--- /dev/null
+/*
+ * Copyright (c) 2003,2004 Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
+ */
+
+#ifndef _LINUX_EXT3_EXTENTS
+#define _LINUX_EXT3_EXTENTS
+
+/*
+ * with AGRESSIVE_TEST defined capacity of index/leaf blocks
+ * become very little, so index split, in-depth growing and
+ * other hard changes happens much more often
+ * this is for debug purposes only
+ */
+#define AGRESSIVE_TEST_
+
+/*
+ * if CHECK_BINSEARCH defined, then results of binary search
+ * will be checked by linear search
+ */
+#define CHECK_BINSEARCH_
+
+/*
+ * if EXT_DEBUG is defined you can use 'extdebug' mount option
+ * to get lots of info what's going on
+ */
+//#define EXT_DEBUG
+#ifdef EXT_DEBUG
+#define ext_debug(tree,fmt,a...) \
+do { \
+ if (test_opt((tree)->inode->i_sb, EXTDEBUG)) \
+ printk(fmt, ##a); \
+} while (0);
+#else
+#define ext_debug(tree,fmt,a...)
+#endif
+
+/*
+ * if EXT_STATS is defined then stats numbers are collected
+ * these number will be displayed at umount time
+ */
+#define EXT_STATS_
+
+
+#define EXT3_ALLOC_NEEDED 3 /* block bitmap + group desc. + sb */
+
+/*
+ * ext3_inode has i_block array (total 60 bytes)
+ * first 4 bytes are used to store:
+ * - tree depth (0 mean there is no tree yet. all extents in the inode)
+ * - number of alive extents in the inode
+ */
+
+/*
+ * this is extent on-disk structure
+ * it's used at the bottom of the tree
+ */
+struct ext3_extent {
+ __u32 ee_block; /* first logical block extent covers */
+ __u16 ee_len; /* number of blocks covered by extent */
+ __u16 ee_start_hi; /* high 16 bits of physical block */
+ __u32 ee_start; /* low 32 bigs of physical block */
+};
+
+/*
+ * this is index on-disk structure
+ * it's used at all the levels, but the bottom
+ */
+struct ext3_extent_idx {
+ __u32 ei_block; /* index covers logical blocks from 'block' */
+ __u32 ei_leaf; /* pointer to the physical block of the next *
+ * level. leaf or next index could bet here */
+ __u16 ei_leaf_hi; /* high 16 bits of physical block */
+ __u16 ei_unused;
+};
+
+/*
+ * each block (leaves and indexes), even inode-stored has header
+ */
+struct ext3_extent_header {
+ __u16 eh_magic; /* probably will support different formats */
+ __u16 eh_entries; /* number of valid entries */
+ __u16 eh_max; /* capacity of store in entries */
+ __u16 eh_depth; /* has tree real underlaying blocks? */
+ __u32 eh_generation; /* generation of the tree */
+};
+
+#define EXT3_EXT_MAGIC 0xf30a
+
+/*
+ * array of ext3_ext_path contains path to some extent
+ * creation/lookup routines use it for traversal/splitting/etc
+ * truncate uses it to simulate recursive walking
+ */
+struct ext3_ext_path {
+ __u32 p_block;
+ __u16 p_depth;
+ struct ext3_extent *p_ext;
+ struct ext3_extent_idx *p_idx;
+ struct ext3_extent_header *p_hdr;
+ struct buffer_head *p_bh;
+};
+
+/*
+ * structure for external API
+ */
+
+#define EXT_CONTINUE 0
+#define EXT_BREAK 1
+#define EXT_REPEAT 2
+
+
+#define EXT_MAX_BLOCK 0xffffffff
+#define EXT_CACHE_MARK 0xffff
+
+
+#define EXT_FIRST_EXTENT(__hdr__) \
+ ((struct ext3_extent *) (((char *) (__hdr__)) + \
+ sizeof(struct ext3_extent_header)))
+#define EXT_FIRST_INDEX(__hdr__) \
+ ((struct ext3_extent_idx *) (((char *) (__hdr__)) + \
+ sizeof(struct ext3_extent_header)))
+#define EXT_HAS_FREE_INDEX(__path__) \
+ ((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max)
+#define EXT_LAST_EXTENT(__hdr__) \
+ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1)
+#define EXT_LAST_INDEX(__hdr__) \
+ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1)
+#define EXT_MAX_EXTENT(__hdr__) \
+ (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1)
+#define EXT_MAX_INDEX(__hdr__) \
+ (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1)
+
+#define EXT_ROOT_HDR(tree) \
+ ((struct ext3_extent_header *) (tree)->root)
+#define EXT_BLOCK_HDR(bh) \
+ ((struct ext3_extent_header *) (bh)->b_data)
+#define EXT_DEPTH(_t_) \
+ (((struct ext3_extent_header *)((_t_)->root))->eh_depth)
+#define EXT_GENERATION(_t_) \
+ (((struct ext3_extent_header *)((_t_)->root))->eh_generation)
+
+
+#define EXT_ASSERT(__x__) if (!(__x__)) BUG();
+
+
+/*
+ * this structure is used to gather extents from the tree via ioctl
+ */
+struct ext3_extent_buf {
+ unsigned long start;
+ int buflen;
+ void *buffer;
+ void *cur;
+ int err;
+};
+
+/*
+ * this structure is used to collect stats info about the tree
+ */
+struct ext3_extent_tree_stats {
+ int depth;
+ int extents_num;
+ int leaf_num;
+};
+
+#ifdef __KERNEL__
+/*
+ * ext3_extents_tree is used to pass initial information
+ * to top-level extents API
+ */
+struct ext3_extents_helpers;
+struct ext3_extents_tree {
+ struct inode *inode; /* inode which tree belongs to */
+ void *root; /* ptr to data top of tree resides at */
+ void *buffer; /* will be passed as arg to ^^ routines */
+ int buffer_len;
+ void *private;
+ struct ext3_extent *cex;/* last found extent */
+ struct ext3_extents_helpers *ops;
+};
+
+struct ext3_extents_helpers {
+ int (*get_write_access)(handle_t *h, void *buffer);
+ int (*mark_buffer_dirty)(handle_t *h, void *buffer);
+ int (*mergable)(struct ext3_extent *ex1, struct ext3_extent *ex2);
+ int (*remove_extent_credits)(struct ext3_extents_tree *,
+ struct ext3_extent *, unsigned long,
+ unsigned long);
+ int (*remove_extent)(struct ext3_extents_tree *,
+ struct ext3_extent *, unsigned long,
+ unsigned long);
+ int (*new_block)(handle_t *, struct ext3_extents_tree *,
+ struct ext3_ext_path *, struct ext3_extent *,
+ int *);
+};
+
+/*
+ * to be called by ext3_ext_walk_space()
+ * negative retcode - error
+ * positive retcode - signal for ext3_ext_walk_space(), see below
+ * callback must return valid extent (passed or newly created)
+ */
+typedef int (*ext_prepare_callback)(struct ext3_extents_tree *,
+ struct ext3_ext_path *,
+ struct ext3_extent *, int);
+void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *);
+extern int ext3_extent_tree_init(handle_t *, struct ext3_extents_tree *);
+extern int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *, struct ext3_ext_path *);
+extern int ext3_ext_insert_extent(handle_t *, struct ext3_extents_tree *, struct ext3_ext_path *, struct ext3_extent *);
+extern int ext3_ext_walk_space(struct ext3_extents_tree *, unsigned long, unsigned long, ext_prepare_callback);
+extern int ext3_ext_remove_space(struct ext3_extents_tree *, unsigned long, unsigned long);
+extern struct ext3_ext_path * ext3_ext_find_extent(struct ext3_extents_tree *, int, struct ext3_ext_path *);
+
+static inline void
+ext3_ext_invalidate_cache(struct ext3_extents_tree *tree)
+{
+ if (tree->cex)
+ tree->cex->ee_len = 0;
+}
+#endif /* __KERNEL__ */
+
+
+#endif /* _LINUX_EXT3_EXTENTS */
+
projects / thirdparty / e2fsprogs.git / commitdiff
