3 files changed, 119 insertions, 15 deletions

diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index 43e3f566aad6..a223cf4faa9b 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -168,16 +168,15 @@ void jfs_dirty_inode(struct inode *inode)
         set_cflag(COMMIT_Dirty, inode);
 }
 
-static int
-jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
-                        struct buffer_head *bh_result, int create)
+int jfs_get_block(struct inode *ip, sector_t lblock,
+                  struct buffer_head *bh_result, int create)
 {
         s64 lblock64 = lblock;
         int rc = 0;
         xad_t xad;
         s64 xaddr;
         int xflag;
-        s32 xlen = max_blocks;
+        s32 xlen = bh_result->b_size >> ip->i_blkbits;
 
         /*
          * Take appropriate lock on inode
@@ -188,7 +187,7 @@ jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
                 IREAD_LOCK(ip);
 
         if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
-            (!xtLookup(ip, lblock64, max_blocks, &xflag, &xaddr, &xlen, 0)) &&
+            (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
             xaddr) {
                 if (xflag & XAD_NOTRECORDED) {
                         if (!create)
@@ -255,13 +254,6 @@ jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
         return rc;
 }
 
-static int jfs_get_block(struct inode *ip, sector_t lblock,
-                         struct buffer_head *bh_result, int create)
-{
-        return jfs_get_blocks(ip, lblock, bh_result->b_size >> ip->i_blkbits,
-                        bh_result, create);
-}
-
 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
 {
         return nobh_writepage(page, jfs_get_block, wbc);
diff --git a/fs/jfs/jfs_inode.h b/fs/jfs/jfs_inode.h
index b5c7da6190dc..1fc48df670c8 100644
--- a/fs/jfs/jfs_inode.h
+++ b/fs/jfs/jfs_inode.h
@@ -32,6 +32,7 @@ extern void jfs_truncate_nolock(struct inode *, loff_t);
 extern void jfs_free_zero_link(struct inode *);
 extern struct dentry *jfs_get_parent(struct dentry *dentry);
 extern void jfs_set_inode_flags(struct inode *);
+extern int jfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 
 extern const struct address_space_operations jfs_aops;
 extern struct inode_operations jfs_dir_inode_operations;
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 4f6cfebc82db..90ee0de829c1 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 +609,112 @@ 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;
+                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 +728,11 @@ 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 = {