/* File block to disk block mapping routines. Copyright (C) 1995 Free Software Foundation, Inc. Converted to work under the hurd by Miles Bader This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. 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 License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* * linux/fs/ext2/inode.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Goal-directed block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993 */ #include #include "ext2fs.h" /* * ext2_discard_prealloc and ext2_alloc_block are atomic wrt. the * superblock in the same manner as are ext2_free_blocks and * ext2_new_block. We just wait on the super rather than locking it * here, since ext2_new_block will do the necessary locking and we * can't block until then. */ void ext2_discard_prealloc (struct node *node) { #ifdef EXT2_PREALLOCATE if (node->dn->info.i_prealloc_count) { int i = node->dn->info.i_prealloc_count; node->dn->info.i_prealloc_count = 0; ext2_free_blocks (node->dn->info.i_prealloc_block, i); } #endif } static int ext2_alloc_block (struct node *node, unsigned long goal) { #ifdef EXT2FS_DEBUG static unsigned long alloc_hits = 0, alloc_attempts = 0; #endif unsigned long result; char *bh; #ifdef EXT2_PREALLOCATE if (node->dn->info.i_prealloc_count && (goal == node->dn->info.i_prealloc_block || goal + 1 == node->dn->info.i_prealloc_block)) { result = node->dn->info.i_prealloc_block++; node->dn->info.i_prealloc_count--; ext2_debug ("preallocation hit (%lu/%lu).\n", ++alloc_hits, ++alloc_attempts); bh = bptr (result); memset (bh, 0, block_size); } else { ext2_discard_prealloc (node); ext2_debug ("preallocation miss (%lu/%lu).\n", alloc_hits, ++alloc_attempts); if (S_ISREG (node->dn_stat.st_mode)) result = ext2_new_block (goal, &node->dn->info.i_prealloc_count, &node->dn->info.i_prealloc_block); else result = ext2_new_block (goal, 0, 0); } #else result = ext2_new_block (goal, 0, 0); #endif return result; } static error_t inode_getblk (struct node *node, int nr, int create, int new_block, char **buf) { u32 block; int goal = 0, i; int blocks = block_size / 512; block = node->dn->info.i_data[nr]; if (block) { *buf = bptr (block); return 0; } if (!create) return EINVAL; if (node->dn->info.i_next_alloc_block == new_block) goal = node->dn->info.i_next_alloc_goal; ext2_debug ("hint = %d,", goal); if (!goal) { for (i = nr - 1; i >= 0; i--) { if (node->dn->info.i_data[i]) { goal = node->dn->info.i_data[i]; break; } } if (!goal) goal = (node->dn->info.i_block_group * EXT2_BLOCKS_PER_GROUP (sblock)) + sblock->s_first_data_block; } ext2_debug ("goal = %d.\n", goal); block = ext2_alloc_block (node, goal); if (!block) return EIO; *buf = bptr (block); node->dn->info.i_data[nr] = block; node->dn->info.i_next_alloc_block = new_block; node->dn->info.i_next_alloc_goal = block; node->dn_set_ctime = 1; node->dn_stat.st_blocks += blocks << log2_stat_blocks_per_fs_block; node->dn_stat_dirty = 1; if (diskfs_synchronous || node->dn->info.i_osync) diskfs_node_update (node, 1); return 0; } error_t block_getblk (struct node *node, char *bh, int nr, int create, int blocksize, int new_block, char **buf) { int i, goal = 0; u32 block; int blocks = block_size / 512; block = ((u32 *)bh)[nr]; if (block) { *buf = bptr (block); return 0; } if (!create) return EINVAL; if (node->dn->info.i_next_alloc_block == new_block) goal = node->dn->info.i_next_alloc_goal; if (!goal) { for (i = nr - 1; i >= 0; i--) { if (((u32 *) bh)[i]) { goal = ((u32 *) bh)[i]; break; } } if (!goal) goal = bptr_block (bh); } block = ext2_alloc_block (node, goal); if (!block) return EIO; /* XXX? */ *buf = bptr (block); ((u32 *)bh)[nr] = block; if (diskfs_synchronous || node->dn->info.i_osync) sync_global_ptr (bh, 1); else pokel_add (&node->dn->pokel, bh, block_size); node->dn_set_ctime = 1; node->dn->info.i_next_alloc_block = new_block; node->dn->info.i_next_alloc_goal = block; node->dn_stat.st_blocks += blocks << log2_stat_blocks_per_fs_block; node->dn_stat_dirty = 1; return 0; } /* Returns in BUF a pointer to the file block BLOCK in NODE. If there is no such block yet, but CREATE is true, then it is created, otherwise EINVAL is returned. */ error_t ext2_getblk (struct node *node, long block, int create, char **buf) { error_t err; char *bh; unsigned long b; unsigned long addr_per_block = EXT2_ADDR_PER_BLOCK (sblock); if (block < 0) { ext2_warning ("ext2_getblk", "block < 0"); return EIO; } if (block > EXT2_NDIR_BLOCKS + addr_per_block + addr_per_block * addr_per_block + addr_per_block * addr_per_block * addr_per_block) { ext2_warning ("ext2_getblk", "block > big"); return EIO; } /* * If this is a sequential block allocation, set the next_alloc_block * to this block now so that all the indblock and data block * allocations use the same goal zone */ ext2_debug ("block %lu, next %lu, goal %lu.\n", block, node->dn->info.i_next_alloc_block, node->dn->info.i_next_alloc_goal); if (block == node->dn->info.i_next_alloc_block + 1) { node->dn->info.i_next_alloc_block++; node->dn->info.i_next_alloc_goal++; } b = block; if (block < EXT2_NDIR_BLOCKS) return inode_getblk (node, block, create, b, buf); block -= EXT2_NDIR_BLOCKS; if (block < addr_per_block) { err = inode_getblk (node, EXT2_IND_BLOCK, create, b, &bh); if (!err) err= block_getblk (node, bh, block, create, block_size, b, buf); return err; } block -= addr_per_block; if (block < addr_per_block * addr_per_block) { err = inode_getblk (node, EXT2_DIND_BLOCK, create, b, &bh); if (!err) err = block_getblk (node, bh, block / addr_per_block, create, block_size, b, &bh); if (!err) err = block_getblk (node, bh, block & (addr_per_block - 1), create, block_size, b, buf); return err; } block -= addr_per_block * addr_per_block; err = inode_getblk (node, EXT2_TIND_BLOCK, create, b, &bh); if (!err) err = block_getblk (node, bh, block / (addr_per_block * addr_per_block), create, block_size, b, &bh); if (!err) err = block_getblk (node, bh, (block / addr_per_block) & (addr_per_block - 1), create, block_size, b, &bh); if (!err) err = block_getblk (node, bh, block & (addr_per_block - 1), create, block_size, b, buf); return err; }