/*
* 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/config.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/locks.h>
#include <linux/quotaops.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. The descriptors are loaded in memory
* when a file system is mounted (see ext2_read_super).
*/
/*
* 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.
*/
44 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);
53 if (!gdp) {
retval = -EIO;
55 goto error_out;
}
bh = bread (sb->s_dev, le32_to_cpu(gdp->bg_inode_bitmap), sb->s_blocksize);
58 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;
72 return retval;
}
/*
* load_inode_bitmap loads the inode bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*
* Return the slot used to store the bitmap, or a -ve error code.
*/
88 static int load_inode_bitmap (struct super_block * sb,
unsigned int block_group)
{
int i, j, retval = 0;
unsigned long inode_bitmap_number;
struct buffer_head * inode_bitmap;
95 if (block_group >= sb->u.ext2_sb.s_groups_count)
ext2_panic (sb, "load_inode_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext2_sb.s_groups_count);
if (sb->u.ext2_sb.s_loaded_inode_bitmaps > 0 &&
sb->u.ext2_sb.s_inode_bitmap_number[0] == block_group &&
102 sb->u.ext2_sb.s_inode_bitmap[0] != NULL)
103 return 0;
104 if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED) {
105 if (sb->u.ext2_sb.s_inode_bitmap[block_group]) {
106 if (sb->u.ext2_sb.s_inode_bitmap_number[block_group] != block_group)
ext2_panic (sb, "load_inode_bitmap",
"block_group != inode_bitmap_number");
109 else
110 return block_group;
111 } else {
retval = read_inode_bitmap (sb, block_group,
block_group);
114 if (retval < 0)
115 return retval;
116 return block_group;
}
}
for (i = 0; i < sb->u.ext2_sb.s_loaded_inode_bitmaps &&
121 sb->u.ext2_sb.s_inode_bitmap_number[i] != block_group;
i++)
;
if (i < sb->u.ext2_sb.s_loaded_inode_bitmaps &&
125 sb->u.ext2_sb.s_inode_bitmap_number[i] == block_group) {
inode_bitmap_number = sb->u.ext2_sb.s_inode_bitmap_number[i];
inode_bitmap = sb->u.ext2_sb.s_inode_bitmap[i];
128 for (j = i; j > 0; j--) {
sb->u.ext2_sb.s_inode_bitmap_number[j] =
sb->u.ext2_sb.s_inode_bitmap_number[j - 1];
sb->u.ext2_sb.s_inode_bitmap[j] =
sb->u.ext2_sb.s_inode_bitmap[j - 1];
}
sb->u.ext2_sb.s_inode_bitmap_number[0] = inode_bitmap_number;
sb->u.ext2_sb.s_inode_bitmap[0] = inode_bitmap;
/*
* There's still one special case here --- if inode_bitmap == 0
* then our last attempt to read the bitmap failed and we have
* just ended up caching that failure. Try again to read it.
*/
142 if (!inode_bitmap)
retval = read_inode_bitmap (sb, block_group, 0);
145 } else {
146 if (sb->u.ext2_sb.s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
sb->u.ext2_sb.s_loaded_inode_bitmaps++;
148 else
brelse (sb->u.ext2_sb.s_inode_bitmap[EXT2_MAX_GROUP_LOADED - 1]);
150 for (j = sb->u.ext2_sb.s_loaded_inode_bitmaps - 1; j > 0; j--) {
sb->u.ext2_sb.s_inode_bitmap_number[j] =
sb->u.ext2_sb.s_inode_bitmap_number[j - 1];
sb->u.ext2_sb.s_inode_bitmap[j] =
sb->u.ext2_sb.s_inode_bitmap[j - 1];
}
retval = read_inode_bitmap (sb, block_group, 0);
}
158 return retval;
}
/*
* 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.
*/
177 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;
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.
*/
197 DQUOT_FREE_INODE(sb, inode);
198 DQUOT_DROP(inode);
lock_super (sb);
es = sb->u.ext2_sb.s_es;
if (ino < EXT2_FIRST_INO(sb) ||
203 ino > le32_to_cpu(es->s_inodes_count)) {
ext2_error (sb, "free_inode",
"reserved inode or nonexistent inode");
206 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);
211 if (bitmap_nr < 0)
212 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.. */
222 if (!ext2_clear_bit (bit, bh->b_data))
ext2_error (sb, "ext2_free_inode",
"bit already cleared for inode %lu", ino);
225 else {
gdp = ext2_get_group_desc (sb, block_group, &bh2);
227 if (gdp) {
gdp->bg_free_inodes_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) + 1);
230 if (is_directory)
gdp->bg_used_dirs_count =
cpu_to_le16(le16_to_cpu(gdp->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);
240 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.
*/
259 struct inode * ext2_new_inode (const struct inode * dir, int mode)
{
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;
int err;
/* Cannot create files in a deleted directory */
273 if (!dir || !dir->i_nlink)
274 return ERR_PTR(-EPERM);
sb = dir->i_sb;
inode = new_inode(sb);
278 if (!inode)
279 return ERR_PTR(-ENOMEM);
lock_super (sb);
es = sb->u.ext2_sb.s_es;
repeat:
gdp = NULL; i=0;
286 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;
}
*/
303 if (!gdp) {
304 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) &&
308 le16_to_cpu(tmp->bg_free_inodes_count) >= avefreei) {
if (!gdp ||
(le16_to_cpu(tmp->bg_free_blocks_count) >
311 le16_to_cpu(gdp->bg_free_blocks_count))) {
i = j;
gdp = tmp;
}
}
}
}
}
319 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);
326 if (tmp && le16_to_cpu(tmp->bg_free_inodes_count))
gdp = tmp;
328 else
{
/*
* Use a quadratic hash to find a group with a
* free inode
*/
334 for (j = 1; j < sb->u.ext2_sb.s_groups_count; j <<= 1) {
i += j;
336 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 &&
340 le16_to_cpu(tmp->bg_free_inodes_count)) {
gdp = tmp;
342 break;
}
}
}
346 if (!gdp) {
/*
* That failed: try linear search for a free inode
*/
i = dir->u.ext2_i.i_block_group + 1;
351 for (j = 2; j < sb->u.ext2_sb.s_groups_count; j++) {
352 if (++i >= sb->u.ext2_sb.s_groups_count)
i = 0;
tmp = ext2_get_group_desc (sb, i, &bh2);
if (tmp &&
356 le16_to_cpu(tmp->bg_free_inodes_count)) {
gdp = tmp;
358 break;
}
}
}
}
err = -ENOSPC;
365 if (!gdp)
366 goto fail;
err = -EIO;
bitmap_nr = load_inode_bitmap (sb, i);
370 if (bitmap_nr < 0)
371 goto fail;
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))) <
376 EXT2_INODES_PER_GROUP(sb)) {
377 if (ext2_set_bit (j, bh->b_data)) {
ext2_error (sb, "ext2_new_inode",
"bit already set for inode %d", j);
380 goto repeat;
}
mark_buffer_dirty(bh);
383 if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
387 } else {
388 if (le16_to_cpu(gdp->bg_free_inodes_count) != 0) {
ext2_error (sb, "ext2_new_inode",
"Free inodes count corrupted in group %d",
i);
/* Is it really ENOSPC? */
err = -ENOSPC;
394 if (sb->s_flags & MS_RDONLY)
395 goto fail;
gdp->bg_free_inodes_count = 0;
mark_buffer_dirty(bh2);
}
400 goto repeat;
}
j += i * EXT2_INODES_PER_GROUP(sb) + 1;
403 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);
err = -EIO;
408 goto fail;
}
gdp->bg_free_inodes_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
412 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);
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_mode = mode;
inode->i_uid = current->fsuid;
422 if (test_opt (sb, GRPID))
inode->i_gid = dir->i_gid;
424 else if (dir->i_mode & S_ISGID) {
inode->i_gid = dir->i_gid;
426 if (S_ISDIR(mode))
mode |= S_ISGID;
428 } 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;
437 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;
446 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);
453 if(DQUOT_ALLOC_INODE(sb, inode)) {
sb->dq_op->drop(inode);
inode->i_nlink = 0;
iput(inode);
457 return ERR_PTR(-EDQUOT);
}
ext2_debug ("allocating inode %lu\n", inode->i_ino);
460 return inode;
fail:
unlock_super(sb);
iput(inode);
465 return ERR_PTR(err);
}
468 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
502 return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_inodes_count);
#endif
}
#ifdef CONFIG_EXT2_CHECK
/* Called at mount-time, super-block is locked */
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;
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);
}
#endif