cifs: use origin fullpath for automounts

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@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Paulo Alcantara 2022-12-18 14:37:32 -03:00 committed by Steve French
parent 25cf01b7c9
commit 7ad54b98fc
4 changed files with 53 additions and 10 deletions

View file

@ -21,8 +21,7 @@
#include "cifsfs.h"
#include "dns_resolve.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "dfs_cache.h"
#include "dfs.h"
#include "fs_context.h"
static LIST_HEAD(cifs_dfs_automount_list);
@ -119,6 +118,17 @@ cifs_build_devname(char *nodename, const char *prepath)
return dev;
}
static int set_dest_addr(struct smb3_fs_context *ctx, const char *full_path)
{
struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
int rc;
rc = dns_resolve_server_name_to_ip(full_path, addr, NULL);
if (!rc)
cifs_set_port(addr, ctx->port);
return rc;
}
/*
* Create a vfsmount that we can automount
*/
@ -156,8 +166,7 @@ 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;
@ -168,6 +177,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path)
tmp = *cur_ctx;
tmp.source = full_path;
tmp.leaf_fullpath = NULL;
tmp.UNC = tmp.prepath = NULL;
rc = smb3_fs_context_dup(ctx, &tmp);
@ -176,6 +186,12 @@ 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);

View file

@ -57,6 +57,9 @@ 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 void *alloc_dentry_path(void)

View file

@ -28,4 +28,19 @@ static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx, const char *p
cifs_remap(cifs_sb), path, ref, tl);
}
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);
}
#endif /* _CIFS_DFS_H */

View file

@ -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.