static int find_group_other(struct super_block *sb, int parent_group) { int ngroups = sb->u.ext2_sb.s_groups_count; struct ext2_group_desc *desc; struct buffer_head *bh; int group, i; /* * Try to place the inode in its parent directory */ group = parent_group; desc = ext2_get_group_desc (sb, group, &bh); if (desc && le16_to_cpu(desc->bg_free_inodes_count)) goto found; /* * Use a quadratic hash to find a group with a * free inode */ for (i = 1; i < ngroups; i <<= 1) { group += i; if (group >= ngroups) group -= ngroups; desc = ext2_get_group_desc (sb, group, &bh); if (desc && le16_to_cpu(desc->bg_free_inodes_count)) goto found; } /* * That failed: try linear search for a free inode */ group = parent_group + 1; for (i = 2; i < ngroups; i++) { if (++group >= ngroups) group = 0; desc = ext2_get_group_desc (sb, group, &bh); if (desc && le16_to_cpu(desc->bg_free_inodes_count)) goto found; } return -1; found: desc->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) - 1); mark_buffer_dirty(bh); return group; }
/* alloc a new block */ int ext2_alloc_block ( unsigned int goal) { unsigned int block; unsigned int block_group; unsigned int bit; struct ext2_group_desc *desc; struct ext2_sb_info * sbi = EXT2_SBI(); void *bitmap; block_group = ext2_get_group_num (goal, BLOCK); bit = ext2_get_group_offset (goal, BLOCK); bitmap = ext2_read_block_bitmap (block_group); block = ext2_grab_block (bitmap, bit); if ( !block) ext2_error ("no free blocks any more"); desc = ext2_get_group_desc (block_group); desc->bg_free_blocks_count --; sbi->s_free_blocks_count --; ext2_set_bit (bitmap, block); return block; }
static struct buffer_head * read_block_bitmap(struct super_block *sb, unsigned int block_group) { struct ext2_group_desc * desc; struct buffer_head * bh = NULL; ext2_fsblk_t bitmap_blk; desc = ext2_get_group_desc(sb, block_group, NULL); if (!desc) return NULL; bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); bh = sb_getblk(sb, bitmap_blk); if (unlikely(!bh)) { ext2_error(sb, __func__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, le32_to_cpu(desc->bg_block_bitmap)); return NULL; } if (likely(bh_uptodate_or_lock(bh))) return bh; if (bh_submit_read(bh) < 0) { brelse(bh); ext2_error(sb, __func__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, le32_to_cpu(desc->bg_block_bitmap)); return NULL; } ext2_valid_block_bitmap(sb, desc, block_group, bh); return bh; }
static int find_group_dir(struct super_block *sb, int parent_group) { struct ext2_super_block * es = sb->u.ext2_sb.s_es; int ngroups = sb->u.ext2_sb.s_groups_count; int avefreei = le32_to_cpu(es->s_free_inodes_count) / ngroups; struct ext2_group_desc *desc, *best_desc = NULL; struct buffer_head *bh, *best_bh = NULL; int group, best_group = -1; for (group = 0; group < ngroups; group++) { desc = ext2_get_group_desc (sb, group, &bh); if (!desc || !desc->bg_free_inodes_count) continue; if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) continue; if (!best_desc || (le16_to_cpu(desc->bg_free_blocks_count) > le16_to_cpu(best_desc->bg_free_blocks_count))) { best_group = group; best_desc = desc; best_bh = bh; } } if (!best_desc) return -1; best_desc->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(best_desc->bg_free_inodes_count) - 1); best_desc->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(best_desc->bg_used_dirs_count) + 1); mark_buffer_dirty(best_bh); return best_group; }
/* * Read the inode allocation bitmap for a given block_group, reading * into the specified slot in the superblock's bitmap cache. * * Return >=0 on success or a -ve error code. */ static int read_inode_bitmap (struct super_block * sb, unsigned long block_group, unsigned int bitmap_nr) { struct ext2_group_desc * gdp; struct buffer_head * bh = NULL; int retval = 0; gdp = ext2_get_group_desc (sb, block_group, NULL); if (!gdp) { retval = -EIO; goto error_out; } bh = bread (sb->s_dev, le32_to_cpu(gdp->bg_inode_bitmap), sb->s_blocksize); if (!bh) { ext2_error (sb, "read_inode_bitmap", "Cannot read inode bitmap - " "block_group = %lu, inode_bitmap = %lu", block_group, (unsigned long) gdp->bg_inode_bitmap); retval = -EIO; } /* * On IO error, just leave a zero in the superblock's block pointer for * this group. The IO will be retried next time. */ error_out: sb->u.ext2_sb.s_inode_bitmap_number[bitmap_nr] = block_group; sb->u.ext2_sb.s_inode_bitmap[bitmap_nr] = bh; return retval; }
unsigned long ext2_count_free_inodes (struct super_block * sb) { #ifdef EXT2FS_DEBUG struct ext2_super_block * es; unsigned long desc_count = 0, bitmap_count = 0; int i; lock_super (sb); es = sb->u.ext2_sb.s_es; for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { struct ext2_group_desc *desc = ext2_get_group_desc (sb, i, NULL); struct buffer_head *bh; unsigned x; if (!desc) continue; desc_count += le16_to_cpu(desc->bg_free_inodes_count); bh = load_inode_bitmap (sb, i); if (IS_ERR(bh)) continue; x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8); printk ("group %d: stored = %d, counted = %lu\n", i, le16_to_cpu(desc->bg_free_inodes_count), x); bitmap_count += x; } printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); unlock_super (sb); return desc_count; #else return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_inodes_count); #endif }
/* Called at mount-time, super-block is locked */ void ext2_check_inodes_bitmap (struct super_block * sb) { struct ext2_super_block * es = sb->u.ext2_sb.s_es; unsigned long desc_count = 0, bitmap_count = 0; int i; for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { struct ext2_group_desc *desc = ext2_get_group_desc(sb, i, NULL); struct buffer_head *bh; unsigned x; if (!desc) continue; desc_count += le16_to_cpu(desc->bg_free_inodes_count); bh = load_inode_bitmap (sb, i); if (IS_ERR(bh)) continue; x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8); if (le16_to_cpu(desc->bg_free_inodes_count) != x) ext2_error (sb, "ext2_check_inodes_bitmap", "Wrong free inodes count in group %d, " "stored = %d, counted = %lu", i, le16_to_cpu(desc->bg_free_inodes_count), x); bitmap_count += x; } if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count) ext2_error (sb, "ext2_check_inodes_bitmap", "Wrong free inodes count in super block, " "stored = %lu, counted = %lu", (unsigned long)le32_to_cpu(es->s_free_inodes_count), bitmap_count); }
int ext2_get_inode(ext2_VOLUME* volume, unsigned int ino, struct ext2_inode *inode) { struct ext2_group_desc desc; unsigned int block; unsigned int group_id; unsigned int offset; struct ext2_inode *le_inode; int i; ino--; group_id = ino / EXT2_INODES_PER_GROUP(volume->super); ext2_get_group_desc(volume, group_id, &desc); ino %= EXT2_INODES_PER_GROUP(volume->super); block = desc.bg_inode_table; block += ino / (EXT2_BLOCK_SIZE(volume->super) / EXT2_INODE_SIZE(volume->super)); ext2_read_block(volume, block); offset = ino % (EXT2_BLOCK_SIZE(volume->super) / EXT2_INODE_SIZE(volume->super)); offset *= EXT2_INODE_SIZE(volume->super); le_inode = (struct ext2_inode *)(volume->buffer + offset); inode->i_mode = __le16_to_cpu(le_inode->i_mode); inode->i_uid = __le16_to_cpu(le_inode->i_uid); inode->i_size = __le32_to_cpu(le_inode->i_size); inode->i_atime = __le32_to_cpu(le_inode->i_atime); inode->i_ctime = __le32_to_cpu(le_inode->i_ctime); inode->i_mtime = __le32_to_cpu(le_inode->i_mtime); inode->i_dtime = __le32_to_cpu(le_inode->i_dtime); inode->i_gid = __le16_to_cpu(le_inode->i_gid); inode->i_links_count = __le16_to_cpu(le_inode->i_links_count); inode->i_blocks = __le32_to_cpu(le_inode->i_blocks); inode->i_flags = __le32_to_cpu(le_inode->i_flags); if (S_ISLNK(inode->i_mode)) { memcpy(inode->i_block, le_inode->i_block, EXT2_N_BLOCKS * 4); } else { for (i = 0; i < EXT2_N_BLOCKS; i++) inode->i_block[i] = __le32_to_cpu(le_inode->i_block[i]); } inode->i_generation = __le32_to_cpu(le_inode->i_generation); inode->i_file_acl = __le32_to_cpu(le_inode->i_file_acl); inode->i_dir_acl = __le32_to_cpu(le_inode->i_dir_acl); inode->i_faddr = __le32_to_cpu(le_inode->i_faddr); inode->osd2.linux2.l_i_frag = le_inode->osd2.linux2.l_i_frag; inode->osd2.linux2.l_i_fsize = le_inode->osd2.linux2.l_i_fsize; inode->osd2.linux2.l_i_uid_high = __le16_to_cpu(le_inode->osd2.linux2.l_i_uid_high); inode->osd2.linux2.l_i_gid_high = __le16_to_cpu(le_inode->osd2.linux2.l_i_gid_high); return 0; }
void ext2_free_block(struct nas *nas, uint32_t bit_returned) { /* Return a block by turning off its bitmap bit. */ int group; /* group number of bit_returned */ int bit; /* bit_returned number within its group */ struct ext2_gd *gd; struct ext2_file_info *fi; struct ext2_fs_info *fsi; fi = nas->fi->privdata; fsi = nas->fs->fsi; if (bit_returned >= fsi->e2sb.s_blocks_count || bit_returned < fsi->e2sb.s_first_data_block) { return; } /* At first search group, to which bit_returned belongs to * and figure out in what word bit is stored. */ group = (bit_returned - fsi->e2sb.s_first_data_block) / fsi->e2sb.s_blocks_per_group; bit = (bit_returned - fsi->e2sb.s_first_data_block) % fsi->e2sb.s_blocks_per_group; gd = ext2_get_group_desc(group, fsi); /* We might be buggy (No way! :P), so check if we deallocate * data block, but not control (system) block. * This should never happen. */ if (bit_returned == gd->inode_bitmap || bit_returned == gd->block_bitmap || (bit_returned >= gd->inode_table && bit_returned < (gd->inode_table + fsi->s_itb_per_group))) { return; } ext2_read_sector(nas, (char *) fi->f_buf, 1, gd->block_bitmap); if (ext2_unsetbit(b_bitmap(fi->f_buf), bit)) { return; /*Tried to free unused block*/ } ext2_write_sector(nas, (char *) fi->f_buf, 1, gd->block_bitmap); fsi->e2sb.s_free_blocks_count++; ext2_write_sblock(nas); gd->free_blocks_count++; ext2_write_gdblock(nas); if (bit_returned < fsi->s_bsearch) { fsi->s_bsearch = bit_returned; } }
static int ext2_check_descriptors(struct super_block *sb) { int i; struct ext2_sb_info *sbi = EXT2_SB(sb); ext2_debug ("Checking group descriptors"); for (i = 0; i < sbi->s_groups_count; i++) { struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL); ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i); ext2_fsblk_t last_block; if (i == sbi->s_groups_count - 1) last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1; else last_block = first_block + (EXT2_BLOCKS_PER_GROUP(sb) - 1); if (le32_to_cpu(gdp->bg_block_bitmap) < first_block || le32_to_cpu(gdp->bg_block_bitmap) > last_block) { ext2_error (sb, "ext2_check_descriptors", "Block bitmap for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap)); return 0; } if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block || le32_to_cpu(gdp->bg_inode_bitmap) > last_block) { ext2_error (sb, "ext2_check_descriptors", "Inode bitmap for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap)); return 0; } if (le32_to_cpu(gdp->bg_inode_table) < first_block || le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 > last_block) { ext2_error (sb, "ext2_check_descriptors", "Inode table for group %d" " not in group (block %lu)!", i, (unsigned long) le32_to_cpu(gdp->bg_inode_table)); return 0; } } return 1; }
/* * Read the bitmap for a given block_group, reading into the specified * slot in the superblock's bitmap cache. * */ void * ext2_read_block_bitmap(unsigned int block_group) { struct ext2_group_desc * desc; void * bitmap = NULL; desc = ext2_get_group_desc (block_group); if (!desc) goto error_out; bitmap = (void *)(EXT2_BITMAP_BUFFER + (block_group << 1) * EXT2_BLOCK_SIZE); if (!bitmap) ext2_error ("read_block_bitmap", "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, desc->bg_block_bitmap); error_out: return bitmap; }
/* * Read the inode allocation bitmap for a given block_group, reading * into the specified slot in the superblock's bitmap cache. * * Return buffer_head of bitmap on success or NULL. */ static struct buffer_head *read_inode_bitmap (struct super_block * sb, unsigned long block_group) { struct ext2_group_desc *desc; struct buffer_head *bh = NULL; desc = ext2_get_group_desc(sb, block_group, NULL); if (!desc) goto error_out; bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap)); if (!bh) ext2_error (sb, "read_inode_bitmap", "Cannot read inode bitmap - " "block_group = %lu, inode_bitmap = %lu", block_group, (unsigned long) desc->bg_inode_bitmap); error_out: return bh; }
/* free the goal block, clean it */ void ext2_free_block(unsigned int block) { unsigned int block_group; unsigned int bit; struct ext2_group_desc *desc; struct ext2_sb_info * sbi = EXT2_SBI(); void * bitmap; block_group = ext2_get_group_num (block, BLOCK); bit = ext2_get_group_offset (block, BLOCK); desc = ext2_get_group_desc (block_group); bitmap = ext2_read_block_bitmap (block_group); if ( !ext2_clear_bit(bitmap, bit) ) ext2_error("bit %d (%d) alread cleard", bit, block_group); desc->bg_free_blocks_count ++; sbi->s_free_blocks_count ++; }
void ext2_check_inodes_bitmap (struct super_block * sb) { struct ext2_super_block * es; unsigned long desc_count, bitmap_count, x; int bitmap_nr; struct ext2_group_desc * gdp; int i; lock_super (sb); es = sb->u.ext2_sb.s_es; desc_count = 0; bitmap_count = 0; gdp = NULL; for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { gdp = ext2_get_group_desc (sb, i, NULL); if (!gdp) continue; desc_count += le16_to_cpu(gdp->bg_free_inodes_count); bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) continue; x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr], EXT2_INODES_PER_GROUP(sb) / 8); if (le16_to_cpu(gdp->bg_free_inodes_count) != x) ext2_error (sb, "ext2_check_inodes_bitmap", "Wrong free inodes count in group %d, " "stored = %d, counted = %lu", i, le16_to_cpu(gdp->bg_free_inodes_count), x); bitmap_count += x; } if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count) ext2_error (sb, "ext2_check_inodes_bitmap", "Wrong free inodes count in super block, " "stored = %lu, counted = %lu", (unsigned long) le32_to_cpu(es->s_free_inodes_count), bitmap_count); unlock_super (sb); }
unsigned long ext2_count_free_inodes (struct super_block * sb) { #ifdef EXT2FS_DEBUG struct ext2_super_block * es; unsigned long desc_count, bitmap_count, x; int bitmap_nr; struct ext2_group_desc * gdp; int i; lock_super (sb); es = sb->u.ext2_sb.s_es; desc_count = 0; bitmap_count = 0; gdp = NULL; for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) { gdp = ext2_get_group_desc (sb, i, NULL); if (!gdp) continue; desc_count += le16_to_cpu(gdp->bg_free_inodes_count); bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) continue; x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr], EXT2_INODES_PER_GROUP(sb) / 8); printk ("group %d: stored = %d, counted = %lu\n", i, le16_to_cpu(gdp->bg_free_inodes_count), x); bitmap_count += x; } printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); unlock_super (sb); return desc_count; #else return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_inodes_count); #endif }
static const struct ext2_inode * ext2_get_inode(struct fs_info *fs, int inr) { const struct ext2_group_desc *desc; const char *data; uint32_t inode_group, inode_offset; uint32_t block_num, block_off; inr--; inode_group = inr / EXT2_INODES_PER_GROUP(fs); inode_offset = inr % EXT2_INODES_PER_GROUP(fs); desc = ext2_get_group_desc(fs, inode_group); if (!desc) return NULL; block_num = desc->bg_inode_table + inode_offset / EXT2_INODES_PER_BLOCK(fs); block_off = inode_offset % EXT2_INODES_PER_BLOCK(fs); data = get_cache(fs->fs_dev, block_num); return (const struct ext2_inode *) (data + block_off * EXT2_SB(fs)->s_inode_size); }
static uint32_t ext2_alloc_block_bit(struct nas *nas, uint32_t goal) { /* try to allocate near this block */ uint32_t block; /* allocated block */ int word; /* word in block bitmap */ uint32_t bit; int group; char update_bsearch = 0; int i; struct ext2_gd *gd; struct ext2_file_info *fi; struct ext2_fs_info *fsi; fi = nas->fi->privdata; fsi = nas->fs->fsi; block = NO_BLOCK; bit = -1; if (goal >= fsi->e2sb.s_blocks_count || (goal < fsi->e2sb.s_first_data_block && goal != 0)) { goal = fsi->s_bsearch; } if (goal <= fsi->s_bsearch) { /* No reason to search in a place with no free blocks */ goal = fsi->s_bsearch; update_bsearch = DIRTY; } /* Figure out where to start the bit search. */ word = ((goal - fsi->e2sb.s_first_data_block) % fsi->e2sb.s_blocks_per_group) / FS_BITCHUNK_BITS; /* Try to allocate block at any group starting from the goal's group. * First time goal's group is checked from the word=goal, after all * groups checked, it's checked again from word=0, that's why "i <=". */ group = (goal - fsi->e2sb.s_first_data_block) / fsi->e2sb.s_blocks_per_group; for (i = 0; i <= fsi->s_groups_count; i++, group++) { if (group >= fsi->s_groups_count) { group = 0; } gd = ext2_get_group_desc(group, fsi); if (gd->free_blocks_count == 0) { word = 0; continue; } ext2_read_sector(nas, fi->f_buf, 1, gd->block_bitmap); bit = ext2_setbit(b_bitmap(fi->f_buf), fsi->e2sb.s_blocks_per_group, word); if (-1 == bit) { if (0 == word) { /* allocator failed to allocate a bit in bitmap with free bits.*/ return 0; } else { word = 0; continue; } } block = fsi->e2sb.s_first_data_block + group * fsi->e2sb.s_blocks_per_group + bit; if (ext2_check_block_number(block, fsi, gd)) { return 0; } ext2_write_sector(nas, fi->f_buf, 1, gd->block_bitmap); fsi->e2sb.s_free_blocks_count--; ext2_write_sblock(nas); gd->free_blocks_count--; ext2_write_gdblock(nas); if (update_bsearch && block != -1 && block != NO_BLOCK) { /* We searched from the beginning, update bsearch. */ fsi->s_bsearch = block; } return block; } return block; }
/* * NOTE! When we get the inode, we're the only people * that have access to it, and as such there are no * race conditions we have to worry about. The inode * is not on the hash-lists, and it cannot be reached * through the filesystem because the directory entry * has been deleted earlier. * * HOWEVER: we must make sure that we get no aliases, * which means that we have to call "clear_inode()" * _before_ we mark the inode not in use in the inode * bitmaps. Otherwise a newly created file might use * the same inode number (not actually the same pointer * though), and then we'd have two inodes sharing the * same inode number and space on the harddisk. */ void ext2_free_inode (struct inode * inode) { struct super_block * sb = inode->i_sb; int is_directory; unsigned long ino; struct buffer_head * bh; struct buffer_head * bh2; unsigned long block_group; unsigned long bit; int bitmap_nr; struct ext2_group_desc * gdp; struct ext2_super_block * es; if (!inode->i_dev) { printk ("ext2_free_inode: inode has no device\n"); return; } if (inode->i_count > 1) { printk ("ext2_free_inode: inode has count=%d\n", inode->i_count); return; } if (inode->i_nlink) { printk ("ext2_free_inode: inode has nlink=%d\n", (int) inode->i_nlink); return; } if (!sb) { printk("ext2_free_inode: inode on nonexistent device\n"); return; } ino = inode->i_ino; ext2_debug ("freeing inode %lu\n", ino); /* * Note: we must free any quota before locking the superblock, * as writing the quota to disk may need the lock as well. */ DQUOT_FREE_INODE(sb, inode); DQUOT_DROP(inode); lock_super (sb); es = sb->u.ext2_sb.s_es; if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { ext2_error (sb, "free_inode", "reserved inode or nonexistent inode"); goto error_return; } block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb); bitmap_nr = load_inode_bitmap (sb, block_group); if (bitmap_nr < 0) goto error_return; bh = sb->u.ext2_sb.s_inode_bitmap[bitmap_nr]; is_directory = S_ISDIR(inode->i_mode); /* Do this BEFORE marking the inode not in use */ clear_inode (inode); /* Ok, now we can actually update the inode bitmaps.. */ if (!ext2_clear_bit (bit, bh->b_data)) ext2_warning (sb, "ext2_free_inode", "bit already cleared for inode %lu", ino); else { gdp = ext2_get_group_desc (sb, block_group, &bh2); if (gdp) { gdp->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) + 1); if (is_directory) gdp->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) - 1); } mark_buffer_dirty(bh2, 1); es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1); mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); } mark_buffer_dirty(bh, 1); if (sb->s_flags & MS_SYNCHRONOUS) { ll_rw_block (WRITE, 1, &bh); wait_on_buffer (bh); } sb->s_dirt = 1; error_return: unlock_super (sb); }
/* * There are two policies for allocating an inode. If the new inode is * a directory, then a forward search is made for a block group with both * free space and a low directory-to-inode ratio; if that fails, then of * the groups with above-average free space, that group with the fewest * directories already is chosen. * * For other inodes, search forward from the parent directory\'s block * group to find a free inode. */ struct inode * ext2_new_inode (const struct inode * dir, int mode, int * err) { struct super_block * sb; struct buffer_head * bh; struct buffer_head * bh2; int i, j, avefreei; struct inode * inode; int bitmap_nr; struct ext2_group_desc * gdp; struct ext2_group_desc * tmp; struct ext2_super_block * es; /* Cannot create files in a deleted directory */ if (!dir || !dir->i_nlink) { *err = -EPERM; return NULL; } inode = get_empty_inode (); if (!inode) { *err = -ENOMEM; return NULL; } sb = dir->i_sb; inode->i_sb = sb; inode->i_flags = 0; lock_super (sb); es = sb->u.ext2_sb.s_es; repeat: gdp = NULL; i=0; *err = -ENOSPC; if (S_ISDIR(mode)) { avefreei = le32_to_cpu(es->s_free_inodes_count) / sb->u.ext2_sb.s_groups_count; /* I am not yet convinced that this next bit is necessary. i = dir->u.ext2_i.i_block_group; for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) { tmp = ext2_get_group_desc (sb, i, &bh2); if (tmp && (le16_to_cpu(tmp->bg_used_dirs_count) << 8) < le16_to_cpu(tmp->bg_free_inodes_count)) { gdp = tmp; break; } else i = ++i % sb->u.ext2_sb.s_groups_count; } */ if (!gdp) { for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) { tmp = ext2_get_group_desc (sb, j, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count) && le16_to_cpu(tmp->bg_free_inodes_count) >= avefreei) { if (!gdp || (le16_to_cpu(tmp->bg_free_blocks_count) > le16_to_cpu(gdp->bg_free_blocks_count))) { i = j; gdp = tmp; } } } } } else { /* * Try to place the inode in its parent directory */ i = dir->u.ext2_i.i_block_group; tmp = ext2_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) gdp = tmp; else { /* * Use a quadratic hash to find a group with a * free inode */ for (j = 1; j < sb->u.ext2_sb.s_groups_count; j <<= 1) { i += j; if (i >= sb->u.ext2_sb.s_groups_count) i -= sb->u.ext2_sb.s_groups_count; tmp = ext2_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) { gdp = tmp; break; } } } if (!gdp) { /* * That failed: try linear search for a free inode */ i = dir->u.ext2_i.i_block_group + 1; for (j = 2; j < sb->u.ext2_sb.s_groups_count; j++) { if (++i >= sb->u.ext2_sb.s_groups_count) i = 0; tmp = ext2_get_group_desc (sb, i, &bh2); if (tmp && le16_to_cpu(tmp->bg_free_inodes_count)) { gdp = tmp; break; } } } } if (!gdp) { unlock_super (sb); iput(inode); return NULL; } bitmap_nr = load_inode_bitmap (sb, i); if (bitmap_nr < 0) { unlock_super (sb); iput(inode); *err = -EIO; return NULL; } bh = sb->u.ext2_sb.s_inode_bitmap[bitmap_nr]; if ((j = ext2_find_first_zero_bit ((unsigned long *) bh->b_data, EXT2_INODES_PER_GROUP(sb))) < EXT2_INODES_PER_GROUP(sb)) { if (ext2_set_bit (j, bh->b_data)) { ext2_warning (sb, "ext2_new_inode", "bit already set for inode %d", j); goto repeat; } mark_buffer_dirty(bh, 1); if (sb->s_flags & MS_SYNCHRONOUS) { ll_rw_block (WRITE, 1, &bh); wait_on_buffer (bh); } } else { if (le16_to_cpu(gdp->bg_free_inodes_count) != 0) { ext2_error (sb, "ext2_new_inode", "Free inodes count corrupted in group %d", i); unlock_super (sb); iput (inode); return NULL; } goto repeat; } j += i * EXT2_INODES_PER_GROUP(sb) + 1; if (j < EXT2_FIRST_INO(sb) || j > le32_to_cpu(es->s_inodes_count)) { ext2_error (sb, "ext2_new_inode", "reserved inode or inode > inodes count - " "block_group = %d,inode=%d", i, j); unlock_super (sb); iput (inode); return NULL; } gdp->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1); if (S_ISDIR(mode)) gdp->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1); mark_buffer_dirty(bh2, 1); es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) - 1); mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); sb->s_dirt = 1; inode->i_mode = mode; inode->i_sb = sb; inode->i_nlink = 1; inode->i_dev = sb->s_dev; inode->i_uid = current->fsuid; if (test_opt (sb, GRPID)) inode->i_gid = dir->i_gid; else if (dir->i_mode & S_ISGID) { inode->i_gid = dir->i_gid; if (S_ISDIR(mode)) mode |= S_ISGID; } else inode->i_gid = current->fsgid; inode->i_ino = j; inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->u.ext2_i.i_new_inode = 1; inode->u.ext2_i.i_flags = dir->u.ext2_i.i_flags; if (S_ISLNK(mode)) inode->u.ext2_i.i_flags &= ~(EXT2_IMMUTABLE_FL | EXT2_APPEND_FL); inode->u.ext2_i.i_faddr = 0; inode->u.ext2_i.i_frag_no = 0; inode->u.ext2_i.i_frag_size = 0; inode->u.ext2_i.i_file_acl = 0; inode->u.ext2_i.i_dir_acl = 0; inode->u.ext2_i.i_dtime = 0; inode->u.ext2_i.i_block_group = i; inode->i_op = NULL; if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL) inode->i_flags |= MS_SYNCHRONOUS; insert_inode_hash(inode); mark_inode_dirty(inode); inc_inode_version (inode, gdp, mode); unlock_super (sb); if(DQUOT_ALLOC_INODE(sb, inode)) { sb->dq_op->drop(inode); inode->i_nlink = 0; iput(inode); *err = -EDQUOT; return NULL; } ext2_debug ("allocating inode %lu\n", inode->i_ino); *err = 0; return inode; }
struct inode * ext2_new_inode (const struct inode * dir, int mode) { struct super_block * sb; struct buffer_head * bh; struct buffer_head * bh2; int group, i; ino_t ino; struct inode * inode; struct ext2_group_desc * desc; struct ext2_super_block * es; int err; sb = dir->i_sb; inode = new_inode(sb); if (!inode) return ERR_PTR(-ENOMEM); lock_super (sb); es = sb->u.ext2_sb.s_es; repeat: if (S_ISDIR(mode)) group = find_group_dir(sb, dir->u.ext2_i.i_block_group); else group = find_group_other(sb, dir->u.ext2_i.i_block_group); err = -ENOSPC; if (group == -1) goto fail; err = -EIO; bh = load_inode_bitmap (sb, group); if (IS_ERR(bh)) goto fail2; i = ext2_find_first_zero_bit ((unsigned long *) bh->b_data, EXT2_INODES_PER_GROUP(sb)); if (i >= EXT2_INODES_PER_GROUP(sb)) goto bad_count; ext2_set_bit (i, bh->b_data); mark_buffer_dirty(bh); if (sb->s_flags & MS_SYNCHRONOUS) { ll_rw_block (WRITE, 1, &bh); wait_on_buffer (bh); } ino = group * EXT2_INODES_PER_GROUP(sb) + i + 1; if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { ext2_error (sb, "ext2_new_inode", "reserved inode or inode > inodes count - " "block_group = %d,inode=%ld", group, ino); err = -EIO; goto fail2; } es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) - 1); mark_buffer_dirty(sb->u.ext2_sb.s_sbh); sb->s_dirt = 1; inode->i_uid = current->fsuid; if (test_opt (sb, GRPID)) inode->i_gid = dir->i_gid; else if (dir->i_mode & S_ISGID) { inode->i_gid = dir->i_gid; if (S_ISDIR(mode)) mode |= S_ISGID; } else inode->i_gid = current->fsgid; inode->i_mode = mode; inode->i_ino = ino; inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->u.ext2_i.i_new_inode = 1; inode->u.ext2_i.i_flags = dir->u.ext2_i.i_flags & ~EXT2_BTREE_FL; if (S_ISLNK(mode)) inode->u.ext2_i.i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL); inode->u.ext2_i.i_block_group = group; if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL) inode->i_flags |= S_SYNC; insert_inode_hash(inode); inode->i_generation = event++; mark_inode_dirty(inode); unlock_super (sb); if(DQUOT_ALLOC_INODE(inode)) { DQUOT_DROP(inode); inode->i_flags |= S_NOQUOTA; inode->i_nlink = 0; iput(inode); return ERR_PTR(-EDQUOT); } ext2_debug ("allocating inode %lu\n", inode->i_ino); return inode; fail2: desc = ext2_get_group_desc (sb, group, &bh2); desc->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1); if (S_ISDIR(mode)) desc->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1); mark_buffer_dirty(bh2); fail: unlock_super(sb); make_bad_inode(inode); iput(inode); return ERR_PTR(err); bad_count: ext2_error (sb, "ext2_new_inode", "Free inodes count corrupted in group %d", group); /* Is it really ENOSPC? */ err = -ENOSPC; if (sb->s_flags & MS_RDONLY) goto fail; desc = ext2_get_group_desc (sb, group, &bh2); desc->bg_free_inodes_count = 0; mark_buffer_dirty(bh2); goto repeat; }
/* * NOTE! When we get the inode, we're the only people * that have access to it, and as such there are no * race conditions we have to worry about. The inode * is not on the hash-lists, and it cannot be reached * through the filesystem because the directory entry * has been deleted earlier. * * HOWEVER: we must make sure that we get no aliases, * which means that we have to call "clear_inode()" * _before_ we mark the inode not in use in the inode * bitmaps. Otherwise a newly created file might use * the same inode number (not actually the same pointer * though), and then we'd have two inodes sharing the * same inode number and space on the harddisk. */ void ext2_free_inode (struct inode * inode) { struct super_block * sb = inode->i_sb; int is_directory; unsigned long ino; struct buffer_head * bh; struct buffer_head * bh2; unsigned long block_group; unsigned long bit; struct ext2_group_desc * desc; struct ext2_super_block * es; ino = inode->i_ino; ext2_debug ("freeing inode %lu\n", ino); /* * Note: we must free any quota before locking the superblock, * as writing the quota to disk may need the lock as well. */ if (!is_bad_inode(inode)) { /* Quota is already initialized in iput() */ DQUOT_FREE_INODE(inode); DQUOT_DROP(inode); } lock_super (sb); es = sb->u.ext2_sb.s_es; is_directory = S_ISDIR(inode->i_mode); /* Do this BEFORE marking the inode not in use or returning an error */ clear_inode (inode); if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { ext2_error (sb, "ext2_free_inode", "reserved or nonexistent inode %lu", ino); goto error_return; } block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb); bh = load_inode_bitmap (sb, block_group); if (IS_ERR(bh)) goto error_return; /* Ok, now we can actually update the inode bitmaps.. */ if (!ext2_clear_bit (bit, bh->b_data)) ext2_error (sb, "ext2_free_inode", "bit already cleared for inode %lu", ino); else { desc = ext2_get_group_desc (sb, block_group, &bh2); if (desc) { desc->bg_free_inodes_count = cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1); if (is_directory) desc->bg_used_dirs_count = cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1); } mark_buffer_dirty(bh2); es->s_free_inodes_count = cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1); mark_buffer_dirty(sb->u.ext2_sb.s_sbh); } mark_buffer_dirty(bh); if (sb->s_flags & MS_SYNCHRONOUS) { ll_rw_block (WRITE, 1, &bh); wait_on_buffer (bh); } sb->s_dirt = 1; error_return: unlock_super (sb); }