[PATCH 6.1] cifs: use origin fullpath for automounts
From: Andrew Paniakin
Date: Fri Jul 12 2024 - 23:12:48 EST
From: Paulo Alcantara <pc@xxxxxx>
commit 7ad54b98fc1f141cfb70cfe2a3d6def5a85169ff upstream.
Use TCP_Server_Info::origin_fullpath instead of cifs_tcon::tree_name
when building source paths for automounts as it will be useful for
domain-based DFS referrals where the connections and referrals would
get either re-used from the cache or re-created when chasing the dfs
link.
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
[apanyaki: backport to v6.1-stable]
Signed-off-by: Andrew Paniakin <apanyaki@xxxxxxxxxx>
---
This patch fixes issue reported in
https://lore.kernel.org/regressions/ZnMkNzmitQdP9OIC@xxxxxxxxxxxxxxxxxxxxxxxxxxx
1. The set_dest_addr function gets ip address differntly. In kernel 6.1
the dns_resolve_server_name_to_ip function returns string instead of
struct sockaddr, this string needs to be converted with
cifs_convert_address then.
2. There's no tmp.leaf_fullpath field in kernel 6.1, it was introduced
later in a1c0d00572fc ("cifs: share dfs connections and supers")
3. __build_path_from_dentry_optional_prefix and
dfs_get_automount_devname were added to fs/smb/client/cifsproto.h
instead of fs/cifs/dfs.h which doesn't exist in 6.1
---
fs/smb/client/cifs_dfs_ref.c | 34 ++++++++++++++++++++++++++++++++--
fs/smb/client/cifsproto.h | 18 ++++++++++++++++++
fs/smb/client/dir.c | 21 +++++++++++++++------
3 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/fs/smb/client/cifs_dfs_ref.c b/fs/smb/client/cifs_dfs_ref.c
index 020e71fe1454..876f9a43a99d 100644
--- a/fs/smb/client/cifs_dfs_ref.c
+++ b/fs/smb/client/cifs_dfs_ref.c
@@ -258,6 +258,31 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
goto compose_mount_options_out;
}
+static int set_dest_addr(struct smb3_fs_context *ctx, const char *full_path)
+{
+ struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
+ char *str_addr = NULL;
+ int rc;
+
+ rc = dns_resolve_server_name_to_ip(full_path, &str_addr, NULL);
+ if (rc < 0)
+ goto out;
+
+ rc = cifs_convert_address(addr, str_addr, strlen(str_addr));
+ if (!rc) {
+ cifs_dbg(FYI, "%s: failed to convert ip address\n", __func__);
+ rc = -EINVAL;
+ goto out;
+ }
+
+ cifs_set_port(addr, ctx->port);
+ rc = 0;
+
+out:
+ kfree(str_addr);
+ return rc;
+}
+
/*
* Create a vfsmount that we can automount
*/
@@ -295,8 +320,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path)
ctx = smb3_fc2context(fc);
page = alloc_dentry_path();
- /* always use tree name prefix */
- full_path = build_path_from_dentry_optional_prefix(mntpt, page, true);
+ full_path = dfs_get_automount_devname(mntpt, page);
if (IS_ERR(full_path)) {
mnt = ERR_CAST(full_path);
goto out;
@@ -315,6 +339,12 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path)
goto out;
}
+ rc = set_dest_addr(ctx, full_path);
+ if (rc) {
+ mnt = ERR_PTR(rc);
+ goto out;
+ }
+
rc = smb3_parse_devname(full_path, ctx);
if (!rc)
mnt = fc_mount(fc);
diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index f37e4da0fe40..6dbc9afd6728 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -57,8 +57,26 @@ extern void exit_cifs_idmap(void);
extern int init_cifs_spnego(void);
extern void exit_cifs_spnego(void);
extern const char *build_path_from_dentry(struct dentry *, void *);
+char *__build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
+ const char *tree, int tree_len,
+ bool prefix);
extern char *build_path_from_dentry_optional_prefix(struct dentry *direntry,
void *page, bool prefix);
+static inline char *dfs_get_automount_devname(struct dentry *dentry, void *page)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb);
+ struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+ struct TCP_Server_Info *server = tcon->ses->server;
+
+ if (unlikely(!server->origin_fullpath))
+ return ERR_PTR(-EREMOTE);
+
+ return __build_path_from_dentry_optional_prefix(dentry, page,
+ server->origin_fullpath,
+ strlen(server->origin_fullpath),
+ true);
+}
+
static inline void *alloc_dentry_path(void)
{
return __getname();
diff --git a/fs/smb/client/dir.c b/fs/smb/client/dir.c
index 863c7bc3db86..477302157ab3 100644
--- a/fs/smb/client/dir.c
+++ b/fs/smb/client/dir.c
@@ -78,14 +78,13 @@ build_path_from_dentry(struct dentry *direntry, void *page)
prefix);
}
-char *
-build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
- bool prefix)
+char *__build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
+ const char *tree, int tree_len,
+ bool prefix)
{
int dfsplen;
int pplen = 0;
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
- struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
char dirsep = CIFS_DIR_SEP(cifs_sb);
char *s;
@@ -93,7 +92,7 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
return ERR_PTR(-ENOMEM);
if (prefix)
- dfsplen = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1);
+ dfsplen = strnlen(tree, tree_len + 1);
else
dfsplen = 0;
@@ -123,7 +122,7 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
}
if (dfsplen) {
s -= dfsplen;
- memcpy(s, tcon->tree_name, dfsplen);
+ memcpy(s, tree, dfsplen);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
int i;
for (i = 0; i < dfsplen; i++) {
@@ -135,6 +134,16 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
return s;
}
+char *build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
+ bool prefix)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+ struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+
+ return __build_path_from_dentry_optional_prefix(direntry, page, tcon->tree_name,
+ MAX_TREE_SIZE, prefix);
+}
+
/*
* Don't allow path components longer than the server max.
* Don't allow the separator character in a path component.
--
2.40.1