2014-08-08 16:45:01

by Li Xi

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] quota: add project quota support

Adds ioctl interface support for ext4 project

This patch adds ioctl interface for setting/getting project of ext4.

Signed-off-by: Li Xi <lixi <at> ddn.com>
Signed-off-by: Dmitry Monakhov <[email protected]>
---
Index: linux.git/fs/ext4/ext4.h
===================================================================
--- linux.git.orig/fs/ext4/ext4.h
+++ linux.git/fs/ext4/ext4.h
@@ -615,6 +615,8 @@ enum {
#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
#define EXT4_IOC_SWAP_BOOT _IO('f', 17)
#define EXT4_IOC_PRECACHE_EXTENTS _IO('f', 18)
+#define EXT4_IOC_GETPROJECT _IOR('f', 19, long)
+#define EXT4_IOC_SETPROJECT _IOW('f', 20, long)

#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
Index: linux.git/Documentation/filesystems/ext4.txt
===================================================================
--- linux.git.orig/Documentation/filesystems/ext4.txt
+++ linux.git/Documentation/filesystems/ext4.txt
@@ -609,6 +609,10 @@ EXT4_IOC_SWAP_BOOT Swap i_blocks a
The data blocks of the previous boot loader
will be associated with the given inode.

+ EXT4_IOC_GETPROJECT Get project ID associated with inode.
+
+ EXT4_IOC_SETPROJECT Set Project ID associated with inode.
+
..............................................................................

References
Index: linux.git/fs/ext4/ioctl.c
===================================================================
--- linux.git.orig/fs/ext4/ioctl.c
+++ linux.git/fs/ext4/ioctl.c
@@ -14,6 +14,8 @@
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/file.h>
+#include <linux/quotaops.h>
+#include <linux/quota.h>
#include <asm/uaccess.h>
#include "ext4_jbd2.h"
#include "ext4.h"
@@ -611,6 +613,104 @@ resizefs_out:
case EXT4_IOC_PRECACHE_EXTENTS:
return ext4_ext_precache(inode);

+ case EXT4_IOC_GETPROJECT:
+ {
+#ifdef CONFIG_QUOTA_PROJECT
+ __u32 projid;
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+ ext4_msg(sb, KERN_ERR,
+ "get project not supported without "
+ "project feature");
+ return -ENOTSUPP;
+ }
+
+ projid = (__u32)from_kprojid(&init_user_ns,
+ EXT4_I(inode)->i_projid);
+ return put_user(projid, (__u32 __user *) arg);
+#else
+ ext4_msg(sb, KERN_ERR,
+ "get project not supported without "
+ "CONFIG_QUOTA_PROJECT");
+ return -ENOTSUPP;
+#endif
+ }
+ case EXT4_IOC_SETPROJECT:
+ {
+#ifdef CONFIG_QUOTA_PROJECT
+ __u32 projid;
+ int err;
+ handle_t *handle;
+ kprojid_t kprojid;
+
+ struct dquot *transfer_to[MAXQUOTAS] = { };
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+ ext4_msg(sb, KERN_ERR,
+ "set project not supported without "
+ "project feature");
+ return -ENOTSUPP;
+ }
+
+ /* Make sure caller can change project. */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (get_user(projid, (__u32 __user *) arg))
+ return -EFAULT;
+
+ kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
+
+ if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
+ return 0;
+
+ err = mnt_want_write_file(filp);
+ if (err)
+ return err;
+
+ err = -EPERM;
+ mutex_lock(&inode->i_mutex);
+ /* Is it quota file? Do not allow user to mess with it */
+ if (IS_NOQUOTA(inode))
+ goto project_out;
+
+ dquot_initialize(inode);
+
+ handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
+ EXT4_QUOTA_INIT_BLOCKS(sb) +
+ EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+ goto project_out;
+ }
+
+ transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
+ if (!transfer_to[PRJQUOTA]) {
+ err = -ESRCH;
+ goto project_stop;
+ }
+ err = __dquot_transfer(inode, transfer_to);
+ dqput(transfer_to[PRJQUOTA]);
+ if (err)
+ goto project_stop;
+
+ EXT4_I(inode)->i_projid = kprojid;
+ err = ext4_mark_inode_dirty(handle, inode);
+project_stop:
+ ext4_journal_stop(handle);
+project_out:
+ mutex_unlock(&inode->i_mutex);
+ mnt_drop_write_file(filp);
+ return err;
+#else
+ ext4_msg(sb, KERN_ERR,
+ "set project not supported without "
+ "CONFIG_QUOTA_PROJECT");
+ return -ENOTSUPP;
+#endif
+ }
default:
return -ENOTTY;
}