diff options
author | Paulo Alcantara <pc@manguebit.com> | 2023-11-25 23:55:04 -0300 |
---|---|---|
committer | Steve French <stfrench@microsoft.com> | 2024-01-07 15:46:06 -0600 |
commit | 514d793e27a310eb26b112c1f8f1a160472907e5 (patch) | |
tree | 54cea0694e0874fe597f8e87a1604f61b9d9a223 /fs/smb/client/smb2ops.c | |
parent | 5408990aa662bcfd6ba894734023a023a16e8729 (diff) | |
download | linux-stable-514d793e27a310eb26b112c1f8f1a160472907e5.tar.gz linux-stable-514d793e27a310eb26b112c1f8f1a160472907e5.tar.bz2 linux-stable-514d793e27a310eb26b112c1f8f1a160472907e5.zip |
smb: client: allow creating symlinks via reparse points
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>
Diffstat (limited to 'fs/smb/client/smb2ops.c')
-rw-r--r-- | fs/smb/client/smb2ops.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 201e951d50e5..8a9029bd9f0f 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -5247,6 +5247,72 @@ 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) @@ -5323,6 +5389,7 @@ 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, @@ -5425,6 +5492,7 @@ 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, @@ -5644,6 +5713,7 @@ 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, |