Commit 5a4b09ec authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: add support for WSL reparse points 



Add support for creating special files via WSL reparse points when
using 'reparse=wsl' mount option.  They're faster than NFS reparse
points because they don't require extra roundtrips to figure out what
->d_type a specific dirent is as such information is already stored in
query dir responses and then making getdents() calls faster.

Signed-off-by: default avatarPaulo Alcantara <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent fa792d8d

fs/smb/client/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -1374,6 +1374,7 @@ struct cifs_open_parms { 
	umode_t mode;

	bool reconnect:1;

	bool replay:1; /* indicates that this open is for a replay */

	struct kvec *ea_cctx;

};



struct cifs_fid {

fs/smb/client/fs_context.c

+2 −2
Original line number Diff line number Diff line
@@ -317,8 +317,8 @@ static int parse_reparse_flavor(struct fs_context *fc, char *value, 
		ctx->reparse_type = CIFS_REPARSE_TYPE_NFS;

		break;

	case Opt_reparse_wsl:

		cifs_errorf(fc, "unsupported reparse= option: %s\n", value);

		return 1;

		ctx->reparse_type = CIFS_REPARSE_TYPE_WSL;

		break;

	default:

		cifs_errorf(fc, "bad reparse= option: %s\n", value);

		return 1;

fs/smb/client/reparse.c

+165 −5
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "cifsproto.h"

#include "cifs_unicode.h"

#include "cifs_debug.h"

#include "fs_context.h"

#include "reparse.h"



int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
@@ -68,7 +69,7 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 
	iov.iov_base = buf;

	iov.iov_len = len;

	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,

				     tcon, full_path, &iov);

				     tcon, full_path, &iov, NULL);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

	else
@@ -114,7 +115,7 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf, 
	return 0;

}



int smb2_make_nfs_node(unsigned int xid, struct inode *inode,

static int mknod_nfs(unsigned int xid, struct inode *inode,

		     struct dentry *dentry, struct cifs_tcon *tcon,

		     const char *full_path, umode_t mode, dev_t dev)

{
@@ -136,7 +137,7 @@ int smb2_make_nfs_node(unsigned int xid, struct inode *inode, 
	};



	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,

				     tcon, full_path, &iov);

				     tcon, full_path, &iov, NULL);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

	else
@@ -145,6 +146,165 @@ int smb2_make_nfs_node(unsigned int xid, struct inode *inode, 
	return rc;

}



static int wsl_set_reparse_buf(struct reparse_data_buffer *buf,

			       mode_t mode, struct kvec *iov)

{

	u32 tag;



	switch ((tag = reparse_mode_wsl_tag(mode))) {

	case IO_REPARSE_TAG_LX_BLK:

	case IO_REPARSE_TAG_LX_CHR:

	case IO_REPARSE_TAG_LX_FIFO:

	case IO_REPARSE_TAG_AF_UNIX:

		break;

	default:

		return -EOPNOTSUPP;

	}



	buf->ReparseTag = cpu_to_le32(tag);

	buf->Reserved = 0;

	buf->ReparseDataLength = 0;

	iov->iov_base = buf;

	iov->iov_len = sizeof(*buf);

	return 0;

}



static struct smb2_create_ea_ctx *ea_create_context(u32 dlen, size_t *cc_len)

{

	struct smb2_create_ea_ctx *cc;



	*cc_len = round_up(sizeof(*cc) + dlen, 8);

	cc = kzalloc(*cc_len, GFP_KERNEL);

	if (!cc)

		return ERR_PTR(-ENOMEM);



	cc->ctx.NameOffset = cpu_to_le16(offsetof(struct smb2_create_ea_ctx,

						  name));

	cc->ctx.NameLength = cpu_to_le16(4);

	memcpy(cc->name, SMB2_CREATE_EA_BUFFER, strlen(SMB2_CREATE_EA_BUFFER));

	cc->ctx.DataOffset = cpu_to_le16(offsetof(struct smb2_create_ea_ctx, ea));

	cc->ctx.DataLength = cpu_to_le32(dlen);

	return cc;

}



struct wsl_xattr {

	const char	*name;

	__le64		value;

	u16		size;

	u32		next;

};



static int wsl_set_xattrs(struct inode *inode, umode_t _mode,

			  dev_t _dev, struct kvec *iov)

{

	struct smb2_file_full_ea_info *ea;

	struct smb2_create_ea_ctx *cc;

	struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;

	__le64 uid = cpu_to_le64(from_kuid(current_user_ns(), ctx->linux_uid));

	__le64 gid = cpu_to_le64(from_kgid(current_user_ns(), ctx->linux_gid));

	__le64 dev = cpu_to_le64(((u64)MINOR(_dev) << 32) | MAJOR(_dev));

	__le64 mode = cpu_to_le64(_mode);

	struct wsl_xattr xattrs[] = {

		{ .name = "$LXUID", .value = uid, .size = 4, },

		{ .name = "$LXGID", .value = gid, .size = 4, },

		{ .name = "$LXMOD", .value = mode, .size = 4, },

		{ .name = "$LXDEV", .value = dev, .size = 8, },

	};

	size_t cc_len;

	u32 dlen = 0, next = 0;

	int i, num_xattrs;

	u8 name_size = strlen(xattrs[0].name) + 1;



	memset(iov, 0, sizeof(*iov));



	/* Exclude $LXDEV xattr for sockets and fifos */

	if (S_ISSOCK(_mode) || S_ISFIFO(_mode))

		num_xattrs = ARRAY_SIZE(xattrs) - 1;

	else

		num_xattrs = ARRAY_SIZE(xattrs);



	for (i = 0; i < num_xattrs; i++) {

		xattrs[i].next = ALIGN(sizeof(*ea) + name_size +

				       xattrs[i].size, 4);

		dlen += xattrs[i].next;

	}



	cc = ea_create_context(dlen, &cc_len);

	if (!cc)

		return PTR_ERR(cc);



	ea = &cc->ea;

	for (i = 0; i < num_xattrs; i++) {

		ea = (void *)((u8 *)ea + next);

		next = xattrs[i].next;

		ea->next_entry_offset = cpu_to_le32(next);



		ea->ea_name_length = name_size - 1;

		ea->ea_value_length = cpu_to_le16(xattrs[i].size);

		memcpy(ea->ea_data, xattrs[i].name, name_size);

		memcpy(&ea->ea_data[name_size],

		       &xattrs[i].value, xattrs[i].size);

	}

	ea->next_entry_offset = 0;



	iov->iov_base = cc;

	iov->iov_len = cc_len;

	return 0;

}



static int mknod_wsl(unsigned int xid, struct inode *inode,

		     struct dentry *dentry, struct cifs_tcon *tcon,

		     const char *full_path, umode_t mode, dev_t dev)

{

	struct cifs_open_info_data data;

	struct reparse_data_buffer buf;

	struct inode *new;

	struct kvec reparse_iov, xattr_iov;

	int rc;



	rc = wsl_set_reparse_buf(&buf, mode, &reparse_iov);

	if (rc)

		return rc;



	rc = wsl_set_xattrs(inode, mode, dev, &xattr_iov);

	if (rc)

		return rc;



	data = (struct cifs_open_info_data) {

		.reparse_point = true,

		.reparse = { .tag = le32_to_cpu(buf.ReparseTag), .buf = &buf, },

	};



	new = smb2_get_reparse_inode(&data, inode->i_sb,

				     xid, tcon, full_path,

				     &reparse_iov, &xattr_iov);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

	else

		rc = PTR_ERR(new);

	cifs_free_open_info(&data);

	kfree(xattr_iov.iov_base);

	return rc;

}



int smb2_mknod_reparse(unsigned int xid, struct inode *inode,

		       struct dentry *dentry, struct cifs_tcon *tcon,

		       const char *full_path, umode_t mode, dev_t dev)

{

	struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;

	int rc = -EOPNOTSUPP;



	switch (ctx->reparse_type) {

	case CIFS_REPARSE_TYPE_NFS:

		rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev);

		break;

	case CIFS_REPARSE_TYPE_WSL:

		rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev);

		break;

	}

	return rc;

}



/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */

static int parse_reparse_posix(struct reparse_posix_data *buf,

			       struct cifs_sb_info *cifs_sb,

fs/smb/client/reparse.h

+12 −1
Original line number Diff line number Diff line
@@ -28,6 +28,17 @@ static inline u64 reparse_mode_nfs_type(mode_t mode) 
	return 0;

}



static inline u32 reparse_mode_wsl_tag(mode_t mode)

{

	switch (mode & S_IFMT) {

	case S_IFBLK: return IO_REPARSE_TAG_LX_BLK;

	case S_IFCHR: return IO_REPARSE_TAG_LX_CHR;

	case S_IFIFO: return IO_REPARSE_TAG_LX_FIFO;

	case S_IFSOCK: return IO_REPARSE_TAG_AF_UNIX;

	}

	return 0;

}



/*

 * Match a reparse point inode if reparse tag and ctime haven't changed.

 *
@@ -64,7 +75,7 @@ bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb, 
int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,

				struct dentry *dentry, struct cifs_tcon *tcon,

				const char *full_path, const char *symname);

int smb2_make_nfs_node(unsigned int xid, struct inode *inode,

int smb2_mknod_reparse(unsigned int xid, struct inode *inode,

		       struct dentry *dentry, struct cifs_tcon *tcon,

		       const char *full_path, umode_t mode, dev_t dev);

int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb, struct kvec *rsp_iov,

fs/smb/client/smb2inode.c

+6 −2
Original line number Diff line number Diff line
@@ -1060,7 +1060,8 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, 
				     const unsigned int xid,

				     struct cifs_tcon *tcon,

				     const char *full_path,

				     struct kvec *iov)

				     struct kvec *reparse_iov,

				     struct kvec *xattr_iov)

{

	struct cifs_open_parms oparms;

	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
@@ -1077,8 +1078,11 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, 
			     FILE_CREATE,

			     CREATE_NOT_DIR | OPEN_REPARSE_POINT,

			     ACL_NO_MODE);

	if (xattr_iov)

		oparms.ea_cctx = xattr_iov;



	cmds[0] = SMB2_OP_SET_REPARSE;

	in_iov[0] = *iov;

	in_iov[0] = *reparse_iov;

	in_iov[1].iov_base = data;

	in_iov[1].iov_len = sizeof(*data);