[PATCH] [9/13] quota-9-format2

Implementation of new quota format. The code is almost the same
as in -ac versions of kernel. All the code for new format is in
quota_v2.c

fs/Config.help

 CONFIG_QUOTA
   If you say Y here, you will be able to set per user limits for disk
-  usage (also called disk quotas). Currently, it works only for the
-  ext2 file system. You need additional software in order to use quota
-  support; for details, read the Quota mini-HOWTO, available from
+  usage (also called disk quotas). Currently, it works for the
+  ext2, ext3, and reiserfs file system. You need additional software
+  in order to use quota support (you can download sources from
+  <http://www.sf.net/projects/linuxquota/>). For further details, read
+  the Quota mini-HOWTO, available from
   <http://www.linuxdoc.org/docs.html#howto>. Probably the quota
   support is only useful for multi user systems. If unsure, say N.
 
@@ -11,6 +13,11 @@ CONFIG_QFMT_V1
   you have quota working and you don't want to convert to new quota
   format say Y here.
 
+CONFIG_QFMT_V2
+  This quota format allows using quotas with 32-bit UIDs/GIDs. If you
+  need this functionality say Y here. Note that you will need latest
+  quota utilities for new quota format with this kernel.
+
 CONFIG_MINIX_FS
   Minix is a simple operating system used in many classes about OS's.
   The minix file system (method to organize files on a hard disk

fs/Config.in

@@ -6,6 +6,7 @@ comment 'File systems'
 
 bool 'Quota support' CONFIG_QUOTA
 dep_tristate '  Old quota format support' CONFIG_QFMT_V1 $CONFIG_QUOTA
+dep_tristate '  VFS v0 quota format support' CONFIG_QFMT_V2 $CONFIG_QUOTA
 tristate 'Kernel automounter support' CONFIG_AUTOFS_FS
 tristate 'Kernel automounter version 4 support (also supports v3)' CONFIG_AUTOFS4_FS
 

fs/Makefile

@@ -83,6 +83,7 @@ obj-$(CONFIG_BINFMT_ELF)	+= binfmt_elf.o
 
 obj-$(CONFIG_QUOTA) += dquot.o
 obj-$(CONFIG_QFMT_V1) += quota_v1.o
+obj-$(CONFIG_QFMT_V2) += quota_v2.o
 
 # persistent filesystems
 obj-y += $(join $(subdir-y),$(subdir-y:%=/%.o))

include/linux/dqblk_v2.h

+/*
+ *	Definitions of structures for vfsv0 quota format
+ */
+
+#ifndef _LINUX_DQBLK_V2_H
+#define _LINUX_DQBLK_V2_H
+
+#include <linux/types.h>
+
+/* id numbers of quota format */
+#define QFMT_VFS_V0 2
+
+/* Inmemory copy of version specific information */
+struct v2_mem_dqinfo {
+	unsigned int dqi_blocks;
+	unsigned int dqi_free_blk;
+	unsigned int dqi_free_entry;
+};
+
+#endif /* _LINUX_DQBLK_V2_H */

include/linux/quota.h

@@ -136,6 +136,7 @@ struct if_dqinfo {
 
 #include <linux/xqm.h>
 #include <linux/dqblk_v1.h>
+#include <linux/dqblk_v2.h>
 
 /*
  * Data for one user/group kept in memory
@@ -163,6 +164,7 @@ struct mem_dqinfo {
 	unsigned int dqi_igrace;
 	union {
 		struct v1_mem_dqinfo v1_i;
+		struct v2_mem_dqinfo v2_i;
 	} u;
 };
 
@@ -214,6 +216,7 @@ struct dquot {
 	/* fields after this point are cleared when invalidating */
 	struct super_block *dq_sb;	/* superblock this applies to */
 	unsigned int dq_id;		/* ID this applies to (uid, gid) */
+	loff_t dq_off;			/* Offset of dquot on disk */
 	short dq_type;			/* Type of quota */
 	short dq_flags;			/* See DQ_* */
 	unsigned long dq_referenced;	/* Number of times this dquot was 

include/linux/quotaio_v2.h

+/*
+ *	Definitions of structures for vfsv0 quota format
+ */
+
+#ifndef _LINUX_QUOTAIO_V2_H
+#define _LINUX_QUOTAIO_V2_H
+
+#include <linux/types.h>
+#include <linux/quota.h>
+
+/*
+ * Definitions of magics and versions of current quota files
+ */
+#define V2_INITQMAGICS {\
+	0xd9c01f11,	/* USRQUOTA */\
+	0xd9c01927	/* GRPQUOTA */\
+}
+
+#define V2_INITQVERSIONS {\
+	0,		/* USRQUOTA */\
+	0		/* GRPQUOTA */\
+}
+
+/*
+ * The following structure defines the format of the disk quota file
+ * (as it appears on disk) - the file is a radix tree whose leaves point
+ * to blocks of these structures.
+ */
+struct v2_disk_dqblk {
+	__u32 dqb_id;		/* id this quota applies to */
+	__u32 dqb_ihardlimit;	/* absolute limit on allocated inodes */
+	__u32 dqb_isoftlimit;	/* preferred inode limit */
+	__u32 dqb_curinodes;	/* current # allocated inodes */
+	__u32 dqb_bhardlimit;	/* absolute limit on disk space (in QUOTABLOCK_SIZE) */
+	__u32 dqb_bsoftlimit;	/* preferred limit on disk space (in QUOTABLOCK_SIZE) */
+	__u64 dqb_curspace;	/* current space occupied (in bytes) */
+	__u64 dqb_btime;	/* time limit for excessive disk use */
+	__u64 dqb_itime;	/* time limit for excessive inode use */
+};
+
+/*
+ * Here are header structures as written on disk and their in-memory copies
+ */
+/* First generic header */
+struct v2_disk_dqheader {
+	__u32 dqh_magic;	/* Magic number identifying file */
+	__u32 dqh_version;	/* File version */
+};
+
+/* Header with type and version specific information */
+struct v2_disk_dqinfo {
+	__u32 dqi_bgrace;	/* Time before block soft limit becomes hard limit */
+	__u32 dqi_igrace;	/* Time before inode soft limit becomes hard limit */
+	__u32 dqi_flags;	/* Flags for quotafile (DQF_*) */
+	__u32 dqi_blocks;	/* Number of blocks in file */
+	__u32 dqi_free_blk;	/* Number of first free block in the list */
+	__u32 dqi_free_entry;	/* Number of block with at least one free entry */
+};
+
+/*
+ *  Structure of header of block with quota structures. It is padded to 16 bytes so
+ *  there will be space for exactly 18 quota-entries in a block
+ */
+struct v2_disk_dqdbheader {
+	__u32 dqdh_next_free;	/* Number of next block with free entry */
+	__u32 dqdh_prev_free;	/* Number of previous block with free entry */
+	__u16 dqdh_entries;	/* Number of valid entries in block */
+	__u16 dqdh_pad1;
+	__u32 dqdh_pad2;
+};
+
+#define V2_DQINFOOFF	sizeof(struct v2_disk_dqheader)	/* Offset of info header in file */
+#define V2_DQBLKSIZE_BITS	10
+#define V2_DQBLKSIZE	(1 << V2_DQBLKSIZE_BITS)	/* Size of block with quota structures */
+#define V2_DQTREEOFF	1		/* Offset of tree in file in blocks */
+#define V2_DQTREEDEPTH	4		/* Depth of quota tree */
+#define V2_DQSTRINBLK	((V2_DQBLKSIZE - sizeof(struct v2_disk_dqdbheader)) / sizeof(struct v2_disk_dqblk))	/* Number of entries in one blocks */
+
+#endif /* _LINUX_QUOTAIO_V2_H */