diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ext2/ialloc.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ext2/ialloc.c | 677 |
1 files changed, 0 insertions, 677 deletions
diff --git a/ANDROID_3.4.5/fs/ext2/ialloc.c b/ANDROID_3.4.5/fs/ext2/ialloc.c deleted file mode 100644 index 8b15cf8c..00000000 --- a/ANDROID_3.4.5/fs/ext2/ialloc.c +++ /dev/null @@ -1,677 +0,0 @@ -/* - * linux/fs/ext2/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@dcs.ed.ac.uk), 1993 - * Big-endian to little-endian byte-swapping/bitmaps by - * David S. Miller (davem@caip.rutgers.edu), 1995 - */ - -#include <linux/quotaops.h> -#include <linux/sched.h> -#include <linux/backing-dev.h> -#include <linux/buffer_head.h> -#include <linux/random.h> -#include "ext2.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 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 = %u", - block_group, le32_to_cpu(desc->bg_inode_bitmap)); -error_out: - return bh; -} - -static void ext2_release_inode(struct super_block *sb, int group, int dir) -{ - struct ext2_group_desc * desc; - struct buffer_head *bh; - - desc = ext2_get_group_desc(sb, group, &bh); - if (!desc) { - ext2_error(sb, "ext2_release_inode", - "can't get descriptor for group %d", group); - return; - } - - spin_lock(sb_bgl_lock(EXT2_SB(sb), group)); - le16_add_cpu(&desc->bg_free_inodes_count, 1); - if (dir) - le16_add_cpu(&desc->bg_used_dirs_count, -1); - spin_unlock(sb_bgl_lock(EXT2_SB(sb), group)); - if (dir) - percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter); - sb->s_dirt = 1; - mark_buffer_dirty(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 ext2_free_inode (struct inode * inode) -{ - struct super_block * sb = inode->i_sb; - int is_directory; - unsigned long ino; - struct buffer_head *bitmap_bh; - unsigned long block_group; - unsigned long bit; - 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. - */ - /* Quota is already initialized in iput() */ - ext2_xattr_delete_inode(inode); - dquot_free_inode(inode); - dquot_drop(inode); - - es = EXT2_SB(sb)->s_es; - is_directory = S_ISDIR(inode->i_mode); - - 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); - return; - } - block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); - bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb); - bitmap_bh = read_inode_bitmap(sb, block_group); - if (!bitmap_bh) - return; - - /* Ok, now we can actually update the inode bitmaps.. */ - if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group), - bit, (void *) bitmap_bh->b_data)) - ext2_error (sb, "ext2_free_inode", - "bit already cleared for inode %lu", ino); - else - ext2_release_inode(sb, block_group, is_directory); - mark_buffer_dirty(bitmap_bh); - if (sb->s_flags & MS_SYNCHRONOUS) - sync_dirty_buffer(bitmap_bh); - - brelse(bitmap_bh); -} - -/* - * We perform asynchronous prereading of the new inode's inode block when - * we create the inode, in the expectation that the inode will be written - * back soon. There are two reasons: - * - * - When creating a large number of files, the async prereads will be - * nicely merged into large reads - * - When writing out a large number of inodes, we don't need to keep on - * stalling the writes while we read the inode block. - * - * FIXME: ext2_get_group_desc() needs to be simplified. - */ -static void ext2_preread_inode(struct inode *inode) -{ - unsigned long block_group; - unsigned long offset; - unsigned long block; - struct ext2_group_desc * gdp; - struct backing_dev_info *bdi; - - bdi = inode->i_mapping->backing_dev_info; - if (bdi_read_congested(bdi)) - return; - if (bdi_write_congested(bdi)) - return; - - block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); - gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL); - if (gdp == NULL) - return; - - /* - * Figure out the offset within the block group inode table - */ - offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) * - EXT2_INODE_SIZE(inode->i_sb); - block = le32_to_cpu(gdp->bg_inode_table) + - (offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb)); - sb_breadahead(inode->i_sb, block); -} - -/* - * 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. - */ -static int find_group_dir(struct super_block *sb, struct inode *parent) -{ - int ngroups = EXT2_SB(sb)->s_groups_count; - int avefreei = ext2_count_free_inodes(sb) / ngroups; - struct ext2_group_desc *desc, *best_desc = NULL; - int group, best_group = -1; - - for (group = 0; group < ngroups; group++) { - desc = ext2_get_group_desc (sb, group, NULL); - 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; - } - } - if (!best_desc) - return -1; - - return best_group; -} - -/* - * 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) or - * it's already running too large debt (max_debt). - * 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. - */ - -#define INODE_COST 64 -#define BLOCK_COST 256 - -static int find_group_orlov(struct super_block *sb, struct inode *parent) -{ - int parent_group = EXT2_I(parent)->i_block_group; - struct ext2_sb_info *sbi = EXT2_SB(sb); - struct ext2_super_block *es = sbi->s_es; - int ngroups = sbi->s_groups_count; - int inodes_per_group = EXT2_INODES_PER_GROUP(sb); - int freei; - int avefreei; - int free_blocks; - int avefreeb; - int blocks_per_dir; - int ndirs; - int max_debt, max_dirs, min_blocks, min_inodes; - int group = -1, i; - struct ext2_group_desc *desc; - - freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); - avefreei = freei / ngroups; - free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); - avefreeb = free_blocks / ngroups; - ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); - - if ((parent == sb->s_root->d_inode) || - (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) { - struct ext2_group_desc *best_desc = NULL; - int best_ndir = inodes_per_group; - int best_group = -1; - - get_random_bytes(&group, sizeof(group)); - parent_group = (unsigned)group % ngroups; - for (i = 0; i < ngroups; i++) { - group = (parent_group + i) % ngroups; - desc = ext2_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); - best_desc = desc; - } - if (best_group >= 0) { - desc = best_desc; - group = best_group; - goto found; - } - goto fallback; - } - - if (ndirs == 0) - ndirs = 1; /* percpu_counters are approximate... */ - - blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs; - - max_dirs = ndirs / ngroups + inodes_per_group / 16; - min_inodes = avefreei - inodes_per_group / 4; - min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4; - - max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST); - if (max_debt * INODE_COST > inodes_per_group) - max_debt = inodes_per_group / INODE_COST; - if (max_debt > 255) - max_debt = 255; - if (max_debt == 0) - max_debt = 1; - - for (i = 0; i < ngroups; i++) { - group = (parent_group + i) % ngroups; - desc = ext2_get_group_desc (sb, group, NULL); - if (!desc || !desc->bg_free_inodes_count) - continue; - if (sbi->s_debts[group] >= max_debt) - 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; - goto found; - } - -fallback: - for (i = 0; i < ngroups; i++) { - group = (parent_group + i) % ngroups; - desc = ext2_get_group_desc (sb, group, NULL); - if (!desc || !desc->bg_free_inodes_count) - continue; - if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei) - goto found; - } - - 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; - -found: - return group; -} - -static int find_group_other(struct super_block *sb, struct inode *parent) -{ - int parent_group = EXT2_I(parent)->i_block_group; - int ngroups = EXT2_SB(sb)->s_groups_count; - struct ext2_group_desc *desc; - int group, i; - - /* - * Try to place the inode in its parent directory - */ - group = parent_group; - desc = ext2_get_group_desc (sb, group, NULL); - if (desc && le16_to_cpu(desc->bg_free_inodes_count) && - le16_to_cpu(desc->bg_free_blocks_count)) - goto found; - - /* - * 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 = ext2_get_group_desc (sb, group, NULL); - if (desc && le16_to_cpu(desc->bg_free_inodes_count) && - le16_to_cpu(desc->bg_free_blocks_count)) - goto found; - } - - /* - * 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 = ext2_get_group_desc (sb, group, NULL); - if (desc && le16_to_cpu(desc->bg_free_inodes_count)) - goto found; - } - - return -1; - -found: - return group; -} - -struct inode *ext2_new_inode(struct inode *dir, umode_t mode, - const struct qstr *qstr) -{ - struct super_block *sb; - struct buffer_head *bitmap_bh = NULL; - struct buffer_head *bh2; - int group, i; - ino_t ino = 0; - struct inode * inode; - struct ext2_group_desc *gdp; - struct ext2_super_block *es; - struct ext2_inode_info *ei; - struct ext2_sb_info *sbi; - int err; - - sb = dir->i_sb; - inode = new_inode(sb); - if (!inode) - return ERR_PTR(-ENOMEM); - - ei = EXT2_I(inode); - sbi = EXT2_SB(sb); - es = sbi->s_es; - if (S_ISDIR(mode)) { - if (test_opt(sb, OLDALLOC)) - group = find_group_dir(sb, dir); - else - group = find_group_orlov(sb, dir); - } else - group = find_group_other(sb, dir); - - if (group == -1) { - err = -ENOSPC; - goto fail; - } - - for (i = 0; i < sbi->s_groups_count; i++) { - gdp = ext2_get_group_desc(sb, group, &bh2); - brelse(bitmap_bh); - bitmap_bh = read_inode_bitmap(sb, group); - if (!bitmap_bh) { - err = -EIO; - goto fail; - } - ino = 0; - -repeat_in_this_group: - ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data, - EXT2_INODES_PER_GROUP(sb), ino); - if (ino >= EXT2_INODES_PER_GROUP(sb)) { - /* - * Rare race: find_group_xx() decided that there were - * free inodes in this group, but by the time we tried - * to allocate one, they're all gone. This can also - * occur because the counters which find_group_orlov() - * uses are approximate. So just go and search the - * next block group. - */ - if (++group == sbi->s_groups_count) - group = 0; - continue; - } - if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group), - ino, bitmap_bh->b_data)) { - /* we lost this inode */ - if (++ino >= EXT2_INODES_PER_GROUP(sb)) { - /* this group is exhausted, try next group */ - if (++group == sbi->s_groups_count) - group = 0; - continue; - } - /* try to find free inode in the same group */ - goto repeat_in_this_group; - } - goto got; - } - - /* - * Scanned all blockgroups. - */ - err = -ENOSPC; - goto fail; -got: - mark_buffer_dirty(bitmap_bh); - if (sb->s_flags & MS_SYNCHRONOUS) - sync_dirty_buffer(bitmap_bh); - brelse(bitmap_bh); - - ino += group * EXT2_INODES_PER_GROUP(sb) + 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=%lu", group, - (unsigned long) ino); - err = -EIO; - goto fail; - } - - percpu_counter_add(&sbi->s_freeinodes_counter, -1); - if (S_ISDIR(mode)) - percpu_counter_inc(&sbi->s_dirs_counter); - - spin_lock(sb_bgl_lock(sbi, group)); - le16_add_cpu(&gdp->bg_free_inodes_count, -1); - if (S_ISDIR(mode)) { - if (sbi->s_debts[group] < 255) - sbi->s_debts[group]++; - le16_add_cpu(&gdp->bg_used_dirs_count, 1); - } else { - if (sbi->s_debts[group]) - sbi->s_debts[group]--; - } - spin_unlock(sb_bgl_lock(sbi, group)); - - sb->s_dirt = 1; - mark_buffer_dirty(bh2); - 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; - 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_flags = - ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED); - ei->i_faddr = 0; - ei->i_frag_no = 0; - ei->i_frag_size = 0; - 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; - ei->i_dir_start_lookup = 0; - ei->i_state = EXT2_STATE_NEW; - ext2_set_inode_flags(inode); - spin_lock(&sbi->s_next_gen_lock); - inode->i_generation = sbi->s_next_generation++; - spin_unlock(&sbi->s_next_gen_lock); - if (insert_inode_locked(inode) < 0) { - ext2_error(sb, "ext2_new_inode", - "inode number already in use - inode=%lu", - (unsigned long) ino); - err = -EIO; - goto fail; - } - - dquot_initialize(inode); - err = dquot_alloc_inode(inode); - if (err) - goto fail_drop; - - err = ext2_init_acl(inode, dir); - if (err) - goto fail_free_drop; - - err = ext2_init_security(inode, dir, qstr); - if (err) - goto fail_free_drop; - - mark_inode_dirty(inode); - ext2_debug("allocating inode %lu\n", inode->i_ino); - ext2_preread_inode(inode); - return inode; - -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); - return ERR_PTR(err); - -fail: - make_bad_inode(inode); - iput(inode); - return ERR_PTR(err); -} - -unsigned long ext2_count_free_inodes (struct super_block * sb) -{ - struct ext2_group_desc *desc; - unsigned long desc_count = 0; - int i; - -#ifdef EXT2FS_DEBUG - struct ext2_super_block *es; - unsigned long bitmap_count = 0; - struct buffer_head *bitmap_bh = NULL; - - es = EXT2_SB(sb)->s_es; - for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { - unsigned x; - - desc = ext2_get_group_desc (sb, i, NULL); - if (!desc) - continue; - desc_count += le16_to_cpu(desc->bg_free_inodes_count); - brelse(bitmap_bh); - bitmap_bh = read_inode_bitmap(sb, i); - if (!bitmap_bh) - continue; - - x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8); - printk("group %d: stored = %d, counted = %u\n", - i, le16_to_cpu(desc->bg_free_inodes_count), x); - bitmap_count += x; - } - brelse(bitmap_bh); - printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", - percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter), - desc_count, bitmap_count); - return desc_count; -#else - for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { - desc = ext2_get_group_desc (sb, i, NULL); - if (!desc) - continue; - desc_count += le16_to_cpu(desc->bg_free_inodes_count); - } - return desc_count; -#endif -} - -/* Called at mount-time, super-block is locked */ -unsigned long ext2_count_dirs (struct super_block * sb) -{ - unsigned long count = 0; - int i; - - for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { - struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL); - if (!gdp) - continue; - count += le16_to_cpu(gdp->bg_used_dirs_count); - } - return count; -} - |