On 08/04/2015 05:46 AM, Richard Weinberger wrote:
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.
Hm, okey. Good suggestion.
+ 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()?
okey, thanx
+ ret = ubifs_read_block(inode, block_buf, block, dn);
+ if (ret) {
+ if (ret != -ENOENT) {
if (ret && ret != -ENOENT)?
Yea, agree.
+ 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()?
Yes, correct.
+
+ /* Break to read the last block */
+ if (tocopy < sb->s_blocksize)
+ break;
Hmm, can't you combine this check with the above condition?
Sure.
+ ret = ubifs_read_block(inode, data, block, dn);
+ if (ret) {
+ if (ret != -ENOENT) {
See above.
Thanx
+ err = ret;
+ goto free_buf;
+ }
+ }
+ block++;;
superfluous semicolon.
Oh, right you are.
+ 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...
Good point. Will try it.
+ 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?
Ha, so we need a special writing function for quota file,
xxxfs_quota_write().
This function would bypass the quota recording, so quota
data would not be contained in by itself.
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.
Agree, thanx
+ 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.
Thanx a lot Richard.
Your review is always helpful to me.
Yang
Thanks,
//richard
.
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