bool ext2_get_block(PEXT2_FILESYS Ext2Sys, ULONG dwContent, ULONG Index, int layer, ULONG *dwRet)
{
ULONG *pData = NULL;
LONGLONG Offset = 0;
ULONG i = 0, j = 0, temp = 1;
ULONG dwBlk = 0;
bool bRet = true;
PEXT2_SUPER_BLOCK pExt2Sb = Ext2Sys->ext2_sb;
Offset = (LONGLONG) dwContent;
Offset = Offset * Ext2Sys->blocksize;
pData = (ULONG *)RtlAllocateHeap(RtlGetProcessHeap(), 0, Ext2Sys->blocksize);
if (!pData)
{
return false;
}
memset(pData, 0, Ext2Sys->blocksize);
if (layer == 0)
{
dwBlk = dwContent;
}
else if (layer <= 3)
{
if (!ext2_read_block(Ext2Sys, dwContent, (void *)pData))
{
bRet = false;
goto errorout;
}
temp = 1 << ((10 + pExt2Sb->s_log_block_size - 2) * (layer - 1));
i = Index / temp;
j = Index % temp;
if (!ext2_get_block(Ext2Sys, pData[i], j, layer - 1, &dwBlk))
{
bRet = false;
DPRINT1("Mke2fs: ext2_get_block: ... error recuise...\n");
goto errorout;
}
}
errorout:
if (pData)
RtlFreeHeap(RtlGetProcessHeap(), 0, pData);
if (bRet && dwRet)
*dwRet = dwBlk;
return bRet;
}
/* Write to quotafile */
static ssize_t ext2_quota_write(struct super_block *sb, int type,
const char *data, size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t towrite = len;
struct buffer_head tmp_bh;
struct buffer_head *bh;
mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?
sb->s_blocksize - offset : towrite;
tmp_bh.b_state = 0;
err = ext2_get_block(inode, blk, &tmp_bh, 1);
if (err < 0)
goto out;
if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
bh = sb_bread(sb, tmp_bh.b_blocknr);
else
bh = sb_getblk(sb, tmp_bh.b_blocknr);
if (!bh) {
err = -EIO;
goto out;
}
lock_buffer(bh);
memcpy(bh->b_data+offset, data, tocopy);
flush_dcache_page(bh->b_page);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
brelse(bh);
offset = 0;
towrite -= tocopy;
data += tocopy;
blk++;
}
out:
if (len == towrite) {
mutex_unlock(&inode->i_mutex);
return err;
}
if (inode->i_size < off+len-towrite)
i_size_write(inode, off+len-towrite);
inode->i_version++;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
mutex_unlock(&inode->i_mutex);
return len - towrite;
}
uint32_t
ext2_get_inode_block_num(
ext2_inodetable_t * inode,
uint32_t block
) {
if (block < 12) {
return inode->block[block];
} else if (block < 12 + (1024 << sblock->log_block_size) / sizeof(uint32_t)) {
return *(uint32_t*)((uintptr_t)ext2_get_block(inode->block[12]) + (block - 12) * sizeof(uint32_t));
}
return 0;
}
// This function returns a pointer to the cache block that corresponds to the indirect block pointer.
int ext2_get_indirect_block_pointer_cache_block(ext2_t *ext2, struct ext2_inode *inode, blocknum_t **cache_block, uint32_t level, uint32_t pos[], uint *block_loaded)
{
uint32_t current_level = 0;
uint current_block = 0, last_block;
blocknum_t *block = NULL;
int err;
if ((level > 3) || (level == 0)) {
err = -1;
goto error;
}
// Dig down into the indirect blocks. When done, current_block should point to the target.
while (current_level < level) {
if (current_level == 0) {
// read the direct block, simulates a prior loop
current_block = LE32(inode->i_block[pos[0]]);
}
if (current_block == 0) {
err = -1;
goto error;
}
last_block = current_block;
current_level++;
*block_loaded = current_block;
err = ext2_get_block(ext2, (void **)(void *)&block, current_block);
if (err < 0) {
goto error;
}
if (current_level < level) {
current_block = LE32(block[pos[current_level]]);
ext2_put_block(ext2, last_block);
}
}
*cache_block = block;
return 0;
error:
*cache_block = NULL;
*block_loaded = 0;
return err;
}
bool ext2_block_map(PEXT2_FILESYS Ext2Sys, PEXT2_INODE inode, ULONG block, ULONG *dwRet)
{
ULONG dwSizes[4] = { 12, 1, 1, 1 };
ULONG Index = 0;
ULONG dwBlk = 0;
PEXT2_SUPER_BLOCK pExt2Sb = Ext2Sys->ext2_sb;
UINT i;
bool bRet = false;
Index = block;
for (i = 0; i < 4; i++)
{
dwSizes[i] = dwSizes[i] << ((10 + pExt2Sb->s_log_block_size - 2) * i);
}
if (Index >= inode->i_blocks / (Ext2Sys->blocksize / SECTOR_SIZE))
{
DPRINT1("Mke2fs: ext2_block_map: beyond the size of the inode.\n");
return false;
}
for (i = 0; i < 4; i++)
{
if (Index < dwSizes[i])
{
dwBlk = inode->i_block[i==0 ? (Index):(i + 12 - 1)];
bRet = ext2_get_block(Ext2Sys, dwBlk, Index , i, &dwBlk);
break;
}
Index -= dwSizes[i];
}
if (bRet && dwBlk)
{
if (dwRet)
*dwRet = dwBlk;
return true;
}
else
return false;
}
/* Read data from quotafile - avoid pagecache and such because we cannot afford
* acquiring the locks... As quota files are never truncated and quota code
* itself serializes the operations (and noone else should touch the files)
* we don't have to be afraid of races */
static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
size_t len, loff_t off)
{
struct inode *inode = sb_dqopt(sb)->files[type];
sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
int err = 0;
int offset = off & (sb->s_blocksize - 1);
int tocopy;
size_t toread;
struct buffer_head tmp_bh;
struct buffer_head *bh;
loff_t i_size = i_size_read(inode);
if (off > i_size)
return 0;
if (off+len > i_size)
len = i_size-off;
toread = len;
while (toread > 0) {
tocopy = sb->s_blocksize - offset < toread ?
sb->s_blocksize - offset : toread;
tmp_bh.b_state = 0;
tmp_bh.b_size = sb->s_blocksize;
err = ext2_get_block(inode, blk, &tmp_bh, 0);
if (err < 0)
return err;
if (!buffer_mapped(&tmp_bh)) /* A hole? */
memset(data, 0, tocopy);
else {
bh = sb_bread(sb, tmp_bh.b_blocknr);
if (!bh)
return -EIO;
memcpy(data, bh->b_data+offset, tocopy);
brelse(bh);
}
offset = 0;
toread -= tocopy;
data += tocopy;
blk++;
}
return len;
}
static inline int
__ext2_get_block(struct inode *inode, pgoff_t pgoff, int create,
sector_t *result)
{
struct buffer_head tmp;
int rc;
memset(&tmp, 0, sizeof(struct buffer_head));
rc = ext2_get_block(inode, pgoff, &tmp, create);
*result = tmp.b_blocknr;
/* did we get a sparse block (hole in the file)? */
if (!tmp.b_blocknr && !rc) {
BUG_ON(create);
rc = -ENODATA;
}
return rc;
}
ext2_inodetable_t *
ext2_finddir(
ext2_inodetable_t * rnode,
char * name
) {
void * block;
ext2_dir_t * direntry = NULL;
block = (void *)ext2_get_block((rnode->block[0]));
uint32_t dir_offset;
dir_offset = 0;
/*
* Look through the requested entries until we find what we're looking for
*/
while (dir_offset < rnode->size) {
ext2_dir_t * d_ent = (ext2_dir_t *)((uintptr_t)block + dir_offset);
char * dname = malloc(sizeof(char) * (d_ent->name_len + 1));
memcpy(dname, &d_ent->name, d_ent->name_len);
dname[d_ent->name_len] = '\0';
if (!strcmp(dname, name)) {
free(dname);
direntry = d_ent;
break;
}
free(dname);
dir_offset += d_ent->rec_len;
}
if (!direntry) {
/*
* We could not find the requested entry in this directory.
*/
fprintf(stderr, "Failed to locate %s!\n", name);
return NULL;
} else {
return ext2_get_inode(direntry->inode);
}
}
long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = filp->f_dentry->d_inode;
struct ext2_inode_info *ei = EXT2_I(inode);
unsigned int flags;
unsigned short rsv_window_size;
int ret;
ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
switch (cmd) {
case EXT2_FAKE_B_ALLOC:
/* Fake allocation for ext2 filesystem.
* */
{
struct ext2_fake_b_alloc_arg config;
struct buffer_head bh_result;
sector_t iblock, off;
int ret = 0;
ret = copy_from_user(&config, (struct ext2_fake_b_alloc_arg __user *)arg,
sizeof(struct ext2_fake_b_alloc_arg));
if (ret != 0) {
printk (KERN_DEBUG "can't copy from user");
return -EIO;
} else ret = 0;
/* Allocate blocks. */
off = config.efba_off;
iblock = config.efba_off >> inode->i_blkbits;
while ((iblock << inode->i_blkbits) <
(config.efba_off + config.efba_size)) {
memset(&bh_result, 0, sizeof(struct ext2_fake_b_alloc_arg));
ret = ext2_get_block(inode, iblock, &bh_result, 1);
if (ret < 0) {
printk (KERN_DEBUG "get_block_error %d, escaping", ret);
break;
}
iblock++;
}
/* Set metadata */
write_lock(&EXT2_I(inode)->i_meta_lock);
if (ret == 0) {
printk (KERN_DEBUG "ok, set size");
inode->i_size = max_t(loff_t, inode->i_size,
config.efba_off + config.efba_size);
} else if(iblock != config.efba_off >> inode->i_blkbits) {
/* Partially allocated, size must be fixed. *
* But `i_blocks` should containt actual information. */
inode->i_size = inode->i_blocks << inode->i_blkbits;
}
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
inode->i_version++;
write_unlock(&EXT2_I(inode)->i_meta_lock);
printk(KERN_DEBUG, "returning %d", ret);
return ret;
}
case EXT2_IOC_GETFLAGS:
ext2_get_inode_flags(ei);
flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
return put_user(flags, (int __user *) arg);
case EXT2_IOC_SETFLAGS: {
unsigned int oldflags;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (!is_owner_or_cap(inode)) {
ret = -EACCES;
goto setflags_out;
}
if (get_user(flags, (int __user *) arg)) {
ret = -EFAULT;
goto setflags_out;
}
flags = ext2_mask_flags(inode->i_mode, flags);
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
oldflags = ei->i_flags;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
}
flags = flags & EXT2_FL_USER_MODIFIABLE;
flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
ei->i_flags = flags;
mutex_unlock(&inode->i_mutex);
ext2_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
setflags_out:
mnt_drop_write(filp->f_path.mnt);
return ret;
}
case EXT2_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *) arg);
case EXT2_IOC_SETVERSION:
if (!is_owner_or_cap(inode))
return -EPERM;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (get_user(inode->i_generation, (int __user *) arg)) {
ret = -EFAULT;
} else {
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
}
mnt_drop_write(filp->f_path.mnt);
return ret;
case EXT2_IOC_GETRSVSZ:
if (test_opt(inode->i_sb, RESERVATION)
&& S_ISREG(inode->i_mode)
&& ei->i_block_alloc_info) {
rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
return put_user(rsv_window_size, (int __user *)arg);
}
return -ENOTTY;
case EXT2_IOC_SETRSVSZ: {
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(rsv_window_size, (int __user *)arg))
return -EFAULT;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
/*
* need to allocate reservation structure for this inode
* before set the window size
*/
/*
* XXX What lock should protect the rsv_goal_size?
* Accessed in ext2_get_block only. ext3 uses i_truncate.
*/
mutex_lock(&ei->truncate_mutex);
if (!ei->i_block_alloc_info)
ext2_init_block_alloc_info(inode);
if (ei->i_block_alloc_info){
struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
mnt_drop_write(filp->f_path.mnt);
return 0;
}
default:
return -ENOTTY;
}
}
/*
* ext3301 regular to immediate: convert the file type.
*
* filesize should be <= EXT3301_IM_SIZE.
* There should only be one block in the file, if it is small enough to
* become an immediate file.
* Returns 0 on success, <0 on failure.
*/
ssize_t ext3301_reg2im(struct file * filp) {
char * data;
struct buffer_head * bh, search_bh;
int err = 0;
long block_offset = 0;
struct inode * i = FILP_INODE(filp);
ssize_t l = INODE_ISIZE(i);
unsigned long blocksize = INODE_BLKSIZE(i);
dbg_im(KERN_DEBUG "- reg2im l=%d\n", (int)INODE_ISIZE(i));
// verify the immediate file size
if (l > EXT3301_IM_SIZE(i)) {
printk(KERN_DEBUG "IM file bad state, size>capacity, ino: %lu\n",
INODE_INO(i));
return -EIO;
}
// prepare a kernel buffer to store the file contents
data = kmalloc((size_t)l, GFP_KERNEL);
if (!data)
return -ENOMEM;
// Lock the inode
INODE_LOCK(i);
// Special case: file length is zero, go straight to freeing blocks
if (l==0)
goto free;
// Use a buffer head to find the block number (of the first data block)
// 'false' option: do not allocate new blocks with ext2_get_block
search_bh.b_state = 0;
search_bh.b_size = blocksize;
err = ext2_get_block(i, block_offset, &search_bh, false);
if (err < 0) {
dbg_im(KERN_DEBUG "- ext2_get_block() failed\n");
goto out;
}
// Retrieve and lock a paged buffer head to the block number
bh = sb_getblk(INODE_SUPER(i), search_bh.b_blocknr);
if (bh==NULL) {
dbg_im(KERN_DEBUG "- sb_getblk() failed\n");
err = -EIO;
goto out;
}
lock_buffer(bh);
// Copy directly from the buffer data segment to our kernel buffer
memcpy((void *)data, (const void *)(bh->b_data), (size_t)l);
dbg_im(KERN_WARNING "GOT DATA: %.*s\n", (int)l, data);
// Release the paged buffer: unlock, release.
flush_dcache_page(bh->b_page);
set_buffer_uptodate(bh);
unlock_buffer(bh);
brelse(bh);
//Write the kernel buffer into the block pointer area
//memcpy((void *)INODE_PAYLOAD(i), (const void *)data, (size_t)l);
memset((void *)INODE_PAYLOAD(i), 'A', (size_t)l);
free:
// Free the block
//
// Set the file type to immediate
INODE_MODE(i) = MODE_SET_IM(INODE_MODE(i));
out:
// Finished - unlock the inode and mark it as dirty.
// Note we haven't updated the ctime, filesize or anything else.
// The previous write operation already did this
mark_inode_dirty(i);
INODE_UNLOCK(i);
kfree(data);
return err;
}
/*
* ext3301 immediate to regular: convert the file type.
* filesize should be > EXT3301_IM_SIZE.
* Returns 0 on success, <0 on failure.
*/
ssize_t ext3301_im2reg(struct file * filp) {
char * data;
struct buffer_head * bh, search_bh;
int err = 0;
long block_offset = 0;
struct inode * i = FILP_INODE(filp);
ssize_t l = INODE_ISIZE(i);
unsigned long blocksize = INODE_BLKSIZE(i);
dbg_im(KERN_DEBUG "- im2reg l=%d\n", (int)INODE_ISIZE(i));
// verify the immediate file size
if (l > EXT3301_IM_SIZE(i)) {
printk(KERN_DEBUG "IM file bad state, size>capacity, ino: %lu\n",
INODE_INO(i));
return -EIO;
}
// prepare a kernel buffer to store the file contents
data = kmalloc((size_t)l, GFP_KERNEL);
if (!data)
return -ENOMEM;
// Lock the inode
INODE_LOCK(i);
// Set the file type to regular
INODE_MODE(i) = MODE_SET_REG(INODE_MODE(i));
// Special case: file length is zero, nothing else to do
if (l==0)
goto out;
// Read the payload (block pointer area) into a buffer
memcpy((void *)data, (const void *)INODE_PAYLOAD(i), (size_t)l);
// Zero the block pointer area (otherwise get_block will treat our old
// immediate data as block pointers, and follow them...)
memset((void *)INODE_PAYLOAD(i), 0, (size_t)EXT3301_IM_SIZE(i));
// Use a buffer head to find the block number (of the first data block)
// 'true' option: allocate new blocks with ext2_get_block
search_bh.b_state = 0;
search_bh.b_size = blocksize;
err = ext2_get_block(i, block_offset, &search_bh, true);
if (err < 0) {
dbg_im(KERN_DEBUG "- ext2_get_block() failed\n");
goto out;
}
// Retrieve and lock a paged buffer head to the block number
bh = sb_getblk(INODE_SUPER(i), search_bh.b_blocknr);
if (bh==NULL) {
dbg_im(KERN_DEBUG "- sb_getblk() failed\n");
err = -EIO;
goto out;
}
lock_buffer(bh);
// Write (directly) to the buffer
memcpy((void *)(bh->b_data), (const void *)data, (size_t)l);
// Flush the paged buffer to disk: mark as dirty, unlock, sync, release.
flush_dcache_page(bh->b_page);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
sync_dirty_buffer(bh);
brelse(bh);
out:
// Finished - unlock the inode and mark it as dirty.
// Note we haven't updated the ctime, filesize or anything else.
// The subsequent write operation will do this
mark_inode_dirty(i);
INODE_UNLOCK(i);
kfree(data);
return err;
}