Currently the default option is -o reparse=default which is same as
-o reparse=nfs. Currently mount option -o reparse=nfs does not create
symlink in NFS reparse point style, which is misleading.
Add new -o reparse= options "native", "native+nfs" and "native+wsl" to make
it more clear and allow to choose the expected reparse point types.
"native" would mean to create new special files only with reparse point
tags which are natively supported by SMB or Windows. Types which are not
natively supported cannot be created.
"native+nfs" would mean same as native, but fallback to "nfs" for
unsupported types.
"native+wsl" would mean to fallback to "wsl".
Change also meaning of "nfs" and "wsl" to always create special types with
nfs / wsl style.
And change also the default option to "native+nfs", so the default behavior
stay same as without this change. Without this change were all symlinks
created in native Windows/SMB form and this stay same with this change too.
Signed-off-by: Pali Rohár <pali@kernel.org>
---
fs/smb/client/cifsglob.h | 15 ++++++++--
fs/smb/client/fs_context.c | 12 ++++++++
fs/smb/client/fs_context.h | 3 ++
fs/smb/client/reparse.c | 58 +++++++++++++++++++++++++++++++-------
fs/smb/client/reparse.h | 2 ++
5 files changed, 77 insertions(+), 13 deletions(-)
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 260b553283ef..367f0ac6400d 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -154,14 +154,23 @@ enum securityEnum {
};
enum cifs_reparse_type {
- CIFS_REPARSE_TYPE_NFS,
- CIFS_REPARSE_TYPE_WSL,
- CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NFS,
+ CIFS_REPARSE_TYPE_NATIVE, /* native symlinks only */
+ CIFS_REPARSE_TYPE_NATIVE_NFS, /* native for symlinks, nfs for others */
+ CIFS_REPARSE_TYPE_NATIVE_WSL, /* native for symlinks, wsl for others */
+ CIFS_REPARSE_TYPE_NFS, /* nfs for everything */
+ CIFS_REPARSE_TYPE_WSL, /* wsl for everything */
+ CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NATIVE_NFS,
};
static inline const char *cifs_reparse_type_str(enum cifs_reparse_type type)
{
switch (type) {
+ case CIFS_REPARSE_TYPE_NATIVE:
+ return "native";
+ case CIFS_REPARSE_TYPE_NATIVE_NFS:
+ return "native+nfs";
+ case CIFS_REPARSE_TYPE_NATIVE_WSL:
+ return "native+wsl";
case CIFS_REPARSE_TYPE_NFS:
return "nfs";
case CIFS_REPARSE_TYPE_WSL:
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index 22b550860cc8..e5de84912e3d 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -303,6 +303,9 @@ cifs_parse_cache_flavor(struct fs_context *fc, char *value, struct smb3_fs_conte
static const match_table_t reparse_flavor_tokens = {
{ Opt_reparse_default, "default" },
+ { Opt_reparse_native, "native" },
+ { Opt_reparse_native_nfs, "native+nfs" },
+ { Opt_reparse_native_wsl, "native+wsl" },
{ Opt_reparse_nfs, "nfs" },
{ Opt_reparse_wsl, "wsl" },
{ Opt_reparse_err, NULL },
@@ -317,6 +320,15 @@ static int parse_reparse_flavor(struct fs_context *fc, char *value,
case Opt_reparse_default:
ctx->reparse_type = CIFS_REPARSE_TYPE_DEFAULT;
break;
+ case Opt_reparse_native:
+ ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE;
+ break;
+ case Opt_reparse_native_nfs:
+ ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_NFS;
+ break;
+ case Opt_reparse_native_wsl:
+ ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_WSL;
+ break;
case Opt_reparse_nfs:
ctx->reparse_type = CIFS_REPARSE_TYPE_NFS;
break;
diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
index 8dd12498ffd8..1011176ba3b7 100644
--- a/fs/smb/client/fs_context.h
+++ b/fs/smb/client/fs_context.h
@@ -43,6 +43,9 @@ enum {
enum cifs_reparse_parm {
Opt_reparse_default,
+ Opt_reparse_native,
+ Opt_reparse_native_nfs,
+ Opt_reparse_native_wsl,
Opt_reparse_nfs,
Opt_reparse_wsl,
Opt_reparse_err
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index 6e9d914bac41..38fe0a710c65 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -14,6 +14,20 @@
#include "fs_context.h"
#include "reparse.h"
+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,
+ const char *symname);
+
+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,
+ const char *symname);
+
+static int create_native_symlink(const unsigned int xid, struct inode *inode,
+ struct dentry *dentry, struct cifs_tcon *tcon,
+ const char *full_path, const char *symname);
+
static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
const unsigned int xid,
const char *full_path,
@@ -23,6 +37,26 @@ static int detect_directory_symlink_target(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)
+{
+ struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;
+
+ switch (ctx->reparse_type) {
+ case CIFS_REPARSE_TYPE_NATIVE:
+ case CIFS_REPARSE_TYPE_NATIVE_NFS:
+ case CIFS_REPARSE_TYPE_NATIVE_WSL:
+ return create_native_symlink(xid, inode, dentry, tcon, full_path, symname);
+ case CIFS_REPARSE_TYPE_NFS:
+ return mknod_nfs(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
+ case CIFS_REPARSE_TYPE_WSL:
+ return mknod_wsl(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int create_native_symlink(const unsigned int xid, struct inode *inode,
+ struct dentry *dentry, struct cifs_tcon *tcon,
+ const char *full_path, const char *symname)
{
struct reparse_symlink_data_buffer *buf = NULL;
struct cifs_open_info_data data = {};
@@ -363,6 +397,7 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
case NFS_SPECFILE_SOCK:
dlen = 0;
break;
+ case NFS_SPECFILE_LNK: /* TODO: add support for NFS symlinks */
default:
return -EOPNOTSUPP;
}
@@ -381,7 +416,8 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
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)
+ const char *full_path, umode_t mode, dev_t dev,
+ const char *symname)
{
struct cifs_open_info_data data;
struct reparse_posix_data *p;
@@ -421,6 +457,7 @@ static int wsl_set_reparse_buf(struct reparse_data_buffer *buf,
case IO_REPARSE_TAG_LX_FIFO:
case IO_REPARSE_TAG_AF_UNIX:
break;
+ case IO_REPARSE_TAG_LX_SYMLINK: /* TODO: add support for WSL symlinks */
default:
return -EOPNOTSUPP;
}
@@ -518,7 +555,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
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)
+ const char *full_path, umode_t mode, dev_t dev,
+ const char *symname)
{
struct cifs_open_info_data data;
struct reparse_data_buffer buf;
@@ -563,17 +601,17 @@ int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
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_NATIVE_NFS:
case CIFS_REPARSE_TYPE_NFS:
- rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev);
- break;
+ return mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
+ case CIFS_REPARSE_TYPE_NATIVE_WSL:
case CIFS_REPARSE_TYPE_WSL:
- rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev);
- break;
+ return mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
+ default:
+ return -EOPNOTSUPP;
}
- return rc;
}
/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
@@ -848,7 +886,7 @@ int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len,
return rc;
}
-static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
+static int parse_reparse_native_symlink(struct reparse_symlink_data_buffer *sym,
u32 plen, bool unicode,
struct cifs_sb_info *cifs_sb,
const char *full_path,
@@ -936,7 +974,7 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
return parse_reparse_posix((struct reparse_posix_data *)buf,
cifs_sb, data);
case IO_REPARSE_TAG_SYMLINK:
- return parse_reparse_symlink(
+ return parse_reparse_native_symlink(
(struct reparse_symlink_data_buffer *)buf,
plen, unicode, cifs_sb, full_path, data);
case IO_REPARSE_TAG_LX_SYMLINK:
diff --git a/fs/smb/client/reparse.h b/fs/smb/client/reparse.h
index eb6854e65e08..a6bdf20ce1b0 100644
--- a/fs/smb/client/reparse.h
+++ b/fs/smb/client/reparse.h
@@ -61,6 +61,7 @@ static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
static inline u64 reparse_mode_nfs_type(mode_t mode)
{
switch (mode & S_IFMT) {
+ case S_IFLNK: return NFS_SPECFILE_LNK;
case S_IFBLK: return NFS_SPECFILE_BLK;
case S_IFCHR: return NFS_SPECFILE_CHR;
case S_IFIFO: return NFS_SPECFILE_FIFO;
@@ -72,6 +73,7 @@ static inline u64 reparse_mode_nfs_type(mode_t mode)
static inline u32 reparse_mode_wsl_tag(mode_t mode)
{
switch (mode & S_IFMT) {
+ case S_IFLNK: return IO_REPARSE_TAG_LX_SYMLINK;
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;
--
2.20.1
This is a good point about how to override the "native" symlink format
when using reparse=nfs (a similar question could come up, if for
security reasons you use "mfsymlinks" for symlinks - ie "client side
symlinks" (which are safer) - but use reparse=nfs for everything else.
But ... there is probably a better way to handle the mount option
for default symlink creation format more clearly (perhaps use of
"nativesymlinks" (default) or "mfsymlinks" if specified, overrides
"reparse=wsl" or "reparse=nfs" for symlink format only. User can
specify "nativesymlinks=no" if they want to use the "reparse=" format
for symlinks. For the sfu case it might be trickier but could fall
back to sfu symlinks if "nativesymlinks=no" or if they fail?!
Thoughts?
On Sun, Oct 6, 2024 at 5:01 AM Pali Rohár <pali@kernel.org> wrote:
>
> Currently the default option is -o reparse=default which is same as
> -o reparse=nfs. Currently mount option -o reparse=nfs does not create
> symlink in NFS reparse point style, which is misleading.
>
> Add new -o reparse= options "native", "native+nfs" and "native+wsl" to make
> it more clear and allow to choose the expected reparse point types.
>
> "native" would mean to create new special files only with reparse point
> tags which are natively supported by SMB or Windows. Types which are not
> natively supported cannot be created.
>
> "native+nfs" would mean same as native, but fallback to "nfs" for
> unsupported types.
>
> "native+wsl" would mean to fallback to "wsl".
>
> Change also meaning of "nfs" and "wsl" to always create special types with
> nfs / wsl style.
>
> And change also the default option to "native+nfs", so the default behavior
> stay same as without this change. Without this change were all symlinks
> created in native Windows/SMB form and this stay same with this change too.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
> fs/smb/client/cifsglob.h | 15 ++++++++--
> fs/smb/client/fs_context.c | 12 ++++++++
> fs/smb/client/fs_context.h | 3 ++
> fs/smb/client/reparse.c | 58 +++++++++++++++++++++++++++++++-------
> fs/smb/client/reparse.h | 2 ++
> 5 files changed, 77 insertions(+), 13 deletions(-)
>
> diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
> index 260b553283ef..367f0ac6400d 100644
> --- a/fs/smb/client/cifsglob.h
> +++ b/fs/smb/client/cifsglob.h
> @@ -154,14 +154,23 @@ enum securityEnum {
> };
>
> enum cifs_reparse_type {
> - CIFS_REPARSE_TYPE_NFS,
> - CIFS_REPARSE_TYPE_WSL,
> - CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NFS,
> + CIFS_REPARSE_TYPE_NATIVE, /* native symlinks only */
> + CIFS_REPARSE_TYPE_NATIVE_NFS, /* native for symlinks, nfs for others */
> + CIFS_REPARSE_TYPE_NATIVE_WSL, /* native for symlinks, wsl for others */
> + CIFS_REPARSE_TYPE_NFS, /* nfs for everything */
> + CIFS_REPARSE_TYPE_WSL, /* wsl for everything */
> + CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NATIVE_NFS,
> };
>
> static inline const char *cifs_reparse_type_str(enum cifs_reparse_type type)
> {
> switch (type) {
> + case CIFS_REPARSE_TYPE_NATIVE:
> + return "native";
> + case CIFS_REPARSE_TYPE_NATIVE_NFS:
> + return "native+nfs";
> + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> + return "native+wsl";
> case CIFS_REPARSE_TYPE_NFS:
> return "nfs";
> case CIFS_REPARSE_TYPE_WSL:
> diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
> index 22b550860cc8..e5de84912e3d 100644
> --- a/fs/smb/client/fs_context.c
> +++ b/fs/smb/client/fs_context.c
> @@ -303,6 +303,9 @@ cifs_parse_cache_flavor(struct fs_context *fc, char *value, struct smb3_fs_conte
>
> static const match_table_t reparse_flavor_tokens = {
> { Opt_reparse_default, "default" },
> + { Opt_reparse_native, "native" },
> + { Opt_reparse_native_nfs, "native+nfs" },
> + { Opt_reparse_native_wsl, "native+wsl" },
> { Opt_reparse_nfs, "nfs" },
> { Opt_reparse_wsl, "wsl" },
> { Opt_reparse_err, NULL },
> @@ -317,6 +320,15 @@ static int parse_reparse_flavor(struct fs_context *fc, char *value,
> case Opt_reparse_default:
> ctx->reparse_type = CIFS_REPARSE_TYPE_DEFAULT;
> break;
> + case Opt_reparse_native:
> + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE;
> + break;
> + case Opt_reparse_native_nfs:
> + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_NFS;
> + break;
> + case Opt_reparse_native_wsl:
> + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_WSL;
> + break;
> case Opt_reparse_nfs:
> ctx->reparse_type = CIFS_REPARSE_TYPE_NFS;
> break;
> diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
> index 8dd12498ffd8..1011176ba3b7 100644
> --- a/fs/smb/client/fs_context.h
> +++ b/fs/smb/client/fs_context.h
> @@ -43,6 +43,9 @@ enum {
>
> enum cifs_reparse_parm {
> Opt_reparse_default,
> + Opt_reparse_native,
> + Opt_reparse_native_nfs,
> + Opt_reparse_native_wsl,
> Opt_reparse_nfs,
> Opt_reparse_wsl,
> Opt_reparse_err
> diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
> index 6e9d914bac41..38fe0a710c65 100644
> --- a/fs/smb/client/reparse.c
> +++ b/fs/smb/client/reparse.c
> @@ -14,6 +14,20 @@
> #include "fs_context.h"
> #include "reparse.h"
>
> +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,
> + const char *symname);
> +
> +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,
> + const char *symname);
> +
> +static int create_native_symlink(const unsigned int xid, struct inode *inode,
> + struct dentry *dentry, struct cifs_tcon *tcon,
> + const char *full_path, const char *symname);
> +
> static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
> const unsigned int xid,
> const char *full_path,
> @@ -23,6 +37,26 @@ static int detect_directory_symlink_target(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)
> +{
> + struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;
> +
> + switch (ctx->reparse_type) {
> + case CIFS_REPARSE_TYPE_NATIVE:
> + case CIFS_REPARSE_TYPE_NATIVE_NFS:
> + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> + return create_native_symlink(xid, inode, dentry, tcon, full_path, symname);
> + case CIFS_REPARSE_TYPE_NFS:
> + return mknod_nfs(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
> + case CIFS_REPARSE_TYPE_WSL:
> + return mknod_wsl(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static int create_native_symlink(const unsigned int xid, struct inode *inode,
> + struct dentry *dentry, struct cifs_tcon *tcon,
> + const char *full_path, const char *symname)
> {
> struct reparse_symlink_data_buffer *buf = NULL;
> struct cifs_open_info_data data = {};
> @@ -363,6 +397,7 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
> case NFS_SPECFILE_SOCK:
> dlen = 0;
> break;
> + case NFS_SPECFILE_LNK: /* TODO: add support for NFS symlinks */
> default:
> return -EOPNOTSUPP;
> }
> @@ -381,7 +416,8 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
>
> 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)
> + const char *full_path, umode_t mode, dev_t dev,
> + const char *symname)
> {
> struct cifs_open_info_data data;
> struct reparse_posix_data *p;
> @@ -421,6 +457,7 @@ static int wsl_set_reparse_buf(struct reparse_data_buffer *buf,
> case IO_REPARSE_TAG_LX_FIFO:
> case IO_REPARSE_TAG_AF_UNIX:
> break;
> + case IO_REPARSE_TAG_LX_SYMLINK: /* TODO: add support for WSL symlinks */
> default:
> return -EOPNOTSUPP;
> }
> @@ -518,7 +555,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
>
> 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)
> + const char *full_path, umode_t mode, dev_t dev,
> + const char *symname)
> {
> struct cifs_open_info_data data;
> struct reparse_data_buffer buf;
> @@ -563,17 +601,17 @@ int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
> 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_NATIVE_NFS:
> case CIFS_REPARSE_TYPE_NFS:
> - rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev);
> - break;
> + return mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
> + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> case CIFS_REPARSE_TYPE_WSL:
> - rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev);
> - break;
> + return mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
> + default:
> + return -EOPNOTSUPP;
> }
> - return rc;
> }
>
> /* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
> @@ -848,7 +886,7 @@ int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len,
> return rc;
> }
>
> -static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
> +static int parse_reparse_native_symlink(struct reparse_symlink_data_buffer *sym,
> u32 plen, bool unicode,
> struct cifs_sb_info *cifs_sb,
> const char *full_path,
> @@ -936,7 +974,7 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
> return parse_reparse_posix((struct reparse_posix_data *)buf,
> cifs_sb, data);
> case IO_REPARSE_TAG_SYMLINK:
> - return parse_reparse_symlink(
> + return parse_reparse_native_symlink(
> (struct reparse_symlink_data_buffer *)buf,
> plen, unicode, cifs_sb, full_path, data);
> case IO_REPARSE_TAG_LX_SYMLINK:
> diff --git a/fs/smb/client/reparse.h b/fs/smb/client/reparse.h
> index eb6854e65e08..a6bdf20ce1b0 100644
> --- a/fs/smb/client/reparse.h
> +++ b/fs/smb/client/reparse.h
> @@ -61,6 +61,7 @@ static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
> static inline u64 reparse_mode_nfs_type(mode_t mode)
> {
> switch (mode & S_IFMT) {
> + case S_IFLNK: return NFS_SPECFILE_LNK;
> case S_IFBLK: return NFS_SPECFILE_BLK;
> case S_IFCHR: return NFS_SPECFILE_CHR;
> case S_IFIFO: return NFS_SPECFILE_FIFO;
> @@ -72,6 +73,7 @@ static inline u64 reparse_mode_nfs_type(mode_t mode)
> static inline u32 reparse_mode_wsl_tag(mode_t mode)
> {
> switch (mode & S_IFMT) {
> + case S_IFLNK: return IO_REPARSE_TAG_LX_SYMLINK;
> 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;
> --
> 2.20.1
>
>
--
Thanks,
Steve
Currently choosing how new symlinks are created is quite complicated.
Without these patch series, by default new symlinks are created via
native reparse points, even when reparse=nfs or reparse=wsl is
specified. There is no possibility to create a NFS-style or WSL-style
symlink yet, and this patch series address this missing functionality.
When option -o sfu is specified then all new symlinks are created in
SFU-style, independently of -o reparse option. And when -o mfsymlinks is
specified then all new symlinks are created in mf style, independently
of -o reparse and -o sfu options.
This patch series does not change -o sfu and -o mfsymlinks overrides, it
just changes the way how -o reparse is handled.
I think that we have too many mount options which specify ability to
choose symlink format and complicated overrides, which option has higher
priority than other.
What about rather introducing a new option like:
-o symlinkformat=native|nfs|wsl|sfu|mf|unix|none
which explicitly say which format will be chosen when creating a new
symlink?
IIRC in SMB we can create a new symlink via:
- ioctl with native symlink reparse point
- ioctl with nfs reparse point
- ioctl with wsl symlink reparse point
- create sfu system file
- create mf file
- SMB1 unix create symlink command
(have I forgot for something?)
On Sunday 06 October 2024 23:28:29 Steve French wrote:
> This is a good point about how to override the "native" symlink format
> when using reparse=nfs (a similar question could come up, if for
> security reasons you use "mfsymlinks" for symlinks - ie "client side
> symlinks" (which are safer) - but use reparse=nfs for everything else.
> But ... there is probably a better way to handle the mount option
> for default symlink creation format more clearly (perhaps use of
> "nativesymlinks" (default) or "mfsymlinks" if specified, overrides
> "reparse=wsl" or "reparse=nfs" for symlink format only. User can
> specify "nativesymlinks=no" if they want to use the "reparse=" format
> for symlinks. For the sfu case it might be trickier but could fall
> back to sfu symlinks if "nativesymlinks=no" or if they fail?!
> Thoughts?
>
> On Sun, Oct 6, 2024 at 5:01 AM Pali Rohár <pali@kernel.org> wrote:
> >
> > Currently the default option is -o reparse=default which is same as
> > -o reparse=nfs. Currently mount option -o reparse=nfs does not create
> > symlink in NFS reparse point style, which is misleading.
> >
> > Add new -o reparse= options "native", "native+nfs" and "native+wsl" to make
> > it more clear and allow to choose the expected reparse point types.
> >
> > "native" would mean to create new special files only with reparse point
> > tags which are natively supported by SMB or Windows. Types which are not
> > natively supported cannot be created.
> >
> > "native+nfs" would mean same as native, but fallback to "nfs" for
> > unsupported types.
> >
> > "native+wsl" would mean to fallback to "wsl".
> >
> > Change also meaning of "nfs" and "wsl" to always create special types with
> > nfs / wsl style.
> >
> > And change also the default option to "native+nfs", so the default behavior
> > stay same as without this change. Without this change were all symlinks
> > created in native Windows/SMB form and this stay same with this change too.
> >
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> > ---
> > fs/smb/client/cifsglob.h | 15 ++++++++--
> > fs/smb/client/fs_context.c | 12 ++++++++
> > fs/smb/client/fs_context.h | 3 ++
> > fs/smb/client/reparse.c | 58 +++++++++++++++++++++++++++++++-------
> > fs/smb/client/reparse.h | 2 ++
> > 5 files changed, 77 insertions(+), 13 deletions(-)
> >
> > diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
> > index 260b553283ef..367f0ac6400d 100644
> > --- a/fs/smb/client/cifsglob.h
> > +++ b/fs/smb/client/cifsglob.h
> > @@ -154,14 +154,23 @@ enum securityEnum {
> > };
> >
> > enum cifs_reparse_type {
> > - CIFS_REPARSE_TYPE_NFS,
> > - CIFS_REPARSE_TYPE_WSL,
> > - CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NFS,
> > + CIFS_REPARSE_TYPE_NATIVE, /* native symlinks only */
> > + CIFS_REPARSE_TYPE_NATIVE_NFS, /* native for symlinks, nfs for others */
> > + CIFS_REPARSE_TYPE_NATIVE_WSL, /* native for symlinks, wsl for others */
> > + CIFS_REPARSE_TYPE_NFS, /* nfs for everything */
> > + CIFS_REPARSE_TYPE_WSL, /* wsl for everything */
> > + CIFS_REPARSE_TYPE_DEFAULT = CIFS_REPARSE_TYPE_NATIVE_NFS,
> > };
> >
> > static inline const char *cifs_reparse_type_str(enum cifs_reparse_type type)
> > {
> > switch (type) {
> > + case CIFS_REPARSE_TYPE_NATIVE:
> > + return "native";
> > + case CIFS_REPARSE_TYPE_NATIVE_NFS:
> > + return "native+nfs";
> > + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> > + return "native+wsl";
> > case CIFS_REPARSE_TYPE_NFS:
> > return "nfs";
> > case CIFS_REPARSE_TYPE_WSL:
> > diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
> > index 22b550860cc8..e5de84912e3d 100644
> > --- a/fs/smb/client/fs_context.c
> > +++ b/fs/smb/client/fs_context.c
> > @@ -303,6 +303,9 @@ cifs_parse_cache_flavor(struct fs_context *fc, char *value, struct smb3_fs_conte
> >
> > static const match_table_t reparse_flavor_tokens = {
> > { Opt_reparse_default, "default" },
> > + { Opt_reparse_native, "native" },
> > + { Opt_reparse_native_nfs, "native+nfs" },
> > + { Opt_reparse_native_wsl, "native+wsl" },
> > { Opt_reparse_nfs, "nfs" },
> > { Opt_reparse_wsl, "wsl" },
> > { Opt_reparse_err, NULL },
> > @@ -317,6 +320,15 @@ static int parse_reparse_flavor(struct fs_context *fc, char *value,
> > case Opt_reparse_default:
> > ctx->reparse_type = CIFS_REPARSE_TYPE_DEFAULT;
> > break;
> > + case Opt_reparse_native:
> > + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE;
> > + break;
> > + case Opt_reparse_native_nfs:
> > + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_NFS;
> > + break;
> > + case Opt_reparse_native_wsl:
> > + ctx->reparse_type = CIFS_REPARSE_TYPE_NATIVE_WSL;
> > + break;
> > case Opt_reparse_nfs:
> > ctx->reparse_type = CIFS_REPARSE_TYPE_NFS;
> > break;
> > diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
> > index 8dd12498ffd8..1011176ba3b7 100644
> > --- a/fs/smb/client/fs_context.h
> > +++ b/fs/smb/client/fs_context.h
> > @@ -43,6 +43,9 @@ enum {
> >
> > enum cifs_reparse_parm {
> > Opt_reparse_default,
> > + Opt_reparse_native,
> > + Opt_reparse_native_nfs,
> > + Opt_reparse_native_wsl,
> > Opt_reparse_nfs,
> > Opt_reparse_wsl,
> > Opt_reparse_err
> > diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
> > index 6e9d914bac41..38fe0a710c65 100644
> > --- a/fs/smb/client/reparse.c
> > +++ b/fs/smb/client/reparse.c
> > @@ -14,6 +14,20 @@
> > #include "fs_context.h"
> > #include "reparse.h"
> >
> > +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,
> > + const char *symname);
> > +
> > +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,
> > + const char *symname);
> > +
> > +static int create_native_symlink(const unsigned int xid, struct inode *inode,
> > + struct dentry *dentry, struct cifs_tcon *tcon,
> > + const char *full_path, const char *symname);
> > +
> > static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
> > const unsigned int xid,
> > const char *full_path,
> > @@ -23,6 +37,26 @@ static int detect_directory_symlink_target(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)
> > +{
> > + struct smb3_fs_context *ctx = CIFS_SB(inode->i_sb)->ctx;
> > +
> > + switch (ctx->reparse_type) {
> > + case CIFS_REPARSE_TYPE_NATIVE:
> > + case CIFS_REPARSE_TYPE_NATIVE_NFS:
> > + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> > + return create_native_symlink(xid, inode, dentry, tcon, full_path, symname);
> > + case CIFS_REPARSE_TYPE_NFS:
> > + return mknod_nfs(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
> > + case CIFS_REPARSE_TYPE_WSL:
> > + return mknod_wsl(xid, inode, dentry, tcon, full_path, S_IFLNK, 0, symname);
> > + default:
> > + return -EOPNOTSUPP;
> > + }
> > +}
> > +
> > +static int create_native_symlink(const unsigned int xid, struct inode *inode,
> > + struct dentry *dentry, struct cifs_tcon *tcon,
> > + const char *full_path, const char *symname)
> > {
> > struct reparse_symlink_data_buffer *buf = NULL;
> > struct cifs_open_info_data data = {};
> > @@ -363,6 +397,7 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
> > case NFS_SPECFILE_SOCK:
> > dlen = 0;
> > break;
> > + case NFS_SPECFILE_LNK: /* TODO: add support for NFS symlinks */
> > default:
> > return -EOPNOTSUPP;
> > }
> > @@ -381,7 +416,8 @@ static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
> >
> > 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)
> > + const char *full_path, umode_t mode, dev_t dev,
> > + const char *symname)
> > {
> > struct cifs_open_info_data data;
> > struct reparse_posix_data *p;
> > @@ -421,6 +457,7 @@ static int wsl_set_reparse_buf(struct reparse_data_buffer *buf,
> > case IO_REPARSE_TAG_LX_FIFO:
> > case IO_REPARSE_TAG_AF_UNIX:
> > break;
> > + case IO_REPARSE_TAG_LX_SYMLINK: /* TODO: add support for WSL symlinks */
> > default:
> > return -EOPNOTSUPP;
> > }
> > @@ -518,7 +555,8 @@ static int wsl_set_xattrs(struct inode *inode, umode_t _mode,
> >
> > 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)
> > + const char *full_path, umode_t mode, dev_t dev,
> > + const char *symname)
> > {
> > struct cifs_open_info_data data;
> > struct reparse_data_buffer buf;
> > @@ -563,17 +601,17 @@ int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
> > 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_NATIVE_NFS:
> > case CIFS_REPARSE_TYPE_NFS:
> > - rc = mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev);
> > - break;
> > + return mknod_nfs(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
> > + case CIFS_REPARSE_TYPE_NATIVE_WSL:
> > case CIFS_REPARSE_TYPE_WSL:
> > - rc = mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev);
> > - break;
> > + return mknod_wsl(xid, inode, dentry, tcon, full_path, mode, dev, NULL);
> > + default:
> > + return -EOPNOTSUPP;
> > }
> > - return rc;
> > }
> >
> > /* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
> > @@ -848,7 +886,7 @@ int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len,
> > return rc;
> > }
> >
> > -static int parse_reparse_symlink(struct reparse_symlink_data_buffer *sym,
> > +static int parse_reparse_native_symlink(struct reparse_symlink_data_buffer *sym,
> > u32 plen, bool unicode,
> > struct cifs_sb_info *cifs_sb,
> > const char *full_path,
> > @@ -936,7 +974,7 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
> > return parse_reparse_posix((struct reparse_posix_data *)buf,
> > cifs_sb, data);
> > case IO_REPARSE_TAG_SYMLINK:
> > - return parse_reparse_symlink(
> > + return parse_reparse_native_symlink(
> > (struct reparse_symlink_data_buffer *)buf,
> > plen, unicode, cifs_sb, full_path, data);
> > case IO_REPARSE_TAG_LX_SYMLINK:
> > diff --git a/fs/smb/client/reparse.h b/fs/smb/client/reparse.h
> > index eb6854e65e08..a6bdf20ce1b0 100644
> > --- a/fs/smb/client/reparse.h
> > +++ b/fs/smb/client/reparse.h
> > @@ -61,6 +61,7 @@ static inline kgid_t wsl_make_kgid(struct cifs_sb_info *cifs_sb,
> > static inline u64 reparse_mode_nfs_type(mode_t mode)
> > {
> > switch (mode & S_IFMT) {
> > + case S_IFLNK: return NFS_SPECFILE_LNK;
> > case S_IFBLK: return NFS_SPECFILE_BLK;
> > case S_IFCHR: return NFS_SPECFILE_CHR;
> > case S_IFIFO: return NFS_SPECFILE_FIFO;
> > @@ -72,6 +73,7 @@ static inline u64 reparse_mode_nfs_type(mode_t mode)
> > static inline u32 reparse_mode_wsl_tag(mode_t mode)
> > {
> > switch (mode & S_IFMT) {
> > + case S_IFLNK: return IO_REPARSE_TAG_LX_SYMLINK;
> > 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;
> > --
> > 2.20.1
> >
> >
>
>
> --
> Thanks,
>
> Steve
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