/* * Copyright (c) 2003,2004 Cluster File Systems, Inc, info@clusterfs.com * Written by Alex Tomas * * 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 */