+++ /dev/null
-/*
- * 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;
-}
-
Code Review / kvmfornfv.git / blobdiff