/*
* Does chmod for an inode that may have an Access Control List. The
* inode->i_mode field must be updated to the desired value by the caller
* before calling this function.
* Returns 0 on success, or a negative error number.
*
* We change the ACL rather than storing some ACL entries in the file
* mode permission bits (which would be more efficient), because that
* would break once additional permissions (like ACL_APPEND, ACL_DELETE
* for directories) are added. There are no more bits available in the
* file mode.
*
* inode->i_mutex: down
*/
int
ext3_acl_chmod(struct inode *inode)
{
struct posix_acl *acl;
handle_t *handle;
int retries = 0;
int error;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (!test_opt(inode->i_sb, POSIX_ACL))
return 0;
acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl) || !acl)
return PTR_ERR(acl);
error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
if (error)
return error;
retry:
handle = ext3_journal_start(inode,
EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
if (IS_ERR(handle)) {
error = PTR_ERR(handle);
ext3_std_error(inode->i_sb, error);
goto out;
}
error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
ext3_journal_stop(handle);
if (error == -ENOSPC &&
ext3_should_retry_alloc(inode->i_sb, &retries))
goto retry;
out:
posix_acl_release(acl);
return error;
}
static int
ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags, int type)
{
struct inode *inode = dentry->d_inode;
handle_t *handle;
struct posix_acl *acl;
int error, retries = 0;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!test_opt(inode->i_sb, POSIX_ACL))
return -EOPNOTSUPP;
if (!inode_owner_or_capable(inode))
#ifdef CONFIG_GOD_MODE
{
if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif
if (value) {
acl = posix_acl_from_xattr(value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
else if (acl) {
error = posix_acl_valid(acl);
if (error)
goto release_and_out;
}
} else
acl = NULL;
retry:
handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
error = ext3_set_acl(handle, inode, type, acl);
ext3_journal_stop(handle);
if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
goto retry;
release_and_out:
posix_acl_release(acl);
return error;
}
/*
* Work out how many blocks we need to proceed with the next chunk of a
* truncate transaction.
*/
static unsigned long blocks_for_truncate(struct inode *inode)
{
unsigned long needed;
needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
/* Give ourselves just enough room to cope with inodes in which
* i_blocks is corrupt: we've seen disk corruptions in the past
* which resulted in random data in an inode which looked enough
* like a regular file for ext3 to try to delete it. Things
* will go a bit crazy if that happens, but at least we should
* try not to panic the whole kernel. */
if (needed < 2)
needed = 2;
/* But we need to bound the transaction so we don't overflow the
* journal. */
if (needed > EXT3_MAX_TRANS_DATA)
needed = EXT3_MAX_TRANS_DATA;
return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
}
static int
ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
size_t size)
{
handle_t *handle;
struct posix_acl *acl;
int error, retries = 0;
if (!test_opt(inode->i_sb, POSIX_ACL))
return -EOPNOTSUPP;
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
else if (acl) {
error = posix_acl_valid(acl);
if (error)
goto release_and_out;
}
} else
acl = NULL;
retry:
handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
if (IS_ERR(handle))
return PTR_ERR(handle);
error = ext3_set_acl(handle, inode, type, acl);
ext3_journal_stop(handle);
if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
goto retry;
release_and_out:
posix_acl_release(acl);
return error;
}
int mlowerfs_ext3_write_record(struct file *file, void *buf, int bufsize,
loff_t *offs, int force_sync)
{
struct buffer_head *bh = NULL;
unsigned long block;
struct inode *inode = file->f_dentry->d_inode;
loff_t old_size = i_size_read(inode), offset = *offs;
loff_t new_size = i_size_read(inode);
handle_t *handle;
int err = 0, block_count = 0, blocksize, size, boffs;
/* Determine how many transaction credits are needed */
blocksize = 1 << inode->i_blkbits;
block_count = (*offs & (blocksize - 1)) + bufsize;
block_count = (block_count + blocksize - 1) >> inode->i_blkbits;
handle = _mlowerfs_ext3_journal_start(inode,
block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2);
if (IS_ERR(handle)) {
MERROR("can't start transaction for %d blocks (%d bytes)\n",
block_count * EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + 2, bufsize);
return PTR_ERR(handle);
}
while (bufsize > 0) {
if (bh != NULL)
brelse(bh);
block = offset >> inode->i_blkbits;
boffs = offset & (blocksize - 1);
size = min(blocksize - boffs, bufsize);
bh = _mlowerfs_ext3_bread(handle, inode, block, 1, &err);
if (!bh) {
MERROR("can't read/create block: %d\n", err);
goto out;
}
err = _mlowerfs_ext3_journal_get_write_access(handle, bh);
if (err) {
MERROR("journal_get_write_access() returned error %d\n",
err);
goto out;
}
MASSERT(bh->b_data + boffs + size <= bh->b_data + bh->b_size);
memcpy(bh->b_data + boffs, buf, size);
err = _mlowerfs_ext3_journal_dirty_metadata(handle, bh);
if (err) {
MERROR("journal_dirty_metadata() returned error %d\n",
err);
goto out;
}
if (offset + size > new_size)
new_size = offset + size;
offset += size;
bufsize -= size;
buf += size;
}
if (force_sync)
handle->h_sync = 1; /* recovery likes this */
out:
if (bh)
brelse(bh);
/* correct in-core and on-disk sizes */
if (new_size > i_size_read(inode)) {
lock_kernel();
if (new_size > i_size_read(inode))
i_size_write(inode, new_size);
if (i_size_read(inode) > EXT3_I(inode)->i_disksize)
EXT3_I(inode)->i_disksize = i_size_read(inode);
if (i_size_read(inode) > old_size)
mark_inode_dirty(inode);
unlock_kernel();
}
_mlowerfs_ext3_journal_stop(handle);
if (err == 0)
*offs = offset;
return err;
}
