6.6-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Alcantara pc@manguebit.com
[ Upstream commit 514d793e27a310eb26b112c1f8f1a160472907e5 ]
Add support for creating symlinks via IO_REPARSE_TAG_SYMLINK reparse points in SMB2+.
These are fully supported by most SMB servers and documented in MS-FSCC. Also have the advantage of requiring fewer roundtrips as their symlink targets can be parsed directly from CREATE responses on STATUS_STOPPED_ON_SYMLINK errors.
Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202311260838.nx5mkj1j-lkp@intel.com/ Signed-off-by: Paulo Alcantara (SUSE) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/cifsglob.h | 6 ++++ fs/smb/client/link.c | 15 ++++++--- fs/smb/client/smb2ops.c | 70 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 86 insertions(+), 5 deletions(-)
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index 3e7c3c3d73a73..414648bf816b2 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -577,6 +577,12 @@ struct smb_version_operations { int (*parse_reparse_point)(struct cifs_sb_info *cifs_sb, struct kvec *rsp_iov, struct cifs_open_info_data *data); + int (*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 smb_version_values { diff --git a/fs/smb/client/link.c b/fs/smb/client/link.c index 691f43a1ec2bc..d86da949a9190 100644 --- a/fs/smb/client/link.c +++ b/fs/smb/client/link.c @@ -569,6 +569,7 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, int rc = -EOPNOTSUPP; unsigned int xid; struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct TCP_Server_Info *server; struct tcon_link *tlink; struct cifs_tcon *pTcon; const char *full_path; @@ -590,6 +591,7 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, goto symlink_exit; } pTcon = tlink_tcon(tlink); + server = cifs_pick_channel(pTcon->ses);
full_path = build_path_from_dentry(direntry, page); if (IS_ERR(full_path)) { @@ -601,17 +603,20 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, cifs_dbg(FYI, "symname is %s\n", symname);
/* BB what if DFS and this volume is on different share? BB */ - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) { rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname); #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY - else if (pTcon->unix_ext) + } else if (pTcon->unix_ext) { rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname, cifs_sb->local_nls, cifs_remap(cifs_sb)); #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ - /* else - rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName, - cifs_sb_target->local_nls); */ + } else if (server->ops->create_reparse_symlink) { + rc = server->ops->create_reparse_symlink(xid, inode, direntry, + pTcon, full_path, + symname); + goto symlink_exit; + }
if (rc == 0) { if (pTcon->posix_extensions) { diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 4fed19d5a81d4..c5957deb1a859 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -5246,6 +5246,72 @@ static int nfs_make_node(unsigned int xid, struct inode *inode, return rc; }
+static 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 reparse_symlink_data_buffer *buf = NULL; + struct cifs_open_info_data data; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct inode *new; + struct kvec iov; + __le16 *path; + char *sym; + u16 len, plen; + int rc = 0; + + sym = kstrdup(symname, GFP_KERNEL); + if (!sym) + return -ENOMEM; + + data = (struct cifs_open_info_data) { + .reparse_point = true, + .reparse = { .tag = IO_REPARSE_TAG_SYMLINK, }, + .symlink_target = sym, + }; + + path = cifs_convert_path_to_utf16(symname, cifs_sb); + if (!path) { + rc = -ENOMEM; + goto out; + } + + plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX); + len = sizeof(*buf) + plen * 2; + buf = kzalloc(len, GFP_KERNEL); + if (!buf) { + rc = -ENOMEM; + goto out; + } + + buf->ReparseTag = cpu_to_le32(IO_REPARSE_TAG_SYMLINK); + buf->ReparseDataLength = cpu_to_le16(len - sizeof(struct reparse_data_buffer)); + buf->SubstituteNameOffset = cpu_to_le16(plen); + buf->SubstituteNameLength = cpu_to_le16(plen); + memcpy(&buf->PathBuffer[plen], path, plen); + buf->PrintNameOffset = 0; + buf->PrintNameLength = cpu_to_le16(plen); + memcpy(buf->PathBuffer, path, plen); + buf->Flags = cpu_to_le32(*symname != '/' ? SYMLINK_FLAG_RELATIVE : 0); + + iov.iov_base = buf; + iov.iov_len = len; + new = smb2_get_reparse_inode(&data, inode->i_sb, xid, + tcon, full_path, &iov); + if (!IS_ERR(new)) + d_instantiate(dentry, new); + else + rc = PTR_ERR(new); +out: + kfree(path); + cifs_free_open_info(&data); + kfree(buf); + return rc; +} + static int smb2_make_node(unsigned int xid, struct inode *inode, struct dentry *dentry, struct cifs_tcon *tcon, const char *full_path, umode_t mode, dev_t dev) @@ -5322,6 +5388,7 @@ struct smb_version_operations smb20_operations = { .parse_reparse_point = smb2_parse_reparse_point, .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, + .create_reparse_symlink = smb2_create_reparse_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, .close = smb2_close_file, @@ -5424,6 +5491,7 @@ struct smb_version_operations smb21_operations = { .parse_reparse_point = smb2_parse_reparse_point, .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, + .create_reparse_symlink = smb2_create_reparse_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, .close = smb2_close_file, @@ -5530,6 +5598,7 @@ struct smb_version_operations smb30_operations = { .parse_reparse_point = smb2_parse_reparse_point, .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, + .create_reparse_symlink = smb2_create_reparse_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, .close = smb2_close_file, @@ -5645,6 +5714,7 @@ struct smb_version_operations smb311_operations = { .parse_reparse_point = smb2_parse_reparse_point, .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, + .create_reparse_symlink = smb2_create_reparse_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, .close = smb2_close_file,