Am 30.07.2015 um 07:48 schrieb Dongsheng Yang:
> We have to implement 3 functions to support quota in ubifs:
> ubifs_quota_read(), ubifs_quota_write() and ubifs_get_quotas()
>
> ubifs_quota_read():
> callback to read quota file.
> ubifs_quota_write():
> callback to write data to quota file.
> ubifs_get_quotas():
> callback to get quota instance for inode.
>
> Signed-off-by: Dongsheng Yang <yangds.fnst@xxxxxxxxxxxxxx>
> ---
> fs/ubifs/super.c | 219 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 219 insertions(+)
>
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index bc57685..3609d7b 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -940,6 +940,220 @@ static int check_volume_empty(struct ubifs_info *c)
> return 0;
> }
>
> +#ifdef CONFIG_QUOTA
> +static ssize_t ubifs_quota_read(struct super_block *sb, int type, char *data,
> + size_t len, loff_t off)
> +{
> + struct inode *inode = sb_dqopt(sb)->files[type];
> + unsigned long block = off >> UBIFS_BLOCK_SHIFT;
> + int offset = off & (sb->s_blocksize - 1);
> + int tocopy = 0;
> + size_t toread;
> + char *block_buf;
> + struct ubifs_data_node *dn;
> + int ret, err = 0;
> +
> + toread = len;
Minor nit, please group same types together and also group assignments
as other UBI/FS codes does.
> + dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
> + if (!dn) {
> + err = -ENOMEM;
> + goto out;
> + }
> +
> + block_buf = kmalloc(sb->s_blocksize, GFP_NOFS);
> + if (!block_buf) {
> + err = -ENOMEM;
> + goto free_dn;
> + }
> +
> + if (offset) {
> + /* Read the un-aligned data in first block */
> + tocopy = sb->s_blocksize - offset;
> + if (toread < tocopy)
> + tocopy = toread;
min()?
> + ret = ubifs_read_block(inode, block_buf, block, dn);
> + if (ret) {
> + if (ret != -ENOENT) {
if (ret && ret != -ENOENT)?
> + err = ret;
> + goto free_buf;
> + }
> + }
> +
> + memcpy(data, block_buf + offset, tocopy);
> +
> + block++;
> + toread -= tocopy;
> + data += tocopy;
> + tocopy = 0;
> + }
> +
> + while (toread > 0) {
> + tocopy = sb->s_blocksize < toread ?
> + sb->s_blocksize : toread;
min()?
> +
> + /* Break to read the last block */
> + if (tocopy < sb->s_blocksize)
> + break;
Hmm, can't you combine this check with the above condition?
> + ret = ubifs_read_block(inode, data, block, dn);
> + if (ret) {
> + if (ret != -ENOENT) {
See above.
> + err = ret;
> + goto free_buf;
> + }
> + }
> + block++;;
superfluous semicolon.
> + toread -= tocopy;
> + data += tocopy;
> + tocopy = 0;
> + }
> +
> + if (tocopy) {
> + /* Read the data in last block */
> + ret = ubifs_read_block(inode, block_buf, block, dn);
> + if (ret) {
> + if (ret != -ENOENT) {
See above. Maybe the -ENOENT stuff can be integrated into ubifs_read_block().
All callers deal with it the same way...
> + err = ret;
> + goto free_buf;
> + }
> + }
> +
> + memcpy(data, block_buf, tocopy);
> + }
> +free_buf:
> + kfree(block_buf);
> +free_dn:
> + kfree(dn);
> +out:
> + if (!err)
> + return len;
> + return err;
> +}
> +
> +static ssize_t ubifs_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];
> + unsigned long block = off >> UBIFS_BLOCK_SHIFT;
> + struct ubifs_info *c = inode->i_sb->s_fs_info;
> + int offset = off & (sb->s_blocksize - 1);
> + union ubifs_key key;
> + int tocopy = 0;
> + size_t towrite = len;
> + int ret, err = 0;
> + struct ubifs_budget_req req = {};
> + int new_block = 0;
> + struct ubifs_data_node *dn;
> + char *block_buf;
See above.
> + /* There are dirtied blocks and new blockes, but we call them all
> + * new blocks here, the budgeting is same for them.
> + */
> + new_block = DIV_ROUND_UP(len - (sb->s_blocksize - offset), sb->s_blocksize);
> + if (offset)
> + new_block += 1;
> +
> + req.new_block_num = new_block;
> +
> + err = ubifs_budget_space(c, &req);
> + if (err)
> + goto out;
> +
> + dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
> + if (!dn) {
> + err = -ENOMEM;
> + goto release_budget;
> + }
> +
> + block_buf = kmalloc(sb->s_blocksize, GFP_NOFS);
> + if (!block_buf) {
> + err = -ENOMEM;
> + goto free_dn;
> + }
> +
> + if (offset) {
> + /* Write the un-aligned data in first block */
> + tocopy = sb->s_blocksize - offset;
> + if (towrite < tocopy)
> + tocopy = towrite;
See above.
> + ret = ubifs_read_block(inode, block_buf, block, dn);
> + if (ret) {
> + if (ret != -ENOENT) {
> + err = ret;
> + goto free_buf;
> + }
> + memset(block_buf, 0, sb->s_blocksize);
> + }
> +
> + memcpy(block_buf + offset, data, tocopy);
> +
> + data_key_init(c, &key, inode->i_ino, block);
> + err = ubifs_jnl_write_data(c, inode, &key, block_buf, sb->s_blocksize);
Hmm, I'm confused. You write the block containing the quota information to an inode's data?
How can be determined whether data is real data and what is quota data?
This clearly shows that I know not much about the quota subsystem. 8^)
> + if (err) {
> + goto free_buf;
> + }
> + block++;
> + towrite -= tocopy;
> + data += tocopy;
> + tocopy = 0;
> + }
> +
> + while (towrite > 0) {
> + tocopy = sb->s_blocksize < towrite ?
> + sb->s_blocksize : towrite;
> +
> + /* Break to read the last block */
> + if (tocopy < sb->s_blocksize)
> + break;
See above. Maybe you can combine all this common code.
> + data_key_init(c, &key, inode->i_ino, block);
> + err = ubifs_jnl_write_data(c, inode, &key, data, sb->s_blocksize);
> + if (err)
> + goto free_buf;
> + block++;;
See above.
I'll review your other patches these days.
For now I'm too sleepy.
Thanks,
//richard
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