ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support

This patch adds FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR ioctl interface
support for ext4. The interface is kept consistent with
XFS_IOC_FSGETXATTR/XFS_IOC_FSGETXATTR.
Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>

fs/ext4/ext4.h

@@ -381,6 +381,13 @@ struct flex_groups {
 #define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
 #define EXT4_FL_USER_MODIFIABLE		0x204380FF /* User modifiable flags */
 
+#define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
+					 EXT4_IMMUTABLE_FL | \
+					 EXT4_APPEND_FL | \
+					 EXT4_NODUMP_FL | \
+					 EXT4_NOATIME_FL | \
+					 EXT4_PROJINHERIT_FL)
+
 /* Flags that should be inherited by new inodes from their parent. */
 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
@@ -619,6 +626,46 @@ enum {
 #define EXT4_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
 #define EXT4_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct ext4_encryption_policy)
 
+#ifndef FS_IOC_FSGETXATTR
+/* Until the uapi changes get merged for project quota... */
+
+#define FS_IOC_FSGETXATTR		_IOR('X', 31, struct fsxattr)
+#define FS_IOC_FSSETXATTR		_IOW('X', 32, struct fsxattr)
+
+/*
+ * Structure for FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR.
+ */
+struct fsxattr {
+	__u32		fsx_xflags;	/* xflags field value (get/set) */
+	__u32		fsx_extsize;	/* extsize field value (get/set)*/
+	__u32		fsx_nextents;	/* nextents field value (get)	*/
+	__u32		fsx_projid;	/* project identifier (get/set) */
+	unsigned char	fsx_pad[12];
+};
+
+/*
+ * Flags for the fsx_xflags field
+ */
+#define FS_XFLAG_REALTIME	0x00000001	/* data in realtime volume */
+#define FS_XFLAG_PREALLOC	0x00000002	/* preallocated file extents */
+#define FS_XFLAG_IMMUTABLE	0x00000008	/* file cannot be modified */
+#define FS_XFLAG_APPEND		0x00000010	/* all writes append */
+#define FS_XFLAG_SYNC		0x00000020	/* all writes synchronous */
+#define FS_XFLAG_NOATIME	0x00000040	/* do not update access time */
+#define FS_XFLAG_NODUMP		0x00000080	/* do not include in backups */
+#define FS_XFLAG_RTINHERIT	0x00000100	/* create with rt bit set */
+#define FS_XFLAG_PROJINHERIT	0x00000200	/* create with parents projid */
+#define FS_XFLAG_NOSYMLINKS	0x00000400	/* disallow symlink creation */
+#define FS_XFLAG_EXTSIZE	0x00000800	/* extent size allocator hint */
+#define FS_XFLAG_EXTSZINHERIT	0x00001000	/* inherit inode extent size */
+#define FS_XFLAG_NODEFRAG	0x00002000  	/* do not defragment */
+#define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
+#define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this */
+#endif /* !defined(FS_IOC_FSGETXATTR) */
+
+#define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR
+#define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR
+
 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 /*
  * ioctl commands in 32 bit emulation

fs/ext4/ioctl.c

@@ -14,6 +14,7 @@
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/random.h>
+#include <linux/quotaops.h>
 #include <asm/uaccess.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"
@@ -202,41 +203,16 @@ static int uuid_is_zero(__u8 u[16])
 	return 1;
 }
 
-long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+static int ext4_ioctl_setflags(struct inode *inode,
+			       unsigned int flags)
 {
-	struct inode *inode = file_inode(filp);
-	struct super_block *sb = inode->i_sb;
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	unsigned int flags;
-
-	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
-
-	switch (cmd) {
-	case EXT4_IOC_GETFLAGS:
-		ext4_get_inode_flags(ei);
-		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
-		return put_user(flags, (int __user *) arg);
-	case EXT4_IOC_SETFLAGS: {
 	handle_t *handle = NULL;
-		int err, migrate = 0;
+	int err = EPERM, migrate = 0;
 	struct ext4_iloc iloc;
 	unsigned int oldflags, mask, i;
 	unsigned int jflag;
 
-		if (!inode_owner_or_capable(inode))
-			return -EACCES;
-
-		if (get_user(flags, (int __user *) arg))
-			return -EFAULT;
-
-		err = mnt_want_write_file(filp);
-		if (err)
-			return err;
-
-		flags = ext4_mask_flags(inode->i_mode, flags);
-
-		err = -EPERM;
-		mutex_lock(&inode->i_mutex);
 	/* Is it quota file? Do not allow user to mess with it */
 	if (IS_NOQUOTA(inode))
 		goto flags_out;
@@ -318,6 +294,178 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	}
 
 flags_out:
+	return err;
+}
+
+#ifdef CONFIG_QUOTA
+static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+{
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	int err, rc;
+	handle_t *handle;
+	kprojid_t kprojid;
+	struct ext4_iloc iloc;
+	struct ext4_inode *raw_inode;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+			EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+		if (projid != EXT4_DEF_PROJID)
+			return -EOPNOTSUPP;
+		else
+			return 0;
+	}
+
+	if (EXT4_INODE_SIZE(sb) <= EXT4_GOOD_OLD_INODE_SIZE)
+		return -EOPNOTSUPP;
+
+	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 out_unlock;
+
+	err = ext4_get_inode_loc(inode, &iloc);
+	if (err)
+		goto out_unlock;
+
+	raw_inode = ext4_raw_inode(&iloc);
+	if (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) {
+		err = -EOVERFLOW;
+		brelse(iloc.bh);
+		goto out_unlock;
+	}
+	brelse(iloc.bh);
+
+	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 out_unlock;
+	}
+
+	err = ext4_reserve_inode_write(handle, inode, &iloc);
+	if (err)
+		goto out_stop;
+
+	if (sb_has_quota_limits_enabled(sb, PRJQUOTA)) {
+		struct dquot *transfer_to[MAXQUOTAS] = { };
+
+		transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
+		if (transfer_to[PRJQUOTA]) {
+			err = __dquot_transfer(inode, transfer_to);
+			dqput(transfer_to[PRJQUOTA]);
+			if (err)
+				goto out_dirty;
+		}
+	}
+	EXT4_I(inode)->i_projid = kprojid;
+	inode->i_ctime = ext4_current_time(inode);
+out_dirty:
+	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
+	if (!err)
+		err = rc;
+out_stop:
+	ext4_journal_stop(handle);
+out_unlock:
+	mutex_unlock(&inode->i_mutex);
+	mnt_drop_write_file(filp);
+	return err;
+}
+#else
+static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+{
+	if (projid != EXT4_DEF_PROJID)
+		return -EOPNOTSUPP;
+	return 0;
+}
+#endif
+
+/* Transfer internal flags to xflags */
+static inline __u32 ext4_iflags_to_xflags(unsigned long iflags)
+{
+	__u32 xflags = 0;
+
+	if (iflags & EXT4_SYNC_FL)
+		xflags |= FS_XFLAG_SYNC;
+	if (iflags & EXT4_IMMUTABLE_FL)
+		xflags |= FS_XFLAG_IMMUTABLE;
+	if (iflags & EXT4_APPEND_FL)
+		xflags |= FS_XFLAG_APPEND;
+	if (iflags & EXT4_NODUMP_FL)
+		xflags |= FS_XFLAG_NODUMP;
+	if (iflags & EXT4_NOATIME_FL)
+		xflags |= FS_XFLAG_NOATIME;
+	if (iflags & EXT4_PROJINHERIT_FL)
+		xflags |= FS_XFLAG_PROJINHERIT;
+	return xflags;
+}
+
+/* Transfer xflags flags to internal */
+static inline unsigned long ext4_xflags_to_iflags(__u32 xflags)
+{
+	unsigned long iflags = 0;
+
+	if (xflags & FS_XFLAG_SYNC)
+		iflags |= EXT4_SYNC_FL;
+	if (xflags & FS_XFLAG_IMMUTABLE)
+		iflags |= EXT4_IMMUTABLE_FL;
+	if (xflags & FS_XFLAG_APPEND)
+		iflags |= EXT4_APPEND_FL;
+	if (xflags & FS_XFLAG_NODUMP)
+		iflags |= EXT4_NODUMP_FL;
+	if (xflags & FS_XFLAG_NOATIME)
+		iflags |= EXT4_NOATIME_FL;
+	if (xflags & FS_XFLAG_PROJINHERIT)
+		iflags |= EXT4_PROJINHERIT_FL;
+
+	return iflags;
+}
+
+long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct super_block *sb = inode->i_sb;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	unsigned int flags;
+
+	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
+
+	switch (cmd) {
+	case EXT4_IOC_GETFLAGS:
+		ext4_get_inode_flags(ei);
+		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
+		return put_user(flags, (int __user *) arg);
+	case EXT4_IOC_SETFLAGS: {
+		int err;
+
+		if (!inode_owner_or_capable(inode))
+			return -EACCES;
+
+		if (get_user(flags, (int __user *) arg))
+			return -EFAULT;
+
+		err = mnt_want_write_file(filp);
+		if (err)
+			return err;
+
+		flags = ext4_mask_flags(inode->i_mode, flags);
+
+		mutex_lock(&inode->i_mutex);
+		err = ext4_ioctl_setflags(inode, flags);
 		mutex_unlock(&inode->i_mutex);
 		mnt_drop_write_file(filp);
 		return err;
@@ -689,6 +837,60 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return -EOPNOTSUPP;
 #endif
 	}
+	case EXT4_IOC_FSGETXATTR:
+	{
+		struct fsxattr fa;
+
+		memset(&fa, 0, sizeof(struct fsxattr));
+		ext4_get_inode_flags(ei);
+		fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE);
+
+		if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				EXT4_FEATURE_RO_COMPAT_PROJECT)) {
+			fa.fsx_projid = (__u32)from_kprojid(&init_user_ns,
+				EXT4_I(inode)->i_projid);
+		}
+
+		if (copy_to_user((struct fsxattr __user *)arg,
+				 &fa, sizeof(fa)))
+			return -EFAULT;
+		return 0;
+	}
+	case EXT4_IOC_FSSETXATTR:
+	{
+		struct fsxattr fa;
+		int err;
+
+		if (copy_from_user(&fa, (struct fsxattr __user *)arg,
+				   sizeof(fa)))
+			return -EFAULT;
+
+		/* Make sure caller has proper permission */
+		if (!inode_owner_or_capable(inode))
+			return -EACCES;
+
+		err = mnt_want_write_file(filp);
+		if (err)
+			return err;
+
+		flags = ext4_xflags_to_iflags(fa.fsx_xflags);
+		flags = ext4_mask_flags(inode->i_mode, flags);
+
+		mutex_lock(&inode->i_mutex);
+		flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
+			 (flags & EXT4_FL_XFLAG_VISIBLE);
+		err = ext4_ioctl_setflags(inode, flags);
+		mutex_unlock(&inode->i_mutex);
+		mnt_drop_write_file(filp);
+		if (err)
+			return err;
+
+		err = ext4_ioctl_setproject(filp, fa.fsx_projid);
+		if (err)
+			return err;
+
+		return 0;
+	}
 	default:
 		return -ENOTTY;
 	}