From: Jan Kara <jack@suse.cz>
Implementation of quota reading and writing functions for ext2.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/ext2/ext2.h | 1
25-akpm/fs/ext2/inode.c | 2
25-akpm/fs/ext2/super.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 107 insertions(+), 1 deletion(-)
diff -puN fs/ext2/ext2.h~fix-of-quota-deadlock-on-pagelock-ext2 fs/ext2/ext2.h
--- 25/fs/ext2/ext2.h~fix-of-quota-deadlock-on-pagelock-ext2 2004-11-30 01:23:16.281291976 -0800
+++ 25-akpm/fs/ext2/ext2.h 2004-11-30 01:23:16.288290912 -0800
@@ -119,6 +119,7 @@ extern int ext2_write_inode (struct inod
extern void ext2_delete_inode (struct inode *);
extern int ext2_sync_inode (struct inode *);
extern void ext2_discard_prealloc (struct inode *);
+extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern void ext2_truncate (struct inode *);
extern int ext2_setattr (struct dentry *, struct iattr *);
extern void ext2_set_inode_flags(struct inode *inode);
diff -puN fs/ext2/inode.c~fix-of-quota-deadlock-on-pagelock-ext2 fs/ext2/inode.c
--- 25/fs/ext2/inode.c~fix-of-quota-deadlock-on-pagelock-ext2 2004-11-30 01:23:16.282291824 -0800
+++ 25-akpm/fs/ext2/inode.c 2004-11-30 01:23:16.289290760 -0800
@@ -524,7 +524,7 @@ changed:
* reachable from inode.
*/
-static int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
{
int err = -EIO;
int offsets[4];
diff -puN fs/ext2/super.c~fix-of-quota-deadlock-on-pagelock-ext2 fs/ext2/super.c
--- 25/fs/ext2/super.c~fix-of-quota-deadlock-on-pagelock-ext2 2004-11-30 01:23:16.285291368 -0800
+++ 25-akpm/fs/ext2/super.c 2004-11-30 01:23:16.291290456 -0800
@@ -200,6 +200,11 @@ static void ext2_clear_inode(struct inod
}
+#ifdef CONFIG_QUOTA
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
+static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
+#endif
+
static struct super_operations ext2_sops = {
.alloc_inode = ext2_alloc_inode,
.destroy_inode = ext2_destroy_inode,
@@ -211,6 +216,10 @@ static struct super_operations ext2_sops
.statfs = ext2_statfs,
.remount_fs = ext2_remount,
.clear_inode = ext2_clear_inode,
+#ifdef CONFIG_QUOTA
+ .quota_read = ext2_quota_read,
+ .quota_write = ext2_quota_write,
+#endif
};
/* Yes, most of these are left as NULL!!
@@ -1000,6 +1009,102 @@ static struct super_block *ext2_get_sb(s
return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
}
+#ifdef CONFIG_QUOTA
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and noone else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t ext2_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 blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+ int err = 0, offset = off & (sb->s_blocksize - 1), tocopy;
+ size_t toread;
+ struct buffer_head tmp_bh, *bh;
+ 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;
+ while (toread > 0) {
+ tocopy = sb->s_blocksize - offset < toread ?
+ sb->s_blocksize - offset : toread;
+
+ tmp_bh.b_state = 0;
+ err = ext2_get_block(inode, blk, &tmp_bh, 0);
+ if (err)
+ return err;
+ if (!buffer_mapped(&tmp_bh)) /* A hole? */
+ memset(data, 0, tocopy);
+ else {
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ if (!bh)
+ return -EIO;
+ memcpy(data, bh->b_data+offset, tocopy);
+ brelse(bh);
+ }
+ offset = 0;
+ toread -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+ return len;
+}
+
+/* Write to quotafile */
+static ssize_t ext2_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 blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+ int err = 0, offset = off & (sb->s_blocksize - 1), tocopy;
+ size_t towrite = len;
+ struct buffer_head tmp_bh, *bh;
+
+ down(&inode->i_sem);
+ while (towrite > 0) {
+ tocopy = sb->s_blocksize - offset < towrite ?
+ sb->s_blocksize - offset : towrite;
+
+ tmp_bh.b_state = 0;
+ err = ext2_get_block(inode, blk, &tmp_bh, 1);
+ if (err)
+ goto out;
+ if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ else
+ bh = sb_getblk(sb, tmp_bh.b_blocknr);
+ if (!bh) {
+ err = -EIO;
+ goto out;
+ }
+ memcpy(bh->b_data+offset, data, tocopy);
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+ brelse(bh);
+ offset = 0;
+ towrite -= tocopy;
+ data += tocopy;
+ blk++;
+ }
+out:
+ if (len == towrite)
+ return err;
+ if (inode->i_size < off+len-towrite)
+ i_size_write(inode, off+len-towrite);
+ inode->i_version++;
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ mark_inode_dirty(inode);
+ up(&inode->i_sem);
+ return len - towrite;
+}
+
+#endif
+
static struct file_system_type ext2_fs_type = {
.owner = THIS_MODULE,
.name = "ext2",
_