[PATCH] [SMB3] Add mfsymlinks support for SMB2.1/SMB3. Part 1 create symlink
Steve French
smfrench at gmail.com
Mon Sep 15 23:52:24 MDT 2014
Resending patch series as attachments to avoid mailer issues
On Mon, Sep 15, 2014 at 1:39 PM, Steve French <smfrench at gmail.com> wrote:
> Adds support on SMB2.1 and SMB3 mounts for emulation of symlinks
> via the "Minshall/French" symlink format already used for cifs
> mounts when mfsymlinks mount option is used (and also used by Apple).
> http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks
> This first patch adds support to create them. The next patch will
> add support for recognizing them and reading them. Although CIFS/SMB3
> have other types of symlinks, in the many use cases they aren't
> practical (e.g. either require cifs only mounts with unix extensions
> to Samba, or require the user to be Administrator to Windows for SMB3).
> This also helps enable running additional xfstests over SMB3 (since some
> xfstests directly or indirectly require symlink support).
>
> Signed-off-by: Steve French <smfrench at gmail.com>
> CC: Stefan Metzmacher <metze at samba.org>
> ---
> fs/cifs/link.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/cifs/smb2ops.c | 2 ++
> fs/cifs/smb2proto.h | 4 +++-
> 3 files changed, 68 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/link.c b/fs/cifs/link.c
> index a5c2812..11657f6 100644
> --- a/fs/cifs/link.c
> +++ b/fs/cifs/link.c
> @@ -28,6 +28,7 @@
> #include "cifsproto.h"
> #include "cifs_debug.h"
> #include "cifs_fs_sb.h"
> +#include "smb2proto.h"
>
> /*
> * M-F Symlink Functions - Begin
> @@ -398,6 +399,68 @@ cifs_create_mf_symlink(unsigned int xid, struct
> cifs_tcon *tcon,
> return rc;
> }
>
> +int
> +smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
> + struct cifs_sb_info *cifs_sb, const unsigned char *path,
> + char *pbuf, unsigned int *pbytes_written)
> +{
> + int rc;
> + struct cifs_fid fid;
> + struct cifs_open_parms oparms;
> + struct cifs_io_parms io_parms;
> + int create_options = CREATE_NOT_DIR;
> + __le16 *utf16_path;
> + __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
> + struct kvec iov[2];
> +
> + if (backup_cred(cifs_sb))
> + create_options |= CREATE_OPEN_BACKUP_INTENT;
> +
> + cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
> +
> + utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
> + if (!utf16_path)
> + return -ENOMEM;
> +
> + oparms.tcon = tcon;
> + oparms.cifs_sb = cifs_sb;
> + oparms.desired_access = GENERIC_WRITE;
> + oparms.create_options = create_options;
> + oparms.disposition = FILE_CREATE;
> + oparms.fid = &fid;
> + oparms.reconnect = false;
> +
> + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
> + if (rc) {
> + kfree(utf16_path);
> + return rc;
> + }
> +
> + io_parms.netfid = fid.netfid;
> + io_parms.pid = current->tgid;
> + io_parms.tcon = tcon;
> + io_parms.offset = 0;
> + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
> + io_parms.persistent_fid = fid.persistent_fid;
> + io_parms.volatile_fid = fid.volatile_fid;
> +
> + /* iov[0] is reserved for smb header */
> + iov[1].iov_base = pbuf;
> + iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
> +
> + rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
> +
> + /* Make sure we wrote all of the symlink data */
> + if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
> + rc = -EIO;
> +
> + SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
> +
> + kfree(utf16_path);
> + return rc;
> +}
> +
> +
> /*
> * M-F Symlink Functions - End
> */
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index f522193..7d3fa29 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1452,6 +1452,7 @@ struct smb_version_operations smb21_operations = {
> .rename = smb2_rename_path,
> .create_hardlink = smb2_create_hardlink,
> .query_symlink = smb2_query_symlink,
> + .create_mf_symlink = smb3_create_mf_symlink,
> .open = smb2_open_file,
> .set_fid = smb2_set_fid,
> .close = smb2_close_file,
> @@ -1531,6 +1532,7 @@ struct smb_version_operations smb30_operations = {
> .rename = smb2_rename_path,
> .create_hardlink = smb2_create_hardlink,
> .query_symlink = smb2_query_symlink,
> + .create_mf_symlink = smb3_create_mf_symlink,
> .open = smb2_open_file,
> .set_fid = smb2_set_fid,
> .close = smb2_close_file,
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index 67e8ce8..e144ecf 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -82,7 +82,9 @@ extern int smb2_rename_path(const unsigned int xid,
> struct cifs_tcon *tcon,
> extern int smb2_create_hardlink(const unsigned int xid, struct cifs_tcon *tcon,
> const char *from_name, const char *to_name,
> struct cifs_sb_info *cifs_sb);
> -
> +extern int smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
> + struct cifs_sb_info *cifs_sb, const unsigned char *path,
> + char *pbuf, unsigned int *pbytes_written);
> extern int smb2_open_file(const unsigned int xid,
> struct cifs_open_parms *oparms,
> __u32 *oplock, FILE_ALL_INFO *buf);
> --
>
> --
> Thanks,
>
> Steve
--
Thanks,
Steve
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