7 +563,7 @@ static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *
  * into the tree.  If there is an error it is returned in err.
  */
 static int htree_dirblock_to_tree(struct file *dir_file,
-				  struct inode *dir, int block,
+				  struct inode *dir, ext4_lblk_t block,
 				  struct dx_hash_info *hinfo,
 				  __u32 start_hash, __u32 start_minor_hash)
 {
@@ -569,7 +571,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	struct ext4_dir_entry_2 *de, *top;
 	int err, count = 0;
 
-	dxtrace(printk("In htree dirblock_to_tree: block %d\n", block));
+	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
+							(unsigned long)block));
 	if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 		return err;
 
@@ -621,9 +624,9 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 	struct ext4_dir_entry_2 *de;
 	struct dx_frame frames[2], *frame;
 	struct inode *dir;
-	int block, err;
+	ext4_lblk_t block;
 	int count = 0;
-	int ret;
+	int ret, err;
 	__u32 hashval;
 
 	dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
@@ -753,7 +756,7 @@ static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 	} while(more);
 }
 
-static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block)
+static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 {
 	struct dx_entry *entries = frame->entries;
 	struct dx_entry *old = frame->at, *new = old + 1;
@@ -848,13 +851,14 @@ static struct buffer_head * ext4_find_entry (struct dentry *dentry,
 	struct super_block * sb;
 	struct buffer_head * bh_use[NAMEI_RA_SIZE];
 	struct buffer_head * bh, *ret = NULL;
-	unsigned long start, block, b;
+	ext4_lblk_t start, block, b;
 	int ra_max = 0;		/* Number of bh's in the readahead
 				   buffer, bh_use[] */
 	int ra_ptr = 0;		/* Current index into readahead
 				   buffer */
 	int num = 0;
-	int nblocks, i, err;
+	ext4_lblk_t  nblocks;
+	int i, err;
 	struct inode *dir = dentry->d_parent->d_inode;
 	int namelen;
 	const u8 *name;
@@ -915,7 +919,8 @@ restart:
 		if (!buffer_uptodate(bh)) {
 			/* read error, skip block & hope for the best */
 			ext4_error(sb, __FUNCTION__, "reading directory #%lu "
-				   "offset %lu", dir->i_ino, block);
+				   "offset %lu", dir->i_ino,
+				   (unsigned long)block);
 			brelse(bh);
 			goto next;
 		}
@@ -962,7 +967,7 @@ static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
 	struct dx_frame frames[2], *frame;
 	struct ext4_dir_entry_2 *de, *top;
 	struct buffer_head *bh;
-	unsigned long block;
+	ext4_lblk_t block;
 	int retval;
 	int namelen = dentry->d_name.len;
 	const u8 *name = dentry->d_name.name;
@@ -1174,7 +1179,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	unsigned blocksize = dir->i_sb->s_blocksize;
 	unsigned count, continued;
 	struct buffer_head *bh2;
-	u32 newblock;
+	ext4_lblk_t newblock;
 	u32 hash2;
 	struct dx_map_entry *map;
 	char *data1 = (*bh)->b_data, *data2;
@@ -1221,8 +1226,9 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	split = count - move;
 	hash2 = map[split].hash;
 	continued = hash2 == map[split - 1].hash;
-	dxtrace(printk("Split block %i at %x, %i/%i\n",
-		dx_get_block(frame->at), hash2, split, count-split));
+	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
+			(unsigned long)dx_get_block(frame->at),
+					hash2, split, count-split));
 
 	/* Fancy dance to stay within two buffers */
 	de2 = dx_move_dirents(data1, data2, map + split, count - split);
@@ -1374,7 +1380,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	int		retval;
 	unsigned	blocksize;
 	struct dx_hash_info hinfo;
-	u32		block;
+	ext4_lblk_t  block;
 	struct fake_dirent *fde;
 
 	blocksize =  dir->i_sb->s_blocksize;
@@ -1455,7 +1461,7 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 	int	retval;
 	int	dx_fallback=0;
 	unsigned blocksize;
-	u32 block, blocks;
+	ext4_lblk_t block, blocks;
 
 	sb = dir->i_sb;
 	blocksize = sb->s_blocksize;
@@ -1532,7 +1538,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 		       dx_get_count(entries), dx_get_limit(entries)));
 	/* Need to split index? */
 	if (dx_get_count(entries) == dx_get_limit(entries)) {
-		u32 newblock;
+		ext4_lblk_t newblock;
 		unsigned icount = dx_get_count(entries);
 		int levels = frame - frames;
 		struct dx_entry *entries2;

fs/ext4/super.c

@@ -2914,7 +2914,7 @@ static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off)
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
-	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
 	int err = 0;
 	int offset = off & (sb->s_blocksize - 1);
 	int tocopy;
@@ -2952,7 +2952,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 				const char *data, size_t len, loff_t off)
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
-	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
 	int err = 0;
 	int offset = off & (sb->s_blocksize - 1);
 	int tocopy;

include/linux/ext4_fs.h

@@ -935,11 +935,14 @@ extern unsigned long ext4_count_free (struct buffer_head *, unsigned);
 /* inode.c */
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
 		struct buffer_head *bh, ext4_fsblk_t blocknr);
-struct buffer_head * ext4_getblk (handle_t *, struct inode *, long, int, int *);
-struct buffer_head * ext4_bread (handle_t *, struct inode *, int, int, int *);
+struct buffer_head *ext4_getblk(handle_t *, struct inode *,
+						ext4_lblk_t, int, int *);
+struct buffer_head *ext4_bread(handle_t *, struct inode *,
+						ext4_lblk_t, int, int *);
 int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
-	sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
-	int create, int extend_disksize);
+				ext4_lblk_t iblock, unsigned long maxblocks,
+				struct buffer_head *bh_result,
+				int create, int extend_disksize);
 
 extern void ext4_read_inode (struct inode *);
 extern int  ext4_write_inode (struct inode *, int);
@@ -1068,7 +1071,7 @@ extern const struct inode_operations ext4_fast_symlink_inode_operations;
 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
-			ext4_fsblk_t iblock,
+			ext4_lblk_t iblock,
 			unsigned long max_blocks, struct buffer_head *bh_result,
 			int create, int extend_disksize);
 extern void ext4_ext_truncate(struct inode *, struct page *);
@@ -1081,11 +1084,17 @@ ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 			unsigned long max_blocks, struct buffer_head *bh,
 			int create, int extend_disksize)
 {
-	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-		return ext4_ext_get_blocks(handle, inode, block, max_blocks,
-					bh, create, extend_disksize);
-	return ext4_get_blocks_handle(handle, inode, block, max_blocks, bh,
-					create, extend_disksize);
+	int retval;
+	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
+		retval = ext4_ext_get_blocks(handle, inode,
+						(ext4_lblk_t)block, max_blocks,
+						bh, create, extend_disksize);
+	} else {
+		retval = ext4_get_blocks_handle(handle, inode,
+						(ext4_lblk_t)block, max_blocks,
+						bh, create, extend_disksize);
+	}
+	return retval;
 }
 
 

include/linux/ext4_fs_extents.h

@@ -124,20 +124,6 @@ struct ext4_ext_path {
 #define EXT4_EXT_CACHE_GAP	1
 #define EXT4_EXT_CACHE_EXTENT	2
 
-/*
- * to be called by ext4_ext_walk_space()
- * negative retcode - error
- * positive retcode - signal for ext4_ext_walk_space(), see below
- * callback must return valid extent (passed or newly created)
- */
-typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *,
-					struct ext4_ext_cache *,
-					void *);
-
-#define EXT_CONTINUE	0
-#define EXT_BREAK	1
-#define EXT_REPEAT	2
-
 
 #define EXT_MAX_BLOCK	0xffffffff
 
@@ -233,8 +219,7 @@ extern int ext4_ext_try_to_merge(struct inode *inode,
 				 struct ext4_extent *);
 extern unsigned int ext4_ext_check_overlap(struct inode *, struct ext4_extent *, struct ext4_ext_path *);
 extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *);
-extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *);
-extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *);
-
+extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
+							struct ext4_ext_path *);
 #endif /* _LINUX_EXT4_EXTENTS */
 

include/linux/ext4_fs_i.h

@@ -27,6 +27,9 @@ typedef int ext4_grpblk_t;
 /* data type for filesystem-wide blocks number */
 typedef unsigned long long ext4_fsblk_t;
 
+/* data type for file logical block number */
+typedef __u32 ext4_lblk_t;
+
 struct ext4_reserve_window {
 	ext4_fsblk_t	_rsv_start;	/* First byte reserved */
 	ext4_fsblk_t	_rsv_end;	/* Last byte reserved or 0 */
@@ -48,7 +51,7 @@ struct ext4_block_alloc_info {
 	 * most-recently-allocated block in this file.
 	 * We use this for detecting linearly ascending allocation requests.
 	 */
-	__u32 last_alloc_logical_block;
+	ext4_lblk_t last_alloc_logical_block;
 	/*
 	 * Was i_next_alloc_goal in ext4_inode_info
 	 * is the *physical* companion to i_next_alloc_block.
@@ -67,7 +70,7 @@ struct ext4_block_alloc_info {
  */
 struct ext4_ext_cache {
 	ext4_fsblk_t	ec_start;
-	__u32		ec_block;
+	ext4_lblk_t	ec_block;
 	__u32		ec_len; /* must be 32bit to return holes */
 	__u32		ec_type;
 };
@@ -95,7 +98,7 @@ struct ext4_inode_info {
 	/* block reservation info */
 	struct ext4_block_alloc_info *i_block_alloc_info;
 
-	__u32	i_dir_start_lookup;
+	ext4_lblk_t		i_dir_start_lookup;
 #ifdef CONFIG_EXT4DEV_FS_XATTR
 	/*
 	 * Extended attributes can be read independently of the main file