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-rw-r--r--fs/jfs/super.c118
1 files changed, 115 insertions, 3 deletions
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 4f6cfeb..143bcd1 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -26,6 +26,7 @@
#include <linux/moduleparam.h>
#include <linux/kthread.h>
#include <linux/posix_acl.h>
+#include <linux/buffer_head.h>
#include <asm/uaccess.h>
#include <linux/seq_file.h>
@@ -298,7 +299,7 @@ static int parse_options(char *options, struct super_block *sb, s64 *newLVSize,
break;
}
-#if defined(CONFIG_QUOTA)
+#ifdef CONFIG_QUOTA
case Opt_quota:
case Opt_usrquota:
*flag |= JFS_USRQUOTA;
@@ -597,7 +598,7 @@ static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
if (sbi->flag & JFS_NOINTEGRITY)
seq_puts(seq, ",nointegrity");
-#if defined(CONFIG_QUOTA)
+#ifdef CONFIG_QUOTA
if (sbi->flag & JFS_USRQUOTA)
seq_puts(seq, ",usrquota");
@@ -608,6 +609,113 @@ static int jfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
return 0;
}
+#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 jfs_quota_read(struct super_block *sb, int type, char *data,
+ size_t len, loff_t off)
+{
+ struct inode *inode = sb_dqopt(sb)->files[type];
+ sector_t blk = off >> sb->s_blocksize_bits;
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t toread;
+ struct buffer_head tmp_bh;
+ struct buffer_head *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;
+ tmp_bh.b_size = 1 << inode->i_blkbits;
+ err = jfs_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 jfs_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];
+ sector_t blk = off >> sb->s_blocksize_bits;
+ int err = 0;
+ int offset = off & (sb->s_blocksize - 1);
+ int tocopy;
+ size_t towrite = len;
+ struct buffer_head tmp_bh;
+ struct buffer_head *bh;
+
+ mutex_lock(&inode->i_mutex);
+ while (towrite > 0) {
+ tocopy = sb->s_blocksize - offset < towrite ?
+ sb->s_blocksize - offset : towrite;
+
+ tmp_bh.b_state = 0;
+ tmp_bh.b_size = 1 << inode->i_blkbits;
+ err = jfs_get_block(inode, blk, &tmp_bh, 1);
+ if (err)
+ goto out;
+ if (offset || tocopy != sb->s_blocksize)
+ bh = sb_bread(sb, tmp_bh.b_blocknr);
+ else
+ bh = sb_getblk(sb, tmp_bh.b_blocknr);
+ if (!bh) {
+ err = -EIO;
+ goto out;
+ }
+ lock_buffer(bh);
+ memcpy(bh->b_data+offset, data, tocopy);
+ flush_dcache_page(bh->b_page);
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+ unlock_buffer(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);
+ mutex_unlock(&inode->i_mutex);
+ return len - towrite;
+}
+
+#endif
+
static struct super_operations jfs_super_operations = {
.alloc_inode = jfs_alloc_inode,
.destroy_inode = jfs_destroy_inode,
@@ -621,7 +729,11 @@ static struct super_operations jfs_super_operations = {
.unlockfs = jfs_unlockfs,
.statfs = jfs_statfs,
.remount_fs = jfs_remount,
- .show_options = jfs_show_options
+ .show_options = jfs_show_options,
+#ifdef CONFIG_QUOTA
+ .quota_read = jfs_quota_read,
+ .quota_write = jfs_quota_write,
+#endif
};
static struct export_operations jfs_export_operations = {
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