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 | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 158 insertions(+)
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 791bed47..647677d 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -37,6 +37,7 @@
#include <linux/math64.h>
#include <linux/writeback.h>
#include <linux/cdev.h>
+#include <linux/quotaops.h>
#include "ubifs.h"
/*
@@ -911,6 +912,158 @@ 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;
+ 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;
+
+ 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;
+ }
+
+ while (toread > 0) {
+ tocopy = sb->s_blocksize - offset < toread ?
+ sb->s_blocksize - offset : toread;
+
+ 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(data, block_buf + offset, tocopy);
+ offset = 0;
+ block++;;
+ toread -= tocopy;
+ data += 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 = {};
+ struct ubifs_data_node *dn;
+ char *block_buf;
+
+ /*
+ * Since we budget at most two blocks (one for dirtied block and
+ * one for new block) here, then error out if the length out of
+ * what allowed. NOTE, the writing length from quota should never
+ * be larger than what we allowed here. Ext3 and Ext4 are also
+ * limiting more strict for the len to one block size.
+ */
+ if (sb->s_blocksize + (sb->s_blocksize - offset) < len) {
+ ubifs_err(c, "Quota write (off=%llu, len=%llu)"
+ " cancelled because length is too large",
+ (unsigned long long)off, (unsigned long long)len);
+ return -EIO;
+ }
+
+ if ((offset + len) > sb->s_blocksize)
+ req.new_block = 1;
+ if (offset)
+ req.dirtied_block = 1;
+
+ 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;
+ }
+
+ while (towrite > 0) {
+ tocopy = sb->s_blocksize - offset < towrite ?
+ sb->s_blocksize - offset : towrite;
+
+ if (offset || tocopy != sb->s_blocksize) {
+ 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);
+ if (err)
+ goto free_buf;
+ offset = 0;
+ block++;;
+ towrite -= tocopy;
+ data += tocopy;
+ }
+free_buf:
+ kfree(block_buf);
+free_dn:
+ kfree(dn);
+release_budget:
+ ubifs_release_budget(c, &req);
+out:
+ if (!err)
+ return len;
+ return err;
+}
+
+static struct dquot **ubifs_get_dquots(struct inode *inode)
+{
+ return ubifs_inode(inode)->i_dquot;
+}
+#endif
+
/*
* UBIFS mount options.
*
@@ -1887,6 +2040,11 @@ const struct super_operations ubifs_super_operations = {
.remount_fs = ubifs_remount_fs,
.show_options = ubifs_show_options,
.sync_fs = ubifs_sync_fs,
+#ifdef CONFIG_QUOTA
+ .quota_read = ubifs_quota_read,
+ .quota_write = ubifs_quota_write,
+ .get_dquots = ubifs_get_dquots,
+#endif
};
/**
--
1.8.4.2
--
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