int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
handle_t *handle, struct inode *inode,
struct buffer_head *bh)
{
int err = 0;
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
if (err) {
/* Errors can only happen if there is a bug */
handle->h_err = err;
__ext4_journal_stop(where, line, handle);
}
} else {
if (inode)
mark_buffer_dirty_inode(bh, inode);
else
mark_buffer_dirty(bh);
if (inode && inode_needs_sync(inode)) {
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh)) {
struct ext4_super_block *es;
es = EXT4_SB(inode->i_sb)->s_es;
es->s_last_error_block =
cpu_to_le64(bh->b_blocknr);
ext4_error_inode(inode, where, line,
bh->b_blocknr,
"IO error syncing itable block");
err = -EIO;
}
}
}
return err;
}
int __ext4_journal_dirty_metadata(const char *where,
handle_t *handle, struct buffer_head *bh)
{
int err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
ext4_journal_abort_handle(where, __func__, bh, handle, err);
return err;
}
int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
handle_t *handle, struct inode *inode,
struct buffer_head *bh)
{
int err = 0;
might_sleep();
set_buffer_meta(bh);
set_buffer_prio(bh);
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
/* Errors can only happen if there is a bug */
if (WARN_ON_ONCE(err)) {
ext4_journal_abort_handle(where, line, __func__, bh,
handle, err);
if (inode == NULL) {
pr_err("EXT4: jbd2_journal_dirty_metadata "
"failed: handle type %u started at "
"line %u, credits %u/%u, errcode %d",
handle->h_type,
handle->h_line_no,
handle->h_requested_credits,
handle->h_buffer_credits, err);
return err;
}
ext4_error_inode(inode, where, line,
bh->b_blocknr,
"journal_dirty_metadata failed: "
"handle type %u started at line %u, "
"credits %u/%u, errcode %d",
handle->h_type,
handle->h_line_no,
handle->h_requested_credits,
handle->h_buffer_credits, err);
}
} else {
if (inode)
mark_buffer_dirty_inode(bh, inode);
else
mark_buffer_dirty(bh);
if (inode && inode_needs_sync(inode)) {
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh)) {
struct ext4_super_block *es;
es = EXT4_SB(inode->i_sb)->s_es;
es->s_last_error_block =
cpu_to_le64(bh->b_blocknr);
ext4_error_inode(inode, where, line,
bh->b_blocknr,
"IO error syncing itable block");
err = -EIO;
}
}
}
return err;
}
int __ext4_handle_dirty_super(const char *where, unsigned int line,
handle_t *handle, struct super_block *sb)
{
struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
int err = 0;
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
} else
sb->s_dirt = 1;
return err;
}
int __ext4_handle_dirty_super(const char *where, unsigned int line,
handle_t *handle, struct super_block *sb,
int now)
{
struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
int err = 0;
if (ext4_handle_valid(handle)) {
ext4_superblock_csum_set(sb,
(struct ext4_super_block *)bh->b_data);
err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
} else if (now) {
ext4_superblock_csum_set(sb,
(struct ext4_super_block *)bh->b_data);
mark_buffer_dirty(bh);
} else
sb->s_dirt = 1;
return err;
}
/* FIXME: The write support is rudimentary. I have not figured out a way to do writes
* from particular offsets (even though I have written some untested code for this below) efficiently. */
ssize_t simplefs_write(struct file * filp, const char __user * buf, size_t len,
loff_t * ppos)
{
/* After the commit dd37978c5 in the upstream linux kernel,
* we can use just filp->f_inode instead of the
* f->f_path.dentry->d_inode redirection */
struct inode *inode;
struct simplefs_inode *sfs_inode;
struct buffer_head *bh;
struct super_block *sb;
struct simplefs_super_block *sfs_sb;
handle_t *handle;
char *buffer;
int retval;
sb = filp->f_path.dentry->d_inode->i_sb;
sfs_sb = SIMPLEFS_SB(sb);
handle = jbd2_journal_start(sfs_sb->journal, 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
retval = generic_write_checks(filp, ppos, &len, 0);
if (retval)
return retval;
inode = filp->f_path.dentry->d_inode;
sfs_inode = SIMPLEFS_INODE(inode);
bh = sb_bread(filp->f_path.dentry->d_inode->i_sb,
sfs_inode->data_block_number);
if (!bh) {
printk(KERN_ERR "Reading the block number [%llu] failed.",
sfs_inode->data_block_number);
return 0;
}
buffer = (char *)bh->b_data;
/* Move the pointer until the required byte offset */
buffer += *ppos;
retval = jbd2_journal_get_write_access(handle, bh);
if (WARN_ON(retval)) {
brelse(bh);
sfs_trace("Can't get write access for bh\n");
return retval;
}
if (copy_from_user(buffer, buf, len)) {
brelse(bh);
printk(KERN_ERR
"Error copying file contents from the userspace buffer to the kernel space\n");
return -EFAULT;
}
*ppos += len;
retval = jbd2_journal_dirty_metadata(handle, bh);
if (WARN_ON(retval)) {
brelse(bh);
return retval;
}
handle->h_sync = 1;
retval = jbd2_journal_stop(handle);
if (WARN_ON(retval)) {
brelse(bh);
return retval;
}
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
brelse(bh);
/* Set new size
* sfs_inode->file_size = max(sfs_inode->file_size, *ppos);
*
* FIXME: What to do if someone writes only some parts in between ?
* The above code will also fail in case a file is overwritten with
* a shorter buffer */
if (mutex_lock_interruptible(&simplefs_inodes_mgmt_lock)) {
sfs_trace("Failed to acquire mutex lock\n");
return -EINTR;
}
sfs_inode->file_size = *ppos;
retval = simplefs_inode_save(sb, sfs_inode);
if (retval) {
len = retval;
}
mutex_unlock(&simplefs_inodes_mgmt_lock);
return len;
}
