diff options
Diffstat (limited to 'kernel/fs/ext3/ialloc.c')
| -rw-r--r-- | kernel/fs/ext3/ialloc.c | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/kernel/fs/ext3/ialloc.c b/kernel/fs/ext3/ialloc.c new file mode 100644 index 000000000..3ad242e58 --- /dev/null +++ b/kernel/fs/ext3/ialloc.c @@ -0,0 +1,706 @@ +/* + * linux/fs/ext3/ialloc.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) + * + * BSD ufs-inspired inode and directory allocation by + * Stephen Tweedie (sct@redhat.com), 1993 + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + */ + +#include <linux/quotaops.h> +#include <linux/random.h> + +#include "ext3.h" +#include "xattr.h" +#include "acl.h" + +/* + * ialloc.c contains the inodes allocation and deallocation routines + */ + +/* + * The free inodes are managed by bitmaps. A file system contains several + * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap + * block for inodes, N blocks for the inode table and data blocks. + * + * The file system contains group descriptors which are located after the + * super block. Each descriptor contains the number of the bitmap block and + * the free blocks count in the block. + */ + + +/* + * 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 ext3_group_desc *desc; + struct buffer_head *bh = NULL; + + desc = ext3_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) + ext3_error(sb, "read_inode_bitmap", + "Cannot read inode bitmap - " + "block_group = %lu, inode_bitmap = %u", + block_group, le32_to_cpu(desc->bg_inode_bitmap)); +error_out: + return bh; +} + +/* + * 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 ext3_free_inode (handle_t *handle, struct inode * inode) +{ + struct super_block * sb = inode->i_sb; + int is_directory; + unsigned long ino; + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *bh2; + unsigned long block_group; + unsigned long bit; + struct ext3_group_desc * gdp; + struct ext3_super_block * es; + struct ext3_sb_info *sbi; + int fatal = 0, err; + + if (atomic_read(&inode->i_count) > 1) { + printk ("ext3_free_inode: inode has count=%d\n", + atomic_read(&inode->i_count)); + return; + } + if (inode->i_nlink) { + printk ("ext3_free_inode: inode has nlink=%d\n", + inode->i_nlink); + return; + } + if (!sb) { + printk("ext3_free_inode: inode on nonexistent device\n"); + return; + } + sbi = EXT3_SB(sb); + + ino = inode->i_ino; + ext3_debug ("freeing inode %lu\n", ino); + trace_ext3_free_inode(inode); + + is_directory = S_ISDIR(inode->i_mode); + + es = EXT3_SB(sb)->s_es; + if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { + ext3_error (sb, "ext3_free_inode", + "reserved or nonexistent inode %lu", ino); + goto error_return; + } + block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); + bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb); + bitmap_bh = read_inode_bitmap(sb, block_group); + if (!bitmap_bh) + goto error_return; + + BUFFER_TRACE(bitmap_bh, "get_write_access"); + fatal = ext3_journal_get_write_access(handle, bitmap_bh); + if (fatal) + goto error_return; + + /* Ok, now we can actually update the inode bitmaps.. */ + if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group), + bit, bitmap_bh->b_data)) + ext3_error (sb, "ext3_free_inode", + "bit already cleared for inode %lu", ino); + else { + gdp = ext3_get_group_desc (sb, block_group, &bh2); + + BUFFER_TRACE(bh2, "get_write_access"); + fatal = ext3_journal_get_write_access(handle, bh2); + if (fatal) goto error_return; + + if (gdp) { + spin_lock(sb_bgl_lock(sbi, block_group)); + le16_add_cpu(&gdp->bg_free_inodes_count, 1); + if (is_directory) + le16_add_cpu(&gdp->bg_used_dirs_count, -1); + spin_unlock(sb_bgl_lock(sbi, block_group)); + percpu_counter_inc(&sbi->s_freeinodes_counter); + if (is_directory) + percpu_counter_dec(&sbi->s_dirs_counter); + + } + BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata"); + err = ext3_journal_dirty_metadata(handle, bh2); + if (!fatal) fatal = err; + } + BUFFER_TRACE(bitmap_bh, "call ext3_journal_dirty_metadata"); + err = ext3_journal_dirty_metadata(handle, bitmap_bh); + if (!fatal) + fatal = err; + +error_return: + brelse(bitmap_bh); + ext3_std_error(sb, fatal); +} + +/* + * Orlov's allocator for directories. + * + * We always try to spread first-level directories. + * + * If there are blockgroups with both free inodes and free blocks counts + * not worse than average we return one with smallest directory count. + * Otherwise we simply return a random group. + * + * For the rest rules look so: + * + * It's OK to put directory into a group unless + * it has too many directories already (max_dirs) or + * it has too few free inodes left (min_inodes) or + * it has too few free blocks left (min_blocks). + * Parent's group is preferred, if it doesn't satisfy these + * conditions we search cyclically through the rest. If none + * of the groups look good we just look for a group with more + * free inodes than average (starting at parent's group). + * + * Debt is incremented each time we allocate a directory and decremented + * when we allocate an inode, within 0--255. + */ + +static int find_group_orlov(struct super_block *sb, struct inode *parent) +{ + int parent_group = EXT3_I(parent)->i_block_group; + struct ext3_sb_info *sbi = EXT3_SB(sb); + int ngroups = sbi->s_groups_count; + int inodes_per_group = EXT3_INODES_PER_GROUP(sb); + unsigned int freei, avefreei; + ext3_fsblk_t freeb, avefreeb; + unsigned int ndirs; + int max_dirs, min_inodes; + ext3_grpblk_t min_blocks; + int group = -1, i; + struct ext3_group_desc *desc; + + freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); + avefreei = freei / ngroups; + freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter); + avefreeb = freeb / ngroups; + ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); + + if ((parent == d_inode(sb->s_root)) || + (EXT3_I(parent)->i_flags & EXT3_TOPDIR_FL)) { + int best_ndir = inodes_per_group; + int best_group = -1; + + group = prandom_u32(); + parent_group = (unsigned)group % ngroups; + for (i = 0; i < ngroups; i++) { + group = (parent_group + i) % ngroups; + desc = ext3_get_group_desc (sb, group, NULL); + if (!desc || !desc->bg_free_inodes_count) + continue; + if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir) + continue; + if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei) + continue; + if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb) + continue; + best_group = group; + best_ndir = le16_to_cpu(desc->bg_used_dirs_count); + } + if (best_group >= 0) + return best_group; + goto fallback; + } + + max_dirs = ndirs / ngroups + inodes_per_group / 16; + min_inodes = avefreei - inodes_per_group / 4; + min_blocks = avefreeb - EXT3_BLOCKS_PER_GROUP(sb) / 4; + + for (i = 0; i < ngroups; i++) { + group = (parent_group + i) % ngroups; + desc = ext3_get_group_desc (sb, group, NULL); + if (!desc || !desc->bg_free_inodes_count) + continue; + if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs) + continue; + if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes) + continue; + if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks) + continue; + return group; + } + +fallback: + for (i = 0; i < ngroups; i++) { + group = (parent_group + i) % ngroups; + desc = ext3_get_group_desc (sb, group, NULL); + if (!desc || !desc->bg_free_inodes_count) + continue; + if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei) + return group; + } + + if (avefreei) { + /* + * The free-inodes counter is approximate, and for really small + * filesystems the above test can fail to find any blockgroups + */ + avefreei = 0; + goto fallback; + } + + return -1; +} + +static int find_group_other(struct super_block *sb, struct inode *parent) +{ + int parent_group = EXT3_I(parent)->i_block_group; + int ngroups = EXT3_SB(sb)->s_groups_count; + struct ext3_group_desc *desc; + int group, i; + + /* + * Try to place the inode in its parent directory + */ + group = parent_group; + desc = ext3_get_group_desc (sb, group, NULL); + if (desc && le16_to_cpu(desc->bg_free_inodes_count) && + le16_to_cpu(desc->bg_free_blocks_count)) + return group; + + /* + * We're going to place this inode in a different blockgroup from its + * parent. We want to cause files in a common directory to all land in + * the same blockgroup. But we want files which are in a different + * directory which shares a blockgroup with our parent to land in a + * different blockgroup. + * + * So add our directory's i_ino into the starting point for the hash. + */ + group = (group + parent->i_ino) % ngroups; + + /* + * Use a quadratic hash to find a group with a free inode and some free + * blocks. + */ + for (i = 1; i < ngroups; i <<= 1) { + group += i; + if (group >= ngroups) + group -= ngroups; + desc = ext3_get_group_desc (sb, group, NULL); + if (desc && le16_to_cpu(desc->bg_free_inodes_count) && + le16_to_cpu(desc->bg_free_blocks_count)) + return group; + } + + /* + * That failed: try linear search for a free inode, even if that group + * has no free blocks. + */ + group = parent_group; + for (i = 0; i < ngroups; i++) { + if (++group >= ngroups) + group = 0; + desc = ext3_get_group_desc (sb, group, NULL); + if (desc && le16_to_cpu(desc->bg_free_inodes_count)) + return group; + } + + return -1; +} + +/* + * 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 *ext3_new_inode(handle_t *handle, struct inode * dir, + const struct qstr *qstr, umode_t mode) +{ + struct super_block *sb; + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *bh2; + int group; + unsigned long ino = 0; + struct inode * inode; + struct ext3_group_desc * gdp = NULL; + struct ext3_super_block * es; + struct ext3_inode_info *ei; + struct ext3_sb_info *sbi; + int err = 0; + struct inode *ret; + int i; + + /* Cannot create files in a deleted directory */ + if (!dir || !dir->i_nlink) + return ERR_PTR(-EPERM); + + sb = dir->i_sb; + trace_ext3_request_inode(dir, mode); + inode = new_inode(sb); + if (!inode) + return ERR_PTR(-ENOMEM); + ei = EXT3_I(inode); + + sbi = EXT3_SB(sb); + es = sbi->s_es; + if (S_ISDIR(mode)) + group = find_group_orlov(sb, dir); + else + group = find_group_other(sb, dir); + + err = -ENOSPC; + if (group == -1) + goto out; + + for (i = 0; i < sbi->s_groups_count; i++) { + err = -EIO; + + gdp = ext3_get_group_desc(sb, group, &bh2); + if (!gdp) + goto fail; + + brelse(bitmap_bh); + bitmap_bh = read_inode_bitmap(sb, group); + if (!bitmap_bh) + goto fail; + + ino = 0; + +repeat_in_this_group: + ino = ext3_find_next_zero_bit((unsigned long *) + bitmap_bh->b_data, EXT3_INODES_PER_GROUP(sb), ino); + if (ino < EXT3_INODES_PER_GROUP(sb)) { + + BUFFER_TRACE(bitmap_bh, "get_write_access"); + err = ext3_journal_get_write_access(handle, bitmap_bh); + if (err) + goto fail; + + if (!ext3_set_bit_atomic(sb_bgl_lock(sbi, group), + ino, bitmap_bh->b_data)) { + /* we won it */ + BUFFER_TRACE(bitmap_bh, + "call ext3_journal_dirty_metadata"); + err = ext3_journal_dirty_metadata(handle, + bitmap_bh); + if (err) + goto fail; + goto got; + } + /* we lost it */ + journal_release_buffer(handle, bitmap_bh); + + if (++ino < EXT3_INODES_PER_GROUP(sb)) + goto repeat_in_this_group; + } + + /* + * This case is possible in concurrent environment. It is very + * rare. We cannot repeat the find_group_xxx() call because + * that will simply return the same blockgroup, because the + * group descriptor metadata has not yet been updated. + * So we just go onto the next blockgroup. + */ + if (++group == sbi->s_groups_count) + group = 0; + } + err = -ENOSPC; + goto out; + +got: + ino += group * EXT3_INODES_PER_GROUP(sb) + 1; + if (ino < EXT3_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { + ext3_error (sb, "ext3_new_inode", + "reserved inode or inode > inodes count - " + "block_group = %d, inode=%lu", group, ino); + err = -EIO; + goto fail; + } + + BUFFER_TRACE(bh2, "get_write_access"); + err = ext3_journal_get_write_access(handle, bh2); + if (err) goto fail; + spin_lock(sb_bgl_lock(sbi, group)); + le16_add_cpu(&gdp->bg_free_inodes_count, -1); + if (S_ISDIR(mode)) { + le16_add_cpu(&gdp->bg_used_dirs_count, 1); + } + spin_unlock(sb_bgl_lock(sbi, group)); + BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata"); + err = ext3_journal_dirty_metadata(handle, bh2); + if (err) goto fail; + + percpu_counter_dec(&sbi->s_freeinodes_counter); + if (S_ISDIR(mode)) + percpu_counter_inc(&sbi->s_dirs_counter); + + + if (test_opt(sb, GRPID)) { + inode->i_mode = mode; + inode->i_uid = current_fsuid(); + inode->i_gid = dir->i_gid; + } else + inode_init_owner(inode, dir, mode); + + inode->i_ino = ino; + /* 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_SEC; + + memset(ei->i_data, 0, sizeof(ei->i_data)); + ei->i_dir_start_lookup = 0; + ei->i_disksize = 0; + + ei->i_flags = + ext3_mask_flags(mode, EXT3_I(dir)->i_flags & EXT3_FL_INHERITED); +#ifdef EXT3_FRAGMENTS + ei->i_faddr = 0; + ei->i_frag_no = 0; + ei->i_frag_size = 0; +#endif + ei->i_file_acl = 0; + ei->i_dir_acl = 0; + ei->i_dtime = 0; + ei->i_block_alloc_info = NULL; + ei->i_block_group = group; + + ext3_set_inode_flags(inode); + if (IS_DIRSYNC(inode)) + handle->h_sync = 1; + if (insert_inode_locked(inode) < 0) { + /* + * Likely a bitmap corruption causing inode to be allocated + * twice. + */ + err = -EIO; + goto fail; + } + spin_lock(&sbi->s_next_gen_lock); + inode->i_generation = sbi->s_next_generation++; + spin_unlock(&sbi->s_next_gen_lock); + + ei->i_state_flags = 0; + ext3_set_inode_state(inode, EXT3_STATE_NEW); + + /* See comment in ext3_iget for explanation */ + if (ino >= EXT3_FIRST_INO(sb) + 1 && + EXT3_INODE_SIZE(sb) > EXT3_GOOD_OLD_INODE_SIZE) { + ei->i_extra_isize = + sizeof(struct ext3_inode) - EXT3_GOOD_OLD_INODE_SIZE; + } else { + ei->i_extra_isize = 0; + } + + ret = inode; + dquot_initialize(inode); + err = dquot_alloc_inode(inode); + if (err) + goto fail_drop; + + err = ext3_init_acl(handle, inode, dir); + if (err) + goto fail_free_drop; + + err = ext3_init_security(handle, inode, dir, qstr); + if (err) + goto fail_free_drop; + + err = ext3_mark_inode_dirty(handle, inode); + if (err) { + ext3_std_error(sb, err); + goto fail_free_drop; + } + + ext3_debug("allocating inode %lu\n", inode->i_ino); + trace_ext3_allocate_inode(inode, dir, mode); + goto really_out; +fail: + ext3_std_error(sb, err); +out: + iput(inode); + ret = ERR_PTR(err); +really_out: + brelse(bitmap_bh); + return ret; + +fail_free_drop: + dquot_free_inode(inode); + +fail_drop: + dquot_drop(inode); + inode->i_flags |= S_NOQUOTA; + clear_nlink(inode); + unlock_new_inode(inode); + iput(inode); + brelse(bitmap_bh); + return ERR_PTR(err); +} + +/* Verify that we are loading a valid orphan from disk */ +struct inode *ext3_orphan_get(struct super_block *sb, unsigned long ino) +{ + unsigned long max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count); + unsigned long block_group; + int bit; + struct buffer_head *bitmap_bh; + struct inode *inode = NULL; + long err = -EIO; + + /* Error cases - e2fsck has already cleaned up for us */ + if (ino > max_ino) { + ext3_warning(sb, __func__, + "bad orphan ino %lu! e2fsck was run?", ino); + goto error; + } + + block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); + bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb); + bitmap_bh = read_inode_bitmap(sb, block_group); + if (!bitmap_bh) { + ext3_warning(sb, __func__, + "inode bitmap error for orphan %lu", ino); + goto error; + } + + /* Having the inode bit set should be a 100% indicator that this + * is a valid orphan (no e2fsck run on fs). Orphans also include + * inodes that were being truncated, so we can't check i_nlink==0. + */ + if (!ext3_test_bit(bit, bitmap_bh->b_data)) + goto bad_orphan; + + inode = ext3_iget(sb, ino); + if (IS_ERR(inode)) + goto iget_failed; + + /* + * If the orphans has i_nlinks > 0 then it should be able to be + * truncated, otherwise it won't be removed from the orphan list + * during processing and an infinite loop will result. + */ + if (inode->i_nlink && !ext3_can_truncate(inode)) + goto bad_orphan; + + if (NEXT_ORPHAN(inode) > max_ino) + goto bad_orphan; + brelse(bitmap_bh); + return inode; + +iget_failed: + err = PTR_ERR(inode); + inode = NULL; +bad_orphan: + ext3_warning(sb, __func__, + "bad orphan inode %lu! e2fsck was run?", ino); + printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%llu) = %d\n", + bit, (unsigned long long)bitmap_bh->b_blocknr, + ext3_test_bit(bit, bitmap_bh->b_data)); + printk(KERN_NOTICE "inode=%p\n", inode); + if (inode) { + printk(KERN_NOTICE "is_bad_inode(inode)=%d\n", + is_bad_inode(inode)); + printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n", + NEXT_ORPHAN(inode)); + printk(KERN_NOTICE "max_ino=%lu\n", max_ino); + printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink); + /* Avoid freeing blocks if we got a bad deleted inode */ + if (inode->i_nlink == 0) + inode->i_blocks = 0; + iput(inode); + } + brelse(bitmap_bh); +error: + return ERR_PTR(err); +} + +unsigned long ext3_count_free_inodes (struct super_block * sb) +{ + unsigned long desc_count; + struct ext3_group_desc *gdp; + int i; +#ifdef EXT3FS_DEBUG + struct ext3_super_block *es; + unsigned long bitmap_count, x; + struct buffer_head *bitmap_bh = NULL; + + es = EXT3_SB(sb)->s_es; + desc_count = 0; + bitmap_count = 0; + gdp = NULL; + for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) { + gdp = ext3_get_group_desc (sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_inodes_count); + brelse(bitmap_bh); + bitmap_bh = read_inode_bitmap(sb, i); + if (!bitmap_bh) + continue; + + x = ext3_count_free(bitmap_bh, EXT3_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; + } + brelse(bitmap_bh); + printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n", + le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); + return desc_count; +#else + desc_count = 0; + for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) { + gdp = ext3_get_group_desc (sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_inodes_count); + cond_resched(); + } + return desc_count; +#endif +} + +/* Called at mount-time, super-block is locked */ +unsigned long ext3_count_dirs (struct super_block * sb) +{ + unsigned long count = 0; + int i; + + for (i = 0; i < EXT3_SB(sb)->s_groups_count; i++) { + struct ext3_group_desc *gdp = ext3_get_group_desc (sb, i, NULL); + if (!gdp) + continue; + count += le16_to_cpu(gdp->bg_used_dirs_count); + } + return count; +} + |