/* vi: set sw=4 ts=4: */ /* * res_gdt.c --- reserve blocks for growing the group descriptor table * during online resizing. * * Copyright (C) 2002 Andreas Dilger * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */ #include <stdio.h> #include <string.h> #include <time.h> #include "ext2_fs.h" #include "ext2fs.h" /* * Iterate through the groups which hold BACKUP superblock/GDT copies in an * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before * calling this for the first time. In a sparse filesystem it will be the * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... */ static unsigned int list_backups(ext2_filsys fs, unsigned int *three, unsigned int *five, unsigned int *seven) { unsigned int *min = three; int mult = 3; unsigned int ret; if (!(fs->super->s_feature_ro_compat & EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) { ret = *min; *min += 1; return ret; } if (*five < *min) { min = five; mult = 5; } if (*seven < *min) { min = seven; mult = 7; } ret = *min; *min *= mult; return ret; } /* * This code assumes that the reserved blocks have already been marked in-use * during ext2fs_initialize(), so that they are not allocated for other * uses before we can add them to the resize inode (which has to come * after the creation of the inode table). */ errcode_t ext2fs_create_resize_inode(ext2_filsys fs) { errcode_t retval, retval2; struct ext2_super_block *sb; struct ext2_inode inode; __u32 *dindir_buf, *gdt_buf; int rsv_add; unsigned long long apb, inode_size; blk_t dindir_blk, rsv_off, gdt_off, gdt_blk; int dindir_dirty = 0, inode_dirty = 0; EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); sb = fs->super; retval = ext2fs_get_mem(2 * fs->blocksize, (void *)&dindir_buf); if (retval) goto out_free; gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize); retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode); if (retval) goto out_free; /* Maximum possible file size (we donly use the dindirect blocks) */ apb = EXT2_ADDR_PER_BLOCK(sb); rsv_add = fs->blocksize / 512; if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) { #ifdef RES_GDT_DEBUG printf("reading GDT dindir %u\n", dindir_blk); #endif retval = ext2fs_read_ind_block(fs, dindir_blk, dindir_buf); if (retval) goto out_inode; } else { blk_t goal = 3 + sb->s_reserved_gdt_blocks + fs->desc_blocks + fs->inode_blocks_per_group; retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk); if (retval) goto out_free; inode.i_mode = LINUX_S_IFREG | 0600; inode.i_links_count = 1; inode.i_block[EXT2_DIND_BLOCK] = dindir_blk; inode.i_blocks = rsv_add; memset(dindir_buf, 0, fs->blocksize); #ifdef RES_GDT_DEBUG printf("allocated GDT dindir %u\n", dindir_blk); #endif dindir_dirty = inode_dirty = 1; inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS; inode_size *= fs->blocksize; inode.i_size = inode_size & 0xFFFFFFFF; inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF; if (inode.i_size_high) { sb->s_feature_ro_compat |= EXT2_FEATURE_RO_COMPAT_LARGE_FILE; } inode.i_ctime = time(NULL); } for (rsv_off = 0, gdt_off = fs->desc_blocks, gdt_blk = sb->s_first_data_block + 1 + fs->desc_blocks; rsv_off < sb->s_reserved_gdt_blocks; rsv_off++, gdt_off++, gdt_blk++) { unsigned int three = 1, five = 5, seven = 7; unsigned int grp, last = 0; int gdt_dirty = 0; gdt_off %= apb; if (!dindir_buf[gdt_off]) { /* FIXME XXX XXX blk_t new_blk; retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk); if (retval) goto out_free; if (new_blk != gdt_blk) { // XXX free block retval = -1; // XXX } */ gdt_dirty = dindir_dirty = inode_dirty = 1; memset(gdt_buf, 0, fs->blocksize); dindir_buf[gdt_off] = gdt_blk; inode.i_blocks += rsv_add; #ifdef RES_GDT_DEBUG printf("added primary GDT block %u at %u[%u]\n", gdt_blk, dindir_blk, gdt_off); #endif } else if (dindir_buf[gdt_off] == gdt_blk) { #ifdef RES_GDT_DEBUG printf("reading primary GDT block %u\n", gdt_blk); #endif retval = ext2fs_read_ind_block(fs, gdt_blk, gdt_buf); if (retval) goto out_dindir; } else { #ifdef RES_GDT_DEBUG printf("bad primary GDT %u != %u at %u[%u]\n", dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off); #endif retval = EXT2_ET_RESIZE_INODE_CORRUPT; goto out_dindir; } while ((grp = list_backups(fs, &three, &five, &seven)) < fs->group_desc_count) { blk_t expect = gdt_blk + grp * sb->s_blocks_per_group; if (!gdt_buf[last]) { #ifdef RES_GDT_DEBUG printf("added backup GDT %u grp %u@%u[%u]\n", expect, grp, gdt_blk, last); #endif gdt_buf[last] = expect; inode.i_blocks += rsv_add; gdt_dirty = inode_dirty = 1; } else if (gdt_buf[last] != expect) { #ifdef RES_GDT_DEBUG printf("bad backup GDT %u != %u at %u[%u]\n", gdt_buf[last], expect, gdt_blk, last); #endif retval = EXT2_ET_RESIZE_INODE_CORRUPT; goto out_dindir; } last++; } if (gdt_dirty) { #ifdef RES_GDT_DEBUG printf("writing primary GDT block %u\n", gdt_blk); #endif retval = ext2fs_write_ind_block(fs, gdt_blk, gdt_buf); if (retval) goto out_dindir; } } out_dindir: if (dindir_dirty) { retval2 = ext2fs_write_ind_block(fs, dindir_blk, dindir_buf); if (!retval) retval = retval2; } out_inode: #ifdef RES_GDT_DEBUG printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks, inode.i_size); #endif if (inode_dirty) { inode.i_atime = inode.i_mtime = time(NULL); retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode); if (!retval) retval = retval2; } out_free: ext2fs_free_mem((void *)&dindir_buf); return retval; }