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/*
* 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/sched.h>
#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/ext3_fs.h>
#include <linux/ext3_jbd.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <linux/quotaops.h>
#include <asm/bitops.h>
#include <asm/byteorder.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 ext3_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.
*/
static int read_inode_bitmap (struct super_block * sb,
unsigned long block_group,
unsigned int bitmap_nr)
{
struct ext3_group_desc * gdp;
struct buffer_head * bh = NULL;
int retval = 0;
gdp = ext3_get_group_desc (sb, block_group, NULL);
if (!gdp) {
retval = -EIO;
goto error_out;
}
bh = sb_bread(sb, le32_to_cpu(gdp->bg_inode_bitmap));
if (!bh) {
ext3_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.ext3_sb.s_inode_bitmap_number[bitmap_nr] = block_group;
sb->u.ext3_sb.s_inode_bitmap[bitmap_nr] = bh;
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 EXT3_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.
*/
static int load_inode_bitmap (struct super_block * sb,
unsigned int block_group)
{
struct ext3_sb_info *sbi = EXT3_SB(sb);
unsigned long inode_bitmap_number;
struct buffer_head * inode_bitmap;
int i, j, retval = 0;
if (block_group >= sbi->s_groups_count)
ext3_panic (sb, "load_inode_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sbi->s_groups_count);
if (sbi->s_loaded_inode_bitmaps > 0 &&
sbi->s_inode_bitmap_number[0] == block_group &&
sbi->s_inode_bitmap[0] != NULL)
return 0;
if (sbi->s_groups_count <= EXT3_MAX_GROUP_LOADED) {
if (sbi->s_inode_bitmap[block_group]) {
if (sbi->s_inode_bitmap_number[block_group] !=
block_group)
ext3_panic(sb, "load_inode_bitmap",
"block_group != inode_bitmap_number");
return block_group;
}
retval = read_inode_bitmap(sb, block_group, block_group);
if (retval < 0)
return retval;
return block_group;
}
for (i = 0; i < sbi->s_loaded_inode_bitmaps &&
sbi->s_inode_bitmap_number[i] != block_group; i++)
/* do nothing */;
if (i < sbi->s_loaded_inode_bitmaps &&
sbi->s_inode_bitmap_number[i] == block_group) {
inode_bitmap_number = sbi->s_inode_bitmap_number[i];
inode_bitmap = sbi->s_inode_bitmap[i];
for (j = i; j > 0; j--) {
sbi->s_inode_bitmap_number[j] =
sbi->s_inode_bitmap_number[j - 1];
sbi->s_inode_bitmap[j] = sbi->s_inode_bitmap[j - 1];
}
sbi->s_inode_bitmap_number[0] = inode_bitmap_number;
sbi->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.
*/
if (!inode_bitmap)
retval = read_inode_bitmap (sb, block_group, 0);
} else {
if (sbi->s_loaded_inode_bitmaps < EXT3_MAX_GROUP_LOADED)
sbi->s_loaded_inode_bitmaps++;
else
brelse(sbi->s_inode_bitmap[EXT3_MAX_GROUP_LOADED - 1]);
for (j = sbi->s_loaded_inode_bitmaps - 1; j > 0; j--) {
sbi->s_inode_bitmap_number[j] =
sbi->s_inode_bitmap_number[j - 1];
sbi->s_inode_bitmap[j] = sbi->s_inode_bitmap[j - 1];
}
retval = read_inode_bitmap (sb, block_group, 0);
}
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.
*/
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 * bh;
struct buffer_head * bh2;
unsigned long block_group;
unsigned long bit;
int bitmap_nr;
struct ext3_group_desc * gdp;
struct ext3_super_block * es;
int fatal = 0, err;
if (!inode->i_dev) {
printk ("ext3_free_inode: inode has no device\n");
return;
}
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;
}
ino = inode->i_ino;
ext3_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_INIT(inode);
DQUOT_FREE_INODE(inode);
DQUOT_DROP(inode);
is_directory = S_ISDIR(inode->i_mode);
/* Do this BEFORE marking the inode not in use or returning an error */
clear_inode (inode);
lock_super (sb);
es = sb->u.ext3_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_nr = load_inode_bitmap (sb, block_group);
if (bitmap_nr < 0)
goto error_return;
bh = sb->u.ext3_sb.s_inode_bitmap[bitmap_nr];
BUFFER_TRACE(bh, "get_write_access");
fatal = ext3_journal_get_write_access(handle, bh);
if (fatal)
goto error_return;
/* Ok, now we can actually update the inode bitmaps.. */
if (!ext3_clear_bit (bit, 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;
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get write access");
fatal = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh);
if (fatal) goto error_return;
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);
}
BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh2);
if (!fatal) fatal = err;
es->s_free_inodes_count =
cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1);
BUFFER_TRACE(sb->u.ext3_sb.s_sbh,
"call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh);
if (!fatal) fatal = err;
}
BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh);
if (!fatal)
fatal = err;
sb->s_dirt = 1;
error_return:
ext3_std_error(sb, fatal);
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 * ext3_new_inode (handle_t *handle,
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 ext3_group_desc * gdp;
struct ext3_group_desc * tmp;
struct ext3_super_block * es;
int err = 0;
/* Cannot create files in a deleted directory */
if (!dir || !dir->i_nlink)
return ERR_PTR(-EPERM);
sb = dir->i_sb;
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
init_rwsem(&inode->u.ext3_i.truncate_sem);
lock_super (sb);
es = sb->u.ext3_sb.s_es;
repeat:
gdp = NULL;
i = 0;
if (S_ISDIR(mode)) {
avefreei = le32_to_cpu(es->s_free_inodes_count) /
sb->u.ext3_sb.s_groups_count;
if (!gdp) {
for (j = 0; j < sb->u.ext3_sb.s_groups_count; j++) {
struct buffer_head *temp_buffer;
tmp = ext3_get_group_desc (sb, j, &temp_buffer);
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;
bh2 = temp_buffer;
}
}
}
}
} else {
/*
* Try to place the inode in its parent directory
*/
i = dir->u.ext3_i.i_block_group;
tmp = ext3_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.ext3_sb.s_groups_count; j <<= 1) {
i += j;
if (i >= sb->u.ext3_sb.s_groups_count)
i -= sb->u.ext3_sb.s_groups_count;
tmp = ext3_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.ext3_i.i_block_group + 1;
for (j = 2; j < sb->u.ext3_sb.s_groups_count; j++) {
if (++i >= sb->u.ext3_sb.s_groups_count)
i = 0;
tmp = ext3_get_group_desc (sb, i, &bh2);
if (tmp &&
le16_to_cpu(tmp->bg_free_inodes_count)) {
gdp = tmp;
break;
}
}
}
}
err = -ENOSPC;
if (!gdp)
goto fail;
err = -EIO;
bitmap_nr = load_inode_bitmap (sb, i);
if (bitmap_nr < 0)
goto fail;
bh = sb->u.ext3_sb.s_inode_bitmap[bitmap_nr];
if ((j = ext3_find_first_zero_bit ((unsigned long *) bh->b_data,
EXT3_INODES_PER_GROUP(sb))) <
EXT3_INODES_PER_GROUP(sb)) {
BUFFER_TRACE(bh, "get_write_access");
err = ext3_journal_get_write_access(handle, bh);
if (err) goto fail;
if (ext3_set_bit (j, bh->b_data)) {
ext3_error (sb, "ext3_new_inode",
"bit already set for inode %d", j);
goto repeat;
}
BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh);
if (err) goto fail;
} else {
if (le16_to_cpu(gdp->bg_free_inodes_count) != 0) {
ext3_error (sb, "ext3_new_inode",
"Free inodes count corrupted in group %d",
i);
/* Is it really ENOSPC? */
err = -ENOSPC;
if (sb->s_flags & MS_RDONLY)
goto fail;
BUFFER_TRACE(bh2, "get_write_access");
err = ext3_journal_get_write_access(handle, bh2);
if (err) goto fail;
gdp->bg_free_inodes_count = 0;
BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh2);
if (err) goto fail;
}
goto repeat;
}
j += i * EXT3_INODES_PER_GROUP(sb) + 1;
if (j < EXT3_FIRST_INO(sb) || j > le32_to_cpu(es->s_inodes_count)) {
ext3_error (sb, "ext3_new_inode",
"reserved inode or inode > inodes count - "
"block_group = %d,inode=%d", i, j);
err = -EIO;
goto fail;
}
BUFFER_TRACE(bh2, "get_write_access");
err = ext3_journal_get_write_access(handle, bh2);
if (err) goto fail;
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);
BUFFER_TRACE(bh2, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, bh2);
if (err) goto fail;
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get_write_access");
err = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh);
if (err) goto fail;
es->s_free_inodes_count =
cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) - 1);
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "call ext3_journal_dirty_metadata");
err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh);
sb->s_dirt = 1;
if (err) goto fail;
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 = j;
/* This is the optimal IO size (for stat), not the fs block size */
inode->i_blksize = PAGE_SIZE;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->u.ext3_i.i_flags = dir->u.ext3_i.i_flags & ~EXT3_INDEX_FL;
if (S_ISLNK(mode))
inode->u.ext3_i.i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
#ifdef EXT3_FRAGMENTS
inode->u.ext3_i.i_faddr = 0;
inode->u.ext3_i.i_frag_no = 0;
inode->u.ext3_i.i_frag_size = 0;
#endif
inode->u.ext3_i.i_file_acl = 0;
inode->u.ext3_i.i_dir_acl = 0;
inode->u.ext3_i.i_dtime = 0;
INIT_LIST_HEAD(&inode->u.ext3_i.i_orphan);
#ifdef EXT3_PREALLOCATE
inode->u.ext3_i.i_prealloc_count = 0;
#endif
inode->u.ext3_i.i_block_group = i;
if (inode->u.ext3_i.i_flags & EXT3_SYNC_FL)
inode->i_flags |= S_SYNC;
if (IS_SYNC(inode))
handle->h_sync = 1;
insert_inode_hash(inode);
inode->i_generation = sb->u.ext3_sb.s_next_generation++;
inode->u.ext3_i.i_state = EXT3_STATE_NEW;
err = ext3_mark_inode_dirty(handle, inode);
if (err) goto fail;
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);
}
ext3_debug ("allocating inode %lu\n", inode->i_ino);
return inode;
fail:
unlock_super(sb);
iput(inode);
ext3_std_error(sb, err);
return ERR_PTR(err);
}
/* Verify that we are loading a valid orphan from disk */
struct inode *ext3_orphan_get (struct super_block * sb, ino_t ino)
{
ino_t max_ino = le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count);
unsigned long block_group;
int bit;
int bitmap_nr;
struct buffer_head *bh;
struct inode *inode = NULL;
/* Error cases - e2fsck has already cleaned up for us */
if (ino > max_ino) {
ext3_warning(sb, __FUNCTION__,
"bad orphan ino %ld! e2fsck was run?\n", ino);
return NULL;
}
block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT3_INODES_PER_GROUP(sb);
if ((bitmap_nr = load_inode_bitmap(sb, block_group)) < 0 ||
!(bh = EXT3_SB(sb)->s_inode_bitmap[bitmap_nr])) {
ext3_warning(sb, __FUNCTION__,
"inode bitmap error for orphan %ld\n", ino);
return NULL;
}
/* 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, bh->b_data) || !(inode = iget(sb, ino)) ||
is_bad_inode(inode) || NEXT_ORPHAN(inode) > max_ino) {
ext3_warning(sb, __FUNCTION__,
"bad orphan inode %ld! e2fsck was run?\n", ino);
printk(KERN_NOTICE "ext3_test_bit(bit=%d, block=%ld) = %d\n",
bit, bh->b_blocknr, ext3_test_bit(bit, 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)=%d\n",
NEXT_ORPHAN(inode));
printk(KERN_NOTICE "max_ino=%ld\n", max_ino);
}
/* Avoid freeing blocks if we got a bad deleted inode */
if (inode && inode->i_nlink == 0)
inode->i_blocks = 0;
iput(inode);
return NULL;
}
return inode;
}
unsigned long ext3_count_free_inodes (struct super_block * sb)
{
#ifdef EXT3FS_DEBUG
struct ext3_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext3_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext3_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext3_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);
bitmap_nr = load_inode_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
x = ext3_count_free (sb->u.ext3_sb.s_inode_bitmap[bitmap_nr],
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;
}
printk("ext3_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.ext3_sb.s_es->s_free_inodes_count);
#endif
}
#ifdef CONFIG_EXT3_CHECK
/* Called at mount-time, super-block is locked */
void ext3_check_inodes_bitmap (struct super_block * sb)
{
struct ext3_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext3_group_desc * gdp;
int i;
es = sb->u.ext3_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext3_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);
bitmap_nr = load_inode_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
x = ext3_count_free (sb->u.ext3_sb.s_inode_bitmap[bitmap_nr],
EXT3_INODES_PER_GROUP(sb) / 8);
if (le16_to_cpu(gdp->bg_free_inodes_count) != x)
ext3_error (sb, "ext3_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)
ext3_error (sb, "ext3_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
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